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Biomedical subjects

A Fleischer

Publications and source records attributed to A Fleischer.

At least 55 records · Page 3Linked to original sources
PubMed1987

Uterine and umbilical artery velocimetry during normal labor.

Twelve normal parturients were studied with a continuous wave Doppler unit to assess changes in uterine and umbilical velocity waveforms during labor. The analysis of these waveforms included the peak systolic/end-diastolic ratio and the evaluation of a diastolic notch. Each woman served as her own control, and all fetal heart rate tracings were normal. In latent phase labor and intact membranes, the umbilical artery systolic/end diastolic ratios before, during, and after a contraction were 2 +/- 0.2, 2 +/- 0.3 and 1.95 +/- 0.3 (N.S.). Similar results were obtained in the active phase, after rupture of membranes, or during oxytocin stimulation. This stability of the fetal cardiovascular system ensures an uninterrupted gas exchange process during the contractions (on the fetal side), enabling the great majority of term fetuses to tolerate labor with minimal if any metabolic changes. The uterine artery end-diastolic velocity fell progressively during the contraction, reaching 0 when the intrauterine pressure exceeded 35 mm Hg. Despite intrauterine pressure of greater than 60 mm Hg, the diastolic notch did not appear. Thus at term, the umbilical artery velocity waveform does not change over a wide range of uterine pressures. The changes seen in the uterine artery waveforms suggest that the end-diastolic component is primarily determined by changes in the arcuate and spiral arteries, both of which are affected during the uterine contraction.

Blood Flow Velocity↗
PubMed1986

Development of uterine artery compliance in pregnancy as detected by Doppler ultrasound.

Uterine artery velocimetry was performed by means of a continuous-wave Doppler ultrasound. Serial studies were done on 12 nonpregnant and 79 normal pregnant women. Measurements were made on both uterine arteries and averaged. From the proliferative phase of the menstrual cycle through 40 weeks of pregnancy, four developmental phases are described. These changes are based on the calculation of the systolic-diastolic ratio and the disappearance of the early diastolic notch in the velocity wave. The ratio after 26 weeks averaged 2 +/- 0.3. These data provide a foundation for the study of pregnancies in which these normal evolutionary changes do not occur.

Compliance↗
PubMed1986

Uterine artery Doppler velocimetry in pregnant women with hypertension.

Uterine and umbilical artery velocimetry was carried out on 71 women with hypertensive disorders in pregnancy. Three categories of hypertensive disease were diagnosed: chronic hypertension, preeclampsia, and chronic hypertension with superimposed preeclampsia. Clinical classifications describe the severity of disease effectively, primarily because the classification is based on the appearance of abnormal physical or laboratory findings. Doppler velocimetry of the uterine arteries shows that normal pregnancy occurs when the systolic/diastolic ratio is less than or equal to 2.6. When the ratio exceeds this level and there is a notch in the waveform, the pregnancy is complicated by stillbirth, premature birth, intrauterine growth retardation, and maternal preeclampsia. The positive and negative predictive value of the examination is 93% and 91%, respectively. It appears that this new technology will be an essential ingredient of optimum pregnancy surveillance.

Adult↗
PubMed1986

Umbilical artery velocimetry in diabetes and pregnancy.

Doppler studies of umbilical artery velocity waveforms were performed during the third trimester of pregnancy in 43 diabetic women (18 class A and 25 insulin dependent). A mean serum glucose value of 120 mg% or more was selected to indicate poor glucose control. Systolic to diastolic ratios of umbilical artery velocity waveforms were calculated to determine the degree of placental vascular resistance. A systolic to diastolic ratio of 3 or more was selected as the cut-off value for determining placental vascular disease. A significant positive correlation between systolic to diastolic ratios and serum glucose level (r = 0.52, P less than .001) was found. Elevated systolic to diastolic ratio was associated with increased number of stillbirths and neonatal morbidity. This study suggests that the risk of adverse outcome in diabetic pregnant women correlates with umbilical artery velocity waveforms.

Blood Glucose↗
PubMed1985

Surveillance of twin pregnancy with umbilical arterial velocimetry.

A continuous-wave Doppler system and a spectrum analyzer provide the tools for the measurement of systolic-diastolic velocity wave ratios in the umbilical arteries. In twins, each umbilical cord can be studied without imaging the fetuses. Results were tabulated by taking the average difference in the ratios between each fetus and plotting these values against the neonatal weight differences. In 43 twin pregnancies, the data revealed that ratio differences between fetuses that averaged 0.4 or more was predictive of a weight difference of greater than 349 gm. The sensitivity was 73% and specificity 82%. Two cases of twin transfusion syndrome were recognized by the simultaneous presence of high- and low-resistance values.

Adult↗
PubMed1985

Umbilical artery velocity waveforms and intrauterine growth retardation.

A continuous-wave Doppler unit was used to obtain umbilical artery velocity waveforms and to calculate the peak-systolic/diastolic ratio, a reflection of vascular resistance distal to the point of measurement. A total of 587 examinations were performed on 189 women between 18 to 42 weeks' gestation. The neonates were divided in four groups based on their centile birth weight: less than 25%, 25% to 50%, 51% to 75%, and greater than 75% for that gestational age. In all four groups the placental vascular resistance as reflected by the systolic/diastolic ratio fell progressively from the 24 weeks onward. In the lower weight group, placental vascular resistance between 31 to 39 weeks' gestation was higher than in the other three groups (p less than 0.05). For measurements taken between 31 and 39 weeks' gestation we calculated the predictive value of this test in identifying the small-for-gestational age fetus. A ratio of greater than or equal to 3 was defined as abnormal. For the entire population tested, sensitivity was 78% and the specificity was 83%. The predictive value of a positive test was 49%, but when hypertension was present, it was 66%. These findings may prove useful in identifying and managing pregnancies at risk for intrauterine growth retardation.

Blood Flow Velocity↗
PubMed1985

Evidence for the cerebral uptake in vivo from two pools of glucose and the role of glucose-6-phosphatase in removing excess substrate from brain.

We propose the following scheme for cerebral uptake and overall metabolism of glucose in vivo: that brain selects from two pools of glucose anomers in arterial blood, that it takes up excess glucose, that glucose enters the brain tissue as glucose-6-phosphate through the actions of mutarotase and hexokinase, that some glucose-6-phosphate becomes metabolized to CO2 and some becomes incorporated into brain carbon pools, and that excess glucose-6-phosphate leaves brain through glucose-6-phosphatase and mutarotase activities. This results from our observations in arterio-venous studies for the determination of cerebral metabolism in humans in vivo that the cerebral uptake of [14C]glucose often appeared to differ from that of unlabeled glucose. With rapidly falling arterial radioactivity, unlabeled glucose uptake was more than [14C]glucose. With rising arterial radioactivity, [14C]glucose extraction exceeded unlabeled glucose. Studies with [14C]glucose-6-phosphate suggested that glucose-6-phosphatase in brain removes excess substrate by dephosphorylation. However, when arterial [14C]glucose increased slowly, [14C]glucose uptake varied considerably and the data resembled human cerebral metabolism of glucose anomers. An experiment employing [13C]glucose and NMR provided further support for our proposed scheme.

Animals↗
PubMed1985

Meconium aspiration and fetal acidosis.

Meconium in labor is associated with increased perinatal morbidity and mortality. To identify the infants at risk, 53 women with moderate-to-thick meconium were followed in labor after obtaining baseline fetal scalp blood pH levels. Although 28 of the newborns (53%) exhibited an arterial cord pH of less than 7.25 at delivery, there were no significant predictive variables found in the electronic fetal monitoring score, Apgar score, or mode of delivery. Nine of the infants with a pH value of less than 7.25 had meconium below the vocal cords at delivery, but none in the infants with pH levels greater than or equal to 7.25. The P50 value for cumulative acidosis is 55 minutes, indicating a more rapid deterioration than an average-for-gestational-age fetus without meconium. Therefore, the presence of thick meconium implies that fetal stress must be avoided during labor, and early intervention is warranted when there is deviation from normal labor progress or fetal heart rate pattern.

Acidosis↗
PubMed1985

Antepartum nonstress test and the postmature pregnancy.

A review of 4320 consecutive term deliveries identified 258 women (6%) delivered at a gestational age of 42 weeks or longer. The group accounted for 30% of all cesarean sections for fetal distress, 30% of all infants with a low five-minute Apgar score, 40% of neonatal intensive care admissions, 60% of neonatal deaths, and 30% of all stillbirths. Nonstress tests were performed on 228 women with a postmature pregnancy. Results were defined as normal (score 7 to 10) in 83.4%, inconclusive (score 5 to 6) in 12.2%, and abnormal (score 1 to 4) in 4.4% of these cases. Monitored patients did significantly better than patients in the nonmonitored group, and so did those with normal nonstress test scores when compared with the abnormal scores. Whereas perinatal mortality in the monitored group was similar to that in the nonpostmature population, the perinatal morbidity was significantly higher.

Apgar Score↗
PubMed1984

Umbilical velocity wave ratios in human pregnancy.

Umbilical artery velocity waves were measured in the fetuses from 130 pregnant women. One hundred eighty-five determinations were carried out from the fourteenth to the fortieth weeks of pregnancy. Detection of waveforms was carried out on an Angioscan Doppler spectrum analyzer. The umbilical artery velocity waves can be differentiated from other fetal signals by recognition of the pattern. The systolic peak of the velocity wave was divided by the end-diastolic value, thereby giving an S/D ratio. The use of a ratio overcomes the obstacle of not knowing the angle between the incident beam and the direction of motion. The umbilical velocity wave S/D ratio in normal pregnancies declines from 2.8 to 2.2 from 25 to 41 weeks. In pregnancies which result in a small-for-gestational age (SGA) fetus, the ratio is significantly higher, showing an average level of 3.8 at 29 weeks and declining to 3.0 at 40 weeks. Abnormal umbilical velocity wave values are seen in an SGA fetus, unexplained fetal death, poorly controlled diabetes mellitus, and a twin transfusion syndrome. Application of this technique has the potential of being an important aid in prenatal care.

Female↗
PubMed1984

Rheumatoid nodulosis of the hand.

Rheumatoid nodulosis is an uncommon variant of rheumatoid disease with distinctive clinical and radiographic characteristics and a favorable prognosis. This is in contrast to the poor prognosis for the severe form of rheumatoid disease with which rheumatoid nodules are often associated. A case of rheumatoid nodulosis of the hand treated with complete resection of the nodules is presented with a 2.5-year follow-up. Fourteen cases of documented rheumatoid nodulosis are reviewed and surgical treatment is recommended for both functional and cosmetic reasons.

Female↗
PubMed1984

Role of prostaglandin-induced cervical changes in labor induction.

The role of the cervix in labor induction has been studied in a previous report. Cervical preparation by mechanical methods did not alter the course of induced labor. The same hypothesis is further elucidated in the present study using prostaglandin E2 vaginal suppositories for cervical preparation. Forty-seven pregnant women near term with Bishop scores of 4 or less were divided into three study groups: control subjects, oxytocin-treated patients, and prostaglandin group. A 12-hour preparation phase procedure was carried out to produce cervical and/or myometrial changes. All women had continuous measurement of uterine activity by an extraovular catheter. At the end of the preparation phase, the Bishop score was reevaluated, amniotomy carried out in all patients, and oxytocin infusion either started or continued. Although prostaglandin and oxytocin both significantly changed the cervix, oxytocin had the shortest induction-to-delivery interval, though the prostaglandin-treated group required lower concentrations of oxytocin. The authors conclude that with rigid control of Bishop score and timing of amniotomy and oxytocin infusion rates, prostaglandin-induced cervical changes alone did not uniquely benefit labor induction in the doses used, or within the time frame of the study.

Adult↗
PubMed1984

Fetal acidosis and the abnormal fetal heart rate tracing: the term breech fetus.

The intrapartum fetal heart rate tracings of 27 terms fetuses in breech presentation were analyzed to evaluate their immediate neonatal outcome. The tracings were quantitatively evaluated for comparison with Apgar scores and umbilical cord gases at delivery. Of the 27 cases, 12 had monitoring strips that scored 4 or less before birth. The P50 for acidosis at delivery (an umbilical artery pH of 7.25 or less) was 55 minutes for an intrapartum tracing that scored 4 or less. Fetuses with intrapartum tracings scoring 8 or more throughout labor had normal Apgar scores and cord gases. In comparing the present data with those of a previous study of vertex presentations, the authors found that given similar tracings, the breech fetus deteriorates more rapidly than the vertex fetus. Cesarean section is recommended if delivery is not imminent in a laboring breech and the intrapartum tracing deteriorates to score 4 or less.

Acidosis↗
PubMed1983

A comparison of the cerebral uptake and metabolism of labeled glucose and deoxyglucose in vivo in rats.

Experimental evidence indicated that: 1) [14C]deoxyglucose-6-phosphate (14C-DG-6-P) in brain (and other rat tissues) did not increase with time after injection of 14C-DG, 2) 14C-DG-6-P in rat brain (and other tissues) did not correlate with glucose metabolism, 3) 14C-DG-6-P in rat brain (and other tissues) had a significant negative correlation with glucose-6-phosphatase activity. Further, arterio-venous studies in rats, in which the cerebral uptake and metabolism of labeled glucose were compared directly with those of labeled DG (and labeled fluorodeoxyglucose, FDG), employing double labeled techniques, showed that DG (and FDG) cannot be used to measure glucose uptake and/or metabolism.

Animals↗