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Biomedical subjects

E Billaud

Publications and source records attributed to E Billaud.

At least 55 records · Page 3Linked to original sources
PubMed1989

Large and small forearm arteries of essential hypertensives are less reactive to angiotensin II than to noradrenaline.

In order to investigate the reactivity to angiotensin II (Ang II) in large and small arteries in situ, brachial artery diameter, blood flow velocity, local volumic blood flow and local vascular resistance (mean arterial pressure divided by local blood flow) were determined non-invasively, using a pulsed Doppler system. Increasing doses of Ang II (0.5, 1.0 and 2.0 ng/kg per min) were given intravenously and double-blind to nine normotensive subjects (group I) and 10 hypertensive patients (group III); placebo (glucose) was given to nine hypertensives (group II). Angiotensin II did not change the brachial artery diameter, blood flow velocity, local blood flow or local resistance. Mean arterial pressure was increased slightly but significantly (P less than 0.05) by Ang II at 2 ng/kg per min in groups I and III. In contrast, we had shown previously, following the same procedure, that subthreshold doses (for the increase in mean arterial pressure) of noradrenaline reduced branchial artery diameter, velocity and local blood flow and increased local resistance in hypertensives. These results indicate that in hypertensives the vascular reactivity of the brachial circulation (1) is lower than that of other territories in response to Ang II and (2) is lower in response to Ang II than in response to noradrenaline.

Angiotensin II↗
PubMed1989

Comparison of increase in the enalapril dose and addition of hydrochlorothiazide as second-step treatment of hypertensive patients not controlled by enalapril alone.

Forty-six patients were randomly allocated to two different groups of treatment if their diastolic blood pressure remained above 90 mm Hg after one month of treatment with 20 mg enalapril mg once daily. In the first group (ENA), 23 patients were given higher daily dosages of enalapril (40 mg and, when necessary, 60 mg). The second group of 23 patients (HCTZ) was given 20 mg/day enalapril and hydrochlorothiazide (25 mg/day and, when necessary, 50 mg). Blood pressure was measured by an automatic device and by the physician with a standard sphygmomanometer. Blood pressure was significantly lower in the HCTZ group, according to both the automatic device (130 +/- 9/80 +/- 8 vs. 141 +/- 5/86 +/- 8 mm Hg, p less than 0.01/p less than 0.05) and the sphygmomanometer (134 +/- 10/89 +/- 6 vs. 149 +/- 16/94 +/- 5 mm Hg, p less than 0.001/p less than 0.01). Plasma renin activity, increased by enalapril at the 20 mg dosage, rose in the HCTZ group but not in the ENA group (22.4 +/- 22 vs. 10.2 +/- 11 pmol/ml/h, p less than 0.05). Plasma aldosterone increased significantly in the HCTZ group (0.44 +/- 0.22 vs. 0.30 +/- 0.17 pmol/ml, p less than 0.05) but did not change in the ENA group (0.31 +/- 0.11 vs. 0.30 +/- 0.17 pmol/ml, NS). In the ENA group, converting enzyme activity was not reinforced (5.7 +/- 8 vs. 6.6 +/- 6 mU/ml, NS) despite an increase in plasma enalaprilat levels (172.4 +/- 108 vs. 72.1 +/- 42 ng/ml, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensinogen↗
PubMed1989

[Anomalies in the hemodynamic response to short lasting emotional stress in essential hypertensive subjects].

Systemic hemodynamics, brachial artery diameter (D) and blood flow velocity (v) were determined non-invasively in 26 normotensive subjects (NT) and 34 age- and sex-matched essential hypertensive patients (HT) using pulsed Doppler systems (4 and 8 MHz), at rest and during 2 min periods of mental arithmetic (MA) inducing reproducible changes in blood pressure. During MA in HT, v increased (from 5.3 +/- 1.1 to 8.4 +/- 1.6 cm/sec) to a greater extent (p less than 0.01) than in NT (from 4.9 +/- 0.7 to 6.3 +/- 1.4 cm/sec). Hand exclusion did not change the increase in v in HT and in NT. During MA, D did not change in both groups. Systolic and diastolic arterial pressure increased to a greater extent (p less than 0.01) in HT than in NT, while HR and pulse pressure increased to the same extent in both groups. Since cardiac output and D did not change during MA, instantaneous variations of v likely reflected modulation of arteriolar tone. These results suggest an enhanced vasodilatory response of muscle resistance vessels in HT as compared to NT. The lack of change in D suggest an increase in vascular tone of large arteries likely contributing to the rise in pulse pressure during MA in both groups.

Adult↗
PubMed1988

Unrelated responses of brachial artery hemodynamics and renin-angiotensin system to acute converting enzyme inhibition by enalaprilat in essential hypertension.

The simultaneous acute effects of converting enzyme inhibition by intravenous enalaprilat on the circulating renin-angiotensin system and on the brachial artery were studied in 12 hypertensive patients by a double-blind comparison with saline effects in 14 hypertensive patients. The brachial artery was investigated in terms of arterial section (measured by pulsed Doppler technique) and wall rigidity (assessed by pulse wave velocity). Arterial and biochemical parameters were measured in baseline before injection and at 20 to 40 minutes (t1) and 80 to 100 minutes (t2) after saline and drug injections. Compared with the saline vehicle, enalaprilat significantly decreased angiotensin enzyme converting activity (p less than 0.001), increased plasma renin activity (p less than 0.01) and decreased plasma aldosterone concentrations (p less than 0.01). The drug reduced blood pressure (p less than 0.01) and increased the brachial artery section (p less than 0.01), but did not change pulse wave velocity. In the enalaprilat group, significant postinjection relations were observed between: (1) enalaprilat concentration and plasma angiotensin converting enzyme activity (r = -0.72, p less than 0.001); (2) plasma renin activity and mean blood pressure (r = -0.46, p less than 0.02); (3) plasma enalaprilat concentration and pulse wave velocity (r = -0.50, p less than 0.01) and (4) pulse wave velocity and brachial artery section (r = 0.42, p less than 0.05). Thus, the brachial artery effects of enalaprilat were not directly related to the blockade of the renin-angiotensin system in plasma.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Flow-dependent vasodilation of the brachial artery in essential hypertension: preliminary report.

Brachial artery haemodynamics including brachial artery diameter and local blood flow velocity were studied in 10 normotensive subjects and 10 age-matched hypertensive patients. A bidimensional pulsed Doppler system was used at rest, during a 2-min period of distal circulatory occlusion and during reactive hyperaemia. The kinetics of changes in blood flow velocity and brachial artery diameter were determined during successive and reproducible manoeuvres. The two parameters decreased significantly during distal artery occlusion in both groups. During reactive hyperaemia, blood velocity reached similar maximal values in both groups and brachial artery diameter increased significantly in both normotensives and hypertensives. Changes in the brachial artery diameter during reactive hyperaemia were positively and significantly correlated to changes in blood flow velocity recorded at the same level. No significant difference was found between normotensives and hypertensives. This study has provided a demonstration of velocity-dependent variations in the diameter of a large artery in humans; the results suggest that velocity-dependent vasodilation of the brachial artery is not impaired in essential hypertension.

Blood Flow Velocity↗
PubMed1988

Treatment for one year with perindopril: effect on cardiac mass and arterial compliance in essential hypertension.

Blood pressure, forearm arterial haemodynamics and echocardiographic parameters were studied in patients with sustained essential hypertension before and after administration of the angiotensin converting enzyme (ACE) inhibitor perindopril for 1 year. Perindopril significantly reduced blood pressure and at the same time increased brachial artery blood flow, diameter and compliance. As part of the haemodynamic investigation, a 5-min period of wrist occlusion was performed. Blood flow velocity decreased significantly to the same extent with perindopril and with placebo, but the corresponding reductions in arterial diameter were smaller with perindopril than with placebo, indicating that the increase in diameter following perindopril could not be explained solely on the basis of a flow-dependent dilation. After 3 months, treatment was stopped for 4 weeks. Blood pressure and forearm arterial haemodynamics returned towards baseline values. However, cardiac mass, which was significantly decreased after perindopril administration, remained decreased 4 weeks after cessation of treatment. In seven responder patients, perindopril was continued as sole therapy for 8 months. Arterial compliance remained elevated and cardiac mass diminished. The study showed that the arterial changes caused by perindopril involved a drug-related relaxation of arterial smooth muscle and that there was a differential response in cardiac and arterial changes following long-term treatment.

Adult↗
PubMed1987

Treatment of mild to moderate hypertension with or without the converting enzyme inhibitor enalapril. Results of a six-month double-blind trial.

A group of 205 patients with mild to moderate essential uncomplicated hypertension was chosen from 3,183 hypertensive patients referred to a hypertension clinic for the first time, and was asked to participate in a six-month double-blind parallel trial. A single physician was in charge of all the patients. After a two-week single-blind placebo period, the patients were randomly assigned to regimens of either enalapril (20 mg per day) or placebo. Both groups were then followed up every two weeks, and increasing doses of hydrochlorothiazide (25 and 50 mg), oxprenolol (160 and 320 mg), and dihydralazine (50 and 100 mg) were added until the diastolic blood pressure was lower than 90 mm Hg. After a six-month follow-up, the enalapril group showed lower systolic and diastolic blood pressures than the control group (129/82 +/- 12/6 mg Hg versus 135/86 +/- 10/5 mm Hg; p less than 0.001). The number of daily tablets of active drugs was 2.7 +/- 1.8 in the enalapril group and 4.4 +/- 2.4 in the control group (p less than 0.01). The mean plasma potassium level was 4.16 +/- 0.4 mmol/liter in the enalapril group versus 3.92 +/- 0.4 mmol/liter in the control group (p less than 0.001), despite more frequent use of amiloride (p less than 0.001). This difference is explained by the lower dose of hydrochlorothiazide used in the enalapril group by comparison to the control group, and a lower excretion of urinary aldosterone in the enalapril group than in the control group (11.6 +/- 7.4 versus 19.8 +/- 11.8 micrograms per 24 hours, p less than 0.001). Drug withdrawal was necessary in eight patients in the enalapril group and in 16 patients in the control group (p less than 0.05). These results show that first-step treatment of mild to moderate uncomplicated essential hypertension with enalapril permits better blood pressure control than the standard treatment, requires fewer tablets to be taken daily, and involves a smaller risk of hypokalemia.

Adult↗
PubMed1987

[Definition and consequences of blocking the renin-angiotensin system by converting enzyme inhibition].

46 patients (39 males), mean age 51 years (range 33-66), were randomly allocated to two different groups of treatment if their diastolic blood pressure was superior to 90 mmHg after a one-month treatment by 20 mg of enalapril. In the first group (ENA), 23 patients were given higher dosages of enalapril (40 and, if necessary 60 mg once-a-day). In the second group (HCTZ) 23 patients were given enalapril 20 mg and hydrochlorothiazide 25 and, if necessary, 50 mg once-a-day. Dosages were eventually increased after 2 weeks and evaluation of the results was performed after 4 weeks on treatment. Blood pressure was monitored in the supine position, at 3 minutes interval for thirty minutes, by an automatic device based on oscillometric method. Two successive measurements with a standard sphygmomanometer were performed by the physician at the end of the recording. No patient withdrew from the study nor was lost to follow-up. At the end of the study, 14 patients in the ENA group were receiving enalapril 60 mg once-a-day and 8 patients in the HCTZ group were receiving 50 mg of hydrochlorothiazide. Blood pressure was significantly lower in teh HCTZ group with the automatic device (130 +/- 9/80 +/- 8 vs 141 +/- 5/86 +/- 8 mmHg, p less than 0.01/p less than 0.05) and with the sphygmomanometer (134 +/- 10/89 +/- 6 vs 149 +/- 16/94 +/- 5 mmHg, p less than 0.001/p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Relationship between biological activity and concentration of a low-molecular-weight heparin (PK 10169) and unfractionated heparin after intravenous and subcutaneous administration.

The pharmacokinetics of unfractionated heparin and the low-molecular-weight (LMW) heparin PK 10169 after intravenous and subcutaneous injection were compared by crossover study in 8 healthy volunteers. The heparin concentrations in plasma were measured by a competitive binding assay, and anti-IIa and anti-Xa activities were also assayed. Unfractionated heparin was cleared after intravenous administration with a half-life of 35 min irrespective of assay method. However, the concentration of PK 10169 declined with the longer half-life of 60 min, and its anti-IIa and anti-Xa activities had half-lives of 40 and 275 min, respectively. Some of this anti-Xa activity may be mediated by a compound released by PK 10169 rather than by the LMW heparin itself. The bioavailability of PK 10169 was 3-fold greater than that of unfractionated heparin, due to more effective absorption after subcutaneous administration.

Adult↗
PubMedDate not supplied

[The Nadis cohort: 6236 HIV-infected patients followed up in French university hospitals].

OBJECTIVE: The Nadis electronic medical patient record allows real time constitution of a database including the clinical, therapeutic, biological, and epidemiological features of HIV-positive patients. METHODS: Data concerning HIV-infected patients followed-up in 6 French University Hospitals was collected. Data quality was assessed on a regular basis in each center. RESULTS: The 6 first University hospitals using Nadis agreed to group their data on March 15, 2004, concerning 6236 patients having consulted at least once in the previous year. Among these, 29% were female patients, 80% were under treatment on March 15, 2004, 9% were off treatment, 29% were co-infected by hepatitis B or C virus, 57% had an undetectable viral load, 15% of the treated patients were in a worrying immunovirological situation, 358 were diagnosed HIV-positive in 2003. 35% of these "new patients" were women, the mode of infection was sexual in 80%, 45% were under treatment on March 15, 04. This recent data allowed us to have an accurate assessment of this population's management in 2004.

Adult↗
PubMedDate not supplied

[Respective prevalences and frequencies of Horton's disease and rhizomelic pseudopolyarthritis. Epidemiological study in the Loire-Atlantic department using a general practice research network (RESOMED 44)].

Using a research network of general practitioners (Resomed 44) representing the 20th of all GP's in the Loire Atlantique region and distributed at random according to district, age and sex made it possible to evaluate the respective prevalences of temporal arteritis (TA) and polymyalgia rheumatica (PMR) in all the systemic immune diseases listed. Among these diseases, rheumatoid arthritis was the most frequent (35.39%). TA (18.8%) and PMR (18.54%) had about the same prevalence. For each of these diseases the year/physician prevalence was evaluated at 0.11, which means that the probability for each GP to see 1 TA and 1 RP at once in 10 years. At the time of the survey, 52.9% of TA patients and 78.8% of PMR patients were surviving. GP's alone follow up more TA's and PMR's than the other systemic immune diseases.

Aftercare↗