L'anticoagulation du patient âgé en fibrillation atriale: que prescrivent les cardiologues, les gériatres et les médecins généralistes [Anticoagulation in the aged patient with atrial fibrillation: What are prescribing cardiologists, geriatricians and general practitioners?].

OBJECTIVE: To assess prescribing of anticoagulants in atrial fibrillation (AF) in the elderly, both a quantitative point of view (rate of anticoagulation) and qualitative (type of anticoagulation). Determinants of prescribing and non-prescribing were also analysed. METHODS: Prospective survey of practice, based on one clinical case and questionnaire conducted in 60 practitioners (20 cardiologists [C], 20 geriatricians [G] and 20 general practitioners [GP]). RESULTS: In reading the clinical case, 88.3% of physicians would have initiated a treatment; three types of treatments would have been chosen: AVK (68.3%), ODA (20.0%) and platelet antiaggregant (11.7%). Criteria taken into account to initiate anticoagulation varied according to the specialty. Cardiologists considered more the age criteria (C: 95.0%, G: 75.0%, MG: 60.0%; P<0.05), diabetes (C: 90.0%, G: 60.0%, MG: 55.0%; P<0.05), hypertension (C: 85.0%, G: 55.0%, MG: 60.0%; P<0.05) and female gender (C: 80.0%, G: 35.0%, MG: 25.0%; P<0.05). The quality of renal function was however a more secondary criteria (C: 15.0%, G: 5.0%, MG: 0.0%; P<0.05). General practitioners considered most frequently the presence of underlying heart disease (C: 35.0%, G: 5.0%, MG: 45.0%; P<0.05) as well as usual cardiovascular risk factors (overweight, dyslipidaemia; P<0.05). Risk of bleeding, however, was observed by 76.7% of physicians in the clinical situation presented (C: 70.0%, G: 75.0%, MG: 85.0%; P<0.05). CONCLUSION: This survey confirms that the FA remains under anticoagulated in the elderly and the barriers to the prescription of oral anticoagulation are often without rational basis.

Plasma cell and terminal B-cell differentiation in mantle cell lymphoma mainly occur in the SOX11-negative subtype.

Mantle cell lymphoma is a mature lymphoid neoplasm characterized by the t(11;14)(q13;q32) and cyclin D1 overexpression. SOX11 is a transcription factor commonly overexpressed in these tumors but absent in most other mature B-cell lymphomas whose function is not well understood. Experimental studies have shown that silencing of SOX11 in mantle cell lymphoma cells promotes the shift from a mature B cell into an early plasmacytic differentiation phenotype, suggesting that SOX11 may contribute to tumor development by blocking the B-cell differentiation program. The relationship between SOX11 expression and terminal B-cell differentiation in primary mantle cell lymphoma and its relationship to the plasmacytic differentiation observed in occasional cases is not known. In this study we have investigated the terminal B-cell differentiation phenotype in 60 mantle cell lymphomas, 41 SOX11-positive and 19 SOX11-negative. Monotypic plasma cells and lymphoid cells with plasmacytic differentiation expressing cyclin D1 were observed in 7 (37%) SOX11-negative but in none of 41 SOX11-positive mantle cell lymphomas (P<0.001). Intense cytoplasmic expression of a restricted immunoglobulin light chain was significantly more frequent in SOX11-negative than -positive tumors (58 vs 13%) (P=0.001). Similarly, BLIMP1 and XBP1 expression was also significantly more frequent in SOX11-negative than in -positive cases (83 vs 34% and 75 vs 11%, respectively) (P=0.001). However, no differences in the expression of IRF4/MUM1 were observed among these subtypes of mantle cell lymphoma. In conclusion, these results indicate that SOX11-negative mantle cell lymphoma may be a particular subtype of this tumor characterized by more frequent morphological and immunophenotypic terminal B-cell differentiation features that may be facilitated by the absence of SOX11 transcription factor.

Fractures de la cheville chez le patient âgé [Ankle fractures in the elderly patient].

Ankle fractures in adults are usually managed by open reduction internal fixation. In elderly patients the surgical dilemma relates to bone quality. Osteoporosis is the enemy of internal fixation, and secure purchase of screws in osteopenic bone may be difficult to achieve. Insufficient screw purchase may lead to loss of reduction, wound breakdown, and infection. Postoperative management after osteosynthesis usually requires an extended period of restricted weight bearing. However, this is not feasible in older patients as a result of their lack of strength in the upper extremities and frequent comorbidities. Therefore, augmen- ted methods of internal fixation and specific surgical techniques have been developed using metal and bone cement. This permits this fragile population to begin early full weight bearing in a removable brace.

Phase diagram and complex patterns in the modeling of the bromate-oxalic acid-Ce-acetone oscillating reaction

Simulations have been carried out on the bromate - oxalic acid - Ce(IV) - acetone oscillating reaction, under flow conditions, using Field and Boyd's model (J. Phys. Chem. 1985, 89, 3707). Many different complex dynamic behaviors were found, including simple periodic oscillations, complex periodic oscillations, quasiperiodicity and chaos. Some of these complex oscillations can be understood as belonging to a Farey sequence. The many different behaviors were systematized in a phase diagram which shows that some regions of complex patterns were nested with one inside the other. The existence of almost all known dynamic behavior for this system allows the suggestion that it can be used as a model for some very complex phenomena that occur in biological systems.

Development of an instrument to measure the degree of critical patient's satisfaction with nursing care: research protocol

Aim: To investigate and understand patient's satisfaction with nursing care in the intensive care unit to identify the dimensions of the concept of"satisfaction" from the patient's point of view. To design and validate a questionnaire that measures satisfaction levels in critical patients. Background: There are many instruments capable of measuring satisfaction with nursing care; however, they do not address the reality for critical patients nor are they applicable in our context. Design: A dual approach study comprising: a qualitative phase employing Grounded Theory and a quantitative and descriptive phase to prepare and validate the questionnaire. Methods: Data collection in the qualitative phase will consist of: in-depth interview after theoretical sampling, on-site diary and expert discussion group. The sample size will depend on the expected theoretical saturation n = 27-36. Analysis will be based on Grounded Theory. For the quantitative phase, the sampling will be based on convenience (n = 200). A questionnaire will be designed on the basis of qualitative data. Descriptive and inferential statistics will be used. The validation will be developed on the basis of the validity of the content, the criteria of the construct and reliability of the instrument by the Cronbach's alpha and test-retest approach. Approval date for this protocol was November 2010. Discussion: Self-perceptions, beliefs, experiences, demographic, socio-cultural epistemological and political factors are determinants for satisfaction, and these should be taken into account when compiling a questionnaire on satisfaction with nursing care among critical patients.

EVALUATION OF A BUFFERED SOLID PHASE DISPERSION PROCEDURE ADAPTED FOR PESTICIDE ANALYSES IN THE SOIL MATRIX

An evaluation of the pesticides extracted from the soil matrix was conducted using a citrate-buffered solid phase dispersion sample preparation method (QuEChERS). The identification and quantitation of pesticide compounds was performed using gas chromatography-mass spectrometry. Because of the occurrence of the matrix effect in 87% of the analyzed pesticides, the quantification was performed using matrix-matched calibration. The method's quantification limits were between 0.01 and 0.5 mg kg-1. Repeatability and intermediate precision, expressed as a relative standard deviation percentage, were less than 20%. The recoveries in general ranged between 62% and 99%, with a relative standard deviation < 20%. All the responses were linear, with a correlation coefficient (r) ≥0.99.

Use of experimental design in the optimisation of a solid phase preconcentration system for Cobalt determination by GFAAS

In this work is proposed a solid phase preconcentration system of Co2+ ions and its posterior determination by GFAAS in which fractional factorial design and response surface methodology (RSM) were used for optimization of the variables associated with preconcentration system performance. The method is based on cobalt extraction as a complex Co2+-PAN (1:2) in a mini-column of polyurethane foam (PUF) impregnated with 1-(2-pyridylazo)-naphthol (PAN) followed by elution with HCl solution and its determination by GFAAS. The chemical and flow variables studied were pH, buffer concentration, eluent concentration and preconcentration and elution flow rates. Results obtained from fractional factorial design 2(5-1) showed that only the variables pH, buffer concentration and interaction (pH X buffer concentration) based on analysis of variance (ANOVA) were statistically significant at 95% confidence level. Under optimised conditions, the method provided an enrichment factor of 11.6 fold with limit of detection and quantification of 38 and 130 ng L-1, respectively, and linear range varying from 0.13 to 10 µg L-1. The precision (n = 9) assessed by relative standard deviation (RSD) was respectively 5.18 and 2.87% for 0.3 and 3.0 µg L-1 cobalt concentrations.

Spatial variability of air dry bulb temperature and black globe humidity index in a broiler house during the heating phase

The air dry-bulb temperature (t db),as well as the black globe humidity index (BGHI), exert great influence on the development of broiler chickens during their heating phase. Therefore, the aim of this study was to analyze the structure and the magnitude of the t db and BGHI spatial variability, using geostatistics tools such as semivariogram analysis and also producing kriging maps. The experiment was conducted in the west mesoregion of the states of Minas Gerais in 2010, in a commercial broiler house with heating system consisting of two furnaces that heat the air indirectly, in the firsts 14 days of the birds' life. The data were registered at intervals of five minutes in the period from 8 a.m. to 10 a.m. The variables were evaluated by variograms fitted by residual maximum likelihood (REML) testing the Spherical and Exponential models. Kriging maps were generated based on the best model used to fit the variogram. It was possible to characterize the variability of the t db and BGHI, which allowed observing the spatial dependence by using geostatistics techniques. In addition, the use of geostatistics and distribution maps made possible to identify problems in the heating system in regions inside the broiler house that may harm the development of chicks.

Generation and Characterization of Knockout Mice and Analysis of Patient Material Demonstrates a Role for Tissue Inhibitor of Metalloproteinases 4 (Timp4) in the Cardiovascular System and Tumor Metastasis

This thesis focuses on tissue inhibitor of metalloproteinases 4 (TIMP4) which is the newest member of a small gene and protein family of four closely related endogenous inhibitors of extracellular matrix (ECM) degrading enzymes. Existing data on TIMP4 suggested that it exhibits a more restricted expression pattern than the other TIMPs with high expression levels in heart, brain, ovary and skeletal muscle. These observations and the fact that the ECM is of special importance to provide the cardiovascular system with structural strength combined with elasticity and distensibility, prompted the present molecular biologic investigation on TIMP4. In the first part of the study the murine Timp4 gene was cloned and characterized in detail. The structure of murine Timp4 genomic locus resembles that in other species and of the other Timps. The highest Timp4 expression was detected in heart, ovary and brain. As the expression pattern of Timp4 gives only limited information about its role in physiology and pathology, Timp4 knockout mice were generated next. The analysis of Timp4 knockout mice revealed that Timp4 deficiency has no obvious effect on the development, growth or fertility of mice. Therefore, Timp4 deficient mice were challenged using available cardiovascular models, i.e. experimental cardiac pressure overload and myocardial infarction. In the former model, Timp4 deficiency was found to be compensated by Timp2 overexpression, whereas in the myocardial infarct model, Timp4 deficiency resulted in increased mortality due to increased susceptibility for cardiac rupture. In the wound healing model, Timp4 deficiency was shown to result in transient retardation of re-epithelialization of cutaneous wounds. Melanoma tumor growth was similar in Timp4 deficient and control mice. Despite of this, lung metastasis of melanoma cells was significantly increased in Timp4 null mice. In an attempt to translate the current findings to patient material, TIMP4 expression was studied in human specimens representing different inflammatory cardiovascular pathologies, i.e. giant cell arteritis, atherosclerotic coronary arteries and heart allografts exhibiting signs of chronic rejection. The results showed that cardiovascular expression of TIMP4 is elevated particularly in areas exhibiting inflammation. The results of the present studies suggest that TIMP4 has a special role in the regulation of tissue repair processes in the heart, and also in healing wounds and metastases. Furthermore, evidence is provided suggesting the usefulness of TIMP4 as a novel systemic marker for vascular inflammation.

Gas-solid two-phase flow in the riser of circulating fluidized beds: mathematical modelling and numerical simulation

A mathematical model is developed for gas-solids flows in circulating fluidized beds. An Eulerian formulation is followed based on the two-fluids model approach where both the fluid and the particulate phases are treated as a continuum. The physical modelling is discussed, including the formulation of boundary conditions and the description of the numerical methodology. Results of numerical simulation are presented and discussed. The model is validated through comparison to experiment, and simulation is performed to investigate the effects on the flow hydrodynamics of the solids viscosity.

The pH-dependent phase distribution of wood pitch components in papermaking processes

Wood contains only a very small amount of lipophilic extractives, commonly known as wood pitch. The pitch is known to cause severe problems in papermaking processes. The amount of pitch in process waters can be decreased by seasoning of the raw material prior to pulping, pulp washing, removal of pitch by flotation, adsorption of pitch onto various mineral surfaces, and retention of pitch to the fibre material by cationic polymers. The aim of this study was to determine the influence of pH on some of the methods used for pitch control. Experiments were performed using laboratory-made wood pitch emulsions with varying pH, salt concentration, hemicellulose concentration and pitch composition. These emulsions were used to study the phase distribution of resin and fatty acids, the colloidal stability of pitch with and without steric stabilisation by galactoglucomannans, and the interactions between wood pitch and mineral particles. Purification of unbleached and peroxidebleached mill process water was performed by froth flotation in combination with a foaming agent. The distribution of resin and fatty acids (RFAs) between colloidal pitch droplets and the water phase was very dependent on pH. At pH 3, almost all of the RFAs were attached to the pitch droplets, while increasing the pH led to increasing concentration of dissolved RFAs in the water phase. The presence of salt shifted the release of RFAs towards higher pH, while lower ratio of neutral pitch in the emulsion resulted in release of RFAs at lower pH. It was also seen that the dissolution and adsorption of RFAs at sudden pHchanges takes place very quickly. Colloidal pitch was more stable against electrolyte-induced aggregation at higher pH, due to its higher anionic charge. The concentration of cationic polymers needed to aggregate colloidal pitch also increased with increasing pH. The surface characteristics of solid particles, such as amount of charged groups, were very important for understanding their interactions with colloidal wood pitch. Water-soluble galactoglucomannans stabilised the colloidal pitch sterically against aggregation, but could not completely prevent interactions between wood pitch and hydrophilic particles. Froth flotation of unbleached and peroxidebleached process water showed that the pitch could be removed more effectively and selectively at low pH, compared to at neutral pH. The pitch was removed more effectively, using lower concentrations of foaming agent, from peroxide-bleached water than from unbleached water. The results show that pH has a major impact on various pulping and papermaking processes. It determines the anionic charge of the colloidal pitch and the solubility of certain pitch components. Because of this, the pH influences the effectiveness of pitch retention and removal of pitch. The results indicate that pitch problems could be diminished by acknowledging the importance of pH in various papermaking processes.

Clearance-inducing antibodies are responsible for protection against the acute phase of Trypanosoma cruzi infection in mice

A study was conducted on mice infected with strains Y and CL of Trypanosoma cruzi. The ability of anti-Y and anti-CL sera to induce complement-mediated lysis, immune clearance and protection against the acute phase of the infection was studied using homologous anti-Y or anti-CL serum tested with the Y or CL strain, or heterologous anti-Y serum tested with the CL strain or anti-CL serum tested with the Y strain. Complement-mediated lysis was induced by both homologous and heterologous antisera but protection was afforded only by homologous antisera. Immune clearance was induced by homologous but not by heterologous antisera. Antisera with high clearance ability were able to confer protection whereas antisera with high lytic ability were not. These results show a high correlation between the antibody ability to induce clearance and to confer protection and suggest that clearance rather than lysis is responsible for protection against the acute phase of the infection. The mechanism of antibody protection against the acute phase of the infection is discussed.

Mirtazapine versus fluoxetine in the treatment of panic disorder

Mirtazapine is an antidepressant whose side effect profile differs from that of first-line agents (selective serotonin reuptake inhibitors) used in the treatment of panic disorder. The present study compared the effect of mirtazapine and fluoxetine in the treatment of panic disorder in a double-blind, randomized, flexible-dose trial conducted with outpatients. After a 1-week single-blind placebo run-in, 27 patients entered an 8-week double-blind phase in which they were randomly assigned to treatment with either mirtazapine or fluoxetine. Both groups improved significantly in all but one efficacy measure (P<=0.01). ANOVA showed no significant differences between the two treatment groups in number of panic attacks, Hamilton Anxiety Scale or Sheehan Phobic Scale, whereas measures of patient global evaluation of phobic anxiety were significantly different between groups (F1,20 = 6.91, P = 0.016) favoring mirtazapine. For the 22 patients who completed the study, the mean daily dose of mirtazapine was 18.3 ± 1.3 vs 14.0 ± 1.0 mg for fluoxetine at the endpoint. Weight gain occurred more frequently in the mirtazapine group (50 vs 7.7%, P = 0.04) and nausea and paresthesia occurred more often in the fluoxetine group (P = 0.01). Results suggest that mirtazapine has properties that make it attractive for the treatment of panic disorder.