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Biomedical subjects

K Takehara

Publications and source records attributed to K Takehara.

277 records · Page 16Linked to original sources

Preparation and characterization of monoclonal antibodies against an avian reovirus.

Thirteen monoclonal antibodies against avian reovirus strain Uchida were derived. Of the 13 antibodies, three (MAb1, MAb2, and MAb3) had the ability to neutralize the infectivity of the virus. MAb1 neutralized strains Uchida, CS-108, and TS-142 equally. MAb2 neutralized the same three strains, but the activity of neutralization was 10 times higher against Uchida than against CS-108 and TS-142. MAb3 neutralized only strain Uchida. It seems that MAb1 and MAb2 have a rather broad neutralization activity and that MAb3 has a type-specific activity. These data indicate that there are both type-specific and more broadly specific neutralization epitopes in avian reovirus particles, as in mammalian reoviruses. In Western blot analysis, MAb1 bound to a sigma protein of strain Uchida, so it was suggested that this protein carries the epitope of the less specific neutralizing activity.

Animals↗

Characterization of Newcastle disease viruses isolated from field cases in Japan.

Seven Newcastle disease viruses isolated in Japan from 1930 to 1984 were cloned on chicken embryo fibroblasts (CEFs) and characterized biologically. All seven produced two or more types of plaques on CEFs. The plaques were classified into four types. Plaque cloning was carried out five times, and 22 cloned viruses were established. The biological characters of the cloned viruses suggested that the strains contain different clones and that their clones are different even among close cases, such as G strain and H strain.

Animals↗

Isolation, identification, and plaque titration of parvovirus from Muscovy ducks in Japan.

Muscovy ducks (Cairina moschata) showed abnormal feathering, leg weakness, and high mortality. A virus was isolated from these ducks after several blind passages in embryonating Muscovy duck eggs. The isolate was resistant to chloroform, to pH 3.2, and to 65 C for 30 min. Electron microscopy showed that the isolate was an icosahedral and nonenveloped virus 20-22 nm in diameter. The isolate reacted with an antiserum against a goose parvovirus in agar gel precipitation tests. After 15 passages of the isolate in embryonating eggs, the isolate was adapted to Muscovy duck embryo fibroblasts. The adapted virus developed cytopathic effects and made clear plaques on sheets of the fibroblasts. When 5-iodo-2-deoxyuridine was added to the culture medium, virus growth was inhibited. From the data shown above, the isolate was identified as a goose parvovirus.

Animals↗

The effect of the flow of air on horizontal transmission of Salmonella enteritidis in chickens.

Horizontal transmission of Salmonella enteritidis and the effect of airflow on spreading were examined in 80 5-wk-old chickens divided into five groups. Sixteen chickens in each group were placed in four cages in a row separated by wire. One among four chickens placed in a cage at the downwind end of the row was inoculated orally with 10(9) colony-forming units of S. enteritidis. Cecal droppings, drinking water, and feed were cultured every day. Horizontal transmission was rapid in the row with low air velocity but slow in the row with high air velocity. However, in another experiment, where the inoculated chicken was situated in a cage upstream in the airflow, horizontal transmission was equally rapid whether the airflow was rapid or slow. Contamination of feed and water never preceded the appearance of positive cecal droppings. These findings suggest that the rapidity of horizontal transmission of S. enteritidis may be affected by airflow patterns.

Animals↗

Detection of goose and Muscovy duck parvoviruses using polymerase chain reaction-restriction enzyme fragment length polymorphism analysis.

By using primers (AL18F2 and AL18R2) designed from goose parvovirus (GPV) strain IHC, an 806-bp band was amplified by polymerase chain reaction (PCR) from all of 17 samples from Thailand. Specificity to GPV was confirmed by Southern hybridization. With restriction enzyme digestion of the PCR products, two isolates differed from the other 15 isolates by the absence of restriction sites for HincII and BglII and the presence of EcoR1 site. Nucleotide sequence analysis of the PCR products from the different groups revealed that one group is GPV and the other group is Muscovy duck parvovirus (MDPV). Thus restriction enzyme fragment length polymorphism analysis of the PCR products could be used to distinguish GPV and MDPV. The data showed that GPV and MDPV are present in Thailand.

Animals↗

Sweet's syndrome associated with granulocyte colony-stimulating factor.

We present two patients who developed Sweet's syndrome (SS) during recombinant granulocyte colony-stimulating factor (G-CSF) treatment. Case 1 : on day 11 of the fifth cycle of G-CSF treatment, a 21-year-old man with relapsed, intracranial germ cell tumor had fever, and painful, subcutaneous nodules on his right arm and right leg concomitant with neutrophilia. Skin biopsy revealed neutrophilic panniculitis. The skin lesions disappeared completely after discontinuance of G-CSF. Case 2 : on day 7 of G-CSF treatment, a 50-year-old woman with small cell lung cancer developed fever, and widely disseminated pruritic erythema on her trunk and extremities. The histopathology of the skin was compatible with SS. Her skin lesions also disappeared after discontinuance of G-CSF treatment. She subsequently received three cycles of additional G-CSF treatments without recurrence of SS. It is possible that G-CSF treatment accidentally induced or augmented the proliferation and differentiation of clonal neutrophils with abnormal functions, since in the cases presented SS developed only once in spite of several treatments with G-CSF.

Adult↗

Urticarial vasculitis in systemic lupus erythematosus: fair response to prednisolone/dapsone and persistent hypocomplementemia.

Two cases of urticarial vasculitis (UV) accompanying systemic lupus erythematosus (SLE) are reported. Both patients developed characteristic wheal and purpuric lesions of UV followed by pigmentation, and histological examination revealed leucocytoclastic vasculitis. Although oral prednisolone was beneficial for the systemic symptoms and various serological abnormalities, one patient needed dapsone and the other needed dapsone and cyclophosphamide to control the UV. In both patients, hypocomplementemia with no evidence of congenital complement deficiency or complement consumption persisted even after all other laboratory data and symptoms improved.

Anti-Inflammatory Agents↗