Photochemical Crosslinking of Tarsal Collagen as a Treatment for Eyelid Laxity: Evaluation in Ex Vivo Human Tissue.

PURPOSE: Experimental investigation in human eyelids to confirm that exposing excised tarsal plates to ultraviolet-A radiation can induce a stiffening effect through the riboflavin-photosensitized crosslinking of tarsal collagen. METHODS: Thirteen tarsal plates excised from nonfrozen human cadavers were irradiated with ultraviolet-A rays (365 nm wavelength) at an irradiance of 75 mW/cm2 for 3 minutes, equivalent to a radiation fluence of 13.5 J/cm2, in the presence of a riboflavin derivative as a photosensitizer. The tensile stress (strength) and Young's modulus (stiffness) of both nonirradiated and irradiated specimens were measured with the BioTester 5000 in the uniaxial mode at a strain of 10% and analyzed statistically. Individual specimens excised from 2 cadavers were also examined by routine histopathologic protocols to assess the effect of radiation on the Meibomian glands and collagen organization. RESULTS: The irradiation enhanced both stiffness and strength of the human tarsal specimens, the difference between the test samples and controls being statistically significant (p < 0.0002 for n = 13). Histology indicated no damage to tarsal connective tissue or to Meibomian glands, and revealed a more compact packing of the collagen network located around the glands, which may be beneficial. The existence of collagen compaction was also supported by the reduction of samples' thickness after irradiation (p = 0.0645). CONCLUSIONS: The irradiation of tarsal tissue with ultraviolet-A light of tarsus appears to be a safe and effective method for reducing eyelid laxity in human patients.

The International Vitreoretinal B-Cell Lymphoma Registry: a protocol paper.

INTRODUCTION: Vitreoretinal lymphoma is a rare ocular cancer with high morbidity and mortality despite treatment. Diagnosis by cytopathology is often delayed, and various molecular and image-based investigations have been developed. Diverse treatments are used, but there is a limited medical evidence to differentiate their effectiveness. We designed an international registry that would collect diagnostic, treatment and outcomes data, to establish new evidence for the management of this cancer. METHODS AND ANALYSIS: The International Vitreoretinal B-Cell Lymphoma Registry will accrue data retrospectively for individuals aged 18 years or older, diagnosed with new or recurrent vitreoretinal B-cell lymphoma on or after 1 January 2020. A steering committee of subspecialised ophthalmologists identified 20 key clinical data items that describe patient demographics, tissue involvements, diagnostic testing, ocular and systemic treatments and treatment complications, and visual acuity and survival outcomes. Customised software was designed to permit collection of these data across a single baseline and multiple follow-up forms. The platform collects data without identifiers and at 3 month reporting intervals. Outcomes of the project will include: (1) descriptions of clinical presentations, and diagnostic and therapeutic preferences; (2) associations between clinical presentations, and diagnostics and treatments, and between diagnostics and treatments (assessed by ORs with 95% CIs); and (3) estimations of rates of vision loss, and progression-free and overall survival (assessed by Kaplan-Meier estimates). ETHICS AND DISSEMINATION: The registry has received Australia-wide approval by a national human research ethics committee. Sites located outside Australia are required to seek local human research ethics review. Results generated through the registry will be disseminated primarily by peer-reviewed publications that are expected to inform clinical practice, as well as educational materials.

Depressive patients are more impulsive and inconsistent in intertemporal choice behavior for monetary gain and loss than healthy subjects--an analysis based on Tsallis' statistics.

OBJECTIVES: Depression has been associated with impaired neural processing of reward and punishment. However, to date, little is known regarding the relationship between depression and intertemporal choice (delay discounting) for gain and loss. This examination is potentially important for advances in neuroeconomics of intertemporal choice, because depression is associated with reduced serotonergic activities in the brain. DESIGN AND SETTING: We compared impulsivity and inconsistency in intertemporal choice for monetary gain and loss between depressive patients and healthy control subjects. METHODS: We conducted delay discounting tasks for gain and loss in depressed and healthy control subjects. We then quantified impulsivity and inconsistency in the delay discounting with parameters in the q-exponential discount function based on Tsallis' statistics. RESULTS: We observed that depressive patients were more impulsive and time-inconsistent in intertemporal choice action for gain and loss, in comparison to healthy controls. MAIN FINDINGS: Depressed patients were more irrational in temporal discounting. CONCLUSIONS: The usefulness of the q-exponential discount function for assessing the impaired decision-making by depressive patients was demonstrated. Furthermore, biophysical mechanisms underlying the altered intertemporal choice by depressive patients are discussed in relation to impaired serotonergic neural systems.

[Effect of contextual factors on patterns of eye-movement: comparing sensitivity to background information between Japanese and Westerners].

Recent cross-cultural research suggests that East Asians are more likely than their Western counterparts to be sensitive to contextual information. In this experimental research study, we presented a blinking circle situated at the center of the computer screen for 30s. Both Japanese and Western participants were alternately engaged in two different tasks: (a) A single target circle, and (b) a target circle with four surrounding circles. In either case, they were asked to focus only on the target circle while ignoring the surrounding information. The results indicated that, even though the Japanese attempted to focus on the center circle, they failed to focus only on the center circle. Their number of fixations and variances from the center to each fixation points were significantly larger than found with the Westerners. This effect was stronger when four circles surrounded the target circle compared to a single circle. These findings suggest that cultural influences on basic psychological processes may be very deep.

Sex differences in the relationship between cortisol levels and the Empathy and Systemizing Quotients in humans.

OBJECTIVE: Little is known regarding the relationship between cortisol (a stress hormone) levels and psychological cognitive styles. Baron-Cohen proposed two fundamental cognitive styles, which are measured by the Empathy Quotient (EQ) and the Systemizng Quotient (SQ). Previous studies have examined the influences of prenatal testosterone exposure on EQ and SQ scores. This study aimed to examine the relationships between morning cortisol levels and EQ and SQ scores, and the 'brain types' which were determined by two quotients in both sexes. These relationships are potentially important in the developmental psychopathology of autism and neuroeconomics of empathy. METHODS: We assessed morning cortisol levels with LC/MS (liquid chromatography-mass spectrometry) and ESQ in healthy male and female university students. CONCLUSIONS: Results indicate clear sex differences between brain types: i.e. E-type males and S-type females (participants with atypical cognitive styles) have significantly higher cortisol levels than S-type males and E-type females (participants with typical cognitive styles). Implications for the role of sex in social adaptation of autistic patients are discussed.

Comparison of probabilistic choice models in humans.

BACKGROUND: Probabilistic choice has been attracting attention in psychopharmacology and neuroeconomics. Several parametric models have been proposed for probabilistic choice; entropy model, Prelec's probability weight function, and hyperbola-like probability discounting functions. METHODS: In order to examine (i) fitness of the probabilistic models to behavioral data, (ii) relationships between the parameters and psychological processes, e.g., aversion to possible non-gain in each probabilistic choice and aversion to unpredictability, we estimated the parameters and AICc (Akaike Information Criterion with small sample correction) of the probabilistic choice models by assessing the points of subjective equality at seven probability values (95%-5%). We examined both fitness of the models parametrized by utilizing AICc, and the relationships between the model parameters and equation-free parameter of aversion to possible non-gain. RESULTS: Our results have shown that (i) the goodness of fitness for group data was [Entropy model>Prelec's function>General hyperbola>Simple hyperbola]; while Prelec's function best fitted individual data, (ii) aversion to possible non-gain and aversion to unpredictability are distinct psychological processes. CONCLUSION: Entropy and Prelec models can be utilized in psychopharmacological and neuroeconomic studies of risky decision-making.

Cortisol levels and prospective and retrospective memory in humans.

OBJECTIVES: The aim of this study was to examine (i) the influence of cortisol on both prospective and retrospective memory performance and (ii) the role of emotional valence in both types of memory. METHODS: Thirty-four male students participated in a memory task, which measured both prospective and retrospective memory performance. Baseline salivary cortisol levels were assessed. RESULTS: Spearman's rank order correlation analysis showed a significant positive correlation between salivary cortisol levels and retrospective memory performance for neutral words. Cortisol levels were not significantly correlated with prospective memory performance for either negative nor neutral words. CONCLUSIONS: The present results indicate chronic cortisol levels are positively associated with retrospective memory at relatively low concentration ranges, but not prospective memory, in healthy young men. Implications for evaluating the beneficial effects of low-dose cortisol treatment on posttraumatic stress disorder is discussed.

Transcultural issues in mood and anxiety disorders: a focus on Japan.

Accurate comparisons of the prevalence of psychiatric disorders across Eastern and Western cultures are difficult and limited by methodological problems. Nevertheless, using standardized diagnostic and evaluation techniques, recent surveys have suggested that depression and anxiety disorders exist in all countries and cultures examined thus far, although variations in the prevalence rates and symptomatology may exist. This article discusses the influence and impact that culture can have on recognizing and treating mood and anxiety disorders, with a particular focus on Japan. Over the last 20 years, studies have consistently reported an increase in mental illness in Japan, especially symptoms of depression and anxiety. While such symptoms have had an adaptive cultural role in the past, current social and economic changes in Japan have turned any adaptive advantage into a potentially significant disadvantage, with a major impact on the capacity of individuals to function adequately. The situation is compounded by the fact that Japanese patients are reluctant to openly discuss disturbances of mood, since these are considered to be indicative of personal weakness rather than treatable medical conditions. Reluctance to discuss personal mental health hinders timely recognition and appropriate treatment.