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Biomedical subjects

R Gonen

Publications and source records attributed to R Gonen.

At least 37 records · Page 2Linked to original sources
PubMed1995

Subendometrial myometrial contractions associated with transcervical chorionic villous sampling.

Thirty-two consecutive patients, referred for prenatal diagnosis by chorionic villous sampling, were examined by transvaginal ultrasound for the presence of myometrial contractions before and after the procedure. Increased myometrial activity was observed in 78% of patients. The mean frequency increased by 3.5 times and the amplitude increased by 4.2 times compared to the preprocedure condition. Cramping was associated with the increased amplitude and/or frequency of contractions. No significant correlation was found between the direction of propagation of the contraction wave and its frequency or amplitude. The sensitivity of ultrasonographically detected myometrial contractions in predicting cramping is 70%, but only 31% in predicting vaginal bleeding or spotting. Further studies are required to elucidate the prognostic significance of this uterine activity.

Adult↗
PubMed1994

Intracervical prostaglandin E2 for induction of labor in patients with premature rupture of membranes and an unripe cervix.

The efficacy and safety of intracervical prostaglandin E2 (PGE2) gel for induction of labor in patients with premature rupture of the membranes (PROM) at term and with an unripe cervix were evaluated. Fifty-two patients who did not start labor 6 to 12 hours after PROM and who had an unripe cervix were randomized to one of two management protocols. Patients randomized to PGE2 received a single intracervical application of 0.5 mg PGE2. Patients randomized to the conservative protocol were managed expectantly for 24 hours. If labor was not established 6 hours after randomization in patients receiving PGE2 or 24 hours after PROM in patients managed expectantly, labor was induced with intravenous oxytocin. Of the patients receiving PGE2, 93% began labor after a single application, and the mean interval between prostaglandin application and delivery was 6.6 hours. In the conservative group, only 57% began labor within 24 hours, and more than half of them required augmentation with oxytocin. The mean latency between PROM and delivery was 15 hours in patients managed with PGE2 and 30 hours in patients managed conservatively (P < 0.01). There were no complications and pregnancy outcome was similar in the two groups. Intracervical PGE2 is safe and effective for inducing labor in patients with PROM and an unfavorable cervix.

Adult↗
PubMed1993

Description and partial characterization of a new Chlamydia-like microorganism.

A new obligate intracellular bacterium which we called 'Z' was isolated as a cell culture contaminant of unknown origin. The organism grew in a variety of cultured cells with a 5-7-day developmental cycle, within cytoplasmic phagosomes, similarly to Chlamydia and some Rickettsia spp. Two alternating developmental forms (elementary bodies and reticulate bodies) were observed by electron microscopy. SDS-PAGE electrophoresis, immunoblotting with chlamydia-specific antibodies, and polymerase chain reaction using chlamydial genus specific primers provided evidence that our bacterium differs significantly from chlamydiae. Further characterization of 'Z' including determination of 16S ribosomal RNA sequences will allow its taxonomic position to be established.

Animals↗
PubMed1993

Serum reactivity to Chlamydia trachomatis and C. pneumoniae antigens in patients with documented infection and in healthy children by microimmunofluorescence and immunoblotting techniques.

Chlamydia trachomatis and C. pneumoniae are both important human pathogens. Antigenic cross-reactivity between the two species may complicate serologic diagnosis of infection with one or the other agent. In this study we examined sera of persons with chlamydia infections and of healthy children by microimmunofluorescence (MIF) against C. trachomatis L2 antigen and against C. pneumoniae TW-183 antigen to explore the degree of cross-reactivity found by these two methods. Likewise, the cross-reactivity seen by immunoblot with sera of rabbits immunized against one of the antigens when tested on the other was examined. While among healthy children stratified by age, MIF seropositivity to C. pneumoniae TW-183 increased with age, no such trend was observed with respect to seropositivity to C. trachomatis L2 antigens, and 81% of children seropositive to TW-183 did not react on L2 antigen. Moreover, 27% of those positive on L2 antigen were negative on TW-183. Immunoblot analysis showed much greater antibody cross-reactivity than that detected by MIF. The immunoblot cross-reactivity was probably not attributable solely to double infection since sera of rabbits immunized to only one species of chlamydia reacted strongly with both chlamydiae in immunoblot analysis. The data presented need to be taken into account in the development of serologic tests based on a small number of antigens or on partially denatured antigens.

Animals↗
PubMed1992

Doppler flow velocity waveforms in fetal surveillance of twins: a prospective longitudinal study.

In 37 consecutive twin pregnancies, monthly Doppler sonographic measurements were made of blood flow velocity waveforms of the internal carotid and umbilical artery of each fetus. A total of 197 Doppler studies were performed. Of the 74 infants, 23 were small for gestational age (SGA). Thirty-five of the SGA Doppler studies were abnormal, giving an overall sensitivity for predicting SGA fetus of 58% and a positive predictive value of 71%. These data are not as sensitive and specific as our earlier data; however, Doppler criteria preceded sonographic diagnosis of SGA by a mean interval of 3.7 weeks and demonstrated better sensitivity and specificity. A combination of these parameters improves sensitivity to 84%. We conclude that Doppler velocimetry complements real-time ultrasonography for the early diagnosis of abnormal growth in twin pregnancies.

Blood Flow Velocity↗
PubMed1992

The association between unexplained second-trimester maternal serum hCG elevation and pregnancy complications.

OBJECTIVE: We conducted this cohort analytic study to determine whether women with unexplained elevations of maternal serum hCG at 16-20 weeks' gestation are at increased risk for pregnancy complications and adverse perinatal outcomes. METHODS: The inclusion criteria were a singleton gestation, a confirmed gestational age, and an hCG level greater than 2.5 multiples of the median (MOM). The exclusion criteria were fetal anomalies, an abnormal karyotype, and a maternal serum alpha-fetoprotein (MSAFP) level greater than 2.5 MOM. A group of randomly selected women with normal hCG and MSAFP levels served as controls. RESULTS: Of the 6011 women screened, 284 (4.7%) had an unexplained elevated hCG level. Patients with elevated levels of hCG had a significantly higher risk for hypertension (odds ratio 4.4; 95% confidence interval [CI] 1.9-10) and fetal growth restriction (odds ratio 2.8; 95% CI 1-7). Women with hCG levels greater than 4 MOM also had an increased risk of preterm delivery (odds ratio 3.3; 95% CI 1.3-8.2). CONCLUSION: Pregnancies with unexplained elevated hCG levels should be regarded as high-risk pregnancies and managed accordingly.

Chorionic Gonadotropin↗
PubMed1991

Can the nonstress test predict congenital sepsis?

The possible role of the nonstress test (NST) in the prediction of congenital sepsis in pregnancies complicated by prolonged premature rupture of the membranes (PROM) was investigated in a retrospective controlled study. Thirteen NSTs performed within 24 hours of the delivery of infants with congenital sepsis were coded, blinded, and mixed with an equal number of blinded NSTs derived from randomly selected patients matched for gestational age with PROM but without neonatal or maternal infection. Eleven of 13 infants with congenital sepsis had a reactive NST, and two had a nonreactive test. Among the controls, there were also 11 reactive and two nonreactive NSTs. The sensitivity and specificity of the NST in predicting congenital sepsis in patients with PROM were 15.4% and 84.6%, respectively. The positive predictive value and the negative predictive value were 50%. Our results suggest that the NST is not a useful tool for prediction of congenital sepsis.

Case-Control Studies↗
PubMed1991

Prediction of lethal pulmonary hypoplasia and chorioamnionitis by assessment of fetal breathing.

Twenty-three pregnancies with fetuses at risk for pulmonary hypoplasia were studied weekly until delivery. The amount of time spent in fetal breathing activity was recorded under controlled conditions during 1 h using real-time ultrasound. An amniotic fluid index was determined. The clinicians and the pathologist were unaware of the ultrasound findings. Eight of 23 fetuses did not breathe at the last ultrasound examination. Three babies died of pulmonary hypoplasia and two of these showed fetal breathing before birth. The three deaths were associated with rupture of the membranes at less than or equal to 20 weeks gestation and of greater than or equal to 44 days duration. One infant developed bronchopulmonary dysplasia. The amniotic fluid index in these four pregnancies was low and the newborn infants had limb contractures. Chorioamnionitis/funisitis was noted in 13 placentas. Eight fetuses were assessed for fetal breathing within 2 days of birth. The lack of fetal breathing had sensitivity, specificity, positive and negative predictive values of 0.75 for chorioamnionitis/funisitis. In this pilot study the absence of fetal breathing was of no value in predicting lethal pulmonary hypoplasia, but was related to chorioamnionitis/funisitis. We recommend further studies of fetal breathing in relation to fetal/neonatal infections.

Chorioamnionitis↗
PubMed1991

Fetal internal carotid artery pulsed Doppler flow velocity waveforms and maternal plasma glucose levels.

Eighteen women at 32-36 weeks' gestation were studied by pulsed Doppler (duplex) for recording blood flow velocity waveforms from the umbilical artery and fetal intracranial internal carotid artery. The pulsatility index was calculated for each artery separately. Each subject was investigated when fasting and 1 hour after a 100-g glucose load. Increases in maternal plasma glucose concentration of 30 mg/dL or more were followed by elevation of the mean pulsatility index in the umbilical artery from 0.9 +/- 0.22 to 1.08 +/- 0.18 (P less than .01) and in the internal carotid artery from 1.17 +/- 0.19 to 1.8 +/- 0.47 (P less than .001). The findings suggest a compensatory increase in cerebrovascular resistance during increases in glucose levels.

Blood Flow Velocity↗
PubMed1990

Lead exposure among mothers and their newborns in Toronto.

Recent studies have suggested that a fetal blood lead level of 0.48 mumol/L (much lower than 1.21 mumol/L, which is the level previously believed to be toxic to the developing brain) may impair brain development permanently. We measured the maternal and umbilical cord blood levels of lead and free erythrocyte protoporphyrin (FEP) among 95 consecutive mother-infant pairs to determine whether neonates in Toronto are in the high-risk group. There was a significant correlation between the maternal and the cord blood lead levels (r = 0.59, p less than 0.0001). Most (99%) of the infants had cord blood lead levels below 0.34 mumol/L; in 11 cases the levels were below the detection limit of 0.01 mumol/L. The cord blood FEP levels were higher than the maternal levels. The US Centers for Disease Control, Atlanta, currently finds acceptable a blood FEP level of 0.62 mumol/L among children up to 10 years of age; however, this is not applicable to newborns since their higher FEP levels apparently reflect immature heme synthesis and increased erythrocyte volume rather than lead poisoning. Our data suggest that living in Toronto does not impose increased teratogenic risk from intrauterine exposure to lead; however, residents in high-risk areas should be followed up.

Adult↗
PubMed1990

The outcome of triplet, quadruplet, and quintuplet pregnancies managed in a perinatal unit: obstetric, neonatal, and follow-up data.

Multifetal gestation is associated with increased frequency of maternal complications and higher perinatal morbidity and mortality. The need for contemporary data on the outcome of multifetal gestations is further underscored when selective reduction is considered. The present study details the obstetric management, neonatal outcome, and follow-up data of 24 triplet, five quadruplet, and one quintuplet pregnancies delivered in a perinatal center. The early neonatal mortality rate was 31.6, the late neonatal mortality rate was 21, and the perinatal mortality rate was 51.5. Survival to discharge was 93%. The incidence of respiratory distress syndrome was 43%, bronchopulmonary dysplasia 6%, retinopathy of prematurity 3%, intraventricular hemorrhage 4%, and cerebral palsy 2%. Follow-up from 1 to 10 years shows that only one child is moderately handicapped, whereas 99% have no significant medical problem. Early diagnosis by ultrasonography, meticulous antenatal care, early hospitalization, delivery by cesarean section, and on-site availability of a neonatologist for each baby at the time of delivery are the probable major determinants of improved outcome.

Child Development↗
PubMed1990

Early spontaneous rupture of the post myomectomy gravid uterus.

Rupture of a pregnant uterus is a serious threat to the mother's life and her fetus. Most of these cases have predisposing factors of which a post myomectomy scar is rare. Rupture of a post myomectomy gravid uterus usually occurs in the third trimester of pregnancy or during labor. We present a case of a very early spontaneous rupture which occurred at the 20th week of gestation in a post myomectomy uterus. To the best of our knowledge no previous report of a ruptured myomectomy scarred uterus has been described at such an early stage.

Adult↗
PubMed1990

Fetal heart rate monitoring at home and transmission by telephone.

We assessed the feasibility of introducing a home fetal heart rate monitoring system into a tertiary care perinatal unit. In the first stage of the study, 38 hospitalized high-risk pregnant patients recorded nonstress tests (NSTs) in their rooms in the hospital and transmitted the data to the receiving unit via the telephone. In the second stage, 34 women accomplished home monitoring in addition to the regular in-hospital NSTs prescribed by their physicians. The total of 72 patients, whose gestations ranged from 29-43 weeks, attempted 307 recordings, of which 93% were transmitted successfully. Ninety-eight percent of the received NSTs were considered interpretable. Based on our results, it seems that the use of the home fetal monitor by the patient in conjunction with all of the other components of a tertiary perinatal care center is feasible, reliable, and safe.

Female↗
PubMed1990

The outcome of triplet gestations complicated by fetal death.

Intrauterine death in twin pregnancies has been reported to be associated with a very high incidence of morbidity and mortality in the surviving co-twin, mostly attributed to vascular disruption when vascular anastomosis exists between the twins' circulations. The present study describes the obstetric, neonatal, and follow-up data of five triplet gestations complicated by intrauterine death of one or two fetuses, compared with a control group of triplets matched for gestational age. Delivery occurred an average of 30 +/- 26 days after the diagnosis of intrauterine fetal death. Four of the five placentas were monochorionic. All nine infants survived, but four were small for gestational age (SGA). A comparison of study cases and controls revealed that monochorionic placentation was found only in the study group, that SGA infants were more likely (but not significantly so) to be in the study group, and that study infants required significantly less ventilatory support. Although the only case of long-term morbidity was in the study group, the cause of this complication was consistent with prematurity.

Embryonic and Fetal Development↗
PubMed1989

Elevated liver enzymes and thrombocytopenia in the third trimester of pregnancy: an unusual case report and a review of the literature.

A woman presented in the third trimester of pregnancy with epigastric pain, elevated liver enzymes, and thrombocytopenia. The frozen-section liver biopsy findings were compatible with acute fatty liver of pregnancy. The light and electron microscopic findings were those of preeclampsia. All clinical and laboratory abnormalities resolved before delivery.

Acute Disease↗