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1.
Air Med J ; 41(4): 380-384, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35750445

RESUMO

OBJECTIVE: The incidence of deterioration and associated characteristics are largely unknown for children transported for admission from referring emergency departments (EDs) to general inpatient units. This study describes this population and identifies associated preadmission characteristics. METHODS: This single-center cohort study included children ≤ 18 years old transferred from an ED and directly admitted to general inpatient units from 2016 to 2019. Deterioration was defined as 1 or more of the following occurring within 24 hours of admission: rapid response team activation, transfer to the intensive care unit (ICU), or cardiac or respiratory arrest. ICU transfer was the secondary outcome. Logistic regression was performed. RESULTS: One thousand nine hundred eighty-eight patients were included; the median age was 4.2 years, 53.9% were male, and 44.1% had respiratory diagnoses. Deterioration occurred in 135 (6.8%) children overall and in 10.1% of children with respiratory complaints. Deterioration was associated with ≥ 2 complex chronic conditions (adjusted odds ratio [aOR] = 2.09; 95% confidence interval [CI], 1.04-4.19) and a longer stabilization time (per 10 minutes) (aOR = 1.17; 95% CI, 1.01-1.36). ICU transfer was associated with ≥ 2 complex chronic conditions (aOR = 2.33; 95% CI, 1.13-4.80), supplemental oxygen via nasal cannula (aOR = 2.13; 95% CI, 1.18-3.85), and nebulizer treatment (aOR = 2.77; 95% CI, 1.21-6.35). CONCLUSION: Deterioration was experienced by 7% of children admitted to a general unit, with the majority having respiratory complaints. Transport teams should consider the potential for increased risk of deterioration among children with respiratory disease, multiple complex chronic conditions, and a nasal cannula or nebulizer therapy. The clinical significance of marginally longer stabilization times is unclear and warrants further investigation.


Assuntos
Serviço Hospitalar de Emergência , Unidades de Terapia Intensiva , Adolescente , Criança , Pré-Escolar , Doença Crônica , Estudos de Coortes , Feminino , Mortalidade Hospitalar , Humanos , Masculino , Razão de Chances , Estudos Retrospectivos
2.
Crit Care Med ; 49(12): 2033-2041, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34259665

RESUMO

OBJECTIVES: To characterize the impact of public health interventions on the volume and characteristics of admissions to the PICU. DESIGN: Multicenter retrospective cohort study. SETTING: Six U.S. referral PICUs during February 15, 2020-May 14, 2020, compared with the same months during 2017-2019 (baseline). PATIENTS: PICU admissions excluding admissions for illnesses due to severe acute respiratory syndrome coronavirus 2 and readmissions during the same hospitalization. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Primary outcome was admission volumes during the period of stay-at-home orders (March 15, 2020-May 14, 2020) compared with baseline. Secondary outcomes were hospitalization characteristics including advanced support (e.g., invasive mechanical ventilation), PICU and hospital lengths of stay, and mortality. We used generalized linear mixed modeling to compare patient and admission characteristics during the stay-at-home orders period to baseline. We evaluated 7,960 admissions including 1,327 during March 15, 2020-May 14, 2020. Daily admissions and patients days were lower during the period of stay-at-home orders compared with baseline: median admissions 21 (interquartile range, 17-25) versus 36 (interquartile range, 30-42) (p < 0.001) and median patient days 93.0 (interquartile range, 55.9-136.7) versus 143.6 (interquartile range, 108.5-189.2) (p < 0.001). Admissions during the period of stay-at-home orders were less common in young children and for respiratory and infectious illnesses and more common for poisonings, endocrinopathies and for children with race/ethnicity categorized as other/unspecified. There were no differences in hospitalization characteristics except fewer patients received noninvasive ventilation during the period of stay-at-home orders. CONCLUSIONS: Reductions in PICU admissions suggest that much of pediatric critical illness in younger children and for respiratory and infectious illnesses may be preventable through targeted public health strategies.


Assuntos
COVID-19/epidemiologia , Controle de Doenças Transmissíveis/estatística & dados numéricos , Unidades de Terapia Intensiva Pediátrica/estatística & dados numéricos , Admissão do Paciente/estatística & dados numéricos , Adolescente , Fatores Etários , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Tempo de Internação , Masculino , Pandemias , Grupos Raciais , Respiração Artificial/estatística & dados numéricos , Estudos Retrospectivos , SARS-CoV-2 , Índice de Gravidade de Doença , Fatores Socioeconômicos , Adulto Jovem
3.
J Neurochem ; 135(5): 958-74, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26303407

RESUMO

Brain iron accumulates in several neurodegenerative diseases and can cause oxidative damage, but mechanisms of brain iron homeostasis are incompletely understood. Patients with mutations in the cellular iron-exporting ferroxidase ceruloplasmin (Cp) have brain iron accumulation causing neurodegeneration. Here, we assessed the brains of mice with combined mutation of Cp and its homolog hephaestin. Compared to single mutants, brain iron accumulation was accelerated in double mutants in the cerebellum, substantia nigra, and hippocampus. Iron accumulated within glia, while neurons were iron deficient. There was loss of both neurons and glia. Mice developed ataxia and tremor, and most died by 9 months. Treatment with the oral iron chelator deferiprone diminished brain iron levels, protected against neuron loss, and extended lifespan. Ferroxidases play important, partially overlapping roles in brain iron homeostasis by facilitating iron export from glia, making iron available to neurons. Above: Iron (Fe) normally moves from capillaries to glia to neurons. It is exported from the glia by ferroportin (Fpn) with ferroxidases ceruloplasmin (Cp) and/or Hephaestin (Heph). Below: In mice with mutation of Cp and Heph, iron accumulates in glia, while neurons have low iron levels. Both neurons and glia degenerate and mice become ataxic unless given an iron chelator.


Assuntos
Ceruloplasmina/genética , Quelantes de Ferro/uso terapêutico , Ferro/metabolismo , Proteínas de Membrana/genética , Mutação/genética , Doenças Neurodegenerativas , Piridonas/uso terapêutico , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Ceruloplasmina/metabolismo , Deferiprona , Modelos Animais de Doenças , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Transgênicos , Atividade Motora/efeitos dos fármacos , Atividade Motora/genética , Força Muscular/efeitos dos fármacos , Força Muscular/genética , Proteína Básica da Mielina/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Doenças Neurodegenerativas/tratamento farmacológico , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/metabolismo , Neuroglia/efeitos dos fármacos , Neuroglia/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Tirosina 3-Mono-Oxigenase/metabolismo
4.
FASEB J ; 28(5): 2029-37, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24558197

RESUMO

The purpose of the study was to identify determinants of placental vitamin D receptor (VDR) expression and placental calcium (Ca) transfer among pregnant adolescents. Placental tissue was obtained in 94 adolescents (≤18 yr) at term. In 12 of these teens, stable Ca isotopes were given intravenously ((42)Ca) and orally ((44)Ca) early in labor. Placental VDR expression was assessed via Western blot and validated by RT-PCR. Maternal-to-fetal Ca transfer was calculated as the enrichment in cord blood at delivery relative to maternal serum enrichment 2 h postdosing. Isotopic study outcomes were examined in relation to fetal long bone length, placental VDR, serum 25-hydroxyvitamin D [25(OH)D], 1,25-dihydroxyvitamin D [1,25(OH)2D], and parathyroid hormone (PTH) in maternal circulation and cord blood at delivery. Placental VDR expression was inversely associated with neonatal 25(OH)D (P=0.012) and positively with neonatal 1,25(OH)2D (P=0.006). Placental VDR was a positive predictor of fetal femur length Z score (P=0.018; R(2)=0.06) and was positively correlated with maternal-to-fetal transfer of intravenous (42)Ca (P=0.004; R(2)=0.62). The fetus may regulate placental VDR expression given the significant associations with neonatal vitamin D metabolites. The association between placental VDR and fetal long bone length may indicate a role for VDR in fetal bone development, potentially by mediating transplacental Ca transfer.


Assuntos
Desenvolvimento Ósseo , Cálcio/metabolismo , Placenta/metabolismo , Receptores de Calcitriol/metabolismo , Vitamina D/metabolismo , Administração Oral , Adolescente , Isótopos de Cálcio/metabolismo , Estudos de Coortes , Dieta , Feminino , Sangue Fetal/metabolismo , Feto/metabolismo , Regulação da Expressão Gênica , Humanos , Exposição Materna , Troca Materno-Fetal , Hormônio Paratireóideo/sangue , Gravidez , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo , Vitamina D/análogos & derivados , Vitamina D/sangue
5.
Am J Emerg Med ; 33(11): 1622-9, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26320671

RESUMO

BACKGROUND: Despite pediatric stroke awareness and pediatric stroke activation systems, recognition and imaging delays along with activation inconsistency still occur. Reliable objective pediatric stroke detection tools are needed to improve detection and activations. Regional cerebral oxygen saturation (rcso2) with cerebral blood volume index (CBVI) can detect abnormal cerebral physiology. OBJECTIVE: To determine cerebral oximetry in detecting strokes in stroke alert and overall stroke patients. METHOD: Left rcso2, right rcso2, and rcso2 side differences for stroke, location, and types were analyzed. RESULTS: Compared with stroke alert (n = 25) and overall strokes (n = 52), rcso2 and CBVI were less than those in nonstrokes (n = 133; P < .0001). Rcso2 side differences in stroke alert and overall strokes were greater than in nonstrokes (P < .0001). Lower rcso2 and CBVI correlated with both groups' stroke location, left (P < .0001) and right rcso2 (P = .004). Rcso2 differences greater than 10 had a 100% positive predictive value for stroke. Both groups' rcso2 and CBVI side differences were consistent for stroke location and type (P < .0001). For both groups, left rcso2 and CBVI were greater than those of the right (P < .0001). Hemorrhagic strokes had lower bilateral rcso2 and CBVI than did ischemic strokes (P < .001). CONCLUSIONS: Cerebral oximetry and CBVI detected abnormal cerebral physiology, stroke location, and type (hemorrhagic or ischemic). Rcso2 side differences greater than 10 or rcso2 readings less than 50% had a 100% positive predictive value for stroke. Cerebral oximetry has shown potential as a detection tool for stroke location and type in a pediatric stroke alert and nonalert stroke patients. Using cerebral oximetry by the nonneurologist, we found that the patient's rcso2 side difference greater than 10 or one or both sides having less than 50% rcso2 readings suggests abnormal hemispheric pathology and expedites the patient's diagnosis, neuroresuscitation, and radiologic imaging.


Assuntos
Volume Sanguíneo , Oximetria/métodos , Acidente Vascular Cerebral/diagnóstico , Adolescente , Biomarcadores/metabolismo , Circulação Cerebrovascular , Criança , Feminino , Indicadores Básicos de Saúde , Humanos , Masculino , Oxigênio/metabolismo , Valor Preditivo dos Testes , Estudos Prospectivos , Acidente Vascular Cerebral/fisiopatologia
6.
J Nutr ; 142(1): 33-9, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22113871

RESUMO

The determinants of placental transport of dietary iron remain largely uncharacterized. The objective of this research was to elucidate determinants of fetal Fe transfer from maternally ingested dietary heme and non-heme Fe. The study was undertaken in 19 pregnant females (16-32 y) who ingested intrinsically labeled (58)Fe-heme and a nonheme Fe source ((57)FeSO(4)) during the third trimester of pregnancy. At delivery, maternal and cord blood was obtained to assess neonatal (57)Fe and (58)Fe enrichment as a function of maternal/neonatal Fe status [serum ferritin (SF), transferrin receptor, hemoglobin (Hb), total body Fe, and hepcidin]. There was a greater percentage of maternally absorbed (58)Fe tracer present in the neonates compared to the (57)Fe tracer (5.4 ± 2.4 vs. 4.0 ± 1.6; P < 0.0001). Net dietary nonheme Fe (mg) and heme Fe (mg) transferred to the fetus were both inversely correlated with measures of maternal serum hepcidin (P = 0.002, r(2) = 0.43; P = 0.004, r(2) = 0.39) and SF (P = 0.0008, r(2) = 0.49; P = 0.003, r(2) = 0.41) and directly associated with neonatal Hb (P = 0.004, r(2) = 0.39; P = 0.008, r(2) = 0.35). The results of this study suggest that during pregnancy there appears to be preferential fetal use of maternally ingested Fe derived from a dietary, animal-based heme source compared to Fe ingested as ferrous sulfate. Maternal serum hepcidin and maternal/neonatal Fe status may play a role in placental uptake of dietary heme and nonheme Fe.


Assuntos
Peptídeos Catiônicos Antimicrobianos/metabolismo , Dieta , Heme/metabolismo , Ferro/metabolismo , Troca Materno-Fetal , Adolescente , Adulto , Feminino , Hepcidinas , Humanos , Gravidez , Adulto Jovem
7.
Crit Care Nurse ; 41(5): 41-50, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34595494

RESUMO

BACKGROUND: In patients with acute neurological injury, abrupt temperature change exacerbates increased intracranial pressures and negatively affects perfusion pressure and cerebral blood flow. Critical care nurses must provide coordinated and effective interventions to maintain normothermia without precipitating shivering immediately after acute neurological injury in pediatric patients. OBJECTIVE: To improve hyperthermia management in a 40-bed pediatric intensive care unit, an interdisciplinary pediatric critical care team developed, implemented, and evaluated a targeted temperature management protocol. METHODS: The project was guided by the organization's plan-do-study-act quality improvement process. Quality improvement was assessed retrospectively using electronic medical records of patients meeting eligibility criteria. Samples of pediatric patients who received temperature interventions were compared before and after protocol implementation. The protocol included environmental, pharmacological, and body surface cooling device interventions, as well as use of a bedside shivering assessment scale and stepwise interventions to prevent and control shivering. RESULTS: Before implementation of the targeted temperature management protocol, 64% of patients had documented temperatures higher than 37.5 °C, and body surface cooling devices were used in 10% of patients. After protocol implementation, more than 80% of patients had documented temperatures higher than 37.5 °C, and body surface cooling devices were used in 62% of patients. Four patients (6%) before and 5 patients (31%) after protocol implementation were treated with body surface cooling without requiring use of neuromuscular blockade. CONCLUSIONS: Creation and implementation of a targeted temperature management protocol increased nurses' documented use of body surface cooling to manage hyperthermia in pediatric intensive care unit patients with acute neurological injury.


Assuntos
Hipotermia Induzida , Melhoria de Qualidade , Temperatura Corporal , Criança , Humanos , Unidades de Terapia Intensiva Pediátrica , Estudos Retrospectivos
8.
Cell Metab ; 2(5): 309-19, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16271531

RESUMO

Ferroxidases are essential for normal iron homeostasis in most organisms. The paralogous vertebrate ferroxidases ceruloplasmin (Cp) and hephaestin (Heph) are considered to have nonidentical functions in iron transport: plasma Cp drives iron transport from tissue stores while intestinal Heph facilitates iron absorption from the intestinal lumen. To clarify the function of Cp, we acutely bled Cp-/- mice to stress iron homeostasis pathways. Red cell hemoglobin recovery was defective in stressed Cp-/- mice, consistent with low iron availability. Contrary to expectations, iron was freely released from spleen and liver stores in Cp-/- mice, but intestinal iron absorption was markedly impaired. Phlebotomy of wild-type mice caused a striking shift of Cp from the duodenal epithelium to the underlying lamina propria, suggesting a critical function of Cp in basolateral iron transport. Regulated relocalization of intestinal Cp may represent a fail-safe mechanism in which Cp shares with Heph responsibility for iron absorption under stress.


Assuntos
Ceruloplasmina/genética , Ceruloplasmina/metabolismo , Ferro/metabolismo , Animais , Proteínas de Transporte de Cátions/metabolismo , Duodeno/citologia , Duodeno/metabolismo , Enterócitos/metabolismo , Homeostase , Humanos , Absorção Intestinal , Ferro/sangue , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mucosa/metabolismo , RNA Mensageiro/metabolismo , Baço/metabolismo , Estresse Fisiológico/metabolismo , Fatores de Tempo , Transferrina/metabolismo
9.
J Nutr ; 140(12): 2162-6, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20980658

RESUMO

Heme iron absorption during pregnancy and the role of hepcidin in regulating dietary heme iron absorption remains largely unexplored. The objective of this research was to examine relative differences in heme (animal based) and nonheme (ferrous sulfate) iron utilization. This study was undertaken in 18 pregnant (ages 16-32 y; wk 32-35 of gestation) and 11 nonpregnant women (ages 18-27 y). Women were randomly assigned to receive both an animal-based heme meal (intrinsically labeled (58)Fe pork) and labeled ferrous sulfate ((57)Fe) fed on alternate days. Blood samples obtained 2 wk postdosing were used to assess iron status indicators and serum hepcidin and iron utilization based on RBC incorporation of iron isotopes. Heme iron utilization was significantly greater than nonheme iron utilization in the pregnant (47.7 ± 14.4 vs. 40.4 ± 13.2%) and nonpregnant women (50.1 ± 14.8 vs. 15.3 ± 9.7%). Among pregnant women, utilization of nonheme iron was associated with iron status, as assessed by the serum transferrin receptor concentration (P = 0.003; r(2) = 0.43). In contrast, heme iron utilization was not influenced by maternal iron status. In the group as a whole, women with undetectable serum hepcidin had greater nonheme iron utilization compared with women with detectable serum hepcidin (P = 0.02; n = 29); however, there were no significant differences in heme iron utilization. Our study suggests that iron utilization from an animal-based food provides a highly bioavailable source of dietary iron for pregnant and nonpregnant women that is not as sensitive to hepcidin concentrations or iron stores compared with ferrous sulfate.


Assuntos
Compostos Ferrosos/metabolismo , Ferro/metabolismo , Adolescente , Adulto , Feminino , Humanos , Gravidez , Adulto Jovem
10.
Resusc Plus ; 4: 100035, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34223312

RESUMO

AIM: To determine if an untrained cardiopulmonary resuscitation (CPR) Coach, with no access to real-time CPR feedback technology, improves CPR quality. METHODS: This was a prospective randomized pilot study at a tertiary care children's hospital that aimed to integrate an untrained CPR Coach into resuscitation teams during simulated pediatric cardiac arrest. Simulation events were randomized to two arms: control (no CPR Coach) or intervention (CPR Coach). Simulations were run by pediatric intensive care unit (PICU) providers and video recorded. Scenarios focused on full cardiopulmonary arrest; neither team had access to real-time CPR feedback technology. The primary outcome was CPR quality. Secondary outcomes included workload assessments of the team leader and CPR Coach using the NASA Task Load Index and perceptions of CPR quality. RESULTS: Thirteen simulations were performed; 5 were randomized to include a CPR Coach. There was a significantly shorter duration to backboard placement in the intervention group (median 20 s [IQR 0-27 s] vs. 52 s [IQR 38-65 s], p = 0.02). There was no self-reported change in the team leader's workload between scenarios using a CPR Coach compared to those without a CPR Coach. There were no significant changes in subjective CPR quality measures. CONCLUSIONS: In this pilot study, inclusion of an untrained CPR Coach during simulated CPR shortened time to backboard placement but did not improve most metrics of CPR quality or significantly affect team leader workload. More research is needed to better assess the value of a CPR Coach and its potential impact in real-world resuscitation.

11.
Invest Ophthalmol Vis Sci ; 49(6): 2728-36, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18326691

RESUMO

PURPOSE: Iron is an essential element in human metabolism but also is a potent generator of oxidative damage with levels that increase with age. Several studies suggest that iron accumulation may be a factor in age-related macular degeneration (AMD). In prior studies, both iron overload and features of AMD were identified in mice deficient in the ferroxidase ceruloplasmin (Cp) and its homologue hephaestin (Heph) (double knockout, DKO). In this study, the location and timing of iron accumulation, the rate and reproducibility of retinal degeneration, and the roles of oxidative stress and complement activation were determined. METHODS: Morphologic analysis and histochemical iron detection by Perls' staining was performed on retina sections from DKO and control mice. Immunofluorescence and immunohistochemistry were performed with antibodies detecting activated complement factor C3, transferrin receptor, L-ferritin, and macrophages. Tissue iron levels were measured by atomic absorption spectrophotometry. Isoprostane F2alpha-VI, a specific marker of oxidative stress, was quantified in the tissue by gas chromatography/mass spectrometry. RESULTS: DKOs exhibited highly reproducible age-dependent iron overload, which plateaued at 6 months of age, with subsequent progressive retinal degeneration continuing to at least 12 months. The degeneration shared some features of AMD, including RPE hypertrophy and hyperplasia, photoreceptor degeneration, subretinal neovascularization, RPE lipofuscin accumulation, oxidative stress, and complement activation. CONCLUSIONS: DKOs have age-dependent iron accumulation followed by retinal degeneration modeling some of the morphologic and molecular features of AMD. Therefore, these mice are a good platform on which to test therapeutic agents for AMD, such as antioxidants, iron chelators, and antiangiogenic agents.


Assuntos
Ceruloplasmina/fisiologia , Modelos Animais de Doenças , Sobrecarga de Ferro/patologia , Degeneração Macular/patologia , Proteínas de Membrana/fisiologia , Animais , Apoferritinas/metabolismo , Corioide/metabolismo , Ativação do Complemento , Complemento C3/metabolismo , Fator B do Complemento/metabolismo , Dinoprosta/análogos & derivados , Dinoprosta/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Ferro/metabolismo , Sobrecarga de Ferro/metabolismo , Macrófagos/patologia , Degeneração Macular/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Estresse Oxidativo , Epitélio Pigmentado Ocular/metabolismo , Receptores da Transferrina/metabolismo , Retina/metabolismo , Espectrofotometria Atômica
12.
Biochem Soc Trans ; 36(Pt 6): 1277-81, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19021540

RESUMO

Two decades ago, patients lacking circulating serum ceruloplasmin (Cp) presented with neurodegeneration associated with brain iron accumulation. These patients, with mutations in the MCO (multi-copper oxidase), Cp, revealed an essential role for Cp in iron homoeostasis. The patients were diagnosed in adulthood with CNS (central nervous system) disease and progressed rapidly, making understanding the mechanism of disease imperative. We now know that (i) Cp regulates the efficiency of iron efflux, (ii) Cp stabilizes ferroportin membrane expression, (iii) GPI (glycosylphosphatidylinositol)-linked Cp is the predominant form expressed in brain, (iv) Cp functions as a ferroxidase and regulates the oxidation of Fe(2+) to Fe(3+), (v) Cp does not bind to transferrin directly, and (vi) Cp is one member of a family of mammalian MCOs, which includes hephaestin. It is still unclear how an absence of Cp results in neurodegeneration: is the iron accumulation a primary or secondary injury? Although it is attractive to invoke an iron-mediated oxidative stress mechanism for the neuronal injury and degeneration in aceruloplasminaemia, our data suggest limited redox injury in the brains of mice lacking MCO. In fact, we propose a role for neuronal iron starvation with associated astrocyte and microglial iron overload. With the defect in aceruloplasminaemia being one of inefficient iron efflux from macrophages, we believe that the iron is trapped in a compartment not readily available to participate in oxyradical injury. It is likely that different mechanisms of neuronal cell protection are offered by astrocytes and microglia, and, once these cells are damaged, neuronal survival is compromised.


Assuntos
Ceruloplasmina/metabolismo , Doenças Neurodegenerativas/metabolismo , Animais , Sistema Nervoso Central/enzimologia , Humanos , Ferro/metabolismo , Neurônios/metabolismo , Oxirredutases/metabolismo
13.
Pediatr Crit Care Med ; 7(2): 180-2, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16446598

RESUMO

OBJECTIVE: To provide the first account of extracorporeal membrane oxygenation therapy failure secondary to abdominal compartment syndrome. DESIGN: Case report. SETTING: Pediatric intensive care unit. PATIENT: A 4-month-old infant with cyanotic congenital heart disease and Escherichia coli sepsis developed abdominal distention and venous return failure on extracorporeal membrane oxygenation. INTERVENTION: Emergency cardiac catheterization and atrial septectomy were performed. MAIN RESULTS: Central venous pressure of 120 mm Hg was measured, confirming the diagnosis of abdominal compartment syndrome. CONCLUSIONS: Abdominal compartment syndrome is a life-threatening condition resulting from an increase in intra-abdominal pressure that compromises abdominal organ perfusion, pulmonary function, and cardiac output. Mortality rates from abdominal compartment syndrome are as high as 60% in adults and children. This report of an infant with congenital heart disease and E. coli sepsis represents the first description of abdominal compartment syndrome that contributed to failure of extracorporeal membrane oxygenation and ultimately death. The pathophysiology, diagnosis, and treatment of abdominal compartment syndrome are also reviewed.


Assuntos
Abdome , Síndromes Compartimentais/complicações , Oxigenação por Membrana Extracorpórea , Cardiopatias Congênitas/complicações , Sepse/complicações , Síndromes Compartimentais/fisiopatologia , Escherichia coli , Evolução Fatal , Feminino , Humanos , Lactente , Unidades de Terapia Intensiva Pediátrica
14.
Mol Vis ; 10: 598-607, 2004 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-15354085

RESUMO

PURPOSE: CNS iron accumulation is associated with several neurodegenerative diseases, including age-related macular degeneration. Intracellular overload of free iron is prevented, in part, by the iron export protein, ferroportin, and the iron storage protein, ferritin. The purpose of this study was to assess retinal localization and regulation of ferroportin and ferritin. METHODS: Normal murine retinas were analyzed by immunohistochemistry to localize ferroportin, cytosolic ferritin, and mitochondrial ferritin, with double-labeling using cell-specific markers to identify cell types. Retinas deficient in the ferroxidases, ceruloplasmin and hephaestin, accumulate iron in their retinas and RPE, while retinas deficient in iron regulatory proteins (IRPs) lack the ability to regulate several proteins involved in iron metabolism; retinas from these knockout mice along with their age matched wild type littermates were also examined to study regulation of ferritin and ferroportin. To enable visualization of label in the retinal pigment epithelial cells, sections from pigmented mice were bleached with H2O2 prior to IHC, a novel use of this technique for study of the RPE. RESULTS: In normal retinas, cytosolic ferritins were found predominantly in rod bipolar cells and photoreceptors. Ferroportin was found in RPE and Müller cells. Iron accumulation in mice deficient in ceruloplasmin and hephaestin was associated with upregulation of ferritin and ferroportin. Mice deficient in IRPs showed upregulation of ferritin and ferroportin, likely because of their inability to repress translation. CONCLUSIONS: Normal retinas contain ferritin and ferroportin, whose levels are regulated by iron-responsive, iron regulatory proteins. Ferroportin colocalizes with ceruloplasmin and hephaestin to RPE and Müller cells, supporting a potential cooperation between these ferroxidases and the iron exporter. Cytosolic ferritin accumulates in rod bipolar synaptic terminals, suggesting that ferritin may be involved in axonal iron transport. Mitochondrial ferritin increases with iron accumulation, suggesting a role in iron storage.


Assuntos
Proteínas de Transporte de Cátions/metabolismo , Ferritinas/metabolismo , Retina/metabolismo , Animais , Apoferritinas , Técnica Indireta de Fluorescência para Anticorpo , Proteínas Ligadas por GPI , Ferro/metabolismo , Proteínas Reguladoras de Ferro/metabolismo , Proteínas de Membrana/metabolismo , Metaloproteínas/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas de Neoplasias/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
15.
Ann N Y Acad Sci ; 1012: 299-305, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15105274

RESUMO

In 1987, Miyajima et al. first characterized an autosomal recessive, adult-onset neurodegenerative disorder resembling Parkinson's disease associated with near-absent circulating serum ceruloplasmin levels. Coined "familial apoceruloplasmin deficiency", they described a patient with a presenting triad of diabetes mellitus, retinal degeneration, and neurodegeneration with blepharospasm. Neuropathological evaluation revealed abundant iron deposition in selected neurons of the basal ganglia and substantia nigra with associated neuronal dropout and spongioform degeneration without evidence of reactive gliosis. Subsequently, mutations in the ceruloplasmin gene have been determined to result in the excessive iron accumulation seen in the pancreas, retina, and brain. Elevated serum ferritin suggests a systemic iron overload syndrome, yet affected patients had low transferrin saturation and a mild anemia. This new disease, "aceruloplasminemia", reveals a role for ceruloplasmin as an essential ferroxidase critical for iron homeostasis. This multicopper oxidase promotes efficient iron efflux such that individuals lacking ceruloplasmin develop a presumed oxidative injury secondary to iron accumulation and significant neuronal damage. Aceruloplasminemic mice provide a valuable model to further study the mechanisms by which ceruloplasmin regulates iron trafficking and the role of iron in oxidative injury. Despite the dependence of ceruloplasmin on copper for its function, aceruloplasminemia represents an iron storage disease and not a defect in copper metabolism. However, recent evidence in Saccharomyces cerevisiae indicates that Fet3, the yeast homologue of ceruloplasmin, functions as an essential cuprous oxidase. Further investigation into the mechanisms by which ceruloplasmin regulates iron and copper homeostasis will provide valuable insight into the pathogenesis of metallo-mediated diseases and elucidate mechanisms for transition metal (copper, iron) neuropathology.


Assuntos
Apoproteínas/deficiência , Ceruloplasmina/deficiência , Cobre/metabolismo , Homeostase , Ferro/metabolismo , Doenças Neurodegenerativas/metabolismo , Animais , Apoproteínas/genética , Encéfalo/metabolismo , Encéfalo/patologia , Ceruloplasmina/genética , Coração/fisiologia , Humanos , Fígado/metabolismo , Fígado/patologia , Doenças Neurodegenerativas/etiologia , Doenças Neurodegenerativas/genética , Pâncreas/metabolismo , Pâncreas/patologia
16.
J Bone Miner Res ; 27(1): 177-86, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21956833

RESUMO

Few large studies have assessed changes in calcitropic hormones and maternal 25-hydroxyvitamin D (25(OH)D) status across pregnancy, and how this may impact maternal bone turnover and neonatal hormone status. We aimed to identify determinants of 25(OH)D, parathyroid hormone (PTH), and calcitriol across pregnancy in a longitudinal study of 168 pregnant adolescents (≤18 years of age). Maternal 25(OH)D, PTH, and calcitriol were assessed at mid-gestation (∼26 weeks), delivery, and in cord blood. Data were related to measures of maternal anthropometrics, dietary intake, physical activity, and bone turnover markers. Approximately 50% of teens and their infants had serum 25(OH)D ≤ 20 ng/mL; 25(OH)D was lower in African Americans versus whites (p < 0.001). PTH increased across gestation (p < 0.001). Elevated PTH (≥60 pg/mL) was detected in 25% of adolescents at delivery, and was associated with increased concentrations of serum N-telopeptide (NTX) (p = 0.028). PTH and calcitriol did not significantly differ across the range of Ca intake consumed (257-3220 mg/d). In the group as a whole, PTH was inversely associated with 25(OH)D in maternal circulation at mid-gestation (p = 0.023) and at delivery (p = 0.019). However, when the cohort was partitioned by 25(OH)D status, this relationship was only present in those with 25(OH)D ≤ 20 ng/mL, suggestive of a threshold below which 25(OH)D impacts PTH during pregnancy. Mid-gestation 25(OH)D was inversely associated with calcitriol at delivery (p = 0.023), irrespective of Ca intake. Neonatal PTH and calcitriol were significantly lower than (p < 0.001), but unrelated to maternal concentrations. These findings indicate that maternal 25(OH)D status plays a role in calcitropic hormone regulation in pregnant adolescents.


Assuntos
Calcitriol/sangue , Hormônio Paratireóideo/sangue , Deficiência de Vitamina D/epidemiologia , Adolescente , Biomarcadores/sangue , Remodelação Óssea , Dieta , Suplementos Nutricionais , Feminino , Hormônios/sangue , Humanos , Recém-Nascido , Estudos Longitudinais , Gravidez , Prevalência , Vitamina D/análogos & derivados , Vitamina D/sangue
17.
Am J Clin Nutr ; 95(5): 1103-12, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22492380

RESUMO

BACKGROUND: Maternal calcium intake and vitamin D status may affect fetal bone development. OBJECTIVE: This study was designed to examine relations between maternal calcium intake, 25-hydroxyvitamin D [25(OH)D] status, and fetal bone growth across pregnancy. DESIGN: This was a prospective longitudinal design. Maternal 25(OH)D, parathyroid hormone, and 1,25-dihydroxyvitamin D [1,25(OH)(2)D] were determined at midgestation (∼26 wk) and at delivery in 171 adolescents (≤ 18 y). Dietary recalls and fetal sonograms were performed up to 3 times across gestation, and fetal femur and humerus z scores were generated. RESULTS: Fetal femur and humerus z scores and neonatal birth length were significantly greater (P < 0.03) in adolescents consuming ≥ 1050 mg than in those consuming <1050 mg Ca/d. Maternal 25(OH)D > 50 nmol/L was significantly positively associated with fetal femur and humerus z scores (P < 0.01). When maternal smoking, height, race, weight gain, and gestational age were controlled for, these relations remained significant. Interactions between calcium intake and 25(OH)D were evident. Calcium intake was associated with fetal femur z scores and birth length only when maternal 25(OH)D was ≤ 50 nmol/L (P < 0.05). Similarly, maternal 25(OH)D was associated with fetal femur and humerus z scores only when maternal calcium intake was <1050 mg/d (P < 0.03). CONCLUSIONS: Optimal calcium intake and adequate maternal vitamin D status are both needed to maximize fetal bone growth. Interactions between these nutrients were evident when either calcium or vitamin D status was limited. Improving maternal calcium intake and/or vitamin D status during pregnancy may have a positive effect on fetal skeletal development in pregnant adolescents.


Assuntos
Desenvolvimento Ósseo/efeitos dos fármacos , Cálcio da Dieta/administração & dosagem , Fenômenos Fisiológicos da Nutrição Materna , Vitamina D/administração & dosagem , Adolescente , Feminino , Fêmur/efeitos dos fármacos , Fêmur/embriologia , Desenvolvimento Fetal/efeitos dos fármacos , Humanos , Modelos Lineares , Estudos Longitudinais , Hormônio Paratireóideo/metabolismo , Gravidez , Estudos Prospectivos
18.
Acad Med ; 86(8): 968-73, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21694562

RESUMO

PURPOSE: To assess equity in compensation and academic advancement in an academic pediatrics department in which a large proportion of the physician faculty hold part-time appointments. METHOD: The authors analyzed anonymized data from Vanderbilt University School of Medicine Department of Pediatrics databases for physician faculty (faculty with MD or MD/PhD degrees) employed during July 1, 2007 to June 30, 2008. The primary outcomes were total compensation and years at assistant professor rank. They compared compensation and years at junior rank by part-time versus full-time status, controlling for gender, rank, track, years since first appointment as an assistant professor, and clinical productivity. RESULTS: Of the 119 physician faculty in the department, 112 met inclusion criteria. Among those 112 faculty, 23 (21%) were part-time and 89 (79%) were full-time faculty. Part-time faculty were more likely than full-time faculty to be women (74% versus 28%, P < .001) and married (100% versus 84%, P = .042). Analyses accounting for gender, years since first appointment, rank, clinical productivity, and track did not demonstrate significant differences in compensation by part-time versus full-time status. In other adjusted analyses, faculty with part-time appointments spent an average of 2.48 more years as an assistant professor than did faculty with full-time appointments. CONCLUSIONS: Overall group differences in total compensation were not apparent in this department, but physician faculty with part-time appointments spent more time at the rank of assistant professor. This study provides a model for determining and analyzing compensation and effort to ensure equity and transparency across faculty.


Assuntos
Mobilidade Ocupacional , Docentes de Medicina , Pediatria , Salários e Benefícios , Adulto , Feminino , Hospitais Universitários , Humanos , Masculino , Pessoa de Meia-Idade , Fatores Sexuais , Fatores de Tempo , Carga de Trabalho
19.
Invest Ophthalmol Vis Sci ; 52(2): 959-68, 2011 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-21051716

RESUMO

PURPOSE: Iron-induced oxidative stress may exacerbate age-related macular degeneration (AMD). Ceruloplasmin/Hephaestin double-knockout (DKO) mice with age-dependent retinal iron accumulation and some features of AMD were used to test retinal protection by the oral iron chelator deferiprone (DFP). METHODS: Cultured retinal pigment epithelial (ARPE-19) cells and mice were treated with DFP. Transferrin receptor mRNA (Tfrc), an indicator of iron levels, was quantified by qPCR. In mice, retinal oxidative stress was assessed by mass spectrometry, and degeneration by histology and electroretinography. RESULTS: DFP at 60 µM decreased labile iron in ARPE-19 cells, increasing Tfrc and protecting 70% of cells against a lethal dose of H(2)O(2). DFP 1 mg/mL in drinking water increased retinal Tfrc mRNA 2.7-fold after 11 days and also increased transferrin receptor protein. In DKOs, DFP over 8 months decreased retinal iron levels to 72% of untreated mice, diminished retinal oxidative stress to 70% of the untreated level, and markedly ameliorated retinal degeneration. DFP was not retina toxic in wild-type (WT) or DKO mice, as assessed by histology and electroretinography. CONCLUSIONS: Oral DFP was not toxic to the mouse retina. It diminished retinal iron levels and oxidative stress and protected DKO mice against iron overload-induced retinal degeneration. Further testing of DFP for retinal disease involving oxidative stress is warranted.


Assuntos
Quelantes de Ferro/administração & dosagem , Sobrecarga de Ferro/prevenção & controle , Piridonas/administração & dosagem , Degeneração Retiniana/prevenção & controle , Epitélio Pigmentado da Retina/efeitos dos fármacos , Administração Oral , Animais , Antígenos CD/metabolismo , Morte Celular , Linhagem Celular , Ceruloplasmina/genética , Deferiprona , Eletrorretinografia , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Peróxido de Hidrogênio/toxicidade , Quelantes de Ferro/farmacologia , Sobrecarga de Ferro/metabolismo , Sobrecarga de Ferro/patologia , Masculino , Espectrometria de Massas , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microscopia de Fluorescência , Estresse Oxidativo/efeitos dos fármacos , Piridonas/farmacologia , RNA Mensageiro/genética , Receptores da Transferrina/genética , Receptores da Transferrina/metabolismo , Degeneração Retiniana/metabolismo , Degeneração Retiniana/patologia , Epitélio Pigmentado da Retina/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
20.
PLoS One ; 6(9): e25077, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21949858

RESUMO

Ceruloplasmin (Cp) is an essential ferroxidase that plays important roles in cellular iron trafficking. Previous findings suggest that the proper regulation and subcellular localization of iron are very important in brain cell function and viability. Brain iron dyshomeostasis is observed during normal aging, as well as in several neurodegenerative disorders such as Alzheimer's, Parkinson's and Huntington's diseases, coincident with areas more susceptible to insults. Because of their high metabolic demand and electrical excitability, neurons are particularly vulnerable to ischemic injury and death. We therefore set out to look for abnormalities in the brain of young adult mice that lack Cp. We found that iron levels in the striatum and cerebral cortex of these young animals are significantly lower than wild-type (WT) controls. Also mRNA levels of the neurotrophin brain derived neurotrophic factor (BDNF), known for its role in maintenance of cell viability, were decreased in these brain areas. Chelator-mediated depletion of iron in cultured neural cells resulted in reduced BDNF expression by a posttranscriptional mechanism, suggesting a causal link between low brain iron levels and reduced BDNF expression. When the mice were subjected to middle cerebral artery occlusion, a model of focal ischemic stroke, we found increased brain damage in Cp-deficient mice compared to WT controls. Our data indicate that lack of Cp increases neuronal susceptibility to ischemic injury by a mechanism that may involve reduced levels of iron and BDNF.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/metabolismo , Ceruloplasmina/fisiologia , Corpo Estriado/metabolismo , Ferro/metabolismo , Neostriado/metabolismo , Acidente Vascular Cerebral/etiologia , Animais , Western Blotting , Encéfalo/citologia , Encéfalo/metabolismo , Fator Neurotrófico Derivado do Encéfalo/genética , Modelos Animais de Doenças , Humanos , Técnicas Imunoenzimáticas , Infarto da Artéria Cerebral Média/metabolismo , Infarto da Artéria Cerebral Média/patologia , Masculino , Camundongos , Camundongos Knockout , Neuroblastoma/metabolismo , Neuroblastoma/patologia , Neurônios/citologia , Neurônios/metabolismo , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Acidente Vascular Cerebral/metabolismo , Acidente Vascular Cerebral/patologia , Células Tumorais Cultivadas
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