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Biomedical subjects

L Schwartz

Publications and source records attributed to L Schwartz.

At least 199 records · Page 11Linked to original sources
PubMed1983

Chondrosarcoma of the bronchus.

A primary chondrosarcoma of the right main bronchus was removed by pneumonectomy in a 74-year-old woman. The presenting symptoms were dyspnea and cough with a lung mass evident for 18 months. She is well and free of tumor 16 months later. Only eight established cases of primary chondrosarcoma arising from the lung, and four originating from the tracheobronchial tree have been previously described. The long preoperative history and the outcome so far confirm the relatively less aggressive character of the tracheobronchial as compared to the lung subdivision of primary pulmonary chondrosarcoma.

Aged↗
PubMed1982

Percutaneous transluminal angioplasty of an anomalous left circumflex coronary artery arising from the right sinus of Valsalva.

This case report describes a patient with isolated stenosis of an anomalous circumflex artery with evidence of left ventricular lateral wall ischaemia. Percutaneous dilatation of this vessel was successfully performed and was facilitated by removing the tip of a standard guiding catheter permitting selective cannulation of the anomalous ostium. Similar innovations in the standard angioplasty technique may permit its application in other unusual anatomical situations.

Adult↗
PubMed1982

Biofunctional evaluation of a hydrogen bond stabilizing the conformation in the cyclic part of oxytocin.

[5-beta-Malamidic acid]oxytocin was synthesized to study the importance of the hydrogen bond between the C=O of Tyr2 and the peptide N-H of Asn5 for the stabilization of a biologically functional conformation of oxytocin. This analog lacks the peptide N-H at residue 5 required for the formation of a hydrogen bond with the C-O of Tyr2. [5-beta-Malamidic acid] oxytocin exhibited 45.1 +/- 2.5 U/mg and 65.6 +/- 5.9 U/mg of uterotonic activity, in vitro, in the absence and in the presence, respectively, of Mg2+, 147 +/- 14 U/mg of uterotonic activity in vivo, 203 +/- 13 U/mg of milk-ejecting activity, 0.37 +/- 0.03 U/mg of pressor activity and 0.32 +/- 0.29 U/mg of antidiuretic activity. It is concluded that devoid of the hydrogen bond under question, an oxytocin-like peptide can still assume the conformation needed to interact with the oxytocin receptors.

Drug Stability↗
PubMed1981

Hodgkin's disease in childhood: therapy results in Argentina.

From 1940 to 1977, a total of 152 children aged 15 years or less with the histologic diagnosis of Hodgkin's disease were treated in Argentina. For analysis, these patients were placed into three periods which displayed the most outstanding changes in diagnostic workup and therapy. The periods are as follows: (1) 1940 to 1966 (43 children), (2) 1967 to 1972 (35 children), and (3) 1973 to 1977 (74 children). The patients were treated with extended field radiation therapy and followed by courses of cyclophosphamide-vinblastine-procarbazine-prednisone, with CCNU added (CCVPP) or not added (CVPP) in a randomized trial. The mean age of the whole group was 7.5 years (range 2 to 15 years) and there was a predominance of males (79%). Crude 6-year survival for the three periods were as follows: 1940 to 1966, 34%; 1967 to 1972, 50%; and 1973 to 1977, 79%. We conclude that (1) survival of Hodgkin's disease of childhood has shown a rather marked improvement during the last decade and this progress is probably due to the use of combined multidrug chemotherapy administered under collaborative controlled clinical trials; (2) preliminary evaluation of the results of CVPP and CCVPP therapy shows that the latter combination (CCVPP) neither increases the percent of patients achieving complete remission nor prolongs relapse-survival in Hodgkin's disease of childhood: and (3) all stages of childhood Hodgkin's disease can be successfully managed with multidrug chemotherapy alone.

Adolescent↗
PubMed1980

Clinicopathological correlations in patients who received an isolated model 104 Beall mitral valve.

Following reports of accelerated wear in the model 104 Beall prosthetic valve, the authors initiated a recall and prospective follow-up study of patients who received Beall valves. In the 3 years of the follow-up program, 12 patients who had an isolated Beall mitral valve implanted have had elective replacement of the prosthesis. Cinefluoroscopy was the most accurate preoperative method of predicting the degree of pathologic wear. The serum lactic dehydrogenase value was the next most helpful measurement. Change in functional class, mitral regurgitation murmur, hemodynamic status, echocardiography and the duration of the valve in situ were not sensitive indicators.

Adult↗
PubMed1979

Giant left atrial V-waves in post-myocardial infarction ventricular septal defect.

A 54-year-old man developed a post-myocardial infarction ventricular septal defect with a 4:1 shunt. The first cardiac catheterization showed left atrial V-waves of 70 mm Hg. Assessment of the presence or absence of mitral regurgitation was not possible because of ventricular irritability and rapid runoff from left ventricle to right ventricle. At the second catheterization two months later, the left atrial V-waves had fallen to 34 mm Hg. The absence of mitral regurgitation was shown by observing the time difference in appearance of indocyanine green in the right ventricle and the left atrium after left ventricular injection. The defect was repaired by right ventriculotomy with subsequent normalization of left atrial V-waves. This case shows that very large left atrial V-waves may occur in postinfarction ventricular septal defects without mitral regurgitation and that these V-waves may decrease with time, probably reflecting increased left atrial compliance.

Cardiac Catheterization↗
PubMed1979

Catecholamines in coronary sinus and peripheral plasma during pacing-induced angina in man.

We measured aortic and coronary sinus dopamine (DA), epinephrine (E), and norepinephrine (NE) in eight patients with cardiac ischemia (I) and eight control subjects (C). Samples were taken at rest (73 +/- 3 beats/min in C and 68 +/- 3 beats/min in I) and during coronary sinus pacing to peak rates (144 +/- 4 beats/min in C and 136 +/- 6 beats/min in I). Arterial NE was higher in the ischemic patients at rest (254 +/- 25 pg/ml in C and 324 +/- 21 in I; p less than 0.05). There were no differences in arterial E and DA. Neither pacing nor angina affected peripheral catecholamine concentrations. Resting myocardial NE flux was similar for both groups. With pacing, coronary sinus flow and net myocardial NE release increased significantly in both groups. The maximum relative increase in net myocardial NE release was less in the ischemic patients than in the controls (575 +/- 145% in C and 255 +/- 40% in I; p less than 0.05). Thus, angina induced by pacing does not augment peripheral sympathetic activity. Furthermore, pacing-induced angina appears to be associated with a decrease in cardiac sympathetic tone compared with that found in paced controls.

Angina Pectoris↗
PubMed1979

The extraction of circulating catecholamines by the lungs in normal man and in patients with pulmonary hypertension.

We directly measured the net pulmonary extraction of circulating norepinephrine, epinephrine and dopamine in control patients and patients with primary or secondary pulmonary hypertension. Mixed pulmonary artery norepinephrine, epinephrine and dopamine were 314 +/- 13 pg/ml, 102 +/- 9 pg/ml, 51 +/- 5 pg/ml, respectively, for the control group; values were similar in patients with pulmonary hypertension. The pulmonary extraction of norepinephrine was 25.4 +/- 2.6% (clearance 266 +/- 62 ng/min) in control patients; epinephrine and dopamine were not extracted. There was no net extraction or production of any of the three catecholamines by the lungs in any of the patients with pulmonary hypertension. We conclude that the lungs play a significant role in the inactivation of circulating norepinephrine in man. This metabolic function of the lungs appear to be lost in pulmonary hypertension.

Adult↗
PubMed1979

Response of patients to participation in psychiatry board examinations.

The patient who volunteers to be a subject for Part II of the certifying examination in psychiatry and neurology is an indispensable but surprisingly invisible participant in a highly controversial process. A survey of the attitudes of 78 patients toward this experience revealed that although they experienced a significant degree of stress, the overwhelming majority viewed their participation in strongly positive terms. The patient's loyalty to the host institution and the manner in which the patient is prepared for the experience appear to be the major factors in determining a positive outcome.

Adult↗
PubMed1978

Computer-assisted reporting system for the follow-up of patients with prosthetic heart valves.

The implantation of large numbers of prosthetic heart valves carries with it the responsibility for continual reassessment of all aspects of patient management. Experience with more than 2,000 prosthetic valve operations since 1963 led to the development of a comprehensive computer-assisted data collection, management and reporting system. Over a 5 year period, data forms were developed for the detailed documentation of preoperative, intraoperative and postoperative information. These were designed in the form of checklists suitable for direct computer entry with use of mark-sense document readers. Special emphasis was placed on preoperative assessment of ventricular function, valve selection, intraoperative myocardial preservation, postoperative rehabilitation and prosthetic valve-related complications. This system makes possible rapid computer generation of a variety of reports to the referring physician regarding the individual patient and to the clinical investigator in relation to patient group statistics. Also, questionnaires to patients of physicians, or both, to update patient data can be produced by the computer at appropriate intervals after valve surgery. Experience indicated that a computer-assisted methodology is the only practical way to provide adequate follow-up of large groups of patients. Additionally direct access to relevant information helps to create an environment in which essential research can be carried out in the face of a demanding clinical practice.

Follow-Up Studies↗
PubMed1978

Sign comprehension in global aphasia.

Ten global aphasics and eight brain-damaged non-aphasics were given a test of sign comprehension. The test contained natural, animal and human signs. Subjects were matched for etiology, age and residual intellectual functioning. The global aphasics scored significantly lower than the nonaphasics on the test of sign comprehension, indicating that global aphasia might be reconsidered as a disorder of sign comprehension.

Aged↗