Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 141
Filtrar
1.
Sci Rep ; 10(1): 8423, 2020 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-32440003

RESUMO

Extracorporeal cardiopulmonary resuscitation (ECPR) is a last resort treatment option for refractory cardiac arrest performed in specialized centers. Following consensus recommendations, ECPR is mostly offered to younger patients with witnessed collapse but without return of spontaneous circulation (ROSC). We report findings from a large single-center registry with 252 all-comers who received ECPR from 2011-2019. It took a median of 52 min to establish stable circulation by ECPR. Eighty-five percent of 112 patients with out-of-hospital cardiac arrest (OHCA) underwent coronary angiography, revealing myocardial infarction (MI) type 1 with atherothrombotic vessel obstruction in 70 patients (63% of all OHCA patients, 74% of OHCA patients undergoing coronary angiography). Sixty-six percent of 140 patients with intra-hospital cardiac arrest (IHCA) underwent coronary angiography, which showed MI type 1 in 77 patients (55% of all IHCA patients, 83% of IHCA patients undergoing coronary angiography). These results suggest that MI type 1 is a frequent finding and - most likely - cause of cardiac arrest (CA) in patients without ROSC, especially in OHCA. Hospital survival rates were 30% and 29% in patients with OHCA and IHCA, respectively. According to these findings, rapid coronary angiography may be advisable in patients with OHCA receiving ECPR without obvious non-cardiac cause of arrest, irrespective of electrocardiogram analysis. Almost every third patient treated with ECPR survived to hospital discharge, supporting previous data suggesting that ECPR may be beneficial in CA without ROSC. In conclusion, interventional cardiology is of paramount importance for ECPR programs.


Assuntos
Reanimação Cardiopulmonar/métodos , Angiografia Coronária/métodos , Oxigenação por Membrana Extracorpórea/métodos , Infarto do Miocárdio/epidemiologia , Parada Cardíaca Extra-Hospitalar/terapia , Injúria Renal Aguda/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/mortalidade , Parada Cardíaca Extra-Hospitalar/mortalidade , Parada Cardíaca Extra-Hospitalar/patologia , Estudos Retrospectivos , Taxa de Sobrevida , Fatores de Tempo , Resultado do Tratamento
2.
Diagn Interv Imaging ; 101(9): 577-588, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32122802

RESUMO

PURPOSE: The purpose of this study was to test fluorine-19 (19F) cellular magnetic resonance (MRI) as a non-invasive imaging modality to track therapeutic cell migration as a surrogate marker of immunotherapeutic effectiveness. MATERIALS AND METHODS: Human peripheral blood mononuclear cell- (PBMC)-derived antigen presenting cell (APC) were labeled with a 19F-perfluorocarbon (PFC) and/or activated with granulocyte macrophage colony-stimulating factor (GM-CSF). Viability, phenotype and cell lineage characterization preceded 19F cellular MRI of PFC+ PBMC under both pre-clinical 9.4 Tesla (T) and clinical 3T conditions in a mouse model. RESULTS: A high proportion of PBMC incorporated PFC without affecting viability, phenotype or cell lineage composition. PFC+ PBMC were in vivo migration-competent to draining and downstream lymph nodes. GM-CSF addition to culture increased PBMC migration to, and persistence within, secondary lymphoid organs. CONCLUSION: 19F cellular MRI is a non-invasive imaging technique capable of detecting and quantifying in vivo cell migration in conjunction with an established APC-based immunotherapy model. 19F cellular MRI can function as a surrogate marker for assessing and improving upon the therapeutic benefit that this immunotherapy provides.


Assuntos
Fator Estimulador de Colônias de Granulócitos e Macrófagos , Leucócitos Mononucleares , Animais , Flúor , Granulócitos , Humanos , Fator Estimulador de Colônias de Macrófagos , Imageamento por Ressonância Magnética , Camundongos
3.
Phys Chem Miner ; 46(1): 15-26, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30880868

RESUMO

The chemically driven propagation of interacting parallel cracks in monoclinic alkali feldspar was studied experimentally. Single crystals of potassium-rich gem-quality sanidine were shifted towards more sodium-rich compositions by cation exchange with a NaCl-KCl salt melt at a temperature of 850 ∘ C and close to ambient pressure. Initially, a zone with elevated sodium content formed at the crystal surfaces due to the simultaneous in-diffusion of sodium and out-diffusion of potassium, where the rate of cation exchange was controlled by sodium-potassium interdiffusion within the feldspar. A chemical shift of potassium-rich alkali feldspar towards more sodium-rich compositions produces highly anisotropic contraction of the crystal lattice. This induced a tensile stress state in the sodium-rich surface layer of the crystals, which triggered the formation of a system of nearly equi-spaced parallel cracks oriented approximately perpendicular to the direction of maximum shortening. Crack propagation following their nucleation was driven by cation exchange occurring along the crack flanks and was controlled by the intimate coupling of the diffusion-mediated build-up of a tensile stress state around the crack tips and stress release by successive crack propagation. The critical energy release rate of fracturing was determined as 1.8-2.2 J m - 2 from evaluation of the near-tip J-integral. The mechanism of diffusion-controlled crack propagation is discussed in the context of high-temperature feldspar alteration.

4.
Phys Rev Lett ; 120(21): 216801, 2018 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-29883178

RESUMO

The topological phases of periodically driven, or Floquet systems, rely on a perfectly periodic modulation of system parameters in time. Even the smallest deviation from periodicity leads to decoherence, causing the boundary (end) states to leak into the system's bulk. Here, we show that in one dimension this decay of topologically protected end states depends fundamentally on the nature of the bulk states: a dispersive bulk results in an exponential decay, while a localized bulk slows the decay down to a diffusive process. The localization can be due to disorder, which remarkably counteracts decoherence even when it breaks the symmetry responsible for the topological protection. We derive this result analytically, using a novel, discrete-time Floquet-Lindblad formalism and confirm our findings with the help of numerical simulations. Our results are particularly relevant for experiments, where disorder can be tailored to protect Floquet topological phases from decoherence.

5.
Metallomics ; 9(7): 902-909, 2017 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-28561856

RESUMO

Trivalent lanthanum (La3+) has the potential to treat bone resorption disorders (such as osteoporosis) by eliciting a bone-building response in the cells which control skeletal remodelling. Because La3+ suffers from extremely poor intestinal absorption, specifically designed chelators are required in order that a biologically active form of lanthanum can be administered orally. Two such chelators, 1,2-dimethyl-3-hydroxy-4-pyridinone (Hdpp) and bis-{[bis(carboxymethyl)amino]methy}phosphinic acid (H5XT), have previously been the subjects of extensive physical, in vitro, and in vivo testing as the tris- and mono-lanthanum(iii) complexes La(dpp)3 and La(XT), respectively. In this manuscript, we expand upon those studies to include 4-week intravenous (IV) and oral La3+ biodistribution profiles, which show that the metal ion initially accumulates in the liver followed by preferential redistribution and retention by bone. Of the two compounds, La(XT) demonstrates the more favourable in vivo characteristics, therefore dose-dependent oral biodistribution studies were carried out with this complex. These show drug saturation above a dose of 100 mg kg-1 day-1, so liver histology was performed in order to assess any potential toxicity. Finally, we improve upon the physical characterization of La(dpp)3 to include a single crystal X-ray structure, which exhibits an 8-coorindate La3+ centre with two bound water molecules, and a disordered exoclathrate-type hydrogen bonded network.


Assuntos
Reabsorção Óssea/tratamento farmacológico , Lantânio/administração & dosagem , Lantânio/uso terapêutico , Administração Intravenosa , Administração Oral , Animais , Reabsorção Óssea/sangue , Reabsorção Óssea/patologia , Creatinina/sangue , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Lantânio/química , Fígado/enzimologia , Conformação Molecular , Ratos , Distribuição Tecidual
6.
Clin Pharmacol Ther ; 101(6): 725-735, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28295234

RESUMO

Adverse drug reactions (ADRs) represent a major health problem worldwide, with high morbidity and mortality rates. ADRs are classified into Type A (augmented) and Type B (bizarre) ADRs, with the former group being more common and the latter less common but often severe and clinically more problematic due to their unpredictable nature and occurrence at any dose. Pediatric populations are especially vulnerable to ADRs due to the lack of data for this age group from the drug development process and because of the wide use of off-label and unlicensed use of drugs. Children are more prone to specific types of ADRs because of the level of maturity of body systems involved in absorption, metabolism, transportation, and elimination of drugs. This state-of-the-art review provides an overview of definitions, classifications, epidemiology, and pathophysiology of ADRs and discusses the available evidence for related risk factors and causes of ADRs in the pediatric population.


Assuntos
Tratamento Farmacológico , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/epidemiologia , Uso Off-Label , Pediatria/métodos , Preparações Farmacêuticas/provisão & distribuição , Farmacologia Clínica/métodos , Adolescente , Adulto , Fatores Etários , Criança , Desenvolvimento Infantil , Mortalidade da Criança , Pré-Escolar , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/classificação , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/mortalidade , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/fisiopatologia , Humanos , Lactente , Recém-Nascido , Farmacogenética , Farmacocinética , Padrões de Prática Médica , Medição de Risco , Fatores de Risco , Terminologia como Assunto
7.
Clin Pharmacol Ther ; 101(2): 274-280, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27556253

RESUMO

The world's 1.89 billion children (age 0-14) too frequently receive treatments that have not been validated through clinical pharmacology research, especially in low- and middle-income countries. Initial findings from an international asset map of professionals and clinician scientists available to address the needs for education, research, and treatment support suggest a critical shortage of clinical pharmacologists, clinical pharmacists, and other professionals with advanced training in the evaluation of therapies for childhood conditions and illnesses. A total of 497 individuals responded to a survey conducted between May 2015 and February 2016. An alarming signal is apparent showing that, while the overall resource pool is unquestionably limited, 87% of relevant qualified personnel are located in high-income countries. The data suggest an urgent need for targeted training in pediatric clinical pharmacology, with particular focus on the needs in Africa, Latin America, and most of Asia.


Assuntos
Pesquisa Biomédica/estatística & dados numéricos , Cooperação Internacional , Pediatria/estatística & dados numéricos , Pesquisadores/provisão & distribuição , Adolescente , Criança , Pré-Escolar , Países Desenvolvidos/estatística & dados numéricos , Países em Desenvolvimento/estatística & dados numéricos , Humanos , Lactente , Recém-Nascido
8.
Cytometry A ; 89(5): 451-60, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26849001

RESUMO

Chlamydiaceae is a family of intracellular bacteria causing a range of diverse pathological outcomes. The most devastating human diseases are ocular infections with C. trachomatis leading to blindness and genital infections causing pelvic inflammatory disease with long-term sequelae including infertility and chronic pelvic pain. In order to enable the comparison of experiments between laboratories investigating host-chlamydia interactions, the infectious titer has to be determined. Titer determination of chlamydia is most commonly performed via microscopy of host cells infected with a serial dilution of chlamydia. However, other methods including fluorescent ELISpot (Fluorospot) and DNA Chip Scanning Technology have also been proposed to enumerate chlamydia-infected cells. For viruses, flow cytometry has been suggested as a superior alternative to standard titration methods. In this study we compared the use of flow cytometry with microscopy and Fluorospot for the titration of C. suis as a representative of other intracellular bacteria. Titer determination via Fluorospot was unreliable, while titration via microscopy led to a linear read-out range of 16 - 64 dilutions and moderate reproducibility with acceptable standard deviations within and between investigators. In contrast, flow cytometry had a vast linear read-out range of 1,024 dilutions and the lowest standard deviations given a basic training in these methods. In addition, flow cytometry was faster and material costs were lower compared to microscopy. Flow cytometry offers a fast, cheap, precise, and reproducible alternative for the titration of intracellular bacteria like C. suis. © 2016 International Society for Advancement of Cytometry.


Assuntos
Chlamydiaceae/isolamento & purificação , Células Epiteliais/microbiologia , Citometria de Fluxo/métodos , Linhagem Celular , Humanos , Microscopia , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
9.
Clin Pharmacol Ther ; 98(3): 266-87, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26088472

RESUMO

The critical importance of membrane-bound transporters in pharmacotherapy is widely recognized, but little is known about drug transporter activity in children. In this white paper, the Pediatric Transporter Working Group presents a systematic review of the ontogeny of clinically relevant membrane transporters (e.g., SLC, ABC superfamilies) in intestine, liver, and kidney. Different developmental patterns for individual transporters emerge, but much remains unknown. Recommendations to increase our understanding of membrane transporters in pediatric pharmacotherapy are presented.


Assuntos
Proteínas de Membrana Transportadoras/metabolismo , Preparações Farmacêuticas/metabolismo , Fatores Etários , Animais , Transporte Biológico , Pesquisa Biomédica/métodos , Criança , Desenvolvimento Infantil , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Preparações Farmacêuticas/administração & dosagem , Farmacocinética
10.
J Dent Res ; 92(11): 1022-8, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24004653

RESUMO

Gingival enlargement is a fibrotic condition that can arise from systemic administration of the dihydropyridine calcium channel blocker nifedipine. Periostin, a transforming growth factor-beta (TGF-ß)-inducible matricellular protein, has been associated with fibrosis in numerous tissues, but its expression has never been examined in nifedipine-influenced gingival enlargement (NIGE). The objective of this study was to assess if periostin up-regulation is associated with NIGE and whether nifedipine induces periostin expression in gingival fibroblasts. In NIGE tissue (n = 6), periostin is overexpressed in the gingival connective tissue compared with healthy control tissue (n = 6). The transcription factor p-SMAD2/3, which is associated with canonical TGF-ß signaling, localizes to the nuclei in both HGFs and oral epithelial cells in NIGE tissues, but not in control healthy tissue. In vitro culture of HGFs with 30 and 100 ng/mL of nifedipine significantly increased periostin mRNA and protein levels, which correlated with increased levels of active TGF-ß and increased phosphorylation and nuclear localization of SMAD3. Blocking of canonical TGF-ß signaling through inhibition of the TGF-ß receptor I with SB431542 significantly reduced nifedipine-induced SMAD3 phosphorylation and periostin expression. Our results demonstrate that nifedipine up-regulates periostin in HGFs in a TGF-ß-dependent manner.


Assuntos
Bloqueadores dos Canais de Cálcio/farmacologia , Moléculas de Adesão Celular/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Gengiva/citologia , Nifedipino/farmacologia , Fator de Crescimento Transformador beta/efeitos dos fármacos , Benzamidas/farmacologia , Moléculas de Adesão Celular/análise , Técnicas de Cultura de Células , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/ultraestrutura , Tecido Conjuntivo/metabolismo , Dioxóis/farmacologia , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Crescimento Excessivo da Gengiva/induzido quimicamente , Crescimento Excessivo da Gengiva/metabolismo , Crescimento Excessivo da Gengiva/patologia , Humanos , Fosforilação , Receptores de Fatores de Crescimento Transformadores beta/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Proteína Smad2/análise , Proteína Smad3/análise , Proteína Smad3/efeitos dos fármacos , Fator de Crescimento Transformador beta/análise , Regulação para Cima/efeitos dos fármacos
11.
Clin Pharmacol Ther ; 94(1): 142-9, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23588310

RESUMO

The occurrence of hypersensitivity reactions including rare but life-threatening Stevens-Johnson syndrome (SJS) and drug-induced hypersensitivity syndrome (HSS) limits the use of the anticonvulsant carbamazepine (CBZ). Human leukocyte antigen-B (HLA)-B 15:02 and HLA-A 31:01 have been identified as predictive genetic markers for CBZ hypersensitivity in Asian and European patients. To replicate these genetic associations in pediatric patients from North America with a diverse ethnic background, we investigated HLA-A 31:01 and HLA-B 15:02 in 42 children with CBZ hypersensitivity and 91 CBZ-tolerant children from across Canada. HLA-A 31:01 was significantly associated with CBZ-HSS (odds ratio (OR): 26.4, P = 0.0025) and maculopapular exanthema (MPE) (OR: 8.6, P = 0.0037) but not with CBZ-SJS. Conversely, HLA-B 15:02 was associated with CBZ-SJS (OR: 38.6, P = 0.002) but not HSS or MPE. This study is the first to demonstrate the association of HLA-A 31:01 with CBZ hypersensitivity in children, providing important replication of this association and highlighting the importance of HLA-A 31:01 as a predictive biomarker across various ancestries.


Assuntos
Anticonvulsivantes/efeitos adversos , Carbamazepina/efeitos adversos , Hipersensibilidade a Drogas/genética , Marcadores Genéticos , Antígenos HLA-A/genética , Antígeno HLA-B15/genética , Adolescente , Criança , Pré-Escolar , Toxidermias/etiologia , Toxidermias/genética , Hipersensibilidade a Drogas/etiologia , Feminino , Predisposição Genética para Doença , Técnicas de Genotipagem , Humanos , Lactente , Masculino , Síndrome de Stevens-Johnson/induzido quimicamente , Síndrome de Stevens-Johnson/etiologia , Síndrome de Stevens-Johnson/genética , Adulto Jovem
12.
Pediatr Blood Cancer ; 60(8): 1375-81, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23441093

RESUMO

BACKGROUND: The use of anthracyclines as effective antineoplastic drugs is limited by the occurrence of cardiotoxicity. Multiple genetic variants predictive of anthracycline-induced cardiotoxicity (ACT) in children were recently identified. The current study was aimed to assess replication of these findings in an independent cohort of children. PROCEDURE: . Twenty-three variants were tested for association with ACT in an independent cohort of 218 patients. Predictive models including genetic and clinical risk factors were constructed in the original cohort and assessed in the current replication cohort. RESULTS: . We confirmed the association of rs17863783 in UGT1A6 and ACT in the replication cohort (P = 0.0062, odds ratio (OR) 7.98). Additional evidence for association of rs7853758 (P = 0.058, OR 0.46) and rs885004 (P = 0.058, OR 0.42) in SLC28A3 was found (combined P = 1.6 × 10(-5) and P = 3.0 × 10(-5), respectively). A previously constructed prediction model did not significantly improve risk prediction in the replication cohort over clinical factors alone. However, an improved prediction model constructed using replicated genetic variants as well as clinical factors discriminated significantly better between cases and controls than clinical factors alone in both original (AUC 0.77 vs. 0.68, P = 0.0031) and replication cohort (AUC 0.77 vs. 0.69, P = 0.060). CONCLUSIONS: . We validated genetic variants in two genes predictive of ACT in an independent cohort. A prediction model combining replicated genetic variants as well as clinical risk factors might be able to identify high- and low-risk patients who could benefit from alternative treatment options.


Assuntos
Antraciclinas/efeitos adversos , Antineoplásicos/efeitos adversos , Cardiotoxinas/efeitos adversos , Doenças Cardiovasculares/genética , Glucuronosiltransferase/genética , Proteínas de Membrana Transportadoras/genética , Modelos Biológicos , Polimorfismo de Nucleotídeo Único , Adolescente , Antraciclinas/administração & dosagem , Antineoplásicos/administração & dosagem , Cardiotoxinas/administração & dosagem , Doenças Cardiovasculares/induzido quimicamente , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Marcadores Genéticos , Humanos , Lactente , Masculino , Neoplasias/tratamento farmacológico , Neoplasias/genética , Valor Preditivo dos Testes
13.
Pharmacogenomics J ; 13(4): 325-9, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22584458

RESUMO

Marked prolongation of the QT interval and polymorphic ventricular tachycardia following medication (drug-induced long QT syndrome, diLQTS) is a severe adverse drug reaction (ADR) that phenocopies congenital long QT syndrome (cLQTS) and is one of the leading causes for drug withdrawal and relabeling. We evaluated the frequency of rare non-synonymous variants in genes contributing to the maintenance of heart rhythm in cases of diLQTS using targeted capture coupled to next-generation sequencing. Eleven of 31 diLQTS subjects (36%) carried a novel missense mutation in genes with known congenital arrhythmia associations or with a known cLQTS mutation. In the 26 Caucasian subjects, 23% carried a highly conserved rare variant predicted to be deleterious to protein function in these genes compared with only 2-4% in public databases (P<0.003). We conclude that the rare variation in genes responsible for congenital arrhythmia syndromes is frequent in diLQTS. Our findings demonstrate that diLQTS is a pharmacogenomic syndrome predisposed by rare genetic variants.


Assuntos
Arritmias Cardíacas/tratamento farmacológico , Arritmias Cardíacas/genética , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/genética , Síndrome do QT Longo/genética , Torsades de Pointes/induzido quimicamente , Adolescente , Adulto , Idoso , Arritmias Cardíacas/complicações , Arritmias Cardíacas/fisiopatologia , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/patologia , Eletrocardiografia , Feminino , Frequência do Gene , Frequência Cardíaca/efeitos dos fármacos , Humanos , Síndrome do QT Longo/induzido quimicamente , Síndrome do QT Longo/complicações , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Torsades de Pointes/complicações , Torsades de Pointes/genética
14.
Anticancer Res ; 32(9): 3791-8, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22993321

RESUMO

BACKGROUND/AIM: Nephrotoxicity is observed in 30% of children treated with ifosfamide. We have shown that n-acetylcysteine (NAC) successfully mitigates nephrotoxicity of ifosfamide in cell and rodent models. However, before this treatment is evaluated clinically, it must be established that NAC does not interfere with the efficacy of ifosfamide. MATERIALS AND METHODS: Mice implanted with Ewing's sarcoma tumours received the following treatments: saline, ifosfamide, ifosfamide + NAC concurrently, pre-treatment with NAC + ifosfamide, or NAC alone. RESULTS: Median volumes of EW-7 tumour xenografts in mice treated with ifosfamide (n=8), ifosfamide with concurrent NAC therapy (n=7), and NAC pre-treatment (n=6) (p<0.05) were significantly reduced compared to median tumour volumes of control mice (n=6). None of the NAC treatments affected ifosfamide-mediated reduction in tumour volumes. CONCLUSION: NAC does not interfere with the efficacy of ifosfamide in a EW-7 xenograft model. These results support the clinical evaluation of NAC as a strategy against ifosfamide-induced nephrotoxicity in children.


Assuntos
Acetilcisteína/farmacologia , Antineoplásicos Alquilantes/farmacologia , Neoplasias Ósseas/tratamento farmacológico , Ifosfamida/farmacologia , Sarcoma de Ewing/tratamento farmacológico , Animais , Neoplasias Ósseas/patologia , Processos de Crescimento Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Interações Medicamentosas , Feminino , Humanos , Camundongos , Sarcoma de Ewing/patologia , Resultado do Tratamento , Ensaios Antitumorais Modelo de Xenoenxerto
16.
Forensic Sci Int ; 196(1-3): 32-7, 2010 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-20096513

RESUMO

Hair analyses for exogenous compounds, specifically drugs of abuse, have been a useful tool in detecting long-term drug exposure. More recently, studies have delved into the exposure of endogenous compounds in hair. Cortisol is synthesized in the adrenal cortex in response to stress-induced activation of the hypothalamic-pituitary-adrenal (HPA) axis. While catecholamines generally indicate acute stress, cortisol can be used as an indicator for sub-acute and chronic stress. Studies on the effects of chronic stress are most often subjective in nature, relying on questionnaires asking the participant to recall on past stressors. This can lead to the issue of recall and reporting bias. A new objective measure of chronic stress is needed for a more accurate understanding of the effects of chronic stress on the body. This review uses emerging evidence to describe the usefulness of hair analysis for cortisol and discusses the current methods used.


Assuntos
Cabelo/metabolismo , Hidrocortisona/metabolismo , Estresse Fisiológico/fisiologia , Estresse Psicológico/diagnóstico , Animais , Biomarcadores/metabolismo , Cromatografia Gasosa , Ensaio de Imunoadsorção Enzimática , Humanos , Espectrometria de Massas , Radioimunoensaio , Estresse Psicológico/metabolismo
17.
Exp Clin Endocrinol Diabetes ; 118(2): 133-8, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19609841

RESUMO

The severity of Cushing's Syndrome (CS) depends on the duration and extent of the exposure to excess glucocorticoids. Current measurements of cortisol in serum, saliva and urine reflect systemic cortisol levels at the time of sample collection, but cannot assess past cortisol levels. Hair cortisol levels may be increased in patients with CS, and, as hair grows about 1 cm/month, measurement of hair cortisol may provide historical information on the development of hypercortisolism. We attempted to measure cortisol in hair in relation to clinical course in six female patients with CS and in 32 healthy volunteers in 1 cm hair sections. Hair cortisol content was measured using a commercially available salivary cortisol immune assay with a protocol modified for use with hair. Hair cortisol levels were higher in patients with CS than in controls, the medians (ranges) were 679 (279-2500) and 116 (26-204) ng/g respectively (P<0.001). Segmental hair analysis provided information for up to 18 months before time of sampling. Hair cortisol concentrations appeared to vary in accordance with the clinical course. Based on these data, we suggest that hair cortisol measurement is a novel method for assessing dynamic systemic cortisol exposure and provides unique historical information on variation in cortisol, and that more research is required to fully understand the utility and limits of this technique.


Assuntos
Síndrome de Cushing/metabolismo , Cabelo/química , Hidrocortisona/análise , Adulto , Índice de Massa Corporal , Progressão da Doença , Feminino , Humanos , Imunoensaio , Masculino , Pessoa de Meia-Idade , Valores de Referência , Índice de Gravidade de Doença , Estatísticas não Paramétricas
18.
Genes Immun ; 10(8): 715-21, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19657357

RESUMO

Signatures of natural selection occur throughout the human genome and can be detected at the sequence level. We have re-sequenced ABCE1, a host candidate gene essential for HIV-1 capsid assembly, in European- (n=23) and African-descent (Yoruban; n=24) reference populations for genetic variation discovery. We identified an excess of rare genetic variation in Yoruban samples, and the resulting Tajima's D was low (-2.27). The trend of excess rare variation persisted in flanking candidate genes ANAPC10 and OTUD4, suggesting that this pattern of positive selection can be detected across the 184.5 kb examined on chromosome 4. Owing to ABCE1's role in HIV-1 replication, we re-sequenced the candidate gene in three small cohorts of HIV-1-infected or resistant individuals. We were able to confirm the excess of rare genetic variation among HIV-1-positive African-American individuals (n=53; Tajima's D=-2.34). These results highlight the potential importance of ABCE1's role in infectious diseases such as HIV-1.


Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Negro ou Afro-Americano/genética , Infecções por HIV/genética , HIV-1/fisiologia , Polimorfismo de Nucleotídeo Único , Transportadores de Cassetes de Ligação de ATP/imunologia , Genética Populacional , Infecções por HIV/imunologia , Humanos , Nigéria , Replicação Viral
19.
Clin Pharmacol Ther ; 84(3): 326-31, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18305455

RESUMO

Initiation of warfarin therapy using trial-and-error dosing is problematic. Our goal was to develop and validate a pharmacogenetic algorithm. In the derivation cohort of 1,015 participants, the independent predictors of therapeutic dose were: VKORC1 polymorphism -1639/3673 G>A (-28% per allele), body surface area (BSA) (+11% per 0.25 m(2)), CYP2C9(*)3 (-33% per allele), CYP2C9(*)2 (-19% per allele), age (-7% per decade), target international normalized ratio (INR) (+11% per 0.5 unit increase), amiodarone use (-22%), smoker status (+10%), race (-9%), and current thrombosis (+7%). This pharmacogenetic equation explained 53-54% of the variability in the warfarin dose in the derivation and validation (N= 292) cohorts. For comparison, a clinical equation explained only 17-22% of the dose variability (P < 0.001). In the validation cohort, we prospectively used the pharmacogenetic-dosing algorithm in patients initiating warfarin therapy, two of whom had a major hemorrhage. To facilitate use of these pharmacogenetic and clinical algorithms, we developed a nonprofit website, http://www.WarfarinDosing.org.


Assuntos
Anticoagulantes/administração & dosagem , Hidrocarboneto de Aril Hidroxilases/genética , Oxigenases de Função Mista/genética , Farmacogenética , Varfarina/administração & dosagem , Idoso , Algoritmos , Anticoagulantes/efeitos adversos , Anticoagulantes/metabolismo , Estudos de Coortes , Citocromo P-450 CYP2C9 , Relação Dose-Resposta a Droga , Feminino , Hemorragia/induzido quimicamente , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo Genético , Valor Preditivo dos Testes , Vitamina K Epóxido Redutases , Varfarina/efeitos adversos , Varfarina/metabolismo
20.
Br J Pharmacol ; 153(7): 1364-72, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18278066

RESUMO

BACKGROUND AND PURPOSE: Ifosfamide nephrotoxicity is a serious adverse effect for children undergoing cancer chemotherapy. Our recent in vitro studies have shown that the antioxidant N-acetylcysteine (NAC), which is used extensively as an antidote for paracetamol (acetaminophen) poisoning in children, protects renal tubular cells from ifosfamide-induced toxicity at a clinically relevant concentration. To further validate this observation, an animal model of ifosfamide-induced nephrotoxicity was used to determine the protective effect of NAC. EXPERIMENTAL APPROACH: Male Wistar albino rats were injected intraperitoneally with saline, ifosfamide (50 or 80 mg kg(-1) daily for 5 days), NAC (1.2 g kg(-1) daily for 6 days) or ifosfamide+NAC (for 6 days). Twenty-four hours after the last injection, rats were killed and serum and urine were collected for biochemical analysis. Kidney tissues were obtained for analysis of glutathione, glutathione S-transferase and lipid peroxide levels as well as histology analysis. KEY RESULTS: NAC markedly reduces the severity of renal dysfunction induced by ifosfamide with a significant decrease in elevations of serum creatinine (57.8+/-2.3 vs 45.25+/-2.1 micromol l(-1)) as well as a reduced elevation of beta2-microglobulin excretion (25.44+/-3.3 vs 8.83+/-1.3 nmol l(-1)) and magnesium excretion (19.5+/-1.5 vs 11.16+/-1.5 mmol l(-1)). Moreover, NAC significantly improved the ifosfamide-induced glutathione depletion and the decrease of glutathione S-transferase activity, lowered the elevation of lipid peroxides and prevented typical morphological damages in renal tubules and glomeruli. CONCLUSIONS AND IMPLICATIONS: Our results suggest a potential therapeutic role for NAC in paediatric patients in preventing ifosfamide nephrotoxicity.


Assuntos
Acetilcisteína/farmacologia , Antineoplásicos Alquilantes/efeitos adversos , Ifosfamida/efeitos adversos , Nefropatias/induzido quimicamente , Animais , Creatinina/sangue , Modelos Animais de Doenças , Sequestradores de Radicais Livres/farmacologia , Glutationa/efeitos dos fármacos , Glutationa/metabolismo , Glutationa Transferase/efeitos dos fármacos , Glutationa Transferase/metabolismo , Nefropatias/prevenção & controle , Peróxidos Lipídicos/metabolismo , Magnésio/metabolismo , Masculino , Ratos , Ratos Wistar , Índice de Gravidade de Doença , Microglobulina beta-2/efeitos dos fármacos , Microglobulina beta-2/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...