Search PubMed⌕ Search

Biomedical subjects

R Dietz

Publications and source records attributed to R Dietz.

At least 235 records · Page 13Linked to original sources
PubMed1988

[5-year survival rate in acute transmural heart infarct following thrombolysis and immediate coronary angioplasty].

Two-hundred-eighty-six patients with acute transmural myocardial infarction underwent thrombolytic treatment (Streptokinase) between 1980 and 1986. In the earlier years patients were treated by thrombolysis only (n = 158) and in more recent years by thrombolysis followed by immediate percutaneous transluminal coronary angioplasty (n = 128). Age, sex, incidence of previous infarction and incidence of multivessel disease were comparable between groups. Patency of the infarct vessel (TIMI 3) was higher after thrombolysis combined with angioplasty than after thrombolysis alone (87% vs. 70%, p less than 0.001), and the residual stenosis of the infarct vessel was lower (46% vs. 84%, p less than 0.05). Hospital mortality (thrombolysis combined with angioplasty vs. thrombolysis alone) was 6% vs. 13%; one-year mortality was 8% vs. 21%, and five-year mortality was 18% vs. 31% (p less than 0.02). We conclude that treatment of patients with acute transmural myocardial infarction by thrombolysis combined with angioplasty is followed by a better long-term prognosis than treatment by thrombolysis only.

Angioplasty, Balloon↗
PubMed1988

[Animal experimental studies on the increase in the humoral immune response caused by whole body irradiation].

The production of antibodies against heterologous erythrocytes (sheep erythrocytes) can be significantly increased in mice and rats by total body irradiation. This effect depends upon the radiation dose applied and can be demonstrated only in animals immunized first and then irradiated at intervals of six hours. In vitro assays show indirectly that the radiogenic immune stimulation is caused by the varying radiosensitivity of the individual cell populations involved in the humoral immune reaction, leading to a relatively selective inactivation of T-suppressor cells.

Animals↗
PubMed1988

[Effects of angiotensin-converting enzyme inhibitors in heart failure].

A critical review of the medical treatment of heart failure reveals an insufficient efficacy of conventional therapy, associated with a lack of effect regarding improved survival. Inclusion of vasodilating substances into the regimen, for reduction of left ventricular impedance, offers the possibility of further improving the quality of life of patients with severe heart failure. In addition, some of these substances have now been proved to alter not only the quality but also the quantity of life in a beneficial way. Among the various vasodilators, ACE-inhibitors appear to exhibit a specific spectrum of effects that may contribute to the prolongation of survival in these patients. In particular, correction of hyponatremia, positive potassium and magnesium balance, reduction in the activity of vasopressor and volume retaining systems, as well as their potential anti-ischemic and antiarrhythmic effects, are plausible candidates for beneficially interfering with the progression of the disease. These documented effects make this type of therapy an invaluable inclusion in the modern treatment of heart failure.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1988

[Reflex regulation of heart rate in patients with heart failure].

The carotid sinus baroreceptors were stimulated in 34 patients with heart failure (NYHA II-III) and sinus rhythm. We found that reflex bradycardia is caused by a selective increase in parasympathetic activity and the increase in cycle length depends on the degree of baroreceptor stimulation, therefore a regression line could be calculated for each patient. The slopes of these regression lines were used as an index of baroreflex sensitivity. Initial heart rate, age, stroke volume index, and plasma-noradrenaline concentration correlated with baroreflex sensitivity. However, according to multiple regression analysis (r = 0.64, p less than 0.001), only age correlated negatively (p less than 0.05), and the stroke volume index correlated positively (p less than 0.001) with baroreflex sensitivity: the lower the stroke volume index the smaller the baroreflex sensitivity. This indicates that reflex increases in parasympathetic activity depend on the degree of heart failure.

Adult↗
PubMed1988

[Painless aortic dissection: the problem of early diagnosis. A case report].

Painless aortic dissections occur very rarely, the absence of the important cardinal symptom "pain" may cause a delayed establishment of diagnosis. As early operation improves prognosis, this delay may have harmful consequences for the patient. The case reported presented initially only with neurological symptoms and later with blood pressure instabilities. Nevertheless, the diagnosis has been established within 48 h, but the patient did not survive operative emergency treatment.

Aged↗
PubMed1987

[Balloon dilatation in unstable angina pectoris and acute myocardial infarct].

Early results after percutaneous transluminal coronary angioplasty (PTCA) in patients with unstable angina or acute myocardial infarction were compared with those in patients with stable angina. The primary success rate in 115 patients with unstable angina was 72%, in 73 with acute myocardial infarction 78%, and in 213 with stable angina 79%, i.e. there was no difference between the three groups. In patients with acute myocardial infarction and primary successful PTCA control angiography was performed one month after PTCA, in patients with unstable and stable angina 6 months after PTCA. Angiographic findings were identical in the three groups. But the results after successful balloon dilatation were dependent on the extent of primary success: in all three groups, patients in whom the post-dilatation control angiography revealed recurrence of stenosis the primary results were worse than in those without. There was no difference between those patients with lasting success and those with recurrence as regards cholesterol level, arterial hypertension, diabetes, and smoking habits. It is concluded that in every patient with acute symptoms of coronary heart disease the indication for PTCA should be considered.

Angina Pectoris↗
PubMed1987

Ramipril and captopril in patients with heart failure: effects on hemodynamics and vasoconstrictor systems.

Fifteen patients with congestive heart failure (New York Heart Association III) were randomly assigned to treatment with either captopril or ramipril, a newly developed angiotensin converting enzyme inhibitor. Both groups were similar with respect to baseline hemodynamic measurements and plasma levels of norepinephrine, renin and vasopressin. The group receiving ramipril showed hemodynamic changes comparable to the group receiving captopril on the seventh day of treatment. The stroke volume index increased by 20% versus 21%, respectively, and the total peripheral resistance decreased by 13% versus 20%, respectively. The decrease in blood pressure and the tendency to decrease heart rate were similar in both groups. All patients had reactive hyperreninemia during therapy with the converting enzyme inhibitor. The resting elevated plasma norepinephrine decreased in both groups significantly, whereas vasopressin did not change. The hemodynamic improvement was more pronounced and comparable in both groups during exercise. Thus, ramipril is equally effective compared with captopril in the treatment of patients with severe congestive heart failure.

Adult↗
PubMed1987

[Thrombolysis in acute myocardial infarct. An improved long-term prognosis following balloon dilatation].

UNLABELLED: A systemic and intracoronary thrombolytic treatment was carried out in 217 patients with acute transmural myocardial infarction between March 1980 and March 1985. 141 patients were only treated with thrombolysis, and 76 were additionally treated by balloon dilation in the same session. Indications for additional balloon dilation were unsuccessful thrombolysis as well as a residual stenosis of more than 50% after primarily successful thrombolysis. Age, sex, proportion of patients with anterior and posterior wall infarction as well as with 1, 2 and 3-vessel disease did not significantly differ in the two groups. The result of therapy (complete reperfusion) was less after thrombolysis than after thrombolysis with balloon dilation (63% as compared to 88%, P less than 0.0003). The patients who were only treated with thrombolysis had a more unfavorable three-year actuarial survival than those in whom thrombolysis and balloon dilation were carried out (70% as compared to 90%, P less than 0.02). CONCLUSION: additional balloon dilation in thrombolytic treatment of acute transmural myocardial infarction improves the long-term prognosis.

Angioplasty, Balloon↗
PubMed1987

[Anticoagulation with low molecular-weight heparin in patients with prosthetic heart valve replacements].

In six patients with prosthetic heart valve replacement anticoagulation was performed with low molecular weight heparin for 4-58 weeks. The treatment was indicated because of one or more severe cerebral or gastrointestinal bleeding complications during therapy with oral anticoagulants or conventional heparin. The dose of the low molecular weight heparin ranged individually from 2,500 to 12,000 units once a day subcutaneously and was adjusted on the basis of the general bleeding tendency of the patient and the specific anticoagulant effect on factor Xa. Under this treatment no heart valve thrombosis occurred. Two minor bleeding complications were observed in two patients. All patients suffered previously from severe bleeding complications with conventional anticoagulants. One additional patient, who had been treated one year earlier with the low molecular weight heparin, again experienced embolism during treatment with only 1 X 5,000 anti factor Xa units per day. We conclude that anticoagulation with low molecular weight heparin may be recommended for patients with prosthetic heart valve replacement and severe bleeding problems with conventional anticoagulants. In patients with recurrent embolism higher doses should be administered.

Adult↗
PubMed1986

A human auto-immune antibody specifically recognizing initiator methionine tRNA from yeast and higher eucaryotes.

Analysis of sera from 168 patients with autoimmune disorders revealed that one patient with Sjôgren's syndrome produced antibodies against deproteinized initiator methionine tRNA in addition to those against La protein. This anti-tRNAimet recognizes also tRNAimet from yeast but not from Phaseolus vulgaris chloroplasts (bean) or E. coli. It appears therefore that the epitope could be located in the TF loop in which an A residue in position 60 and the AUCG sequence are the only common features in yeast and human tRNAimet.

Autoantibodies↗
PubMed1986

Aster-free spindle poles in insect spermatocytes: evidence for chromosome-induced spindle formation?

Tipulid spermatocytes form normally functioning bipolar spindles after one of the centrosomes is experimentally dislocated from the nucleus in late diakinesis (Dietz, R., 1959, Z. Naturforsch., 14b:749-752; Dietz, R., 1963, Zool. Anz. Suppl., 23:131-138; Dietz, R., 1966, Heredity, 19:161-166). The possibility that dissociated pericentriolar material (PCM) is nevertheless responsible for the formation of the spindle in these cells cannot be ruled out based on live observation. In studying serial sections of complete cells and of lysed cells, it was found that centrosome-free spindle poles in the crane fly show neither pericentriolar-like material nor aster microtubules, whereas the displaced centrosomes appear complete, i.e., consist of a centriole pair, aster microtubules, and PCM. Exposure to a lysis buffer containing tubulin resulted in an increase of centrosomal asters due to aster microtubule polymerization. Aster-free spindle poles did not show any reaction, also indicating the absence of PCM at these poles. The results favor the hypothesis of chromosome-induced spindle pole formation at the onset of prometaphase and the dispensability of PCM in Pales.

Animals↗
PubMed1986

Plasma atrial natriuretic peptide values in cardiac disease.

The plasma concentrations of atrial natriuretic peptides (ANP) were measured during cardiac catheterization in 137 patients with heart disease. Atrial natriuretic peptides were elevated in all types of cardiac disease investigated, including valve disease, coronary heart disease and cardiomyopathy. The highest plasma ANP concentrations were found in patients with the most marked impairment of ventricular function and mitral valve disease. In patients with coronary heart disease, a significant, direct linear correlation was found between left ventricular filling pressure and plasma ANP concentrations (r = 0.42, P less than 0.001). Similarly, in patients with cardiomyopathy, a linear relationship was found between mean pulmonary artery pressure and plasma ANP concentration (r = 0.80, P less than 0.01). These observations suggest that measurement of ANP may be of value as a non-invasive humoral marker in the diagnosis of various cardiac diseases.

Atrial Natriuretic Factor↗
PubMed1986

Pressure dependent release of atrial natriuretic peptide (ANP) in patients with chronic cardiac diseases: does it reset?

In patients with chronic cardiac disease plasma concentrations of atrial natriuretic peptide are elevated. The close relationships obtained between right (and/or left) atrial pressure and the peptide concentrations suggest a non-resetting phenomenon of the pressure induced release mechanism in the presence of a maintained responsiveness to acute stimuli.

Atrial Natriuretic Factor↗
PubMed1986

Relationships between haemodynamic parameters and concentrations of atrial natriuretic peptide in human plasma.

Plasma concentrations of the atrial natriuretic peptide (ANP) were measured during cardiac catheterization in 289 patients with heart disease. It was elevated in all types of cardiac disease investigated, irrespective of the nature and duration of the disease. Close relationships were observed between the elevated ANP concentrations and the increased right and/or left atrial pressure. Further increments in ANP concentration were measured during exercise in direct response to the rise in mean pulmonary artery pressure. Thus, ANP concentrations may be regarded as a non-invasive marker of the haemodynamic burden in cardiac disease.

Atrial Natriuretic Factor↗
PubMed1986

[Irradiation of grades III and IV astrocytomas with new types of radiation].

Until 1983, more than 300 astrocytomas of degree III and IV have been irradiated all over the world with new types of radiation such as neutrons, protons, alpha particles, heavy ions, and pions. Up to now a therapeutic progress could not be achieved. Radiobiologic experimentations suggest that the dense ionisation is unfavorable in the irradiation of malignant cerebral tumors. The clinical radiotherapy research with protons should therefore be intensified and hyperfractionation should be critically reviewed.

Alpha Particles↗
PubMed1986

Cyclosporine: an immunosuppressive panacea?

Between March 29, 1979, and March 1, 1985, 62 heart transplants were done in 61 patients at the University Medical Center, University of Arizona. There were two treatment groups with nearly equal numbers in each; conventional immunosuppression (1979 to 1982) and cyclosporine (1982 to the present). Comparison of actuarial survival, number of rejection episodes, number of fatal rejection episodes, number of infections, and number of "other complications" failed to reveal any significant difference between the two groups. The cyclosporine-treated patients had a documented increase in blood urea nitrogen and serum creatinine accompanied by an increase in diastolic blood pressure. The length of hospital stay of the cyclosporine group was approximately one half of that of the conventionally treated patients, and they required fewer rehospitalizations. The cost for initial hospitalization was not significantly different between the two groups. Therefore, in 1979 dollars, the cost for cyclosporine-treated patients has decreased. This difference in cost was only minimally diminished by the difference in expenditure for outpatient pharmaceuticals, which was four times higher in the cyclosporine group. We believe that cyclosporine is a potent immunosuppressive agent but that it has toxic, possibly irreversible effects on the kidney. In view of the minimal differences that we were able to demonstrate in survival rejection and infection, it seems prudent to reduce or modify present doses of cyclosporine in an attempt to avoid irreversible renal damage.

Actuarial Analysis↗
PubMed1985

Paradoxical role of neuronal uptake for the locally mediated release of endogenous noradrenaline in the ischemic myocardium.

The accumulation of endogenous noradrenaline within the extracellular space of the ischemic myocardium was studied in the isolated perfused (Langendorff) rat heart. The hearts were subjected to various periods of ischemia, and the noradrenaline overflow that occurred during the ensuing period of reperfusion was estimated radioenzymatically. Ischemic periods of less than 10 min are not associated with an increased overflow of noradrenaline during reperfusion. Longer periods are accompanied by an overflow, increasing with lengthening of the preceding ischemia to 1,270 +/- 48 pmol/g heart after 60 min of ischemia, as compared with 3.7 +/- 0.6 pmol/g during control perfusion. The kinetics of noradrenaline overflow suggest that the noradrenaline detected during reperfusion is released from the sympathetic neurons predominantly during ischemia and is then washed out from the extracellular space. The noradrenaline overflow induced by ischemia is not influenced by the lack of extracellular calcium. Blockade of neuronal uptake reduces noradrenaline overflow after ischemic periods of between 10 and 40 min (at 30 min from 481 +/- 56 to 91 +/- 12 pmol/g heart). The noradrenaline overflow after longer periods of ischemia is not affected by blockade of neuronal uptake. The results suggest that noradrenaline released from the sympathetic nerve terminals by ischemic periods of between 10 and 40 min is not due to exocytosis, but to a carrier-mediated efflux using the same carrier as is normally responsible for transporting noradrenaline from the synaptic clefts back into the neuron.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗