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Biomedical subjects

R Suzuki

Publications and source records attributed to R Suzuki.

At least 721 records · Page 40Linked to original sources
PubMed1983

Immunologic aspects of the nonobese diabetic (NOD) mouse. Abnormalities of cellular immunity.

Experiments were performed on 12-wk-old nonobese diabetic (NOD) mice to investigate the immunologic background of the condition, using ICR mice as controls. The results indicate the following: (1) absolute decreases in number of T lymphocytes, (2) depression of natural killer activity, (3) normal responsiveness in delayed type hypersensitivity and functional depression of killer T cells against allogeneic tumors, (4) diminished resistance to herpes virus infection, and (5) enhanced production of polyclonal antibodies to T cell-dependent antigens. These features are similar to those noted in other autoimmune diseases of man and in their experimental models in laboratory animals. Elucidation of the pathogenetic mechanism of autoimmune diabetes mellitus in NOD mice, therefore, may contribute to the diagnosis, treatment, and prevention of a wide variety of autoimmune diseases.

Animals↗
PubMed1983

Different effects of substance P and vasoactive intestinal peptide on the motor function of bovine intraocular muscles.

Effects of substance P (SP) and vasoactive intestinal peptide (VIP) on motor function of bovine sphincter, dilator, and ciliary muscles were investigated pharmacologically, with and without field stimulation. SP contracted the sphincter and the maximum response was only about 25% of that in the presence of equimolar doses of carbachol. SP had no significant influence on the bovine dilator, and VIP lowered the tone of the iris muscles. The responses to these peptides seemed mainly to be caused by a direct action on the smooth muscles of the iris. The ciliary muscle did not respond to application of these peptides. There was no influence on the amplitude of the acetylcholine- or norepinephrine-induced responses of any of these bovine intraocular muscles. The nerve-mediated responses of the iris muscles were not altered by application of low doses of these peptides, yet with doses over 5 X 10(-6) M, the evoked response of the iris muscles was lowered. In the ciliary muscle tissue, high concentrations of SP slightly decreased the evoked contraction. These observations indicate that SP and VIP play different roles on the motor function of the bovine intraocular muscles.

Animals↗
PubMed1983

Natural killer (NK) cells as a responder to interleukin 2 (IL 2). II. IL 2-induced interferon gamma production.

In the accompanying paper, we showed that natural killer (NK) cells were a major population in the naive spleens of normal mice that responded directly to a T cell growth factor, interleukin 2 (IL 2), and clonally replicated without other stimulating agents. The cloned cells growing in IL 2 showed a potent NK activity against several NK targets without addition of an NK-activating agent, interferon (IFN). In the present study, therefore, we examined whether these cloned NK cells on their own produced IFN. It was found that all NK clones growing in IL 2 produced IFN in the culture fluids. The titers of IFN produced in the IL 2-containing media correlated well with the number of growing cells. With the culture in the absence of IL 2, neither cell growth nor IFN production could be detected. Addition of Con A into the culture in the IL 2-free media showed no IFN production. The antiserum neutralizing IFN alpha and IFN beta failed to significantly neutralize IFN produced by NK clones. Treatment with either a pH of 2.0 or antiserum neutralizing mouse IFN gamma resulted in a marked reduction of IL 2-induced NK IFN, indicating that a major part of IFN produced was IFN gamma. These results indicate that IL 2 stimulates NK clones to proliferate, accompanied by IFN gamma production. The results also show that an NK clone, when stimulated with Sendai virus, produced a type 1 IFN (IFN alpha and/or IFN beta), suggesting that murine NK cells can produce both type 1 (alpha and/or beta) and type 2 (gamma) IFN, depending on inducers.

Animals↗
PubMed1983

Natural killer (NK) cells as a responder to interleukin 2 (IL 2). I. Proliferative response and establishment of cloned cells.

The proliferative response of murine natural killer (NK) cells to a T cell growth factor, interleukin 2 (IL 2) was investigated by using the NK-enriched, low-density fractions (F.1) and NK-depleted, T cell-enriched, and high-density fractions (F.3) of normal spleen cells after Percoll-discontinuous density gradient centrifugation. When F.1 and F.3 cells were cultivated with IL 2-containing medium without addition of any other factors, like lectins, feeder layer, or macrophage products, F.1 but not F.3 cells showed an IL 2-dependent proliferative response. Growing populations showed a potent NK activity and consisted largely of cells with a morphology of large granular lymphocyte (LGL) and a surface marker profile characteristic for murine NK cells. By limiting dilution in the liquid culture and colony formation in the soft agar medium, F.1 but not F.3 cells showed a high frequency of clonal replication in IL 2. Almost all growing colonies in either medium showed a typical morphology of LGL. Further, F.1 cells treated with anti-asialo GM1 antibody and C, from which NK cells and cytolytic activity were almost completely abrogated and for which T cells were enriched, conversely formed a few IL 2-dependent colonies. From the colonies in soft agar, 11 clones, all of which showed a typical morphology (LGL), a typical surface profile with the exception of lacking IgG-Fc receptors for NK cells (Thy-1 +/-, Ly-5+, ASGM1+, Lyt-1-, Lyt-2-, Fc gamma R-), and a cytotoxic activity of activated nature, were established and maintained for a period of longer than 1 yr in the medium containing IL 2 alone. These results indicate that a major population in the naive spleens of normal mice that respond directly to IL 2 and clonally replicate without other stimulating factors may be NK cells.

Animals↗
PubMed1983

Vasoactive intestinal peptide and cholinergic neurotransmission in the ciliary muscle.

The effects of vasoactive intestinal peptide (VIP) on mechanical activity and electrical stimulation of the bovine ciliary muscle in vitro were compared. The generated contractions were enhanced by application of eserine and were abolished completely in the presence of atropine. VIP (10(-8)-10(-6) M) enhanced the response to electrical stimulation, while the contractile amplitude of the ciliary muscle to exogenous carbachol was not altered significantly by application of 10(-7)-10(-6) M VIP. The exogenous VIP had no direct effect on the muscle. As these data indicate that VIP exerts its stimulant effect, prejunctionally, ie, on the nerve terminals, this peptide probably contributes to the control of accommodation as a modulator of cholinergic neurotransmission between short ciliary nerves and the ciliary muscle.

Accommodation, Ocular↗
PubMed1983

Cholinergic inhibitory response in the bovine iris dilator muscle.

Isometric tension changes of the bovine iris dilator muscle were investigated in vitro. Electrical field stimulation (0.03-1 msec duration) produced a relaxation, which was abolished by the addition of tetrodotoxin, thereby suggesting a neuronal origin. Marked relaxation was also initiated in high K solution. Both of these relaxations were potentiated by neostigmine, while atropine abolished the relaxations. Exogenous application of acetylcholine or carbachol produced dose-dependent relaxations that were not antagonized by adrenoceptor blocking agents. These observations indicate that the relaxations induced either by electrical nerve stimulation or by high K are mainly mediated via excitation of cholinergic nerves and that the consequent release of acetylcholine relaxes the muscle. The cholinergic inhibitory mechanism may be accompanied by hyperpolarization of the muscle membrane or be due to a direct transmitter action via "pharmacomechanical coupling." Adrenergic agonists and high K produced weak contractions even when the muscle relaxed with carbachol application. The adrenergic system and the depolarization of the muscle seem to play some role on the motor function of the bovine dilator. The present experiment suggests that the cholinergic system plays an unexpectedly dominant part in dilation of the bovine pupil, since cholinergic agents produced considerable responses of the dilator muscle, as compared to findings in the case of adrenergic agonists. The inhibitory cholinergic nerves innervating the bovine dilator are closely related to the miotic action of the sphincter muscle. The unexpected inhibitory action of acetylcholine may possibly be a general occurrence among mammals.

Acetylcholine↗
PubMed1983

[Evaluation of radiation therapy of brain metastases from lung carcinoma using multivariate analysis].

A randomized clinical trial of whole brain irradiation for brain metastases arising from lung cancer is in progress to improve survival and the quality of life. Between September 1980 and July 1982, 40 patients were treated using 4 MV X-ray. Concerning the radiation dose, laboratory tests and the physical condition of the patients, we analyzed 22 data items by means of quantification II, one of the methods of multivariate analysis. We found that neurologic function, performance status and LDH are important factors in assessing the 120-day survival.

Adult↗
PubMed1982

The haemodynamics of Perthes' disease. An intraosseous venographic study combined with measurement of the intramedullary pressure.

Intraosseous venography and measurement of intramedullary pressure have been carried out in the metaphyses of 55 patients with unilateral Perthes' disease. Flow of the opaque medium into the diaphysis is the most important finding in intraosseous venography of the metaphysis. This was related to a rise of intramedullary pressure which indicates the presence of venous congestion within the metaphysis. While such congestion was seen both in the sclerotic stage and the segmentation stage, it was not related to the severity of Perthes' disease as judged by Catterall's [1] classification. Such venous congestion could be relevant to the pathogenesis of Perthes' disease, but there are probably different factors which determine the prognosis.

Child↗
PubMed1982

Nephrotic syndrome developed in the healing stage of necrotizing angiitis.

A case of necrotizing angiitis is reported. After acute inflammatory changes had subsided, the patient developed the nephrotic syndrome. Postmortem examination disclosed a unique sclerotic glomerular lesion with deposition of eosinophilic material which contained IgM, IgA, C1, and C3. The lesion was distributed in rather selective areas perfused by some of the arcuate arteries.

Adult↗
PubMed1982

Histological study of immune parameters of regional lymph nodes of gastric cancer patients.

A total of 6,394 regional lymph nodes (RLNs) from 319 gastric cancer patients was evaluated histologically for sinus histiocytosis (SH), paracortical lymphocytes (PCL), overall lymphoid cell content (OL), germinal centers (GC), and medullary cord plasma cells (P1). High grade SH, PCL, and OL reactivity was found in cancers confined to the mucosa and submucosa of the stomach wall, and GC and P1 reactivity in cancers that had invaded the subserosa or the serosa of the stomach wall. No stable relationship was found between the RLNs reactivity of patients with and without metastasis to the RLNs. Differences among RLNs reactivities according to location (n1, n2, n3+4) as defined by the Japanese Research Society for Gastric Cancer were evaluated, and n1, the most proximal nodes to the primary cancer, usually had the highest reactivity. As regards the prognostic value of these factors, OL and GC, but not SH, had a significant favorable relation to the 5-year survival rate. In addition, sarcoid-like reaction was evaluated.

Follow-Up Studies↗