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H J Herrmann

Publications and source records attributed to H J Herrmann.

At least 55 records · Page 3Linked to original sources
PubMed1982

[Morphologic reactions and long-term vasal tonus behavior of the coronary microvascular system in different states of spontaneous hypertension in the rat].

The morphological reactions and the long-term vasotonus behaviour of the coronary microvasculature including its smallest ramifications as well as the relationships existing between these reactions and the myocardial activity in the different stages of spontaneous hypertension of rats (SHR) are unknown. Therefore 80 1-12 month-old male SH- and 60 normotensive Wistar control rats were histomorphometrically investigated. Already in the prestage of hypertension (1 month) an increase of wall thickness and phosphatase activity in blood vessels alpha less than 10,5 microns occurred. These appearances of vasotonus increase were regressed in the acute phase (2nd-4th month). When the rise of myocardial activity is lowered in the stabile stage the mentioned signs of vasotonus increase returned (6th month) and showed a strong spreading in the late stage (12th month), which is characterized by enzyme histochemically detected disturbances of heart muscle metabolism. The behaviour of long-term vasotonus of the microvasculature and myocardial metabolism in 6 month-old and older rats provides a hypothesis concerning the cause of the unknown increase of coronary contraction in the stabile phase. It points to the existence of a vicious circle which perhaps plays a role in the genesis of heart insufficiency in hypertension.

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↗
PubMed1980

[Possibilities and limitations of histomorphometric studies of arterial vessels of the microcirculation].

The choice of a procedure for measurements of blood vessels (b.v.) should depend on the type of b.v. investigated: For vessels defined anatomically and in respect to their function of organ supply the method of SUWA et al. (1961) is the most adequate one, provided that b.v. dilatations developing during lifetime and persisting after death as a result of special methods of fixation or shock-freezing or being generated by postmortal perfusion can be excluded. Changes in wall thickness of defined b.v. sectioned transversally can also be determined by measurement of the wall area and/or the maximal chord length. At undefined vessels procedures which measure the wall-to-lumen ratio are useless, because lumen changes are not quantifiable. Thus lumen changes can mask of mimick changes in wall thickness. The especially interesting b.v. either with a pathologically changed or without an elastic membrane are not measurable. The unsable method to detect changes in wall thickness at undefined b.v. is founded on the determination of the vessel wall area and/or the number of all the b.v. classified according to their diameter of a certain organ region. But the investigation of the smallest precapillary vessels presupposes their visualization by a special modification of the ATPase reaction.

Adenosine Triphosphatases↗
PubMed1980

[Determination of arterial wall thickness variations of vessels in the microcirculation by the ATPase-Quantimet method].

The use of the Quantimet for measurements of structural wall reactions of blood vessels (b.v.), visualized selectively by a modification of the ATPase reaction, requires that changes in wall thickness are not mimicked by differences in deposition of the reaction product, by changes of the b.v. lumen, and/or by b.v. elongations, especially meanderings occurring independently of thickenings of vessel walls and caused solely by increase of the intravascular pressure or by vasoconstriction. The article has substantiated the conclusion that these requirements are fulfilled.

Adenosine Triphosphatases↗
PubMed1979

Automated image analysis for measurements of morphological reactions of blood vessels of the microvascular system.

Using a modification of the Mg-ATPase reaction, the arterial blood vessels of the microcirculatory bed of the rat including the smallest precapillary vessels are visualized in a grey-level difference against their environment which permits to utilize the automatic image analyser QUANTIMET 720 and the programmable desk-top calculator HEWLETT-PACKARD 9100B. The article describes the method for preparing the sections, the measuring procedure, and the statistical verification of the results by means of the computer assisted two-way analysis of variance as well as studies demonstrating the reliability of the method. It is concluded that the procedure at heart, skeletal muscle and pancreas specimens of the rat demonstrates reliably and effectively changes of the number of vessels and the projected whole vessel wall area as well as differences of enzyme activities. Thus it is possible to detect structural wall reactions and enzyme histochemical changes of arterial blood vessels of the microvasculatory bed including its smallest precapillaries which have been practically inaccessible to histomorphometrical investigations in the past.

Adenosine Triphosphatases↗
PubMed1978

[Release of toxic agents from ceramic utensils].

Under the influence of acidic agents, ceramic glazes and decorations for ceramics may release certain toxicants, especially lead and cadmium. Both elements are essential constituents of ceramic colours and glazes; their release to acidic foods is technologically unavoidable, but it may be minimized by the utilization of appropriate decoration agents and techniques. In most industrial countries, the release of toxicants from utensils is severely limited, the maximum permissible values and the methods of test and analysis being in part very different and not always in agreement with the demands and conditions of practice. The problems related to the release of toxicants from ceramic utensils are treated from the aspects of ceramics, test techniques, analytics, toxicology and food law, with special regard to the necessity for a well-balanced compromise between the justified hygienic demands of health protection and the actual technological possibilities. The endeavours of the ceramic industry of the GDF to produce ceramic utensils releasing as little toxicants as possible are outlined.

Cadmium Poisoning↗
PubMed1978

[The computed tomography of the malignant thoracic space-occupying process under special consideration of radiotherapeutic points of view (author's transl)].

The data of 70 patients with a malignant thoracic space-occupying process were compared in order to find out the differences between computed tomography and conventional X-ray diagnosis (thorax radiography, hilum tomography), the radiotherapeutic aspects of these methods being taken under special consideration. Computed tomography is excellently suited for the establishment of therapeutic schemes because it is the only technique producing individual cross-sectional views of the thorax which are in correct scale and have a high resolving power. Contrary to thorax radiography and hilum shadow, the computed tomography offers some additional diagnostic information in several special fields.

Bronchial Neoplasms↗
PubMed1977

[Pathomorphological reactions and noradrenalin content of the heart after administration of depot angiotensin in trained and untrained rats].

A 14-days' training of rats designed to adapt the animals to the procedure of blood-pressure measurement caused in the myocardium a decrease, in serum an increase in noradrenaline ( NA) content. The latter remained unchanged following 3 days of treatment with 2.5 mg depot angiotensin II (AII) but decreased by more than one-half in the myocardium of untreated animals, and increased in serum. Despite the considerable difference in myocardial NA content and blood-pressure behaviour, both trained and untrained rats showed the same morphological reactions following administration of A II. These myocardial alterations which largely correspond to the so-called epinephrine myocarditis should not therefore be due solely to NA action; rather, the involvement of A II should be considered also.

Adaptation, Physiological↗
PubMed1976

[Studies on the blood pressure effects of various high doses of angiotensin II in depot form in rats under defined conditions].

Daily s.c. injections of 0.02--10.0 mg angiotensin in depot form for 14 days caused in rats, under defined conditions, pronounced dose-dependent effects, with an unusual tolerance to the drug being observed. The behaviour of the systolic and diastolic blood pressure and heart rate allowed to define 4 dose ranges. In the lowest dose range of 0.02 mg angiotensin-II a lasting borderline hypertension with only straight-line changes of diastolic blood pressure and bradycardia were observed. The doses of 0.15--1.25 mg angiotensin-II caused a continual blood pressure rise and led, between day 4 and 6 of the experiment, to a pronounced lasting resistance high-pressure without appreciable changes in heart rate. The strongest resistance high-pressure, which occurred as early as on day 3, with pronounced tachycardia was achieved with a dose of 2.5 mg angiotensin-II. Higher doses produced pronounced tachycardia but no significant effects on blood pressure. The varying dose-dependent effects of depot angiotensin are discussed, and the possibility is pointed out to study by the angiotensin-II hypertension model various mechanisms of a long-time hypertensive dysregulation.

Angiotensin II↗
PubMed1976

[Angiotensin-induced hypertension in pigs].

In pigs receiving up to 14 days daily injections of depot angiotensin, repeated daily bloody measurements of the blood pressure at the carotid artery proved unsuitable because of ensueing septic processes, in contrast to the unbloody measurement at the caudal artery. The depot angiotensin, despite the use of preparations with varying content of angiotensin-II and carrier solution, caused immediately after the injections a very strong maximal rise in systolic and diastolic blood pressure that occurred also with longer periods of the experiment; this rise gradually diminished in the course of the day but remained mostly in the hypertonic range and showed daily initial values above normal. The pig proved to be much more sensitive to angiotensin than the rat, for instance. Despite the proved vasoconstricting action of angiotensin, light-microscopic alterations at the vessels, kidneys, and the myocardium could not be observed. Part of the arterioles showed an increased wall thickness in animals killed on the 8th and 15th day of the experiment. The differences in the pathomorphological and blood pressure behaviour from the rat are discussed. The first experimental results qualify the pig as an experimental animal for comparative hypertension studies.

Angiotensin II↗
PubMed1975

[Blood pressure behavior and pathomorphology in the rat following application of high doses of depot angiotensin].

In 55 rats, not accustomed to the process of blood pressure measurement and given daily doses from 1.25 - 10.0 mg angiotensin in depot form for up to 3 days, as much as 70% of the animals died of circulatory failure. Blood pressure increase was either absent or was very low after low doses. Histologically, the myocardium revealed focal destruction of muscle fibres with mesenchymal cell proliferation in many places; the epithelium of numerous renal tubuli was changed hydropically; the liver showed focal necroses of the parenchyma; the adrenal cortex showed stress reactions, and the arterioles of the splanchnic area -- changes of the plasmatic vasculose from the 3rd day of experiment. By contrast, in 51 rats accustomed to the measuring process prior to the experiment and given high doses of angiotensin, only moderate blood pressure rise and scattered cases of death (4%) occurred, low doses caused a strong blood pressure elevation. With otherwise equal histologic organ diagnoses, liver necroses were absent, except for two cases. This differential response of the two animal groups to varying angiotensin doses and the pathogenesis of the changes observed are discussed.

Angiotensin II↗
PubMed1975

[Ultrastructural observations in the lamina elastica interna and adjacent tissue regions of the arterioles of rats impaired by hypertension of different pathogenesis (author's transl)].

QUESTION: The experiments aim to answer the question whether early changes in the lamine elastica interna of peripheral arteries causing consecutive plasmatic insudation of the vascular wall ("plasmatic vasculosis" according to GOLDBLATT) can be visualized by electron microscopy. Demonstration of early lesions in the elastica interna would facilitate the interpretation of structural changes in the arterial periphery during acute hypertension and its consecutive symptoms. MATERIALS AND METHODS EXPERIMENTAL ANIMALS: 37 male albino rats, 3 to 4 1/2 months of age, body weight: 250 to 350 g. Controls 19 rats of similar age and body weight, 6 of which were injected the carrier substance of depot angiotensin PVP (VEB Berlin-Chemie). The test arrangement is represented in table 1. 3 hours to 10 weeks after starting the treatment different groups of experimental animals were sacrificed. Several animals were administered tracer substances for demonstration of early disturbances in permeability (ferritin: 20 to 40 mg per 100 g body weight, 3 to 60 min ante mortem; charcoal: 10 to 20 mg per 100 g body weight diluted in 1.5 to 3.0 ml of distilled water 15 to 30 min ante mortem). Electron microscopic investigations were carried out in arterioles of 15 mum to 100 mum in diameter which had been removed from the stomach, colon, jejunum, pancreas, mesenterium, partially from the brain and heart, in cases also from the lungs. For comparable specimens with respect to early ultrastructural changes only such tissue sections were selected that were light microscopically free from lesions. Preparation for electron microscopy was done in the common way. RESULTS: in light microscopically intact arterioles of all 3 groups (see table 1) the well-known disturbances of intimal permeability were electron microscopically observed already after 3 hours of experimentation. These changes occur always in the splanchnic organs and in the heart. Contrarily they do not regularly occur in the brain. In rats impaired by experimental neurosis (group III) the disturbances in perfusion of the intima recede, the consequences of enhanced metabolix activity in the media predominate in the sence of a "non-specific mesenchymal reaction" (HAUSS et al. 1964). However, it should be taken into consideration that this enhanced metabolic activity and cell proliferation may actually warrant the relative stability of the elastic barrier observed in this experimental group. In rats with nephrogenic and angiotensin-induced hypertension the experiments result in principally similar lesions of the lamina elastica interna originating from the vascular lumen. The diverging results in rats impaired by neurotically conditioned disturbed regulation of the blood pressure speak in favor of a prevailing reaction of the media at well preserved structures of the lamina elastica interna.

Angiotensin II↗