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Biomedical subjects

H Kotani

Publications and source records attributed to H Kotani.

At least 181 records · Page 10Linked to original sources

Isolation of ureaplasmas from poultry and experimental infection in chickens.

Ureaplasmas were isolated from the oropharynxes of 47 of 247 (19 per cent) Leghorn chickens (Gallus gallus domesticus) and from five Japanese bantams but none was isolated from the oropharynx or cloaca of other poultry comprising 10 Japanese game, 75 common quails (Coturnix coturnix japonica), 17 turkeys (Meleagris gallopavo) and 10 guinea fowls (Numida galeata). In apparently healthy chickens, ureaplasmas were found at various sites, including the conjunctiva, nasal cavity, oropharynx, upper and lower tracheas, but not from the air sac, lungs, yolk, oviduct, urine or cloaca. All the isolates were antigenically similar but had no serological relation to those isolated from man, monkey, cattle, goat, sheep, dog and cat. In chickens experimentally infected with an avian ureaplasma, the organisms infected the oropharynx and nasal cavity but none of the birds inoculated demonstrated any clinical signs or macroscopic lesions.

Animals↗

Functional aberration of T cell subsets in patients with Behçet's disease.

Abnormalities of concanavalin A-induced suppressor activity and autologous mixed lymphocyte reaction (which is part of the regulatory role of T cells on lymphocyte functions) were observed in patients with preactive Behçet's disease. However, both the functions returned to normal when the patients entered an active or inactive phase of disease. Thus, a diminution of suppressor function appears to be necessary for the initiation or potentiation of autoimmune and/or inflammatory abnormalities in Behçet's disease. Results of studies of T cell subsets and their functional analysis in patients with preactive Behçet's disease provide further evidence in support of this hypothesis.

Adult↗

Characterization of human peripheral blood T lymphocytes bearing receptors for autologous erythrocytes and T lymphocytes lacking these receptors.

When human T cells were treated with neuraminidase from Vibrio cholerae, the capacity of T cells to form rosettes with autologous erythrocytes was markedly enhanced. The neuraminidase-treated T cells wee separated with autologous erythrocytes into autorosetting and nonrosetting cell populations, and these two populations examined for their reactivity to mitogens and B cells and for their regulatory activities. Autorosetting T cells proliferated poorly in response to mitogens and autologous and allogeneic B cells; these cells were particularly enriched for cells capable of becoming concanavalin A-induced suppressor cells. Nonrosetting T cells capable of most actively proliferating in response to the mitogens and the B cells failed to exhibit such suppressor function after concanavalin A activation. Coculture experiments between autorosetting and nonrosetting cells further demonstrated that the nonrosetting T cells were able to potentiate the proliferation of the autorosetting T cells with concomitant expression of the suppressor properties.

Antibodies, Monoclonal↗

Effects of methyl-B12 on the in vitro immune functions of human T lymphocytes.

Studies were performed using an in vitro assay system to determine whether or not methyl-B12 could affect human T-cell function. When T cells were stimulated with phytohemagglutinin and allogeneic B cells, methyl-B12 did not enhance T-cell proliferation. In contrast, remarkable enhancing effects of methyl-B12 on the proliferative response to concanavalin A (Con A) and autologous B cells at suboptimal concentrations were observed, ranging from 0.1 to 10 micrograms/ml. Concentrations of methyl-B12 sufficient to enhance cellular proliferation were able to enhance the activity of helper T cells for immunoglobulin synthesis of B cells by pokeweed mitogen. Furthermore, the presence of methyl-B12 significantly potentiated the induction of suppressor cells in Con A-activated cultures. These results suggest that methyl-B12 could modulate lymphocyte function through augmenting regulatory T-cell activities.

Antibody-Producing Cells↗

Effect of occlusal splints on the EMG activity of masseter and temporal muscles in bruxism with clinical symptoms.

An electromyographic study of the masseter and anterior temporal muscles was performed on fifteen bruxism patients with clinical symptoms such as muscle pain, fatigue and tenderness. The slopes of the voltage tension (V/T) curves (calculated as the value of the relative inclination between the integrated electromyogram and the biting force) were compared before and after treatment with an occlusal splint. Following use of the splint, the steep slopes of the V/T curves, common in bruxism, became gentle and similar to those of healthy subjects. The difference found in the slopes of different types of bruxism (grinding, clenching, grinding and clenching) might be useful as a diagnostic tool. Follow-up recording of the slopes was considered to be a useful indicator of treatment effectiveness.

Adolescent↗

Studies of immune functions of patients with systemic lupus erythematosus: antibodies to desialized, rather than intact, T cells preferentially bind to and eliminate suppressor effector T cells.

Patients with systemic lupus erythematosus (SLE) were found to have in their plasma antibodies specific for desialized T cells. Adsorption studies with intact or desialized T cells indicated that SLE anti-T cell antibodies consisted of two populations with different target cell specificities, one capable of recognizing unique determinants on desialized T cells and another able to bind to both intact and desialized T cells. Normal T cells did not remove the antibodies specific for desialized T cells. moreover, the antibodies to desialized T cells were not removed by adsorption with either desialized non-T cells or desialized erythrocytes. Thus, the antibodies to desialized T cells recognize a determinant that is unique to a T cell subset and also includes a sugar. Inhibition studies with various sugars indicated that lactose was the most potent inhibitor of antibody binding. The anti-desialized T cell antibody appears to recognize a T cell determinant which includes lactose, probably in the form of a beta-galactosyl residue, but which also includes additional T cell determinants. The antibodies to desialized T cells were found to bind preferentially to concanavalin A-induced autorosetting T cells, which had been already demonstrated to contain suppressor effector cells. Indeed, such antibodies were effective in eliminating suppressor effector function without interfering with T cells necessary for such activation (such as precursor or inducer cells). Finally, studies of patients with SLE yielded a highly significant correlation (r = 0.92) between impaired suppressor effector function of their cells and the presence of antibodies to desialized T cells in their plasma.

Antibody Specificity↗

Isolation of mycoplasmas from experimental ferrets (Mustela putorius).

A total of 21 apparently healthy experimental ferrets, 8 males and 13 females, comprizing 1, 2 and 3 year-old animals were examined for Mycoplasmatales. Mycoplasmas were isolated from 17 samples of 21 oral cavities (81.0%), and from 2 of 21 nasal cavities (9.5%), but not from the prepuce or vagina of the animals. Neither ureaplasma nor acholeplasma was demonstrated in any of the locations of the ferrets examined. These mycoplasma strains proved to metabolize glucose but not arginine and urea. The growth inhibition test revealed that all the strains had similar antigenicity but were not related antigenically to any reference strains from dogs, cats, sheep, cattle, mice, raccoon dogs and a Japanese badger. They are the first mycoplasmas to be isolated from ferrets.

Animals↗

New procedure on making a thumb--one-stage reconstruction with free neurovascular flap and iliac bone graft.

A new method for reconstruction of an amputated thumb with a free neurovascular flap and an iliac bone graft in one stage is described. The method consists of four operative steps: (1) preparation of the recipient hand, (2) elevation of a free dorsalis pedis flap, (3) iliac bone graft, and (4) transfer of the flap with microvascular anastomoses. Four successful results with this operation are presented. The method, which reconstructs the thumb in a single operation, is suitable for patients who refuse other reconstructive methods which sacrifice uninjured digits or toes.

Adult↗

Separation of concanavalin A-induced human suppressor and helper T cells by the autologous erythrocyte rosette technique.

Very few normal human peripheral blood T cells are capable of binding autologous erythrocytes to form rosettes, whereas in the T cell population activated by concanavalin A (Con A) the autorosette levels are markedly enhanced. Fractionation of the Con A-activated T cells with autologous erythrocytes into autorosetting and nonrosetting cells demonstrates that suppressor, but not helper, activity resides in the autorosetting population, whereas the reverse is true of the nonrosetting population. Both these activities are found to be Con A dependent. The Con A-induced human suppressor cells can be identified and separated from the Con A-induced human helper cells by the autorosette technique. Studies on the surface properties of autorosetting and nonrosetting T cells indicate that there is little correlation between the activated suppressor and helper T cell subsets defined by autorosette technique and either those defined by monoclonal antibodies (which are able to distinguish these subsets in the resting but not activated T cells) or those defined by Fc receptors. Since the autorosetting T cell population (which acts as suppressor cells) bears receptors for peanut agglutinin, the nature of Con A-induced human suppressor cells appears to be analogous to that of Con A-induced murine suppressor cells.

Antigens, Surface↗