Biomedical subjects
Publications and source records attributed to J Beyer.
A case of left-ventricular-right-atrial septal defect secundary to blunt chest trauma is described. The etiology of this type of septal defect, e. g. congenital, following aortic and mitral valve replacement, endocarditis and trauma, is discussed. Early defect closure is recommended in the presence of significant shunt volume.
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The fracture of a permanent cardiac pacing lead may be complete or incomplete. In the first case, the function of the pacemaker system will completely cease. An incomplete fracture, however, is defined as a capillary interruption of the wire and will lead to a loose connexion between both parts of the electrode. This, in turn, may result in sudden changes of the electrical resistance of the lead and, therefore, in alterations of the electrode voltage during the second part of the biphasic current wave delivered by the pacemaker; this voltage change--in the 10-mV-range--will inhibit a blocking demand pacemaker with an intermittent, irregular increase of the pacemaker escape interval as the corresponding ECG finding. Usually, this "oversensing" phenomenon can be eliminated by turning the pacemaker function to the fixed rate mode with a test magnet applied. -- Although this malfunction is more often seen with bipolar pacemaker systems and with epicardial wires, it may also occur in a unipolar, transvenous system. -- Among 2100 patients, we have seen this malfunction in 6 cases in whom other, even more rare causes--such as a defect of the electronic circuit of the pulse generator, muscle potentials, etc.--could be ruled out. The x-ray findings revealed no evidence of a lead fracture in any case. The diagnosis was established on the ECG, the examination of the surgically removed electrode in 2 cases, and the finding, that only the implantation of a new lead abolished the malfunction, whereas the implantation of a new pacemaker alone ws ineffective.
The tumours associated to lymphoid leucosis and Marek's disease are compared with lymphoproliferative diseases of man and other species, by morphological, immunomorphological, and aetiological criteria. Morphological and immunomorphological similarities were found to exist between lymphoid leucosis and malignant lymphomas of the B-cell system in man, more particularly, follicular lymphoma, lamphoblastic lymphosarcoma of the B-cell type, Burkitt's lymphoma, and immunoblastic lymphoma. Equivalent similarities with Marek's disease are relating particularly to Hodgkin's disease, infectious mononucleosis, and malignant lymphomas of the T-cell system. Aetiological relations were found to exist between lymphoid leucosis and the oncorna-virus-dependent lymphatic tumours in mammals, while similarities with Marek's disease were relating to infectious mononucleosis, Burkitt's lymphoma, and herpes-virus-dependent lymphatic tumours in monkey. Reference is made to the model nature of both lymphoid leucosis and Marek's disease and the resulting relevance to tumour research.
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Saralasin, an angiotensin II inhibitor was infused in 10 hypertensive patients. A blood pressure reduction was achieved after stimulation of the renin-angiotensin-system by salt depletion. Heart rate and cardiac output failed to compensate for reduction of blood pressure. Thus circulatory reflex-mechanisms are inhibited by saralasin. A direct influence on baroreceptor mechanism and/or catecholamines is probable. Failure of the hypotensive effect of saralasin in salt-depleted patients after administration of beta-blockers supports this hypothesis.
Fasting C-peptide levels and those after tolbutamide or glucose stimulation were measured in normal subjects. In patients with various hypo- or hyper-functions of the endocrine pancreas, C-peptide levels were compared with the corresponding insulin levels. In insulin-dependent maturity-onset diabetics there were both normal and elevated serum C-peptide levels. In juvenile diabetics and patients with total duodenopancreatectomy there was no measureable C-peptide. It is concluded that the half-life of C-peptide is three times that of insulin.
The present experiment was designed to test the theory that psychological procedures achieve changes in behavior by altering the level and strength of self-efficacy. In this formulation, perceived self-efficacy. In this formulation, perceived self-efficacy influences level of performance by enhancing intensity and persistence of effort. Adult phobics were administered treatments based upon either performance mastery experiences, vicarious experiences., or they received no treatment. Their efficacy expectations and approach behavior toward threats differing on a similarity dimension were measured before and after treatment. In accord with our prediction, the mastery-based treatment produced higher, stronger, and more generalized expectations of personal efficacy than did the treatment relying solely upon vicarious experiences. Results of a microanalysis further confirm the hypothesized relationship between self-efficacy and behavioral change. Self-efficacy was a uniformly accurate predictor of performance on tasks of varying difficulty with different threats regardless of whether the changes in self-efficacy were produced through enactive mastery or by vicarious experience alone.
The thermodilution (TD) technique can be considered as the most useful method for cardiac output (CO) determinations in clinical routine. However, surgical procedures for pulmonary stenosis or atresia frequently induce pulmonary insufficiency (PI) of various degree; due to abnormal flow conditions, this may interfere with the validity of transvenous CO-determinations. This experimental study shows that the TD technique is accurate even in the presence of PI. This observation may be explained by the fact that PI results, on the one hand, in a higher distribution volume and, on the other hand, in an increased transit time of the indicator; both of these factors have opposite effects on CO calculations, thus possibly leading to a balance of either error.
Among a total of 6000 patients of the Herzchirurgische Klinik of the University of Munich, 16 patients had an aneurysm of the sinus of Valsalva. Mostly, this was localized in the right sinus, less often in the non-coronary sinus, and only in one case in the left sinus. In 9 patients the aneurysm had ruptured into the right ventricle or into the right atrium. In 2/3 of the cases the aneurysm was associated with a VSD or an acquired malformation of the aortic valve. The diagnosis in part was based on the typical history with a sudden begin of cardiac symptoms secondary to rupture of the aneurysm; however, the most useful diagnostic procedure was the heart catheterization including an angiogram of the aortic root. Surgical treatment led to good early and late results; there was a low operative risk, and complications were rare; however, the prognosis may be less favorable in the presence of an acquired malformation of the aortic valve.
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Patterns of blood glucose, serum insulin and non-esterified fatty acids (NEFA) were measured over a period of eight-and-a-half hours in eleven maturity-onset diabetics receiving 8 mg glisoxepide in the morning and 4 mg in the evening (while on a standard diet). The effects of administering the tablets in the morning with breakfast were compared to those on administering the drug half-an-hour (five patients) or one hour (six patients) before breakfast. Although there was a slightly earlier increase in serum insulin when tablets were taken half-an-hour or an hour before breakfast, different times of administration did not significantly affect the blood glucose or NEFA pattern. In particular, the extreme rise in blood glucose levels after the first breakfast could not be avoided.
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