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Biomedical subjects

T Higashi

Publications and source records attributed to T Higashi.

At least 361 records · Page 20Linked to original sources
PubMed1985

Effect of cimetidine on portal pressure and systemic hemodynamics in patients with and without liver cirrhosis.

Portal pressure and systemic hemodynamics were evaluated for 30 minutes after intravenous injection of 400 mg of cimetidine in patients with and without liver cirrhosis when they were operated upon for varying surgical diseases. A transient fall of arterial pressure was seen in both groups of patients, but the change was statistically significant only in those with cirrhosis. Cimetidine did not substantially alter pulse rate, CVP, and portal pressure in both groups. The present results seem to indicate that rapid administration of cimetidine does not induce a fall of portal venous pressure in both cirrhotic and non-cirrhotic patients.

Adult↗
PubMed1985

Accumulation of hepatic collagen following long-term administration of sake to rats.

Sake, a rice wine, induced hepatic collagen accumulation in rats. This was noted after 16 weeks of a liquid diet containing 35% ethanol by caloric content. However, under similar experimental conditions, whiskey and ethanol did not produce any changes. Hepatic collagenase activities in sake-fed rats were slightly, but significantly, higher than in the whiskey group. The central and pericellular liver fibrosis in sake-fed rats was caused possibly by either accelerated collagen synthesis or maturation, exceeding the increased collagen degradation. Mechanisms of enhanced fibrogenesis in sake-fed rats were discussed.

Acetaldehyde↗
PubMed1985

Computed panoramic tomography with scanning laser-stimulated luminescence.

A new imaging system for the dental field that combines recent advances in both the electronics and computer technologies was developed. It is a panoramic tomography process based on the newly developed laser-scan system and an imaging system featuring (1) clear images with abundant diagnostic information and wide latitude; (2) the possibility of new diagnostic methods through image-information processing; and (3) reduction of exposure to a minimum.

Adult↗
PubMed1985

Interaction with deoxycholate of rat liver peroxisomal and cytosolic catalase.

Rat liver catalase was found to interact with deoxycholate (DOC). When purified, the peroxisomal catalase was precipitated at pH 6 in the presence of DOC, whereas in the peroxisomal extract (with DOC) it was unsedimentable at pH 6. The membrane fraction in the extract interacted with the catalase instead of DOC, and prevented the precipitation of catalase with DOC at pH 6. The peroxisomal catalase seemed to be easily modified by lysosomal protease during manipulation, and this proteolytic cleavage rendered the molecule able to interact with the membrane. On the other hand, the cytosolic catalase, both in the cytosol fraction and in the purified preparation, sedimented at pH 6 in the presence of DOC. The cytosolic catalase was far more resistant to proteolytic modification than the peroxisomal catalase. The molecule of peroxisomal catalase is assumed to have a site for recognizing the membrane, whereas such a structure may be absent in the cytosolic catalase or may not be easily exposed by proteolytic cleavage.

Animals↗
PubMed1985

Re-evaluation of protein-bound glutathione in rat liver.

The extent of intracellular glutathione binding to proteins through a disulfide linkage in rat liver was examined quantitatively. The content of glutathione associated with the acid-precipitable fraction and releasable on borohydride treatment was 0.024 +/- 0.016 mumol/g liver, which accounted for less than one per cent of the total glutathione (6-7 mumol/g liver) in the liver of fed rats. Most of the thiol (2-4 mumol/g liver) liberated from liver proteins into the acid-soluble fraction on borohydride reduction in the presence of guanidine hydrochloride was not glutathione but was proteinaceous in nature. The amounts of thiols liberated per g of liver were similar in fed, fasted, and dibutyryl-3',5'-cyclic AMP-treated rats.

Animals↗
PubMed1985

Cerebral edema associated with acute hepatic failure.

The clinicopathological findings of cerebral edema were investigated in patients with acute hepatic failure autopsied at Okayama University Hospital between 1970 and 1980 retrospectively. Nine (64%) of 14 hepatic failure cases were found to have cerebral edema during a post-mortem examination of the brain. Clinical features of the patients with cerebral edema were not significantly different from those of the patients without cerebral edema. However, general convulsions were observed more frequently in patients later found to have cerebral edema. Moreover, the length of time from deep coma to death was much shorter in the brain edema cases with cerebral herniation than without herniation.

Acute Disease↗
PubMed1985

[A comparative study of experimental models for cardiac preservation through orthotopic transplantation].

Various kinds of models for canine heart preservation were evaluated through orthotopic transplantation. Following warm ischemic (WIT) and preservation times (PT), donor hearts were orthotopically transplanted to recipients and observed for 2 hours. The study was divided into four groups. A heart-lung preparation (Group A) was preserved by coronary perfusion with diluted blood for an hour following 15-minute WIT in A-1 (n = 33), and 2 hours following 30-minute WIT in A-2 (n = 19). Following 30-minute WIT, the heart (Group B) was preserved for an hour by coronary perfusion with diluted blood in B-1 (n = 20), a modified Krebs solution in B-2 (n = 14), and a EL-solution in B-2 (n = 14). Following 30-minute WIT, the heart (Group C) was preserved for 2 hours by a Langendorff's model with coronary perfusion using perfluorochemical in C-1 (n = 5) and Hydroxyethyl starch in C-2 (n = 1). In Group D, electromechanical arrest of the heart and coronary vascular washout were performed in D-1 (n = 8) with K+ cardioplegia, D-2 (n = 8) with K+-verapamil cardioplegia, and D-3 (n = 5) with Collins M-verapamil cardioplegia. The heart was then removed and suspended in the same solution. The graft was preserved at 4 degrees C for 6 hours in D-1 and D-2, and 24 hours in D-3. Fourty-eight % in A-1 and 26% in A-2 were successfully transplanted.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Comparison of drug-metabolizing activities in the livers of carcinogen-sensitive parent rats and carcinogen-resistant descendants.

Donryu strain albino rats were maintained on a diet containing 0.06% 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB) for nine successive generations. Some rats in the fourth to eighth generations showed marked resistance to the carcinogenic action of 3'-Me-DAB. In the liver where we found tumors, their size and number are smaller than in the corresponding original strain of rats fed on a diet containing 3'-Me-DAB. No significant differences were found in the total cytochrome P-450 contents or epoxide hydrolase activities of the livers of the resistant variant and the original strain, but the benzo(a)pyrene hydroxylase activity which is mainly attributed to cytochrome P-448 and glutathione S-transferase activity of the resistant variant were lower. The inductions of hepatic cytochrome P-488 and benzo(a)pyrene hydroxylase on administration of polychlorinated biphenyls or 3-methylcholanthrene were also lower in the resistant rats. In the mutagenicity test on Salmonella typhimurium TA 98 the liver 9000 X g supernatant fraction from 3'-Me-DAB-resistant F7 rats did not fully induce the mutagenicities of 3'-Me-DAB and several other carcinogens. Thus the resistance of F7 rats to the chemical carcinogen may be related to the lower activities of some drug-metabolizing enzymes and the poor inducibility of cytochrome P-448 in their liver, although selection of resistant rats should be continued for further generations before coming to a definite conclusion on biochemical basis of apparent resistance to 3'-Me-DAB.

Animals↗
PubMed1984

Qualitative discrimination of gustatory stimuli in three different strains of mice.

Qualitative similarities and differences among various taste stimuli were examined by comparing the generalization patterns of a conditioned aversion from single chemicals to other compounds in 3 different strains of mice (BALB, C3H and C57BL mice). It was observed as a common characteristic in all 3 strains of mice that generalization gradients among sugars and saccharin Na appeared in the order sucrose--saccharin Na--fructose--glucose--maltose, in which the closer stimuli generalized more strongly to each other. Strain differences were found in sensitivities to D-phenylalanine and L-proline, which generalized to sugars and saccharin Na in C57BL mice, but not in BALB and C3H mice. These strain differences correspond quite well to those previously observed in the responses of single chorda tympani fibers to these amino acids in the 3 strains of mice. A hierarchical cluster analysis and a multidimensional scaling analysis showed that 15 compounds including the 4 basic taste stimuli (sucrose, NaCl, HCl and quinine-HCl) were classified into 7 different groups according to their behavioral similarities and some amino acids were not grouped with any of the 4 basic taste stimuli in the 3 strains of mice. These results suggest the possibility that mice perceive tastes of these amino acids in a way different from human taste primaries.

Animals↗
PubMed1984

Serum amino acid levels in patients with hepatocellular carcinoma.

Serum amino acid concentrations in cirrhotic patients with and without hepatocellular carcinoma (HCC) were investigated. Elevation of serum aromatic amino acids (AAA) and methionine levels observed in cirrhotic patients without malignancy was not apparent in cirrhotic cases with HCC, and thus the ratio of branched chain amino acids (BCAA) to AAA was not so diminished in the latter cases. Development of hepatic encephalopathy in cirrhotic patients with HCC led to only a slight change in the serum aminogram characteristic of hepatic failure. In patients who underwent operations, tissue amino acid compositions of hepatocellular, gastric, and colon cancers were compared with each other and their respective surrounding epithelia. Amino acid contents in the tumor tissue were generally higher than those in the respective nontumorous parts, especially in the case of HCC. The methionine, tyrosine, and phenylalanine contents in HCC were much higher than in cirrhotic or normal liver. Serum aminograms in rats with ethionine-induced HCC were similar to those in cirrhotic patients with HCC. Amino acid contents in HCC were much higher than those in the surrounding cirrhotic liver tissue of rats. Serum and liver tyrosine and isoleucine contents rose significantly in rats 5 to 6 weeks after the initiation of a 0.25% ethionine-containing diet. After the 20th week of the experiment, by which time well-differentiated HCC had developed, liver tyrosine and isoleucine contents increased whereas serum isoleucine concentrations decreased. The results suggest that the serum amino acid patterns characteristic of cirrhotic patients with HCC may result from the increased consumption of amino acids by HCC. Determinations of the amino acid levels are also useful for estimating the prognosis and discovering imminent hepatic encephalopathy in cirrhotic patients with HCC.

Adult↗
PubMed1984

Gustatory neural responses in three different strains of mice.

Taste sensitivity in mice and its strain variation were studied by examining integrated responses and single fiber discharges of the chorda tympani nerve to various taste stimuli in the 3 different strains of mice (BALB, C3H and C57BL mice). A comparison among integrated responses of the 3 strains demonstrated that C57BL mice possess the highest sensitivity to sucrose and the lowest to acids, whereas the opposite is true for BALB mice. These 3 strains of mice commonly possess higher sensitivity to divalent chloride salts than to NaCl. Measures of the breadth of responsiveness showed that single fibers of all 3 strains of mice are relatively more narrowly tuned to taste stimuli than those of rats and hamsters, although the specificity of fibers tends to be greater in the order of C57BL greater than C3H greater than BALB mice. A cluster analysis of fibers demonstrated that two distinct fiber types, a sweet- and Na-type, commonly exist in all 3 strains of mice. The most clear strain difference was found in the sensitivity to D-phenylalanine, which produced good responses in 'sweet-type' fibers of C57BL mice but not in those of C3H and BALB mice. This suggests the possibility that D-phenylalanine has a taste to C57BL mice that is similar to that of sucrose and that it tastes different to C3H and BALB mice.

Animals↗
PubMed1984

A dynamic dialysis method for studying protein-ligand binding using chromatographic theory.

A new dynamic dialysis method has been developed for studying protein-ligand binding phenomena. The method depends on analysis of the elution pattern of ligand in a single dialyzing process where the ligand concentration in the sample compartment changes greatly with time. The dialyzer is composed of a long, narrow chamber (the sample compartment) between two sheets of semipermeable membrane and two outside chambers (the sink compartment) connected as a single path. Eluting buffer flows in the sink compartment to exchange the ligand with the solution in the sample compartment. Therefore, the ligand concentration gradient in the sink compartment is in the longitudinal direction. The mathematical expressions to analyze the experimental data were derived from a modified theory of chromatography. Examination of the binding of sulfanilamide to bovine serum albumin using this method shows that these equations are valid for use in studying protein-ligand binding.

Animals↗
PubMed1984

Glutamic acid and glutamine levels in serum and cerebrospinal fluid in hepatic encephalopathy.

Significant elevation of glutamic acid and glutamine concentrations in CSF was observed in hepatic encephalopathic patients with fulminant hepatitis and liver cirrhosis. However, the ratios of CSF glutamic acid to CSF glutamine levels and of CSF to serum glutamic acid and glutamine levels were significantly higher only in cirrhotic patients with hepatic encephalopathy. CSF glutamine levels were positively correlated with blood ammonia and CSF tyrosine levels in cirrhotic patients. The results indicate that CSF glutamic acid and glutamine levels are important tools in diagnosing hepatic encephalopathy in severe liver disease.

Adult↗
PubMed1984

Purification and characterization of rat liver cytosol catalase.

Rat liver cytosol catalase was purified by making use of its interaction with deoxycholate and by the various methods used to purify peroxisomal catalase. The purified preparation was both enzymatically and immunologically identical with the purified peroxisomal catalase, but differed in its chromatographic behaviour and electrophoretic mobility. Amino acid analysis also revealed a slight difference between the two catalase molecules.

Amino Acids↗
PubMed1984

Prevention of methionine and ammonia-induced coma by intravenous infusion of a branched chain amino acid solution to rats with liver injury.

The prevention of hepatic encephalopathy by the intravenous infusion of a branched chain amino acid (BCAA)-enriched solution was investigated in methionine and ammonium acetate-treated rats whose liver was already injured with carbon tetrachloride. A BCAA-enriched solution protected the rats from entering a coma. The brain BCAA contents became higher, and the brain methionine and tyrosine levels and the ratio of glutamine to glutamic acid in the brain diminished after administering the BCAA-enriched solution.

Acetates↗