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Biomedical subjects

K Tagawa

Publications and source records attributed to K Tagawa.

At least 145 records · Page 8Linked to original sources
PubMed1987

Percutaneous ethanol injection in the treatment of liver neoplasms.

The effectiveness of percutaneous ethanol injection therapy was investigated in 30 patients who had hepatocellular carcinoma (18 had a single lesion and 12 had multiple lesions). In patients who had a single lesion, ethanol injection was especially effective. Histopathologic examination, performed in nine cases in this group, showed that the tumor was completely necrotic in six cases, 90% necrotic in two cases, and 70% necrotic in the remaining case. In eight other cases with a single tumor, follow-up angiography showed complete disappearance of the tumor stain. In the other case, CT showed the nonenhanced low-density area. In the 12 patients with multiple lesions, ethanol injection was performed as part of an integrated treatment plan. Eleven were still alive at the end of the study (the mean follow-up period was 5.8 months). We conclude that ethanol injection may be a valuable treatment for hepatocellular carcinoma.

Adult↗
PubMed1986

Anomer specificity of glucose-6-phosphatase and glucokinase.

The anomeric form of glucose produced by glucose-6-phosphatase was studied using an apparatus that specifically measures beta-D-glucose. The time course of beta-D-glucose formation from glucose-6-P by glucose-6-phosphatase is essentially linear. In the presence of mutarotase, this rate is reduced to 70% of that obtained in the absence of mutarotase. When detergent treated microsomes were used, the rate of beta-D-glucose formation is unaffected by mutarotase. These results suggest that only beta-anomer of glucose is produced by microsomal glucose-6-phosphatase and this specificity is determined by translocase for glucose-6-P or glucose. It was also demonstrated that alpha-D-glucose is the substrate for glucokinase.

Animals↗
PubMed1986

Existence of stoichiometric amounts of an intrinsic ATPase inhibitor and two stabilizing factors with mitochondrial ATP synthase in yeast.

Two proteinaceous factors, 15K and 9K proteins, which acted together to stabilize the inactivated yeast F1F0-ATPase-inhibitor complex [Hashimoto, T., et al. (1984) J. Biochem. 95, 131-136] were hardly distinguishable from the sigma and epsilon subunits, respectively, of yeast F1-ATPase by sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis. However, they were clearly distinguishable from these subunits by analyses of the sequences at their amino terminals and by immunoblotting combined with SDS polyacrylamide gel electrophoresis. The two stabilizing factors and an ATPase inhibitor existed in mitochondria in equimolar ratios to F1-ATPase. These three protein factors were not present in purified F1-ATPase or in F1F0-ATPase preparations, but remained in the mitochondrial membranes after extraction of F1F0-ATPase with Triton X-100. These observations strongly suggest that the two stabilizing factors and the ATPase inhibitor form a regulatory substructure of mitochondrial ATP synthase, in addition to the F1 and F0 subunits.

Amino Acid Sequence↗
PubMed1986

Evaluation of N-isopropyl-[125I]p-iodoamphetamine affinity sites in rat brain by autoradiography.

Affinity sites of N-isopropyl-[125I]p-iodoamphetamine (IMP) were studied in rat brain employing in vitro technique of receptor autoradiography. High degrees of IMP accumulation were observed in almost regions of white matter and some of gray matter. Phenethylamine, glutamic acid and serotonin suppressed IMP accumulation in all brain regions, in cerebral cortex and in hypothalamus, respectively. These results indicated that IMP was accumulated mainly due to its physicochemical property of lipophilicity and might have some interactions with neurotransmitter receptors.

Amphetamines↗
PubMed1986

Positron emission tomography in patients with a primary intracerebral hematoma.

Using positron emission tomography, the regional cerebral blood flow (CBF), oxygen extraction fraction (OEF) and oxygen consumption (CMRO2) were studied in 21 patients with hypertensive intracerebral hematomas. The study showed a very localized decrease of CBF and CMRO2 around a hematoma, and revealed in two cases (9.1%) distinct luxury perfusion around it. There was diffuse reduction of CBF with increased OEF in hematomas larger than 4.5 cm in diameter. The results suggested that surgical evacuation should be considered for hematomas with a diameter exceeding 4.5 cm.

Adult↗
PubMed1985

Interaction with mitochondrial membranes of a synthetic peptide with a sequence common to extra peptides of mitochondrial precursor proteins.

A hepta-peptide, Arg-Leu-Leu-Pro-Ser-Leu-Gly, which has a sequence involved in the extra peptides of mitochondrial proteins, was synthesized chemically. The peptide was found to bind specifically to mitochondria, but not to microsomes. The binding was blocked by pretreatment of mitochondria with trypsin but was not affected by the presence of apocytochrome c. The synthetic peptide inhibited the binding to mitochondria of the precursor protein of ATPase inhibitor, which was synthesized in vitro, but did not inhibit that of the precursor of the 9 K stabilizing factor, which has an entirely different extra-peptide sequence. The peptide also did not inhibit the binding of apocytochrome c. These results suggest the existence of a common protein receptor on mitochondrial membranes that facilitates entrance of a group of mitochondrial precursor proteins, including pre-ATPase inhibitor.

Amino Acid Sequence↗
PubMed1985

Acute hemolysis associated with hepatitis A.

A 62-yr-old woman, admitted to Mitsui Memorial Hospital with complaints of jaundice, general malaise and anorexia, was diagnosed as acute hepatitis A by positive IgM anti-HA. On the 13th hospital day, indirect hyperbilirubinemia (total bilirubin 57 mg/dl, indirect bilirubin 38.5 mg/dl) and splenomegaly were noted. Hemoglobin concentration decreased to 8.4 g/dl and reticulocytes increased to 6%. Bone marrow showed hyperplastic marrow with erythroid hyperplasia. Coombs test was negative. After administration of prednisolone 40 mg daily for 30 days, hemoglobin concentration increased to 11.9 g/dl and total bilirubin was decreased to 0.4 mg/dl. The liver biopsy specimen obtained on the 62nd day, revealed recovery stage of acute hepatitis. Jaundice with increased indirect bilirubin, anemia with reticulocytosis, elevated plasma hemoglobin concentration and predominance of LDH1 were indicative of hemolysis. The enzyme activities in the red blood cells, which were taken 1 year after the onset, were within normal limits. Scanning electron microscopy of the red cells showed no significant abnormalities in their shape and the nature of the surface.

Anemia, Hemolytic↗
PubMed1985

Diffuse hepatic calcification as a sequela to shock liver.

A 31-yr-old Japanese woman who was on chronic hemodialysis for 3 yr died of intractable congestive heart failure. Three years before death, the patient was in a state of shock for 48 h due to ventricular tachycardia and gastrointestinal bleeding, which was followed by marked elevation of serum transaminase. Four months later, abdominal plain radiography demonstrated diffuse hepatic calcification. At autopsy, microscopic examination of the liver revealed parenchymal necrosis and tiny calcifications in the central to midzonal area of the lobule. Calcification in the degenerative area of the hepatic lobule occurred subsequent to parenchymal ischemia after overt shock that lasted for 2 days. Although a definitive explanation for the calcification was not obtained, it may be related to the disturbances of intracellular Ca2+ homeostasis as a result of ischemic liver injury or it may be related to an elevated calcium-phosphorus product in the uremic state.

Adult↗
PubMed1985

Energy-independent protection of the oxidative phosphorylation capacity of mitochondria against anoxic damage by ATP and its non-metabolizable analogs.

Preservation of the oxidative phosphorylation capacity of mitochondria by addition of ATP under anaerobic conditions was analyzed by use of non-metabolizable adenine nucleotide analogs. The capacity was well preserved in the presence of ATP and did not require the hydrolysis of ATP, since ATP analogs, such as beta, gamma-methylene adenosine triphosphate (AMPPCP), alpha, beta-methylene adenosine triphosphate (AMPCPP), and adenylyl imidodiphosphate (AMPPNP), were as effective as ATP. These analogs were incorporated into mitochondria through ATP/ADP translocase to maintain the original level of total adenine nucleotides in the mitochondria. ADP apparently had the same effect as ATP, but its effect was shown to be due to ATP generated from it by adenylate kinase in mitochondria. An analog of ADP, alpha, beta-methylene adenosine diphosphate (AMPCP), which was found to be a substrate of the translocase but not of adenylate kinase, could not replace ADP or ATP. From these results, it was concluded that the oxidative phosphorylation capacity of mitochondria was maintained by ATP, but not ADP, through a process not requiring energy.

Adenosine Diphosphate↗
PubMed1985

Correlation between cellular ATP level and bile excretion in the rat liver.

The influence of the cellular level of adenosine triphosphate (ATP) in the liver on bile excretion was studied in rats. In ischemia, the cellular ATP level decreased rapidly--and, concomitantly, bile flow stopped within 5 min. Administration of L-ethionine i.p. to rats reduced the bile flow rate with decrease in the cellular ATP level. The correlation between the bile flow rate and the cellular ATP level was confirmed in a liver perfusion system. On anoxic perfusion, the ATP level and bile flow rate changed in the same manner as in ischemia. The recovery rates of both on reoxygenation decreased with increase in the anoxic perfusion period. During perfusion under oxygenated conditions, decrease in cellular ATP to various levels by infusion of various concentrations of potassium cyanide, an inhibitor of respiration, resulted in corresponding and concomitant suppression of bile excretion. Kinetic analysis of the bile flow rate revealed a Michaelis-Menten-type curve for the cellular ATP level. The apparent Kms for ATP of bile flow rate in L-ethionine-treated rat liver and liver perfused with potassium cyanide were 1.0 and 1.6 mM, and their Vmax values were 4.1 and 2.5 microliter/min/g liver, respectively. The concentrations of main bile components, such as phospholipids, cholesterol, and taurocholate increased, but their total outputs decreased with decrease in the ATP level, and returned to the normal range with recovery of the ATP level. Thus, it was shown experimentally that the extent of hepatic injury can be assessed simply by monitoring the bile flow rate, which reflects the cellular level of ATP.

Adenosine Triphosphate↗
PubMed1985

Purification of astroprotein (astrocyte-specific cerebroprotein) by reversed-phase C-1 HPLC.

A method for purification of astroprotein (an astrocyte-specific cerebroprotein) with HPLC is described. A linear gradient from 30 to 70% acetonitrile in 0.1% trifluoroacetic acid (pH 2.2) was applied to the reversed-phase C-1 (particle size 10 micron) column. Cerebroproteins from the crude extract from human glioma were clearly separated by this procedure. Highly purified astroprotein was homogeneous by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and has immunoreactivity to antiserum against astroprotein. Reversed-phase C-1 HPLC offers advantages over previously available preparative techniques in the higher purity and better separation time of the products.

Chromatography, High Pressure Liquid↗