Abstract: BACKGROUND:: Anatomic reduction of the zygomatic arch, a key surgical landmark for midfacial width and projection, is essential for the treatment of combined fractures of the zygomaticomaxillary complex and zygomatic arch. Reduction control in surgery for this common facial fracture would be facilitated by intraoperative real-time assessment using widely available and reliable equipment. Although C-arm fluoroscopy is routinely used in the repair of orthopedic fractures, its use in the maxillofacial region, particularly for combined zygomatic fractures, has been scarcely reported. METHODS:: We prospectively evaluated C-arm-guided reduction in 38 patients of combined zygomatic fracture without concurrent craniofacial fractures. Patients were classified according to the presence or absence of bone contact in the displaced zygomatic arch, namely as conserved (C) and loss (L) types, respectively. Reduction status was determined by the degree of recovery of the malar prominence and arch shape. RESULTS:: In all cases, C-arm imaging clearly displayed the displaced zygomatic arch and body in a single image. Cumulative fluoroscopic time was a few minutes in all cases. Total reduction status was excellent in 21 patients and good in 17. No case was classified as fair or poor. Repair was significantly more favorable in type C than in type L cases (p = 0.0016). CONCLUSIONS:: In combined zygomatic fractures, the C-arm technique provides easy, flexible, and time-efficient adjustment. Its comprehensive imaging for zygomatic arch shape and body contour markedly facilitates the control of fracture reduction and protects against unexpected, unsatisfactory outcomes.
Abstract: Clinical and pathologic findings in extranodal non-Hodgkin lymphoma (NHL) often raise challenging problems in diagnosis. We demonstrate the first established case of lymphoma with precursor natural killer (NK) cell origin in the oral and maxillofacial region. An 81-year-old Japanese man had an enlarged facial mass mainly in the parotid region but hyposensitivity in the affected side of the mental and lingual region, and diagnostic imaging revealed the origin to be in the masticator space and indicated an advanced-stage lymphoma. The tumor cell immunophenotype was CD56(+)CD3(-)CD4(-), with no B-cell- or myeloid-associated markers. The genotype was of the germ-line configuration of T-cell receptor genes, and no association with Epstein-Barr virus was evident, leading to a diagnosis of NK-cell lymphoblastic lymphoma. This report discusses diagnostic challenges of NHL, including manifestation of numb chin syndrome as a clinical indicator and immunophenotyping of NK-cell-lineage neoplasms.
Abstract: Spindle cell lipoma (SCL) typically occurs in elderly men as a solitary lesion in the posterior neck and back, but less commonly also involves the oral cavity. Here, we describe a rare case of bilateral multiple SCLs of the tongue. The patient was a 72-year-old Japanese man with multiple painless soft nodules in the bilateral margins of the tongue. The patient was not obese, and had used alcohol moderately for more than 40 years. A clinical diagnosis of multiple tongue lipomas was made. The tumors were resected surgically, and they exhibited the histopathological features of SCL, composed of mature fat cells, collagen-forming CD34-positive spindle cells, and sparse mast cells. This suggests that differential diagnosis of intraoral multiple lipomatous nodules should include not only lipomatosis but also multiple SCLs, notwithstanding the rare incidence of the latter.
Abstract: Two type I DnaJ homologs DjA1 (DNAJA1; dj2, HSDJ/hdj-2, rdj1) and DjA2 (DNAJA2; dj3, rdj2) work similarly as a cochaperone of Hsp70s in protein folding and mitochondrial protein import in vitro. To study the in vivo role of DjA1, we generated DjA1-mutant mice. Surprisingly, loss of DjA1 in mice led to severe defects in spermatogenesis that involve aberrant androgen signaling. Transplantation experiments with green fluorescent protein-labeled spermatogonia into DjA1(-/-) mice revealed a primary defect of Sertoli cells in maintaining spermiogenesis at steps 8 and 9. In Sertoli cells of DjA1(-/-) mice, the androgen receptor markedly accumulated with enhanced transcription of several androgen-responsive genes, including Pem and testin. Disruption of Sertoli-germ cell adherens junctions was also evident in DjA1(-/-) mice. Experiments with DjA1(-/-) fibroblasts and primary Sertoli cells indicated aberrant androgen receptor signaling. These results revealed a critical role of DjA1 in spermiogenesis and suggest that DjA1 and DjA2 are not functionally equivalent in vivo.
Abstract: In the mammalian postnatal testis, the biochemical and structural features of Sertoli cells change, depending on developmental stage and spermatogenic cycle, to support efficient spermatogenesis. Consequently, basic transcription factors that determine fundamental properties should be strictly maintained in postnatal Sertoli cells. We have confirmed that GATA-4 expression is kept at a constant level in mouse Sertoli cells during postnatal development, and is also maintained at a constant level in primary cultures, independent of treatment with hormones or the addition of germ cell fractions. In transient transfection assays with the testicular cell line TM3, established from Leydig cells, GATA-4 induced several Sertoli cell-specific genes. In the Sertoli cell line TM4, and in Sertoli cells in primary culture, GATA-4 slightly up-regulated these genes. These results suggest that GATA-4 plays an important role in the regulation of Sertoli cell function, and is exactly regulated in these cells.
Abstract: The 34-kDa translocase of the outer mitochondrial membrane (Tom34) is a putative mammalian-specific factor involved in protein import into mitochondria. We analyzed the genomic sequence of the mouse Tom34 gene and found it has two alternative initial exons. Using reverse transcription and the polymerase chain reaction (RT-PCR), we found that these two mRNAs differs only in the 5'-proximal sequences corresponding to the two initial exons (exon 1a and 1b). Tom34 mRNA with exon 1a (Tom34a) is expressed ubiquitously, while that with exon 1b (Tom34b) is expressed only in mature testicular germ cells. To explore the in vivo function of Tom34 proteins, we generated Tom34-deficient mice by targeted disruption. The Tom34(-/-) mice were viable and grew normally and had a normal Mendelian inheritance pattern. Male as well as female Tom34(-/-) mice were fertile. In vitro-preprotein import into isolated mitochondria showed no apparent difference between Tom34(-/-) and wild-type mice. These results indicate that Tom34 is dispensable for mouse growth and development under optimal conditions.
