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Biomedical subjects

M Sano

Publications and source records attributed to M Sano.

At least 541 records · Page 30Linked to original sources
PubMed1986

Interaction of GTP-binding proteins with calmodulin.

Two GTP-binding proteins (Gi and Go), which were the substrates for islet-activating protein, pertussis toxin, were purified from bovine cerebral cortical membranes. Both Gi and Go completely inhibited calmodulin-stimulated cyclic nucleotide phosphodiesterase activity. The same concentrations of these proteins, however, had no appreciable effect on the basal phosphodiesterase activity. The isolated Gi alpha and beta gamma subunits of GTP-binding proteins were potent inhibitors of the calmodulin-stimulated phosphodiesterase activity, but Go alpha was very weak. Therefore, the beta gamma subunits were likely to be the major active molecules in the brain membranes. GTP-binding proteins were shown to bind directly to calmodulin in a Ca2+-dependent manner by a gel permeation binding experiment.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗
PubMed1986

Glomerular lesions associated with the Crow-Fukase syndrome.

Three cases of the Crow-Fukase syndrome without radiographic changes of multiple myeloma are reported, with special reference to the glomerular changes seen. Proteinuria was detected in one case, although decreased renal function was observed in all (GFR: 41.0, 62.0, 74.1 ml/min respectively) at the time of renal biopsy. Glomerular changes were similar in all three cases. The main characteristic changes were mesangial proliferation and thickening of the glomerular capillary walls. Pictures by light microscopy were therefore similar to that of MPGN. On electron microscopy, the thickened capillary walls showed circumferential mesangial interposition and the subendothelial zone was electron-lucent and contained small dense granules or flocculent deposits. By immunofluorescent microscopy, no immunoglobulins, complement components or light chain were detected in the glomeruli except in one case.

Adult↗
PubMed1986

Infectivity and development of the gamma-irradiated first stage larvae of Angiostrongylus cantonensis.

Effects of gamma-ray irradiation on the first-stage larvae of Angiostrongylus cantonensis were studied. There was a significant reduction in the infectivity of the 10,000 R-irradiated larvae to intermediate host snails compared to other groups. In the final host infection, both the worm populations and worm body length of irradiated groups differed markedly from those of the non-irradiated control.

Angiostrongylus↗
PubMed1986

Effects of diethylcarbamazine on the motility of Angiostrongylus cantonensis and Dirofilaria immitis.

Effects of piperazine derivatives, especially of diethylcarbamazine (DEC) on adult Angiostrongylus cantonensis and Dirofilaria immitis were examined. Piperazine (3 X 10(-5)-10(-4) M) paralyzed A. cantonensis and the action was antagonized by picrotoxin. 1,1-dimethyl-4-phenylpiperazinium iodide (DMPP) (10(-5)-10(-4) M) caused contraction but little effect was produced by strychnine. An inhibitory effect on untreated preparations was caused by lower concentrations (3 X 10(-6)-10(-5) M) of diethylcarbamazine citrate (DEC) and also on the preparations contracted by eserine. A stimulatory effect was also seen when higher concentrations (10(-4)-3 X 10(-4) M) of this drug were applied to both preparations. The inhibitory action of DEC was antagonized by gabergic antagonists such as picrotoxin and bicuculline, but not by alpha-adrenergic antagonists like dibenamine and phentolamine. When the worm preparation was paralyzed by strychnine or hexylresorcinol (inhibitors of the release of acetylcholine in this worm), the stimulatory effect of DEC was blocked, but pyrantel (a nicotinic cholinergic agonist) contracted the paralyzed preparation. However, the effect of DEC on D. immitis (10(-7)-3 X 10(-4) M) was inhibitory, and this action was also antagonized by picrotoxin. These results suggest that the DEC inhibitory and stimulatory action is through the gabergic and cholinergic mechanisms in adult A. cantonensis and D. immitis.

Angiostrongylus↗
PubMed1986

The relaxing effect of SKF 38393 on the catch contraction of Mytilus smooth muscle.

The relaxing effect of SKF 38393 on the catch contraction in the anterior byssus retractor muscle (ABRM) of Mytilus and the effect of SKF 38393 on the cyclic AMP (cAMP) levels in the ABRM were investigated. The catch contraction was relaxed by SKF 38393 in a dose-dependent manner. The dose-response curves of SKF 38393 were shifted in parallel to the right by butaclamol (3 X 10(-6) and 6 X 10(-6) M) and haloperidol (3 X 10(-6) and 3 X 10(-5) M). Their pA2 values were 5.69 +/- 0.05 and 5.80 +/- 0.07. The cAMP levels in the ABRM were not altered by SKF 38393 at a concentration (10(-5) M) sufficient to relax. These findings indicate that the dopamine receptors of the ABRM are D-1 like receptors but somewhat different from those of the vertebrates.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1986

Halogenated hydrocarbon and hydroperoxide-induced peroxidation in rat tissue slices.

Tissue slices were used to compare relative peroxidation capacity of bromotrichloromethane (BrCCl3) and t-butyl hydroperoxide (BHP) by measurement of both peroxidation products and biochemical indices of damage. In liver and testes slices, BHP increased thiobarbituric acid reactive-substances (TBARS) and total aldehydes, measured as cyclohexanedione-reactive substances (CHDRS), to a greater extent than did an equimolar amount of BrCCl3. GSH was decreased more by BHP than by BrCCl3. Neither compound released lactate dehydrogenase or glutamic-pyruvic transaminase from liver slices. Treatment of rats with cyanamide, an aldehyde dehydrogenase inhibitor, increased the total CHDRS in liver slices and medium after incubation with BHP or BrCCl3. HPLC of the CHDRS showed hexanal and propanal increased to the greatest extent. The hydroperoxide, BHP, which does not require metabolism to an active species, was a better initiator of peroxidation than the halogenated hydrocarbon, BrCCl3, which must be metabolized to a radical species before it can initiate peroxidation.

Animals↗
PubMed1986

Impairment of T cell-mediated immunity to Listeria monocytogenes in pregnant mice.

In order to study pregnancy-induced changes in cell-mediated immunity to Listeria monocytogenes, acquired resistance and T cell functions in pregnant mice were compared with those in nonpregnant mice after immunization with viable listerial cells. Impaired generation of acquired resistance was evident in pregnant mice from the impaired elimination of bacteria and poor survival after secondary challenge. Delayed footpad reactivity to listerial antigen was also lower in the pregnant mice. When immune spleen cells were examined for their ability to produce macrophage activating factor in vitro, culture supernatants from pregnant-mouse spleen cells with listerial antigen showed far less ability to render macrophages cytostatic for P815 mastocytoma cells. To elucidate further the impairment of listeria-immune T cell generation in pregnant mice, a local transfer experiment was carried out. When a given number of immune spleen cells was transferred locally into the footpads of naive mice, both delayed footpad reaction and local protection were much lower in the pregnant mice. This local transferability of the reactions was abrogated after treatment of cells with anti-Thy 1 antibody plus complement. These findings indicate that pregnancy impairs the generation of specific T cells capable of contributing to acquired resistance to L. monocytogenes. Possible mechanisms for this impairment and the relationship to macrophage functions are discussed.

Animals↗
PubMed1986

Enhanced resistance against Listeria monocytogenes at an early phase of primary infection in pregnant mice: activation of macrophages during pregnancy.

We investigated the pregnancy-induced changes in macrophage activity which are important in the expression of host defense against infections. Several macrophage functions were examined by using Listeria monocytogenes. In pregnant mice, prolonged survival and enhanced in vivo elimination of bacteria were observed in the early phase of primary infection. Functions of peritoneal macrophages, including in vitro phagocytosis intracellular killing, glucose consumption, generation of superoxide anion, and intracellular beta-glucuronidase activity were shown to be enhanced in pregnant mice. These findings indicate that pregnancy enhances macrophage functions qualitatively. Possible mechanisms for this enhancement and the significance of macrophage activation for pregnant hosts are discussed.

Animals↗
PubMed1986

Ultrastructural study of gaps of the glomerular basement membrane in IgA nephropathy.

Renal biopsy specimens from 163 patients with IgA nephropathy were examined by electron microscopy to clarify the significance of gaps of the glomerular basement membrane (GBM) in IgA nephropathy. Gaps of the GBM were observed in 21 cases. In 1 case the capillary lumen was partially filled with fibrin-like materials, basement membrane-like materials, and epithelial cells, and in 6 cases wide gaps of the GBM were observed. In 10 cases the gaps of the GBM were covered by epithelial and/or endothelial cells, and in 4 cases spherical microparticles were seen at the gaps of the GBM. Microscopic hematuria of less than 5 red blood cells per high-power field of vision at the time of biopsy was less frequently observed in patients with gaps of the GBM than in patients without (p less than 0.05). Marked local thinning or splitting of the GBM and electron-dense deposits or spherical microparticles on peripheral capillary walls were more frequently observed in patients with gaps of the GBM than in those without (p less than 0.001, less than 0.005, less than 0.05, and less than 0.001, respectively).

Adolescent↗
PubMed1986

Roles of the arcuate nucleus and ovary in the maturation of growth hormone, prolactin, and nongranulated cells in the mouse adenohypophysis during postnatal development: a stereological morphometric study by electron microscopy.

With the use of monosodium L-glutamate (MSG) treatment and ovariectomy, we studied how the arcuate nucleus and ovary are involved in the maturation of GH, PRL, and nongranulated cells in the anterior pituitary lobe during postnatal development. From day 1 to day 7 female pups were injected sc daily with MSG (2 mg/g BW) (MSG mice) or distilled water (control mice). Just before puberty (at 30 days of age) some control and MSG mice were ovariectomized (OVX) (control + OVX mice and MSG + OVX mice, respectively). All animals were killed at 60-70 days of age by decapitation. Populations of GH, PRL, and nongranulated cells in the anterior pituitary lobe were calculated by applying morphometric procedures. Percentages of GH, PRL, and nongranulated cells in MSG mice were not different from those of control mice. In control + OVX mice the percentage of GH cells was greater than that of control mice, while PRL cells were markedly decreased. On the other hand, in MSG + OVX mice the percentage of PRL cells was less than that of MSG mice, while GH cells showed no difference; nongranulated cells were increased. The number of parenchymal cells in the anterior pituitary lobe in MSG mice was approximately two thirds that of control mice. The parenchymal cells in control + OVX mice were the same in number as those in control mice, while those in MSG + OVX mice were approximately half the number of the parenchymal cells in MSG mice. Numbers of GH and PRL cells in MSG mice were half those of control mice. There was no difference in the number of nongranulated cells between MSG and control mice. GH cells in control + OVX mice were more abundant than those of control mice, while PRL cells were fewer. On the other hand, both GH and PRL cells in MSG + OVX mice were fewer when compared with those of MSG mice. The numbers of nongranulated cells in most groups showed no significant differences among each other. All of these data taken from control mice were the same as those taken from normal mice. These results suggest that the arcuate nucleus in the hypothalamus stimulates the differentiation of GH and PRL cells during postnatal life, and that the ovary stimulates the differentiation of PRL cells through a direct effect on the anterior pituitary lobe but inhibits that of GH cells via the arcuate nucleus in the hypothalamus, while the differentiation of nongranulated cells is little affected.

Animals↗
PubMed1986

Investigation of regional differences in water and electrolyte absorption across the human colon by in vivo perfusion method.

Colonic perfusion studies were performed to evaluate regional differences in water and electrolyte absorption across the human colon. In 19 healthy male volunteers, a 5-lumen tube with two balloons was inserted into the colon by the endoscopic retrograde bowel insertion (ERBI) method and a 25 cm segment of either the right or the left colon was perfused with an isotonic electrolyte solution simulating the fasting ileal content at a rate of 5 ml/min. Additionally into 5 subjects of the right colon and 5 subjects of the left colon, PSP solution was injected and mean transit time was calculated by the dilution method. Higher absorption rates of water, Na and Cl were observed in the right than in the left colon. Mean transit time was longer in the left than in the right colon. It was considered that the right colon had greater absorptive capacity than the left. The colonic perfusion study by the use of ERBI method made it possible to determine the absorption of water and electrolytes in the right and left colon directly in man, and would be useful to elucidate the pathophysiology of colonic diarrhea.

Adolescent↗