Publications by authors named "Mark Meyer"

Temporomandibular disorders (TMD) affect a significant portion of the population, with profound psychological, behavioral, and social repercussions. Recent investigations have explored the genetic basis underlying pain perception in individuals with TMD, aiming to elucidate the role of specific genetic factors in modulating the condition. Notably, genetic variations have been implicated in the pathogenesis of TMD, particularly genes involved in pain perception pathways.

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CYP24A1 is a multifunctional, P450 mitochondrial enzyme that catabolizes the vitamin D hormone (calcitriol, 1,25(OH)2D3), its precursor (calcifediol, 25(OH)D3), and numerous vitamin D metabolites. In the kidney, Cyp24a1 is induced by 1,25(OH)2D3 and fibroblast growth factor 23 (FGF23) and potently suppressed by PTH to control the circulating levels of 1,25(OH)2D3. Cyp24a1 is controlled by a pair of promoter proximal (PRO) vitamin D response elements (VDREs) that are aided by distal, downstream (DS) enhancers.

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CYP24A1 is a multifunctional, P450 mitochondrial 24-hydroxylase enzyme that is responsible for catabolism of the most active vitamin D hormone (calcitriol, 1,25(OH)D), its precursor (calcifediol, 25(OH)D), and numerous other vitamin D metabolites at the 23- and 24-carbon positions. In the kidney, is induced by 1,25(OH)D, induced by FGF23, and potently suppressed by PTH to tightly control the circulating blood levels of 1,25(OH)D. This gene is believed to be under the control of a pair of classic promoter proximal (PRO) vitamin D response elements (VDREs) that are aided by distal, downstream (DS) containing enhancers that we identified more recently.

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Article Synopsis
  • Estrogen receptor-positive (ER-positive) breast cancer often recurs later after initial treatment, and high levels of the protein GRHL2 are linked to a worse prognosis compared to ER-negative types.
  • *GRHL2 boosts traits associated with stem cells and dormancy in ER-positive breast cancer cells, resulting in a stronger epithelial identity and a shift towards a hybrid epithelial to mesenchymal transition (EMT).
  • *Research shows that increased GRHL2 leads to reduced cell growth and greater dormancy marker expression, along with enhanced self-renewal capabilities and changes in influential transcription factor motifs, suggesting it plays a significant role in cancer progression.*
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The immune benefits of vitamin D3 supplementation beyond calcium and phosphate maintenance are highly clinically debated. Kidney expression of CYP27B1 is the source of endocrine, circulating 1,25(OH)2D3 (active form of vitamin D) that maintains serum calcium and phosphate. 1,25(OH)2D3 may also be made by the CYP27B1 enzyme in nonrenal cells, like immune cells, in a process driven by cellular availability of 25(OH)D3 and inflammation.

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Introduction: Neuropilin 2 (NRP2) mediates the effects of class 3 semaphorins and vascular endothelial growth factor and is implicated in axonal guidance and angiogenesis. Moreover, NRP2 expression is suggested to be involved in the regulation of bone homeostasis. Indeed, osteoblasts and osteoclasts express NRP2 and male and female global knockout mice have a reduced bone mass accompanied by reduced osteoblast and increased osteoclast counts.

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Line work is a core element for the stylization of computer animations used by recent shows. However, existing stylization techniques are limited to edge treatments based on brush strokes or textures applied solely on top of curves. In this work, we propose new stylization effects by offering artists direct control over the inside and outside of surface contours.

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The regulation of mineral homeostasis involves the three mineralotropic hormones PTH, FGF23 and 1,25-dihydroxyvitamin D (1,25(OH)D). Early research efforts focused on PTH and 1,25(OH)D and more recently on FGF23 have revealed that each of these hormones regulates the expression of the other two. Despite early suggestions of transcriptional processes, it has been only recently that research effort have begun to delineate the genomic mechanisms underpinning this regulation for 1,25(OH)D and FGF23; the regulation of PTH by 1,25(OH)D, however, remains obscure.

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The vitamin D receptor with its ligand 1,25 dihydroxy vitamin D (1,25D) regulates epidermal stem cell fate, such that VDR removal from Krt14 expressing keratinocytes delays re-epithelialization of epidermis after wound injury in mice. In this study we deleted Vdr from Lrig1 expressing stem cells in the isthmus of the hair follicle then used lineage tracing to evaluate the impact on re-epithelialization following injury. We showed that Vdr deletion from these cells prevents their migration to and regeneration of the interfollicular epidermis without impairing their ability to repopulate the sebaceous gland.

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Phosphate (P) is an essential element involved in various biological actions, such as bone integrity, energy production, cell signaling and molecular component. P homeostasis is modulated by 4 main tissues; intestine, kidney, bone, and parathyroid gland, where 1,25-dihydroxyvitamin D (1,25(OH)D), parathyroid hormone and fibroblast growth factor 23 (FGF23) are produced and/or have an influence. In bone, serum P level modulates the production of FGF23 which then controls not only P excretion but also vitamin D metabolism in kidney in an endocrine manner.

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National laboratories are a fundamental capacity for public health, contributing to disease surveillance and outbreak response. The establishment of regional laboratory networks has been posited as a means of improving health security across multiple countries. Our study objective was to assess whether membership in regional laboratory networks in Africa has an effect on national health security capacities and outbreak response.

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The renal actions of parathyroid hormone (PTH) promote 1,25-vitamin D generation; however, the signaling mechanisms that control PTH-dependent vitamin D activation remain unknown. Here, we demonstrated that salt-inducible kinases (SIKs) orchestrated renal 1,25-vitamin D production downstream of PTH signaling. PTH inhibited SIK cellular activity by cAMP-dependent PKA phosphorylation.

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Vitamin D metabolism centers on regulation in the kidney of CYP27B1 induction by PTH, suppression by FGF23 and 1,25(OH)D, and reciprocal CYP24A1 suppression by PTH, and induction by FGF23 and 1,25(OH)D. This coordinated genomic regulation through enhancer modules results in the production and dynamic maintenance of circulating endocrine 1,25(OH)D which, together with PTH and FGF23, controls mineral homeostasis. We discovered enhancers near Cyp27b1 in the mouse kidney located within intronic regions of Mettl1 and Mettl21b genes.

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Background: Interviewer effects can have consequential impacts on survey data, particularly for reporting sensitive attitudes and behaviours such as sexual activity and drug use, yet these effects remain understudied in low- and middle-income countries. The Demographic and Health Surveys (DHS) present a unique opportunity to study interviewer effects on the self-report of sensitive topics in low- and middle-income countries by including interviewer characteristics data. This paper aims to narrow the gap in research on interviewer effects by studying the effects that age difference between interviewer and respondent and interviewer survey experience have on the reporting of ever having sexual intercourse.

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The 24th Workshop on Vitamin D was held September 7-9, 2022 in Austin, Texas and covered a wide diversity of research in the vitamin D field from across the globe. Here, we summarize the meeting, individual sessions, awards and presentations given.

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Though billions of passengers and crew travel by air each year and are exposed to altitude equivalents of 7000-8000 feet, the health impact of cabin oxygenation levels has not been well studied. The hypoxic environment may produce ectopic heartbeats that may increase the risk of acute in-flight cardiac events. We enrolled forty older and at-risk participants under a block-randomized crossover design in a hypobaric chamber study to examine associations between flight oxygenation and both ventricular (VE) and supraventricular ectopy (SVE).

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Research in functional regression has made great strides in expanding to non-Gaussian functional outcomes, but exploration of ordinal functional outcomes remains limited. Motivated by a study of computer-use behavior in rhesus macaques (), we introduce the Ordinal Probit Functional Outcome Regression model (OPFOR). OPFOR models can be fit using one of several basis functions including penalized B-splines, wavelets, and O'Sullivan splines-the last of which typically performs best.

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Purpose: To assess the impact of virtual interviewing during the COVID-19 pandemic on the residency application process and to compare applicant costs and time spent interviewing during the 2020-2021 application cycle with prior years.

Method: Fourth-year medical students at the University of Kansas School of Medicine applying for first-year residency positions via the National Resident Matching Program Match completed an electronic 46-item survey after submitting their rank lists during each application cycle from 2015-2016 to 2020-2021. The authors used descriptive statistics and t tests to analyze and compare responses to demographics questions and questions regarding number of submitted applications, offered and completed interviews, ranked programs, costs, and time spent interviewing.

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Vitamin D metabolism centers on kidney regulation of Cyp27b1 by mineralotropic hormones, including induction by parathyroid hormone (PTH), suppression by fibroblast growth factor 23 (FGF23) and 1,25-dihydroxyvitamin D (1,25(OH)D), and reciprocal regulations for Cyp24a1. This coordinated genomic regulation results in production of endocrine 1,25(OH)D, which, together with PTH and FGF23, controls mineral homeostasis. However, how these events are coordinated is unclear.

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Recent studies of transcription have revealed an advanced set of overarching principles that govern vitamin D action on a genome-wide scale. These tenets of vitamin D transcription have emerged as a result of the application of now well-established techniques of chromatin immunoprecipitation coupled to next-generation DNA sequencing that have now been linked directly to CRISPR-Cas9 genomic editing in culture cells and in mouse tissues in vivo. Accordingly, these techniques have established that the vitamin D hormone modulates sets of cell-type specific genes via an initial action that involves rapid binding of the VDR-ligand complex to multiple enhancer elements at open chromatin sites that drive the expression of individual genes.

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Robotic resection of the "offending portion" of the first rib in patients with thoracic outlet syndrome (TOS) has been associated with excellent results. The results have been due to (I) a better understanding of the pathogenesis of TOS, and (II) the technical advantages of the robotic platform. This article outlines the recent understanding of the pathogenesis of TOS, and reports the experience with robotic resection of the "offending portion" of the first rib in patients with neurogenic and venous TOS.

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Population-based seroprevalence surveys can provide useful estimates of the number of individuals previously infected with serious acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and still susceptible, as well as contribute to better estimates of the case-fatality rate and other measures of coronavirus disease 2019 (COVID-19) severity. No serological test is 100% accurate, however, and the standard correction that epidemiologists use to adjust estimates relies on estimates of the test sensitivity and specificity often based on small validation studies. We have developed a fully Bayesian approach to adjust observed prevalence estimates for sensitivity and specificity.

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