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1.
Front Aging Neurosci ; 16: 1387082, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38694259

RESUMO

Introduction: Inconsistencies of reports contributes to the underreporting of Alzheimer's disease (AD) on death certificates. Whether underreporting exists within South Carolina has not been studied. Methods: We conducted a prospective, population-based study on a cohort of persons (N = 78,534) previously diagnosed with AD and died between 2014-2019. We linked vital records with the South Carolina Alzheimer's Disease and Related Dementias Registry to investigate their cause of death and survival rates. Descriptive analyses calculated frequencies of demographic and health-related characteristics. Turnbull's method estimated the survival probabilities for different subgroups of patients. Hazard ratios were computed from the Cox proportional hazards model, adjusting for the following confounding variables of age at diagnosis, education level, gender, and race. Results: The top immediate cause of death was Alzheimer's disease among all racial groups, except for Native American/American Indian. More females (60.3%) were affected by AD compared to males (39.7%). There is a 25% probability of survival, beyond 5 years, after AD diagnosis. Black/African American AD patients have the smallest risk of all-cause mortality across all racial/ethnic groups (HR 0.87; 95% CI, 0.85-0.89). Individuals with lower education had a lower likelihood of mortality. Conclusion: Although AD was not underreported in the state of South Carolina further research is needed to develop protocols around classification of deaths among those diagnosed with dementia and comorbidities, including cardiovascular disease, to ensure dementia is properly reported as we move to prevent and treat Alzheimer's disease by 2025 and beyond.

2.
Biometrics ; 79(4): 3111-3125, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37403227

RESUMO

We propose a broad class of so-called Cox-Aalen transformation models that incorporate both multiplicative and additive covariate effects on the baseline hazard function within a transformation. The proposed models provide a highly flexible and versatile class of semiparametric models that include the transformation models and the Cox-Aalen model as special cases. Specifically, it extends the transformation models by allowing potentially time-dependent covariates to work additively on the baseline hazard and extends the Cox-Aalen model through a predetermined transformation function. We propose an estimating equation approach and devise an expectation-solving (ES) algorithm that involves fast and robust calculations. The resulting estimator is shown to be consistent and asymptotically normal via modern empirical process techniques. The ES algorithm yields a computationally simple method for estimating the variance of both parametric and nonparametric estimators. Finally, we demonstrate the performance of our procedures through extensive simulation studies and applications in two randomized, placebo-controlled human immunodeficiency virus (HIV) prevention efficacy trials. The data example shows the utility of the proposed Cox-Aalen transformation models in enhancing statistical power for discovering covariate effects.


Assuntos
Algoritmos , Projetos de Pesquisa , Humanos , Modelos de Riscos Proporcionais , Simulação por Computador , Modelos Estatísticos
3.
J Am Stat Assoc ; 118(542): 1090-1101, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37333855

RESUMO

Uncontrolled glycated hemoglobin (HbA1c) levels are associated with adverse events among complex diabetic patients. These adverse events present serious health risks to affected patients and are associated with significant financial costs. Thus, a high-quality predictive model that could identify high-risk patients so as to inform preventative treatment has the potential to improve patient outcomes while reducing healthcare costs. Because the biomarker information needed to predict risk is costly and burdensome, it is desirable that such a model collect only as much information as is needed on each patient so as to render an accurate prediction. We propose a sequential predictive model that uses accumulating patient longitudinal data to classify patients as: high-risk, low-risk, or uncertain. Patients classified as high-risk are then recommended to receive preventative treatment and those classified as low-risk are recommended to standard care. Patients classified as uncertain are monitored until a high-risk or low-risk determination is made. We construct the model using claims and enrollment files from Medicare, linked with patient Electronic Health Records (EHR) data. The proposed model uses functional principal components to accommodate noisy longitudinal data and weighting to deal with missingness and sampling bias. The proposed method demonstrates higher predictive accuracy and lower cost than competing methods in a series of simulation experiments and application to data on complex patients with diabetes.

4.
Clin Cosmet Investig Dermatol ; 15: 2177-2186, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36267690

RESUMO

Vitiligo is a chronic depigmenting disorder of the skin and mucosa caused by the destruction of epidermal melanocytes. Although the exact mechanism has not been elucidated, studies have shown that oxidative stress plays an important role in the pathogenesis of vitiligo. High mobility group box protein B1 (HMGB1) is a major nonhistone protein and an extracellular proinflammatory or chemotactic molecule that is actively secreted or passively released by necrotic cells. Recent data showed that HMGB1 is overexpressed in both blood and lesional specimens from vitiligo patients. Moreover, oxidative stress triggers the release of HMGB1 from keratinocytes and melanocytes, indicating that HMGB1 may participate in the pathological process of vitiligo. Overall, this review mainly focuses on the role of HMGB1 in the potential mechanisms underlying vitiligo depigmentation under oxidative stress. In this review, we hope to provide new insights into vitiligo pathogenesis and treatment strategies.

5.
Redox Rep ; 27(1): 193-199, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36154894

RESUMO

OBJECTIVES: The pathogenesis of vitiligo remains unclear. In this review, we comprehensively describe the role of damage associated molecular patterns (DAMPs) during vitiligo pathogenesis. METHODS: Published papers on vitiligo, oxidative stress and DAMPs were collected and reviewed via database searching on PubMed, MEDLINE and Embase, etc. RESULTS: Oxidative stress may be an important inducer of vitiligo. At high oxidative stress levels, damage-associated molecular patterns (DAMPs) are released from keratinocytes or melanocytes in the skin and induce downstream immune responses during vitiligo. Treatment regimens targeting DAMPs can effectively improve disease severity. DISCUSSION: DAMPs play key roles in initiating host defenses against danger signals, deteriorating the condition of vitiligo. DAMP levels in serum and skin may be used as biomarkers to indicate vitiligo activity and prognosis. Targeted therapies, incorporating HMGB1, Hsp70, and IL-15 could significantly improve disease etiology. Thus, novel strategies could be identified for vitiligo treatment by targeting DAMPs.


Assuntos
Melanócitos , Estresse Oxidativo , Vitiligo , Biomarcadores , Proteína HMGB1/metabolismo , Proteínas de Choque Térmico HSP70 , Humanos , Interleucina-15 , Melanócitos/patologia , Vitiligo/patologia , Vitiligo/terapia
6.
Clin Cosmet Investig Dermatol ; 15: 1105-1107, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35734146

RESUMO

Most patients are anxious about the skin lesions on the penis. This study reports a case of lichen nitidus on the penis and reviews related literature. A 40-year-old male has presented with small papules with skin color on the penis for one year. The patient was diagnosed with lichen nitidus, and tacrolimus cream and humectant were topically administered after diagnosis. The symptoms were alleviated after treatment. We first report a series of the cases with lichen nitidus on the penis, knowing the clinical and pathological manifestations of this disease can reduce misdiagnosis and unnecessary treatment.

7.
Leukemia ; 36(4): 1123-1131, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35039639

RESUMO

Hematopoietic stress drives quiescent hematopoietic stem cells (HSCs) to proliferate, generating reactive oxygen species (ROS) and oxidative DNA damage including abasic sites. Such a coupling between rapid DNA replication and a burst of abasic site formation during HSC stress responses, however, presents a challenge to accurately repair abasic sites located in replication-associated single-stranded DNA. Here we show that HMCES, a novel shield of abasic sites, plays pivotal roles in overcoming this challenge upon HSC activation. While HMCES was dispensable for steady-state hematopoiesis, Hmces-deficient HSCs exhibited compromised long-term self-renewal capacity in response to hematopoietic stress such as myeloablation and transplantation. Loss of HMCES resulted in accumulation of DNA lesions due to impaired resolution of abasic sites generated by activation-induced ROS in activated HSCs and broad downregulation of DNA damage response and repair pathways. Moreover, Hmces-deficient mice died from bone marrow failure after exposure to sublethal irradiation, which also produces ROS. Notably, dysregulation of HMCES occurs frequently in acute lymphocytic leukemia (ALL) and is associated with poor clinical outcomes. Together, our findings not only highlighted HMCES as a novel genome protector in activated HSCs, but also position it as a potential selective target against ALL while sparing normal hematopoiesis.


Assuntos
Dano ao DNA , Células-Tronco Hematopoéticas , Animais , DNA/metabolismo , Replicação do DNA , Proteínas de Ligação a DNA/genética , Células-Tronco Hematopoéticas/metabolismo , Humanos , Camundongos
8.
J Am Stat Assoc ; 116(533): 283-294, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34024961

RESUMO

Individualized treatment rules (ITRs) recommend treatment according to patient characteristics. There is a growing interest in developing novel and efficient statistical methods in constructing ITRs. We propose an improved doubly robust estimator of the optimal ITRs. The proposed estimator is based on a direct optimization of an augmented inverse-probability weighted estimator (AIPWE) of the expected clinical outcome over a class of ITRs. The method enjoys two key properties. First, it is doubly robust, meaning that the proposed estimator is consistent when either the propensity score or the outcome model is correct. Second, it achieves the smallest variance among the class of doubly robust estimators when the propensity score model is correctly specified, regardless of the specification of the outcome model. Simulation studies show that the estimated ITRs obtained from our method yield better results than those obtained from current popular methods. Data from the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study is analyzed as an illustrative example.

9.
Sci Bull (Beijing) ; 66(24): 2489-2497, 2021 12 30.
Artigo em Inglês | MEDLINE | ID: mdl-36654208

RESUMO

Polycomb group (PcG) proteins are crucial chromatin regulators during development. H2AK119ub1 (H2Aub) and H3K27me3 are catalyzed by Polycomb-repressive complex 1 and 2 (PRC1/2) respectively, and they largely overlap in the genome due to mutual recruitment of the two complexes. However, it is unclear whether PRC1/H2Aub and PRC2/H3K27me3 can also function independently. By developing an ultra-sensitive carrier-DNA-assisted chromatin immunoprecipitation sequencing method termed CATCH-Seq, we generated allelic H2Aub profiles in mouse gametes and early embryos. Our results revealed an unexpected genomewide decoupling of H2Aub and H3K27me3 in mouse preimplantation embryos, where H2Aub but not H3K27me3 was enriched at PcG targets while only H3K27me3 was deposited in the broad distal domains associated with DNA methylation-independent non-canonical imprinting. These observations suggest that H2Aub represses future bivalent genes during early embryogenesis without H3K27me3, but it is not required for the maintenance of non-canonical imprinting, which is mediated by maternal H3K27me3. Thus, our study reveals the distinct depositions and independent functions of H2Aub and H3K27me3 during early mammalian development.


Assuntos
Cromatina , Histonas , Animais , Camundongos , Histonas/genética , Proteínas do Grupo Polycomb/genética , Complexo Repressor Polycomb 2/genética , Metilação de DNA/genética , Mamíferos/genética
10.
Stat Med ; 37(15): 2321-2337, 2018 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-29682775

RESUMO

Outcome-dependent sampling (ODS) scheme is a cost-effective way to conduct a study. For a study with continuous primary outcome, an ODS scheme can be implemented where the expensive exposure is only measured on a simple random sample and supplemental samples selected from 2 tails of the primary outcome variable. With the tremendous cost invested in collecting the primary exposure information, investigators often would like to use the available data to study the relationship between a secondary outcome and the obtained exposure variable. This is referred as secondary analysis. Secondary analysis in ODS designs can be tricky, as the ODS sample is not a random sample from the general population. In this article, we use the inverse probability weighted and augmented inverse probability weighted estimating equations to analyze the secondary outcome for data obtained from the ODS design. We do not make any parametric assumptions on the primary and secondary outcome and only specify the form of the regression mean models, thus allow an arbitrary error distribution. Our approach is robust to second- and higher-order moment misspecification. It also leads to more precise estimates of the parameters by effectively using all the available participants. Through simulation studies, we show that the proposed estimator is consistent and asymptotically normal. Data from the Collaborative Perinatal Project are analyzed to illustrate our method.


Assuntos
Interpretação Estatística de Dados , Avaliação de Resultados em Cuidados de Saúde/métodos , Estudos de Amostragem , Anormalidades Congênitas/etiologia , Feminino , Humanos , Recém-Nascido , Modelos Estatísticos , Gravidez , Probabilidade , Fatores de Risco , Resultado do Tratamento
11.
Biometrics ; 74(3): 1014-1022, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29286533

RESUMO

Case-cohort study design has been widely used for its cost-effectiveness. In any real study, there are always other important outcomes of interest beside the failure time that the original case-cohort study is based on. How to utilize the available case-cohort data to study the relationship of a secondary outcome with the primary exposure obtained through the case-cohort study is not well studied. In this article, we propose a non-parametric estimated likelihood approach for analyzing a secondary outcome in a case-cohort study. The estimation is based on maximizing a semiparametric likelihood function that is built jointly on both time-to-failure outcome and the secondary outcome. The proposed estimator is shown to be consistent, efficient, and asymptotically normal. Finite sample performance is evaluated via simulation studies. Data from the Sister Study is analyzed to illustrate our method.


Assuntos
Estudos de Coortes , Análise de Regressão , Estatísticas não Paramétricas , Simulação por Computador , Humanos , Funções Verossimilhança , Irmãos , Estatística como Assunto
12.
J Allergy Clin Immunol ; 141(4): 1231-1238.e1, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-28736267

RESUMO

BACKGROUND: We and others have shown that the gamma tocopherol (γT) isoform of vitamin E has multiple anti-inflammatory and antioxidant actions and that γT supplementation reduces eosinophilic and endotoxin (LPS)-induced neutrophilic airway inflammation in animal models and healthy human volunteers. OBJECTIVE: We sought to determine whether γT supplementation reduces eosinophilic airway inflammation and acute neutrophilic response to inhaled LPS challenge in volunteers with asthma. METHODS: Participants with mild asthma were enrolled in a double-blinded, placebo-controlled crossover study to assess the effect of 1200 mg of γT daily for 14 days on sputum eosinophils, mucins, and cytokines. We also assessed the effect on acute inflammatory response to inhaled LPS challenge following γT treatment, focusing on changes in sputum neutrophilia, mucins, and cytokines. Mucociliary clearance was measured using gamma scintigraphy. RESULTS: Fifteen subjects with mild asthma completed both arms of the study. Compared with placebo, γT notably reduced pre-LPS challenge sputum eosinophils and mucins, including mucin 5AC and reduced LPS-induced airway neutrophil recruitment 6 and 24 hours after challenge. Mucociliary clearance was slowed 4 hours postchallenge in the placebo group but not in the γT treatment group. Total sputum mucins (but not mucin 5AC) were reduced at 24 hours postchallenge during γT treatment compared with placebo. CONCLUSIONS: When compared with placebo, γT supplementation for 14 days reduced inflammatory features of asthma, including sputum eosinophils and mucins, as well as acute airway response to inhaled LPS challenge. Larger scale clinical trials are needed to assess the efficacy of γT supplements as a complementary or steroid-sparing treatment for asthma.


Assuntos
Asma/tratamento farmacológico , Endotoxinas/efeitos adversos , Eosinofilia/tratamento farmacológico , Eosinófilos/efeitos dos fármacos , Infiltração de Neutrófilos/efeitos dos fármacos , Vitaminas/uso terapêutico , gama-Tocoferol/uso terapêutico , Adulto , Asma/imunologia , Asma/metabolismo , Biomarcadores/metabolismo , Estudos Cross-Over , Método Duplo-Cego , Esquema de Medicação , Endotoxinas/administração & dosagem , Endotoxinas/imunologia , Eosinofilia/metabolismo , Eosinófilos/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mucinas/metabolismo , Escarro/efeitos dos fármacos , Escarro/metabolismo , Resultado do Tratamento , Vitaminas/farmacologia , gama-Tocoferol/farmacologia
13.
Respir Res ; 17(1): 89, 2016 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-27450419

RESUMO

UNLABELLED: Sulforaphane (SFN), a naturally occurring isothiocyanate found in cruciferous vegetables, is implicated as a possible therapy for airway inflammation via induction of the transcription factor NF-E2-related factor 2 (NRF2). In this proof-of-concept clinical study, we show that supplementation of SFN with broccoli sprout homogenate in healthy human subjects did not induce expression of antioxidant genes or protect against neutrophilic airway inflammation in an ozone-exposure model. Therefore, dietary sulforaphane supplementation is not a promising candidate for larger scale clinical trials targeting airway inflammation. TRIAL REGISTRATION: NCT01625130 . Registered 19 June, 2012.


Assuntos
Anti-Inflamatórios/uso terapêutico , Isotiocianatos/uso terapêutico , Transtornos Leucocíticos/prevenção & controle , Pulmão/efeitos dos fármacos , Fator 2 Relacionado a NF-E2/agonistas , Infiltração de Neutrófilos/efeitos dos fármacos , Neutrófilos/efeitos dos fármacos , Pneumonia/prevenção & controle , Adolescente , Adulto , Anti-Inflamatórios/isolamento & purificação , Brassica/química , Estudos Cross-Over , Feminino , Voluntários Saudáveis , Humanos , Isotiocianatos/isolamento & purificação , Transtornos Leucocíticos/induzido quimicamente , Transtornos Leucocíticos/imunologia , Transtornos Leucocíticos/metabolismo , Pulmão/imunologia , Pulmão/metabolismo , Masculino , Pessoa de Meia-Idade , Fator 2 Relacionado a NF-E2/metabolismo , Neutrófilos/imunologia , Neutrófilos/metabolismo , Ozônio , Fitoterapia , Plantas Medicinais , Pneumonia/induzido quimicamente , Pneumonia/imunologia , Pneumonia/metabolismo , Sulfóxidos , Adulto Jovem
14.
Am J Physiol Lung Cell Mol Physiol ; 308(9): L855-60, 2015 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-25770180

RESUMO

Bacterial infection is a major cause of morbidity affecting outcome following burn and inhalation injury. While experimental burn and inhalation injury animal models have suggested that mediators of cell damage and inflammation increase the risk of infection, few studies have been done on humans. This is a prospective, observational study of patients admitted to the North Carolina Jaycee Burn Center at the University of North Carolina who were intubated and on mechanical ventilation for treatment of burn and inhalational injury. Subjects were enrolled over a 2-yr period and followed till discharge or death. Serial bronchial washings from clinically indicated bronchoscopies were collected and analyzed for markers of tissue injury and inflammation. These include damage-associated molecular patterns (DAMPs) such as hyaluronic acid (HA), double-stranded DNA (dsDNA), heat-shock protein 70 (HSP-70), and high-mobility group protein B-1 (HMGB-1). The study population was comprised of 72 patients who had bacterial cultures obtained for clinical indications. Elevated HA, dsDNA, and IL-10 levels in bronchial washings obtained early (the first 72 h after injury) were significantly associated with positive bacterial respiratory cultures obtained during the first 14 days postinjury. Independent of initial inhalation injury severity and extent of surface burn, elevated levels of HA dsDNA and IL-10 in the central airways obtained early after injury are associated with subsequent positive bacterial respiratory cultures in patients intubated after acute burn/inhalation injury.


Assuntos
Infecções Bacterianas/patologia , Biomarcadores/metabolismo , Queimaduras por Inalação/metabolismo , Lesão Pulmonar/patologia , Adulto , Broncoscopia , DNA/metabolismo , Feminino , Proteína HMGB1/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Humanos , Ácido Hialurônico/metabolismo , Interleucina-10/metabolismo , Pulmão/patologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Respiração Artificial
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