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Biomedical subjects

F Schwarz

Publications and source records attributed to F Schwarz.

At least 145 records · Page 8Linked to original sources
PubMed1982

Native collaterals in the development of collateral circulation after chronic coronary stenosis in mongrel dogs.

The response of native collateral circulation to chronic stenosis of the left circumflex coronary artery (LCx) was studied in 17 mongrel dogs. Stenosis restricted reactive hyperemia of the LCx without affecting resting flow. Regional myocardial blood flow was measured by the tracer microsphere technique. Coronary collateral blood flow to the LCx was determined during maximal reactive hyperemia of the left anterior descending branch before and 5 weeks after implantation of a fixed LCx stenosis in the open-chest preparation. The protective effect of collaterals was tested by LCx ligation 5 weeks after implantation of stenosis. Presence of acute myocardial infarction was determined by nitroblue tetrazolium staining. Eleven dogs had a myocardial infarction (group A), but six dogs showed no evidence of infarction at autopsy (group B). In group A, collateral flow and minimal coronary resistance of the LCx bed changed little after LCx stenosis, from 12 to 15 ml/min/100 g and from 10.5 to 10.0 mm Hg/ml/min/100 g, respectively (both p less than 0.05). In contrast, collateral flow in group B increased from 22 to 102 ml/min/100 g (p less than 0.05), and minimal coronary resistance of the LCx bed decreased from 4.8 to 1.4 mm Hg/ml/min/100 g (p less than 0.01). Group A had lower native collateral flow (p less than 0.05) and higher native minimal coronary resistance of the LCx bed than group B (p less than 0.05). Postobstructive LCx pressure correlated well with blood flow data. The LCx risk region was of comparable size in groups A and B, 36.4% vs 39.0% of total left ventricle (p greater than 0.05). Two responses of collateral circulation to chronic stenosis were documented: lack of collateral growth in group A, but significant collateral growth in group B. The natural variation of collateral circulation was the major determinant of the different responses that were important with stenosis of a major coronary artery.

Animals↗
PubMed1982

Thrombolysis in acute myocardial infarction using intracoronary streptokinase: assessment by thallium-201 scintigraphy.

Twenty-one patients with acute myocardial infarction, admitted to the hospital within 4 hours after the onset of symptoms, were studied by seven-pinhole thallium-201 scintigraphy before and 1 hour and 24 hours after intracoronary fibrinolysis using streptokinase. The size of the thallium-201 perfusion defect was assessed from myocardial cross sections reconstructed from the original seven-pinhole data and expressed as a fraction of left ventricular circumference. Recanalization was achieved in 16 patients within 3.9 +/- 1.6 hours after onset of symptoms (group A). In these patients, the size of the perfusion defect had decreased from 36 +/- 17% to 19% +/- 15% (p less than 0.001) at 24 hours. No significant change was detected by redistribution at 1 hour after the intervention. In five patients, intracoronary fibrinolysis was unsuccessful, and the vessel remained occluded (group B). The thallium-201 perfusion defect affected 40 +/- 15% of the left ventricular circumference before the intervention; it remained virtually unchanged at 1 hour (37 +/- 16%) and at 24 hours (41 +/- 15%) after fibrinolysis. The perfusion defect was most reduced in patients with extensive collaterals supplying the ischemic area or with subtotal occlusion of the affected coronary artery. We conclude that successful intracoronary fibrinolysis may reduce the size of the thallium-201 perfusion defect in many patients with acute myocardial infarction. One important factor in the final result may be the presence of residual coronary flow supplied by extensive collaterals or by subtotal occlusion of the affected coronary artery when reperfusion is achieved around 4 hours after the onset of symptoms.

Adult↗
PubMed1982

The effect of aortic valve replacement on survival.

We retrospectively studied 252 operated and 47 unoperated patients with isolated aortic valve disease. Aortic valve replacement (AVR) was recommended to all patients based on clinical and hemodynamic data. Preoperative hemodynamic and angiographic data were similar in operated and unoperated cohorts. Seventy-one percent of patients received a Björk-Shiley prosthesis. Operative mortality was 7% for the entire surgical series. For patients with predominant aortic stenosis (AS), survival at 3 years was 87% in operated and 21% in unoperated patients (p less than 0.001). For patients with predominant aortic insufficiency (AI), the 5-year survival rate was 86% in operated and 87% in unoperated patients (NS). AVR improved long-term survival in patients with AS who had normal or impaired left ventricular (LV) function. In patients with AI and normal LV function, survival was not improved after AVR, but those with LV dysfunction who were operated on tended to survive longer (NS). Long-term survival of unoperated patients with AI was better than that in unoperated patients with AS. We conclude that AVR improves long-term survival in patients with AS who were normal or abnormal LV function, and that AVR does not change long-term survival in patients with AI, although those with LV dysfunction tended to survive longer.

Adult↗
PubMed1982

[Prognostic criteria in institutional group psychotherapy of neurotically depressed and compulsive neurotic patients].

20 neurotic depressive and 16 obsessive compulsive in-patients who took part at a psychoanalytic group psychotherapy were reexamined 2--9 years later. The question was pursued whether there are relations between data of life history and severity of neurosis on the one hand and outcome on the other hand. On account of further individual and group psychotherapy after discharge different durations of treatment were reached. Their influence on the outcome was studied. The findings were: 1. Some data concerning education, profession/capacity for work, contact, sexuality/partnership could be related to favorable and unfavorable outcomes. 2. It was possible too, to find relations between items which characterize the severity of neurosis and outcome. 3. Longer duration of treatment results in significant better outcomes. 4. A tendency was found, that changes of neurotic personality traits in comparison with symptomatic improvement are more close connected with duration of treatment than with severity of neurosis.

Adult↗
PubMed1982

[Sudden cardiac death in aortic stenosis].

The sudden cardiac death of a patient with severe aortic stenosis and impaired left ventricular function is reported. At the time of death an ambulatory ECG was recorded. Without prior exertion, without syncope, and without any ventricular arrhythmias within the last hour a sudden ventricular tachycardia ended the patient's life. This case demonstrates that a malign ventricular arrhythmia may lead to sudden death in patients with aortic stenosis and reduced left ventricular function.

Aortic Valve Stenosis↗
PubMed1981

[Direct contrast medium demonstration of acute and chronic pericardial effusion and of the pericardium (author's transl)].

After aspiration of the pericardial space 10 to 20 ml of contrast medium were injected into the pericardial sac in 11 patients with in part large pericardial effusions. Thus the effusion became directly visible on fluoroscopy and a satisfactory position of the aspiration cannula in the pericardial sac was ascertained. Complete drainage of the pericardial effusion could be well observed by fluoroscopy. The pericardial effusion dyed by contrast medium and the surrounding structures could be filmed by kinecardiography with a 35 mm camera ("pericardiography"). In contrast to echocardiography pericardiography resulted in additional important diagnostic information in two patients. Direct contrast medium demonstration of pericardial effusions and of the pericardium improves the safety during pericardial aspiration and enlarges the diagnostic possibilities particularly in ill-defined pericardial diseases and septated pericardial processes.

Adult↗
PubMed1981

Ultrastructural correlates of left ventricular contraction abnormalities in patients with chronic ischemic heart disease: determinants of reversible segmental asynergy postrevascularization surgery.

The relationships between structural alterations and left ventricular (LV) contraction abnormalities were studied in patients with coronary artery disease (CAD). Transmural biopsies of the LV anterior free wall were taken during aortocoronary bypass surgery (CABG) in 62 patients. When preoperative anterior wall motion (AWM) was reduced, significant myocardial cell degeneration was found in patients with as well as without previous anterior infarction (MI). The amount of myocardial fibrosis was increased only in patients with ECG evidence of previous anterior MI (p less than 0.001). In a second series of 139 CAD patients, cineventriculograms performed before and 8 months after CABG were examined. In patients with patent grafts to the LV anterior wall not previously infarcted, reduced AWM became normal. In patients with previous anterior MI the outcome of AWM was unpredictable (usually unimproved). Thus the histologic correlate of reduced AWM in segments not previously infarcted was progressive loss of contractile material in otherwise viable myocardial cells. Some reversibility was suggested by restoration of resting function after CABG. Unpredictable results in segments associated with pathologic Q waves appear related to the fibrous component of these previously infarcted areas.

Adult↗
PubMed1981

(Des-tyrosine1)-gamma-endorphin in schizophrenia: clinical, biochemical, and hormonal aspects.

The neuropeptide (des-tyrosine1)-gamma-endorphin (DT gamma E; beta-LPH 62-77) was given to 10 schizophrenic patients who had been free of neuroleptic medication for at least 3 weeks. DT gamma E was injected intramuscularly in a dose of 1 mg daily for 10 days following a double-blind placebo-controlled crossover design. In 4 of the 10 patients a pronounced antipsychotic effect was observed; in 3 a temporary or slight reduction of psychotic symptoms occurred; and in 3 no response was noted. DT gamma E led to decreased plasma levels of prolactin and in some patients to increased concentrations of homovanillic acid in cerebrospinal fluid (CSF). Neither plasma levels of growth hormone and cortisol nor CSF concentrations of 5-hydroxyindoleacetic acid were affected by DT gamma E. These data confirm that DT gamma E has antipsychotic properties in a number of schizophrenic patients and suggest an interaction between DT gamma E and central dopaminergic systems.

Adult↗
PubMed1981

Reduced coronary dilatory capacity and ultrastructural changes of the myocardium in patients with angina pectoris but normal coronary arteriograms.

Hemodynamic and metabolic studies were performed in 15 patients without heart disease (controls, group A), in 21 patients with typical stress-induced anginal pain but normal coronary and left ventricular angiograms (angina pectoris with normal arteriogram, group B), and in 10 patients with angiographically proved coronary artery disease (CAD, group C). Coronary dilatory capacity, determined by measuring total myocardial blood flow at rest and during maximal coronary vasodilatation (dipyridamole, 0.5 mg/kg i.v.), was markedly reduced in group B and C patients. In group B patients, left ventricular catheter biopsy specimens revealed no evidence of small-vessel disease, but did show histologic alterations of mitochondria. During atrial pacing, the control subjects showed no changes in myocardial lactate uptake, whereas in group B patients, myocardial lactate production occurred. In contrast to controls, patients in group B showed a significant decline in ejection fraction and circumferential fiber shortening during isometric exercise. These findings suggest that myocardial ischemia is the cause of angina pectoris in patients who have angina but normal coronary arteriograms.

Adult↗
PubMed1981

Actions and interactions of delta 5-androstene-3 beta, 17 beta-diol and 17 beta-estradiol in the immature rat uterus.

delta 5-Androstene-3 beta, 17 beta-diol (Adiol), in a dosage of 1000 microgram/24 h injected ip into immature female Wistar rats (21-23 days old), induced 72 h after the injection the same elevations of uterine weight, cytosol protein, nuclear DNA, cytosol estrogen and progesterone receptors, and nuclear estrogen receptor levels as did 17 beta-estradiol (E2) in a dosage of 2.5 microgram/24 h. Adiol appeared to translocate the estrogen receptor and induce the synthesis of estrogen and progesterone cytosol receptors in a manner almost identical to that of E2. Studies on the metabolism of tritiated Adiol ruled out the possibility that the estrogenic effects of Adiol might be mediated by conversion to E2. Small doses of Adiol (100 microgram), which alone did not result in estrogenic effects, enhanced the effect of 2.5 microgram E2 on uterine weight and progesterone receptor levels, whereas a dosage of 100 microgram dihydrotestosterone neither enhanced nor inhibited the uterine growth induced by 2.5 microgram E2. A role for the androgen receptor in the synergism between Adiol and E2, therefore, appears to be ruled out. When Adiol in a dosage of 1000 microgram was administered together with 2.5 microgram E2, there was no important difference compared to either steroid alone up to 6 h. Thereafter, a very pronounced and prolonged secondary wave of translocation of the E2 receptor to the nucleus occurred which can explain the synergism between E2 and Adiol that became apparent in the same time interval. This secondary wave of translocation is most likely related to the persistent presence of both Adiol and E2 at the time of replenishment of the cytosol receptor (3-6 h after the injection). It is concluded that delta 5-androstene-3 beta, 17 beta-diol acts in the immature rat uterus like a fully potent estrogen with a complete lack of antiestrogenic effects. In this respect it differs from androgens like testosterone and dihydrotestosterone which can display both estrogenic and antiestrogenic activities.

Androstenediol↗