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Biomedical subjects

N Yamaguchi

Publications and source records attributed to N Yamaguchi.

At least 883 records · Page 49Linked to original sources
PubMed1978

Ribonucleic acid in the immune response.

In the studies of experimental salmonellosis, immunization of mice with a live vaccine SER of S. enteritidis was found to be effective against further infection with virulent S. enteritidis 116--54. Macrophages obtained from the peritoneal cavity, subcutaneous tissue or liver of immunized mice inhibited intracellular growth of bacteria and resisted cell degeneration caused by engulfment of virulent 116--54 bacteria. This immunity was called cellular immunity. We discovered by chance in 1961 a transfer agent of immunity (TA) from the culture fluid of immunized macrophages. This agent is RNA in nature and can be extracted from the spleen, peritoneal exudate cells or the lymph node of immunized animals and is called immune (i) RNA. We could demonstrate antibody activity in macrophages treated in vitro or in vivo with iRNA by the immune adherence hemagglutination technique. Cellulr immunity against tumor cells could be transferred in vitro or in vivo to lymphocytes through iRNA prepared from the spleen cells of syngeneic, allogeneic and xenogeneic animals immunized with the tumor cells. We prepared iRNA against antigens capable of inducing humoral antibody production in animals, i.e., RBCs, bacterial toxin, bacterial flagella and hapten-protein conjugates. Serum antibody was not demonstrated in recipient animals of iRNA's by single or repeated injections of these agents. However, in these animals an increase in the number of specific antibody-carrying cells was found as rosette-formers. It was found further that prior injection of iRNA could induce immunologic memory and produced a high titer of humoral antibody after a boosting stimulation with a small dose of the corresponding antigen. The required interval between the first iRNA and the second antigenic stimulation, and the minimal effective doses of iRNA and antigen are described. We studied the interaction of iRNA with either T- or B-cells and with both cells using adoptive transfer system, athymic nude mice and neonatally thymectomized (NT) mice. Immune rna's against T-dependent and T-independent antigens could not induce the proliferation of antibody-carrying cells in cyclophosphamide-treated (B-cell depleted) mice. But these agents could induce the proliferation of rosette-formers, implying that iRNA's can replace some role of T-cells even against T dependent antigens. B-cells can be directly activated by treatment with iRNA against both T-dependent and T-independnet antigens, and they differentiated into rosette-formers. Passive transfers of iRNA were successful in establishing immunity against infection with S. enteritidis, or immunity to Salmonella flagella, RBCs and hapten-protein conjugates. The ability of iRNA to confer a secondary response of antibody formation is serially and passively transmissible in recipient animals. These facts suggest the presence of some mechanism that is responsible for the amplification of antigenic stimulation in the immune response...

Animals↗
PubMed1978

Surgical treatment of infantile lobar emphysema in cardiovascular disease with left-to-right shunts.

Serious symptoms associated with the lobar emphysema in congenital heart diseases with left-to-right shunt disappeared after radical operation for cardiac lesion. The study of seven autopsied cases revealed that the lobar emphysema resulted from check valve mechanism created by compression of the bronchi by distended pulmonary artery. Eight cases of our experience of lobar emphysema disappeared shortly after the operation for congenital heart disease with left-to-right shunt seems to indicate infantile lobar emphysema in congenital heart diseases with left-to-right shunt should not be treated by resection but rather by radical operation for cardiac lesion as soon as possible even in infancy.

Bronchi↗
PubMed1978

The effects of sleep deprivation on the circadian rhythm of plasma cortisol levels in depressive patients.

The circadian rhythm of plasma cortisol levels was studied in 20 endogenous depressive patients who received one-night sleep deprivation therapy and 10 normal controls who were also deprived of sleep together with patients by estimation at four-hourly intervals over 36 hours. The mean values at each sampling time were compared. The result can be summarized as follows: The mean values of depressive patients tended to be higher than those of controls on the day following sleep deprivation. In depressive patients the mean values on the following day were higher compared to those on the preceding day. In the patients who responded well to sleep deprivation therapy, the circadian variation of mean values which was obscure the preceding day showed an evident rhythm the following day. These findings suggest that sleep deprivation may cause a different effect between depressive patients and normal subjects, and that the possible mechanism of the anti-depressive efficacy of sleep deprivation may be to normalize the disturbed rhythm of the physiological function in depressive patients.

Adolescent↗