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Biomedical subjects

S Yuasa

Publications and source records attributed to S Yuasa.

At least 181 records · Page 10Linked to original sources
PubMed1985

Change of hepatic histamine content during hepatic fibrosis.

Hepatic function was studied by measuring the time courses of several variables in blood and liver using a chronic liver-injury model produced by administering CCl4 consecutively for 12 weeks in rats. A marked increase in liver histamine content occurred after 10 weeks of treatment with CCl4. At weeks 10 and 12, liver histamine levels in the CCl4-treated group were 1.95 and 4.61 times higher, respectively, than in the control group. This change in liver histamine content appeared after that in other variables such as glutamic pyruvic transaminase, alkaline phosphatase, and white blood cells, but it corresponded to a change in liver hydroxyproline. Increased mast cells were seen in fibrotic foci around Glisson's sheath by microscopic morphological observation of the liver 12 weeks after treatment with CCl4. The histamine concentration in plasma tended to decrease after CCl4 treatment, and at week 12 the decrease was statistically significant compared with control. The liver activities of histamine-metabolizing enzymes, histamine-N-methyltransferase and histaminase, decreased to 1/3.4 and 1/6.0 times those of the nontreated group, respectively, 12 weeks after treatment with CCl4, whereas blood histaminase increased about 9.2 times. The increase in histamine content in injured liver was presumedly derived from the increase in mast cells in the inflamed area of the liver; also, the deficiency of histamine-metabolizing enzymes in liver might have caused the high histamine content in the liver. On the other hand, the decrease in plasma histamine concentration might have occurred as a consequence of the enzyme leakage from hepatocytes that accompanied the breakdown of hepatocytes by CCl4 and thus, of the histamine metabolism in blood by the leaked enzymes. The same kind of experiment was performed using a dimethylnitrosamine-induced liver injury model in rats. The increase of hydroxyproline in the liver occurred 11 days after that of histamine content in liver. These results suggest the possibility that increased histamine in the liver may participate in the biosynthesis of collagen.

Animals↗
PubMed1985

[Prophylactic effect of tritoqualine (TRQ) on the CCl4-induced chronic liver injury model in rats].

Tritoqualine (TRQ) administered at doses of 100 or 200 mg/kg, perorally, had a preventive effect on the liver injury in rats induced by the treatment with CCl4 for 12 weeks consecutively. Rats subjected to this chronic treatment with CCl4 showed a decrease in body weight gain and changes in several serum parameters that are indicators of hepatic function were observed: the increase of transaminases, as a parameter of hepatocyte breakdown; the increase of alkaline phosphatase, as a parameter of biliary system abnormalities, the reduction of prothrombin time, as a marker of protein biosynthesis in the liver; and the change of lipids concentrations, reflecting liver injury. After the administration of TRQ perorally, there was a notable suppression of the increment in leaked enzymes in the serum and a marked improvement of the parameters concerning protein biosynthesis and lipid metabolism in comparison with CCl4 control rats. Marked fibrosis in the liver was observed after CCl4 treatment for 12 weeks, and the collagen content in the liver was 5 times higher than that of control rats. TRQ suppressed the increment in collagen formation and also showed improvement of the decrease of the liver function with regards to protein biosynthesis in CCl4-treated rats. Judging from these results, it was concluded that TRQ had a remarkable protecting action on the liver injury chronically induced by CCl4 treatment and was a effective compound for restoring liver function.

Animals↗
PubMed1985

[Therapeutic effect of TRQ on chronic liver injury model in rats induced by CCl4].

Rats were treated with CCl4 for 12 weeks to induce chronic liver injury. An administration of tritoqualine (TRQ) to rats was begun 3 weeks after the first CCl4 treatment, and the therapeutic effect of TRQ on this model was investigated. On the 12th week after CCl4 treatment, a marked increase in content of hydroxyproline and histamine in the liver was found. In addition, increased fibrosis around Glisson's sheath was observed under microscopic observation. The increase in these biochemical parameters was suppressed significantly in the rats administered TRQ at doses of 25-100 mg/kg. The histopathological observation demonstrated the suppression of the formation of pseudolobules with fibrinogenesis in the liver of TRQ administered rats. In addition, there was a noticeable improvement in the activity of the liver protein synthesis in the TRQ administered rats when the parameters that represented the hepatic functions were measured. Glutamic oxaloacetic transaminase in the serum of TRQ-administered rats also decreased significantly, compared with the CCl4 treated control rats. From these results, TRQ was shown to exhibit a marked therapeutic effect on liver damage accompanied by chronically accelerated fibrosis in rats which have been treated with CCl4 for 12 weeks.

Alanine Transaminase↗
PubMed1985

[Effect of tritoqualine on liver regeneration after partial hepatectomy in rats].

Effect of tritoqualine (TRQ) on liver regeneration after partial hepatectomy in normal rats and chronically injured rats treated with carbon tetrachloride (CCl4) for 12 weeks were investigated by the measurement of serum and liver biochemical parameters concerning the hepatic function. The results are as follows: 1) In normal rats, the liver regeneration rate after partial hepatectomy was increased dose-dependently with the administration of TRQ for 7 days after the operation. TRQ improved BSP retention rate which was decreased after partial hepatectomy. In addition, protein synthetic activity in the liver microsomes prepared from TRQ-administered rats was higher than that prepared from control rats, and the contents of serum total protein, serum albumin and liver protein were also higher in TRQ-administered rats. 2) In the rats treated with CCl4 for 12 weeks, the liver regeneration rate after partial hepatectomy was increased dose-dependently with the administration of TRQ for 6 days. TRQ also improved the contents of serum total protein, serum albumin and liver protein. Though the amount of collagen in the liver chronically injured by CCl4 increased more than twice compared with that in the normal liver, the amount of collagen in the regenerating liver of CCl4-treated rats whose liver regeneration was accelerated by TRQ was not different from that in the normal liver. These results suggest that TRQ has the effect of improving the various hepatic functions through the activation of the protein synthesis in hepatocytes.

Animals↗
PubMed1985

Inhibitory effect of tritoqualine (TRQ) on histamine release from mast cells.

Tritoqualine (TRQ), used clinically as an antiallergic drug, did not inhibit histidine decarboxylase activity (HDC, EC. 4.1.1.22.) partially purified from fetal rats and the enzymes prepared from mastocytoma P-815 cells. However, TRQ inhibited the histamine release from rat peritoneal mast cells induced by compound 48/80 and ATP. TRQ was also effective in inhibiting antigen-induced histamine release in rat mast cells sensitized actively or passively by the homologous anti-DNP-Ascaris antibody. Preincubation of cultured mastocytoma P-815 cells in a medium including TRQ inhibited non-cytotoxically the histamine release of mastocytoma cells induced by compound 48/80, and the effect of TRQ became more marked with lengthening of the culture period in the presence of TRQ. It was concluded from these results that one of the main actions of TRQ as an antiallergic drug was not the inhibitory action on HDC, but might be ascribed to its inhibitory effect on histamine release from mast cells.

Animals↗
PubMed1985

Evaluation of Talbot's safety zone of infusion volume and osmolality in infusion therapy for decompensated liver cirrhosis.

Problems with infusion therapy for correcting fluid and sodium imbalance in decompensated liver cirrhosis (DLC) were investigated by establishing the safety zone of Talbot et al. for parenteral fluid therapy in 4 DLC patients infused with over 900 ml of fluid each day for at least 9 days. The safety zone was different in each case. The safe infusion volume decreased and the safe electrolyte concentration shifted to a lower osmolality when there was ascites with renal failure than ascites without renal failure. Infusion therapy was performed without deterioration of the water and sodium balance in those patients whose infusion volume and fluid osmolality were in the safety zone. In contrast, ascites retention increased and peripheral edema appeared in patients whose infusion volume and osmolality were out of the safety zone. Therefore, the safety zone should be determined repeatedly during infusion therapy.

Aged↗
PubMed1984

In vitro protein synthesis using D-amino acids and its evolutionary significance.

The in vitro incorporations of D-Trp or -Ala into peptides were investigated using a crude system. Although none of aminoacylation to the former was observed under the present condition, the latter was utilized for peptide synthesis at the same rate as the opposite enantiomer. The results of analyzing the peptides showed that the peptides, which were synthesized with either D-, L- or DL-Ala as the substrate, were composed of mostly similar molecular size. The study of incorporations of radioisotopes (14C-D- and 3H-L-Ala) into peptides also indicated that D-Ala was by no means inferior to L-Ala for the substrate. Basing upon the present experiment, the evolutionary significance for utilizing D-amino acids is discussed.

Amino Acids↗
PubMed1984

Abiotic synthesis of purines and other heterocyclic compounds by the action of electrical discharges.

The synthesis of purines and pyrimidines using Oparin-Urey-type primitive Earth atmospheres has been demonstrated by reacting methane, ethane, and ammonia in electrical discharges. Adenine, guanine, 4-aminoimidazole-5-carboxamide (AICA), and isocytosine have been identified by UV spectrometry and paper chromatography as the products of the reaction. The total yields of the identified heterocyclic compounds are 0.0023%. It is concluded that adenine synthesis occurs at a much lower concentration of hydrogen cyanide than has been shown by earlier studies. Pathways for the synthesis of purines from hydrogen cyanide are discussed, and a comparison of the heterocyclic compounds that have been identified in meteorites and in prebiotic reactions is presented.

Biological Evolution↗
PubMed1984

On the abiotic formation of amino acids. I. HCN as a precursor of amino acids detected in extracts of lunar samples. II. Formation of HCN and amino acids from simulated mixtures of gases released from lunar samples.

Two studies on the abiotic formation of amino acids are presented. The first study demonstrates the role of hydrogen cyanide as a precursor of amino acids detected in extracts of lunar samples. The formation of several amino acids, including glycine, alanine, aspartic acid, and glutamic acid, under conditions similar to those used for the analysis of lunar samples is demonstrated. The second study investigates the formation of hydrogen cyanide as well as amino acids from lunar-sample gas mixtures under electrical discharge conditions. These results extend the possibility of synthesis of amino acids to planetary bodies with primordial atmospheres less reducing than a mixture of methane, ammonia, hydrogen and water.

Amino Acids↗
PubMed1984

Resolution of amino acids by a native-cellulose column.

Seventeen aliphatic, hydroxyl, sulfur-containing, aromatic, imino, and heterocyclic DL-amino acids were resolved without derivatization using a native-cellulose column. Chirality was assigned by either CD spectra or co-chromatography. Under these conditions, it is known that the hydrophobic interaction of amino acids with the hydroxyl groups on the cellulose played an important role in the separations. The cellulose column chromatographic system for resolution of amino acid enantiomers was combined with an amino acid analyzer. Thus, the DL-amino acids separated by the latter system were successively resolved by the former.

Amino Acids↗
PubMed1984

Clinical studies of resistant ascites in liver cirrhosis.

Resistant ascites was studied in 34 patients with liver cirrhosis and ascites. The patients were initially divided into 3 groups on the basis of the weekly cumulative ascites retention curve: patients relieved of ascites within 3 weeks of admission, patients relieved between 4 and 12 weeks and patients with ascites persisting beyond 13 weeks. "Resistant ascites" was defined as "ascites persisting for more than 13 weeks after admission to the hospital". The patients were then reclassified into 3 groups : Group A being those patients relieved of ascites within 12 weeks, Group B being those with resistant ascites and group C being those who died within 12 weeks of admission. There were no differences in age and sex distribution, etiology of liver cirrhosis, past medical history or physical findings among the 3 groups. However, Group B had higher levels of serum creatinine and blood urea nitrogen than Group A on admission. Serum bilirubin was higher and serum albumin was lower in Group C than in Group B, which indicates that Group C had greater liver cell failure.

Adult↗
PubMed1984

Clinical studies of hepatocellular carcinoma with liver cirrhosis and ascites.

A comparison was made of the clinical findings of 59 patients with liver cirrhosis (LC) accompanied with hepatocellular carcinoma (HCC) (of which 35 had ascites and 24 did not at the time of admission) and 164 patients with LC, but without HCC (of which 39 had ascites and 125 did not). HCC patients were older and more often had hepatomegaly, vascular spider and pleural effusion than LC patients. Ascites was more frequently observed in HCC than in LC patients when the serum albumin level and the indocyanine green disappearance rate were relatively well maintained and when peripheral edema was absent. There was no difference in the ascitic protein concentration between LC and HCC patients. Malignant cells were detected in ascites only in 14% of the HCC patients. These facts indicate the presence of ascites-inducing factors in HCC patients which have no direct relation to serum colloid osmotic pressure and effective hepatic blood flow. Almost all of the HCC patients with ascites (96%) died with ascites, whereas 54% of the LC patients with ascites recovered from the ascitic condition.

Adolescent↗
PubMed1984

[Clinical trials of plasma exchange therapy in patients with recurrent colon cancer].

Plasma exchange was performed in patients with recurrent colon cancer with evaluable liver metastasis or abdominal tumor with dissemination. This therapy was undertaken a total of 19 times in 11 cases. The cases were divided into effective and ineffective cases according in terms of the clinical effects, and changes in blood parameters and prognosis were examined in each case. Subjective symptoms, such as increase in appetite and disappearance of general fatigue or pain, were remarkably improved in 6 cases, and these patients were allowed to be discharged from the hospital. Marked regression of hepatomegalia was observed in 2 cases out of these 6 cases, but no remarkable effect was noted in patients with abdominal dissemination. In the effective cases the following parameters were significantly improved; beta- and gamma-globulin of serum protein fractions, IgG, IgA and IgM of immunoglobulin, alpha 2-macroglobulin, ceruloplasmin, and transferrin. However, since these effects are temporal and short-lived, one must consider applying plasma exchange therapy in conjunction with anticancer drugs, and the like. Plasma exchange seems applicable to cases of colon cancer with metastasis in the liver, because this therapy showed improvement in clinical symptoms, decreased hepatomegaly and prolonged survival.

Abdominal Neoplasms↗