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Biomedical subjects

E Klaus

Publications and source records attributed to E Klaus.

At least 19 recordsLinked to original sources
PubMed1999

HMR 1883, a cardioselective K(ATP) channel blocker, inhibits ischaemia- and reperfusion-induced ventricular fibrillation in rats.

Ventricular fibrillation (VF) is a major cause of sudden cardiac death in which myocardial ischemia plays a leading role. During ischaemia activation of ATP-sensitive potassium channels (K(ATP)) occurs, leading to potassium efflux from cardiomyocytes and shortening of the action potential favoring the genesis of ventricular fibrillation. In confirmation of this concept the sulfonylurea glibenclamide, which stimulates insulin release by inhibition of pancreatic K(ATP) channels, has been shown to inhibit VF in different models of ischaemia by inhibition of myocardial K(ATP) channels. HMR 1883 (1-[15-12-(5-chloro-o-anisamido)ethyl]-methoxyphenyl]sulfonyl]-3-m ethylthiourea) was designed as a cardioselective K(ATP) channel blocker. The aim of this study was to show that with this compound it is possible to separate the antifibrillatory from the insulin-releasing effect for the treatment of patients at risk of ischaemia-induced arrhythmias and sudden death. In the present study HMR 1883 reduced VF in Sprague-Dawley rats during prolonged ischaemia and also diminished mortality and the duration of VF in a separate reperfusion experiment at 3 mg/kg and 10 mg/kg with no effect on blood glucose or insulin. Glibenclamide, which was antifibrillatory at 0.3 mg/kg and 1 mg/kg, increased plasma insulin and lowered blood glucose already at a dose as low as 0.01 mg/kg. In conclusion, based on its antifibrillatory action and the absence of significant pancreatic effects at therapeutic doses, HMR 1883 is of potential clinical utility for the prevention of severe arrhythmias in patients with ischaemic heart disease.

Adenosine Triphosphate↗
PubMed1996

Determination of 113Cd shielding tensor components in cadmium-phosphine complexes from 31P-decoupled 113Cd cross-polarisation/magic angle spinning spectra.

Owing to the simultaneous presence of various anisotropic interactions within the isolated M-31P and M(31P)2 fragments in solid transition metal phosphine complexes MX2.PR3 and MX2.2PR3 with, for instance, M = Cd, Hg or Pt, it is not normally possible to unequivocally determine the shielding tensor components of the metal nucleus M from simple 113Cd, 199Hg or 195Pt cross-polarisation/magic angle spinning (CP/MAS) spectra. In this paper it is shown that additional 31P on-resonance high-power decoupling during the acquisition time does allow the determination of the shielding tensor components of M from CP/MAS spectra. Two cadmium(II) complexes, Cd(OAc)2.Pchex3, (chex = cyclohexyl) and Cd(ClO4)2.2Pchex3 were chosen as examples; the 113Cd CP/MAS experiments were carried out at a low external magnetic field strength B0 = 2.35 T.

Cadmium↗
PubMed1996

[Principles of pain therapy with local anesthesia].

The treatment of chronic pain consists of four basic concepts: Drugs (analgetic drugs, TAD, etc.), treatment by physicians (chiropraxis, massage, TENS, etc.), injection with local anesthetics and autosuggestion. Necessary for diagnosis and treatment of chronical pain is the knowledge of pathophysiology and anatomy of nerves, ligaments, muscles and the sympathetic nervous system. Diagnosis of chronical pain rarely includes roentgenograms or other technical procedures, mainly to exclude tumors, fractures or specific infections. The knowledge of pathophysiology means the knowledge of sympathetic and motoric efferences on one side and the functional examination of the anatomic structures on the other side.

Anesthesia, Local↗
PubMed1994

Ramipril prevents the detrimental sequels of chronic NO synthase inhibition in rats: hypertension, cardiac hypertrophy and renal insufficiency.

Inhibition of the angiotensin converting enzyme (ACE) with ramipril was studied in male Wistar rats during long-term inhibition of nitric oxide (NO) synthase by NG-nitro-L-arginine methyl ester (L-NAME). Chronic treatment with L-NAME in a dose of 25 mg/kg per day over 6 weeks caused myocardial hypertrophy and a significant increase in systolic blood pressure (245 +/- 16 mmHg) as compared to controls (155 +/- 4 mmHg). Animals receiving simultaneously L-NAME and ramipril were protected against blood pressure increase and partially against myocardial hypertrophy. L-NAME caused a significant reduction in glomerular filtration rate (GFR: 2.56 +/- 0.73 ml.kg-1.min-1) and renal plasma flow (RPF: 6.93 +/- 1.70 ml.kg-1.min-1) as compared to control (GFR: 7.29 +/- 0.69, RPF: 21.36 +/- 2.33 ml.kg-1.min-1). Addition of ramipril prevented L-NAME-induced reduction in GFR and renal plasma flow. L-NAME produced an elevation in urinary protein excretion and serum creatinine and a decrease in potassium excretion which was antagonised by ramipril. L-NAME-induced increase in plasma renin activity (PRA) was further elevated with ramipril treatment. Isolated hearts from rats treated with L-NAME showed increased post-ischaemic reperfusion injuries. Compared to controls duration of ventricular fibrillation was increased and coronary flow reduced. During ischemia the cytosolic enzymes lactate dehydrogenase and creatine kinase, as well as lactate in the venous effluent were increased. Myocardial tissue values of glycogen, ATP, and creatine phosphate were decreased, whereas lactate was increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Oxidoreductases↗
PubMed1993

[Value of computed tomography in the differential diagnosis of postoperative lumbar disc herniation recurrence and fibrotic changes].

Plain computed tomography scans and after intravenous contrast enhancement were used to investigate a group of 26 patients after an operation for lumbar disc herniation with signs of failed back surgery syndrome. The diagnosis of relapsing disc herniation was established in 12 patients. It was confirmed by surgery in 10, while massive epidural fibrosis was discovered in two. Own experience with the above method, which is considered by the authors the most reliable, is presented.

Diagnosis, Differential↗
PubMed1992

Cardiovascular effects of the novel potassium channel opener (3S,4R)-3-hydroxy-2,2-dimethyl-4-(2-oxo- 1-pyrrolidinyl)-6-phenylsulfonylchromane hemihydrate.

Cardiovascular effects of the novel potassium channel opener (3S,4R)-3-hydroxy-2,2-dimethyl-4-(2-oxo-1-pyrrolidinyl)-6- phenylsulfonylchromane hemihydrate (Hoe 234, CAS 132014-21-2) were investigated in rats, dogs and monkeys. In all species and independent of the route of administration Hoe 234 lowered systemic blood pressure accompanied with increases in heart rate. In rats after intravenous (i.v.) application Hoe 234 was 3 times more potent than cromakalim and its effects were reduced by pretreatment with the potassium channel blocker glibenclamide. Following intraduodenal application again Hoe 234 was more potent but mean arterial blood pressure (MAP) decreased more slowly and maximal effects were obtained later than after cromakalim. Oral administration of either single or repeated doses, however, revealed a somewhat higher potency for cromakalim. In anesthetized dogs Hoe 234 i.v. reduced MAP more potently than cromakalim whereas changes in heart rate were less pronounced. Cardiac output was increased and total peripheral resistance decreased for either agent. These results show that Hoe 234 is a novel potassium channel opener lowering blood pressure in animals due to peripheral vasodilation. It compares favourable with known potassium channel openers except for oral administration.

Administration, Oral↗
PubMed1990

Coronal radiographs and videofluoroscopy improve the diagnostic quality of temporomandibular joint arthrography.

Detection of mediolateral displacement of the temporomandibular joint (TMJ) meniscus and evaluation of the reducibility of this displacement are necessary because surgery is indicated when the displacement is irreducible. During TMJ arthrography, the routine sagittal study does not allow detection of this type of meniscal displacement. In a prospective study of 158 TMJ arthrograms in 83 patients, coronal radiographs were obtained and videofluoroscopy was performed (in addition to routine sagittal films and fluoroscopy) to detect mediolateral shift of the meniscus and to evaluate the reducibility of this displacement. Both upper and lower joint spaces were opacified. Coronal and lateral radiographs were obtained with the mouth open and closed. On coronal images, in 79 cases (50%) the meniscus was shifted medially, in 22 cases (14%) laterally, and in 57 cases (36%) it was in the normal position. In 90 (89%) of the 101 abnormal cases, anterior displacement was associated with a mediolateral shift. In 59 cases (58%), the mediolateral shift was irreducible. Coronal and lateral views and fluoroscopy were reviewed separately by two observers, whose conclusions were identical for all cases. In 32 (54%) of the 59 joints with irreducible mediolateral displacement, surgery was performed. For all of these, comparison of radiologic data with surgical findings indicated that coronal views and videofluoroscopy were diagnostic, whereas mediolateral displacements were not detectable on routine sagittal studies.

Adult↗
PubMed1990

Loose bodies of the temporomandibular joint: arthrographic and CT findings in five patients.

We report a series of five patients with symptoms of internal derangements of the temporomandibular joint (TMJ), in whom intraarticular loose bodies were found. Three patients with a single loose body had osteochondrosis dissecans of the temporal part of the joint; one trauma patient had two loose bodies (including a bony and a meniscal fragment). The fifth patient presented with a loose meniscal fragment and a complete meniscal rupture, complicating a long-lasting TMJ dysfunction due to non-reducible anterior meniscus displacement. The diagnosis was made by arthrotomography (3 cases), CT (one case) and by CT and arthrotomography (one case). Surgical confirmation was obtained in all patients. Arthrography and CT are accurate in diagnosing TMJ loose bodies; characteristic findings disclosed in both examinations are described.

Adult↗
PubMed1990

Influence of seasonal biorhythms on urinary excretion of enzymes and other parameters.

Urinary excretion of enzymes, electrolytes, creatinine, protein and the consumption of food and water in female and male Wistar rats was examined over two seasons of summer and wintertime, respectively. The evaluation of data revealed that gamma-glutamyltransferase, inorganic phosphate, and the lysosomal enzymes, N-acetyl-beta-D-glucosaminidase and acid phosphatase, were significantly different between the collection periods in both seasons. Other parameters showed significant differences only in male rats, whereas urinary electrolytes, with the exception of chloride, showed no significant differences.

Animals↗
PubMed1986

Enzymuria in streptozotocin-diabetic rats.

Twenty four hour urine samples of male control and streptozotocin-diabetic Wistar rats were analysed for a series of commonly known kidney-specific enzymes, for electrolytes, creatinine, glucose, total protein and urine volume. The examination was done during two periods of 5 days between the 25th and 30th and the 32nd and 36th day after streptozotocin application. In the first period the animals had free access to food and water, whereas in the second period on days 32, 34 and 36 food was withdrawn. In the first observation period the diabetic rats showed increased excretion rates of 15 measured urinary parameters, while alanine aminopeptidase (EC 3.4.1.2) and gamma-glutamyltransferase (EC 2.3.2.2) activities were lowered and inorganic phosphate was unchanged. The removal of food resulted in decreased excretion values for alanine aminopeptidase, gamma-glutamyltransferase and total protein as compared with fasted nondiabetic animals. The activities of N-acetyl-beta-D-glucosaminidase (EC 3.2.1.30), acid phosphatase (EC 3.1.3.2), lactate dehydrogenase (EC 1.1.1.27), pyruvate kinase (EC 2.7.1.40), C1-fructose 1.6-diphosphatase (EC 3.1.3.11) and the excretion values for sodium, calcium, magnesium, chloride and glucose were higher than in fasted nondiabetic rats. beta-Glucosidase (EC 3.2.1.21), potassium, inorganic phosphate, creatinine, and urine volume showed no differences between fasted diabetic and fasted control animals. The enzymes in the renal cortex at the end of the experiment showed only decreased activity of alanine aminopeptidase in diabetic rats. Lactate dehydrogenase, pyruvate kinase, beta-glucosidase, C1-fructose 1.6-diphosphatase and glucose 6-phosphatase (EC 3.1.3.9) were increased and gamma-glutamyltransferase, N-acetyl-beta-D-glucosaminidase, acid phosphatase and glucose 6-phosphate dehydrogenase (EC 1.1.1.49) showed no change.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Effect of rat atriopeptin III on renal function in dogs during water diuresis and hydropenia.

Experiments have been performed in conscious male beagle dogs under maximal water diuresis or hydropenia to determine the effects of synthetic rat atriopeptin III [r-AP III = r-ANF- (103-126)] (Geller et al. 1984), in an intravenous dose of 50 micrograms/kg body weight, on renal function and plasma renin activity. Intravenous injection of r-AP III resulted in an increase in urine and sodium excretion lasting up to 20 minutes, while the glomerular filtration rate and renal plasma flow were hardly influenced under either of the experimental conditions. r-AP III induced an increase in free water clearance from 7.51 +/- 2.45 ml/min in controls to 12.15 +/- 2.25 ml/min in the first clearance period, whereas the free water reabsorption was only slightly reduced (5.56 +/- 1.22 vs. 5.02 +/- 1.23 ml/min). r-AP III caused a slight increase in plasma renin activity from 0.65 +/- 0.46 in controls to 1.02 +/- 0.47 ng X ml-1 X h-1 in water diuretic dogs and from 3.19 +/- 0.51 in controls to 3.72 +/- 0.81 ng X ml-1 X h-1 in hydropenic dogs. These experiments show that the r-AP III-induced salidiuretic response seems not to be mediated by changes in the glomerular filtration rate and renal plasma flow. Moreover, the increase in free water clearance and the absence of change in free water reabsorption indicate a proximal site of action of r-AP III.

Animals↗