523 research outputs found

    La rodilla : Influencias anatomofuncionales en su biomecánica

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    Un conocimiento minucioso de la articulación de la rodilla interesa al profesor en educación física, por ser la articulación más utilizada, más expuesta, y menos protegida en las actividades de la vida diaria. La articulación de la rodilla además de unir el fémur, la tibia y la rótula, es un elemento de alta complejidad mecánica en cuanto a su anatomía a pesar de estar dotada de un solo sentido de libertad de movimiento: la flexión-extensión. De manera accesoria, posee un segundo sentido de movimientos: la rotación sobre el eje longitudinal de la pierna, que solo aparece cuando la rodilla ha sido flexionada. Asimismo los músculos que la rodean y actúan sobre ella tienen la capacidad no solo de ejecutar los movimientos normales, sino también, según su tono, modificar la alineación de los segmentos óseos en la postura estática. A través del siguiente trabajo, no solo se tratara de describir aspectos de la biomecánica de la rodilla, sino la relación que presentan todos los elementos anatómicos que la rodean y que influyen en su funcionamiento, determinando la importancia que lleva este conocimiento en cada actividad planteada desde la educación físicaFil: Parenti, Sebastián David. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina

    CELL SORTING IN THE PRESENCE OF CYTOCHALASIN B

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    The ability of cytochalasin B to inhibit ruffled membrane activity and cellular locomotion of vertebrate cells in monolayer culture prompted its use to study the necessity for this kind of active cellular locomotion in cell sorting in heterotypic cell aggregates. Cell sorting was inhibited in chick embryo heart-pigmented retina aggregates but a remarkable degree of sorting did occur in neural retina-pigmented retina aggregates. In these experiments, the levels of cytochalasin B employed (5 or 10 µg/ml) are sufficient to inhibit completely locomotion of these cell types in monolayer culture. It is proposed that the degree of cell movement achieved during sorting in neural retina-pigmented retina aggregates in the presence of cytochalasin B is the result of changes in cell contact resulting from adhesive interaction of cells. The effect of cytochalasin B on the initial aggregation of dissociated cells was also tested. With the cell types used in this study (chick embryo neural retina and limb bud), aggregation was not affected for a period of several hours

    Prevalence and Trends in Transmitted and Acquired Antiretroviral Drug Resistance, Washington, DC, 1999-2014.

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    Background Drug resistance limits options for antiretroviral therapy (ART) and results in poorer health outcomes among HIV-infected persons. We sought to characterize resistance patterns and to identify predictors of resistance in Washington, DC. Methods We analyzed resistance in the DC Cohort, a longitudinal study of HIV-infected persons in care in Washington, DC. We measured cumulative drug resistance (CDR) among participants with any genotype between 1999 and 2014 (n = 3411), transmitted drug resistance (TDR) in ART-naïve persons (n = 1503), and acquired drug resistance (ADR) in persons with genotypes before and after ART initiation (n = 309). Using logistic regression, we assessed associations between patient characteristics and transmitted resistance to any antiretroviral. Results Prevalence of TDR was 20.5%, of ADR 40.5%, and of CDR 45.1% in the respective analysis groups. From 2004 to 2013, TDR prevalence decreased for nucleoside and nucleotide analogue reverse transcriptase inhibitors (15.0 to 5.5%; p = 0.0003) and increased for integrase strand transfer inhibitors (INSTIs) (0.0–1.4%; p = 0.04). In multivariable analysis, TDR was not associated with age, race/ethnicity, HIV risk group, or years from HIV diagnosis. Conclusions In this urban cohort of HIV-infected persons, almost half of participants tested had evidence of CDR; and resistance to INSTIs was increasing. If this trend continues, inclusion of the integrase-encoding region in baseline genotype testing should be strongly considered

    Human immunodeficiency virus (HIV) in Washington, D.C.: Prevalence of antiretroviral resistance in treatment naïve patients from 2007 to 2010

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    HIV treatment has been greatly impacted by transmitted resistance to antiretrovirals (ARV). Several studies have documented resistance in naïve individuals and estimates of transmitted drug resistance mutations range from \u3c5% to as high as 25%. Washington, D.C. has one of the highest human immunodeficiency virus (HIV) prevalence rates in the United States (3.2% in 2009), but local data regarding the frequency of major mutations and antiretroviral (ARV) resistance has been limited. Medical records of HIV positive, ARV-naïve adults at two facilities in Washington, D.C., The George Washington University Medical Center and the Veterans Affairs Medical Center, were retrospectively analyzed in subjects who had genotypic resistance testing from 2007 to 2010. Of 407 ARV-naïve patients, at least one transmitted drug resistance mutation was detected in 17% of our patients, with non-nucleoside reverse transcriptase (NNRTI) mutations observed in 15%. Among patients with at least one reverse transcriptase (RT) or major protease region (Pr) resistance mutation, 85% had resistance against a single ARV class. Dual and triple class resistance mutations were seen in 8 patients (2%) and 3 patients (0.7%), respectively. Most of the multiple class resistance was seen in 2010. A gradual increase in NNRTI resistance was noted during 2008 to 2010. Our prevalence of transmitted RT, major Pr mutations (17.4%) and ARV resistance (8.6%) were high but similar to rates reported by others within the United States. Given the high HIV prevalence in the District of Columbia, this has important implications for treatment of these ARV-naïve patients

    Care of HIV-Infected Pregnant Women in Maternal–Fetal Medicine Programs

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    Objective: To survey the evolution over the past decade of attitudes and practices of obstetricians in maternal–fetal medicine fellowship programs regarding the management of human immunodeficiency virus (HIV)-infected pregnant women. Methods: Directors of all 65 approved maternal–fetal medicine training programs were sent questionnaires, responses to which were to reflect the consensus among members of their faculties. Programs were stratified based upon the number of HIV-infected pregnant patients cared for in the previous year. Results: Responses reflect experience with over 1000 infected pregnantwomen per year, nearly one-quarter with advanced disease. Combination antiretroviral therapy was prescribed by all respondents, universally in the 2nd and 3rd trimesters. A three-drug regimen (often containing a protease inhibitor) was used more often by those who treated at least 20 HIV-infected pregnant patients per year than by those programs seeing a lower number of patients (80 vs 59%).Despite the known and unknown risks of the use of antiretrovirals during pregnancy, only half of all responding programs report adverse events to the Antiretroviral Pregnancy Registry; reporting was more common among the institutions seeing a higher number of patients (61 vs 45%). Seventy-eight percent of higher volume programs enroll their patients in clinical studies, usually multicenter, versus 35% of lower volume programs. Conclusions: Care for HIV² pregnant women has dramatically changed over the past decade. Antiretroviral therapy is now universally prescribed by physicians involved in maternal–fetal medicine training programs. Given limited experience with these agents in the setting of pregnancy, it is essential for maternal–fetal medicine practitioners to actively report on adverse events and participate in clinical trials

    Equation of state at high densities and modern compact star observations

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    Recently, observations of compact stars have provided new data of high accuracy which put strong constraints on the high-density behaviour of the equation of state of strongly interacting matter otherwise not accessible in terrestrial laboratories. The evidence for neutron stars with high mass (M =2.1 +/- 0.2 M_sun for PSR J0751+1807) and large radii (R > 12 km for RX J1856-3754) rules out soft equations of state and has provoked a debate whether the occurence of quark matter in compact stars can be excluded as well. In this contribution it is shown that modern quantum field theoretical approaches to quark matter including color superconductivity and a vector meanfield allow a microscopic description of hybrid stars which fulfill the new, strong constraints. The deconfinement transition in the resulting stiff hybrid equation of state is weakly first order so that signals of it have to be expected due to specific changes in transport properties governing the rotational and cooling evolution caused by the color superconductivity of quark matter. A similar conclusion holds for the investigation of quark deconfinement in future generations of nucleus-nucleus collision experiments at low temperatures and high baryon densities such as CBM @ FAIR.Comment: 6 pages, 2 figures, accepted for publication in J. Phys. G. (Special Issue

    CELL SORTING IN THE PRESENCE OF CYTOCHALASIN B

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    The Conservation Ideological State Apparatus

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    This article considers Louis Althusser's theory of the ideological state apparatuses (ISAs) for advancing political ecology scholarship on the functioning of the state in violent environments. I reflect on a series of events in which a state forest department in South India attempted to recast violent conflicts between themselves and local communities over access to natural resources and a protected area as a debate over human-wildlife conflicts. Through the example of conservation as ideology in Wayanad, Kerala, I show how the ISAs articulate the functioning of ideology within the state apparatuses in order for us to understand the larger mechanics of the state apparatus and the reproduction of the relations of production necessary for the reproduction of capitalism. Revisiting the ISAs as a theoretical framework for studies in political ecology and conservation is timely given the resurgence of militarised conservation tactics, the emancipatory aims of Althusser's theory, and political ecology's turn towards praxis

    Mis-splicing of the GALNS gene resulting from deep intronic mutations as a cause of Morquio a disease

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    Background Mucopolysaccharidosis-IVA (Morquio A disease) is a lysosomal disorder in which the abnormal accumulation of keratan sulfate and chondroitin-6-sulfate is consequent to mutations in the galactosamine-6-sulfatase (GALNS) gene. Since standard DNA sequencing analysis fails to detect about 16% of GALNS mutant alleles, gross DNA rearrangement screening and uniparental disomy evaluation are required to complete the molecular diagnosis. Despite this, the second pathogenic GALNS allele generally remains unidentified in ~ 5% of Morquio-A disease patients. Methods In an attempt to bridge the residual gap between clinical and molecular diagnosis, we performed an mRNA-based evaluation of three Morquio-A disease patients in whom the second mutant GALNS allele had not been identified. We also performed sequence analysis of the entire GALNS gene in two patients. Results Different aberrant GALNS mRNA transcripts were characterized in each patient. Analysis of these transcripts then allowed the identification, in one patient, of a disease-causing deep intronic GALNS mutation. The aberrant mRNA products identified in the other two individuals resulted in partial exon loss. Despite sequencing the entire GALNS gene region in these patients, the identity of a single underlying pathological lesion could not be unequivocally determined. We postulate that a combination of multiple variants, acting in cis, may synergise in terms of their impact on the splicing machinery. Conclusions We have identified GALNS variants located within deep intronic regions that have the potential to impact splicing. These findings have prompted us to incorporate mRNA analysis into our diagnostic flow procedure for the molecular analysis of Morquio A disease
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