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Biomedical subjects

S Oishi

Publications and source records attributed to S Oishi.

At least 55 records · Page 3Linked to original sources
PubMed1995

[How should we treat intestinal ischemia?--II: Effects of pentoxifylline, glucagon and prostaglandin E1].

It is important to repair or ameliorate the intestinal ischemia in critically ill patients. Recent study of our suggests the superiority of dobutamine, but not dopamine, in improving the intestinal oxygenation. In this study we examined the effects of pentoxifylline (PF), glucagon (GL) and prostaglandin E1 (PGE1) during reduced blood flow of the superior mesenteric artery (SMA) in 20 anesthetized dogs. As an index of the intestinal oxygenation, tonometrically measured intestinal intramural pH (pHi) was used. A tonometer was inserted into the midjejunum through enterotomy. The SMA blood flow was measured by a transit-time flow meter. A vascular screw clamp for blood flow reduction was placed around the origin of the SMA, proximal to the flow probe. The SMA blood flow was adjusted to 70% of baseline for three hours. After two hours of decreased blood flow, pHi dropped significantly from baseline. Then, either PF (20 mg.kg-1.min-1 over 10 min, followed by 0.1 mg.kg-1.min-1), GL (1 microgram.kg-1.min-1) or PGE1 (0.05 and 0.5 microgram.kg-1.min-1) was infused intravenously for one hour. With infusions of GL and large dose of PGE1, pHi tended to decrease further, although GL increased the cardiac output. Small dose of PGE1 had no significant effect on pHi. PF treatment showed beneficial effects not only on the cardiac output and the SMA blood flow, but also on pHi. We conclude that PF therapy may restore the intestinal microvascular blood flow. Further study of the effects of PF on tissue oxygenation and blood rheology is warranted.

Alprostadil↗
PubMed1994

Chronic toxicity studies of piperonyl butoxide in F344 rats: induction of hepatocellular carcinoma.

Male and female F344 rats (30-33 rats/group) were administered piperonyl butoxide (alpha-[2-(2-butoxyethoxy)ethoxy]-4,5-methylenedioxy-2-propylto luene) in the diet at levels of 0 (control), 0.6, 1.2, and 2.4% for nearly 2 years. Beginning at about 40 weeks, 10 rats in the 1.2% treated male group died due to cecal hemorrhages. Piperonyl butoxide induced hepatocellular carcinoma in both sexes in a dose-dependent manner. Hepatocellular carcinoma was found even in the 1.2% treated male group (incidence, 26.7%), and incidences in the 2.4% groups of males and females were 80.0 and 57.7% respectively of all those surviving. Piperonyl butoxide also caused essential thrombocythemia with a dose-response relationship. Hemorrhages in stomach and cecum, anemia, degenerative lesions of alveoli, and nephrotoxicity were also observed related to exposure. These results indicate that piperonyl butoxide is a hepatocarcinogen to the rat.

Animals↗
PubMed1994

Prevention of di(2-ethylhexyl)phthalate-induced testicular atrophy in rats by co-administration of the vitamin B12 derivative adenosylcobalamin.

The administration of 2g/kg of di(2-ethylhexyl)-phthalate (DEHP)-induced severe testicular atrophy coincident with the reduction of testicular specific lactate dehydrogenase (LDH-X) activity, zinc, magnesium, and potassium concentrations in rats. Co-administration of DEHP and adenosyl cobalamin (AdoCbl), one of the active vitamin B12s, prevented these testicular specific changes including fluctuations in testicular weight. On the other hand, co-administration of DEHP and methylcobalamin (MeCbl), the other active vitamin B12, did not prevent the testicular atrophy induced by DEHP under the present experimental conditions. In the liver, DEHP administration caused hypertrophy with changes in several metal concentrations and serum biochemical parameters. Co-administration of DEHP and AdoCbl or MeCbl did not prevent these hepatic changes, but aggravated hypolipidemia. The results demonstrated that the preventive effect of AdoCbl was a testicular specific action, and this effect may be stimulated solely by AdoCbl in vitamin B12 groups.

Animals↗
PubMed1994

Piperonyl butoxide induces hepatocellular carcinoma in male CD-1 mice.

Male CD-1 mice in groups of 52, 53 or 100 were administered piperonyl butoxide (alpha-[2-(2-butoxyethoxy)ethoxy-4,5-methylenedioxy-2-propyltol uene) in the diet at levels of 0 (control), 0.6 and 1.2% for 12 months. Hepatocellular carcinoma was induced in treated groups in a dose-dependent manner but not in the control group. The incidences of hepatocellular carcinoma were 11.3 and 52.0% in mice given 0.6 and 1.2% piperonyl butoxide, indicating that piperonyl butoxide can cause hepatocellular carcinoma in mice as it is known to do in rats.

Animals↗
PubMed1994

Developmental toxicity evaluation of piperonyl butoxide in CD-1 mice.

Piperonyl butoxide was administered to pregnant mice by gavage at a level of 0 (control), 1065, 1385 and 1800 mg/kg body weight only on day 9 of gestation. The animals were sacrificed on day 18 of gestation. Early and late foetal deaths were significantly increased in the higher dose groups and those effects were significantly dose-related. The average body weights of male and female foetuses were significantly reduced in a dose-related fashion. The external malformation of oligodactyly in forelimbs was significantly increased in higher treatment groups in a dose-related manner. The dose levels of piperonyl butoxide in the present study produced adverse effects on developmental parameters.

Abnormalities, Drug-Induced↗
PubMed1994

Elevated immunoreactive endothelin levels in patients with pheochromocytoma.

Plasma immunoreactive endothelin-1 (ET-1) concentrations were measured in 44 patients with pheochromocytoma, 31 patients with essential hypertension, and 20 healthy control subjects. Plasma ET-1 concentrations in patients with pheochromocytoma were 18.2 +/- 3.2 fmol/mL (mean +/- SEM), which was significantly higher than those of essential hypertension and healthy control subjects (7.3 +/- 0.4, 7.1 +/- 0.4 fmol/mL, respectively, P < .01). Plasma ET-1 concentrations in patients with essential hypertension and control subjects were similar. In patients with pheochromocytoma, hypertensive group had higher ET-1 than normotensive group (23.0 +/- 5.5 v 12.4 +/- 2.2 fmol/mL), but the difference was not significant. In 17 patients with pheochromocytoma, the elevated plasma ET-1 concentrations (17.4 +/- 4.7 fmol/mL) returned to normal levels (7.9 +/- 0.6 fmol/mL, P < .05) after surgical resection of the tumor. ET-1 contents in the 26 tumor tissues (1.40 +/- 0.29 pmol/g) were higher than those in 7 normal adrenal medullas (0.44 +/- 0.12 pmol/g). Systolic, diastolic, and mean blood pressures were better correlated with plasma norepinephrine than ET-1 in patients with pheochromocytoma. These data indicate that pheochromocytoma might produce and secrete excessive amounts of ET-1. The hypertension in patients with pheochromocytoma is mainly catecholamine-dependent, but may be secondarily ET-1-dependent.

Adolescent↗
PubMed1994

[The inhibitory effect of mouse monoclonal IgM antibody E5 against endotoxin on limulus activity of various lipopolysaccharides].

The anti-endotoxin activity of mouse monoclonal IgM antibody E5 was determined against various lipopolysaccharides (LPSs) derived from Escherichia coli J5, E. coli O111:B4, Klebsiella pneumoniae and Pseudomonas aeruginosa by measuring limulus activity by endospecy method. In general, above 0.2 microgram/ml of E5 reduced almost dose-dependently the limulus activities of all LPSs tested, although the degree of reduction in limulus activity somewhat varied among bacterial species. The limulus activities of LPS from E. coli J5, E. coli O111:B4, K. pneumoniae and P. aeruginosa decreased by 72%, 50%, 44%, and 58%, respectively, by exposure to 5.0 micrograms/ml of E5 for 2 hrs.

Animals↗
PubMed1994

A case of Sipple's syndrome with malignant pheochromocytoma treated with 131I-metaiodobenzyl guanidine and a combined chemotherapy with cyclophosphamide, vincristine and dacarbazine.

A 39-year-old woman with Sipple's syndrome and a malignant pheochromocytoma (PHE) is presented. She is a member of a big family with this syndrome and had undergone bilateral, subtotal adrenalectomy because of bilateral PHE six years prior to the present admission. In 1989, a small nodule was identified in her right thyroid lobe by ultrasonography and was suspected to be a medullary thyroid carcinoma (MTC). Further examinations revealed the coexistence of multiple lung and liver masses. These tumors were considered to be metastases of PHE because of the increased urinary excretion of catecholamines as well as extremely high catecholamines both in the hepatic venous blood and in the cystic fluid of the liver tumor even though there was no apparent recurrences of PHE in the adrenal region. After surgical removal of the MTC in August, 1989, she was given 3.7 GBq of 131I-metaiodobenzyl guanidine (131I-MIBG) infusions twice--in October, 1989 and in August, 1990. 131I-MIBG showed a strong accumulation in the lung and liver masses on both occasions. Periodic increases in blood pressure and tachycardia with an excessive catecholamine secretion were observed over two weeks after the first treatment. However, this treatment was not effective in reducing urinary catecholamines nor the size of the metastatic tumors. She, therefore, underwent chemotherapy with cyclophosphamide, vincristine and decarbazine in 1991, which slightly but significantly reduced urinary excretion of catecholamines and the size of the lung tumors. She had clinically stable period for one year after the treatment but rapid growth of these metastatic tumors occurred afterwards and she died in August, 1992.(ABSTRACT TRUNCATED AT 250 WORDS)

3-Iodobenzylguanidine↗
PubMed1994

Pheochromocytoma in pregnancy: a review of the Japanese literature.

We review the 35 cases with pheochromocytoma associated with pregnancy including our own 3 cases in the Japanese literature from 1958 to 1993. In a total of 35 cases, the overall maternal mortality rate was 11% and the fetal loss 22%. Recently, after 1981, the maternal mortality rate and the fetal loss were significantly reduced to one patient (6%). Although antepartum diagnosis of pheochromocytoma was made in only 32% of the patients, maternal mortality was reduced to zero and fetal loss to 18%. An initial diagnosis of toxemia of pregnancy was made in 17 patients (49%) and of pheochromocytoma in 10 patients (29%). A diagnosis of pheochromocytoma was made before delivery in 11 patients (31%), after delivery in 22 patients (63%), at autopsy in one patient (3%), and unknown in one patient (3%). The symptoms mostly suggestive of pheochromocytoma were paroxysmal hypertension in 27 (77%) of the 35 patients. The clinical symptoms generally appeared in the third trimester in 23 patients (66%). Pheochromocytoma is a rare disease, but a high index of clinical suspicion must be kept in mind and pheochromocytoma must be listed in the differential diagnosis of hypertension associated with pregnancy. Recently, abdominal ultrasound study and MR imaging can be used to localize the tumor during the antepartum period. Once the diagnosis is confirmed, alpha-blockade is essential and beta-blockade may be required. In the first and second trimesters, tumor resection has a good fetal outcome; in later pregnancy, delivery by elective caesarean section followed by tumor resection is recommended.

Adult↗
PubMed1993

Three generation toxicity study of butylated hydroxytoluene administered to mice.

Butylated hydroxytoluene (BHT) was administered to mice, from 5 weeks of age of the F0 generation to the weaning of the F2 generation, in the diet at levels of 0 (control), 0.015, 0.045, 0.135, and 0.405%, and some reproductive and neurobehavioural parameters were measured. There was no consistent significant effect on number of litters, litter size, and litter weight at birth for each generation. The body weight of the pups of the 0.015% BHT group was increased at birth and during the lactation period for each generation. In the F2 generation, the body weights of the pups of other treatment groups were increased during the lactation period, particularly at postnatal day (PND) 21. In the neurobehavioural parameters, a few parameters were increased in treatment groups; i.e., surface righting at PND 7 in the F1 generation, surface righting at PND 4 and negative geotaxis at PND 7 in the F2 generation. The dose levels of BHT in this study showed little adverse effect on reproductive and neurobehavioural parameters on mice.

Animals↗
PubMed1993

Strain differences in susceptibility to di-2-ethylhexyl phthalate-induced testicular atrophy in mice.

It is well known that the oral administration of di-2-ethylhexyl phthalate (DEHP) produces severe seminiferous tubular atrophy in rats, but mice are far less sensitive. In the present experiment, we demonstrated that one strain of mice derived from ICR mice, Crj:CD-1, was very sensitive to DEHP-induced testicular injury. This atrophy was accompanied by lowered zinc concentration and lactate dehydrogenase isozyme X in the testis. This fact and the effect of genetic background will need to be considered for assessing the risk of testicular toxicity in men exposed to phthalate esters.

Animals↗
PubMed1993

Soft-tissue coverage of the shoulder and brachium.

Injuries to the upper extremity often involve bone and soft-tissue elements, as do injuries to the lower extremity. Proper reconstruction of the soft-tissue deficits in concert with bone restoration is essential to final recovery. Better understanding of the blood supply and newer concepts of managing severely injured limbs has improved the ability to manage these challenging problems.

Arm↗