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Biomedical subjects

D Duprez

Publications and source records attributed to D Duprez.

At least 91 records · Page 5Linked to original sources

Medical treatment of peripheral vascular disease: good or bad?

The majority of patients with intermittent claudication are treated conservatively; smoking must be stopped and exercise therapy commenced. There are various classes of drugs that are widely prescribed for the treatment of peripheral vascular disease. In this editorial the medical treatment of peripheral vascular disease is claimed to achieve at least one of three goals: (1) improvement of the functional capability; (2) inhibition of the progression of the atherosclerotic and anatomical lesions; (3) reduction of the cardiac and cerebrovascular morbidity and mortality. Guidelines are given for well controlled trials for newly developed drugs for the treatment of peripheral vascular disease in the future.

Arterial Occlusive Diseases↗

Impaired microcirculation in mild-to-moderate essential arterial hypertension.

OBJECTIVE: The aim of this study was to correlate capillary morphology and erythrocyte velocity to blood pressure in mild-to-moderate essential arterial hypertension. DESIGN: Ambulatory blood pressure measurement may provide more precise information about a patient's mean blood pressure than office measurements. METHODS: Fifteen patients with recently diagnosed, previously untreated mild-to-moderate essential hypertension underwent 24-h ambulatory blood pressure recording and a capillaroscopic examination of finger microcirculation. Erythrocyte velocity was determined by the flying spot technique. RESULTS: Both mean 24-h ambulatory systolic blood pressure (SBP) and mean 24-h ambulatory diastolic blood pressure (DBP) were significantly inversely correlated with capillary erythrocyte velocity. However, the correlation between erythrocyte velocity and office SBP and office DBP was less significant. Capillary length was related to 24-h ambulatory DBP but not to office DBP. Capillary number was not related to any blood pressure parameter. CONCLUSIONS: These results indicate that, in patients with mild-to-moderate essential hypertension, erythrocyte velocity is significantly lower than for matched controls. It is also inversely related to mean 24-h ambulatory SBP and 24-h ambulatory DBP.

Blood Flow Velocity↗

Evaluation of the metabolic compensation after treadmill test in patients with peripheral occlusive arterial disease.

Patterns of release of lactate, hypoxanthine, and arginine into the bloodstream after a standardized treadmill test (twelve minutes, 1.6-2.8 mph, inclination 0,5,10,15%) were recorded in 21 consecutive patients with stage II peripheral arterial occlusive disease. Heart rate, systolic blood pressure, ankle blood pressure, and ankle/brachial systolic blood pressure ratio (A/B ratio), as well as plasma lactate, plasma hypoxanthine and serum arginine were recorded before and at fifteen to thirty-minute intervals for up to two hours after the treadmill test. Immediately after the treadmill test, lactate levels (36.6 +/- 3.7 mg/L) and hypoxanthine levels (2.73 +/- 0.19 mmol/L) were significantly (p less than 0.001) increased but returned to preexercise levels after thirty and sixty minutes, respectively. Arginine levels did not change significantly. Ankle blood pressure (57 +/- 5 mm Hg) and A/B ratio (0.40 +/- 0.04) were significantly (p less than 0.001) decreased after exercise, while heart rate and systolic blood pressure were increased. These parameters returned to normal as well within a half hour after exercise. Absolute walking distance correlated significantly (p less than 0.01) with the postexercise systolic blood pressure (r = -0.62), ankle pressure (r = 0.63) and A/B ratio (r = 0.72). Induced hypoxanthine and lactate production intercorrelated significantly positively (r = 0.57, p = 0.007) but were independent of the absolute walking distance. In contrast with lactate, hypoxanthine production correlated significantly with postexercise ankle pressure (r = 0.49, p = 0.02) and exercise-induced fall in A/B ratio (r = 0.66, p = 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Arginine↗

Examination of Raynaud's phenomenon in traumatic vasospastic disorders.

Certain types of occupation-related vibrations can cause traumatic vasospastic disorders. Findings from clinical examination are often normal at the office consultation. Measurements of finger blood flow using plethysmography while the local ambient temperature is changed can give important information about the severity of traumatic vasospastic disorder and the concomitant disability. This technique can also be used for follow-up of the finger blood flow after withdrawal from vibrations.

Adult↗

Value of ambulatory blood pressure recordings.

In the present paper, the value of ambulatory blood pressure recordings is discussed. Such recordings can be very helpful in the management of high and low blood pressure. The fact that more readings are obtained and that they are made in normal life conditions are the strongest arguments in favour of those recordings. Whether ambulatory recordings predict long term prognosis better than office blood pressure is still open for discussion; the long term European study OvA should help clarifying this important question. Data coming from these techniques are especially useful when conflicting elements are present such as high pressure with no organ damage or blood pressure resistant to all drugs and side effects occurring with even minor doses of antihypertensive drugs. Short term episodes of high or low pressure are best documented with ambulatory blood pressure recordings and this holds particularly true in patients with arterial hypotension. Finally several research aspects can be approached by ambulatory recordings of pressure such as the study of pharmacokinetics of drugs and analysis of blood pressure variability.

Adrenergic beta-Antagonists↗

Decreased exercise capacity in mild essential hypertension: non-invasive indicators of limiting factors.

Available data suggest that exercise capacity is limited in hypertension. The mechanism of this reduced maximal exercise capacity has not been fully elucidated. In this study 22 patients with mild essential hypertension (162 +/- 22 mmHg systolic and 95 +/- 8 mmHg diastolic) and 36 normotensive control subjects (128 +/- 13 mmHg systolic and 80 +/- 7 mmHg diastolic) (P less than 0.01) performed an ergometer test till exhaustion. Body mass index in the two groups did not differ. The maximal oxygen consumption VO2 was lower in the hypertensive group (18 +/- 7 versus 23 +/- 8 ml/kg/min; P less than 0.02) as was the maximal workload (141 +/- 52 vs. 185 +/- 70 Watt; P less than 0.01). Rate pressure product rose only 2.7 fold in hypertensive patients versus 3.5 fold in the control group (P less than 0.001). In hypertensive patients maximal workload decreased with increasing resting systolic blood pressure (P less than 0.05) while in the normotensive subjects maximal workload rose with increasing resting systolic blood pressure (P less than 0.05). In conclusion both high and low blood pressure was associated with a decreased maximal voluntary exercise capacity. Even mild hypertension was accompanied by lower maximal exercise capacity. Hypertensive patients also had a lower maximal VO2 and lower maximal rate pressure product than did normotensive subjects.

Blood Pressure↗

Molecular cloning of RI-HB, a heparin binding protein regulated by retinoic acid.

RI-HB is an extracellular heparin binding protein regulated by retinoic acid and essentially expressed during embryogenesis. This study reports the cloning and sequencing of the cDNA that encodes RI-HB. The sequence of RI-HB contains 121 amino acid residues and is very rich in basic amino acids and cysteines. This sequence was compared to those of HBGAM and MK protein, two other heparin binding proteins exhibiting growth and/or neurotrophic activities. Northern blot analysis indicates that RI-HB mRNA is strongly expressed during early chicken embryogenesis and that it is induced by retinoic acid treatment of chicken fibroblasts and myotubes in culture.

Animals↗

A new heparin binding protein regulated by retinoic acid from chick embryo.

A 19 KDa heparin binding protein was previously purified from chicken embryos. Essentially localized within basement membranes in early embryonic tissues, this protein is very rich in basic and cystein residues. Its N-terminal fragment is similar to corresponding fragment of two other proteins expressed during embryogenesis and postnatal period. Its synthesis and secretion are induced by retinoic acid in chicken myoblasts and fibroblasts. This new retinoic acid induced heparin binding protein (RI-HB) does stimulate neurite outgrowth and proliferation on PC12 cells. These results suggest that retinoic acid could regulate some aspect of differentiation and development by inducing the synthesis of a new family of growth and neurotrophic factors.

Adrenal Gland Neoplasms↗

Influence of nebivolol on the cardiovascular hemodynamics during postural changes and isometric exercise.

Nebivolol (R67555), a drug with beta 1 receptor antagonizing properties, was administered once daily (5 mg) for 7 days in 10 healthy volunteers. The hemodynamic parameters were measured noninvasively during postural changes (supine, sitting, standing) and during isometric handgrip at 50% maximal voluntary contraction, before and 3, 8, and 23 hours after the first nebivolol intake of 5 mg; the same measurements were done 23 hours after the last intake. Nebivolol lowered arterial blood pressure acutely and chronically due to a decrease in heart rate and cardiac output. The stroke volume seemed to be preserved, while the total peripheral vascular resistance did not change. Nebivolol did not change the orthostatic responses, except that the absolute value was lowered. Nebivolol was unable to prevent the blood pressure increase during isometric handgrip. However, this blood pressure increase was obtained by an increase in the total peripheral vascular resistance and not by an increase in the cardiac output, as observed during control measurements before nebivolol intake.

Adrenergic beta-Antagonists↗

Diagnostic approach to patients with primary hyperaldosteronism.

We report the case of a 38-year-old patient with primary hyperaldosteronism. The diagnosis was made by the demonstration of a non-suppressible high aldosterone level in association with a hypokalemia, an inappropriate kaliuresis and low plasma renin activity. As the choice of the therapeutic approach is dictated by the subtype, further investigation was needed. Using a number of hormonal studies and noninvasive imaging techniques, we could establish the diagnosis of adrenocortical adenoma. Histological examination confirmed our diagnosis. We further discuss briefly the characteristics of the four subtypes of primary hyperaldosteronism and show that the used biochemical markers and imaging techniques are able to differentiate them.

Adenoma↗

Influence of nonhemodynamic factors on the microcirculation in moderate arterial essential hypertension.

This study is aimed at examining the role of non-hemodynamic factors on the impaired microcirculation in patients with moderate essential hypertension. In a series of 31 patients (mean age, 47.8 +/- 1.1 years) with newly diagnosed untreated moderate essential hypertension (mean systolic blood pressure 161.7 +/- 2.0 mm Hg, mean diastolic blood pressure 102.4 +/- 1.5 mm Hg), parameters of the capillaroscopic examination of the finger microcirculation (mean number of capillaries, NRCAP), length of the capillaries (LECAP, microns), diameter micron) of the efferent (EFDI) and afferent (AFDI) apillaries, and mean red blood cell velocity (RBCV, microns/sec), which was measured by the flying spot technique, were correlated with a number of hormones (sampled after an overnight fast) including: plasma renin activity, aldosterone, and parathyroid hormone (PTH). A significant correlation (P less than .05) could be obtained between several parameters of the microcirculation and PTH:PTH (23.8 +/- 1.4 pg/mL)-NRCAP (14.9 +/- 0.5): r = -0.440, P = .013; PTH-AFDI (4.0 +/- 0.5 microns): r = 0.442, P = .012; PTH-EFDI (2.8 +/- 0.5 microns): r = 0.416, P = .019; PTH-RBCV (711 +/- 69 microns/sec): r = -0.351, P = .05. Furthermore, 24-h urinary norepinephrine (U-NOR) and afferent and efferent diameter of the capillaries intercorrelated significantly: U-NOR (46.0 +/- 6.2 micrograms/24 h)-AFDI: r = 0.439, P = .034; U-NOR-EFDI; r = 0.462, P = .025. This study shows that in patients with moderate essential arterial hypertension nonhemodynamic factors have an influence at the level of the microcirculation.

Aldosterone↗

Effects of isradipine on peripheral hemodynamic reflex responses in mild-to-moderate essential hypertension.

In a randomized double-blind, placebo-controlled, crossover study of isradipine (5 mg twice daily), effects on peripheral hemodynamic reflex responses were studied in nine patients (mean age 48 years) at baseline and after six weeks of active treatment. Assessments included vital signs, resting blood flow in the calf and finger (using an electrocardiograph-triggered venous occlusion plethysmograph), reflex responses during isometric exercise and cold pressor resistance, and venous capacitance in the forearm and calf. Isradipine lowered systolic and diastolic blood pressure as well as mean arterial pressure in patients with mild-to-moderate essential hypertension without reflex tachycardia or venoconstriction. All of the reflex responses studied were attenuated. It is concluded that vasodilatation of the peripheral circulation induced by isradipine contributes partially to the blood pressure-lowering effect.

Adult↗

[A new family of proteins with high activity for heparin and regulated by retinoic acid].

An heparin binding protein (RIHB) was purified from chick embryos. Essentially expressed during early embryogenesis it is mainly localized within basement membranes. Its synthesis and that of the RIHB mRNA are induced by retinoic acid in chicken myoblasts cell culture. This protein belongs to the same family that HBGAM or Pleiotropin and MK protein two other heparin binding proteins exhibiting growth and/or neurotrophic activities.

Animals↗

Comparison of the fibrinolytic response to desmopressin acetate (DDAVP) infusion versus venous occlusion in patients with coronary artery disease.

A 20-min venous occlusion and a desmopressin acetate (DDAVP, 0.4 microgram.Kg-1, 15 min) infusion test have been compared to evaluate fibrinolytic capacity in proven coronary artery disease. Basal values of plasma tissue plasminogen activator (t-PA) activity and antigen and of t-PA inhibitor (PAI) were normally distributed in this patient group. However, after both stimuli, highly significant (P less than 0.005) increases of t-PA antigen and activity have been observed. Renormalization of t-PA levels after DDAVP infusion occurred more rapidly for antigen (120 min) than for activity concentrations (greater than 240 min). A DDAVP infusion test seems more appropriate for evaluation of the fibrinolytic capacity as the induced decrease in PAI level was significant (P less than 0.005) and lasted for at least 240 min, while it was not significant for the venous occlusion test.

Arm↗