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E Amon

Publications and source records attributed to E Amon.

34 records · Page 2Linked to original sources
PubMed1988

How perinatologists manage the problem of the presenting breech.

A questionnaire regarding controversies in management of the breech presentation was answered by 405 maternal-fetal medicine subspecialists. Legal concerns strongly influenced clinical management in 63% of respondents. External cephalic version was considered both safe and effective in 90 and 83% of respondents, respectively. Three-quarters of those who responded usually allow a trial of labor in selected term frank breech presentations. Of the respondent subset, 43% usually augment hypotonic contractions with oxytocin. Only 57% agreed there was sufficient literature to favor cesarean section for the 28 to 31 weeks breech presentation, and only 43% so agreed for the 32 to 34 week frank breech. Nevertheless, in these situations, 94 and 83%, respectively, actually perform cesarean section in clinical practice. More than 75% agreed that a prospective study is needed to determine the correct delivery mode of the preterm breech. Ninety-two percent agreed that such data could change their current opinion regarding delivery management. Implications are discussed.

Breech Presentation↗
PubMed1988

Fetal vibro-acoustic stimulation: magnitude and duration of fetal heart rate accelerations as a marker of fetal health.

The relationship between intrapartum fetal acid-base status and fetal heart rate (FHR) response to vibro-acoustic stimulation was investigated in 100 patients. Fetal heart rate responses were classified into three groups: acceleration of 15 or more beats per minute lasting 15 or more seconds, acceleration of ten or more beats per minute lasting 10 seconds but less than 15 beats per minute and 15 seconds, or no acceleration. The mean fetal scalp blood pH was 7.29 in both groups with acceleratory responses, and such responses were highly predictive (98-100%) of scalp pH 7.20 or above. The mean pH value for the no-acceleration group (7.22) was significantly lower than the mean pH value for both groups with an acceleratory response (P less than .05), and the lack of response to the stimulus detected 90-100% of fetuses with a pH below 7.20. This sensitivity was reduced to 45% in the detection of fetuses with pH less than 7.25.

Acid-Base Equilibrium↗
PubMed1987

Chromosomal mapping of tRNA genes from Dictyostelium discoideum.

Different wild-type isolates of Dictyostelium discoideum exhibit extensive polymorphism in the length of restriction fragments carrying tRNA genes. These size differences were used to study the organisation of two tRNA gene families which encode a tRNA Val(GUU) and a tRNA Val(GUA) gene. The method used involved a combination of classical D. discoideum parasexual genetics and molecular genetics. The tRNA genes were mapped to specific linkage groups (chromosomes) by correlating the presence of polymorphic DNA bands that hybridized with the tRNA gene probes with the presence of genetic markers for those linkage groups. These analyses established that both of the tRNA gene families are dispersed among sites on several of the chromosomes. Information of nine tRNA Val(GUU) genes from the wild-type isolate NC4 was obtained: three map to linkage group I (C, E, F), two map to linkage group II (D, I), one maps to linkage group IV (G), one, which corresponds to the cloned gene, maps to either linkage group III or VI (B), and two map to one of linkage groups III, VI or VII (A, H). Six tRNA Val(GUA) genes from the NC4 isolate were mapped: one to linkage group I (D), two to linkage group III, VI or VII (B, C) and three to linkage group VII or III (A, E, F).

Chromosome Mapping↗
PubMed1987

Obstetric variables predicting survival of the immature newborn (less than or equal to 1000 gm): a five-year experience at a single perinatal center.

The immature neonate constitutes less than 3% of total births and yet accounts for almost 50% of all perinatal deaths. In a 5-year period, 476 consecutive live and inborn neonates weighing less than or equal to 1000 gm were studied. The purpose of this study was to describe our experience with these pregnancies and determine the obstetric predictors of survival. Statistical methods of univariate and multivariate analysis were used. Survival was defined as the discharge home of an alive infant. The overall survival rate without exclusions was 40.3%. The following variables were most significant and accurately predicted survivors in 76.2% and nonsurvivors in 69.2% of cases: a combination of birth weight, 5-minute Apgar score, gestational age, cervical dilatation on admission, sex, a more recent study time interval, and race. Of the factors studied, the following were directly related to advancing gestational age and birth weight: higher Apgar scores at 1 and 5 minutes, increased operative delivery rate, and increased frequency of tocolysis and glucocorticoid usage; of these factors, only the 5-minute Apgar score remained statistically significant, when controlling for gestational age and birth weight by multivariate analysis.

Adult↗
PubMed1987

Factors responsible for preterm delivery of the immature newborn infant (less than or equal to 1000 gm).

Although there are excellent studies examining factors responsible for preterm delivery in general, there is a scarcity of data describing factors specifically associated with delivery of the immature newborn infant. Our purpose is to characterize these factors in order to determine what may be done to limit preterm delivery rate of extremely low birth weight infants. Obstetric variables responsible for the birth of 338 live in-born immature neonates in a large single perinatal center were determined. We were unable to affect 65% of these pregnancies because there was no chance for intervention prior to admission in 63% of these mothers, and 66% had nonpreventable obstetric complications responsible for delivery. The median time interval from admission to delivery was 7 hours. Mortality was significantly higher in those delivered within 7 hours. We also found that neonatal mortality was twice as high in infants born to women with a previous perinatal loss. The clinical implications of these results are discussed.

Adolescent↗
PubMed1987

A comparative trial of labetalol and hydralazine in the acute management of severe hypertension complicating pregnancy.

Sixty peripartum patients with diastolic blood pressures (BP) 110 mmHg or higher were randomized in a 2:1 ratio to receive repeated intravenous injections of either labetalol (20-80 mg) or hydralazine (5 mg) until the diastolic BP was below 100 mmHg. There were four treatment failures in the labetalol group (N = 40) and none in the hydralazine group (N = 20). Hydralazine lowered mean arterial pressure (MAP) more than did labetalol (33.3 +/- 13.2 versus 25.5 +/- 11.2 mmHg; mean +/- SD), but labetalol had a more rapid effect. There was considerable interpatient variability in the dose of labetalol required to control BP, which could not be predicted by any clinical characteristic before therapy. The duration of action also varied in the labetalol group, with the shortest duration occurring in those patients who required the highest dosage for BP control. No significant fetal or neonatal problems ascribable to drug treatment were noted in the 13 instances in which labetalol was given before delivery. However, fetal distress occurred in two of the six cases involving antenatal hydralazine. We conclude that labetalol appears to be a safe and effective alternative to hydralazine for treating hypertension in the peripartum period, but serious rare side effects have not yet been quantified.

Adult↗
PubMed1987

Ultrasonically guided direct umbilical cord blood sampling.

Ultrasonically guided umbilical cord blood sampling (funicentesis) allows rapid karyotyping and diagnosis of fetal viral infections and other fetal diseases. This technique may also aid in the management of fetal disease. One of three fetuses studied had a chromosomal abnormality, trisomy 18. None had evidence of viral infection.

Adult↗
PubMed1986

Maternal-perinatal outcome associated with the syndrome of hemolysis, elevated liver enzymes, and low platelets in severe preeclampsia-eclampsia.

During an 8-year period, 112 severe preeclamptic-eclamptic patients with the above syndrome were studied. The incidence of this syndrome was significantly higher in white patients, in patients with delayed diagnosis of preeclampsia and/or delayed delivery, and in multiparous patients. Twenty-six patients had amniocentesis and 16 received epidural anesthetics. There was one maternal bleeding episode associated with epidural anesthetics. The use of steroids in 17 patients did not improve maternal platelet count. The overall perinatal mortality was 367 per 1000 and neonatal morbidity was significant. There were two maternal deaths and two patients with ruptured liver hematoma, and nine had acute renal failure. Thirty-eight percent had intravascular coagulopathy and 20% had abruptio placentae. On follow-up, 44 patients used oral contraceptives without maternal morbidity and 38 patients had 49 subsequent pregnancies. Only one patient had recurrence of the syndrome in subsequent pregnancies. The presence of a "true" syndrome of hemolysis, elevated liver enzymes, and low platelets (HELLP syndrome) in preeclampsia is associated with poor maternal-perinatal outcome.

Abruptio Placentae↗
PubMed1986

Quantitative analysis of amniotic fluid phospholipids in diabetic pregnant women.

Controversy exists regarding the fetal lung maturity profiles in diabetic and normal pregnancies. Diabetic and control patients at term were compared. A comprehensive lung profile was obtained using high performance liquid chromatography, lecithin:sphingomyelin ratio by conventional thin-layer chromatography, and the Lumadex foam stability index. There was no statistically significant difference in the phospholipids measured by any of the three techniques despite the fact that the control patients had a significantly higher mean gestational age at amniocentesis. As expected, the diabetic pregnancies had a significantly higher mean birth weight. There was no case of respiratory distress syndrome in either group. The present data do not allow rejection of the null hypothesis of no difference in amniotic fluid phospholipids, between diabetic and normal pregnancy, at term.

Amniotic Fluid↗
PubMed1985

Characterisation of a Dictyostelium discoideum DNA fragment coding for a putative tRNAValGUU gene. Evidence for a single transcription unit consisting of two overlapping class III genes.

A genomic DNA fragment from Dictyostelium discoideum was characterized. This DNA, although 74% d(A + T)-rich, codes for a putative tRNAValGUU. The tRNAVal gene overlaps at its 5' half with another RNA polymerase III transcription unit. This RNA polymerase III transcription unit can be folded into a tRNA-like shape and is comprised of significant amounts of invariant and semi-invariant nucleotides present in all eukaryotic tRNAs. This unit contains the two promoter blocks defined for RNA polymerase III, which are homologous to recently defined promoter elements to the extent of 76-88% (A block) and 86-93% (B block) respectively [Sharp et al. (1981) Proc. Natl Acad. Sci. USA 78, 6657-6661]. Both of the overlapping class III genes are transcribed in germinal vesicle extracts prepared from Xenopus laevis oocytes as a single transcription unit, resulting in an unusually large product compared to primary transcripts of other tRNA genes. The unit is not transcribed in HeLa extracts but it competes very strongly for transcription factor(s) under the conditions of stable transcription complex formation. Although the whole unit is transcribed, it is believed that only one functional product is formed. Therefore we define the tRNA-like structure, coded for on this class III transcription unit, as a putative tRNA 'pseudogene' meaning that, although it is transcribed by RNA polymerase III, it is not likely to mature to a functional tRNA.

Base Sequence↗
PubMedDate not supplied

Effects of serum from preeclamptic women on prostacyclin production by human endothelial cells.

There is growing evidence that proteinuric hypertension of pregnancy (preeclampsia) is associated with endothelial dysfunction. The aim of this study was to evaluate the effects of serum from preeclamptic patients on basal and agonist-stimulated prostacyclin production by human umbilical vein endothelial cells (HUVEC) in culture and to compare these to the effects of serum from normal pregnant and nonpregnant women. During a 24 h incubation of HUVEC with 20% of preeclampsia serum, baseline prostacyclin output was significantly (P < 0.01) increased over the control groups. However, this response was attenuated by extending the exposure to 72 h. Histamine, thrombin and the calcium ionophore, A23187, all acutely increased prostacyclin production, but the increase relative to baseline levels was greatest in HUVEC preincubated for 24 h in normal serum transiently promotes prostacyclin production in HUVEC derived from normal pregnancies, preeclampsia serum transiently promotes prostacyclin production in HUVEC derived from normal pregnancies, and 2) the relative increase in response to agonists is reduced by preeclampsia serum, compared to normal pregnancy sera.

Calcimycin↗
PubMedDate not supplied

Impact of oligohydramnios on maternal and perinatal outcomes of spontaneous premature rupture of the membranes at 18-28 weeks.

OBJECTIVE: We compare the maternal and perinatal outcomes between 69 patients with oligohydramnios and 49 patients with adequate fluid at the time of initial evaluation for PROM. METHODS: One hundred and eighteen patients with spontaneous premature rupture of the membranes (PROM) at 18-28 weeks are included in the study. Inclusion criteria are singleton gestation, normal fetal anatomical survey and normal amniotic fluid prior to PROM, and absence of labor or abruption at the time of PROM. Oligohydramnios is defined as an amniotic fluid index (AFI) <5 cm of measurable pockets of amniotic fluid which are free of umbilical cord. Expectant management was carried during the 3-year period. The overall perinatal survival is 66%. Pulmonary hypoplasia is present in 18%, and skeletal deformities in 3% of all neonates. RESULTS: There is no significant difference between the two groups in the mean gestational ages at PROM (172+/-17 d vs. 171+/-14 d), latency periods (9+/-14 d vs. 8+/-13 d), incidences of chorioamnionitis (48 vs. 39%), endometritis (19 vs. 14%), neonatal sepsis (11 vs. 13%), or skeletal deformities (6 vs. 0%). Patients with oligohydraminos have significantly higher incidences of fetal heart rate decelerations (59 vs. 38%) and C-section (38 vs. 16%) (P < 0.05) than patients with adequate amniotic fluid. CONCLUSIONS: After adjusting for confounding variables, neonates with oligohydramnios are twice as likely to develop pulmonary hypoplasia (20 vs. 10%) and more likely to experience neonatal death (30 vs. 20%) when compared to those with adequate fluid, even though the difference is not statistically significant.

Adult↗
PubMedDate not supplied

Serial changes in the biophysical profile in patients undergoing cervical ripening with a controlled release PGE2 vaginal pessary.

OBJECTIVE: The purpose of this study was to evaluate the effects of exogenous administration of PGE2 upon the components of the biophysical profile. METHODS: The study group included 17 nulliparas at > or = 38 weeks gestation, with a Bishop score of < or = 4, requiring induction of labor. A controlled release vaginal pessary containing 10 mg of PGE2, designed to release hormones at approximately 0.8 mg per hour in vitro, was used for 12 hours of cervical ripening. The BPP was performed by the same sonographer at three intervals: prior to pessary insertion, at 6 hours, and 12 hours. RESULTS: None of these patients had membrane rupture or went into spontaneous labor during the ripening process. All patients subsequently required amniotomy and oxytocin. The proportion of patients scoring 2 points for fetal breathing movements decreased from 59% at baseline to 0% at 12 hours, P < 0.0005, and the proportion of patients with fetal body movements decreased from 100% at baseline to 25% at 12 hours, P < 0.0005. However, the other components of the biophysical profile were not affected. The mean maternal plasma PGE2 metabolite concentrations were 235 pg/ml, 475 pg/ml, and 466 pg/ml at 0, 6 and 12 hours, respectively, P < 0.005. CONCLUSIONS: In term patients, vaginal administration of the PGE2 pessary was associated with improved Bishop score over 12 hours and significant increases in maternal plasma PGEM levels at 6 hours and 12 hours. These changes were inversely related to fetal breathing and body movements.

Administration, Intravaginal↗