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Biomedical subjects

Y Minamoto

Publications and source records attributed to Y Minamoto.

26 records · Page 2Linked to original sources
PubMed1992

[Anesthesia and postoperative stroke in patients with previous cerebrovascular disease].

A retrospective study was performed to determine the incidence of perioperative stroke in patients with previous history of cerebrovascular disease (CVD). One hundred and seventy eight out of 20048 patients who underwent anesthesia and surgery during the period of 1985 to 1989 had history of prior CVD. Of them, 137 patients were managed with general anesthesia and 41 with regional anesthesia. Factors analyzed were interval between the prior CVD and the operation, intraoperative hemodynamic changes, perioperative changes in the hematocrit and urinary output, and postoperative neurological complications. Postoperative neurological complications occurred in 31 of the patients given general anesthesia (delayed awakening in 26, dementia syndrome in 6 and deterioration of paralysis in 1), whereas only one patient developed dementia syndrome postoperatively in those given regional anesthesia. None of the patients developed a postoperative stroke. There was no direct relationship between the factors analyzed and the incidence of postoperative neurological complications. Further studies are needed to identify more precisely factors contributing to the occurrence of cerebrovascular complication in a high risk patients.

Aged↗
PubMed1991

Development of a serum-free and heat-sterilizable medium and continuous high-density cell culture.

We tried to establish a new serum-free and heat-sterilizable medium, based on our serum-free medium in which many lymphoblastoid cells and hybridoma could grow as well as in a conventional serum-containing medium. As is well-known, L-glutamine (L-Gln) is one of the most heat-labile but essential components for cell growth. As a substitute for L-Gln, dipeptide such as Gly-L-Gln or L-Ala-L-Gln, which was quite stable even after autoclaving, was found to be utilizable for mammalian cell growth. The L-Gln dipeptide-containing serum-free medium was quite stable in a solution even after storing at 37 degrees C for 4 months. In the serum-free medium containing L-Ala-L-Gln, mouse hybridola could grow and produce more antibody than in RPMI 1640 + 10% FBS. It has been proved that BSA and transferrin, which are also heat-labile but essential for the growth of various cell lines, can be substituted by heat-stable alpha-cyclodextrin and cholesterol, and Fe-gluconate, respectively. Insulin has also proved to be heat stable in a solution of Fe-gluconate. We thus established a new serum-free medium, all the components of which could be heat-sterilizable. Moreover, by adding EGF and BSA but without the adhesion factor included in FBS, the serum-free medium was found to support a long-term serial culture of a human diploid fibroblast. Finally, with this auotoclavable serum-free medium in a perfusion culture apparatus, we were able to continuously cultivate a human lymphoblastoid cell line. The production rate of IgM was found to be markedly increased by feeding the serum-free medium enriched by glucose, bicarbonate, L-Cys, and approtinin. The cell density reached as high as 2 x 10(8)/ml in the serum-free medium. Although the working volume in the reactor was only 1 1, the rate of IgM production reached 480 mg/day. The new heat-sterilizable serum-free medium has several advantages, because L-Gln peptide is a heat-stable and available precursor of L-Gln.

Animals↗
PubMed1990

Pulmonary hypertensive response to declamping of the aorta during abdominal aortic reconstructive surgery-role of metabolic derangement and anaphylatoxin in the reaction.

Metabolic parameters and anaphylatoxin activities in mixed venous blood were measured in 16 patients undergoing abdominal aortic reconstructive surgery to study the mechanism of pulmonary hypertensive response after aortic declamping. This reaction was confirmed by a rise in ratio between mean pulmonary arterial pressure and mean systemic arterial pressure (Pp/Ps). Aortic declamping was followed by a significant increase in lactate level and lactate-pyruvate ratio (L/P ratio) as compared with pre-declamping level ( P << 0.01). Although anaphylatoxin C3a concentration rose significantly after declamping ( P << 0.01), C5a showed no change at any stage. When the patients were divided into two groups according to the degree of Pp/Ps change by declamping, significant elevation of L/P ratio and C3a level were observed in the group with higher increase (Post-/Pre-declamp value >/=1.25) of Pp/Ps compared to the lower (>>1.25) group. After declamping, in the higher Pp/Ps group, a positive correlation existed not only between Pp/Ps change and aortic clamp time, but also between L/P ratio and C3a level. The present results suggest that muscular metabolic derangement distal to the aortic clamp may play an important role in the development of post-declamping pulmonary hypertensive response through anaphylatoxin C3a.

Journal Article↗
PubMed1989

[Behavioral pharmacological properties of the novel antidepressant paroxetine, a selective 5-HT uptake inhibitor].

The behavioral effects of paroxetine were investigated in mice and rats in comparison with imipramine and amitriptyline. 1) Locomotor activities were decreased by imipramine and amitriptyline but not by paroxetine in both animal species. 2) Paroxetine antagonized methamphetamine-induced hyperactivity in mice as did imipramine and amitriptyline. 3) Paroxetine showed a more potent antimuricidal effect in raphe-lesioned rats than imipramine and amitriptyline, and it also inhibited muricide in olfactory bulbectomized rats. 4) The immobility of rats in the forced swimming test was markedly decreased by imipramine and amitriptyline, but only slightly by paroxetine. 5) Like imipramine and amitriptyline, paroxetine potentiated the methamphetamine- or L-DOPA-induced stereotyped sniffing, and it inhibited oxotremorine-induced tremor. 6) Paroxetine antagonized reserpine-induced hypothermia, tetrabenazine-induced ptosis, and enhanced ether-induced anesthesia, all less potently than imipramine and amitriptyline. 7) The analgesic action of paroxetine was stronger than that of imipramine and amitriptyline. 8) Paroxetine did not antagonize maximal electroshock- or pentetrazol-induced convulsions and haloperidol- or THC-induced catalepsy in rats. In addition, paroxetine neither exerted muscle relaxation nor affected the shuttle-box type conditioned avoidance in rats. From these results, the behavioral effects of paroxetine, as compared with imipramine and amitriptyline, were characterized by its potent antimuricidal action in raphe-lesioned rats and its weak effect in the forced swimming test and by its less potent muscle relaxant, anticonvulsant, anticataleptic and anesthesia-potentiating actions.

Aggression↗
PubMedDate not supplied

Effect of the noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist MK-801 on food-anticipatory activity rhythm in the rat.

When feeding was restricted to a single meal scheduled at a fixed time (1300-1700 h) in the day, rats exhibited increased prefeeding locomotor activity 1-3 h before the feeding time, which increased over 6 days. The activity increase was seen for about 5 h (1100-1600 h) on the seventh day when no food was provided (fasting day), as the rat anticipated mealtime. Thus, mealtime-associated activity rhythm on the fasting day was considered to be another good index of food-anticipatory activity. In this study, we investigated the effects of the noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist, MK-801, which has been reported to cause impairment of spatial learning, on food-anticipatory activity in rats. Daily injection of MK-801 (0.2 mg/kg) at 1700 h for 6 successive days impaired the development of increased prefeeding activity. The appearance of mealtime-associated activity was impaired by daily injection of MK-801 (0.2 mg/kg) at 1700 h (immediately after food restriction, FR) or at 1900 h (2 h after FR) but not at 0900 (16 h after FR). In addition, mealtime-associated activity was impaired by MK-801 injected at 1700 h in a dose-dependent manner (0.1-1 mg/kg). The present results demonstrate that NMDA receptor mechanisms were involved in learning processes of food anticipation and suggest that an impairment of food-anticipatory activity may be considered an animal model of a deficit of "temporal learning".

Animals↗
PubMedDate not supplied

Attenuating effect of serotonin receptor antagonists on impairment of mealtime-associated activity rhythm in old rats.

In the present study, we examined attenuating effect of serotonin (5-HT) receptor antagonists on the impairment of the time perception presented by daily scheduled feeding in old rats. When feeding was restricted to a single meal at a fixed time of day (1300-1700 h) for six consecutive days, young rats exhibited intense locomotor activity from 1-3 h before feeding time. Intense locomotor activity was observed between 1200 adn 1700 h in young animals even on the fasting day (day 7) (mealtime-associated activity). However, this mealtime-associated activity was impaired in 24-mo-old rats. Daily injections of 5-HT2 receptor antagonists, mianserin or ritanserin, or a 5-HT3 receptor antagonist, Y25130, at 1700 h for 6 consecutive days significantly and dose-dependently attenuated the impairment of mealtime-associated activity on the fasting day in old rats without affecting the food intake. Our results suggest that the blockade of 5-HT2 and/or 5-HT3 receptors attenuates impairment of the manifestation of mealtime-associated anticipatory activity related to temporal learning in old rats.

Aging↗