4,956 research outputs found

    Vitamin D Supplementation and Pain-Related Emergency Department Visits in Children with Sickle Cell Disease

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    Objectives: Sickle cell disease (SCD) is the most prevalent inherited hematological disorder and affects 100,000 individuals in the United States. Pain is the most common cause of emergency department (ED) visits in the SCD population, which profoundly affects quality of life. Vitamin D supplementation is a potential target for reducing pain. Thus, the goal of the present study was to identify the prevalence of vitamin D deficiency and explore the relationship between vitamin D supplementation and ED visits in pediatric patients with SCD. / Design: We conducted a retrospective chart review of 110 patients with SCD aged 8 to 16 years who had at least one ED visit for SCD pain during the 6-year study period. Patients were categorized into three vitamin D supplementation groups: patients who did not receive supplementation, patients supplemented with 25-hydroxyvitamin D levels (< 30 ng/mL), and patients supplemented with at least one sufficient 25-hydroxyvitamin D level (≥ 30 ng/mL). / Results: Overall, 45% of patients were vitamin D deficient. Only 20% of patients had sufficient vitamin D levels. This number increased to 55% when examining only patients who did not receive vitamin D supplementation. For patients supplemented with vitamin D, the number of ED visits was significantly lower after they reached the sufficient range (≥ 30 ng/mL), p = .03. / Conclusions: Our findings indicate that reductions in the number of pain-related ED visits may be achieved by normalizing 25-hydroxyvitamin D levels with supplementation. In addition, findings highlight the need for screening and vitamin D supplementation being incorporated into routine care for pediatric patients with SCD

    Invariant Peano curves of expanding Thurston maps

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    We consider Thurston maps, i.e., branched covering maps f ⁣:S2S2f\colon S^2\to S^2 that are postcritically finite. In addition, we assume that ff is expanding in a suitable sense. It is shown that each sufficiently high iterate F=fnF=f^n of ff is semi-conjugate to zd ⁣:S1S1z^d\colon S^1\to S^1, where dd is equal to the degree of FF. More precisely, for such an FF we construct a Peano curve γ ⁣:S1S2\gamma\colon S^1\to S^2 (onto), such that Fγ(z)=γ(zd)F\circ \gamma(z) = \gamma(z^d) (for all zS1z\in S^1).Comment: 63 pages, 12 figure

    Mobile health use predicts self-efficacy and self-management in adolescents with sickle cell disease

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    Sickle cell disease (SCD) is associated with significant health challenges that often worsen during adolescence. Living with SCD requires a substantial amount of self-management and mobile health (mHealth) holds considerable promise for assessing and changing behaviors to improve health outcomes. We integrated a mobile app as an adjunct to a group intervention (SCThrive) and hypothesized that more engagement with the mHealth app would increase self-management and self-efficacy for adolescents and young adults (AYA) with SCD. Twenty-six AYA ages 13–21 years (54% female; 46% HbSS genotype; all African-American/Black) received six weekly group sessions (three in-person, three online). Participants were provided with the mobile app (iManage for SCD) to record progress on their self-management goals and log pain and mood symptoms. The Transition Readiness Assessment Questionnaire (TRAQ-5) assessed self-management skills and the Patient Activation Measure (PAM-13) assessed self-efficacy at baseline and post-treatment. Logging on to the app more frequently was associated higher mood ratings (r = .54, CI[.18, .77], p = .006) and lower pain ratings (r = −.48, CI[−.77, −.02], p = .04). Regression analyses demonstrated that after controlling for scores at baseline, the number of logins to the app predicted self-management skills (p = .05, η2 = .17) and possibly self-efficacy (p = .08, η2 = .13). Our study findings indicate that it can be challenging to maintain engagement in mHealth for AYA with SCD, but for those who do engage, there are significant benefits related to self-management, self-efficacy, and managing pain and mood

    A Clinical and Epidemiological Investigation of the First Reported Human Infection With the Zoonotic Parasite Trypanosoma evansi in Southeast Asia

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    Background. Trypanosoma is a genus of unicellular parasitic flagellate protozoa. Trypanosoma brucei species and Trypanosoma cruzi are the major agents of human trypanosomiasis; other Trypanosoma species can cause human disease, but are rare. In March 2015, a 38-year-old woman presented to a healthcare facility in southern Vietnam with fever, headache, and arthralgia. Microscopic examination of blood revealed infection with Trypanosoma. Methods. Microscopic observation, polymerase chain reaction (PCR) amplification of blood samples, and serological testing were performed to identify the infecting species. The patient's blood was screened for the trypanocidal protein apolipoprotein L1 (APOL1), and a field investigation was performed to identify the zoonotic source. Results. PCR amplification and serological testing identified the infecting species as Trypanosoma evansi. Despite relapsing 6 weeks after completing amphotericin B therapy, the patient made a complete recovery after 5 weeks of suramin. The patient was found to have 2 wild-type APOL1 alleles and a normal serum APOL1 concentration. After responsive animal sampling in the presumed location of exposure, cattle and/or buffalo were determined to be the most likely source of the infection, with 14 of 30 (47%) animal blood samples testing PCR positive for T. evansi. Conclusions. We report the first laboratory-confirmed case of T. evansi in a previously healthy individual without APOL1 deficiency, potentially contracted via a wound while butchering raw beef, and successfully treated with suramin. A linked epidemiological investigation revealed widespread and previously unidentified burden of T. evansi in local cattle, highlighting the need for surveillance of this infection in animals and the possibility of further human cases

    An Immersive Virtual Reality Curriculum for Pediatric Hematology Clinicians on Shared Decision-making for Hydroxyurea in Sickle Cell Anemia

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    Although hydroxyurea (HU) is an effective treatment for sickle cell anemia, uptake remains low. Shared decision-making (SDM) is a recommended strategy for HU initiation to elicit family preferences; however, clinicians lack SDM training. We implemented an immersive virtual reality (VR) curriculum at 8 pediatric institutions to train clinicians on SDM that included counseling virtual patients. Clinicians’ self-reported confidence significantly improved following the VR simulations on all communication skills assessed, including asking open-ended questions, eliciting specific concerns, and confirming understanding (Ps≤0.01 for all). VR may be an effective method for educating clinicians to engage in SDM for HU

    Transient peak-strain matching partially recovers the age-impaired mechanoadaptive cortical bone response

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    Mechanoadaptation maintains bone mass and architecture; its failure underlies age-related decline in bone strength. It is unclear whether this is due to failure of osteocytes to sense strain, osteoblasts to form bone or insufficient mechanical stimulus. Mechanoadaptation can be restored to aged bone by surgical neurectomy, suggesting that changes in loading history can rescue mechanoadaptation. We use non-biased, whole-bone tibial analyses, along with characterisation of surface strains and ensuing mechanoadaptive responses in mice at a range of ages, to explore whether sufficient load magnitude can activate mechanoadaptation in aged bone. We find that younger mice adapt when imposed strains are lower than in mature and aged bone. Intriguingly, imposition of short-term, high magnitude loading effectively primes cortical but not trabecular bone of aged mice to respond. This response was regionally-matched to highest strains measured by digital image correlation and to osteocytic mechanoactivation. These data indicate that aged bone’s loading response can be partially recovered, non-invasively by transient, focal high strain regions. Our results indicate that old murine bone does respond to load when the loading is of sufficient magnitude, and bones’ age-related adaptation failure may be due to insufficient mechanical stimulus to trigger mechanoadaptation

    Anomalous dependence of the c-axis polarized Fe B1g_{1g} phonon mode with Fe and Se concentrations in Fe1+y_{1+y}Te1x_{1-x}Sex_x

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    We report an investigation of the lattice dynamical properties in a range of Fe1+y_{1+y}Te1x_{1-x}Sex_{x} compounds, with special emphasis on the c-axis polarized vibration of Fe with B1g_{1g} symmetry, a Raman active mode common to all families of Fe-based superconductors. We have carried out a systematic study of the temperature dependence of this phonon mode as a function of Se xx and excess Fe yy concentrations. In parent compound Fe1+y_{1+y}Te, we observe an unconventional broadening of the phonon between room temperature and magnetic ordering temperature TNT_N. The situation smoothly evolves towards a regular anharmonic behavior as Te is substituted for Se and long range magnetic order is replaced by superconductivity. Irrespective to Se contents, excess Fe is shown to provide an additional damping channel for the B1g_{1g} phonon at low temperatures. We performed Density Functional Theory (DFT) ab-initio calculations within the local density approximation (LDA) to calcuate the phonon frequencies including magnetic polarization and Fe non-stoichiometry in the Virtual Crystal Approximation (VCA). We obtained a good agreement with the measured phonon frequencies in the Fe-deficient samples, while the effects of Fe excess are poorly reproduced. This may be due to excess Fe-induced local magnetism and low energy magnetic fluctuations that can not be treated accurately within these approaches. As recently revealed by neutron scattering and μ\mu-SR studies, these phenomena occur in the temperature range where anomalous decay of the B1g_{1g} phonon is observed, and suggests a peculiar coupling of this mode with local moments and spin fluctuations in Fe1+y_{1+y}Te1x_{1-x}Sex_{x}
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