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Biomedical subjects

H Yamamura

Publications and source records attributed to H Yamamura.

At least 379 records · Page 21Linked to original sources
PubMed1983

Effect of prolonged administration of gastrin on experimental carcinogenesis in rat colon induced by intrarectal instillation of N-methyl-N'-nitro-N-nitrosoguanidine.

The effect of tetragastrin on the incidence and histology of colonic tumors induced by intrarectal instillation of N-methyl-N'-nitro-N-nitrosoguanidine was investigated in Wistar rats. Prolonged administration of tetragastrin in depot form during and after treatment with N-methyl-N'-nitro-N-nitrosoguanidine resulted in a significant reduction in the incidence of colonic tumors in Experimental Week 35. Histological examinations showed that, unlike the well-differentiated adenocarcinomas with a typical glandular pattern in control groups, the adenocarcinomas that developed in rats treated with tetragastrin had high mucin-producing activity.

Adenocarcinoma↗
PubMed1982

Carcinoembryonic antigen in the bile in patients with pancreatic and biliary cancer. Correlation with cytology and percutaneous transhepatic cholangiography.

The level of carcinoembryonic antigen (CEA) in the bile of 17 patients with benign pancreatic and biliary diseases and 50 patients with pancreatic and biliary cancer were determined by enzyme immunoassay. The bile specimens were obtained at the time of percutaneous transhepatic cholangiography. The bile was centrifuged and the supernatant was used for CEA measurement, while the cell pellet was examined cytologically. High CEA values in the bile were significantly more frequent in patients with pancreatic and biliary cancer than in those with benign pancreatic or biliary diseases; increased CEA concentrations in the bile were observed in 76.0% and 60.0%, respectively, of all the patients and of the patients with localized cancer. The location of the cancer had no influence on the bile CEA level, but the CEA levels in the bile tended to be high when the tumor had distant metastases, or when the biliary tract was completely obstructed. Although patients with pancreatic and biliary cancer had a high CEA value in the bile significantly more frequently, bile CEA measurement is not sufficient to distinguish an individual patient with pancreatic or biliary cancer from those with other disease, since the overlap between the values is too great, and therefore, additional examinations are required. Correct diagnosis of malignancy were made by cytological examination alone, by bile CEA assay alone and visual examination of dye in the biliary tract alone in 72.0, 76.0, and 88.0% respectively, of the patients examined, while the combination of these methods raised the diagnostic rate to 100%.

Bile↗
PubMed1982

Comparison of glycogen phosphorylase kinases of various rat tissues.

Glycogen phosphorylase kinases in soluble fractions of various rat tissues were examined for the pH 6.8/8.5 activity ratio, Ca2+-dependency, activation by cyclic AMP-dependent protein kinase (protein kinase A), and reactivity with anti-skeletal muscle phosphorylase kinase serum. The enzymes could be divided into at least two major groups; muscle and liver types. The muscle type, that has a low value of pH 6.8/8.5 activity ratio, is highly dependent on Ca2+, markedly activated by protein kinase A, and strongly inhibited by the antiserum. Inversely, the liver type, that has a high value of pH 6.8/8.5 activity ratio, is poorly dependent on Ca2+, not activated by protein kinase A, and weakly inhibited by the antiserum. The enzymes from heart and skeletal muscle were similar and belonged to the former entity. Whereas, the enzymes from liver, kidney, spleen, lung, and testis appeared to belong to the latter entity. The enzyme from brain apparently differs from these entities, and seems to be an intermediate type or a hybrid of the two.

Animals↗
PubMed1982

Effects of ortho-iodo-sodium benzoate (OISB) on oxygen-hemoglobin affinity and its relation to plasma concentrations in dogs.

Effects of ortho-iodo-sodium benzoate (OISB) on oxygen-hemoglobin affinity were studied in unanesthetized beagles with simultaneous measurement of its plasma concentrations. Oxygen-hemoglobin affinity changes correlated well with the plasma concentrations of the drug. Intravenous administration of 100 mg/kg of OISB increased P50 significantly from the control value of 28.6 +/- 0.8 mmHg to 29.5 +/- 0.7 mmHg and 30.0 +/- 0.5 mmHg, 5 min and 30 min after the infusion, respectively. P50 gradually decreased thereafter, and after 1 hr period, elevation was no longer significant. Administration of 200 mg/kg of OISB caused a significant increase in P50 from the control of 29.3 +/- 0.3 mmHg to 30.5 +/- 0.4 mmHg, 31.1 +/- 0.3 mmHg, 31.1 +/- 0.3 mmHg and 30.5 +/- 0.5 mmHg, at 5 min, 30 min, 1 hr and 3 hr, respectively. P50 elevation declined thereafter to control levels. Plasma concentrations of the drug reached its highest level 5 min after the administration and declined gradually thereafter. All significant elevations of P50 were accompanied by the plasma concentrations of the drug more than 200 micrograms/ml. Biological half-life of the drug was found to be about 5.5 hr.

Animals↗
PubMed1982

Gastrin protection against chemically induced gastric adenocarcinomas in Wistar rats: histopathology of the glandular stomach and incidence of gastric adenocarcinoma.

The effects of gastrin on the histopathology of the glandular stomach and on the incidence of gastric carcinoma induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) were investigated in inbred Wistar (W) rats. Prolonged administration of gastrin after treatment with MNNG significantly reduced the incidence of adenocarcinomas of the glandular stomach. In addition, atypical glandular proliferations were significantly less frequent and were smaller, and the incidence of marked mucosal atrophy was significantly reduced in both the antral and oxyntic gland mucosae. Both atypical glandular hyperplasia and mucosal atrophy are precursors of gastric cancers; prolonged administration of gastrin to rats after treatment with MNNG suppressed development of precursors of gastric cancer and so prevented development of gastric cancers.

Adenocarcinoma↗
PubMed1981

Phosphorylation of calf thymus H1 histone by muscle glycogen phosphorylase kinase.

Muscle glycogen phosphorylase kinase [EC 2.7.1.38] has the ability to phosphorylate five fractions of calf thymus histone. H1 histone is the most preferable substrate, and maximally about 1.3 mol of phosphate is incorporated into every mole of this histone. This reaction absolutely depends on CA2+, and the molecular activity is about one third of that of cyclic AMP-dependent protein kinase (protein kinase A). The affinity of phosphorylase kinase for H1 histone is higher than that of protein kinase A. Calmodulin stimulates this histone phosphorylation. Analysis of the N-bromosuccinimide-bisected fragments of fully phosphorylated H1 histone has revealed that the enzyme phosphorylates mostly seryl residues in both amino- and carboxyl-terminal portions, although phosphorylation of the carboxyl-terminal portion is twice as much as that of the amino-terminal portion. Fingerprint analysis indicates that the phosphorylation sites in H1 histone for this enzyme are different from the sites phosphorylated by protein kinase A. This catalytic activity also differs from that of a newly found multifunctional protein kinase which may be activated by the simultaneous presence of Ca2+ and phospholipid.

Animals↗
PubMed1981

Dialysis for schizophrenia: an uncontrolled study of 11 patients.

The authors evaluated hemodialysis as a treatment for schizophrenia in an uncontrolled study of 11 patients. Eight men and two women with chronic schizophrenia who had responded poorly to conventional treatments or who had sought alternate treatments received three dialyses weekly for 3 weeks; 1 additional subject dropped out after eight treatments. MMPI, Psychiatric Status Scale, and Inpatient Multidimensional Psychiatric Scale scores were obtained before, immediately following, and at intervals after the nine treatments. Preliminary results, including 1-month follow-up, suggest that subjects with pretreatment anxiety and depression improved. No endorphins were discovered in the dialysate.

Adult↗
PubMed1981

Inhibition of gastrin secretion by pirenzepine (LS 519) in treatment of gastric ulcer.

The effects of pirenzepine on the serum gastrin levels in the basal state and in response to a liquid test meal were investigated in nine patients with gastric ulcer. Single-dose administration of the drug caused a significant decrease in the basal gastrin level and significant inhibition of the serum gastrin response. When measured 12 h after the end of drug treatment for 7 days, the serum gastrin levels in the basal state and in response to a test meal tended to be high, but the differences were not statistically significant.

Adult↗