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.     

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.     

Virus diversity and an outbreak of group C rotavirus among infants and children with diarrhea in Maizuru city, Japan during 2002-2003

A total of 236 fecal specimens collected from infants and children with gastroenteritis in Maizuru city, Japan from July 2002 to June 2003, were tested for the presence of rotaviruses, noroviruses, sapoviruses, astroviruses, and adenoviruses by RT-PCR, PAGE, RPHA, and latex agglutination methods. Among diarrheal viruses detected, group A rotavirus was the most prevalent (32.2%; 76 of 236) followed by norovirus GII (21.2%; 50 of 236), group C rotavirus (10.2%; 24 of 236), adenovirus (3.8%; 9 of 236), sapovirus (2.5%; 6 of 236), astrovirus (1.3%; 3 of 236), and norovirus GI (0.8%; 2 of 236), respectively. It is noteworthy that group C rotavirus infection was apparently confined only within the period of 5 months (December 2002 through April 2003). This pattern of infection implied that the outbreak of group C rotavirus in these patients, which was the first outbreak of gastroenteritis attributed to group C rotavirus in Maizuru city. Moreover, about half (12 of 24) of group C rotavirus infected cases were confined to infants and young children less than 3 years old. Another interesting feature of the study was the demonstration of the mixed infections with group C rotavirus and group A rotavirus, as well as group C rotavirus and norovirus GII in 20.8% (5 of 24) and 8.3% (2 of 24), respectively. This is the first report of gastroenteritis associated with the mixed infections with group C rotavirus and other viral enteropathogens such as norovirus. The results indicate that group C rotavirus could infect not only older children and adults but also infants and young children under 3 years old.     

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.     

Unique three-way translocation, t(3;14;18)(q27;q32;q21), in follicular lymphoma

A 43-year-old woman was diagnosed as having stage IV follicular lymphoma. Phenotypically, the lymphoma cells were CD5(-), CD10(+), CD19(+), CD20(+), CD23(-), HLA-DR(+), and IgM-lambda(+). Conventional chromosomal analysis showed a three-way t(3;14;18)(q27;q32;q21) in the lymphoma cells, which was confirmed by spectral karyotyping (SKY) and fluorescence in situ hybridization (FISH). Immunohistochemistry revealed that both BCL2 and BCL6 proteins were expressed in the lymphoma cells, whereas only the BCL6 gene, and not the BCL2 gene, was rearranged by Southern blotting. The patient received combination chemotherapy and has been well for 3 years. This is the first reported case showing a three-way translocation involving 2 major lymphoma-specific abnormalities, 3q27 and t(14;18)(q32;q21).     

11q trisomy detected by fluorescence in situ hybridization

Takano T, Yamanouchi Y, Kawashima S, Date M, Hashira S, Kida M, Abe T, Nakahori Y, Nakagome Y. 11q trisomy detected by fluorescence in situ hybridization. Clin Genet 1993: 44: 324–328. © Munksgaard, 1993 A patient with psychomotor developmental delay, multiple minor anomalies, congenital heart disease and left inguinal hernia is reported. His karyotype was 45,X/46,X,+mar (3 : 37 cells), and the marker chromosome was identified as t(Y;11) (q12;q14?) using fluorescence in situ hybridization and fluorescent chromosome painting. He was diagnosed as mosaic for de novo 11q trisomy.     

Effect of finish line design on stress distribution in bilayer and monolithic zirconia crowns: a three‐dimensional finite element analysis study

This study evaluated the influence of different finish line designs and abutment materials on the stress distribution of bilayer and monolithic zirconia crowns using three‐dimensional finite element analysis (FEA). Three‐dimensional models of two types of zirconia premolars – a yttria‐stabilized zirconia framework with veneering ceramic and a monolithic zirconia ceramic – were used in the analysis. Cylindrical models with the finish line design of the crown abutments were prepared with three types of margin curvature radius (CR): CR = 0 (CR0; shoulder margin), CR = 0.5 (CR0.5; rounded shoulder margin), and CR = 1.0 (CR1.0; deep chamfer margin). Two abutment materials (dentin and brass) were analyzed. In the FEA model, 1 N was loaded perpendicular to the occlusal surface at the center of the crown, and linear static analysis was performed. For all crowns, stress was localized to the occlusal loading area as well as to the axial walls of the proximal region. The lowest maximum principal stress values were observed when the dentin abutment with CR0.5 was used under a monolithic zirconia crown. These results suggest that the rounded shoulder margin and deep chamfer margin, in combination with a monolithic zirconia crown, potentially have optimal geometry to minimize occlusal stress.