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Biomedical subjects

S Veit

Publications and source records attributed to S Veit.

26 records · Page 2Linked to original sources
PubMed1989

Dose-related effects of intracoronary application of nisoldipine on central and peripheral circulatory parameters.

In a randomized study central and peripheral circulatory parameters were determined in 12 anaesthetized mongrel dogs before and after intracoronary injection of nisoldipine and placebo. Administration of 0.2 to 0.8 micrograms/kg nisolpine was followed by a 46% to 62% decrease in coronary vascular resistance and a 109% to 141% increase in myocardial blood flow lasting 10 min. There was no significant change in myocardial contractility or peripheral circulatory parameters. An increase in dosage to 1.6 micrograms/kg did not cause a further increase in myocardial blood flow or decrease in coronary vascular resistance. However, there was a significant decrease in total peripheral resistance of up to 32% and a 36% increase in heart rate attributable to counter-regulation lasting 3 to 5 min. At this dosage level a significant decrease in myocardial contractility and an increase in left ventricular end-diastolic pressure are to be expected. This implies a major dissociation between coronary vascular effects and changes in parameters of myocardial performance and peripheral resistance after intracoronary administration of nisoldipine, an effect which is dose-related. Injection of 0.4 to 0.8 micrograms/kg would seem to be the optimal dosage range for intracoronary administration of nisoldipine producing maximum coronary dilatation without myocardial depression.

Animals↗
PubMed1986

The haemodynamic effects of amrinone in patients with mitral stenosis and pulmonary hypertension.

The aim of this study was to investigate the haemodynamic effects of amrinone in patients with pulmonary hypertension and impaired right ventricular function. Twelve patients with mitral stenosis (NYHA classification III and IV) took part in the study. The haemodynamic measurements were performed in the steady state under anaesthesia prior to surgery. The patients received a bolus injection of 1.5 mg kg-1 amrinone; haemodynamic measurements were taken at 3, 5, 10, 15, 20 and 30 min. Amrinone increased cardiac index by approximately 30%, heart rate rose from on average 76 to 82 beats per minute. Whereas pulmonary capillary pressure did not change significantly, mean pulmonary artery pressure fell clearly from 33 to 28 mmHg. A decrease in the elevated pulmonary vascular resistance of about 40% was calculated. The higher the initial value for resistance in the pulmonary circulatory system, the more marked was the reduction (r = 0.96). The study shows that amrinone induces a vasodilation in the pulmonary circulatory system. A reduction in ventricular afterload is of great significance particularly for the therapy of right heart insufficiency. Amrinone therefore appears to be a suitable substance with its observed vasodilating and its well known positive inotropic effects for the treatment of right heart failure in cases of pulmonary hypertension.

Adult↗
PubMed1985

Comparison of phentolamine and urapidil in controlling acute intra-operative hypertension in patients subjected to coronary artery bypass surgery.

Intra-operative hypertensive episodes are a frequent problem in patients undergoing coronary artery bypass grafting. The haemodynamic effects of the alpha-adrenergic blocking drugs phentolamine and urapidil, two alpha-adrenergic blocking drugs with a different alpha-receptor subtype specificity, when used to control intra-operative hypertension were evaluated. Ten patients received phentolamine (about 25 micrograms kg-1 min-1) and ten patients received urapidil (about 100 micrograms kg-1 min-1) to return arterial blood pressure to control levels. Both drugs decreased arterial pressure to baseline values within 2-3 minutes by reducing the elevated systemic vascular resistance. Treatment with phentolamine was accompanied by a marked increase in heart rate with a concomitant increase in cardiac index and the rate-pressure product. Urapidil caused no change in heart rate, but the cardiac index increased. Urapidil lowered the rate-pressure product significantly. Both drugs reduced mean pulmonary artery and pulmonary capillary wedge pressures. The different selectivity of phentolamine and urapidil to alpha 1-and alpha 2-adrenergic receptors induces the diverse haemodynamic effects. We conclude that the use of urapidil is the superior regimen when an alpha-adrenergic blocking agent is favoured as a vasodilator.

Acute Disease↗
PubMed1985

[Dose-dependent effect of amrinone on hemodynamics, myocardial circulation and myocardial energy requirement. An experimental study].

This study was designed to assess the dose-dependent effects of amrinone (1, 2 and 4 mg/kg i.v.) on hemodynamics, myocardial blood flow and myocardial oxygen consumption in anesthetised closed chest dogs (n = 8). Heart rate (HR), cardiac output, mean aortic pressure (MAP), left ventricular end-diastolic pressure (LVEDP), maximum dp/dt (dp/dtmax), myocardial blood flow (MBF) and aorto-coronary sinus oxygen difference (AVDO2 cor) were measured. Cardiac index (CI), stroke volume index (SVI), ejection fraction (EF), total peripheral resistance (TPR), coronary vascular resistance (CVR) and myocardial oxygen consumption (MVO2) were calculated from standard formulas. Amrinone improved myocardial pump function by a direct positive inotropic effect on the myocardium. EF and SVI increased to a maximal degree with 1 mg/kg amrinone (28% resp. 30%). dp/dtmax increased dose dependent (46, 64, 71%). Following a systemic vasodilation due to amrinone, left ventricular filling pressure and TPR decreased significantly. With 1 and 2 mg/kg amrinone MAP remained unchanged. 4 mg/kg produced a distinct fall in MAP accompanied by an increase in HR. The improvement in myocardial contractility did not cause a comparable increase of myocardial oxygen consumption. Due to an unloading of the heart 1 and 2 mg/kg amrinone induced no significant and prolonged augmentation of the myocardial oxygen demand. In the coronary circulation a non energy dependent vasodilation occurred followed by a marked decrease of AVDO2 cor (10, 18, 28%).

Aminopyridines↗
PubMed1981

Eccrine sweat glands are not innervated in hereditary sensory neuropathy type IV. An electron-microscopic study.

The ultrastructural study of a skin biopsy in a patient afflicted with hereditary sensory neuropathy type IV (congenital insensitivity to pain with anhidrosis) did not reveal any unmyelinated axons or axonal terminals around eccrine sweat glands but only processes, partially covered by a basement membrane and therefore resembling Schwann cell processes. The absence of such unmyelinated axons in close proximity to eccrine sweat glands where they normally occur appears to be the morphological equivalent to the anhidrosis and also corresponds to the deficiency of unmyelinated axons in the sural nerve of the same patient, as previously reported.

Basement Membrane↗
PubMed1980

Confirmation of virtual unmyelinated fiber absence in hereditary sensory neuropathy type IV.

Sural nerves from two unrelated young boys were virtually without unmyelinated fibers (UFs). Small myelinated fibers (MFs) may also have been slightly reduced in number. Since no degeneration or regeneration is observed, UF absence is assumed to be congenital, due to either lack of neuron formation or to premature degeneration. The main clinical features of this inherited sensory neuropathy (previously identified by us as type IV) are the inherited nature and abnormality of nociception, of sweating, and of thermal regulation associated with mild mental retardation. Our findings confirm the congenital absence of UFs of cutaneous nerves in cases such as these and provide further evidence that this disorder has a different natural history and pathology than do the other three types of hereditary sensory neuropathy.

Humans↗
PubMed1975

[Normal values for Lactate- and Glutamate dehydrogenate by new optimized methods (author's transl)].

The activities of the enzymes LDH (Lactatdehydrogenase), HBDH (Hydroxybutyratdehydrogenase), and GIDH (Glutamate dehydrogenase), as well as LAP (Leucine aryl peptidase) were measured in the serum of 934 children in order to get normal values of these enzyme activities in dependence on the age. We used again the optimized methods (Boehringer und Merck). The form of the distribution of the single values of these 4 enzymes can be described by a lognormal distribution. This applies not to newborns and young sucklings. All measured enzyme activities were depended on the age of the children; newborn and sucklings had significantly higher enzyme activities than infants. After the second year of life the enzyme activities for LDH, HBDH, GlDH and LAP remained constantly. The physiological variations are very high in the newborns. The diagnostic selectivity of the enzyme GIDH is very good, this of LDH and HBDH turned out unspecifically. No difference could be supplied for the sex of the children.

Adolescent↗