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Biomedical subjects

A Itakura

Publications and source records attributed to A Itakura.

At least 55 records · Page 3Linked to original sources
PubMed1997

Increased mitochondrial damage by lipid peroxidation in trophoblast cells of preeclamptic placentas.

Lipid peroxides and their related free radicals have been implicated in the pathogenesis of placental dysfunction in preeclampsia. Recent studies suggest that the placenta is a source of the increased lipid peroxides in the maternal circulation of women with preeclampsia. We examined intracellular localization of 4-hydroxy-2-nonenal (HNE: a major aldehydic product of lipid peroxidation)-modified proteins in human placentas by immunohistochemistry, and immunoblotting. The trophoblast layer of the chorionic villi showed intense immunoreactivity for HNE-modified proteins in 4 of 12 preeclamptic placentas, whereas no staining was observed in 12 normal placentas. Immunoblotting revealed that three immunoreactive proteins with apparent molecular mass of 110 kDa, 75 kDa, and 70 kDa were localized in the mitochondrial fraction. The present results indicate that the damage to mitochondrial proteins by lipid peroxidation by products and subsequent dysfunction of trophoblasts contribute to the pathophysiology of preeclampsia.

Aldehydes↗
PubMed1997

Levels of hepatocyte growth factor and its messenger ribonucleic acid in uncomplicated pregnancies and those complicated by preeclampsia.

The purpose of this study was to elucidate the possible relationship between hepatocyte growth factor (HGF) expression and the pathogenesis of preeclampsia. The concentration of immunoreactive HGF was measured and the expression of HGF messenger ribonucleic acid (mRNA) assessed in human placentas obtained from two groups: uncomplicated and preeclamptic pregnancies at various gestational weeks. In addition, the localization of HGF mRNA and c-met protein was analyzed using in situ hybridization and immunohistochemical staining, respectively. The expression of HGF mRNA and the concentration of immunoreactive HGF were highest in second trimester and were significantly decreased in preeclamptic placentas compared with the uncomplicated cases in third trimester. HGF mRNA was localized to placental mesenchymal cells, whereas c-met protein was demonstrated on cytotrophoblast. These results provide evidence of an abnormality of HGF expression in the preeclamptic placentas. Such placentas exhibit the abnormally shallow trophoblast invasion of the uterus, and reduced expression of HGF could well account for this morphometric change.

Blotting, Northern↗
PubMed1997

A live birth from intracytoplasmic injection of a testicular spermatozoon.

Testicular sperm was retrieved from a man with complete epididymal obstruction, and intracytoplasmic sperm injection was performed on his wife's oocytes. In four mature treated, two fertilized eggs were obtained, and a clinical pregnancy was established with embryo transfers. One healthy girl (2715 g) was delivered by cesarean section at 38 weeks' gestation. Our case shows that the use of testicular sperm can result in a normal live birth.

Adult↗
PubMed1997

Conservative handling of the uterus in a 10-week cervical pregnancy case.

A patient with a living 10-week old cervical pregnancy who desired to preserve fertility was successfully treated with methotrexate, intraamniotic KCI injection and endocervical curettage. In the case of living cervical pregnancy even after 10 weeks, conservative treatment remains an option, although intensive management and care should be given.

Adult↗
PubMed1996

Oxytocin is hydrolyzed by an enzyme in human placenta that is identical to the oxytocinase of pregnancy serum.

The hydrolysis of oxytocin (OT) by human placental subcellular fractions and pregnant sera was studied in the presence of bestatin, a potent inhibitor of aminopeptidases, and the antibody against pregnant serum oxyotocinase (P-LAP)(EC 3.4 11.3) by measuring liberated amino acids by high performance liquid chromatography (HPLC). Our immunotitration study and the effect of bastatin on the oxytocin-degrading protease showed that the initiating and responsible protease in oxyotocin degradation in human placenta and pregnant serum is P-LAP.

Amino Acid Sequence↗
PubMed1996

Timing of periventricular leukomalacia using neonatal electroencephalography.

OBJECTIVE: To estimate the timing of brain damage involved in the onset of periventricular leukomalacia in the perinatal period we recorded and analyzed neonatal electroencephalograms (EEGs). METHODS: Twenty-four preterm birth infants proved by real time ultrasonic examination or MRI to be suffering from periventricular leukomalacia underwent serial electroencephalography from soon after birth. RESULTS: Thirteen (54%) demonstrated intrauterine injury patterns, 2 infants (8%) showed postnatal injury, and in the remaining 9 cases (38%) the time of injury could not be determined by electroencephalography. Antepartum maternal hemorrhage (6), premature rupture of membranes (3), twining (3), chorioamnionitis (2), and perinatal asphyxia (2) were complications encountered in the group with intrauterine injury patterns. CONCLUSIONS: Our observations suggest that more than half of periventricular leukomalacia cases are associated with premature birth infants showing intrauterine injury patterns on electroencephalography, indicating the existence of intrauterine insult.

Brain Injuries↗
PubMed1996

Relationship between the changes in maternal serum placental leucine aminopeptidase (P-LAP) activity and umbilical artery waveforms in normal pregnancy.

The relation between placental leucine aminopeptidase (P-LAP) activity in maternal sera and umbilical artery waveforms (systolic/diastolic ratio, S/D) obtained by pulsed Doppler has been examined by cross-sectional study in 26 normal pregnancies during weeks 26-38. A negative correlation was seen to exist suggesting that P-LAP may have a role in the regulation of uteroplacental blood flow.

Adult↗
PubMed1996

A prospective study on the relationship between intrapartum maternal group-B streptococcal concentration and signs of infection in neonates.

OBJECTIVE: Our purpose was to examine the effects of intrapartum vaginal Group-B streptococcal (GBS) colonization on neonatal signs of infection. STUDY DESIGN: We performed a quantitative GBS culture of vaginal specimens in 1,280 pregnancies within 24 hours before delivery and examined signs of neonatal infection within 48 hours after birth. Among them, 287 pregnant women had premature ruptures of membranes. RESULTS: The rate of vaginal GBS colonization in groups with and without ruptured membranes was 22.0% and 11.3%, respectively. The incidence of neonates with signs of infection born to GBS-carrier women in each group was 28.6% and 8.8%, respectively. There were significant differences between the groups with regard to both the rate of colonization and the incidence of infection. Signs of neonatal infection increased in proportion to the maternal GBS concentration only in women with ruptured membranes. CONCLUSION: This study suggests that there is an important association between maternal GBS concentration and mild neonatal infections after birth, especially in women with premature ruptures of membranes.

Female↗
PubMed1996

Trophoblast cell monolayers on polycarbonate membranes as a preparative approach for studies of transcellular transport.

To investigate mechanisms of transplacental transfer, the trophoblast-derived cells were cultured on a polycarbonate membrane with 0.4 micron pores and medium on each side. The cells could form microscopically continuous cellular sheets over Transwell polycarbonate membranes. Permeability studies suggested however that the cell layer possesses a significant leak that must be controlled for. The results indicate that the transfer of substances through lateral intercellular spaces must be considered when studies of trans-trophoblast transfer are performed using cell monolayers.

Biological Transport↗
PubMed1995

Initiating and responsible enzyme of arginine vasopressin degradation in human placenta and pregnancy serum.

The hydrolysis of arginine vasopressin (AVP) by human placental subcellular fractions and pregnancy sera was studied in the presence of selective inhibitors and the antibody against pregnancy serum oxytocinase (P-LAP) (EC 3.4.11.3) by measuring liberated amino acids by high-performance liquid chromatography (HPLC). AVP degradation by placental subcellular fractions and pregnancy sera was inhibited by bestatin. The IC50 values of bestatin on AVP degradation by placental subcellular fractions and pregnancy sera were similar to that of this inhibitor on the P-LAP measured by L-Leu-p-nitroamnilide as a substrate (LAP activity), which we reported previously. Our immunotitration study clearly showed that the initiating and responsible protease in AVP degradation in human placenta and pregnancy serum is P-LAP. Since N-benzylcarbonyl-valyl-prolinal (Z-Val-prolinal), a selective inhibitor of post-proline endopeptidase, and phosphoramidon, a putative endopeptidase-24.11 inhibitor, could not significantly influence the degradation of AVP by placental microsomal fractions. Neither enzyme seems to be actively involved in AVP degradation.

Amino Acid Sequence↗
PubMed1995

Levels of hepatocyte growth factor in maternal serum and amniotic fluid.

OBJECTIVE: The purpose of our study was to investigate hepatocyte growth factor levels in maternal serum and amniotic fluid during pregnancy. We also demonstrated production and secretion of hepatocyte growth factor by placenta and amnion at different stages of gestation. STUDY DESIGN: Hepatocyte growth factor levels in maternal serum (n = 219), cord blood (n = 20), and amniotic fluid samples (n = 90) were measured by an enzyme-linked immunosorbent assay. The secretion of hepatocyte growth factor by placenta and amnion was evaluated by measuring the amount released into the culture supernatant. RESULTS: Most hepatocyte growth factor levels in maternal serum were below the detection limit before 10 weeks of pregnancy. Levels increased significantly thereafter and continued to increase until term. On the other hand, levels in amniotic fluid were significantly higher between 20 and 29 weeks of gestation than after 30 weeks. Hepatocyte growth factor secretion from the placental tissue per weight seemed unchanged throughout pregnancy. Its secretion from amnion was, however, approximately 300 to 400-fold higher in the second trimester compared with that at term. CONCLUSION: Both placenta and amnion produce and secrete hepatocyte growth factor, suggesting its role in fetal growth and the growth and differentiation of placenta.

Adult↗
PubMed1995

Decrease in severity of intrauterine growth retardation in subsequent pregnancies.

OBJECTIVE: Intrauterine growth retardation (IUGR) is likely to recur in a subsequent pregnancy. We investigated the obstetric features of recurrent cases and the severity of IUGR by comparing initial and subsequent deliveries. METHODS: From a total of 12,567 deliveries, 95 women who were delivered of small-for-gestational-age (SGA) infants and who became pregnant again within 5 years, were enrolled. A retrospective, comparative study of recurrent and non-recurrent groups was performed. RESULTS: Twenty-two of ninety-five women gave birth to SGA infants again, and a relatively high risk of recurrence was confirmed, but no single recurrence-associated features were revealed. Within the recurrent group, the degree of IUGR was more severe in only five cases in the subsequent pregnancy. CONCLUSIONS: IUGR tends to recur, but does not increase in severity in most cases. We conclude that there is no need for excessive concern about the recurrence of IUGR.

Adult↗
PubMed1995

The concentration of hepatocyte growth factor (HGF) in human amniotic fluid at second trimester: relation to fetal birth weight.

Hepatocyte growth factor (HGF) was measured in 28 samples of amniotic fluid, 1 of fetal urine and 5 of first neonatal urine. The mean level of HGF was 12.4 +/- 4.5 ng/ml (second trimester) and 10.5 +/- 6.6 ng/ml (third trimester). These values were extremely high compared to that in plasma from normal subjects and greater than the plasma levels from patients with acute hepatitis. The concentration of amniotic HGF at second trimester showed a significant inverse correlation both with birth weight (r = 0.47; p < 0.05) and birth weight deviation (r = 0.54; p < 0.02). The level of HGF in fetal urine (0.10 ng/ml) and in the first neonatal urine (0.08 +/- 0.02 ng/ml) were much less than that in amniotic fluid. HGF stimulated DNA synthesis of human fetal liver cells in vitro. While the effect was dose dependent, a maximal response was reached with about 0.2 ng/ml, attaining a 1.3-fold stimulation. The presence of extremely high levels of HGF in the amniotic fluid may be involved not in fetal growth, but rather in maturation of fetal organs such as the lung and the digestive tract.

Amniotic Fluid↗
PubMed1995

Interaction between pregnancy-induced bioactive peptides and the placental proteases.

Studies have shown that placental proteases metabolize vasoactive peptides, possibly derived from the fetus, and protect the exchange of peptide hormones across the placenta in order to maintain feto-placental homeostasis. Changes in maternal serum protease activities were useful for monitoring pre-eclampsia and predicting the onset of labour. The study showed that possible role of oxytocinase in the maintenance of gestation and the possible involvement of angiotensinase in the attenuated pressor responses to angiotensin II during pregnancy, respectively. In addition, the ratio of peak systolic over least diastolic pressure (S/D) of uterine or umbilical artery assessed by the Doppler technique was closely correlated with the concentrations of maternal serum proteases in pre-eclampsia, which suggested that placental proteases might control utero-placental circulation via the regulation of concentrations of vasoactive peptides in uteroplacental circulation.

Cystinyl Aminopeptidase↗
PubMed1995

[The levels of aztreonam in the cord bloods and tissues after administration to pregnant women].

The monobactam antibiotic aztreonam (AZT) was administered by intravenous drip infusion to women with intrauterine infections at 6-hour intervals and its concentrations in the maternal blood, umbilical blood, and umbilical tissue were determined at parturition to evaluate its transport to the umbilicus and fetus, and this accumulation in the tissue. Further, umbilical tissue was cultured to detect bacteria and examined histologically to evaluate the efficacy of AZT its treatment of omphalitis. Neither maternal nor umbilical blood showed any signs of drug accumulation, and there was a correlation between maternal and umbilical blood levels of AZT and time lapsed after most recent administration. Umbilical tissue levels of AZT tended to increase with time for about 12 hours after the start of administration, but showed no tendency to further rise thereafter. The umbilical tissue cultures were negative for causative pathogens 12 hours or more after the initial dosing. Histological examination of umbilical tissue was negative for omphalitis 12 hours or more after the start of administration in all but one patient. After the administration of AZT to pregnant women with intrauterine infections, it was detected in the umbilicus and fetus in high concentrations at parturition without appreciable tissue accumulation, newborn infection or adverse reaction. The overall results suggest that AZT is clinical effective when used in the treatment of omphalitis.

Aztreonam↗
PubMed1995

[Neonatal EEG findings soon after birth in the intrauterine growth retarded infant].

We performed electroencephalograms in 32 neonates of intrauterine growth retardation (IUGR) within seven days of birth. EEG findings were compared with those observed in neonatal brain damage. Seven EEGs had a dysmature pattern which is seen in the subacute and chronic stages of prolonged and mild neonatal brain depression, and five had a disorganized pattern which is seen in the subacute and chronic stages of severe neonatal brain depression. The other EEGs had a normal neonatal pattern. Seven neonates who had a dysmature pattern were severe IUGR (< or = 2.5 SD). Their head circumference was retarded at birth, and the S/D ratio of the umbilical artery increased, suggesting chronic brain damage in utero. On the other hand, five neonates displaying a disorganized pattern were preterm IUGR (< 37 weeks). They had NST abnormalities. The abnormal EEG pattern observed in IUGR was similar to that observed in postnatally injured neonates. The abnormalities in EEGs are correlated with the degree of later neurological sequelae. The present study suggested that the EEG of IUGR recorded immediately after birth was useful in evaluating their intrauterine environments and postnatal neurological outcome.

Brain Diseases↗
PubMed1994

Differential diagnosis of ovarian tumors by transvaginal color-pulse Doppler sonography.

To investigate the clinical significance of transvaginal color-pulse Doppler sonography in ovarian tumors, 109 patients were examined at Nagoya University Hospital. Ultrasonographic patterns were classified and the levels of three circulating tumor markers, CA125, CA72-4, and CA19-9, were simultaneously evaluated. In differentiating benign and malignant ovarian tumors, transvaginal color-pulse Doppler and ultrasonographic pattern classification were superior to the tumor markers. Of 49 cases with benign pattern, 45 were benign (91.8%). Of 60 cases with malignant pattern, 24 (40%) were benign and 36 (60%) were malignant or borderline malignant. In this group color-pulse Doppler sonography was the most useful procedure, and sensitivity, specificity, and accuracy were 75.0, 79.2, and 76.7%, respectively. Menopausal status and site of the arterial wave form in the tumor were also important. Transvaginal color-pulse Doppler sonography was a reliable diagnostic method for differentiating ovarian tumors.

Adenocarcinoma↗