41 research outputs found
Integrated maps in quail (Coturnix japonica) confirm the high degree of synteny conservation with chicken (Gallus gallus) despite 35 million years of divergence
BACKGROUND: By comparing the quail genome with that of chicken, chromosome rearrangements that have occurred in these two galliform species over 35 million years of evolution can be detected. From a more practical point of view, the definition of conserved syntenies helps to predict the position of genes in quail, based on information taken from the chicken sequence, thus enhancing the utility of this species in biological studies through a better knowledge of its genome structure. A microsatellite and an Amplified Fragment Length Polymorphism (AFLP) genetic map were previously published for quail, as well as comparative cytogenetic data with chicken for macrochromosomes. Quail genomics will benefit from the extension and the integration of these maps. RESULTS: The integrated linkage map presented here is based on segregation analysis of both anonymous markers and functional gene loci in 1,050 quail from three independent F2 populations. Ninety-two loci are resolved into 14 autosomal linkage groups and a Z chromosome-specific linkage group, aligned with the quail AFLP map. The size of linkage groups ranges from 7.8 cM to 274.8 cM. The total map distance covers 904.3 cM with an average spacing of 9.7 cM between loci. The coverage is not complete, as macrochromosome CJA08, the gonosome CJAW and 23 microchromosomes have no marker assigned yet. Significant sequence identities of quail markers with chicken enabled the alignment of the quail linkage groups on the chicken genome sequence assembly. This, together with interspecific Fluorescence In Situ Hybridization (FISH), revealed very high similarities in marker order between the two species for the eight macrochromosomes and the 14 microchromosomes studied. CONCLUSION: Integrating the two microsatellite and the AFLP quail genetic maps greatly enhances the quality of the resulting information and will thus facilitate the identification of Quantitative Trait Loci (QTL). The alignment with the chicken chromosomes confirms the high conservation of gene order that was expected between the two species for macrochromosomes. By extending the comparative study to the microchromosomes, we suggest that a wealth of information can be mined in chicken, to be used for genome analyses in quail
Availability and price of malaria rapid diagnostic tests in the public and private health sectors in 2011: results from 10 nationally representative cross-sectional retail surveys.
OBJECTIVES: To describe the state of the public and private malaria diagnostics market shortly after WHO updated its guidelines for testing all suspected malaria cases prior to treatment. METHODS: Ten nationally representative cross-sectional cluster surveys were conducted in 2011 among public and private health facilities, community health workers and retail outlets (pharmacies and drug shops) in nine countries (Tanzania mainland and Zanzibar surveyed separately). Eligible outlets had antimalarials in stock on the day of interview or had stocked antimalarials in the past 3 months. RESULTS: Three thousand four hundred and thirty-nine rapid diagnostic test (RDT) products from 39 manufacturers were audited among 12,197 outlets interviewed. Availability was typically highest in public health facilities, although availability in these facilities varied greatly across countries, from 15% in Nigeria to >90% in Madagascar and Cambodia. Private for-profit sector availability was 46% in Cambodia, 20% in Zambia, but low in other countries. Median retail prices for RDTs in the private for-profit sector ranged from 3.13 in Zambia. The reported number of RDTs used in the 7 days before the survey in public health facilities ranged from 3 (Benin) to 50 (Zambia). CONCLUSIONS: Eighteen months after WHO updated its case management guidelines, RDT availability remained poor in the private sector in sub-Saharan Africa. Given the ongoing importance of the private sector as a source of fever treatment, the goal of universal diagnosis will not be achievable under current circumstances. These results constitute national baselines against which progress in scaling-up diagnostic tests can be assessed
An assessment of the malaria-related knowledge and practices of Tanzania's drug retailers: exploring the impact of drug store accreditation.
BACKGROUND: Since 2003 Tanzania has upgraded its approximately 7000 drug stores to Accredited Drug Dispensing Outlets (ADDOs), involving dispenser training, introduction of record keeping and enhanced regulation. Prior to accreditation, drug stores could officially stock over-the-counter medicines only, though many stocked prescription-only antimalarials. ADDOs are permitted to stock 49 prescription-only medicines, including artemisinin combination therapies and one form of quinine injectable. Oral artemisinin monotherapies and other injectables were not permitted at any time. By late 2011 conversion was complete in 14 of 21 regions. We explored variation in malaria-related knowledge and practices of drug retailers in ADDO and non-ADDO regions. METHODS: Data were collected as part of the Independent Evaluation of the Affordable Medicines Facility - malaria (AMFm), involving a nationally representative survey of antimalarial retailers in October-December 2011. We randomly selected 49 wards and interviewed all drug stores stocking antimalarials. We compare ADDO and non-ADDO regions, excluding the largest city, Dar es Salaam, due to the unique characteristics of its market. RESULTS: Interviews were conducted in 133 drug stores in ADDO regions and 119 in non-ADDO regions. Staff qualifications were very similar in both areas. There was no significant difference in the availability of the first line antimalarial (68.9% in ADDO regions and 65.2% in non-ADDO regions); both areas had over 98% availability of non-artemisinin therapies and below 3.0% of artemisinin monotherapies. Staff in ADDO regions had better knowledge of the first line antimalarial than non-ADDO regions (99.5% and 91.5%, p = 0.001). There was weak evidence of a lower price and higher market share of the first line antimalarial in ADDO regions. Drug stores in ADDO regions were more likely to stock ADDO-certified injectables than those in non-ADDO regions (23.0% and 3.9%, p = 0.005). CONCLUSIONS: ADDO conversion is frequently cited as a model for improving retail sector drug provision. Drug stores in ADDO regions performed better on some indicators, possibly indicating some small benefits from ADDO conversion, but also weaknesses in ADDO regulation and high staff turnover. More evidence is needed on the value-added and value for money of the ADDO roll out to inform retail policy in Tanzania and elsewhere
Circulating and gut-resident human Th17 cells express CD161 and promote intestinal inflammation
The C-type lectin-like receptor CD161, which has recently been described to promote T cell expansion, is expressed on a discrete subset of human CD4 T cells. The function of such cells, however, has remained elusive. We now demonstrate that CD161+ CD4 T cells comprise a circulating and gut-resident T helper 17 (Th17) cell population. During Crohn's disease (CD), these CD161+ cells display an activated Th17 phenotype, as indicated by increased expression of interleukin (IL)-17, IL-22, and IL-23 receptor. CD161+ CD4 T cells from CD patients readily produce IL-17 and interferon γ upon stimulation with IL-23, whereas, in healthy subjects, priming by additional inflammatory stimuli such as IL-1β was required to enable IL-23–induced cytokine release. Circulating CD161+ Th17 cells are imprinted for gut homing, as indicated by high levels of CC chemokine receptor 6 and integrin β7 expression. Supporting their colitogenic phenotype, CD161+ Th17 cells were found in increased numbers in the inflammatory infiltrate of CD lesions and induced expression of inflammatory mediators by intestinal cells. Our data identify CD161+ CD4 T cells as a resting Th17 pool that can be activated by IL-23 and mediate destructive tissue inflammation
Prostaglandin E2 regulates Th17 cell differentiation and function through cyclic AMP and EP2/EP4 receptor signaling
Prostaglandins, particularly prostaglandin E2 (PGE2), play an important role during inflammation. This is exemplified by the clinical use of cyclooxygenase 2 inhibitors, which interfere with PGE2 synthesis, as effective antiinflammatory drugs. Here, we show that PGE2 directly promotes differentiation and proinflammatory functions of human and murine IL-17–producing T helper (Th17) cells. In human purified naive T cells, PGE2 acts via prostaglandin receptor EP2- and EP4-mediated signaling and cyclic AMP pathways to up-regulate IL-23 and IL-1 receptor expression. Furthermore, PGE2 synergizes with IL-1β and IL-23 to drive retinoic acid receptor–related orphan receptor (ROR)-γt, IL-17, IL-17F, CCL20, and CCR6 expression, which is consistent with the reported Th17 phenotype. While enhancing Th17 cytokine expression mainly through EP2, PGE2 differentially regulates interferon (IFN)-γ production and inhibits production of the antiinflammatory cytokine IL-10 in Th17 cells predominantly through EP4. Furthermore, PGE2 is required for IL-17 production in the presence of antigen-presenting cells. Hence, the combination of inflammatory cytokines and noncytokine immunomodulators, such as PGE2, during differentiation and activation determines the ultimate phenotype of Th17 cells. These findings, together with the altered IL-12/IL-23 balance induced by PGE2 in dendritic cells, further highlight the crucial role of the inflammatory microenvironment in Th17 cell development and regulation
Improving access to malaria medicine through private-sector subsidies in seven African countries.
Improving access to quality-assured artemisinin combination therapies (ACTs) is an important component of malaria control in low- and middle-income countries. In 2010 the Global Fund to Fight AIDS, Tuberculosis, and Malaria launched the Affordable Medicines Facility--malaria (AMFm) program in seven African countries. The goal of the program was to decrease malaria morbidity and delay drug resistance by increasing the use of ACTs, primarily through subsidies intended to reduce costs. We collected data on price and retail markups on antimalarial medicines from 19,625 private for-profit retail outlets before and 6-15 months after the program's implementation. We found that in six of the AMFm pilot programs, prices for quality-assured ACTs decreased by US4.34, and absolute retail markups on these therapies decreased by US1.03. Prices and markups on other classes of antimalarials also changed during the evaluation period, but not to the same extent. In all but two of the pilot programs, we found evidence that prices could fall further without suppliers' losing money. Thus, concerns may be warranted that wholesalers and retailers are capturing subsidies instead of passing them on to consumers. These findings demonstrate that supranational subsidies can dramatically reduce retail prices of health commodities and that recommended retail prices communicated to a wide audience may be an effective mechanism for controlling the market power of private-sector antimalarial retailers and wholesalers
Cytokine-Mediated Crosstalk Between Keratinocytes and T Cells in Atopic Dermatitis
International audienceAtopic dermatitis (AD) is a chronic inflammatory skin disease characterized by barrier dysfunction, dysregulated immune response, and dysbiosis with increased Staphylococcus aureus colonization. Infiltration of various T helper cell subsets into lesional skin and subsequent cytokine release are a hallmark of AD. Release of cytokines by both T cells and keratinocytes plays a key role in skin inflammation and drives many AD features. This review aims to discuss cytokine-mediated crosstalk between T cells and keratinocytes in AD pathogenesis and the potential impact of virulence factors produced by Staphylococcus aureus on these interactions.</jats:p
IL-17 in the Rheumatologist’s Line of Sight
Over the past decades, the identification of several new cytokines, including interleukin (IL)-17 and IL-23, and of new T helper cell subsets, including Th17 cells, has changed the vision of immunological processes. The IL-17/Th17 pathway plays a critical role during the development of inflammation and autoimmunity, and targeting this pathway has become an attractive strategy for a number of diseases. This review aims to describe the effects of IL-17 in the joint and its roles in the development of autoimmune and inflammatory arthritis. Furthermore, biotherapies targeting directly or indirectly IL-17 in inflammatory rheumatisms will be developed