403 research outputs found
Arginase and Arginine Dysregulation in Asthma
In recent years, evidence has accumulated indicating that the enzyme arginase, which converts L-arginine into L-ornithine and urea, plays a key role in the pathogenesis of pulmonary disorders such as asthma through dysregulation of L-arginine metabolism and modulation of nitric oxide (NO) homeostasis. Allergic asthma is characterized by airway hyperresponsiveness, inflammation, and remodeling. Through substrate competition, arginase decreases bioavailability of L-arginine for nitric oxide synthase (NOS), thereby limiting NO production with subsequent effects on airway tone and inflammation. By decreasing L-arginine bioavailability, arginase may also contribute to the uncoupling of NOS and the formation of the proinflammatory oxidant peroxynitrite in the airways. Finally, arginase may play a role in the development of chronic airway remodeling through formation of L-ornithine with downstream production of polyamines and L-proline, which are involved in processes of cellular proliferation and collagen deposition. Further research on modulation of arginase activity and L-arginine bioavailability may reveal promising novel therapeutic strategies for asthma
Family and home correlates of television viewing in 12β13 year old adolescents: The Nepean Study
BACKGROUND: Few young people meet television viewing guidelines. PURPOSE: To determine the association between factors in the family and home environment and watching television, including videos and DVDs, in early adolescence. METHODS: Cross-sectional, self-report survey of 343 adolescents aged 12β13 years (173 girls), and their parents (338 mothers, 293 fathers). Main measures were factors in the family and home environment potentially associated with adolescents spending β₯ 2 hours per day in front of the television. Factors examined included family structure, opportunities to watch television/video/DVDs, perceptions of rules and regulations on television viewing, and television viewing practices. RESULTS: Two-thirds of adolescents watched β₯ 2 hours television per day. Factors in the family and home environment associated with adolescents watching television β₯ 2 hours per day include adolescents who have siblings (Adjusted Odds Ratio [95%CI] AOR = 3.0 [1.2, 7.8]); access to pay television (AOR = 2.0 [1.1, 3.7]); ate snacks while watching television (AOR = 3.1 [1.8, 5.4]); co-viewed television with parents (AOR = 2.3 [1.3, 4.2]); and had mothers who watched β₯ 2 hours television per day (AOR = 2.4 [1.3, 4.6]). CONCLUSION: There are factors in the family and home environment that influence the volume of television viewed by 12β13 year olds. Television plays a central role in the family environment, potentially providing a means of recreation among families of young adolescents for little cost. Interventions which target family television viewing practices and those of parents, in particular, are more likely to be effective than interventions which directly target adolescent viewing times
Respiratory and sleep disorders in mucopolysaccharidosis
MPS encompasses a group of rare lysosomal storage disorders that are associated with the accumulation of glycosaminoglycans (GAG) in organs and tissues. This accumulation can lead to the progressive development of a variety of clinical manifestations. Ear, nose, throat (ENT) and respiratory problems are very common in patients with MPS and are often among the first symptoms to appear. Typical features of MPS include upper and lower airway obstruction and restrictive pulmonary disease, which can lead to chronic rhinosinusitis or chronic ear infections, recurrent upper and lower respiratory tract infections, obstructive sleep apnoea, impaired exercise tolerance, and respiratory failure. This review provides a detailed overview of the ENT and respiratory manifestations that can occur in patients with MPS and discusses the issues related to their evaluation and management. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s10545-012-9555-1) contains supplementary material, which is available to authorized users
The development, implementation and early learnings of a training program to advance interest in behavioral research careers among undergraduate BIPOC students majoring in psychology.
OBJECTIVES: Black, indigenous and people of color (BIPOC) remain underrepresented in research occupations. This report discusses a collaboration to train undergraduate BIPOC students in clinical research between a public health institute, two medical schools, and a historically Black College or University (HBCU). This nine-month program trained BIPOC undergraduates in research methodology, psychology, and addiction science, and immersed trainees in real-world research. The program included didactic seminars, experiential activities, and a mentored research project culminating in a poster and oral presentation.
METHODS: Key learnings, program satisfaction survey results, and preliminary outcomes from the first three program cohorts (Nβ=β6 students) are presented. This program addressed several barriers hypothesized to contribute to the limited number of BIPOC students pursuing research careers, including mentorship from BIPOC faculty and financial concerns.
RESULTS: Students reported moderate to high satisfaction with the program and endorsed gaining new research skills. Limitations and future directions are discussed.
CONCLUSION: The expansion of the BIPOC health and research workforce is an urgent priority given the importance of BIPOC professionals to the health of our nation.
TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04650386
Identification of novel subgroup a variants with enhanced receptor binding and replicative capacity in primary isolates of anaemogenic strains of feline leukaemia virus
<b>BACKGROUND:</b>
The development of anaemia in feline leukaemia virus (FeLV)-infected cats is associated with the emergence of a novel viral subgroup, FeLV-C. FeLV-C arises from the subgroup that is transmitted, FeLV-A, through alterations in the amino acid sequence of the receptor binding domain (RBD) of the envelope glycoprotein that result in a shift in the receptor usage and the cell tropism of the virus. The factors that influence the transition from subgroup A to subgroup C remain unclear, one possibility is that a selective pressure in the host drives the acquisition of mutations in the RBD, creating A/C intermediates with enhanced abilities to interact with the FeLV-C receptor, FLVCR. In order to understand further the emergence of FeLV-C in the infected cat, we examined primary isolates of FeLV-C for evidence of FeLV-A variants that bore mutations consistent with a gradual evolution from FeLV-A to FeLV-C.<p></p>
<b>RESULTS:</b>
Within each isolate of FeLV-C, we identified variants that were ostensibly subgroup A by nucleic acid sequence comparisons, but which bore mutations in the RBD. One such mutation, N91D, was present in multiple isolates and when engineered into a molecular clone of the prototypic FeLV-A (Glasgow-1), enhanced replication was noted in feline cells. Expression of the N91D Env on murine leukaemia virus (MLV) pseudotypes enhanced viral entry mediated by the FeLV-A receptor THTR1 while soluble FeLV-A Env bearing the N91D mutation bound more efficiently to mouse or guinea pig cells bearing the FeLV-A and -C receptors. Long-term in vitro culture of variants bearing the N91D substitution in the presence of anti-FeLV gp70 antibodies did not result in the emergence of FeLV-C variants, suggesting that additional selective pressures in the infected cat may drive the subsequent evolution from subgroup A to subgroup C.<p></p>
<b>CONCLUSIONS:</b>
Our data support a model in which variants of FeLV-A, bearing subtle differences in the RBD of Env, may be predisposed towards enhanced replication in vivo and subsequent conversion to FeLV-C. The selection pressures in vivo that drive the emergence of FeLV-C in a proportion of infected cats remain to be established
FIRE (facilitating implementation of research evidence) : a study protocol
Research evidence underpins best practice, but is not always used in healthcare. The Promoting Action on Research Implementation in Health Services (PARIHS) framework suggests that the nature of evidence, the context in which it is used, and whether those trying to use evidence are helped (or facilitated) affect the use of evidence. Urinary incontinence has a major effect on quality of life of older people, has a high prevalence, and is a key priority within European health and social care policy. Improving continence care has the potential to improve the quality of life for older people and reduce the costs associated with providing incontinence aids
Reduced Expression of IFIH1 Is Protective for Type 1 Diabetes
IFIH1 (interferon induced with helicase C domain 1), also known as MDA5 (melanoma differentiation-associated protein 5), is one of a family of intracellular proteins known to recognise viral RNA and mediate the innate immune response. IFIH1 is causal in type 1 diabetes based on the protective associations of four rare variants, where the derived alleles are predicted to reduce gene expression or function. Originally, however, T1D protection was mapped to the common IFIH1 nsSNP, rs1990760 or Thr946Ala. This common amino acid substitution does not cause a loss of function and evidence suggests the protective allele, Ala946, may mark a haplotype with reduced expression of IFIH1 in line with the protection conferred by the four rare loss of function alleles. We have performed allele specific expression analysis that supports this hypothesis: the T1D protective haplotype correlates with reduced IFIH1 transcription in interferon-Ξ² stimulated peripheral blood mononuclear cells (overall pβ=β0.012). In addition, we have used multiflow cytometry analysis and quantitative PCR assays to prove reduced expression of IFIH1 in individuals heterozygous for three of the T1D-associated rare alleles: a premature stop codon, rs35744605 (Glu627X) and predicted splice variants, rs35337543 (IVS8+1) and rs35732034 (IVS14+1). We also show that the nsSNP, Ile923V, does not alter pre-mRNA levels of IFIH1. These results confirm and extend the new autoimmune disease pathway of reduced IFIH1 expression and protein function protecting from T1D
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The impact of biogenic carbon emissions on aerosol absorption inMexico City
In order to determine the wavelength dependence of atmospheric aerosol absorption in the Mexico City area, the absorption angstrom exponents (AAEs) were calculated from aerosol absorption measurements at seven wavelengths obtained with a seven-channel aethalometer during two field campaigns, the Mexico City Metropolitan Area study in April 2003 (MCMA 2003) and the Megacity Initiative: Local and Global Research Observations in March 2006 (MILAGRO). The AAEs varied from 0.76 to 1.56 in 2003 and from 0.54 to 1.52 in 2006. The AAE values determined in the afternoon were consistently higher than the corresponding morning values, suggesting the photochemical formation of absorbing secondary organic aerosols (SOA) in the afternoon. The AAE values were compared to stable and radiocarbon isotopic measurements of aerosol samples collected at the same time to determine the sources of the aerosol carbon. The fraction of modern carbon (fM) in the aerosol samples, as determined from {sup 14}C analysis, showed that 70% of the carbonaceous aerosols in Mexico City were from modern sources, indicating a significant impact from biomass burning during both field campaigns. The {sup 13}C/{sup 12}C ratios of the aerosol samples illustrate the significant impact of Yucatan forest fires (C-3 plants) in 2003 and local grass fires (C-4 plants) at site T1 in 2006. A direct comparison of the fM values, stable carbon isotope ratios, and calculated aerosol AAEs suggested that the wavelength dependence of the aerosol absorption was controlled by the biogenically derived aerosol components
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