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Biomedical subjects

H Momoi

Publications and source records attributed to H Momoi.

At least 37 records · Page 2Linked to original sources
PubMed1984

Binding of benzo(a)pyrene with peroxidase and its oxidation by peroxidase-H2O2 intermediate.

The oxidation of benzo(a)pyrene (BP) by horseradish peroxidase (HRP) (EC 1.11.1.7) was examined spectrophotometrically by the decomposition of peroxidase-H2O2 intermediate "compound II." The rate constant of the oxidation of BP was 9.5 X 10(4) M-1 sec-1. The oxidation of BP by HRP was inhibited at high BP concentrations, and the hydrogen donor (BP) inhibition constant, KA', was 1.48 microM. The association constant, Kassoc, of the formation of a complex of BP and HRP at 403 nm was 4.37 X 10(4) M-1. The oxidation products of BP have been identified as 1,6-, 3,6- and 6,12-quinone BP. These products showed no mutagenicity in the mutagenicity assay.

Benzo(a)pyrene↗
PubMed1983

Electrophysiologic study on atrioventricular nodal reetrant tachycardia with special reference to recent controversies.

Electrocardiographic and electrophysiologic studies were performed in 21 patients with atrioventricular (A-V) nodal reentrant tachycardia (AVNRT). Patients were classified into three types according to the patterns during the tachycardia, i.e., (1) type I; an atrial echo (Ae) occurred simultaneously with a ventricular electrogram (VE) (14 patients), (2) type II; an Ae occurred in front of the next VE (four patients) and (3) type III; an Ae followed immediately after the preceding VE (three patients). All patients with type I AVNRT showed discontinuous A-V and continuous ventriculoatrial (V-A) conduction curves. "Enhanced V-A conduction" (1:1 V-A conduction at the ventricular paced rate of 200 beats/min) was demonstrated in five of the 14 and after verapamil in two of the five patients. In type II AVNRT the tachycardia was initiated with a minimal amount of A-V nodal conduction delay and second degree A-V or V-A block was observed in all four patients. V-A conduction was poor in these patients. In type III AVNRT A-V conduction curves were discontinuous and retrograde study revealed the presence of retrograde dual A-V nodal pathways. In conclusion, A-V and V-A conduction in patients with AVNRT were variable and this variability seemed to be responsible for different patterns of AVNRT.

Adolescent↗
PubMed1983

Effect of cholinergic stimulation on the distribution of amylase activity.

The amylase activity was measured in the several tissues and plasma after pancreatectomy in the rat. Pancreatectomy decreased the alpha-amylase content of the blood and several tissues in the rat, whereas the amylase activity did not change in the submandibular gland. Especially, the content of the small intestine lost about 99% of its amylase activity as did the small intestinal mucosa. After cholinergic stimulation, the amylase activity in several tissues and plasma tended to increase but the increase was not statistically significant. Only the enzyme activity in the lumen of the small intestine and distal intestine increased substantially after cholinergic stimulation. However, the maximal concentration in the small intestine was still only 2% of that in the normal non-pancreatectomized animal. The data suggest that the absence of the dramatic increase in the amylase activity in the plasma and several tissues that was observed in the normal rat after this pattern of cholinergic stimulation was due to the absence of the potential source of amylase, the pancreas.

Animals↗
PubMed1982

Effects of aclacinomycin-A on murine leukemia.

Effects of aclacinomycin-A (ACM) on leukemic cells and normal hematopoietic stem cells were studied for the purpose of evaluating the usefulness of this agent as an antileukemic agent. ACM suppressed not only leukemic colony-forming unit (LCFU) in the radiation-induced murine erythroleukemia, but also normal hematopoietic stem cells (CFU-S, CFU-C) in mice. However, LCFU was the most sensitive to ACM. After the administration of ACM at a dose of 5 mg/kg. LCFU was suppressed to 0.02 of the control on day 3 and recovered within 5 days. Splenic CFU-S and CFU-C were suppressed to the nadirs on day 2 and day 1, respectively, and they recovered within 5 days. On the basis of the differences in the sensitivities to ACM and recovery patterns between LCFU and normal hematopoietic stem cells. ACM at a single dose of 5 mg/kg was administered every 3 days (total dose of 25 mg/kg) into leukemic mice, and the increase in mean lifespan obtained 113.9%. Effectiveness of ACM in the treatment of acute leukemia was discussed.

Aclarubicin↗
PubMed1981

Effects of leukemic cells on hematopoiesis in radiation-induced murine erythroleukemia.

Erythroleukemia occurred in a BCF1 mouse after X-irradiation. This leukemia was maintained by leukemic cell transplantation successively without changes in the characters of leukemia. According to leukemic cell proliferation, peripheral blood leukemic cells increased in number, and anemia and granulocytopenia developed. Following leukemic cell infiltration, granuloid-committed stem cells (CFU-C) in bone marrow decreased but those in spleen increased. Neither leukemic cells nor leukemic cell-conditioned medium inhibited CFU-C culture in vitro. Effects of leukemic cells on hematopoiesis were discussed.

Animals↗