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Biomedical subjects

Y Ohno

Publications and source records attributed to Y Ohno.

At least 631 records · Page 35Linked to original sources

Sero-epizootiological study on swine influenza in a prefecture of Japan.

A total of 1799 swine sera collected in Toyama prefecture in the central part of Japan during the years 1978-82 were tested for antibody against swine influenza virus (SIV), A/New Jersey/8/76 (H1N1). A high prevalence of antibody was observed in the years after the severe epizootic of SI, 34.5% in 1979 and 51.7% in 1982. In other years, the percentages of positive sera were low and ranged from 1.7 to 12.4%. Regional variations were seen in relation to a small scale epizootic. No antibody to SIV was detected in any of the sera collected during the warm season. In the following dry and cold winter, however, a severe epizootic occurred among the swine populations.

Animals↗

Influence of temperature and growth phase on desaturase activity of the mesophilic yeast Candida lipolytica.

Microsomal membranes prepared from Candida lipolytica cells grown at 10 degrees C had a higher lipid content and degree of unsaturation than membranes prepared from cells grown at 25 degrees C. The specific activities of stearoyl-CoA (18:0-CoA), oleoyl-CoA (18:1-CoA), and dioleoyl phosphatidylcholine (18:1-PC) desaturases in microsomes of cells grown at either 25 or 10 degrees C showed maximum values near midlog phase, coinciding with the respective maximum absolute content of linoleic (18:2) in the microsomal preparations. The 18:1-CoA desaturase activity in 10 degrees C cells was nearly double that in 25 degrees C cells, while the 18:0-CoA and 18:1-PC desaturases had considerably lower activities in 10 degrees C cells. An increase in aeration rate (shaking speed, 70 to 130 rpm) resulted in increased proportions of 18:2 (32 to 47%, respectively) in microsomes of cells grown at 25 degrees C and in increased 18:1-CoA desaturase specific activity (83 to 140 pmol X min-1 X mg-1); however, no significant changes occurred in 18:0-CoA or 18:1-PC desaturase activities.

Candida↗

Effects of vitamin E depletion and repletion on renin release from renin granules.

The present study was carried out to investigate the effects of vitamin E-deficiency and supplementation of alpha-tocopheryl acetate (TOCA) on renin release from renin granules. Male Wistar rats were fed either a control or a vitamin E-deficient diet for 4 weeks. Subsequently, the vitamin E-deficient rats received dietary supplementation of TOCA (40 mg/100 g diet) for 5 d. The renin granule fraction was prepared from the kidney cortex homogenate by a discontinuous sucrose density gradient centrifugation. The intake of vitamin E-deficient diet for 4 weeks resulted in an increased level of endogenous lipid peroxides in the renin granule fraction, accompanied by a marked decrease in alpha-tocopherol content, and led to a significant increase in the rate of renin release from the granules during incubation at 37 degrees C. These changes in alpha-tocopherol content, lipid peroxide level and renin release in the renin granule fraction were restored to the control values by dietary TOCA supplementation. Similarly, dietary supplementation of N,N'-diphenyl-p-phenylenediamine (80 mg/100 g diet), which has an antioxidative ability, suppressed the increases in lipid peroxidation and renin release due to vitamin E-deficiency, although this compound was ineffective in restoring alpha-tocopherol levels. These results suggest that vitamin E functions in maintenance of membrane integrity of renin granules by inhibiting the lipid peroxidation.

Animals↗

Stimulation of renin release from rat kidney cortical slices by vitamin E-deficiency.

Effect of vitamin E-deficiency on renin release was examined with rat kidney cortical slices. Male Wistar rats were fed either a control or a vitamin E-deficient diet for 4 weeks. When kidney cortical slices were incubated in a Krebs-Ringers' bicarbonate solution (pH 7.4) at 37 degrees C, the rate of renin release into the incubation medium in vitamin E-deficient group was significantly higher than that in the control group. However, dietary supplementation of alpha-tocopheryl acetate (TOCA) or N,N'-diphenyl-p-phenylenediamine (DPPD) to the vitamin E-deficient rats for 5 d suppressed the stimulation of renin release from kidney cortical slices by vitamin E-deficiency. On the other hand, the release of protein, acid phosphatase and alkaline phosphatase during incubation of kidney cortical slices was not affected by vitamin E-deficiency or supplementations of TOCA and DPPD. These findings indicate that vitamin E-deficiency specifically stimulates renin release from kidney cortical slices and this effect is attenuated by the dietary supplementation of TOCA or DPPD.

Acid Phosphatase↗

Renin release and lipid peroxidation by ascorbic acid in the renin granule fraction of rat kidney cortex.

This study was carried out to investigate the effect of lipid peroxidation in the renin granule fraction on renin release from the granules. Ascorbic acid was used to cause lipid peroxidation in the renin granule fraction prepared from rat kidney cortex homogenate. Renin activity was measured by radioimmunoassay and lipid peroxidation was estimated by means of the thiobarbituric acid test. Ascorbic acid, at the concentrations from 5 to 100 microM, produced a dose-dependent increase in lipid peroxidation during incubation of the renin granule fraction at 37 degrees C for 30 min, accompanied by increased release of renin from the granules. On the other hand, dehydroascorbic acid showed no effects on lipid peroxidation and renin release. The simultaneous increases in lipid peroxidation and renin release induced by ascorbic acid in the renin granule fraction were markedly suppressed by the addition of disodium ethylenediaminetetra-acetic acid and antioxidants such as N,N'-diphenyl-p-phenylenediamine and hydroquinone. These findings indicate that lipid peroxidation in the renin granule fraction results in the stimulation of renin release from the granules.

Animals↗

A possible role of "steroidogenic factor" in the corticoidogenic response to ACTH; effect of ACTH, cycloheximide and aminoglutethimide on the content of cholesterol in the outer and inner mitochondrial membrane of rat adrenal cortex.

The role of a "steriodogenic factor" in the corticoidogenic response to adrenocorticotropic hormone (ACTH) was studied in this experiment. ACTH caused an accumulation of cholesterol within the adrenocortical mitochondria in rat after pretreatment with either cycloheximide (CH) or aminoglutethimide (AG). The cholesterol distribution in these cholesterol-rich mitochondria was examined by measuring the cholesterol concentrations in the outer and inner mitochondrial membranes. In the case of pretreatment with CH, cholesterol was accumulated in the outer membrane and not in the inner membrane. In contrast, in the case of pretreatment with AG, cholesterol was accumulated in the inner membrane and not in the outer membrane. It could be concluded from the presented data that the function of a "steroidogenic factor" in the corticoidogenic response to ACTH might take place at the step of cholesterol translocation from the outer mitochondrial membrane to the inner membrane.

Adrenal Cortex↗

Mechanism of surface-mediated activation of bovine Factor XII and prekallikrein.

The mechanism of kaolin-mediated activation of bovine Factor XII was studied in the presence of prekallikrein and HMW kininogen. The activated enzymes were assayed using fluorogenic peptides, Boc-Glu (OBzl)-Gly-Arg-4-methylcoumaryl-7-amide (MCA) for Factor XIIa and Z-Phe-Arg-MCA for plasma kallikrein. The rates of activation of the zymogens were separately measured by blocking either of the active enzymes with specific inhibitors, corn inhibitor for Factor XIIa (Ki = 6.7 nM) and Trasylol for plasma kallikrein (Ki = 3.9 nM). The result was as follows: (1) At the early stage of the activation reaction, kallikrein activity was first generated after short lag time, and then Factor XIIa activity was generated with a sigmoidal curve. In the presence of corn inhibitor, the activation of prekallikrein was observed, but in the presence of Trasylol, the activation of Factor XII was not observed. In the presence of high concentration of Ala-Phe-Arg-Ch2Cl, which inactivates immediately both of the active enzymes, the cleavage of a single chain prekallikrein into the two chain form by Factor XII was shown by SDS-PAGE, using nonlabelled and tritiated prekallikrein. (2) The incubation of Factor XII alone in a quartz cuvette or in the presence of kaolin and HMW kininogen did not result in the activation of Factor XII. The concave upward curve due to an autocatalytic activation was not observed even after the addition of Factor XIIa to Factor XII preparation. Moreover, no structural change of Factor XII during the incubation with kaolin and HMW kininogen was shown by SDS-PAGE, using 3H-Factor XII. (3) The rates of activation of prekallikrein by Factor XII and by Factor XIIa were approximately the same at higher concentration of prekallikrein. However, at lower concentration of prekallikrein the rate of activation of prekallikrein by Factor XII was shown to be a sigmoidal curve and slower than that by Factor XIIa. These results indicate that the activation of bovine Factor XII is initiated by the attack of Factor XII on prekallikrein, followed by the reciprocal activation of Factor XII by plasma kallikrein generated. The autocatalytic activation of bovine Factor XII by Factor XIIa was not demonstrated.

Amino Acid Chloromethyl Ketones↗

Enhancement by potassium bromate of renal tumorigenesis initiated by N-ethyl-N-hydroxyethylnitrosamine in F-344 rats.

The effect of potassium bromate, a food additive, was examined in male F-344 rats based on two-stage renal carcinogenesis with N-ethyl-N-hydroxyethylnitrosamine (EHEN) as an initiator. Average numbers of dysplastic foci and renal cell tumors were significantly increased in rats given potassium bromate after initiation with EHEN. It was concluded that potassium bromate has an enhancing effect on renal tumorigenesis.

Animals↗

Relationship between adenylate cytokinin production and Ti plasmid of Agrobacterium tumefaciens.

To know whether the tumor-inducing plasmid of Agrobacterium tumefaciens carries genetic information of the biosynthesis of cytokinins, the levels of 6-(3-methyl-2-butenyl-amino)purine (iPAde) and its 4-hydroxy derivative trans-zeatin (trans-Z) and its p-beta-D-ribofuranoside (trans-ZR) produced in media by wild-type virulent strain, plasmid-cured avirulent strain and the deletion mutant were compared. The highest levels of iPAde and trans-Z were found in the culture filtrate of late-log phase growth of plasmid-containing virulent strain, then the levels of iPAde and trans-Z were reduced rapidly at stationary phase. The plasmid-cured avirulent strain and deletion mutant had low levels of iPAde and trans-Z throughout the growth. Results obtained here showed Ti plasmid plays an important role in cytokinin biosynthesis.

Adenine↗

Spontaneous tumors in F-344/DuCrj rats.

Spontaneous tumors in 296 male and 297 female F-34/DuCrj rats used as control groups in six carcinogenicity tests were tabulated and evaluated. In males the most frequent tumors were testicular interstitial cell tumors, followed by mammary fibromas and fibroadenomas, mononuclear cell leukemias, pheochromocytomas, C-cell adenomas of the thyroid, pituitary adenomas, preputial adenomas, neoplastic nodules of the liver, and lung adenomas. In contrast, in females pituitary adenomas, uterine endometrial stromal polyps, mammary fibroadenomas, mononuclear cell leukemias and C-cell adenomas were the most common. Various other tumors of almost all other organs and/or tissues were found, although their incidences were low. Variability in the rates of incidence in some tumors was observed in different control groups.

Age Factors↗

Histologic features of bladder cancer in Boston, USA, Manchester, UK, and Nagoya, Japan.

Histologic characteristics of bladder cancer in Boston, USA, Manchester, UK, and Nagoya, Japan, were evaluated. In each of these areas broadly-based series of cases were assembled during a collaborative case-control study. The present analysis was based on 589 cases in Boston, 484 cases in Manchester, and 241 cases in Nagoya. A single pathologist reviewed a slide of the primary tumor without reference to identifying information or other data. The primary histologic type of nearly all tumors was transitional-cell, and there was little variation in the proportion of transitional-cell tumors among the study areas. Nor was there much variation in the distribution of histologic grade, the proportion of tumors showing submucosal invasion, or the proportion of tumors with a papillary surface. Age at diagnosis was strongly correlated with histologic grade. The proportion of grade III (most malignant) tumors was about twice as high among patients 80 years of age and over as among those aged less than 50. An apparent association between age and submucosal invasion was explained in large part by the relationships of histologic grade to submucosal invasion and to age. Other histologic features had only weak and inconsistent relations with age. None of the features evaluated showed consistent associations with history of cigarette-smoking or with sex.

Adenocarcinoma↗

Homicidal and camouflaged carbon monoxide poisoning in Japan.

There were 1,985 fatal cases of CO poisoning in the Tohoku district of Japan in the period from 1969 to 1980. Among them, 1,322 cases were suicidal, 662 accidental, and one homicidal, in which a man killed his wife with the self-made CO gas to obtain by fraud a large amount of life insurance. Our nationwide survey revealed four other cases of homicidal CO poisoning and two cases of camouflaged CO poisoning. The police and police surgeons should be cautious enough in cases of CO poisoning.

Adult↗