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Biomedical subjects

K Kihara

Publications and source records attributed to K Kihara.

At least 109 records · Page 6Linked to original sources
PubMed1994

Effects of prostaglandins E1, E2 and F2 alpha on contractility and cAMP and cGMP contents in lower urinary tract smooth muscle.

Prostaglandin (PG) E1, E2 and F2 alpha contracted smooth muscle strips from male adult rabbit urinary bladder. Contractile responses to each PG were significantly greater in urinary bladder body than in urinary bladder base. The magnitude of contractile response to each PG was F2 alpha > E2 > E1 in both of the bladder body and the bladder base. These contractions were almost completely eliminated by a calcium entry blocker, verapamil but not by atropine, phentolamine, propranolol or tetrodotoxin. PG E1 and E2 significantly relaxed the male rabbit urethral smooth muscle strips, whereas PG F2 alpha contracted the urethral smooth muscle strips. Cyclic adenosine monophosphate (cAMP) but not cyclic guanosine monophosphate (cGMP) increased significantly after administration of PG E1 or E2 in the urethral muscle strip. These results suggest that the regional differences in the magnitude of contractile responses to PG E1, E2 and F2 alpha between the bladder dome and the base and also suggest the contractile differences of PG E1 and E2 for the urinary bladder and the urethra; contractions for bladder and relaxations for urethra. These results also demonstrate that contractions induced by PG E1, E2 and F2 alpha in urinary bladder smooth muscles and by PG F2 alpha in urethral smooth muscles are mainly mediated by calcium influx and that relaxations induced by PG E1 and E2 in urethral smooth muscles are mediated by cAMP but not by cGMP.

Alprostadil↗
PubMed1993

Regulation of the bladder neck closure by lumbar splanchnic nerves at ejaculation in the dog.

To clarify the role of canine thoracolumbar splanchnic nerves for bladder neck closure during ejaculation, these nerves of adult male mongrel dogs were exposed under anesthesia using ketamine hydrochloride and pentobarbital, and electrical stimulation and anatomical dissection studies were performed. Bladder neck closure by the stimulation of each sympathetic nerve was monitored with a 10 Fr silicon catheter equipped with pressure-sensitive rubber balloon placed at the bladder neck. The dissection study revealed that canine thoracolumbar splanchnic nerves consisted of two nerve groups: one branching from the sympathetic trunks at thoracic and L1 ganglia, reaching caudal mesenteric plexus (CMP) through the anterior wall of the aorta, the other branching from the sympathetic trunks at level L2-L5 ganglia, reaching CMP through the posterior side of the bilateral spermatic arteries. The former were designated intermesenteric splanchnic nerves, the latter lumbar splanchnic nerves. No bladder neck closure was observed by electrical stimulation of the distal end of severed intermesenteric splanchnic nerves or of the sympathetic trunks at the lumbopelvic level among 10 dogs examined. At least one lumbar splanchnic nerve generated the closure in all 10 dogs and generally, a few lumbar splanchnic nerves, generated the closure. The results indicate that bladder neck closure during ejaculation is generated by lumbar splanchnic nerves regardless of their branching levels from lumbar sympathetic ganglia, but not by either intermesenteric splanchnic nerves or pelvic sympathetic trunks.

Animals↗
PubMed1993

Species differences in cAMP production and contractile response induced by beta-adrenoceptor subtypes in urinary bladder smooth muscle.

The contractile activity of urinary bladder smooth muscle has been shown to be inhibited by beta-adrenoceptor agonists. beta-Adrenoceptor subtypes in the rabbit, canine, and human urinary bladder smooth muscles were studied by measuring changes in contractile forces and in intracellular cAMP concentrations on administration of beta-adrenoceptor agonists. In the rabbit bladder, only beta 2-receptors may have functional roles in the detrusor muscle, while both beta 1- and beta 2-receptors may have functional roles in the detrusor muscles of the canine bladder. Only beta 2-receptors may have functional roles in the human detrusor muscles, similar to the rabbit detrusor muscles. Thus, species differences may exist in beta-adrenoceptor subtypes in smooth muscles of urinary bladder.

Animals↗
PubMed1993

Isolation and mapping of microsatellites from a library microdissected from the Werner syndrome region, 8p11.2-p22.

We have constructed a new genetic linkage map of the Werner syndrome (WRN) region, using microsatellites from a library which was developed by a chromosome microdissection and enzymatic amplification method. These microsatellites were used to genotype members of CEPH families using a simplified detection system of polymerase chain reaction (PCR) products. Two-point analysis was used to assign 4 microsatellite markers relative to each marker and other markers reported in the CEPH public data base. We confirmed that these 4 markers are located to the WRN region, 8p11.2-p22. Such microsatellites microdissected from the definite chromosome region may be useful for positional cloning.

Base Sequence↗
PubMed1993

Low-density lipoprotein receptor mutation that deletes exons 2 and 3 by Alu-Alu recombination.

A deletion mutant in the low density lipoprotein receptor gene of a Japanese patient with heterozygous familial hypercholesterolemia was analyzed. Genomic Southern blotting showed abnormal size restriction fragments with BamHI (7.8 kb), EcoRI (3.8 kb), BglII (17 kb), KpnI (> 23 kb), EcoRV (13 kb), and XbaI (14 kb). The abnormal EcoRI fragment, 3.8 kb, was cloned into lambda phage vector, and the deleted region of 10 kb including exons 2 and 3 was identified. The nucleotide sequence around the deletion joint was determined. The sequence of the eight nucleotides in the deletion-joint region of the mutant gene was identical to the corresponding sequences of both introns 1 and 3 of the normal gene. The deletion seemed to occur by an unequal recombination between the Alu-like sequences in the same direction in introns 1 and 3.

Base Sequence↗
PubMed1993

Control of bilateral seminal emissions from ejaculatory ducts by a lumbar splanchnic nerve.

To investigate the route of efferent signals for seminal emissions from ejaculatory ducts (SEEDs), canine lumbar splanchnic nerves (LSNs) were electrically stimulated. SEED was confirmed by visual verification of seminal flow into the exposed posterior urethra. In intact dogs, electrical stimulation of an LSN caused bilateral SEEDs in 13 of 16 dogs examined, with a greater volume at the stimulated side. After transection of a unilateral hypogastric nerve, bilateral SEEDs occurred by electrical stimulation of the contralateral LSN in 11 of 14 dogs with a greater volume at the stimulated side and by the stimulation of the ipsilateral LSN in 13 of 15 dogs with a greater volume at the contralateral side. Contraction pressure of the epididymal tail under the same conditions harmonized with the above results. We conclude that each LSN generates bilateral SEEDs by sending signals to bilateral epididymal tails and that some of the signals through each LSN cross to the other side at the caudal mesenteric plexus and/or the prostatic plexus.

Animals↗
PubMed1993

Close linkage of the gene for Werner's syndrome to ANK1 and D8S87 on the short arm of chromosome 8.

Werner's syndrome (WRN) is a rare autosomal recessive disorder characterized by the appearance of features of premature aging in a young adult. Skin fibroblasts from WRN patient demonstrate slow growth, reduced life span in vitro and mutator phenotype. The genetic defect in WRN is unknown. We have studied 23 WRN patients mainly from first or second cousin marriage and have applied homozygosity mapping to search for the WRN locus. A peak lod score of 5.58 at a recombination fraction of 0.03 was obtained with D8S87. We confirmed that the WRN locus was located on the short arm of chromosome 8, 8p11.2-p12.

Adult↗
PubMed1993

[Subtypes of alpha 1-adrenoceptors in urinary bladder and urethral smooth muscle and prostatic adenoma].

Two alpha 1-adrenoceptor subtypes (alpha 1A and alpha 1B) have been distinguished by competitive antagonists and alkylating agent chloroethylclonidine (CEC). The CEC-insensitive subtype (alpha 1A) had been suggested to selectively activate Ca2+ influx through Ca-channels in smooth muscle cell membrane. We examined the effects of WBC4101, CEC and verapamil on contractile responses to phenylephrine in rabbit aorta, urinary bladder and urethral smooth muscle and in human prostatic adenoma to examine the alpha 1-adrenoceptor subtypes in these tissue. Pretreatment with WB4101 caused a large shift to the right for phenylephrine-induced dose response curves and verapamil decreased the phenylephrine-induced contractions of rabbit aorta, urinary bladder and urethral smooth muscles and human prostatic adenomas. CEC inhibited only phenylephrine induced contractions of human prostatic adenomas. The pA2 value for WB4101 was significantly lower in human prostate than in rabbit aorta, urinary bladder and urethra. These results suggest that functional alpha 1-adrenoceptor subtypes involve alpha 1A and alpha 1B in human prostatic adenoma, while only alpha 1A in rabbit aorta, urinary bladder and urethral smooth muscles.

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

[Intra-arterial CDDP and CDDP plus THP-ADM therapy for bladder cancer].

From 1983 to 1988, 20 patients (group A: 3 stage T1, 4 stage T2 and 13 stage T3-4 tumors) with bladder cancer were treated with single injection of CDDP (150-200 mg/body), and 28 patients (group B: 4 stage T1, 9 stage T2 and 15 stage T3-4 tumors) were treated twice with injection of CDDP (100 mg/m2) and THP-ADM (40 mg/m2) mixture from the internal iliac artery. As a rule, one half of the agents was equally given for the both sides, while 75% dose was given to the tumor side to the case with unilateral localized tumors. Then total or partial cystectomy was followed. When residual invasive cancer was pathologically present in operative specimens, patients underwent three to six courses of adjuvant chemotherapy including CDDP. Clinical response rate (CR+PR) to the intra-arterial chemotherapy in group A and B were 39% and 62%, respectively. Pathological response rate (grade 3 and grade 4 by Oboshi and Shimozato classification) were 17% in both group. After total cystectomy, the 2-year cancer specific survival rates of 17 patients in group A and 22 patients in group B were 75% and 59%, respectively. The 2-year cancer specific survival rates of 8 patients in group A and 10 patients in group B with pT3b were 63% and 54%, respectively. No cancer death occurred thereafter in the patients of group A during another three years. The 3-year cancer specific survival rate of 9 patients after partial cystectomy (3 in group A, 6 in group B) was 86%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

[DNA diagnosis of myotonic dystrophy in a family].

Myotonic Dystrophy (MyD) is the most common form of muscular dystrophy affecting adults. Recently a heritable unstable DNA sequence containing CTG repeat in the region associated with MyD was detected. We have analyzed DNA from the members of an MyD family using Southern hybridization and PCR method. Unaffected individuals of this family had no expansion of unstable DNA sequence after EcoRI and BglI digestion and had CTG repeats under 12, while affected individuals had more than 0.2 kb expansion of DNA sequence and had over 50 CTG repeats. We confirmed that the length of unstable MyD region correlated with severity of the disease in a family and that the diagnosis of MyD had been improved by development of DNA probes for the CTG repeats.

Adult↗
PubMed1992

Direct effect of basic fibroblast growth factor on gene transcription in a cell-free system.

Recent findings on the translocation of intact fibroblast growth factor (FGF) into the cell nucleus suggest that it functions directly in nuclear events. We examined the effect of human basic FGF (bFGF) on gene transcription in a cell-free system. When mouse genes encoding phosphoglycerate kinases 1 and 2 (Pgk-1 and Pgk-2) were transcribed by using nuclear extracts of Ehrlich ascites tumor cells, FGF affected transcription in different ways: in the presence of bFGF, transcription of the Pgk-1 gene was inhibited, whereas that of the Pgk-2 gene was enhanced. When viral genes were tested, transcription of the adenovirus major late DNA was slightly stimulated but that of the adenovirus early E1A DNA or the human immunodeficiency virus DNA was not changed by the addition of bFGF. Moreover, the presence of a distinct 5' upstream region of the Pgk-2 gene, which includes a negative cis-acting element, was required for transcription stimulation by bFGF. These results suggest that bFGF can regulate transcription directly in the nucleus in a gene-specific manner.

Adenovirus Early Proteins↗