We investigated the association between anticipatory stress, also known as racism-related vigilance, and hypertension prevalence in Black, Hispanic, and White adults.
We used data from the Chicago Community Adult Health Study, a population-representative sample of adults (n=3105) surveyed in 2001 to 2003, to regress hypertension prevalence on the interaction between race/ethnicity and vigilance in logit models.
Blacks reported the highest vigilance levels. For Blacks, each unit increase in vigilance (range=0–12) was associated with a 4% increase in the odds of hypertension (odds ratio [OR]=1.04; 95% confidence interval [CI]=1.00, 1.09). Hispanics showed a similar but nonsignificant association (OR=1.05; 95% CI=0.99, 1.12), and Whites showed no association (OR=0.95; 95% CI=0.87, 1.03).
Vigilance may represent an important and unique source of chronic stress that contributes to the well-documented higher prevalence of hypertension among Blacks than Whites; it is a possible contributor to hypertension among Hispanics but not Whites.
To examine whether allostatic load (AL), a measure of cumulative physiologic dysregulation across biological systems, was associated with sleep apnea, insomnia, and other sleep disturbances.
Data from the National Health and Nutrition Examination Survey 2005-2008 were used. AL was measured using nine biomarkers representing cardiovascular, inflammatory, and metabolic system functioning. A total of 7,726 US adults aged 18 years and older were included in this study.
The prevalence of high AL (AL score ≥3) was the highest among African Americans (25.2%), followed by Hispanic Americans (21.0%), Whites (18.8%), and other racial/ethnic group (16.5%). After adjustment for sociodemographic and lifestyle factors and depression status, high AL was significantly associated with sleep apnea (odds ratio (OR)=1.49, 95% confidence interval (CI): 1.14-1.95), snoring (1.65, 95% CI: 1.41-1.93), snorting/stop breathing (OR=1.62, 95% CI: 1.25-2.10), prolonged sleep latency (OR=1.33, 95% CI: 1.13-1.56), short sleep duration (<6 hours) (OR=1.29, 95% CI: 1.04-1.61), and diagnosed sleep disorder (OR=1.85, 95% CI: 1.53-2.24). There was no clear evidence that observed associations varied by sociodemographic characteristics or depression status.
This study suggests significant associations of high AL with sleep apnea, sleep apnea symptoms, insomnia component, short sleep duration, and diagnosed sleep disorder among US adults.
adult; allostatic load; insomnia; national survey; short sleep duration; sleep apnea; sleep disorder; sleep disturbance
Davunetide (AL-108, NAP) is an eightamino acid peptide that promotes microtubule stability and decreases tau phosphorylation in pre-clinical studies. Since PSP is tightly linked to tau pathology, davunetide could be an effective treatment for PSP.The goals of this study were to evaluate the efficacy and safety of davunetide in PSP.
A phase 2/3 double-blind, parallel group, clinical trial of davunetide 30 mg or placebo (randomized 1:1) administered intranasally twice daily for 52 weeks was conducted at 48centers. Participants met modifiedNNIPPS criteria for possible or probable PSP. Co-primary endpointswere the change from baseline in PSP Rating Scale (PSPRS) and Schwab and England ADL(SEADL) scale at up to 52 weeks. Data from all individuals who received at least one dose of medication and had a post-baseline efficacy assessment were compared using a rank-based method.Secondary outcomes included the Clinical Global Impression of Change (CGIC) and the change in regional brain volumeon MRI. Clinicaltrials.gov identifier: NCT01110720.
360 participants were screened, 313 were randomized and 243 (77.6%) completed the study. There were no group differences in PSPRS (mean difference: 0.49 [95% CI: −1.5, 2.5], p = 0.72) or SEADL (1% [−2, 4%], p = 0.76) change from baseline (CFB) and mean 52 week CFB PSPRS scores were similar between the davunetide (11.3 [9.8,12.8]) and placebo groups (10.9 [9.1, 13.0]). There wereno differences in any of the secondary or exploratory endpoints. There were 11deaths in the davunetide group and tenin the placebo group. There were more nasal adverse events in the davunetide group.
Davunetide is well tolerated but is not an effective treatment for PSP. Clinical trials of disease modifying therapy are feasible in PSP and should be pursued with other promising tau-directed therapies.
Although Black-white differences in depression are well documented, vigilant coping style as an explanation for the observed inequalities in depression is less understood. Using data from 718 adults in the Exploring Health Disparities in Integrated Communities (EHDIC) Study, we estimated logistic regression models to examine the cross sectional relationship between race, vigilant coping style, and depression. After controlling for demographic variables, white adults were more likely to report depression than Black adults. Moreover, when accounting for coping style, the Black-white difference in depression widened. This association persisted even with the addition of the covariates. While high rates of depression among whites compared with Blacks are well documented, the degree of the differences appears to be greater than previously reported once vigilance is accounted for. This finding suggests that if it were not for the high prevalence of vigilant coping in blacks, the well-documented black advantage regarding depression compared to whites would likely be even greater.
race disparities; depression; anticipatory coping; coping; stress
To develop a conceptual framework for investigating the role of racial/ethnic residential segregation on health care disparities.
Data Sources and Settings
Review of the MEDLINE and the Web of Science databases for articles published from 1998 to 2011.
The extant research was evaluated to describe mechanisms that shape health care access, utilization, and quality of preventive, diagnostic, therapeutic, and end-of-life services across the life course.
The framework describes the influence of racial/ethnic segregation operating through neighborhood-, health care system-, provider-, and individual-level factors. Conceptual and methodological issues arising from limitations of the research and complex relationships between various levels were identified.
Increasing evidence indicates that racial/ethnic residential segregation is a key factor driving place-based health care inequalities. Closer attention to address research gaps has implications for advancing and strengthening the literature to better inform effective interventions and policy-based solutions.
Racial/ethnic residential segregation; health care disparities; health care access; social determinants of health
To illustrate the complex patterns that emerge when race/ethnicity, socioeconomic status (SES), and gender are considered simultaneously in health care disparities research and to outline the needed research to understand them by using disparities in lung cancer risks, treatment, and outcomes as an example.
SES, gender, and race/ethnicity are social categories that are robust predictors of variations in health and health services utilization. These are usually considered separately, but intersectionality theory indicates that the impact of each depends on the others. Each reflects historically and culturally contingent variations in social, economic, and political status. Distinct patterns of risk and resilience emerge at the intersections of multiple social categories and shape the experience of health, health care access, utilization, quality, and outcomes where these categories intersect. Intersectional approaches call for greater attention to understand social processes at multiple levels of society and require the collection of relevant data and utilization of appropriate analytic approaches to understand how multiple risk factors and resources combine to affect the distribution of disease and its management.
Understanding how race/ethnicity, gender, and SES are interactive, interdependent, and social identities can provide new knowledge to enhance our efforts to effectively address health disparities.
Health care disparities; smoking; lung cancer; race/ethnicity; socioeconomic status; gender
Here we demonstrate a new imaging system that addresses several major problems limiting the clinical utility of conventional adaptive optics scanning light ophthalmoscopy (AOSLO), including its small field of view (FOV), reliance on patient fixation for targeting imaging, and substantial post-processing time. We previously showed an efficient image based eye tracking method for real-time optical stabilization and image registration in AOSLO. However, in patients with poor fixation, eye motion causes the FOV to drift substantially, causing this approach to fail. We solve that problem here by tracking eye motion at multiple spatial scales simultaneously by optically and electronically integrating a wide FOV SLO (WFSLO) with an AOSLO. This multi-scale approach, implemented with fast tip/tilt mirrors, has a large stabilization range of ± 5.6°. Our method consists of three stages implemented in parallel: 1) coarse optical stabilization driven by a WFSLO image, 2) fine optical stabilization driven by an AOSLO image, and 3) sub-pixel digital registration of the AOSLO image. We evaluated system performance in normal eyes and diseased eyes with poor fixation. Residual image motion with incremental compensation after each stage was: 1) ~2–3 arc minutes, (arcmin) 2) ~0.5–0.8 arcmin and, 3) ~0.05–0.07 arcmin, for normal eyes. Performance in eyes with poor fixation was: 1) ~3–5 arcmin, 2) ~0.7–1.1 arcmin and 3) ~0.07–0.14 arcmin. We demonstrate that this system is capable of reducing image motion by a factor of ~400, on average. This new optical design provides additional benefits for clinical imaging, including a steering subsystem for AOSLO that can be guided by the WFSLO to target specific regions of interest such as retinal pathology and real-time averaging of registered images to eliminate image post-processing.
(110.1080) Active or adaptive optics; (120.3890) Medical optics instrumentation; (170.3880) Medical and biological imaging; (170.4470) Ophthalmology; (330.2210) Vision - eye movements
Retinal densitometry provides objective information about retinal function. But, a number of factors, including retinal reflectance changes that are not directly related to photopigment depletion, complicate its interpretation. We explore these factors and suggest a method to minimize their impact.
An adaptive optics scanning light ophthalmoscope (AOSLO) was used to measure changes in photoreceptor reflectance in monkeys before and after photopigment bleaching with 514-nm light. Reflectance measurements at 514 nm and 794 nm were recorded simultaneously. Several methods of normalization to extract the apparent optical density of the photopigment were compared.
We identified stimulus-related fluctuations in 794-nm reflectance that are not associated with photopigment absorptance and occur in both rods and cones. These changes had a magnitude approaching those associated directly with pigment depletion, precluding the use of infrared reflectance for normalization. We used a spatial normalization method instead, which avoided the fluctuations in the near infrared, as well as a confocal AOSLO designed to minimize light from layers other than the receptors. However, these methods produced a surprisingly low estimate of the apparent rhodopsin density (animal 1: 0.073 ± 0.006, animal 2: 0.032 ± 0.003).
These results confirm earlier observations that changes in photopigment absorption are not the only source of retinal reflectance change during dark adaptation. It appears that the stray light that has historically reduced the apparent density of cone photopigment in retinal densitometry arises predominantly from layers near the photoreceptors themselves. Despite these complications, this method provides a valuable, objective measure of retinal function.
Retinal densitometry has the potential to provide objective information about the function of the retina. However, a number of factors complicate the interpretation of retinal reflectance. We have discovered additional sources of reflectance change and have defined a method to minimize their impact.
dark adaptation; densitometry; intrinsic signals; adaptive optics; rhodopsin regeneration
Advances in retinal imaging have led to the discovery of long-lasting retinal changes caused by light exposures below published safety limits, including disruption of the RPE. To investigate the functional consequences of RPE disruption, we combined adaptive optics ophthalmoscopy with retinal densitometry.
A modified adaptive optics scanning light ophthalmoscope (AOSLO) measured the apparent density and regeneration rate of rhodopsin in two macaques before and after four different 568-nm retinal radiant exposures (RREs; 400–3200 J/cm2). Optical coherence tomography (OCT) was used to measure the optical path length through the photoreceptor outer segments before and after RPE disruption.
All tested RREs caused visible RPE disruption. Apparent rhodopsin density was significantly reduced following 1600 (P = 0.01) and 3200 J/cm2 (P = 0.007) exposures. No significant change in apparent density was observed in response to 800 J/cm2. Surprisingly, exposure to 400 J/cm2 showed a significant increase in apparent density (P = 0.047). Rhodopsin recovery rate was not significantly affected by these RREs. Optical coherence tomography measurements showed a significant decrease in the optical path length through the photoreceptor outer segments for RREs above 800 J/cm2 (P < 0.001).
At higher RREs, optical path length through the outer segments was reduced. However, the rate of photopigment regeneration was unchanged. While some ambiguity remains as to the correlation between measured reflectivity and absolute rhodopsin density; at the lowest RREs, RPE disruption appears not to be accompanied by a loss of apparent rhodopsin density, which would have been indicative of functional loss.
Advances in retinal imaging have led to the discovery of disruption of the RPE caused by light exposures below published safety limits. To investigate the functional consequences of this RPE disruption, we combined adaptive optics ophthalmoscopy with retinal densitometry.
light damage; retinal pigment epithelium; rhodopsin regeneration; densitometry; dark adaptation
Black/African-American women are more likely to get breast cancer at a
young age and/or be diagnosed at a late disease stage, pointing to a greater
need to promote mammography for Black women at earlier ages than are currently
recommended. This study explores how perceived neighborhood social capital, that
is, perceptions of how tight-knit a neighborhood is and what power that confers
to neighborhood members, relates to use of mammography for Black women in
Philadelphia. Living in a community with tight social ties (social cohesion) or
that have a collective motivation for community change (collective efficacy) may
increase the likelihood that an individual woman in that community will hear
health messages from other community members and neighbors (diffusion of
information) and will have access to health-related resources that allow them to
engage in healthy behaviors. No prior studies have explored the role of social
capital in decisions for mammography use. Using multilevel logistic regression,
we analyzed self-report of mammography in the past year for 2,586, Black women
over age 40 across 381 Philadelphia, Pennsylvania USA census tracts. Our study
included individual demographic and aggregates of individual-level social
capital data from the Public Health Management Corporation's 2004, 2006, and
2008 Community Health Database waves, and 2000 US Census sociodemographic
characteristics. Individual perceptions that a Black woman's neighborhood had
high social capital, specifically collective efficacy, had a positive and
statistically significant association with mammography use (OR=1.40, CI: 1.05,
1.85). Our findings suggest that an individual woman's perception of greater
neighborhood social capital may be related to increased mammography use.
Although this analysis could not determine the direction of causality, it
suggests that social capital may play a role in cancer preventive screening for
African-American women in Philadelphia, which warrants further study.
USA; cancer; screening; Black/African-American; social capital; community participation; mammography
Despite South Africa’s history of violent political conflict, and the link between stressful experiences and smoking in the literature, no public health study has examined South Africans’ experiences of human rights violations and smoking. Using data from participants in the nationally representative cross-sectional South Africa Stress and Health study (SASH), this analysis examined the association between respondent smoking status and both human rights violations experienced by the respondent and violations experienced by the respondents’ close friends and family members. SAS-Callable SUDAAN was used to construct separate log-binomial models by political affiliation during apartheid (government or liberation supporters). In comparison to those who reported no violations, in adjusted analyses, government supporters who reported violations of themselves but not others (RR=1.76, 95%CI: 1.25–2.46) had a significantly higher smoking prevalence. In comparison to liberation supporters who reported no violations, those who reported violations of self only (RR=1.56, 95%CI: 1.07–2.29), close others only (RR=1.97, 95%CI: 1.12–3.47), or violations of self and close others due to close others’ political beliefs and the respondent’s political beliefs (RR=2.86, 95%CI: 1.70–4.82) had a significantly higher prevalence of smoking. The results of this analysis suggest that a relationship may exist between human rights violations and smoking among South Africa adults. Future research should use longitudinal data to assess causality, test the generalizability of these findings, and consider how to apply these findings to smoking cessation interventions.
South Africa; human rights; trauma; smoking; cigarettes
Insertion of light-gated channels into inner retina neurons restores neural light responses, light evoked potentials, visual optomotor responses and visually-guided maze behavior in mice blinded by retinal degeneration. This method of vision restoration bypasses damaged outer retina, providing stimulation directly to retinal ganglion cells in inner retina. The approach is similar to that of electronic visual protheses, but may offer some advantages, such as avoidance of complex surgery and direct targeting of many thousands of neurons. However, the promise of this technique for restoring human vision remains uncertain because rodent animal models, in which it has been largely developed, are not ideal for evaluating visual perception. On the other hand, psychophysical vision studies in macaque can be used to evaluate different approaches to vision restoration in humans. Furthermore, it has not been possible to test vision restoration in macaques, the optimal model for human-like vision, because there has been no macaque model of outer retina degeneration. In this study, we describe development of a macaque model of photoreceptor degeneration that can in future studies be used to test restoration of perception by visual prostheses. Our results show that perceptual deficits caused by focal light damage are restricted to locations at which photoreceptors are damaged, that optical coherence tomography (OCT) can be used to track such lesions, and that adaptive optics retinal imaging, which we recently used for in vivo recording of ganglion cell function, can be used in future studies to examine these lesions.
retina; light damage; ganglion cells; macaque; adaptive optics
Socioeconomic status is associated with health disparities, but underlying psychosocial mechanisms have not been fully identified. Dispositional optimism may be a psychosocial process linking socioeconomic status with health. We hypothesized that lower optimism would be associated with greater social disadvantage and poorer social mobility. We also investigated whether life satisfaction and positive affect showed similar patterns. Participants from the Midlife in the United States study self-reported their optimism, satisfaction, positive affect, and socioeconomic status (gender, race/ethnicity, education, occupational class and prestige, income). Social disparities in optimism were evident. Optimistic individuals tended to be white and highly educated, had an educated parent, belonged to higher occupational classes with more prestige, and had higher incomes. Findings were generally similar for satisfaction, but not positive affect. Greater optimism and satisfaction were also associated with educational achievement across generations. Optimism and life satisfaction are consistently linked with socioeconomic advantage and may be one conduit by which social disparities influence health.
Researchers have long speculated that exposure to discrimination may increase cardiovascular disease (CVD) risk but compared to other psychosocial risk factors, large-scale epidemiologic and community based studies examining associations between reports of discrimination and CVD risk have only emerged fairly recently. This review summarizes findings from studies of self-reported experiences of discrimination and CVD risk published between 2011–2013. We document the innovative advances in recent work, the notable heterogeneity in these studies, and the considerable need for additional work with objective clinical endpoints other than blood pressure. Implications for the study of racial disparities in CVD and clinical practice are also discussed.
Racial; Ethnic; Discrimination; Cardiovascular disease
Two-photon excitation microscopy (TPM) can image retinal molecular processes in vivo. Intrinsically fluorescent retinyl esters in sub-cellular structures called retinosomes are an integral part of the visual chromophore regeneration pathway. Fluorescent condensation products of all–trans–retinal accumulate in the eye with age and are also associated with age-related macular degeneration (AMD). Here we report repetitive, dynamic imaging of these compounds in live mice, through the pupil of the eye. Leveraging advanced adaptive optics we developed a data acquisition algorithm that permitted the identification of retinosomes and condensation products in the retinal pigment epithelium (RPE) by their characteristic localization, spectral properties, and absence in genetically modified or drug-treated mice. This imaging approach has the potential to detect early molecular changes in retinoid metabolism that trigger light and AMD-induced retinal defects and to assess the effectiveness of treatments for these conditions.
Noninvasive two-photon imaging of a living mammalian eye can reveal details of molecular processes in the retina and RPE. Retinyl esters and all-trans-retinal condensation products are two types of retinoid fluorophores present in these tissues. We measured the content of these two types of retinoids in monkey and human eyes to validate the potential of two-photon imaging for monitoring retinoid changes in human eyes.
Two-photon microscopy (TPM) was used to visualize excised retina from monkey eyes. Retinoid composition and content in human and monkey eyes were quantified by HPLC and mass spectrometry (MS).
Clear images of inner and outer segments of rods and cones were obtained in primate eyes at different eccentricities. Fluorescence spectra from outer segments revealed a maximum emission at 480 nm indicative of retinols and their esters. In cynomolgus monkey and human retinal extracts, retinyl esters existed predominantly in the 11-cis configuration along with notable levels of 11-cis-retinol, a characteristic of cone-enriched retinas. Average amounts of di-retinoid-pyridinium-ethanolamine (A2E) in primate and human eyes were 160 and 225 pmol/eye, respectively.
These data show that human retina contains sufficient amounts of retinoids for two-photon excitation imaging. Greater amounts of 11-cis-retinyl esters relative to rodent retinas contribute to the fluorescence signal from both monkey and human eyes. These observations indicate that TPM imaging found effective in mice could detect early age- and disease-related changes in human retina.
Two-photon excitation tracks early changes in primate retina.
rod photoreceptors; cone photoreceptors; retinoid cycle; two-photon microscopy; primate retina
Large, pervasive and persistent racial inequalities exist in the onset, course and outcomes of illness. A comprehensive understanding of the patterning of racial disparities indicates that racism in both its institutional and individual forms remains an important determinant. Despite our extensive knowledge of the magnitude, trends and determinants of these social inequalities in health, there is still much that we need to learn about the forces that drive them. There is also an even greater opportunity to build the science base that would identify how to trigger the conditions that would facilitate needed societal change, and identify the optimal interventions that would confront and dismantle the societal conditions that create and sustain health inequalities.
Mental and physical disorders are associated with total disability, but their effects on days with partial disability (i.e. the ability to perform some, but not full-role, functioning in daily life) are not well understood.
To estimate individual (i.e. the consequences for an individual with a disorder) and societal effects (i.e. the avoidable partial disability in the society due to disorders) of mental and physical disorders on days with partial disability around the world.
Respondents from 26 nationally representative samples (n = 61 259, age 18+) were interviewed regarding mental and physical disorders, and day-to-day functioning. The Composite International Diagnostic Interview, version 3.0 (CIDI 3.0) was used to assess mental disorders; partial disability (expressed in full day equivalents) was assessed with the World Health Organization Disability Assessment Schedule in the CIDI 3.0.
Respondents with disorders reported about 1.58 additional disability days per month compared with respondents without disorders. At the individual level, mental disorders (especially post-traumatic stress disorder, depression and bipolar disorder) yielded a higher number of days with disability than physical disorders. At the societal level, the population attributable risk proportion due to physical and mental disorders was 49% and 15% respectively.
Mental and physical disorders have a considerable impact on partial disability, at both the individual and at the societal level. Physical disorders yielded higher effects on partial disability than mental disorders.
Asian Americans experience significant underuse of mental health treatment. Religious clergy and spiritual advisors play a critical role in delivering mental health care in the United States. Limited knowledge exists about their use among Asian Americans.
We describe mental health service use from a religious/spiritual advisor among Asian Americans.
We analyzed data from 2095 respondents in the 2002–2003 National Latino and Asian American Study.
Lifetime and 12-month prevalence of mental health service use from a religious/spiritual advisor (5.5% and 1% overall, respectively) was generally higher among U.S.-born Asians and those with a 12-month mental disorder (23.6% and 7.5%, respectively). Religious/spiritual advisors were seen by 35% of treatment-seeking Asian Americans with a lifetime mental disorder. They were seen as commonly as psychiatrists but less commonly than a mental health specialist or general medical provider. Approximately 70% of those seeking treatment had a mental disorder, significant proportions of whom sought treatment in the absence of a psychiatrist, a mental health specialist or even a healthcare provider. A significant majority with 12-month use perceived the care as helpful, felt accepted/understood and satisfied (71–86%). However, only 31% rated the care as excellent, 28% quit completing care, and referral rates for specialty mental health treatment were low, even among those with a mental disorder (9.5%).
Religious/spiritual advisors are a key source of treatment-seeking for Asian Americans with a mental disorder. Quality of care and low referral rates for specialty mental health treatment warrant further attention and need for increased collaboration with the mental health system.
Asian Americans; Religious and spiritual advisor; Mental health service use; Mental disorder; Ethnicity; Nativity
Assessment of cortisol concentrations in hair is one of the latest innovations for measuring long-term cortisol exposure. We performed a systematic review of correlates of cortisol in human hair to inform the design, analysis and interpretation of future epidemiologic studies. Relevant publications were identified through electronic searches on PubMed, WorldCat, and Web of Science using keywords, “cortisol” “hair” “confounders” “chronic” “stress” and “correlates.” Thirty-nine studies were included in this review. Notwithstanding scarce data and some inconsistencies, investigators have found hair cortisol concentrations to be associated with stress-related psychiatric symptoms and disorders (e.g., PTSD), medical conditions indicating chronic activation of the hypothalamic-pituitary-adrenal axis (e.g., Cushing´s syndrome) and other life situations associated with elevated risk of chronic stress (e.g., shiftwork). Results from some studies suggest that physical activity, adiposity, and substance abuse may be correlates of hair cortisol concentrations. In contrast to measures of short-term cortisol release (saliva, blood, and urine), cigarette smoking and use of oral contraceptives appear to not be associated with hair cortisol concentrations. Studies of pregnant women indicate increased hair cortisol concentrations across successive trimesters. The study of hair cortisol presents a unique opportunity to assess chronic alterations in cortisol concentrations in epidemiologic studies.
hair; cortisol; chronic stress; correlates; assessment; analysis; determinants; psychiatric disorders
Many retinal imaging instruments use infrared wavelengths to reduce the risk of light damage. However, we have discovered that exposure to infrared illumination causes a long-lasting reduction in infrared autofluorescence (IRAF). We have characterized the dependence of this effect on radiant exposure and investigated its origin.
A scanning laser ophthalmoscope was used to obtain IRAF images from two macaques before and after exposure to 790-nm light (15-450 J/cm2). Exposures were performed with either raster-scanning or uniform illumination. Infrared autofluorescence images also were obtained in two humans exposed to 790-nm light in a separate study. Humans were assessed with direct ophthalmoscopy, Goldmann visual fields, multifocal ERG, and photopic microperimetry to determine whether these measures revealed any effects in the exposed locations.
A significant decrease in IRAF after exposure to infrared light was seen in both monkeys and humans. In monkeys, the magnitude of this reduction increased with retinal radiant exposure. Partial recovery was seen at 1 month, with full recovery within 21 months. Consistent with a photochemical origin, IRAF decreases caused by either raster-scanning or uniform illumination were not significantly different. We were unable to detect any effect of the light exposure with any measure other than IRAF imaging. We cannot exclude the possibility that changes could be detected with more sensitive tests or longer follow-up.
This long-lasting effect of infrared illumination in both humans and monkeys occurs at exposure levels four to five times below current safety limits. The photochemical basis for this phenomenon remains unknown.
Exposure to infrared illumination at irradiances well below current safety limits can cause a long-lasting decrease in infrared autofluorescence from the retina. It is unclear whether this effect is benign or indicative of a subcellular change that could be cumulatively harmful.
retina; light damage; radiation damage; scanning laser ophthalmoscopy; retinal pigment epithelium
Our goal in this study was to better understand racial and socioeconomic status (SES) variations in experiences of racial and nonracial discrimination.
We used 1999 and 2000 data from the YES Health Study, which involved a community sample of 50 Black and 50 White respondents drawn from 4 neighborhoods categorized according to racial group (majority Black or majority White) and SES (≤ 150% or > 250% of the poverty line). Qualitative and quantitative analyses examined experiences of discrimination across these neighborhoods.
More than 90% of Blacks and Whites described the meaning of unfair treatment in terms of injustice and felt certain about the attribution of their experiences of discrimination. These experiences triggered similar emotional reactions (most frequently anger and frustration) and levels of stress across groups, and low-SES Blacks and Whites reported higher levels of discrimination than their moderate-SES counterparts.
Experiences of discrimination were commonplace and linked to similar emotional responses and levels of stress among both Blacks and Whites of low and moderate SES. Effects were the same whether experiences were attributed to race or to other reasons.
The fovea dominates primate vision, and its anatomy and perceptual abilities are well studied, but its physiology has been little explored because of limitations of current physiological methods. In this study, we adapted a novel in vivo imaging method, originally developed in mouse retina, to explore foveal physiology in the macaque, which permits the repeated imaging of the functional response of many retinal ganglion cells (RGCs) simultaneously. A genetically encoded calcium indicator, G-CaMP5, was inserted into foveal RGCs, followed by calcium imaging of the displacement of foveal RGCs from their receptive fields, and their intensity-response functions. The spatial offset of foveal RGCs from their cone inputs makes this method especially appropriate for fovea by permitting imaging of RGC responses without excessive light adaptation of cones. This new method will permit the tracking of visual development, progression of retinal disease, or therapeutic interventions, such as insertion of visual prostheses.
calcium imaging; in vivo adaptive optics imaging; intrinsic signal imaging; primate fovea; retinal ganglion cells