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J Richard

Publications and source records attributed to J Richard.

At least 253 records · Page 14Linked to original sources

Inter- and intra-subject variability of metoprolol kinetics after intravenous administration.

The pharmacokinetics of metoprolol were assessed from the data of 3 experiments in which intravenous deuterated metoprolol was given concomitantly with various oral metoprolol formulations to healthy volunteers. The plasma levels after intravenous administration were well described by a biexponential equation. However, a deviation from a pure biphasic decline was observed over a short period of time, immediately after the rapid elimination phase. The inter- and intra-subject variability of the parameters describing the two-compartment model was large. The intra-subject variability of the terminal half-life and the plasma clearance was lower than their inter-subject variability. The plasma clearance was linearly related to 1/t1/2. Contrarily to the other parameters of the model, t1/2 appeared to be a characteristic of the subject.

Adult↗

Stable isotope methodology for studying the performance of metoprolol Oros tablets in comparison to conventional and slow release formulations.

Metoprolol Oros tablets were designed to deliver their drug content as a constant rate over a period of time longer than that currently recorded with slow-release dosage forms. The bioavailability of 7/95, 14/190 and 21/285 Oros tablets was compared to that of either 100 mg conventional or 200 mg slow-release Lopresor tablets in 3 two-period change over experiments. In each experiment, 6 healthy volunteers received intravenous deuterated metoprolol concomitantly with one of the Oros systems or with one of the other two formulations. The Oros tablets gave rise to lower and steady plasma levels of metoprolol over 24 h than the other formulations. Their mean absorption time was around 3 times longer than that of the slow-release tablets. The amount of the drug absorbed unchanged was linearly related to the dose. The influence of the gastrointestinal transit time on the performance of Oros tablet was limited. These studies demonstrated the value of the stable isotope methodology in bioavailability assessment for drugs presenting a high inter-subject variability in their plasma clearance such as metoprolol.

Absorption↗

[Neuropsychology and senile dementia].

The study of senile plaque dementias and neurofibrillary degenerations, represented by Alzheimer's disease, presbyophrenia, simple senile dementia, and senile dementia of the Alzheimer type, enables, by means of its specificity, a privileged method of approach to be taken in the comprehension of cerebral mechanisms, with a resulting different conception of neuropsychology. That which is described in this paper has evolved from the application of Genetic Psychology methods developed by J. Piaget. It demonstrates the value of a synchronic qualitative analysis of dementia, even for determination of etiology. It tries to avoid as much somatomorphism as adultomorphism, infantomorphism, and normomorphism. It is concerned with the modalities of individual disorganization and associated changes in various higher functions of the central nervous system. It also attempts to take the patient, his disease and his environment into account simultaneously, and to orientate the symptomatology in a more precise manner towards the adaptation of the patient to his environment, by demonstrating that the process of diagnosis is not independent of the objectives of treatment.

Adaptation, Psychological↗

Rheological interfacial properties of plant protein-arabic gum coacervates at the oil-water interface.

This study concerns the interfacial properties of the plant proteins-arabic gum coacervates, which are involved in encapsulation processes based on complex coacervation. The results make it possible to deduce the prerequisite characteristics of the protein, which are involved in the coacervate interfacial properties. The influence of pH and concentration on protein interfacial properties was also studied so as to enable us to predict the best conditions to achieve encapsulation. It has been established that, to obtain a good encapsulation yield, the coacervate must show high surface-active properties and its adsorption on the oil droplets must be favored compared to the free protein adsorption. On the other hand, mechanical properties of the interfacial film made of the coacervate, appear to be a key parameter, as reflected by the dilational viscoelasticity measurements. When compared to the properties of the proteins films, an increase of the rigidity of the interfacial film was shown with the coacervates. It was also observed that viscoelastic properties of the coacervate film were strongly reduced, as well as the associated relaxation times. In acidic conditions, the coacervates containing alpha-gliadin are characterized by an interfacial viscoelastic behavior. This behavior reflects the softness of the interfacial film. This viscoelasticity allows also the formation of a continuous layer around the oil droplets to be encapsulated. Drop tensiometry is shown to be a method that could allow the most adapted protein to be selected and the conditions of the coacervation process to be optimized with regard to concentration and pH.

Adsorption↗

Adsorption kinetics and rheological interfacial properties of plant proteins at the oil-water interface.

Adsorption and rheological properties of plant proteins were determined by means of the dynamic pendant drop technique. The plant protein properties were compared with the interfacial properties of gelatin, which is well-known for its surface-active properties and is commonly used in food and health products. The results showed that alpha gliadins (wheat proteins) and pea globulins have the highest surface active properties at the oil-water interface, even higher than gelatin at the same concentration (weight/volume). After a short time of adsorption, alpha gliadin interfacial behavior is characterized by a pronounced viscoelasticity, which was confirmed with time whereas pea protein interfacial behavior became elastic after a long initial adsorption period. Finally, the behavior of gelatin is very close to the alpha gliadin behavior for the short initial adsorption period, whereas it looks like the behavior of legume seed proteins for longer times of the adsorption kinetics. This study emphasizes the importance of the choice of the proteins and the emulsification time in the encapsulation process, according to the interfacial behavior.

Adsorption↗

[Life cycle of the trematode Echinostoma caproni Richard, 1964 (Echinostomatoidea) (author's transl)].

The life cycle of the Trematode Echinostomatoidea Echinostoma caproni Richard, 1964, develops under natural conditions in Madagascar in a bird Falco newtoni and in a Gastropod Biomphalaria pfeifferi. Metacercaries encyst in other Molluscs and in the kidney of an Amphibian Ptychadaena mascareniensis. The cycle has been reproduced experimentaly in France. The defivitive hosts are the white mouse, the rat and the chick. Biomphalaria galbrata is the first and the second intermediate host. Metacercaries encyst in different Molluscs and in the kidney of tadpoles of Rana esculenta. The larval stages are described. The cycle pattern and the morphology of larval stages are quite similar to those of Echinostoma liei Jeyarasasingam and coll., 1972.

Animals↗

[Chaetotaxy of cercariae of two Microphallid Trematodes, Microphallus gracilis Baer, 1943 and Maritrema pyrenaica Deblock and Combes, 1965 parasiting Neomys fodiens (author's transl)].

The distribution of papillae on the cercariae of Microphallus gracilis and Maritrema pyrenaica parasites of Neomys fodiens is studied. The comparison between several cercariae of Microphallidae parasites of Birds had allowed to separate the ciliary characters of the two genera Microphallus and Maritrema. The ciliary characters of the two cercariae parasites of Mammals described in this paper, and those previously pointed out in Microphallidae of Birds are identical.

Animals↗

A supercritical fluid-based coating technology. 3: preparation and characterization of bovine serum albumin particles coated with lipids.

Solvent-free microparticles, loaded with bovine serum albumin as a model protein, were produced using a novel supercritical (SC) fluid-based coating technology. Coating material consists either of trimyristin (Dynasan 114) or of Gelucire 50-02. Microparticles obtained were characterized as regards their morphology, protein content and in vitro release profile. A discontinuous coating made of micro-needles of trimyristin led to an initial burst release of approximately 70% in 30 min. However, a prolonged release of the BSA could be achieved in a phosphate buffer solution at 37 degrees C over a 24 h period from particles coated with Gelucire 50-02. Furthermore, it was shown that BSA does not undergo any degradation after SC CO(2) treatment under the conditions used in the coating process.

Capsules↗

A supercritical fluid-based coating technology. 2: solubility considerations.

Solubility measurements of candidate coating materials have been performed in supercritical (SC) CO(2) so as to select appropriate coating materials for implementation of a solvent-free coating process previously described. Solubility of lipidic compounds such as waxes (paraffin, beeswax, Carnauba wax), pure triglycerides (tricaprin, trimyristin, tripalmitin, tristearin) and mixture of glycerides and fatty acid esters (Gelucire) in SC CO(2) were evaluated in a static mode under different temperature and pressure conditions, ranging from 13-52 degrees C and from 50-220 bar, whether the CO(2)was in its liquid or SC state. It was shown that the compounds which are mixtures of various components give rise to a selective extraction of the lower melting point components, as evidenced from thermal analysis of soluble and insoluble fractions of the coating materials.

Capsules↗

Prescribing exercise for cardiac patients: knowledge, practices, and needs of family physicians and specialists.

PURPOSE: To determine the following about prescribing exercise for cardiac patients: physicians' present and needed knowledge; their present practices; barriers that hinder them; and perceived need for and content of a protocol for prescribing exercise. METHODS: (1) Questionnaire mailed to 371 family physicians (FPs), 31 internists, and 25 cardiologists; and (2) four focus groups consisting of 25 FPs, 1 internist, and 3 cardiologists. RESULTS: Questionnaire response rate was 45% (n = 192). Because responses were similar and the group was small, internists and cardiologists were combined as "specialists." Generally, questionnaire data agreed with focus group data, with the latter providing more detail. Family physicians perceived they know little about prescribing a specific exercise program while specialists perceived they know little about motivating patients to begin an exercise program. The method most frequently used by both physician groups to increase exercise is providing general advice. The main barriers to prescribing exercise were inadequate knowledge (FPs only), patient education materials, and community resources. Both groups rated highly the need for a protocol for prescribing exercise and indicated it should: (1) include identification of patient's stage of change; (2) include indications and contraindications for exercise; (3) provide guidelines for developing a specific exercise prescription; (4) contain patient education materials, and (5) be simple and short. CONCLUSIONS: Family physicians perceive they know little about prescribing a specific exercise program for cardiac patients while specialists perceive they know little about motivating patients. Physicians rate highly the need for a protocol to help them prescribe exercise for cardiac patients.

Adult↗

Implementing computer simulations as a strategy for evaluating decision-making skills of nursing students.

This article describes the implementation of a computer assisted instruction clinical simulation, as an evaluation strategy for determining baccalaureate students' clinical decision-making skills. Students' reactions toward this strategy have been consistently positive. Similarly, faculty were satisfied with this method of assessment. Our experience has convinced us that computer simulation is an objective, efficacious, and pragmatic method for measuring students' clinical decision-making skills.

Clinical Competence↗

The impact of hand dominance and ulnar and median nerve impairment on strength and basic daily activities.

The authors sought to determine the impact of hand dominance and its relation to function among ulnar alone and combined ulnar and median nerve lesions in leprosy patients. The study sample consisted of 62 persons affected with leprosy (mean age 36.1 years) who were either suffering from ulnar nerve lesions alone (34 patients) or combined ulnar and median lesions (28 patients). The data from the earlier work of this institution with normal hands in the adjacent rural uninvolved population were taken as controls. Grip, pulp-to-pulp, lateral, and three-jaw-chuck pinch strengths were measured using a hydraulic hand dynamometer and a pinch gauge. Basic daily activities were assessed using the battery developed at Karigiri. Means, standard errors, correlations, and t-tests were used in the analyses. The overall difference between grip and pinch strength measurements in both dominant and nondominant hands was 40% less than those in normal hands if the ulnar nerve alone was involved. If impairment of this nerve was combined with that of the median nerve, the overall difference in strength measurements increased to 51%. The hand strength of the dominant side was statistically significant between single and two nerves for pulp-to-pulp pinch (p = 0.019). No other strength tests produced statistically significantly results related to hand dominance (grip strength, lateral, chuck pinch) with either one or two nerve involvement. To observe differences in basic daily activities, scores were compared to Karigiri norms. The bilateral basic daily activities score was impaired by 45% compared with norms with only ulnar nerve involvement and by 59% with ulnar and median nerve involvement. The different pinch strengths related to basic daily activities was not significantly affected in nondominant hands, whether it was ulnar alone or combined ulnar and median nerve lesions. In this population diagnosed with leprosy, ulnar nerve impairment at the level of the elbow reduced the grip and pinch strengths and performance in basic daily activities by 40% and 45%, respectively. If combined with median nerve lesion at wrist level, the strengths and daily activity losses increased to 50% and 60%, respectively. There is no effect on grip strength either in ulnar or ulnar and median nerve injuries, irrespective of whether dominant or nondominant hands were involved. Different pinch strengths related to basic daily activities were significantly affected only in the dominant hand with involvement of these nerves.

Activities of Daily Living↗

Human tears: normal protein pattern and individual protein determinations in adults.

Proteins in tears are known to be highly heterogeneous. We have tried to take into consideration some of the difficulties encountered in studying tear proteins such as tear collection, the choice of the parameters to be studied, the adequacy of techniques for small sample volumes, etc. Levels of total tear proteins were determined in 101 samples and the electrophoreses were performed. On gel slabs, four major proteins were always found to be present: lactoferrin, lysozyme and two tear specific proteins. Concentrations of some individual proteins, lactoferrin, lysozyme, IgA, IgG and albumin were determined. Comparisons of lactoferrin and lysozyme contents were found to be more reliable when based on total protein rather than on their own concentrations as such.

Adult↗