Biomedical subjects

Kimio Sugaya

Publications and source records attributed to Kimio Sugaya.

10 recordsLinked to original sources

PubMed2002

Capillary electrophoresis assay of alanine:glyoxylate aminotransferase activity in rat liver.

We measured hepatic alanine:glyoxylate aminotransferase (AGT) activity using capillary electrophoresis. After rat liver homogenate was incubated in the presence of substrates and pyridoxal 5'-phosphate, the pyruvate and glycine produced by AGT were measured. The AGT activity was 10.02+/-0.31 micro mol pyruvate/h/mg protein and 10.21+/-0.15 micro mol glycine/h/mg protein. This method is relatively simple and shows superior sensitivity, allowing the measurement of enzyme activity in 5 micro g of protein. Therefore, it appears to be suitable for laboratory use and may also have advantages for measuring AGT activity in liver biopsy specimens.

Animals↗

PubMed2002

Inhibitory control of the urinary bladder in the neonatal rat in vitro spinal cord-bladder preparation.

Urinary bladder activity of the neonatal rat is tonically inhibited by neural input from the spinal cord passing through axons in the pelvic nerve. The present study was undertaken to examine the organization of this inhibitory mechanism using in vitro spinal cord-bladder preparations of neonatal rats in which the lumbosacral dorsal roots (DRs) or ventral roots (VRs) were transected. Isovolumetric bladder contractions occurring spontaneously or induced by electrical stimulation of the bladder wall (ES-BW) were measured. In DR transected (DRT) preparations, removal of the spinal cord significantly enhanced (50-59%) the amplitude of spontaneous and ES-BW-evoked bladder contractions; whereas in VR transected (VRT) preparations removal of the spinal cord produced only a small enhancement (6.7-12%). However, in VRT preparations, electrical stimulation of the dorsal roots reduced the amplitude of spontaneous contractions, an effect blocked by a nicotinic ganglionic blocking agent, hexamethonium. In DRT preparations, MK-801 enhanced the amplitude of spontaneous and ES-BW-evoked contractions. These results demonstrate that bladder activity of the neonatal rat is tonically inhibited by input from the lumbosacral spinal cord via parasympathetic pathways in the pelvic nerve. The inhibitory outflow is not dependent upon afferent input to the cord but is facilitated by NMDA glutamatergic transmission in the spinal cord. Antidromic activation of afferent axons also appears to induce inhibition in the bladder via a mechanism involving nicotinic cholinergic receptors. These findings suggest that spinal and peripheral inhibitory mechanisms may play an important role in controlling voiding in the neonatal rat.

Animals↗

PubMed2002

Effects of intrathecal injection of tamsulosin and naftopidil, alpha-1A and -1D adrenergic receptor antagonists, on bladder activity in rats.

The effects of intrathecal injection of tamsulosin (an alpha-1A adrenergic receptor antagonist) and naftopidil (an alpha-1D adrenergic receptor antagonist) on isovolumetric bladder contraction were investigated in rats under urethane anesthesia. Intrathecal injection of tamsulosin (10-30 microg) or naftopidil (0.1-30 microg) transiently abolished isovolumetric rhythmic bladder contraction. Following the recovery of bladder contraction, the interval between contractions was the same as the control value before the injection. The amplitude of bladder contraction was decreased by intrathecal injection of naftopidil (3-30 microg), but not by tamsulosin. Therefore, in addition to the antagonistic action of these agents on the alpha-1 adrenergic receptors of prostatic smooth muscle, both agents (especially naftopidil) may also act on the lumbosacral cord, and thus may improve collecting disorders in patients with benign prostatic hyperplasia.

Adrenergic alpha-1 Receptor Antagonists↗

PubMed2002

Biochemical and morphological effects of bladder pumping on the urinary bladder in rats.

AIMS: To study the influence of bladder pumping on the urinary bladder in 44 female rats. METHODS: Under halothane anesthesia, a urethral catheter was inserted into the bladder of 27 rats, and air (0.4-0.8 mL) was pumped in and out of the bladder at 0.5 cycles/second for a period of 5 minutes. Twenty-four hours after pumping, the bladder was harvested for measurement of the tissue levels of myosin, actin, and nerve growth factor, as well as for electron microscopy. In nine of the 27 rats, cystometry was performed without anesthesia before and 1, 7, 30, and 90 days after bladder pumping. The remaining 17 rats that did not undergo pumping were anesthetized and their bladders were harvested as a control. RESULTS: Bladder pumping increased the bladder capacity and decreased the maximum bladder contraction pressure, but did not increase the residual volume. Bladder pumping also increased the tissue level of nerve growth factor and decreased the levels of myosin and actin. Electron microscopy showed degeneration of bladder smooth muscle cells and nerve fibers after bladder pumping, as well as derangement and disruption of collagen fiber bundles in the bladder wall. These functional and morphological effects of pumping disappeared within 90 days. CONCLUSIONS: Bladder pumping therapy appears to have various effects on the bladder wall collagen fiber bundles, smooth muscle cells, and nerves.

Actins↗

PubMed2002

Molecular analysis of adrenergic receptor genes and interleukin-4/interleukin-4 receptor genes in patients with interstitial cystitis.

PURPOSE: Interstitial cystitis is a chronic and sterile inflammatory disease of the bladder. Clinically many patients with interstitial cystitis also have allergic or autoimmune diseases. Recent studies have suggested that allelic variations in the adrenergic receptor beta2 gene, the interleukin (IL)-4 gene and its receptor gene are closely associated with immune diseases. Therefore, we studied adrenergic receptor genes alpha1d (ADRA1d), beta2 (ADRB2) and beta3 (ADRB3), and IL-4/IL-4 receptor genes in patients with interstitial cystitis. MATERIALS AND METHODS: We studied 55 patients with interstitial cystitis and 228 controls. Genomic DNA was extracted from a whole blood sample collected from each subject. We analyzed 5 gene polymorphisms (G404781T, Arg16Gly, Trp64Arg, C589T and Ile50Val) per gene (ADRA1d, ADRB2, ADRB3, IL-4 and IL-4 receptor, respectively) and their relationship to interstitial cystitis. RESULTS: The frequency of the Arg/Arg genotype of the ADRB2 gene and the TT genotype of the IL-4 gene were significantly higher in patients with interstitial cystitis than in controls. A significant difference of ADRA1d genotype prevalence was also observed. However, there were no remarkable differences of IL-4 receptor or ADRB3 genotype prevalences. CONCLUSIONS: Variants of the ADRB2, ADRA1d and IL-4 genes may be related to a predisposition to interstitial cystitis.

Cystitis, Interstitial↗

PubMed2002

[The effects of the antagonists of muscarinic acetylcholine receptor subtypes in rat brain on urinary bladder contraction].

BACKGROUND: Pontine micuturition center and storage center are controlled by upper brain. Pharmacological and molecular biological data indicate the distribution of muscarinic receptor subtypes in rat brain, however, the effect of central muscarinic cholinergic mechanisms on the bladder activity has not been evaluated. We investigated the diversity of effect of each subtype in rat brain. METHODS: The muscarinic agents such as muscarine (non-specific agonist), atropine (non-specific antagonist), pirenzepine (M1 receptor antagonist), AF-DX116 (M2 receptor antagonist) and 4-DAMP (M3 receptor antagonist) were administrated with intracerebroventricular injection (I.C.V. group) or intravenous injection (i.v. group). The drug effects on rhythmic bladder contraction were investigated. RESULTS: In I.C.V. group, the bladder contraction pressure were reduced by atropine, pirenzepine and 4-DAMP. The contraction time were shortened by pirenzepine and 4-DAMP but extended by AF-DX116. The contraction frequency was decreased by AF-DX116. Whereas AF-DX116 in i.v. group reduced the contraction pressure but did not cause any changes of the contraction time and the frequency. Other agents in i.v. group had same tendency with those of I.C.V. group except for intensity. CONCLUSION: That is to say AF-DX116 in I.C.V. group facilitate both micuturition center and storage center. In other words, these data indicate M2 receptor in rat brain inhibits both micurition and storage center. In addition, the effect of AF-DX116 in brain suggests that the development of new drug which proceed to central neuron system might provide a new treatment of neurogenic bladder.

Animals↗

PubMed2002

[Risk factors for duration of urinary incontinence after radical prostatectomy].

PURPOSE: In this study, we examined risk factors for duration of incontinence after radical prostatectomy at our hospital. MATERIALS AND METHODS: From April 1988 to March 2000, 45 patients with prostate cancer underwent retropubic radical prostatectomy at our hospital. Thirty-eight of 45 patients could be followed up. The patients' age, height, weight, body mass index (BMI), preoperative prostatic specific antigen level, clinical stage, nerve-sparing surgery or none, operation time, bleeding volume, resected prostate weight, cancer positive or negative at surgical margins, postoperative stage, radiation therapy or none, anti-androgen therapy or none, duration of postoperative incontinence, and follow-up period were examined. RESULTS: All patients had postoperative stress incontinence, and no one had urge incontinence. Medians of duration of postoperative incontinence and follow-up period were 5.5 and 12 months, respectively. When the patients were divided into 2 groups by the value of each parameter, postoperative anti-androgen therapy (chi 2 test, p = 0.0429) and high BMI (> or = 25.0 kg/m2, p = 0.0206) were related to the long duration (> or = 5.5 months) of postoperative incontinence. CONCLUSION: These results suggest that common factors are involved in the etiology of prolonged incontinence after radical prostatectomy and genuine stress incontinence in women. Therefore, both body weight control and pelvic floor muscle exercise might be also important for the treatment of incontinence after radical prostatectomy.

Aged↗

PubMed2002

[Analysis of immune response to tumor specific antigen restricted to HLA class II on renal cell carcinoma and its recognition mechanism].

PURPOSE: In this study, we studied the immune response against to human renal cell carcinoma and its antigensity. METHODS: Mixed lymphocyte tumor culture test was performed using tumor cells as stimulator cells, peripheral blood lymphocytes from tumor patient (autologous) or healthy volunteer (allogeneic) as responder cells, and tumor cells or peripheral blood lymphocytes from tumor patient as target cells. The cytotoxic activity of mixed lymphocyte tumor culture test was assayed by 51Cr-relase test, and cell surface antigens presented on tumor cells or peripheral blood lymphocytes were assayed by antibody block test. RESULTS: The cytotoxic activity against to tumor cells was induced from allogeneic peripheral blood lymphocytes by mixed lymphocyte tumor culture test. Its cytotoxic activity was inhibited by anti-CD8 antibody treatment of peripheral blood lymphocytes and anti-HLA class II antibody treatment of tumor cells. Furthermore, allogeneic peripheral blood lymphocytes induced to tumor cells did not damage peripheral blood lymphocyte of the tumor patient derivation. CONCLUSION: Renal cell carcinoma may express tumor specific antigen restricted to HLA class II antigens that could be recognized by allogeneic CD8 positive T lymphocytes.

CD8 Antigens↗

PubMed2002

Partial nephrectomy using a vascular sealing system.

PURPOSE: The margin resected at partial nephrectomy is so fragile that it is not easy to control bleeding. To control bleeding we developed a new technique using a vascular sealing system for hemostasis. MATERIALS AND METHODS: A 38-year-old woman with renal cell carcinoma underwent partial nephrectomy. A tumor was identified in the lower pole of the left kidney. The kidney was exposed with the perinephric fat and the main renal artery was identified and clamped. Along the incision line the renal cortex was cut sharply to 10 to 15 mm. deep. A jaw of the vascular sealing system was carefully inserted into the sinus space between the renal pelvis and medulla. The jaws were gradually clamped together, and the renal medulla and vasculature were compressed and then sealed completely by computer controlled current. Because the renal pelvis was involved by tumor, the pelvis was removed partially with the tumor and approximated with absorbable sutures. RESULTS: Before reperfusion only a few additional sutures were needed for hemostasis. Warm ischemia time was 19 minutes. CONCLUSIONS: Our technique seems to be a promising method of rapidly achieving reliable hemostasis for partial nephrectomy.

Adult↗

PubMed2002

Association of vitamin D receptor gene polymorphism with urolithiasis.

PURPOSE: Recent studies suggest that allelic variations of the vitamin D receptor (VDR) gene can influence calcium absorption and excretion. Therefore, we studied the association of VDR gene polymorphism with urolithiasis. SUBJECTS AND METHODS: We studied 83 patients with urinary stones and 83 controls. Patients were scored for certain clinical characteristics, including long axis diameter of the largest stone (1 point-less than 10 mm. and 2-10 mm. or greater), number of stones (1 point-1 and 2-multiple) and history of calcium stone disease (1 point-absent and 2-present). They were classified into 3 groups according to the total score, including low-3, intermediate-4 or 5 and high-6 points. The 2 VDR gene polymorphisms TaqI and ApaI were detected by polymerase chain reaction-restriction fragment length polymorphism and their relationships with the urinary calcium level were examined. RESULTS: The incidence of TaqI Tt and tt genotypes was significantly higher in the high score group than in controls. The TaqI t allele was associated with a 5.2-fold increase in the risk of severe stone disease. The urinary calcium level in patients with the Tt and tt genotypes was also higher than in those with the TT genotype. The rate of the ApaI genotype was not different in the high score group and controls. CONCLUSIONS: The TaqI t allele of the VDR gene may be a risk factor for severe stone disease and recurrent stones.

Adult↗