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Biomedical subjects

S Briançon

Publications and source records attributed to S Briançon.

At least 91 records · Page 5Linked to original sources

[Prognostic value of a new perfusion index calculated from coronarography].

A new perfusion index was determined from the study of the coronary vascular bed in 8 myocardial territories: upper septal, lower septal, upper anterior, lower anterior, apical, lateral, posterior and inferior. Stenosis of a vessel reduces perfusion in all territories fed by that vessel, downstream of the stenosis. The perfusion index is calculated by adding up the lesions in all 8 territories. In a population of 418 consecutive patients who had undergone coronary arteriography in 1972 and 1973, survival was evaluated according to the perfusion index and to those parameters which classically have the greatest influence on survival. The perfusion index came out as the most important prognostic factor since such parameters as the number of stenotic vessels and ventricular kinetics lose their prognostic value when adjusted to that index. According to the perfusion index, the 8-year prognosis is the same as in subjects without coronary disease when the reduction in overall perfusion does not exceed 40%. With a 40 to 79% reduction the death risk at 8 years is 30% whatever the exact percentage in each individual. When perfusion is reduced by 80% the death risk at 8 years rises to 72%. This perfusion index, easy to determine, provides a better evaluation of prognosis than the conventional parameters.

Adult↗

[Evaluation of an immunological test for detecting occult fecal blood for case-finding in colorectal tumors].

Screening for colorectal tumours (cancers and polyps) by searching for blood in stools using the gaiac test is a well-known method. We evaluated a new gaiac test, the originality of which from its coupling with an enzyme immuno-assay specifically measuring human hemoglobin (Fecatest). The objectives of this new test were to decrease false positives and thus to improve the positive predictive value of screening. Subjects over 45 years of age attending health examinations at a Center of Preventive Medicine were studied. Of the 5,185 subjects who received the test, 4,376 (84 p. 100) performed it correctly, demonstrating good compliance in this population. For 664 (15 p. 100), the results of the gaiac test were positive. This positivity rate was higher for men than for women (20 p. 100 vs. 10 p. 100) but was not influenced by age. After positive results, 471 (70 p. 100) patients completed investigations decreasing the overall compliance to 80 p. 100. Fifteen cases of cancer and 78 cases of adenomas were found. The positive predictive value of the test was 20 p. 100 for tumours. A benign cause was found in 44 p. 100 of 471 patients, and investigations were negative in 36 p. 100. When the gaiac test was positive, the immunoenzymatic method significantly improved the positive predictive value for cancer (6 p. 100 vs. 3 p. 100) but not for polyps (20 p. 100 vs. 17 p. 100). Three of the 15 cancers and half of the 78 adenomas would not have been discovered with the immunoenzymatic method.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

[10-year outcome of patients with isolated anterior interventricular stenosis technically accessible to coronary angioplasty].

Between April 1972 and March 1976, 70 patients were found to have an isolated stenosis of the left anterior descending artery at coronary angiography which could have been treated by coronary angioplasty, had the technique been available at that time. A questionnaire was sent to these patients and 65 (93 p. 100) replies were received 9 to 13 years after initial coronary angiography. They provided information about 61 men and 4 women with an average age of 48.1 +/- 8.4 years. Thirty eight patients had undergone surgery and 27 were treated medically, each group having distinct clinical characteristics. The 10 year survival rate was excellent (91 p. 100) and was high in both groups. The quality of life was good: 56 p. 100 claimed to be in good or very good health and 67 p. 100 were improved with respect to their functional state at the time of coronary angiography; only one quarter of these patients had been readmitted to hospital for cardiac problems during the follow up period, and 76 p. 100 of patients in work before the coronary angiography had returned to work. This date illustrates the excellent results of classical medical and surgical management of potential candidates for coronary angioplasty for isolated left anterior descending artery stenosis.

Adult↗

[Surgery of microcellular bronchial cancer: retrospective multicenter study apropos of 110 cases].

The results of a multicentric retrospective study of 110 cases of small cell bronchial cancer are reported. In 57 of these patients the histological diagnosis was unknown before surgery. Among the remaining 53 patients, 22 were operated upon immediately and 31 after chemo-and/or radiotherapy (12 full responders, 10 partial responders, 5 no change and 4 in relapse). Operative data were as follows: 100 excisions and 10 exploratory thoracotomies; 19 perioperative complications, including 12 deaths; excision considered complete in 78 cases; pericardial involvement in 14 cases; invasion of the hilar lymph nodes in 57 cases, of the mediastinal lymph nodes in 39 cases; positive bronchial section in 16 cases. Overall median survival was 13.8 months for all patients and 18.3 months (perioperative deaths excluded) for patients whose tumour had been excised. At the moment, 46 patients have relapsed with recurrence at the initial site of malignancy alone in 6 cases (13%) and both at this site and at one or several metastatic sites in 10 cases (21.7%). Nineteen patients have survived for more than 2 years. An analysis of the subgroups in this population showed that the longest survivals were obtained in patients who had undergone preoperative chemotherapy.

Adult↗

[Epidemiology of minor electrocardiographic anomalies predictive of the occurrence of ischemic cardiopathy].

Common electrocardiographic manifestations (CEM) are predictors of ischemic heart disease (IHD). If precursors of the disease, their risk factors should be similar to those of IHD. This hypothesis has been assessed on results of multiphasic screening recorded in 1976 and 1981, in 1,347 45-65 year old men. Risk factors are social class (blue collar relative risk rr = 2.3), physical activity at work (sedentariness rr = 2.4), systolic blood pressure, no beer consumption and blood urea nitrogen with an exponential risk curve. Cholesterolemia, smoking, diabetes mellitus, overweight and uricemia are not predictors of CEM incidence within 5 years. These results support the idea that CEM are partially asymptomatic expression of IHD; they also have another significance. Subgroups should be individualized and analysis yielded on larger samples. Correlation analysis has been performed between IHD mortality and beer consumption on basis of French counties. A positive correlation (r = 62, p less than 0.01) is opposed to individual results.

Coronary Disease↗

[Isolation, social support, life events and health status].

Research on the influence of social networks and social support on health status, conducted in English-speaking countries over the past decade, is not yet widespread in France. A review of the literature reveals that this social support has undeniable effects on mental health, and less obvious effects on physical health; it also stresses the major conceptual and methodological problems encountered in socio-epidemiological approaches. It would appear necessary to construct an overall model integrating life events, coping abilities and individual psychological factors; Social support is considered as a function of social networks, fulfilling roles of emotional support, material help, information provider, egostrengthener and social normalizer. Its mechanisms for dealing with stress, especially the buffer-role hypothesis, are also discussed.

Health↗

[Arterial spasm of the lower limbs caused by pheochromocytoma].

The authors report the case of a 66-year-old man hospitalised with a clinical picture of stage III arterial disease of the lower limbs. Aortography revealed complete spasm of both popliteal arteries and a right adrenal tumour. Excision of the phaeochromocytoma led to the disappearance of symptoms of obliterative arterial disease and normalisation of Doppler results. The role of catecholamines in spasm is discussed.

Adrenal Gland Neoplasms↗

[Abnormal vascularisation of the right inferior pulmonary lobe by an aberrant coronary artery. Apropos of 2 uncommon cases].

Pulmonary vascularisation by the coronary vessels does not seem to have been previously described. The authors report 2 cases of vascularisation of the righ lower lobe by an atrial branch of the right coronary or circumflex arteries. Several pathogenic hypotheses are discussed. No definite conclusions can be drawn despite postmortem examination in one case. Pulmonary sequestration would seem to be very probably although there are a few contradictory findings. Acquired inflammatory conditions alone or associated with the congenital malformation cannot be excluded. These anomalies pose difficult therapeutic problems for cardiologists as they are discovered during coronary angiography for angina. The question of a "pulmonary steal" syndrome aggravating the coronary insufficiency possibly requiring both a pulmonary and a cardiac operation may be raised. From the pulmonary point of view, other methods of investigating patients with pulmonary sequestration and haemoptysis of unknown origin could be indicated.

Coronary Vessel Anomalies↗

Assessment of deep vein thrombosis prophylaxis in surgical patients: a study conducted at Nancy University Hospital, France.

OBJECTIVE: This retrospective evaluation aimed to assess the adequacy of prophylaxis against thromboembolism prescribed to surgical patients at the authors' institution, and to compare it with generally accepted published guidelines. Aspects considered were indications for prophylaxis, regimens used and monitoring. METHODS: Eleven units (nine surgical and two surgical intensive care) took part in the survey on a voluntary basis. The clinical audit system used involved developing a set of criteria based on existing guidelines, comparing observed practice with those recommendations, analysing the factors underlying any deviation and developing corrective measures. RESULTS: When the medical records of 117 patients hospitalized in October 1995 were examined, prophylaxis against deep vein thrombosis was documented in 86 (low molecular weight heparin in 85, dextran in one). No associated physical preventative measures were recorded. Indications and dosage were appropriately handled in 90.7% and 75.2% of patients, respectively. Ninety-five cases were outside the reference criteria: 74 for excluded surgical indications, 13 which involved laparoscopy, and eight in which spinal or epidural anaesthesia was administered. Platelet count was performed in 73.8% of cases before prophylactic treatment, and in 23.10% during its course. Anti-Xa activity was measured in 0.4% of cases. Analysis of causes showed that guidelines were not complied with either because of lack of organization, or because of disagreement with them. DISCUSSION: In this study, indications for prophylaxis were well established and heparin dosages used were not fundamentally flawed. The weak point in practice was a failure to carry out platelet counts, particularly during the course of treatment. Appropriate corrective action consists of disseminating guidelines and relevant information, and using a preoperative checklist to assess thromboembolic risk. CONCLUSION: Physicians agree that opportunities to improve preventative practices exist, and that the quality improvement programme should be pursued.

Adult↗

"The SU.VI.MAX Study": a primary prevention trial using nutritional doses of antioxidant vitamins and minerals in cardiovascular diseases and cancers. SUpplementation on VItamines et Minéraux AntioXydants.

The "SUpplementation en VItamines et Minéraux AntioXydants" (SU.VI.MAX) Study is a randomized double-blind, placebo-controlled, primary-prevention trial which started in 1994 in France. This epidemiologic study is designed to test the efficacy of a daily supplementation with antioxidant vitamins (vitamin C, 120 mg, vitamin E, 30 mg, and beta-carotene, 6 mg) and minerals (selenium, 100 microg, and zinc, 20 mg) at nutritional doses, in reducing the main causes of premature death (cancers and cardiovascular diseases); 12,735 eligible subjects (women aged 35 to 60 years, and men aged 45 to 60 years) were included in 1994 and and will be followed up for 8 years. Participants undergo a yearly visit consisting, every other year, of either biological sampling or clinical examination. They also regularly provide information on health events and dietary intake by filling out computerized questionnaires using the Minitel Telematic Network. After 2 years of supplementation, biochemical indicators of vitamin and trace element status reach reasonable level without reaching concentrations as high as those observed in intervention studies, which tested relatively high doses of antioxidants, and ended up with higher risk of pathology.

Adult↗

Microencapsulation of dehydroepiandrosterone (DHEA) with poly(ortho ester) polymers by interfacial polycondensation.

An original encapsulation process of DHEA was developed, based on the formation of poly(ortho ester) membrane from interfacial polycondensation in an oil-in-oil emulsion. First, the formation of poly(ortho ester) (POE) in solution under anhydrous conditions between a polyol, a lactide diol and a diketene acetal (3,9-diethylidene-2,4,8,10-tetraoxaspiro-[5.5]-undecane) was studied in order to determine the structural and thermal characteristics of the POE polymer. The optimization of the formation of a fine and stable emulsion with the required size distribution was performed in relation with the type of the internal and external phases, the type and the concentration of the surfactant and the stirring rate and duration. The diffusion of monomers and DHEA was evaluated by GC-MS analysis in order to determine the mechanisms of the membrane formation. Finally the synthesis of poly(ortho ester) DHEA-loaded microcapsules was performed under anhydrous conditions required by the particular synthesis of POE. Stable poly(ortho ester) microcapsules containing DHEA were obtained with particle sizes; 1 micro m.

Biocompatible Materials↗

Stability studies on colloidal suspensions of polyurethane nanocapsules.

Generally nanocapsules suspensions are a colloidal system in a metastable state, there is aggregation due to attraction and repulsion forces between particles. The objective of this work was to bring the role of the polymeric membrane in the protection of the active drug against damaging caused by external agents and to select the monomer which leads to obtain stable formulation with the highest possible payload of the active drug. The stability testing involving visual aspect, particle size measurement, transmission electron microscopy (TEM) examination, and drug loss was conduced after 6 months of storage at different temperatures (4, 25, and 45 degrees C). The colloidal suspensions of nanocapsules were obtained using the combined interfacial polycondensation and spontaneous emulsification, the technique was used to encapsulate alpha-tocopherol using polyurethanes polymers. It is a one step procedure: An organic phase composed of a water miscible solvent (acetone), lipophilic monomer (Isophorone diisocyanate IPDI), oil, and a lipophilic surfactant, is injected in an aqueous phase containing hydrophilic monomer (diol with various molecular weight: 1,2-ethanediol (ED), 1,4-butanediol (BD), and 1,6-hexanediol (HD)) and hydrophilic emulsifying agent. The water miscible solvent diffuses to the aqueous phase, the oil precipitates as nano-droplets, and the two monomers react at the interface, forming a membrane around the nanoemulsion leading to nanocapsules. A good physical stability of suspensions corresponds to absence of symptoms such as sedimentation or agglomeration, significant size change and alpha-tocopherol degradation due to external agents such as oxygen, temperature, and ultraviolet (UV) irradiation. The size of nanocapsules before storage was about 232 +/- 3, 258 +/- 29, and 312 +/- 4 nm for ED, BD, and HD, respectively. After 6 months of storage, polyurethanes nanocapsules possess good stability against aggregation at 4 and 25 degrees C. Comparing results obtained using different monomers, it reveals that the polyurethane based on HD offers good protection of alpha-tocopherol against damaging caused by the temperature and UV irradiation.

Antioxidants↗

Nanoparticles for drug delivery: review of the formulation and process difficulties illustrated by the emulsion-diffusion process.

The elaboration of nanoparticles aqueous suspensions aimed at the drug delivery and related process development appear as difficult tasks, due to specificities related to the nanometric size. Such small sizes are required for specific applications in pharmacy. The switch of micrometric to nanometric field represents an actual challenge and cannot be considered as a simple scaling-down of chemical engineers. Ideas and concepts developed first in nanosciences have been adapted to the pharmaceutical application in drug delivery. In spite of drastic constraints due to pharmaceutical application, some parameters allow the control. A brief and not exhaustive review of the state-of-the-art on polymer particles used in the drug delivery field is presented. Attention was more particularly paid on preparation processes and their constraints by describing advantages and drawbacks of each process. The adaptation to the pharmaceutical field, the difficulties and pitfalls which are shared, with most research works in nanoscience, are illustrated thanks to our own results on nanocapsules obtained by "emulsion-diffusion" process presented as a case-study. Thanks to these results, we illustrate the peculiar features and difficulties encountered regarding nanocapsules preparation and characterization. Indeed, such a process allows to prepare nanocapsules of few hundreds nanometers diameter having an oil core surrounded by a polymeric membrane. The characterization of such soft particles colloidal suspensions is often difficult and involves heavy investigation techniques in order to highlight physical mechanisms leading to the nanocapsule properties. This is a key step regarding the final properties as a drug delivery system.

Capsules↗

Validity and discriminant ability of the HAQ Functional Index in early rheumatoid arthritis.

A sensitive and valid instrument is needed in the earliest stages of rheumatoid arthritis (RA) for the measurement of functional disability. A French version of the Health Assessment Questionnaire Functional Disability Index (HAQ) has been developed, validated in an early RA sample (i.e. with disease duration less than 5 yr; n = 50), and compared with longstanding RA (n = 32) and control subjects (n = 59). Five factors provided by principal components analysis accounted for 75% of the variability of the HAQ score (construct validity). It appeared to be significantly correlated with clinical and radiological variables and to be reproducible (r intraclass = 0.964). It proved to be discriminant in groups with various levels of disability (HAQ score = 1.332 in early RA, 1.745 in longstanding RA, and 0.152 in controls; p less than 10(-5). Finally, the validity of the original scoring method of the HAQ, as compared with other scoring methods, was confirmed.

Activities of Daily Living↗

[Clinical research, evaluation of care and quality assurance].

This paper aims to clarify the concepts and terminology of clinical research, evaluation, and quality. Clinical research or clinical epidemiology aims to demonstrate the efficacy of medical care. The optimal methodology is a randomized, double-blind trial that allows a causal inference in respect of efficacy. This should be the first stage before generalization of all medical practice. Evaluation of quality of care aims to verify the effectiveness of medical care by comparing practice with references. The optimal methodology is clinical audit that allows fine-tuned diagnosis of the existence of deviant practices. The analysis of causes and correction of the care process are an integral part of the evaluation work. Thus quality assurance and quality management concepts and methods have been developed which tend to ensure solutions for better care and to maintain the level of quality of care to achieve patient satisfaction. Evaluation, clinical research and management quality could in fact be seen as the complementary facets of a comprehensive approach to quality of care.

Clinical Protocols↗