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Biomedical subjects

R E Ringel

Publications and source records attributed to R E Ringel.

22 records · Page 2Linked to original sources

Ductus arteriosus in premature infants beyond the second week of life.

Persistent patency of the ductus arteriosus (PDA), common in premature infants, is associated with severe respiratory distress. The likelihood and significance of finding PDA in premature infants beyond the second week of life is unknown. We retrospectively analyzed all echocardiograms obtained between 1987 and 1992 on infants <35 weeks' gestational age. Of 446 echocardiograms 77 were obtained from infants >/=14 days. Of the 77 infants, 17 (22%) were found to have PDA (group 1) and the remainder did not (group 2). Forty-eight infants had been diagnosed as having PDA prior to 14 days of age. Of these infants, 16 were from group 1. Thus only 1/17 (6%) infants diagnosed as having PDA after 2 weeks did not have a history of PDA. The presence of PDA after 2 weeks did not relate to duration of oxygen therapy, ventilator therapy, or hospital stay. Furthermore, late closure of PDA in a subgroup of 11 infants did not appear to affect these parameters. It was concluded that premature infants beyond the second week of life are unlikely to have PDA if PDA had not been diagnosed during the first 14 days. Closure of PDA beyond the second week may not improve the infant's respiratory status.

Case-Control Studies↗

Red cell cotransport activity and sodium content in black men. Relationship to essential hypertension.

Furosemide-sensitive sodium and potassium cotransport and intracellular sodium content ([Na]i) were measured in erythrocytes (red blood cells, RBCs) from a population of 90 adult black men with and without essential hypertension (EH). The mean values for sodium cotransport activity, expressed as furosemide-sensitive Na efflux (mmol/liter RBC/hr), were not significantly different among the EH patients and two control groups, normotensive subjects with a positive history (N+) and those with a negative family history (N-) for hypertensive disease (EH: 154 +/- 123, n = 53; N+: 167 +/- 93, n = 12; and N-: 207 +/- 142, n = 20; all values are means +/- SD). The mean [Na]i 9.66 +/- 3.02 mmol/liter RBC (n = 56) for the EH group was greater than the mean value for the N- control group (7.96 +/- 1.97, n = 20; p less than 0.05). The N+ group also displayed a higher mean [Na]i (10.38 +/- 3.18, n = 12; N+ vs N- p less than 0.01). Although there was substantial overlapping of [Na]i values between the groups and no clear dividing line, the distribution curve of the [Na]i values in EH was skewed toward higher concentrations than in N-. Nevertheless, we must conclude that erythrocyte cotransport and [Na]i are not clinically useful in the identification of EH in black men.

Adult↗