73 research outputs found
Natural anti-CCR5 antibodies in HIV-infection and -exposure
Natural antibodies constitute a first-line of defence against pathogens; they may also play other roles in immune regulation and homeostasis, through their ability to bind host antigens, surface molecules and receptors. Natural anti-CCR5 antibodies can be decisive in preventing HIV infection in mucosal tissues and offer prompt and effective protection just at major sites of virus entry. Among natural anti-CCR5 antibodies, IgG and IgA to the ECL1 domain have been shown to block HIV effectively and durably without causing harm to the host. Their biological properties and their uncommon generation in subsets of HIV-infected and HIV-exposed individuals (so called ESN) will be introduced and discussed, with the aim at exploiting their potential in therapy and prevention
Socio-economic status, racial composition and the affordability of fresh fruits and vegetables in neighborhoods of a large rural region in Texas
<p>Abstract</p> <p>Background</p> <p>Little is known about how affordability of healthy food varies with community characteristics in rural settings. We examined how the cost of fresh fruit and vegetables varies with the economic and demographic characteristics in six rural counties of Texas.</p> <p>Methods</p> <p>Ground-truthed data from the Brazos Valley Food Environment Project were used to identify all food stores in the rural region and the availability and lowest price of fresh whole fruit and vegetables in the food stores. Socioeconomic characteristics were extracted from the 2000 U.S. Census Summary Files 3 at the level of the census block group. We used an imputation strategy to calculate two types of price indices for both fresh fruit and fresh vegetables: a <it>high variety </it>and a <it>basic </it>index; and evaluated the relationship between neighborhood economic and demographic characteristics and affordability of fresh produce, using linear regression models.</p> <p>Results</p> <p>The mean cost of meeting the USDA recommendation of fruit consumption from a high variety basket of fruit types in our sample of stores was just over 17.25 per week, a reduction of 37.6%. The effect of moving from a high variety to a low variety basket was much less when considering vegetable consumption: a 4.3% decline from 27.97 per week. Univariate regression analysis revealed that the cost of fresh produce is not associated with the racial/ethnic composition of the local community. However, multivariate regression showed that holding median income constant, stores in neighborhoods with higher percentages of Black residents paid more for fresh fruits and vegetables. The proportion of Hispanic residents was not associated with cost in either the univariate or multivariate analysis.</p> <p>Conclusion</p> <p>This study extends prior work by examining the affordability of fresh fruit and vegetables from food stores in a large rural area; and how access to an affordable supply of fresh fruit and vegetables differs by neighborhood inequalities. The approach and findings of this study are relevant and have important research and policy implications for understanding access and availability of affordable, healthy foods.</p
Functional Comparison of Innate Immune Signaling Pathways in Primates
Humans respond differently than other primates to a large number of infections. Differences in susceptibility to infectious agents between humans and other primates are probably due to inter-species differences in immune response to infection. Consistent with that notion, genes involved in immunity-related processes are strongly enriched among recent targets of positive selection in primates, suggesting that immune responses evolve rapidly, yet providing only indirect evidence for possible inter-species functional differences. To directly compare immune responses among primates, we stimulated primary monocytes from humans, chimpanzees, and rhesus macaques with lipopolysaccharide (LPS) and studied the ensuing time-course regulatory responses. We find that, while the universal Toll-like receptor response is mostly conserved across primates, the regulatory response associated with viral infections is often lineage-specific, probably reflecting rapid host–virus mutual adaptation cycles. Additionally, human-specific immune responses are enriched for genes involved in apoptosis, as well as for genes associated with cancer and with susceptibility to infectious diseases or immune-related disorders. Finally, we find that chimpanzee-specific immune signaling pathways are enriched for HIV–interacting genes. Put together, our observations lend strong support to the notion that lineage-specific immune responses may help explain known inter-species differences in susceptibility to infectious diseases
The Phospholipid Scramblases 1 and 4 Are Cellular Receptors for the Secretory Leukocyte Protease Inhibitor and Interact with CD4 at the Plasma Membrane
Secretory leukocyte protease inhibitor (SLPI) is secreted by epithelial cells in all the mucosal fluids such as saliva, cervical mucus, as well in the seminal liquid. At the physiological concentrations found in saliva, SLPI has a specific antiviral activity against HIV-1 that is related to the perturbation of the virus entry process at a stage posterior to the interaction of the viral surface glycoprotein with the CD4 receptor. Here, we confirm that recombinant SLPI is able to inhibit HIV-1 infection of primary T lymphocytes, and show that SLPI can also inhibit the transfer of HIV-1 virions from primary monocyte-derived dendritic cells to autologous T lymphocytes. At the molecular level, we show that SLPI is a ligand for the phospholipid scramblase 1 (PLSCR1) and PLSCR4, membrane proteins that are involved in the regulation of the movements of phospholipids between the inner and outer leaflets of the plasma membrane. Interestingly, we reveal that PLSCR1 and PLSCR4 also interact directly with the CD4 receptor at the cell surface of T lymphocytes. We find that the same region of the cytoplasmic domain of PLSCR1 is involved in the binding to CD4 and SLPI. Since SLPI was able to disrupt the association between PLSCR1 and CD4, our data suggest that SLPI inhibits HIV-1 infection by modulating the interaction of the CD4 receptor with PLSCRs. These interactions may constitute new targets for antiviral intervention
A systematic review of methods for increasing vegetable consumption in early childhood
PURPOSE OF REVIEW: This study aims to synthesise the body of research investigating methods for increasing vegetable consumption in 2- to 5-year-old children, while offering advice for practitioners. RECENT FINDINGS: Repeated exposure is a well-supported method for increasing vegetable consumption in early childhood and may be enhanced with the inclusion of non-food rewards to incentivise tasting. Peer models appear particularly effective for increasing 2-5-year-olds' vegetable consumption. There is little evidence for the effectiveness of food adaptations (e.g. flavour-nutrient learning) for increasing general vegetable intake among this age group, although they show some promise with bitter vegetables. SUMMARY: This review suggests that practitioners may want to focus their advice to parents around strategies such as repeated exposure, as well as the potential benefits of modelling and incentivising tasting with non-food rewards. Intervention duration varies greatly, and considerations need to be made for how this impacts on success
Increasing vegetable intakes: rationale and systematic review of published interventions
Purpose
While the health benefits of a high fruit and vegetable consumption are well known and considerable work has attempted to improve intakes, increasing evidence also recognises a distinction between fruit and vegetables, both in their impacts on health and in consumption patterns. Increasing work suggests health benefits from a high consumption specifically of vegetables, yet intakes remain low, and barriers to increasing intakes are prevalent making intervention difficult. A systematic review was undertaken to identify from the published literature all studies reporting an intervention to increase intakes of vegetables as a distinct food group.
Methods
Databases—PubMed, PsychInfo and Medline—were searched over all years of records until April 2015 using pre-specified terms.
Results
Our searches identified 77 studies, detailing 140 interventions, of which 133 (81 %) interventions were conducted in children. Interventions aimed to use or change hedonic factors, such as taste, liking and familiarity (n = 72), use or change environmental factors (n = 39), use or change cognitive factors (n = 19), or a combination of strategies (n = 10). Increased vegetable acceptance, selection and/or consumption were reported to some degree in 116 (83 %) interventions, but the majority of effects seem small and inconsistent.
Conclusions
Greater percent success is currently found from environmental, educational and multi-component interventions, but publication bias is likely, and long-term effects and cost-effectiveness are rarely considered. A focus on long-term benefits and sustained behaviour change is required. Certain population groups are also noticeably absent from the current list of tried interventions
Utilisation des Gibbérellines comme Facteur de Remodelage du cycle fructifère du citronnier ‘Euréka’ (Citrus limon L.)
Objectif : Cette étude de deux années a été menée afin d’essayer de remodeler la répartition des récoltes des citronniers "Euréka" (Citrus limon L.) dans le but d’approvisionner le marché local tunisien au printemps et en été, où la demande est la plus élevée, par l’utilisation de l'acide gibbérellique (GA3).Méthodologie et Résultat : Deux traitements de GA3 à 20 et à 40 ppm ont été effectués en Novembre, période correspondant à la l’induction florale printanière, dans le but d'accentuer la floraison estivale et automnale, et par conséquent obtenir une production au printemps suivant et surtout en été de l’année d’après. Les traitements au GA3 effectués en automne ont permis de retarder le développement des boutons floraux printaniers de deux semaines par rapport aux arbres témoins. En outre une diminution significative de la floraison printanière a été enregistrée pour le traitement à 40 ppm (- 25%) ce qui a influencé la production hivernale l’année suivante. Ainsi une corrélation positive a été révélée entre le taux de nouaison des fleurs estivales et automnales avec le niveau de concentration de GA3 apporté. En effet, on a pu constater une amélioration significative du taux de nouaison des fleurs estivales (+11%) et des fleurs automnales (+20%) des arbres qui ont reçu les traitements à 40 ppm par rapport aux arbres témoins. De plus, un remodelage de la répartition des récoltes a été réalisé à la 2ème année de traitement, par un transfert de la récolte hivernale vers les récoltes printanières et estivales et les effets ont été plus prononcés pour le traitement à 40 ppm. Ce traitement avait augmenté significativement la production printanière de +4.9% et estivale de +15.9% par rapport au témoin. Egalement une réduction de -20,8% de la production d'hiver, comparativement aux arbres témoins, a été observée.Conclusion et application : Cette étude a permis de remodeler le cycle fructifère du citronnier Euréka par l’utilisation de l’acide gibbérellique pour mieux répondre aux besoins du marché local au printemps et en été.Mots clés : Citronnier ‘Euréka’, floraison, productions, remodelage, acide gibbérellique
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