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Biomedical subjects

C Gatzka

Publications and source records attributed to C Gatzka.

6 recordsLinked to original sources
PubMed1997

Is endothelial function of the radial artery altered in human essential hypertension?

There is controversy over whether endothelial function is impaired in human essential hypertension. All studies to date have used measurements of forearm blood flow by plethysmography to assess endothelium-dependent vasodilation and endothelial function. In contrast to these studies, which have focused on resistance vessels, we have determined what effects the endothelium has on underlying smooth muscle cells in conduit arteries by measuring arterial compliance of the radial arteries (change in diameter of radial artery over pressure for each arterial pulse). In 13 normotensive healthy subjects and 11 young patients with essential hypertension, arterial compliance of the radial artery was assessed directly with a new high-precision ultrasonic device (NIUS 02) after infusion of acetylcholine (endothelium-dependent response) or sodium nitroprusside (endothelium-independent response). Arterial compliance of the radial artery was similar at baseline and with increasing doses of acetylcholine and sodium nitroprusside in normotensive and in hypertensive subjects. The increase in arterial compliance from baseline at each individual concentration of acetylcholine and sodium nitroprusside was the same in both normotensive and hypertensive subjects. However, after a single oral dose of a combination of the angiotensin converting enzyme inhibitor spirapril and the calcium entry blocker isradipine, the increase in arterial compliance in response to the maximum dose of intraarterial acetylcholine was enhanced in normotensives (0.38 +/- 1.23 to 0.76 +/- 1.01 mm2/mm Hg x 10(-3), P < .05), but not in hypertensives (+0.41 +/- 1.26 to 0.36 +/- 1.31 mm2/mm Hg x 10(-3), not significant), and differed significantly between normotensive and hypertensive subjects (P < .05). Thus, pharmacologic stimulation disclosed a blunted response of endothelium-dependent action in the arterial compliance of the conduit arteries in hypertensive subjects. This suggests an impaired endothelial function reserve in persons with essential hypertension.

Acetylcholine↗
PubMed1997

[New developments in the application of resorbable implants].

The application of biodegradable implants is combined with advantages and disadvantages. They offer a great deal of innovative ideas. Best evaluation has been done with pins for the fixation of low loaded osteochondral fractures. When using 2.7 mm Polypin primary mechanical stability of distal radius fractures is comparable with the fixation by 1.8 mm K-wires. A prospective and randomised study with two years follow up, including 183 radial head fractures, showed no significant difference in results and complications in metal and polyactide implants. For this localisation and other comparable indications the implant can be recommended. Despite the more extensive degradable device overall costs can be reduced with the polymer implant. Orientruded polyactide screws showed good clinical results, newetheless resorption was extremely late within 5 to 7 years.

Adolescent↗
PubMed1996

Treatment and post-treatment effects of alpha- versus beta-receptor blockers on left ventricular structure and function in essential hypertension.

This study was undertaken to compare the effects of alpha-receptor blockade and beta-receptor blockade on left ventricular structure and function in essential hypertension. The increase in left ventricular mass in patients with essential hypertension is at least partly induced by the sympathetic nervous system. We conducted a double-blind, randomized, controlled clinical trial to compare the effects of alpha-blockers and beta-blockers on left ventricular structure and function. Forty-three patients with mild to moderate essential hypertension were randomly allocated to receive antihypertensive therapy with either the alpha-blocker bunazosin (n = 23) or the beta-blocker metoprolol (n = 20). Twenty-four-hour blood pressure measurements and echocardiographic measurements of left ventricular structure and function were performed before therapy, after 6 months of therapy, and 4 weeks after discontinuation of therapy. Bunazosin and metoprolol led to similar reductions in systolic/diastolic blood pressure (-11 +/- 11/-9 +/- 8 mm Hg vs -11 +/- 12/-8 +/- 9 mm Hg, respectively) and left ventricular mass (-25 +/- 42 gm vs -28 +/- 44 gm, respectively) (p = no significant difference, bunazosin vs metoprolol). Neither metoprolol nor bunazosin significantly affected left ventricular systolic function. Diastolic left ventricular filling, however, was increased with beta-blocker medication, as indicated by a decrease in atrial filling fraction (39% +/- 5% to 34% +/- 5%; p < 0.05), but not with the alpha-blocker. The effect of metoprolol resulted from its bradycardiac effect. Four weeks after discontinuation of therapy, blood pressure and left ventricular mass increased to pretreatment levels in both groups similarly. Furthermore, the increase in diastolic filling was lost shortly after withdrawal of metoprolol concomitant with the increase in heart rate. We conclude that alpha-blockers and beta-blockers are equally capable of reducing left ventricular mass in hypertensive patients. beta-Blockers lead to an increase in diastolic left ventricular filling. This effect may be of therapeutic value because diastolic dysfunction may precede systolic dysfunction in hypertensive heart disease.

Adrenergic alpha-Antagonists↗
PubMed1994

Renal hemodynamic response to stress is influenced by ACE-inhibitors.

Cardiovascular responses to new antihypertensive agents have been studied extensively under resting and stress conditions. However, the effects of antihypertensive agents on renal hemodynamics have only been investigated at rest. To test whether antihypertensive therapy leads to disparate renal hemodynamic effects during exposure to mental stress as opposed to resting conditions, we performed a double-blind, placebo-controlled crossover study. In 17 normotensive healthy men, glomerular filtration rate (GFR; inulin clearance) and renal plasma flow (RPF; para-aminohippuric acid clearance) were measured at rest and after a standardized mental stress test, with or without one week's treatment with a new, long-acting ACE-inhibitor cilazapril 2.5 mg/day. ACE-inhibition did not change resting blood pressure, RPF, GFR, or derived parameters, such as filtration fraction, renal vascular resistance and renal fraction of cardiac output. Mental stress caused an acute increase in GFR (p < 0.001) and filtration fraction with both treatments (0.001). However, the increase in GFR and filtration with mental stress was greater (p < 0.05) with cilazapril treatment than with placebo. Thus, renal hemodynamic responses to mental stress were influenced by ACE inhibitors. We conclude that the impact of antihypertensive agents on renal hemodynamics during stress cannot a priori be delineated from measurements at rest.

Adult↗
PubMed1993

Obesity as a determinant for response to antihypertensive treatment.

OBJECTIVE: To test the hypothesis that beta blockers lower blood pressure more effectively than calcium entry blockers in obese hypertensive patients and that calcium entry blockers are more effective in lean patients. DESIGN: Double blind, randomised controlled trial of treatment over six weeks. SETTING: Tertiary referral centre. SUBJECTS: 42 white men with uncomplicated mild to moderate essential hypertension (World Health Organisation stage I or II); 36 completed the study. INTERVENTION: Patients were randomised to metoprolol 50-100 mg twice daily or isradipine 2.5-5.0 mg twice daily for six weeks after a two week run in phase. MAIN OUTCOME MEASURE: Blood pressure after six weeks of treatment. RESULTS: When stratified according to treatment and presence of obesity (body mass index < or = 27 kg/m2), the mean (SD) fall in blood pressure in the beta blocker group was 24 (13)/18 (10) mm Hg in obese patients and 18 (19)/12 (13) mm Hg in lean patients. In the calcium entry blocker group, the fall in blood pressure was 21 (15)/17 (6) mm Hg in lean patients and 18 (11)/8 (10) mm Hg in obese patients. After taking age and blood pressure before treatment into account there was a significant interaction between obesity and drug therapy (p = 0.019) with a better diastolic blood pressure response to calcium entry blockers in lean patients and to beta blockers in obese hypertensive patients. CONCLUSION: Obesity affects the efficacy of metoprolol and isradipine in reducing blood pressure.

Blood Pressure↗