25 research outputs found
The Role of Supplemental Oxygen and JAK/STAT Signaling in Intravitreous Neovascularization in a ROP Rat Model
To investigate whether oxygen stresses experienced in retinopathy of prematurity (ROP) would trigger signaling through reactive oxygen species (ROS) and the Janus kinase-signal transducer and activator of transcription (JAK/STAT) pathways to lead to intravitreous neovascularization (IVNV) in an oxygen-induced retinopathy (OIR) rat model
Reduction in endothelial tip cell filopodia corresponds to reduced intravitreous but not intraretinal vascularization in a model of ROP
To determine the effect of a vascular endothelial growth factor receptor 2 tyrosine kinase (VEGFR2) inhibitor on intravitreous neovascularization (IVNV), endothelial tip cell filopodia, and intraretinal vascularization in a rat model of retinopathy of prematurity (ROP)
Activated NAD(P)H Oxidase from Supplemental Oxygen Induces Neovascularization Independent of VEGF in Retinopathy of Prematurity Model
To study NAD(P)H oxidase-dependent outcomes after oxygen stresses that are similar to those experienced by preterm infants today using a rat model of retinopathy of prematurity
VEGF-Mediated STAT3 Activation Inhibits Retinal Vascularization by Down-Regulating Local Erythropoietin Expression
Avascular, hypoxic retina has been postulated to be a source of angiogenic factors that cause aberrant angiogenesis and intravitreal neovascularization (IVNV) in retinopathy of prematurity. Vascular endothelial growth factor (VEGF) is an important factor involved. However, VEGF is also required for normal retinal vascular development, which raises concerns about inhibiting its activity to treat IVNV in retinopathy of prematurity. Therefore, understanding the effects that VEGF has on other factors in the development of avascular retina is important to prevent aberrant angiogenesis and IVNV. Here, we show that STAT3 was activated by increased retinal VEGF in the rat 50/10 oxygen-induced retinopathy model. Phospho-STAT3 colocalized with glutamine synthetase-labeled Müller cells. Inhibition of STAT3 reduced avascular retina and increased retinal erythropoietin (Epo) expression. Epo administered exogenously also reduced avascular retina in the model. In an in vitro study, hypoxia-induced VEGF inhibited Epo gene expression by STAT3 activation in rat Müller cells. The mechanism by which activated STAT3 regulated Epo was by inhibition of Epo promoter activity. Together, these findings show that increased retinal VEGF contributes to avascular retina by regulating retinal Epo expression through Janus kinase/STAT signaling. Our results suggest that rescuing Epo expression in the retina before the development of IVNV may promote normal developmental angiogenesis and, therefore, reduce the stimulus for later pathologic IVNV
Neutralizing VEGF Decreases Tortuosity and Alters Endothelial Cell Division Orientation in Arterioles and Veins in a Rat Model of ROP: Relevance to Plus Disease
To study the effects of vascular endothelial growth factor (VEGF) on endothelial nitric oxide synthetase (eNOS) and retinal vascular tortuosity and cleavage planes in a rat model of retinopathy of prematurity (ROP)
Parental Guidance Suggested: Engaging Parents as Partners in Research Studies of Genomic Screening for a Pediatric Population
Recent advances in genomic sequencing and genomic medicine are reshaping the landscape of clinical care. As a screening modality, genetic sequencing has the potential to dramatically expand the clinical utility of newborn screening (NBS), though significant barriers remain regarding ethical, legal, and social implications (ELSI) and technical and evidentiary challenges. Stakeholder-informed implementation research is poised to grapple with many of these barriers, and parents are crucial stakeholders in this process. We describe the formation and activities of a Community Research Board (CRB) composed of parents with diverse backgrounds assembled to participate in an ongoing research partnership with genomic and public health researchers at the University of North Carolina. The mission of the CRB is to provide insight into parental perspectives regarding the prospect of adding genomic sequencing to NBS and collaboratively develop strategies to ensure its equitable uptake. We describe how these contributions can improve the accessibility of research and recruitment methods and promote trust and inclusivity within diverse communities to maximize the societal benefit of population genomic screening in healthy children
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Ancestral origin of ApoE ε4 Alzheimer disease risk in Puerto Rican and African American populations
The ApoE ε4 allele is the most significant genetic risk factor for late-onset Alzheimer disease. The risk conferred by ε4, however, differs across populations, with populations of African ancestry showing lower ε4 risk compared to those of European or Asian ancestry. The cause of this heterogeneity in risk effect is currently unknown; it may be due to environmental or cultural factors correlated with ancestry, or it may be due to genetic variation local to the ApoE region that differs among populations. Exploring these hypotheses may lead to novel, population-specific therapeutics and risk predictions. To test these hypotheses, we analyzed ApoE genotypes and genome-wide array data in individuals from African American and Puerto Rican populations. A total of 1,766 African American and 220 Puerto Rican individuals with late-onset Alzheimer disease, and 3,730 African American and 169 Puerto Rican cognitively healthy individuals (> 65 years) participated in the study. We first assessed average ancestry across the genome (“global” ancestry) and then tested it for interaction with ApoE genotypes. Next, we assessed the ancestral background of ApoE alleles (“local” ancestry) and tested if ancestry local to ApoE influenced Alzheimer disease risk while controlling for global ancestry. Measures of global ancestry showed no interaction with ApoE risk (Puerto Rican: p-value = 0.49; African American: p-value = 0.65). Conversely, ancestry local to the ApoE region showed an interaction with the ApoE ε4 allele in both populations (Puerto Rican: p-value = 0.019; African American: p-value = 0.005). ApoE ε4 alleles on an African background conferred a lower risk than those with a European ancestral background, regardless of population (Puerto Rican: OR = 1.26 on African background, OR = 4.49 on European; African American: OR = 2.34 on African background, OR = 3.05 on European background). Factors contributing to the lower risk effect in the ApoE gene ε4 allele are likely due to ancestry-specific genetic factors near ApoE rather than non-genetic ethnic, cultural, and environmental factors
Dementia Caregiver Experiences and Recommendations for Using the Behavioral and Environmental Sensing and Intervention System at Home: Usability and Acceptability Study
BackgroundCaregiver burden associated with dementia-related agitation is one of the most common reasons for a community-dwelling person living with dementia to transition to a care facility. The Behavioral and Environmental Sensing and Intervention (BESI) for the Dementia Caregiver Empowerment system uses sensing technology, smartwatches, tablets, and data analytics to detect and predict agitation in persons living with dementia and to provide just-in-time notifications and dyad-specific intervention recommendations to caregivers. The BESI system has shown that there is a valid relationship between dementia-related agitation and environmental factors and that caregivers prefer a home-based monitoring system.
ObjectiveThe aim of this study is to obtain input from caregivers of persons living with dementia on the value, usability, and acceptability of the BESI system in the home setting and obtain their insights and recommendations for the next stage of system development.
MethodsA descriptive qualitative design with thematic analysis was used to analyze 10 semistructured interviews with caregivers. The interviews comprised 16 questions, with an 80% (128/160) response rate.
ResultsPostdeployment caregiver feedback about the BESI system and the overall experience were generally positive. Caregivers acknowledged the acceptability of the system by noting the ease of use and saw the system as a fit for them. Functionality issues such as timeliness in agitation notification and simplicity in the selection of agitation descriptors on the tablet interface were identified, and caregivers indicated a desire for more word options to describe agitation behaviors. Agitation intervention suggestions were well received by the caregivers, and the resulting decrease in the number and severity of agitation events helped confirm that the BESI system has good value and acceptability. Thematic analysis suggested several subjective experiences and yielded the themes of usefulness and helpfulness.
ConclusionsThis study determined preferences for assessing caregiver strain and burden, explored caregiver acceptance of the technology system (in-home sensors, actigraph or smart watch technology, and tablet devices), discerned caregiver insights on the burden and stress of caring for persons living with dementia experiencing agitation in dementia, and solicited caregiver input and recommendations for system changes. The themes of usefulness and helpfulness support the use of caregiver knowledge and experience to inform further development of the technology
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Leveraging African American family connectors for Alzheimer's disease genomic studies
The underrepresentation of African Americans (AAs) in Alzheimer's disease (AD) research may limit potential benefits from translational applications. This article describes an approach to recruit AA families into an AD genomic study and characteristics of seeds (family connectors) used to overcome recruitment barriers of AA families into AD research.
A four-step outreach and snowball sampling approach relying on family connectors was used to recruit AA families. Descriptive statistics of a profile survey were gathered to understand the demographic and health characteristics of family connectors.
Twenty-five AA families (117 participants) were enrolled in the study via family connectors. Most family connectors self-identified as female (88%), were 60 years of age or older (76%), and attained post-secondary education (77%).
Community-engaged strategies were essential to recruit AA families. Relationships between study coordinators and family connectors build trust early in the research process among AA families.
Community events were most effective for recruiting African American families. Family connectors were primarily female, in good health, and highly educated. Systematic efforts by researchers are necessary to "sell" a study to participants