Search PubMed⌕ Search

Biomedical subjects

T Satoh

Publications and source records attributed to T Satoh.

At least 1,153 records · Page 64Linked to original sources
PubMed1985

NAD-coupled enzymatic oxidation of O-ethyl O-p-nitrophenyl phenylphosphonothioate (EPN) to its oxygen analog with liver microsomes of rats.

O-Ethyl O-p-nitrophenyl phenylphosphonothioate (EPN)-induced inhibition of rat liver microsomal carboxylesterase (CEase) and formation of O-ethyl O-p-nitrophenyl phenylphosphonate (EPNoxon), an oxygen analog of EPN, were enhanced remarkably by addition of NAD in vitro. This potentiation of the anti-CEase action of EPN by NAD was significantly inhibited by addition of SKF 525-A or potassium thiocyanate (KSCN); and a simultaneous decrease in cytochrome P-450 contents were also observed. Addition of N-ethylmaleimide (NEM) at various concentrations inhibited potentiation of the anti-CEase action of EPN by NAD in parallel with inhibition of liver microsomal dehydrogenase activities. In conclusion, NAD was enzymatically reduced to NADH, a cofactor of microsomal dehydrogenase(s), and then formation of EPNoxon through microsomal cytochrome P-450-coupled monooxygenase was accelerated. Consequently, inhibition of CEase by EPN was potentiated.

Aldehyde Dehydrogenase↗
PubMed1985

Enhancement of the binding of O-ethyl O-p-nitrophenyl phenylphosphonate (EPNoxon) to microsomal carboxylesterase by NAD in vitro.

Inhibition of rat liver microsomal carboxylesterase (CEase) by O-ethyl O-p-nitrophenyl phenylphosphonothioate (EPN) and binding of EPN oxygen analog to microsomal CEase were enhanced by addition of NAD or NADP. This was more prominent in addition of NAD than NADP. No potentiation of anti-CEase action of EPN by NAD was seen when pure esterase (E.C. 3.1.1.1) instead of liver microsomes was used as an enzyme source. This effect of NAD in microsomal CEase was significantly decreased when N-ethylmaleimide or p-chloromercuribenzoic acid was added. From these findings, it is strongly suggested that NAD-mediated potentiation of the anti-CEase action of EPN might be attributed to the increase in formation of NADH from NAD by microsomal dehydrogenase(s) containing a sulfhydryl group, leading to a subsequent increase in formation of the EPN oxygen analog from EPN, and in turn, CEase inhibition was enhanced.

Animals↗
PubMed1985

A possible role of gonad and renal prostaglandin E2 on the development of hypertension in spontaneously hypertensive rats.

A possible role of prostaglandin E2 (PGE2) in the regulation of blood pressure in spontaneously hypertensive rats (SHR) was investigated. The inhibition of PG synthesis by chronic indomethacin treatment accelerated the elevation of blood pressure with the tendency to decrease renal PGE2. We, therefore, confirmed that PGE2 in SHR may play a role in the antihypertensive mechanism. In this connection, the participation of renal PGE2 in the retardation of the development of hypertension in male SHR induced by orchiectomy was examined. Urinary PGE2 which reflects the renal PGE2 level tended to keep a higher level in the castrated group. Urinary electrolytes excretion also inclined to augment in the castrated group throughout the experiment. These results indicate that renal PGE2 may participate in the gonads-mediated blood pressure regulation system, although the mechanism of the retardation of spontaneous hypertension induced by orchiectomy remains obscure.

Aging↗
PubMed1985

Establishment of a brain-tumor model in adult monkeys.

A brain-tumor model in adult monkeys may be significant because of the biological similarity to humans as well as the feasibility for surgical manipulation and for sequential computerized tomography (CT) scanning. In the present study, brain tumors were successfully produced in Japanese monkeys (Macaca fuscata), each weighing 2 to 10.8 kg, with an average age of 5.1 years old. Tumor cells were implanted by intracerebral inoculation of 4 X 10(7) chick embryo fibroblasts infected with the Schmidt-Ruppin strain of Rous sarcoma virus (RSV). With a 15- to 67-day latency, brain tumors were induced in 11 (73.3%) of 15 RSV-inoculated monkeys. Contrast-enhanced CT scans delineated all solitary intracerebral tumors greater than 4 to 6 mm in diameter. The CT images were proved at autopsy to be accurate within 2 mm in determining the size of tumor. Five of the 11 monkeys with intracerebral tumors died, with an average survival time of 26.6 days after RSV inoculation. The induced tumors were classified as either glioma or sarcoma by the presence or absence of glial fibrillary acidic protein (GFAP) and S-100 protein. A chromosome analysis of cultured tumor cells showed a diploid number of 42, indicating monkey origin. It is concluded that the reproducible brain tumor in the adult Japanese monkey inoculated with RSV can serve as a good experimental brain-tumor model for the further study of human malignant brain tumors.

Animals↗
PubMed1985

[A clinical study on testicular tumor].

The 19 cases of testicular tumors treated at our Hospital between 1974 and 1983, were reviewed retrospectively. The incidence of testicular tumors among the male outpatients in our urologic clinic was 0.31%. The patients ranged in age from 1 to 76 years old (average: 27.8 years old). The affected side was the left side in 11 and the right side in 8 cases. The most frequent symptom was a painless mass of the testis. Histopathological diagnosis according to the classification by Dixon and Moore was type I in 9 cases, type II in 4 cases, type II in 1 case, type IV in 4 cases. Thus germinal tumors accounted for 18 (94.7%) of the cases. One case (5.3%) of malignant lymphoma was non-germinal. As for the age distribution, two peaks were noted in testicular tumors, especially in cases with potential embryonal carcinoma, between 1 and 2 years and between 19 and 32 years. On the other hand, the cases with potential seminoma showed one peak between 25 and 44 years. The treatment consisted of high orchiectomy alone, orchiectomy with radiation, orchiectomy with chemotherapy or orchiectomy with radiation and chemotherapy. Retroperitoneal lymphadenectomy was not done in any case. The over-all 3-year and 5-year actual survival rates were both 92%.

Adolescent↗
PubMed1985

Effect of repeated administration of monomethyl-aminoantipyrine on the activities of gamma-glutamyltranspeptidase and microsomal drug metabolizing enzymes in rat liver.

The effects of consecutive administration of 4-monomethylaminoantipyrine, a metabolite of aminopyrine, on the gamma-glutamyltranspeptidase activities of liver, kidney, urine and serum were investigated in rats. On day 5 after repeated treatment, a pronounced increase of gamma-glutamyltranspeptidase activity was seen in the liver homogenate as well as in the hepatic microsomes. Furthermore, simultaneous administration of 4-monomethylaminoantipyrine with phenobarbital increased to the same degree as compared with the single administration of aminopyrine. However, no change in gamma-glutamyltranspeptidase activity was observed in kidney, urine, serum and hepatic cytosolic fractions. Under the same experimental condition, the contents of cytochrome P-450 and b5, NADPH cytochrome c reductase, the activities of aminopyrine N-demethylase and aniline hydroxylase were also enhanced.

Aminopyrine↗
PubMed1985

[A case report of a double cancer of the ureter and stomach].

A 63-year-old man complained of hunger epigastralgia. X-ray and endoscopic examination demonstrated Borrmann II type gastric carcinoma. Radical gastrectomy was performed on October 20, 1982. The histological findings revealed moderately differentiated tubular adenocarcinoma. In May 1983, right hydronephrosis was recognized by ultrasonography. A papillary tumor was visualized in the right ureter in retrograde pyelography, and percutaneous transrenal urinary tract drainage was performed. Cytological findings revealed class V. Total nephro-uretectomy was performed on June 16, 1983. The histological findings revealed transitional cell carcinoma.

Carcinoma, Intraductal, Noninfiltrating↗
PubMed1985

Autopsy findings in chronic pyelonephritis patients under dialysis--collected from the Annuals of Pathological Autopsy Cases in Japan.

Autopsy findings in chronic pyelonephritis patients on dialysis were studied in 122 cases. The greatest number of cases was in the 50-59 year-old group among males and in the 60-69 year-old group among females. Infection was the most frequent cause of death (39.3%), followed by bleeding (23.5%). The total number of patients with infections and bleeding was 68 cases (55.7%) and 39 cases (32.0%), respectively. Pneumonia and bronchitis were the most frequent (27.0%) in cases with infections and gastrointestinal bleeding was the most frequent (21.3%) in cases with bleeding. The incidence of tuberculosis (16.4%) as a complication was high.

Adolescent↗
PubMed1985

Age and sex distribution in chronic renal failure patients at dialysis induction.

Age distribution at dialysis induction among patients with chronic renal failure was studied in 579 cases. Age distribution differed depending on the primary renal diseases and sex. In chronic glomerulonephritis, males were most numerous in the 30-39 year-old group, followed by the 40-49 and 20-29 year-old groups. They decreased with age. Females showed the same frequencies among the 20-29, 30-39, 40-49, 50-59, 60-69 and 70-79 year-old groups. However, the 50-59 year-old group had the most cases. Among cases of diabetic nephropathy, males were most numerous in the 50-59 year-old group and females in the 60-69 year-old group. Progression of the disease to renal failure seemed to be more rapid in males than in females. Natural history and possible risk factors in patients with chronic renal failure maintained on hemodialysis were discussed.

Adult↗
PubMed1985

Reduction of testicular testosterone levels in rats by prostaglandin E2.

The effect of intratesticular administration of prostaglandin (PG) E2, PGF2 alpha and PGD2 on rat testes testosterone levels were studied. The intratesticular administration of PGE2 or PGD2 markedly decreased the testicular testosterone levels in rats. The decrease of testosterone concentration in rat testis was not obtained by PGF2 alpha. In the incubation experiment, PGE2 reduced the release of testosterone from fragment rat testis. These results suggest that PGE2 acts on androgen biosynthesis in rat testes.

Animals↗
PubMed1985

A possible role of antihypertensive polar renomedullary lipid (APRL) and prostaglandin E2 in the kidney in the antihypertensive action of pindolol.

The influence of the pretreatment with CV-3988, a specific antagonist of antihypertensive polar renomedullary lipid (APRL), and/or indomethacin on the antihypertensive effect of pindolol was examined in order to clarify a possible role of APRL and prostaglandin E2 (PGE2) in the kidney in the effect of pindolol in male spontaneously hypertensive rats (SHR). CV-3988 effectively attenuated the antihypertensive effect of pindolol, although pindolol still significantly lowered blood pressure following CV-3988 treatment. Besides, the pretreatment with CV-3988 showed no significant effect on an increased PGE2 level and a decreased volume of urine after pindolol treatment. The antihypertensive effect of pindolol disappeared after the CV-3988 treatment in combination with indomethacin.

Animals↗