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1.
Proc Natl Acad Sci U S A ; 119(49): e2203925119, 2022 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-36442118

RESUMO

Genotype-by-environment interactions (GxE) indicate that variation in organismal traits cannot be explained by fixed effects of genetics or site-specific plastic responses alone. For tropical coral reefs experiencing dramatic environmental change, identifying the contributions of genotype, environment, and GxE on coral performance will be vital for both predicting persistence and developing restoration strategies. We quantified the impacts of G, E, and GxE on the morphology and survival of the endangered coral, Acropora cervicornis, through an in situ transplant experiment exposing common garden (nursery)-raised clones of ten genotypes to nine reef sites in the Florida Keys. By fate-tracking outplants over one year with colony-level 3D photogrammetry, we uncovered significant GxE on coral size, shape, and survivorship, indicating that no universal winner exists in terms of colony performance. Rather than differences in mean trait values, we found that individual-level morphological plasticity is adaptive in that the most plastic individuals also exhibited the fastest growth and highest survival. This indicates that adaptive morphological plasticity may continue to evolve, influencing the success of A. cervicornis and resulting reef communities in a changing climate. As focal reefs are active restoration sites, the knowledge that variation in phenotype is an important predictor of performance can be directly applied to restoration planning. Taken together, these results establish A. cervicornis as a system for studying the ecoevolutionary dynamics of phenotypic plasticity that also can inform genetic- and environment-based strategies for coral restoration.


Assuntos
Antozoários , Animais , Humanos , Antozoários/genética , Região do Caribe , Recifes de Corais , Adaptação Fisiológica , Etnicidade
2.
Diabetologia ; 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39354095

RESUMO

AIMS/HYPOTHESIS: The aim of this work was to explore molecular amino acids (AAs) and related structures of HLA-DQA1-DQB1 that underlie its contribution to the progression from stages 1 or 2 to stage 3 type 1 diabetes. METHODS: Using high-resolution DQA1 and DQB1 genotypes from 1216 participants in the Diabetes Prevention Trial-Type 1 and the Diabetes Prevention Trial, we applied hierarchically organised haplotype association analysis (HOH) to decipher which AAs contributed to the associations of DQ with disease and their structural properties. HOH relied on the Cox regression to quantify the association of DQ with time-to-onset of type 1 diabetes. RESULTS: By numerating all possible DQ heterodimers of α- and ß-chains, we showed that the heterodimerisation increases genetic diversity at the cellular level from 43 empirically observed haplotypes to 186 possible heterodimers. Heterodimerisation turned several neutral haplotypes (DQ2.2, DQ2.3 and DQ4.4) to risk haplotypes (DQ2.2/2.3-DQ4.4 and DQ4.4-DQ2.2). HOH uncovered eight AAs on the α-chain (-16α, -13α, -6α, α22, α23, α44, α72, α157) and six AAs on the ß-chain (-18ß, ß9, ß13, ß26, ß57, ß135) that contributed to the association of DQ with progression of type 1 diabetes. The specific AAs concerned the signal peptide (minus sign, possible linkage to expression levels), pockets 1, 4 and 9 in the antigen-binding groove of the α1ß1 domain, and the putative homodimerisation of the αß heterodimers. CONCLUSIONS/INTERPRETATION: These results unveil the contribution made by DQ to type 1 diabetes progression at individual residues and related protein structures, shedding light on its immunological mechanisms and providing new leads for developing treatment strategies. DATA AVAILABILITY: Clinical trial data and biospecimen samples are available through the National Institute of Diabetes and Digestive and Kidney Diseases Central Repository portal ( https://repository.niddk.nih.gov/studies ).

3.
Proc Biol Sci ; 291(2019): 20232447, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38531406

RESUMO

As environments are rapidly reshaped due to climate change, phenotypic plasticity plays an important role in the ability of organisms to persist and is considered an especially important acclimatization mechanism for long-lived sessile organisms such as reef-building corals. Often, this ability of a single genotype to display multiple phenotypes depending on the environment is modulated by changes in gene expression, which can vary in response to environmental changes via two mechanisms: baseline expression and expression plasticity. We used transcriptome-wide expression profiling of eleven genotypes of common-gardened Acropora cervicornis to explore genotypic variation in the expression response to thermal and acidification stress, both individually and in combination. We show that the combination of these two stressors elicits a synergistic gene expression response, and that both baseline expression and expression plasticity in response to stress show genotypic variation. Additionally, we demonstrate that frontloading of a large module of coexpressed genes is associated with greater retention of algal symbionts under combined stress. These results illustrate that variation in the gene expression response of individuals to climate change stressors can persist even when individuals have shared environmental histories, affecting their performance under future climate change scenarios.


Assuntos
Antozoários , Humanos , Animais , Antozoários/fisiologia , Recifes de Corais , Genótipo , Aclimatação/fisiologia , Adaptação Fisiológica , Mudança Climática
4.
J Biol Chem ; 298(12): 102669, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36334630

RESUMO

Mutations in C10orf11 (oculocutaneous albinism type 7 [OCA7]) cause OCA, a disorder that presents with hypopigmentation in skin, eyes, and hair. The OCA7 pathophysiology is unknown, and there is virtually no information on the OCA7 protein and its cellular function. Here, we discover that OCA7 localizes to the limiting membrane of melanosomes, the specialized pigment cell organelles where melanin is synthesized. We demonstrate that OCA7 is recruited through interaction with a canonical effector-binding surface of melanosome proteins Rab32 and Rab38. Using newly generated OCA7-KO MNT1 cells, we show OCA7 regulates overall melanin levels in a melanocyte autonomous manner by controlling melanosome maturation. Importantly, we found that OCA7 regulates premelanosome protein (PMEL) processing, impacting fibrillation and the striations that define transition from melanosome stage I to stage II. Furthermore, the melanosome lumen of OCA7-KO cells displays lower pH than control cells. Together, our results reveal that OCA7 regulates pigmentation through two well-established determinants of melanosome biogenesis and function, PMEL processing, and organelle pH.


Assuntos
Melanossomas , Proteínas de Membrana , Melaninas/metabolismo , Melanócitos/metabolismo , Melanossomas/genética , Melanossomas/metabolismo , Proteínas de Membrana/metabolismo , Pigmentação/genética , Humanos
5.
J Am Chem Soc ; 145(39): 21514-21526, 2023 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-37737824

RESUMO

Deposits of the microtubule-associated protein Tau (MAPT) serve as a hallmark of neurodegenerative diseases known as tauopathies. Numerous studies have demonstrated that in diseases such as Alzheimer's disease (AD), Tau undergoes extensive remodeling. The attachment of post-translational modifications distributed throughout the entire sequence of the protein correlates with clinical presentation. A systematic examination of these protein alterations can shed light on their roles in both healthy and diseased states. However, the ability to access these modifications in the entire protein chain is limited as Tau can only be produced recombinantly or through semisynthesis. In this article, we describe the first chemical synthesis of the longest 2N4R isoform of Tau, consisting of 441 amino acids. The 2N4R Tau was divided into 3 major segments and a total of 11 fragments, all of which were prepared via solid-phase peptide synthesis. The successful chemical strategy has relied on the strategic use of two cysteine sites (C291 and C322) for the native chemical ligations (NCLs). This was combined with modern preparative protein chemistries, such as mercaptothreonine ligation (T205), diselenide-selenoester ligation (D358), and mutations of mercaptoamino acids into native residues via homogeneous radical desulfurization (A40, A77, A119, A157, A246, and A390). The successful completion of the synthesis has established a robust and scalable route to the native protein in multimilligram quantities and high purity. In broader terms, the presented strategy can be applied to the preparation of other shorter isoforms of Tau as well as to introduce all post-translational modifications that are characteristic of tauopathies such as AD.


Assuntos
Doença de Alzheimer , Tauopatias , Humanos , Proteínas tau/química , Doença de Alzheimer/metabolismo , Processamento de Proteína Pós-Traducional , Isoformas de Proteínas/química , Técnicas de Síntese em Fase Sólida
6.
J Am Chem Soc ; 145(41): 22354-22360, 2023 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-37812507

RESUMO

We introduce a direct conversion of alkyl thiols into boronic acids, facilitated by a water-soluble phosphine, 1,3,5-triaza-7-phosphaadamantane (PTA), in conjunction with tetrahydroxydiboron (B2(OH)4), acting as both a radical initiator and a boron source. This desulfurative borylation reaction has been successfully applied to various substrates, including cysteine residues in oligopeptides and small proteins, primary alkyl thiols found in pharmaceutical compounds, disulfides, and selenocysteine. Optimization of reaction conditions was undertaken to reduce the formation of unwanted reactions, such as the reduction of alanyl or other primary radicals, and to prevent deleterious reactions between the phosphine and N-terminal amine that lead to methylene adducts by utilizing a buffer containing glycine-glycine (GG) dipeptide. The developed method is characterized by its operational simplicity and robustness. Moreover, its compatibility with various functional groups present in peptides and proteins makes it a promising tool for late-stage functionalization, extending its potential application across a broad spectrum of chemical and biological targets.


Assuntos
Peptídeos , Proteínas , Proteínas/química , Peptídeos/química , Compostos de Sulfidrila/química , Glicina
7.
J Org Chem ; 88(9): 6192-6202, 2023 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-37027833

RESUMO

Oxazolines and thiazolines are important constituents of bioactive natural products and pharmaceuticals. Here, we report the development of an effective and practical method of oxazoline and thiazoline formation, which can facilitate the synthesis of natural products, chiral ligands, and pharmaceutical intermediates. This method capitalized on a Mo(VI) dioxide catalyst stabilized by substituted picolinic acid ligands, which is tolerant to many functional groups that would otherwise be sensitive to highly electrophilic alternative reagents.

8.
Angew Chem Int Ed Engl ; 61(31): e202207153, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35653581

RESUMO

Non-proteogenic amino acids and functionalized peptides are important motifs in modern drug discovery. Here we report that AlaB can serve as universal building blocks in the synthesis of a diverse collection of modified amino acids, peptides, and proteins. First, we develop the synthesis of AlaB from redox-active esters of aspartic acid resulting in a series of ß-boronoalanine derivatives. Next, we show that AlaB can be integrated into automated oligopeptide solid-phase synthesis. AlaB is compatible with common transformations used in preparative peptide chemistry such as native chemical ligation and radical desulfurization as showcased by total synthesis of AlaB -containing ubiquitin. Furthermore, AlaB reagents participate in Pd-catalyzed reactions, including C-C cross-couplings and macrocyclizations. Taken together, AlaB synthons are practical reagents to access modified peptides, proteins, and in the synthesis of cyclic/stapled peptides.


Assuntos
Aminoácidos , Peptídeos , Aminoácidos/química , Indicadores e Reagentes , Peptídeos/química , Peptídeos Cíclicos , Proteínas , Técnicas de Síntese em Fase Sólida
9.
Proc Biol Sci ; 288(1960): 20210923, 2021 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-34641725

RESUMO

Knowledge of multi-stressor interactions and the potential for tradeoffs among tolerance traits is essential for developing intervention strategies for the conservation and restoration of reef ecosystems in a changing climate. Thermal extremes and acidification are two major co-occurring stresses predicted to limit the recovery of vital Caribbean reef-building corals. Here, we conducted an aquarium-based experiment to quantify the effects of increased water temperatures and pCO2 individually and in concert on 12 genotypes of the endangered branching coral Acropora cervicornis, currently being reared and outplanted for large-scale coral restoration. Quantification of 12 host, symbiont and holobiont traits throughout the two-month-long experiment showed several synergistic negative effects, where the combined stress treatment often caused a greater reduction in physiological function than the individual stressors alone. However, we found significant genetic variation for most traits and positive trait correlations among treatments indicating an apparent lack of tradeoffs, suggesting that adaptive evolution will not be constrained. Our results suggest that it may be possible to incorporate climate-resistant coral genotypes into restoration and selective breeding programmes, potentially accelerating adaptation.


Assuntos
Antozoários , Mudança Climática , Animais , Antozoários/genética , Recifes de Corais , Ecossistema , Espécies em Perigo de Extinção
10.
Proc Biol Sci ; 288(1961): 20211613, 2021 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-34666521

RESUMO

The rapid loss of reef-building corals owing to ocean warming is driving the development of interventions such as coral propagation and restoration, selective breeding and assisted gene flow. Many of these interventions target naturally heat-tolerant individuals to boost climate resilience, but the challenges of quickly and reliably quantifying heat tolerance and identifying thermotolerant individuals have hampered implementation. Here, we used coral bleaching automated stress systems to perform rapid, standardized heat tolerance assays on 229 colonies of Acropora cervicornis across six coral nurseries spanning Florida's Coral Reef, USA. Analysis of heat stress dose-response curves for each colony revealed a broad range in thermal tolerance among individuals (approx. 2.5°C range in Fv/Fm ED50), with highly reproducible rankings across independent tests (r = 0.76). Most phenotypic variation occurred within nurseries rather than between them, pointing to a potentially dominant role of fixed genetic effects in setting thermal tolerance and widespread distribution of tolerant individuals throughout the population. The identification of tolerant individuals provides immediately actionable information to optimize nursery and restoration programmes for Florida's threatened staghorn corals. This work further provides a blueprint for future efforts to identify and source thermally tolerant corals for conservation interventions worldwide.


Assuntos
Antozoários , Termotolerância , Animais , Antozoários/fisiologia , Censos , Recifes de Corais , Florida
11.
HIV Med ; 22(5): 325-333, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33247876

RESUMO

OBJECTIVES: To assess the risk of chronic kidney disease (CKD) associated with tenofovir disoproxil fumarate (TDF) use by baseline D:A:D CKD risk score. METHODS: Adult antiretroviral therapy (ART)-naïve people living with HIV (PLWH) initiating treatment, with estimated glomerular filtration rate (eGFR) ≥ 60 mL/min/1.73 m2 , were identified in the OPERA cohort. CKD was defined as two or more consecutive eGFR < 60 mL/min/1.73 m2 , > 90 days apart. Associations between TDF use, baseline D:A:D CKD risk and incident CKD were assessed with incidence rates (IRs; Poisson regression) and adjusted pooled logistic regression. The impact of pharmacoenhancers on the observed association between TDF and CKD was also evaluated. RESULTS: Of 9802 PLWH included, 6222 initiated TDF and 3580 did not (76% and 79% low D:A:D CKD risk, respectively). Overall, 125 CKD events occurred over 24 382 person-years of follow-up. Within strata of D:A:D CKD risk score, IRs were similar across TDF exposure, with high baseline CKD risk associated with highest incidence. Compared with the low-risk group without TDF, there was no statistical difference in odds of incident CKD in the low-risk group with TDF (adjusted odds ratio = 0.55, 95% confidence interval: 0.19-1.54). Odds of incident CKD did not differ statistically significantly by pharmacoenhancer exposure, with or without TDF. CONCLUSIONS: In this large cohort of ART-naïve PLWH, incident CKD following ART initiation was infrequent and strongly associated with baseline CKD risk. TDF-containing regimens did not increase the odds of CKD in those with a low baseline D:A:D CKD risk, the largest group of ART-naïve PLWH, and may remain a viable treatment option in appropriate settings.


Assuntos
Fármacos Anti-HIV , Infecções por HIV , Insuficiência Renal Crônica , Adulto , Fármacos Anti-HIV/efeitos adversos , Taxa de Filtração Glomerular , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Humanos , Insuficiência Renal Crônica/induzido quimicamente , Insuficiência Renal Crônica/epidemiologia , Fatores de Risco , Tenofovir/efeitos adversos
12.
Artigo em Inglês | MEDLINE | ID: mdl-31493555

RESUMO

The planktonic larval phase of scleractinian coral life-history represents a crucial stage when dispersal takes place and genetic diversity among populations is maintained. Understanding the dynamics influencing larval survival is especially relevant in the context of climate change, as larvae may be more vulnerable to environmental disturbances than adults. Several physiological parameters of coral larvae have been shown to vary by release time and past environmental history. However, the contribution of parental or genetic effects is largely unknown. To investigate these potential familial effects, we collected adult Porites astreoides colonies in April 2018 from two reef zones in the lower Florida Keys and quantified physiological traits and thermal tolerance of the newly released larvae. Family accounted for more variation than day of release and reef origin, with >60% of the variation in chlorophyll a and protein content explained by family. The survivorship of larvae under 36 °C acute temperature stress was also tightly linked to what parent colony they were released from. During a 32 °C moderate temperature stress experiment, inshore larvae tended to bleach less than offshore larvae, mirroring the enhanced bleaching resistance previously observed in inshore adult coral populations. The significant familial effects identified in the present study suggest that researchers should be cautious when interpreting results of studies which pool larvae among families, and that future studies should take care to account for this variation.


Assuntos
Antozoários/fisiologia , Animais , Clorofila A/metabolismo , Ritmo Circadiano/fisiologia , Larva/fisiologia , Estresse Fisiológico , Análise de Sobrevida , Temperatura
13.
J Org Chem ; 83(17): 10487-10500, 2018 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-30039699

RESUMO

Chiral 1,2-amino alcohols are privileged scaffolds with important applications as drug candidates and chiral ligands. Although various methods for the preparation of this structural motif have been reported, these methods are limited because of the use of precious metals and ligands. Here, we report a practical and high yielding synthesis of chiral 1,2-amino alcohols using arylglyoxals and pseudoephedrine auxiliary. This reaction is catalyzed by a Brønsted acid and provides morpholinone products in high yields and selectivities. The morpholine ring was converted into 1,2-amino alcohols in a two-step protocol.


Assuntos
Amino Álcoois/química , Amino Álcoois/síntese química , Glioxal/química , Morfolinas/química , Morfolinas/síntese química , Técnicas de Química Sintética , Estereoisomerismo
14.
Diabetes Metab Res Rev ; 33(8)2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28755385

RESUMO

AIM: It is of interest to predict possible lifetime risk of type 1 diabetes (T1D) in young children for recruiting high-risk subjects into longitudinal studies of effective prevention strategies. METHODS: Utilizing a case-control study in Sweden, we applied a recently developed next generation targeted sequencing technology to genotype class II genes and applied an object-oriented regression to build and validate a prediction model for T1D. RESULTS: In the training set, estimated risk scores were significantly different between patients and controls (P = 8.12 × 10-92 ), and the area under the curve (AUC) from the receiver operating characteristic (ROC) analysis was 0.917. Using the validation data set, we validated the result with AUC of 0.886. Combining both training and validation data resulted in a predictive model with AUC of 0.903. Further, we performed a "biological validation" by correlating risk scores with 6 islet autoantibodies, and found that the risk score was significantly correlated with IA-2A (Z-score = 3.628, P < 0.001). When applying this prediction model to the Swedish population, where the lifetime T1D risk ranges from 0.5% to 2%, we anticipate identifying approximately 20 000 high-risk subjects after testing all newborns, and this calculation would identify approximately 80% of all patients expected to develop T1D in their lifetime. CONCLUSION: Through both empirical and biological validation, we have established a prediction model for estimating lifetime T1D risk, using class II HLA. This prediction model should prove useful for future investigations to identify high-risk subjects for prevention research in high-risk populations.


Assuntos
Autoanticorpos , Diabetes Mellitus Tipo 1/genética , Predisposição Genética para Doença , Antígenos HLA-DQ/genética , Alelos , Estudos de Casos e Controles , Criança , Diabetes Mellitus Tipo 1/imunologia , Feminino , Genótipo , Humanos , Masculino , Modelos Teóricos , Medição de Risco , Fatores de Risco , Suécia
15.
J Viral Hepat ; 23(1): 32-8, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26189719

RESUMO

Chronic hepatitis C virus (HCV) infection may cause kidney injury, particularly in the setting of cryoglobulinemia or cirrhosis; however, few studies have evaluated the epidemiology of acute kidney injury in patients with HCV. We aimed to describe national temporal trends of incidence and impact of severe acute kidney injury (AKI) requiring renal replacement 'dialysis-requiring AKI' in hospitalized adults with HCV. We extracted our study cohort from the Nationwide Inpatient Sample of the Healthcare Cost and Utilization Project using data from 2004 to 2012. We defined HCV and dialysis-requiring acute kidney injury based on previously validated ICD-9-CM codes. We analysed temporal changes in the proportion of hospitalizations complicated by dialysis-requiring AKI and utilized survey multivariable logistic regression models to estimate its impact on in-hospital mortality. We identified a total of 4,603,718 adult hospitalizations with an associated diagnosis of HCV from 2004 to 2012, of which 51,434 (1.12%) were complicated by dialysis-requiring acute kidney injury. The proportion of hospitalizations complicated by dialysis-requiring acute kidney injury increased significantly from 0.86% in 2004 to 1.28% in 2012. In-hospital mortality was significantly higher in hospitalizations complicated by dialysis-requiring acute kidney injury vs those without (27.38% vs 2.95%; adjusted odds ratio: 2.09; 95% confidence interval: 1.74-2.51). The proportion of HCV hospitalizations complicated by dialysis-requiring acute kidney injury increased significantly between 2004 and 2012. Similar to observations in the general population, dialysis-requiring acute kidney injury was associated with a twofold increase in odds of in-hospital mortality in adults with HCV. These results highlight the burden of acute kidney injury in hospitalized adults with HCV infection.


Assuntos
Injúria Renal Aguda/terapia , Hepatite C Crônica/virologia , Hospitalização/estatística & dados numéricos , Diálise Renal/estatística & dados numéricos , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Estudos de Coortes , Comorbidade , Feminino , Hepacivirus/isolamento & purificação , Mortalidade Hospitalar , Humanos , Lactente , Recém-Nascido , Pacientes Internados/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Índice de Gravidade de Doença , Estados Unidos , Adulto Jovem
16.
Osteoarthritis Cartilage ; 24(8): 1399-407, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-26973330

RESUMO

OBJECTIVE: To evaluate whether baseline T1ρ and T2 relaxation times of hip cartilage are associated with magnetic resonance imaging (MRI) based progression of hip osteoarthritis (OA) at 18 months. METHODS: 3T MRI studies of the hip were obtained at baseline and 18-month follow-up for 54 subjects without evidence of severe OA at baseline [Kellgren-Lawrence (KL) score of 0-3]. 2D fast spin-echo sequences were used for semi-quantitative morphological scoring of cartilage lesions and a combined T1ρ/T2 sequence was used to quantitatively assess cartilage composition. Progression of hip OA was defined based on incident or progression of morphological semi-quantitative grade at 18 months. Baseline T1ρ and T2 relaxation times were compared between progressors and non-progressors using one-way analysis of variance and Mann-Whitney U tests and used to predict progression with binary logistic regression after adjusting for age, gender, body mass index, and KL score. Additionally, a novel voxel-based relaxometry technique was used to compare the spatial distribution of baseline T1ρ and T2 between progressors and non-progressors. RESULTS: Significantly higher baseline T1ρ and T2 values were observed in hip OA progressors compared to non-progressors, particularly in the posterosuperior and anterior aspects of the femoral cartilage. Logistic regression showed that higher baseline T1ρ or T2 values in the femoral cartilage were significantly associated with progression of femoral cartilage lesions at 18 months. CONCLUSION: T1ρ and T2 relaxation parameters are associated with morphological cartilage degeneration at 18 months and may serve as potential imaging biomarkers for progression of cartilage lesions in hip OA.


Assuntos
Osteoartrite do Quadril , Índice de Massa Corporal , Cartilagem Articular , Progressão da Doença , Humanos , Imageamento por Ressonância Magnética , Osteoartrite do Joelho
17.
HIV Med ; 16 Suppl 1: 55-63, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25711324

RESUMO

OBJECTIVES: HIV infection has been associated with an increased risk of chronic kidney disease (CKD). Little is known about the prevalence of CKD in individuals with high CD4 cell counts prior to initiation of antiretroviral therapy (ART). We sought to address this knowledge gap. METHODS: We describe the prevalence of CKD among 4637 ART-naïve adults (mean age 36.8 years) with CD4 cell counts > 500 cells/µL at enrolment in the Strategic Timing of AntiRetroviral Treatment (START) study. CKD was defined by estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m(2) and/or dipstick urine protein ≥ 1+. Logistic regression was used to identify baseline characteristics associated with CKD. RESULTS: Among 286 [6.2%; 95% confidence interval (CI) 5.5%, 6.9%] participants with CKD, the majority had isolated proteinuria. A total of 268 participants had urine protein ≥ 1+, including 41 with urine protein ≥ 2+. Only 22 participants (0.5%) had an estimated glomerular filtration rate < 60 mL/min/1.73 m(2) , including four who also had proteinuria. Baseline characteristics independently associated with CKD included diabetes [adjusted odds ratio (aOR) 1.73; 95% CI 1.05, 2.85], hypertension (aOR 1.82; 95% CI 1.38, 2.38), and race/ethnicity (aOR 0.59; 95% CI 0.37, 0.93 for Hispanic vs. white). CONCLUSIONS: We observed a low prevalence of CKD associated with traditional CKD risk factors among ART-naïve clinical trial participants with CD4 cell counts > 500 cells/µL.


Assuntos
Infecções por HIV/complicações , Infecções por HIV/patologia , Nefropatias/diagnóstico , Nefropatias/epidemiologia , Adulto , Contagem de Linfócito CD4 , Doença Crônica , Estudos Transversais , Feminino , Taxa de Filtração Glomerular , Infecções por HIV/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco
18.
Osteoarthritis Cartilage ; 23(12): 2214-2223, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26187574

RESUMO

OBJECTIVE: To evaluate the longitudinal reproducibility and variations of cartilage T1ρ and T2 measurements using different coils, MR systems and sites. METHODS: Single-Site study: Phantom data were collected monthly for up to 29 months on four GE 3T MR systems. Data from phantoms and human subjects were collected on two MR systems using the same model of coil; and were collected on one MR system using two models of coils. Multi-site study: Three participating sites used the same model of MR systems and coils, and identical imaging protocols. Phantom data were collected monthly. Human subjects were scanned and rescanned on the same day at each site. Two traveling human subjects were scanned at all three sites. RESULTS: Single-Site Study: The phantom longitudinal RMS-CVs ranged from 1.8% to 2.7% for T1ρ and 1.8-2.8% for T2. Significant differences were found in T1ρ and T2 values using different MR systems and coils. Multi-Site Study: The phantom longitudinal RMS-CVs ranged from 1.3% to 2.6% for T1ρ and 1.2-2.7% for T2. Across three sites (n = 16), the in vivo scan-rescan RMS-CV was 3.1% and 4.0% for T1ρ and T2, respectively. Phantom T1ρ and T2 values were significantly different between three sites but highly correlated (R > 0.99). No significant difference was found in T1ρ and T2 values of traveling controls, with cross-site RMS-CV as 4.9% and 4.4% for T1ρ and T2, respectively. CONCLUSION: With careful quality control and cross-calibration, quantitative MRI can be readily applied in multi-site studies and clinical trials for evaluating cartilage degeneration.


Assuntos
Cartilagem Articular/patologia , Articulação do Joelho/patologia , Osteoartrite do Joelho/diagnóstico , Imagens de Fantasmas , Voluntários Saudáveis , Humanos , Processamento de Imagem Assistida por Computador , Estudos Longitudinais , Imageamento por Ressonância Magnética/instrumentação , Imageamento por Ressonância Magnética/métodos , Reprodutibilidade dos Testes
19.
HIV Med ; 15(2): 116-23, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24024499

RESUMO

OBJECTIVES: The accuracy and precision of glomerular filtration rate (GFR) estimating equations based on plasma creatinine (GFR(cr)), cystatin C (GFR(cys)) and the combination of these markers (GFR(cr-cys)) have recently been assessed in HIV-infected individuals. We assessed the associations of GFR, estimated by these three equations, with clinical events in HIV-infected individuals. METHODS: We compared the associations of baseline GFR(cr), GFR(cys) and GFR(cr-cys) [using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations] with mortality, cardiovascular events (CVEs) and opportunistic diseases (ODs) in the Strategies for the Management of Antiretroviral Therapy (SMART) study. We used Cox proportional hazards models to estimate unadjusted and adjusted hazard ratios per standard deviation (SD) change in GFR. RESULTS: A total of 4614 subjects from the SMART trial with available baseline creatinine and cystatin C data were included in this analysis. Of these, 99 died, 111 had a CVE and 121 had an OD. GFR(cys) was weakly to moderately correlated with HIV RNA, CD4 cell count, high-sensitivity C-reactive protein, interleukin-6, and D-dimer, while GFR(cr) had little or no correlation with these factors. GFR(cys) had the strongest associations with the three clinical outcomes, followed closely by GFR(cr-cys), with GFR(cr) having the weakest associations with clinical outcomes. In a model adjusting for demographics, cardiovascular risk factors, HIV-related factors and inflammation markers, a 1-SD lower GFR(cys) was associated with a 55% [95% confidence interval (CI) 27-90%] increased risk of mortality, a 21% (95% CI 0-47%) increased risk of CVE, and a 22% (95% CI 0-48%) increased risk of OD. CONCLUSIONS: Of the three CKD-EPI GFR equations, GFR(cys) had the strongest associations with mortality, CVE and OD.


Assuntos
Infecções Oportunistas Relacionadas com a AIDS/sangue , Doenças Cardiovasculares/sangue , Creatinina/sangue , Cistatina C/sangue , Taxa de Filtração Glomerular , Infecções por HIV/sangue , HIV-1 , Adulto , Fármacos Anti-HIV/uso terapêutico , Biomarcadores/sangue , Feminino , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Infecções por HIV/mortalidade , Humanos , Nefropatias/diagnóstico , Nefropatias/mortalidade , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Modelos de Riscos Proporcionais , Estudos Prospectivos , RNA Viral/sangue
20.
Thromb Res ; 240: 109063, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38878741

RESUMO

BACKGROUND: Imaging evaluation of acute deep vein thrombosis (DVT) or post-thrombotic syndrome (PTS) in animal or clinical models is limited to anatomical assessment of the location and extent of thrombi. We hypothesize that Fe-MRI, used to evaluate macrophage content in other inflammatory diseases, can be useful to evaluate the thromboinflammatory features after DVT over time. METHODS: Nineteen wild-type CD-1 mice underwent surgical IVC ligation to induce DVT. Mice received either saline or 5 mg/kg of 14E11, a Factor XI inhibitor, before the procedure. Fe-MRI was performed on days 6-7 after ligation to evaluate thrombus volume, perfusion, and macrophage content via T2-weighted images. Mice were euthanized at days 3-15 after surgery. The thrombi and adjacent vein walls were excised, weighed, formalin-fixed, and paraffin-embedded for immunohistological analysis. Specimens were stained with specific antibodies to evaluate macrophage content, collagen deposition, neovascularization, and recanalization. Significance was determined using the Mann-Whitney U or Student's t-test. RESULTS: After IVC-ligation in control mice, thrombus weights decreased by 59 % from day 3 to 15. Thrombus volumes peaked on day 5 before decreasing by 85 % by day 13. FXI inhibition led to reduced macrophage content in both thrombi (p = .008) and vein walls (p = .01), decreased thrombus volume (p = .03), and decreased thrombus mass (p = .01) compared to control mice. CCR2+ staining corroborated these findings, showing significantly reduced macrophage presence in the thrombi (p = .002) and vein wall (p = .002). CONCLUSIONS: Fe-MRI T2 relaxation times can be used to characterize and quantify post-thrombotic changes of perfusion, macrophage content, and thrombus volume over time in a surgical mouse model of venous thrombosis. This approach could lead to better quantification of in vivo inflammation correlating monocyte and macrophage content within resolving thrombi and veins and may serve as a useful tool for research and clinically in the evaluation of the post-thrombotic environment.


Assuntos
Modelos Animais de Doenças , Óxido Ferroso-Férrico , Macrófagos , Imageamento por Ressonância Magnética , Trombose Venosa , Animais , Trombose Venosa/diagnóstico por imagem , Trombose Venosa/patologia , Camundongos , Macrófagos/patologia , Imageamento por Ressonância Magnética/métodos , Masculino , Meios de Contraste
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