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Biomedical subjects

K Kawabe

Publications and source records attributed to K Kawabe.

At least 19 recordsLinked to original sources
PubMed1992

Binding characteristics of naftopidil and alpha 1-adrenoceptor antagonists to prostatic alpha-adrenoceptors in benign prostatic hypertrophy.

Binding properties of naftopidil and alpha 1-adrenoceptor antagonists to alpha-adrenoceptors in prostates from benign prostatic hypertrophy (BPH) were characterized by radioreceptor assays using [3H]prazosin and [3H]rauwolscine. Specific binding of [3H]prazosin and [3H]rauwolscine in human prostatic membranes was saturable and of high affinity, and it showed a pharmacological specificity which characterized alpha 1 and alpha 2-adrenoceptors, respectively. Naftopidil and several alpha 1 antagonists competed for prostatic [3H]prazosin binding in order: R-(-)-YM-12617 greater than prazosin greater than bunazosin greater than terazosin greater than naftopidil greater than urapidil, and the inhibitory effect (Ki = 11.6 nM) of naftopidil was 10 to 45 times less potent than quinazoline derivatives such as prazosin, bunazosin and terazosin. The potencies of these antagonists in competing for [3H]prazosin binding sites in human prostates correlated well with their pharmacological potencies (pA2). Scatchard analysis indicated that the decrease of prostatic [3H]prazosin binding by naftopidil was due to a marked increase in the Kd value without a change in the Bmax value. The inhibition of prostatic [3H]prazosin binding by naftopidil was reversible. Naftopidil also inhibited prostatic [3H]rauwolscine binding (Ki = 70.0 nM). Thus, it is suggested that naftopidil antagonizes alpha 1-adrenoceptors in human prostates in a competitive and reversible manner.

Adrenergic alpha-Antagonists↗
PubMed1992

Epitopes for CD1a, CD1b, and CD1c antigens are differentially mapped on Langerhans cells, dermal dendritic cells, keratinocytes, and basement membrane zone in human skin.

BACKGROUND: CD1 antigens are classified serologically into at least three groups, CD1a, CD1b, and CD1c, and many kinds of monoclonal antibodies are available for each subgroup of CD1 antigens. CD1a, CD1b, and CD1c antigens have been shown to be selectively and differentially expressed on epidermal Langerhans cells and dermal dendritic cells in normal human skin. OBJECTIVE: The objective was to further delineate the localization of epitopes of CD1 antigens in human skin. METHODS: We examined the immunoreactivity of 14 different CD1 antibodies (seven CD1a, five CD1b, and two CD1c antibodies) with the immunoperoxidase technique. We also studied the reactivity of NU-T2 (CD1b) antibody by immunogold electron microscopy. RESULTS: The epitopes for CD1a, CD1b, and CD1c antigens were differentially mapped on epidermal Langerhans cells, dermal dendritic cells, keratinocytes, the luminal portion of eccrine gland ducts, and the basement membrane zone in human skin. CONCLUSION: These CD1 antibodies may be useful to analyze the phenotypic alteration of immune and nonimmune cells in various skin diseases.

Antigens, CD↗
PubMed1992

Effect of various polyamino acids and D- and L-amino acids on the blood fibrinolytic system.

1. Comparative additional effects of 24 commercially obtained amino acids and their derivatives were studied by the whole blood clot lysis time (WBCLT) method. D-Arg and L-Lys (greater than 50 micrograms/ml) activated the fibrinolytic system, and poly-L-Glu (mol. wt 6000-90,000) (less than 50 micrograms/ml) were less effective. 2. Poly-L-Arg, poly-L-Lys and poly-(Lys-Ala-Glu-Tyr) accelerated the TPA inhibition in the presence of human plasma. 3. For in vivo experiments, 5 mg of poly-L-Glu were given intravenously to 10 rats. 4. The shortening of WBCLT and elevation of EFA (P less than 0.01) were found after 1 hr administration. 5. The main enzymes which increased in plasma were proved to be the endogenous plasminogen activators with mol. wt higher than 70,000, by zymography.

Amino Acid Sequence↗
PubMed1992

Epitope mapping of CD1a, CD1b, and CD1c antigens in human skin: differential localization on Langerhans cells, keratinocytes, and basement membrane zone.

CD1 antigens are classified into at least three groups, CD1a, CD1b, and CD1c. In order to delineate the localization of epitopes of CD1 antigens in human skin, we examined the immunoreactivity of fourteen different CD1 antibodies (seven CD1a, five CD1b, and two CD1c antibodies). The epitopes for CD1a, CD1b, and CD1c are differentially localized on epidermal Langerhans cells, dermal dendritic cells, keratinocytes, the luminal portion of eccrine gland ducts, and the basement membrane zone in normal human skin.

Antibodies↗
PubMed1992

[Primary tumor of the ureteral stump following nephrectomy for non-malignant disease. A case report].

Primary tumor in the ureteral stump is rare. A 66-year-old woman visited our hospital because of microscopic hematuria. She had undergone right nephrectomy for the contracted kidney 36 years ago. Intravenous pyelography and cystoscopy showed no positive findings for hematuria. But urine cytology indicated class V. The flexible ureterorenoscopy disclosed a nonpapillary sessile tumor in the ureteral stump. We also did the biopsy of the tumor under the direct vision before open surgery. The specimen showed transitional cell carcinoma, grade 3. The ureteral stump was successfully removed. The flexible ureterorenoscopy was most useful for the diagnosis in this case.

Aged↗
PubMed1992

[Percutaneous nephrostomy versus the placement of double pigtail ureteral stent for the treatment of postrenal failure secondary to malignancies].

From August 1989 through September 1991 we performed percutaneous nephrostomy under ultrasonic guidance in 26 kidneys of 25 patients. We also indwelled double pigtail ureteral stents by endoscopy in 14 kidneys of 13 patients. No patients died because of renal failure. The survival was dependent on progression of primary disease and performance status. Neither significant nor life-threatening complications were encountered. The difference in the improvement of renal function between nephrostomy group and stent group was not statistically significant. Although the indwelling ureteral stent method requires no external drainage bag, this method has certain drawback such as occasional obstruction of stent. Especially in poor risk patients, percutaneous nephrostomy technique seems to be better than placement of double pigtail ureteral stent in the treatment of postrenal failure secondary to malignancies.

Adult↗
PubMed1992

[Erectile function and urinary function].

In recent years, with the great advance in neuro-urophysiological concept, the evaluation and limitations of clinical investigation for sexual (erection) function and bladder (urinary) function are continuously changing, so they should be correctly recognized at the time of actual interpretation. The common problems on these functional tests are standardization of terminology and of methodology, and difference of individual sensitivity. From a viewpoint of respective evaluation and limitations, AVSS, NPT, papaverine test, BCR for erectile function tests and CM, UFM, EMG, complex urodynamics for urinary function tests are reviewed.

Autonomic Nervous System Diseases↗
PubMed1991

[3H]bunazosin, a novel selective radioligand of alpha 1 adrenoceptors in human prostates.

The binding properties of a new radioligand, [3H]bunazosin, were studied in membranes of human prostates with benign prostatic hypertrophy (BPH). Specific binding of [3H]bunazosin was saturable, reversible, and of high affinity (Kd = 0.55 +/- 0.04 nM). The density of [3H]bunazosin binding sites (Bmax) was 676 +/- 33 fmol/mg. protein. [3H]Bunazosin rapidly associated with its binding sites in membranes of human prostates and reached steady state by 20 min. at 25C. The rate constants for association and dissociation of [3H]bunazosin binding were calculated to be 0.11 +/- 0.01/nM/min. and 0.05 +/- 0.02/min. (n = 4), respectively. Seven alpha 1 adrenoceptor antagonists competed with [3H]bunazosin for the binding sites in the rank order: R-(-)-YM-12617 greater than prazosin greater than SGB-1534 greater than bunazosin greater than terazosin greater than naftopidil greater than urapidil. In parallel studies with [3H]bunazosin, the Kd and Bmax values for [3H]prazosin binding in human prostates were slightly lower. There was a similarity in the potency and rank order of seven alpha 1, adrenoceptor antagonists for the inhibition of [3H] bunazosin and [3H]prazosin binding in human prostates. The new [3H]bunazosin binding assay in human prostates is remarkable for its low degree of nonspecific binding as compared to [3H]prazosin, especially at high ligand concentrations. Thus, [3H]bunazosin may become a useful radioligand for the further analysis of the alph 1 adrenoceptor binding sites in human prostates.

Adrenergic alpha-Antagonists↗
PubMed1991

[Localization of alpha 1-adrenoceptors in hypertrophic prostate].

In order to determine the localization of alpha 1-adrenoceptors in human hypertrophied prostates, in vitro autoradiography was performed on the frozen specimens from 13 enucleated hypertrophied prostates with [125I]-HEAT (iodo-2-[beta-(4-hydroxyphenyl)-ethylaminomethyl] tetralone) and [3H]-prazosin. In vitro autoradiograms showed macroscopically the specific binding site on the areas seemed to the nodular area for [125I]-HEAT, but not so clear specific binding sites for [3H]-prazosin. Microscopic autoradiograms seemed to show binding sites located mainly on the interstitial beneath the gland, and partly on the basement membrane and epithelium of the prostatic gland. Further studies are needed to show clearer specific binding sites of alpha 1-adrenoceptors.

Aged↗
PubMed1991

[Cyclosporine induced nephrotoxicity and renal blood flow].

To elucidate the relationship between cyclosporine (Cs) nephrotoxicity and renal blood flow (RBF), we carried our experiments using rats. Adult male Wistar strain rats each weighing about 100 g were used. Rats were divided into 2 groups; the Cs group (Cs 50 mg/kg/day was intraperitoneally given for 10 consecutive days) and the control group (normal saline solution for 10 consecutive days). The renal cortical blood flow was measured in each group by electrolytic hydrogen gas clearance method. We also carried out renal angiography with barium sulfate (BaSO4). Then we measured blood vessel area/renal sagittal section area ratio and the diameter of interlobar arteries. The Cs group showed a significant decrease of renal cortical blood flow compared with the control group. On the other hand there was no significant change in renal angiogram. In conclusion, Cs decreased renal cortical blood flow. We suppose that vascular resistance increased following afferent arteriolopathy caused by Cs administration.

Animals↗
PubMed1990

Use of an alpha 1-blocker, YM617, in the treatment of benign prostatic hypertrophy. YM617 Clinical Study Group.

A recently synthesized alpha 1-blocker, (R)(-)-5-[2-[[2-(o-ethoxyphenoxy)ethyl]amino]propyl]-2- methoxybenzenesulfonamide hydrochloride (YM617), was evaluated in 270 patients with benign prostatic hypertrophy in a double-blind study. After 2 weeks on placebo the patients were assigned at random to 4 groups: group P--placebo, group L--0.1 mg., group M--0.2 mg. and group H--0.4 mg. of YM617. Comparing the placebo to the treatment period, subjective symptoms, such as nocturia and urgency, were significantly decreased in group H (p less than 0.01). The sensation of incomplete voiding was significantly improved in groups M and H (p less than 0.01). However, the differences among the groups were statistically insignificant. Residual urine volume was significantly decreased in groups L, M and H after instillation of saline into the bladder (p less than 0.01) but not in group P. The maximum and average flow rates were significantly increased in groups L, M and H (p less than 0.01) but not in group P. Average flow rate showed significant differences between groups M or H versus group P. Neither orthostatic hypotension nor a decrease in blood pressure was noted. Adverse side effects and changes in laboratory data were all slight and disappeared when the second tests were performed. In summary, the irritative and obstructive symptoms caused by benign prostatic hypertrophy were decreased and urodynamic studies were markedly improved by the alpha 1-blocker, YM617. The drug seems to be useful in the treatment of patients with benign prostatic hypertrophy.

Adrenergic alpha-Antagonists↗
PubMed1990

Density and localization of alpha 1-adrenoceptors in hypertrophied prostate.

Alpha-adrenoceptors have been considered to play an important role in the regulation of the voiding force. In order to determine the density and localization of the alpha-adrenoceptors in the prostate, binding assays for alpha-adrenoceptors were performed with [3H]prazosin and [3H] yohimbine in membrane preparations from enucleated hyperplastic prostate tissues. Furthermore, autoradiographic analysis of alpha-adrenoceptors in the sliced tissue specimens from benign prostatic hypertrophy was performed. Specific binding of both ligands were saturable and of high affinity in membrane preparations, and Scatchard analyses indicated Bmax = 104 fmole/mg. protein, Kd = 0.488 nM for [3H]prazosin, and Bmax = 41 fmole/mg, protein, Kd = 1.83 nM for [3H] yohimbine. Bmax and Kd for [3H]prazosin were greater in the adenoma than in the submucosal tissue of the prostatic urethra. No relationship was noted between the size of enucleated prostate and the density of alpha-adrenoceptors. Image analysis of autoradiograms using [3H]prazosin showed specific binding sites could not be clearly demonstrated, but only [125I]HEAT slightly exposed specific binding sites in the prostate.

Aged↗
PubMed1979

Influence of steric factors on oxygen binding. I. Studies on 2,4-diisopropyldeuteroheme-myoglobin.

Sperm whale apomyoglobin was recombined with 2,4-diisopropyldeuterohemin to form 2,4-diisopropyldeuteroheme-myoglobin and its various physico-chemical properties were investigated to get an insight into the structural and functional role of the peripheral vinyl groups. 2,4-Diisopropyldeuteroheme-myoglobin showed a four times lower oxygen affinity at 25 degrees C and larger enthalpy and entropy changes of oxygenation than the corresponding values of native myoglobin. 2,4-Diisopropyldeuteroheme-metmyoglobin shows a pKa value of 9.68 which is higher than those of native metmyoglobin and mesoheme-metmyoglobin. The rate of autooxidation of oxy-form was about seven times larger in 2,4-diisopropyldeuteroheme-myoglobin than in native myoglobin. The electron-donating effect of isopropyl groups does not give straightforward explanation for these anomalous properties of 2,4-diisopropyldeuteroheme-myoglobin. It is proposed that site and stereospecific van der Waals' interaction between the polypeptide side chains and the peripheral 2,4-diisopropyl groups may weaken the interaction between the bound oxygen molecule and the distal His, resulting in the decrease in the stability of oxyform.

Animals↗