426 research outputs found
Drug resistance mediating Plasmodium falciparum polymorphisms and clinical presentations of parasitaemic children in Uganda.
BackgroundPlasmodium falciparum genetic polymorphisms that mediate altered drug sensitivity may impact upon virulence. In a cross-sectional study, Ugandan children with infections mutant at pfcrt K76T, pfmdr1 N86Y, or pfmdr1 D1246Y had about one-fourth the odds of symptomatic malaria compared to those with infections with wild type (WT) sequences. However, results may have been confounded by greater likelihood in those with symptomatic disease of higher density mixed infections and/or recent prior treatment that selected for WT alleles.MethodsPolymorphisms in samples from paired episodes of asymptomatic and symptomatic parasitaemia in 114 subjects aged 4-11 years were followed longitudinally in Tororo District, Uganda. Paired episodes occurred within 3-12 months of each other and had no treatment for malaria in the prior 60 days. The prevalence of WT, mixed, and mutant alleles was determined using multiplex ligase detection reaction-fluorescent microsphere assays.ResultsConsidering paired episodes in the same subject, the odds of symptomatic malaria were lower for infections with mutant compared to WT or mixed sequence at N86Y (OR 0.26, 95% CI 0.09-0.79, p = 0.018), but not K76T or D1246Y. However, symptomatic episodes (which had higher densities) were more likely than asymptomatic to be mixed (for N86Y OR 2.0, 95% CI 1.04-4.0, p = 0.036). Excluding mixed infections, the odds of symptomatic malaria were lower for infections with mutant compared to WT sequence at N86Y (OR 0.33, 95% CI 0.11-0.98, p = 0.046), but not the other alleles. However, if mixed genotypes were grouped with mutants in this analysis or assuming that mixed infections consisted of 50% WT and 50% mutant genotypes, the odds of symptomatic infection did not differ between infections that were mutant or WT at the studied alleles.ConclusionsAlthough infections with only the mutant pfmdr1 86Y genotype were associated with symptomatic infection, this association could primarily be explained by greater parasite densities and therefore greater prevalence of mixed infections in symptomatic children. These results indicate limited association between the tested polymorphisms and risk of symptomatic disease and highlight the value of longitudinal studies for assessing associations between parasite factors and clinical outcomes
The Effect Of Warm-Up Modalities on Trampoline Flight Time Performance
Trampoline flight time is a recent addition to Olympic scoring and was sufficient in weight to displace a formed medal winner from a podium placement at the 2012 Olympics. The aim of our study was to examine different warm-up routines on trampoline flight time. We examined ten elite, female trampolinists (mean ± SD: age 19.2 ±5.4 y) who performed six different warm-up routines in a randomised, cross-over, counter-balanced manner: (a) static stretching (STAT, control), (b) STAT+10 trampoline bounces, (c) dynamic stretching (DYN), (d) DYN+10 trampoline bounces, (e) DYN+Drop jumps (DYN+DJ) and (f) DYN+isometric mid-thigh pulls (DYN+IP). Data were analysed using general linear models, Dunnett-HSU post-hoc tests vs. Control/STAT and magnitude based inferences vs. control. Our analysis demonstrated that total flight time following DYN 10 (17.29 ±0.52s, 83% likely beneficial, P < 0.002) was significantly longer versus STAT (16.59 ±0.49 s), with a trend toward significance for DYN (16.97 ±0.20 s; 22% likely beneficial, P = 0.077). The DYN-IP (14.04 ± 0.48 s) and DYN-DJ (14.15 ±0.66 s) produced the shortest vs. all warm-up forms (P < 0.005). To the contrary, the DYN+DJ and DYN+IP conditions were >99% likely to be detrimental to performance. Our results demonstrate a clear improvement in flight times when using a dynamic warm-up coupled with a trampoline specific bouncing task (DYN+10)
A Strategic Analysis of the Nebraska Alumni Association
The Nebraska Alumni Association (NAA) is in a unique position regarding where it fits in the lives of the people it serves and the potential growth of their programs. Being separate from the University system, yet still driven by mission to help the university grow, has given the association several advantages as to being able to act in an agile manner. However, only 24,000 of the over 200,000 University of Nebraska-Lincoln alumni have paid to become a part of the Nebraska Alumni Association. This is shocking, and we believe that our recommendations can turn the tide through engagement of the Millennial and Generation Z target groups. The trend is that membership directly correlates to the excitement level of the Husker football and other sports teams. Our recommendations play to this strength by offering child care during football games, but our main focus is driving engagement with families by giving them a value proposition that rids them of the “my family keeps me from being involved” excuse. Based on our research and analysis, we have created a Future Huskers program that, if implemented, could grow the membership and member involvement of the Nebraska Alumni Association
Regressive Evolution in the Mexican Cave Tetra, Astyanax mexicanus
Cave adapted animals generally have reduced pigmentation and eyes, but the evolutionary forces driving the reductions are unknown; Darwin famously questioned the role of natural selection in eye loss in cave fishes; “As it is difficult to imagine that eyes, although useless, could be in any way injurious to animals living in darkness, I attribute their loss wholly to disuse” [1]. We studied the genetic basis of this phenomenon in the Mexican cave tetra, Astyanax mexicanus, by mapping the quantitative trait loci (QTL) determining differences in eye/lens sizes and melanophore number between cave and surface fish. In addition, we mapped QTL for the putatively constructive traits of jaw size, tooth number, and numbers of taste buds. The data suggest that eyes and pigmentation regressed through different mechanisms. Cave alleles at each eye/lens QTL we detected caused size reductions. This uniform negative polarity is consistent with evolution by natural selection and inconsistent with evolution by drift. In contrast, QTL polarities for melanophore number were mixed, consistent with evolution by genetic drift or indirect selection through pleiotropy. Past arguments against a role for selection in regression of cave fish eyes cited the insignificant cost of their development [2,3], but we argue that the energetic cost of their maintenance is sufficiently high for eyes to be detrimental in the cave environment. Regression, a ubiquitous aspect of all evolutionary change, can be caused either by selection or genetic drift/pleiotropy
Patient and healthcare professional perspectives on implementing patient-reported outcome measures in gender-affirming care: a qualitative study
Objectives: Patient and healthcare professional perspectives are needed to develop a gender-affirming care patient-reported outcome measure (PROM) implementation plan. We aimed to identify top considerations relevant to gender-affirming care PROM implementation from patient and healthcare professional perspectives.
Design, settings and participants: This qualitative study conducted in the UK between January and April 2023 includes focus groups with a patient sample diverse in age and gender identity, and a healthcare professional sample diverse in age and role. Established methods in implementation science and the Consolidated Framework for Implementation Research were used to create interview guides, and analyse data. Focus groups were audio recorded, transcribed verbatim and analysed by two independent researchers. Patient and healthcare professional focus groups were conducted separately.
Primary outcome measures: Patient and healthcare professional perspectives on PROM implementation were explored through focus groups and until data saturation.
Results: A total of 7 virtual focus groups were conducted with 24 participants (14 patients, mean (SD) age, 43 (14.5); 10 healthcare professionals, mean (SD) age, 46 (11.3)). From patient perspectives, key barriers to PROM implementation were mistrust with PROMs, lack of accessibility, burden, and lack of communication on why PROMs are important and how they will help care. From healthcare professional perspectives, key barriers to PROM implementation were lack of accessibility, burden with PROM administration and scoring, costs of implementation (financial and time), and lack of communication on what PROMs are and how they benefit service provision.
Conclusion: Gender-affirming care PROM implementation must address: patient mistrust with PROMs, accessibility, communication on what PROMs are and how they can be used, reducing burden, and hybridised implementation. These factors may also be applicable to other clinical areas interested in implementing PROMs
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Spatial epidemiological patterns suggest mechanisms of land-sea transmission for Sarcocystis neurona in a coastal marine mammal.
Sarcocystis neurona was recognised as an important cause of mortality in southern sea otters (Enhydra lutris nereis) after an outbreak in April 2004 and has since been detected in many marine mammal species in the Northeast Pacific Ocean. Risk of S. neurona exposure in sea otters is associated with consumption of clams and soft-sediment prey and is temporally associated with runoff events. We examined the spatial distribution of S. neurona exposure risk based on serum antibody testing and assessed risk factors for exposure in animals from California, Washington, British Columbia and Alaska. Significant spatial clustering of seropositive animals was observed in California and Washington, compared with British Columbia and Alaska. Adult males were at greatest risk for exposure to S. neurona, and there were strong associations with terrestrial features (wetlands, cropland, high human housing-unit density). In California, habitats containing soft sediment exhibited greater risk than hard substrate or kelp beds. Consuming a diet rich in clams was also associated with increased exposure risk. These findings suggest a transmission pathway analogous to that described for Toxoplasma gondii, with infectious stages traveling in freshwater runoff and being concentrated in particular locations by marine habitat features, ocean physical processes, and invertebrate bioconcentration
Balanced impacts of fitness and drug pressure on the evolution of PfMDR1 polymorphisms in Plasmodium falciparum.
BACKGROUND: Anti-malarial drug resistance may be limited by decreased fitness in resistant parasites. Important contributors to resistance are mutations in the Plasmodium falciparum putative drug transporter PfMDR1.
METHODS: Impacts on in vitro fitness of two common PfMDR1 polymorphisms, N86Y, which is associated with sensitivity to multiple drugs, and Y184F, which has no clear impact on drug sensitivity, were evaluated to study associations between resistance mediators and parasite fitness, measured as relative growth in competitive culture experiments. NF10 P. falciparum lines engineered to represent all PfMDR1 N86Y and Y184F haplotypes were co-cultured for 40 days, and the genetic make-up of the cultures was characterized every 4 days by pyrosequencing. The impacts of culture with anti-malarials on the growth of different haplotypes were also assessed. Lastly, the engineering of P. falciparum containing another common polymorphism, PfMDR1 D1246Y, was attempted.
RESULTS: Co-culture results were as follows. With wild type (WT) Y184 fixed (N86/Y184 vs. 86Y/Y184), parasites WT and mutant at 86 were at equilibrium. With mutant 184 F fixed (N86/184F vs. 86Y/184F), mutants at 86 overgrew WT. With WT N86 fixed (N86/Y184 vs. N86/184F), WT at 184 overgrew mutants. With mutant 86Y fixed (86Y/Y184 vs. 86Y/184F), WT and mutant at 86 were at equilibrium. Parasites with the double WT were in equilibrium with the double mutant, but 86Y/Y184 overgrew N86/184F. Overall, WT N86/mutant 184F parasites were less fit than parasites with all other haplotypes. Parasites engineered for another mutation, PfMDR1 1246Y, were unstable in culture, with reversion to WT over time. Thus, the N86 WT is stable when accompanied by the Y184 WT, but incurs a fitness cost when accompanied by mutant 184F. Culturing in the presence of chloroquine favored 86Y mutant parasites and in the presence of lumefantrine favored N86 WT parasites; piperaquine had minimal impact.
CONCLUSIONS: These results are consistent with those for Ugandan field isolates, suggest reasons for varied haplotypes, and highlight the interplay between drug pressure and fitness that is guiding the evolution of resistance-mediating haplotypes in P. falciparum
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