GLUTATHIONE S-TRANSFERASE PLACENTAL FORM IS A MARKER FOR BILE DUCT CARCINOMA, BUT NOT HEPATOCELLULAR CARCINOMA, IN HUMANS.

Immunohistochemical studies using anti-human glutathione S-transferase placental form (GST-π) rabbit antibody were carried out to investigate various hepatobiliary diseases in humans. Hepatocytes in fetal and adult liver without disease were negatively or positively stained while intra-or extrahepatic bile duct epithelial cells were positively or strongly positively stained with GST-π. Hepatocytes in regenerated nodules in liver cirrhosis were positively stained. Hepatocellular carcinomas were not strongly positively stained, while cholangiocarcinomas and cancers of the biliary tract were positively or strongly positively stained. These results indicate that GST-π staining is a useful marker for the diagnosis of intra-or extra-hepatic bile duct carcinomas in humans, and that enzyme activity is not phenotypically expressed in hepatocellular carcinomas

MALIGNANT ONCOCYTOMA OF THE PARANASAL SINUS

A case of malignant oncocytoma developing in the paranasal sinus of a 37-year-old Japanese man with a habit of heavy smoking is described. The primary tumor was found in the right maxillary sinus with local invasion to the nose and right ethmoidal sinus ; it was composed of nests of large oncocytic cells, with finely granular and eosinophilic cytoplasm, nuclear pleomorphism and prominent nucleoli, surrounded by proliferation of spindle-shaped cells in some areas. Electron microscopically, the cytoplasm of oncocytic tumor cells was characterized by abundant mitochondria, and immunohistochemical investigation revealed positive binding for antibodies to S-100 protein and α₁-antitrypsin, but a negative reaction for both cytokeratin and vimentin. At autopsy, metastatic nodules of tumor in the lungs, liver and pancreas independently exhibited both oncocytic cell- and sarcomatous cell compartments. This phenomenon is rare, and to the authors' knowledge, this would be histologically an ususual report of malignant oncocytoma with sarcomatous metastatic nodules arising from the paranasal sinus to be described in the literature

Isolation and characterization of a virus (CvV-BW1) that infects symbiotic algae of Paramecium bursaria in Lake Biwa, Japan

<p>Abstract</p> <p>Background</p> <p>We performed an environmental study of viruses infecting the symbiotic single-celled algae of <it>Paramecium bursaria </it>(<it>Paramecium bursaria Chlorella </it>virus, PBCV) in Lake Biwa, the largest lake in Japan. The viruses detected were all <it>Chlorella variabilis </it>virus (CvV = NC64A virus). One of them, designated CvV-BW1, was subjected to further characterization.</p> <p>Results</p> <p>CvV-BW1 formed small plaques and had a linear DNA genome of 370 kb, as judged by pulsed-field gel electrophoresis. Restriction analysis indicated that CvV-BW1 DNA belongs to group H, one of the most resistant groups among CvV DNAs. Based on a phylogenetic tree constructed using the <it>dnapol </it>gene, CvV was classified into two clades, A and B. CvV-BW1 belonged to clade B, in contrast to all previously identified virus strains of group H that belonged to clade A.</p> <p>Conclusions</p> <p>We conclude that CvV-BW1 composes a distinct species within <it>C. variabilis </it>virus.</p

Histological Study of the Left Atrial Wall: A Consideration of the Compound Myocardial Architecture and Potential Durability with Respect to Catheter Ablation in Pulmonary Vein Isolation Procedures

Pulmonary vein isolation using radiofrequency energy is performed extensively to treat symptomatic, drug-refractory atrial fibrillation. However, anatomical knowledge of the left atrial wall surrounding the pulmonary vein (PV) openings is insufficient to create an ablation line. Using autopsy hearts from 23 individuals (median age of 63 years), we studied the histological nature of anatomical obstacles or related isthmuses near the PV openings. None of the individuals had a history of tachyarrhythmia or other major cardiac abnormalities. After macroscopic measurement of the minimum width of each isthmus, the following areas were excised and histologically prepared: atrial roof-mitral valve annulus (MVA), left superior pulmonary vein (LSPV) -left atrial appendage (LAA), LAA-MVA, left inferior pulmonary vein (LIPV) -MVA, right superior pulmonary vein (RSPV) -fossa ovalis (FO), right inferior pulmonary vein (RIPV) -FO, and FO-MVA. Within the obstacles near the PV openings, the LSPV-LAA isthmus was found to be the narrowest, whereas the LIPV-MVA was the widest and thickest isthmus. Histological complexity of each isthmus was determined, and the compound architecture of the myocardium was revealed. The further presence of a variety of nerve endings as well as myocardial blood supply enhanced the tissue diversity. Such an insight into the diversity of myocardial architecture or histological complexity in each isthmus might be helpful in creating a reliable ablation line in pulmonary vein isolation procedures

Novel Plant-Associated Acidobacteria Promotes Growth of Common Floating Aquatic Plants, Duckweeds

Duckweeds are small, fast growing, and starch- and protein-rich aquatic plants expected to be a next generation energy crop and an excellent biomaterial for phytoremediation. Despite such an importance, very little is known about duckweed–microbe interactions that would be a key biological factor for efficient industrial utilization of duckweeds. Here we first report the duckweed growth promoting ability of bacterial strains belonging to the phylum Acidobacteria, the members of which are known to inhabit soils and terrestrial plants, but their ecological roles and plant–microbe interactions remain largely unclear. Two novel Acidobacteria strains, F-183 and TBR-22, were successfully isolated from wild duckweeds and phylogenetically affiliated with subdivision 3 and 6 of the phylum, respectively, based on 16S rRNA gene sequence analysis. In the co-culture experiments with aseptic host plants, the F-183 and TBR-22 strains visibly enhanced growth (frond number) of six duckweed species (subfamily Lemnoideae) up to 1.8–5.1 times and 1.6–3.9 times, respectively, compared with uninoculated controls. Intriguingly, both strains also increased the chlorophyll content of the duckweed (Lemna aequinoctialis) up to 2.4–2.5 times. Under SEM observation, the F-183 and TBR-22 strains were epiphytic and attached to the surface of duckweed. Taken together, our findings suggest that indigenous plant associated Acidobacteria contribute to a healthy growth of their host aquatic plants