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S Oku

Publications and source records attributed to S Oku.

At least 19 recordsLinked to original sources
PubMed2003

Overexpression of cyclooxygenase-2 in high-grade human transitional cell carcinoma of the upper urinary tract.

OBJECTIVE: To examine cyclooxygenase (COX)-2 expression (a key enzyme in the synthesis of prostaglandins, and involved in carcinogenesis of human epithelial tumours) in human transitional cell carcinomas (TCCs) of the renal pelvis and ureter, and to determine whether COX-2 expression correlates with the clinicopathological characteristics of the disease. MATERIALS AND METHODS: Specimens from 144 patients with TCC of the upper urinary tract who had undergone nephroureterectomy were analysed immunohistochemically, and 23 were also analysed by immunoblotting. RESULTS: Immunoblot analysis showed COX-2 immunoreactivity in 17 (74%) of 23 tumours, but not in normal transitional epithelium. COX-2 was localized to the cytoplasm of cancer cells and expressed in 108 (75%) of 144 tumours, as assessed by immunohistochemical analysis. COX-2 expression correlated with tumour grade (P < 0.008), being detected in one of nine grade 1, 77 (79%) of 97 grade 2 and 30 (79%) of 38 grade 3 tumours. Other variables including tumour stage were not associated with COX-2 expression. CONCLUSIONS: We show for the first time that COX-2 is frequently expressed in TCC of the upper urinary tract and is associated with the degree of tumour cell differentiation, indicating that COX-2 may be involved in TCC carcinogenesis at an early and/or late stage, and could be a useful target for chemoprevention of this type of cancer.

Aged↗
PubMed2001

Pharmacological actions of AH-9700 on micturition reflex in anesthetized rats.

In radioligand binding assays, AH-9700 (1-[2-(3,4-dihydro-6,7-dimethyl-2-naphthalenyl)ethyl]pyrrolidine fumarate) had high affinity for sigma receptors and moderate affinity for muscarinic receptors. The affinity of AH-9700 for sigma(1) receptors was significantly reduced in the presence of 5'-guanylyl-imidodiphosphate (GppNHp). In isolated bladder strips of rats, AH-9700 inhibited carbachol-induced contractions. In anesthetized rats, i.v. administration of AH-9700 and typical sigma receptor ligands, (+)-pentazocine and 1,3-di-o-tolylguanidine (DTG), but not oxybutynin, dose-dependently inhibited rhythmic isovolumetric reflex bladder contractions. AH-9700 and oxybutynin suppressed the amplitude of rhythmic bladder contractions. On the other hand, at doses lower than used i.v., the i.c.v. administration of AH-9700 or the sigma receptor ligands inhibited rhythmic bladder contractions without suppressing the amplitude. This inhibitory effect of AH-9700 was markedly reduced by pretreatment with i.c.v. pertussis toxin. These results suggest that AH-9700 exerts a marked anti-micturition reflex effect through central sigma receptors possibly related to pertussis toxin-sensitive Gi/o-proteins and a moderate spasmolytic effect based on its peripheral anti-muscarinic activity.

Anesthesia↗
PubMed2000

Comparison of the in vitro caffeine-halothane contracture test with the Ca-induced Ca release rate test in patients suspected of having malignant hyperthermia susceptibility.

PURPOSE: We compared the results of the in vitro caffeine-halothane contracture test (CHCT) according to the protocols of the North American Malignant Hyperthermia Group (NAMHG) and the European Malignant Hyperthermia Group (EMHG) with the Ca-induced Ca release (CICR) rate test in the same patients with suspected malignant hyperthermia (MH). METHODS: Five normal controls and 16 patients suspected of having MH susceptibility were studied. Muscle biopsies were usually obtained from the musculus vastus lateralis. Diagnostic cutoff points and procedures for CHCT protocols were as described in the original and renewal versions of NAMHG and EMHGs. The CICR rate test was performed according to the protocol reported by Endo et al. RESULTS: All five normal controls and two patients with abortive MH, two with postoperative hyperthermia, and three with high serum creatine kinase levels were normal in the three tests. Three patients with MH reactions and one patient with a history of masseter spasm were classified as MH positive according to NAMHG criteria and MH susceptible and MH equivocal according to EMHG criteria. There were five cases with discordant results between the CHCT and CICR rate tests. CONCLUSION: We propose that muscle biopsy for diagnosis of MH susceptibility should combine the CHCT with the CICR rate test, which may identify the defective site of Ca release channels.

Journal Article↗
PubMed2000

Interactions among protein molecules in freeze-gel of soymilk and protein structures in heated soymilk during cooling.

To estimate the interactions forming in soymilk freeze-gel, lyophilized gel was extracted successively with various solvents. A mixture of urea, sodium dodecyl sulfate (SDS), and 2-mercaptoethanol (2-ME) dissolved the proteins effectively. The thiol-disulfide exchange reactions and hydrophobic interactions were shown to have a complex relation with a three-dimensional network. The addition of SDS or 2-ME resulted in an incomplete gel or no precipitation of soymilk. In our previous paper (Shimoyamada et al. Food Sci. Technol. Res. 1999, 5, 284-288), the significance of precooling to form small, homogeneously distributed ice crystals in soymilk was reported. In this study, precooling was shown to maintain the partially denatured structures of soybean proteins in soymilk that had unfolded due to heat treatment. These phenomena were considered to be other important functions of precooling in freeze-gelation.

Animals↗
PubMed1999

[Anesthetic and perioperative management of 1000 cases of congenital heart surgery--massive vasodilator therapy and early extubation].

We report our anesthetic and perioperative management of 1000 cases of congenital heart surgery in Okayama University Medical School over the last six and a half years. Most of these patients were anesthetized by fentanyl and all patients were managed in our ICU postoperatively. Although hospital death rate in all patients was 4.5%, almost half of dead patients were patients with hypoplastic left heart syndrome. Neonatal mortality rate has been still high, 18.9%, which has been our main problem. We tried to extubate patients with complex congenital heart diseases earlier postoperatively for the last three years, using massive dose of vasodilators without nitric oxide.

Adolescent↗
PubMed1998

Twenty-five types of T-cell receptor Vbeta family repertoire in patients with Kawasaki syndrome.

UNLABELLED: Recently, a possible relationship between Kawasaki syndrome (KS) and superantigen has been discussed since the report of selective expansion of specific Vbeta family in the acute phase of KS. To further investigate the relationship between KS and superantigens, we examined 25 types of T-cell receptor Vbeta family repertoire in patients with KS using the reverse transcription polymerase chain reaction. This is the first attempt to examine all of 25 Vbeta families in KS. A non radioisotope method was used to quantify mRNA so that the experiment was safer, simpler, and faster. An expression index (EI) for each Vbeta was defined as: (the amount of each Vbeta mRNA)/(the sum of all Vbeta mRNA) x 100. Ten patients with KS and ten normal children were studied. The Vbeta9 and Vbeta15 of acute phase of KS showed both significantly lower mean EI and significantly higher frequency of a decreased EI value as compared with control children. Selective expansion of the Vbeta family in the patients with KS was not observed. Although highly increased EIs were observed in various Vbetas, their frequency was not statistically significant. The pattern of increased Vbetas did not show the specific pattern that indicates a particular superantigen. CONCLUSION: In Kawasaki syndrome non-radioisotope method for analysing Vbeta mRNA is useful in cases where many samples have to be handled. The depletion of Vbeta9 and Vbeta15 or highly increased expression index in the acute phase of Kawasaki syndrome might suggest a relationship to superantigens.

Bacterial Toxins↗
PubMed1998

[Analysis of cerebral blood flow SPECT imaging on standard brain atlas in patients with dementia of Alzheimer type].

Statistical parametric map (SPM) has been developed by Friston et al. to analyze focal changes in rCBF induced by brain activation. This automated and objective approach has the potential of being applied to SPECT image data sets. This study evaluated an automated analysis of brain SPECT imaging in patients with dementia of Alzheimer type (DAT) using SPM95. Seventeen patients with clinically diagnosed moderate to severe DAT and nine normal control subjects were studied. The SPECT device used was a triple-headed rotation gamma camera GCA9300A/HG. All images were transformed into the standard anatomical space of the stereotactic brain atlas of Talairach and Tournoux, and then smoothed. Statistical analysis was made between DAT and normal control groups. SPM analysis of SPECT images revealed that the parieto-temporal areas and posterior cingulate gyrus of both cerebral hemispheres were significantly decreased in DAT patients compared to normal controls. In conclusion, SPM analysis of SPECT images proved to be useful in the evaluation of abnormal perfusion areas of demented patients.

Aged↗
PubMed1998

[Stepwise analysis of cerebral blood flow SPECT imaging on standard brain atlas in patients with dementia of Alzheimer's type].

Statistical parametric mapping (SPM) has been developed by Friston et al. to analyze focal changes in regional cerebral blood flow (rCBF) induced by brain activation. This automated and objective approach has the potential of being applied to single photon emission computed tomography (SPECT) image data sets. This study evaluated an automated analysis of N-isopropyl-p[123I]iodoamphetamine SPECT (123I-IMP) imaging in patients with dementia of Alzheimer's type (DAT) using statistical parametric mapping '95 (SPM'95). Eighteen patients with clinically diagnosed mild to severe DAT who were classified into two groups and ten normal control subjects were studied. The SPECT device used was a triple-headed rotation gamma camera. All images were transformed into the standard anatomical space of the stereotaxic brain atlas of Talairach and Tournoux, and then smoothed. Statistical analyses were made between severe DAT, mild DAT and normal control groups. SPM analysis of 123I-IMP SPECT images revealed that the parietotemporal association areas and posterior cingulate gyri of both cerebral hemispheres were significantly decreased in CBF in mild DAT group compared to normal controls. In comparison of DAT groups, the right hippocampal area and basal forebrain were significantly decreased in CBF in severe DAT group. In conclusion, these results obtained by SPM analysis of SPECT images suggested that the right hippocampal area and basal forebrain followed the parietotemporal association areas and posterior cingulate gyri in the reduction of the rCBF in patients with DAT.

Aged↗
PubMed1997

Comparison of effect of mosapride citrate and existing 5-HT4 receptor agonists on gastrointestinal motility in vivo and in vitro.

Mosapride citrate is a new gastroprokinetic agent that enhances the upper GI motility by stimulating 5-hydroxytryptamine4 (5-HT4) receptors. The purpose of this study was to compare the effects of mosapride and the existing 5-HT4 receptor agonists on GI motility in conscious dogs and on various 5-HT4 receptor-mediated responses in vitro. In conscious dogs with force transducers implanted, mosapride (0.3-3 mg/kg i.v.) stimulated the antral motility without affecting the colonic motility. However, cisapride, zacopride and BIMU 8 (0. 1-1 mg/kg i.v.) stimulated both antral and colonic motility. The enhanced GI motility induced by mosapride or cisapride was antagonized by pretreatment with GR113808 (1 mg/kg bolus i.v., thereafter 1 mg/kg/hr infusion), a selective 5-HT4 receptor antagonist. In the receptor binding studies, mosapride inhibited [3H]-GR113808 binding to 5-HT4 receptor sites of guinea pig striatum with an IC50 value of 113 nM. In addition, mosapride caused relaxation of the carbachol-precontracted rat esophagus, enhanced the electrically evoked contractions of guinea pig ileum and evoked the contractions of guinea pig distal colon with EC50 values of 208, 73, and 3029 nM, respectively; this indicates that mosapride has a low affinity for colon than for the rest of the GI tract. In contrast, cisapride, zacopride or BIMU 8 had similar potencies in all preparations examined. In conclusion, these studies indicate that mosapride selectively stimulates upper GI motility in vivo and in vitro. These results also suggest heterogeneity of 5-HT4 receptors in the GI tract.

Animals↗
PubMed1996

Mitral regurgitation may be related with previous streptococcal infection.

UNLABELLED: We measured anti M protein antibody (AMPA) titres in children with idiopathic mitral regurgitation (MR), streptococcal infection, rheumatic fever (RF), post-streptococcal acute glomerulonephritis (AGN) and normal healthy children. We investigated the association of MR with streptococcal infection and whether high AMPA titres can be used as persisting evidence of previous streptococcal infection. AMPA titres were measured with an enzyme-linked immunosorbent assay. We found significantly higher antibody titres in patients with MR and in streptococcal infection, RF, and AGN than in healthy controls. In the MR group (n = 15), 54% patients had AMPA titres above the 90th percentile value that was found in normal controls. An elevated AMPA titre persisted for a long period even when the anti-streptolysin O titres had declined to normal in RF patients. Our data suggest that the high AMPA titres in MR should be further investigated to clarify the probable association with previous streptococcal infection. CONCLUSION: High AMPA titre is a risk factor for developing complications after streptococcal infection. Our serological evidence suggests that in some patients, MR may be related to previous streptococcal infection.

Adolescent↗
PubMed1996

Renal sympathetic nerve activity after dexmedetomidine in nerve-intact and baroreceptor-denervated rabbits.

To determine the effects of intravenous dexmedetomidine (DMED) on the sympathetic nervous system and to elucidate the mechanism of hypotension, we administered 3 micrograms/kg of DMED to nerve-intact and baroreceptor-denervated rabbits and compared the changes in renal sympathetic nerve activity (RSNA) and hemodynamic variables. In nerve-intact animals, mean arterial pressure (MAP) was increased briefly and then decreased significantly. Changes in RSNA were reciprocal to those of MAP. Heart rate decreased throughout the period of observation. In baroreceptor-denervated rabbits, both MAP and RSNA decreased significantly (-39.4% +/- 3.8% and -21.3% +/- 4.7%, respectively) after the initial increase of MAP. Twenty minutes after administration, hypotension had still continued (-21.1% +/- 3.2%) although RSNA returned to the baseline value. These results indicate that suppression of sympathetic nerve discharge is indeed one of the mechanisms of DMED-induced hypotension, although it may not be the principal one.

Action Potentials↗
PubMed1996

[Cutis laxa].

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Cardiovascular Diseases↗
PubMed1995

Effect of total adipose weight and systemic hypertension on left ventricular mass in children.

To investigate the effect of obesity and hypertension on left ventricular (LV) mass in children, we performed echocardiography and measured the height, weight, and blood pressure of 267 healthy children (145 boys and 122 girls) aged 12 years. The percentage of body fat was estimated using bioelectric impedance to derive the total adipose weight and lean body weight. End-diastolic measurements of LV parameters were obtained from M-mode echocardiograms. The LV mass was calculated by using the formula of Devereux et al. A strong positive correlation was demonstrated between non-normalized LV mass and height or other measures of body size. Systolic blood pressure was weakly correlated with non-normalized LV mass in boys. The impact of height on LV mass differed between boys and girls. Thus, different allometric formulas to normalize the LV mass for height were determined, using the height to the 3.1 and 1.9 powers for boys and girls, respectively. Regression analysis revealed that only total adipose weight affected the normalized LV mass, and that the effect of total adipose weight was greater in girls than in boys. The obese children had a significantly greater normalized LV mass than the nonobese children. The increase in the LV mass due to obesity appeared to be eccentric, because of the lack of an association between the indices of obesity and relative wall thickness. Our data indicate that appropriate normalization of LV mass is necessary for each study population, and that LV hypertrophy due to obesity begins in childhood.

Adipose Tissue↗