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Biomedical subjects

T Ochiai

Publications and source records attributed to T Ochiai.

At least 199 records · Page 11Linked to original sources
PubMed1992

[Studies on reinforcing effects of methylephedrine, caffeine and their mixture with intravenous-self administration in rhesus monkeys].

The reinforcing effects of methylephedrine hydrochloride (ME), anhydrous caffeine (CA) and their mixture (ME+CA) were studied by the intravenous cross self-administration experiment and by the progressive ratio experiment in four male rhesus monkeys each. In the intravenous cross self-administration experiment, ME, CA and ME+CA were found to have reinforcing effects. Self-administration rates above the level of cocaine, a typical reinforcing drug, were not observed in ME or CA alone, but observed in their mixture (120 + 126 micrograms/kg/inj.: M dose or 480 + 504 micrograms/kg/inj.: H dose). The minimum reinforcing doses were 120 micrograms/kg/inj. (M dose) for ME, 126 micrograms/kg/inj.: (M dose) for CA, and ME 30 micrograms+CA 32 micrograms/kg/inj. (L dose) for the mixture. Vomiting was observed during the session in monkeys which showed higher self-administration rates of ME and the mixture, and decreases in the rates were observed in these animals on the next day. One animal at H dose of the mixture, which showed a high self-administration rate on both the 1st and 2nd days, died after the end of the session on the 2nd day. In the progressive ratio experiment, the final ratios at 120 micrograms/kg/inj. of ME, 126 micrograms/kg/inj. of CA and the mixture of ME 120 micrograms/CA 126 micrograms/kg/inj. were almost equal to or less than that of saline (negative control). Thus, these drugs didn't show reinforcing effects at the above levels. However, a reinforcing effect was observed in three out of four monkeys administered 1920 micrograms/kg/inj. of ME, 2016 micrograms/kg/inj. of CA, and the mixture of ME 1920 and CA 2016 micrograms/kg/inj.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

[The effect of FK506 on segmental pancreas allograft in mongrel dogs].

FK506 is a potent immunosuppressive agent on experimental and clinical organ transplantation. We studied the the effect of this agent on segmental pancreas allograft in mongrel dogs. Graft survival was prolonged significantly with continuous administration of FK506, 0.3mg/kg/day intramuscular and 1.0mg/kg/day orally. However such symptoms as loss of appetite, nausea and extreme emaciation were observed and caused death. While bolus therapy of FK506 (3 days administration with the dose of 1.0mg/kg i.m. from 4 to 6 day postoperatively) showed the same immunosuppressive effect as continuous therapy and less side effect. Furthermore it was suggested that FK506 plasma levels were concerned with the appearance of side effect. In conclusion, the administration of FK506 with plasma level monitoring was thought to be useful on pancreas transplantation.

Animals↗
PubMed1992

[Signification of liver metastases of colorectal cancer with special reference to recurrence in the residual liver after hepatic resection].

In the patients with liver metastases of colorectal cancer, pre-and post operative intra-arterial infusion chemotherapy was evaluated for prevention of recurrence in the residual liver after hepatic resection. Materials are sixty-five hepatectomized patients from May 1981 to 1992. Therapies were subdivided into five groups. I: pre-and postoperative non-therapy (n = 3); II: postoperative chemotherapy (n = 22); III: postoperative intra-arterial infusion chemotherapy (n = 12); IV: pre-operative intra-arterial infusion chemotherapy + postoperative chemotherapy (n = 15); and V: pre-and postoperative intra-arterial infusion chemotherapy (n = 13). In recurrence rate in the residual liver, I to IV groups showed as high as 50-100%. However, the disease-free survival rate was 100% in V group, revealing a significant difference between the other four groups. Accordingly, in order to prevent recurrence in the residual liver of hepatectomized patients with liver metastases of colorectal cancer and prolong the disease-free interval, we consider that pre-and post-operative intra-arterial infusion chemotherapy can be effective, compared to pre-or postoperative intra-arterial infusion chemotherapy alone.

Administration, Oral↗
PubMed1992

[The effect of ethanol on the metabolism of methamphetamine].

In order to clarify the effects of ethanol (EtOH) on metabolism of methamphetamine hydrochloride (MA-HCl), the plasma and urine samples were taken from three groups of three male crab-eating monkeys (Macaca fascicularis). MA-HCl was given to the first group, both MA-HCl and EtOH were given once to the second group, the after consecutive administration of EtOH for four weeks, both MA-HCl and EtOH were given to the third group. Comparisons were made of the sequential change in the concentration of unchanged methamphetamine (MA) and its supposed metabolites, amphetamine (AP), p-hydroxymethamphetamine (p-HOMA), and p-hydroxyamphetamine (p-HOAP). Additional hematological and plasma-biochemical tests were performed to monitor the influences under the administration of MA-HCl and EtOH on the animals. For the extraction of MA and its metabolites from blood and urine, a solid phase extraction was carried out with which an excellent recovery was achieved. Gas chromatography mass spectrometry (GC-MS) was used to measure the metabolites after changing them to the form of TFA derivative, producing good results. EtOH concentration in the blood was measured by GC using a head-space method. The biological half-life (t1/2) of MA tended to be shortened slightly in the plasma when EtOH was given consecutively. The maximum concentration of AP obtained by administration of EtOH was half that obtained by single administration of MA-HCl and the detectable time was shortened. A high concentration of p-hydroxy metabolites that the been almost undetectable when both MA-HCl and EtOH were administered once, was detected when EtOH was administered consecutively, compared with that when only MA-HCl was administered. Particularly, considerable amounts of p-HOAP was detected even after 72 hours. The trends seen in the excretion of MA and its metabolites into the urine were the same as seen in their plasma concentrations, although there was a difference in the detectable time. The urine collected in a metabolic cage for the monkey was contaminated with drinking water, so that the total amounts of metabolites, rather than sequential change as in the case of plasma, were considered to be of greater significance. When EtOH was administered consecutively, the excreted amounts of p-HOAP in the urine increased saliently and characteristically.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1991

Pharmacological studies on TA-6366, a new ACE inhibitor: II. Effect of long-term administration from the pre-hypertensive stage on blood pressure, relative heart weight and ACE activity of various tissues in spontaneously hypertensive rats (SHRs).

The long-term oral administration of TA-6366 (5 mg/kg/day) from 4-weeks old impeded the genetic hypertension development with only a slight decrease in heart rate in spontaneously hypertensive rats (SHRs). However, the lower dose (1 mg/kg/day) of TA-6366 did not affect the development, but it lowered blood pressure after the development was almost accomplished. Concomitantly, relative heart weights in both the groups were markedly decreased to almost the same degree. The reduction of ACE activity in the aorta, brain and lung of both groups was found at 24 hr after the final administration, particularly at the 5 mg/kg/day dose; and that of the aorta was kept at almost the same low level even on the 9th day after withdrawal. After withdrawal of TA-6366 (5 mg/kg/day), the significant decrease in blood pressure was sustained at least for 10 weeks. The beneficial effect of TA-6366 on the hypertension development in SHRs seems to be related to its strong and long-lasting ACE inhibition, especially in the vasculature.

Administration, Oral↗
PubMed1991

Chronic toxicity of 2,4,6-tri-tert-butylphenol in rats.

In order to study the chronic toxicity of 2, 4, 6-tri-tert-butylphenol (TTBP), groups of 40 Slc: Wistar rats of either sex were fed diet containing 0, 30, 100, 300 or 1000 ppm of TTBP for up to 24 months. Hematological, biochemical and histopathological examinations performed periodically revealed slight microcytic anemia, changes in some biochemical parameters relating to liver function and focal necrosis of liver cells following TTBP administration, and these changes observed in females were severer than those in males. No neoplastic responses following TTBP administration were noted. Noticeable changes were not observed in the 30 ppm group throughout the experimental period. Thus, it was concluded that TTBP causes liver injury characterized by focal necrosis with microcytic anemia and elevations of serum phospholipids and cholesterol levels presumably occurring as secondary effects following the liver injury.

Anemia↗