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Biomedical subjects

H Katoh

Publications and source records attributed to H Katoh.

At least 469 records · Page 26Linked to original sources
PubMed1983

Induction of hepatic long-chain acyl-CoA hydrolase by clofibric acid administration.

The induction of hepatic long-chain acyl-CoA hydrolase in the cytosolic fraction by administration of clofibric acid (p-chlorophenoxyisobutyric acid) was compared in rats, mice and guinea-pigs. In rats, two long-chain acyl-CoA hydrolases were induced by the administration of clofibric acid. In mice, only one long-chain acyl-CoA hydrolase was induced, and this hydrolase had properties similar to those of the lower-molecular-weight hydrolase induced in the hepatic cytosol of rats. In hepatic cytosol of guinea-pig, no hydrolase was induced by the administration of clofibric acid.

Animals↗
PubMed1983

Differential effects of altered hormonal state on the induction of acyl-CoA hydrolases and peroxisomal beta-oxidation by clofibric acid.

Induction of hydrolase I, hydrolase II, peroxisomal beta-oxidation and hepatomegaly caused by clofibric acid (rho-chlorophenoxyisobutyric acid) administration was investigated in relation to alterations in hormonal state of glucocorticoid, thyroid hormone and insulin. (1) In adrenalectomized rats, the ability to induce hydrolase I was depressed effectively and little hepatomegaly was produced. Hydrolase II and peroxisomal beta-oxidation were induced to a similar extent, compared to those of intact rats. (2) In hypothyroid rats, induction of hydrolase I, hydrolase II, peroxisomal beta-oxidation and hepatomegaly was reduced. In hyperthyroid rats, the ability to induce hydrolase I, hydrolase II and peroxisomal beta-oxidation was depressed, although hepatomegaly was produced by the same or a greater extent as in intact rats. (3) In diabetic rats, marked reduction of ability to induce both hydrolase I and II was observed and induction of hepatomegaly was depressed slightly, although peroxisomal beta-oxidation was induced normally. Differences in the response of four parameters (hydrolase I, hydrolase II, peroxisomal beta-oxidation and liver size) to alterations in hormonal state suggest that the four biological responses to clofibric acid may each be mediated through distinct mechanism(s) other and regulated by distinct hormone(s).

Adrenalectomy↗
PubMed1983

Difference between adrenergic beta 1- and beta 2-blocking effects on isoproterenol-induced Ca spike suppression in guinea-pig taenia coli.

Ca spike suppressions induced by isoproterenol (IsP) and a beta 2-agonist, 5-hydroxymethyl-6-hydroxy-2-isopropylamino-1,2,3,4-tetrahydronaphthalene -1-ol (AA497), were investigated in the presence of butoxamine or practolol. The relaxations were isotonically recorded, and the Ca spike frequency was recorded using the single sucrose gap method. IsP-induced relaxation was not inhibited by butoxamine (Butox, 0.16 microM), but was inhibited by practolol (Prac, 0.188 microM). In 24 mM K+-Krebs' solution, AA497 caused relaxation in a lower dose range and suppressed to a small extent the Ca spike frequency in a higher dose range, as was observed for IsP-induced curves of log dose-spike frequency and log dose-relaxation. In normal K+-Krebs' solution, both IsP and AA497 greatly suppressed the Ca spike frequency. IsP (1.21 microM)-induced suppression of the Ca spike frequency was blocked by Prac (113 microM), and it was blocked by Butox (96 microM) to a greater extent. AA497-induced suppression of the spikes was not blocked by Prac (37.6 microM), but completely blocked by Butox (32 microM). These selective inhibitory effects of butoxamine on AA497-induced and IsP-induced Ca spike suppression demonstrate that in the adrenergic beta-receptor-mediated process in taenia coli, beta 2-mechanisms are more closely related to the Ca spike suppression than the beta 1-mechanisms are.

Adrenergic beta-Antagonists↗
PubMed1983

Does single Kanji process dominantly in the right hemisphere? Some implication from Stroop-test results.

Naming times to single character Kanji, which consisted of small alphabetic letters, Kanji (Stroop stimuli), and solid lines, presented in the left or the right visual field were measured. When subjects tried to respond to Alphabet Stroop stimuli, they showed a greater interference effect in the case of right visual field presentation. Kanji Stroop stimuli yielded no visual field difference in the size of interference effect. These findings suggest that Kanji has a different property from phonetic symbols and a specialization of the right hemisphere for single character Kanji processing.

Adult↗
PubMed1983

[A clinical study on surgical patients with disseminated intravascular coagulation: with special reference to the occurrence of major organ failures].

Among 113 consecutive patients with disseminated intravascular coagulation (DIC), twenty cases who developed this condition under surgical intervention are the subject of this study. At the onset of DIC, fourteen cases were suffered from severe infection. Coagulation study in these patients revealed decreased platelet counts and prolonged prothrombin time. There was marked increase in fibrinogen degradation products and positive ethanol gelation test was frequently observed. These findings were analogous to those found in the more chronic presentations of DIC in the patients with neoplastic diseases, however, plasma concentration of fibrinogen was normal. Antithrombin III level was extremely low in the patients with surgical DIC. The patients with DIC in surgery took acute or subacute courses with very high incidence of major organ failure. The patients with dysfunction of more than three organs were seen in eight of 20 cases. The lungs, kidneys, liver and gastrointestinal tracts were involved in the descending order of frequency. Fourteen patients died and six of these were autopsied. All had multiple fibrin thrombi in more than two organs. The numbers and sites of microthrombi in the major organs were well matched with the clinical manifestations. These results suggested that DIC might be one of the precipitating factors of multiple organ failure.

Acidosis↗
PubMed1983

Alteration of immunogenicity of xenogenized tumor cells in syngeneic rats by the immune responses to virus-associated antigens produced on immunizing cells.

A strong transplantation resistance to a fibrosarcoma (KMT-17) is induced in syngeneic Wistar King Aptekman/Hok rats after a single s.c. immunization with Friend virus-infected (xenogenized) viable KMT-17 cells. The resistance induced by the repeated immunizations with irradiated Friend virus-infected KMT-17 cells, however, was unexpectedly weaker when compared with that induced by irradiated KMT-17 cells. The immunogenicity of tumor-associated antigen on xenogenized Friend virus-infected KMT-17 cells was correlated with their shortened survival time in the peritoneal cavity after i.p. inoculation, especially in rats preimmunized with xenogenized tumor cells. Furthermore, xenogenized tumor cells producing a medium amount of virus-associated antigen (VAA) but not those producing a large amont of VAA showed an augmented immunogenicity even in normal rats. On the other hand, the tumor-associated antigen immunogenicity was augmented by immunization with xenogenized tumor cells which expressed a relatively small amount of VAA in rats presensitized with VAA. These findings indicate that the immunogenicity of xenogenized tumor cells is augmented by the middle-grade immune responses to VAA produced on xenogenized tumor cells.

Animals↗
PubMed1982

Sex-related difference in the effect of clofibric acid on induction of two novel long-chain acyl-CoA hydrolases in rat liver.

The sex differences in the induction of two novel long-chain acyl-CoA hydrolases in hepatic cytosol of rats by clofibric acid (p-chlorophenoxyisobutyric acid)-feeding and the properties of the induced acyl-CoA hydrolases were investigated. Marked sex-related difference was observed in the induction of acyl-Coa hydrolase activity. The sex difference was mainly due to the difference in the induction of acyl-CoA hydrolase with higher molecular weight (hydrolase I), but not to the difference in the induction of acyl-CoA hydrolase with lower molecular weight (hydrolase II). The extent of the induction of the hydrolase I in hepatic cytosol of male rats was 3.5 times over that of female rats. Castration of male rats resulted in the marked depression of the ability to induce hydrolase I. The administration of testosterone to the castrated male rats recovered completely the ability to induce hydrolase I. Unlike hydrolase I, the ability to induce hydrolase II did not respond to the changes in state of androgen. The administration of di-(2-ethylhexyl)phthalate also induced both hydrolase I and II, although the extent of the induction of hydrolase I was less compared to that by clofibric acid treatment. Likewise, marked sex difference was observed in the induction of the hydrolase I on di-(2-ethylhexyl)phthalate administration. These two hydrolases showed different kinetic properties and different substrate specificities to each other. Hydrolase I was inhibited by bovine serum albumin in vitro, but was not affected by Mg2+. Hydrolase II was activated slightly in the presence of lower concentrations of bovine serum albumin, Mg2+ or Ca2+.

Animals↗
PubMed1982

[Immunological regression of metastatic tumor cells after surgical excision of primary tumor (author's transl)].

Metastases in lymph nodes and lungs regressed spontaneously by surgical excision of high antigenic tumor. The regression of metastases were most frequently observed when surgical excision was performed at the elevated stage of host immunological responses against tumor. On the other hand spontaneous regression of metastases of low antigenic tumor after surgical excision was not observed at any stage of tumor growth. Therefore the grade of antigenicity of tumor cells and the strength of host specific cell-mediated immunity against the tumor might be the very important points to the regression of metastasis after the excision of primary tumor.

Animals↗
PubMed1981

Studies on blood groups in the Japanese quail: the common antigens possessed by red blood cells and leukocytes, and their inheritance.

Two alloantigens, Ly1 and Ly2, were detected with alloantisera made by immunization with leukocytes. These antigens were present on red blood cells, peripheral leukocytes and spleen cells and found to be controlled by the autosomal codominant alleles. The phenotypic frequencies of Ly1 antigen in the three quail stocks, 1, 2, and 3, were 6.7, 0, and 100 percent, respectively, and those of Ly2 antigen were 0 percent in stocks 1 and 2, 7.1 percent in stock 3. It was suggested that Ly1 and Ly2 antigens might be associated with the system controlling A (QN1) antigen which was originally detected by the natural alloantibody. However, it remains to be investigated whether these antigens are associated with the major histocompatibility complex (MHC) of the Japanese quail.

Absorption↗
PubMed1981

Regulation of allergic reaction by aerobic Corynebacterium equi extract, CEF. I. Antigen-nonspecific suppression of reaginic antibody response in mice.

The effect of a water-soluble fraction (CEF) that was prepared from an extract of Corynebacterium equi on primary reaginic antibody formation was studied in Balb/c mice. Mice were immunized with a hapten carrier (DNP-OVA) and received intraperitoneal injections of CEF 7 and 2 days prior to, or 2 and 7 days after the immunization. PCA titers of both antihapten (DNP) and anticarrier (OVA) antibodies of IgE class were reduced significantly by the CEF treatment. Evidence was presented in adoptive transfer experiments that the number of IgE-producing cells in the CEF-treated mice was lower than that of controls. Suppression of IgG1 anti-DNP antibody formation was also achieved by the CEF treatment. Formation of IgG1 anti-OVA antibodies, however, was not suppressed significantly by the treatment. The suppressive activities of CEF were shown to be dose-dependent, but timing of CEF administration did not appear critical.

Aerobiosis↗
PubMed1981

Effect of clofibric acid administration on palmitoyl-CoA hydrolase activity in rat liver.

The activity of palmitoyl-CoA hydrolase (EC 3.1.2.2.) in the liver from clofibric acid (p-chlorophenoxyisobutyric acid)-treated rats was studied. The study for subcellular localization showed that palmitoyl-CoA hydrolase was found in both cytosolic and microsomal fractions. Feeding of diet containing 0.5% clofibric acid for 6 days, the specific activities of palmitoyl-CoA hydrolase in homogenates, microsomes and cytosol were increased 5, 2 and 22 times, respectively, compared with that in control rats. Gel filtration of cytosolic fraction showed two new peaks, which have the activity capable of hydrolyzing palmitoyl-CoA and different molecular weights compared with the peaks in cytosol of control rat liver. Acyl-CoA hydrolases in cytosolic fraction showed different kinetic properties with each other.

Animals↗