16 research outputs found
Correction to: Childhood disability in Malawi: a population based assessment using the key informant method.
Following the publication of this article [1] it was brought to our attention that inadvertently the COSECSA Oxford Orthopaedic Link (COOL) programme was not acknowledged for funding this study
Assessing the prevalence of sensory and motor impairments in childhood in Bangladesh using key informants.
OBJECTIVES: The study was conducted to determine whether trained key informants (KI) could identify children with impairments. DESIGN: Trained KI identified children with defined impairments/epilepsy who were then examined by a medical team at a nearby assessment centre (Key Informant Methodology: KIM). A population-based household randomised sample survey was also conducted for comparing the prevalence estimates. SETTING: Three districts in North Bangladesh. PARTICIPANTS: Study population of approximately 258â
000 children aged 0-<18â
years, within which 3910 children were identified by KI, 94.8% of whom attended assessment camps. In the household survey, 8120 children were examined, of whom 119 were identified with an impairment/epilepsy. MAIN OUTCOME MEASURES: Prevalence estimates of severe visual impairment (SVI), moderate/severe hearing impairment (HI), substantial physical impairment (PI) and epilepsy. RESULTS: Overall prevalence estimates of impairments, including presumed HI, showed significant differences comparing KIM (9.0/1000 (95% CI 8.7 to 9.4)) with the household survey (14.7/1000 (95% CI 12.0 to 17.3)). Good agreement was observed for SVI (KIM 0.7/1000 children: survey 0.5/1000), PI (KIM 6.2/1000 children: survey 8.0/1000) and epilepsy (KIM 1.5/1000 children: survey 2.2/1000). Prevalence estimates for HI were much lower using KIM (2/1000) compared to the survey (6.4/1000). Excluding HI, overall prevalence estimates were similar (KIM: 7.5/1000 children (95% CI 7.2 to 7.8) survey: 8.4/1000 (95% CI 6.4 to 10.4)). CONCLUSIONS: KIM offers a low cost and relatively rapid way to identify children with SVI, PI and epilepsy in Bangladesh. HI is underestimated using KIM, requiring further research
A bi-functional IL-6-HaloTagÂź as a tool to measure the cell-surface expression of recombinant odorant receptors and to facilitate their activity quantification
The functional cell surface expression of recombinant odorant receptors typically has been investigated by expressing N-terminally extended, âtaggedâ receptors in test cell systems, using antibody-based immunocytochemistry or flow cytometry, and by measuring odorant/receptor-induced cAMP signaling, mostly by an odorant/receptor-induced and cAMP signaling-dependent transcriptional activation of a luciferase-based luminescence assay. In the present protocol, we explain a method to measure the cell-surface expression and signaling of recombinant odorant receptors carrying a bi-functional, N-terminal âIL-6-HaloTagÂźâ. IL-6, being a secreted cytokine, facilitates functional cell surface expression of recombinant HaloTagÂź-odorant receptors, and the HaloTagÂź protein serves as a highly specific acceptor for cell-impermeant or cell-permeant, fluorophore-coupled ligands, which enable the quantification of odorant receptor expression by antibody-independent, chemical live-cell staining and flow cytometry. Here, we describe how to measure the cell surface expression of recombinant IL-6-HaloTagÂź-odorant receptors in HEK-293 cells or NxG 108CC15 cells, by live-cell staining and flow cytometry, and how to measure an odorant-induced activation of these receptors by the fast, real-time, luminescence-based GloSensorÂź cAMP assay
IL-6
The assignment of cognate odorant/agonist pairs is a prerequisite for an understanding of odorant coding at the receptor level. However, the identification of new ligands for odorant receptors in cell-based assays has been challenging, due to their individual and rather sub-optimal plasma membrane expression, as compared with other G protein-coupled receptors. Accessory proteins, such as the chaperone RTP1S, or Ric8b, have improved the surface expression of at least a portion of odorant receptors. Typically, recombinant odorant receptors carry N-terminal tags, which proved helpful for their functional membrane expression. The most common tag is the âRho-tagâ, representing an N-terminal part of rhodopsin, but also âLucy-â or âFlag-tagâ extensions have been described. Here, we used a bi-functional N-terminal tag, called âIL-6-HaloTagÂźâ, with IL-6 facilitating functional cell surface expression of recombinant odorant receptors, and the HaloTagÂź protein, serving as a highly specific acceptor for cell-impermeant or cell-permeant, fluorophore-coupled ligands, which enable the quantification of odorant receptor expression by live-cell flow cytometry. Our experiments revealed on average an about four-fold increased surface expression, a four-fold higher signaling amplitude, and a significant higher potency of odorant-induced cAMP signaling of six different human IL-6-HaloTagÂź-odorant receptors across five different receptor families in NxG 108CC15 cells, as compared to their Rho-tagâHaloTagÂź constructs. We observed similar results in HEK-293 cells. Moreover, screening an IL-6âHaloTagÂź-odorant receptor library with allyl phenyl acetate, revealed both known receptors as best responders for this compound. In summary, the IL-6âHaloTagÂź represents a promising tool for the de-orphaning of odorant receptors
OR2M3: A highly specific and narrowly tuned human odorant receptor for the sensitive detection of onion key food odorant 3-Mercapto-2-methylpentan-1-ol
The detection of key food odorants appears to be an important capability of odorant receptors. Here, thiols occupy an outstanding position among the 230 known key food odorants because of their very low odor thresholds. Members of the homologous series of 3-mercapto-2-methylalkan-1-ols have been described as onion key food odorants or food constituents and are detected at logarithmically different thresholds. 3-Mercapto-2-methylpentan-1-ol being the only key food odorant within this series also has the lowest odor threshold. Most odorants typically activate combinations of odorant receptors, which may be narrowly or broadly tuned. Consequently, a specific receptor activation pattern will define an odor quality. In contrast, here we show that just 1 of the 391 human odorant receptors, OR2M3, responded exclusively to 3-mercapto-2-methylpentan-1-ol of the 190 key food odorants tested, with a half maximal effective concentration at submicromolar concentration. Moreover, neither the Denisovan OR2M3 nor the closest OR2M3 homologs from five species did respond to this compound. This outstanding specificity of extremely narrowly tuned human OR2M3 can explain both odor qualities and odor threshold trend within a homologous series of 3-mercapto-2-methylalkan-1-ols and suggests a modern human-specific, food-related function of OR2M3 in detecting a single onion key food odorant
Monthly or Weekly Supplementation with Cholecalciferol 20,000 IU in People Living with HIV: Results from a Nested Cohort Study
Background. There is still considerable uncertainty in handling vitamin D deficiency in people living with HIV (PLWH), due to a lack of comparative data and the wide range of recommended daily intake. Nondaily supplementation might be preferred in many PLWH, but recommendation on dosing has not been established. We aimed to compare the efficacy of weekly versus monthly supplementation with cholecalciferol 20,000 IU in a group of PLWH with vitamin D deficiency in Western Europe. Study Design. Longitudinal, retrospective nested cohort study of PLWH from two large clinical care centers in Munich, Germany. Results. Of 307 patients with vitamin D deficiency, 124 patients received vitamin D supplementation (weekly supplementation in 84 (67.7%)). 46.4% and 22.5% of patients achieved 25(OH)D levels â„30 ng/mL after 12 months of weekly and monthly supplementation with cholecalciferol 20,000 IU, respectively (p=0.011). Dosing interval as well as 25(OH)D baseline levels >15 ng/mL were associated with the normalization of 25(OH)D. Conclusion. A higher rate of 25(OH)D level normalization can be achieved via weekly supplementation. For several PLWH, even a weekly dose of cholecalciferol 20,000 IU might not be adequate to maintain 25(OH)D levels >30 ng/mL without an initial âloadingâ dose. The response to supplementation is poorly predictable at an individual level
International REgistry to assess medical Practice with lOngitudinal obseRvation for Treatment of Heart Failure (REPORT-HF): Rationale for and design of a global registry
Aims. The clinical characteristics, initial presentation, management, and outcomes of patients hospitalized with new-onset (first diagnosis) heart failure (HF) or decompensation of chronic HF are poorly understood worldwide. REPORT-HF (International REgistry to assess medical Practice with lOngitudinal obseRvation for Treatment of Heart Failure) is a global, prospective, and observational study designed to characterize patient trajectories longitudinally during and following an index hospitalization for HF. Methods. Data collection for the registry will be conducted at âŒ300 sites located in âŒ40 countries. Comprehensive data including demographics, clinical presentation, co-morbidities, treatment patterns, quality of life, in-hospital and post-discharge outcomes, and health utilization and costs will be collected. Enrolment of âŒ20 000 adult patients hospitalized with new-onset (first diagnosis) HF or decompensation of chronic HF over a 3-year period is planned with subsequent 3 years follow-up. Perspective. The REPORT-HF registry will explore the clinical characteristics, management, and outcomes of HF worldwide. This global research programme may have implications for the formulation of public health policy and the design and conduct of international clinical trials
Impaired expression and function of the bile salt export pump due to three novel ABCB11 mutations in intrahepatic cholestasis
BACKGROUND/AIMS: Inherited dysfunction of the bile salt export pump BSEP (ABCB11) causes a progressive and a benign form of familial intrahepatic cholestasis, denominated as PFIC2 and BRIC2, respectively. We functionally characterized novel ABCB11 mutations encountered in two patients with a PFIC2 and a BRIC2 phenotype, respectively. METHODS: BSEP expression was determined in liver biopsies by immunohistochemistry. ABCB11 mutations were functionally characterized by taurocholate transport in SF9 cells transfected with human ABCB11. RESULTS: The PFIC2 patient was compound heterozygous for a splicing mutation in intron 4 ((+3)A < C) combined with an early stop codon at position 930 (R930X), while the BRIC2 patient was compound heterozygous for two nonsynonymous mutations in exon 9 (E297G) and exon 12 (R432T), respectively. Hepatic BSEP expression was absent in PFIC2 and preserved in BRIC2. In BRIC2, taurocholate transport was decreased to 13% and 20% of reference levels for R432T and E297G, respectively. CONCLUSIONS: The intron 4 (+3)A < C, R930X and R432T represent previously undescribed mutations of the ABCB11 gene that confer a PFIC2 and a BRIC2 phenotype, respectively. By combining functional in-vitro characterization with immunohistochemical detection of variant BSEP we provide direct evidence for the role of ABCB11 mutations in the pathogenesis of different forms of intrahepatic cholestasis
Correction to: Childhood disability in Malawi: a population based assessment using the key informant method
Helicobacter pylori HtrA is a new secreted virulence factor that cleaves E-cadherin to disrupt intercellular adhesion
Hoy B, Loewer M, Weydig C, et al. Helicobacter pylori HtrA is a new secreted virulence factor that cleaves E-cadherin to disrupt intercellular adhesion. EMBO REPORTS. 2010;11(10):798-804.Mammalian and prokaryotic high-temperature requirement A (HtrA) proteins are chaperones and serine proteases with important roles in protein quality control. Here, we describe an entirely new function of HtrA and identify it as a new secreted virulence factor from Helicobacter pylori, which cleaves the ectodomain of the cell-adhesion protein E-cadherin. E-cadherin shedding disrupts epithelial barrier functions allowing H. pylori designed to access the intercellular space. We then designed a small-molecule inhibitor that efficiently blocks HtrA activity, E-cadherin cleavage and intercellular entry of H. pylori