253 research outputs found
Bronchiectasis in rheumatoid arthritis. A clinical appraisial
Bronchiectasis is defined as irreversibly damaged and dilated bronchi and is one of the most common pulmonary manifestations in patients with rheumatoid arthritis (RA). The model of RA-associated autoimmunity induced in some individuals by chronic bacterial infection in bronchiectasis is becoming increasingly acceptable, although a genetic predisposition to RA-associated bronchiectasis has also been demonstrated. Bronchiectasis should be suspected in RA patients with chronic cough and sputum production or frequent respiratory infections and the diagnosis must be confirmed by thoracic high-resolution computed tomography. Management of patients with RA-associated bronchiectasis includes a multimodal treatment approach. Similar to all patients with non-cystic fibrosis bronchiectasis, patients with RA-associated bronchiectasis benefit from a pulmonary rehabilitation program, including an exercise/muscle strengthening program and an education program with a specific session on airway clearance techniques. Prophylactic antibiotics are recommended for patients with frequent (3 or more infective exacerbations per year) or severe infections requiring hospitalization/intravenous antibiotics and inhaled corticosteroids and long-acting β2-agonists should be used in patients with non-cystic fibrosis bronchiectasis and associated airway hyper-responsiveness. In patients with RA-associated bronchiectasis the use of immunomodulatory drugs has to be carefully considered, as they are essential to control disease activity, despite being associated with an increased infectious risk. Pneumococcal and influenza vaccines are advised to all patients with RA-associated bronchiectasis in order to reduce the risk of infection. Patients with RA-associated bronchiectasis have a poorer prognosis than those with either RA or bronchiectasis alone and require regular follow-up, under the joint care of a rheumatologist and a pulmonologist
Cystathionine beta-synthase mutants exhibit changes in protein unfolding: conformational analysis of misfolded variants in crude cell extracts
Protein misfolding has been proposed to be a common pathogenic mechanism in many inborn errors of metabolism including cystathionine β-synthase (CBS) deficiency. In this work, we describe the structural properties of nine CBS mutants that represent a common molecular pathology in the CBS gene. Using thermolysin in two proteolytic techniques, we examined conformation of these mutants directly in crude cell extracts after expression in E. coli. Proteolysis with thermolysin under native conditions appeared to be a useful technique even for very unstable mutant proteins, whereas pulse proteolysis in a urea gradient had limited values for the study of the majority of CBS mutants due to their instability. Mutants in the active core had either slightly increased unfolding (p.A114V, p.E302K and p.G307S) or extensive unfolding with decreased stability (p.H65R, p.T191M, p.I278T and p.R369C). The extent of the unfolding inversely correlated with the previously determined degree of tetrameric assembly and with the catalytic activity. In contrast, mutants bearing aminoacid substitutions in the C-terminal regulatory domain (p.R439Q and p.D444N) had increased global stability with decreased flexibility. This study shows that proteolytic techniques can reveal conformational abnormalities even for CBS mutants that have activity and/or a degree of assembly similar to the wild-type enzyme. We present here a methodological strategy that may be used in cell lysates to evaluate properties of proteins that tend to misfold and aggregate and that may be important for conformational studies of disease-causing mutations in the field of inborn errors of metabolism
Nutritional status and functional capacity of hospitalized elderly
Background: The nutritional status of the aging individual results from a complex interaction between personal and environmental factors. A disease influences and is influenced by the nutritional status and the functional capacity of the individual. We asses the relationship between nutritional status and indicators of functional capacity among recently hospitalized elderly in a general hospital.Methods: A cross-sectional study was done with 240 elderly (women, n = 127 and men, n = 113) hospitalized in a hospital that provides care for the public and private healthcare systems. The nutritional status was classified by the MNA (Mini Nutritional Assessment) into: malnourished, risk of malnutrition and without malnutrition (adequate). The functional autonomy indicators were obtained by the self-reported Instrumental Activity of Daily Living (IADL) and Activity of Daily Living (ADL) questionnaire. The chi-square test was used to compare the proportions and the level of significance was 5%.Results: Among the assessed elderly, 33.8% were classified as adequate regarding nutritional status; 37.1% were classified as being at risk of malnutrition and 29.1% were classified as malnourished. All the IADL and ADL variables assessed were significantly more deteriorated among the malnourished individuals. Among the ADL variables, eating partial (42.9%) or complete (12.9%) dependence was found in more than half of the malnourished elderly, in 13.4% of those at risk of malnutrition and in 2.5% of those without malnutrition.Conclusion: There is an interrelationship between the nutritional status of the elderly and reduced functional capacity
Impulsivity and the 5-HTTLPR Polymorphism in a Non-Clinical Sample
BACKGROUND: Impulsivity has been associated with serotonergic system functions. However, few researchers have investigated the relationship between a polymorphism in the promoter of the serotonin transporter gene (5-HTTLPR) and the different components of impulsivity in a non-clinical population. The aim of this study was to investigate the relationship between a polymorphism in the promoter region of the serotonin transporter gene (5-HTTLPR) and the different components of impulsivity in a non-clinical population. METHODOLOGY/PRINCIPAL FINDINGS: We administered two neuropsychological tests, the Continuous Performance Task and the Iowa Gambling Task, to 127 healthy participants to measure their levels of motor, attentional and non-planning impulsivity. Then, these participants were grouped by genotype and gender, and their scores on impulsivity measures were compared. There were no significant differences between group scores on attentional, motor and non-planning impulsivity. CONCLUSIONS/SIGNIFICANCE: Our results suggest that 5-HTTLPR genotype is not significantly associated with subsets of impulsive behavior in a non-clinical sample when measured by neuropsychological tests. These findings are discussed in terms of the sensitivity of neuropsychological tests to detect impulsivity in a non-clinical population and the role of gender and race in the relationship between the 5-HTTLPR and impulsivity
Evolutionary and pulsational properties of white dwarf stars
Abridged. White dwarf stars are the final evolutionary stage of the vast
majority of stars, including our Sun. The study of white dwarfs has potential
applications to different fields of astrophysics. In particular, they can be
used as independent reliable cosmic clocks, and can also provide valuable
information about the fundamental parameters of a wide variety of stellar
populations, like our Galaxy and open and globular clusters. In addition, the
high densities and temperatures characterizing white dwarfs allow to use these
stars as cosmic laboratories for studying physical processes under extreme
conditions that cannot be achieved in terrestrial laboratories. They can be
used to constrain fundamental properties of elementary particles such as axions
and neutrinos, and to study problems related to the variation of fundamental
constants.
In this work, we review the essentials of the physics of white dwarf stars.
Special emphasis is placed on the physical processes that lead to the formation
of white dwarfs as well as on the different energy sources and processes
responsible for chemical abundance changes that occur along their evolution.
Moreover, in the course of their lives, white dwarfs cross different
pulsational instability strips. The existence of these instability strips
provides astronomers with an unique opportunity to peer into their internal
structure that would otherwise remain hidden from observers. We will show that
this allows to measure with unprecedented precision the stellar masses and to
infer their envelope thicknesses, to probe the core chemical stratification,
and to detect rotation rates and magnetic fields. Consequently, in this work,
we also review the pulsational properties of white dwarfs and the most recent
applications of white dwarf asteroseismology.Comment: 85 pages, 28 figures. To be published in The Astronomy and
Astrophysics Revie
Hepatitis C incidence in hemodialysis patients in Brazil from 2000 to 2003.
O estudo visou estimar a incid?ncia dos fatores associados ? soroconvers?o
para o anti-HCV em pacientes em hemodi?lise no Sistema ?nico de
Sa?de (SUS). Trata-se de um estudo prospectivo, n?o concorrente, utilizando
dados de pacientes identificados por relacionamento determin?stico-
probabil?stico nos registros dos sistemas de informa??o do SUS. Foram
inclu?dos 47.079 pacientes que iniciaram em hemodi?lise no per?odo
de 1o de janeiro de 2000 a 31 de dezembro de 2003, acompanhados at? a
soroconvers?o ou o t?rmino do estudo em 2004. Nesta pesquisa, 3% dos
pacientes em hemodi?lise apresentaram soroconvers?o para anti-HCV
(incid?ncia de 1,7 soroconvers?o por 100 pacientes/ano). Maior risco de
soroconvers?o para o anti-HCV foi associado com idade, glomerulonefrites,
regi?o de resid?ncia, anti-HIV positivo e efeito da unidade de di?lise.
A incid?ncia observada de soroconvers?o para anti-HCV foi semelhante ?
registrada em alguns pa?ses desenvolvidos, destacando-se a evid?ncia de
transmiss?o entre os pacientes em hemodi?lise
Microvertebrates preserved in mammal burrows from the Holocene of the Argentine Pampas: a taphonomic and paleoecological approach
Microvertebrates are a major component of many assemblages recovered from the Quaternary of the Argentine Pampas. The main goal of this paper is to analyse the taphonomic history of a Holocene microfossil bonebed, recovered from the infilling of a burrow. Evidences suggest the plains vizcacha Lagostomus maximus as the putative producer of the burrow. The assemblage includes individuals belonging to different taxa of mammals (marsupials and rodents) and reptiles (snakes). Taphonomic features suggest that the accumulation inside the burrow was related to flooding processes in the plain. The burrow was a natural trap that favoured the accumulation and preservation of remains corresponding to individuals from different sources. According to the taphonomic evidence, some individuals (Lagostomus maximus, Lestodelphys halli and Serpentes indet.) died inside the burrow, whereas others (Microcavia australis, Reithrodon auritus and Ctenomys sp.) died outside the burrow, and after a time of being exposed on the surface their remains were transported by surface run-offs into the burrow. The record of Lestodelphys halli and Serpentes indet. in the burrow produced by Lagostomus maximus could be related to a circumstantial use. Mammal burrows are a significant taphonomic mode for the late Cenozoic of the Argentine Pampas
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