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Biomedical subjects

H Frenzel

Publications and source records attributed to H Frenzel.

At least 55 records · Page 3Linked to original sources
PubMed1988

Ultrastructural findings in endomyocardial biopsy of patients with Kearns-Sayre syndrome.

Kearns-Sayre syndrome is clinically defined by progressive external ophthalmoplegia, atypical retinitis pigmentosa and the potential occurrence of complete atrioventricular (AV) block. Right septal endomyocardial biopsy specimens from nine patients (four men and five women with a mean [+/- SD] [corrected] age of 36.3 +/- 14.4 years) with chronic progressive external ophthalmoplegia and mitochondrial skeletal myopathy were studied. Three patients had atypical retinal pigmentation. An atrioventricular or intraventricular conduction defect was observed in five patients. A pacemaker was prophylactically implanted in one patient because of abnormal conduction distal to the His bundle. Ultrastructural investigations revealed mitochondriosis in many heart muscle cells and an increased variability of mitochondrial form and size in all patients. In seven patients, 0.4 to 2.1% of all examined myocytes contained exclusively abnormal mitochondria. Three main types were observed: huge, mainly round mitochondria with concentric cristae; large, round or oval mitochondria with transverse or curved cristae; and small, vacuolated mitochondria. The volume density of myofibrils was reduced (41.9 +/- 11.1 compared with the normal value of 56.5 +/- 2.5 volume density [in percent], p less than 0.01) in these myocytes. Increasing numbers of vacuolated mitochondria correlated significantly with a reduction of myofibrils (r = -0.64, p less than 0.01). The data suggest that the ventricular myocardium of most patients with complete and even incomplete Kearns-Sayre syndrome is affected by disseminated mitochondrial cytopathy.

Adolescent↗
PubMed1988

[Alcohol and the cardiovascular system].

Because of the high frequency of cardiovascular diseases and a steadily increasing consumption of alcohol the potentially causal relationship between alcohol and cardiovascular diseases gains great interest for public health policy. Alcohol and its metabolites induce a toxic damage of myocardial metabolism with an injury of electromechanic coupling. As a consequence of acute alcoholic intake cardiac arrhythmias and a reduced contractility of the myocardium are found not only for chronic alcoholics but also in healthy non-drinkers. Chronic abuse of alcoholic beverages for many years can be the cause of alcoholic cardiomyopathy in a small percentage of patients, who have a bad prognosis. Atria and ventricles are dilated, light and electron microscopic changes of the myocardium are unspecific. The pathogenesis of alcoholic cardiomyopathy is unknown, modulations of cardiomyocytic membranes are discussed in the course of a toxic damage. In the genesis of atherosclerosis alcohol can approach from different sites: Changings on thrombocytes and an increase of HDL-cholesterin can be protective, however an increase in blood pressure support the process of atherosclerosis. In numerous investigations a smaller degree of atherosclerosis was found for little or moderate alcohol intake, while in chronic heavy abuse of alcohol a higher extent of atherosclerosis was observed. As the amount of alcohol, assumed to be protective against the development of atherosclerosis, is consumed already by the majority of the population, there is no reason to propagate a regulate consume of moderate amount of alcoholic beverages.

Alcoholism↗
PubMed1987

[The combination of atrial myxoma and multiple skin myxomas: a characteristic symptom complex?].

In 1980, a then 7-year-old boy from Yugoslavia had an atrial myxoma removed. Since then there have been no abnormal cardiac signs or symptoms. Between 1982 and 1986 five cutaneous myxomas in the trunk region were removed. None of the tumours had histological signs of malignancy. These observations can be fitted into the symptom complex (described in 1985 by Carney et al.) of cardiac myxoma, cutaneous myxoma, changes in skin pigmentation, and abnormal endocrine functions--although not all signs need be present together. A disposition towards the development of myxomatous tumours is to be assumed in these patients. One should, therefore, always suspect an occult cardiac myxoma in the presence of multiple cutaneous myxomas. Appropriate diagnostic measures need to be taken before the typical and sometimes lethal consequences of a cardiac myxoma have occurred.

Child↗
PubMed1987

Morphologic criteria of progression and regression of cardiac hypertrophy.

The heart is able to adapt itself to a demanded load by increasing (hypertrophy) or decreasing (regression of hypertrophy) its muscular mass within a wide range. Overstressing of the ability of adaptation is accompanied by degenerative changes of myocytes. Semiquantitative investigations of endomyocardial biopsies (EMCBs) of patients with dilative cardiomyopathy (DCM) and hypertrophic nonobstructive cardiomyopathy (HNCM) show a fibrosis of the interstitial space, as well as almost similar changes of myofibrils and mitochondria. A reduced number of myocytes in hearts with DCM could explain the decreased functional capacity. Quantitative investigations of endomyocardial biopsies and myectomy specimens in patients with hypertrophic obstructive cardiomyopathy have revealed that hypertrophy and, to a certain extent, hyperplasia of muscle fibers cause asymmetrical thickening of the septum. Experimental investigations of the regression of training-induced hypertrophy in rats have shown that nearly all parameters (cardiac weight, thickness of muscle fibers, myofibrillar mass, interstitial space, and capillary width) returned to the values of controls 14 days after termination of a swimming training regimen. A significantly higher density of capillaries after regression of muscle fiber hypertrophy compared to controls points to a temporal dissociation in the regression of myocyte size and capillary network. Decrease in RNA concentration and an increased number of autophagic vacuoles give evidence for decreased anabolism and increased catabolism may occur during regression. In humans, fibrosis of the myocardium and scar formation explain the irreversibility of cardiac hypertrophy, as observed in some patients with valvular heart disease, despite valve replacement.

Adult↗
PubMed1987

Evidence for muscle fiber hyperplasia in the septum of patients with hypertrophic obstructive cardiomyopathy (HOCM). Quantitative examination of endomyocardial biopsies (EMCB) and myectomy specimens.

Asymmetric thickening of the septum is one of the hallmarks of hypertrophic obstructive cardiomyopathy (HOCM). Endomyocardial biopsies (EMCB) from the right side of the septum and myectomy specimens from its left part were morphometrically investigated to determine the size of septal myocytes, as well as the volume density of the interstitium and fibrous tissue, and to estimate the number of transseptal muscle fiber layers. EMCBs of seven patients with normally shaped hearts, taken as controls (N), EMCBs of seven consecutively examined patients with HOCM (HOCM 1), and of seven HOCM patients with additionally available myectomy specimens (HOCM 2) were evaluated. In myectomy specimens muscle fiber thickness and volume density of the interstitium and fibrous tissue were significantly increased, as compared with the findings in the EMCBs. The echocardiographically determined septal thickness was increased by 93% in HOCM 1 and by 150% in HOCM 2 compared with controls; however, the increase in muscle fiber thickness and volume density of the interstitium did not give a sufficient explanation for the increased septal thickness in both groups of HOCM. Based on EMCB data, the estimated number of septal muscle fiber layers was 715 +/- 93 in group N, 1242 +/- 149 in HOCM 1, and 1119 +/- 177 in HOCM 2, while 810 +/- 232 layers were estimated according to the findings from myectomy specimens. Taking into account that EMBC represent only 1 mm of septal thickness, and myectomy specimens up to 15 mm, an increase in the septal muscle cell layers of about 30% can be estimated in HOCM hearts.(ABSTRACT TRUNCATED AT 250 WORDS)

Biopsy↗
PubMed1987

Variability and reproducibility of morphologic findings in endomyocardial biopsies of patients with hypertrophic obstructive cardiomyopathy.

Morphometric investigations of endomyocardial catheter biopsies (EMCB) promise to give more insight in the morphologic-functional relationship in patients with hypertrophic obstructive cardiomyopathy (HOCM), and may disclose the morphologic course of the disease. Variability and reproducibility of morphologic findings in EMCB of patients with HOCM are still undefined. We investigated 112 right ventricular biopsies of 25 patients with HOCM of a mean age of 38.3 +/- 15.2 years (six women, 19 men). Mean EMCB size was 0.755 +/- 0.567 mm2. 28.6% of EMCB were not suitable for morphometric investigation. Variability of morphologic findings was investigated by analysis of variance and described by the coefficient of variation (CV). Sampling variabilities of muscle fiber diameter (CV = 5%), volume density of interstitium (CV = 9%) and fibrous tissue (CV = 17%) differed. Reproducibility in terms of intra- and interobserver variations for these variables reached a comparable level, diminishing observed differences between biopsies from the same heart, which became non-significant. Sampling variability of endocardial thickness (CV = 79%) and muscle fiber disarray (CV = 100%) were higher than intra- and interobserver variations. For an estimate of muscle fiber size, one EMCB specimen is sufficient, three for volume density of interstitium and nine for fibrous tissue. High sampling variability of endocardial thickness and muscle fiber disarray demand numerous biopsies; here the greatest measured value from a few biopsies may be of more clinical relevance. From our data, five EMBC are desirable, and give the most information at an acceptable strain.

Adult↗
PubMed1986

Cardiac amyloid deposits in endomyocardial biopsies. Light microscopic, ultrastructural, and immunohistochemical studies.

In four patients with unexplained, abnormal thickening of the interventricular septum as demonstrated by echocardiography, right ventricular endomyocardial biopsy revealed unexpected cardiac amyloid deposits that resulted in increased myocardial thickness and rapidly progressive heart failure. Light microscopically, amyloid was observed in the subendocardial layer, interstitium, and walls of the intramural arterioles. Electron-microscopically, the amyloid fibrils were adjacent to the basement membranes of the heart muscle cells and the vascular smooth muscle cells. Immunohistochemical typing with specific antibodies against different amyloid fibril proteins on glutaraldehyde-fixed paraffin sections revealed different amyloid types. In two patients with generalized idiopathic amyloidosis and in two others with amyloidosis in multiple myeloma, the A-lambda form was diagnosed. In a fifth patient, AA-amyloidosis was found in familial Mediterranean fever with cardiac manifestation without thickening of the interventricular septum. The amyloid deposits were located almost exclusively within the walls of the myocardial arterioles. The amount of amyloid as observed in the myocardial biopsies correlates with the rapidly progressive cardiac failure. It is suggested that in patients with abnormal thickening of the interventricular septum of unknown origin the diagnosis should be clarified by endomyocardial biopsy.

Adult↗
PubMed1986

[Infectious endocarditis in hypertrophic obstructive cardiomyopathy].

Clinical and pathological findings in a 37-year-old female patient with HOCM and infective endocarditis of the aortal and mitral valves were reported. The patient died of septic shock. Infective endocarditis with acute insufficiency of the aortal and/or mitral valves is a severe complication in patients with HOCM, because the left ventricle with a disturbed compliance is unable to compensate the acute volume overload. The standard use of nitrates for congestive lung failure and catecholamines for septic shock is problematic. As with other valvular heart diseases, preventive treatment for infective endocarditis is also recommended for patients with HOCM. In the case of acute endocarditis combined with HOCM early surgical intervention must be discussed.

Adult↗
PubMed1986

[Heart involvement in progressive external ophthalmoplegia (Kearns-Sayre syndrome): electrophysiologic, hemodynamic and morphologic findings].

The Kearns-Sayre syndrome is combined with a progressive external ophthalmoplegia (PEO), retinal pigmentary degeneration and heart block. In some patients, progression of incomplete forms has been described and potentially fatal conduction disturbances may occur. The disease is considered as a systemic mitochondrial disorder. As part of an ongoing prospective study 6 patients (3 female, 3 male; age 32 +/- 9 years) with PEO and typical ultrastructural changes of a mitochondrial myopathy in their skeletal muscle were examined. The ECG disclosed atrio/intraventricular conduction defects in 5 patients: 1 patient had a third degree AV block which was treated by a pacemaker. Another patient had left anterior fascicular block with complete right bundle branch block. In 3 other patients an incomplete right bundle branch block was registered. In 1 patient, His-bundle electrography disclosed a block distal to His by atrial high rate pacing before and after i.v. injection of ajmaline; prophylactically a pacemaker was implanted. The mean HV-interval increased significantly under ajmaline by 44% in patients with sinus rhythm. Hemodynamic studies were normal in 5 patients at rest; only 1 patient was abnormal during exercise. Myocardial biopsy demonstrated mitochondrial abnormalities such as variability in shape and size. In 4 patients concentric cristae mitochondriales were seen. Our results suggest that atrioventricular conduction defects are common in patients with PEO. By means of endomyocardial catheterbiopsy a mitochondrial cardiomyopathy could be detected.

Adolescent↗
PubMed1985

An immunohistochemical and electron-microscopic study of vascular endothelial cells in vocal fold polyps.

Gelatinous and telangiectatic types can be differentiated among the human vocal fold polyps. Telangiectatic polyps are characterized by eosinophilic deposits consisting of fibrin and cellular blood constituents. Labyrinthine vascular channels are characteristic of these polyps, and are partially or completely lined by a single layer of flat cells. Using electron microscopy and immunohistochemical stainings (antibodies against factor VIII-related antigen, Ulex europaeus I lectin, and antibodies against lysozyme), we found that the lining cells are true vascular endothelial cells and are not organizing histiocytic cells that are arranged in an endothelial-like pattern.

Antigens↗
PubMed1985

Cardiomyopathy associated with Leigh's disease.

Clinical and postmortem findings in a female infant, suffering from Leigh's disease and cardiomegaly are described. The cardiac enlargement was due to symmetrical thickening of both ventricular walls and the septum. On light microscopy a widespread fibre disarray with a slight predilection for the ventricular septum was observed. Ultrastructural changes included an extreme reduction in the number of myofibrils and an excess of mitochondria. Abnormalities of the mitochondrial structure with tubular and myelinic transformation of the cristae suggested that a mitochondriopathy is responsible for the cardiomegaly in Leigh's disease.

Autopsy↗
PubMed1985

Progressive cardiac involvement by Fabry's disease despite successful renal allotransplantation.

Enzyme replacement by renal allotransplantation has been suggested as a specific mode of therapy for Fabry's disease. We report a case of Fabry's disease who developed symptoms and signs of heart failure despite successful renal transplantation 14 years ago. Echo- and angiocardiographic features resembled findings in patients with hypertrophic non-obstructive cardiomyopathy. Endomyocardial biopsy specimens demonstrated cardiac manifestation of Fabry's disease.

Biopsy↗
PubMed1985

[Morphologic findings during regression of heart hypertrophy].

The heart is capable of adapting to widely different loads. Increased load will cause hypertrophy with thickening and elongation of the cardiac muscle cells. Beyond the critical heart weight hyperplasia will develop in man. The volume ratio of mitochondria and myofibrils as well as the volume of interstitial tissue and capillaries depends on the type of hypertrophy (training, volume or pressure overload). Hypertrophy will regress when its cause is removed. Training: In experiments with rats 80% of an increase in heart weight caused by swimming was reduced within 14 days after the training program had been stopped. During this time the size of heart muscle cells and the volume ratio of cell organelles had almost completely normalized. From quantitative morphological and biochemical studies, it is supposed that a reduced synthesis but not an obvious increase of catabolism is important in the regression of cardiac hypertrophy. A significant increase in capillary density during the regression period suggests that more time is needed for the regression of capillary length than is required by muscle cells. Training will cause harmonious growth of the left and right chamber wall. During the regression period no quantitative differences of left and right ventricular wall were observed. Pressure overload: Regression of pressure induced hypertrophy is characterized by a reduction of the muscle cell size but not of the amount of collagen in the interstitium. Preliminary studies on pig hearts with an over 100% increase of the weight of their right chamber wall caused by slowly rising pressure load using ameroid constrictors on the A. pulmonalis have shown a 60% reduction of the weight of the right ventricular wall 10 days after removing the constrictor. A reduced mitochondria/myofibrillar ratio becomes normalized. An incomplete or even lacking reduction of the heart weight in rats with spontaneous hypertension (SHR) after therapeutic depression of blood pressure suggests that other factors besides elevated blood pressure are important for inducing hypertrophy in these rats. Valve replacement: An incomplete reduction of heart weight can be observed in patients even after replacement of damaged cardiac valves. Extensive morphological studies on these hearts disclosed recidive infarction or a high degree of cardiac fibrosis as the cause of irreversible hypertrophy. It is still not known whether a case of hypertropied heart with hyperplasia regression will be accompanied by a reduction of the number of myocytes.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗