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1.
Blood Adv ; 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38809136

RESUMO

Guidelines recommend transfer to adult healthcare within six months of completing pediatric care, however this has not been studied in sickle cell (SCD). We hypothesized that longer transfer gaps are associated with increased resource utilization. Transfer gaps were defined as the time between the last pediatric and first adult visits. We estimated the association between varying transfer gaps and the rate of inpatient, emergency department (ED), and outpatient visits using negative binomial regression. Healthcare utilization was evaluated in a mid-south comprehensive program for a follow-up period of up to eight years (2012-2020) and also restricted to the first two years of adult healthcare. In total, 183 young adults (YAs) with SCD (51% male, 67% HbSS/HbSß0-thalassemia) transferred to adult healthcare between 2012-2018. YAs with transfer gaps ≥6 months compared to <2 months had 2.01 (95%CI: 1.31, 3.11) times the rate of hospitalizations in the 8-year follow-up and 1.89 (95%CI: 1.17, 3.04) when restricted to the first two years of adult healthcare. In the first two years of adult care, those with transfer gaps ≥6 months compared to <2 months, had 1.75 (95%CI: 1.10, 2.80) times the rate of ED encounters. Those with gaps ≥2 to <6 months compared to <2 months had 0.71 (95%CI: 0.53, 0.95) times the rate of outpatient visits. Among YAs with SCD, a longer transfer gap was associated with increased inpatient and decreased outpatient encounters in adult healthcare and more ED encounters in the first two years of adult healthcare. Strategies to reduce transfer gaps are needed.

2.
Expert Rev Hematol ; 15(12): 1063-1072, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36356169

RESUMO

BACKGROUND: Transition-age patients with sickle cell disease (SCD) are at risk for poor outcomes associated with incomplete transition readiness and neurocognitive deficits. Study objectives were to: 1) test if a SCD-specific measure of self-management skills was associated with transition outcomes and 2) evaluate if caregiver-reported executive functioning was associated with self-management skills and transition outcomes among youth with SCD. RESEARCH DESIGN AND METHODS: Youth/caregivers were selected from a longitudinal cohort study. Caregivers completed the Behavior Rating Inventory of Executive Function (BRIEF); caregivers and youth completed the Self-Management Skills Checklist (SMSC) at a median age of 16.8 ± 0.6 years. Non-parametric tests compared SMSC and transition outcomes. Regression assessed the incremental validity of SMSC in predicting transition outcomes. RESULTS: In total, 95 participants (54% male, 55% severe genotype) completed the SMSC assessment. Most participants (87%) transferred to adult care within six months and 87% were retained for at least 12 months. BRIEF and caregiver-reported SMSC assessments were weakly, negatively correlated (ρ = -0.25, p = 0.0392) but were not significant in predicting transition outcomes (p > 0.05). CONCLUSIONS: The SMSC and executive function did not predict adult care engagement. Development of readiness assessments that predict care engagement and reflect self-efficacy is important for monitoring transition-aged patients with SCD.


Assuntos
Anemia Falciforme , Transição para Assistência do Adulto , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Cuidadores , Estudos Longitudinais , Aceitação pelo Paciente de Cuidados de Saúde
3.
Am J Physiol Renal Physiol ; 322(1): F89-F103, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34843656

RESUMO

Chronic kidney disease involves disturbances in iron metabolism including anemia caused by insufficient erythropoietin (EPO) production. However, underlying mechanisms responsible for the dysregulation of cellular iron metabolism are incompletely defined. Using the unilateral ureteral obstruction (UUO) model in Irp1+/+ and Irp1-/- mice, we asked if iron regulatory proteins (IRPs), the central regulators of cellular iron metabolism and suppressors of EPO production, contribute to the etiology of anemia in kidney failure. We identified a significant reduction in IRP protein level and RNA binding activity that associates with a loss of the iron uptake protein transferrin receptor 1 (TfR1), increased expression of the iron storage protein subunits H- and L-ferritin, and a low but overall variable level of stainable iron in the obstructed kidney. This reduction in IRP RNA binding activity and ferritin RNA levels suggests the concomitant rise in ferritin expression and iron content in kidney failure is IRP dependent. In contrast, the reduction in the Epo mRNA level in the obstructed kidney was not rescued by genetic ablation of IRP1, suggesting disruption of normal hypoxia-inducible factor (HIF)-2α regulation. Furthermore, reduced expression of some HIF-α target genes in UUO occurred in the face of increased expression of HIF-α proteins and prolyl hydroxylases 2 and 1, the latter of which is not known to be HIF-α mediated. Our results suggest that the IRP system drives changes in cellular iron metabolism that are associated with kidney failure in UUO but that the impact of IRPs on EPO production is overridden by disrupted hypoxia signaling.NEW & NOTEWORTHY This study demonstrates that iron metabolism and hypoxia signaling are dysregulated in unilateral obstructive nephropathy. Expression of iron regulatory proteins (IRPs), central regulators of cellular iron metabolism, and the iron uptake (transferrin receptor 1) and storage (ferritins) proteins they target is strongly altered. This suggests a role of IRPs in previously observed changes in iron metabolism in progressive renal disease. Hypoxia signaling is disrupted and appeared to dominate the action of IRP1 in controlling erythropoietin expression.


Assuntos
Anemia/etiologia , Ferro/metabolismo , Rim/metabolismo , Insuficiência Renal/etiologia , Obstrução Ureteral/complicações , Anemia/metabolismo , Anemia/patologia , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Hipóxia Celular , Modelos Animais de Doenças , Eritropoetina/genética , Eritropoetina/metabolismo , Ferritinas/genética , Ferritinas/metabolismo , Fibrose , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Prolina Dioxigenases do Fator Induzível por Hipóxia/genética , Prolina Dioxigenases do Fator Induzível por Hipóxia/metabolismo , Proteína 1 Reguladora do Ferro/genética , Proteína 1 Reguladora do Ferro/metabolismo , Rim/patologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pró-Colágeno-Prolina Dioxigenase/genética , Pró-Colágeno-Prolina Dioxigenase/metabolismo , Receptores da Transferrina/genética , Receptores da Transferrina/metabolismo , Insuficiência Renal/metabolismo , Insuficiência Renal/patologia , Obstrução Ureteral/metabolismo , Obstrução Ureteral/patologia
4.
Cureus ; 14(12): e32157, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36601216

RESUMO

On March 11, 2020, coronavirus disease 2019 (COVID-19) was classified as a pandemic, setting in motion unprecedented practice changes across the healthcare industry. Never was this more evident than in Skilled Nursing Facilities (SNFs). SNFs were tested on multiple fronts, requiring innovation and perseverance at levels never before seen. Lessons learned from this setting to better prepare for the next pandemic include: updating and standardizing infection control and prevention policies, ensuring the supply chain keeps up with demand, updating infrastructure, creating a work environment that promotes well-being, and having clear communication plans.

5.
Pediatr Blood Cancer ; 68(10): e29209, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34286896

RESUMO

BACKGROUND/OBJECTIVES: Care continuity prevents increased health care utilization and mortality during transition from pediatric to adult care. Our program employs a co-located care delivery model, in which pediatric provider involvement continues during young adulthood. We tested the hypothesis that individuals who participated in the co-located model have greater retention in adult care compared to those who only received pediatric transition services. METHODS: This study consisted of 311 youth with SCD (51.4% male; 63.0% HbSS/HbSß0 -thalassemia) who transferred to adult care from 2007 to 2017. Retention was defined as continuation with an adult provider for ≥12 or ≥24 months post-pediatric care. Logistic regression estimated the association between co-location status and retention at 12 and 24 months. Logistic regression and t-tests were used to evaluate potential predictors of retention in adult care. RESULTS: Individuals who participated in the co-location model were 1.9 times more likely to remain in adult care 12 (95% CI: 1.01, 3.47) and 24 (95% CI: 1.01, 3.70) months post-pediatric care compared to those who did not participate. Individuals with HbSS/HbSß0 -thalassemia were 1.9 times more likely to be retained at 12 months compared to those with HbSC/HbSß+ -thalassemia/HbS/HPFH (95% CI: 1.12, 3.09). For every clinic encounter in the last 2 years of pediatric care, the odds of being retained at least 24 months after initiating adult care increased 1.1 times (95% CI: 1.02, 1.13). CONCLUSIONS: Continuity of providers from pediatric to adult care may increase long-term retention in adult care. Longitudinal monitoring of adult outcomes is critical to identifying the efficacy of transition services.


Assuntos
Anemia Falciforme , Talassemia , Transição para Assistência do Adulto , Cuidado Transicional , Adolescente , Anemia Falciforme/terapia , Criança , Feminino , Hemoglobina Falciforme , Humanos , Masculino , Adulto Jovem
6.
Metallomics ; 12(12): 2186-2198, 2020 12 23.
Artigo em Inglês | MEDLINE | ID: mdl-33325950

RESUMO

Iron regulatory proteins (IRPs) are iron-responsive RNA binding proteins that dictate changes in cellular iron metabolism in animal cells by controlling the fate of mRNAs containing iron responsive elements (IREs). IRPs have broader physiological roles as some targeted mRNAs encode proteins with functions beyond iron metabolism suggesting hierarchical regulation of IRP-targeted mRNAs. We observe that the translational regulation of IRP-targeted mRNAs encoding iron storage (L- and H-ferritins) and export (ferroportin) proteins have different set-points of iron responsiveness compared to that for the TCA cycle enzyme mitochondrial aconitase. The ferritins and ferroportin mRNA were largely translationally repressed in the liver of rats fed a normal diet whereas mitochondrial aconitase mRNA is primarily polysome bound. Consequently, acute iron overload increases polysome association of H- and L-ferritin and ferroportin mRNAs while mitochondrial aconitase mRNA showed little stimulation. Conversely, mitochondrial aconitase mRNA is most responsive in iron deficiency. These differences in regulation were associated with a faster off-rate of IRP1 for the IRE of mitochondrial aconitase in comparison to that of L-ferritin. Thus, hierarchical control of mRNA translation by IRPs involves selective control of cellular functions acting at different states of cellular iron status and that are critical for adaptations to iron deficiency or prevention of iron toxicity.


Assuntos
Anemia Ferropriva/genética , Sobrecarga de Ferro/genética , Proteínas Reguladoras de Ferro/genética , RNA Mensageiro/genética , Animais , Proteínas de Transporte de Cátions/genética , Ferritinas/genética , Masculino , Camundongos , Biossíntese de Proteínas , Ratos Sprague-Dawley
8.
Am J Clin Exp Urol ; 7(5): 341-345, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31763365

RESUMO

TMPRSS2-ERG gene fusion occurs in approximately 50% of prostatic adenocarcinoma and their expression is associated with aggressive phenotype, higher tumor stage, and tumor metastasis. A case of prostatic adenocarcinoma with IRF2BP2-NTRK1 translocation was previously reported. We report a prostatic adenocarcinoma with novel NTRK3 gene fusion that occurs in a 71-year-old male patient with aggressive histologic phenotype and multiple bony metastases. Prostatic biopsy revealed that there is a prostatic adenocarcinoma with a Gleason score of 9 (4+5), grade group 5, and multiple sites of perineural and ganglional invasion. Fluorescence in-situ hybridization (FISH) and next-generation sequencing were performed. FISH studies showed a breakage within the NTRK3 gene in prostatic adenocarcinoma cells. Next-generation sequencing confirmed that there is a PRPSAP1-NTRK3 translocation in the prostatic adenocarcinoma. In addition, ASXL1, KIF5B, MED12, PIK3CA mutations were found. NTRK alterations or dysregulation of PI3K signaling pathway were found in many types of cancers. TRK inhibitors including larotrectinib and entrectinib were approved by the US Food and Drug Administration for treating TRK fusion-positive malignant tumors and PI3K/AKT/mTOR pathway inhibitors were under clinical studies on various cancers including prostate cancer. In our current case, both NTRK3 and PIK3CA may serve as biomarkers for precision targeted therapy.

10.
BMC Health Serv Res ; 17(1): 782, 2017 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-29183318

RESUMO

BACKGROUND: Chronic obstructive pulmonary disease (COPD) has substantial economic and human costs; it is expected to be the third leading cause of death worldwide by 2030. To minimize these costs high quality guidelines have been developed. However, guidelines alone rarely result in meaningful change. One method of integrating guidelines into practice is the use of clinical pathways (CPWs). CPWs bring available evidence to a range of healthcare professionals by detailing the essential steps in care and adapting guidelines to the local context. METHODS/DESIGN: We are working with local stakeholders to develop CPWs for COPD with the aims of improving care while reducing utilization. The CPWs will employ several steps including: standardizing diagnostic training, unifying components of chronic disease care, coordinating education and reconditioning programs, and ensuring care uses best practices. Further, we have worked to identify evidence-informed implementation strategies which will be tailored to the local context. We will conduct a three-year research project using an interrupted time series (ITS) design in the form of a multiple baseline approach with control groups. The CPW will be implemented in two health regions (experimental groups) and two health regions will act as controls (control groups). The experimental and control groups will each contain an urban and rural health region. Primary outcomes for the study will be quality of care operationalized using hospital readmission rates and emergency department (ED) presentation rates. Secondary outcomes will be healthcare utilization and guideline adherence, operationalized using hospital admission rates, hospital length of stay and general practitioner (GP) visits. Results will be analyzed using segmented regression analysis. DISCUSSION: Funding has been procured from multiple stakeholders. The project has been deemed exempt from ethics review as it is a quality improvement project. Intervention implementation is expected to begin in summer of 2017. This project is expected to improve quality of care and reduce healthcare utilization. In addition it will provide evidence on the effects of CPWs in both urban and rural settings. If the CPWs are found effective we will work with all stakeholders to implement similar CPWs in surrounding health regions. TRIAL REGISTRATION: Clinicaltrials.gov ( NCT03075709 ). Registered 8 March 2017.


Assuntos
Procedimentos Clínicos , Doença Pulmonar Obstrutiva Crônica/terapia , Bases de Dados Factuais , Serviço Hospitalar de Emergência/estatística & dados numéricos , Medicina Geral/estatística & dados numéricos , Fidelidade a Diretrizes/normas , Humanos , Análise de Séries Temporais Interrompida , Readmissão do Paciente/estatística & dados numéricos , Melhoria de Qualidade/normas , Projetos de Pesquisa , Saskatchewan
11.
Infant Ment Health J ; 38(6): 726-742, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-29069537

RESUMO

The purpose of this study was to explore the influence of the quality of early father-child rough-and-tumble play (RTP) on toddler aggressive behaviors and more fully understand how child, mother, and father characteristics were associated with higher quality father-child RTP among contemporary urban Chinese families. Participants included 42 families in Changsha, China. Play observations of fathers and their children were coded for RTP quality. The specific RTP quality of father-child reciprocity of dominance was associated with fewer toddler aggressive behaviors, as rated by both fathers and mothers. Mothers' democratic parenting attitudes were associated with higher quality father-child RTP. These findings suggest that higher quality father-child RTP may be one way in which some fathers influence children's expression of aggressive behaviors, and the quality of father-child RTP may be influenced by the broader family, social, and cultural contexts.


Assuntos
Agressão/psicologia , Comportamento Infantil/psicologia , Relações Pai-Filho , Jogos e Brinquedos/psicologia , Desenvolvimento Infantil , Pré-Escolar , China , Exercício Físico/psicologia , Pai/psicologia , Feminino , Humanos , Lactente , Masculino , Predomínio Social
12.
Clin Pract Pediatr Psychol ; 5(4): 319-329, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31131180

RESUMO

Youth with sickle cell disease (SCD) are living longer, requiring transition from pediatric to adult health care. Transition programs have been created to improve transition readiness and help patients take responsibility for their health. The aim of this study was to explore the usefulness of current transition materials and identify unmet transition needs from the perspective of adolescents with sickle cell disease (SCD) and caregivers to refine transition programming and interventions. Focus groups were conducted with 14 adolescents with SCD (Mean age = 14.6 years, SD = 1.9) and 20 caregivers (Mean age = 43.2 years, SD = 9.3) to gather perspectives about transition to adult care, current transition program materials and recommendations for future programming. Four themes emerged: (a) transition skills and knowledge needs, (b) change in health care responsibility, (c) concerns with adult SCD care, and (d) useful transition readiness strategies and resources. The findings of this study were used to develop Web based educational modules, experiential transition skills learning, and an adolescent and caregiver hematology support group. Findings highlight the need to conduct periodic readiness assessments, provide opportunities and scaffolding to learn skills based on readiness level, and help build social support networks to encourage and facilitate learning.

13.
J Biol Chem ; 290(7): 4432-46, 2015 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-25550162

RESUMO

Matriptase-2 (MT2) is a type II transmembrane serine protease that is predominantly expressed in hepatocytes. It suppresses the expression of hepatic hepcidin, an iron regulatory hormone, by cleaving membrane hemojuvelin into an inactive form. Hemojuvelin is a bone morphogenetic protein (BMP) co-receptor. Here, we report that MT2 is up-regulated under iron deprivation. In HepG2 cells stably expressing the coding sequence of the MT2 gene, TMPRSS6, incubation with apo-transferrin or the membrane-impermeable iron chelator, deferoxamine mesylate salt, was able to increase MT2 levels. This increase did not result from the inhibition of MT2 shedding from the cells. Rather, studies using a membrane-permeable iron chelator, salicylaldehyde isonicotinoyl hydrazone, revealed that depletion of cellular iron was able to decrease the degradation of MT2 independently of internalization. We found that lack of the putative endocytosis motif in its cytoplasmic domain largely abolished the sensitivity of MT2 to iron depletion. Neither acute nor chronic iron deficiency was able to alter the association of Tmprss6 mRNA with polyribosomes in the liver of rats indicating a lack of translational regulation by low iron levels. Studies in mice showed that Tmprss6 mRNA was not regulated by iron nor the BMP-mediated signaling with no evident correlation with either Bmp6 mRNA or Id1 mRNA, a target of BMP signaling. These results suggest that regulation of MT2 occurs at the level of protein degradation rather than by changes in the rate of internalization and translational or transcriptional mechanisms and that the cytoplasmic domain of MT2 is necessary for its regulation.


Assuntos
Regulação da Expressão Gênica , Deficiências de Ferro , Proteínas de Membrana/química , Proteínas de Membrana/fisiologia , Serina Endopeptidases/química , Serina Endopeptidases/fisiologia , Animais , Biotinilação , Western Blotting , Proteínas Morfogenéticas Ósseas/genética , Proteínas Morfogenéticas Ósseas/metabolismo , Células Cultivadas , Proteínas Ligadas por GPI , Proteína da Hemocromatose , Células Hep G2 , Hepatócitos/citologia , Hepatócitos/metabolismo , Homeostase , Humanos , Técnicas Imunoenzimáticas , Imunoprecipitação , Fígado/citologia , Fígado/metabolismo , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Knockout , RNA Mensageiro/genética , Ratos , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais
14.
J Pediatr Hematol Oncol ; 36(7): 572-7, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25089602

RESUMO

Sickle cell disease (SCD) genetic knowledge is important when individuals make reproductive decisions. This study assessed feasibility and efficacy of delivering basic genetic information to 101 adolescents with SCD. Participants completed a questionnaire to test SCD genetic knowledge at 3 timepoints: before genetic education session (pretest), after the session (posttest), and 6 months later (follow-up). Scores at 3 timepoints were compared by Wilcoxon signed-rank tests, and group differences were compared by Wilcoxon-Mann-Whitney and Kruskal-Wallis tests. Participants' median scores significantly increased from pretest to posttest and from pretest to follow-up. Males had a greater change in scores than females. Scores decreased slightly from posttest to follow-up. Participants with HbSS/HbSß°-thal genotype and participants with more prior pain episodes exhibited a smaller increase in median scores than those with HbSC/HbSß⁺-thal genotype and no prior pain history; however, all groups had substantial gains from pretest to posttest and follow-up tests demonstrating that adolescents with SCD can learn basic genetics. This study established that genetic education can successfully be incorporated in transition to adult care programs for adolescents with SCD. Genetic education should be included in the standard plan of care for adolescents with SCD to assist them in making informed reproductive choices.


Assuntos
Serviços de Saúde do Adolescente/organização & administração , Anemia Falciforme/genética , Anemia Falciforme/psicologia , Aconselhamento Genético/organização & administração , Educação de Pacientes como Assunto/organização & administração , Adolescente , Atitude Frente a Saúde , Estudos de Viabilidade , Feminino , Genótipo , Humanos , Masculino , Avaliação de Programas e Projetos de Saúde , Psicologia do Adolescente , Estudos Retrospectivos , Caracteres Sexuais , Inquéritos e Questionários
15.
J Biol Chem ; 289(11): 7835-43, 2014 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-24509859

RESUMO

Mitochondrial iron is essential for the biosynthesis of heme and iron-sulfur ([Fe-S]) clusters in mammalian cells. In developing erythrocytes, iron is imported into the mitochondria by MFRN1 (mitoferrin-1, SLC25A37). Although loss of MFRN1 in zebrafish and mice leads to profound anemia, mutant animals showed no overt signs of porphyria, suggesting that mitochondrial iron deficiency does not result in an accumulation of protoporphyrins. Here, we developed a gene trap model to provide in vitro and in vivo evidence that iron regulatory protein-1 (IRP1) inhibits protoporphyrin accumulation. Mfrn1(+/gt);Irp1(-/-) erythroid cells exhibit a significant increase in protoporphyrin levels. IRP1 attenuates protoporphyrin biosynthesis by binding to the 5'-iron response element (IRE) of alas2 mRNA, inhibiting its translation. Ectopic expression of alas2 harboring a mutant IRE, preventing IRP1 binding, in Mfrn1(gt/gt) cells mimics Irp1 deficiency. Together, our data support a model whereby impaired mitochondrial [Fe-S] cluster biogenesis in Mfrn1(gt/gt) cells results in elevated IRP1 RNA-binding that attenuates ALAS2 mRNA translation and protoporphyrin accumulation.


Assuntos
5-Aminolevulinato Sintetase/metabolismo , Regulação da Expressão Gênica , Proteína 1 Reguladora do Ferro/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Porfirias/metabolismo , Animais , Blastocisto/citologia , Diferenciação Celular , Linhagem Celular Tumoral , Feminino , Genótipo , Células HEK293 , Heme/química , Humanos , Ferro/química , Proteínas Ferro-Enxofre/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Biossíntese de Proteínas , Protoporfirinas/metabolismo , Peixe-Zebra
16.
Cell Metab ; 17(2): 282-90, 2013 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-23395174

RESUMO

Red blood cell production is a finely tuned process that requires coordinated oxygen- and iron-dependent regulation of cell differentiation and iron metabolism. Here, we show that translational regulation of hypoxia-inducible factor 2α (HIF-2α) synthesis by iron regulatory protein 1 (IRP1) is critical for controlling erythrocyte number. IRP1-null (Irp1(-/-)) mice display a marked transient polycythemia. HIF-2α messenger RNA (mRNA) is derepressed in kidneys of Irp1(-/-) mice but not in kidneys of Irp2(-/-) mice, leading to increased renal erythropoietin (Epo) mRNA and inappropriately elevated serum Epo levels. Expression of the iron transport genes DCytb, Dmt1, and ferroportin, as well as other HIF-2α targets, is enhanced in Irp1(-/-) duodenum. Analysis of mRNA translation state in the liver revealed IRP1-dependent dysregulation of HIF-2α mRNA translation, whereas IRP2 deficiency derepressed translation of all other known 5' iron response element (IRE)-containing mRNAs expressed in the liver. These results uncover separable physiological roles of each IRP and identify IRP1 as a therapeutic target for manipulating HIF-2α action in hematologic, oncologic, and other disorders.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Eritropoese , Proteína 1 Reguladora do Ferro/metabolismo , Ferro/metabolismo , Oxigênio/metabolismo , Transdução de Sinais , Absorção , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Duodeno/metabolismo , Duodeno/patologia , Células Eritroides/metabolismo , Células Precursoras Eritroides/metabolismo , Eritropoetina/sangue , Regulação da Expressão Gênica , Hematopoese Extramedular , Proteína 1 Reguladora do Ferro/deficiência , Camundongos , Policitemia/sangue , Policitemia/patologia , Biossíntese de Proteínas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Baço/metabolismo
17.
J Biol Chem ; 288(1): 552-60, 2013 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-23135277

RESUMO

Maintenance of cellular iron homeostasis requires post-transcriptional regulation of iron metabolism genes by iron regulatory protein 2 (IRP2). The hemerythrin-like domain of F-box and leucine-rich repeat protein 5 (FBXL5), an E3 ubiquitin ligase subunit, senses iron and oxygen availability and facilitates IRP2 degradation in iron replete cells. Disruption of the ubiquitously expressed murine Fbxl5 gene results in a failure to sense increased cellular iron availability, accompanied by constitutive IRP2 accumulation and misexpression of IRP2 target genes. FBXL5-null mice die during embryogenesis, although viability is restored by simultaneous deletion of the IRP2, but not IRP1, gene. Mice containing a single functional Fbxl5 allele behave like their wild type littermates when fed an iron-sufficient diet. However, unlike wild type mice that manifest decreased hematocrit and hemoglobin levels when fed a low-iron diet, Fbxl5 heterozygotes maintain normal hematologic values due to increased iron absorption. The responsiveness of IRP2 to low iron is specifically enhanced in the duodena of the heterozygotes and is accompanied by increased expression of the divalent metal transporter-1. These results confirm the role of FBXL5 in the in vivo maintenance of cellular and systemic iron homeostasis and reveal a privileged role for the intestine in their regulation by virtue of its unique FBXL5 iron sensitivity.


Assuntos
Proteínas F-Box/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Ubiquitina-Proteína Ligases/química , Absorção , Alelos , Animais , Sobrevivência Celular , Cruzamentos Genéticos , Heterozigoto , Homeostase , Humanos , Ferro/química , Proteína 1 Reguladora do Ferro/metabolismo , Proteína 2 Reguladora do Ferro/metabolismo , Camundongos , Modelos Genéticos , Ligação Proteica , Complexos Ubiquitina-Proteína Ligase , Ubiquitina-Proteína Ligases/metabolismo
18.
J Pediatr Health Care ; 26(6): e45-9, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22819193

RESUMO

INTRODUCTION: Transition from pediatric to adult care is challenging for adolescents with chronic illnesses, including those with sickle cell disease (SCD). We describe a pilot program created to facilitate transition from pediatric to adult care by helping adolescents with SCD identify an adult medical home. METHODS: We investigated the feasibility of this program by evaluation of overall participation, satisfaction, and acceptance. A secondary objective was to compare the proportion of adolescents who fulfilled a first appointment with an adult hematologist among participants and nonparticipants. RESULTS: During the first 18 months of the program, 83 adolescents were invited and 34 (41%) agreed to participate; 25 (74%) completed their first visit within 3 months after leaving the pediatric program, compared with 16 of 49 (33%) of nonparticipants (p = .0002). Overall, 41 of 83 adolescents (49%) completed an appointment with an adult SCD program, regardless of program participation, in contrast with 11 of 75 adolescents (15%) who did so during the 18 months before the program was created (p < .0001). DISCUSSION: This transition pilot program was feasible, and most adolescent participants with SCD established an adult medical home.


Assuntos
Serviços de Saúde do Adolescente/organização & administração , Anemia Falciforme/terapia , Continuidade da Assistência ao Paciente/organização & administração , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Transição para Assistência do Adulto/organização & administração , Adolescente , Serviços de Saúde do Adolescente/normas , Anemia Falciforme/epidemiologia , Continuidade da Assistência ao Paciente/normas , Feminino , Humanos , Masculino , Satisfação do Paciente , Autonomia Pessoal , Projetos Piloto , Avaliação de Programas e Projetos de Saúde , Qualidade da Assistência à Saúde , Tennessee/epidemiologia , Transição para Assistência do Adulto/normas
19.
Blood ; 117(5): 1687-99, 2011 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-21115976

RESUMO

Recent studies demonstrate a pivotal role for bone morphogenic protein-6 (BMP6) and matriptase-2, a protein encoded by the TMPRSS6 gene, in the induction and suppression of hepatic hepcidin expression, respectively. We examined their expression profiles in the liver and showed a predominant localization of BMP6 mRNA in nonparenchymal cells and exclusive expression of TMPRSS6 mRNA in hepatocytes. In rats fed an iron-deficient (ID) diet for 24 hours, the rapid decrease of transferrin saturation from 71% to 24% (control vs ID diet) was associated with a 100-fold decrease in hepcidin mRNA compared with the corresponding controls. These results indicated a close correlation of low transferrin saturation with decreased hepcidin mRNA. The lower phosphorylated Smad1/5/8 detected in the ID rat livers suggests that the suppressed hepcidin expression results from the inhibition of BMP signaling. Quantitative real-time reverse transcription polymerase chain reaction analysis revealed no significant change in either BMP6 or TMPRSS6 mRNA in the liver. However, an increase in matriptase-2 protein in the liver from ID rats was detected, suggesting that suppression of hepcidin expression in response to acute iron deprivation is mediated by an increase in matriptase-2 protein levels.


Assuntos
Peptídeos Catiônicos Antimicrobianos/metabolismo , Proteínas Morfogenéticas Ósseas/metabolismo , Hepatócitos/metabolismo , Deficiências de Ferro , Fígado/metabolismo , Proteínas de Membrana/metabolismo , Serina Endopeptidases/metabolismo , Animais , Peptídeos Catiônicos Antimicrobianos/antagonistas & inibidores , Proteínas Morfogenéticas Ósseas/genética , Hepcidinas , Immunoblotting , Hibridização In Situ , Ferro da Dieta/administração & dosagem , Fígado/citologia , Masculino , Proteínas de Membrana/genética , RNA Mensageiro/genética , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Serina Endopeptidases/genética , Transferrina/metabolismo
20.
Philos Trans A Math Phys Eng Sci ; 368(1925): 3779-96, 2010 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-20643676

RESUMO

The application of e-Science technologies to disciplines in the arts and humanities raises major questions as to how those technologies can be most usefully exploited, what tools and infrastructures are needed for that exploitation, and what new research approaches can be generated. This paper reviews a number of activities in the UK and Europe in the last 5 years which have sought to address these questions through processes of experimentation and targeted infrastructure development. In the UK, the AHeSSC (Arts and Humanities e-Science Support Centre) has played a coordinating role for seven projects funded by the Arts and Humanities e-Science Initiative. In Europe, DARIAH (Digital Research Infrastructure for the Arts and Humanities) has sought to develop a deeper understanding of research information and communication in the arts and humanities, and to inform the development of e-infrastructures accordingly. Both sets of activity have indicated a common requirement: to construct a framework which consistently describes the methods and functions of scholarly activity which underlie digital arts and humanities research, and the relationships between them. Such a 'methodological commons' has been formulated in the field of the digital humanities. This paper describes the application of this approach to arts and humanities e-Science, with reference to the early work of DARIAH and AHeSSC.

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