Search PubMed⌕ Search

Biomedical subjects

M Wan

Publications and source records attributed to M Wan.

65 records · Page 4Linked to original sources

Can ultrasonography replace amniocentesis in fetal gender determination during the early second trimester?

Fetal gender was prospectively determined by ultrasonography in 115 patients with singleton pregnancies between 16 and 20 weeks of gestation. Gender determination was performed as a part of the sonographic examination preceding genetic amniocentesis, and the results were compared to the amniotic fluid fetal karyotype results. Our rate of visualization of the fetal external genitalia was 83.5%. The accuracy rate for gender determination was 90% in male infants and 100% in female infants, with an overall rate of prediction of 92.7%.

Amniocentesis↗

Arachidonate lipoxygenase metabolites in amniotic fluid of women with intra-amniotic infection and preterm labor.

This study was undertaken to examine the effects of intrauterine infection and preterm labor on the amniotic fluid concentrations of arachidonate lipoxygenase metabolites in women with premature rupture of membranes. Amniotic fluid was obtained from four groups of women with premature rupture of membranes: group 1, women without labor or infection; group 2, women with labor but without infection; group 3, women with intra-amniotic infection but without labor; and group 4, women with both infection and labor. 12-Hydroxyeicosatetraenoic acid, 15-hydroxyeicosatetraenoic acid, and leukotriene B4 were measured by radioimmunoassays. Amniotic fluid concentrations of 12-hydroxyeicosatetraenoic acid were found not to differ significantly among the four groups. Amniotic fluid concentrations of 15-hydroxyeicosatetraenoic acid in group 4 were significantly higher than in women in groups 1 and 3 (p less than 0.05). In addition, amniotic fluid concentrations in leukotriene B4 were significantly higher in group 4 than in any of the other three groups (p less than 0.05). Leukotriene B4 concentrations were higher in groups 2 and 3 than in group 1, suggesting that the presence of both labor and infection increases the concentration of this metabolite in amniotic fluid. Infection and labor had an additive effect in the elevation of amniotic fluid concentrations of leukotriene B4. These results suggest that the amniotic fluid concentrations of arachidonate lipoxygenase metabolites are affected differently by the presence of infection and labor in women with premature rupture of membranes.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗

Prostaglandin concentrations in amniotic fluid of women with intra-amniotic infection and preterm labor.

This study was undertaken to examine the effects of intrauterine infection and preterm labor on the amniotic fluid concentrations of prostaglandins in women with premature rupture of the membranes. Amniotic fluid was obtained from four groups of patients with premature rupture of the membranes: group 1, patients without labor or infection; group 2, patients with labor but without infection; group 3, patients with an intra-amniotic infection but without labor; group 4, patients with both infection and labor. Prostaglandins E2 and F2a were measured by radioimmunoassays. Preterm labor, in the absence of infection, was not associated with significant increases in amniotic fluid concentrations of prostaglandins. Women with preterm labor and intra-amniotic infections had higher amniotic fluid concentrations of prostaglandins than women with preterm labor in the absence of infection or women with intra-amniotic infection in the absence of labor. These observations are compatible with the participation of prostaglandins in the mechanisms of onset of preterm labor associated with intra-amniotic infection.

Adult↗

Growth of the fetal stomach in normal pregnancies.

Fetal stomach dimensions were measured sonographically in 152 fetuses with gestational ages ranging from nine to 40 weeks. Nomograms of the mean +/- 2 standard deviations (SD) for the longitudinal, anteroposterior, and transverse diameters of the fetal stomach were generated throughout pregnancy. A linear growth function was observed across gestational age, and a high degree of correlation existed between gestational age and the transverse (r = 0.809, P less than .0001), anteroposterior (r = 0.798, P less than .0001), and longitudinal (r = 0.749, P less than .0001) diameters. These data provide a method by which variations from the norm can be assessed, and offer potential prenatal diagnosis of a variety of gastrointestinal lesions.

Embryonic and Fetal Development↗

Increased concentrations of arachidonic acid lipoxygenase metabolites in amniotic fluid during parturition.

This study was undertaken to examine whether spontaneous labor at term is associated with changes in the amniotic fluid concentrations of arachidonate lipoxygenase metabolites. Amniotic fluid was obtained from 15 women at term in active labor (with cervical dilatation of at least 6 cm) and from 15 nonlaboring control women matched for maternal age, parity, and gestational age. Cultures of amniotic fluid for bacteria and mycoplasma were negative. Products of arachidonate lipoxygenase metabolism--12-hydroxyeicosatetraenoic acid (12-HETE), 15-hydroxyeicosatetraenoic acid (15-HETE), and leukotriene B4--were measured by radioimmunoassay. The median concentrations of 12-HETE, 15-HETE, and leukotriene B4 in the amniotic fluid of nonlaboring women were 11.50 ng/mL, 0.45 ng/mL, and 21 pg/mL, respectively, and in the amniotic fluid of laboring women, 24.63 ng/mL, 4.34 ng/mL, and 96 pg/mL, respectively. The differences between labor and nonlabor amniotic fluid concentrations of all three lipoxygenase products were significant (P less than .05, Wilcoxon test). These observations are consistent with involvement of products of the lipoxygenase pathway of arachidonic acid metabolism in the mechanism of human parturition.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗

Intrapartum fetal weight estimation: a comparison of three formulae.

To determine the relative accuracy of fetal weight estimation using the biparietal diameter (BPD), the abdominal circumference (AC), and the femur length (FL) in three formulae (BPD/AC, FL/AC, and BPD/AC/FL), 63 patients in labor were examined. All patients delivered within 24 hours of ultrasound examination. A good correlation was found between the estimated fetal weight and the actual birth weight, using the three formulae: BPD/AC (r = 0.96); FL/AC (r = 0.95); and BPD/AC/FL (r = 0.96). The FL/AC formula overestimated fetal weight (P less than 0.01), however, particularly in fetuses weighing more than 2000 g. The mean percentage error with the BPD/AC formula was 0.99 per cent, 3.82 per cent with the FL/AC, and 2.43 per cent with the BPD/AC/FL formula. This study showed that although all three formulae were comparable, the best estimation of the birth weight was obtained when either the BPD/AC or the BPD/AC/FL formulae were used. Additionally, the results demonstrate that reliable estimates of fetal weight can be made even at term or in laboring patients.

Birth Weight↗

Evaluation of evaporative light-scattering detector for combinatorial library quantitation by reversed phase HPLC.

A quantitation study using reversed phase HPLC with UV and evaporative light-scattering detector (ELSD) was conducted on 90 library standards selected from 15 small molecule combinatorial libraries (six standards from each library). This study assessed the quantitation errors using a single calibration curve for rapid purity analysis of combinatorial libraries. The average quantitation error of six standards from one library at 200 microM by UV was 13. 4%, 20.6%, and 60.3%, at 214, 220, and 254 nm, respectively. By ELSD, the average quantitation error of these six standards at 200 micro was only 7.7%. Applying this ELSD calibration curve to 84 standards from 14 structurally diverse libraries, an average quantitation error of 16.4% was obtained. The average quantitation error of all 90 standards from 15 libraries using 15 calibration curves was 18.5%.

Calibration↗