Search PubMed⌕ Search

Biomedical subjects

S Kondo

Publications and source records attributed to S Kondo.

At least 757 records · Page 42Linked to original sources
PubMed1992

Human glioma-specific antigens detected by monoclonal antibodies.

Three murine monoclonal antibodies, designated GA-17, GB-4, and GC-3, were prepared by the hybridization of murine myeloma cells (NS-1) and spleen cells of BALB/c mice immunized with the crude membrane fraction of cultured human gliosarcoma cells (GI-1). Two of them (GA-17 and GB-4) reacted exclusively with the membrane of glioma cells, and the other (GC-3) reacted with the membrane of glioma cells and a T cell line (MOLT-4). Although these antibodies reacted with almost all of the gliomas, the reactions differed. GA-17 reacted equally well with all glioblastoma (17 cases) and low-grade astrocytoma (10 cases), whereas GB-4 reacted poorly with 7 cases of glioblastoma and GC-3 did not react with 7 cases of low-grade astrocytoma. The antigens, exclusively expressed on the cell surface, were analyzed by surface labeling with 125I followed by a cell lysis and immunoprecipitation with these antibodies. The findings obtained by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that GA-17, GB-4, and GC-3 reacted with Mr 140,000-145,000, Mr 160,000, and Mr 145,000-150,000 proteins, respectively. Some evidence has been obtained indicating that these antigens are composed of the same polypeptide chain (Mr 120,000) with the carbohydrate chains being different.

Animals↗
PubMed1992

Mechanism of interferon gamma-induced protection of human gliosarcoma cells from lymphokine-activated killer lysis: division of lymphokine-activated killer cells into natural killer- and T-like cells.

The mechanism by which interferon gamma (IFN-gamma) decreases the susceptibility of the established cultured gliosarcoma line Gl-1 to lymphokine-activated killer (LAK) lysis was analyzed. The results of monolayer depletion and lectin-dependent cellular cytotoxicity assays by LAK cells revealed that the resistance to LAK lysis of IFN-gamma-treated Gl-1 cells is manifested at the stage of LAK cell target recognition alone. We have also divided LAK cells into populations of phenotypically natural killer (NK)- and T-like cells with monoclonal antibodies and complement, respectively. We have used these cells to examine the mechanism of IFN-gamma-induced protection of Gl-1 cells from LAK lysis in cold target inhibition, monolayer depletion, and direct binding assays. The results revealed that NK-like cells do not recognize IFN-gamma-treated Gl-1 cells as efficiently as they do untreated targets, whereas T-like cells show the opposite tendency. In conclusion, we have demonstrated that the IFN-gamma induced protection of tumor cells from LAK lysis is predominantly regulated by the target recognition of NK-like cells. On the other hand, IFN-gamma-treated tumor cells may bind to T-like cells but fail to trigger them to initiate further stages for lysis as effectively as NK-like cells.

Cell Division↗
PubMed1992

The amplitude of circadian FEV1 variation suitable for phase determination by cosinor analysis in stable asthmatic children.

To elucidate the criterion for amplitude of circadian FEV1 variation suitable for phase analysis, six FEV1 measurements within a day were made on 346 days in 125 stable asthmatic children aged 8 to 12 years. Since coefficient of variation (CV) of FEV1 within a day in nonasthmatic children in our laboratory is less than 5 percent, circadian FEV1 variations were divided into CV greater than or equal to 5 percent and CV less than 5 percent groups. Forty-two (12 percent) variations with significant fit of cosinor rhythm were CV greater than or equal to 5 percent. Troughs in 32 (76 percent) variations of the 42 were distributed between 12 PM and 6 AM, and the deviation was highly significant against a uniform distribution (p less than 0.001). This was consistent with nocturnal asthma. Thirty-five (10 percent) variations with significant fit of cosinor rhythm were CV less than 5 percent. Troughs in 12 (34 percent) variations of the 35 were distributed between 12 PM and 6 AM, and the deviation from a uniform distribution was nonsignificant. These suggest that 5 percent or more of CV of FEV1 may be clinically suitable for analysis of circadian FEV1 variation.

Asthma↗
PubMed1992

Dissociation of magnitude of relaxation from cyclic AMP levels in rabbit urinary bladder smooth muscles.

The effects of forskolin and isoproterenol on contractile force and cyclic AMP levels were compared in smooth muscle strips from rabbit urinary bladder dome. Both of forskolin and isoproterenol produced the time- and the dose-dependent relaxation and the time- and the dose-dependent increases in cAMP levels. The relaxant response to forskolin caused more slowly than that to isoproterenol. The two agents caused almost the same relaxant responses at same concentration. However, cAMP levels induced by forskolin was much more than those induced by isoproterenol. These results that amounts of cAMP in urinary bladder don't correlate with the relaxation responses in urinary bladder smooth muscle strips suggest that some forms of functional compartmentalization of cAMP may exist in the urinary bladder.

Animals↗
PubMed1992

Changes of autonomic receptors following castration and estrogen administration in the male rabbit urethral smooth muscle.

Effects of castration and estrogen administration on the distribution of autonomic receptors in the male rabbit urethral smooth muscle were examined. Thirty-eight mature Japanese white rabbits were used. Eight rabbits were used as untreated control. The other 30 rabbits were castrated and 10 of them were administered intramuscularly with 5 mg/kg estrogen 3 times a week for 4 weeks from 12 weeks after castration. Autonomic receptor densities in the urethral smooth muscle were measured by radioligand binding techniques. alpha 1-Adrenergic and muscarinic cholinergic receptor densities decreased significantly after castration and were not affected by estrogen administration. alpha 2-Adrenergic receptor density increased slightly after castration and markedly after estrogen administration. beta-Adrenergic receptors were not affected either by castration or estrogen administration. No significant changes were observed in any receptor affinities. These results demonstrate the effects of castration and estrogen administration on the autonomic receptors in the male rabbit urethral smooth muscle.

Animals↗
PubMed1992

Direct measurement of endothelin receptor in human bladder base and dome using 125I-endothelin.

The amount of endothelin receptor in human bladder base and dome was measured by radioligand binding techniques using 125I-endothelin-1 (125I-ET). Specimens were obtained from 5 patients who underwent total cystectomy under diagnosis of bladder cancer. 125I-ET bound to the bladder base with the KD value of 0.004 +/- 0.003 nM and to the bladder dome with the KD value of 0.007 +/- 0.003 nM. These values were not significantly different. The Bmax values (fmol/mg protein) of 125I-ET binding to human bladder were 2.74 +/- 2.81 to the base and 47.3 +/- 9.52 to the dome. There were much larger amount of endothelin receptors in the dome compared to the base. The existence of endothelin receptors in human bladder suggests the possible roles of endothelin on the human bladder function.

Endothelins↗
PubMed1992

Effect of cimetidine on the density of adrenergic alpha-1 and alpha-2 receptors in the rat whole prostate.

In order to study the antiprostatic effect of cimetidine, we measured adrenergic alpha-1 and alpha-2 receptors of the whole prostate of cimetidine-administered rats using radioligand binding techniques. Saturation experiments using 3H-prazosin and 3H-yohimbine revealed that there were significant amounts of alpha-1 and alpha-2 receptors in the rat whole prostate. There were more alpha-1 receptors than alpha-2 receptors in both the control and treated groups. In the treated group, the density of alpha-1 receptors showed little change, while that of alpha-2 receptors showed a significant decrease in comparison to the control group without changes in KD values. These data suggest that cimetidine affects the prostatic alpha receptors and consequently decreases the density of adrenergic alpha-2 receptors in the prostate.

Animals↗
PubMed1992

The quantitative difference in adrenergic alpha-1, alpha-2 and beta receptors between the prostatic and epididymal ends of dog vas deferens.

In order to study the regional differences in the distribution of adrenergic receptors of the vas deferens, we measured the amounts of adrenergic alpha-1, alpha-2 and beta receptors in prostatic, intermediate, and epididymal portions of the dog vas deferens using radioligand binding techniques. Saturation experiments with 3H-prazosin, 3H-yohimbine, and 3H-dihydroxy-alprenolol demonstrated that there were significant amounts of adrenergic alpha-1, alpha-2, and beta receptors, respectively, in these three portions. alpha-1 receptors existed most densely in the whole vas deferens. The prostatic portion was found to have the largest amounts of alpha-1 and alpha-2 receptors among three portions studied. beta-Receptors were distributed most densely in the intermediate portion. alpha-1, alpha-2, and beta adrenergic receptors show different distribution patterns throughout the whole length of vas deferens.

Animals↗
PubMed1992

[Chemical and serological study of lipopolysaccharide isolated from Shigella flexneri 88-893 possessing a new type-antigen].

The O-specific polysaccharide chain which represents a new type-antigen in lipopolysaccharide (LPS) of Shigella flexneri 88-893 was investigated. The O-polysaccharide chain was found to be composed of repeating units comprising rhamnose, N-acetylglucosamine and glucose (3:1:2). In the passive hemolysis test, group-6 antiserum of S. flexneri exhibited a high hemolytic titer (50% hemolysis titer: 7,900) against sheep red blood cells (SRBC) sensitized with intact 893 LPS, but virtually no hemolytic activity against SRBC sensitized with alkali-treated 893 LPS. None of the type-specific antisera (I-VI), showed any significant hemolytic titer against SRBC sensitized with either intact or alkali-treated 893 LPS. Thus, 893 LPS contained both the group-6 antigen and a new type-antigen which is distinct from any known type-antigen of S. flexneri.

Animals↗
PubMed1992

[Experimental studies of urinary incontinence. Effect of tiropramide on the urinary stage and evacuation].

Tiropramide, a tyrosine derivative, has an antispasmodic effect on the gastrointestinal smooth muscles and it is suggested that the effect is mediated by cAMP. Therefore, we studied the effects of tiropramide on the lower urinary tract smooth muscle functions. In animal experiments, the effects of tiropramide on vesicourethral smooth muscle contraction were investigated and cAMP and cGMP levels following tiropramide administration were measured in the vesicourethral and gastrointestinal smooth muscles. In clinical trials, five healthy volunteers and five patients with neurogenic bladder dysfunction were treated orally with tiropramide 300 mg a day for two weeks and examined for urodynamic parameters before and after tiropramide treatment. Tiropramide significantly inhibited contraction of the vesicourethral smooth muscle and the inhibitory effect upon the bladder was remarkable particularly at the lower concentrations. Tiropramide remarkably increased cAMP level but it had no effect on cGMP level in the bladder at the lower concentrations. Tiropramide at the lower concentrations did not affect cAMP and cGMP levels in the smooth muscles of the urethra, stomach and intestines. In the patients with neurogenic bladder dysfunction treated with tiropramide orally, the urine volume at first desire to void and maximum bladder capacity increased significantly, but the volume of residual urine did not significantly increase. In the healthy volunteers, there were no significant changes in urodynamic parameters. These findings indicate that tiropramide relaxes the urinary bladder smooth muscle via cAMP to increase the urinary bladder capacity.

Adult↗
PubMed1992

[Quantitative analyses of alpha-adrenoceptors in human prostatic capsule, adenoma and urethra--a comparison between normal prostate and hypertrophied prostate].

The adrenergic alpha-1 and -2 receptors in the three layers of the prostate (capsule, adenoma and urethra) were measured in humans with or without benign prostatic hypertrophy to examine the differences between the hypertrophied and non-hypertrophied (normal) prostate. Both alpha-1 and -2 receptors were found to exist in similar amounts in prostatic adenoma of both hypertrophied and normal prostate groups. In the prostatic capsule and urethra of both groups alpha-1 receptors were more abundant than alpha-2 receptors. Both alpha-1 and -2 receptors in all three prostatic layers were found to be increased significantly in hypertrophied group compared to normal group. Further more the increases in alpha-1 and -2 receptors of hypertrophied group were most remarkable in prostatic adenoma. These results seems to demonstrate that not only alpha-1 but also alpha-2 receptors play some important roles in benign prostatic hypertrophy.

Adenoma↗
PubMed1992

[Comparison of selective alpha-1 blockades for alpha-receptors in human hypertrophied prostatic adenomas].

The adrenergic alpha-1 and -2 adrenoceptors in six human hypertrophied prostatic adenomas were measured in the saturation experiment using 3H-prazosin and 3H-yohimbine. Not only alpha-1 adrenoceptons, but also alpha-2 adrenoceptors were found to exist in large amounts in prostatic adenomas. In the inhibition experiment selective alpha-1 antagonists inhibited the 3H-prozosin or 3H-yohimbine bindings to adenomas. The potency of alpha-1 antagonists in the order prazosin greater than bunazosin greater than alfuzosin greater than urapidil greater than terazosin and that of alpha-2 antagonists is urapidil greater than alfuzosin greater than terazosin greater than bunazosin greater than prazosin. These data suggest that urapidil, alfuzosin and terazosin may affect the human hypertrophied prostatic adenoma like phenoxybenzamine, nonselective alpha-1 antagonist, which was used for benign prostatic hypertrophy.

Adenoma↗
PubMed1992

Amino acid analogs of benanomicin A through desalaninebenanomicin A.

Desalaninebenanomicin A has been synthesized in good yield by the cleavage of the amido bond of benanomicin A using MEERWEIN's reagent. This is a useful intermediate to prepare amino acid analogs of benanomicin A. MEERWEIN's reagent reacts with totally protected benanomicin A to give a stable imino ether. After deprotection, the imino ether is treated with aqueous acetone at reflux to afford a methyl ester of desalaninebenanomicin A. Desalaninebenanomicin A was coupled with a variety of amino acids by the active ester method to afford new benanomicin analogs.

Amino Acids↗
PubMed1992

Total syntheses of bellenamine and its isomers.

The total synthesis of bellenamine was achieved by a modified CURTIUS procedure starting with D-beta-lysine. Bis(N-benzyloxycarbonyl)-D-beta-lysylglycine was converted to tris(N-benzyloxycarbonyl)bellenamine which was catalytically hydrogenated to yield bellenamine. D-beta-Lysine was synthesized from D-ornithine by the ARNDT-EISTERT homologation sequence. Three isomers, L-beta-lysyl, D- and L-lysyl congeners synthesized by a similar method, showed no antibacterial activities.

Anti-Bacterial Agents↗
PubMed1992

Production of bellenamine and new metabolites in a synthetic medium.

A streptomyces antibiotic, bellenamine has been produced in a simple synthetic medium consisting of D-galactose, dextrin, ammonium sulfate and calcium carbonate. Three new minor metabolites, N-(aminomethyl)succinamic acid, 1'-N-acetylbellenamine and D-beta-lysinamide have been isolated from the synthetic medium culture. They showed no antibiotic activity.

Ammonium Sulfate↗
PubMed1992

Biosynthesis of bellenamine by Streptomyces nashvillensis using stable isotope labeled compounds.

The biosynthesis of bellenamine was studied by feeding 13C and 15N labeled precursors to the synthetic medium culture of Streptomyces nashvillensis MD743-GF4. The high degree of incorporation of D-[1-13C]beta-lysine indicated that it is a direct intermediate, while supplemented L-beta-lysine repressed the production of bellenamine. [2-13C]Glycine was well incorporated into the C-1' of the open-chain aldoaminal structure. All four nitrogens of bellenamine were derived from [15NH4]2SO4 present in the synthetic medium. In the addition of L-lysine and glycine, [15NH4]2SO4 was highly incorporated into CONH. The feeding experiments of 13C labeled acetates suggested that the D-beta-lysine moiety was derived from L-lysine by catalysis of a new 2,3-aminomutase, and L-lysine was biosynthesized from acetates via the TCA cycle and diaminopimelic acid pathway.

Acetates↗