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S Onishi

Publications and source records attributed to S Onishi.

At least 37 records · Page 2Linked to original sources
PubMed2001

Cerebral metabolism and regional cerebral blood flow during moderate systemic cooling in newborn piglets.

BACKGROUND: Clinical trials of hypothermic therapy in asphyxiated infants have started recently. However, clinical studies have been delayed by the difficulty in selecting infants with a bad neurological prognosis and by the concern regarding adverse effects of hypothermia. The purpose of this study is to examine the effects of systemic cooling on cerebral metabolism (CMR) and the regional cerebral blood flow (rCBF) in newborn piglets. METHODS: The rCBF in the seven parts of the brain were measured with colored microspheres. The blood samples for the measurement of cerebral oxygen consumption (CMRO2) and cerebral glucose consumption (CMRglc) was collected from the umbilical artery and the superior sagittal sinus. RESULTS: Reductions of cerebral cortex temperature to 32 degrees C decreased blood flow in all brain regions. In particular, blood flow in the brainstem decreased more significantly than in any other region. The total cerebral blood flow (CBF), CMRO2 and CMRglc, respectively, decreased to 32.3+/-3.9 mL/100 g per min, 2.8+/-1.0 mLO2/100 g per min and 22+/-12 mmol/100 g per min at 32 degrees C (41, 53 and 46% of the initial value). The CBF decreased in parallel with CMRO2 and CMRglc down to 35 degrees C, but CBF decreased to a greater extent than CMRO2 and CMRglc at below 35 degrees C. CONCLUSIONS: The indication of hypothermic therapy and the degree of cooling have to be performed very carefully. Systemic cooling is especially dangerous for the total asphyxiated infants who might have damage to the brainstem because the blood flow in the brainstem has significantly decreased during hypothermia.

Animals↗
PubMed2001

Evaluation of endoscopic and histopathological features of serrated adenoma of the colon.

BACKGROUND AND STUDY AIMS: The aim of this study was to reveal the clinical features of serrated colonic adenoma by investigating its endoscopic features using a magnifying videoscope. MATERIALS AND METHODS: 68 colorectal serrated adenomas presented for colonoscopic examination were included in this study. A magnifying videoscope with a zoom ranging from x 1 to x 100 magnification was employed to observe the pit patterns of colonic lesions, and 39 of the serrated adenoma specimens were evaluated using this. Some pit patterns appeared as elongated oval and stellar-like orifices of the crypts; we termed these type which was detected III(SA) patterns. Other pit patterns showed a flower petal-like or pineal form, and this was termed a type IV(SA) pit pattern. RESULTS: In the entire sample of serrated adenomas, 53 were of the protruded type, and 15 were superficial, for a protruded/superficial ratio of 3.5 : 1. The protruded type of serrated adenoma predominated in the distal portion. The superficial type was preferentially located in the proximal portion of the colon (P < 0.0001). Among the 13 superficial types in which the magnifying videoscope was used, all 13 showed the type III(SA) basic pit pattern. In these serrated adenomas of the superficial type, an additional IV(SA) pit pattern was found in 23.1% (3/13), which was detected in 53.8% (14/26) in the protruded type. Small serrated adenomas measuring less than 10 mm in diameter were preferentially mild to moderate atypia (odd's ratio = 15.9, P = 0.0216). CONCLUSION: The pit pattern may prove useful for the endoscopic diagnosis of serrated adenoma. Furthermore, endoscopic treatment is indicated for serrated adenoma; in particular those of 10 mm or more in diameter should be treated because of the possibility of high-grade glandular intraepithelial neoplasia.

Adenoma↗
PubMed2001

Effects of ethanol on L-arginine transport in rat Ito cells in relation to nitric oxide production.

BACKGROUND: Nitric oxide (NO) is a potent mediator of hepatic sinusoidal hemodynamics that is synthesized in the hepatic stellate cells (Ito cells, fat-storing cells) and affects these cells. NO production may depend on the induction of inducible nitric oxide synthase and on transport of extracellular L-arginine. The precise mechanism that controls NO production in stellate cells was characterized recently. METHODS: Kinetic analysis of L-arginine transport and reverse transcription-polymerase chain reaction for cationic amino acid transporter (CAT) were carried out by using stellate cells prepared from the male Wistar rat. The effect of ethanol on L-arginine transport and NO production of stellate cells was assessed in the presence of tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma. RESULTS: The L-arginine transport system functioning in the hepatic stellate cells was system y+, possibly mediated by CAT-1 and CAT-2B (Km approximately 50 microM). IFN-gamma in combination with TNF-alpha induced NO production with an enhancement in CAT-2B mRNA expression and L-arginine transport, whereas L-arginine transport and NO production were suppressed by coincubated ethanol. CONCLUSIONS: In hepatic stellate cells, ethanol has suppressive effects on NO production and extracellular L-arginine transport in the presence of TNF-alpha and IFN-gamma. The estimated Km of L-arginine transporter in hepatic stellate cells is very similar to the physiological L-arginine concentration in portal vein. Our findings may support the merit of further studies on the modulation of NO production via access to portal blood L-arginine concentration to control disturbed hepatic sinusoidal blood flow in patients with alcoholic liver disease.

Amino Acid Transport Systems, Basic↗
PubMed2001

Time of closure of ductus venosus in term and preterm neonates.

AIM: To investigate the relation between gestational age, birth weight, and antenatal corticosteroid administration and the time of ductus venosus closure. METHODS: Ninety eight neonates of 30-41 weeks gestational age were studied by daily ultrasonography until ductus venosus closure. RESULTS: In neonates of 30-33 weeks gestational age, the ductus venosus closed at 6.0 (2.4)days (mean (SD)); in those of 34-36 weeks gestational age, it closed at 6.1 (2.8) days; and in those of 37-41 weeks gestational age, it closed at 4.2 (2.1) days. The effect of antenatal administration of corticosteroids on the time of closure was also investigated in neonates of 30-34 weeks gestational age. Closure occurred by 5.5 (2.4) days in the group given corticosteroids compared with 7.5 (2.1) days in the remainder. CONCLUSIONS: The ductus venosus closed sooner after birth in neonates of greater gestational age or higher birth weight. Antenatal corticosteroid administration had a significant effect in promoting closure.

Birth Weight↗
PubMed2001

The fine form of Helicobacter pylori on the metaplastic duodenal mucosa is associated with recurrent duodenal ulcers.

BACKGROUND/AIM: It is well known that Helicobacter pylori changes its shapes according to various environmental conditions. The aim of this study was to examine the morphological differences between H. pylori in the duodenum and that in the stomach. METHODS: Duodenal biopsy specimens were obtained from patients with duodenal mucosal lesions, and these specimens were then histopathologically examined. Morphological and genetic properties of cultured H. pylori isolates were analyzed. RESULTS: H. pylori was identified in 16 out of 50 duodenal biopsy specimens. Along with the regular form, we found a fine form of H. pylori in the gastric metaplastic mucosa of ten duodenal specimens that was shorter in length and thinner in diameter than the regular helical form. There were no detectable differences between the ureA-ureB polymorphism of the duodenal fine form and that of gastric regular form in a single patient. As compared with patients without H. pylori in the duodenum, the prevalence of recurrent duodenal ulcers significantly increased in patients with the fine form (p < 0.05), but not in patients with the regular form. CONCLUSION: The fine form of H. pylori in the metaplastic duodenal mucosa could result from its adaptation to the duodenal environment and may be associated with the recurrence of a duodenal ulcer.

Adolescent↗
PubMed2001

Hereditary pancreatitis in Japan: a review of pancreatitis-associated gene mutations.

Pancreatitis-associated gene mutations have been reported in patients with hereditary pancreatitis and idiopathic pancreatitis in the Caucasian population and involve the cationic trypsinogen gene, the pancreatic secretory trypsin inhibitor gene and the cystic fibrosis transmembrane conductance regulator gene. In the Japanese population, mutational screening analyses of these genes have shown several mutations. The present study reviews previous reports from Japan in order to evaluate the racial specificity of pancreatitis-associated gene mutations.

Cystic Fibrosis Transmembrane Conductance Regulato↗
PubMed2001

Relationships between serum (ZZ)-bilirubin, its subfractions and biliverdin concentrations in infants at 1-month check-ups.

In 150 infants, including those with breast milk jaundice, who were brought to our hospital for their 1-month check-ups, the serum concentrations of (ZZ)-bilirubin, its subfractions and biliverdin were measured by high-performance liquid chromatography and the relationships among them investigated. (ZZ)-Bilirubin was found to have the highest serum concentration, followed by (ZE)-bilirubin, accounting for 14.0 (geometric mean) % of (ZZ)-bilirubin. Biliverdin had a serum concentration of 0.95% of (ZZ)-bilirubin. There was only a small amount of total (di- and mono-) glucuronosyl bilirubin, 0.42% of (ZZ)-bilirubin. (ZE)-Bilirubin, (EZ)-bilirubin, (EZ)-cyclobilirubin. biliverdin, diglucuronosyl bilirubin and monoglucuronosyl bilirubin (C-8 and C-12) showed positive logarithmic correlations with (ZZ)-bilirubin (R2=0.16 or above, P<0.05). (ZE)-Bilirubin showed a significant positive logarithmic correlation with (ZZ)-bilirubin (R2=0.863, P<0.0001). Furthermore, (EZ)-cyclobilirubin, the most important photoisomer in phototherapy for neonatal hyperbilirubinaemia, was detected in very small amounts in approximately half of the neonates (84 of 150) when they were in conditions of only weak ambient light. The relationship between total glucuronosyl bilirubin and (ZZ)-bilirubin concentrations fitted a model of saturation kinetics of bilirubin UDP-glucuronosyltransferase.

Bilirubin↗
PubMed2001

A loss of aggressive behaviour and its reinstatement by oestrogen in mice lacking the aromatase gene (Cyp19).

Aromatase P450 (CYP19) is an enzyme responsible for conversion of androgens to oestrogens. We generated CYP19 knockout (ArKO) mice by targeting disruption of the CYP19 gene and observed that the ArKO males exhibited a complete loss of aggressive behaviour against intruder mice when examined using a resident-intruder paradigm. The defect in the behaviour of ArKO males was reinstated when the mice received supplements of 17beta-oestradiol soon after birth. Nevertheless, the cumulative duration of the behaviour displayed by the treated mice during the test period of 15 min was 19+/-10 s, which was much shorter than that displayed by wild-type males, 90+/-17 s. When the supplementation was started at 7 days after birth, the defect was not restored. These findings illustrate an absolute requirement for oestrogen during the neonatal stage of a male's life for the development of the potential for aggression observed in adulthood. Furthermore, the present study demonstrates that ArKO males are a useful model in which to investigate the neural mechanisms by which aggressive behaviour is controlled.

Age Factors↗
PubMed2001

Oestrogen at the neonatal stage is critical for the reproductive ability of male mice as revealed by supplementation with 17beta-oestradiol to aromatase gene (Cyp19) knockout mice.

Aromatase P450 (CYP19) is an enzyme responsible for the conversion of androgens to oestrogens. We generated CYP19 knockout (ArKO) mice by targeted disruption of Cyp19 and studied the role of oestrogens in male reproductive ability. Approximately 85% of ArKO males were unable to sire offspring. However, no obvious difference was found in testicular and epididymal weights, numbers of sperm in the epididymis or the ability of sperm to fertilize eggs in vitro between wild-type and ArKO males. An examination of mating behaviour demonstrated that ArKO males showed an impairment in mounting behaviour against sexually mature females. The inability of more than 90% of ArKO males to sire offspring was reversed by repeated subcutaneous injections of 17beta-oestradiol when initiated on the day of birth. The effects of 17beta-oestradiol on reproduction were concentration dependent and evident when supplementation was initiated on day 7, but not on day 15 after birth. These findings suggest that oestrogens acting during neonatal life are required for normal mating behaviour in adulthood.

Age Factors↗
PubMed2001

Targeted disruption of the aromatase P450 gene (Cyp19) in mice and their ovarian and uterine responses to 17beta-oestradiol.

Aromatase P450 (CYP19) is an enzyme catalysing the conversion of androgens into oestrogens. We generated mice lacking aromatase activity (ArKO) by targeted disruption of Cyp19 and report the characteristic features of the ArKO ovaries and uteri as revealed by histological and biochemical analyses. ArKO females were totally infertile but there were as many developing follicles in their ovaries at 8 weeks of age as in wild-type ovaries. Nevertheless, no typical corpus luteum was observed in the ArKO ovaries. Electron microscopy revealed the presence of well-developed smooth endoplasmic reticulum, few lipid droplets and mitochondria with less organized tubular structures in the ArKO luteinized interstitial cells. These ultrastructural features were different from those of the wild-type interstitial cells, where there are many lipid droplets and mitochondria with well-developed tubular structures, characteristic of steroid-producing cells. When ArKO mice were supplemented with 17beta-oestradiol (E(2); 15 microg/mouse) every fourth day from 4 weeks of age for 1 month, increased numbers of follicles were observed in the ovaries as compared with those of untreated ArKO mice, although no typical corpus luteum was detectable. Ultrastructural analysis revealed the disappearance of the accumulated smooth endoplasmic reticulum in the luteinized interstitial cells after E(2 )supplementation. Transcripts of pro-apoptotic genes such as p53 and Bax genes were markedly elevated in the ArKO ovaries as compared with those of wild-type mice. Although E(2) supplementation did not cause suppression of the elevated expression of p53 and Bax mRNAs, it caused marked enhancement of expression levels of lactoferrin and progesterone receptor mRNAs in the uteri as well as increases in uterine wet weight. At 8 months of age, ArKO mice developed haemorrhages in the ovaries, in which follicles were nearly depleted, while age-matched wild-type females still had many ovarian follicles. Furthermore, macrophage-like cells were occasionally observed in the ArKO ovarian follicles. These results suggested that targeted disruption of Cyp19 caused anovulation and precocious depletion of ovarian follicles. Additionally, analysis of mice supplemented with E(2) demonstrated that E(2) apparently supports development of ovarian follicles, although it did not restore the defect in ovulation.

Animals↗
PubMed2001

[Systemic inflammatory response syndrome triggered by necrotizing cholecystitis after treatment of underlying low titer cold agglutinin disease].

In April 1996, a 77-year-old man initially presented with fever, rash and polyarthralgia, and was diagnosed as having low titer cold agglutinin disease with acute hemolytic anemia. The patient's condition and laboratory findings improved after administration of corticosteroid (prednisolone 60 mg). In June 1996, however, he developed acute cholecystitis and died due to sepsis, disseminated intravascular coagulation and multiple organ failure. During the course, the levels of inflammatory cytokines such as TNF-alpha and IL-6 were correlated with the pathology, and the disease was diagnosed as systemic inflammatory response syndrome (SIRS). Autopsy revealed necrotizing cholecystitis, erythrophagocytosis in the liver, and cytomegalovirus infection in the lung and gall bladder. This was considered to be a rare case of low titer cold agglutinin disease complicated by SIRS.

Aged↗
PubMed2001

Fortuitously discovered persistent left superior vena cava in young competitive athletes. Clinical implications of sports physicians.

This report describes two athletes with persistent left superior vena cava (PLSVC) accidentally identified during preparticipation medical evaluation. The clinical implications of PLSVC for sports physicians are also discussed. A 16-year-old male ice hockey player and an 18-year-old male high-level field hockey player visited our institute for medical evaluation prior to participating in competition. Neither complained of palpitation, faintness or syncope, which would have suggested a possible cardiac rhythm disturbance, or had been informed of any abnormalities in previous physical examinations. Nonetheless, echocardiography revealed dilated coronary sinuses, and venography confirmed PLSVC and, in one case, showed the absence of the right superior vena cava. Electrocardiograms showed the field hockey player to have an ectopic atrial rhythm with left axis deviation of the frontal plane P-wave and the ice hockey player to have normal sinus rhythm. Symptom-limited treadmill testing revealed nothing abnormal, and after explaining the possible rhythm instability and the potential risk associated with cardiac surgery, the subjects were permitted full participation in competitive sports. Although information is scarce, available data on PLSVC suggest it is benign for competitive athletes. Nevertheless, complications arising from other cardiovascular anomalies, from potential cardiac rhythm disturbances, and from cardiac surgery necessitated by major injuries should be considered prior to participation in competitive sports.

Adolescent↗
PubMed2001

[Refractory idiopathic cold agglutinin disease successfully treated with intermittent high-dose cyclophosphamide].

A 56-year-old woman, who had been suffering from idiopathic cold agglutinin disease and treated unsuccessfully with prednisolone and cyclosporine A for 6 months, was referred to our hospital in November 1998. She was given methylprednisolone pulse therapy followed by low-dose cyclophosphamide, but her anemia did not improve. We then began administration of intermittent high-dose cyclophosphamide (1,200 mg/day, every 4 weeks), and this resulted in a dramatic increase of her hemoglobin level and improvement of her symptoms. She is currently receiving 500 mg of cyclophosphamide every 2 months and showing a good response. Intermittent high-dose cyclophosphamide therapy can be an effective treatment for refractory cold agglutinin disease.

Anemia, Hemolytic, Autoimmune↗
PubMed2001

[Small cell carcinoma of the urinary bladder: a case report].

We report a case of small cell carcinoma of the urinary bladder. A 60-year-old man with microscopic hematuria was referred to our hospital. Cystoscopy revealed a sessile tumor on the left lateral wall of the urinary bladder. The patient underwent transurethral resection of the bladder tumor (TUR-Bt). Because of muscle invasion (pT2), total cystectomy was recommended, but was not performed because the patient would not give consent for the operation. Six months after TUR-Bt, invasive bladder tumor recurred and total cystectomy was performed. Pathological examination of the operative specimen revealed small cell carcinoma. Adjuvant combined therapy of irradiation and chemotherapy (nedaplatin and etoposide) was ineffective. Metastases to retroperitoneal lymph nodes, lung and liver were detected soon after the adjuvant therapy. The patient died 15 months after his first visit to our hospital.

Carcinoma, Small Cell↗