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Biomedical subjects

H Kotani

Publications and source records attributed to H Kotani.

At least 163 records · Page 9Linked to original sources

Ureaplasma infection of cell cultures.

Studies were performed to characterize the effects of ureaplasmas in HeLa, 3T6, and CV-1 cell cultures. The ureaplasmas studied were human Ureaplasma urealyticum T960 (serotype VIII), bovine U. diversum T95, simian strain T167-2, ovine strain 1202, canine strain D1M-C, and feline strains 382 and FT2-B. FT2-B was the only ureaplasma to grow in the cell free culture medium, Dulbecco modified Eagle-Earle medium containing 10% fetal bovine serum. The growth pattern of the ureaplasmas varied in the different cell cultures, but each strain grew in at least two of the cell cultures, suggesting a requirement for a product of the cell culture and for low concentrations of urea. When growth occurred, organisms grew to concentrations that approached, but did not equal, those observed in 10B broth. Most, but not all, ureaplasmas grew quickly, reaching peak titers 2 days after infection. Canine strain D1M-C did not grow in 3T6, but showed rapid growth in HeLa and CV-1 cells, killing both cultures, In some systems, e.g., U. urealyticum T960 and simian strain T167-2, the infection persisted, and ureaplasmas could be recovered from cell cultures four passages after infection, when studies were terminated. The cell culture ureaplasmas grew on T agar, but not on mycoplasma agar medium.

Adhesiveness↗

Identification of mycoplasma colonies by immunobinding.

An immunobinding assay was developed to identify mycoplasma colonies on agar in pure and mixed cultures. Mycoplasma colonies on agar were transferred to nitrocellulose. The nitrocellulose was treated with specific rabbit antisera against mycoplasmas, peroxidase-conjugated goat anti-rabbit immunoglobulin G, 4-chloro-1-naphthol, and H2O2. Purple developed in the presence of specific reactions. The procedure was superior to epifluorescence.

Antibodies, Bacterial↗

Rapid and simple identification of mycoplasmas by immunobinding.

A simple and rapid method of species identification of mycoplasmas by immunobinding assay is described. Small amounts of antigen of supernatant from cell cultures, broth cultures or clinical specimens were spotted onto nitrocellulose paper. This was followed by application of specific anti-mycoplasma antisera. After incubation, an enzyme-conjugated antiserum against the first antiserum was applied. A positive reaction was indicated by the development of intense blue color reaction when substrate was added. This method identified mycoplasma species with monoclonal and polyclonal antibodies. It detected 9.3 X 10(3) - 7.5 X 10(4) CFU/ml of organisms depending on mycoplasma species. For identification of mycoplasma, ureaplasma, acholeplasma and spiroplasma species, this assay is useful and rapid compared with other serological methods. In limited studies, the method correlated with microbiological assay of clinical specimens for Mycoplasma pneumoniae.

Animals↗

Automatic milking apparatus for the insufficient venous drainage of the replanted digit.

An automatic milking apparatus composed of a finger attachment and a pump to push out the air was devised in order to perform the forced drainage from replanted digits with insufficient venous drainage. Seven replanted digits with insufficient venous drainage after replantation were applied, and remarkable improvement was found in five digits. An interesting case is reported in which a replanted digit without venous anastomosis survived as a consequence of applying the milking apparatus. The advantages of our milking apparatus are also discussed.

Amputation, Traumatic↗

Activation of immune regulatory circuits among OKT4+ cells by autologous mixed lymphocyte reactions.

We examined the nature of an autologous mixed lymphocyte reaction (AMLR) using T cell subsets defined by monoclonal antibodies. Cells capable of proliferating in the AMLR were demonstrated to reside in an OKT4+, but not an OKT8+, cell subset. With regard to the role of the T cell subsets recoverable from AMLR in the immune regulation, OKT4+ cells isolated from cells that had been activated for 3 days in AMLR did help pokeweed mitogen (PWM) stimulated immunoglobulin synthesis by autologous B cells. However, the OKT4+ cells activated for 6 days in AMLR exerted strong suppressor activity for PWM-induced immunoglobulin synthesis. Irradiation with 1,500 rad on activated OKT4+ cells in AMLR for 6 days not only eliminated the suppressor function but allowed for re-emergence of helper function. Cells exerting suppressor activity alone were recovered from OKT8+ cells stimulated with or without autologous non-T cells. These data suggest that OKT4+ cells activated in AMLR contain two functionally different subsets; one as helper cells and the other as suppressor cells. In addition, the emergence of OKT4+ suppressor function follows activation of the OKT4+ helper population, suggesting that a part of AMLR reflects a mechanism of 'feedback suppression' among OKT4+ cells.

Antibodies, Monoclonal↗

Serological analysis of ureaplasmas isolated from various animals.

Ureaplasmas from various animal species were serologically characterized by the growth inhibition test as well as by the metabolism inhibition test. The animals positive for ureaplasmas included 9 common squirrel monkeys, 9 green monkeys, 164 cynomolgus monkeys, 58 chimpanzees, 73 goats, 11 sheep, 102 dogs, 116 cats, 64 cattle, 290 chickens, 3 red jungle fowls and 5 Japanese bantams. Simian ureaplasmas were divided into four serogroups in accordance with the zoological classification of the primates' families. Caprine ureaplasmas were all similar antigenically, and ovine ureaplasmas cross-reacted with the caprine ones, except for one strain. Canine, feline and bovine ureaplasmas were divided into groups of four, two and three, respectively. Avian ureaplasmas contained only one serogroup. All these ureaplasma serogroups were remarkably unrelated antigenically to each other, as shown by the growth inhibition test. Ureaplasmas could not be isolated from rhesus monkeys, Japanese monkeys, orangutans, gorillas, mice, rats, mongolian gerbils, hamsters, guinea pigs, rabbits, opossums, pigs, quails and turkeys.

Animals↗

Use of cell cultures to study spiroplasma infections.

Invertebrate and mammalian cell cultures have been utilized to study various properties of spiroplasmas. Recent studies have focused on the interaction of Spiroplasma mirum with AG-4676, a cell line derived from the rat eye lens. S. mirum produced cytotoxicity in this cell line, consisting of vacuolization and an increase in the number of binucleated cells. The number of S. mirum organisms attached to the cell increased with increased age of infection. S. mirum does not grow in Dulbecco's modified Earle's medium + 10% fetal bovine serum, the growth medium for AG-4676. It does, however, grow in conditioned medium obtained as supernatant of 1- to 5-day-old AG-4676. This conditioned medium from AG-4676 also supported growth of S. mirum (GT-48), corn stunt spiroplasmas (Rio Grande) and the following unspeciated strains: M-55 (I-6), N-525 (I-7), CN-5 (IX) and AES-1 (X). It did not support S. citri, honeybee BC-3, EA-1 (VIII), MQ-6 (XII) or CC-1 (XIII). The growth promotion titer for S. mirum was 1:8, but this varied with the lot of fetal bovine serum. Biochemical characterization of this growth-promoting factor is in progress.

Adsorption↗

Isolation of Mycoplasma and Ureaplasma species from raccoon dogs (Nyctereutes procyonoides viverrinus).

Mycoplasma spp. were isolated from five wild raccoon dogs (Nyctereutes procyonoides viverrinus). On the basis of biochemical properties and serological tests, nine isolates were identified as Mycoplasma edwardii and four were similar to a possibly new Mycoplasma sp. represented by strain LM2 which is negative for both glucose fermentation and arginine hydrolysis. In addition, ureaplasmas were detected from these animals. Ureaplasmas were compared serologically with ureaplasma strains isolated from human, monkey, cattle, goat, sheep, cat, chicken and dog and cross-reacted with one of four serological groups of canine ureaplasmas.

Animals↗

A defect in the suppressor circuits among OKT4+ cell populations in patients with systemic lupus erythematosus occurs independently of a defect in the OKT8+ suppressor T cell function.

The autologous mixed lymphocyte reaction (MLR) is thought to be part of a regulatory role of T cells on B cell function. OKT4+, but not OKT8+, cells can proliferate in response to autologous non-T cells. Moreover, the OKT4+ cell population activated early in the course of autologous MLR functioned as inducer cells for the differentiation of B cells, whereas later in the response, the activated OKT4+ cells were particularly enriched in suppressor cells. A part of the autologous MLR appears to be an important pathway for the activation of feedback suppression mechanisms among cells contained within the OKT4+ populations. Patients with systemic lupus erythematosus (SLE) were studied with regard to the following OKT4+ cell functions in vitro after activation in the autologous MLR: a) proliferative response, and b) helper and suppressor activities for differentiation of B cells. A marked reduction in the proliferative response of OKT4+ cells was observed in SLE patients. SLE OKT4+ cells activated in the autologous MLR could function as helper cells but could not exert any suppressor activity. This OKT4+ cell abnormality was present regardless of the disease activity, and occurred in the absence of autoantibodies including anti-T cell antibodies. Instead, SLE anti-T cell antibodies could preferentially eliminate cells bearing the OKT8+ phenotype characteristic of suppressor cells in populations of normal T cells. These results suggest that the defect in the suppressor circuits among OKT4+ cell populations is intrinsic to SLE lymphocytes and that the OKT8+ suppressor T cell defect is caused by antibodies produced by the B cells of SLE patients.

Adult↗