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Biomedical subjects

L D Devoe

Publications and source records attributed to L D Devoe.

At least 109 records · Page 6Linked to original sources
PubMed1986

Nonimmune hydrops fetalis: clinical experience and factors related to a poor outcome.

Twenty-one cases of nonimmune hydrops fetalis diagnosed at the Medical College of Georgia during a 2-year period are presented. All fetuses satisfied strict diagnostic criteria and were evaluated according to a standard protocol. The corrected mortality rate was 95% with pulmonary hypoplasia being the most common cause of perinatal death. The mean gestational age at diagnosis was 24.8 weeks; in 57% of the cases the cause of nonimmune hydrops fetalis was identified. Fifteen fetuses had serial ultrasound assessment and in 19 cases postnatal evaluation was performed. Two factors that consistently conveyed a poor perinatal outcome were ultrasonographic evidence of malformation and/or the presence of persistent pleural effusions. A method for the quantification of fetal pleural effusions is presented and its clinical relevance is discussed.

Adolescent↗
PubMed1986

Pregnancy outcome in renal transplant recipients: experience at the Medical College of Georgia and review of the literature.

Between 1970 and 1982, 13 renal transplant recipients had 17 pregnancies with follow-up at the Medical College of Georgia (MCG). Nine patients received related donor grafts and four received cadaver kidneys; 11 mothers survived their pregnancies. Preeclampsia, urinary tract infections, and preterm labor were frequent complications. complications. Perinatal complications were rare, and 12 of 13 continuing pregnancies produced surviving infants. Only one infant had congenital abnormalities (premature closure of the fontanelles and umbilical hernia). We present maternal and neonatal details, with prognostic considerations for pregnancy in such patients.

Abnormalities, Multiple↗
PubMed1986

Na+-H+ exchanger of human placental brush-border membrane: identification and characterization.

Syncytiotrophoblast brush-border membrane vesicles isolated from full-term human placentas were shown to transport Na+ against a concentration gradient in the presence of an outward proton gradient [( H+i] greater than [H+]o). This proton gradient-coupled Na+ uptake was markedly inhibited and the uphill transport abolished when the electrochemical proton gradient was dissipated by carbonylcyanide 4-(trifluoromethoxy) phenylhydrazone. The presence of nigericin also eliminated the concentrative uptake of Na+ in these vesicles. Dimethylamiloride and harmaline inhibited the proton gradient-induced Na+ uptake. The apparent inhibition constant for this process was 0.32 microM for dimethylamiloride was freely reversible and the inhibitor reduced the Na+ uptake by directly interacting with the exchanger protein rather than by dissipating the H+ gradient. The dimethylamiloride-sensitive Na+ uptake was saturable with respect to Na+. The affinity constant for Na+ was 7.8 +/- 1.2 mM and the maximal velocity was 38.7 +/- 2.4 nmol X mg protein-1 X min-1. The dimethylamiloride-insensitive Na+ uptake was not saturable and probably represented simple diffusion. The diffusional component accounted for only 10% of the total uptake. Li+ strongly competed with Na+ for the uptake process and the apparent inhibition constant was 3.6 +/- 0.4 mM. Tetraethylammonium also caused significant inhibition of Na+ uptake, whereas K+, Rb+, Cs+, and choline had no effect. These data provide evidence for the existence of a Na+-H+ exchanger in human placental brush-border membrane, and the properties of this exchanger are similar to those of the Na+-H+ exchanger identified in the brush-border membrane of mammalian kidney and small intestine.(ABSTRACT TRUNCATED AT 250 WORDS)

Amiloride↗
PubMed1986

Metastatic pheochromocytoma in pregnancy and fetal biophysical assessment after maternal administration of alpha-adrenergic, beta-adrenergic, and dopamine antagonists.

Metastatic pheochromocytoma, a rare complication of pregnancy, was managed from 30 weeks' gestation until delivery three weeks later with a combination of alpha-adrenergic blockade (Minipres) beta-adrenergic blockade (Timolol), and dopamine synthesis inhibition (Demser). The biophysical parameters of fetal heart rate (FHR) baseline, variability, and reactivity, as well as fetal breathing movements, body movements, tone, and amniotic fluid volume were followed sequentially during this period. A 1450-g growth-retarded infant, who subsequently did well, was delivered by cesarean section; the mother received combined surgical and medical therapy for her metastatic disease in the postpartum period. The initial fetal biophysical alteration observed was a reduction in mean FHR baseline rate; further biophysical test abnormalities appeared only after overt fetal compromise was evident. Sequential multiple parameter biophysical testing in such circumstances appears to be a valid and valuable approach to antepartum management.

Adult↗
PubMed1986

Inhibition of human placental Na+-H+ exchanger by cimetidine.

The Na+-H+ exchanger of human placental brush-border membrane was strongly inhibited by cimetidine, a histamine type II receptor antagonist. The inhibition was freely reversible and the apparent inhibition constant for the process was 38 microM. The nature of inhibition was found to be competitive with respect to Na+. Cimetidine inhibition was specific as other related compounds had no inhibitory effect. Treatment of the membrane vesicles with diethylpyrocarbonate inactivated the exchanger, but the presence of cimetidine during the treatment provided complete protection from this inhibition. These results show that histidine residues are located at the external Na+-binding site of the exchanger and cimetidine interacts with this site. The Na+-H+ exchanger of rabbit renal brush-border membrane was also susceptible to inhibition by the drug. However, transport of proline and glucose in placental brush-border membrane vesicles was not affected by cimetidine. The placental Na+-H+ exchanger was also inhibited by amiloride and the inhibition was freely reversible and competitive with respect to Na+. These results show that the characteristics of the inhibition of Na+-H+ exchanger by cimetidine and amiloride are very similar.

Amiloride↗
PubMed1986

Percent acceleration time: a new method of fetal assessment.

The percent acceleration time (PAT) is a fetal heart rate parameter, which may be derived from the nonstress test (NST). It is based on measurement of the duration of individual movement-associated fetal heart rate accelerations (MAFAs), obtained during a nonstress test, and is calculated by the formula: (formula, see text) The authors studied 148 fetuses undergoing four or more serial nonstress tests who were delivered within one week of their last test. Percent acceleration time of fetuses with normal outcomes had a mean value of 15.5 +/- 10.0 (SD)%, correlated well with the frequency and amplitude of movement-associated fetal heart rate accelerations but was independent of gestational age and mean baseline fetal heart rate. No normal fetus had a percent acceleration time of less than 5% on its last nonstress test, while only one abnormal fetus had a percent acceleration time that exceeded the mean percent acceleration time of the normal group. All abnormal fetuses had a significant progressive decline in percent acceleration time (mean: 50.6%). Percent acceleration time values were more sensitive in identifying fetuses with perinatal compromise than were conventional criteria for nonstress test reactivity, and may provide a useful alternative to assessment of fetal status when other quantitative methods are unavailable (continuous ultrasound visualization) or less reliable (maternal perception, tokodynamometry, palpation).

Female↗
PubMed1986

Frequency of asymptomatic bacteriuria in preeclampsia.

Asymptomatic bacteriuria has a reported prevalence of 4 to 7% during pregnancy. Preeclampsia has been reported to increase susceptibility to infection; therefore, the authors examined asymptomatic bacteriuria (greater than 100,000 colonies/mL of urine) as a possible marker for host resistance in preeclamptic pregnancies. One hundred preeclamptic primigravidas at term were compared with 100 nonpreeclamptic primigravidas undergoing primary cesarean section and 100 multigravidas undergoing elective repeat cesarean section. Urine cultures were obtained by bladder catheterization. A significant difference (P less than .005) in the rate of asymptomatic bacteriuria was found in patients with preeclampsia (19%), when compared with that of primigravid (3%), or multigravid (6%) control subjects. Preeclamptic patients with bacteriuria had significantly lower total serum protein and albumin than preeclamptic patients without bacteriuria (P less than .001).

Bacteriuria↗
PubMed1985

Computer-assisted assessment of the fetal biophysical profile.

The biophysical profile assesses fetal heart rate, breathing movements, fetal body movements, amniotic fluid volume, and fetal tone. In the past, these data have been scored by an arbitrary, unweighted system. While this approach is useful in detecting major anomalies and oligohydramnios, both static observations, the dynamic variables (fetal heart rate, fetal breathing movements, and fetal body movements) have added little information beyond that of an extended nonstress test alone. We have evaluated an alternative biophysical assessment system, modeled after extended physiologic studies, which not only acquires dynamic fetal variables simultaneously but, with computer assistance, quantifies the biophysical information. With an ADR 4000/L scanner, a Hewlett-Packard 8040 A monitor, and a specially programmed IBM microcomputer, we studied 100 normal term fetuses during 60-minute epochs. Each gestation had normal amniotic fluid volume and fetal tone. Normative values for the dynamic variables, expressed as means +/- SD were: fetal heart rate, 137 +/- 6.3 bpm; incidence of fetal breathing movements, 25.0% +/- 17.3%; rate of fetal breathing movements, 46.0 +/- 9.4 breaths/min; total fetal breathing movements, 823 +/- 61; incidence of fetal body movements, 8.5% +/- 3.9%; accelerations (greater than 15 bpm, 15 seconds), 14.1 +/- 6.3. We conclude that this approach is practicable, respects the biologic cycles of fetal behavior, and provides a basis for population standards and sequential study of the same fetus.

Amniotic Fluid↗
PubMed1985

Dipeptide transport in brush-border membrane vesicles isolated from normal term human placenta.

We studied the transport of glycylsarcosine by the brush-border membrane vesicles isolated from normal term human placentas. This dipeptide resisted hydrolysis by placental membrane vesicles and was transported intact into an osmotically responsive intravesicular space. The transport process was Na+-independent and probably occurred down a concentration gradient. Many peptides inhibited the transport of glycylsarcosine whereas amino acids had no effect. These results demonstrate, for the first time, the presence of a dipeptide transport system in the human placenta.

Amino Acids↗
PubMed1985

The nonstress test as a diagnostic test: a critical reappraisal.

In the past decade the nonstress test has become a major method of assessing high-risk pregnancy. Although many studies have been published, there has been a lack of rigorous adherence to the standard criteria for diagnostic testing, that is, presentation of test specificity, sensitivity, predictive value, and the prevalence of abnormal outcomes in the populations studied. Furthermore, the populations studied vary widely in composition, testing conditions, methods of test interpretation, and clinical management. The authors undertake a review of these studies, with a focus on these issues, in an attempt to indicate potential problems involved in current test usage and to suggest avenues for needed clinical investigation.

Evaluation Studies as Topic↗
PubMed1985

Clinical sequelae of the extended nonstress test.

Two hundred eighty-one high-risk gravida women undergoing a collective total of 661 nonstress tests entered a protocol to determine whether extending initially nonreactive tests improved the positive predictive value of this test modality. Reactivity required the occurrence of at least three fetal heart rate accelerations (15 bpm, 15 seconds' duration), associated with fetal movement during a 30-minute episode. Tests failing these criteria were extended by sequential 30-minute increments until a reactive 30-minute window appeared or 90 minutes had elapsed. After 90 minutes, a nonreactive test was followed by a contraction stress test. Reactive tracings occurred in 266 patients (95%) and in all cases were evident by the end of 70 minutes. Corrected perinatal mortality and morbidity in this group were 0% and 5.6%, respectively. Nonreactive fetuses not only produced abnormal (positive or persistently equivocal) contraction stress tests in nearly all cases (93.3%) but had mortality and morbidity rates of 6.7% and 93.3%, respectively. Furthermore, in five of 15 instances, the contraction stress test was associated with profound fetal heart rate decelerations necessitating emergency delivery. We conclude that prolonged nonreactivity, in the absence of significant immaturity, congenital abnormalities, or pharmacologic agents, identifies significant fetal jeopardy. Expeditious termination of pregnancy should be considered and, under these circumstances, a subsequent contraction stress test may be relatively contraindicated.

Congenital Abnormalities↗
PubMed1985

Simultaneous antepartum testing of twin fetal heart rates.

Assessment of twin gestation in the antepartum period has been a problem because most methods either fail to distinguish twins individually or require serial study over several weeks before reaching diagnostic end points. Electronic monitoring of the fetal heart rate (FHR) allows individual focus on each twin with a high degree of specificity and permits immediate status evaluation. In this study 44 sets of twins had simultaneous Doppler monitoring in an outpatient testing center. Transducer position was aided by real-time ultrasonic location of each fetal heart; 198 tests were satisfactory, each patient receiving 3.9 +/- 2.9 (mean +/- SD) studies. The rate of unsatisfactory tests was 15.4%, though each fetus was satisfactorily tested within one week of delivery. Testing was begun at 32.9 +/- 2.9 weeks and delivery occurred at 36.8 +/- 2.6 weeks. Perinatal mortality was 22.7/1,000, significant morbidity 15.9%, and cesarean section rate 18.1%. Reactive (R) patterns were seen in 69 fetuses and nonreactive (NR) in 19. Although there were no significant differences in gestational age at delivery between R and NR groups, (36.9 vs 36.2 wk) NR fetuses had significantly lower birth weights and higher rates of neonatal depression, perinatal mortality, and retarded intrauterine growth. Similarities in FHR patterns within twin pairs were frequently observed (30/44). Twins exhibiting dissimilar patterns had significant differences in birth weight and tended to have separate rather than common placentas. Simultaneous FHR testing of twins appears to be an effective means of providing immediately accessible data on the comparative well-being of each twin.

Adult↗
PubMed1985

Central hemodynamic findings associated with cortical blindness in severe preeclampsia. A case report.

Amaurosis, or cortical blindness, is a rare complication of preeclampsia. Recent technologic advances have permitted a more accurate assessment of the affected cortical regions using computerized tomography (CT). A better understanding of the hemodynamic events in this illness has been afforded by central monitoring techniques, such as Swan-Ganz flow-directed arterial catheters. A patient with severe preeclampsia and amaurosis documented by CT scan was followed with invasive hemodynamic monitoring.

Adult↗
PubMed1985

Nonstress test: dimensions of normal reactivity.

Despite the widespread use of the nonstress test, there has been no consensus on the criteria for normal reactivity. The authors studied 495 nonstress tests of 230 normal term fetuses, using a standardized protocol. The frequency distribution of movement-associated fetal heart rate (FHR) accelerations exceeding 15 beats per minute and 15 seconds' duration was examined in windows, ranging from ten to 40 minutes. Mean, median, and modal frequencies of movement-associated FHR accelerations were determined in 1910, 1418, 895, and 473 windows of ten, 20, 30, and 40 minutes, respectively. No significant difference in movement-associated FHR acceleration frequency was observed for any sequential ten-minute window, but movement-associated FHR accelerations were absent in 19.5, 8.8, 5.2, and 5.0% of 10-, 20-, 30-, and 40-minute windows, respectively. The broad frequency distributions of movement-associated FHR accelerations, produced by normal fetuses, precludes discrete diagnostic cutoffs in short time windows, unless one is willing to accept significant negative predictive errors.

Female↗
PubMed1984

The effects of maternal hyperoxia on fetal breathing movements in third-trimester pregnancies.

Fetal breathing movements and gross fetal body movements were observed before, during, and after maternal hyperoxia induced by inhalation of 50% oxygen in 14 women with normal term pregnancies. Studies were performed with real-time B-scan linear-array ultrasound and were standardized for time of day, maternal nutritional status, postprandial interval, and length of observation. Each study included a 30-minute baseline, followed by 15 minutes of hyperoxia, and 45 minutes of continued monitoring. No significant changes occurred in the mean incidences of fetal breathing movements, gross fetal body movements, the mean breathing rate, or breath interval variability, as analyzed in 5-minute epochs. Maternal PO2, as measured by transcutaneous electrodes, increased to the maximum level after 5 minutes of hyperoxia (155% over control levels). The breathing activity of normal third-trimester fetuses appears to be stimulated maximally in the second and third postprandial hours and cannot be further increased by maternal hyperoxia. This protocol represents a possible clinical strategy for investigating fetuses at risk for intrauterine hypoxia, provided that similar experimental conditions are maintained.

Female↗