Search PubMed⌕ Search

Biomedical subjects

H Steinberg

Publications and source records attributed to H Steinberg.

At least 145 records · Page 8Linked to original sources
PubMed1981

Effect of dexamethasone on the synthesis of dipalmitoyl phosphatidylcholine.

Glucocorticoids are known to enhance surfactant production by stimulating the formation of phosphatidylcholine. This study was performed to determine the effect of steroids on one of the pathways involved in the incorporation of palmitic acid into phosphatidylcholine--the 'deacylation-reacylation pathway'. Palmitoyl CoA synthetase, lysopalmitoyl cholineacyltransferase and phospholipase A2 were enhanced significantly as a result of direct administration of dexamethasone into 27-day fetal rabbits. Cycloheximide inhibited the steroid induced enhancement of activity. Immunologic studies demonstrated an accelerated rate of synthesis of palmitoyl CoA as a result of the dexamethasone treatment. The data suggest that steroids are capable of inducing enzymes of the 'deacylation-reacylation pathway' involved in palmitate incorporation into phosphatidylcholine thereby contributing to the acceleration of dipalmitoyl phosphatidylcholine biosynthesis.

1-Acylglycerophosphocholine O-Acyltransferase↗
PubMed1981

Effect of aminophylline on the synthesis of dipalmitoyl phosphatidyl choline in fetal rabbit lung.

Aminophylline (A) administration to pregnant rabbits resulted in accelerated formation of phospholipids, the known important components of pulmonary surfactant [1]. The present study was undertaken to determine the effect of A on one of the pathways involved in the incorporation of palmitic acid into phosphatidyl choline (PC)--the "deacylation-reacylation pathway." A was injected intraperitoneally into rabbit fetuses at 27 days of gestation and its effect on palmitoyl CoA synthetase (PCS) and lysopalmitoyl choline acyl transferase (LPC-AT) were studied. Only LPC-AT was enhanced significantly (P less than 0.05) as a result of direct administration of A. This study supports the suggestions by previous investigators that antenatal administration of aminophylline may prove to be an effective means of enhancing lung maturation by stimulating the formation of pulmonary surfactant production before premature delivery. However, the dose that was used in this experimental study was far more than the usual clinical dose that had been suggested previously.

1-Acylglycerophosphocholine O-Acyltransferase↗
PubMed1980

An analysis of physician resistance to psychiatric consultations.

Although it has been estimated that between 30% and 60% of hospital patients have an emotional problem related to and sometimes affecting the course of their hospitalization, psychiatric consultations for such patients are rarely requested. We conducted chart rounds with house and nursing staffs to identify those patients with prominent psychiatric problems relating to hospitalization. It was found that physician resistance to consultation was involved in more than 50% of cases not referred, usually because the physicians believed that there was no psychiatric problem or that psychiatry could not help, and less often because the physician thought that the patient might become upset or the patient-doctor relationship would be destroyed. The basis of the physicians' resistance was found not justified in 26 of 29 patients seen, and 23 of these patients were judged to have been helped by the psychiatrist.

Attitude of Health Personnel↗
PubMed1980

Supervision in liaison and consultation psychiatry.

This paper reports special problems and techniques of teaching liaison and consultation psychiatry to psychiatric residents. It has become apparent that traditional methods of resident training are inadequate, and that specialized techniques of supervision are required to help the resident deal with the unique aspects of the liaison and consultation environment. Specific recommendations are made and discussed.

Countertransference↗
PubMed1980

Imipramine normalizes naturally-occurring and drug-induced differences in the exploratory activity of rats.

1 Exploratory activity of female hooded rats was measured in a Y maze on two occasions, 1 week apart. Locomotion (maze arm entries), rearing, and head-dipping into pots were scored for 5 min at each trial. 2 In control rats, differences between individuals in the amount of locomotion and rearing were consistent, as shown by significant test-retest correlations (r = +0.55, and +0.83 respectively). There was no correlation between head-dipping scores obtained in the two tests. 3 Imipramine (Imip) pretreatment before the second trial (10 mg/kg i.p on the 3 preceding days, and 2.5 mg/kg 1 h before) abolished these correlations. The scatter of the scores about the mean was also reduced by Imip, but there was no significant change in mean scores. Thus Imip appeared to have a 'normalizing' effect on locomotion and rears: after pretreatment, scores tended to be more uniform, and no longer reflected naturally-occurring individual differences. 4 Imip abolished the changes in exploratory activity produced by drugs which alter brain 5-hydroxytryptamine metabolism: p-chlorophenylalanine (100 mg/kg 24 h before testing) increased and DL-5-hydroxytryptophan (12.5 mg/kg 1 h before testing) decreased the fall in activity over the trial in saline-treated rats but not that in Imip-treated rats. In this case, Imip also produced an overall reduction in activity scores. 5 The normalizing effects of Imip on rat behaviour may be analogous to its therapeutic effects in human depressive disorders.

5-Hydroxytryptophan↗
PubMed1980

Acute hydrogen selenide inhalation.

Acute exposure to selenium hydrochloride resulted in severe dyspnea and a pneumomediastinum in a young healthy man. Pulmonary function tests revealed restrictive and obstructive airways disease. Although the patient's pulmonary function slowly improved, subsequent studies revealed persistent impairment. Therefore, exposure to selenium gas may result acutely in severe coughing and wheezing and may lead to irreversible obstructive lung disease.

Adult↗
PubMed1980

Competition between platelets and lung for 5-hydroxytryptamine uptake.

The pulmonary endothelial cell removes 5-5-hydroxytryptamine (5-HT) from the circulation by a process of uptake and metabolism. The platelet, the major source of 5-HT in the circulation, represents another potential site of uptake for this amine. Platelet uptake of 5-HT infused into the pulmonary circulation was evaluated using isolated ventilated rat lungs. Lungs were perfused with buffer, platelet-poor, platelet-rich, or thrombin-treated platelet-rich plasma followed by an infusion of (14C) 5-HT. Platelet counts, aggregation response to adenosine diphosphate, and in vitro uptake of 55-HT were unchanged after circulation through the lung. In the presence of buffer or platelet-poor plasma, the lung removed 65.5 +/- 1.4% and 67.8 +/- 0.8%, respectively, of the infused (14C) 5-HT. In the presence of platelet-rich plasma, the lung removed 51.3 +/- 3.0 and platelet fraction 30.1 +/- 1.4% of the infused (14C) 5-HT. Recently aggregated platelets removed 24.4 +/- 1.8%, whereas platelets exposed to low oxyygen tensions removed 14.7+/- 0.6% of the (14C) 5-HT. These results indicate that 5-HT released inot the pulmonary circulation is either taken up by the endothelium and metabolized or taken back up by the platelet and stored.

Animals↗
PubMed1979

Reversal of 2-deoxyglucose inhibition of serotonin uptake in isolated guinea pig lung.

The effect of various substrates on the rate of uptake of 5-hydroxytryptamine (serotonin) from the pulmonary circulation was studied with isolated guinea pig lungs. Lungs were ventilated and were perfused with an electrolyte solution in a recirculating system. Uptake of serotonin was calculated from the rate of disappearance of [14C]serotonin from the perfusate. Serotonin uptake was inhibited by approximately 40% when 5 mM 2-deoxyglucose was substituted for glucose in the pulmonary perfusate. The inhibition due to 2-deoxyglucose was reversed by addition to the perfusate of pyruvate, lactate, acetate, alanine, beta-hydroxybutyrate, palmitate, or glycerol. Fructose ans succinate were less efficient substrates while no significant effect was noted with L-glycerol 1-phosphate or L-phenylalanine. These results indicate that a wide variety of metabolizable substrates can be utilized by the pulmonary endothelium to support uptake of serotonin.

Acetates↗