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Biomedical subjects

R Burstein

Publications and source records attributed to R Burstein.

At least 91 records · Page 5Linked to original sources

Effect of patent ductus arteriosus on left ventricular output in premature infants.

A 5 MHz range-gated portable pulsed Doppler velocity meter was used to measure mean ascending aortic blood flow velocity noninvasively. Studies were performed from a suprasternal approach in 18 preterm infants with patent ductus arteriosus. Measurements were made in each patient before and after medical or surgical closure of the PDA. The internal ascending aortic diameter was determined echocardiographically and aortic cross-sectional area calculated according to the equation AAo = pi d2/4. Ascending aortic blood flow was computed as QAo (ml/min) = VAo (cm/sec) x AAo (cm2) x 60 (sec/min). Prior to PDA closure, QAo averaged 343 ml/min/kg, well above predicted normal values. After PDA closure, QAo fell to 252 ml/min/kg, significantly lower than the preclosure level (P less than 0.001), but slightly higher than the mean cardiac output of healthy newborn infants. The mean QAo after surgical ligation of the PDA was closer to the predicted normal value than after treatment with indomethacin alone. This study reflects the effect of left-to-right ductus shunting on left ventricular output and emphasizes the demands placed on the neonatal left ventricle by PDA.

Cardiac Output↗

Evaluation of infants with bronchopulmonary dysplasia using cardiac catheterization.

Nine infants with bronchopulmonary dysplasia underwent cardiac catheterization to define thier circulatory status. In room air, the mean cardiac index was normal (3.4 liters/min/sq m), but pulmonary arterial pressure (39 mm Hg, mean) and pulmonary vascular resistance (8.6 Wood units . sq m) were elevated. Preejection period/right ventricular ejection time ratios determined echocardiographically correlated well with values obtained at catheterization, but did not correlate well with hemodynamic values. Administration of 40% and 88% oxygen caused variable responses in hemodynamic measurements. Studies of left ventricular function were normal in all patients. These findings raise questions about the long-term prognosis of infants with bronchopulmonary dysplasia.

Bronchopulmonary Dysplasia↗

Posthemorrhagic hydrocephalus in low-birth-weight infants: treatment by serial lumbar punctures.

We have performed weekly computed tomographic brain scans on 28 surviving low-birth-weight infants with cerebral intraventricular hemorrhage and acute ventricular dilatation. Evolving hydrocephalus was observed in 15 infants. Twelve of the 15 infants were treated by removing large volumes of cerebrospinal fluid with serial lumbar punctures. Arrest in the progression of hydrocephalus was evident in 11 of the 12. Clinical hydrocephalus requiring surgical intervention occurred in one of the treated infants and in all three untreated infants. No complications of serial lumbar punctures were noted, whereas shunt-related morbidity was 100%. Our results suggest that serial lumbar punctures are effective in arresting the development of posthemorrhagic hydrocephalus.

Brain↗

Intraventricular hemorrhage and hydrocephalus in premature newborns: a prospective study with CT.

In a prospective study, 100 premature infants were studied with computed tomography (CT) brain scans within the first week of life. In 44 of these,hemorrhages originated from the subependymal germinal matrix, and ranged in severity from isolated germinal matrix hemorrhages to blood-filled, dilated ventricles with extension of hemorrhage into the brain parenchyma. A system of grading the severity of hemorrhage was developed. Grades I and II hemorrhages resolved spontaneously and grades III and IV were associated with progressive hydrocephalus. Asymptomatic hemorrhages that would not have been diagnosed on clinical grounds were detected by CT. This study offers a clearer understanding of the true incidence and natural history of cerebroventricular hemorrhage and associated hydrocephalus in premature neonates and may clarify etiologic factors and identify children at risk for subsequent neurologic abnormalities.

Cerebral Hemorrhage↗

Incidence and evolution of subependymal and intraventricular hemorrhage: a study of infants with birth weights less than 1,500 gm.

We have performed brain scanning by computed tomography on 46 consecutive live-born infants whose birth weights were less than 1,500 gm; 20 of them had evidence of cerebral intraventricular hemorrhage. Nine of the 29 infants who survived had IVH. Four grades of IVH were identified. Grade I and II lesions resolved spontaneously, but there was prominence of the interhemispheric fissue on CT of the infants at six months of age. Hydrocephalus developed in infants with Grade III and IV lesions. Seven of the surviving infants with IVH did not have clinical evidence of hemorrhage. There were no significant differences between the infants with and without IVH in birth weight, gestational age, one- and five-minute Apgar scores, or the need for resuscitation at birth or for subsequent respiratory assistance.

Cerebral Hemorrhage↗

Relationship of intravenous sodium bicarbonate infusions and cerebral intraventricular hemorrhage.

The incidence of cerebral intraventricular hemorrhage was determined by computed tomography in 100 infants with birth weights less than or equal to 1,500 gm. A comparison of IVH with serum sodium concentrations and the amount of intravenous sodium bicarbonate administered did not reveal a significant relationship. Analysis of the method of infusion of sodium bicarbonate indicated that the rapid infusion of hyperosmolar (M to M/12) sodium bicarbonate is associated with a significantly increased incidence of IVH.

Bicarbonates↗

Subependymal germinal matrix and intraventricular hemorrhage in premature infants: diagnosis by CT.

Hemorrhage into the subependymal germinal matrix with rupture into the cerebral ventricles causes significant morbidity and mortality in premature infants. CT brain scanning was performed on eight premature infants on whom autopsy confirmation was obtained. Excellent sensitivity and accuracy in detecting germinal matrix hemorrhage and intraventricular hemorrhage were found. Germinal matrix hemorrhage appears as a parenchymal collection of blood adjacent to the foramen of Monroe and has a convex margin laterally. CT scanning of living premature infants is feasible in diagnosing nonfatal episodes of germinal matrix and intraventricular hemorrhage as well as subsequent development of hydrocephalus and porencephaly.

Cerebral Hemorrhage↗

Association between oral contraceptive use and thromboembolism: a new approach to itsinvestigation based on plasma fibrinogen chromatography.

Longitudunal and cross-dectional blood coagulation studies were made in patients receiving oral contraceptive therapy and in unmedicated women used as control subjects. These studies have included use of a new procedure, plasma fibrinogen chromatgraphy, which, by assay for a high molecular weight fibrinogen complexes in plasma, detects or excludes the presence of small thrombi, even when these are of the clinically silent type. New contraceptives users (n=154) received either Ovulen (100 pg of mestranol) or Demulen (50pg of ethinyl estradiol) and were followed serially for one year. During the cross-sectional study (193 women and 1,350 samples), serial examination was preformed on those taking oral contraceptives for 3 months to 10 years. Over-all, pathologic plasma fibrinogen chromatographic findings, indicative of thrombosis, were detected in 6 per cent of hte control examinations and in 27 per cent samples from oral contraceptive users. These findings suggest that oral contraceptive users developed mainlyclinically silent thrombotic lesions, with four-to-fivefold greater frequency than the control subjects. Consequently, it is inferred that they are at four-to fivefold greaterrisk of developing clinically overt disease, a risk factor estimate in line with that derived by epidemiologic study.

Alpha-Globulins↗

Mixed leukocyte culture reactivity in operationally tolerant rats: Relationship of lymphocyte-mediated reactivity and serum-blocking activity.

Tolerance to Brown Norway (BN) allografts was induced in Wistar Furth rats by neonatal inoculation of BN bone marrow cells or mixtures of (W/Fu x BN)F-1 hybrid spleen and bone marrow cells. Lymphoid cells from rats in which operational tolerance had been induced (maintenance of BN skin graft for more than 100 days) were studied for mixed leukocyte culture (MLC) reactivity. Peripheral blood lymphocytes from 10 of 25 W/Fu rats operationally tolerant to BN skin grafts showed MLC reactivity when exposed to BN antigens in vitro, implying that some degree of MLC reactivity is compatible with prolonged skin graft survival. These same rats also showed cytotoxic activity to BN fibroblasts in vitro regardless of their MLC status. MLC is quantitatively decreased and possibly qualitatively altered as compared to that of control W/Fu lymphocytes. The decrease was specific for the tolerated antigens. Serum from the tolerant rats inhibited cytotoxic but not normal MLC reactivity of W/Fu cells against BN antigens.

Animals↗