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Biomedical subjects

S Hanada

Publications and source records attributed to S Hanada.

At least 145 records · Page 8Linked to original sources
PubMed1986

Decreased serotonin S2 and increased dopamine D2 receptors in chronic schizophrenics.

Serotonin S2 and dopamine D2 receptors in the prefrontal cortex and caudate nucleus of postmortem brains of chronic schizophrenics were studied using 3H-ketanserin and 3H-spiperone, respectively. In the prefrontal cortex of schizophrenics, we found a significant decrease in the maximum number of 3H-ketanserin binding sites (Bmax), with no change in the dissociation constant (Kd). Conversely, both Bmax and Kd of 3H-spiperone binding to the caudate nucleus were significantly increased in the schizophrenic patients. There were no differences in receptor indices between patients who were taking neuroleptics until their death and those who had taken none for 2 months or more prior to death. These findings suggest that alterations in S2 receptors in the prefrontal cortex may reflect the disease process, per se, and that the increase in the number of D2 receptors in the caudate nucleus of schizophrenics is not due solely to neuroleptic medication.

Adult↗
PubMed1986

Reverse tolerance to the swimming time prolonging effect of d-amphetamine in mice.

Development and disappearance of reverse tolerance to the swimming time prolonging effect of d-amphetamine (AMP) was studied in mice in comparison with that to the ambulation accelerating effect. The swimming time prolonging effect was progressively enhanced by daily administration of 2 mg/kg AMP. The development of reverse tolerance to the effect was more rapid than that to the ambulation accelerating effect and reached its maximal level by 5-6 repetitions. Repetition at a daily interval was more effective than at the interval of 3-4 days, and administration at a weekly interval failed to develop the reverse tolerance. Restriction of swimming space or immobilization in a small box after administration of AMP blocked the development of reverse tolerance. Reverse tolerance to the swimming time prolonging effect disappeared faster than that to the ambulation accelerating effect, but the enhancement was well maintained after 30 days of withdrawal. Thus, many factors affect the development of reverse tolerance to the various effects of AMP; however, the swimming time prolonging effect is a simple, sensitive, and reproducible index for the study of this phenomenon.

Animals↗
PubMed1985

Regional distribution of [3H]nitrendipine binding in human brain.

Evidence for the binding of a calcium antagonist, [3H]nitrendipine, to human brain membranes was obtained. This binding was saturable, specific and of high affinity with a dissociation constant (Kd) of 0.62 nM in the prefrontal cortex and 0.82 nM in the caudate. The maximal numbers of binding sites (Bmax) in these areas were 57.5 and 32.3 fmol/mg protein, respectively. [3H]Nitrendipine binding to membranes from 27 regions in the post-mortem human brains was measured. The highest levels of 0.5 nM [3H]nitrendipine binding were seen in the cerebral cortex, amygdala and thalamus, and levels in the midbrain, cerebellum and pallidum were considerably lower.

Adult↗
PubMed1985

Autoreceptors regulate gamma-[3H]aminobutyric acid release from the guinea pig small intestine.

The possible presence of a presynaptic gamma-aminobutyric acid (GABA) receptor capable of regulating the release of GABA was investigated using the guinea pig small intestine. Muscimol at 10(-8) M and 10(-7) M, but not baclofen at 10(-6) M, inhibited the K+ (40 mM)-evoked Ca2+-dependent release of [3H]GABA from the small intestine preloaded with [3H]GABA, in the presence of 10(-6) M tetrodotoxin. The effect of muscimol on the K+-evoked GABA release was inhibited by bicuculline and furosemide. These results show that the guinea pig small intestine possesses presynaptic GABA receptors which may be involved in the regulation of the evoked GABA release. The presynaptic GABA receptor is bicuculline-sensitive and is probably coupled to the Cl- ion channel.

Animals↗
PubMed1985

Some characteristics of econazole-induced pleurisy in rats.

Aqueous suspension of econazole nitrate injected into the pleural cavity of rats induces sharp exudate formation and small leucocyte mobilization. The econazole pleurisy development is monophasic and its peak value occurs between 8 and 12 hr after econazole injection. The exudate volume and the leucocyte mobilization are inhibited by chlorpheniramine, cyproheptadine and steroidal and non-steroidal anti-inflammatory drugs.

Animals↗
PubMed1985

Diversity of underlying mechanisms in the production of analgesic and pentobarbital-hypnosis prolonging effects of various analgesic drugs and stresses.

Stressful stimuli, electric footshock (FS), immobilized-water immersion (IW), and cold-water swimming (CWS), produced analgesia and prolonged the pentobarbital hypnosis as well as morphine and clonidine. Naloxone completely antagonized the analgesic effects of morphine and FS and partially that of IW; however, that of clonidine and CWS were not reversed by naloxone. Naloxone eliminated the hypnosis prolonging effect of morphine and FS, but failed to reverse the effect of clonidine, IW and CWS. Differences in the analgesic and hypnosis prolonging effects and also the respective naloxone sensitivity of each drug and stress suggest the diversity of the underlying mechanisms.

Analgesics↗
PubMed1985

[Fundamental and clinical studies on aztreonam in the gynecological field].

Aztreonam (AZT), a new monocyclic beta-lactam antibiotic was studied on clinical efficacy for infectious disease in gynecological field. At about 80 minutes following intravenous injection of 1 g dose of AZT, it penetrated well into internal genital organs at therapeutic levels. Moreover it transferred very fast and enough into intrapelvic dead space exudate, and its level was kept still as high at 12 hours after administration. AZT was given to 20 women affected with gynecological infectious disease. The outcome of AZT therapy was as follows: effective in 5 out of 6 patients (83.3%) administered intravenously and in all of 14 patients (100%) received intramuscularly. Notable adverse effects or abnormal laboratory findings were not observed except 1 case of diarrhea and 2 cases of transient and slight elevation of serum CPK and transaminases. Based on these results, we may conclude that AZT is a highly effective and a very safe antibiotic for the treatment of infectious disease in gynecological field.

Adult↗
PubMed1985

A preliminary study on rabbit tubal anastomosis with the Nd-YAG laser.

This is the first report on the use of the Nd-YAG laser in performing tubal end to end anastomosis in rabbit. At first, the optimal intensity of laser exposure was evaluated using histological preparations of tubal ampullary tissues which were exposed in various conditions. It was determined that the most suitable condition was 12 watts/cm2 of energy density of 0.2 second duration and a 0.6mm focal spot. Subsequently, these treatment conditions were applied practically to end end anastomosis of severed tubal ampulla of three rabbits. Four weeks later, the second laparotomy was done to confirm the restoration of tubal patency by chromopertubation in vivo, and to excise the restored tube to study the reconstruction of luminal epithelium histologically by scanning electron microscope. Proven by chromopertubation in vivo, tubal patency was restored in 4 out of 6 tubal samples, but in two, tubes were dehisced at the anastomosed line. By scanning electron microscopic observation of tubal samples in which patency was restored some injury to mucosal epithelial cells was seen at the anastomosed site. It is concluded that the Nd-YAG laser technique is useful in tubal end to end anastomosis of rabbit and accurate placement of tubal stumps is essential to the proper restoration of tubal patency.

Animals↗