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Laurence de Leval

L.deLeval@ulg.ac.be

Journal articles

2008
 
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Kavitha Chandrikakumari, Jean Baptiste Giot, Laurence de Leval, Etienne Creemers, Philippe Leonard, Didier Mukeba, Michel Moutschen, Frederic Frippiat (2008)  Report of a Case of Streptococcus agalactiae Mycotic Aneurysm and Review of the Literature.   Int J Surg Pathol 16: 3. 314-319 Jul  
Abstract: A unique case of mycotic aneurysm of the abdominal aorta caused by Streptococcus agalactiae in an afebrile patient presenting with abdominal pain is described. Although this bacterium is associated with a variety of infections in human beings, aortitis is uncommon. Chronic alcoholism and diabetes mellitus are the 2 major predisposing conditions for group B Streptococci infection and both were present in this case. The abdominal pain and elevated inflammatory markers in the absence of fever were elusive in presentation; however, the diagnosis of mycotic aneurysm was established by abdominal computed tomography scan. The patient was treated successfully by resection of the diseased aorta and aortic allograft replacement. Culture of the excised tissue grew Streptococcus agalactiae sensitive to penicillin G and (other commonly tested antibiotics) fluoroquinolones. A prolonged course of moxifloxacin (for 6 months) was administered due to the persistence of elevated inflammatory markers and was remarkably well tolerated. Sixteen months after stopping the antibiotics, the patient is doing well, and the control imaging studies are satisfactory.
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Karin Bink, Eugenia Haralambieva, Marcus Kremer, German Ott, Christine Beham-Schmid, Laurence de Leval, Suat Cheng Peh, Hubert R Laeng, Uta Jütting, Peter Hutzler, Leticia Quintanilla-Martinez, Falko Fend (2008)  Primary extramedullary plasmacytoma: similarities with and differences from multiple myeloma revealed by interphase cytogenetics.   Haematologica 93: 4. 623-626 Apr  
Abstract: Primary extramedullary plasmacytoma is an indolent neoplasm that infrequently converts to multiple myeloma. Since cytogenetic data on extramedullary plasmacytoma are lacking, we studied 38 cases of this type of neoplasm by fluorescence in situ hybridization. Fourteen cases (37%) contained IGH breaks, including six with a t(4;14) translocation. No translocations t(11;14), t(14;16), t(8;14), nor breaks involving MALT1, BCL6 or FOXP1 were found. Loss of 13q (40%), as well as chromosomal gains (82%) were common. There was no correlation between chromosomal alterations and clinical features or local relapse. Cytogenetically, extramedullary plasmacytoma and multiple myeloma are closely related. However, the distribution of IGH translocation partners, with the notable absence of t(11;14), is different. Key words: extramedullary plasmacytoma, multiple myeloma, cytogenetics, IGH translocation, fluorescence in situ hybridization.
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Goval, Thielen, Bourguignon, Greimers, Dejardin, Choi, Boniver, de Leval (2008)  The prevention of spontaneous apoptosis of follicular lymphoma B cells by a follicular dendritic cell line: involvement of caspase-3, caspase-8 and c-FLIP.   Haematologica Jun  
Abstract: Background Follicular lymphoma, the neoplastic counterpart of germinal center B cells, typically recapitulates a follicular architecture. Several observations point to the crucial role of the cellular microenvironment in the development and/or progression of follicular lymphoma cells in vivo. The aim of our study was to characterize the spontaneous apoptosis of follicular lymphoma cells in vitro, and the modulation of this apoptosis by follicular dendritic cells. DESIGN AND METHODS: We used a cell line derived from follicular dendritic cells (HK cells) to model the functional interactions of these cells and lymphoma cells in co-culture. Follicular lymphoma cells were isolated from tissue biopsies. Apoptosis was quantified by flow cytometry and apoptotic pathways were investigated by western blotting. RESULTS: The spontaneous apoptosis of follicular lymphoma cells in vitro involves the activation of cas-pases-3 and -8 but not of caspase-9, occurs despite persistent high levels of BCL-2 and MCL-1, and is associated with down-regulation of c-FLIP(L). Spontaneous apoptosis of FL cells is partially prevented by coculture with the HK cells, which prevents activation of caspase-8, caspase-3 and induces an upregulation of c-FLIP(L). Using neutralizing antibodies, we demonstrated that interactions involving CD54 (ICAM-1), CD106 (VCAM-1) and CD40 are implicated in this biological process. Conclusions HK cells constitute a useful tool to study the functional interactions between follicular lymphoma cells and follicular dendritic cells in vitro. Understanding the molecular mechanisms involved in these protective interactions may lead to the identification of therapeutic agents that might suppress the survival and growth of follicular lymphoma cells.
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Caroline Thielen, Vincent Radermacher, Mounir Trimeche, Florence Roufosse, Michel Goldman, Jacques Boniver, Laurence de Leval (2008)  TARC and IL-5 expression correlates with tissue eosinophilia in peripheral T-cell lymphomas.   Leuk Res 32: 9. 1431-1438 Sep  
Abstract: The current study attempts to characterize the eosinophilia associated with T-cell lymphomas and to investigate its possible relationship with the secretion of eosinophil-stimulating factors by lymphoma cells and/or intra-tumoral surrounding cells. Paraffin-embedded specimens from 50 patients diagnosed with peripheral T-cell lymphomas, either unspecified (PTCL-U, n=30) or angioimmunoblastic (AITL, n=20) were morphologically assessed for intra-tumoral eosinophilia and analyzed by immunohistochemistry using specific antibodies directed against TARC, IL-5, RANTES, and eotaxin. The AITL and PTCL-U cases contained a mean of 147+/-41 and 102+/-37 eosinophils per 10 high power fields, respectively. Thirty-two of 47 cases (68%) showed IL-5-positive lymphoma cells while 15/50 (30%) tumors showed variable staining for TARC in scattered non-lymphoid cells with dendritic morphology. TARC and IL-5-positive cases possessed significantly more eosinophils. Our data indicate that IL-5 and TARC expression highly correlate with eosinophilia in T-cell lymphomas, suggesting that these chemokines are involved in the recruitment of eosinophils into the tumors.
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2007
 
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Esther Oliva, Laurence de Leval, Robert A Soslow, Christian Herens (2007)  High frequency of JAZF1-JJAZ1 gene fusion in endometrial stromal tumors with smooth muscle differentiation by interphase FISH detection.   Am J Surg Pathol 31: 8. 1277-1284 Aug  
Abstract: The most common cytogenetic alteration observed in low-grade endometrial stromal tumors (EST) is the t(7;17)(p15;q21) translocation, resulting in the fusion of the JAZF1 and JJAZ1 genes. By reverse-transcription polymerase chain reaction, the translocation has been detected overall in one-third of ESTs, but only rarely in its variants. The purpose of this study was to develop a fluorescence in situ hybridization assay for detection of this translocation using archival paraffin-embedded samples of ESTs with smooth muscle differentiation and to assess the nature of the smooth muscle component of these tumors. Representative paraffin blocks of 9 endometrial stromal nodules and 1 low-grade endometrial stromal sarcoma were collected for the study. In 1 case, the block selected also contained areas of sex cordlike differentiation. A fluorescence in situ hybridization probe set was designed to detect the t(7;17)(p15;q12) on tissue sections. Six out of 10 collected ESTs were assessable. Fusion signals were detected in 3 out of 6 cases (50%) in both the conventional endometrial stromal and the smooth muscle components of the tumors. The tumor sample with sex cordlike differentiation harbored the fusion signal in all the 3 components. Our results support the contention that the endometrial stromal and smooth muscle components of these tumors have the same origin, either from a common precursor cell with pluripotential differentiation or from endometrial stromal cells that have undergone smooth muscle metaplasia. Our results indicate that the detection of this chromosomal abnormality can be used to diagnose ESTs with smooth muscle differentiation when the smooth muscle component is predominant.
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Vincent Castronovo, Philippe Kischel, François Guillonneau, Laurence de Leval, Thierry Deféchereux, Edwin De Pauw, Dario Neri, David Waltregny (2007)  Identification of specific reachable molecular targets in human breast cancer using a versatile ex vivo proteomic method.   Proteomics 7: 8. 1188-1196 Apr  
Abstract: Targeting of tumoral tissues is one of the most promising approaches to improve both the efficacy and safety of anticancer treatments. The identification of valid targets, including proteins specifically and abundantly expressed in cancer lesions, is of utmost importance. Despite state-of-the-art technologies, the discovery of cancer-associated target proteins still faces the limitation, in human tissues, of antigen accessibility to suitable high-affinity ligands such as human mAb bound to bioactive molecules. Terminal perfusion of tumor-bearing mice or ex vivo perfusion of human cancer-bearing organs with a reactive biotin ester solution has successfully led to the identification of novel accessible biomarkers. This methodology is however restricted to perfusable organs, and excludes most of the tissues of interest to targeted therapies, e.g. primary breast cancer and metastases. Herein, we report on the development of a new chemical proteomic method that bypasses the perfusion step and thus offers the potential to identify accessible molecular targets in virtually all types of animal and human tissues. We have validated our new procedure by identifying biomarkers selectively expressed in human breast carcinoma. Overall, this powerful technology may lay the ground not only for custom-made therapies in cancer, but also for the development of therapies that need to be selectively delivered in a specific tissue.
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Laurence de Leval, David S Rickman, Caroline Thielen, Aurélien de Reynies, Yen-Lin Huang, Georges Delsol, Laurence Lamant, Karen Leroy, Josette Brière, Thierry Molina, Françoise Berger, Christian Gisselbrecht, Luc Xerri, Philippe Gaulard (2007)  The gene expression profile of nodal peripheral T-cell lymphoma demonstrates a molecular link between angioimmunoblastic T-cell lymphoma (AITL) and follicular helper T (TFH) cells.   Blood 109: 11. 4952-4963 Jun  
Abstract: The molecular alterations underlying the pathogenesis of angioimmunoblastic T-cell lymphoma (AITL) and peripheral T-cell lymphoma, unspecified (PTCL-u) are largely unknown. In order to characterize the ontogeny and molecular differences between both entities, a series of AITLs (n = 18) and PTCLs-u (n = 16) was analyzed using gene expression profiling. Unsupervised clustering correlated with the pathological classification and with CD30 expression in PTCL-u. The molecular profile of AITLs was characterized by a strong microenvironment imprint (overexpression of B-cell- and follicular dendritic cell-related genes, chemokines, and genes related to extracellular matrix and vascular biology), and overexpression of several genes characteristic of normal follicular helper T (T(FH)) cells (CXCL13, BCL6, PDCD1, CD40L, NFATC1). By gene set enrichment analysis, the AITL molecular signature was significantly enriched in published T(FH)-specific genes. The enrichment was higher for sorted AITL cells than for tissue samples. Overexpression of several T(FH) genes was validated by immunohistochemistry in AITLs. A few cases with molecular T(FH)-like features were identified among CD30(-) PTCLs-u. Our findings strongly support that T(FH) cells represent the normal counterpart of AITL, and suggest that the AITL spectrum may be wider than suspected, as a subset of CD30(-) PTCLs-u may derive from or be related to AITL.
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Mounir Trimèche, Christophe Bonnet, Sadok Korbi, Jacques Boniver, Laurence de Leval (2007)  Association between Epstein-Barr virus and Hodgkin's lymphoma in Belgium: a pathological and virological study.   Leuk Lymphoma 48: 7. 1323-1331 Jul  
Abstract: The association between Epstein-Barr virus (EBV) and classical Hodgkin's lymphoma (cHL) varies according to the geographic location. In this work we sought to characterize EBV involvement in a series of 111 cHL cases diagnosed in Belgium. The overall prevalence of EBV infection detected by in situ hybridization in Reed-Sternberg cells was 33%. EBV positivity correlated with older age at diagnosis (>54 years; p = 0.01), mixed cellularity subtype (p = 0.000001), male gender (p = 0.004) and tended to be associated with higher clinical stage (III/IV; p = 0.02). The molecular features of the virus in EBV-positive cHL were studied by comparison with a series of reactive tonsils. A 30-bp deletion within the LMP-1 gene was in 15/28 (53.6%) EBV-positive cHL cases, and in 41.7% of reactive tonsil samples. This variant did not correlate with any clinical or pathological feature. The EBV strain was type A in all cHL and reactive samples.
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Catherine Verhaeghe, Katty Delbecque, Laurence de Leval, Cecile Oury, Vincent Bours (2007)  Early inflammation in the airways of a cystic fibrosis foetus.   J Cyst Fibros 6: 4. 304-308 Jul  
Abstract: In cystic fibrosis patients, inflammation is often considered to be secondary to chronic infections. In the present study, we show increased levels of pro-inflammatory proteins in the lungs of a cystic fibrosis foetus compared to the lungs of two normal foetuses. Our findings suggest therefore the existence of an early intrinsic pro-inflammatory state in cystic fibrosis airways.
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Julia Turbiner, Mahul B Amin, Peter A Humphrey, John R Srigley, Laurence De Leval, Anuradha Radhakrishnan, Esther Oliva (2007)  Cystic nephroma and mixed epithelial and stromal tumor of kidney: a detailed clinicopathologic analysis of 34 cases and proposal for renal epithelial and stromal tumor (REST) as a unifying term.   Am J Surg Pathol 31: 4. 489-500 Apr  
Abstract: Cystic nephroma (CN) and mixed epithelial and stromal tumor (MEST) are rare benign renal neoplasms that have overlapping clinical and morphologic features, including predominance in middle-aged women, variably cystic architecture, eosinophilic cells, and hobnail cells lining the cysts and ovarian-type stroma. The aim of this study was to analyze and compare the histologic features and immunohistochemical profile of these tumors. We studied 34 cases from 5 large academic institutions. Twenty tumors were diagnosed as CNs, 18 in women and 2 in men, their age ranged from 24 to 63 (mean 48; median 50) years. Fourteen tumors were diagnosed as MESTs, all in women, their age ranged from 26 to 84 (mean 52; median 51) years. Histologically, all tumors were well-circumscribed except for one MEST. The stromal/epithelial ratio was approximately 2.3 in MESTs versus 0.3 in CNs; cellular ovarian-type stroma composed 45% of the stroma in MESTs and 12% of the stroma of CNs. Stromal hyalinization was prominent in both. Five MESTs showed stromal luteinization. In the epithelial component, the relative amount of large cysts, medium to small cysts, and phyllodes-type glands was: 65%/25%/10% in CNs versus 25%/40%/35% in MESTs. The epithelial component ranged from flat to cuboidal to hobnail cells in both types of tumors. No significant atypia of either component was seen, although the epithelial cells showed reactive changes. Immunohistochemical stains for estrogen receptors and progesterone receptors showed 62% and 85% positivity in the stromal component of MESTs versus 19% and 40% in CNs. CD10 positivity was seen in 77% of MESTs versus 50% of CNs, calretinin was seen in 69% of MESTs versus 41% of CNs, and inhibin in 42% of MESTs versus 36% of CNs, although the staining was focal. Follow-up in both categories of tumors (mean 3.2 y, median 3 y for CNs and mean 2.5 y, median of 2 y for MESTs) showed no evidence of recurrence or metastases in keeping with their benign nature. This study highlights the remarkable similarity between CN and MEST in sex predilection, age distribution, and morphologic attributes of both the epithelial and stromal components and immunohistochemical profile albeit with variation in individual categories with higher prevalence of stromal to epithelial ratio, prominent ovarian stroma, smaller cysts with phyllodes glands pattern and stromal luteinization being more common in MEST; and large cysts, thin septae and low stromal to epithelial ratio in CN. The presence of ovarian-type stroma and müllerian related immunohistochemical markers raises the possibility that these tumors may originate from müllerian remnants misplaced during embryogenesis. On the basis of detailed morphologic analysis of this series of CN and MEST, we propose a unifying term of "renal epithelial and stromal tumor" (REST) to encompass the spectrum of findings observed in these tumors at least until new molecular studies can prove or disprove this challenging hypothesis.
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I Scagnol, O Detry, L De Leval, F Masy, J Boniver (2007)  Anatomo-clinical comparison: caecal duplication cyst   Rev Med Liege 62: 2. 118-121 Feb  
Abstract: Enteric duplication cysts, and particularly caecal duplication cysts, are rare and generally benign congenital anomalies for which a diagnosis is difficult to make because they mimic other surgical diseases. A surgical management is the treatment of choice. The diagnosis can then be made or confirmed by histopathologic analysis.
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S Maweja, R Materne, N Detrembleur, L de Leval, Th Defechereux, M Meurisse, E Hamoir (2007)  Adrenal ganglioneuroma. A neoplasia to exclude in patients with adrenal incidentaloma.   Acta Chir Belg 107: 6. 670-674 Nov/Dec  
Abstract: OBJECTIVE: To determinate the MRI and CT scanning appearance of adrenal ganglioneuroma and correlate the imaging with histological features. SUMMARY BACKGROUND DATA: In the last 10 years, eight patients with a pathologically proven adrenal ganglioneuroma were operated on in our department of endocrine surgery. To our knowledge, these patients represent one the largest reported cohorts of adrenal ganglioneuroma treated in a single institution. METHODS: All these eight patients had a comprehensive hormonal work up and underwent CT and/or MRI. Biological data, radiological features and histological findings were thoroughly reviewed in order to further characterize these tumours. RESULTS: The most relevant characteristics of adrenal GN resected in our patients were: No hormonal hypersecretion, Presence of calcifications; no vessel involvement; and a non-enhanced attenuation of less than 40 HU on CT, A low non-enhanced T1W signal, a slightly high and heterogeneous T2W signal, a late and gradual enhancement on dynamic MRI, especially if associated with a whorled pattern. CONCLUSIONS: Even if many aggressive tumours, mainly adrenal carcinoma, may share some of these radiological features, the presence of all or most of them must made the clinician evoke the diagnosis of GN.
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C Boudry, N Markine-Goriaynoff, C Delforge, J - Y Springael, L de Leval, P Drion, G Russell, D M Haig, A F Vanderplasschen, B Dewals (2007)  The A5 gene of alcelaphine herpesvirus 1 encodes a constitutively active G-protein-coupled receptor that is non-essential for the induction of malignant catarrhal fever in rabbits.   J Gen Virol 88: Pt 12. 3224-3233 Dec  
Abstract: Many gammaherpesviruses encode G-protein-coupled receptors (GPCRs). Several in vivo studies have revealed that gammaherpesvirus GPCRs are important for viral replication and for virus-induced pathogenesis. The gammaherpesvirus alcelaphine herpesvirus 1 (AlHV-1) is carried asymptomatically by wildebeest, but causes malignant catarrhal fever (MCF) following cross-species transmission to a variety of susceptible species. The A5 ORF of the AlHV-1 genome encodes a putative GPCR. In the present study, we investigated whether A5 encodes a functional GPCR and addressed its role in viral replication and in the pathogenesis of MCF. In silico analysis supported the hypothesis that A5 could encode a functional GPCR as its expression product contained several hallmark features of GPCRs. Expression of A5 as tagged proteins in various cell lines revealed that A5 localizes in cell membranes, including the plasma membrane. Using [35S]GTPgammaS and reporter gene assays, we found that A5 is able to constitutively couple to alpha i-type G-proteins in transfected cells, and that this interaction is able to inhibit forskolin-triggered cAMP response element-binding protein (CREB) activation. Finally, using an AlHV-1 BAC clone, we produced a strain deleted for A5 and a revertant strain. Interestingly, the strain deleted for A5 replicated comparably to the wild-type parental strain and induced MCF in rabbits that was indistinguishable from that of the parental strain. The present study is the first to investigate the role of an individual gene of AlHV-1 in MCF pathogenesis.
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Sylvie Maweja, Roland Materne, Nancy Detrembleur, Laurence de Leval, Thierry Defechereux, Michel Meurisse, Etienne Hamoir (2007)  Adrenal ganglioneuroma.   Am J Surg 194: 5. 683-684 Nov  
Abstract: BACKGROUND: A 20-year-old man was referred after having been discovered a left adrenal incidentaloma. Characteristics on magnetic resonance imaging (MRI) suggested the diagnosis of adrenal ganglioneuroma or carcinoma. Pathological examination after adrenalectomy concluded it was an adrenal ganglioneuroma. We studied the characteristics of adrenal ganglioneuroma. METHODS: We retrospectively reviewed hormonal status, computed tomography and MRI features, and histological findings of our series of 8 adrenal ganglioneuromas. RESULTS: Specific features were: (1) no hormonal hypersecretion; (2) presence of calcifications, no vessel involvement; and a non-enhanced attenuation of less than 40 Hounsfield units on computed tomography; and (3) low non-enhanced T1-weighted signal, a slightly high and heterogeneous T2-weighted signal, and a late and gradual enhancement on dynamic MRI, especially if associated with a whorled pattern. CONCLUSIONS: Even if many aggressive tumors share some of those radiological features, the presence of all or most of them must lead the clinician to consider the diagnosis of adrenal ganglioneuroma.
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I Schrouff, H Valdes-Socin, F Frippiat, L De Leval, D Soyeur, M A Radermecker, A J Scheen (2007)  Isolated tricuspid valve endocarditis as a cause of fever of unknown origin   Rev Med Liege 62: 11. 654-658 Nov  
Abstract: Isolated tricuspid valve endocarditis is the least common endocarditis with an incidence of 5 to 10% in the literature. It is usually described in drug abusers and as a complication of nosocomial infections (catheter, post-surgery...). We present the case of a 70 year-old patient admitted for a fever of unknown origin lasting for 2 months. He had an isolated tricuspid endocarditis with Enterococcus faecalis. We review the diagnostic criterias predisposing factors and treatment of right-sided valvular endocarditis, particularly the endocarditis produced by Enterococcus faecalis, a rare etiopathogenic agent of tricuspid endocarditis.
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2006
 
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Sabine Olivier, Pierre Close, Emilie Castermans, Laurence de Leval, Sebastien Tabruyn, Alain Chariot, Michel Malaise, Marie-Paule Merville, Vincent Bours, Nathalie Franchimont (2006)  Raloxifene-induced myeloma cell apoptosis: a study of nuclear factor-kappaB inhibition and gene expression signature.   Mol Pharmacol 69: 5. 1615-1623 May  
Abstract: Because multiple myeloma remains associated with a poor prognosis, novel drugs targeting specific signaling pathways are needed. The efficacy of selective estrogen receptor modulators for the treatment of multiple myeloma is not well documented. In the present report, we studied the antitumor activity of raloxifene, a selective estrogen receptor modulator, on multiple myeloma cell lines. Raloxifene effects were assessed by tetrazolium salt reduction assay, cell cycle analysis, and Western blotting. Mobility shift assay, immunoprecipitation, chromatin immunoprecipitation assay, and gene expression profiling were performed to characterize the mechanisms of raloxifene-induced activity. Indeed, raloxifene, as well as tamoxifen, decreased JJN-3 and U266 myeloma cell viability and induced caspase-dependent apoptosis. Raloxifene and tamoxifen also increased the cytotoxic response to vincristine and arsenic trioxide. Moreover, raloxifene inhibited constitutive nuclear factor-kappaB (NF-kappaB) activity in myeloma cells by removing p65 from its binding sites through estrogen receptor alpha interaction with p65. It is noteworthy that microarray analysis showed that raloxifene treatment decreased the expression of known NF-kappaB-regulated genes involved in myeloma cell survival and myeloma-induced bone lesions (e.g., c-myc, mip-1alpha, hgf, pac1,...) and induced the expression of a subset of genes regulating cellular cycle (e.g., p21, gadd34, cyclin G2,...). In conclusion, raloxifene induces myeloma cell cycle arrest and apoptosis partly through NF-kappaB-dependent mechanisms. These findings also provide a transcriptional profile of raloxifene treatment on multiple myeloma cells, offering the framework for future studies of selective estrogen receptor modulators therapy in multiple myeloma.
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B Dewals, C Boudry, L Gillet, N Markine-Goriaynoff, L de Leval, D M Haig, A Vanderplasschen (2006)  Cloning of the genome of Alcelaphine herpesvirus 1 as an infectious and pathogenic bacterial artificial chromosome.   J Gen Virol 87: Pt 3. 509-517 Mar  
Abstract: Alcelaphine herpesvirus 1 (AlHV-1), carried asymptomatically by wildebeest, causes malignant catarrhal fever (MCF) following cross-species transmission to a variety of susceptible species of the order Artiodactyla. The study of MCF pathogenesis has been impeded by an inability to produce recombinant virus, mainly due to the fact that AlHV-1 becomes attenuated during passage in culture. In this study, these difficulties were overcome by cloning the entire AlHV-1 genome as a stable, infectious and pathogenic bacterial artificial chromosome (BAC). A modified loxP-flanked BAC cassette was inserted in one of the two large non-coding regions of the AlHV-1 genome. This insertion allowed the production of an AlHV-1 BAC clone stably maintained in bacteria and able to regenerate virions when transfected into permissive cells. The loxP-flanked BAC cassette was excised from the genome of reconstituted virions by growing them in permissive cells stably expressing Cre recombinase. Importantly, BAC-derived AlHV-1 virions replicated comparably to the virulent (low-passage) AlHV-1 parental strain and induced MCF in rabbits that was indistinguishable from that of the virulent parental strain. The availability of the AlHV-1 BAC is an important advance for the study of MCF that will allow the identification of viral genes involved in MCF pathogenesis, as well as the production of attenuated recombinant candidate vaccines.
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Jean-Jacques Goval, Roland Greimers, Jacques Boniver, Laurence de Leval (2006)  Germinal center dendritic cells express more ICAM-1 than extrafollicular dendritic cells and ICAM-1/LFA-1 interactions are involved in the capacity of dendritic cells to induce PBMCs proliferation.   J Histochem Cytochem 54: 1. 75-84 Jan  
Abstract: Germinal center dendritic cells (GCDCs) have been identified as CD11c(+) CD4(+) CD3(-) cells located in GCs with the ability of inducing marked proliferation of allogenic T cells. Using immunofluorescence techniques, we have observed that this CD11c(+) CD4(+) CD3(-) immunophenotype identified GCDCs but also a subset of extrafollicular DCs. By flow cytometry, we were able to discriminate the GCDCs (CD11c(high) CD4(high) lin(-)) from the other tonsil DCs. By immunofluorescence and flow cytometry, we found that dendritic cells of germinal centers express more intracellular adhesion molecule-1 (ICAM-1) (CD54) than extrafollicular dendritic cells. Proliferation of peripheral blood mononuclear cells (PBMCs) induced by coculture with purified CD11c(+) CD4(+) CD3(-) DCs was reduced by addition of blocking anti-CD54 antibodies. In summary, distinct levels of ICAM-1 expression allow the distinction between GCDCs and extrafollicular DCs, and cellular interactions mediated by CD54 are likely to play a role in the capacity of GCDC to stimulate allogenic PBMC proliferation.
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Thibaut Dassesse, Xavier de Leval, Laurence de Leval, Bernard Pirotte, Vincent Castronovo, David Waltregny (2006)  Activation of the thromboxane A2 pathway in human prostate cancer correlates with tumor Gleason score and pathologic stage.   Eur Urol 50: 5. 1021-31; discussion 1031 Nov  
Abstract: OBJECTIVE: We investigated the potential involvement of the thromboxane A(2) (TXA(2)) pathway in human prostate cancer (PCa). METHODS: Expression of cyclooxygenase-2 (COX-2), TXA(2) synthase (TXS), and TXA(2) receptors (TPRs), the main actors of the TXA(2) pathway, was analyzed on serial tissue sections from 46 human PCa specimens. RESULTS: The expression levels of COX-2, TXS, and TPRs were significantly higher in malignant than in corresponding nontumoral prostatic epithelial cells. Increased immunoreactivity for these antigens was also observed in high-grade prostate intraepithelial neoplasia (HGPIN) glands. COX-2, TXS, and TPR proteins usually displayed a coordinated overexpression pattern in PCa lesions, as assessed in serial tissue sections. Increased levels of these proteins in the tumors were all significantly associated with higher Gleason scores and pathologic stages. CONCLUSIONS: Proteins specifically involved in the TXA(2) pathway are up-regulated in human PCa and their level of expression is associated with tumor extraprostatic extension and loss of differentiation. Our study is the first to examine simultaneously all key proteins involved in this pathway including TXA(2) receptors and results suggest that the TXA(2) pathway may be a potential target for PCa prevention/therapy.
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Laurence de Leval, Nancy Lee Harris, Serge Lampertz, Christian Herens (2006)  T-cell/histiocyte-rich large B-cell lymphoma associated with a near-tetraploid karyotype and complex genetic abnormalities.   APMIS 114: 6. 474-478 Jun  
Abstract: Cytogenetic data for T-cell/histiocyte-rich large B-cell lymphoma (THRLBCL) are scarcely available. We report here a case of THRLBCL with a near-tetraploid karyotype and complex chromosomal aberrations, without rearrangement of BCL2 or BCL6, and characterized pathologically by a variegated morphologic appearance with areas resembling nodular lymphocyte-predominant Hodgkin's lymphoma (NLPHL).
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Laurence de Leval, David Waltregny, Jacques Boniver, Robert H Young, Vincent Castronovo, Esther Oliva (2006)  Use of histone deacetylase 8 (HDAC8), a new marker of smooth muscle differentiation, in the classification of mesenchymal tumors of the uterus.   Am J Surg Pathol 30: 3. 319-327 Mar  
Abstract: Uterine smooth muscle tumors (SMTs) are usually recognized on the basis of their routine morphologic features; however, their distinction from endometrial stromal tumors (ESTs), the second most common mesenchymal tumor of the uterus, is sometimes problematic. Histone deacetylases (HDACs) were originally identified as nuclear enzymes regulating histone acetylation. We have recently shown that in normal human tissues, HDAC8 is exclusively expressed in the cytoplasm of cells showing smooth muscle differentiation. In this study, we examined HDAC8 expression in SMTs and ESTs of the uterus to determine whether HDAC8 may be a useful diagnostic tool in the classification of problematic uterine mesenchymal tumors. HDAC8 immunohistochemical staining was performed in 15 leiomyomas (LMs), 9 highly cellular leiomyomas (HCLs), 8 epithelioid SMTs, 13 leiomyosarcomas (LMSs), and 17 ESTs, including 3 with sex-cord differentiation and 5 with smooth muscle differentiation. All tumors were also stained for other smooth muscle markers (desmin, h-caldesmon, smooth muscle actin [SMA], smooth muscle myosin heavy chain) and for CD10. All LMs had moderate to strong expression of all smooth muscle markers. HDAC8 was detected in 8 of 9 HCLs and in all epithelioid SMTs (8 of 8); however, it was weak in 4 epithelioid SMTs. In contrast, desmin, h-caldesmon and smooth muscle myosin were positive in only 2 of 8, 1 of 8 and 4 of 8 epithelioid SMTs, respectively. All smooth muscle markers had similar frequency of staining in LMSs; however, HDAC8 showed overall moderate intensity compared with other smooth muscle markers, which showed stronger staining. HDAC8, h-caldesmon, and smooth muscle myosin did not stain conventional areas of ESTs or ESTs with sex-cord differentiation, whereas SMA and desmin were positive in those areas in 4 of 12 and 3 of 12 ESTs, respectively. Areas of smooth muscle differentiation in ESTs were positive for HDAC8 in all cases, but they were less constantly positive for the other smooth muscle markers. CD10 was expressed in most ESTs (14 of 17), but it was also positive in 15 of 45 SMTs. In conclusion: 1) HDAC8 seems to be a specific marker of SM differentiation because conventional ESTs and ESTs with sex-cord differentiation are negative for HDAC8, whereas areas of smooth muscle differentiation in these tumors are consistently positive; 2) HDAC8 gives similar results to those obtained with desmin, h-caldesmon, and smooth muscle myosin in both LMs and LMSs, although the staining for HDAC8 in LMSs tends to be less intense; 3) HDAC8 may be a more sensitive marker than desmin and h-caldesmon in epithelioid SMTs. Thus, HDAC8 detection may be useful in helping the differential diagnosis of uterine mesenchymal tumors.
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Caroline Thielen, Christian Herens, Marie-France Fassotte, Elisabeth Detrooz, Pierre Drion, Tim Diss, Jacques Boniver, Laurence de Leval (2006)  Establishment and characterisation of two novel human KSHV- and EBV-negative Burkitt cell lines, GAL-01 and GAL-02, from a primary lymphomatous effusion.   Eur J Haematol 77: 4. 318-326 Oct  
Abstract: OBJECTIVES: Burkitt's lymphoma (BL) is a highly aggressive mature B-cell neoplasm comprising endemic, sporadic and immunodeficiency-associated variants. Human cell lines constitute a very useful tool to investigate the biology of lymphoid neoplasia. In this study, we succeeded in establishing two human cell lines, GAL-01 and GAL-02, from a HIV-negative patient with Epstein-Barr virus (EBV) -negative sporadic BL presenting as an effusion. GAL-01 and GAL-02 were established at diagnosis and after one course of polychemotherapy, respectively. The in vivo effusion occurred in a very peculiar clinical setting; the patient having a previous history of intestinal diffuse large B-cell lymphoma. METHODS: The morphologic, immunophenotypic and molecular genetic features of GAL cell lines are reported and compared with those of the parental tumour. The findings clearly demonstrated that the Burkitt effusion did not represent disease progression of the intestinal tumour, but represented a second primary haematological malignancy. The in vivo tumorigenic properties of the cells were tested by subcutaneous injection to NOD/SCID mice. RESULTS: Both cell lines were composed of medium-sized lymphoid cells with clumped chromatin, multiple medium-sized nucleoli and moderate amounts of vacuolated cytoplasm. GAL cells display the phenotype and genotype of a B-cell lineage (positive for CD20, CD79a and clonal rearrangement of Ig heavy chain), carry the c-MYC rearrangement by t(8;22)(q24;q11) translocation and are characterised by the expression of the germinal centre-associated antigens CD10, BCL6, CD38 and absent to low BCL2 expression. EBV and HHV8 were not identified within parental tumour or in cultured cells. Subcutaneous injection of both cell lines to NOD/SCID mice induced tumour formation. CONCLUSIONS: GAL-01 and GAL-02, two novel EBV-negative human BL cell lines represent a potentially useful experimental model to study the biology of BL possibly including the resistance to chemotherapy.
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Arnaud de Roover, Olivier Detry, Laurence de Leval, Carla Coimbra, Claude Desaive, Pierre Honoré, Michel Meurisse (2006)  Report of two cases of gastric cancer after bariatric surgery: lymphoma of the bypassed stomach after Roux-en-Y gastric bypass and gastrointestinal stromal tumor (GIST) after vertical banded gastroplasty.   Obes Surg 16: 7. 928-931 Jul  
Abstract: We report two new cases of gastric cancer diagnosed after a bariatric operation. The first case is a 66-year-old male who 3 years after gastric bypass suffered from a perforation of the fundus that was found to be secondary to a diffuse large B-cell lymphoma of the distal stomach. The second case is a 47-year-old woman who presented 12 years after a vertical banded gastroplasty with a gastric pouch outlet obstruction caused by a gastrointestinal stromal tumor (GIST). Based on the few reports of cancer in the literature, analysis of these cases suggests that the main risk of gastric cancer after bariatric surgery comes from the delayed diagnosis of malignancy.
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A Radermecker, X Nelissen, A Bous, A Kerzmann, L De Leval, B Ghaye, O Heymans, R Limet (2006)  Surgical treatment of chest wall tumors   Rev Med Liege 61: 11. 771-774 Nov  
Abstract: The observation of a primary chest wall desmoid tumor discovered incidentally in a young patient is an opportunity to review the nosology, diagnosis and treatment of this uncommon pathology. Surgical intervention should aim at resecting completely the lesion with sufficient margins. Subsequent reconstruction of the bony thorax uses synthetic materials and muscle or myocutaneous flaps.
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2005
 
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Friedrich Feuerhake, Jeffery L Kutok, Stefano Monti, Wen Chen, Ann S LaCasce, Giorgio Cattoretti, Paul Kurtin, Geraldine S Pinkus, Laurence de Leval, Nancy L Harris, Kerry J Savage, Donna Neuberg, Thomas M Habermann, Riccardo Dalla-Favera, Todd R Golub, Jon C Aster, Margaret A Shipp (2005)  NFkappaB activity, function, and target-gene signatures in primary mediastinal large B-cell lymphoma and diffuse large B-cell lymphoma subtypes.   Blood 106: 4. 1392-1399 Aug  
Abstract: Primary mediastinal large B-cell lymphoma (MLBCL) shares important clinical and molecular features with classic Hodgkin lymphoma, including nuclear localization of the nuclear factor kappaB (NFkappaB) subunit c-REL (reticuloendotheliosis viral oncogene homolog) in a pilot series. Herein, we analyzed c-REL subcellular localization in additional primary MLBCLs and characterized NFkappaB activity and function in a MLBCL cell line. The new primary MLBCLs had prominent c-REL nuclear staining, and the MLBCL cell line exhibited high levels of NFkappaB binding activity. MLBCL cells expressing a superrepressor form of inhibitor of kappa B alpha signaling (IkappaB alpha) had a markedly higher rate of apoptosis, implicating constitutive NFkappaB activity in MLBCL cell survival. The transcriptional profiles of newly diagnosed primary MLBCLs and diffuse large B-cell lymphomas (DLBCLs) were then used to characterize the NFkappaB target gene signatures of MLBCL and specific DLBCL subtypes. MLBCLs expressed increased levels of NFkappaB targets that promote cell survival and favor antiapoptotic tumor necrosis factor alpha (TNFalpha) signaling. In contrast, activated B cell (ABC)-like DLBCLs had a more restricted, potentially developmentally regulated, NFkappaB target gene signature. Of interest, the newly characterized host response DLBCL subtype had a robust NFkappaB target gene signature that partially overlapped that of primary MLBCL. In this large series of primary MLBCLs and DLBCLs, NFkappaB activation was not associated with amplification of the cREL locus, suggesting alternative pathogenetic mechanisms.
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Olivier Detry, Arnaud De Roover, Laurence de Leval, Christian Herens, Jean Delwaide, Pierre Honoré, Michel Meurisse (2005)  Transmission of an undiagnosed sarcoma to recipients of kidney and liver grafts procured in a non-heart beating donor.   Liver Transpl 11: 6. 696-699 Jun  
Abstract: Transmission of an undiagnosed cancer with solid organ transplantation is a rare but dreadful event. In this paper the authors report the transmission of an undiagnosed sarcoma to recipients of kidney and liver grafts procured in a Maastricht category 3 non-heart beating donor. To the authors' knowledge this case is the first report of such a transmission with a liver graft procured in a non-heart beating donor. The cancer transferal was diagnosed 1 year after transplantation in the recipients of the liver and of one kidney. The liver recipient died from multiple organ failure after a failed attempt of tumor resection. The kidney recipient underwent immunosuppression withdrawal and transplantectomy. Non-heart beating donors should not be particularly at risk for undiagnosed cancer transmission if the procurement is performed according to the same rules of careful inspection of the abdominal and thoracic organs. After diagnosis of donor cancer transmission, kidney recipients should have the graft removed, and immunosuppression should be interrupted. The management of liver graft recipients is very difficult in this setting, and long-term survival was very rarely reported.
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M Trimeche, S Korbi, S Ziadi, K Amara, J Boniver, L de Leval (2005)  Molecular characterization of Epstein-Barr virus associated with classical Hodgkin's lymphoma in Tunisia: prevalence of the LMP1 oncogene deletions and A and B viruses strains   Ann Biol Clin (Paris) 63: 2. 193-199 Mar/Apr  
Abstract: Epstein-Barr virus (EBV) is detected in Hodgkin's lymphoma (HL) at variable frequencies, depending on various factors including the geographic location. The prevalence of EBV is high among HL diagnosed in the region of the center of Tunisia. The aim of the current work was to define the genotypic features of EBV in a series of EBV-positive HL in this area, in comparison to those of EBV found in association with benign lymphoadenopathies. A 30 bp and a 69 bp deletion within the LMP1 gene were detected in 41% and 11% of HL cases, respectively. In reactive lymph nodes, the 30 bp deletion was found in 43% of the cases. Type A EBV was detected in 84% of HL cases and in 96% of reactive lymphoadenopathies, and type B EBV was detected in others. No significant association was found between histological type of HL, age of the patients, or stage at diagnosis, and the molecular configuration of LMP1. However, LMP1 deletions were found more frequently among male patients. The significance of these results is discussed.
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Mounir Trimeche, Sonia Ziadi, Laurence De Leval, Sihem Hmissa, Badredine Sriha, Moncef Mokni, Intissar Toumi, Halima Elomri, Adnène Laatiri, Abderrahim Kehlif, Jacques Boniver, Sadok Korbi (2005)  Prevalence of Epstein-Barr virus in non-Hodgkin's lymphomas in central region of Tunisia   Ann Pathol 25: 2. 95-102 Apr  
Abstract: The purpose of this study was to evaluate the prevalence of EBV in non-Hodgkin's lymphomas occuring in non-immunocopromised patients in Tunisia through a series of 126 cases. EBV was investigated by EBER oligonucleotide in situ hybridization (ISH) and LMP1-immunohistochemistry. Serological study of EBV has been performed before therapy in 28 patients. EBV was detected in tumor cells by ISH in 28/126 (22.2%) cases. Variable proportions of tumor cells were positive. LMP1 was identified in only 8 cases. EBV was more frequently observed in T-cell lymphomas (9/24 patients; 37.5%) than in B-cell lymphomas (19/102 patients; 18.6%) (p=0.04). There was a strong relationship between EBV and small intestine lymphomas (6/8 patients; 75%) and T/NK nasal type lymphomas (3/3 patients; 100%). EBV serological reactivation was noted in 7/13 patients in clinical stages III/IV and in only 1/10 patients in stages I/II (p=0.03). In conclusion, the prevalence of EBV in Tunisian non-Hodgkin's lymphomas is low but variable depending on the histological type and anatomical location with a predilection for small intestine and nasal lymphomas.
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O Detry, P Léonard, J Delwaide, L de Leval, V Radermacher, A De Roover, M Meurisse, P Honoré (2005)  Laparoscopic liver resection of a hydatid cyst   Rev Med Liege 60: 9. 700-702 Sep  
Abstract: Most of the echinococcosis cases treated in Belgium are contracted in African and Mediterranean countries. In this paper the authors describe the case of a Mediterranean patient suffering from a hepatic hydatid cyst treated by oral albendazole and laparoscopic liver resection.
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Henry Y Dong, David T Scadden, Laurence de Leval, Zuoqin Tang, Peter G Isaacson, Nancy L Harris (2005)  Plasmablastic lymphoma in HIV-positive patients: an aggressive Epstein-Barr virus-associated extramedullary plasmacytic neoplasm.   Am J Surg Pathol 29: 12. 1633-1641 Dec  
Abstract: AIDS-associated aggressive B-cell lymphomas often have plasmacytoid features. Plasma cell neoplasms in HIV patients were commonly described to have atypical morphology and an aggressive clinical course in the literature. We reviewed 14 cases of neoplasms with marked plasmacytic differentiation in HIV-positive patients to determine their clinicopathologic features. Of these, 13 of 14 had homogeneous morphology and were generally CD45(+), CD20-, PAX-5-, and CD138(+). All were positive for Epstein-Barr virus-encoded RNA (EBER) but lacked EBV late membrane proteins (LMP). Human herpes virus 8 (HHV8) DNA was detected in 6 of 10 cases by nested PCR, but HHV8 latent nuclear antigen (LNA) was absent. The 13 patients ranged in age from 28 to 44 years (median, 41 years) (11 male patients; 2 female patients). All patients had extramedullary and 11 of 13 had extranodal tumor at the initial presentation; 2 had distant marrow involvement. The most commonly involved location was the oral cavity (6 of 13 cases), followed by bone and soft tissue (4 of 13), and the gastrointestinal tract (3 of 13). All 11 patients with follow-up died within 34 months (median, 7 months). The 14th patient who had a nodal disease with more undifferentiated morphology and expression of the HHV8 LNA protein was alive without disease at last follow-up (>72 months), probably representing a novel HHV8(+) lymphoma. We conclude that most plasmacytic tumors in HIV-positive individuals are extramedullary, clinically aggressive EBV(+) tumors identical to plasmablastic lymphoma that does not have the clinical features of plasma cell myeloma.
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Laurent Gillet, Benjamin Dewals, Frédéric Farnir, Laurence de Leval, Alain Vanderplasschen (2005)  Bovine herpesvirus 4 induces apoptosis of human carcinoma cell lines in vitro and in vivo.   Cancer Res 65: 20. 9463-9472 Oct  
Abstract: The idea of using oncolytic viruses for the treatment of cancers was proposed a century ago. During the last two decades, viruses able to replicate specifically in cancer cells and to induce their lysis were identified and were genetically modified to improve their viro-oncolytic properties. More recently, a new approach consisting of inducing selective apoptosis in cancer cells through viral infection has been proposed; this approach has been called viro-oncoapoptosis. In the present study, we report the property of bovine herpesvirus-4 (BoHV-4) to induce, in vitro and in vivo, apoptosis of some human carcinomas. This conclusion relies on the following observations: (a) In vitro, BoHV-4 infection induced apoptosis of A549 and OVCAR carcinoma cell lines in a time- and dose-dependent manner. (b) Apoptosis was induced by the expression of an immediate-early or an early BoHV-4 gene, but did not require viral replication. (c) Cell treatment with caspase inhibitors showed that apoptosis induced by BoHV-4 relied mainly on caspase-10 activation. (d) Infection of cocultures of A549 or OVCAR cells mixed with human 293 cells (in which BoHV-4 does not induce apoptosis) showed that BoHV-4 specifically eradicated A549 or OVCAR cancer cells from the cocultures. (e) Finally, in vivo experiments done with nude mice showed that BoHV-4 intratumoral injections reduced drastically the growth of preestablished A549 xenografts. Taken together, these results suggest that BoHV-4 may have potential as a viro-oncoapoptotic agent for the treatment of some human carcinomas. Moreover, further identification of BoHV-4 proapoptotic gene(s) and the cellular pathways targeted by this or these gene(s) could lead to the design of new cancer therapeutic strategies.
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2004
 
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A deRoover, L de Leval, J Gilmaire, O Detry, J Boniver, P Honoré, M Meurisse (2004)  A new model for human intestinal preservation: comparison of University of Wisconsin and Celsior preservation solutions.   Transplant Proc 36: 2. 270-272 Mar  
Abstract: AIM: We compared University of Wisconsin (UW) and Celsior preservation solutions using a new model of human intestinal preservation that mimics the clinical conditions of small bowel procurement. METHODS: Intestinal grafts were harvested from four multiorgan donors. After classic warm dissection for organ procurement, an ileal segment of 50 cm was immediately flushed with Celsior. After the perfusion of the abdominal organs with UW, a second segment of adjacent ileum was harvested. The two intestinal grafts were then divided into segments by stapling, before immersion into the corresponding preservation solution (Celsior or UW) for 0-, 6-, 12-, or 24-hour incubation at 4 degrees C. A histological score was graded after blinded examination of three random specimens within each ileal graft for each duration of preservation. RESULTS: Control specimens showed normal histology. After 6 hours of preservation, most villi showed complete epithelial detachment although the crypts appeared intact. After 12 hours of preservation, a larger proportion of the villi showed extensive epithelial sloughing. After 24 hours, the damage involved the entire mucosa with the crypt epithelium largely detached from the basal membrane. No statistical difference in histological score was observed between the two preservation solutions. CONCLUSION: This study showed severe histological alterations of graft mucosa after short periods of preservation by UW or Celsior solutions. This model may be useful to evaluate improvements in the quality of preservation of human intestinal transplants.
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Jean-Michel Dogné, Julien Hanson, Xavier de Leval, Philippe Kolh, Vincent Tchana-Sato, Laurence de Leval, Stéphanie Rolin, Alexandre Ghuysen, Patrick Segers, Bernard Lambermont, Bernard Masereel, Bernard Pirotte (2004)  Pharmacological characterization of N-tert-butyl-N'-[2-(4'-methylphenylamino)-5-nitrobenzenesulfonyl]urea (BM-573), a novel thromboxane A2 receptor antagonist and thromboxane synthase inhibitor in a rat model of arterial thrombosis and its effects on bleeding time.   J Pharmacol Exp Ther 309: 2. 498-505 May  
Abstract: The present study was undertaken to characterize the antiplatelet and antithrombotic effects of BM-573 [N-tert-butyl-N'-[2-(4'-methylphenylamino)-5-nitrobenzenesulfonyl]urea], an original combined thromboxane receptor antagonist and thromboxane synthase inhibitor in rats, and to determine its effects on mice bleeding time. Intraperitoneal injection of a single dose of 5 mg/kg BM-573 to rats inhibited U-46619 (9,11-dideoxy-9,11-methanoepoxy-prostaglandin F(2))-induced washed platelet aggregation 30 min and 1, 2, and 4 h after drug administration with a maximum antiplatelet effect observed after 1 and 2 h. In a rat model of thrombosis induced by ferric chloride application on the abdominal aorta, BM-573 significantly reduced the thrombus weight by 92.53, 80.20, 64.75, and 18.21% at doses of 5, 2, 0.5, and 0.2 mg/kg, respectively. Time to occlusion of abdominal aorta in the BM-573-treated group (41.50 +/- 5.21 min) was significantly prolonged compared with the vehicle-treated rats (16.16 +/- 0.79 min). Like furegrelate, seratrodast, and acetylsalicylic acid, BM-573 did not affect the tail bleeding time induced by tail transection in mice compared with vehicle-treated mice. Moreover, BM-573, a close derivative of the loop diuretic torasemide, failed to induce a significant increase in diuresis in rat and did not produce a decrease in blood glucose concentration as observed with the sulfonylurea glibenclamide. In conclusion, we have demonstrated that the nitrobenzenic sulfonylurea BM-573, an original combined thromboxane receptor antagonist and thromboxane synthase inhibitor, is a potent antithrombotic agent that does not affect bleeding time. Moreover, BM-573 lost the diuretic property of torasemide and has no impact on glycemia.
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A DeRoover, L De Leval, J Gilmaire, O Detry, C Coimbra, J Boniver, P Honoré, M Meurisse (2004)  Luminal contact with University of Wisconsin solution improves human small bowel preservation.   Transplant Proc 36: 2. 273-275 Mar  
Abstract: AIM: Under clinical conditions small bowel mucosa is stored without any contact between the mucosa and the preservation solution. We evaluated the impact of luminal contact with University of Wisconsin solution (UW) on the structural quality of small bowel preservation. METHODS: Segments of ileum harvested from stable multi-organ donors were flushed with UW. For each donor, ileal segments were placed in UW without any contact between the mucosa and the preservation solution (group A), as is practiced in clinical conditions. Adjacent segments were cut on their antimesenteric side and placed in UW so that their mucosa was widely in contact with the solution (group B). The grafts preserved in ice were removed from the preservation fluid at different times (0, 3, 6, or 12 hours). Tissues were studied by optical microscopy after H&E staining of formalin-fixed, paraffin-embedded specimens. A median histologic score was calculated after examination of three random slides for each ileal segment per time point. Comparisons were performed between tissues of groups A and B from the same donor. RESULTS: Control (0h) specimens showed normal histology. As early as 3 hours of preservation, group A tissues showed detachment of the villar epithelium. At 6 and 12 hours of preservation in this group further tissue alteration were obvious with complete epithelial detachment from the basal membrane of the villi. The histologic score of the segments preserved by luminal contact with UW was always significantly higher than the controls from the same donor. CONCLUSION: Luminal contact between the mucosa of intestinal grafts and UW improves the quality of human small bowel preservation.
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T Weber, R Broux, F Damas, L de Leval, J Boniver, G Hermans (2004)  Anatomo-clinical confrontation: idiopathic pulmonary fibrosis   Rev Med Liege 59: 7-8. 430-434 Jul/Aug  
Abstract: Idiopathic pulmonary fibrosis and pulmonary fibrosis associated with systemic diseases are the most frequent diffuse interstitial pulmonary diseases. They slowly but irrevocably progress towards terminal respiratory failure. They can also be complicated by severe acute respiratory failure and admission in the intensive care unit can be discussed. Despite invasive mechanical ventilation, anti-infectious and immunosuppressive treatments, the disease carries a high mortality rate. We report and discuss the case of a patient with idiopathic, pulmonary fibrosis (UIP) who underwent rapid clinical deterioration.
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David Waltregny, Laurence De Leval, Wendy Glénisson, Siv Ly Tran, Brian J North, Akeila Bellahcène, Ulrich Weidle, Eric Verdin, Vincent Castronovo (2004)  Expression of histone deacetylase 8, a class I histone deacetylase, is restricted to cells showing smooth muscle differentiation in normal human tissues.   Am J Pathol 165: 2. 553-564 Aug  
Abstract: Histone deacetylases (HDACs) were originally identified as nuclear enzymes involved in gene transcription regulation. Until recently, it was thought that their activity was restricted within the nucleus, with histones as unique substrates. The demonstration that specific HDACs deacetylate nonhistone proteins, such as p53 and alpha-tubulin, broadened the field of activity of these enzymes. HDAC8, a class I HDAC, is considered to be ubiquitously expressed, as suggested by results of Northern blots performed on tissue RNA extracts, and transfection experiments using various cell lines have indicated that this enzyme may display a prominent nuclear localization. Using immunohistochemistry, we unexpectedly found that, in normal human tissues, HDAC8 is exclusively expressed by cells showing smooth muscle differentiation, including visceral and vascular smooth muscle cells, myoepithelial cells, and myofibroblasts, and is mainly detected in their cytosol. These findings were confirmed in vitro by nucleo-cytoplasmic fractionation and immunoblot experiments performed on human primary smooth muscle cells, and by the cytosolic detection of epitope-tagged HDAC8 overexpressed in fibroblasts. Immunocytochemistry strongly suggested a cytoskeleton-like distribution of the enzyme. Further double-immunofluorescence staining experiments coupled with confocal microscopy analysis showed that epitope-tagged HDAC8 overexpressed in murine fibroblasts formed cytoplasmic stress fiber-like structures that co-localized with the smooth muscle cytoskeleton protein smooth muscle alpha-actin. Our works represent the first demonstration of the restricted expression of a class I HDAC to a specific cell type and indicate that HDAC8, besides being a novel marker of smooth muscle differentiation, may play a role in the biology of these contractile cells.
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Laurence de Leval, Manuela Vivario, Bernard De Prijck, Yuanping Zhou, Jacques Boniver, Nancy Lee Harris, Peter Isaacson, Ming-Qing Du (2004)  Distinct clonal origin in two cases of Hodgkin's lymphoma variant of Richter's syndrome associated With EBV infection.   Am J Surg Pathol 28: 5. 679-686 May  
Abstract: Occurrence of an aggressive lymphoma in patients with chronic lymphocytic leukemia (CLL), clinically referred to as Richter's syndrome, occasionally manifests as a lymphoproliferation resembling Hodgkin's lymphoma (HL) and often containing the Epstein-Barr virus (EBV). Only a limited number of HL variants have been subject to informative analysis regarding their clonal relationship to the CLL, with evidence of a same clonal origin in some cases and of clonally unrelated neoplasms in other cases. In this paper, we performed a detailed pathologic, virologic, and molecular analysis of two cases of Richter's syndrome with HL features. The first case occurred in a 65-year-old man with a 5-year history of CLL as a mediastinal and supraclavicular mass histologically diagnosed as lymphocyte depleted HL with no background CLL. The second case occurred in a 78-year-old woman with a 4-year history of CLL as an inguinal mass with a composite histologic appearance comprising areas of CLL, areas of CLL with Hodgkin Reed-Sternberg cells, and areas of HL. Both patients had received fludarabine therapy. The HRS cells were CD20-/CD30+/CD15-/J-chain- in case no. 1 and CD20+/-/CD30+/CD15-/J-chain- in case no. 2. In both cases, the Hodgkin's Reed-Sternberg cells (HRS) were positive for type A EBV, and a 30-bp deletion of the LMP-1 gene was detected in case no. 2. Using microdissection and polymerase chain reaction amplification of the immunoglobulin heavy chain gene (IgH) complementarity determining region III of each cell type, we demonstrated a distinct clonal origin for the CLL cells and the HRS in both cases. These cases bring support to the hypothesis that EBV+ HL in CLL patients occurs as unrelated secondary neoplasms most likely as the result of the immune depression associated with CLL and also raise the question of a possible causal role of fludarabine.
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2003
 
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L de Leval, N L Harris (2003)  Variability in immunophenotype in diffuse large B-cell lymphoma and its clinical relevance.   Histopathology 43: 6. 509-528 Dec  
Abstract: Diffuse large B-cell lymphoma (DLBCL), the single largest category of lymphoma, is a clinically and biologically heterogeneous disease entity. Clinically, patients differ in their mode of presentation and respond variably to therapy. A combination of clinical parameters can be used to predict the patient's response to therapy and survival. The pathological variability of DLBCL is expressed in morphology, immunophenotype, cytogenetic and molecular genetic features. Numerous markers detectable by immunohistochemistry and linked to different aspects of tumour biology have been studied in DLBCL, including lineage-associated and immune markers, proliferation and apoptosis markers, cell adhesion molecules, and more recently stage-specific markers of B-cell differentiation. This review summarizes these studies in regard to their clinical significance and in the light of recent advances in our understanding of the molecular pathology and histogenesis of DLBCL.
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Christian Herens, Marc Radermecker, Anne Servais, Pascale Quatresooz, Claire Jardon-Jeghers, Vincent Bours, Laurence de Leval (2003)  Deletion (6)(p22p25) is a recurrent anomaly of thymoma: report of a second case and review of the literature.   Cancer Genet Cytogenet 146: 1. 66-69 Oct  
Abstract: A patient with type AB thymoma and del(6)(p22p25) as the sole cytogenetic anomaly is described. This is the second report of a del(6)(p22p25) in a thymoma. The same deletion was previously found in association with a type A thymoma. Both patients presented with benign tumors. These data suggest that partial deletion of the short arm of chromosome 6 is a nonrandom change associated with benign thymomas.
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Laurence de Leval, Kristina M Braaten, Marek Ancukiewicz, Edward Kiggundu, Thomas Delaney, Henry J Mankin, Nancy Lee Harris (2003)  Diffuse large B-cell lymphoma of bone: an analysis of differentiation-associated antigens with clinical correlation.   Am J Surg Pathol 27: 9. 1269-1277 Sep  
Abstract: Twenty-nine patients with diffuse large B-cell lymphomas presenting with bone involvement, including 18 localized primary bone lymphomas (group 1), 2 multifocal primary bone lymphomas (group 2), and 9 patients with extraskeletal disease at diagnosis (group 3), were studied. The tumors were subclassified according to the criteria of the WHO classification and evaluated by immunohistochemistry for expression of antigens associated with germinal center (GC) and non-GC stages of B-cell differentiation (bcl-6, CD10, MUM-1, VS38c, CD138, bcl-2, and CD44). The presence of a BCL-2/IgH gene rearrangement was investigated by polymerase chain reaction. All cases were characterized by similar clinicopathologic and morphologic features and had similarly good overall outcome. The patients (23 males, 6 females, median age 44 years) had tumors in long bones (14), axial skeleton (8), limb girdles (3), and multiple sites (4). Most tumors (24) were centroblastic, with multilobated cells in 12 cases. Almost half of the tumors (14 of 29, 48%) were bcl-6+CD10+ (GC-like), 9 of 29 cases (31%) were bcl-6+CD10- (indeterminate phenotype), and 6 of 29 cases (21%) were CD10-bcl-6- (post-GC like). The indeterminate phenotype was seen only in primary bone lymphoma. MUM-1 was frequently expressed in GC-like and non-GC-like categories. We found no evidence of plasmacytic differentiation by CD138, and VS38c immunoreactivity was distinctly rare (2 of 29 cases). CD44 was detected in 6 tumors, all CD10-. Bcl-2 was expressed by 70% of the tumors, but only 1 of 23 cases tested had a Bcl-2/JH rearrangement by polymerase chain reaction. A survival analysis showed that GC-like tumors had a longer overall survival duration compared with non-GC-like tumors (P = 0.0046). In conclusion, a GC-like immunophenotype characterizes roughly half of large B-cell lymphomas of bone and is associated with an improved survival.
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Richard J Bende, Laura A Smit, Janneke G Bossenbroek, Wilhelmina M Aarts, Marcel Spaargaren, Laurence de Leval, Guy E E Boeckxstaens, Steven T Pals, Carel J M van Noesel (2003)  Primary follicular lymphoma of the small intestine: alpha4beta7 expression and immunoglobulin configuration suggest an origin from local antigen-experienced B cells.   Am J Pathol 162: 1. 105-113 Jan  
Abstract: Primary follicular lymphoma of the gastrointestinal tract (GI-FL) is a rare so far poorly studied entity. We analyzed four FL cases located in the small intestine and duodenum to gain insight in their pathogenesis and to find an explanation for their low tendency to disseminate outside the GI tract. GI-FLs resemble nodal FLs with respect to morphology and expression of typical GC markers such as CD10, CD38, and BCL-6. We established that the high levels of the anti-apoptosis protein BCL-2 in the tumor cells are in all cases due to a t(14;18) involving the immunoglobulin heavy chain and BCL-2 loci. Detailed immunoglobulin gene analyses on microdissected tissue samples further supported the GC-cell derivation: GI-FLs carry extensively mutated variable heavy-chain genes. The mutation patterns indicated that at some time point in development stringent antigen receptor-based selection processes must have occurred. Interestingly, three of four neoplasms expressed surface IgA, an immunoglobulin class typical of the mucosal immune system and seldom found in nodal FL. In contrast to nodal FLs, the GI-FLs expressed the alpha4beta7 integrin, an established mucosa-homing receptor also expressed by normal intestinal B and T lymphocytes and by low-grade mucosa-associated lymphoid tissue lymphomas. However, the chemokine receptor CXCR3, expressed on low-grade mucosa-associated lymphoid tissue lymphomas, was not detected on the GI-FLs or on nodal FLs. The combined data suggests that primary FL of the small intestine is a distinct entity that originates from local antigen-responsive B cells.
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Kristina M Braaten, Rebecca A Betensky, Laurence de Leval, Yoshifumi Okada, Fred H Hochberg, David N Louis, Nancy L Harris, Tracy T Batchelor (2003)  BCL-6 expression predicts improved survival in patients with primary central nervous system lymphoma.   Clin Cancer Res 9: 3. 1063-1069 Mar  
Abstract: PURPOSE: The purpose of this study was to investigate the histogenetic origin of primary central nervous system lymphoma (PCNSL) with respect to stage of B-cell differentiation and to identify prognostic markers in a cohort of patients with PCNSL treated with i.v. high-dose methotrexate therapy. EXPERIMENTAL DESIGN: This study included 33 patients with PCNSL treated with high-dose i.v. methotrexate at the Massachusetts General Hospital for whom archival tumor tissue was available. All 33 patients tested negative for HIV. The lymphomas were morphologically subclassified according to the Kiel system, as modified in the WHO classification. Immunohistochemistry for the following antigens was performed: BCL-6; BCL-2; MUM1; CD10; vs38c; CD138; CD44; p16; and p53. Fluorescence in situ hybridization and multiplex PCR for CDKN2A/p16 were also performed. RESULTS: There were 17 women and 16 men enrolled, with a median age of 60 years. All tumors were diffuse large B-cell lymphomas. Of the 23 cases that could be subclassified, 22 were centroblastic, and 1 was immunoblastic. Twenty-six of 33 tumors were BCL-6+, 6 of 32 tumors were CD10+, 27 of 29 tumors were BCL-2+, 31 of 32 tumors were MUM1+, 11 of 31 tumors were CD44+, 4 of 33 tumors were vs38c+, and 0 of 32 tumors were CD138+. There were 18 of 32 (56%) complete responses and 8 of 32 (25%) partial responses to methotrexate, whereas 6 of 33 (18%) progressed during treatment. Ten patients died of disease. Expression of BCL-6 was significantly associated with longer overall survival (P = 0.002; median survival, 101 versus 14.7 months, with approximately 95% lower confidence limits of 41.7 and 8.8 months, respectively). CONCLUSIONS: In this group of 33 patients with PCNSL, expression of BCL-6 was significantly associated with longer overall survival. BCL-6 warrants further investigation as a potentially important prognostic marker in this disease.
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PMID 
Laurence de Leval, Jean-Olivier Defraigne, Gilberte Hermans, Florence Dôme, Jacques Boniver, Christian Herens (2003)  Malignant solitary fibrous tumor of the pleura: report of a case with cytogenetic analysis.   Virchows Arch 442: 4. 388-392 Apr  
Abstract: The majority of solitary fibrous tumors (SFTs) of the pleura are benign, but 10-30% locally recur or metastasize. Pathogenic factors relevant to the determinism of their biological properties are largely unknown. Cytogenetic data on SFTs of the pleura are sparse. We report herein a case of a malignant SFT of the pleura where successful karyotyping was obtained from the primary and recurrent tumors. The initial karyotype showed two abnormal clones: 48, XY; +8; +8; del(9)(q22; q32) [19] and 46, XY, t(1;16)(q25;p12) [7]. Culture of the recurrent tumor yielded one clone identical to the dominant clone of the initial karyotype. Demonstration of a recurrent abnormal karyotype largely supports its relevance to the malignant clone and suggests a role of supernumerary chromosome(s) 8 in the determinism of malignant behavior in SFT.
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DOI   
PMID 
Kerry J Savage, Stefano Monti, Jeffery L Kutok, Giorgio Cattoretti, Donna Neuberg, Laurence De Leval, Paul Kurtin, Paola Dal Cin, Christine Ladd, Friedrich Feuerhake, Ricardo C T Aguiar, Sigui Li, Gilles Salles, Francoise Berger, Wen Jing, Geraldine S Pinkus, Thomas Habermann, Riccardo Dalla-Favera, Nancy Lee Harris, Jon C Aster, Todd R Golub, Margaret A Shipp (2003)  The molecular signature of mediastinal large B-cell lymphoma differs from that of other diffuse large B-cell lymphomas and shares features with classical Hodgkin lymphoma.   Blood 102: 12. 3871-3879 Dec  
Abstract: Mediastinal large B-cell lymphoma (MLBCL) is a recently identified subtype of diffuse large B-cell lymphoma (DLBCL) that characteristically presents as localized tumors in young female patients. Although MLBCL has distinctive pathologic features, it clinically resembles the nodular sclerosis subtype of classical Hodgkin lymphoma (cHL). To elucidate the molecular features of MLBCL, we compared the gene expression profiles of newly diagnosed MLBCL and DLBCL and developed a classifier of these diseases. MLBCLs had low levels of expression of multiple components of the B-cell receptor signaling cascade, a profile resembling that of Reed-Sternberg cells of cHL. Like cHLs, MLBCLs also had high levels of expression of the interleukin-13 (IL-13) receptor and downstream effectors of IL-13 signaling (Janus kinase-2 [JAK2] and signal transducer and activator of transcription-1 [STAT1]), tumor necrosis factor (TNF) family members, and TNF receptor-associated factor-1 (TRAF1). Increased expression of STAT1 and TRAF1 in MLBCL was confirmed by immunohistochemistry. Given the TRAF1 expression and known link to nuclear factor-kappa B (NF- kappa B), MLBCLs were also evaluated for nuclear translocation of c-REL protein. In almost all cases, c-REL was localized to the nucleus, consistent with activation of the NF-kappa B pathway. These studies identify a molecular link between MLBCL and cHL and a shared survival pathway.
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PMID 
M Chaplet, L De Leval, D Waltregny, C Detry, G Fornaciari, G Bevilacqua, L W Fisher, V Castronovo, A Bellahcène (2003)  Dentin matrix protein 1 is expressed in human lung cancer.   J Bone Miner Res 18: 8. 1506-1512 Aug  
Abstract: We have previously shown that breast and prostate cancers express bone matrix proteins. DMP1 expression was evaluated in 59 human lung cancer samples at the protein and mRNA levels. It was detectable in 80% of the cases, suggesting a potential role for DMP1 in tumor progression and bone metastasis. INTRODUCTION: Previously, we and others have shown that bone extracellular matrix proteins such as bone sialoprotein (BSP) and osteopontin (OPN) are expressed in various types of cancer that are characterized by a high affinity for bone including breast, prostate, and lung adenocarcinoma. Based on biochemical and genetic features, BSP, OPN, dentin matrix protein 1 (DMP1), and dentin sialophosphoprotein (DSPP) have been recently classified in a unique family named SIBLING (small integrin-binding ligand, N-linked glycoprotein). Therefore, we investigated whether DMP1 could also be detected in osteotropic cancers. MATERIALS AND METHODS: We first used a cancer array for evaluating the relative abundance of DMP1 transcript in a broad spectrum of human cancer tissues. This screening showed that DMP1 was strongly detectable in lung tumors compared with normal corresponding tissue. In a second step, we used an immunophosphatase technique and a specific polyclonal antibody directed against DMP1 to examine the expression of DMP1 in 59 human non-small cell lung cancer samples, including 29 squamous carcinoma, 20 adenocarcinoma, and 10 bronchioloalveolar carcinoma. Student's t-test was used to determine the statistical significance of immunostaining scores between the lung cancer histological groups studied and between cancer and normal lung tissues. RESULTS: Our results show that DMP1 is detectable in 90% of the adenocarcinoma and squamous carcinoma analyzed while 8 of 10 bronchioloalveolar specimens were negative. DMP1 immunostaining intensity and extent scores were significantly higher in adenocarcinoma (p = 0.0004) and squamous carcinoma (p < 0.0001) samples compared with adjacent normal lung tissue. In situ hybridization experiments confirmed that DMP1 mRNA is localized in lung cancer cells. CONCLUSION: In this study, we show that a third SIBLING protein is ectopically expressed in lung cancer. The role of DMP1 in lung cancer is largely unknown. Further studies are required to determine the implication of this protein, next to its sisters SIBLING proteins, in tumor progression and bone metastasis development.
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DOI   
PMID 
P Viatour, M Bentires-Alj, A Chariot, V Deregowski, L de Leval, M - P Merville, V Bours (2003)  NF- kappa B2/p100 induces Bcl-2 expression.   Leukemia 17: 7. 1349-1356 Jul  
Abstract: The NF-kappaB2/p100 and bcl-3 genes are involved in chromosomal translocations described in chronic lymphocytic leukemias (CLL) and non-Hodgkin's lymphomas, and nuclear factor kappaB (NF-kappaB) protects cancer cells against apoptosis. Therefore, we investigated whether this transcription factor could modulate the expression of the Bcl-2 antiapoptotic protein. Bcl-2 promoter analysis showed multiple putative NF-kappaB binding sites. Transfection assays of bcl-2 promoter constructs in HCT116 cells showed that NF-kappaB can indeed transactivate bcl-2. We identified a kappaB site located at position -180 that can only be bound and transactivated by p50 or p52 homodimers. As p50 and p52 homodimers are devoid of any transactivating domains, we showed that they can transactivate the bcl-2 promoter through association with Bcl-3. We also observed that stable overexpression of p100 and its processed product p52 can induce endogenous Bcl-2 expression in MCF7AZ breast cancer cells. Finally, we demonstrated that, in breast cancer and leukemic cells (CLL), high NF-kappaB2/p100 expression was associated with high Bcl-2 expression. Our data suggest that Bcl-2 could be an in vivo target gene for NF-kappaB2/p100.
Notes:
2002
 
PMID 
R Andrianne, B Detroz, K Delbecque, F Leduc, D Szapiro, J Boniver, L de Leval (2002)  Anatomic-clinical confrontation. Large pelvic mass in a young man   Rev Med Liege 57: 3. 148-154 Mar  
Abstract: The authors report the case of a gastro-intestinal stromal tumor (GIST) with unusual clinico-pathological features, presenting as a large cystic rectal mass in a young man. The differential diagnosis of pelvic masses is discussed. In light of this case, the recent literature related to the pathogenesis, diagnosis and treatment of GIST is reviewed.
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PMID 
M G Malaise, O Kaye, M Radermecker, B Duysinx, R Hustinx, G Hermans, L de Leval (2002)  Chronic thoracic pain   Rev Med Liege 57: 5. 270-273 May  
Abstract: The etiological diagnosis of chronic thoracic pain is wide, from benign mechanical disorders to tumors. Reaching the exact diagnosis in often time consuming. Despite the availability of new techniques of imagery, a meticulous clinical history and physical examination remain mandatory. They will lead the exploration. Idiopathic intercostal neuralgia does not exist.
Notes:
 
DOI   
PMID 
Laurence de Leval, Noëlle Hardy, Manuel Deprez, Jean Delwaide, Jacques Belaïche, Jacques Boniver (2002)  Gastric collision between a papillotubular adenocarcinoma and a gastrinoma in a patient with Zollinger-Ellison syndrome.   Virchows Arch 441: 5. 462-465 Nov  
Abstract: We report a unique case of a gastric collision tumor composed of an intramural gastrin-secreting tumor and a papillotubular adenocarcinoma of the intestinal type discovered at autopsy in a patient with Zollinger-Ellison syndrome. There was extensive metastatic dissemination of the neuroendocrine component to regional lymph nodes and to the liver. The unusual macroscopical, histological, and immunohistochemical features of this case and its specific clinical setting are discussed.
Notes:
2001
 
PMID 
L de Leval, N L Harris, J Longtine, J A Ferry, L M Duncan (2001)  Cutaneous b-cell lymphomas of follicular and marginal zone types: use of Bcl-6, CD10, Bcl-2, and CD21 in differential diagnosis and classification.   Am J Surg Pathol 25: 6. 732-741 Jun  
Abstract: Cutaneous follicular lymphomas (FLs) and cutaneous B-cell lymphomas of extranodal marginal zone (MZL)/mucosal-associated lymphoid tissue (MALT) type may have morphologic overlap, despite the fact that they are thought to be of distinct derivation (germinal center vs. postgerminal center). The problem is compounded by the reported absence of bcl-2 expression by many cutaneous FLs, leading to speculation that cutaneous FL may be unrelated to nodal FL. The authors analyzed the expression of the germinal center-associated antigens bcl-6 and CD10 and of bcl-2 in 18 cutaneous B-cell lymphomas (10 FLs and eight MZLs), in relationship to CD21+ follicular structures, to clarify the relationship of nodal to cutaneous FLs and to explore the value of these antigens in differential diagnosis. The authors studied 10 cutaneous FLs (seven primary and three secondary) and eight MZLs (six primary and two secondary). The FLs (found in six men and four women age 45-75 years) involved the trunk (n = 3) and scalp, face and neck (n = 7). The MZLs (found in five women and three men age 34-81 years) involved the trunk (n = 4), face and neck (n = 2), and arm (n = 2). Immunostaining for CD21, bcl-6, CD10, and bcl-2 allowed the delineation of compartments within the tumors and yielded distinct patterns of staining in FL and MZL. In both follicular and interfollicular/diffuse areas of FL the neoplastic cells were bcl-6+ (10 of 10), often CD10+ (seven of 10, four of seven primary), and bcl-2+ (nine of 10, six of seven primary). Only three of seven cases (one of five primary) had bcl-2 rearrangement detectable by polymerase chain reaction. In the MZLs, the neoplastic B-cells were bcl-6-, CD10-, and bcl-2+ (eight of eight). Three patterns of CD21+ follicles were identified in MZL: reactive germinal centers, uniformly bcl-6+, CD10+, and bcl-2- (five of eight MZLs); colonized follicles, both bcl-6-, bcl-2+, and L26+ cells, and bcl-6+ and bcl-2- cells (five of eight MZLs); and expanded/colonized follicular dendritic cell meshworks, bcl-6- and bcl-2+ B cells with rare residual bcl-6+ and bcl-2- cells (four of eight MZLs). The authors conclude that cutaneous FLs express bcl-6 uniformly, usually express CD10 and bcl-2, and have a follicular pattern similar to nodal FL and consistent with a germinal center origin. The immunophenotype of cutaneous FL is distinct from that of cutaneous MZL, which is negative for bcl-6 and CD10. Colonized follicles in MZL, identified by CD21+ follicular dendritic cell meshworks, contained numerous bcl-6- and bcl-2+ B cells, and were readily distinguished from neoplastic follicles in FL. Conversely, CD21- interfollicular and diffuse areas in FLs contained bcl-6+ and CD10+ cells, which were not seen in diffuse areas of MZLs. Thus, the combination of bcl-2, bcl-6, and CD21 staining is useful for the distinction of cutaneous MZL from cutaneous FL.
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PMID 
L de Leval, J A Ferry, B Falini, M Shipp, N L Harris (2001)  Expression of bcl-6 and CD10 in primary mediastinal large B-cell lymphoma: evidence for derivation from germinal center B cells?   Am J Surg Pathol 25: 10. 1277-1282 Oct  
Abstract: Primary mediastinal large B-cell lymphomas (LBCLs) constitute a unique subtype of diffuse LBCLs, with distinct clinical, immunophenotypic, and morphologic features. These lymphomas are thought to originate from the thymus, and it has been hypothesized that they derive from a population of B lymphocytes normally present in the thymic medulla. Most diffuse LBCLs harbor somatic mutations in their immunoglobulin genes, suggesting that they have been exposed to the germinal center. To investigate the possible relationship of mediastinal LBCLs to germinal center B cells, we analyzed the expression of bcl-6 and CD10 in 19 mediastinal LBCLs, using an immunoperoxidase technique on formalin-fixed tissue. We found that 19 of 19 (100%) mediastinal LBCLs were bcl-6+ and 6 of 19 (32%) mediastinal LBCLs were CD10+. Because mediastinal LBCLs usually lack BCL-6 gene rearrangement or mutations, expression of bcl-6 and CD10 in these tumors tends to support a germinal center derivation.
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PMID 
L de Leval, E Savilo, J Longtine, J A Ferry, N L Harris (2001)  Peripheral T-cell lymphoma with follicular involvement and a CD4+/bcl-6+ phenotype.   Am J Surg Pathol 25: 3. 395-400 Mar  
Abstract: A truly follicular pattern is thought to be restricted to B-cell lymphomas. We observed a prominent follicular growth pattern in three cases of nodal peripheral T-cell lymphomas, of which two were initially diagnosed as follicular lymphomas. All three patients were male, ranged in age from 50 to 70 years, and had generalized lymphadenopathy at the time of diagnosis. The follicles were sharply demarcated in two cases and large and vague in one case; in all cases, they contained abundant follicular dendritic cells. Neoplastic cells were small to medium, with irregular cleaved or round nuclei and clear cytoplasm, which was abundant in one case. Lymphoma cells in all cases were CD4+ CD8- CD57- bcl-6, with CD10 coexpression in 2 cases. Clonal rearrangement of the gamma chain of the T-cell receptor gene was demonstrated in each case. These cases expand the differential diagnosis of lymphomas with a follicular growth pattern and suggest that neoplastic T cells may have the capacity to induce or home to follicular structures.
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PMID 
H Husson, E G Carideo, A A Cardoso, S M Lugli, D Neuberg, O Munoz, L de Leval, J Schultze, A S Freedman (2001)  MCP-1 modulates chemotaxis by follicular lymphoma cells.   Br J Haematol 115: 3. 554-562 Dec  
Abstract: The localization and establishment of follicular lymphoma (FL) cells in distinct anatomic sites probably involves chemokine and adhesion receptors on the neoplastic cells and appropriate chemokines and adhesion receptor ligands in the microenvironment. Several chemokines play an important role in normal B-cell trafficking and differentiation. Monocyte chemoattractant protein-1 (MCP-1) is a C-C chemokine that induces chemotaxis of a variety of lymphoid cells through its receptor CCR2. CCR2 is also expressed on B cells, and MCP-1 induces chemotaxis of normal B cells. In this report, we investigated expression and function of CCR2 on FL cells. We found FL cells as well as the t(14; 18)+ B-cell lymphoma line H2 expressed CCR2. MCP-1 potentiated SDF-1-induced chemotaxis of FL cells and H2 cells, but MCP-1 alone did not induce chemotaxis. The specificity of the effects of MCP-1 and SDF-1 was demonstrated by antibody blocking studies. Because FL cells are generally associated with follicular dendritic cells (FDCs), FDCs may be an important source of chemokines. We found that cultured FDCs produced MCP-1, and this production was enhanced by tumour necrosis factor. These data implicate MCP-1 in the migration and localization of FL cells.
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PMID 
A De Roover, O Detry, P Honoré, K Delbecque, L de Leval, J Delwaide, J Joris, J L Canivet, P Damas, J Boniver, M Lamy, M Meurisse, N Jacquet (2001)  Alpha-1-antitrypsin deficiency. An indication for pediatric liver transplantation   Rev Med Liege 56: 11. 753-758 Nov  
Abstract: Alpha-1-antitrypsin deficiency is the most common inborn error of metabolism leading to liver transplantation, and the second cause of liver transplantation in children after biliary atresia. The authors report the case of a 6-year-old girl, who was suffering from end-stage liver disease secondary to alpha-1-antitrypsin deficiency. She was successfully treated by whole liver transplantation, the hepatic graft coming from a 3-year-old donor. Three months later she went back to school. The authors discuss the pathogenesis and the natural history of this frequent cause of liver transplantation in children.
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PMID 
D Waltregny, L de Leval, L Coppens, E Youssef, J de Leval, V Castronovo (2001)  Detection of the 67-kD laminin receptor in prostate cancer biopsies as a predictor of recurrence after radical prostatectomy.   Eur Urol 40: 5. 495-503 Nov  
Abstract: OBJECTIVES: Reliable prognostic indicators are needed for a better pretherapeutic assessment of the agressiveness of organ-confined prostate cancer (PC) lesions. The 67-kD laminin receptor (67LR) is a cell-surface-associated protein involved in the acquisition of the invasive and metastatic phenotype of a variety of human cancer cell types. We have previously shown that 67LR detection in PC tissues from radical prostatectomy (RP) specimens is an independent predictor of biochemical (PSA) relapse in patients with clinically localized PC. In this study, we assessed 67LR detection in diagnostic PC biopsies as a predictor of biochemical relapse after RP. METHODS: Diagnostic biopsy and subsequent RP tissue specimens from 151 patients with clinically localized PC were immunohistochemically analyzed for 67LR expression. The level of 67LR expression was evaluated by both intensity and extent of the staining. Clinicopathological preoperative and postoperative parameters, including 67LR expression, were correlated with each other and tested as predictors of biochemical relapse. RESULTS: 67LR was detected in 67.5 and 68.2% of biopsies and RPs, respectively. 67LR detection in RP specimens was an independent predictor of relapse. The level of 67LR expression in the biopsy was significantly associated with the biopsy Gleason score (p<0.05) but failed to predict the pathological stage (p>0.1). Biochemical progression-free estimates for patients whose biopsy did or did not express the protein differed with only borderline statistical significance (p = 0.05). Multivariate analysis identified biopsy Gleason score as the only independent preoperative predictor of recurrence. Significant discrepancies in levels of 67LR expression were found between matched biopsy and RP specimens (p<0.05), with exact agreement rates <40%. CONCLUSIONS: 67LR detection in PC biopsies was not a significant preoperative predictor of outcome after RP. Heterogeneity of 67LR expression and biopsy sampling errors most likely represented the main reasons for discordant results between biopsy and RP specimens.
Notes:
2000
 
DOI   
PMID 
C Grignet-Debrus, V Cool, N Baudson, B Degrève, J Balzarini, L De Leval, S Debrus, T Velu, C M Calberg-Bacq (2000)  Comparative in vitro and in vivo cytotoxic activity of (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU) and its arabinosyl derivative, (E)-5-(2-bromovinyl)-1-beta-D-arabinofuranosyluracil (BVaraU), against tumor cells expressing either the Varicella zoster or the Herpes simplex virus thymidine kinase.   Cancer Gene Ther 7: 2. 215-223 Feb  
Abstract: The inhibitory effects of (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU) and its arabinosyl derivative (E)-5-(2-bromovinyl)-1-beta-D-arabinofuranosyluracil (BVaraU) on the growth of both MDA-MB-435 human breast carcinoma and 9L rat gliosarcoma cells expressing the thymidine kinase (tk)-encoding gene of the Varicella zoster virus (VZV) or the Herpes simplex virus (HSV) were evaluated. In vitro, BVDU and BVaraU effectively killed both cell types expressing VZVtk, with 50% inhibitory concentration values ranging from 0.06 to 0.4 microM, whereas ganciclovir (GCV) lacked activity. On HSVtk+ cells, BVDU had high cytotoxic activity, with 50% inhibitory concentration values that were similar to those of GCV, whereas BVaraU was inactive. In vivo, BVDU applied intraperitoneally caused a 50% tumor growth inhibition in nude mice inoculated subcutaneously with VZVtk+ as well as HSVtk+ mammary tumor cells. In mice and at variance with the in vitro results, BVaraU had very little activity against the VZVtk+ mammary cells; GCV had the highest activity on the HSVtk+ cells, resulting in a 50% eradication of the tumors. With the 9L rat gliosarcoma model, the VZVtk/BVDU system completely failed to inhibit the development of VZVtk+ glioma tumors induced subcutaneously in syngeneic rats, although BVDU had a similar 45-minute half-life in both rats and mice. Factors other than degradation of the prodrug and related to the mode of action of these analogs are possibly involved in the observed discrepancies between the in vitro and in vivo results.
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1999
 
PMID 
M Deprez, M D'Hooghe, J P Misson, L de Leval, C Ceuterick, M Reznik, J J Martin, M D'Hooge (1999)  Infantile and juvenile presentations of Alexander's disease: a report of two cases.   Acta Neurol Scand 99: 3. 158-165 Mar  
Abstract: We describe 2 new cases of Alexander's disease, the first to be reported in Belgium. The first patient, a 4-year-old girl, presented with progressive megalencephaly, mental retardation, spastic tetraparesis, ataxia and epilepsy: post-mortem examination showed widespread myelin loss with Rosenthal fibers (RFs) accumulation throughout the neuraxis. She was the third of heterozygotic twins, the 2 others having developed normally and being alive at age 5 years. The second patient developed at age 10 years and over a decade spastic paraparesis, palatal myoclonus, nystagmus, thoracic hyperkyphosis and thoraco-lumbar scoliosis with radiological findings of bilateral anterior leukoencephalopathy. Brain stereotactic biopsy at age 16 years demonstrated numerous RFs. With these 2 cases, we review the literature on the various clinico-pathological conditions reported as Alexander's disease. We discuss the nosology of this entity and the pathogeny of RFs formation and dysmyelination. Clues to the diagnosis of this encephalopathy in the living patient are briefly described.
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PMID 
L De Leval, S Debrus, P Lane, J Boniver, M Moutschen (1999)  Mice transgenic for a soluble form of murine cytotoxic T lymphocyte antigen 4 are refractory to murine acquired immune deficiency sydrome development.   Immunology 98: 4. 630-638 Dec  
Abstract: Interactions between B and CD4+ T cells are central to the pathogenesis of retrovirus-induced murine acquired immune deficiency virus (MAIDS). Prompted by previous work showing that treatment with cytotoxic T lymphocyte antigen 4 immunoglobulin (CTLA4Ig) partly inhibited the disease, we studied the course of infection in mice deficient for CD28-B7 interactions (mCTLA4-Hgamma1 transgenic mice). Despite a relative viral load identical to that of non-transgenic mice, the transgenic mice did not develop any of the major MAIDS symptoms (i.e. lymphoproliferation and immune anergy). The mCTLA4-Hgamma1 did not however, completely inhibit B-cell activation as indicated by a slight hypergammaglobulinaemia and microscopic blastic transformation. Absence of MAIDS in transgenic mice was associated with much lower levels of both interleukin-4 and interferon-gamma transcripts following viral infection. These results support the theory that the CD28/B7 costimulatory pathway is a critical determinant to MAIDS development.
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1998
 
PMID 
V Boniver, L de Leval, G Daenen, P Honoré, C Davin, N Hardy, J Boniver (1998)  Anatomo-clinical correlation. A case of invasive pulmonary aspergillosis   Rev Med Liege 53: 10. 592-596 Oct  
Abstract: This report describes a case of invasive pulmonary aspergillosis affecting a young female patient who had benefited from a liver transplantation for a fulminant hepatic failure. Infections following liver transplantation can happen but in this case the short delay to the fatal outcome is unusual (6 days). Corticotherapy given prior to transplantation could have impaired the immune system. The authors discuss the infections due to Aspergillus species and particularly invasive pulmonary aspergillosis.
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PMID 
L de Leval, S Colombi, S Debrus, M A Demoitié, R Greimers, P Linsley, M Moutschen, J Boniver (1998)  CD28-B7 costimulatory blockade by CTLA4Ig delays the development of retrovirus-induced murine AIDS.   J Virol 72: 6. 5285-5290 Jun  
Abstract: Mouse AIDS (MAIDS) induced in C57BL/6 mice by infection with a replication-defective retrovirus (Du5H) combines extensive lymphoproliferation and profound immunodeficiency. Although B cells are the main target of viral infection, recent research has focused on CD4(+) T cells, the activation of which is a key event in MAIDS induction and progression. A preliminary observation of increased expression of B7 molecules on B cells in MAIDS prompted us to address the possible involvement of the CD28/B7 costimulatory pathway in MAIDS. Mice infected with the MAIDS-inducing viral preparation were treated with murine fusion protein CTLA4Ig (3 x 50 microg/week given intraperitoneally), a competitive inhibitor of physiological CD28-B7 interactions. In CTLA4Ig-treated animals, the onset of the disease was delayed, lymphoproliferation progressed at a much slower rate than in untreated mice, and the loss of in vitro responsiveness to mitogens was reduced. Relative expression of Du5H did not differ between treated and untreated animals. These results suggest that the CD28/B7 costimulatory pathway contributes to MAIDS development.
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1997
 
PMID 
L de Leval, B Lambermont, V D'Orio, J Boniver (1997)  Fatal massive liver steatosis--a clinicopathological case report.   Acta Gastroenterol Belg 60: 2. 180-183 Apr/Jun  
Abstract: Hepatic fatty change is a common lesion. Two forms are recognized: micro- and macrovesicular steatosis, the former being much less frequent and more serious than the latter. The case of an alcoholic woman under anticonvulsivant therapy and with medications for a syndrome of inappropriate secretion of antidiuretic hormone (SIADH) who presented with rapidly progressive cholestasis and hepatocellular failure is reported. Massive macro- and micro-vesicular hepatic steatosis was diagnosed at autopsy. The authors review the clinico-pathological features associated with this condition, and causal factors possibly implicated in this case are discussed in regard with currently considered pathophysiological mechanisms.
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PMID 
S Colombi, M Moutschen, L de Leval, M A Demoitié, M Trebak, M T Martin, J Boniver (1997)  Peyer's patches in murine AIDS: dissociation between lymphoproliferation and anergy.   Scand J Immunol 45: 2. 175-181 Feb  
Abstract: RadLV-Rs infection induces a murine immunodeficiency syndrome associated with a dramatic enlargement of spleen and lymph nodes. Surprisingly, the lymphoproliferation excludes thymus and Peyer's patches (PP). To understand the cellular interactions underlying lymphoproliferation further, the authors investigated the fate of PP in RadLV-Rs infected mice. The atrophy of PP was mostly due to the depletion of B cells, while the proportion of CD4+ and CD8+ T cells was increased. Nevertheless, B cell phenotype was modified with the emergence of lymphocytes with a low expression of B220 in infected PP. T cells characterized by a memory/activated phenotype in control PP did not undergo phenotypical changes after viral infection (i.e. regarding Thy-1 and CD44 expression). Despite the absence of lymphoproliferation, PP T and B cells displayed altered responses to mitogens in vitro. Finally, alterations of the expression of adhesion molecules and vascular addressins could not explain the atrophy of PP by a reduced homing to this lymphoid site. B cells and T cells from normal PP are clearly different from lymph nodes (LN) lymphocytes. The authors propose that the particular functional state which characterizes PP lymphocytes influences the B cell/T cell crosstalk necessary for RadLV-Rs-induced lymphoproliferation.
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PMID 
H Van Damme, L De Leval, E Creemers, R Limet (1997)  Thrombangiitis obliterans (Buerger's disease): still a limb threatening disease.   Acta Chir Belg 97: 5. 229-236 Oct  
Abstract: A series of 29 well-documented and properly analysed patients with thrombangiitis obliterans (Buerger's disease) is presented. The diagnosis of Buerger's disease was based on following criteria: smoking history, onset before the age of 50 years, infrapopliteal arterial occlusive disease, either upper limb involvement or phlebitis migrans, absence of atherosclerotic risk factors other than smoking. In the last 10 years (1986-1996), we identified 29 patients who met these rigid criteria. There were 24 men and 5 women, aged 32.4 years at the moment of the disease first clinical symptom. The cumulative tobacco use averaged 16 pack-years for each patient. The initial symptom was limited gangrene of a toe (n = 9) or a finger (n = 2), foot claudication (n = 6), calf claudication (n = 3), rest pain (n = 3), migratory superficial phlebitis (n = 4), and Raynaud phenomenon (n = 2). Angiography and/or Doppler ultrasound revealed digital, pedal and calf artery involvement in all patients, with proximal extension in ten patients (femoropopliteal in ten, including three cases with external iliac artery involvement). Seven patients had also evidence of upper limb involvement. Histologic proof was available in only seven patients. Only nine patients completely stopped smoking. Treatment was exclusively medical in five cases. Twenty-four underwent sympathectomy (20 at lumbar, and four at thoracic level), with good immediate result in 16. In 11 patients a vascular reconstruction was done (eight femorocrural and three iliofemoral bypasses), with a patency rate of only 36% at two years. Amputation was required in 16 patients (a mean of 2.7 amputations per patient) at one or more levels: toe (n = 19), forefoot (n = 5), below knee (n = 8), above knee (n = 2), finger (n = 3). Two patients ended up with bilateral leg amputation. Overall, 23% (7/30) of the patients required major leg amputation during the course of the disease. Disease progression was moderately related to continued tobacco use. Buerger's disease still entails considerable risk of major amputation. Complete abstinence from tobacco use is crucial to expect stabilization of the process. However, in advanced stages of the disease and despite cessation of smoking recurrent episodes of ischaemia or tissue loss are not excluded.
Notes:
1996
 
PMID 
J Schoenen, L De Leval, M Reznik (1996)  Gliomatosis cerebri: clinical, radiological and pathological report of a case with a stroke-like onset.   Acta Neurol Belg 96: 4. 294-300 Dec  
Abstract: A 62 year-old man was admitted with a right hemiparesis, sensory aphasia and right hemianopia which appeared on awakening. He was initially thought to have a stroke, but EEG showed diffuse slowing and both CT scan and MRI irregular white matter lesion suggesting a leucoencephalopathy. His neurological deficit regressed, and he was discharged after 2 weeks. He was readmitted 6 months later because of mental confusion. MRI revealed diffuse white matter lesions extending up to the frontal lobes, these were hyperintense on T2 weighted images and suggested the diagnosis of gliomatosis cerebri (GC). The patient became progressively comatose and died 6 weeks later. At autopsy the brain looked diffusely swollen with irregular greyish areas of the white matter of both centrum ovale and brain stem. On microscopic examination the cerebrum and brain stem were diffusely and asymmetrically infiltrated by numerous neoplastic glial cells without angiogenesis or disruption of architectonic boundaries. There were no mitoses nor necrosis. Many tumour cells were GFAP- and S100-positive. A high proportion of cells contained the leucocyte antigen Leu-7. This case of gliomatosis cerebri is compared to the 9 published cases of GC with an initial focal neurological deficit and to the 19 publications reporting MRI results. The controversial nosological boundaries and etiopathogenetic hypotheses of this peculiar neoplastic disease are discussed.
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1995
 
PMID 
L de Leval, M Deprez, S Colombi, C Humblet, M P Defresne, J Boniver, M Moutschen (1995)  Morphological changes of thymus in retrovirus-induced murine acquired immunodeficiency syndrome (MAIDS).   Pathol Res Pract 191: 6. 506-512 Jul  
Abstract: The possible contribution of the thymus in the setting of acquired immunodeficiencies is still questioned. Here we report some new findings regarding a potential involvement of the thymus in mice infected with RadLV-Rs, a viral mixture inducing murine acquired immunodeficiency syndrome (MAIDS). Thymi were sequentially removed, weighted and morphologically analyzed at different time intervals post-infection. Infection with RadLV-Rs led to a decrease in thymus weight mostly apparent from the fourth week. The first changes were seen at the third week as perivascular clusters of B-cells at the cortico-medullary junction. The ensuing process of atrophy mainly involved the cortex, while a mixed population of large T- and B-cells filled the medulla. These observations are discussed with regard to the pathological changes occurring in other lymphoid and non-lymphoid organs, in the context of the lymphoproliferation and immunodeficiency characterizing the disease, and by comparison with other models of retrovirus-induced immunodeficiencies.
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1994
 
PMID 
S Colombi, M Deprez, L De Leval, C Humblet, R Greimers, M P Defresne, J Boniver, M Moutschen (1994)  Thymus involvement in murine acquired immunodeficiency (MAIDS).   Thymus 23: 1. 27-37  
Abstract: Due to self-renewal of the peripheral pool of T-cells, adult thymectomy has normally little influence on immunocompetence. However, thymus might play a more important role in the setting of viral-induced cytopathic effects on T-cells in the periphery. Therefore, thymus weight, cell numbers, and subset distribution were sequentially analysed after infection with RadLV-Rs, a viral mixture known to induce murine retrovirus induced immunodeficiency (MAIDS). Infection induced thymic atrophy (concerning organ weight as well as total cell number) which culminated seven weeks after inoculation. The atrophic process mostly reflected the depletion of double positive CD4+ CD8+ cells since their proportion sharply decreased around week 6. Single positive T-cells were less affected by the process. The proportion of B-cells progressively increased. Surprisingly, there was a strong correlation between the extent of atrophy and the frequency of B-cells in the thymus. Finally, an abnormal CD4+ T-cell subset lacking Thy-1 and previously described in the periphery also appeared in the thymus and its frequency was strongly correlated with the expansion of B-cells in this organ.
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PMID 
H Van Damme, M Deprez, L de Leval, O Vahdat, N Calteux, J Boniver, R Limet (1994)  Rupture of a superficial femoral aneurysm in the context of neurofibromatosis. Report of a case   J Mal Vasc 19: 1. 62-65  
Abstract: The authors observed the spontaneous rupture of a dysplastic superficial femoral artery in a 47 years old patient with Von Recklinghausen disease. The patient presents a gigantism of his right lower limb. On angiography, the femoropopliteal axis is polyaneurysmal and there is evidence of rupture at mid-thigh. The diseased artery is excluded by interposition of a dacron prosthesis, with reimplantation of the deep femoral artery. Histology shows fibrohyalin thickening of the intima. Dysplasia of large limb arteries is excessively rare in Von Recklinghausen disease.
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PMID 
I Frangi, L de Leval, G Herman, A Andrianne, J de Leval (1994)  Benign testicular and paratesticular tumors   Acta Urol Belg 62: 3. 25-30 Sep  
Abstract: Five cases of benign testicular and paratesticular tumors are reported which have been treated by conservative methods. A literature review is presented about the most frequent benign testicular and paratesticular neoplasms. The preoperative diagnosis and the choice of treatment are discussed.
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PMID 
L de Leval, D Waltregny, R Greimers, J Boniver (1994)  Flow cytometry in prostate cancer: histological and clinical correlation.   Acta Urol Belg 62: 1. 37-43 Apr  
Abstract: DNA histograms were obtained by flow cytometry for 39 human prostate carcinomas (27 total prostatectomy specimens, 5 biopsies and 7 transuretral resections). The study was performed on formalin-fixed and paraffin-embedded material. In this report, ploidy index did not seem to be a good marker of prognosis as no significant variation in ploidy was found neither among the different stages nor among the different Gleason categories. Proliferative index of the tumors seemed to be a more sensitive parameter; a significant relation was observed between proliferative index and stage of the tumor. The authors discuss these results under the light of previously reported observations.
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1992
 
PMID 
P Coucke, L De Leval, P Leyh, K Bonjean, B Siwek, A Noel, M C De Pauw-Gillet, J M Paulus, R Bassleer, J M Foidart (1992)  Influence of laminin or fibroblasts upon colony formation in the mouse by B16 melanoma cell spheroids: a morphometric analysis.   In Vivo 6: 2. 119-124 Mar/Apr  
Abstract: By microscopical observation and using an original morphometric method, we analyzed on histological sections the rate of lung colony formation after the intravenous injection into the mouse of B16 melanoma cells previously cultivated in vitro as aggregates. After the injection of B16 pure spheroids, superficial lung colonies were more numerous than internal lung colonies. After the injection of mixed spheroids (B16 + 3T3 fibroblasts), the size of colony sections was increased. Addition of laminin to pure or mixed spheroids decreased the size of colony sections but increased the number of internal lung colonies.
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PMID 
P Coucke, M C De Pauw-Gillet, L De Leval, A Noel, R Bassleer, J M Foidart (1992)  Fibronectin promotes lung colony formation in the mouse by B16 melanoma cells spheroids.   In Vivo 6: 5. 481-486 Sep/Oct  
Abstract: By microscopical observation and using an original method of automatic image analysis, we studied on histological sections the rate of lung colony formation after intravenous injection into the mouse of B16 melanoma cells previously cultivated in vitro as pure or mixed spheroids (B16 + 3T3 fibroblasts). The preincubation in vitro of pure spheroids with fibronectin significantly increased the percentages of lung section area occupied by tumors and the relative number of internal lung colonies. This effect of fibronectin was even more obvious when mixed spheroids were injected.
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