Abstract: Dbl is the prototype of a large family of GDP-GTP exchange factors for small GTPases of the Rho family. In vitro, Dbl is known to activate Rho, Rac, and Cdc42 and to induce a transformed phenotype in murine fibroblasts. We previously reported that Dbl-null mice are viable and fertile but display defective dendrite elongation of distinct subpopulations of cortical neurons, suggesting a role of Dbl in controlling dendritic growth. To gain deeper insights into the role of Dbl in development and disease, we attempted a knock-in approach to create an endogenous allele that encodes a missense-mutation-mediated loss of function in the DH domain. We generated, by gene targeting technology, a mutant mouse strain by inserting a mutagenized human proto-Dbl cDNA clone expressing only the Dbl N terminus regulatory sequence at the starting codon of murine exon 1. Animals were monitored over a 21-month period, and necropsy specimens were collected for histological examination and immunohistochemistry analysis. Dbl knock-in mice are viable and did not manifest either decreased reproductive performances or gross developmental phenotype but revealed a reduced lifespan compared to wild-type (w.t.) mice and showed, with aging, a B cell lymphoproliferation that often has features of a frank diffuse large B cell lymphoma. Moreover, Dbl knock-in male mice displayed an increased incidence of lung adenoma compared to w.t. mice. These data indicate that Dbl is a tumor susceptibility gene in mice and that loss of function of Dbl DH domain by genetic missense mutations is responsible for induction of diffuse large B cell lymphoma.
Abstract: BACKGROUND: Standardized criteria for assessing microscopic esophageal lesions are required to test their utility as markers of gastroesophageal reflux disease (GERD). AIMS: To finalize draft criteria for assessing microscopic esophageal lesions associated with gastroesophageal reflux and to test them for interobserver agreement. METHODS: An international group of gastrointestinal pathologists was convened to finalize, using a consensus-based approach, draft criteria for recognizing microscopic esophageal lesions. Finalized criteria were retested for interobserver variability by four of the pathologists using 120 digitized esophageal biopsy slides from patients with GERD. RESULTS: The finalized criteria included further clarification on lesion definitions and new guidance on how to select the area for assessing each lesion. This latter refinement was guided by the high interobserver agreement observed when draft criteria were previously applied to biopsies where the assessment area was preselected. When finalized criteria were applied in the current study to digitized biopsies without a preselected assessment area, the pairwise agreement was 73-97% for basal cell hyperplasia, papillary elongation, intraepithelial eosinophil, neutrophil and mononuclear cell numbers, and active/healed erosions, with slightly lower agreement (64%) for dilated intercellular spaces (DIS). When a combined severity score was applied, the level of agreement was 77%. The mean kappa ranged from fair to high (0.26-0.77) for individual lesions and was high for the combined score (0.64). CONCLUSIONS: These levels of agreement are comparable with or higher than those for other accepted histologic definitions. Further steps include clinical validation of these criteria by correlating microscopic lesions with clinical variables such as esophageal acid exposure.
Abstract: No gold standard test exists for gastroesophageal reflux disease (GERD). Diagnostic difficulties are greatest when reflux symptoms occur without visible esophageal mucosal damage at conventional endoscopy. However, two thirds of such patients do have microscopic esophageal lesions. This study aimed to develop and standardize criteria for recognizing these microscopic esophageal lesions in GERD. Draft histologic criteria were developed and tested by an international group of 5 independent gastrointestinal pathologists using 167 biopsy specimens from GERD patients and healthy controls (phase I). Draft criteria were refined and reassessed using 250 photographs of biopsy specimens (phase II). Histologic lesions evaluated were basal cell hyperplasia, papillary elongation, intraepithelial eosinophil, neutrophil and mononuclear cell number, necrosis/erosion, healed erosion, and dilated intercellular spaces. Interobserver agreement and kappa values increased significantly from phase I to II. When tested in annotated photographs (phase II), mean pairwise agreements were 74%, 89%, 93%, 97%, 81%, 97%, 94%, and 74%, respectively. Mean pairwise kappa estimates (+/-SD) were 0.49 (0.16), 0.81 (0.05), 0.87 (0.05), 0.84 (0.09), 0.60 (0.09), 0.90 (0.04), 0.73 (0.14), and 0.61 (0.08), respectively. Estimated intraclass correlation coefficients for basal cell layer thickness and papillary length increased from 0.38 and 0.56 to 0.69 and 0.95, respectively, when revised criteria were used. The draft criteria achieved promising levels of agreement when assessed independently by 5 pathologists. Further steps include evaluation of lesions without indicating the area to be assessed and exploring the correlation of microscopic esophagitis with symptoms and esophageal acid exposure.
Abstract: Gastroesophageal reflux disease (GERD)-associated changes in esophageal histology have been reported mainly after short-term medical antireflux therapy, and few individual lesions have been examined. We report detailed histological findings from the LOTUS study, at baseline and at 1 and 3 years after laparoscopic antireflux surgery (LARS) or esomeprazole treatment in patients with chronic GERD.
Abstract: Causes of thrombocytopenia (TP) in patients affected by small-cell lung cancer (SCLC) include myelophtysis, immunomediated TP, disseminated intravascular coagulation, thrombotic thrombocytopenic purpura, drug-related TP, and amegakaryocytic TP. However, isolated TP is an exceedingly rare presentation of SCLC.
Abstract: Patients with non-erosive reflux disease may show microscopic damage. This study is aimed to describe distribution, sensitivity, and specificity of histological lesions (i.e., basal cell hyperplasia-BH, papillae elongation-PE, dilatation of intercellular spaces-DIS, intraepithelial eosinophils-IE, neutrophils, and erosions) and sampling criteria. Four groups were identified on the basis of symptoms, endoscopy, and pH monitoring: (1) erosive esophagitis (n = 48), (2) non-erosive esophagitis with abnormal pH (n = 59), (3) non-erosive esophagitis with normal pH (n = 12), and (4) controls (n = 20). Biopsies were taken at the Z-line and 2 and 4 cm above it. BH, PE, DIS, IE, neutrophils, and erosions were assessed. A global severity score was calculated on the basis of the above parameters and allowed the distinction of patients from controls with 80% sensitivity and 85% specificity. Lesions were more severe at Z-line than proximally and more expressed in erosive than in non-erosive disease, although more than 70% of latter patients still showed histological damage. Esophageal biopsy seems very attractive in non-erosive disease where it may contribute to diagnosis and play a role in the comparative evaluation of different therapies.
Abstract: Arginase 1 (ARG1) inhibits T-cell proliferation by degrading extracellular arginine, which results in decreased responsiveness of T cells to CD3/TCR stimulation. In humans, ARG1 is stored in inactive form within granules of polymorphonuclear neutrophils (PMNs) and gets activated on release. We studied the role of PMNs-related ARG1 activity in nonsmall cell lung cancer (NSLC), in which tumor-infiltrating lymphocytes showed reduced proliferation in response to CD3/TCR triggering. Patients with NSCLC had increased ARG1 plasma levels as compared to healthy controls. Furthermore, immunohistochemistry showed that tumor-infiltrating PMNs display reduced intracellular ARG1, in comparison to intravascular or peritumoral PMNs, suggesting a role of tumor microenvironment in ARG1 release. Indeed, supernatants of NSCLC cell lines induced exocytosis of ARG1 from PMNs. All (4/4) NSCLC cell lines and all (7/7) CD14- cell samples from NSCLC expressed interleukin (IL)-8 mRNA, whereas TNFalpha mRNA was expressed by 1 cell line and by 2 tumor specimens. Furthermore, all NSCLC cell lines secreted immunoreactive IL-8, albeit at different levels. IL-8 was as effective as TNFalpha in triggering ARG1 release and the 2 cytokines acted synergistically. Secreted ARG1 was biologically active and catabolized extracellular arginine. The supernatant of IL-8 gene-silenced NSCLC cells did not mediate ARG1 release by PMNs. Altogether these findings demonstrate a role of IL-8 in ARG1 exocytosis by PMNs and indicate that, due at least in part to IL-8 secreted by NSCLC cells, PMNs infiltrating NSCLC release ARG1. This phenomenon could contribute to local immune suppression.
Abstract: Our discovery that the perinatal period involves nucleotide modifications and gene overexpression in mouse lung prompted us to evaluate whether mice may become more susceptible to cigarette smoke when exposure starts immediately after birth. We previously showed that mainstream cigarette smoke is a quite potent carcinogen in neonatal mice. Further on, we showed that exposure of mice to environmental cigarette smoke (ECS), starting at birth, results in alterations of a variety of intermediate biomarkers. However, after 4 months of exposure to ECS followed by 7 months of recovery in filtered air, the lung tumor yield was rather low. In the present study, we evaluated the protective effects of the glucocorticoid budesonide and of the dietary agent phenethyl isothiocyanate in mice exposed to ECS for 9 months followed by 2 months of recovery. After weanling, the mice exposed to ECS since birth underwent a variety of alterations of molecular and cytogenetical end points, and 11 months after birth, they exhibited significant histopathologic changes, such as pulmonary anthracosis, emphysema, hemorrhagic areas, alveolar bronchiolarization, bronchial hyperplasia, and tumors, both benign and malignant. The carcinogenic response was less evident in dams exposed to ECS under identical conditions. Both phenethyl isothiocyanate and budesonide, administered daily with the diet after weanling, attenuated several alterations of ECS-related biomarkers and moderately protected the lungs from histopathologic alterations, including tumors. Thus, although not as efficiently as the bioassay in mainstream cigarette smoke-exposed mice, the model in neonatal mice is suitable to evaluate both ECS carcinogenicity and its modulation by chemopreventive agents.
Abstract: Lynch syndrome is an inherited cancer syndrome caused by germline mutations in mismatch repair (MMR) genes MLH1, MSH2, MSH6 and PMS2. LS predisposes to high risk of early-onset colorectal, endometrial and other tumors. Patients with Lynch syndrome have also been shown to have an elevated risk for pancreatic cancer (PC). In this study, we aimed to estimate the frequency of suspected Lynch syndrome among a series of 135 PC patients. Further, we wanted to determine the frequency of MMR gene mutations in the suspected Lynch syndrome cases. We also aimed to verify the pathogenicity of any novel non-truncating variants we might detect with a functional assay. Based on personal and/or familial cancer history, 19 patients were classified as suspected Lynch syndrome cases. DNA material for mutation analysis was available for eleven of them. Four patients were found to carry a total of five MLH1 or MSH2 variants. Of these, MSH2-Q402X, MSH2-G322D, and MLH1-K618A had been previously reported, while the MSH2-E205Q and MSH2-V367I variants were novel. MSH2-Q402X is a known stop mutation and reported here for the first time here in association with PC. MLH1-K618A was found in the unaffected branch of a kindred, suggesting that it may be a polymorphism or a low penetrance variant. MSH2-G322D likely does not cause a MMR defect, although this variant has also been associated with breast cancer as indeed seen in our patient. The novel variants MSH2-E205Q and MSH2-V367I were found in the same patient. Both novel variants were however functional in the applied MMR assay. Our findings suggest that only a small subset of pancreatic cancer patients carry pathogenic MMR mutations.
Abstract: The limited prognostic value of currently used histologic classifications of gastric cancer and their failure to account for the complexity of the disease as revealed by more recent investigations prompted a combined reinvestigation of histologic, molecular, and clinicopathologic patterns in 294 extensively sampled, invasive gastric cancers representing all main histotypes and stages of the disease and followed for a median of 150 months. Among histologic parameters tested, only cellular atypia, angio-lympho- or neuroinvasion, Ki67 proliferation index, expansile/infiltrative type growth, and T8 cell-rich high lymphoid intra-/peritumor response (HLR) proved to be stage-independent predictors of patient survival. Among molecular tests, p53 gene exon 7 (loop 3) and 8 (loop-sheet-helix motif and S-10 band), but not p53 protein overexpression, TP53 LOH or 18qLOH, were found to worsen prognosis. Microsatellite DNA instability was a favorable prognostic factor when coupled with HLR. Patient survival analysis of the main histotypes and their subtypes confirmed the favorable prognosis of HLR, well-differentiated tubular, muconodular, and low grade diffuse desmoplastic cancers, and highlighted the worse prognosis of anaplastic and infiltrative-lymphoinvasive mucinous cancers compared to ordinary cohesive and diffuse cancers. Distinct roles of individual morphologic and molecular factors in tumor progression of the different histotypes have been recognized. The combination of survival-predictive histotypes and individual histologic or molecular parameters allowed us to develop a classification of all gastric cancers into three grades of increasing malignancy which proved to be of high prognostic value.
Abstract: Intestinal metaplasia is a risk factor for gastric carcinoma. So far few studies have focused on the efficacy of endoscopic biopsies in detecting intestinal metaplasia in relation with the site and number of biopsies performed. The present study is aimed to assess the efficacy of single and multiple gastric biopsies in the detection and staging of intestinal metaplasia.
Abstract: In human prostate cancer, Arginase 2 (ARG2) and nitric oxide synthase (NOS) are concomitantly expressed by tumor cells, and induce tumor immune escape via peroxynitrite-dependent Tyrosine nitrosylation. Since there were no data regarding this immune suppressive mechanism in other tumor types, and an evaluation of its clinical relevance in human tumors had still to be provided, we have investigated presence and clinical relevance of ARG2 and NOS expression in lung cancer. No evidence of NOS expression was found, no significant NOS enzymatic activity was detected. Instead, ARG2 protein was expressed by tumor cells. In a cohort of 120 patients, the amount of ARG2-positive tumor cells was significantly higher in small cell lung cancers (SCLC) than in non-small cell lung cancers (NSCLC). Large cell undifferentiated carcinomas had twice ARG2 than the other NSCLC subtypes. ARG2 expression was increased in Grade 3 tumors, as compared to Grades 1 and 2. However, no relationship was found with tumor size and stage, and with patient survival. Indeed, the enzyme was active, since the Arginine catabolite Ornithine was produced, but Arginine depletion was not attained. In addition, nitrotyrosine was not found in tumor tissue. Accordingly, when tumor cells isolated from lung cancer were incubated with activated autologous T cells, no inhibition of proliferation was detected. Our results indicate that ARG2 is expressed in lung cancer, but it does not induce tumor immune escape and does not affect disease progression, most probably due to the lack of concomitant NOS expression.
Abstract: The microscopic assessment of squamous epithelium lesions in gastro-oesophageal reflux disease (GERD) is subjective. The Ki67 nuclear antigen expressed by proliferating cells provides an objective measure of regeneration in the squamous epithelium.
Abstract: Identification of the presence of significant fibrosis is an important part of the diagnostic work-up of patients with chronic hepatitis C (CHC).
Abstract: Indoleamine 2,3-dioxygenase (IDO), a catabolizing enzyme of tryptophan, is supposed to play a role in tumor immune escape. Its expression in solid tumors has not yet been well elucidated: IDO can be expressed by the tumor cells themselves, or by ill-defined infiltrating cells, possibly depending on tumor type. We have investigated IDO expression in 25 cases of non-small cell lung cancer (NSCLC). Using histochemistry and immunohistochemistry, we found that IDO was expressed not by tumor cells, but by normal cells infiltrating the peritumoral stroma. These cells were neither macrophages nor dendritic cells, and were identified as eosinophil granulocytes. The amount of IDO-positive eosinophils varied in different cases, ranging from a few cells to more than 50 per field at x200 magnification. IDO protein in NSCLC was enzymatically active. Therefore, at least in NSCLC cases displaying a large amount of these cells in the inflammatory infiltrate, IDO-positive eosinophils could exert an effective immunosuppressive action. On analyzing the 17 patients with adequate follow-up, a significant relationship was found between the amount of IDO-positive infiltrate and overall survival. This finding suggests that the degree of IDO-positive infiltrate could be a prognostic marker in NSCLC.
Abstract: There are conflicting reports on the role of gastro-oesophageal reflux disease (GERD) and Helicobacter pylori infection in the aetiology of carditis.
Abstract: A case of parosteal ossifyng lipoma of femour in 67 years-old female patient is described. Review of literature (1966-1999) about parosteal lipoma reveals less then 70 referred cases; much less common is the ossifyng type; in our knowledge five cases of this very rare subtype are referred in last thirty years.
Abstract: Damage to bile ducts in chronic hepatitis C is a characteristic histological lesion. Moreover, the presence of abnormal levels of gammaGT in these patients is also a common finding. Assessing whether the presence of bile duct lesions is indicated by biochemical abnormalities or whether virological characteristics can influence their development may help in the definition of clinical-histological relationships in chronic hepatitis C. In this study we evaluated the relationships among routine biochemical parameters, serum bile acids, and pi-class glutathione S-transferase levels, and the presence of bile duct lesions in 60 patients with chronic hepatitis C. Furthermore, we assessed whether the presence of bile duct lesion might be related to HCV genotype, HCV-RNA serum levels, and positivity for HGV-RNA. We found that gammaGT was the only parameter related to the presence of bile duct lesions. Although a trend towards higher serum bile acids and pi-class glutathione S-transferase levels was observed in patients with bile duct lesions, this trend did not reach statistical significance. Different HCV genotypes and RNA levels, and HGV-RNA positivity did not seem to influence the presence of bile duct damage. In conclusion we found that gammaGT levels point out the presence of bile duct lesions in patients with chronic hepatitis C. Since we observed a different pattern of alteration of gammaGT, serum bile acids, and pi-class glutathione S-transferase, we suggest that these various biochemical alterations reflect a more complex damage to bile duct structures, which is not likely represented by the common assessment of bile duct lesions. Viral factors such as HCV genotype and RNA levels as well as HGV-RNA positivity are probably not the main cause of this histological damage.
Abstract: Host and viral factors have been suggested as possible causative factors for the presence of liver iron accumulation in chronic hepatitis C. However, there is no agreement regarding the influence of liver iron accumulation on the biochemical and histological severity of chronic hepatitis C. Moreover, data concerning the relationships between both viral load and genotype and liver iron accumulation are scanty.
Abstract: Gastric cancer develops through the accumulation of multiple genetic lesions that involve oncogenes, tumor suppressor genes and DNA mismatch repair genes. Lauren's classification of gastric carcinoma does not correlate with cellular phenotypes expressed by neoplastic cells and gastric and intestinal cell differentiation markers are widely expressed in both types (intestinal and diffuse) of gastric carcinoma. In contrast, the study of the correlation between morphologic events and genetic alterations, which come about in the cancerogenetic process, seems to indicate the existence of distinct cancerogenetic pathways for the intestinal (or glandular) and diffuse type carcinoma, both originating from a HP-positive gastritis. In particular there seem to be three different profiles of cancerogenesis: 1) p53 mutations which accompany the onset of dysplasia and intestinal-type carcinoma; 2) DNA repair mechanism alterations conditioning microsatellite instability, seem mutually exclusive with regards to p53 mutations. Microsatellite instability correlates with antrally located intestinal-type carcinoma, with little metastatic tendency and a better prognosis; microsatellite instability frequently involves the TGF beta RII, IGF II R genes or the BAX proapoptotic gene, in as much as these contain microsatellite sequences; 3) alterations of E-cadherin, both with regards to mutations and abnormal expression. These lead to junctional and cell polarity loss and are primarily associated with diffuse type carcinoma, which is characterized by poorly cohesive neoplastic cells. Some tumors, initially arising as intestinal-type (glandular structure), acquire a mixed histotype during neoplastic progression, in which both the typical alterations of the intestinal cancerogenesis (p53, microsatellite instability) and those of the diffuse carcinoma (E-cadherin) coexist. The identification of a mixed histotype could have importance both in epidemiologic, pathogenetic and prognostic terms.
Abstract: The presence of steatosis is a common histological finding in patients with chronic hepatitis C (CHC). The causes of the severity of this condition are not yet clear, although both metabolic and viral factors supposedly are involved. In this study our aim was to examine the possible influence that leptin levels, hepatitis C virus (HCV) RNA levels, and hepatitis G virus (HGV) infection have on the severity of steatosis and on the presence and degree of fibrosis in patients with CHC.
