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

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

Ketamine coadministration attenuates morphine tolerance and leads to increased brain concentrations of both drugs in the rat

Background and Purpose The effects of ketamine in attenuating morphine tolerance have been suggested to result from a pharmacodynamic interaction. We studied whether ketamine might increase brain morphine concentrations in acute coadministration, in morphine tolerance and morphine withdrawal. Experimental Approach Morphine minipumps (6mg center dot day(-1)) induced tolerance during 5 days in Sprague-Dawley rats, after which s.c. ketamine (10mg center dot kg(-1)) was administered. Tail flick, hot plate and rotarod tests were used for behavioural testing. Serum levels and whole tissue brain and liver concentrations of morphine, morphine-3-glucuronide, ketamine and norketamine were measured using HPLC-tandem mass spectrometry. Key Results In morphine-naive rats, ketamine caused no antinociception whereas in morphine-tolerant rats there was significant antinociception (57% maximum possible effect in the tail flick test 90min after administration) lasting up to 150min. In the brain of morphine-tolerant ketamine-treated rats, the morphine, ketamine and norketamine concentrations were 2.1-, 1.4- and 3.4-fold, respectively, compared with the rats treated with morphine or ketamine only. In the liver of morphine-tolerant ketamine-treated rats, ketamine concentration was sixfold compared with morphine-naive rats. After a 2 day morphine withdrawal period, smaller but parallel concentration changes were observed. In acute coadministration, ketamine increased the brain morphine concentration by 20%, but no increase in ketamine concentrations or increased antinociception was observed. Conclusions and Implications The ability of ketamine to induce antinociception in rats made tolerant to morphine may also be due to increased brain concentrations of morphine, ketamine and norketamine. The relevance of these findings needs to be assessed in humans.Peer reviewe

Pollutant dispersion in a developing valley cold-air pool

Pollutants are trapped and accumulate within cold-air pools, thereby affecting air quality. A numerical model is used to quantify the role of cold-air-pooling processes in the dispersion of air pollution in a developing cold-air pool within an alpine valley under decoupled stable conditions. Results indicate that the negatively buoyant downslope flows transport and mix pollutants into the valley to depths that depend on the temperature deficit of the flow and the ambient temperature structure inside the valley. Along the slopes, pollutants are generally entrained above the cold-air pool and detrained within the cold-air pool, largely above the ground-based inversion layer. The ability of the cold-air pool to dilute pollutants is quantified. The analysis shows that the downslope flows fill the valley with air from above, which is then largely trapped within the cold-air pool, and that dilution depends on where the pollutants are emitted with respect to the positions of the top of the ground-based inversion layer and cold-air pool, and on the slope wind speeds. Over the lower part of the slopes, the cold-air-pool-averaged concentrations are proportional to the slope wind speeds where the pollutants are emitted, and diminish as the cold-air pool deepens. Pollutants emitted within the ground-based inversion layer are largely trapped there. Pollutants emitted farther up the slopes detrain within the cold-air pool above the ground-based inversion layer, although some fraction, increasing with distance from the top of the slopes, penetrates into the ground-based inversion layer.Peer reviewe

Ultraviolet Completion of Flavour Models

Effective Flavour Models do not address questions related to the nature of the fundamental renormalisable theory at high energies. We study the ultraviolet completion of Flavour Models, which in general has the advantage of improving the predictivity of the effective models. In order to illustrate the important features we provide minimal completions for two known A4 models. We discuss the phenomenological implications of the explicit completions, such as lepton flavour violating contributions that arise through the exchange of messenger fields.Comment: 18 pages, 8 figure

Buzz pollination: studying bee vibrations on flowers

Approximately 6% of flowering plant species possess flowers with anthers that open through small pores or slits. Extracting pollen from this type of specialised flower is achieved most efficiently by vibrating the anthers, a behaviour that has evolved repeatedly among bees. Here I provide a brief overview of studying vibrations produced by bees and their effects on pollen release. I discuss how bee morphology and behaviour affect the mechanical properties of vibrations, and how floral traits may influence the transmission of those vibrations from the bee to the anther, thus mediating pollen release, and ultimately bee and plant fitness. I suggest that understanding the evolution of buzz pollination requires studying the biomechanics of bee vibrations and their transmission on flowers

Beyond MFV in family symmetry theories of fermion masses

Minimal Flavour Violation (MFV) postulates that the only source of flavour changing neutral currents and CP violation, as in the Standard Model, is the CKM matrix. However it does not address the origin of fermion masses and mixing and models that do usually have a structure that goes well beyond the MFV framework. In this paper we compare the MFV predictions with those obtained in models based on spontaneously broken (horizontal) family symmetries, both Abelian and non-Abelian. The generic suppression of flavour changing processes in these models turns out to be weaker than in the MFV hypothesis. Despite this, in the supersymmetric case, the suppression may still be consistent with a solution to the hierarchy problem, with masses of superpartners below 1 TeV. A comparison of FCNC and CP violation in processes involving a variety of different family quantum numbers should be able to distinguish between various family symmetry models and models satisfying the MFV hypothesis.Comment: 34 pages, no figure

Historical Criminology and the Explanatory Power of the Past

To what extent can the past ‘explain’ the present? This deceptively simple question lies at the heart of historical criminology (research which incorporates historical primary sources while addressing present-day debates and practices in the criminal justice field). This article seeks first to categorise the ways in which criminologists have used historical data thus far, arguing that it is most commonly deployed to ‘problematize’ the contemporary rather than to ‘explain’ it. The article then interrogates the reticence of criminologists to attribute explicative power in relation to the present to historical data. Finally, it proposes the adoption of long time-frame historical research methods, outlining three advantages which would accrue from this: the identification and analysis of historical continuities; a more nuanced, shared understanding of micro/macro change over time in relation to criminal justice; and a method for identifying and analysing instances of historical recurrence, particularly in perceptions and discourses around crime and justice

A large gastrointestinal stromal tumor of the duodenum: a case report

<p>Abstract</p> <p>Introduction</p> <p>Gastrointestinal stromal tumors of the duodenum are uncommon. They can reach a large size. Diagnosis can be elusive and managing them can be difficult. Our case report aims to increase awareness and highlight some issues related to the diagnosis and management of duodenal gastrointestinal stromal tumors.</p> <p>Case presentation</p> <p>We present the case of a 38-year-old Middle Eastern woman with a large, slowly-growing gastrointestinal stromal tumor of the duodenum. Her complaints were minor epigastric discomfort and swelling. A pancreaticoduodenectomy with complete tumor excision was performed. She was doing very well with no evidence of disease recurrence when she was last seen 34 months after her operation.</p> <p>Conclusion</p> <p>Gastrointestinal stromal tumors of the duodenum should be suspected in any patient with a duodenal wall mass. Extramural growth and central ulceration with or without bleeding should alert the endoscopist to the possibility of a duodenal gastrointestinal stromal tumor diagnosis. There is more than one surgical approach available; however, complete surgical excision, with negative margins, is the absolute requirement. Preoperative imatinib mesylate can be considered in unresectable or borderline resectable cases.</p