Search PubMed⌕ Search

Biomedical subjects

M Ogata

Publications and source records attributed to M Ogata.

At least 361 records · Page 20Linked to original sources
PubMed1988

[Stimulative effect of chlordanes on guinea pig polymorphonuclear leukocytes].

To investigate the toxicity of chlordane, an organochlorine insecticide, effects of cis-Chlordane, trans-Chlordane, Heptachlor and Heptachlor epoxide were examined on stimulus responses of guinea pig polymorphonuclear leukocytes (PMNs). Results obtained were as follows. These chlordane-related compounds stimulated superoxide (O2-) generation, altered membrane potential and increased intracellular Ca2+ concentration ((Ca2+]i). As a significant tendency was not found in the stimulating effects of these compounds, the relationship between the effect and molecular structure of these substances remains unknown. Of these response reactions of PMN stimulated by chlordanes, stimulation of O2- generation lagged behind the others. Increase in [Ca2+]i was due to both acceleration of extracellular Ca2+ influx and Ca2+ release from intracellular pool. These results indicate that these chlordane-related compounds stimulate PMN and suggest a causal relationship between the stimulation of O2- generation by these substances and their toxicity.

Animals↗
PubMed1988

Effect of phenol and halogenated phenols on energy transfer reactions of rat liver mitochondria.

The in vitro effects of phenol and p-halogenated phenols on mitochondrial energy transfer reactions were examined using isolated rat liver mitochondria. The relationship between physiochemical properties of phenolic compounds and their effects on mitochondria were studied. Phenol and p-halogenated phenols induced the release of K+ ions from mitochondria, suggesting a change in permeability to K+ ions. A decrease in the respiratory control index, an increase in K+ release and stimulation of latent ATPase activity were observed with these compounds in the descending order of p-iodophenol, p-bromophenol, p-chlorophenol, p-fluorophenol and phenol. The concentrations of the phenolic compounds resulting in fifty percent inhibition of the respiratory control index and those resulting in fifty percent release of K+ ions significantly correlated with Hammett's substituent constant (sigma) and the hydrophobic binding constant (pi) of the compounds.

Adenosine Triphosphatases↗
PubMed1988

[Ultrasonographic findings of adhesion ileus--with special reference to surgical indications].

Eighty-one cases with adhesion ileus were examined by ultrasonography from January 1983 to July 1987. In this study, the association of ultrasonographic findings with surgical indications for adhesion ileus was evaluated. The subjects were divided into three groups: Group I, consisting of 29 cases of simple ileus improved by conservative treatment; Group II, 24 cases of simple ileus which required surgical treatment and Group III, 28 cases of strangulation ileus. In comparison with Group I, Group mean value of II + III which required surgical treatment showed a significantly larger maximum diameter of the dilated intestine (3.2 +/- 0.7 cm for Group I vs 3.8 +/- 0.5 cm for Group mean value of II + III) and significantly higher incidences of wall thickening and ascites (respectively 21% and 31% from Group I vs 54% and 73% from Group mean value of II + III). In comparison with the cases of simple ileus (Group mean value of I + II), those of strangulation ileus (Group III) showed significantly higher incidences of akinetic dilated intestine and ascites (respectively 17% and 43% from Group mean value of I + II vs 93% and 86% from Group III). These results make us conclude that ultrasonography is highly useful in deciding surgical indications for adhesion ileus.

Humans↗
PubMed1988

Diminished synthesis of catalase due to the decrease in catalase mRNA in Japanese-type acatalasemia.

In order to characterize the genetic defect in Japanese-type acatalasemia, we examined catalase synthesis in the cultured fibroblasts isolated from a patient suffering from this disease. The transcript of the mutant catalase gene was also analyzed by Northern blotting. It was demonstrated that the severe reduction in catalase protein in the acatalasemic patient is due to the defective synthesis of the enzyme caused by the lack of catalase mRNA. Using Southern blotting, we did not detect large deletion, insertion or rearrangement in the mutant catalase gene as compared with the normal one. We conclude that Japanese-type acatalasemia in this study is resulted by a small mutation in the non-coding region of catalase gene which affects some step in the catalase mRNA metabolism.

Acatalasia↗
PubMed1988

Levels of metallic mercury and mercuric ion in the venous and arterial bloods of normal and acatalasemic mice following exposure to mercury vapor.

Levels of metallic mercury and mercuric ion in the arterial and venous bloods of normal and acatalasemic mice exposed to metallic mercury vapor in vitro and in vivo were investigated. Mercury uptake in venous blood from air saturated with mercury vapor with or without hydrogen peroxide in vitro was determined. Level of mercuric ion in venous blood of normal mice was significantly higher than that of acatalasemic mice. By contrast, metallic mercury in venous blood of acatalasemic mice was elevated relative to level in normal mice. Metallic mercury level in red blood cells and plasma was also significantly higher in acatalasemic mice. The ratio of metallic mercury to total mercury (Hg degrees + Hg2+) in the arterial and venous bloods of acatalasemic mice exposed to metallic mercury vapor was increased relative to normal mice. This ratio in red blood cells and plasma in the venous bloods of acatalasemic mice in vivo was also significantly higher than those of normal mice. The significance of metallic mercury in plasma for distribution of mercury in organs is discussed.

Acatalasia↗
PubMed1988

Thymic stroma-derived T cell growth factor: its role in the growth of immature thymocytes and T cell repertoire selection.

A newly established thymic stromal cell clone, MRL104.8a exhibited capacities to express Ia antigens and to support the growth of antigen-specific, interleukin-2 (IL-2)-dependent helper T cell (Th) clones without requirement of antigen and exogenous IL-2. Such growth was substituted by a factor produced into cultures by the MRL104.8a clone. This substance designated as thymic stroma-derived T cell growth factor (TSTGF) was demonstrated to be the protein that has an apparent molecular weight of about 25,000 and a pI of 6.0 and to be distinct from the previously described interleukins and cytokines. While the capacity of TSTGF to promote T cell proliferation was initially found by using various Th clones, further studies have demonstrated its capability of supporting the growth of immature (L3T4- Lyt-2-) thymocytes. TSTGF alone failed to function for the proliferation of double-negative thymocytes, whereas this novel growth factor was capable of inducing the proliferation of immature thymocytes by synergy with IL-1. Such growth promotion was further enhanced by the addition of IL-2 or IL-4 to cultures. The data were also presented that TSTGF could contribute to the clonal elimination in the thymus. The growth of a Th clone, 9-16, was supported on the TSTGF-producing and Ia-expressing MRL104.8a monolayer in the absence of the antigen against which this Th clone is directed. In contrast, the presence of the relevant antigen in the MRL104.8a culture elicited the lethal growth-inhibition of Th clone cells. Taken collectively, the results provide strong support for the proposition that TSTGF may play an essential role in the intrathymic T cell development in the context of T cell growth promotion and T cell repertoire selection.

Animals↗
PubMed1988

[Diagnosis and timing of operation for strangulation ileus--especially concerning the usefulness of ultrasonography].

This is a clinical report on the usefulness of ultrasonography in the diagnosis of strangulation ileus and the timing of operation for this entity. Fifty-eight cases of strangulation ileus were investigated retrospectively and twenty-five cases had undergone ultrasonography. Ultrasonography delineated the strangulated intestinal tract as an akinetic distended intestinal tract and the intestinal tract on the oral side of the strangulated part as a movable distended tract with peristalsis and to-and-fro movement of the intestinal content. Retention of ascites was seen in many cases. Utilization of ultrasonography improved the rate of accurate preoperative diagnosis of strangulation ileus to 92%, resulting in timely surgery. Consequently, the number of cases requiring enterectomy because of intestinal necrosis sharply decreased. Shock, peritoneal irritation sign, leukocytosis, roentgenographic findings were inferior to ultrasonography in the preoperative diagnosis for the prediction of intestinal necrosis in strangulation ileus.

Humans↗
PubMed1987

Thymic stroma-derived T cell growth factor (TSTGF). I. Functional distinction of TSTGF from interleukins 2 and 4 and its preferential growth-promoting effect on helper T cell clones.

A recently established thymic stroma-derived cell line (TSCL) supported the growth of the interleukin (IL) 2-dependent, antigen-specific helper T cell (Th) clone, 9-16, without requirement for IL-2 and antigen, and such growth was substituted by a factor produced into cultures by this established TSCL. This substance, thymic stroma-derived T cell-growth factor (TSTGF), was capable of inducing the proliferation of various Th clones including 9-16 Th clone, but not of cytotoxic T cell clones. TSTGF-induced growth promotion was obtained in a dose-dependent fashion and in maintaining antigen specificity of Th clones. The culture supernatant from the TSCL did not contain detectable level of IL-1, IL-2, IL-3, IL-4, or interferon activity. The proliferation of 9-16 Th clone was stimulated by recombinant IL-2 and IL-4 as well as TSTGF, but not by IL-1, IL-3, or interferons. However, the proliferation of this Th clone by IL-2 or IL-4 was almost completely inhibited by anti-IL-2 receptor or anti-IL-4 monoclonal antibody, respectively, whereas TSTGF-induced growth of 9-16 Th clones was not affected by either type of antibody, demonstrating that TSTGF is functionally distinct from IL-2 and IL-4. In addition, TSTGF activity was also obtained from the culture supernatant of the primary thymic explant, which was freshly prepared. These results indicate that the primary thymic explant as well as an established TSCL produce factors capable of promoting the growth of helper but not cytotoxic type of T cells in the absence of T cell growth factors thus far defined.

Animals↗
PubMed1987

Clinical study of glucose metabolism during partial gastrectomy--comparison between epidural and general anesthesia.

Plasma glucose, insulin, glucagon, growth hormone (GH) and cyclic-AMP (C-AMP) were measured in 14 patients undergoing partial gastrectomy under 5 g/hr glucose loading. Seven patients received general anesthesia (GOF; Group G) and the other seven, GO + epidural anesthesia (analgesia Th4-L1; Group E). Blood glucose increased in both groups, although it remained consistently lower in Group E than in Group G. Serum IRI and IRI/glucose ratio appeared consistently higher in Group E than in Group G and a significant difference was found between the two groups at the early period of surgery. The changes in plasma glucagon and GH were found independent of those in glucose. Cyclic-AMP was also consistently higher in Group G than in Group E and a significant difference was observed at the end of anesthesia. These results suggest that epidural anesthesia with 5 g/hr glucose loading may facilitate insulin release from the islet and peripheral blood uptake particularly during the early period of surgery while many other factors such as GH, cortisol and vagal stimulation seemed to be involved in the later period of surgery.

Journal Article↗
PubMed1987

[Usefulness of nerve block therapy in patients with herpetic pain].

A retrospective study was performed on 230 patients with Herpes zoster. Among these patients, 156 patients (67.8%) were over 50 years old. Ninety-four percent of the patients who received the nerve block therapy within a month from the onset became ultimately free from pain while only seventy-nine percent of the patients upon whom this therapy was started after 2 months or more were relieved of pain. It was suggested that the earlier the therapy and the younger the patients, the more easily herpetic pain could be controlled. In conclusion, it became apparent that early treatment of Herpes zoster with nerve block therapy, is extremely important for prevention of post-herpetic neuralgia.

Age Factors↗