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Biomedical subjects

M Nakabayashi

Publications and source records attributed to M Nakabayashi.

At least 37 records · Page 2Linked to original sources
PubMed1999

Perinatal and infant outcome of pregnant patients undergoing chronic hemodialysis.

Recently, perinatal outcome in patients undergoing chronic hemodialysis has been improved. But the conditions that will most likely result in successful pregnancy are still obscure. We retrospectively analyzed 15 pregnant patients who were undergoing chronic hemodialysis before pregnancy treated in our perinatal center. We divided these 15 cases into 2 groups: one group of 11 patients whose infants survived and the other group of 4 patients whose infants died 6 h to 8 months after birth due to prematurity. The rate of successful pregnancies having a surviving infant was 73.3% (11/15). We compared the maternal conditions and the progress of pregnancy in the 2 groups. Significant differences (p<0.01) were seen as follows. The patients in the group whose infants survived underwent hemodialysis for a shorter term before pregnancy (1-6 years), most of them (9/11) could produce urine (> or =50 ml/day), and the period of gestation was extended (33.3+/-4.7 weeks), so the infants were heavier (1,782.9+/-678.3 g). All the patients who underwent more than 9 years of hemodialysis could not have a surviving infant. From this we can assume that the shorter the period of dialysis before pregnancy, the better the condition is that is likely to result in women giving birth and the better is their infant's chance of survival.

Adult↗
PubMed1999

Time course of changes in mu-opioid receptor mRNA levels in the periaqueductal gray of rat brain by a single or repeated injections of antisense oligodeoxynucleotides.

The effect of phosphorothioated antisense oligodeoxynucleotide (AS ODN) against the mu-opioid receptor (MOR) on MOR mRNA level in the periaqueductal gray (PAG) of rat brain was investigated. The MOR mRNA levels at 3, 6, 12, 24, 48 and 72 h after MOR AS ODN microinjection into the PAG were determined by reverse transcriptase-polymerase chain reaction. The MOR mRNA level was significantly decreased only at 12 h after the injection of 10 microg MOR AS ODN. When 10 microg MOR AS ODN was given three times at the interval of 48 h, MOR mRNA levels were significantly decreased at 6, 12 and 24 h after the last injection of the AS ODN. However, MOR mRNA levels were not significantly changed by three injections at 48-h interval of MOR sense ODN or AS ODNs against delta- and kappa-opioid receptors, although the two latter AS ODNs significantly reduced the respective targeted mRNA levels. In conclusion, the present results show that the selective decrease in MOR mRNA is at least one reason why the reported diminished effects of MOR agonists are produced in animals pretreated with MOR AS ODN, although they could be produced through several mechanisms in which MOR mRNA level does not change.

Animals↗
PubMed1998

Prenatal diagnosis of Fukuyama type congenital muscular dystrophy in eight Japanese families by haplotype analysis using new markers closest to the gene.

We conducted prenatal diagnosis by haplotype analysis, using newly developed microsatellite markers, in eight Fukuyama type congenital muscular dystrophy (FCMD) families. In addition to six new families, two previously reported families were reexamined by haplotype analysis including detection of an ancestral founder haplotype (138-183-301) for 3 microsatellite markers closest to the FCMD gene, designated D9S2105-D9S2107-D9S172, the distances of which from the FCMD gene are presumed to be approximately 140, approximately 20, and approximately 280 kb, respectively. Five fetuses from five families were diagnosed as nonaffected, and were subsequently confirmed to be healthy. Three fetuses of the other three families were diagnosed as having a high probability of being affected by FCMD. In the prenatal diagnosis conducted for these eight families, the ancestral founder allele was observed in 13 of 16 (81%) FCMD-bearing chromosomes. Detection of the ancestral haplotype facilitated achieving accurate prenatal diagnosis of FCMD. The brains of all three fetuses prenatally diagnosed as FCMD-affected showed the initial stage of cortical dysplasia, strong evidence of FCMD.

Brain↗
PubMed1998

Advances in perinatal medical care--from our experience.

In the last 30 years, maternal and perinatal mortality rates have markedly improved in Japan. These results are supported by the advanced technologies and newly developed treatments in obstetric and neonatal medicine, the evidence of which will be described through the authors' experiences. Ultrasound-guided treatments for fetuses and pediatric surgery for extremely tiny infants have been performed with cooperation among cardiac surgeons, anesthesiologists and perinatologists. The remarkable achievements in neonatal medicine are surfactant replacement therapy, application of high frequency oscillation (HFO) respirator, nitric oxide and extracorporeal membrane oxygenation (ECMO) systems and transcutaneous blood gas monitoring. The possibility to have a safe pregnancy and delivery arose for women with severe medical complications such as diabetes mellitus (DM), heart diseases, and hemo-dialysis, factors formerly regarded as contraindications to pregnancy. The accumulative data of these high-risk pregnancies treated in our center are introduced. It is noted that molecular mechanisms in fetal growth have been elucidated to some extent. The insulin-like growth factor I (IGF-I) and IGF-binding protein 1 (IGFBP1) system, and cytokines, are involved in the fetal growth. Newly developed treatments such as urinary trypsin inhibitor (Urinastatin) for prevention of preterm delivery and amnioinfusion to cases of preterm premature rupture of the membrane are summarized. Finally, the reference to advanced medicine and its side effects lead to broad discussions regarding the future development of perinatal medicine.

Adolescent↗
PubMed1998

Management of venous thrombosis and pulmonary embolism after gynecological surgery.

We experienced 23 cases of venous thrombosis after gynecological surgery for the past 12 years at Tokyo Women's Medical University Hospital, representing 0.345 % of all patients. Eighteen of the 23 cases had deep venous thrombosis (DVT) including five cases followed by pulmonary embolism (PE), and five cases had PE without any symptoms of DVT. The main risk factors for thrombosis in these 23 patients were (1) obesity, DM, hyperlipidemia; (2) huge abdominal tumor, severe adhesion; and (3) hemoconcentration, post-treatment of severe anemia. The onset of PE varied from 1 to 3 postoperative days, when the patients started to walk. Five cases had dyspnea, chest pain, and decreased PaO2 levels without leg pain, while five cases showed only calf pain and tenderness with decreased PaO2 levels. PE was confirmed by immediate diagnostic images such as RI venography with ventilation and perfusion lung scan, pulmonary arterial CT, or pulmonary arteriography. Two patients died and eight patients recovered. The best way of managing venous thrombosis might be as follows: (1) identify the risk factors of thrombosis before surgery; (2) perform prophylactic leg exercises in bed and/or active anticoagulant therapy depending on the degree of risk factors; (3) rapid diagnosis with the images; and (4) proper treatment.

Adult↗
PubMed1998

Elevated fetal fibronectin in midtrimester amniotic fluid is involved with the onset of preeclampsia.

OBJECTIVE: To examine early midtrimester amniotic fluid for its significance in pregnancy outcomes, especially with connection to the pathogenesis of preeclampsia. METHODS: A prospective, nested, case-control study was conducted. Fetal fibronectin in early midtrimester (16-20 weeks gestation) amniotic fluid was measured by EIA method. Results were compared by their pregnancy outcomes. RESULTS: Amniotic fluid levels of fetal fibronectin were significantly higher in the group subsequently developing severe preeclampsia (106.8 +/- 13.2 micrograms/ml, mean +/- SD, n = 12) compared with matched controls (66.7 +/- 7.1 micrograms/ml, n = 12) (p < 0.05). CONCLUSION: High levels of fetal fibronectin were found in the amniotic fluid of women subsequently developing severe preeclampsia before any symptom appear. Involvement of extracellular injury or cellular hyperactivity in the midtrimester placental site with the onset of preeclampsia is suggested.

Adult↗
PubMed1998

Elevated IL-6 in midtrimester amniotic fluid is involved with the onset of preeclampsia.

PROBLEM: The primary defect of placental development in preeclampsia is speculated to occur at midtrimester gestation. Abnormal feto-maternal immune reactions have been considered as factors in such defective placentation. METHOD OF STUDY: Midtrimester amniotic fluid specimens were retrospectively identified as coming from gestations that later had severe preeclampsia develop, gestations with normal outcomes, and gestations measured for cytokines tumor necrosis factor-alpha (TNF-alpha), interleukin (IL-1 beta, IL-6, and IL-8). The effect of each cytokine on thrombomodulin levels was tested in cultured trophoblast cells. RESULTS: Among the measured cytokines, IL-6 and IL-8 were significantly elevated in the midtrimester amniotic fluid of the future preeclamptic group. Trophoblasts stimulated with TNF-alpha plus IL-6 had significantly decreased levels of cellular thrombomodulin compared to those without cytokine addition. CONCLUSIONS: Elevated cytokines in midtrimester amniotic fluid suggest an abnormal fetomaternal immune response occurring before the clinical manifestation of preeclampsia. Cytokine-induced suppression of thrombomodulin in trophoblasts may be directly involved in the pathogenesis of preeclampsia.

Amniocentesis↗
PubMed1998

Bronchial hyperresponsiveness, hypersensitivity to analgesics and urinary leukotriene E4 excretion in patients with aspirin-intolerant asthma.

This study was designed to investigate the protective effect of cromolyn sodium on airway sensitivity to sulpyrine, and bronchial responsiveness to methacholine, and to investigate whether this protective activity is associated with reduction in aspirin-induced excretion of urinary leukotriene E4 (u-LTE4), a marker of the cysteinyl LT overproduction that participates in the pathogenesis of aspirin-induced asthma. We assessed the effects of pretreatment with cromolyn sodium on bronchoconstriction precipitated by inhalation of methacholine and sulpyrine in 16 adult patients with mild or moderate aspirin-intolerant asthma; those who were in stable clinical condition and were hypersensitive to a sulpyrine provocation test were included in this study. A double-blind, randomized, crossover design was used. u-LTE4 was measured using combined reverse-phase high-performance liquid chromatography enzyme immunoassay. Cromolyn sodium protected against analgesic-induced bronchoconstriction through mechanisms that are not related to its bronchodilator property, but to the improvement of both bronchial hyperresponsiveness and hypersensitivity to analgesics (p<0.01 and p<0.001). Although excretion of u-LTE4 did not increase after the methacholine provocation test, it significantly increased after sulpyrine provocation (p<0.01). Furthermore, after pretreatment with cromolyn sodium, the maximum level of u-LTE4 after the sulpyrine provocation test was significantly lower than in controls (p<0.01). These results support the hypothesis that cysteinyl LT is one of the most important components in the pathogenesis of aspirin-intolerant asthma. Cromolyn sodium improves both hypersensitivity to analgesics, and bronchial hyperresponsiveness in aspirin-intolerant asthma.

Adult↗
PubMed1998

[Clear cell ependymoma--a case report].

A case of intraaxial clear cell ependymoma is reported. A 46-year-old man complained of right hemiparesis. CT scan showed a mass lesion on the median plane with a huge cyst in the left frontal lobe. MRI showed an iso-low intensity mass by T1-weighted image. The tumor was heterogeneously enhanced by Gd-DTPA and the wall was enhanced as well. Angiogram revealed a tumor stain from the right internal carotid artery. The main mass of the tumor was totally removed but the cystic wall was left removed. Histopathological examination revealed clear cell ependymoma. Immunohistochemical examination revealed that, although vimentin and NSE were positive, GFAP, synaptophysin and S-100 were negative. Ultrastructual examination revealed cilia, microvilli and desmosomal junctions. The patient fully recovered after operation and showed no sign of recurrence after an year of follow-up. Clear cell ependymoma is a rare variant of ependymoma. Ultrastructual examination was more useful than immunohistochemical examination for diagnosis.

Brain Neoplasms↗
PubMed1997

Statistical analysis of perinatal outcomes in pregnancy complicated with diabetes mellitus.

OBJECTIVE: To evaluate the outcomes of pregnancies complicated with diabetes mellitus (DM) in the maternal and perinatal center of Tokyo Women's Medical College (TWMC), and compare the results with reports of other countries. METHODS: A retrospective study of 482 cases of DM pregnancies were included over a 13-year period in a tertiary care hospital in Tokyo. Information were obtained from medical records of both mothers and babies. RESULTS: The prevalence of pregnancies complicated with DM was 5.1%. Preeclampsia developed in 124 cases at a rate of 25.8%. Incidence of preterm delivery was 16.6%. Caesarean sections were performed in 36.7% patients. There were significant differences of caesarean section rates between diabetic complication group (retinopathy and nephropathy) and non-complication group (69.5% vs 30.5%, p < 0.0001), and between preterm and term deliveries (60.0% vs 32.1%, p < 0.0001). Maternal backgrounds significantly involved with preterm delivery were DM nephropathy and severe preeclampsia. Babies with heavy for gestational age (HGA) were observed at a rate of 21% in all. There were 3 perinatal deaths (intrauterine fetal deaths, IUFD) with the perinatal mortality rate of 6.1/1,000 births. The incidence of caesarean section and perinatal mortality rate of non-DM pregnancies in our center during the same study period were 16.3% and 7.7/1,000 births respectively. CONCLUSIONS: The perinatal outcome in our study was better compared to other worldwide reports. With accurate perinatal management, perinatal mortality rate of DM pregnancies in the current study was almost same as that of non-DM pregnancies in our center. The main factors to promote adverse perinatal outcomes were presence of DM nephropathy and severe preeclampsia.

Adult↗
PubMed1997

[Pregnancy after augmentation cystoplasty. A case report].

A 31-year-old woman with a history of spina bifida occulta became pregnant after ileocystoplasty for her neurogenic bladder. During the pregnancy she had frequent episodes of febrile urinary tract infections, and progressive hydronephrosis appeared in the second trimester. At 25 weeks gestation she was complicated by severe pyelonephritis requiring the intervention with the placement of double pigtail ureteral stent. However, long term efficacy of ureteral stent was questionable and this indwelling catheter caused bacteriuria which was not eradicated by intravenous antibiotics. Classical cesarean section was performed at 32 weeks of gestation due to the fear of fetal distress. Neobladder and mesenteric blood supply were adherent to the anterior surface of the uterus. Urinary tract infection is extremely common during pregnancy after enterocystoplasty. The most important point is prophylactic antibiotics throughout the pregnancy. At the time of cesarean section, a reconstructive urological surgeon should be part of the operative team and take great care to avoid injury to the blood supply of cystoplasty.

Adult↗
PubMed1997

Neonatal hypoglycemia in infants with intrauterine growth retardation due to pregnancy-induced hypertension.

The early-onset type (onset earlier than 28 gestational weeks) of pregnancy induced hypertension (PIH) has the clinical characteristics of a high incidence of intrauterine growth retardations (IUGR), fetal distress, neonatal hypoglycemia and hypertensive disposition. Moreover, the infants from early-onset type of PIH mothers showed a statistically significant higher incidence of neurological handicap (cerebral palsy, mental retardation and epilepsy) than late onset type. The infants with a neurological handicap had severe IUGR and intractable hypoglycemia in the early neonatal period, probably due to low storage of glucose in the liver and fetal hypoxia. Appropriate perinatal management, including proper evaluation of fetal well-being and good timing of delivery, could improve the outcome of infants from early-onset type of PIH mothers.

Anthropometry↗
PubMed1996

The imbalance of plasminogen activators and inhibitor in preeclampsia.

OBJECTIVE: To evaluate the role of plasminogen activators (tPA uPA) and inhibitor (PAI-1) in the pathogenesis of preeclampsia. STUDY DESIGN: tPA uPA and PAI-1 antigens were measured in amniotic fluid, maternal plasma, and placental homogenates in normal pregnancy by ELISA method and compared with that of preeclampsia. RESULTS: In normal pregnancy, tPA, uPA and PAI-1 levels increase as the gestation advance, but the increment of PAI-1 in amniotic fluid (28.3-fold) is larger than that of tPA and uPA (1.8-fold, 8.5-fold) (p < 0.001). Decidua homogenates contained larger amount of PAI-1 than villi. Whereas, villi had higher levels of tPA uPA than decidua (p < 0.01). In preeclampsia, the significantly higher levels of PAI-1 were observed in AF and decidua tissue as compared to the normals (p < 0.01), and the increment of PAI-1 in preeclampsia is larger than that of tPA, uPA. CONCLUSIONS: The elevated PAI-1 level is associated with the preeclampsia and the imbalance between the plasminogen activators (tPA, uPA) and the inhibitor (PAI-1) might be involved in the pathogenesis of preeclampsia.

Amniotic Fluid↗
PubMed1995

Regulation of the plasminogen activator/plasmin system by epidermal growth factor in cultured human endometrial cells.

Recent studies have suggested that epidermal growth factor (EGF) and plasminogen activators (PA) are involved in the implantation of concepti. Therefore we attempted to evaluate the effect of EGF on the release of PA in primary cultures of human endometrial cells. The addition of EGF to culture medium increased the release of tissue-type PA (t-PA). The effect of EGF was significant at 5 ng/ml, which produced a 45% increase in t-PA release. EGF also stimulated the release of urokinase-type PA (u-PA), as well as the release of PA inhibitor type 1 (PAI-1). These stimulatory effects on the release of t-PA and PAI-1, but not of u-PA, were enhanced by the concomitant addition of progesterone. The modulatory effect of EGF on PA release seemed to be selective in that other growth factors, such as basic fibroblast growth factor, transforming growth factor beta and interleukin-1 beta, did not affect the release of PA. From these data, we propose that EGF in concert with progesterone participates in embryo implantation, the process entailing tissue remodelling and cell migration in part by modulating the PA/plasmin system.

Cells, Cultured↗