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Biomedical subjects

T Higashi

Publications and source records attributed to T Higashi.

At least 451 records · Page 25Linked to original sources

Studies on rat liver catalase. X. Effect of hemin and an inhibitor on the translation of catalase messenger RNA1.

Rat liver catalase mRNA was translated in a rabbit reticulocyte lysates and wheat germ cell-free system in the presence or absence of hemin and/or a translational inhibitor prepared from reticulocytes, liver cells, and wheat germs. Failure to add hemin to the lysates, or the addition of a hemin-regulated translational inhibitor (HRI) to the hemin-supplemented lysates caused a repressed translation. A preparation of inhibitor from rat liver showed activity similar to that of HRI for this translating system. The translation repression by rat liver inhibitor was reversed by eIF-2 (initiation factor) or GTP, but ATP enhanced the repression. The translation of catalase mRNA in the wheat germ system was not affected by the addition of hemin. An inhibitor prepared from wheat germ extracts, as well as the rat liver inhibitor, markedly decreased the rate of translation. eIF-2, GTP, and ATP behaved in the manner described above. Catalase synthesis in a cell-free system derived from rat liver (using endogenous mRNA) was not influenced by either hemin or the inhibitor. The possibilities are discussed that the synthesis of catalase in liver cells is controlled by a translational inhibitor at the level of chain initiation, and that the formation of the inhibitor from its inactive proinhibitor is regulated by the amount of heme.

Adenosine Triphosphate↗

Effect of treatment with hemin on rat liver catalase.

Rats were injected with a single or repeated doses of hemin intraperitoneally, and the effect on liver catalase [EC 1.11.1.6] was studied. A single administration of hemin caused a reduction in the concentration of liver catalase, both in enzymatic activity and in catalase protein determined immunochemically. The reduction occurred a few hours after the hemin injection, and is probably due to stimulated degradation. Disappearance of radioactivity from liver catalase prelabelled with [14C]leucine was enhanced following the administration of hemin. No evidence for a repression in vivo incorporation of [14C]leucine and [3H]sigma-aminolevulinic acid into liver catalase was obtained with hemin-treated rats. When the hemin was given repeatedly at 12-h intervals, the level of liver catalase decreased considerably. However, the impairment in catalase-synthesizing activity of liver cells of rats thus treated was rather slight, when examined in a cell-free system. Some differences were noted between the results in the present study and those in previous investigations with Sedormid-treated rats.

Animals↗

Medicosocial aspect of people with epilepsy in Japan--a survey from standpoint of epilepsy center.

Medicosocial aspects of 2,000 patients with epilepsy were outlined on the basis of international classification of epilepsies and epileptic seizures. 1. The incidence of secondary generalized epilepsy was higher compared with that reported previously. It was possible that we have been dealing with rather intractable epilepsy. Non-convulsive epileptic seizures should be treated as intensively as convulsive attacks. 2. Contrary to primary generalized epilepsy, secondary generalized epilepsy and partial epilepsy, a part of which was complex partial seizures, were more prone to be associated with psychological difficulties. 3. The rate of normal mentality was apparently proportional to the actual ease of employment among adult patients. Fortunately, the general attitude of education toward younger people with epilepsy was seemingly generous. However, the marital status of both sexes was far from satisfactory. The stigma might have been felt more by adult patients than younger ones. 4. It appeared to be conceivable that two-thirds of the people with epilepsy are treatable to a certain extent by adequate regimens while one-tenth are obliged to stay in residential centers for a lengthy period of time. Thus, various rehabilitation activities are indicated for one-fourth of the patient population. Actual strategy for rehabilitation of epileptics should be individually designed in accordance with the natural history of each epilepsy.

Adolescent↗

Fulminant hepatic failure during remission from leukemia: three cases associated with massive liver cell necrosis and hepatitis B virus.

Three patients at various stages of remission from leukemia died following the development of massive liver necrosis within only 4-6 days. All had either hepatitis B surface antigen or antibody in their sera, and two of them experienced severe epigastric pain before the onset of liver injury. Hepatitis B surface antigen appeared in two of these patients after remission from leukemia. Serum gamma-globulin levels increased with decreasing doses of prednisolone and other antileukemic drugs, and hepatic cell necrosis occurred extensively. Localization of hepatitis B surface antigen in their livers revealed a strong positive reaction in the phagocytic cells. These observations strongly suggest that hepatitis B virus may be causally related to the fulminant hepatic failure at least in two of the reported leukemic patients.

Adolescent↗

An animal model of fulminant hepatic failure in the rat.

A reproducible animal model of fulminant hepatic failure was developed by intraperitoneal administration of D-galactosamine hydrochloride to Sprague-Dawley rats. Biochemical and morphological hepatic injury and brain edema resembled human fulminant hepatic failure. This model would facilitate further studies of the pathogenesis of brain dysfunction and evaluation of treatment in fulminant hepatic failure.

Amino Acids↗

Technetium 99m bone imaging in the evaluation of cancer of the maxillofacial region.

Technetium 99m bone images were obtained from five patients with mandibular gingival carcinoma and six patients with maxillary sinus carcinoma. Ten to 15 mCi of 99mTc-polyphosphate was administered intravenously, and imaging was performed three hours after injection. The anterior and lateral views of the maxillofacial skeleton were obtained with a gamma camera. Resultant gamma camera images were compared with the radiographic skeletal survey. 99mTc bone survey is a safe and simple diagnostic technique that can demonstrate abnormality of the bone with greater sensitivity than routine radiographs.

Adult↗

Serum amino acids in hepatic encephalopathy--effects of branched chain amino acid infusion on serum aminogram.

Encephalopathic patients with cirrhosis of the liver consistently showed elevated levels of the aromatic amino acids, phenylalanine, tyrosine and free tryptophan as well as methionine in serum, whereas levels of the branched chain amino acids, valine, leucine and isoleucine, were depressed. Comatose patients with fulminant hepatitis had markedly elevated levels of all amino acids, the results being greatly different from those of cirrhotic patients. Molar ratios of (valine + leucine + isoleucine)/(phenylalanine + tyrosine) decreased both in cirrhotics with and without encephalopathy and in cases with fulminant hepatitis. Infusion of a commercially available L-amino acid solution in a cirrhotic patient induced a strikingly abnormal aminogram documented in hepatic encephalopathy. Therefore, effects of branched chain amino acid infusion on the deranged amino acid pattern were primarily studied for the purpose of improvement in hepatic encephalopathy by normalization of serum amino acid patterns. Elevated levels of the aromatic amino acids and methionine could be apparently depressed in a cirrhotic patient by this type of infusion but not in a case of fulminant hepatitis probably because of the poor utilization of these amino acids in severely impaired liver.

Adult↗