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1.
Front Neurosci ; 17: 1120086, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36875643

RESUMO

Alzheimer's disease (AD) is the most common cause of dementia, with no current cure. Consequently, alternative approaches focusing on early pathological events in specific neuronal populations, besides targeting the well-studied amyloid beta (Aß) accumulations and Tau tangles, are needed. In this study, we have investigated disease phenotypes specific to glutamatergic forebrain neurons and mapped the timeline of their occurrence, by implementing familial and sporadic human induced pluripotent stem cell models as well as the 5xFAD mouse model. We recapitulated characteristic late AD phenotypes, such as increased Aß secretion and Tau hyperphosphorylation, as well as previously well documented mitochondrial and synaptic deficits. Intriguingly, we identified Golgi fragmentation as one of the earliest AD phenotypes, indicating potential impairments in protein processing and post-translational modifications. Computational analysis of RNA sequencing data revealed differentially expressed genes involved in glycosylation and glycan patterns, whilst total glycan profiling revealed minor glycosylation differences. This indicates general robustness of glycosylation besides the observed fragmented morphology. Importantly, we identified that genetic variants in Sortilin-related receptor 1 (SORL1) associated with AD could aggravate the Golgi fragmentation and subsequent glycosylation changes. In summary, we identified Golgi fragmentation as one of the earliest disease phenotypes in AD neurons in various in vivo and in vitro complementary disease models, which can be exacerbated via additional risk variants in SORL1.

2.
Stem Cell Reports ; 16(5): 1276-1289, 2021 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-33891871

RESUMO

Sequestosome-1 (SQSTM1/p62) is involved in cellular processes such as autophagy and metabolic reprogramming. Mutations resulting in the loss of function of SQSTM1 lead to neurodegenerative diseases including frontotemporal dementia. The pathogenic mechanism that contributes to SQSTM1-related neurodegeneration has been linked to its role as an autophagy adaptor, but this is poorly understood, and its precise role in mitochondrial function and clearance remains to be clarified. Here, we assessed the importance of SQSTM1 in human induced pluripotent stem cell (iPSC)-derived cortical neurons through the knockout of SQSTM1. We show that SQSTM1 depletion causes altered mitochondrial gene expression and functionality, as well as autophagy flux, in iPSC-derived neurons. However, SQSTM1 is not essential for mitophagy despite having a significant impact on early PINK1-dependent mitophagy processes including PINK1 recruitment and phosphorylation of ubiquitin on depolarized mitochondria. These findings suggest that SQSTM1 is important for mitochondrial function rather than clearance.


Assuntos
Córtex Cerebral/citologia , Mitocôndrias/metabolismo , Neurônios/metabolismo , Proteína Sequestossoma-1/metabolismo , Diferenciação Celular , Respiração Celular , Regulação da Expressão Gênica , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Potencial da Membrana Mitocondrial , Mitocôndrias/patologia , Mitofagia , Fosforilação Oxidativa , Proteínas Quinases/metabolismo , Reprodutibilidade dos Testes
3.
BMC Cardiovasc Disord ; 20(1): 217, 2020 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-32393179

RESUMO

BACKGROUND: Prior studies have shown insulin resistance is associated with reduced cardiac autonomic function measured at rest, but few studies have determined whether insulin resistance is associated with reduced cardiac autonomic function measured during daily activities. METHODS: We examined older adults without diabetes with 48-h ambulatory electrocardiography (n = 759) in an ancillary study of the Atherosclerosis Risk in Communities Study. Insulin resistance, the exposure, was defined by quartiles for three indexes: 1) the homeostatic model assessment of insulin resistance (HOMA-IR), 2) the triglyceride and glucose index (TyG), and 3) the triglyceride to high-density lipoprotein cholesterol ratio (TG/HDL-C). Low heart rate variability, the outcome, was defined by <25th percentile for four measures: 1) standard deviation of normal-to-normal R-R intervals (SDNN), a measure of total variability; 2) root mean square of successive differences in normal-to-normal R-R intervals (RMSSD), a measure of vagal activity; 3) low frequency spectral component (LF), a measure of sympathetic and vagal activity; and 4) high frequency spectral component (HF), a measure of vagal activity. Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals weighted for sampling/non-response, adjusted for age at ancillary visit, sex, and race/study-site. Insulin resistance quartiles 4, 3, and 2 were compared to quartile 1; high indexes refer to quartile 4 versus quartile 1. RESULTS: The average age was 78 years, 66% (n = 497) were women, and 58% (n = 438) were African American. Estimates of association were not robust at all levels of HOMA-IR, TyG, and TG/HDL-C, but suggest that high indexes were associated consistently with indicators of vagal activity. High HOMA-IR, high TyG, and high TG/HDL-C were consistently associated with low RMSSD (OR: 1.68 (1.00, 2.81), OR: 2.03 (1.21, 3.39), and OR: 1.73 (1.01, 2.91), respectively). High HOMA-IR, high TyG, and high TG/HDL-C were consistently associated with low HF (OR: 1.90 (1.14, 3.18), OR: 1.98 (1.21, 3.25), and OR: 1.76 (1.07, 2.90), respectively). CONCLUSIONS: In older adults without diabetes, insulin resistance was associated with reduced cardiac autonomic function - specifically and consistently for indicators of vagal activity - measured during daily activities. Primary prevention of insulin resistance may reduce the related risk of cardiac autonomic dysfunction.


Assuntos
Sistema Nervoso Autônomo/fisiopatologia , Frequência Cardíaca , Coração/inervação , Resistência à Insulina , Fatores Etários , Idoso , Biomarcadores/sangue , Glicemia/análise , Feminino , Humanos , Insulina/sangue , Masculino , Estudos Prospectivos , Triglicerídeos/sangue , Estados Unidos
4.
Cardiovasc Diabetol ; 19(1): 11, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31992297

RESUMO

BACKGROUND: Insulin resistance may contribute to aortic stiffening that leads to end-organ damage. We examined the cross-sectional association and prospective association of insulin resistance and aortic stiffness in older adults without diabetes. METHODS: We analyzed 2571 men and women at Visit 5 (in 2011-2013), and 2350 men and women at repeat examinations from baseline at Visit 1 (in 1987-1989) to Visit 5 (in 2011-2013). Linear regression was used to estimate the difference in aortic stiffness per standard unit of HOMA-IR, TG/HDL-C, and TyG at Visit 5. Linear mixed effects were used to assess if high, as opposed to non-high, aortic stiffness (> 75th percentile) was preceded by a faster annual rate of change in log-HOMA-IR, log-TG/HDL-C, and log-TyG from Visit 1 to Visit 5. RESULTS: The mean age of participants was 75 years, 37% (n = 957) were men, and 17% (n = 433) were African American. At Visit 5, higher HOMA-IR, higher TG/HDL-C, and higher TyG were associated with higher aortic stiffness (16 cm/s per SD (95% CI 6, 27), 29 cm/s per SD (95% CI 18, 40), and 32 cm/s per SD (95% CI 22, 42), respectively). From Visit 1 to Visit 5, high aortic stiffness, compared to non-high aortic stiffness, was not preceded by a faster annual rate of change in log-HOMA-IR from baseline to 9 years (0.030 (95% CI 0.024, 0.035) vs. 0.025 (95% CI 0.021, 0.028); p = 0.15) or 9 years onward (0.011 (95% CI 0.007, 0.015) vs. 0.011 (95% CI 0.009, 0.013); p = 0.31); in log-TG/HDL-C from baseline to 9 years (0.019 (95% CI 0.015, 0.024) vs. 0.024 (95% CI 0.022, 0.026); p = 0.06) or 9 years onward (- 0.007 (95% CI - 0.010, - 0.005) vs. - 0.009 (95% CI - 0.010, - 0.007); p = 0.08); or in log-TyG from baseline to 9 years (0.002 (95% CI 0.002, 0.003) vs. 0.003 (95% CI 0.003, 0.003); p = 0.03) or 9 years onward (0 (95% CI 0, 0) vs. 0 (95% CI 0, 0); p = 0.08). CONCLUSIONS: Among older adults without diabetes, insulin resistance was associated with aortic stiffness, but the putative role of insulin resistance in aortic stiffness over the life course requires further study.


Assuntos
Envelhecimento , Doenças Cardiovasculares/fisiopatologia , Resistência à Insulina , Rigidez Vascular , Fatores Etários , Idoso , Biomarcadores/sangue , Glicemia/metabolismo , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/etnologia , Estudos Transversais , Feminino , Humanos , Insulina/sangue , Resistência à Insulina/etnologia , Lipídeos/sangue , Masculino , Prognóstico , Estudos Prospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo , Estados Unidos/epidemiologia
5.
Am Heart J ; 216: 1-8, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31352135

RESUMO

BACKGROUND: A lower prevalence of atrial fibrillation (AF), but paradoxically higher burden of cardiovascular disease risk factors, has been observed among African Americans compared to Whites in studies of AF identified by mostly 12-lead electrocardiograms (ECGs) and clinically. METHODS: We performed 48-hour ambulatory electrocardiography (aECG) in a biracial sample of 1,193 participants in the Atherosclerosis Risk in Communities (ARIC) (mean age = 78 years, 62% African Americans, 64% female). Atrial fibrillation was identified from aECG, study visit ECGs, and discharge codes from cohort hospitalizations. We used covariate-adjusted logistic regression to estimate prevalence odds ratios (ORs) for AF in African Americans versus Whites, with adjustment for sampling and nonresponse. RESULTS: African Americans were more likely than Whites to have hypertension and diabetes but less likely to have coronary heart disease. The prevalence of AF detected by aECG or ARIC study ECG (adjusted for age and coronary heart disease) was lower in African Americans than Whites (2.7% vs 5.0%). White men had a higher (although not significant) AF prevalence of 7.8% compared to the other race and gender groups at 2.3%-2.8%. The adjusted OR for AF was 0.49 (0.24-0.99) comparing African Americans to Whites. Findings were similar when AF was defined to include prior AF hospitalizations (OR = 0.42, 0.25-0.72). There were no significant differences by race for asymptomatic or paroxysmal AF. CONCLUSIONS: Atrial fibrillation was less prevalent in African American than white older adults, regardless of detection method. Although overall detection of new AF cases with aECG was low, future studies should consider longer-term monitoring to characterize AF by race.


Assuntos
Fibrilação Atrial/epidemiologia , Negro ou Afro-Americano/estatística & dados numéricos , População Branca/estatística & dados numéricos , Idoso , Fibrilação Atrial/etnologia , Eletrocardiografia Ambulatorial/estatística & dados numéricos , Feminino , Humanos , Estudos Longitudinais , Masculino , Razão de Chances , Prevalência , Fatores Sexuais , Fatores de Tempo , Estados Unidos/epidemiologia
6.
Clin Transplant ; 32(7): e13291, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29791039

RESUMO

Racial disparities in living donor kidney transplantation (LDKT) persist but the most effective target to eliminate these disparities remains unknown. One potential target could be delays during completion of the live donor evaluation process. We studied racial differences in progression through the evaluation process for 247 African American (AA) and 664 non-AA living donor candidates at our center between January 2011 and March 2015. AA candidates were more likely to be obese (38% vs 22%: P < .001), biologically related (66% vs 44%: P < .001), and live ≤50 miles from the center (64% vs 37%: P < .001) than non-AAs. Even after adjusting for these differences, AAs were less likely to progress from referral to donation (aHR for AA vs non-AA: 0.26 0.47 0.83; P = .01). We then assessed racial differences in completion of each step of the evaluation process and found disparities in progression from medical screening to in-person evaluation (aHR: 0.41 0.620.94; P = .02) and from clearance to donation (aHR: 0.28 0.510.91; P = .02), compared with from referral to medical screening (aHR: 0.78 1.021.33; P = .95) and from in-person evaluation to clearance (aHR: 0.59 0.931.44; P = .54). Delays may be a manifestation of the transplant candidate's social network, thus, targeted efforts to optimize networks for identification of donor candidates may help address LDKT disparities.


Assuntos
Negro ou Afro-Americano/estatística & dados numéricos , Disparidades em Assistência à Saúde/tendências , Falência Renal Crônica/etnologia , Transplante de Rim/estatística & dados numéricos , Doadores Vivos/estatística & dados numéricos , População Branca/estatística & dados numéricos , Adulto , Seleção do Doador , Feminino , Seguimentos , Humanos , Falência Renal Crônica/cirurgia , Masculino , Pessoa de Meia-Idade , Avaliação das Necessidades , Resultado do Tratamento , Estados Unidos
7.
J Clin Endocrinol Metab ; 103(6): 2175-2181, 2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29618016

RESUMO

Context: The homeostatic model assessment of insulin resistance (HOMA-IR) and triglyceride (TG)/high-density lipoprotein cholesterol (HDL-C) ratio (TG/HDL-C) are insulin resistance indexes routinely used in clinical and population-based studies; however, their short-term repeatability is not well characterized. Objective: To quantify the short-term repeatability of insulin resistance indexes and their analytes, consisting of fasting glucose and insulin for HOMA-IR and TG and HDL-C for TG/HDL-C. Design: Prospective cohort study. Participants: A total of 102 adults 68 to 88 years old without diabetes attended an initial examination and repeated examination (mean, 46 days; range, 28 to 102 days). Blood samples were collected, processed, shipped, and assayed following a standardized protocol. Main Outcome Measures: Repeatability was quantified using the intraclass correlation coefficient (ICC) and within-person coefficient of variation (CV). Minimum detectable change (MDC95) and minimum detectable difference with 95% confidence (MDD95) were quantified. Results: For HOMA-IR, insulin, and fasting glucose, the ICCs were 0.70, 0.68, and 0.70, respectively; their respective within-person CVs were 30.4%, 28.8%, and 5.6%. For TG/HDL-C, TG, and HDL-C, the ICCs were 0.80, 0.68, and 0.91, respectively; their respective within-person CVs were 23.0%, 20.6%, and 8.2%. The MDC95 was 2.3 for HOMA-IR and 1.4 for TG/HDL-C. The MDD95 for a sample of n = 100 was 0.8 for HOMA-IR and 0.6 for TG/HDL-C. Conclusions: Short-term repeatability was fair to good for HOMA-IR and excellent for TG/HDL-C according to suggested benchmarks, reflecting the short-term variability of their analytes. These measurement properties can inform the use of these indexes in clinical and population-based studies.


Assuntos
Aterosclerose/etiologia , Glicemia , Resistência à Insulina/fisiologia , Insulina/sangue , Idoso , Idoso de 80 Anos ou mais , Aterosclerose/sangue , Biomarcadores/sangue , HDL-Colesterol/sangue , Feminino , Teste de Tolerância a Glucose , Humanos , Masculino , Estudos Prospectivos , Reprodutibilidade dos Testes
8.
Stem Cells Dev ; 26(24): 1804-1817, 2017 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-29017378

RESUMO

Human induced pluripotent stem cells (hiPSCs) hold great hopes for application in regenerative medicine due to their inherent capacity to self-renew and differentiate into cells from the three embryonic germ layers. For clinical applications, a large quantity of hiPSCs produced in standardized and scalable culture processes is required. Several groups, including ours, have developed methodologies for scaled-up hiPSC production in stirred bioreactors in chemically defined medium. In this study, we optimized the critical steps and factors that affect hiPSC expansion and yield in stirred-suspension cultures, including inoculation conditions, seeding density, aggregate size, agitation rate, and cell passaging method. After multiple passages in stirred-suspension bioreactors, hiPSCs remained pluripotent, karyotypically normal, and capable of differentiating into all three germ layers.


Assuntos
Células-Tronco Pluripotentes Induzidas/citologia , Reatores Biológicos , Agregação Celular/fisiologia , Contagem de Células , Técnicas de Cultura de Células/métodos , Diferenciação Celular/fisiologia , Proliferação de Células/fisiologia , Células Cultivadas , Camadas Germinativas/citologia , Humanos , Suspensões/metabolismo
9.
N Biotechnol ; 39(Pt B): 190-198, 2017 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-28579476

RESUMO

The rising prevalence of progressive neurodegenerative diseases coupled with increasing longevity poses an economic burden at individual and societal levels. There is currently no effective cure for the majority of neurodegenerative diseases and disease-affected tissues from patients have been difficult to obtain for research and drug discovery in pre-clinical settings. While the use of animal models has contributed invaluable mechanistic insights and potential therapeutic targets, the translational value of animal models could be further enhanced when combined with in vitro models derived from patient-specific induced pluripotent stem cells (iPSCs) and isogenic controls generated using CRISPR-Cas9 mediated genome editing. The iPSCs are self-renewable and capable of being differentiated into the cell types affected by the diseases. These in vitro models based on patient-derived iPSCs provide the opportunity to model disease development, uncover novel mechanisms and test potential therapeutics. Here we review findings from iPSC-based modeling of selected neurodegenerative diseases, including Alzheimer's disease, frontotemporal dementia and spinocerebellar ataxia. Furthermore, we discuss the possibilities of generating three-dimensional (3D) models using the iPSCs-derived cells and compare their advantages and disadvantages to conventional two-dimensional (2D) models.


Assuntos
Células-Tronco Pluripotentes Induzidas/patologia , Modelos Biológicos , Doenças Neurodegenerativas/patologia , Técnicas de Cultura de Células , Humanos , Neurônios/patologia
10.
Artigo em Inglês | MEDLINE | ID: mdl-28058808

RESUMO

BACKGROUND: The purpose of this study was to characterize the repeatability of ectopic beats, defined by premature atrial contractions (PACs) and premature ventricular contractions (PVCs), on ambulatory electrocardiogram (aECG) monitoring and evaluate the effect of length of aECG monitoring on the repeatability estimates. METHODS: This analysis includes 95 randomly selected participants from the Atherosclerosis Risk in Communities Study (ARIC; 2011-2013). The participants wore a Holter monitor for two, 48-hr periods separated by a mean of 38 days following an identical, standardized protocol. We divided each 48-hr recording into 3-, 6-, 12-, and 24-hr recording periods and calculated intraclass correlation coefficients (ICCs) for PACs and PVCs and also as a percentage of the corresponding total of recorded beats per hour among these periods. RESULTS: All participants had ≥1 PAC during the 48-hr recordings, and only two participants had no PVCs. ICCs were >0.83 for all indices and recording lengths ≥12 hrs. ICCs were intermediate for 6-hr recordings (range 0.80-0.83) and lower for 3-hr recordings (range 0.74-0.80). The ratio of the between- to within-participant variation increased with recording length. CONCLUSION: Repeatability of PACs and PVCs was excellent for recording lengths of 6-24 hr and fair for 3 hr. Repeatability varies over shorter duration recordings within the 48-hr recording period, and thus the present results have implications for detection algorithms for ectopic beats and can facilitate epidemiologic and clinical applications in which knowledge of measurement variability and misclassification are needed.


Assuntos
Aterosclerose/complicações , Complexos Atriais Prematuros/diagnóstico , Eletrocardiografia Ambulatorial/estatística & dados numéricos , Avaliação Geriátrica/estatística & dados numéricos , Inquéritos Epidemiológicos/estatística & dados numéricos , Complexos Ventriculares Prematuros/diagnóstico , Idoso , Complexos Atriais Prematuros/complicações , Complexos Atriais Prematuros/fisiopatologia , Estudos de Coortes , Eletrocardiografia Ambulatorial/métodos , Feminino , Avaliação Geriátrica/métodos , Inquéritos Epidemiológicos/métodos , Humanos , Vida Independente , Estudos Longitudinais , Masculino , Reprodutibilidade dos Testes , Risco , Fatores de Risco , Fatores de Tempo , Complexos Ventriculares Prematuros/complicações , Complexos Ventriculares Prematuros/fisiopatologia
11.
Stem Cell Res ; 17(2): 285-288, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27879212

RESUMO

Alzheimer's disease (AD) is a progressive and irreversible neurodegenerative disease causing neural cell degeneration and brain atrophy and is considered to be the most common form of dementia. We previously generated an induced pluripotent stem cell (iPSC) line from an AD patient carrying an A79V mutation in PSEN1 as an in vitro disease model. Here we generated a gene-corrected version from this hiPSC line by substituting the point mutation with the wild-type sequence. The reported A79V-GC-iPSCs line is a very useful resource in combination with the A79V-iPSC line in order to study pathological cellular phenotypes related to this particular mutation.


Assuntos
Doença de Alzheimer/patologia , Reprogramação Celular , Células-Tronco Pluripotentes Induzidas/citologia , Presenilina-1/genética , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Sequência de Bases , Sistemas CRISPR-Cas/genética , Células Cultivadas , Análise Mutacional de DNA , Feminino , Fibroblastos/citologia , Genótipo , Heterozigoto , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Cariótipo , Microscopia de Fluorescência , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
12.
Stem Cell Res ; 17(3): 466-469, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27789395

RESUMO

Mutations in the presenilin 1 (PSEN1) gene lead to the most aggressive form of familial Alzheimer's disease (AD). Human induced pluripotent stem cells (hiPSCs) derived from AD patients and subsequently differentiated can be used for disease modeling. We have previously generated a hiPSC line from a familial AD patient carrying a L150P point mutation in PSEN1. Here we used CRISPR/Cas9 gene editing to correct for the single base pair mutation. This gene-corrected line, L150P-GC-hiPSC, serves as an isogenic control to the mutant line for future investigation of mechanisms and cellular phenotypes altered by this specific PSEN1 mutation.


Assuntos
Doença de Alzheimer/patologia , Células-Tronco Pluripotentes Induzidas/citologia , Presenilina-1/genética , Doença de Alzheimer/genética , Sequência de Bases , Sistemas CRISPR-Cas/genética , Diferenciação Celular , Linhagem Celular , Reprogramação Celular , Fibroblastos/citologia , Genótipo , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Cariótipo , Masculino , Microscopia de Fluorescência , Fenótipo , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA , Pele/citologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
13.
Stem Cell Res ; 17(3): 470-473, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27789396

RESUMO

Mutations in presenilin 1 (PSEN1) lead to the most aggressive form of familial Alzheimer's disease (AD). Human induced pluripotent stem cells (hiPSCs) derived from AD patients can be differentiated and used for disease modeling. Here, we derived hiPSC from skin fibroblasts obtained from an AD patient carrying a L282F mutation in PSEN1. We transfected skin fibroblasts with episomal iPSC reprogramming vectors targeting human OCT4, SOX2, L-MYC, KLF4, NANOG, LIN28, and short hairpin RNA against TP53. Our hiPSC line, L282F-hiPSC, displayed typical stem cell characteristics with consistent expression of pluripotency genes and the ability to differentiation into the three germ layers.


Assuntos
Doença de Alzheimer/patologia , Células-Tronco Pluripotentes Induzidas/citologia , Presenilina-1/genética , Doença de Alzheimer/genética , Sequência de Bases , Diferenciação Celular , Linhagem Celular , Reprogramação Celular , Corpos Embrioides/citologia , Corpos Embrioides/metabolismo , Fibroblastos/citologia , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Cariótipo , Fator 4 Semelhante a Kruppel , Masculino , Microscopia de Fluorescência , Polimorfismo de Nucleotídeo Único , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Análise de Sequência de DNA , Pele/citologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteína Supressora de Tumor p53/antagonistas & inibidores , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
15.
Methods Mol Biol ; 1516: 47-56, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27032942

RESUMO

Efficient cryopreservation of human pluripotent stem cells (hPSCs) in chemically defined, xeno-free conditions is highly desirable for medical research and clinical applications such as cell-based therapies. Here we present a simple and effective slow freezing-rapid thawing protocol for the cryopreservation of feeder-free, single hPSCs. This cryopreservation protocol involves the supplementation of 10 % dimethyl sulfoxide (DMSO) and 10 µM Rho-associated kinase inhibitor Y-27632 into two types of xeno-free, defined media supplements (Knockout Serum Replacement and TeSR2). High post-thaw cell recovery (~90 %) and cell expansion (~70 %) can be achieved using this protocol. The cryopreserved single cells retain the morphological characteristics of hPSCs and differentiation capabilities of pluripotent stem cells.


Assuntos
Proliferação de Células/efeitos dos fármacos , Criopreservação/métodos , Células-Tronco Pluripotentes/efeitos dos fármacos , Análise de Célula Única/métodos , Amidas/farmacologia , Diferenciação Celular/efeitos dos fármacos , Crioprotetores/farmacologia , Meios de Cultura Livres de Soro/química , Congelamento , Humanos , Piridinas/farmacologia
16.
Am J Hypertens ; 29(9): 1038-45, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27068705

RESUMO

BACKGROUND: To determine whether prediabetes and diabetes in older adults are associated with arterial stiffness measured in central and peripheral arteries and to examine characteristics that modify these associations. METHODS: Cohort members attending the 5th exam (2011-2013) of the Atherosclerosis Risk in Communities (ARIC) study had pulse wave velocity (PWV) measures performed at the carotid-femoral (cfPWV), brachial-ankle (baPWV), and femoral-ankle (faPWV) segments. Fasting glucose ≥126mg/dl, glycated hemoglobin (HbA1c) ≥6.5%, or currently taking diabetes medication defined diabetes. Fasting glucose 100-125mg/dl or HbA1c 5.7%-6.4% among those without diabetes defined prediabetes. Cross-sectional associations were modeled using multivariable linear regression. RESULTS: Among 4,279 eligible participants with cfPWV measures (mean age 75 years), 22% were African-American, 25.5% had diabetes, and 54.7% had prediabetes. Compared to those with normal glucose, cfPWV was 95.8cm/s higher (stiffer) on average for those with diabetes (for reference: being 1 year older was associated with 14.4cm/s higher cfPWV). Similar findings were seen for diabetes and baPWV, although attenuated. Interestingly, faPWV was 17.6cm/s lower for those with diabetes compared to normal glucose. There was a significant positive association between baPWV and prediabetes. Among those with diabetes, cfPWV was higher for those with albuminuria, reduced kidney function, duration of diabetes ≥10 years, and elevated HbA1c (HbA1c ≥7). CONCLUSION: Among older adults, diabetes is associated with higher central arterial stiffness and lower peripheral arterial stiffness, and prediabetes is associated with higher baPWV. Cross-sectionally, the magnitude of the effect of diabetes on central stiffness is equivalent to 6 years of arterial aging.


Assuntos
Estado Pré-Diabético/fisiopatologia , Rigidez Vascular , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Estudos Transversais , Feminino , Humanos , Masculino , Análise de Onda de Pulso
17.
Am J Hypertens ; 29(4): 470-5, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26232036

RESUMO

BACKGROUND: Arterial stiffness measures are emerging tools for risk assessment and stratification for hypertension and cardiovascular disease (CVD). Carotid-femoral pulse wave velocity (cfPWV) is an established measure of central arterial stiffness. Other measures of PWV include femoral-ankle (faPWV), a measure of peripheral stiffness, and brachial-ankle PWV (baPWV), a composite measure of central and peripheral stiffness. Repeatability of central, peripheral, and composite PWV measures has not been adequately examined or compared. METHODS: Participants (n = 79; mean age 75.7 years; USA) from a repeatability study nested within the Atherosclerosis Risk in Communities (ARIC) Study visit 5 (2011-2013) underwent 2 standardized visits, 4-8 weeks apart. Trained technicians obtained 2 PWV measurements at each visit using the VP-1000 Plus system. We calculated the intraclass correlation coefficient (ICC), SE of measurement, and minimal detectable change (MDC95; 95% confidence interval) and difference (MDD). RESULTS: The ICCs and 95% confidence intervals (95% CIs) were 0.70 (0.59, 0.81) for cfPWV, 0.84 (0.78, 0.90) for baPWV, and 0.69 (0.59, 0.79) for faPWV. The MDC95 between repeat measures within an individual was 411.0 cm/s for cfPWV, 370.6 cm/s for baPWV, and 301.4 cm/s for faPWV. The MDD for 2 independent samples of 100 per group was 139.3 cm/s for cfPWV, 172.3 cm/s for baPWV, and 100.4 cm/s for faPWV. CONCLUSIONS: Repeatability was acceptable for all PWV measures in a multicenter, population-based study of older adults and supports its use in epidemiologic studies. Quantifying PWV measurement variation is critical for applications to risk assessment and stratification and eventual translation to clinical practice.


Assuntos
Artérias/fisiopatologia , Doenças Cardiovasculares/diagnóstico , Análise de Onda de Pulso/métodos , Rigidez Vascular , Idoso , Índice Tornozelo-Braço , Pressão Arterial , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/fisiopatologia , Feminino , Humanos , Masculino , Variações Dependentes do Observador , Valor Preditivo dos Testes , Prognóstico , Fluxo Pulsátil , Reprodutibilidade dos Testes , Medição de Risco , Fatores de Risco , Fatores de Tempo , Estados Unidos/epidemiologia
18.
Liver Transpl ; 21(5): 683-9, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25762287

RESUMO

Liver allocation is based on current Model for End-Stage Liver Disease (MELD) scores, with priority in the case of a tie being given to those waiting the longest with a given MELD score. We hypothesized that this priority might not reflect risk: registrants whose MELD score has recently increased receive lower priority but might have higher wait-list mortality. We studied wait-list and posttransplant mortality in 69,643 adult registrants from 2002 to 2013. By likelihood maximization, we empirically defined a MELD spike as a MELD increase ≥ 30% over the previous 7 days. At any given time, only 0.6% of wait-list patients experienced a spike; however, these patients accounted for 25% of all wait-list deaths. Registrants who reached a given MELD score after a spike had higher wait-list mortality in the ensuing 7 days than those with the same resulting MELD score who did not spike, but they had no difference in posttransplant mortality. The spike-associated wait-list mortality increase was highest for registrants with medium MELD scores: specifically, 2.3-fold higher (spike versus no spike) for a MELD score of 10, 4.0-fold higher for a MELD score of 20, and 2.5-fold higher for a MELD score of 30. A model incorporating the MELD score and spikes predicted wait-list mortality risk much better than a model incorporating only the MELD score. Registrants with a sudden MELD increase have a higher risk of short-term wait-list mortality than is indicated by their current MELD score but have no increased risk of posttransplant mortality; allocation policy should be adjusted accordingly.


Assuntos
Doença Hepática Terminal/cirurgia , Transplante de Fígado/métodos , Seleção de Pacientes , Obtenção de Tecidos e Órgãos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Sistema de Registros , Alocação de Recursos , Estudos Retrospectivos , Risco , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do Tratamento , Estados Unidos , Listas de Espera
19.
BMJ Open Diabetes Res Care ; 2(1): e000002, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25452853

RESUMO

OBJECTIVE: To compare the associations of diabetes mellitus risk factors with nontraditional markers of hyperglycemia (glycated albumin, fructosamine, 1,5-anhydroglucitol (1,5-AG)) to those observed with traditional markers (fasting glucose, hemoglobin A1c (HbA1c)). DESIGN: Cross-sectional study. SETTING: The community-based Atherosclerosis Risk in Communities (ARIC) Study cohort. PARTICIPANTS: A subsample of 1764 participants (309 with diagnosed diabetes and 1455 without diagnosed diabetes) from the ARIC Study who attended a clinic visit in 2005-2006. MAIN OUTCOME MEASURES: Elevated levels of glycated albumin, fructosamine, 1,5-AG, fasting glucose, and HbA1c in persons with and without a diagnosis of diabetes. RESULTS: The mean age of participants was 70 years (SD, 6), 43% were men, and 20% were African-American. Black race and family history of diabetes were generally positively associated with elevated levels of all biomarkers of hyperglycemia except 1,5-AG, which showed inverse but weaker associations with the risk factors examined. In general, patterns of risk factor associations observed for fasting glucose and HbA1c were similar to those observed for the nontraditional biomarkers of hyperglycemia but with one clear exception: body mass index (BMI). In persons without a diagnosis of diabetes, BMI was positively associated with fasting glucose and HbA1c, but the associations of BMI with glycated albumin and fructosamine were inverse, with high values of these markers at low levels of BMI. 1,5-AG, which is lowered in the setting of hyperglycemia, was positively associated with BMI. CONCLUSIONS: Traditional diabetes risk factors have similar associations with glycated albumin and fructosamine as those for fasting glucose and HbA1c, with the exception of BMI. Risk factor associations with 1,5-AG were mostly inverse. The inverse associations of BMI with glycated albumin and fructosamine, and positive associations with 1,5-AG, may reflect pathways independent of glucose metabolism and merit further examination.

20.
Rev Urol ; 16(1): 1-9, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24791150

RESUMO

A number of patients are diagnosed with renal malignancies incidentally worldwide. Once a diagnosis of a renal malignancy is established, after a careful evaluation, patients can be offered a robotic nephrectomy or partial nephrectomy. We present a review of the physiologic and anesthetic considerations in elderly patients who are being considered for robotic renal surgery.

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