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Biomedical subjects

G Chatellier

Publications and source records attributed to G Chatellier.

At least 127 records · Page 7Linked to original sources
PubMed1995

Benefits of a computer-assisted education program for hypertensive patients compared with standard education tools.

ISIS (Initiation Sanitaire Informatisée et Scénarisée), a French computer-assisted hypertension and cardiovascular risk education program, was developed to provide patients at cardiovascular risk with a modern interactive educational tool combining rigorously scientific information with the aesthetic attractiveness of multimedia communication. To test the impact of this tool on patient health information retention, 158 hypertensives hospitalized for initial work-up (day hospital) or therapeutic adjustments (3 days) were randomized into control (n = 79) and ISIS (n = 79) groups. Both groups received cardiovascular education through standard means: physicians, nurses, dietitians and pamphlets. In addition, ISIS patients underwent a 30- to 60-min session on the computer with the ISIS program. Cardiovascular knowledge was tested by the same investigator administering a standardized 28-item questionnaire before and 2 months after education. Retesting was made by telephone. At the time of first assessment, all patients were aware that they would be retested. A total of 138 completed questionnaires (69 from each group) was analyzed. Overall mean cardiovascular knowledge score before education improved significantly after education. This improvement was greater in the ISIS than the control group. These results confirm the potential of computer-assisted education in hypertensives from a specialized center.

Adult↗
PubMed1995

Non specific resistance against malaria pre-erythrocytic stages: involvement of acute phase proteins.

Levels of different acute phase proteins were compared in sera from parasitaemic and non-parasitaemic women living in a Plasmodium falciparum endemic area of Thailand. The ability of their sera to interfere with hepatic stage development of the parasite was examined. Correlations were found between levels of alpha-1 antitrypsin, alpha-2 macroglobulin, hemopexin and the potential of sera to block hepatocyte invasion by the sporozoite.

Acute-Phase Proteins↗
PubMed1995

Intraoperative blood loss in pediatric liver transplantation: analysis of preoperative risk factors.

The relative contribution of 14 preoperative risk factors to a high intraoperative blood loss was studied in 95 consecutive first pediatric orthotopic liver transplantations (OLT). Patients were distributed in two groups according to red blood cell (RBC) requirements. Wide interindividual RBC requirements were observed (median, 79 mL/kg; range, 4-586). The upper quartile of the population was defined as the high blood loss group and required 123 mL/kg or more (median, 161). On univariate analysis, the high blood loss group had a significantly higher proportion of patients with portal vein hypoplasia, intraabdominal malformations, signs of severe liver failure (encephalopathy, ascites, prolonged prothrombin time), and requiring inpatient support. Age, previous abdominal surgery, and platelet count had no prognostic value. All variables used in the univariate analysis were included in a stepwise logistic regression analysis. Only presence of portal vein hypoplasia, inpatient support, and use of a reduced-size liver graft were independently associated with a high blood loss. Adjusted odds ratios were 40.4 (95% confidence interval; 5.9-278), 5.4 (1.6-17.9), and 3.8 (0.9-15.2), respectively, highlighting the importance of portal vein hypoplasia as a risk factor for high blood loss.

Abdomen↗
PubMed1995

Short-term effects of octreotide on blood pressure and plasma catecholamines and neuropeptide Y levels in patients with phaeochromocytoma: a placebo-controlled trial.

OBJECTIVE: The observation that phaeochromocytoma possess specific somatostatin binding sites led us to test the hypothesis that octreotide may have antisecretory potential in patients with phaeochromocytoma. We therefore compared the effects of octreotide and placebo on blood pressure and plasma catecholamines and neuropeptide Y. PATIENTS: Ten consecutive patients referred to a tertiary care centre for the diagnosis and treatment of a phaeochromocytoma. DESIGN AND MEASUREMENTS: We performed a crossover comparison of either three 100 micrograms subcutaneous injections of octreotide over one day or 3 injections of octreotide vehicle over another. Blood pressure was measured over 24 hours on each test day using an automatic ambulatory recorder. Blood samples were collected before (at 0800 and 0900 h) and after (at 1000, 1100, 1200, 1300 and 1500 h) placebo or octreotide injection. Plasma catecholamines were assayed by high-performance liquid chromatography and neuropeptide Y was determined using a two-site amplified enzyme immunoassay. All patients then underwent surgery and tumoral somatostatin binding site density was determined by quantitative autoradiography. RESULTS: Compared to placebo, octreotide did not alter mean 24-hour ambulatory blood pressure or plasma neuropeptide Y, or plasma or urinary catecholamine, levels. Although a moderate reduction in plasma noradrenaline was found in the two patients with the highest tumoral somatostatin binding site densities, overall octreotide-induced variations in plasma noradrenaline did not correlate with somatostatin binding site density. Blood glucose increased from 5.4 +/- 0.3 on placebo to 7.8 +/- 0.5 mmol/l on octreotide (P < 0.01). CONCLUSION: In the present controlled conditions, short-term administration of octreotide had no antisecretory effect in patients with phaeochromocytoma.

Adrenal Gland Neoplasms↗
PubMed1995

Strecker stent implantation in iliac arteries: patency and predictive factors for long-term success.

PURPOSE: To evaluate Strecker stent implantation in iliac arteries. MATERIALS AND METHODS: Sixty-four iliac arteries with Strecker stents were prospectively studied. Stents were placed for dissection (n = 31), total occlusion (n = 28), unsatisfactory results (n = 3) or restenosis (n = 1) after percutaneous transluminal angioplasty, and a calcified atherosclerotic lesion that bulged into the lumen (n = 1). RESULTS: Stent placement was successful in 63 arteries (98%). The overall complication rate was 12% (n = 8). During follow-up, three patients died. The stent was compromised in 18 cases because of hyperplasia (n = 10) or occlusion (n = 8). The primary patency rate was 84% at 1 year and 69% at 2 years; the secondary patency rate was 90% at 1 year and 81% at 2 years. Initial dissection (P = .046), a length of 60 mm or less for the stent region (P = .007), and total covering of the abnormal segment with the stent (P = .03) were significant predictive factors for good, long-term results. CONCLUSION: Use of the Strecker endoprosthesis appears useful but not ideal. Determination of predictive factors for long-term success may help identify indications for its use.

Aortic Dissection↗
PubMed1995

Feasibility study of N-of-1 trials with blood pressure self-monitoring in hypertension.

The objective of this study was to assess individual responses to antihypertensive treatment by N-of-1 trials using blood pressure self-monitoring in 79 patients of both sexes referred to a hypertension clinic. Thirty-five patients who remained untreated (study 1) and 44 N-of-1 trial participants (study 2) were consecutively selected if their clinic blood pressure was between 160/95 and 220/115 mm Hg and there were no hypertensive complications. Blood pressure was measured daily at home for 21 days (three consecutive measures, morning and evening). Each N-of-1 trial was a single-blind treatment consisting of two successive 10-day treatment pairs, each pair comprising 5 days of placebo followed by 5 days of 20 mg enalapril once daily in the morning. Study 1 showed no significant blood pressure regression toward the mean over 20 days and justified the choice of 5-day treatment periods in study 2. In study 2, blood pressure fell significantly 12 hours after the first administration of enalapril and rose within 24 hours of the end of the 5-day active treatment period. Using evening blood pressure values (12 hours after enalapril intake) from the first treatment pair, 33 patients were classified as responders (diastolic blood pressure fall > or = mm Hg). In 16 of these 33 patients, the fall in blood pressure above 6 mm Hg was not maintained in the morning, 24 hours after drug intake. Response reproducibility was tested by comparison with the second treatment pair: the observed agreement was only 0.71 (chance-corrected agreement: 0.34) when defined according to both evening and morning values.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Limiting factors in the control of BP: why is there a gap between theory and practice?

The benefits of BP reduction are undisputed, and management guidelines are well established. Nevertheless, epidemiological studies and randomised clinical trials have consistently shown that, although treated, BP frequently remains inadequately controlled. This failure to control BP adequately is not fully recognised by physicians or their patients. Furthermore, even when BP control is not achieved, there is evidence that many physicians do little to modify therapy. This gap between theory and practice in the control of hypertension is a multifactorial phenomenon. Patients may not take medication or adhere to their physician's advice; physicians appear satisfied with sub-optimal therapy; the underlying pathophysiology of hypertension is heterogeneous and thus it can be difficult to predict which patients will respond to a specific treatment; there is poor communication between physicians and their patients; and treatment guidelines may be too complex, theoretical and unclear to be followed in general practice. Despite these difficulties, it is clear that BP control can be improved by combining several antihypertensive drugs. This requires careful consideration with regard both to the mechanisms of action of the agents selected and their tolerability.

Antihypertensive Agents↗
PubMed1995

[How to evaluate the contribution of fixed dose combinations: the standpoint of the methodologist].

For the epidemiologist, the development of any new therapy or strategy must respond to the following three questions: does a need exist? Is there a new way of meeting that need? Can a valid assessment be made of the efficacy of the new therapy? New antihypertensive treatments or strategies are needed, even in 1994: in France, as in other high-income countries, many hypertensive patients remain inadequately controlled. In the 1993 report of the American Joint National Committee, only 55% of treated hypertensives had blood pressure (BP) measurements of less than 160/95 mm Hg. Therapeutic failure is partly due to ineffective treatment and partly to nonspecific factors, eg inappropriate drug choice or inadequate compliance. Concerning the drug, an innovation beyond new pharmacological approaches may equally involve combinations between already available drugs. As for any new treatment, the choice of drugs and their respective doses must be based on phase I and II trials with appropriate outcome criteria (to evaluate the effect of the combination on any counter-regulatory mechanisms that may be involved). The combination is then compared to other available combinations in phase III and IV studies. The real question, however, would appear to be: does first-line combination therapy improve BP control in comparison with conventional strategy?(ABSTRACT TRUNCATED AT 250 WORDS)

Dose-Response Relationship, Drug↗
PubMed1995

[Effect of 2 types of diet changes on dietary habits, body weight and cholesterol levels in high risk cardiovascular patients].

Several non-pharmacological interventions such as weight reduction in obese subjects or diet alteration in subjects having hypercholesterolemia have been shown to be effective in therapeutic trials. Our aim was to test the value of two different ways of teaching patients about their diet. From March 1, 1993, to May 30, 1994, 300 consecutive patients seen in a one-day care hospital were randomised into two groups. The 2 inclusion criteria were: 1) body mass index > 27 kg/m2 in men and > to 25 kg/m2 in women and/or 2) presence of a hypercholesterolemia defined by a total cholesterol > 6.5 mmol/l. Patients in the first group (C) were educated in a 20 to 50 minutes consultation tailored to their needs. Patients in the second group (CC) were given in addition a one-hour course about diet. The goal of the diet was to loss at least 3 kg of body weight and/or to have a cholesterol value below 6.5 mmol/l without treatment. All Patients were followed-up by the same 3 dietician nurses. An out-patient visit was planned at 3 months, and a recall letter was sent to the patients who missed their appointments. Among the 300 patients, 169 (55%) were seen at the 3-month outpatient visit. This proportion did not differ between the 2 groups. Knowledge on diet was assessed by the same 33-item self-administered questionnaire. At baseline scores were comparable between groups (16 vs 17). Scores improved more in the CC than in the C group both at the end of the teaching question (27 vs 23 in the CC and C group respectively, p < 0.001), and at 3 months (25 vs 23 in the CC and C group respectively; p < 0.001). Total cholesterol decreased below 6.5 mmol/l in 28% of the patients with dyslipidemia and a weight loss > 3 kg was observed in 32% of the obese subjects, but improvement did not differ between the 2 groups. We conclude that a specific one-hour course on diet is able to improve knowledge of patients more than a consultation alone, but that better knowledge did not result in improved alteration of risk factors at 3 months.

Adult↗
PubMed1995

Do physicians estimate reliably the cardiovascular risk of hypertensive patients?.

For hypertension management, it is increasingly recommended to individualize treatment according to the individual patient's characteristics. However, the ability of physicians to predict the patient's risk in the absence of a computer aid is unknown. Our aim was to determine if senior hypertension specialists were able to assess reproducibly cardiovascular disease (cvd) risk in hypertensive patients. The records of 100 patients were selected at random from the ARTEMIS database. The group comprised 53% of males, mean age was 43.7 (15), blood pressure 160 (25) / 99 (12) mmhg and serum cholesterol 5.6 (1.1) mmol/l. The records were summarized on a standardized form. Nineteen items were devoted to general characteristics and medical history of patients, 15 to clinical examination and 7 to biological tests. These items have been chosen because they were used in the framingham cvd risk prediction equation and/or had decisional value in a bayesian program designed for secondary hypertension diagnosis. Six physicians, twice at one month intervals, assigned each patient to one of the three categories of risk (low, moderate, high). The order of cases was randomized. Chance corrected agreement (intra-physician agreement) between the two estimations was only moderate except for one expert (kappa values: 0.658, 0,543, 0.439, 0.363, 0.328 and 0.207 for each expert, respectively). The proportion of patients assigned by each physician to each category ranged from 22.7% to 77.3% for the low risk, and from 4.5% to 43.9% for the high risk category. One physician overestimated risk, one underestimated it and the three others were in keeping with framingham predictions. Bias and lack of reproducibility influence physician judgment in assessing cvd risk of hypertensive patients. Application of computer aids could result in more rational assessments and better decision making.

Adolescent↗
PubMed1995

Comparison of biological activities of two low molecular weight heparins in 10 healthy volunteers.

1. Low molecular weight heparins (LMWHs) are produced by different depolymerization processes and may therefore differ with respect to their pharmacokinetic properties. 2. We designed a single dose, randomized cross-over study in 10 healthy volunteers to compare the 24 h pharmacokinetics of two LMWHs, reviparin and enoxaparin, which have been previously shown to be clinically equivalent in terms of post-operative deep vein thrombosis prevention, despite significant differences in their in vivo biological activity. The two LMWHs were subcutaneously administered at the same dosages that are used in clinical studies: 4250 anti-Xa iu for reviparin and 40 mg for enoxaparin which have similar in vitro anti-Xa activities. 3. The overall 24 h profiles of the plasma anti-Xa and anti-thrombin activities were similar for reviparin and enoxaparin. The Amax and the AUC(0, 24h) of plasma anti-Xa activity after reviparin administration were both slightly but significantly lower than those observed after enoxaparin administration (difference between treatments of 0.03 95% CI[0.01-0.05] iu ml-1 h and 0.56 95% CI[0.22-0.90] iu ml-1 for Amax and AUC(0, 24h) respectively). After adjustment for in vitro anti-Xa activity, the statistical difference between the two LMWHs persisted for the AUC(0, 24h) but not for the Amax of plasma anti-Xa activity. The tmax and the MRT values for plasma anti-Xa activity did not significantly differ between the two drugs. The t1/2 for reviparin did not significantly differ from that of enoxaparin (2.7 +/- 0.7 h vs 3.5 +/- 0.9 h respectively, NS). The Amax of the plasma anti-thrombin activity after reviparin administration was also slightly but significantly lower than that observed after enoxaparin administration, (difference between treatments of 0.018 95% CI[0.01-0.025] iu ml-1) whereas the AUC(0, 24h) of anti-thrombin activity vs time was not. A slight but significant increase of the activated partial thromboplastin time of a similar magnitude was observed after both reviparin and enoxaparin injections. 4. The calculated surface under the thrombin generation curve vs time (or thrombin potential) at peak was significantly higher after reviparin than after enoxaparin (367 +/- 53 UA vs 305 +/- 48 UA respectively, P < 0.05). Four hours after injection, thrombin potential was significantly correlated to plasma anti-Xa activity after reviparin but not after enoxaparin injection (r = 0.65, n = 10, P = 0.05 and r = -0.38, n = 10, P = 0.25 respectively). 5. After a single-dose injection in healthy subjects, two LMWHs with comparable in vitro activities differed slightly kinetically. Such minor differences are probably of little importance in the prevention of post-operative deep vein thrombosis, since these two LMWHs were previously shown to be comparable in this setting.

Adult↗
PubMed1995

Decision support systems from the standpoint of knowledge representation.

Relationships between decision-support systems and knowledge representation are examined from three different points of view: the characteristics of medical decisions that might influence the selection of appropriate knowledge representations,--the extent to which different knowledge representations can support efficient medical decisions and,--the validation of knowledge hypotheses through the practice of decision support systems. A three-level model of knowledge representation is proposed that includes a contextual, a conceptual and a computational level. Taking into consideration the context that leads to the selection of a given representation raises the issue of multiexpertise and multirepresentation modeling. Implementation of decision support systems as sets of cooperative agents and integration in the health information systems are considered.

Artificial Intelligence↗
PubMed1994

[Therapeutic approach in arterial hypertension with renal artery stenosis].

Screening for renal artery stenoses in hypertensive patients aims at detecting lesions whose treatment (renal revascularization) will normalize or reduce blood pressure and correct or prevent reduced glomerular filtration. Consequently, screening tests such as renal artery duplex Doppler scanning, renal scintigraphy or digital-subtraction angiography are used in patients in whom hypertension is severe, drug-resistant or associated with renal failure. Surgical repair or transluminal angioplasty is not warranted for all stenoses, however, particularly in atheromatous stenoses where these procedures have a 1% mortality, a 10% morbidity and a 30% failure rate to improve blood pressure despite adequate anatomical outcome. Predictors of favourable blood pressure outcome following revascularization are aetiological (fibrous dysplasia rather than atheroma), historical (young age, short duration of hypertension), physiological (renal ischaemia confirmed by scintigraphy, lateralizing renal vein renin ratio) and anatomical (truncal rather than ostial or branch stenoses). Outcome of surgery and transluminal angioplasty has only been documented in retrospective, uncontrolled reports in which blood pressure improvement is overestimated via the placebo effect, habituation to blood pressure readings and optimization of drug treatment, the latter being frequently required despite adequate revascularization. The first prospective randomized trials evaluating angioplasty in atheromatous stenoses are underway and should provide objective information concerning the risk/benefit ratio of this procedure.

Dilatation↗
PubMed1994

Determination of left ventricular mass with electron beam computed tomography in deformed, hypertrophic human hearts.

This study firstly determined the accuracy of left ventricular mass (LVM) determination by electron beam CT in normal and distorted human cadaver hearts, and secondly the in vivo reproducibility of these measurements, in normal subjects and patients with various cardiac diseases, over a wide range of LVM (104-631 g). In cadaver hearts, there was a close correlation between electron beam CT and autopsy LVM values: r = 0.97, SEE = 16 g. Intra-observer variability: results of LVM measurements obtained in cadaver hearts by observer 1 and in in vivo studies by observer 2 were y = 1.001 x -1.34, r = 0.99, SEB = 6 g and y = 0.99 x +3.78, r = 0.99, SEE = 19 g, respectively. Inter-observer variability: results in cadaver and in vivo studies were y = 1.05 x -5.94, r = 0.98, SEE = 14 g and y = 1.13 x -23, r = 0.99, SEE = 28 g, respectively. Thus, these results over a wide LVM range provide extensive validation of electron beam CT measurements in hearts with marked left ventricular distortion. This method should play a valuable role, within the scope of clinical research, in assessing left ventricular remodelling in various conditions in which echocardiographic data are inaccurate.

Adult↗
PubMed1994

Prevalence of associated diseases in different types of dementia among elderly institutionalized patients: analysis of 3447 records.

OBJECTIVE: To determine the prevalence of dementia in a population of hospitalized or institutionalized elderly patients, and that of associated diseases according to dementia type. DESIGN: Retrospective analysis of a database of diagnostic codes. SUBJECTS: All patients admitted to 1 of the 4 geriatric units participating in the study at the Charles Foix Hospital between 1980 and 1989. MEASUREMENTS: All diagnoses mentioned in the discharge summary that could cause or contribute to hospitalization were recorded for each patient. A final list of 54 different diagnoses could be recorded for each patient. Dementia was subdivided into 3 subtypes: Alzheimer dementia (DAT), vascular dementia (VD), and other types of dementia (unclassifiable dementia). MAIN RESULTS: The study involved 3447 patients aged 81.0 +/- 8.3 years, of whom 27.7% were men. Dementia was the most frequent disease in this population (34.3%); Alzheimer disease was responsible for 15%, vascular dementia for 9.5%, and other types for 9.8%. The average number of associated diseases was 3.23 +/- 2.10 in the Alzheimer dementia group, 4.73 +/- 2.38 in the vascular dementia group, and 3.96 +/- 2.26 in the nondemented group. Parkinson disease was present in 15.5% of patients with unclassifiable dementia, compared with 7.6% in the nondemented group (P < 0.001). There were significantly more diseases commonly seen in bedridden patients in the group of patients with both other types of dementia and Parkinson disease than in the group of other types of dementia patients without Parkinson disease (P < 0.01). CONCLUSION: Dementia was the most common disease observed in our elderly institutionalized population. Alzheimer patients had significantly fewer associated diseases than nondemented patients, whereas the reverse was found in the vascular dementia group. The co-existence of Parkinson disease and dementia in our population was associated with the poorest health status, as these patients were more likely to present simultaneously such conditions as pressure sores, incontinence, dehydration, or iatrogenesis.

Aged↗
PubMed1994

Self-measurement of blood pressure at home to evaluate drug effects by the trough: peak ratio.

AIM: Studies were carried out to assess (1) the statistical and clinical meaning of the trough:peak ratio and (2) the value of self-measurement of blood pressure at home in monitoring the duration of action of antihypertensive drugs in individual patients and in groups of patients. PATIENTS AND METHODS: Data from previous single-blind trials in 44 individual patients were reanalysed. The trough:peak ratio was calculated from mean blood pressure values. RESULTS: There are two major limitations in using this method. (1) Estimates of the trough:peak ratio are biased by the inclusion of non-responders. These patients have the usual random variations in blood pressure, and small differences can result in a spuriously high trough:peak ratio which may lead to an overestimate of the actual ratio. (2) The standard deviation of the trough:peak ratio is large; for a given mean trough:peak ratio some patients have the required 24-h drug cover, whereas others do not. The large standard deviation is partly a result of statistical problems, since four different blood pressure values are used to calculate the ratio. It is therefore essential to increase the precision of the measurement to decrease the standard deviation. CONCLUSIONS: Self-measurement of blood pressure at home might be a useful and inexpensive way of estimating the trough:peak ratio. As repeated measurements of blood pressure can be carried out at home under standardized conditions, this method increases the precision of each measurement. It is possible, therefore, to calculate individual trough:peak ratios and the drug regimen (once or twice a day) can be individualized.

Antihypertensive Agents↗
PubMed1994

HYPERGENE: a clinical and genetic database for genetic analysis of human hypertension.

OBJECTIVE: Genetic studies of essential human hypertension require the recording and management of numerous data concerning multiple hypertensive families. The present paper describes a new family database, HYPERGENE, and demonstrates its potential usefulness in such a complex disease. METHODS: The database was implemented on an Apple Macintosh computer using the 4TH DIMENSION software program. Through a user-friendly interface, it offers a high-quality data record, easy data retrieval and compatibility with other software. PATIENTS: HYPERGENE contains a prospective collection of 187 families with at least two hypertensive sibs (826 subjects). Each subject was analysed according to the same protocol. To allow definition of clinical and biological phenotypes and genetic analysis, clinical and biological data were recorded and, at the same time, plasma, urine and DNA libraries were stored. RESULTS: Probands were 50.6 years old with an early onset (39.1 years of age) of hypertension (157.7/97.8 mmHg); 125 had moderate-to-severe hypertension. According to our selection criteria, only one out of 187 sibships had familial dislipidaemic hypertension. Of the living fathers, 45% were examined, and 54% of the living mothers: 48.6% had an onset of hypertension before age 50 years. Children (mean age 28.7 years) of hypertensive sibs presented a high percentage of hypertension (8.3%). CONCLUSION: The HYPERGENE database facilitates data storage and analysis on familial hypertension, and should prove a useful tool for assessing molecular biology results in the field of hypertension and for allowing collaborative research.

Adolescent↗