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Biomedical subjects

H Minakami

Publications and source records attributed to H Minakami.

At least 73 records · Page 4Linked to original sources
PubMed1999

Enzyme-cytochemically detectable NADPH-diaphorase activity is present in the endoplasmic reticulum and nuclear envelope of the syncytiotrophoblast of the human placenta.

We investigated the subcellular localization of nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) activity, a histo- and cyto-chemical marker of nitric oxide synthase, in human placental trophoblast obtained from women with normal term pregnancies. Tetrazolium salt BSPT was used as the capturing agent. Precipitates of BSPT-formazan indicative of NADPH-d reaction were observed on the membranes of endoplasmic reticulum and nuclear envelope of syncytiotrophoblasts. Our results indicate these two intracytoplasmic organellae are the sites of nitric oxide generation in the syncytiotrophoblasts of normal term human placenta.

Benzothiazoles↗
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

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

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↗
PubMed1997

Calcium-to-creatinine ratio in spot urine samples in early pregnancy and its relation to the development of preeclampsia.

We investigated the relation between an alteration in calcium (Ca) excretion in early pregnancy and the risk of preeclampsia in 1,147 pregnant women. We measured Ca and creatinine (Cr) concentrations in spot urine samples obtained at 12 weeks or less of gestation. Seventy-one (6.2%) had hypertension alone, nine (0.8%) developed superimposed preeclampsia, 39 (3.4%) developed proteinuria alone, and 13 (1.1%) developed preeclampsia; 1,015 women did not develop hypertension or proteinuria. The Ca/Cr ratio was significantly reduced in the 39 women who eventually developed proteinuria (0.116 +/- .103) and 13 who developed preeclampsia (0.121 +/- .063) compared with 1,015 women who had neither hypertension nor proteinuria (0.158 +/- .239). The relative risk of development of preeclampsia, proteinuria, or superimposed preeclampsia was 1.98 (95% confidence interval, 1.22 to 3.22) for women with a Ca/Cr ratio less than the 30th percentile (0.082) compared with women with a Ca/Cr ratio greater than the 30th percentile. These results suggest that preeclampsia may be related, in part, to a relative Ca intake deficiency. Determination of the Ca/Cr ratio in spot urine samples in the first trimester is of only limited clinical value for identifying women with an increased risk of preeclampsia.

Biomarkers↗
PubMed1997

Decrease in cytochrome c oxidase activity detected cytochemically in the placental trophoblast of patients with pre-eclampsia.

This study was designed to explore the possible relationship between cytochemically detectable cytochrome c oxidase (COX) activity in the trophoblast and placental dysfunction in patients with pre-eclampsia. Fifteen placentae (10 from women with an uncomplicated pregnancy and five from patients with pre-eclampsia) were involved in this study. Localization of COX activity in the placental trophoblast was determined by ultrastructural enzyme cytochemistry using DAB as a capturing agent. COX activity was observed in the intracristal spaces and intermembrane spaces of trophoblastic mitochondria. The number of mitochondria positive for COX staining was decreased markedly in the placentae of the women with pre-eclampsia. Trophoblastic mitochondrial dysfunction may be present in placenta of patients with pre-eclampsia.

Electron Transport Complex IV↗
PubMed1997

Comparison of the long-term effects of oral estriol with the effects of conjugated estrogen, 1-alpha-hydroxyvitamin D3 and calcium lactate on vertebral bone loss in early menopausal women.

We investigated the long-term effects of oral estriol (E3) on bone mineral density (BMD) at the lumbar spine and biochemical indices of bone turnover in early menopausal women. We studied 64 healthy early menopausal women who were treated for 24 months with 2.0 mg E3 plus 2.5 mg medroxyprogesterone acetate daily (E3 group, n = 15), 0.625 mg of conjugated estrogen plus 2.5 mg medroxyprogesterone acetate daily (CE group, n = 19), 1.0 microgram 1-alpha-hydroxyvitamin D3 daily (D3 group, n = 13), or 1.8 g calcium lactate containing 250 mg of elemental calcium daily (Ca group, n = 17). The BMD at the third lumbar vertebra was determined by quantitative computed tomography, and serum levels of osteocalcin (OC) and total alkaline phosphatase (Alp), as well as urinary ratios of calcium-to-creatinine (Ca/Cr) and hydroxyproline-to-creatine (Hyp/Cr), were evaluated at baseline and every 6 months. After 24 months of treatment, the BMD decreased significantly by 12 +/- 4.5% (mean +/- S.E.) in the D3 group and 14 +/- 2.5% in the Ca group, but not in the E3 group (-4.1 +/- 4.8% from baseline) and in the CE group (-0.9 +/- 3.2% from baseline). The serum levels of Alp and OC decreased or remained unchanged in the E3 and CE groups, but increased in the D3 and Ca groups. The urinary Ca/Cr was decreased in the E3 and CE groups, but not in the D3 and Ca groups. The urinary Hyp/Cr decreased in the CE group, was unchanged in the E3 and D3 groups, and increased in the Ca group. Uterine bleeding occurred less frequently in the E3 than in the CE group (2.4 +/- 4.2 versus 13.1 +/- 14.8 days/person per year, P < 0.001). The bone-preserving effect of 2.0 mg of oral E3 was comparable to that of 0.625 mg of conjugated estrogen and was superior to that of 1.0 microgram 1-alpha-hydroxyvitamin D3 and 1.8 g Ca. Our findings suggest that a reduction in bone turnover in the E3 group may have contributed to the preservation of bone.

Administration, Oral↗
PubMed1997

Accuracy and utility of a new reflectance pulse oximeter for fetal monitoring during labor.

OBJECTIVE: To evaluate the accuracy of a new pulse oximeter in estimating the oxyhemoglobin (O2Hb) concentration in fetal arterial blood (SaO2) with either a high concentration of hemoglobin F (HbF) or a low concentration of O2Hb during labor. PATIENTS AND METHODS: Fetal forehead arterial oxygenation was determined in 44 fetuses by reflectance pulse oximeter (SpO2) during labor and was compared with SaO2 determined immediately after birth. Because HbF has little or no known effect on pulse oximetry, but does affect the laboratory multiwavelength "CO-oximeter" type reading, the SaO2 was corrected by HbF concentration. SpO2 and SaO2 were simultaneously measured in five hypoxic adult volunteers achieved by inhaling 11% oxygen. RESULTS: A gradual decline in HbF concentration was seen during weeks 37 to 40 of gestation. HbF concentration varied near term, ranging between 53 and 88% of the fetal hemoglobin concentration (mean +/- SD = 74.6 +/- 6.3%). This alteration produced a lower %O2Hb percent by 4% at the most. The corrected SaO2 in cord blood correlated with fetal SpO2 (y = 0.974, x -7.279, r = 0.90). In five adults, SpO2 reflected well SaO2 with a mean +/- SD of bias of -1.1 +/- 2.9%. CONCLUSIONS: SpO2 determined by a new reflectance pulse oximeter at the end of labor correlated with an immediate post-natal cord arterial blood sample before the first breath, with a mean and SD of bias of 8.5 +/- 6.2%. Reflectance pulse oximetry is a useful tool for continuous noninvasive monitoring of the fetal oxygen status during labor.

Adult↗
PubMed1997

Cellular and subcellular localization of nicotinamide adenine dinucleotide phosphate diaphorase activity.

OBJECTIVE: To determine the cellular and subcellular distribution of nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) in the human placenta and thereby to shed light on the possible role of nitric oxide (NO) and NO synthase in this tissue. METHODS: NADPH-d activity in 10 term placenta and in 10 first-trimester placentas was examined by enzyme histochemistry and by both light microscopy and electron microscopy. RESULTS: Light microscopy revealed that NADPH-d activity was marked in the syncytiotrophoblasts, moderate in the endothelium of cord vessels, and weak in the amniotic epithelia and chorionic trophoblasts. At the electron-microscopic level, NADPH-d activity was apparent as small patches distributed throughout the cytoplasm of the syncytiotrophoblasts. CONCLUSION: NO might be generated in the syncytiotrophoblast of the human placenta and might play a role in the regulation of placental hemodynamics or in the signaling between the syncytium and the villous mesenchyme.

Amnion↗