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Biomedical subjects

J A Pritchard

Publications and source records attributed to J A Pritchard.

At least 19 recordsLinked to original sources

Pregnancy complicated by hereditary spherocytosis.

Hereditary spherocytosis is a spectrum of inherited erythrocyte membrane defects that result in hemolysis and varying degrees of anemia. Among 50 pregnancies in 23 women with spherocytosis, maternal complications were infrequent except for anemia, and perinatal outcomes were generally good. In six women, blood volume expansion estimated by 51chromium-tagged erythrocytes was similar to that for normal pregnant women. Mean red cell survival measured during seven pregnancies in six women ranged at 30-90 days, consistent with the heterogeneity of this disorder.

Female

On reducing the frequency of severe abruptio placentae.

At Parkland Memorial Hospital the frequency of abruptio placentae so severe as to kill the fetus has decreased from 1 in 420 deliveries during 1956 through 1969 to 1 in 830 during 1974 through 1989. Major factors in this reduction were elimination of very high parity and a marked increase in the percentage of Latin American women, in whom the risk was 1 in 1473 deliveries compared with 1 in 595 for black women and 1 in 876 for white women. Abdominal trauma was encountered rarely, as was fetoplacental-to-maternal hemorrhage sufficient to impair fetal perfusion seriously. Abnormal development of Müllerian ducts and uterine myomas were encountered rarely. Neither red blood cell macrocytosis characteristic of folate deficiency nor iron deficiency could be implicated in the genesis of severe abruptio placentae. Abruptio placentae recurred in 12% of subsequent pregnancies and proved fatal to the fetus in 7%, unchanged from our earlier experience.

Abruptio Placentae

Chronic renal disease and pregnancy outcome.

During the 18-year period from 1971 through 1988, 37 women whose pregnancies were complicated by moderate or severe renal insufficiency were managed at Parkland Memorial Hospital. Common maternal complications included anemia, chronic hypertension, and preeclampsia. Perinatal complications included midpregnancy losses and low birth weight from preterm delivery, fetal growth retardation, or both. Despite the high incidence of maternal morbidity, 85% of pregnancies in the 26 women with moderate renal insufficiency resulted in a live-born infant; there was one stillbirth and no neonatal deaths. Of the 11 women with severe disease, seven were delivered of live-born infants after greater than or equal to 26 weeks' gestation. Although six of these 37 women had worsening renal function during pregnancy, it seems unlikely that pregnancy per se caused this. More importantly, in four of these six women and in four others who had stable function throughout pregnancy, end-stage renal disease developed within a mean of 4 years after delivery. In 14 women blood volume was determined during pregnancy, and whereas those with moderate disease had normal volume expansion, women with severe disease had significantly attenuated expansion. Finally, serial creatinine clearances did not increase during pregnancy in half the women with moderate insufficiency and none with severe dysfunction.

Anemia

Pregnancy complicated by hemoglobin CC and C-beta-thalassemia disease.

The outcomes of 72 pregnancies in 20 women with either hemoglobin CC or C-beta-thalassemia are described. Except for mild to moderate hemolytic anemia, maternal complications caused by the hemoglobinopathy were infrequent and perinatal outcomes were generally good. In eight women, blood volume expansion determined by 51chromium-tagged erythrocytes was similar to that for normally pregnant women. Mean red-cell survival was determined 11 times in eight women, and the red-cell half-life of 22 days was significantly shorter than that of 35 days for normally pregnant women.

Black People

Cesarean section: the House of Horne revisited.

In 1983, obstetricians from Dublin, Ireland, alleged that the perinatal mortality rate in the United States could be achieved with a cesarean section rate of approximately 5%. We responded in 1985 that population and infant outcome differences precluded such a low rate of cesarean sections at Parkland Memorial Hospital. The Dublin obstetricians responded 3 years later that it was unfair to compare obstetric services for only 1 year (1983). We respond again.

Cesarean Section

Routine clinical application of the lymphocyte fluorescence polarization test for malignant disease.

The technique of Lymphocyte Fluorescence Polarization (LFP) can confirm or exclude the presence of malignant disease. The results from tests on a total of 566 subjects showed a false-positive rate of 3.8% and a false-negative rate of 2.2%. The LFP test has been used as an aid in the differential diagnosis of patients whose symptoms are not typical of primary or recurrent malignant disease. In over 40 such cases there has been total agreement between the LFP results and subsequent clinical or pathological investigations. The LFP Test has been used to monitor the response of cancer patients to various therapeutic regimes. Ovarian cancer patients giving negative LFP results after treatment with Cisplatin have been found free of disease at laparotomy, indicating that LFP may be an acceptable alternative to the surgical investigation. The LFP test has been shown to provide information of much value in the management of patients with malignant disease.

Adult

Transplacental hemorrhage associated with placental neoplasms.

We report a case of choriocarcinoma in situ arising from a term placenta in an otherwise normal pregnancy that resulted in fetal hydrops and intrauterine fetal death from chronic fetal-maternal hemorrhage (FMH). The clinical and pathologic features are described and compared with the few similar cases reported and with an additional placental choriocarcinoma found in our files. We also describe the clinical and pathologic observations of two chorangiomas that caused massive FMH and led to fetal death.

Adult

Convulsions in hypertensive, proteinuric primiparas more than 24 hours after delivery. Eclampsia or some other cause?

A diagnosis of eclampsia has been considered inappropriate when the onset of a convulsion is greater than 24 hours after delivery. The observations presented here provide strong support for waiving the 24-hour rule, at least when convulsions from no other apparent cause and accompanied by hypertension and proteinuria occur in a primipara as late as 10 days postpartum. Late postpartum eclampsia seems an appropriate term for this very uncommon condition.

Adolescent

How often does maternal preeclampsia-eclampsia incite thrombocytopenia in the fetus?

Overt thrombocytopenia (defined as a platelet count of less than 100,000/microL) was not identified at or soon after delivery in any of 262 infants of mothers with hypertension induced or exacerbated by pregnancy. The platelet counts were 100,000 to 149,000/microL in 11 (4.2%) of the offspring and 150,000/microL or higher in the rest, even though the platelet counts of the 258 mothers were less than 150,000/microL in 77 (30%), less than 100,000/microL in 51 (20%), and less than 50,000/microL in 17 (7%). Some infants of hypertensive mothers did develop overt thrombocytopenia later; however, the frequency and intensity appeared to be no greater than it was in infants with similar complications (prematurity, growth retardation, infection, and meconium aspiration) whose mothers were normotensive. We conclude that the fetus whose mother has preeclampsia-eclampsia is very unlikely to be thrombocytopenic during labor and delivery, even when the mother is thrombocytopenic. Therefore, neither cesarean delivery to avoid labor nor scalp blood platelet counts during labor need be performed.

Eclampsia

Peripartum heart failure: idiopathic cardiomyopathy or compounding cardiovascular events?

During a 12-year period, when more than 106,000 women were delivered, 28 women with peripartum heart failure of obscure etiology that initially was diagnosed as peripartum cardiomyopathy were studied. None had obvious underlying cardiac disease or iatrogenic fluid overload, and in all an assiduous search for underlying cardiovascular disease was launched. In 21 of these 28 women, heart failure was attributed to chronic underlying disease (chronic hypertension in 14, forme fruste mitral stenosis in four, and morbid obesity in one) or viral myocarditis. Importantly, these women also had multiple compounding cardiovascular factors--preeclampsia, cesarean section, anemia, and infection--which, when superimposed on those of pregnancy, acted in concert to cause heart failure. In seven women, the cause for cardiomegaly and global hypokinesis was not found, and peripartum cardiomyopathy was diagnosed. Compared with women with explicable causes of peripartum heart failure, these women did poorly: six had persistent cardiomegaly and heart failure, and four of these died within four months to eight years. From these observations, the authors conclude that idiopathic peripartum cardiomyopathy is uncommon, and that in most women with peripartum heart failure of obscure etiology, underlying chronic disease will be identified. Heart failure in these women ensues when the cardiovascular demands of normal pregnancy are amplified further by common pregnancy complications superimposed upon these underlying conditions that cause compensated ventricular hypertrophy.

Adult

Cesarean section: an answer to the House of Horne.

The incidence of cesarean delivery in the United States has at least tripled in the past 20 years, and this has generated a great deal of concern within the profession, by the government, and by the consumer. Recent data from the National Maternity Hospital in Dublin, Ireland, from which a stable 5% cesarean section rate was reported, have led those investigators to conclude that more frequent delivery by cesarean section in the United States was due in part to less aggressive management of labor in nulliparous patients. In this report, we compare obstetric practices and outcomes during 1983 for Parkland Memorial Hospital with those of the National Maternity Hospital. The overall cesarean delivery rate was 18% in Dallas and 6% in Dublin, and racial population differences along with an increased number of nulliparous patients likely account for a higher incidence of primary cesarean sections for dystocia in Dallas. Importantly, when we compared the results in Dublin with our own, more liberal use of cesarean delivery for presumed fetal jeopardy in Dallas was associated with a sevenfold decreased incidence of intrapartum fetal death and a twofold decrease in infants with seizures. From these data, we advise caution before one attempts to emulate, on faith alone, someone else's low and seemingly safe cesarean delivery rate.

Birth Weight

A video image correlation technique for the measurement of electrophoretic mobility.

The electrophoretic movement of blood cells has been examined with a video image correlator using the signal from a 625 line monochrome television camera attached to the optical arrangement. The diffraction pattern of a cell produces a characteristic signal which can be detected and registered in any television scan line to form the data of the first image frame. Under the influence of an electric field, cells moved across the television field of view and after a short interval appeared on different scan lines. The detection and registering process was repeated, and a cross-correlation function between the first and second image frame was computed. This function was stored in an output buffer which was continuously updated as fresh functions were integrated with the existing contents. The mean electrophoretic mobility of a suspension of particles can be calculated from the peak position of the integrated correlation function. Using a triangle deconvolution procedure, the relative contributions of subpopulations of lymphocytes prepared from peripheral blood samples were examined.

Blood Cells

The Parkland Memorial Hospital protocol for treatment of eclampsia: evaluation of 245 cases.

Since 1955, a standardized treatment regimen has been used to manage 245 cases of eclampsia at Parkland Memorial Hospital. Magnesium sulfate alone effectively controlled controlled convulsions in the great majority of cases. The only maternal death among the 245 cases reemphasizes the risk of respiratory arrest that is inherent in the administration of magnesium sulfate when given in large doses intravenously. Hydralazine to lower the diastolic blood pressure somewhat, when it was 110 mm Hg or higher, prevented intracranial hemorrhage. Avoidance of diuretics and hyperosmotic agents and limitation of fluid intake were not associated with severe renal failure. Pulmonary edema was rare. Vaginal delivery was achieved in the majority of cases. Oxytocin often proved effective for initiating and maintaining labor even remote from term. The results obtained with this regimen justify its continued clinical application.

Analgesics