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Biomedical subjects

I Sato

Publications and source records attributed to I Sato.

At least 145 records · Page 8Linked to original sources
PubMed1998

Loss of heterozygosity on chromosome 6q27 and p53 mutations in epithelial ovarian cancer.

Loss of heterozygosity (LOH) in chromosome region 6q27 and p53 mutations were studied to attempt to clarify the genetic etiology of ovarian cancer, with particular reference to clear cell adenocarcinoma (CCC), which has a poor prognosis. 6q27 LOH in 70 epithelial ovarian cancer patients was examined using four restriction fragment length polymorphism markers located at 6q27; p53 mutations in tumor DNA were detected using polymerase chain reaction single-strand conformation polymorphism and sequencing. 6q27 LOH was confirmed in 26 of 48 informative cases (54.2%). No differences in the incidence of 6q27 LOH were seen by histologic type; 6q27 LOH was observed in 45% (5/11) of CCCs. p53 mutations were detected in 19 of the 48 tumors (39.6%), but in only one (9%) CCC. These results suggest that a putative tumor suppressor gene involved in the onset of epithelial ovarian cancer is located at 6q27. This gene is one of the keys to clarifying the genetic etiology of epithelial ovarian cancer and particularly CCC, given the low incidence of p53 mutations in this tumor type.

Adenocarcinoma, Clear Cell↗
PubMed1998

Expression of chemokines and induction of rapid cell death in human blood neutrophils by Mycobacterium tuberculosis.

To elucidate the role of neutrophils in the early inflammatory response to mycobacterial infection, expression of chemokines interleukin (IL)-8 and macrophage inflammatory protein-1alpha (MIP-1alpha) was examined in human blood neutrophils in response to the lipopolysaccharide (LPS) of Escherichia coli, which induces acute inflammation, or to Mycobacterium tuberculosis or purified protein derivative (PPD), which induce chronic mycobacterial inflammation. Neutrophils stimulated with LPS, M. tuberculosis, or PPD expressed both IL-8 and MIP-1alpha. Expression of IL-8 and MIP-1alpha was lower after stimulation with M. tuberculosis or PPD than after stimulation with LPS, but the kinetics of expression did not differ significantly. In contrast, both M. tuberculosis and PPD with tumor necrosis factor-alpha induced neutrophils to undergo rapid cell death, which might remove neutrophils and activate macrophages at sites of mycobacterial inflammation. The findings suggest that neutrophils play important roles in the host defense against mycobacterial infection.

Apoptosis↗
PubMed1998

Lower risks of adverse outcome in twins conceived by artificial reproductive techniques compared with spontaneously conceived twins.

The outcomes of twins conceived by 136 women after medical assistance (MA) such as ovulation induction with or without assisted reproductive techniques, and twins conceived spontaneously (SP) by 72 women were compared. All 208 women were monitored from < 20 weeks gestation; they all delivered at > or = 24 weeks gestation. The chorionicity of the placenta was diagnosed antenatally and confirmed after delivery. There were 10 perinatal deaths; the physical and neurological status of the remaining 406 infants was assessed at 1 year of corrected age. There were no differences in gestational age at birth, the birth weights of the larger and smaller twins, the birth weight discordance, or the incidence of life-threatening major malformations between groups. Adverse infant outcomes, such as death, cerebral palsy and mental retardation occurred in nine (3.3%) of 272 MA twins compared with 12 (8.3%) of 144 SP twins (P < 0.05). The placenta was monochorionic in only three (2.2%) of 136 MA twin pregnancies compared with 41 (57%) of 72 SP twin pregnancies (P < 0.001). Of the 21 infants with adverse outcomes, nine had monochorionic placentas. Thus, the risk of an adverse outcome was 2.8-fold higher (95% confidence interval (CI) 1.2-6.4) in monochorionic twins than in dichorionic twins (10 versus 3.7%; P < 0.05). There was no difference in the incidence of adverse infant outcomes between SP (4.8%) and MA (3.4%) twins with dichorionic placentas. These findings suggest that ovulation induction in itself was not associated with an adverse outcome of twin pregnancies. The lower frequency of monochorionic placentas in MA twins may have been responsible for the lower risk of an adverse outcome in MA twins.

Birth Weight↗
PubMed1998

Vaginal birth after cesarean delivery: results in 310 pregnancies.

OBJECTIVE: To assess and compare the risk associated with a trial of vaginal birth after cesarean section (VBAC) with the risk of an elective repeat cesarean section. METHODS: A retrospective review of the records of 310 consecutive women who, at the Jichi Medical School Hospital in the 6-year period of 1990 through 1995, had previously undergone a primary cesarean section and gave birth to a singleton infant weighing > or = 2,000 g at > or = 36 weeks of gestation in a subsequent pregnancy. RESULTS: Elective cesarean sections were performed on 96 (31%) of 310 women, and VBACs were attempted by 214 women (69%). Vaginal deliveries were successful in 132 (43%) of the 310 pregnancies. No maternal death or perinatal deaths occurred in either group. A uterine rupture occurred in 2 (0.9%) of the 214 women who attempted a VBAC, and 5 women (2.3%) gave birth to neonates with a 1-minute Apgar score < or = 6. None of the 96 women who underwent an elective cesarean section had such complications, although the difference in these complication rates did not reach a significant level. CONCLUSIONS: A trial of a VBAC significantly reduced the rate of cesarean sections. Although the rates of uterine rupture and neonatal asphyxia were slightly higher in women who attempted a VBAC than in women who underwent an elective cesarean section, obstetricians should offer the option of a trial of labor, because more than one-half of the women with a previous cesarean delivery might have successful vaginal deliveries, and the VBAC-related maternal mortality rate does not reportedly differ between women undergoing a trial of labor and women undergoing an elective repeat cesarean section.

Adult↗
PubMed1998

Triplet pregnancy complicated by a gradual decline in antithrombin-III activity and HELLP syndrome: a case report.

We prospectively evaluated the antenatal changes in antithrombin-III (AT-III) activity and liver enzymes in a woman with a triplet pregnancy. A gradual decline in AT-III activity occurred in the absence of clinical signs of preeclampsia and preceded the onset of the typical HELLP syndrome in this patient. Monitoring of AT-III activity might help to avoid the development of severe HELLP syndrome.

Adult↗
PubMed1998

Effect of daily vaginal disinfection on duration of gestation after premature rupture of the membranes and on infant outcome.

OBJECTIVES: We examined the effects of daily vaginal disinfection on the interval between premature rupture of the membranes (PROM) and delivery and on infant outcome. METHODS: Daily vaginal disinfection with povidone iodine was performed on 43 women with PROM. The control group consisted of 59 women with PROM who did not undergo vaginal disinfection. In both groups, the infants born to these women were followed until 1 year of corrected age. RESULTS: The degree of cervical dilatation, the leukocyte count, and the serum C-reactive protein level on admission did not differ between the 2 groups. Although there was no difference in the gestational week at delivery between the groups, the interval between PROM and delivery was significantly longer in the disinfectant group than among the control subjects (9.5 +/- 14.9 days vs. 3.9 +/- 5.1 days, p < 0.01). There was no difference in infant outcome between the 2 groups. CONCLUSIONS: These findings suggest that daily vaginal disinfection with povidone iodine prolongs the duration of gestation in women with PROM and dose not have an adverse effect on the fetus.

Adolescent↗
PubMed1998

Effect of desmopressin on plasma factor VIII and von Willebrand factor concentrations in Greyhounds.

OBJECTIVE: To determine the effect of 1-Deamino-8-D-arginine vasopressin on plasma concentrations of von Willebrand factor and factor VIII in Greyhound blood donors, and to compare the response of 1-Deamino-8-D-arginine vasopressin injection on plasma concentrations of von Willebrand factor between groups with different resting plasma concentrations of von Willebrand factor. ANIMALS: Fifteen Greyhound blood donors were used. Dogs were grouped into three categories depending on their von Willebrand factor concentrations. PROCEDURE: Desmopressin was administered subcutaneously at 1 microgram/kg [corrected] to all dogs. Plasma von Willebrand factor and factor VIII concentrations were measured before and 10, 20, 30, 45, 60, 90 and 120 min after desmopressin injection. RESULTS: The von Willebrand factor and factor VIII concentrations in all dogs increased significantly and remained higher than base-line throughout the 2 h period. CONCLUSION: Desmopressin is useful in increasing von Willebrand factor concentrations in Greyhound blood donors, including those with low resting concentrations.

Animals↗
PubMed1998

Changes in polymorphonuclear leukocytes in the vagina of patients with preterm labor.

To evaluate changes in vaginal polymorphonuclear leukocytes (vPMNL) in patients with preterm labor, we obtained vPMNL-rich suspensions from vaginal fluids of 77 women (21 with preterm labor and 56 control women with uncomplicated pregnancy). Total counts of vPMNL and % viability of vPMNL (viable vPMNL:total vPMNL) were significantly higher in patients with preterm labor (37 +/- 92 x 10(5), 23 +/- 29%) vs. controls (11 +/- 15 x 10(5), 6.9 +/- 8.3%). The concentration of granulocyte elastase in vaginal fluid diluted to 20 ml was also higher in patients with preterm labor than in controls (4,806 +/- 3,818 vs. 2,739 +/- 2,556 ng/ml). We conclude that PMNL and granulocyte elastase are abundant in the vagina in patients with preterm labor, which suggests that the PMNL may be involved in the pathogenesis of preterm labor.

Adult↗
PubMed1998

Stimulated polymorphonuclear leukocytes in vaginal secretions from patients with preterm labor.

The purpose of this study was to examine evidence for the presence of activated vaginal leukocytes in women with preterm labor. Vaginal polymorphonuclear leukocytes from 7 patients in preterm labor (24-32 weeks of gestation) as well as from 7 control women with uncomplicated pregnancy were analyzed morphologically using transmission electron microscopy. Peroxidase and NADPH oxidase cytochemistry was also performed. Viable leukocytes were abundant in patients in preterm labor. Phagosomes, phagocytosis of bacteria, attachment of primary granules to the phagosomal membrane, and cell surface projections were observed in the vaginal leukocytes but not in the peripheral blood leukocytes. Peroxidase activity was visible on the cell surface, the phagosomal membrane, and the primary granules. NADPH oxidase activity was demonstrated on the cell surface of leukocytes. Morphological and cytochemical features indicated that vaginal polymorphonuclear leukocytes were stimulated in situ. Such stimulated leukocytes may play a role in the pathogenesis or pathophysiology of preterm labor.

Cell Survival↗
PubMed1998

Comparative changes in uterine artery blood flow waveforms in singleton and twin pregnancies.

We prospectively studied 99 women with uncomplicated singleton pregnancies and 24 women with uncomplicated twin pregnancies to examine the effect of the location of the placenta on the pulsatility index (PI) in the uterine arteries in twin pregnancies and to compare singleton and twin pregnancies with regard to changes in the PI of uterine arteries over the course of the pregnancy. The flow velocity waveforms in both the right and left parametrial uterine arteries were recorded longitudinally at 2-week intervals from a gestational age of 19 weeks until delivery. The location of the placenta was determined by real-time ultrasonography at 18-20 weeks of gestation to determine which uterine artery was the ipsilateral artery. In both the ipsilateral and contralateral uterine arteries, the PI exhibited a steady decrease toward term in singleton pregnancies. In twin pregnancies, the PI exhibited a steady decrease until 27 weeks of gestation and remained unchanged thereafter. The PI in the ipsilateral artery was consistently lower than that in the contralateral artery in singleton as well as twin pregnancies. The mean values of PI of the ipsilateral and contralateral uterine arteries of twin pregnancies was consistently lower than that of singleton pregnancies at any gestational week. These results suggest that the ipsilateral uterine artery contributes more to placental perfusion than does the contralateral uterine artery in twin as well as in singleton pregnancies. Twin pregnancies differed from singleton pregnancies with respect to changes in PI in the uterine artery according to gestational age. The PI of uterine arteries declined more rapidly and reached a plateau earlier in twin than in singleton pregnancies.

Adult↗
PubMed1998

Relation between gestational thrombocytopenia and the syndrome of hemolysis, elevated liver enzymes, and low platelet count (HELLP syndrome).

OBJECTIVE: To define the clinical features of gestational thrombocytopenia and to determine its relationship to the syndrome of hemolysis, elevated liver enzymes, and low platelet count (HELLP syndrome). STUDY DESIGN: Retrospective cohort study. We reviewed the records of 24 women with gestational thrombocytopenia among 637 nonpreeclamptic women who had serial determinations of the platelet count during pregnancy between 1992 and 1995. Gestational thrombocytopenia was defined as an antenatal gradual decline in the platelet count to <150 x 10(9)/l in nonpreeclamptic women. The control group consisted of 213 nonpreeclamptic women whose platelet counts were > or = 150 x 10(9)/l at -3 to 0 days from delivery and in whom the perinatal serum level of aspartate transaminase (AST) had been determined. RESULTS: The platelet count decreased gradually, from 210+/-31 x 10(9)/l at < 13 weeks' gestation to 127+/-24 x 10(9)/l at -3 to 0 days from delivery, in the 24 women with gestational thrombocytopenia. The platelet count was 251+/-62 x 10(9)/l at -3 to 0 days from delivery in the 213 control women. The serum level of AST was elevated perinatally in 5 (21%) of 24 women with gestational thrombocytopenia compared with 6 (2.8%) of the 213 control subjects (p < 0.001). There had been 28 previous term or near-term pregnancies among 17 women with gestational thrombocytopenia, 14 of which were complicated by gestational thrombocytopenia or a decline in the platelet count by > 50 x 10(9)/l; 1 pregnancy was associated with the features typical of the HELLP syndrome. CONCLUSION: Gestational thrombocytopenia may be a risk factor for the development of the HELLP syndrome and is likely to recur in subsequent pregnancies.

Aspartate Aminotransferases↗
PubMed1998

Developmental changes in enzyme activities and in structural features of rat masticatory muscle mitochondria.

The functional ability of a muscle is closely related to the activities of the mitochondria, which are energy-producing organelles in muscle cells. The development of the mammalian masticatory muscle progresses dramatically when feeding behavior changes from suckling to mastication, but it is unclear how the energy-producing systems of the mitochondria change. In this paper, the development of rat masticatory muscle mitochondria was investigated in terms of enzyme activities of the mitochondrial respiratory chain and the structural and numerical development of mitochondria, especially regarding the change in feeding behavior from suckling to mastication. Using isolated mitochondria from the masticatory muscle, we measured succinate dehydrogenase, NADH dehydrogenase, succinate-O2 oxidoreductase, and NADH-O2 oxidoreductase. These were found to be increased in the 15-day postnatal rat compared with the 0- to 10-day postnatal rat. The structural development of mitochondria was gradual in the 0- to 15-day postnatal rat. However, a notable increase was found in the cross-sectional area of mitochondria between 10 and 15 days postnatally. The number of mitochondria per muscle fiber was apparently constant during the same period. We demonstrated that the change in feeding behavior was well-correlated with an increase in mitochondrial enzyme activity, also supported by the early structural development of mitochondria.

Aging↗
PubMed1998

A possible role of nitric oxide formation in the vasodilatation of rabbit ear artery induced by a topically applied Capsaicin analogue.

Effects of topical application of a capsaicin analogue, nonylic acid vanillylamide (NVA, 0.032-10.0 mM) on the arterial diameter in the ear skin were examined in conscious rabbits using a precise dial caliper. In addition, the possibility of nitric oxide (NO) participating in a vasodilatation induced by low concentrations of NVA was tested by an NO synthase inhibitor. At the lowest concentration of NVA (0.032 mM), no significant change in the diameter was observed after external application of the NVA ointment. At concentrations of 0.32 mM or more, NVA produced a significant vasodilator response. However, at higher concentrations of 3.2 and 10.0 mM, -NVA induced substantial shrinkage in the arterial diameter and oedema formation, which was not affected by L-NAME (NG-nitro-L-arginine methyl ester, 3 mg/kg, i.v.), suggesting fluid leakage induced by oedema from the vessels might suppress the vasodilatation. Thus, the concentration-response curve for NVA was bell-shaped. NVA (0.32 mM)-induced vasodilatation was not significantly affected by atropine (1 mg/kg, i.v.) or propranolol (80 micrograms/kg, i.v.). However, the NVA-induced vasodilatation was completely suppressed by an NO synthase inhibitor, L-NAME (3 mg/kg, i.v.) which had no influence on the resting diameter, but not by an inactive stereoisomer, D-NAME (3 mg/kg, i.v.). These findings suggest that vanilloid receptor activation results in the release of sensory neuropeptides, which in turn stimulate the synthesis of endothelial NO which is responsible for the vasodilatation.

Administration, Topical↗
PubMed1998

Difference in outcome of twins between early and delayed referrals.

Data on the prognosis of twins from tertiary institutions may not represent the general incidence of adverse infant outcomes. We retrospectively investigated the infant outcome in 32 twin gestations referred to us at 29.9 +/- 3.7 weeks of gestation (range, 21 to 38 weeks) (late referral group) and 237 twin gestations that had been monitored by us since < 20 weeks' gestation (control group). The physical and neurological status of infants was assessed at 1 year of corrected age. Delivery occurred 3.1 weeks earlier in the late referral group than in the control group (32.4 +/- 3.9 vs 35.5 +/- 2.4 weeks, p < 0.001). Deaths by 1 year of age and disabilities such as cerebral palsy, mental retardation, and epilepsy occurred in 16 (25%) of 64 infants in the late referral group compared with 24 (5.1%) of 474 infants in the control group (p < 0.001). Thus, the inclusion of data on women who were referred late increased the incidence of adverse infant outcomes in our tertiary hospital from 5.1% to 7.4% (40/538). It was not known whether an early referral to a tertiary hospital would have improved the outcome in the late referral group. These findings suggest that data from tertiary institutions on the prognosis of twins may be affected adversely by the inclusion of data on women who are referred because of complications.

Birth Weight↗
PubMed1998

Expression and purification of biologically active porcine follicle-stimulating hormone in insect cells bearing a baculovirus vector.

Biologically active recombinant porcine FSH (rec-pFSH) free from the cognate pituitary glycoprotein hormone LH was produced. It was synthesized by a baculovirus vector-insect cell system using two cDNAs encoding the glycoprotein alpha and FSH beta subunits. Its antigenicity was the same as that of pFSH prepared from the pituitary. Glycosylation of rec-pFSH was shown by tunicamycin treatment but the molecular mass of each subunit was lower than that of pituitary-derived FSH, because of the absence of trimming of terminal sugars in insect cells. Rec-pFSH was secreted into the culture medium at about 1 mg/l and purified in six fractions, because of the heterogeneity of the sugar group, by S-Sepharose and concanavalin A-Sepharose column chromatography. The biological activity of rec-pFSH was examined by measuring its effect on progesterone secretion from porcine granulosa cells and germinal vesicle breakdown (GVBD) of porcine oocytes. It showed adequate activity with respect to progesterone secretion, although some fractions rich in the sugar group showed lower activity than that of pituitary-derived FSH. It exhibited higher GVBD activity than that of pituitary-derived FSH at concentrations as low as 1 ng/ml. These results demonstrate that the baculovirus vector-insect cell system can provide biologically active rec-pFSH.

Animals↗
PubMed1998

The endomysium of human embryonic hyoid muscle during development.

A computer analysis was performed on the endomysium of the hyoid muscle in human fetuses, which ranged in gestational week from 12 to 32 weeks. During development of the human hyoid muscle a level of intramuscular connective tissue as reticular fibers displays a specific change in morphology. We examined quantitates and distributions of endomysium in human hyoid muscles from 12 to 32 weeks. The endomysium of the hyoid muscles formed complex structures, and volume rates increased from 20 weeks gestation. On the other hand, the cross sectional area (CSA) of muscle fibers had almost the same profile. The reticular fibers increased during development from 16 to 28 weeks gestation.

Connective Tissue↗