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Biomedical subjects

O Kurauchi

Publications and source records attributed to O Kurauchi.

At least 55 records · Page 3Linked to original sources
PubMed1994

[Maternal working status and low birthweight: findings from a cohort study].

To explore possible associations of maternal working status with birthweight, a cohort study was conducted from July, 1989 to June, 1991 in 8 general hospitals in the Tokai district. Using a self-administered questionnaire, data on job employment were collected mostly in the first or second trimester. Information on delivery outcome was recorded by doctors, midwives or nurses after child birth. Included in this analysis were 1,360 pregnants who delivered a live singleton without major malformations at gestation of 37 weeks or more. The following major findings emerged. (1) No significant difference in mean birthweight was detected between working and non-working pregnants. (2) Working pregnants were at greater risk of delivering a low birthweight (< 2,500g) baby. (3) Delivery of a low birthweight baby was more frequent in multiparous than nulliparous mothers. (4) The risks of delivering a low birthweight baby significantly differed according to the maternal working status. (5) These results suggest that not only the maternal working factor itself but the working status should be deliberately taken into consideration in order to provide proper prenatal care.

Adolescent↗
PubMed1994

Decrease in cytochrome c oxidase and cytochrome oxidase subunit I messenger RNA levels in preeclamptic pregnancies.

OBJECTIVE: To elucidate the possible relation between mitochondrial gene expression and placental dysfunction. METHODS: We measured the activity of cytochrome c oxidase and the expression of cytochrome oxidase subunit I in mitochondria from human placentas of women whose gestations were appropriate for gestational age (AGA) and those with preeclampsia. In addition, the amounts of normal mtDNA and deleted mitochondrial DNA were examined in the two groups by Southern blot analysis and polymerase chain reaction, respectively. RESULTS: Cytochrome c oxidase activity and expression of cytochrome oxidase subunit I were significantly lower in the preeclamptic group than in the AGA group. There were no differences between the groups in the amounts of mitochondrial DNA. In addition, no mutant mitochondrial DNA with a 4977-base pair deletion was detected in the two groups. CONCLUSION: These results suggest that reduced expression of the mitochondrial gene is involved in placental dysfunction in preeclamptic pregnancy.

Actins↗
PubMed1994

Expression of angiotensin-converting enzyme in human placenta and its physiologic role in the fetal circulation.

OBJECTIVE: To clarify the physiologic function of angiotensin-converting enzyme (EC 3.4.15.1) in the human placenta. METHODS: The concentrations of angiotensin I and angiotensin II were measured in the umbilical artery and vein. In addition, the expression of angiotensin-converting enzyme messenger RNA (mRNA) and its activity in the human placenta were studied. The amount of angiotensin-converting enzyme mRNA was measured by Northern blot hybridization with specific human complementary DNA. RESULTS: The mean (+/- standard deviation) level of angiotensin I was significantly higher in the umbilical artery than in the umbilical vein (1044.5 +/- 626.5 versus 796.5 +/- 372.8 pg/mL; P < .05). In contrast, the mean level of angiotensin II was significantly lower in the umbilical artery than in the umbilical vein (97.3 +/- 102.9 versus 129.3 +/- 110.3 pg/mL; P < .05). Angiotensin-converting enzyme mRNA was detected in the human placenta at 4.5 and 3.9 kilobases. The amount of angiotensin-converting enzyme mRNA increased over the course of pregnancy but decreased near term, whereas angiotensin-converting enzyme activity in the human placenta continued to increase from the first trimester to term. CONCLUSION: The placenta appears to contribute to the conversion of angiotensin I to angiotensin II in the fetal circulation.

Angiotensin I↗
PubMed1993

Studies on transmission of hepatitis C virus from mother-to-child in the perinatal period.

To elucidate whether breast milk, vaginal discharge and contamination with maternal blood at birth are possible routes of mother-to-child transmission of hepatitis C virus (HCV), we examined HCV RNA in the cord and peripheral blood of infants, and in the blood, vaginal discharge, and breast milk of anti-HCV seropositive mothers. From July 1991 to July 1992, we studied 20 healthy pregnant women, who were seropositive with the Ortho anti-HCV EIA, and their infants. Using a sensitive nested polymerase chain reaction (nested PCR), we investigated the presence or absence of hepatitis C virus in the above-mentioned specimens. Moderate elevation of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) was observed in only one woman in the first and third trimesters. The nested PCR and subsequent Southern hybridization detected 0.5-5.5 copies of HCV c-DNA. HCV RNA was detected in 17/20 blood samples (85%), 7/14 vaginal discharge samples (50%) and 4/10 cord blood samples (40%). However, no HCV RNA was identified in the peripheral blood of infants or breast milk. The mother-to-child transmission of HCV at delivery or via breast milk does not appear to contribute much to maintaining the global HCV reservoir.

Adult↗
PubMed1993

Enhanced proliferation of fetal rat hepatocytes in primary culture induced by ritodrine.

OBJECTIVE: Although ritodrine crosses the placenta, its direct effect on fetal cell proliferation has not been reported. We hypothesized that beta 2-adrenergic receptor stimulation could promote fetal liver growth. STUDY DESIGN: Ritodrine was added to serum- and hormone-free primary cultures of fetal, neonatal, or adult rat hepatocytes. We measured both tritiated thymidine incorporation into deoxyribonucleic acid and nucleus number. The effect of ritodrine on cell cycle was also analyzed with flow cytometry. RESULTS: Ritodrine enhanced the proliferation of fetal rat hepatocytes. Ritodrine remarkably stimulated deoxyribonucleic acid synthesis of fetal and neonatal but not adult hepatocytes. The effect was dose dependent and was antagonized by propranolol. Analysis of the nuclear deoxyribonucleic acid content derived from flow cytometry revealed that cells stimulated by ritodrine entered S phase. CONCLUSION: These results indicate that ritodrine may promote the proliferation of fetal hepatocytes through the stimulation of beta 2-adrenergic receptors, followed by induction of deoxyribonucleic acid synthesis.

Animals↗
PubMed1993

Pregnancy and successful delivery in a patient with triple heart valve prosthesis.

A 42-year-old patient had a history of rheumatic fever in childhood. At 37 years of age, she underwent a triple heart valve replacement; thereafter, she was followed with the administration of warfarin and methyldigoxin. Her third pregnancy occurred with the last menstruation on 12 March 1990. At the 30th gestational week, she was admitted to the Nagoya University Hospital for the control of anticoagulation and rest. She delivered by cesarean section a healthy male infant weighing 2070 g at 34 weeks of gestation. The post-operative course was uneventful. This report shows that a patient with a three heart valve prosthesis tolerated pregnancy well under intense medical supervision.

Adult↗
PubMed1993

Possible action of human placental aminopeptidase N in feto-placental unit.

Aminopeptidase N purified from human placenta actively hydrolyzed various immunomodulating peptides from their N-terminus such as splenopentin, thymopentin, thymic humoral factor gamma 2, tuftsin and rigin in vitro. Aminopeptidase N also actively hydrolyzed neuropeptide hormones (met-enkephalin, somatostatin and neurokinin A) and vasoactive peptides (lysyl-bradykinin and angiotensin III) from their N-terminus. In addition, angiotensin II, secretin, thymopoietin II peptide fragment, motilin, endothelin-I and insulin were tested for hydrolysis by aminopeptidase N. Km and Vmax values for the N-terminal amino acid, Thr, a liberation from tuftsin were 267 microM and 8.33 mumol/min/mg protein, respectively. L-Leucyl-p-nitroanilidase activity in the human placental membrane fraction was almost completely neutralized by anti-aminopeptidase N antibody. Our present study suggests that possible roles for surface enzyme aminopeptidase N in the human placenta would be to down-regulate the action of immunomodulating peptides as well as vasoactive and neuropeptide hormones, and to control both immunology and endocrinology of pregnancy.

Amino Acid Sequence↗
PubMed1993

[Determination of intrauterine pressure using catheter-tip transducer inserted outside fetal membranes].

To determining intrauterine pressure outside fetal membranes, we used a catheter-tip transducer to study 20 women before the occurrence membrane rupture. Their mean age was 28.2 +/- 3.4 years and all women were in weeks 37 to 41 of pregnancy when studied. In the first stage of labor, the peak intrauterine pressure was 60.0 +/- 12.5 mmHg (mean +/- SD) when the external os was dilated 4 to 6 cm, 90.0 +/- 14.8 mmHg, at 7 to 8 cm dilation, and 80.0 +/- 11.5 mmHg at 9 cm or greater dilation. Each pressure wave lasted 45 to 55 sec. The highest baseline pressure (28.0 +/- 4.5 mmHg) was obtained when the subjects were sitting. A baseline pressure of 17.0 +/- 4.0 mmHg was obtained in the supine position, as well as a value of 21.0 +/- 3.5 mmHg in the recumbent position. There were no complications related to the catheter-tip transducer. Our findings indicate that this method is both accurate and reliable in determining the amounts of intrauterine pressure to which fetal membranes are subjected.

Adult↗
PubMed1993

Identification of the pregnancy responsible for gestational trophoblastic disease by DNA analysis.

In three cases of choriocarcinoma, genetic loci including a variable number of tandem repeat regions were amplified by the polymerase chain reaction method on DNA from three established cell lines and from lymphocytes of patients and their husbands to identify the responsible pregnancy. Case 1, from whom NaUCC-3 was derived, had only one full-term fetal death. Case 2, from whom NaUCC-4 was derived, had one normal delivery followed by one complete molar delivery and one normal delivery. Case 3, from whom NaUCC-2 was derived, had one normal delivery followed by one complete molar delivery. In case 1, NaUCC-3 was found to be of parental origin and derived from the pregnancy with full-term fetal death. In cases 2 and 3, NaUCC-4 and NaUCC-2 were of probable androgenetic origin and were derived from the pregnancy with complete hydatidiform mole. We also conducted the restriction fragment length polymorphism method using case 1 samples, and it confirmed the results based on the polymerase chain reaction method product patterns. All nine cases of hydatidiform mole and three cases of invasive mole were of androgenetic origin. The polymerase chain reaction method thus makes it possible to identify easily the pregnancy responsible for choriocarcinoma using only a few specimens without isotopes.

Adult↗
PubMed1992

Rapid determination of fetal sex using amniotic fluid cells and the polymerase chain reaction.

We determined the sex of 50 fetuses by an amplification of the Y-chromosome specific fragment using the polymerase chain reaction (PCR). Amniotic fluid cells were collected by amniocentesis from pregnant women at 14 to 17 weeks of gestation. Total DNA was purified from cells in 1 ml of amniotic fluid. When only the expected 130 base pair X-chromosome specific fragment was detected, we identified the fetus as female, while when both the expected 170 base pair Y-chromosome specific and X-chromosome specific fragments were detected, we identified it as male. In all cases, identification was confirmed either by chromosome analysis or post partum.

Amniotic Fluid↗
PubMed1992

Induction by cortisol of aminopeptidases production from the human placenta in tissue culture.

Human placental aminopeptidase M and A and post-proline endopeptidase are known to act as degrading enzymes of bioactive peptides such as angiotensin II, oxytocin and endogenous opioids. We tested the effects of cortisol on the activities of human placental aminopeptidase A and M and post-proline endopeptidase using short-cultured placental tissues. From 34.5 nM to 3.45 microM of cortisol significantly increased the activities of 3 enzymes. Our present data suggest a possible important role of cortisol in the growth of human placenta via induction of placental aminopeptidases.

Aminopeptidases↗
PubMed1992

Relationship between the changes in placental blood flow resistance assessed by Doppler technique and maternal serum placental aminopeptidases, which degrade vaso-active peptides, in pre-eclampsia.

Our study showed that there were statistically significant correlations between the systolic and diastolic ratio (S/D) of maternal uterine or umbilical artery and the levels of maternal serum aminopeptidase activities in pre-eclampsia. Kininase I was positively correlated with the S/D ratios, whereas placental leucine aminopeptidase (P-LAP) and aminopeptidase A were negatively correlated with the S/D ratios. It is known that the increased S/D ratios reflect the increased utero-placental blood flow resistance. Since our previous study showed that placental aminopeptidases degrade vasoactive peptides such as oxytocin, angiotensin and bradykinin, which the fetus actively produces, our present study suggests that the increased vascular resistance in feto-placental circulation in pre-eclampsia is partly controlled by changes in vaso-active peptides, via degradation by placental aminopeptidases.

Adult↗
PubMed1991

Organization of the 5' end of the rat gamma-glutamyl transpeptidase gene: structure of a promoter active in the kidney.

Two gamma-glutamyl transpeptidase mRNAs (mRNAI and mRNAII), with alternate 5'-untranslated regions, are expressed in the rat kidney. Oligonucleotides were designed based upon these two alternate 5' sequences and used as primers to amplify GGT genomic DNA sequences. The genomic organization of the mRNAI and mRNAII 5'-untranslated sequences reveals that the mRNAs are encoded from two separate promoters which are 2.1 kbp apart on the single GGT gene. A 2775 base pair genomic sequence, which contains the proximal GGT promoter, was cloned from two overlapping amplified fragments. S1 mapping analysis shows that the kidney GGT mRNAI is transcribed from several start sites on this promoter which displays neither a classical TATA box nor Sp1 binding sites. Chimeric plasmids, including the GGT promoter region for mRNAI, associated with the chloramphenicol acetyltransferase (CAT) reporter gene, were transiently expressed in a kidney (LLCPK) and in a hepatoma (HTC) cell line. A sequence extending 308 bases upstream from the major GGT mRNAI start site drives a promoter activity which is 5-fold higher in LLCPK than in HTC cells and is sufficient to confer cell specificity to the GGT proximal promoter.

Animals↗
PubMed1991

Purification and properties of human placental aminopeptidase B.

Aminopeptidase B (EC 3.4.11.6; L-arginyl-beta-naphthylamidase) was purified 1,800-fold from human placental cytoplasm and characterized. The enzyme was subjected to ammonium sulfate fractionation and a series of chromatographies on DE-52, hydroxylapatite, Bio-gel A 0.5 m and L-arginine-Sepharose. The native molecular mass of the enzyme was estimated to be 220,000 by gel filtration. The molecular mass was estimated to be about 83,000 by SDS/PAGE in the absence of 2-mercaptoethanol, suggesting that the enzyme exists in a polymeric form. The isoelectric point of the enzyme was 5.4. The purified enzyme was most active at pH 7.2 with L-arginyl-beta-naphthylamide as substrate and the Km value for this enzyme was 0.3 mmol/l. Human placental aminopeptidase B was markedly activity by Cl-. Bestatin and arphamenin, low molecular weight peptides, showed appreciable inhibition of this enzyme. However, amastatin and puromycin did not inhibit the enzyme. Bacitracin markedly activated this enzyme.

Aminopeptidases↗
PubMed1990

Tissue-specific expression of two gamma-glutamyl transpeptidase mRNAs with alternative 5' ends encoded by a single copy gene in the rat.

Two different cDNAs have been isolated and characterized from a rat kidney cDNA library. The two cDNA sequences are identical in the coding region and in the 144 bases upstream from the initiation codon but have alternate sequences (154 and 138 bases) at their 5' ends. Primer extension analysis on kidney mRNA reveals that both cDNAs are full-length and correspond to two mRNAs of nearly the same size (2142 and 2127 bases). Synthesis of two mRNAs with alternative 5' ends can be explained only by initiation at two separate promoters on the single rat gamma-glutamyl transpeptidase (GGT) gene. The alternate 5' end nucleotide sequences were used as probes to detect the corresponding mRNAs in several rat tissues. In the kidney, the expression of both RNAs was detected by in situ hybridization in the distal part of the proximal convolutions of the renal tubule. Northern blot analysis of kidney mRNAs reveals that the expression of both mRNAs increases from birth to the adult stage. Neither of these two transcripts is expressed in the liver or in seminal vesicles in which a larger mRNA (2.4 kilobase pairs) is transcribed from the same gene. Thus, two GGT mRNAs, initiated on two separate promoters on the single GGT gene, are expressed in the rat in a tissue-specific manner and coordinately regulated.

Animals↗
PubMed1990

Increased serum kininase I activity in pregnancy complicated by pre-eclampsia.

Serum kininase I activity was measured in normal pregnancy and pre-eclampsia. The mean value in nonpregnant controls was 180 +/- 25 (SD) nmol/min/ml. Kininase I activity during normal pregnancy significantly increased after week 14, reaching the highest value (240 +/- 20 nmol/min/ml) at weeks 38 and 40. The kininase I activity in pregnancy complicated by severe pre-eclampsia was higher than that in normal pregnancy. The possible role played by elevated kininase I levels in pre-eclampsia was discussed.

Adult↗