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Biomedical subjects

H Kreuzer

Publications and source records attributed to H Kreuzer.

At least 217 records · Page 12Linked to original sources
PubMed1987

Capillary density and oxygen supply in human dilated cardiomyopathy.

Human hearts with dilated cardiomyopathy (DCM) exhibit a hypertrophy of the myocytes; consequently, the intercapillary distance increases, which may impede the diffusionable metabolic supply. Therefore in the following study the microcirculation of living human hearts with DCM, excised during cardiac transplantation, was investigated. The hearts were reperfused with a FITC-stained salt-solution, this allowed the precise detection of all plasma perfused capillaries. Thus, functional capillary density, capillary distribution and its effect on oxygen supply could be determined. In eight human hearts, the average functional capillary density amounted to 1245 +/- 345 capillaries/mm2, while 50% of the tissue was within 12 micron from the nearest capillary. However, a small portion of the tissue (1%) might become anoxic under the assumption of a simple oxygen diffusion model. The results favor the view that capillary density is low in human DCM and tissue is at the border of hypoxia.

Biological Availability↗
PubMed1986

[Acute coronary angiography in therapy-refractory angina pectoris].

UNLABELLED: Emergency coronary angiography was performed in 188 patients with treatment-resistant unstable angina. Criteria analysed were: duration of angina less than 72 h; angina despite heparin and nitroglycerin infusion; no significant S-T segment elevation in the ECG; creatine-kinase rise up to 150 U/l. Coronary heart disease (CHD) was found in 130 patients (group A). In 47 of them a recent coronary occlusion was demonstrated angiographically (main stem: 1; anterior interventricular branch: 8; circumflex branch: 27; right coronary artery: 11 patients). An at least 90% occlusion of one coronary artery was found in 58 patients. A 75% stenosis of several vessels was found in 25 patients making it impossible to identify the vessel that had caused the angina. A bypass operation was performed in 62 patients within two weeks. During the acute coronary angiography, intracoronary streptokinase infusion was performed in 11 (success rate 55%), percutaneous transluminal coronary angioplasty in 26 (success rate 88%). In 58 patients (group B) CHD was excluded. The final diagnosis in these was: mitral valve prolapse (31); pericarditis (6), dilated cardiomyopathy (3); coronary anomaly (3); muscle bridge in the anterior interventricular branch (2): normal (13). CONCLUSION: It is not possible to decide with certainty, in the absence of typical infarction signs in the ECG and clinically, whether treatment-resistant angina is due to CHD or other causes. Acute coronary angiography is indicated in such cases, because even without S-T segment elevation an acute coronary occlusion is present in 25%, and in 50% of cases an acute therapeutic intervention is indicated.

Adult↗
PubMed1986

[Amiodarone therapy--behavior of serum and fatty tissue concentrations].

Thirty-eight patients with refractory supraventricular and ventricular tachyarrhythmias were administered a mean oral dosage of 400 mg amiodarone daily (200-600 mg). A high-pressure liquid chromatography method was used to measure serum concentrations of amiodarone and its metabolite desethylamiodarone after one week, one month, three months, and then at 6-month intervals. In 24 patients subcutaneous fatty tissue concentrations were also measured. The mean follow-up was 9 months (4 days to 29 months). A linear correlation was found between amiodarone and its metabolite in serum (r = 0.56, p less than 0.001) as well as in subcutaneous fatty tissue (r = 0.67, p less than 0.001). While serum concentrations were dose dependent, tissue concentrations accumulated during chronic therapy (p less than 0.01, both). Clinical efficacy was achieved in 84% of the patients. No statistically significant difference was found between responders and non-responders as regards serum and subcutaneous fatty tissue concentrations. Side effects of amiodarone occurred in 63%. The incidence of adverse effects was related to significantly higher serum and subcutaneous fatty tissue concentrations of amiodarone and its metabolite (p less than 0.001, both). Thus, although the determination of serum and subcutaneous fatty tissue concentrations does not seem to be helpful for assessing clinical efficacy of this antiarrhythmic drug, these values may predict the occurrence of adverse effects.

Adipose Tissue↗
PubMed1986

[Verapamil, diltiazem or nifedipine in severe left ventricular functional disorder? A comparative study of the immediate hemodynamic effects].

High doses of verapamil, diltiazem or nifedipin were administered to three groups of eight patients each, with severely abnormal left-ventricular (LV) function (mean ejection fraction 0.29). Various haemodynamic measurements were made immediately before and 30 minutes after drug administration: LV ejection fraction, ratio of peak systolic pressure to endsystolic volume index, stroke index, pulmonary capillary closing pressure, and maximal diastolic filling rate. None of these were reduced. In fact, ejection fraction rose by a mean of 0.05, stroke index by a mean of 5 ml/m2, while p.c. closing pressure and contractility did not alter significantly. Verapamil and diltiazem reduced the pressure X rate product (an important determinant of oxygen consumption); nifedipine reduced total systemic resistance. It is concluded that verapamil and diltiazem can be used with advantage in cases of unstable angina, if there are severe abnormalities of LV function; they are to be preferred to beta-blockers in this situation. Nifedipin is the calcium antagonist of choice in hypertension and abnormal LV function.

Adult↗
PubMed1986

Comparative analysis of myocardial enzyme activities of the energy-supplying metabolism in patients with dilative cardiomyopathies and valve diseases.

We determined representative enzyme activities of glycogenolysis (glycogen phosphorylase) glycolysis (d-glyceraldehyde-3-phosphate dehydrogenase, GAPDH), beta oxidation of free fatty acids (1-3-hydroxyacyl CoA dehydrogenase, HADH), citric acid cycle (citrate synthase, CS), lactate fermentation (lactate dehydrogenase LDH), and creatine phosphate metabolism (creatine kinase, CK) in left ventricular samples of 36 patients to investigate if the metabolic capacities of the energy-supplying pathways are differently affected in different heart diseases. There were 17 patients with mitral valve diseases (MVD), 8 patients with aortic valve diseases (AVD), and 11 patients who suffered from dilative cardiomyopathies (DCM). The main metabolic characteristic on the level of enzymatic organization in patients with DCM was an increased ratio of GAPDH/HADH activities and a decreased ratio of HADH/CS activities compared to the valve-diseased patients. This result indicates that the capacity of glucose oxidation is enhanced at the expense of fatty acid metabolism in patients with DCM. Furthermore, we determined significantly lower myocardial CK activities in this group of patients, most probably reflecting a diminished content of myofibrils. Citrate synthase activity was lowest in patients with AVD. Although we cannot rule out that the impaired left ventricular function is in part responsible for the shift of the capacities of the energy-supplying metabolism in patients with DCM, we favor the assumption that it is a specific feature of this myocardial disease.

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed1986

Fatal outcome of aortocoronary bypass grafting in a 62-year-old man with unsuspected coronary arteritis.

A 62-year-old man was admitted to our hospital with unstable angina. The coronary arteriography showed the occlusion of the left anterior descending artery and other stenotic lesions. The patient underwent an aortocoronary bypass operation, but unfortunately he did not survive. Surprisingly, the necropsy revealed him to be affected by an inflammatory process, involving the aorta and the coronary arteries. According to the clinical history and examination, the findings at necropsy and the histologic picture, the diagnosis of Takayasu's arteritis appears the most probable. Coronary arteritis has to be considered as a possible etiology of ischemic symptoms also in subjects who appear affected by typical atherosclerotic ischemic heart disease.

Angina Pectoris↗
PubMed1986

The association between serum Lp(a) concentrations and angiographically assessed coronary atherosclerosis. Dependence on serum LDL levels.

Lipoprotein(a) concentrations were measured by radial immunodiffusion in a cohort of 40-60 year males who had been classified by coronary angiography as CAD+ with 50% stenosis of one or more of the major coronary arteries or CAD- with no signs of coronary lesions. Sample odds ratios were calculated as a measure of association between serum Lp(a) values and the presence of coronary artery disease. An odds ratio of 2.706 (P less than 0.001) was derived for elevated (greater than or equal to 30 mg/dl) Lp(a) levels vs low (less than 5 mg/dl) Lp(a) levels indicating a strong association between the presence of coronary artery disease and elevated Lp(a) concentrations. This association was independent of the known risk factors smoking, hypertension and diabetes as well as the serum concentrations of total triglycerides, HDL-cholesterol, alpha-Lp-cholesterol and pre-beta-Lp-cholesterol. In contrast to these variables the association between Lp(a) and coronary artery disease was dependent upon the serum concentrations of LDL-cholesterol, beta-Lp-cholesterol and total cholesterol. At concentrations below the respective median for each variable, odds ratios of between 1.42 and 1.67 were calculated whereas at concentrations above the respective medians the odds ratios ranged from 4.50 to 6.33 (P less than 0.001). Our data, therefore, suggest that increasing LDL concentrations markedly increase the risk of coronary artery disease due to elevated Lp(a) levels.

Adult↗
PubMed1986

Experiences with the identification of small rodents.

Own experiences with the identification of mice and rats using ear tags, ear punching, toe clipping (for newborns only) and ear tattooing are given and compared with methods presented in literature. By far, ear tattooing by the newly developed pincers is the most suitable method for marking adult rodents for life. Tattooing is easy to apply, easy to read and not harmful to the animals. For newborn pups on day 4 p. p., the s. c. injection of India ink into the palm of paw is recommended.

Animal Identification Systems↗
PubMed1986

[Occlusion of the common trunk of the left coronary artery. Physiopathological features and clinical findings].

The total occlusion of the left main coronary artery is rarely observed (approximately 0.05% of coronary angiographic studies). We have tried to draw the clinical and pathophysiological outline of this condition, starting from our experience and reviewing the published reports. A hard selection, principally by the high mortality in patients with left main coronary stenosis, limits the number of those who present total occlusion. These subjects show a remarkable variability in their clinical presentation. It is not possible to find out a significant correlation with a single risk factor, clinical manifestation or electrocardiographic picture. Therefore, these patients cannot be distinguished from other subjects affected by severe atherosclerotic ischemic heart disease. The angiographic finding of a dominant right coronary artery is most frequent. A rich collateral circulation to the left coronary is usually observed. From a pathophysiological point of view, the efficiency of coronary collateral circulation is confirmed by the significant correlation of its extent with the left ventricular function. An important role is also played by the rate of progression of left main stenosis in total occlusion and by the presence of right coronary lesions. Even if statistical evidence is still lacking, surgical treatment is unanimously indicated and achieves satisfying results. The use of nonsurgical recanalization techniques, such as intracoronary thrombolysis and transluminal angioplasty, may be lifesaving in those patients in whom left main coronary occlusion suddenly occurs.

Angiography↗
PubMed1986

[Hemodynamic effect and duration of action of Deponit 10 in patients with congestive heart insufficiency].

The haemodynamic effect of transdermal nitroglycerin treatment with Deponit 10 was investigated in 10 patients with chronic cardiac failure due to coronary artery disease (8 patients) or congestive cardiomyopathy (2 patients). The patients had elevated mean pulmonary artery (PA) and pulmonary capillary wedge pressures (PC) at rest (32.1 +/- 5.9 and 24.1 +/- 6.6 mm Hg). Heart rate (87 +/- 10), arterial blood pressure (133 +/- 20/77 +/- 8 mm Hg) and cardiac index (3.73 +/- 0.85 l/min/m2) were in the normal range. During treatment with Deponit 10 mean PA and PC pressures decreased significantly (p less than 0.01) to 25.5 +/- 6.3 and 18.1 +/- 6.4 mm Hg, respectively. The effect was seen within 1 hour after application of the transdermal therapeutic system and reached its nadir after 2 hours. PA and PC pressures remained significantly below control for 12-16 hours. Heart rate, arterial blood pressure and cardiac index were not changed. After removal of the patch 4 patients showed a rebound haemodynamic deterioration. Their mean PA pressure rose by more than 4 mm Hg above the respective control values. These patients had the highest control PA pressures of the group studied (37.5 +/- 2.4 mm Hg). Thus, transdermal nitroglycerin treatment with Deponit 10 reduces cardiac preload in patients with congestive heart failure for 12-16 hours, whereas cardiac afterload remains unaffected. After removal of the patch a rebound phenomenon can occur especially in patients with severe cardiac failure.

Administration, Cutaneous↗
PubMed1986

[Hemodynamic findings in the adult form of type II glycogenosis].

This report describes a family with late-onset acid maltase deficiency. In two sisters a disturbed left ventricular function could be demonstrated, although skeletal muscle involvement with respiratory insufficiency was responsible for the clinical symptoms. The findings present evidence that myocardial involvement may exist in adult type II glycogenosis.

Cardiac Catheterization↗
PubMed1986

Safety assessment of brotizolam.

Brotizolam (2-bromo-4-(2-chlorophenyl)-9-methyl-6H-thieno [3,2-f]-1,2,4-triazolo[4,3-a]-1,4-diazepine, We 941, Lendormin), a new hypnotic, was submitted to a comprehensive range of safety assessment tests. Acute (single dose) toxicity was very low, while in subacute and chronic studies in rodents, signs of toxicity were first seen at doses of 400 mg/kg or more. Histopathological changes were only seen in the 1 1/2-year study. Ataxia, salivation, and diarrhea were observed in a 4-week intravenous study in dogs, and ataxia, increased feed intake, muscular spasms, increased liver weight, and lipid depletion of the adrenal cortex in two oral studies in monkeys. Reproductive studies in the rat and the rabbit revealed no disturbances in fertility, nor were any embryotoxic or teratogenic effects detected in doses of up to 30 mg/kg. Only at 400 mg/kg was litter mortality increased. Local tolerance tests in rabbits indicated good compatibility of brotizolam when administered intramuscularly, intra-arterially, or intravenously. No signs of any genotoxic action could be detected. A carcinogenicity study in mice showed no evidence of any oncogenic effect, while in rats, although the incidence of certain tumors appeared somewhat higher in the high-dose group, this could be explained by the range of biological variation within the strain, a possible modulating effect on the immune system due to the stress of a very high dose, and a functional effect on the thyroid. These studies thus demonstrate that brotizolam has a remarkably wide therapeutic range.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗