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Biomedical subjects

R Sawa

Publications and source records attributed to R Sawa.

At least 37 records · Page 2Linked to original sources
PubMed2000

Plasma adenosine levels increase in women with normal pregnancies.

OBJECTIVE: The aim of this study was to investigate plasma adenosine levels during normal pregnancy and to evaluate the possible roles of platelet activation and 5'-nucleotidase as causes of changes in adenosine levels. STUDY DESIGN: We measured plasma adenosine levels, the platelet activation markers beta-thromboglobulin and platelet factor 4, and 5'-nucleotidase activity, which catalyzes dephosphorylation from adenosine monophosphate to adenosine, in 34 nonpregnant women and 34 women with normal pregnancies in the third trimester. RESULTS: The mean plasma adenosine level in pregnant women was 0.59 +/- 0.08 micromol/L (mean +/- SEM), which was significantly higher than that found in nonpregnant women (0.18 +/- 0.04 micromol/L; P <.01). In pregnant women plasma beta-thromboglobulin levels, platelet factor 4 levels, and 5'-nucleotidase activity were significantly higher than in nonpregnant women (P <.05). CONCLUSION: The increase of plasma adenosine may be attributed at least in part to platelet activation and an increase of 5'-nucleotidase activity during normal pregnancy. This increase may be an endogenous compensatory mechanism that diminishes platelet activation and maintains vessel integrity during normal pregnancy.

5'-Nucleotidase↗
PubMed2000

Clinical usefulness of maternal body mass index in twin pregnancies.

OBJECTIVE: We examined whether maternal body mass index (BMI) during prepregnancy is useful for prediction of maternal preeclampsia in twin pregnancies. METHODS: We studied 250 dichorionic twin pregnancies and 3196 singleton pregnancies. Maternal BMI was calculated during prepregnancy in both twin and singleton pregnancies. The incidence of maternal preeclampsia was compared among three groups, low-BMI [< -1.5 standard deviations (SD)], normal-BMI, and high-BMI (> + 1.5 SD) groups, in both singleton and twin pregnancies. RESULTS: In singleton pregnancies, the incidence of maternal preeclampsia in the high-BMI group was significantly higher than that in the normal-BMI group (p < 0.05). The relative risk by high BMI was 8.5 (95% confidence interval: 5.6-12.0). However, in twin pregnancies, no significant differences were observed in these values. CONCLUSIONS: Body mass index during prepregnancy was not useful for the prediction of preeclampsia in twin pregnancies. Mechanisms other than maternal weight may be associated with the beginning of preeclampsia in twin pregnancies.

Adult↗
PubMed2000

B-cell-type malignant lymphoma with placental involvement.

We present here a case of B-cell-type mediastinal malignant lymphoma during pregnancy complicated by placental involvement. In this case, some nodular high-echo patterns were recognized in the placenta by ultrasonography. A cesarean section and resection of the mediastinal tumor were performed at 33 weeks and 6 days of gestation due to the deterioration of the dyspnea. A female infant weighing 1,868 g was delivered and she is now a healthy 2-year-old. The mother, however, died of the disease 1 month after surgery, due to progression of the tumor. The placenta showed numerous white firm nodules varying from 3 mm to 3 cm in diameter. The pathologic findings of both the mediastinal tumor and the placenta indicated primary mediastinal (thymic) B-cell lymphoma.

Adult↗
PubMed2000

Preoperative diagnosis of dehiscence of the lower uterine segment in patients with a single previous Caesarean section.

Preoperative diagnoses were checked during surgery in 39 patients who underwent elective repeat Caesarean section with (n = 20) and without (as control, n = 19) a preoperative diagnosis of wall dehiscence (thinning) of the lower uterine segment (LUS). All patients were examined manually and by ultrasonography at 36 weeks gestation before labour. A preoperative diagnosis of wall dehiscence was made when the wall thickness was less than 2 mm and/or the patient felt pain and tenderness in the LUS. Surgical findings of dehiscence were defined as a subperitoneal separation of the uterine scar in the LUS. The sensitivity and specificity of our ultrasonographic evaluations were found to be 100% and 83% (p < 0.05), respectively. On the other hand, there were no surgical findings of dehiscence in patients who felt pain and tenderness in the LUS with a wall thickness greater than 2 mm, nor among those in the control group.

Case-Control Studies↗
PubMed2000

Clinical trial of induction of labor versus expectant management in twin pregnancy.

OBJECTIVE: The appropriate date of delivery in twin pregnancies is supposed to be earlier than that in singleton pregnancy. The aim of this study was to compare two strategies for managing twin pregnancies (i.e., immediate induction and expectant management). METHODS: Seventeen patients underwent immediately induced labor by administration of oral prostaglandin E(2) at 37 weeks, while 19 patients underwent expectant management. RESULTS: The average gestational age at delivery in the induction group was 37.5 +/- 0.4 weeks, significantly earlier than that in the expectant management group (39.0 +/- 1.1 weeks). However, there were no significant differences in the average birth weight between the two groups (2, 700 +/- 330 g in the induction group vs. 2,672 +/- 392 g in the expectant management group). The cesarean delivery rate in the induction group was 18%, not significantly different from that in the expectant management group (32%). The most common indication for cesarean section in the expectant management group was maternal infection, while there was no maternal infection in the induction group (p = 0.08). CONCLUSION: It may be acceptable do intervene in twin pregnancies earlier than in singleton pregnancies during term.

Adult↗
PubMed2000

Changes in plasma adenosine concentrations during normal pregnancy.

The aim of this study was to measure changes in plasma adenosine concentration [ADO] during a normal pregnancy and to evaluate the possible role of platelets and red blood cells (RBC) as causes of changes in plasma [ADO]. We measured the plasma [ADO] in normal pregnant women (n = 11) during the first, second and third trimesters. The mean plasma [ADO] in the third trimester was 0.41 +/- 0.08 microM (means +/- SEM), significantly higher than in the first and second trimesters (p < 0.05). In pregnant women, platelet and RBC counts, hematocrit and hemoglobin concentration decreased slightly throughout the pregnancy. The elevation in the plasma [ADO] correlated inversely with the platelet count (r = -0.43, p < 0.05). These results suggest that an increase in the plasma [ADO] in the third trimester may be attributed to the enhanced adenosine release from activated platelets.

Adenosine↗
PubMed2000

Changes in fetal plasma adenosine and xanthine concentrations during fetal asphyxia with maternal oxygen administration in ewes.

In this study, we measured fetal plasma adenosine and xanthine concentrations during and after severe asphyxia, and investigated the key issues related to oxygen therapy. Asphyxia was induced by occluding the umbilical cord for 5 minutes in 6 fetal sheep with and without the administration of oxygen to the ewe. Plasma adenosine concentration increased significantly during cord occlusion in the all fetuses, and the differences between the values in the fetuses with and without maternal oxygen administration was not significant. By 30 minutes after cord release, plasma adenosine concentration in all fetuses had returned to levels similar to those at the start of the experiment. Plasma xanthine concentration also increased during cord occlusion in all fetuses. However, 30 minutes after cord release, plasma xanthine concentration had decreased significantly in fetuses without additional oxygen, while it did not change significantly in fetuses with maternal oxygen administration. Thus, we speculated that maternal oxygen administration before fetal asphyxia may not contribute to additional ATP stores in fetal organs and may produce oxygen free radicals following asphyxia.

Adenosine↗
PubMed1999

Amniotic fluid alpha-fetoprotein testing in native Japanese women.

Owing to differences in maternal serum alpha-fetoprotein, human chorionic gonadotrophin and oestriol levels between native Japanese and Caucasian women screened in this laboratory, a study was conducted to measure amniotic fluid alpha-fetoprotein (AFAFP) levels in native Japanese pregnancies. When the native Japanese AFAFP levels were compared with a United States (non-Black) population, the Japanese medians did not decrease as rapidly over the 14 to 22 weeks of gestation period investigated. At 14 weeks, the difference was negligible, graduating to a difference of 20 per cent by 22 weeks' gestation. Native Japanese pregnancy AFAFP levels should be interpreted based upon population data from that group alone. From these findings, prenatal screening laboratories should be encouraged to collect preliminary data for comparison before screening is initiated for a defined ethnic group.

Amniocentesis↗
PubMed1999

Prediction of oligohydramnios in prolonged pregnancy.

A decrease in amniotic fluid in prolonged pregnancy is associated with increased fetal morbidity. However, few investigations have been reported on the prediction of this condition. Fetal renal arterial pulsatility index (PI), hourly fetal urine production rate (HFUPR) and amniotic fluid index (AFI) at 39 weeks were studied in 51 singleton pregnancies with (n = 14) and without oligohydramnios (AFI < 5, n = 37) in prolonged pregnancy. There was no difference in the average fetal renal arterial PI and HFUPR between the oligohydramnios group and the normal group. However, the average AFI in the oligohydramnios group was 7.5 +/- 0.9, which was lower than that in the normal group (p < 0.05). We speculated that AFI value at 39 weeks is useful for predicting the incidence of oligohydramnios in prolonged pregnancy.

Female↗
PubMed1999

Fetal middle cerebral artery Doppler waveforms in twin-twin transfusion syndrome.

The aim of this study was to compare the fetal middle cerebral artery (MCA) Doppler waveforms in growth-retarded twin fetuses with (n = 11) and without (n = 24) twin-twin transfusion syndrome (TTTS). Umbilical artery (UA) and fetal MCA Doppler velocity waveforms were recorded on admission. The mean values of the UA pulsatility index (PI) of smaller twin fetuses with and without TTTS were significantly higher than those of normal singleton pregnancies. The mean values of the MCA PI of smaller twin fetuses in the TTTS group (+0.7 +/- 1 SD) were significantly higher than those of normal singleton pregnancies on admission, and these levels did not markedly change following amniocentesis. On the other hand, the values of the MCA of the growth-retarded fetuses without TTTS (-0.9 +/- 1 SD) were significantly lower than those of normal singleton pregnancies. Our findings suggest that measurement of fetal MCA PI is a useful method to assess growth-retarded fetuses in monochorionic twin pregnancies.

Adult↗
PubMed1999

Prenatal diagnosis of autosomal recessive polycystic kidney disease. A case report.

We present a case of autosomal recessive polycystic kidney disease diagnosed at 28 weeks' gestation by ultrasonographic examination and magnetic resonance imaging (MRI). The fetal kidneys were symmetrically enlarged and highly echogenic by ultrasonographic examination and showed high-signal intensity on T2-weighted images by MRI. Cystic lesions were recognized by neither examination. In addition, the pulsatility index of the fetal renal artery was normal. These findings suggest a high water content in the renal parenchyma with tiny cysts and normal blood flow in autosomal recessive polycystic kidney disease.

Adult↗
PubMed1999

Prenatal diagnosis of acute massive fetomaternal hemorrhage.

We present here 2 cases of acute and 2 cases of chronic massive fetomaternal hemorrhage. A sinusoidal fetal heart rate pattern may indicate chronic fetomaternal hemorrhage, but, when increased variability is observed in fetal monitoring, maternal hemoglobin F should be measured to exclude acute fetomaternal hemorrhage.

Acute Disease↗
PubMed1999

Characteristics of monochorionic-diamniotic growth-retarded twins during the third trimester.

The goal of this study was to assess the characteristics of monochorionic-diamniotic (MD) growth-retarded twin infants with twin-twin transfusion syndrome (TTTS) compared with those without TTTS during the third trimester. Retrospective analyses of the growth patterns and amniotic fluid volumes were performed on 5 MD twin pregnancies in which one or both twins showed growth retardation with TTTS, and the results weve compared with those without TTTS. Eighty-three percent of growth-retarded twin infants without TTTS in MD twin gestation showed an asymmetric growth pattern, while all TTTS cases showed a symmetric pattern (p < 0.05). Polyhydramnios of the co-twin was found in 80% of TTTS cases, while no polyhydramnios was found in patients without TTTS (p < 0.05). Assessment of growth patterns and amniotic fluid volume may be useful to exclude the possibility of TTTS in MD growth-retarded twin pregnancies during the third trimester.

Adult↗
PubMed1999

Lactonamycin, a new antimicrobial antibiotic produced by Streptomyces rishiriensis MJ773-88K4. II. Structure determination.

The absolute structure of a new antibiotic lactonamycin is described. The NMR studies deduced one of four possible structures for the aglycon attached by a rhodinose through glycosidic bond. The stereochemistry of the sugar obtained by an acid hydrolysis was determined to be L-form by measuring optical rotation. The stereochemistry of the aglycon was determined by X-ray crystallographic analysis.

Anti-Bacterial Agents↗