To What Extent do Sleep Quality and Duration Mediate the Effect of Perceived Discrimination on Health? Evidence from Philadelphia

Little research investigates whether sleep mediates the adverse effect of perceived discrimination on health and even less is known about whether sleep quality and sleep duration mediate the relationships in the same fashion. We applied a recently developed mediation analysis approach to a survey administered in 2008 in Philadelphia, PA, that includes 9042 adults. Health was measured with self-rated health, stress, and mental illness. Perceived discrimination was operationalized with self-reported discriminatory experience in two social contexts, namely health care system and housing market. Sleep quality and duration were measured with a five-point Likert scale and the self-reported sleep time at night, respectively. After controlling for one’s demographic, socioeconomic, and health-related characteristics, the mediation analysis quantified how much sleep quality and duration can account for the effect of perceived discrimination on these health outcomes. The key findings are: (a) sleep quality and duration accounted for approximately 15 to 25 % of the adverse effect of perceived discrimination. (b) Sleep quality is more important than sleep duration in mediating the relationship between perceived discrimination and health. (c) The proportion of the effect mediated by sleep differs by the social context where perceived discrimination occurred. It was confirmed that sleep mediates the relationship between perceived discrimination and health and the interventions to improve sleep, particularly sleep quality, should help to attenuate the effect of perceived discrimination on health.     

This child can: participation in sport for children with vision impairment

All children benefit from access to sports, exercise and leisure. It is important not just for physical health, but also for emotional wellbeing and social connectivity. Vision impairment refers to a bilateral uncorrectable reduction in vision and is experienced by 1 in 1000 young people under the age of 16 in the UK. Many children with vision impairment experience barriers in their access to sport and exercise, and a traditional medical model of disability would associate these barriers with the pathology of ophthalmological disease. The social model of disability favours consideration of environmental, behavioural, organisational and attitudinal factors in considering barriers to inclusion. Considering clinical, developmental, social and environmental factors, we can explore the opportunities available to maximise participation in sport by children with vision impairment.     

Does cigarette smoke exposure lead to histopathological alterations in the olfactory epithelium? An electron microscopic study on a rat model

Objective: This study was conducted to examine the influence of smoke exposure of variable duration on the ultrastructure of and histopathologic and morphologic alterations in the olfactory epithelium.

Methods: A total of 24 Wistar albino rats were randomly assigned to three groups and fed a standard rat chow and tap water. Experimental rats in groups I and II were exposed to cigarette smoke in a glass cabin over a period of 2 months for 5 or 15 min, respectively, four times daily; control rats (group III) were not exposed to cigarette smoke. After dissection, all tissue specimens were processed using routine procedures for TEM.

Results: Groups I and II exhibited the presence of intraepithelial inflammatory cells and especially deep invaginations in the nuclear membrane of supporting cells. Extended intercellular spaces, cytoplasmic protrusions on the apical surface of supporting cells, atrophy of microvilli and olfactory neuron cilia as well as numerous electron-dense granular structures and lysosome-like structures were observed to an increasing degree from group I to group II. Particularly in group II, both supporting cells and olfactory neurons exhibited a cytoplasmic edema, mitochondrial degeneration, and numerous vacuolar structures, as well as apoptotic and minimal necrotic changes. In this group, hyperplasia of basal cells was also observed.

Conclusion: Our electron microscopic findings show that cigarette smoke leads to toxic degenerative changes in the rat olfactory mucosa.     

Intensity discrimination deficits cause habituation changes in middle-aged Caenorhabditis elegans

The ability to learn and remember is critical for all animals to survive in the ever-changing environment. As we age, many of our biological faculties decay and of these, decline in learning and memory can be the most distressing. To carefully define age-dependent changes in learning during reproductive age in the nematode Caenorhabditis elegans, we performed a parametric behavioral study of habituation to nonlocalized mechanical stimuli (petri plate taps) over a range of intensities in middle-aged worms. We found that as worms age (from the onset of reproduction to the end of egg laying), response probability habituation increases (at both 10- and 60-second interstimulus intervals) and that these age-related changes were associated with a decrease in the discrimination between stimuli of different intensities. We also used optogenetics to investigate where these age-dependent changes occur. Our data suggest that the changes occur upstream of mechanosensory neuron depolarization. These data support the idea that declines in stimulus intensity discrimination abilities during aging may be one variable underlying age-related cognitive deficits.     

Adaptive Adjustment of the Generalization-Discrimination Balance in Larval Drosophila

Abstract

Learnt predictive behavior faces a dilemma: predictive stimuli will never ‘replay’ exactly as during the learning event, requiring generalization. In turn, minute differences can become meaningful, prompting discrimination. To provide a study case for an adaptive adjustment of this generalization-discrimination balance, the authors ask whether Drosophila melanogaster larvae are able to either generalize or discriminate between two odors (1-octen-3-ol and 3-octanol), depending on the task. The authors find that after discriminatively rewarding one but not the other odor, larvae show conditioned preference for the rewarded odor. On the other hand, no odor specificity is observed after nondiscriminative training, even if the test involves a choice between both odors. Thus, for this odor pair at least, discrimination training is required to confer an odor-specific memory trace. This requires that there is at least some difference in processing between the two odors already at the beginning of the training. Therefore, as a default, there is a small yet salient difference in processing between 1-octen-3-ol and 3-octanol; this difference is ignored after nondiscriminative training (generalization), whereas it is accentuated by odor-specific reinforcement (discrimination). Given that, as the authors show, both faculties are lost in anosmic Or83b¹ mutants, this indicates an adaptive adjustment of the generalization-discrimination balance in larval Drosophila, taking place downstream of Or83b-expressing sensory neurons.     

The Alarm Response in Zebrafish: Innate Fear in a Vertebrate Genetic Model

The alarm response is an antipredator behavior displayed by many fish species and was first described 70 years ago. It is triggered through the olfactory system by substances released from injured skin and is characterized by dramatic, measurable changes in locomotion as well as physiology. We propose that this is an ideal time to revisit this response and to utilize it as an assay for understanding how neural circuits mediate innate fear. A suitable organism for these studies is the zebrafish, a genetic model with a rapidly expanding toolkit for molecular manipulation of the nervous system. Individual neurons mediating the response, ranging from receptor neurons to those in higher brain centers, should first be identified. New tools, specifically transgenic lines that allow spatial and temporal control of neural activity, provide a way to define and test the role of specific neurons, while genetic screens provide a route to identifying individual molecules essential for a normal response. Optical recording, which has proven successful in studies of information processing in the bulb, will provide valuable insights into neural circuitry function during the alarm response. When carried out on mutants, physiological analysis can provide insight into aspects of signal processing that are essential for normal behavior. The alarm response thus provides a paradigm to examine innate fear in a vertebrate system, enabling analysis at multiple levels from genes to the entire neural circuit. Additionally, the context dependency of the response can be utilized to investigate attention and decision making.     

Histological observations on the anterior olfactory nucleus in human

Aim: Localization of isolated clusters of anterior olfactory nucleus (AON) in a human olfactory bulb and tract. Materials and methods: This investigation was done on human olfactory bulbs and their tracts, collected from the freshly donated cadavers, before embalming, in the Department of Anatomy, IPGMER, Kolkata. H&E stained histological slides were prepared along the whole length of specimens and examined under a Leica DM 2000 microscope and with a Leica Quin image analyzer. Results: The anterior olfactory nucleus was detected in the form of a major cluster and in two smaller clusters of neurons. The major cluster was located at the caudal pole of the bulb and was composed of medium-sized triangular cells which had an average diameter of 13.92 ± 3.43 μm. Out of the two minor clusters, one was detected at the beginning and another at the middle of the olfactory tract. Here neurons were little larger in size and their diameter ranged approximately 15–17 μm. Olfactory striae also accommodated some neurons in a scattered manner. Conclusion: This observation will be helpful in exploration of the complex role of AON in the organization and function of the olfactory system and its clinical significance in human.     

Discrimination and abuse in internal medicine residency

OBJECTIVE: To survey the extent to which internal medicine housestaff experience abuse and discrimination in their training. DESIGN: Through a literature review and resident focus groups, we developed a self-administered questionnaire. In this cross-sectional survey, respondents were asked to record the frequency with which they experienced and witnessed different types of abuse and discrimination during residency training, using a 7-point Likert scale. PARTICIPANTS: Internal medicine housestaff in Canada. MEASUREMENTS AND MAIN RESULTS: Of 543 residents in 13 programs participating (84% response rate), 35% were female. Psychological abuse, as reported by attending physicians (68%), patients (79%), and nurses or other health workers (77%), was widespread. Female residents experienced gender discrimination by attending physicians (70%), patients (88%), and nurses (71%); rates for males were 23%, 38%, and 35%, respectively. Females reported being sexually harassed more often than males, by attending physicians (35% vs 4%,p<.01), peers (30% vs 6%,p<.01), and patients (56% vs 18%,p<.01). Physical assault by patients was experienced by 40% of residents. Half of the residents surveyed reported racial discrimination and homophobic remarks in the workplace, perpetrated by all groups of health professionals. CONCLUSIONS: Psychological abuse, gender discrimination, sexual harassment, physical abuse, homophobia, and racial discrimination are prevalent problems during residency training. Housestaff, medical educators, allied health workers, and the public need to work together to address these problems in the training environment. Dr. Cook is a Career Scientist with the Ontario Ministry of Health. For a complete listing, see Appendix A. This study was supported by the Royal College of Physicians and Surgeons of Canada.     

Examining implicit bias of physicians who care for individuals with spinal cord injury: A pilot study and future directions

Context

Despite evidence that healthcare providers have implicit biases that can impact clinical interactions and decisions, implicit bias among physicians caring for individuals with spinal cord injury (SCI) has not been examined.

Objective

Conduct a pilot study to examine implicit racial bias of SCI physicians and its association with functioning and wellbeing for individuals with SCI.

Design

Combined data from cross-sectional surveys of individuals with SCI and their SCI physicians.

Setting

Four national SCI Model Systems sites.

Participants

Individuals with SCI (N = 162) and their SCI physicians (N = 14).

Outcome measures

SCI physicians completed online surveys measuring implicit racial (pro-white/anti-black) bias. Individuals with SCI completed questionnaires assessing mobility, physical independence, occupational functioning, social integration, self-reported health, depression, and life satisfaction. We used multilevel regression analyses to examine the associations of physician bias and outcomes of individuals with SCI.

Results

Physicians had a mean bias score of 0.62 (SD = 0.35), indicating a strong pro-white/anti-black bias. Greater physician bias was associated with disability among individuals with SCI in the domain of social integration (odds ratio = 4.80, 95% confidence interval (CI) = 1.44, 16.04), as well as higher depression (B = 3.24, 95% CI = 1.06, 5.41) and lower life satisfaction (B = −4.54, 95% CI= −8.79, −0.28).

Conclusion

This pilot study indicates that SCI providers are susceptible to implicit racial bias and provides preliminary evidence that greater implicit racial bias of physicians is associated with poorer psychosocial health outcomes for individuals with SCI. It demonstrates the feasibility of studying implicit bias among SCI providers and provides guidance for future research on physician bias and patient outcomes.