Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 122
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Brain Behav Immun ; 116: 101-113, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38043871

RESUMO

Perinatally acquired HIV infection (PHIV) currently affects approximately 1.7 million children worldwide. Youth with PHIV (YPHIV) are at increased risk for emotional and behavioral symptoms, yet few studies have examined relationships between these symptoms and brain structure. Previous neuroimaging studies in YPHIV report alterations within the salience network (SN), cognitive control network (CCN), and default mode network (DMN). These areas have been associated with social and emotional processing, emotion regulation, and executive function. We examined structural brain network integrity from MRI using morphometric similarity networks and graph theoretical measures of segregation (transitivity), resilience (assortativity), and integration (global efficiency). We examined brain network integrity of 40 YPHIV compared to 214 youths without HIV exposure or infection. Amongst YPHIV, we related structural brain network metrics to the Emotional Symptoms Index of the Behavioral Assessment System for Children, 2nd edition. We also examined the relationship of inflammatory biomarkers in YPHIV to brain network integrity. YPHIV had significantly lower global efficiency in the SN, DMN, and the whole brain network compared to controls. YPHIV also demonstrated lower assortativity or resilience (i.e., network robustness) compared to controls in the DMN and whole brain network. Further, higher emotional symptom score was associated with higher global efficiency in the SN and lower global efficiency in the DMN, signaling more emotional challenges. A significant association was also found between several inflammatory and cardiac markers with structural network integrity. These findings suggest an impact of HIV on developing brain networks, and potential dysfunction of the SN and DMN in relation to network efficiency.


Assuntos
Infecções por HIV , Criança , Humanos , Adolescente , Infecções por HIV/psicologia , Encéfalo , Imageamento por Ressonância Magnética , Função Executiva/fisiologia , Emoções
2.
AIDS Care ; 36(2): 220-226, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37757482

RESUMO

Understanding factors associated with internalized HIV-related stigma among mothers living with HIV may improve health outcomes. We examined factors (age, race/ethnicity, education, income, employment, marital status, health limitations, and years since HIV diagnosis) associated with internalized HIV-related stigma among biological mothers of children enrolled in the Surveillance Monitoring for ART Toxicities study of the US-based Pediatric HIV/AIDS Cohort Study. Stigma was measured with the Internalized HIV Stigma Scale (IHSS), completed biennially at their child's 11-17-year visits. Linear regression models were fit with generalized estimating equations to evaluate the association between the factors of interest and internalized HIV-related stigma using all completed IHSS surveys. Among 438 eligible mothers, the mean IHSS score was 43.7 (SD = 19.5). Higher IHSS scores were observed for widowed women compared to married women, with an estimated mean difference of 8.91 (95% CI: 2.25, 15.57) after adjusting for age, education, income, and health limitations. Years since HIV diagnosis was associated with internalized HIV-related stigma. For every year of increase since HIV diagnosis, IHSS scores decreased by 0.54 per year, after adjusting for age (95% CI: -0.92, -0.17). Interventions to reduce internalized HIV-related stigma should target mothers who are widowed and those with a more recent HIV diagnosis.


Assuntos
Síndrome da Imunodeficiência Adquirida , Infecções por HIV , Humanos , Feminino , Criança , Infecções por HIV/epidemiologia , Estudos de Coortes , HIV , Estigma Social
3.
AIDS Behav ; 25(9): 2827-2840, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33616833

RESUMO

This study examined associations of self-regulatory behavior and cognitive functioning with substance use (SU) to inform interventions for youth with perinatal HIV infection (YPHIV) or exposure but uninfected (YPHEU). Youth aged 7-15 years (YPHIV, n = 390; YPHEU, n = 211) were followed longitudinally with cognitive testing and behavioral questionnaires including self-report of alcohol, marijuana, tobacco, and other SU. Cox proportional hazards analyses were used to examine correlates of initiating each substance for those without prior use at baseline and generalized estimating equation analyses were used to address associations of cognitive/behavioral measurements with SU prevalence for the entire sample. Lower self-reported self-regulation skills, but higher cognitive functioning abilities, were associated with initiation and prevalent use of alcohol and marijuana regardless of HIV status. Our findings suggest SU screening tools and self-regulation interventions developed for general adolescent populations should be implemented for those with PHIV, who may be at heightened risk for SU-related health consequences.


RESUMEN: En este estudio se examina el vínculo del comportamiento autorregulado y la función cognoscitiva con el consumo de sustancias para argumentar intervenciones para los jóvenes con infección perinatal por el VIH (JIPVIH) y los jóvenes con exposición perinatal sin infección por el VIH (JEPSIVIH). Se hizo un seguimiento longitudinal de jóvenes de 7 a 15 años de edad (JIPVIH, n = 390; JEPSIVIH, n = 211) por medio de pruebas cognoscitivas y cuestionarios sobre el comportamiento, incluyendo el autoinforme de consumo de alcohol, marihuana, tabaco y otras sustancias. Se usaron los análisis Cox de riesgos proporcionales para examinar factores correlacionados con el inicio del consumo de cada sustancia por personas no consumidoras en el punto de referencia inicial. Asimismo, se usaron análisis de ecuaciones de estimación generalizadas para examinar la asociación entre la prevalencia del consumo de sustancias y las medidas cognoscitivas y las medidas conductuales para toda la muestra. Habilidades de autorregulación disminuidas, según autoinforme, pero capacidades superiores de función cognoscitiva, fueron vinculadas con el inicio y consumo frecuente de alcohol y marihuana, independientemente de la condición de VIH. Nuestros hallazgos sugieren que herramientas para detectar el consumo de sustancias e intervenciones de autorregulación creadas para la población general de adolescentes se deberían implementar para los JIPVIH que podrían correr mayores riesgos de sufrir consecuencias en la salud relacionadas con el consumo de sustancias.


Assuntos
Infecções por HIV , Transtornos Relacionados ao Uso de Substâncias , Adolescente , Cognição , Feminino , Infecções por HIV/epidemiologia , Humanos , Transmissão Vertical de Doenças Infecciosas , Testes Neuropsicológicos , Gravidez , Transtornos Relacionados ao Uso de Substâncias/complicações , Transtornos Relacionados ao Uso de Substâncias/epidemiologia
4.
BMC Public Health ; 21(1): 988, 2021 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-34039306

RESUMO

BACKGROUND: COVID-19 lockdowns have reduced opportunities for physical activity (PA) and encouraged more sedentary lifestyles. A concomitant of sedentariness is compromised mental health. We investigated the effects of COVID-19 lockdown on PA, sedentary behavior, and mental health across four Western nations (USA, UK, France, and Australia). METHODS: An online survey was administered in the second quarter of 2020 (N = 2541). We measured planned and unplanned dimensions of PA using the Brunel Lifestyle Physical Activity Questionnaire and mental health using the 12-item General Health Questionnaire. Steps per day were recorded only from participants who used an electronic device for this purpose, and sedentary behavior was reported in hours per day (sitting and screen time). RESULTS: In the USA and Australia samples, there was a significant decline in planned PA from pre- to during lockdown. Among young adults, Australians exhibited the lowest planned PA scores, while in middle-aged groups, the UK recorded the highest. Young adults exhibited the largest reduction in unplanned PA. Across nations, there was a reduction of ~ 2000 steps per day. Large increases in sedentary behavior emerged during lockdown, which were most acute in young adults. Lockdown was associated with a decline in mental health that was more pronounced in women. CONCLUSIONS: The findings illustrate the deleterious effects of lockdown on PA, sedentary behavior, and mental health across four Western nations. Australian young and lower middle-aged adults appeared to fare particularly badly in terms of planned PA. The reduction in steps per day is equivalent to the non-expenditure of ~ 100 kcal. Declines in mental health show how harmful lockdowns can be for women in particular.


Assuntos
COVID-19 , Saúde Mental , Austrália , Controle de Doenças Transmissíveis , Estudos Transversais , Exercício Físico , Feminino , França , Humanos , Pessoa de Meia-Idade , SARS-CoV-2 , Adulto Jovem
5.
Nutr Metab Cardiovasc Dis ; 29(8): 856-864, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31272869

RESUMO

BACKGROUND AND AIM: Increased homocysteine (Hcy) is associated with coronary artery disease (CAD). Hcy increases reactive oxygen species (ROS) via NADPH oxidases (Nox), reducing acetylcholine-mediated vasorelaxation. We aimed to determine if putative Nox2 inhibitors prevent Hcy-impaired acetylcholine-mediated vasorelaxation. METHODS AND RESULTS: New Zealand White rabbit and wild-type (C57BL/6) and Nox2-/- (NOX) mice aortic rings were mounted in organ baths. Rabbit rings were incubated with either apocynin (10 µM), gp91ds-tat (GP, 1 µM) or PhoxI2 (1 µM) and mice rings GP (1 µM) only. Some rabbit rings were incubated with 3 mM Hcy, before pre-contraction, followed by dose-response relaxation to acetylcholine (ACh; 0.01µM-10µM). In rabbit rings treated with Hcy and GP, O2‾ donor pyrogallol (1 µM) or Akt activator SC79 (1 µM) was added 5 min before ACh. Mice rings were used to compare Nox2 deletion to normal acetylcholine-mediated relaxation. In rabbits, Hcy reduced acetylcholine-mediated relaxation vs. control (p < 0.0001). Treatment + Hcy reduced relaxation compared with treatment alone (p < 0.0001). Pyrogallol and SC79 reversed the response of GP + Hcy (p = 0.0001). In mice, Nox2 deletion reduced acetylcholine-mediated vasorelaxation. Rabbit tissue analysis revealed that Hcy reduced eNOS phosphorylation at Thr495 and increased eNOS phosphorylation at Ser1177; no further alteration at Thr495 was observed with GP. In contrast, GP prevented increased phosphorylation at Ser1177. CONCLUSIONS: Apocynin, GP and PhoxI2 worsens acetylcholine-mediated vascular relaxation in rabbit aorta, which is supported by results from mouse Nox2 deletion data. These inhibitors worsen Hcy-induced vascular dysfunction, suggesting that current putative Nox2 inhibitors might not be useful in treating HHcy.


Assuntos
Acetilcolina/farmacologia , Aorta/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Homocisteína/farmacologia , NADPH Oxidase 2/antagonistas & inibidores , Vasodilatação/efeitos dos fármacos , Vasodilatadores/farmacologia , Acetofenonas/farmacologia , Animais , Aorta/enzimologia , Glicoproteínas/farmacologia , Técnicas In Vitro , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , NADPH Oxidase 2/genética , NADPH Oxidase 2/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Fosforilação , Coelhos , Serina , Treonina
6.
Mol Ecol ; 26(18): 4644-4656, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28664982

RESUMO

The composition and diversity of bacteria forming the microbiome of parasitic organisms have implications for differential host pathogenicity and host-parasite co-evolutionary interactions. The microbiome of pathogens can therefore have consequences that are relevant for managing disease prevalence and impact on affected hosts. Here, we investigate the microbiome of an invasive parasitic fly Philornis downsi, recently introduced to the Galápagos Islands, where it poses extinction threat to Darwin's finches and other land birds. Larvae infest nests of Darwin's finches and consume blood and tissue of developing nestlings, and have severe mortality impacts. Using 16s rRNA sequencing data, we characterize the bacterial microbiota associated with P. downsi adults and larvae sourced from four finch host species, inhabiting two islands and representing two ecologically distinct groups. We show that larval and adult microbiomes are dominated by the phyla Proteobacteria and Firmicutes, which significantly differ between life stages in their distributions. Additionally, bacterial community structure significantly differed between larvae retrieved from strictly insectivorous warbler finches (Certhidea olivacea) and those parasitizing hosts with broader dietary preferences (ground and tree finches, Geospiza and Camarhynchus spp., respectively). Finally, we found no spatial effects on the larval microbiome, as larvae feeding on the same host (ground finches) harboured similar microbiomes across islands. Our results suggest that the microbiome of P. downsi changes during its development, according to dietary composition or nutritional needs, and is significantly affected by host-related factors during the larval stage. Unravelling the ecological significance of bacteria for this parasite will contribute to the development of novel, effective control strategies.


Assuntos
Tentilhões/parasitologia , Microbiota , Muscidae/microbiologia , Animais , Equador , Espécies Introduzidas , Ilhas , Larva/microbiologia , Parasitos/microbiologia , RNA Ribossômico 16S/genética
7.
AIDS Behav ; 21(9): 2703-2715, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27475941

RESUMO

Among perinatally HIV-infected (PHIV) and perinatally HIV-exposed, uninfected (PHEU) youth, we evaluated the contributions of home environment, psychosocial, and demographic factors and, among PHIV only, HIV disease severity and antiretroviral treatment (ART), to cognitive functioning (CF) and behavioral functioning (BF). A structural equation modeling (SEM) approach was utilized. Exploratory factor analysis was used to reduce predictor variables to major latent factors. SEMs were developed to measure associations between the latent factors and CF and BF outcomes. Participants included 231 PHIV and 151 PHEU youth (mean age = 10.9 years) enrolled in the PHACS adolescent master protocol. Youth and caregivers completed assessments of CF, BF, psychosocial factors and HIV health. Medical data were also collected. Clusters of predictors were identified, establishing four parsimonious SEMs: child-assessed and caregiver-assessed BF in PHIV and PHEU youth. Among both groups, higher caregiver-child stress predicted worse BF. Caregiver resources and two disease severity variables, late presenter and better past HIV health, were significant predictors of CF in PHIV youth. Higher youth CF was associated with better caregiver-reported BF in both groups. Caregiver resources predicted caregiver-reported BF in PHEU youth, which was mediated via youth CF. Among PHIV youth, better past HIV health and caregiver resources mediated the effects of CF on caregiver-assessed BF. Using SEMs, we found a deleterious impact of caregiver and child stress on BF in both groups and of HIV disease factors on the CF of PHIV youth, reinforcing the importance of early comprehensive intervention to reduce risks for impairment.


Assuntos
Comportamento do Adolescente , Cuidadores/psicologia , Cognição/fisiologia , Infecções por HIV/tratamento farmacológico , Infecções por HIV/psicologia , Efeitos Tardios da Exposição Pré-Natal , Adolescente , Criança , Feminino , Humanos , Transmissão Vertical de Doenças Infecciosas , Masculino , Adesão à Medicação , Gravidez , Estudos Prospectivos , Índice de Gravidade de Doença
8.
Ecol Lett ; 19(3): 240-8, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26743135

RESUMO

Current theory presumes that natural selection on vascular traits is controlled by a trade-off between efficiency and safety of hydraulic architecture. Hence, traits linked to efficiency, such as vessel diameter, should show biogeographic patterns; but critical tests of these predictions are rare, largely owing to confounding effects of environment, tree size and phylogeny. Using wood sampled from a phylogenetically constrained set of 28 Eucalyptus species, collected from a wide gradient of aridity across Australia, we show that hydraulic architecture reflects adaptive radiation of this genus in response to variation in climate. With increasing aridity, vessel diameters narrow, their frequency increases with a distribution that becomes gradually positively skewed and sapwood density increases while the theoretical hydraulic conductivity declines. Differences in these hydraulic traits appear largely genotypic in origin rather than environmentally plastic. Data reported here reflect long-term adaptation of hydraulic architecture to water availability. Rapidly changing climates, on the other hand, present significant challenges to the ability of eucalypts to adapt their vasculature.


Assuntos
Clima , Eucalyptus/anatomia & histologia , Madeira/anatomia & histologia , Austrália
9.
Plant Cell Environ ; 39(1): 3-11, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26147129

RESUMO

Circadian resonance, whereby a plant's endogenous rhythms are tuned to match environmental cues, has been repeatedly shown to be adaptive, although the underlying mechanisms remain elusive. Concomitantly, the adaptive value of nocturnal transpiration in C3 plants remains unknown because it occurs without carbon assimilation. These seemingly unrelated processes are interconnected because circadian regulation drives temporal patterns in nocturnal stomatal conductance, with maximum values occurring immediately before dawn for many species. We grew individuals of six Eucalyptus camaldulensis genotypes in naturally lit glasshouses and measured sunset, predawn and midday leaf gas exchange and whole-plant biomass production. We tested whether sunrise anticipation by the circadian clock and subsequent increases in genotype predawn stomatal conductance led to rapid stomatal opening upon illumination, ultimately affecting genotype differences in carbon assimilation and growth. We observed faster stomatal responses to light inputs at sunrise in genotypes with higher predawn stomatal conductance. Moreover, early morning and midday stomatal conductance and carbon assimilation, leaf area and total plant biomass were all positively correlated with predawn stomatal conductance across genotypes. Our results lead to the novel hypothesis that genotypic variation in the circadian-regulated capacity to anticipate sunrise could be an important factor underlying intraspecific variation in tree growth.


Assuntos
Carbono/metabolismo , Relógios Circadianos , Eucalyptus/genética , Variação Genética , Biomassa , Dióxido de Carbono/metabolismo , Eucalyptus/fisiologia , Eucalyptus/efeitos da radiação , Genótipo , Luz , Modelos Biológicos , Folhas de Planta/genética , Folhas de Planta/fisiologia , Folhas de Planta/efeitos da radiação , Estômatos de Plantas/genética , Estômatos de Plantas/fisiologia , Estômatos de Plantas/efeitos da radiação , Transpiração Vegetal , Árvores
10.
Ecology ; 97(6): 1626, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27859219

RESUMO

We present two comprehensive data sets that describe xylem vessel diameters and related sapwood traits for species of Eucalyptus from arid and semi-arid woodlands and forests in Australia. Between 2009 and 2014, sapwood of mature trees was sampled in south-western, south-eastern and eastern Australia. One additional species was sampled from tropical north-western Australia. The first data set describes samples collected from the basal stem section (130 cm above ground) of three individuals of 31 species of which eight species were replicated at sites that differed in climatic conditions. The second data set describes vessel characteristics of three trees from each of 10 species that were sampled at 8 m below the tree apex. The sampled trees of these 10 species are also part of the first data set. In total, we report diameters (D) for over 25 100 vessels, from 494 digital images taken from 117 trees. We also report vessel frequencies, void-to-wood ratios, sapwood densities and hydraulically weighted vessel diameters (Dh). Supporting data of the first data set include tree diameter at breast height (130 cm above ground), tree height, sample locations, and summary climate data. In this data set, diameter of individual vessels ranges from 10 to over 300 µm, and vessel frequency from 360 to 9070 vessels cm-2 . Wood density ranges from 0.47 to 0.96 g cm-3 . Void-to-wood ratio ranges from 6% to 27% and Dh ranges from 46 to 236 µm. Mean annual rainfall (P) at sample sites ranges from 246 to 2274 mm and FAO56 reference evaporation (E) from 777 to 2110 mm. The aridity index (E/P) ranges from 0.15 to 2.93 (dimensionless). Tree diameters range from 9 to 90 cm and tree heights range from 6 to 70 m. D and Dh in the second data set range from 11 to 271 and 68 to 205 µm, respectively. These datasets will make a valuable contribution to future continental-scale and global-scale studies of the relationship between xylem hydraulic architecture and climate. The data sets are unique in the sense that they are phylogenetically constrained, allowing in-depth assessment of plasticity of hydraulic attributes within a single tree genus.


Assuntos
Eucalyptus/fisiologia , Xilema/fisiologia , Eucalyptus/classificação , Eucalyptus/metabolismo , Austrália Ocidental , Madeira
11.
Eur J Nutr ; 55(4): 1331-43, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26932503

RESUMO

Caffeine is a most widely consumed physiological stimulant worldwide, which is consumed via natural sources, such as coffee and tea, and now marketed sources such as energy drinks and other dietary supplements. This wide use has led to concerns regarding the safety of caffeine and its proposed beneficial role in alertness, performance and energy expenditure and side effects in the cardiovascular system. The question remains "Which dose is safe?", as the population does not appear to adhere to the strict guidelines listed on caffeine consumption. Studies in humans and animal models yield controversial results, which can be explained by population, type and dose of caffeine and low statistical power. This review will focus on comprehensive and critical review of the current literature and provide an avenue for further study.


Assuntos
Cafeína/administração & dosagem , Cafeína/efeitos adversos , Doenças Cardiovasculares/epidemiologia , Animais , Vasos Sanguíneos/efeitos dos fármacos , Vasos Sanguíneos/metabolismo , Estudos Clínicos como Assunto , Café/efeitos adversos , Café/química , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Coração/efeitos dos fármacos , Coração/fisiologia , Humanos , Metanálise como Assunto , Síndrome Metabólica/epidemiologia
12.
Glob Chang Biol ; 21(10): 3800-13, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26033432

RESUMO

Intraspecific variation in phenotypic plasticity is a critical determinant of plant species capacity to cope with climate change. A long-standing hypothesis states that greater levels of environmental variability will select for genotypes with greater phenotypic plasticity. However, few studies have examined how genotypes of woody species originating from contrasting environments respond to multiple climate change factors. Here, we investigated the main and interactive effects of elevated [CO2 ] (CE ) and elevated temperature (TE ) on growth and physiology of Coastal (warmer, less variable temperature environment) and Upland (cooler, more variable temperature environment) genotypes of an Australian woody species Telopea speciosissima. Both genotypes were positively responsive to CE (35% and 29% increase in whole-plant dry mass and leaf area, respectively), but only the Coastal genotype exhibited positive growth responses to TE . We found that the Coastal genotype exhibited greater growth response to TE (47% and 85% increase in whole-plant dry mass and leaf area, respectively) when compared with the Upland genotype (no change in dry mass or leaf area). No intraspecific variation in physiological plasticity was detected under CE or TE , and the interactive effects of CE and TE on intraspecific variation in phenotypic plasticity were also largely absent. Overall, TE was a more effective climate factor than CE in exposing genotypic variation in our woody species. Our results contradict the paradigm that genotypes from more variable climates will exhibit greater phenotypic plasticity in future climate regimes.


Assuntos
Mudança Climática , Interação Gene-Ambiente , Proteaceae/crescimento & desenvolvimento , Proteaceae/genética , Dióxido de Carbono/análise , Genótipo , New South Wales , Fenótipo , Temperatura
13.
Glob Chang Biol ; 21(1): 459-72, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25378195

RESUMO

As rapid climate warming creates a mismatch between forest trees and their home environment, the ability of trees to cope with warming depends on their capacity to physiologically adjust to higher temperatures. In widespread species, individual trees in cooler home climates are hypothesized to more successfully acclimate to warming than their counterparts in warmer climates that may approach thermal limits. We tested this prediction with a climate-shift experiment in widely distributed Eucalyptus tereticornis and E. grandis using provenances originating along a ~2500 km latitudinal transect (15.5-38.0°S) in eastern Australia. We grew 21 provenances in conditions approximating summer temperatures at seed origin and warmed temperatures (+3.5 °C) using a series of climate-controlled glasshouse bays. The effects of +3.5 °C warming strongly depended on home climate. Cool-origin provenances responded to warming through an increase in photosynthetic capacity and total leaf area, leading to enhanced growth of 20-60%. Warm-origin provenances, however, responded to warming through a reduction in photosynthetic capacity and total leaf area, leading to reduced growth of approximately 10%. These results suggest that there is predictable intraspecific variation in the capacity of trees to respond to warming; cool-origin taxa are likely to benefit from warming, while warm-origin taxa may be negatively affected.


Assuntos
Aclimatação/fisiologia , Altitude , Eucalyptus/crescimento & desenvolvimento , Aquecimento Global , Análise de Variância , Demografia , Geografia , New South Wales , Fotossíntese/fisiologia , Especificidade da Espécie
14.
Clin Exp Pharmacol Physiol ; 42(6): 648-52, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25854545

RESUMO

Cardiovascular disease remains a burden for Westernized countries. Peptide YY (PYY) raises blood pressure, yet its role has not yet been determined in diseased arteries. This study aimed at identifying PYY and eNOS in diseased blood vessels and to determine which blood vessels respond to PYY. New Zealand White rabbits were fed an atherogenic diet (n = 6, 0.5% cholesterol + 1% methionine + 5% peanut oil) and control animals fed a normal diet (n = 6) for 4 weeks. Immunohistochemistry was used to determine the localization of PYY and eNOS in the aorta. The aorta, carotid, renal, iliac, inferior mesenteric, and renal interlobular arteries were removed, mounted in organ baths, and subjected to doses of PYY (10(-9) -10(-7) mol/L) and then acetylcholine (10(-6) mol/L). Immunohistochemistry of the aorta shows PYY staining in plaque macrophages, smooth muscle cells and endothelium, and these cells co-expressed eNOS. PYY caused a minor vasoconstrictive response in all blood vessels studied but was blunted in arteries from control animals. Acetylcholine caused relaxation of PYY constricted blood vessels. This data clearly shows that PYY is present in atherosclerotic plaque and is a minor constrictor of the vasculature tree. Further studies aimed at understanding the role of PYY in cardiovascular disease are warranted.


Assuntos
Aterosclerose/metabolismo , Aterosclerose/patologia , Modelos Animais de Doenças , Endotélio Vascular/fisiologia , Peptídeo YY/fisiologia , Vasoconstrição/fisiologia , Animais , Artérias/química , Artérias/patologia , Artérias/fisiologia , Endotélio Vascular/química , Masculino , Técnicas de Cultura de Órgãos , Peptídeo YY/análise , Coelhos
15.
Clin Exp Pharmacol Physiol ; 42(8): 860-4, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25998981

RESUMO

Antioxidants have not reduced the burden of cardiovascular disease, and current evidence suggests a beneficial role of oxidative stress, via NADPH oxidase (Nox) upregulation, in endothelial function. Homocysteine thiolactone (HcyT) induces blood vessel dysfunction and this correlates with increased vascular oxidative stress. This study aimed to determine if pharmacological inhibition of Nox could impair HcyT induced blood vessel dysfunction. Abdominal aorta were excised from New Zealand White rabbits (n = 6), cut into rings and sequentially mounted in organ baths. Rings were preincubated with 0.55 µmol/L homocysteine thiolactone for 1 h, or combinations of putative Nox inhibitors (plumbagin for Nox4, gp91ds-tat for Nox2, and ML090 for Nox1), 30 min prior to the addition of HcyT, followed by a dose response curve to acetylcholine on phenylephrine preconstricted rings. Plumbagin, ML090 + gp91ds-tat and HcyT reduced responses to acetylcholine, and Plumbagin + Hcyt caused constriction to acetylcholine, which was normalised to plumbagin by ML090. Plumbagin + ML090 or plumbagin + gp91ds-tat completely impaired the effect of acetylcholine. ML090 inhibited the effect of HcyT on reduced response to acetylcholine, whereas gp91ds-tat had no effect. This study concludes that inhibition of Nox1 prevents, whereas inhibition of Nox4 worsens, acetylcholine induced blood vessel relaxation caused by HcyT, while Nox2 inhibition has no effect. However combinations of Nox inhibitors worsen acetylcholine induced blood vessel relaxation. These results suggest that there is cross-talk between Nox isoforms during physiological and pathophysiological processes.


Assuntos
Aorta Abdominal/efeitos dos fármacos , Aorta Abdominal/fisiopatologia , Inibidores Enzimáticos/farmacologia , Homocisteína/análogos & derivados , NADPH Oxidases/antagonistas & inibidores , Quinoxalinas/farmacologia , Animais , Relação Dose-Resposta a Droga , Glicoproteínas/farmacologia , Homocisteína/farmacologia , Masculino , Naftoquinonas/farmacologia , Coelhos
16.
Plant Cell Environ ; 37(7): 1598-613, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24372529

RESUMO

It has been reported that elevated temperature accelerates the time-to-mortality in plants exposed to prolonged drought, while elevated [CO(2)] acts as a mitigating factor because it can reduce stomatal conductance and thereby reduce water loss. We examined the interactive effects of elevated [CO(2)] and temperature on the inter-dependent carbon and hydraulic characteristics associated with drought-induced mortality in Eucalyptus radiata seedlings grown in two [CO(2)] (400 and 640 µL L(-1)) and two temperature (ambient and ambient +4 °C) treatments. Seedlings were exposed to two controlled drying and rewatering cycles, and then water was withheld until plants died. The extent of xylem cavitation was assessed as loss of stem hydraulic conductivity. Elevated temperature triggered more rapid mortality than ambient temperature through hydraulic failure, and was associated with larger water use, increased drought sensitivities of gas exchange traits and earlier occurrence of xylem cavitation. Elevated [CO(2)] had a negligible effect on seedling response to drought, and did not ameliorate the negative effects of elevated temperature on drought. Our findings suggest that elevated temperature and consequent higher vapour pressure deficit, but not elevated [CO(2)], may be the primary contributors to drought-induced seedling mortality under future climates.


Assuntos
Dióxido de Carbono/farmacologia , Secas , Eucalyptus/crescimento & desenvolvimento , Eucalyptus/fisiologia , Plântula/crescimento & desenvolvimento , Temperatura , Biomassa , Carboidratos/análise , Eucalyptus/efeitos dos fármacos , Eucalyptus/efeitos da radiação , Luz , Fotossíntese/efeitos dos fármacos , Desenvolvimento Vegetal/efeitos dos fármacos , Desenvolvimento Vegetal/efeitos da radiação , Caules de Planta/efeitos dos fármacos , Caules de Planta/fisiologia , Caules de Planta/efeitos da radiação , Estômatos de Plantas/efeitos dos fármacos , Estômatos de Plantas/fisiologia , Estômatos de Plantas/efeitos da radiação , Plântula/efeitos dos fármacos , Plântula/efeitos da radiação , Solo/química , Água
17.
AIDS Care ; 26(1): 107-15, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23800360

RESUMO

Poor adherence to antiretroviral therapy (ART) contributes to disease progression and emergence of drug-resistant HIV in youth with perinatally acquired HIV infection (PHIV +), necessitating reliable measures of adherence. Although electronic monitoring devices have often been considered the gold-standard assessment in HIV research, they are costly, can overestimate nonadherence and are not practical for routine care. Thus, the development of valid, easily administered self-report adherence measures is crucial for adherence monitoring. PHIV+youth aged 7-16 (n = 289) and their caregivers, enrolled in a multisite cohort study, were interviewed to assess several reported indicators of adherence. HIV-1 RNA viral load (VL) was dichotomized into >/≤ 400 copies/mL. Lower adherence was significantly associated with VL >400 copies/mL across most indicators, including ≥ 1 missed dose in past seven days [youth report: OR = 2.78 (95% CI, 1.46-5.27)]. Caregiver and combined youth/caregiver reports yielded similar results. Within-rater agreement between various adherence indicators was high for both youth and caregivers. Inter-rater agreement on adherence was moderate across most indicators. Age ≥ 13 years and living with biological mother or relative were associated with VL >400 copies/mL. Findings support the validity of caregiver and youth adherence reports and identify youth at risk of poor adherence.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Infecções por HIV/tratamento farmacológico , Adesão à Medicação , Carga Viral , Adolescente , Contagem de Linfócito CD4 , Criança , Estudos Transversais , Feminino , Infecções por HIV/sangue , Infecções por HIV/virologia , Humanos , Transmissão Vertical de Doenças Infecciosas , Masculino , Autorrelato , Fatores Socioeconômicos , Inquéritos e Questionários , Resultado do Tratamento
18.
Front Nutr ; 11: 1237698, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38863587

RESUMO

Introduction: Language skills, such as the ability to understand words (receptive language), develop during infancy and are built through interactions with the environment, including eating. Exposure to complementary foods also begins in infancy and may play a significant role in language development, especially in understanding of food-related words. However, the relationship between the complementary foods to which a child is exposed and early language acquisition has not been previously studied. We hypothesized that young children's food-related receptive language (FRL) would reflect the complementary foods to which they were frequently offered by caregivers. Methods: Caregivers of young children (4-26 months; n = 408) in the Approaching Eating through Language (APPEAL) Study in the US were surveyed via Qualtrics. FRL was assessed by caregiver-report via a modified MacArthur-Bates Communicative Development Inventory. Complementary foods offered (CFO) by caregivers were assessed using a modified Food Frequency Questionnaire. Latent Class Analysis (LCA) was implemented to identify, 1) groupings of foods frequently offered (>1x/week) and 2) groupings of food-related words understood by the young children. Results: A 5-class best fit LCA model was identified for CFO (-log likelihood [-llik]=-8727) and for FRL (-llik=-5476). Cross-classification of the CFO and FRL derived classes revealed that children with higher exposure to complementary foods were perceived by caregivers to be most likely to also understand a greater number of food-related words (Probability=0.48). As expected, children having been offered a greater number of complementary foods and who understood a greater number of food-related words were older, compared to those with less complementary food exposure and food-related language acquisition (p < 0.001). Discussion: These findings support the potential role of introduction to complementary foods in development of food-related language.

19.
Clin Infect Dis ; 56(2): 283-90, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23139252

RESUMO

BACKGROUND: Factors associated with initiation of sexual activity among perinatally human immunodeficiency virus (HIV)-infected (PHIV(+)) youth, and the attendant potential for sexual transmission of antiretroviral (ARV) drug-resistant HIV, remain poorly understood. METHODS: We conducted cross-sectional and longitudinal analyses of PHIV(+) youth aged 10-18 years (mean, 13.5 years) enrolled in the US-based Pediatric HIV/AIDS Cohort Study between 2007 and 2009. Audio computer-assisted self-interviews (ACASI) were used to collect sexual behavior information. RESULTS: Twenty-eight percent (95% confidence interval [CI], 23%-33%) (92/330) of PHIV(+) youth reported sexual intercourse (SI) (median initiation age, 14 years). Sixty-two percent (57/92) of sexually active youth reported unprotected SI. Among youth who did not report history of SI at baseline, ARV nonadherence was associated with sexual initiation during follow-up (adjusted hazard ratio, 2.87; 95% CI, 1.32-6.25). Youth living with a relative other than their biological mother had higher odds of engaging in unprotected SI than those living with a nonrelative. Thirty-three percent of youth disclosed their HIV status to their first sexual partner. Thirty-nine of 92 (42%) sexually active youth had HIV RNA ≥5000 copies/mL after sexual initiation. Viral drug resistance testing, available for 37 of these 39 youth, identified resistance to nucleoside reverse transcriptase inhibitors in 62%, nonnucleoside reverse transcriptase inhibitors in 57%, protease inhibitors in 38%, and all 3 ARV classes in 22%. CONCLUSIONS: As PHIV(+) youth become sexually active, many engage in behaviors that place their partners at risk for HIV infection, including infection with drug-resistant virus. Effective interventions to facilitate youth adherence, safe sex practices, and disclosure are urgently needed.


Assuntos
Comportamento Perigoso , Infecções por HIV/transmissão , Comportamento Sexual , Adolescente , Fármacos Anti-HIV/uso terapêutico , Criança , Estudos Transversais , Farmacorresistência Viral , Feminino , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Humanos , Estudos Longitudinais , Masculino , Fatores de Risco , Estados Unidos/epidemiologia , Sexo sem Proteção
20.
J Int AIDS Soc ; 26 Suppl 4: e26167, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37909234

RESUMO

INTRODUCTION: Decisions to disclose HIV serostatus may be complicated by internalised HIV stigma. We evaluated the association of internalised HIV stigma in biological mothers living with HIV with disclosure of their serostatus to their children perinatally HIV-exposed but uninfected (CHEU). METHODS: Mothers and their CHEU were enrolled in the United States (U.S.)-based Surveillance Monitoring for Antiretroviral Therapy (ART) Toxicities (SMARTT) study of the Pediatric HIV/AIDS Cohort Study (PHACS), a longitudinal study of outcomes related to in utero exposure to HIV and ART among CHEU. Mothers completing at least one stigma and disclosure assessment starting at the child's age 11-, 13-, 15- and/or 17-year study visits between 16 August 2016 and 1 October 2020 were eligible. Stigma was measured with the 28-item Internalised HIV Stigma Scale (IHSS). Mean stigma scores were linearly transformed to a range of 0-100, with higher scores indicating greater levels of stigma. At each visit, mothers were asked if their child was aware of their HIV diagnosis and at what age the child became aware. The Kaplan-Meier estimator evaluated the cumulative probability of disclosure at each child age. Logistic regression models with generalised estimating equations to account for repeated measures were fit to examine the association between stigma and disclosure, controlling for relevant socio-demographic variables. RESULTS: Included were 438 mothers of 576 children (mean age 41.5 years, 60% U.S.-born, 60% Black/African American and 37% with household income ≤$10,000). The prevalence of disclosure across all visits was 29%. Mothers whose children were aware versus not aware of their serostatus reported lower mean IHSS scores (38.2 vs. 45.6, respectively). The cumulative proportion of disclosure by age 11 was 18.4% (95% CI: 15.5%, 21.8%) and 41% by age 17 (95% CI: 35.2%, 47.4%). At all child ages, disclosure was higher among children of U.S.-born versus non-U.S.-born mothers. After adjusting for age, marital status and years since HIV diagnosis, higher IHSS scores were associated with lower odds of disclosure (OR = 0.985, 95% CI: 0.975, 0.995). CONCLUSIONS: Providing support to women as they make decisions about serostatus disclosure to their children may entail addressing internalised HIV stigma and consideration of community-level factors, particularly for non-U.S.-born mothers.


Assuntos
Síndrome da Imunodeficiência Adquirida , Infecções por HIV , Criança , Humanos , Feminino , Estados Unidos/epidemiologia , Adulto , Adolescente , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Revelação , Estudos Prospectivos , Estudos de Coortes , Estudos Longitudinais , Mães
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA