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Biomedical subjects

W Klein

Publications and source records attributed to W Klein.

At least 361 records · Page 20Linked to original sources
PubMed1985

Formation and fate of bound residues of [14C]benzene and [14C]chlorobenzenes in soil and plants.

Outdoor experiments with [14C]hexachlorobenzene, [14C]pentachlorobenzene, [14C]1,2,4-trichlorobenzene, and [14C]benzene in soil-crop systems indicate that the formation rate of bound residues in soil and plants, expressed as bound residues in percentage of total residue in the sample, decreases with increasing number of chlorine in the molecule and, thus, with increasing chemical stability. The time course of formation and fate of bound residues in soil and plants is characterized by a very slow decrease of residue levels in soil, indicating that biodegradation of bound residues hardly exceeds their reformation from the parent compound during one vegetation period, and by a decrease of residue levels in plants. The portion of bound residues as compared to the total residue increases with time, indicating that bound residues are more persistent than the parent compounds and their soluble metabolites; benzene is an exception. Cress plants, in general, contain less bound residues than do barley plants. Again, benzene is an exception. In deeper soil layers, soil-bound residues occur also. The ratio between bound and extractable residues does not differ to a larger extent between the soil layers.

Benzene↗
PubMed1985

Influence of benzene on the phytoplankton and on Daphnia pulex in compartments of an experimental pond.

Benzene, with initial concentrations of 100 and 50 mg per liter, was dosed in duplicates into four compartments of a small pond. The decrease of chemical concentration in the water was exponential with a mean half-life of 4.7 +/- 0.9 days. Following benzene application, the phytoplankton density and diversity slightly increased relative to the controls. Both concentrations were lethal for the daphnids present. During 24-hr in vitro tests with Daphnia pulex (initial benzene concentrations less than 50 mg per liter), a direct correlation between mobility and decreasing chemical concentration was observed.

Animals↗
PubMed1984

[Epidemiology and risk factors of myocardial infarct].

From the epidemiological point of view the reduction of risk factors, such as increased blood lipids, hypertension, smoking, decreased the incidence of myocardial infarction in the USA by 13,5%. In contrast the arteriosclerotic diseases in Austria and the other Western European industrial countries increased. The reasons are obvious: Thus in the Federal Republic of Germany in 3,3 to 5% of adolescents between 15 and 19 years of age a hypercholesterolemia and in 10% an overweight was found. According to recent epidemiological studies already up to 12% of children had increased blood pressure values. 36% of all pupils in the Federal Republic of Germany are smoking regularly or occasionally, for the first time with 10 years on the average. Besides of regular controls of important biochemical parameters the physician should stress the importance of preventive measures for reduction of cardiovascular risk factors.

Cross-Sectional Studies↗
PubMed1984

[Catecholamines in internal medicine emergencies].

The most important indications for the application of the catecholamines dopamine and dobutamine in the internal intensive medical care are acute disturbances of the peripheral vascular regulation and acute heart failure. Differential therapeutic considerations are due to the different actions of both pharmaceutics. Disturbances in peripheral circulation and in renal function are of great importance in case of the septic shock. Dopamine is highly advisable for its vascular and renal efficacy. Whereas the application of dobutamine or a therapy combining the application of dobutamine and dopamine has to be preferred in case of a cardiogenic shock. A retrospective examination has shown that the mortality of patients with a cardiogenic shock after an acute myocardial infarction could be lowered by a therapy of the current catecholamines dobutamine and dopamine.

Acute Disease↗
PubMed1984

Acetoacetate is a cholesterogenic precursor for myelinating rat brain and spinal cord. Incorporation of label from [3-14C]acetoacetate, [14C]glucose and 3H2O.

Rat pups, 3 weeks old, were injected i.p. with combinations of 3H2O and either [3-14C]acetoacetate or [14C]glucose. 3H/14C incorporation ratios were measured in lipid fractions of homogenates and myelin prepared from whole brain and spinal cord. Spinal cord synthesized at least twice as much fatty acids and 3-fold more sterols than whole brain. Both tissues used acetoacetate preferentially for sterol synthesis, whereas label from [14C]glucose was distributed between fatty acids and sterols in the same way as 3H from 3H2O. The relative contributions of acetoacetate to sterol synthesis in whole tissue and in the purified myelin fraction were about the same, both for the cerebrum and for the spinal cord.

Acetoacetates↗
PubMed1984

The effects of EDTA-Tris infusion on the equine endometrium.

Four groups of five pony mares each were used to determine if the intrauterine infusion of EDTA-Tris solution caused adverse effects on the endometrium. The uteri of mares were infused with either saline or EDTA-Tris solution or biopsied or sham-biopsied without infusion. Acute endometritis developed in one (20%) to three (60%) mares in each group during the seven days following treatment, but there were no differences (P > 0.05) in the incidence of endometritis among the groups. Endometrial fibrosis was not evident in biopsies taken on days 14, 30 and 60 following infusion of saline or EDTA-Tris. It was concluded that the endometrial response to saline and EDTA-Tris was not different and that EDTA-Tris may be a useful adjunct to treatment of uterine infections in the mare.

Journal Article↗
PubMed1983

Effect of calcium antagonists on cardiac performance in patients with dilatative cardiomyopathy evaluated by noninvasive methods.

We present 14 patients with dilatative cardiomyopathy, proven by hemodynamic and angiographic assessment who received in a single-blind, randomized study, equipotent doses of the three calcium blockers: verapamil (0.1 mg/kg i.v., followed by an infusion of 0.01 mg/kg/min), nifedipin (20 mg sublingually), or diltiazem (0.2 mg/kg i.v., followed by infusion of 0.02 mg/kg/min). Before and after treatment in 8 patients systolic time intervals were recorded with an AVL-Myocard-Check (Q-S2, pre-ejection period, left ventricular ejection time, and pre-ejection period/left ventricular ejection time) and end-systolic and end-diastolic diameter, fractional shortening, and circumferential fiber shortening velocity were measured by M-mode echocardiography. In another 6 patients radionuclide ventriculography was performed before and after each treatment (ejection fraction, cardiac index). PEP/LVET increased slightly after verapamil (+ 15%) and decreased after nifedipin (-5%) and diltiazem (-3%), the changes being not significant. Fractional shortening and circumferential fiber shortening velocity however, decreased after verapamil (-5%, resp. -15%) and increased after nifedipin (+ 14%, resp. + 25%) and after diltiazem (+ 23%, resp. + 16%). In the radionuclide studies ejection fraction increased after verapamil (+ 9%), nifedipin (+ 14%), and diltiazem (+ 13%), while cardiac index remained unchanged with verapamil and nifedipin and increased with diltiazem (+ 14%). In conclusion there are no significant changes in myocardial performance with the calcium blockers verapamil, nifedipin, and diltiazem. However, under verapamil there is a tendency to deterioration of myocardial performance, while it was slightly improved after nifedipin and diltiazem. Calcium antagonists may be used safely, therefore, also in patients with impaired myocardial performance.

Adult↗
PubMed1983

Arthroscopic meniscectomy. Technique, problems, complications, and follow-up results.

After gaining experience in 1,000 diagnostic arthoscopies arthroscopic surgery has been performed in 300 patients between 1979 and 1982, including 100 cases of meniscectomy. A report is given on the technique, problems, complications, and early follow-up results. A select approach to endoscopic surgery has been chosen for the treatment of different meniscus lesions. A combination of motorized instruments and modified manual Gillquist technique has been applied. The legholder is of great help for arthroscopic surgery of posterior horn lesion, especially in tight knees. There were only few problems with endoscopic meniscectomy. The reason for performing arthrotomy in eight cases was the lack of a suitable legholder and inaccurate placement of the instruments in the early stages of our experience. Hospital stay was generally 3-5 days. Postoperative pain was markedly reduced. The majority of those patients with a meniscus lesion as the exclusive abnormality in their knee joint experienced a rapid recovery and returned to work within 2 weeks after surgery. After surgery there was a moderate swelling of the knee joint in 40% of our patients. The swelling diminished rapidly within the 1st week after surgery.

Arthroscopy↗
PubMed1983

The medial shelf of the knee. A follow-up study.

After a publication in 1979 on Plica Synovialis Mediopatellaris a review of 1328 arthroscopies from 1978 onwards has been done at the Orthopedic Department of the University Clinic Duesseldorf. One hundred and eighty knees with medial shelf of the knee were found. Forty-three patients were treated by arthroscopic surgery. Plica excision alone was carried out in 17 knees. Twenty-six times multiple intraarticular surgery like patella-shave, lateral release, meniscectomy or local synovectomy have been performed in addition to plica excision. A shelf alone was present in 21.1%. Additional lesion like chondromalacia of the patella occurred in 38.8%. Control of biopsy material and tissue specimen from arthroscopic surgery revealed shelf fibrosis in 15.5% of the 180 knees with Plica Synovialis Mediopatellaris. The best results were obtained in those patients with a medial shelf as the only abnormality in the knee joint. The reason for the relatively high amount of unsatisfactory results in knees with multiple lesion and medial shelf excision is caused by overlap of other lesions accompanied by the Plica Synovialis Mediopatellaris. Under the impression of the results of the follow-up study a detailed proposal as indication for Plica excision is discussed.

Arthroscopy↗
PubMed1983

Fate of chemicals in plant-soil systems: comparison of laboratory test data with results of open air long-term experiments.

Three laboratory short-term test systems were used to determine volatilization rates, mineralization rates, and conversion rates of 14 14C-labeled chemicals in soils or soil-plant systems. The chemicals covered a wide range of water solubility, vapor pressure, chemical stability, and biodegradability. In order to compare the data obtained with the environmental behavior of the respective chemicals, data from an outdoor experimental setup which had been shown to give residue data within the range limits of field conditions were used. Volatilization rates, mineralization rates, and conversion rates obtained in the laboratory were correlated to those found under outdoor conditions. Based on these correlations, predictions of field residues were made. The predicted values for total field residues were comparable to those found experimentally with the exception of two chemicals. The prediction of residues of unchanged parent compounds in the field was less satisfactory. The reasons for differences observed are discussed.

Environmental Pollutants↗
PubMed1983

Elimination- and biodistribution studies of [14C]dodecylbenzene sulfonate in rats, following low dosing in the daily diet and a single i.p. administration.

14C-labelled sodium dodecylbenzene sulfonate (DBS) was administered daily in the diet at a concentration of 1.4 mg/kg to male rats for 5 weeks. From the total uptake (1.213 +/- 0.08 mg/animal) of DBS, 81.8% was excreted during the dosing period; 52.4% in feces and 29.4% in urine. Low levels of [14C]DBS-derived residues were detected in all tissues analyzed on day 35 of the experiment. Following 1 week on normal diet only 7.8% of the nominally stored amount of 14C was found in the excreta. Single i.p. application of 0.385 mg [14C]DBS/rat (2.26 +/- 0.15 mg/kg body wt.) resulted in a total elimination of 94.5% within 10 days. 84.7% of the dose was eliminated in the first 24 h. All fecal and renal [14C]DBS-derived activity consisted of highly polar metabolites.

Administration, Oral↗
PubMed1983

[Effect of sulmazol on left ventricular function in congestive cardiomyopathy].

In 11 patients with congestive cardiomyopathy (NYHA class III and IV, mean cardiothoracic ratio 0.59) the effect of a new positive inotropic agent, 2[(2-methoxy-4-methylsulfinyl)phenyl ))-1H-imidazo[4,5-b]pyridine (AR-L 115 BS, sulmazol, Vardax), on haemodynamics was studied. Simultaneously plasma levels of the drug were measured. All patients were pretreated with digitalis and diuretics. The following results were obtained: Heart rate increased only slightly, by 8% (n.s.), maximal left ventricular pressure rise by 37% (p less than 0.01), left ventricular enddiastolic pressure decreased by 42% (p less than 0.01), mean pulmonary artery pressure by 23% (p less than 0.01) and pulmonary vascular resistance by 22% (p less than 0.05). Left ventricular enddiastolic volume was reduced by 20% and left ventricular systolic volume by 31% (p less than 0.01). Ejection fraction increased by 36% (p less than 0.05), cardiac index, stroke index, stroke work index and systolic aortic pressure as well as systemic vascular resistance remained unchanged. In conclusion, sulmazol is an effective inotropic agent with vasodilating properties (especially on the venous capacity system). The lacking increase of cardiac output despite the augmentation of ejection fraction must be due to the prominent reduction of preload, decrease of left ventricular volume and heart size. Sulmazol therefore should not increase oxygen consumption of the heart and should be especially advantageous in patients with predominant backward failure.

Adult↗
PubMed1983

Elastica-positive material in the atrial endocardium. Light and electron microscopic identification.

The elastic layer of the endocardium is studied in various laboratory animals (mouse, rat, rabbit, cat, and dog) and in man. Coarse elastica-positive fibers form a tightly woven layer in the endocardium of the left atrium; the elastic layer consists of loosely arranged delicate fibers in the endocardium of the right atrium. Electron microscopy shows the elastic material to consist of homogeneous elastin (E) and of elastic fiber microfibrils (EFM). Elastic material in the endocardium of the left atrium is mainly formed of E with few EFM present. By contrast, the portion of EFM predominated that of E in elastic fibers from the right atrium, where some elastica-positive fibers even appear as pure bundles of microfibrils. This was also observed in human material obtained from aged individuals (8th decennium). It is concluded that EFM are not only progenitors of E but represent an independent fibrous component of the connective tissue.

Aged↗