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M Shono

Publications and source records attributed to M Shono.

85 records · Page 5Linked to original sources

Kinetic behaviour of succinate dehydrogenase of three fibre types in skeletal muscle. I. Effects of temperature and a competitive inhibitor.

The kinetic behaviour of succinate dehydrogenase [EC 1.3.99.1] in three fibre types of rat gastrocnemius was examined by a quantitative histochemical method without disruption of the cellular structure. 2-(2-Benzothiazolyl)-3-(4-phthalhydrazidyl)-5-styryl-t etrazolium chloride (BPST) and phenazine methosulphate were used as electron acceptors. On measurement of the absorbance value at 530 nm of BPST formazan, produced by the succinate dehydrogenase reaction in sections, it was found that the staining intensity of succinate dehydrogenase was linearly proportional to both the incubation time and the thickness of the slice therefore, the initial velocity of the staining could be calculated. By Michaelis-Menten (1913) treatment of the dependence of the initial velocity on the substrate concentration in the absence and the presence of a competitive inhibitor, malonate, the Km and Vmax values for succinate and the Ki value for malonate were obtained. The Km and Ki values of the three fibre types were similar. The ration of the Vmax values of type A, B and C fibres was 1.0:2.0:3.3. The temperature dependence of the kinetic parameters was very similar in the three fibre types. These findings confirm that the differences in the staining intensity of the three fibre types reflect differences in the amounts, but not the properties, of succinate dehydrogenase.

Animals↗

Mercury exanthem.

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Dermatitis, Contact↗

Potential value of liposomes containing muramyl dipeptide for augmenting the tumoricidal activity of human alveolar macrophages.

Potentiation of the tumoricidal activity of human alveolar macrophages (AM) by muramyl dipeptide (MDP) and MDP in liposomes (liposome-MDP) was examined. Significant increase in AM-mediated cytotoxicity against allogeneic melanoma cells required the interaction of AM with liposome-MDP for a minimum of 4 h. The uptake by human AM of liposomes containing fluorescent quinacrine was examined. A linear correlation was found between the amount of liposomes added to AM monolayers and their phagocytosis of liposome-entrapped quinacrine. Addition of phosphatidylserine to liposomes composed of phosphatidylcholine enhanced both the phagocytosis of liposomes and the ability of liposome-MDP to potentiate the tumoricidal activity of human AM. In experiments on the dose response of liposomes containing 10 micrograms/ml MDP, 50 nmol of liposomes/10(5) AM caused maximal activation of human AM, and greater than 100 nmol of liposomes was less effective. These results show that multilamellar vesicle liposomes containing MDP are more effective than free MDP in potentiating the tumoricidal activity of human AM during culture for 4 h.

Acetylmuramyl-Alanyl-Isoglutamine↗

Mercury exanthem.

We experienced 15 patients with generalized rash, mostly appearing a day or two after breaking a clinical thermometer or during dental treatment. Similar skin manifestations were revealed, suggestive at first glance of mercury exanthem, i.e. diffuse symmetrical erythema predominantly on major fluxural areas. An inverted triangular or V-shaped erythema on both upper antero-medial thighs was a common feature. Severe cases had miliary pustules and/or purpura on erythematous skin. Pruritus or burning sensation was relatively mild. Pyrexia or malaise was a complaint of more than half the patients. Most of the patients had a previous history of contact dermatitis to Mercurochrome, and by patch-testing were found to have contact allergy to several mercurials, especially inorganic ones. Until recently, Mercurochrome had been most widely used as a topical disinfectant in Japan. This seems to be a possible cause of the high incidence of contact allergy to mercurials in this country. From our findings we feel that our patients had developed systemic contact dermatitis due to inhalation of mercury vapor.

Adolescent↗

Combined quantitative cytophotometric method for staining indolyl and sulfhydryl groups and protein.

Sulfenylation with 2-nitrophenylsulfenyl chloride (NPS-Cl), which is specific for tryptophyl and cysteinyl residues in protein, was applied to quantitative histochemistry. By measurement of the absorbance values at 370 nm of sections stained with NPS-Cl, Beer-Lambert's law was found to hold for NPS staining. Treatment of NPS-stained sections with 2-mercaptoethanol (ME) (NPS-ME staining) resulted in sulfenylation of tryptophyl residues only. For determination of the amounts of tryptophyl and cysteinyl residues per unit of protein, protein staining with Coomassie Brilliant Blue (CB) was combined with NPS and NPS-ME staining. CB and NPS-CBB staining also followed Beer-Lambert's law. By measuring the absorbance values at 370 and 650 nm of doubly stained sections, the relative contents of tryptophyl and cysteinyl residues in various tissue proteins were calculated. This method will be useful for the investigation of changes in both protein amount and composition.

Animals↗

Apolipoprotein E epsilon4 and tardive dyskinesia in a Japanese population.

The findings that free radicals play a causative role in the occurrence of tardive dyskinesia (TD) and that apolipoprotein E (ApoE) 4 has decreased anti-oxidant activity suggest a potential link between TD and ApoE alleles. We, therefore, examined ApoE allelic frequencies in schizophrenic subjects with TD and non-TD. Serum samples were obtained from 333 DSM IV-diagnosed schizophrenic patients and 191 controls in Japan. The presence of TD was evaluated by research diagnostic criteria for TD. ApoE phenotypes of the serum samples were determined by polyacrylamide gel isoelectricfocusing. A total of 62 TD subjects (31 males, 31 females) were identified among all patients examined. No significant differences in ApoE allelic frequency were found between TD and non-TD groups. ApoE epsilon4 allele frequency, however, was significantly lower in the female TD group than in the male TD group. These findings do not clearly demonstrate a certain association between TD and the epsilon4 allele, but may preliminarily reveal a difference in influence of this allele on the development of TD between males and females.

Adult↗

Characteristics of calcium ion influx induced by human follicular fluid in individual human sperm.

The mechanism of Ca2+ influx into human spermatozoa was investigated. Human follicular fluid (hFF), which contains progesterone, stimulated an increase in the concentration of intracellular free Ca2+ ([Ca2+]i) as measured by fluorescence spectroscopy using Fura-2/AM. The technique allowed the measurement of [Ca2+]i in individual, motile spermatozoa, by improvement of the previous methods. The role of Ca2+ channels was investigated using selective blocking agents. Neither blockade of L-type channels with verapamil or lanthanum (La3+) nor blockade of N-type channels with omega-conotoxin affected the hFF-stimulated increase in [Ca2+]i. Blockade of T-type channels with either nickel (Ni2+) or amiloride significantly reduced the hFF-stimulated increase in [Ca2+]i and amiloride significantly decreased baseline [Ca2+]i. Incubation of sperm in Na(+)-free medium did not affect [Ca2+]i, indicating that Na+/Ca2+ exchange has no major role in Ca2+ influx. The results suggest that calcium influx induced by hFF occurs via T-type voltage-independent Ca2+ channels. The method described allows accurate measurement of [Ca2+]i in individual, motile human spermatozoa.

Amiloride↗

Separate histogenesis of combined hepatocellular and cholangiocellular carcinoma in two patients.

Double primary liver carcinomas, i.e. hepatocellular carcinoma (HCC) and cholangiocellular carcinoma (CCC) are rare. Two patients in whom double primary liver carcinomas were surgically resected are described herein. Case 1: A 51-year-old Japanese man with chronic type B hepatitis underwent hepatectomy for primary HCC with intrahepatic metastasis. Case 2: A 67-year-old Japanese man with a history of rectal cancer and CCC underwent lateral hepatic segmentectomy for a suspected recurrence of intrahepatic CCC. Lack of direct contact between tumors, no evidence of histological transition and clearly different immunohistochemical staining for cytokeratin support a distinct histogenesis of the tumors in these two patients. The findings indicate that combined HCC and CCC can arise synchronously or metachronously as an intrahepatic double cancer.

Aged↗