Cell cycle control and CDC28/Cdc2 homologue and related gene cloning of Cryptococcus neoformans]

In Cryptococcus neoformans the DNA content of cells having tiny buds varied rather widely, depending on growth phases and strains used. Typically, buds of C. neoformans emerged soon after initiation of DNA synthesis in the early exponential phase. However, bud emergence was delayed to G2 during transition to the stationary phase, and in the early stationary phase budding scarcely occurred, although roughly half of the cells completed DNA synthesis. The timing of budding in C. neoformans was shifted to later cell cycle points with progression of the growth phase of the culture. Similarly, a deficit in oxygen was demonstrated to delay the timing of budding, prolong the G2 phase and cause accumulation of cells after DNA synthesis, but before commitment to budding. The C. neoformans homologue of the main cell cycle control gene CDC28/Cdc2 was isolated using degenerate RT-PCR. The full-length coding region was then amplified using primers to target the regions around the start and stop codons. The gene was called CnCdk1 and was found to have high homologies to S. cerevisiae CDC28 and S. pombe cdc2. To determine its function, its ability to rescue S. cerevisiae cdc28-temperature sensitive mutants was tested. S. cerevisiae cdc28-4 and cdc28-1N strains transformed with the pYES2-CnCdk1 construct exhibited growth at the restrictive temperature. Results of the sequence analysis and the ability of CnCdk1 to complement the S. cerevisiae cdc28-ts mutations support its assumed role as the CDC28/cdc2 homologue in C. neoformans.     

A case of autoimmune hepatitis needed to be differentiated from EBV hepatitis, in that the histology of liver biopsy specimen was useful for diagnosis]

A 10-year-old girl with autoimmune hepatitis (AIH) was reported. She was admitted to our hospital because of cholestasis and elevation of liver enzymes for 2 months. Laboratory examination revealed that EBV-DNA copy number in the PBMNC (peripheral mononuclear cells) was 1.2 x 10(3) copies/microg of DNA, hypergammaglobulinemia, and positive antinuclear antibody, positive anti-smooth muscle antibody. The histology of her liver biopsy specimen revealed interface hepatitis, dense mononuclear cell infiltrates, mild fibrosis, and negative for EBV in situ hybridization assay indicating AIH and not EBV-associated hepatitis. She was treated firstly with methylprednisolone pulses, then will prednisolone p.o.+azathioprine p.o.. Intravenous cyclophosphamide pulse therapy was introduced because of her abnormal immune pathology. All abnormal laboratory parameters improved to normal levels within 2 months, and EBV-DNA copy number in the PBMNC became negative after 4 months. The histology of liver biopsy specimen was useful for the diagnosis of AIH in such a difficult case needed to be differentiated from EBV hepatitis.     

Gliomatosis peritonei

Gliomatosis peritonei, the miliary implants of mature glial tissues on the peritoneum or omentum, is a rare complication of solid ovarian teratoma. Our case is reported and 38 previously reported cases are reviewed. The grade of the primary tumors varied from grade 0 to grade 3. Only five cases were composed entirely of mature tissues. Five of the 39 patients died. Despite of varied therapy, the rest of the patients were alive from 3 months to 38 years later. Inspite of intraperitoneal implants, the prognosis in patients with these tumors is good, irrespective of the mode of therapy. On the basis of this study, we recommended a conservative therapy for the primary tumor and therapy for the implants is not required.     

An Evaluation of the Residual Activity of Antiseptic Handrub Lotions: An ‘In Use’ Setting Study

An evaluation of the residual activity of quick-drying agents (alcoholic solutions) used for hygienic hand disinfection is described. We looked for residual efficacy following hand disinfection with soap and water alone or followed by one of two alcoholic handrub lotions supplied from an automatic hand washing machine. The bacterial counts on the hands obtained before and within 2 successive hours after disinfection showed that alcoholic chlorhexidine was the most effective for 10 minutes after contamination of the hands. WELPAS® (alcoholic chlorbenzarconium) followed this in its immediate effect and was better than soap and water alone. There were no significant differences after 30‘ or 120‘ between the three disinfecting methods.     

Solitary right ventricle metastasis by renal cell carcinoma.

A 57-year-old man with a history of renal cell carcinoma presented with presyncope. He underwent nephrectomy years earlier followed by HLA-matched allogeneic peripheral-blood stem-cell transplantation. Echocardiographic investigation revealed a solitary right ventricle mass without contiguous vena caval or right atrial involvement. The mass was pathologically confirmed to be metastatic carcinoma in the right ventricular cavity. This case highlights the need to consider an underlying neoplastic syndrome in patients presenting isolated right ventricle mass by echocardiography.     

Combined aortic and mitral valve repair in active infective endocarditis

We describe a case of successful combined repair of the aortic and mitral valves for an indication of active infective endocarditis involving both valves. Mitral valve repair was achieved by vegetation debridement, fixation of the anterior mitral commissure, resection and suturing of the posterior mitral leaflet, and posterior annuloplasty with autologous pericardium. Aortic valve repair was achieved by vegetectomy and commissural plication. Postoperative clinical course was without signs of recurrent infection, and echocardiogram demonstrated mitral valve competence with trivial aortic regurgitation. We concluded that simultaneous valve repair is a viable option in the context of active endocarditis.     

Effect of errors in baseline optical properties on accuracy of transabdominal near-infrared spectroscopy in fetal sheep brain during hypoxic stress

A continuous-wave (cw) near-infrared spectroscopy (NIRS) instrument has been developed to noninvasively quantify fetal cerebral blood oxygen saturation (StO2). A linear Green's function formulism was used to analytically solve the photon diffusion equation and extract the time-varying fetal tissue oxy- and deoxy-hemoglobin concentrations from the NIR measurements. Here we explored the accuracy with which this instrument can be expected to perform over a range of fetal hypoxic states. We investigated the dependence of this accuracy on the accuracy of the reference optical properties chosen based on the literature. The fetal oxygenation of a pregnant ewe model was altered via maternal aortic occlusion. The NIR cw instrument was placed on the maternal abdomen directly above the fetal head, continuously acquiring diffuse optical measurements. Blood was sampled periodically from the fetus to obtain fetal arterial saturation (SaO2) measurements from blood gas analysis. The NIR StO2 values were compared with the fetal SaO2 measurements. Variations in the NIR results due to uncertainty in the reference optical properties were relatively small within the fetal SaO2 range of 30 to 80%. Under hypoxic conditions, however, the variability of the NIR StO2 calculations with changes in the assumed reference properties became more significant.     

Establishment of an HIV cell-cell fusion assay by using two genetically modified HeLa cell lines and reporter gene

Infection of human cells with the human immunodeficiency virus type I (HIV-1) can be mimicked by a fusion process between cells expressing the HIV envelope protein (Env) and cells expressing both human CD4 together with the appropriate human chemokine receptors. In this study, a T-tropic HIV cell-cell fusion assay was established that utilized CD4, human CXCR4 and HIV NL4-3 gp160 as fusion components and a T7 polymerase-activated luciferase as a reporter system. The HeLa T4 cells used, expressed CD4 and CXCR4, and the applied HeLa KS386 cells expressed HIV NL4-3 gp160. By combining HeLa T4 cells with HeLa KS386 cells, an approximately about 100- to 300-fold increase in luciferase activity could be elicited relative to the control. The addition of anti-CD4 monoclonal antibody (Mab) (RPA-T4) or anti-CXCR4 Mab (12G5) in the assay significantly inhibited the fusion event; in contrast, an anti-CCR5 Mab (2D7) had no effect, indicating that the fusion assay was CD4 and CXCR4 dependent. In this report, fusion events could be monitored by both the luciferase reporter system and syncytia formation. Fusion events were monitored and compared using these two approaches. The luciferase reporter system was found to be more sensitive than syncytia formation. Moreover, compared with previous HIV fusion models, such as using recombinant vaccinia viruses, this system has several advantages, including simplicity and sensitivity. Finally, the system provides a powerful tool to study fusion mechanisms mediated by T-tropic HIV gp160, as well as to screen for fusion-blocking antibodies and antiviral agents.     

Numerous eosinophilic globules (skeinoid fibers) in a duodenal stromal tumor: An exceptional case showing smooth muscle differentiation

A unique case of duodenal stromal tumor In a 51-year-old man is reported. The tumor histologically showed spindle cell proliferation and numerous eosinophilic globules. Most globules were composed of tangled 45 nm thick fibrils, which were ultrastructurally Identical to 'skelnoid fibers'. The presence of glycogen granules in the tumor cells and the Immunoreactivity for α-smooth muscle actin suggested smooth muscle differentiation. Focal ultrastructural findings also supported the smooth muscle nature of this tumor. There were no immunohistochemical and ultra-structural features indicating neural differentiation. In previous studies, the presence of such 'skeinoid fibers' was suggested to be a histological marker for neural differentiation in gastrointestinal stromal tumor. However, the findings In the present case suggest that numerous 'skeinoid fibers' can be Identified in duodenal stromal tumor with smooth muscle differentiation, although this condition may be rare.     

CD34+ stromal cells and hyalinized vascular changes in the anal fibroepithelial polyps

AIMS: To elucidate the pathogenesis of the anal fibroepithelial polyp, we examined surgically resected lesions histopathologically. METHODS AND RESULTS: Twenty-seven surgically resected anal fibroepithelial polyps were investigated histologically with an additional immunohistochemical examination using anti-CD34. For a control study, the surgical specimens of the anal canal showing non-polypoid lesions, obtained from haemorrhoidectomy (18 specimens) and rectectomy (five specimens) due to rectal cancer without anal canal involvement, were also analysed. We demonstrated characteristic spindle or stellate cells immunohistochemically positive for CD34 in the anal fibroepithelial polyps (24/27, 89%). The number of CD34+ cells was statistically related to the size of anal fibroepithelial polyps, although CD34+ stromal cells were recognized in the non-polypoid anal submucosa and haemorrhoids. We also found hyalinized vascular changes in the base of six anal fibroepithelial polyps examined. These features were not detected in the non-polypoid anal canal. CONCLUSIONS: An increase in CD34+ stromal cells may play a role in the enlargement of anal fibroepithelial polyps. CD34+ stromal cells are suggested to be distinctive mesenchymal cells with a capability for tissue repair and overgrowth. The vascular impairment could be secondary change associated with localized tissue damage by abnormal traction.