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Biomedical subjects

S Kondo

Publications and source records attributed to S Kondo.

At least 703 records · Page 39Linked to original sources
PubMed1993

[Effects of prostaglandin E1, E2 and F2 alpha on the changes in the adenylate cyclase activities of rabbit urinary tract tissues].

Effects of prostaglandin E1, E2 and F2 alpha (PGE1, PGE2 and PGF2 alpha) on the changes in the adenylate cyclase (AC) activities of rabbit urinary tract tissues were studied in order to clarify whether the PGs' actions are mediated by cAMP in the urinary tract. AC activities were measured by the method of Salomon et al. The three PGs studied were all found to increase the AC activities dose-dependently in the renal pelvis, ureter, bladder dome and bladder base. Among the changes in AC activities, PGE1 and PGE2 significantly increased the AC activities of the renal pelvis and ureter. PGE1 significantly increased the AC activities of the bladder dome. It was reported that Ca2+ influx plays an important role in the PGs' action on the urinary tract. Our data suggest that the PGs act on the urinary tract via cAMP as well as Ca2+ influx.

Adenylyl Cyclases↗
PubMed1993

[A study on the affinities of various muscarinic antagonists to the human detrusor muscle].

The affinities of various muscarinic antagonists to human detrusor muscle were determined using radioligand binding techniques. Saturation experiments with 3H-QNB revealed that there were significant amount of muscarinic cholinergic receptors in human detrusor muscle. Displacement of 3H-QNB binding by various muscarinic subtype selective drugs was studied in the inhibition experiment. Pirenzepine, AFDX-116 and 4-DAMP inhibited the 3H-QNB binding to human detrusor muscle with the Ki values (nM) (mean +/- S.D., n = 6) of 243 +/- 62.5, 59.7 +/- 15.3 and 2.69 +/- 0.96, respectively. These data indicate that M3-selective drug possesses the highest affinity to human detrusor muscle. The Ki values of oxybutynin and tiquizium bromide were similar to those of 4-DAMP, suggesting that these two drugs have strong affinities to human detrusor muscle.

Adamantane↗
PubMed1993

Magnetic resonance imaging in kainic acid-induced limbic seizure status in cats.

Magnetic resonance imaging before, during, and after kainic acid (KA)-induced limbic seizure status in cats demonstrated the bilateral hippocampi as slightly high-intensity areas on the T2-weighted images during the limbic seizure status, and isointensity areas 1-2 weeks after KA injection when the limbic seizure status subsided. However, the hippocampi again became high-intense 1-3 months after KA injection. Histological study suggested that the high-intensity area during the limbic seizure status resulted from regional edema, and in the chronic period from marked gliosis and/or atrophic change as a consequence of tissue damage in the hippocampus.

Amygdala↗
PubMed1993

[A study of muscarinic cholinergic receptor subtypes in human detrusor muscle using radioligand binding techniques].

The subtypes of the muscarinic cholinergic receptor in human detrusor muscle were studied using radioligand binding techniques. It was found that there were significant amount of M1, M2 and M3 receptors labeled by 3H-pirenzepine, 3H-AFDX and 3H-4DAMP, respectively, in human detrusor muscle. The rank order of the amount of these receptors was M3 > M1 > or = M2. The amount of M3 receptors was about 10-fold of M1 or M2. In the inhibition experiment of 3H-QNB binding to human detrusor muscle, the Ki values of pirenzepine or AFDX was 50-100 fold of that of 4DAMP and the rank order of Ki values was pirenzepine > AFDX > 4DAMP. The M3 selective drug, 4DAMP showed smallest Ki value among the three drugs studied, indicating that the affinity of M3 receptor was highest among the three muscarinic subtypes. These data suggest that M3 receptors are predominant in human detrusor muscle biochemically.

Aged↗
PubMed1993

[Effects of endothelin-1 on the smooth muscle contractility of human urinary bladder, spermatic cord and prostatic adenoma].

Effects of endothelin-1 (ET-1) on the smooth muscle contractility of human detrusor, spermatic cord and hypertrophied prostatic adenoma were examined in muscle bath studies. ET-1 increased the contractile forces of all above smooth muscle strips in concentration dependent manner. The contractile force induced by 10(-6) M ET-1 was approximately 30% of that induced by 3 x 10(-5) M carbachol in detrusor muscle strips, approximately 40% of that induced by 10(-4) M norepinephrine in spermatic cord muscle strips and almost equal to that induced by 10(-5) M phenylephrine in prostatic adenoma muscle strips. The contractions induced by ET-1 in those muscle strips were not inhibited by any of tetrodoxine, atropine, phentolamine, propranolol and indomethacine. These results suggest that ET-1 may act as a constrictor on lower urinary tract and genital smooth muscles and especially on prostatic adenoma and that ET-1 may affect those smooth muscles directly not through autonomic receptors or prostaglandins.

Aged↗
PubMed1993

[Effect of benign prostatic hypertrophy on the endothelin-1 receptor density in human urinary bladder and prostate].

We measured the amount of binding sites for endothelin-1 (ET-1) in the bladder and prostate in patients with and without benign prostatic hypertrophy (PH and NPH group) using 125I-ET-1. Also the localization of ET-1 binding sites in hypertrophied adenoma was studied using autoradiography. Saturation experiments with 125I-ET-1 revealed that there were single class of saturable high affinity binding sites for 125I-ET-1 in the homogenate of the bladder (dome and base) and prostate (adenoma and capsule). The KD values to the bladder and prostate were not different between PH and NPH group. The Bmax values in the bladder (base and dome) were significantly lower in the PH group. While those in the prostate (adenoma and capsule) were significantly higher in the PH group. Autoradiograms of hypertrophied adenoma showed that ET-1 binding sites were localized to the stromal smooth muscles as well as to the glandular epithelium. These data suggest that ETs affect the pathophysiology of BPH through the changes in receptor density in both the bladder and prostate.

Aged↗
PubMed1993

Structures of enzymatically modified products of arbekacin by methicillin-resistant. Staphylococcus aureus.

Only a limited number of strains of methicillin-resistant Staphylococcus aureus (MRSA) moderately resistant to arbekacin (ABK) have been isolated clinically. Three inactivated products of ABK have been obtained by reaction with excess amounts of a crude enzyme preparation extracted from an ABK-resistant MRSA strain (MIC, 25 micrograms/ml). The 2"-O-phosphate was the major product together with small amounts of the 6'-N-acetate and the double modification product. The structures of these modification products were determined by MS and NMR spectral analyses.

Aminoglycosides↗
PubMed1993

Induction of apoptosis in rat somatotrophin-secreting pituitary adenoma cells by bromocriptine.

Bromocriptine, a dopamine agonist, is now an accepted primary therapeutic agent for patients with prolactinomas and other pituitary adenomas. In this study, we demonstrated that bromocriptine inhibited the proliferation of rat somatotrophin-secreting pituitary adenoma (GH1) cells. In addition, the antitumor activity of bromocriptine was inhibited both by actinomycin D and cycloheximide, suggesting that it was dependent upon new RNA and protein synthesis. Interestingly, the results of DNA fragmentation assay and cell cycle analysis clearly demonstrated that bromocriptine induced apoptosis in GH1 cells.

Adenoma↗
PubMed1993

Sedative and hypnotic activities of pyrimidine nucleoside derivatives.

N3-Substituted pyrimidine nucleoside and their related compounds were synthesized. The central nervous system (CNS) depressant effect of the compounds such as hypnotic activity and synergistic effect with pentobarbital have been evaluated. N3-Phenacyl derivatives of uridine (2), thymidine (3), deoxyuridine (4), 6-azauridine (5) and arabinofuranosyluracil (6) exhibited the hypnotic activity, whereas N3-phenacyl-2',3'-O-isopropylideneuridine did not. Compound 2, 3, 4 and 6 significantly enhanced pentobarbital-induced sleep. The results indicate that CNS depressant effect of pyrimidine nucleoside derivatives might relate to functional group at the N3-position on oxopyrimidine ring and stereospecificity of sugar moiety at the N1-position.

Animals↗
PubMed1993

[Cerebral circulation and metabolism in patients with mitochondrial myopathies].

In order to study the cerebral circulation and metabolism in 6 patients with mitochondrial myopathies and 6 normal control subjects, positron emission tomography with oxygen-15 labelled tracers was performed. Four patients had predominantly central nervous system involvement, whereas 2 had myopathy alone. In comparison with normal control subjects, patients with mitochondrial myopathies showed decreased cerebral blood flow (CBF), decreased cerebral oxygen metabolic rate (CMRO2), and low oxygen extraction fraction (OEF) value due to an uncoupling of CBF and CMRO2. The reduction of OEF was remarkable in the 2 patients having predominantly central nervous disease and 1 having myopathy alone. We suppose that these findings are greatly related to mitochondrial myopathies and that they reflect the disturbance of mitochondrial oxidative metabolism in the brain. The patients whose central nervous symptoms progressed rapidly tended to show the reduction of OEF, but the degree of the reduction of OEF was not necessarily related to the severity of the central nervous symptoms. These findings suggest that the disturbance of cerebral metabolism is not uniform in patients with the same central nervous disease.

Adult↗
PubMed1993

[Study of patients with spinocerebellar degeneration using positron emission tomography].

We studied cerebral blood flow, oxygen metabolism and their relation to clinical symptoms in 45 patients with spinocerebellar degeneration (SCD) and 12 normal control subjects using positron emission tomography (PET). Regions of interest were acquired for the cerebellar hemispheres, cerebellar vermis, brainstem, thalami, and cerebral cortices. PET studies in these patients revealed that regional cerebral blood flow (CBF), regional cerebral oxygen metabolic rate (CMRO2), CBF/mean CBF of each cerebral cortex (CBF/mCBF) and CMRO2/mean CMRO2 of each cerebral cortex (CMRO2/mCMRO2) in the cerebellar hemispheres, cerebellar vermis, and brainstem showed a significant decrease in comparison with the normal control subjects, while in the cerebral cortices and thalami, SCD patients showed normal values. CBF/mCBF and CMRO2/mCMRO2 were significantly decreased in patients with olivopontocerebellar atrophy (OPCA) and Menzel type of hereditary ataxia (Menzel type) in the cerebellar hemispheres, cerebellar vermis, and brainstem, whereas patients with late cortical cerebellar atrophy (LCCA) and Holmes type of hereditary ataxia (Holmes type) revealed a significant decrease of CBF/mCBF and CMRO2/mCMRO2 in the cerebellar hemispheres and cerebellar vermis, but not in the brainstem. Patients with OPCA showed a significant decrease of CBF in the cerebellar hemispheres, cerebellar vermis, brainstem and that of CMRO2 in the cerebellar hemispheres and cerebellar vermis. Patients with LCCA showed a significant decrease of CBF in the right cerebellar hemisphere and cerebellar vermis. However, a significant reduction of CBF and CMRO2 was not observed in patients with Menzel type or Holmes type in these regions. In patients with LCCA and Holmes type, the severity of upper limb ataxia and dysdiadochokinesis were significantly correlated with CBF/mCBF and CMRO2/mCMRO2 in the cerebellar hemispheres and brainstem.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Subtemporal amygdalohippocampectomy for treating medically intractable temporal lobe epilepsy.

A SUBTEMPORAL AMYGDALOHIPPOCAMPECTOMY technique has been developed for mesial temporal lobe epilepsy. The conventional subtemporal approach has been modified to diminish temporal lobe retraction and the risk of damage to the temporal lobe. In the new technique, the surgeons' position has moved from above to below and the approach has been changed from anterolateral to posterolateral, thereby avoiding the voluminous and steeply inclined anterior temporal lobe. By this modified approach, it was unnecessary to remove the roof of the external auditory meatus and it was estimated that both the retraction pressure and the extent of temporal lobe retraction were reduced. To date, surgeons using this approach have operated on four patients with temporal lobe epilepsy whose epileptic foci were in the mesial temporal structure; the inferior temporal gyrus, the temporal tip, the vein of Labbé, and the ventral bridging veins were preserved. After surgery, two patients became completely free of seizures and the other two showed over 90% reduction in seizure frequency without neurological sequelae. Postoperative visual field examination revealed full visual fields without quadrantanopsia. This approach can preserve the temporal stem and lateral temporal lobe, it can be used to remove as much of the posterior hippocampus as necessary, and it can be extended to conventional lobectomy if it is indicated.

Adult↗