1,123 research outputs found
The active metabolite of leflunomide, A77 1726, increases proliferation of human synovial fibroblasts in presence of IL-1β and TNF-α
Abstract.: Objective and design: Excessive synovial fibroblast (SF) proliferation is detrimental in rheumatoid arthritis. We therefore sought to determine the effects of A77 1726, the active metabolite of leflunomide, on SF proliferation. Methods: Human SFs were used. Cell proliferation was investigated using MTS assay, by 3H-thymidine incorporation and cell counts. Results: Whereas A77 1726 alone had no effects, it significantly increased the mitogenic effects of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). Cyclooxygenase inhibition might be at least partly involved, since indomethacin displayed similar effects, and since prostaglandin E2 inhibited SF proliferation. In contrast, the effect of A77 1726 did not appear to be mediated through depletion of the pyrimidine pool or inhibition of tyrosine kinases. Conclusion: A77 1726 displays proliferative effects in presence of IL-1β and TNF-α. Further elucidation of involved mechanisms may prove useful for the utilization of leflunomide, the development of related compounds or elaboration of new therapeutic strategie
Poor provision of sanitary facilities in markets of lusaka district Zambia
Background: Although provision of sanitary facilities in workplaces is an important issue, very few studies have been undertaken in this regard.
Objective: This study assessed the provision of sanitary facilities for market traders and their perceptions of the provided facilities in Lusaka district Zambia.
Methods: A cross-sectional study of workplace observations in 12 randomly selected markets and interviews with 386 traders, conducted in Lusaka district.
Findings: The study revealed that eleven of the twelve markets provided toilets, hand-washing and drying facilities, water, urinals, soap, and toilet paper. However, most of the markets did not comply with the Zambian laws in terms of the adequacy and privacy of facilities. One market did not have any of the listed facilities. Most traders perceived facilities to be unsatisfactory and used them only because of the lack of alternatives. Poor provision of sanitary facilities was observed at markets thus predisposing its workforce and trading population to multiple public health hazards.
Conclusions: The findings of this study call for urgent investments in sanitary structures and surveillance systems to guarantee the safety of the population and to promote the health of market traders as well as the community at large.publishedVersio
Incompressible Quantum Liquids and New Conservation Laws
In this letter we investigate a class of Hamiltonians which, in addition to
the usual center-of-mass (CM) momentum conservation, also have center-of-mass
position conservation. We find that regardless of the particle statistics, the
energy spectrum is at least q-fold degenerate when the filling factor is ,
where and are coprime integers. Interestingly the simplest Hamiltonian
respecting this type of symmetry encapsulates two prominent examples of novel
states of matter, namely the fractional quantum Hall liquid and the quantum
dimer liquid. We discuss the relevance of this class of Hamiltonian to the
search for featureless Mott insulators.Comment: updated version, to be published by PR
Dust exposure and chronic respiratory symptoms among coffee curing workers in Kilimanjaro: a cross sectional study
Background: Coffee processing causes organic dust exposure which may lead to development of respiratory symptoms. Previous studies have mainly focused on workers involved in roasting coffee in importing countries. This study was carried out to determine total dust exposure and respiratory health of workers in Tanzanian primary coffee-processing factories. Methods: A cross sectional study was conducted among 79 workers in two coffee factories, and among 73 control workers in a beverage factory. Personal samples of total dust (n = 45 from the coffee factories and n = 19 from the control factory) were collected throughout the working shift from the breathing zone of the workers. A questionnaire with modified questions from the American Thoracic Society questionnaire was used to assess chronic respiratory symptoms. Differences between groups were tested by using independent t-tests and Chi square tests. Poisson Regression Model was used to estimate prevalence ratio, adjusting for age, smoking, presence of previous lung diseases and years worked in dusty factories. Results: All participants were male. The coffee workers had a mean age of 40 years and were older than the controls (31 years). Personal total dust exposure in the coffee factories were significantly higher than in the control factory (geometric mean (GM) 1.23 mg/m³, geometric standard deviation (GSD) (0.8) vs. 0.21(2.4) mg/m³). Coffee workers had significantly higher prevalence than controls for cough with sputum (23% vs. 10%; Prevalence ratio (PR); 2.5, 95% CI 1.0 - 5.9) and chest tightness (27% vs. 13%; PR; 2.4, 95% CI 1.1 - 5.2). The prevalence of morning cough, cough with and without sputum for 4 days or more in a week was also higher among coffee workers than among controls. However, these differences were not statistically significant. Conclusion: Workers exposed to coffee dust reported more respiratory symptoms than did the controls. This might relate to their exposure to coffee dust. Interventions for reduction of dust levels and provision of respiratory protective equipment are recommended.publishedVersio
Evaluating the capacity of human gut microorganisms to colonize the zebrafish larvae (Danio rerio)
Indexación: Scopus.In this study we evaluated if zebrafish larvae can be colonized by human gut microorganisms. We tested two strategies: (1) through transplantation of a human fecal microbiota and (2) by successively transplanting aerotolerant anaerobic microorganisms, similar to the colonization in the human intestine during early life. We used conventionally raised zebrafish larvae harboring their own aerobic microbiota to improve the colonization of anaerobic microorganisms. The results showed with the fecal transplant, that some members of the human gut microbiota were transferred to larvae. Bacillus, Roseburia, Prevotella, Oscillospira, one unclassified genus of the family Ruminococcaceae and Enterobacteriaceae were detected in 3 days post fertilization (dpf) larvae; however only Bacillus persisted to 7 dpf. Successive inoculation of Lactobacillus, Bifidobacterium and Clostridioides did not improve their colonization, compared to individual inoculation of each bacterial species. Interestingly, the sporulating bacteria Bacillus clausii and Clostridioides difficile were the most persistent microorganisms. Their endospores persisted at least 5 days after inoculating 3 dpf larvae. However, when 5 dpf larvae were inoculated, the proportion of vegetative cells in larvae increased, revealing proliferation of the inoculated bacteria and better colonization of the host. In conclusion, these results suggest that it is feasible to colonize zebrafish larvae with some human bacteria, such as C. difficile and Bacillus and open an interesting area to study interactions between these microorganisms and the host. © 2018 Valenzuela, Caruffo, Herrera, Medina, Coronado, Feijóo, Muñoz, Garrido, Troncoso, Figueroa, Toro, Reyes-Jara, Magne and Navarrete.https://www.frontiersin.org/articles/10.3389/fmicb.2018.01032/ful
Personal Exposure to Dust and Endotoxin in Robusta and Arabica Coffee Processing Factories in Tanzania
Introduction: Endotoxin exposure associated with organic dust exposure has been studied in several industries. Coffee cherries that are dried directly after harvest may differ in dust and endotoxin emissions to those that are peeled and washed before drying. The aim of this study was to measure personal total dust and endotoxin levels and to evaluate their determinants of exposure in coffee processing factories. Methods: Using Sidekick Casella pumps at a flow rate of 2l/min, total dust levels were measured in the workers’ breathing zone throughout the shift. Endotoxin was analyzed using the kinetic chromogenic Limulus amebocyte lysate assay. Separate linear mixed-effects models were used to evaluate exposure determinants for dust and endotoxin. Results: Total dust and endotoxin exposure were significantly higher in Robusta than in Arabica coffee factories (geometric mean 3.41 mg/m³ and 10 800 EU/m3 versus 2.10 mg/m³ and 1400 EU/m³, respectively). Dry pre-processed coffee and differences in work tasks explained 30% of the total variance for total dust and 71% of the variance for endotoxin exposure. High exposure in Robusta processing is associated with the dry pre-processing method used after harvest. Conclusions: Dust and endotoxin exposure is high, in particular when processing dry preprocessed coffee. Minimization of dust emissions and use of efficient dust exhaust systems are important to prevent the development of respiratory system impairment in workers
Intrinsic Coupling between Current and Domain Wall Motion in (Ga,Mn)As
We consider current-induced domain wall motion and, the reciprocal process,
moving domain wall-induced current. The associated Onsager coefficients are
expressed in terms of scattering matrices. Uncommonly, in (Ga,Mn)As, the
effective Gilbert damping coefficient and the effective out-of-plane
spin transfer torque parameter are dominated by spin-orbit
interaction in combination with scattering off the domain wall, and not
scattering off extrinsic impurities. Numerical calculations give and in dirty (Ga,Mn)As. The extraordinary large
parameter allows experimental detection of current or voltage induced
by domain wall motion in (Ga,Mn)As.Comment: Final version accepted by Physical Review Letter
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The Musical Abilities, Pleiotropy, Language, and Environment (MAPLE) framework for understanding musicality-language links across the lifespan
Using individual differences approaches, a growing body of literature finds positive associations between musicality and language-related abilities, complementing prior findings of links between musical training and language skills. Despite these associations, musicality has been often overlooked in mainstream models of individual differences in language acquisition and development. To better understand the biological basis of these individual differences, we propose the Musical Abilities, Pleiotropy, Language, and Environment (MAPLE) framework. This novel integrative framework posits that musical and language-related abilities likely share some common genetic architecture (i.e., genetic pleiotropy) in addition to some degree of overlapping neural endophenotypes, and genetic influences on musically and linguistically enriched environments. Drawing upon recent advances in genomic methodologies for unraveling pleiotropy, we outline testable predictions for future research on language development and how its underlying neurobiological substrates may be supported by genetic pleiotropy with musicality. In support of the MAPLE framework, we review and discuss findings from over seventy behavioral and neural studies, highlighting that musicality is robustly associated with individual differences in a range of speech-language skills required for communication and development. These include speech perception-in-noise, prosodic perception, morphosyntactic skills, phonological skills, reading skills, and aspects of second/foreign language learning. Overall, the current work provides a clear agenda and framework for studying musicality-language links using individual differences approaches, with an emphasis on leveraging advances in the genomics of complex musicality and language traits
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