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Biomedical subjects

I Sato

Publications and source records attributed to I Sato.

At least 109 records · Page 6Linked to original sources
PubMed1999

Induction of neuronal nitric oxide synthase by methylmercury in the cerebellum.

A free radical, nitric oxide (NO), besides being a messenger molecule in the brain, becomes a neurotoxin if overproduced. We recently reported that methylmercury (MeHg) induces neuronal NO synthase (nNOS) in Purkinje cells. In the present study, we examined the distribution and the mechanism of nNOS induction by MeHg. Subcutaneous administration of MeHg chloride to mice, 10 mg/kg/day for 9 days, increased calcium-dependent NOS activity to 60% more than the controls only in the cerebellum but not in other brain regions. The Western blots showed a comparable increase in nNOS protein in the cerebellum. A N-methyl-D-aspartate (NMDA) receptor antagonist, MK-801, did not block, but rather enhanced, the increase in the nNOS activity. Another NMDA antagonist, 3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP), did not affect the nNOS activity. The Western blots of protein kinase C (PKC), which is an important cofactor regulating nNOS, did not change after the administration of MeHg. These results show that MeHg induces biologically active nNOS selectively in the cerebellum. The induction is independent of PKC and is not reduced by the blockade of the NMDA receptor.

Animals↗
PubMed1999

Fetus with long QT syndrome manifested by tachyarrhythmia: a case report.

We encountered a fetus who exhibited transient (at most 30 s), repeated episodes of tachyarrhythmia (240 bpm). This female neonate was born at 36 weeks of gestation and showed a markedly prolonged QT interval and transient, repeated episodes of polymorphic ventricular tachycardia. Congenital long QT syndrome was diagnosed. Retrospective analysis of the videotape showing fetal cardiac movement revealed that atrio-ventricular dissociation was present prenatally and thus, the fetal tachyarrhythmia was due to ventricular tachycardia. To our knowledge, there are few reports of a fetus with the long QT syndrome who exhibited ventricular tachycardia in utero. In the presence of unexplained fetal tachyarrhythmia, long QT syndrome should be considered as a possible underlying cause disorder. The presence of atrio-ventricular dissociation may be useful in prenatal diagnosis of long QT syndrome.

Adult↗
PubMed1999

A patient with brain metastasis from ovarian cancer who showed complete remission after multidisciplinary treatment.

We describe a case with brain metastasis from ovarian cancer who showed complete remission after multidisciplinary treatment. The case was diagnosed as epithelial ovarian cancer, FIGO stage IIIc. She underwent cisplatin-based chemotherapy after optimal cytoreductive surgery and achieved clinical complete remission. Thirty-two months after surgery for ovarian cancer, a solitary metastasis occurred in the left frontal lobe of the brain. No recurrent lesions were observed outside the brain. The metastatic tumor was resected. Five days after operation, adjuvant chemotherapy comprising carboplatin and cisplatin was initiated (a total of three courses at 4-week intervals), and whole brain irradiation at 55 Gy was added. After these treatment methods, complete remission of the brain metastasis has been observed for 57 months with good quality of life.

Brain Neoplasms↗
PubMed1999

The STR polymorphisms in intron 8 may provide information about the molecular evolution of RH haplotypes.

We identified simple-sequence repeat polymorphisms in intron 8 of the RHD and RHCE genes, both of which contained the 5-bp repeat unit (AAAAT)n. We analyzed the polymorphisms of this short tandem repeat (STR) in 104 Japanese RhD-positive and 124 RhD-negative (87 RHD gene negative and 37 nonfunctional RHD gene positive) donors by the polymerase chain reaction (PCR) and subsequent typing by electrophoresis and silver staining. We found five alleles (10, 11, 12, 13, and 14 repeats) in the RHD gene and four (7, 8, 9, and 10 repeats) in the RHCE gene. The Rh phenotypes were closely associated with polymorphisms of the STR. The Ce allele had 12 repeats in the RHD gene and 9 repeats in the RHCE gene at high frequency. The cE allele frequently had 10-12 repeats in the RHD gene and 10 repeats in the RHCE gene. The 10 repeats in the RHCE gene were identified exclusively in the 87 RHD gene-negative donors and 9 repeats were identified only in those with the RhC antigen. These results indicate that both haplotypes of dce and dcE arose from single RHD gene deletion and recombination events, respectively. In the 37 RhD-negative donors with a nonfunctional RHD gene, 12 repeats in the RHD gene and 9 repeats in the RHCE gene were frequently observed. Thus, the RhD-negative with a nonfunctional RHD gene combination might have arisen from the DCe haplotype via a mutation that abolished RHD gene expression. These findings suggest that the STR polymorphisms might shed light upon the molecular evolution of RH haplotypes.

Alleles↗
PubMed1999

Neuronal nitric oxide synthase is resistant to ethanol.

To test for a possible role of nitric oxide (NO) in the neurotoxicity of ethanol, we studied the effects of ethanol on the neuronal NO synthase (nNOS) both in vitro and in vivo. Ethanol, up to 200 mM, did not change the NOS activity in the cerebellar homogenate or the production of NO by the cultured cerebellar granule cells. The number of NADPH diaphorase-positive cells in the culture did not change after the exposure to 200 mM ethanol in vitro. The NOS activity in the various brain regions of mice remained similar to the controls after the acute (3 g/kg) and the chronic (33 g/kg/day, 3.5 days) administration of ethanol. N(omega)-nitro-L-arginine, a NOS inhibitor, did not affect the ethanol-withdrawal behavior. These results indicate that nNOS is resistant to ethanol at clinically relevant concentrations and that ethanol affects the NO-operated system in the brain through a pathway other than that of nNOS.

Animals↗
PubMed1999

Association of a decrease in antithrombin III activity with a perinatal elevation in aspartate aminotransferase in women with twin pregnancies: relevance to the HELLP syndrome.

BACKGROUND/AIMS: Decreased antithrombin III (AT-III) activity and/or thrombocytopenia associated with an elevated serum level of aspartate aminotransferase in late pregnancy can threaten the lives of both the mother and the fetus. We investigated whether antenatal declines in AT-III activity and the platelet count occur in late twin pregnancy and whether reduced AT-III activity and/or thrombocytopenia precedes an increase in the serum level of aspartate aminotransferase. METHODS: The platelet count, AT-III activity, and the serum level of aspartate aminotransferase were determined weekly or biweekly in 237 women with twin pregnancies in a longitudinal and partly prospective study. RESULTS: Both AT-III activity and the platelet count decreased gradually in the last month of pregnancy, irrespective of the presence or absence of clinical signs of pre-eclampsia. A perinatal elevation in aspartate aminotransferase occurred in 36 (15%) of 237 women. The risk of a perinatal elevation in aspartate amino-transferase increased as the antenatal AT-III activity and/or the platelet count decreased. Pre-eclampsia developed in 60 women (25%). The relative risk of a perinatal aspartate aminotransferase elevation (95% confidence interval) for the 60 women with pre-eclampsia, the 60 women with a platelet count < or = the 25th percentile (164 x 10(9)/1), and the 60 women with AT-III activity < or = the 25th percentile (76% of normal) was 1.9 (1.0 to 3.4), 4.1 (2.3 to 7.5), and 5.9 (3.2 to 11.1), respectively, compared with the remaining 177 women. CONCLUSIONS: AT-III activity and platelet count gradually decreased in the last month of twin pregnancies. A perinatal aspartate aminotransferase elevation was preceded by marked decreases in these parameters in women with twin pregnancies. The monitoring of AT-III activity and platelet count in women who exhibit a gradual decline in these parameters may help to avoid the development of severe HELLP syndrome.

Adult↗
PubMed1999

Glucose-6-phosphatase is present in normal and pre-eclamptic placental trophoblasts: ultrastructural enzyme-histochemical evidence.

The purpose of the present study was to localize glucose-6-phosphatase (G6Pase) activity in the human placenta at various gestational stages and to compare them to pre-eclamptic placenta activity. Ultrastructural enzyme-histochemical analysis of G6Pase was performed using cerium and lead as capturing agents. Precipitates indicative of G6Pase activity were observed in the endoplasmic reticulum and the nuclear envelope of the syncytiotrophoblasts in near-term placenta obtained from women with normal pregnancies. In placenta taken from women with severe pre-eclampsia, the localization pattern, enzyme activity intensity, and morphology of the endoplasmic reticulum did not differ from normal pregnancies. Stringent control experiments were performed also to ensure specific detection of G6Pase activity. The results indicate that cytochemically detectable G6Pase is present in the human placenta. This enzyme may play significant roles in carbohydrate metabolism in the human placenta.

Endoplasmic Reticulum↗
PubMed1999

Effect of vaginal delivery on the Q-Tc interval in a patient with the long Q-T (Romano-Ward) syndrome.

Twelve ECG leads were monitored continuously during peripartum in a 23-year-old Japanese woman diagnosed as having the long Q-T (Romano-Ward) syndrome. Corrected Q-T (Q-Tc) intervals determined by 2 investigators blinded from the clinical informations disclosed that the Q-Tc interval increased during labor, suggesting that physical and/or emotional stress during labor might cause prolonged Q-Tc intervals in women with the long QT syndrome.

Adult↗
PubMed1999

Uterine leiomyoma in pregnancy: its influence on obstetric performance.

OBJECTIVE: To assess the effects of uterine leiomyoma on obstetrical performance. METHODS: We reviewed the medical records of 102 women with singleton pregnancies who were found ultrasonographically to have uterine leiomyomas during the first half of their pregnancy and who gave birth at our hospital at > or = 22 weeks of gestation between January 1990 and December 1997. RESULTS: The 102 women gave birth to 101 healthy infants, weighing 2,974 +/- 579 g at 38.8 +/- 2.6 weeks of pregnancy. One woman experienced an unexplained antepartum fetal death at 24 weeks of gestation. Bleeding at the first trimester occurred in 16% of the women. Pain localized in the lower abdomen and requiring relief occurred in 28% of the women during the first or second trimester. Tocolytic treatment was required in 25% of the pregnancies, and preterm delivery occurred in 12% thereof. A cesarean section was performed in 39% of the pregnancies. Bleeding > or = 500 ml occurred at delivery in 48% of the cases. The largest fibroid, > 6 cm in diameter, which was seen in 51 women, was associated with higher frequencies of tocolytic treatment (41%), preterm delivery (24%), bleeding > or = 500 ml at delivery (59%), and cesarean delivery (51%). In 76 women (75%) who attempted vaginal delivery, the obstetrical outcome was comparable to that of 115 control women who were matched regarding age, parity, and gestational week. CONCLUSIONS: Although pain in the lower abdomen, the requirement of tocolytic treatment, preterm delivery, and cesarean delivery were common, the neonatal outcome was fairly good in women with uterine leiomyomas. The present data might be encouraging to pregnant women with uterine leiomyomas.

Abdominal Pain↗
PubMed1999

Causes of stillbirth: an analysis of 77 cases.

OBJECTIVE: To devise preventive measures for stillbirths, which account for more than 70% of perinatal deaths in Japan. METHODS: We retrospectively reviewed the medical records of 77 women with singleton pregnancies who gave birth to stillborn infants at > or = 30 weeks between 1979 and 1996 at our hospital. RESULTS: Major malformations were present in 21 (27%) of 77 infants, including 11 infants with anencephaly. Two infants (2.6%) were severely hydropic. Preeclampsia preceded the stillbirth and might have been an indirect cause of stillbirth in 21 (39%) of 54 women whose infants had normal formations. The cause of stillbirth in 33 non-preeclamptic women was unclear in 15 (28%), abruptio placentae in 9, fetal growth retardation in 3, the HELLP syndrome in 3, chorioamnionitis in 2, and cord accident in 1. Abruptio placentae also occurred in 9 of 21 preeclamptic patients. Thus, abruptio placentae was responsible for 18 (33%) of 54 stillborn infants with a grossly normal appearance. An autopsy was performed on only 13 (24%) of 54 infants with grossly normal appearance and did not provide new information relating to deaths. CONCLUSIONS: The causes of stillbirth were many and varied, with a large proportion having no obvious cause, although autopsies were underused. Increased monitoring for women with preeclampsia and early diagnosis and prompt delivery for women with abruptio placentae might be helpful in reducing the number of stillbirths.

Abruptio Placentae↗
PubMed1999

Clear cell variant of calcifying epithelial odontogenic tumor (CEOT) in the maxilla: report of a case with immunohistochemical and ultrastructural investigations.

A rare case of clear cell variant of calcifying epithelial odontogenic tumor is presented with immunohistochemical and ultrastructural investigations. A 14-year-old Japanese girl was admitted with a complaint of swelling in the right posterior maxilla. Radiological examination showed a well-circumscribed radiolucent lesion located close to the impacted third molar. After only a partial tumor excision, the tumor recurred 13 years later. It appeared radiologically as an irregular radiodensity, and a subtotal maxillectomy was performed. Histological examination showed sheets and/or strands composed almost entirely of clear vacuolated epithelial cells in a stroma containing intercellular amyloid-like material and calcification. Histochemical and ultrastructural analysis detected cytoplasmic glycogen granules in the clear cells, and positive immunoreactivities for cytokeratins 8, 13 and 19; filaggrin and anti-ameloblastoma antibodies suggested an odontogenic epithelial origin.

Adolescent↗
PubMed1999

[Studies on growth of verotoxin-producing Escherichia coli (VTEC) O157 in enrichment broth and minimal broth].

Growth of 10 strains of VTEC O157, which were isolated from faecal specimens, was evaluated in conventionally recommended enrichment broth media Trypticase soy broth (TSB) and Davis's Minimal Medium (DMM) at different temperatures. Five strains of VTEC O157 used in the test proliferated well in TSB and reached to 10(9) CFU/ml at 36 degrees C in 24 hours incubation and to the same population densities at 25 degrees C in 48 hours. Whereas in DMM at 36 degrees C there was no proliferation in 6 hours, but grew to 10(6) CFU/ml in 24 hours and 10(8) CFU/ml in 48 hours. Three strains of VTEC O157 tested at 25 degrees C grew to 1.52 x 10(4) CFU/ml in 24 hours, 1.67 x 10(8) CFU/ml in 48 hours and 6.80 x 10(8) CFU/ml in 72 hours. No proliferation was observed at 4 degrees C in 72 hours in growth TSB and DMM. The growth in glucose free DMM was found in 7 out of 10 strains, and 4 out of these 7 strains grew profusely to 10(5) CFU/ml in 48 hours. One out of 3 strains showed no proliferation but survived 72 hours postinoculation, decreasing from 179 CFU to 29 CFU in 100 microliters of medium. The other 2 strains became completely extinct in 48 hours after inoculation with 263 CFU and 2,420 CFU in 100 microliters of medium respectively. However, these 3 strains which showed no growth in glucose free DMM could proliferate in DMM containing 1/10 of the usual glucose concentration, at a rate depending on the concentration. In conclusion, it is suggested that the finding of increase of VTEC O157 in glucose free DMM would be a useful solution for the food poisoning problem caused by VTEC O157.

Culture Media↗
PubMed1999

Emergency cervical cerclage: relation between its success, preoperative serum level of C-reactive protein and WBC count, and degree of cervical dilatation.

OBJECTIVE: To assess the relation between the preoperative serum level of C-reactive protein (CRP) and the WBC count and the efficacy of emergency cervical cerclage. STUDY DESIGN: We retrospectively reviewed the medical records of 17 women (16 singleton pregnancies and 1 twin pregnancy) who underwent emergency cervical cerclage (McDonald technique) between 21 and 26 weeks of gestation. The uterine cervix was dilated >/=3.0 cm and the intact (not ruptured) fetal membranes were visible or protruded into the vagina in all patients. The serum level of CRP and the WBC count were determined preoperatively and postoperatively. Emergency cervical cerclage was considered successful if delivery occurred >/=14 days after the procedure. RESULTS: Emergency cervical cerclage was successful in 12 women, including the woman with a twin pregnancy, but failed in 5 women. The preoperative serum level of CRP and the WBC count were significantly lower and dilatation of the cervix was significantly less in the success group than in the failure group. Cerclage was successful in all eight patients with cervical dilatation </=4.0 cm, but in only 4 of 9 patients with cervical dilatation >4.0 cm (p < 0. 05). Cerclage was successful in all 11 women with a preoperative serum level of CRP </=4.0 mg/dl and a WBC count </=14,000/ microl compared with 1 of 6 women with either a CRP level >4.0 mg/dl or a WBC count >14,000/ microl (p < 0.01). CONCLUSION: A preoperative CRP value </=4.0 mg/dl, a WBC count </=14,000/ microl, and cervical dilatation </=4.0 cm were significantly associated with prolongation of pregnancy after emergency cervical cerclage.

Adult↗
PubMed1999

Birth-weight-specific perinatal mortality in Japan, 1989-1993: singleton versus multifetal pregnancies.

OBJECTIVE: To investigate the relation between birth weight and perinatal mortality in multifetal pregnancies, which is more than 5 times higher than for singleton infants. METHODS: We assessed the incidence of perinatal deaths based on birth weight in 89,566 infants of multifetal pregnancies and 6,025,199 infants of singleton pregnancies in Japan. Perinatal death was defined as stillbirth and early neonatal death (death <1 week of age). RESULTS: The incidence of perinatal death was consistently lower for infants of multifetal pregnancies than for infants of singleton pregnancies at birth weights of 500-2,499 g. However, the incidence of infants of multifetal pregnancies with birth weights >/=2,500 g consistently exceeded that in singleton infants weighing >/=2,500 g. The relative risk (95% CI) of perinatal death among infants of multifetal pregnancies compared with singleton infants in the same category of birth weight was 0.88 (0.84-0.93) at 500 g. The relative risk decreased to 0.31 (0.25-0.39) at 1,900 g, increased to >1.0 at 2,500 g, to 3.7 (2.2-6.1) at 3,000 g, and to 14.9 (7.8-28.4) at >/=3,500 g. CONCLUSIONS: Japanese infants of multifetal pregnancies reaching >/=2,500 g in body weight have a significantly higher risk of perinatal death than singleton infants in the same category of body weight. Increased monitoring of fetuses of multifetal pregnancies who weigh >/=2,500 g may be helpful in reducing the incidence of perinatal mortality.

Birth Weight↗
PubMed1999

Risk of complications and uterine malignancies in women undergoing hysterectomy for presumed benign leiomyomas.

OBJECTIVES: To determine the incidences of complications and uterine malignancies among women undergoing hysterectomies for presumed benign leiomyomas. METHODS: We retrospectively reviewed the medical records of 923 women who underwent total hysterectomies between January 1983 and December 1997 at our hospital due to presumed benign leiomyomas. RESULTS: The mean age (SD) of the patients was 44. 5 +/- 5.2 years, 105 +/- 35 minutes was required for the procedure, and 405 +/- 312 ml of blood was lost during the procedure. Forty-one (4.4%) women demonstrated complications of intraoperative hemorrhages and required transfused blood. Urinary tract and bowel injuries occurred in 10 (1.1%) and 2 (0.2%) women, respectively. One woman (0.1%) died from pulmonary embolism that occurred on postoperative day 1. One woman (0.1%) required relaparotomy to control intraabdominal hemorrhage. Uterine malignancies were discovered postoperatively in 4 (0.4%) women, including 2 endometrial carcinoma, 1 leiomyosarcoma, and 1 endometrial stromal sarcoma. CONCLUSIONS: The incidences of complications and unrecognized uterine malignancies were similar to the results of previous studies. Of patients undergoing hysterectomy for presumed benign leiomyomas, the risk of major complications was 6.0% (55/923) and the risk of preoperatively undiagnosed uterine malignancies was 0.4%.

Adult↗
PubMed1999

Enhanced expression of thymidylate synthase may be of prognostic importance in advanced cervical cancer.

The enhanced expression of thymidylate synthase (TS) has been associated with a poor prognosis in patients with several types of epithelial tumors. To determine the association between TS expression and the prognosis of patients with advanced cervical cancer after radiation therapy, we immunohistochemically assayed TS levels in paraffin-embedded tissue sections from 66 patients with stage IIIb cervical cancer using a polyclonal antibody to recombinant human TS. In the 30 patients with high TS expression, the cumulative 5- and 8-year survival rates were 36.8% (95% CI: 17. 4-56.2) and 31.6% (95% CI: 12.4-50.7), respectively. In contrast, the 36 patients with low TS expression showed a significantly (p < 0. 001) better prognosis, with cumulative 5- and 8-year survival rates of 87.2% (95% CI: 75.5-99.0) and 69.2% (95% CI: 50.7-87.7), respectively. These results suggest that TS expression may be useful in determining the prognosis of patients with advanced cervical cancer.

Adult↗
PubMed1999

Quantitative analysis of extracellular matrix proteins in hypertrophic layers of the mandibular condyle and temporal bone during human fetal development.

A computer image analysis of immunostained extracellular matrix (ECM) proteins (collagen types I, II, III and V, fibronectin and tenascin) in hypertrophic layers in the mandibular condyle and temporal bone of human fetuses, which ranged in gestational age from 12 to 32 weeks, was performed. The percentage of cells positive for proliferating cell nuclear antigen (PCNA) increased in almost the same manner in each region. The level of PCNA was markedly elevated at 16 weeks. The percentage of PCNA-positive cells was low in temporal bone and in the bone-forming layer of the mandibular condyle at 24 weeks. Specific concentration patterns of proteins in the ECM were found at each stage of development. The extent of accumulation of fibrillar collagen and of fibronectin differed, while those of other proteins in the ECM, such as tenascin, osteocalcin and osteonectin, were similar at the two sites.

Bone Density↗