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T C Wascher

Publications and source records attributed to T C Wascher.

64 records · Page 4Linked to original sources
PubMed1994

Influence of weight reduction on platelet volume: different effects of a hypocaloric diet and a very low calorie diet.

Since platelet volume reflects platelet activity, the mean platelet volume (MPV) is proposed to be a further independent risk factor for cardiovascular disease (CVD). Even if it is well established that weight reduction reduces some of the risk factors of CVD in obese patients, an increase of MPV occurs during periods of weight loss. We therefore prospectively investigated the effects of different weight reduction therapies on platelet mass, platelet volume, body weight and serum lipid profile in patients undergoing an 8 week weight reduction therapy either by a hypocaloric diet (HD) or a nutritionally completed very low calorie diet (VLCD) with a subsequent maintenance period of 40 weeks. In both groups, MPV transiently increased during the 8 week diet period. After 48 weeks the MPV was decreased to initial values. The change in MPV was significantly (P < 0.05) smaller in the VLCD group. We therefore suggest that fasting might alter the control of platelet size with a possible impact on platelet activity. This might result in an increased risk for thromboembolic ischaemic events in atherosclerotic patients. Thus, we conclude that the use of a VLCD is potentially superior for weight reduction in patients with pre-existing atherosclerosis.

Adult↗
PubMed1994

Serum levels of interleukin-6 and tumour-necrosis-factor-alpha are not correlated to disease activity in patients with rheumatoid arthritis after treatment with low-dose methotrexate.

Cytokines are major mediators of inflammatory responses in rheumatoid arthritis. Some of them have been shown to correlate with the disease activity and thus are proposed to be used for monitoring patients. Therefore the effects of a low-dose therapy with methotrexate on serum concentrations of interleukin-6 (IL-6) and tumour-necrosis-factor-alpha (TNF-alpha) were examined in eight patients with seropositive rheumatoid arthritis. Serum levels of IL-6 and TNF-alpha were significantly elevated in patients compared to healthy controls. Before the onset of MTX treatment IL-6 concentrations were correlated to the c-reactive protein (P < 0.05) but the correlation was abolished after treatment. For TNF-alpha no correlations neither before nor after treatment were observed. Both cytokines remained substantially elevated after MTX treatment despite a clear reduction in disease activity. Thus we suggest that one of the effects of MTX might be the inhibition of some of the actions of IL-6 and TNF-alpha.

Arthritis, Rheumatoid↗
PubMed1994

Intracellular mechanisms involved in D-glucose-mediated amplification of agonist-induced Ca2+ response and EDRF formation in vascular endothelial cells.

Prolonged treatment of vascular endothelial cells with pathologically high D-glucose amplifies autacoid-induced Ca2+ mobilization and thus formation of nitric oxide. This study investigated the Ca2+ source for the change in endothelial CA2+ response on agonist stimulation. Pretreatment with high D-glucose (44 vs. 5 mM) enhanced release of intracellular Ca2+ by bradykinin as a result of a 2.0-fold increased formation of inositol 1,4,5-trisphosphate. High D-glucose also amplified Ca2+ influx (2.0-fold). In high D-glucose preincubated cells, stimulation with bradykinin significantly increased transplasmalemmal 45Ca2+ flux (3.2-fold) and caused a 2.0-fold increase in permeability to Mn2+, a surrogate for endothelial plasma membrane Ca2+ channels. A significant 2.0-fold increase occurred in the maximal slope, suggesting a higher rate of Mn2+ (Ca2+) influx. Ca2+ influx, stimulated by an inositol phosphate-independent depletion of intracellular Ca2+ stores with 2,5-di-(tert-butyl)-hydroquinone was also significantly increased 2.4-fold by high D-glucose, with no effect on intracellular Ca2+ release. D-glucose failed to modulate resting or stimulated cAMP levels. We suggest that prolonged exposure to pathologically high D-glucose increases formation of inositol polyphosphates, thus increasing Ca2+ release. Ca2+ entry is increased by amplification of unknown signal transduction mechanisms triggered by Ca2+ store depletion.

Animals↗
PubMed1994

Cardiovascular risk factors in obesity. The effect of weight reduction on platelet size in overweight patients.

Platelet volume, indicating platelet activity has been proposed as a further independent risk factor for cardiovascular disease (CVD). It is well established that weight reduction reduces some of the risk factors for CVD in obese patients. We therefore retrospectively investigated the effects of weight reduction on platelet mass, platelet volume and serum lipid profile in patients undergoing an eight-week weight reduction therapy. During weight reduction, the body mass index (P < 0.005), serum total cholesterol (P < 0.05), LDL cholesterol (P < 0.01) and serum triglycerides (P < 0.01) were significantly reduced, while HDL cholesterol remained unchanged. On the other hand, platelet mass (P < 0.005) and platelet volume (P < 0.0005) increased significantly within the same period. We therefore conclude that fasting might alter the control of platelet size with a possible impact on platelet activity. This might result in an increased risk of thrombo-embolic ischaemic events in atherosclerotic patients.

Adult↗
PubMed1993

Exposure to elevated D-glucose concentrations modulates vascular endothelial cell vasodilatory response.

The possible role of endothelial dysfunction in early stages of uncomplicated diabetes mellitus was investigated in porcine aortic endothelial cells. Prolonged exposure to various D-glucose concentrations resulted in concentration-dependent amplification of agonist-induced Ca2+ mobilization, whereas L-glucose and D-mannitol failed to mimic the effect of D-glucose. This stimulatory effect of high D-glucose on endothelial Ca2+ mobilization could be antagonized by coincubation with cytochalasin B, which prevented D-glucose uptake into the cells. In agreement with its effect on agonist-induced Ca2+ response, prolonged preincubation with pathological D-glucose concentrations amplified formation of endothelium-derived relaxing factor, which is well established to be strictly attributable to increases in endothelial free Ca2+. In contrast to endothelium-derived relaxing factor formation stimulated by receptor-interacting autacoids, preincubation with high D-glucose failed to modulate A 23,187-induced endothelium-derived relaxing factor formation, which is attributable to unphysiological increases in endothelial free Ca2+ by this ionophore. Similar to its effect on D-glucose-mediated amplification of agonist-stimulated Ca2+ mobilization, cytochalasin B abolished the stimulatory effect of high D-glucose on endothelium-derived relaxing factor formation. We therefore suggest that prolonged exposure to pathological high D-glucose concentrations results in an enhanced endothelium-derived relaxing factor formation caused by amplification of agonist-stimulated Ca2+ mobilization in endothelial cells. This mechanism may be of particular importance representing a possible basis of pathological vasodilation and reduced peripheral resistance in early stages of diabetes mellitus.

Animals↗
PubMed1992

LG 6-101 and LG 6-102, two new propafenone-related antiarrhythmic agents with good oral activity in rats.

LG 6-101 (1-[3-(2-methoxy-3-(2-methylpropylamino)-propoxy)-4-methyl- 2-thienyl]-3-phenyl-1-propanon hydrochloride; MW: 426.02) and LG 6-102 (2-(2-methoxy-3-propylamino-propoxy)-3-phenyl-propiophenon hydrochloride; MW: 391.92) are two new antiarrhythmic substances. They are structurally related to propafenone which is a widely used class Ic-antiarrhythmic drug. In man the oral bioavailability of propafenone is only about 5-40%. Therefore the development of compounds with similar mode of action but higher oral bioavailability seems to be meaningful. Both, LG 6-101 and LG 6-102 proved to be effective in isolated auricles and in experimental animals after intravenous administration. In the present study we tested the antiarrhythmic effects of LG 6-101 and LG 6-102 in rats after oral administration. Animals were treated with LG 6-101 (16, 32, 64, 128, 256 mg kg-1 bodyweight), LG 6-102 (4, 8, 16, 32, 64 mg kg-1 bodyweight) and propafenone (32, 64, 128, 256 mg kg-1 bodyweight) by gavage twice daily during 4 days. Both, LG 6-101 and LG 6-102 showed strong antiarrhythmic effects against arrhythmias induced on the fifth day by infusion of aconitine (10 micrograms kg-1 min-1). LG 6-102 was significantly more effective against cardiac arrest caused by infusion of aconitine (P less than or equal to 0.05) than LG 6-101. Both substances had good effects on the delay of ventricular premature beats.(ABSTRACT TRUNCATED AT 250 WORDS)

Aconitine↗
PubMed1991

Antiarrhythmic effects of two new propafenone related drugs. A study on four animal models of arrhythmia.

LG 6-101 (1-[3-(2-methoxy-3-(2-methylpropylamino)-propoxy)-4-methyl- 2-thienyl]-3-phenyl-1-propanone, hydrochloride) and LG 6-102 (2-(2-methoxy-3-propylamino-propoxy)-3-phenyl-propiophenone, hydrochloride) are two new antiarrhythmic drugs. They are structurally related to propafenone which is a widely used class 1 antiarrhythmic drug with relatively low bioavailability. Both substances were characterized in four animal models of arrhythmia and compared to propafenone. In isolated guinea pigs left auricles LG 6-101 and LG6-102 were about twice as effective as propafenone regarding the prolongation of the functional refractory period but did not decrease contractility more than propafenone. LG 6-101 was significantly more effective (p less than or equal to 0.002) than propafenone or LG 6-102 in delaying the onset of ventricular premature beats in ouabain induced arrhythmias in guinea pigs. In aconitine induced arrhythmias in rats, LG 6-101 and LG 6-102 did not differ in their antiarrhythmic effects from propafenone, whereas the protection against cardiac arrest was significantly (p less than or equal to 0.003) better for LG 6-101 than for propafenone or LG 6-102. In arrhythmias induced by occlusion of the left descending coronary artery in rats the drugs tested showed as good antiarrhythmic effects as propafenone. In this model the size of the ischemic area was also measured and LG 6-101 was the most effective drug in that respect. These results suggest that both LG 6-101 and LG 6-102 are potent antiarrhythmic substances which in some models were more effective than propafenone.

Aconitine↗