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Biomedical subjects

A Shimada

Publications and source records attributed to A Shimada.

At least 271 records · Page 15Linked to original sources
PubMed1988

Ovine ceroid-lipofuscinosis II: Pathologic changes interpreted in light of biochemical observations.

Ceroid-lipofuscinosis is studied in a breed of sheep and the histochemical and ultrastructural changes are interpreted in light of the known chemical composition of cytosomes. It is concluded that the ovine disease is a lysosomal proteinosis. It is postulated that the multilamellar arrays reflect a complex three-dimensional structure of alternating lipid and protein with the proteinaceous component being specific polypeptides. This is supported by powder X-ray diffractions at 10A implying a repeating proteinaceous unit in the structures. The coherent size of diffracting units was remarkably similar to the periodicity of lamellae observed in electron micrographs of lipopigment cytosomes. The fluorescent and staining characteristics of lipopigment can be explained by the above conclusion and postulate.

Animals↗
PubMed1988

Induction of mutations in males of the fish Oryzias latipes at a specific locus after gamma-irradiation.

We have studied frequencies of mutations induced at the b locus of the fish, Medaka Oryzias latipes, after gamma-irradiation. Homozygotes for the b locus have colorless melanophores whose phenotypic expression can be distinguished from that of the wild type. An advantage of the use of oviparous fish for detection of skin color mutations is that the mutant phenotype can be confirmed as early as 1.5 days after fertilization because of the transparent egg membrane of the embryo. Wild-type (B/B) male fish were exposed to 4.75 or 9.5 Gy of 137Cs gamma-rays at a dose rate of 0.95 Gy/min and then mated with the female testers (b/b). A total of 77,761 F1 offspring were examined for mutation and other abnormalities. In the control, we had 1 mutant among 22,068 offspring, resulting in a mutation rate of 4.53 X 10(-5)/locus/gamete. However, this mutant embryo died before hatching. Therefore, in an attempt to present specific-locus mutation frequencies in the fish, the frequencies of color mutants that survived more than 4 days after hatching were used as frequencies of viable mutants; (number of viable color mutants)/(number of hatched fry that survived more than 4 days after hatching). In the 4.75 Gy-irradiated group the viable mutant frequencies were 45.0 X 10(-5), 69.7 X 10(-5) and 0/locus/gamete, while exposure to 9.5 Gy resulted in mutation rates of 217 X 10(-5), 130 X 10(-5) and 8.06 X 10(-5), respectively, for sperm, spermatids and spermatogonia. In comparison with viable color mutant frequencies those of the total color mutants, which include such mutants as ones that died before hatching (defined as number of total color mutants/number of fertilized eggs minus number of early deaths), were considerably higher. For sperm, spermatids, and spermatogonia after exposure to 4.75 Gy, the frequencies were 1180 X 10(-5), 629 X 10(-5) and 9.90 X 10(-5)/locus/gamete, respectively, and in 9.5-Gy-irradiated fish, the frequencies were 1940 X 10(-5), 953 X 10(-5) and 55.5 X 10(-5). Although our data are incomplete, the present results were compared with mutation induction in mice. We concluded that the frequencies of viable color mutants in the fish can be compared with those in mice.

Animals↗
PubMed1988

Mode of potentiating action of cocaine in morphine analgesia.

The mechanism of antinociceptive interactions among morphine, cocaine and alcohol was studied in mice, guinea pigs and rabbits. In the tail-pressure test in mice, cocaine and alcohol alone showed almost no antinociceptive effects at doses up to 8 mg/kg, s.c., and 4 g/kg, respectively. Alcohol at 2 g/kg, i.g., also did not influence the effect of morphine, while cocaine at 4 mg/kg, s.c., significantly potentiated the antinociceptive effects of not only morphine but also pentazocine. In an analysis of serum and brain concentration levels of morphine in mice, when morphine and cocaine were simultaneously administered at 2 mg/kg, s.c., and 4 mg/kg, s.c., respectively, both serum and brain levels of morphine showed neither increase nor decrease in comparison with the levels in mice administered morphine alone. In myenteric plexus-longitudinal muscle preparations of isolated guinea pig ileum, 1 microM cocaine enhanced the agonistic effects of both pentazocine and ethylketocyclazocine. Furthermore, cocaine as well as ethylketocyclazocine showed naloxone-reversible agonistic effects in isolated rabbit vas deferens. These results indicate that cocaine may potentiate the antinociceptive effects of morphine and pentazocine by acting on the kappa-opioid receptors as an agonist.

Analgesia↗
PubMed1988

Influence of cefotaxime on renal function during the treatment of infections.

A study was conducted of the effects of cefotaxime, a third generation cephalosporin antibiotic, on the function of the kidney, using several indices of renal function including urinary concentrations of the renal enzyme N-acetyl-beta-D-glucosaminidase (NAG). In 6 patients with respiratory infections and normal renal function (group I), the urinary concentrations of NAG before and after the administration of cefotaxime 2 to 4g daily were 5.7 +/- 0.6 U/L and 5.5 +/- 0.9 U/L, respectively (NS). Similarly, 9 patients with chronic renal failure who were not undergoing haemodialysis showed pre- and post-treatment urinary NAG concentrations of 8.7 +/- 4.0 U/L and 6.6 +/- 1.7 U/L, respectively (NS), while the corresponding values in 12 renally impaired patients undergoing haemodialysis (group III) were 8.1 +/- 3.5 U/L and 8.9 +/- 3.8 U/L, respectively (NS). With regard to other parameters of renal function (serum creatinine, BUN, beta 2M, and creatinine clearance), no statistically significant differences were found between the values obtained before and after therapy with cefotaxime. Therefore, it was concluded that the influence of cefotaxime on renal function is slight, and that this antibiotic can be safely used to treat patients with infections in the presence of renal dysfunction.

Acetylglucosaminidase↗
PubMed1988

[Preoperative intra-arterial infusion chemotherapy in locally advanced primary breast cancer-tissue concentrations of 5-fluorouracil and adriamycin, and the histological evaluation].

The effect of preoperative intra-arterial infusion of mitomycin C, 5-fluorouracil (5-FU) and adriamycin (ADM) were studied in seven patients with locally advanced breast cancer, including five inflammatory carcinomas, and a patient with stromal sarcoma of the breast. Reducing rate of the primary tumor of more than 30% was observed in all cases, and remarkable degenerative changes of tumor cells were histologically noted in six out of eight surgical specimens. The tissue concentrations of 5-FU and ADM were also studied in five breast cancer patients. There was no correlation between the concentration of 5-FU or ADM and histological effect. In intra-arterial infusion, ADM seemed to have a high affinity to the regional lymphnode and breast tumor, compared to normal breast tissue and might also be applicable to the control of lymphnode metastasis. Three out of six cases which received radical mastectomy subsequently had recurrence except in the regional lymphnodes and the prognosis was unsatisfactory (5 year survival was 2/4). Other alternative or multi-disciplinary treatment seems to be necessary for improving the survival rate.

Adult↗
PubMed1987

Mannosidosis: ocular lesions in the bovine model.

The ocular pathology of mannosidosis was studied in the bovine model. There was wide-spread vacuolation of many cell types including corneal epithelium, Descemet's endothelium, corneal fibroblasts, pigmented cells, lens epithelium, lens fibres, pigment epithelium and all cell types of the neuroretina. On electron-microscopy most vacuoles were seen to be membrane bound vesicles compatible with being secondary lysosomes and similar to those previously described elsewhere in the body. Additional vacuoles were seen due to dilatations between lens epithelial cells and between lens fibres. The cause of lens and corneal opacities seen in human patients is unclear from the present study but are presumably a consequence of the lesions noted.

Animals↗
PubMed1987

Cancer patterns among Koreans in Japan, Koreans in Korea and Japanese in Japan in relation to life style factors.

Cancer incidences for major sites were compared among Koreans in Osaka, Japan, Koreans in Korea and Japanese in Osaka by calculating standardized proportional incidence ratios (SPIR's), in addition to updating the findings on cancer mortality experiences of Koreans and Japanese in Osaka reported before. Compared with Japanese, Koreans in Osaka had significantly higher mortality rates from cancers of the esophagus, liver and lung in males, and liver in females. Mortality rates among Koreans in Osaka were significantly lower for stomach cancer in both sexes and for breast cancer in females. Compared with Korean counterparts in the homeland, Koreans in Osaka had a reduced risk for cancers of the stomach in males and the uterus in females. On the other hand, an elevated risk was observed for cancers of the esophagus, colon, liver and lung among Korean males in Osaka and for cancers of the colon and liver among Korean females in Osaka. The risk for cancer of the breast in females was similar among Koreans in the host and home countries. These different cancer patterns among Koreans in the host and home countries and Japanese are discussed in relation to their life styles, such as smoking, drinking and dietary habits, which have been investigated by means of questionnaire surveys.

Adult↗
PubMed1987

Urinary excretion of N-nitrosamino acids and nitrate by inhabitants in high- and low-risk areas for stomach cancer in northern Japan.

Three samples of 24-h urine were collected from each of 104 inhabitants of high-risk (Akita) and low-risk (Iwate) areas for stomach cancer in northern Japan, according to the following protocols: (i) when they were undosed, (ii) after ingestion of proline three times a day and (iii) after ingestion of proline together with vitamin C three times a day. These samples were analysed for N-nitrosamino acids, nitrate and chloride ion as indices of the exposure. The median values of N-nitrosoproline (NPRO) and N-nitroso-2-methylthiazolidine 4-carboxylic acid (NMTCA) excreted in the urine of undosed subjects were not different between the two areas; however, that of N-nitrosothiazolidine 4-carboxylic acid (NTCA) was significantly higher in subjects of the high-risk area. Salt intake, estimated from the level of chloride ion in the urine, did not differ in two areas. After intake of proline, the NPRO level increased significantly only in subjects of the high-risk area, but not in those of the low-risk area; intake of vitamin C inhibited this increase of NPRO and lowered the levels of other nitrosamino acids only in the high-risk subjects. In contrast, the urinary level of nitrate was higher in subjects of the low-risk area than in those of the high-risk area; nitrate levels were found to correlate well with the amounts of vegetables consumed.(ABSTRACT TRUNCATED AT 250 WORDS)

Ascorbic Acid↗
PubMed1986

Studies on glucosyltransferase and endogenous glucosyl acceptor in Bacillus cereus AHU 1030 membranes.

A glucosyltransferase, extracted from the membranes of Bacillus cereus AHU 1030 with Tris-HCl buffer containing 0.1% Triton X-100 at pH 9.5, was separated from an endogenous glucosyl acceptor by chromatography on DEAE-Sepharose CL-6B subsequent to chromatography on Sepharose 6B. Structural analysis data showed that the glucosyl acceptor was a glycerol phosphate polymer linked to beta-gentiobiosyl diglyceride. The enzyme catalyzed the transfer of glucosyl residues from UDP-glucose to C-2 of the glycerol residues of repeating units of the acceptor. On the other hand, a lipoteichoic acid which contained 0.3 D-alanine residue per phosphorus was isolated from the cells by phenol treatment at pH 4.6. Except for the presence of D-alanine, this lipoteichoic acid had the same structure as the glucosyl acceptor. The rate of glucosylation observed with the D-alanine-containing lipoteichoic acid as the substrate was less than 40% of that observed with the D-alanine-free lipoteichoic acid, indicating that the ester-linked D-alanine in the lipoteichoic acid interferes with the action of the glucosyltransferase. The enzyme also catalyzed glucosylation of poly(glycerol phosphate) which was synthesized in the reaction of a separate enzyme fraction with CDP-glycerol. Thus, it is likely that the glucosyltransferase functions in the synthesis of cell wall teichoic acid.

Bacillus cereus↗
PubMed1986

Comparative studies of lipoteichoic acids from several Bacillus strains.

Structural studies were carried out on lipoteichoic acids obtained from defatted cells of 10 Bacillus strains by phenol-water partition followed by chromatography on DEAE-Sephacel and Octyl-Sepharose columns. A group of the tested bacteria (group A), Bacillus subtilis, Bacillus licheniformis, and Bacillus pumilus, was shown to have a diacyl form of lipoteichoic acids which contained D-alanine, D-glucose, D-glucosamine, fatty acids, and glycerol in molar ratios to phosphorus of 0.35 to 0.69, 0.07 to 0.15 to 0.43, 0.06 to 0.11, and 0.95 to 1.18, respectively, whereas the other group (group B), Bacillus coagulans and Bacillus megaterium, had diacyl lipoteichoic acids which contained D-galactose, fatty acids, and glycerol in molar ratios to phosphorus of 0.05 to 0.42, 0.06 to 0.12, and 0.96 to 1.07, respectively. After treatment with 47% hydrogen fluoride, the lipoteichoic acids obtained from group A strains commonly gave a hydrophobic fragment, gentiobiosyl-beta (1----1 or 3)diacylglycerol, in addition to dephosphorylated repeating units, glycerol, 2-D-alanylglycerol, N-acetyl-D-glucosaminyl-alpha (1----2)glycerol, and D-alanyl-N-acetyl-D-glucosaminyl-alpha (1----2)glycerol, whereas the lipoteichoic acids from group B strains yielded diacylglycerol in addition to glycerol and D-galactosyl-alpha (1----2)glycerol. The results together with data from Smith degradations indicate that in the lipoteichoic acids of group A strains the polymer chains, made up of partially alanylated glycerol phosphate and glycosylglycerol phosphate units, are joined to the acylglycerol anchors through gentiobiose. However, in the lipoteichoic acids of group B strains, the partially galactosylated poly(glycerolphosphate) chains are believed to be directly linked to the acylglycerol anchors.

Alanine↗
PubMed1986

Experimental combined hormone therapy on human breast carcinomas serially transplanted into nude mice.

Experimental combined hormone therapy with tamoxifen, aminoglutethimide and medroxyprogesterone acetate was investigated using three hormone-dependent human breast carcinomas serially transplanted into nude mice. The antitumor effect of combined tamoxifen and aminoglutethimide was better than that of either tamoxifen or aminoglutethimide alone. Since aminoglutethimide significantly reduced the level of estrogen and the uterine weight in normal female mice, the antitumor effect of combined tamoxifen and aminoglutethimide was assumed to be a result of the low estrogen level produced by aminoglutethimide, favoring the competition of tamoxifen with estrogen receptors. There was no additive antitumor effect of the combination of tamoxifen and medroxyprogesterone acetate, although serum medroxyprogesterone acetate levels in nude mice were almost equivalent to those of humans. These results indicate that combination hormone therapy, especially with and aminoglutethimide, might be a promising method for clinical application.

Adult↗
PubMed1986

[Eating habits and bowel transit time].

Bowel transit times of Chokai (Akita Pref.) and Ohasama (Iwate Pref.) peoples were 34.1 and 43.9 hours, respectively, and the difference between the two populations was 0.05 less than p less than 0.10. There was no significant difference in weight of stools passed per day, and they were 191.6 g, and 174.2 g, respectively. Stool weight per excretion of Chokai people was 196.1 g and that of Ohasama people was 167.9 g, and the difference between the two was p less than 0.05. Significant negative correlation between the stool weight and the bowel transit time was observed among Chokai people, but it was not significant among Ohasama people. Dietary fiber was not analysed, but from the view point of intake frequency of each food item or food group, there were no clear differences in eating habits which affect directly to the differences of bowel habits of the two populations.

Defecation↗