Retinal correlates of neurological disorders

Considering the retina as an extension of the brain provides a platform from which to study diseases of the nervous system. Taking advantage of the clear optical media of the eye and ever-increasing resolution of modern imaging techniques, retinal morphology can now be visualized at a cellular level in vivo. This has provided a multitude of possible biomarkers and investigative surrogates that may be used to identify, monitor and study diseases until now limited to the brain. In many neurodegenerative conditions, early diagnosis is often very challenging due to the lack of tests with high sensitivity and specificity, but, once made, opens the door to patients accessing the correct treatment that can potentially improve functional outcomes. Using retinal biomarkers in vivo as an additional diagnostic tool may help overcome the need for invasive tests and histological specimens, and offers the opportunity to longitudinally monitor individuals over time. This review aims to summarise retinal biomarkers associated with a range of neurological conditions including Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS) and prion diseases from a clinical perspective. By comparing their similarities and differences according to primary pathological processes, we hope to show how retinal correlates can aid clinical decisions, and accelerate the study of this rapidly developing area of research

Impact of internal female migration on unmet need for modern contraception in Zambia

Background Unmet need for contraception, the proportion of women who want to limit or delay childbirth but use no form of contraception, is the core indicator to evaluate the effectiveness of family planning programs. Understanding how migration influences unmet need is important to identify to whom and how to target sexual and reproductive health programs. We assessed how migration status in rural and urban settings is associated with having an unmet need for family planning. Methods Data on sexually active, fecund, reproductive-aged (15–49 years) women from the 2013–14 Zambia Demographic and Health Survey were analysed through univariate and multivariate logistic regression models. Results Unmet need for modern contraceptive methods was significantly higher among rural to rural migrant women (OR 1.30, 95%CI 1.00–1.70 p < 0.05) and rural non-migrant women (OR 1.41, 95%CI 1.06–1.85 p < 0.01) compared to urban non-migrant women after controlling for age, marital status, parity, religion, education and wealth. Conclusion Women residing in, and migrating between, rural areas were significantly more likely to have an unmet need for contraception. Our findings highlight the importance of understanding migration and migrant streams to strengthen family planning programs. In Zambia, a focus on rural-rural migrants, rural non-migrants and the poorest could improve the health of the entire population

Retinal correlates of psychiatric disorders

Diagnosis and monitoring of psychiatric disorders rely heavily on subjective self-reports of clinical symptoms, which are complicated by the varying consistency of accounts reported by patients with an impaired mental state. Hence, more objective and quantifiable measures have been sought to provide clinicians with more robust methods to evaluate symptomology and track progression of disease in response to treatments. Owing to the shared origins of the retina and the brain, it has been suggested that changes in the retina may correlate with structural and functional changes in the brain. Vast improvements in retinal imaging, namely optical coherence tomography (OCT) and electrodiagnostic technology, have made it possible to investigate the eye at a microscopic level, allowing for the investigation of potential biomarkers in vivo. This review provides a summary of retinal biomarkers associated with schizophrenia, bipolar disorder and major depression, demonstrating how retinal biomarkers may be used to complement existing methods and provide structural markers of pathophysiological mechanisms that underpin brain dysfunction in psychiatric disorders

Segregated audio–tactile events destabilize the bimanual coordination of distinct rhythms

We examined to what extent the CNS can efficiently bind together the perception of non-coincident multimodal events with coordinated movements. To do so, we selected a bimanual coordination with left–right asymmetry, which was, achieving 3:2 polyrhythmic movements. We asked participants to synchronize left and right fingers’ movements to events presented, respectively, to the left and to the right side. In two segregated conditions, sound was presented on one side at one frequency while touch was presented on the other side at the other frequency; thus, the left and right rhythms were paced via a distinct sensory modality. In the three control conditions, the stimuli on both sides were presented via the same sensory modality: sound, touch, or coincident sound and touch. Our aim was to contrast two opposing hypotheses: Sensory segregated pacing (1) stabilizes polyrhythmic coordination because it favors the distinction between the fast and the slow rhythm versus (2) destabilizes polyrhythmic coordination because it introduces a very strong asymmetry. We performed a parametric study in which the ability to maintain the polyrhythmic coordination was explored over a broad range of pacing rates. We found that switches from the polyrhythmic coordination to an isofrequency pattern took place only in the sensory segregated conditions, at the highest frequencies. Moreover, transitions were preceded by an increase in the variability of the synchronization of movement to stimuli. We therefore propose that the destabilization originating from the asymmetry between sensory modalities overrides the assumed segregation effect. We discuss the possible neuronal underpinnings of this failure of binding of movement to segregated sound and touch

The association of DNA Repair with breast cancer risk in women. A comparative observational study

<p>Abstract</p> <p>Background</p> <p>Previous studies have found a link between a low DNA repair capacity (DRC) level and increased cancer risk. Our aim was to assess the statistical association of DRC level and breast cancer (BC) using a case–control epidemiological study in a Hispanic community.</p> <p>Methods</p> <p>We conducted a comparative observational study to assess the validity of DRC in detecting BC in 824 women throughout Puerto Rico. Over a 6-year period, we compared 285 women newly diagnosed with BC to 539 without BC. DRC levels were measured in lymphocytes by means of a host-cell reactivation assay. We assessed the sensitivity, specificity, and association using the receiver operating characteristic curve analysis. Multiple logistic regression-adjusted odds ratios were estimated with 95% confidence level to measure the strength of the association of DRC and BC after adjusting for all confounders simultaneously.</p> <p>Results</p> <p>Compared to women without cancer, women with BC showed an average decrease of 60% in their DRC levels (<it>p</it> < 0.001). Validity of the association of DRC as a measure of BC risk showed a sensitivity of 83.2% and specificity of 77.6% (<it>p</it> < 0.0001).</p> <p>Conclusions</p> <p>Our results support the usefulness of DRC level as a measure of BC risk. Additional studies in other populations are needed to further verify its usefulness.</p

Incidence and trends of childhood Type 1 diabetes worldwide 1990-1999.

Aims. To examine incidence and trends of Type 1 diabetes worldwide for the period 1990–1999. Methods. The incidence of Type 1 diabetes (per 100000/year) was analysed in children aged ≤ 14 years from 114 populations in 112 centres in 57 countries. Trends in the incidence of Type 1 diabetes were analysed by fitting Poisson regression models to the dataset. Results. A total of 43013 cases were diagnosed in the study populations of 84 million children. The age-adjusted incidence of Type 1 diabetes among 112 centres (114 populations) varied from 0.1 per 100000/year in China and Venezuela to 40.9 per 100000/year in Finland. The average annual increase in incidence calculated from 103 centres was 2.8% (95% CI 2.4–3.2%). During the years 1990–1994, this increase was 2.4% (95% CI 1.3–3.4%) and during the second study period of 1995–1999 it was slightly higher at 3.4% (95% CI 2.7– 4.3%). The trends estimated for continents showed statistically significant increases all over the world (4.0% in Asia, 3.2% in Europe and 5.3% in North America), except in Central America and the West Indies where the trend was a decrease of 3.6%. Only among the European populations did the trend in incidence diminish with age. Conclusions. The rising incidence of Type 1 diabetes globally suggests the need for continuous monitoring of incidence by using standardized methods in order to plan or assess prevention strategies