Three-Dimensional Spectral-Domain Optical Coherence Tomography Data Analysis for Glaucoma Detection

Purpose: To develop a new three-dimensional (3D) spectral-domain optical coherence tomography (SD-OCT) data analysis method using a machine learning technique based on variable-size super pixel segmentation that efficiently utilizes full 3D dataset to improve the discrimination between early glaucomatous and healthy eyes. Methods: 192 eyes of 96 subjects (44 healthy, 59 glaucoma suspect and 89 glaucomatous eyes) were scanned with SD-OCT. Each SD-OCT cube dataset was first converted into 2D feature map based on retinal nerve fiber layer (RNFL) segmentation and then divided into various number of super pixels. Unlike the conventional super pixel having a fixed number of points, this newly developed variable-size super pixel is defined as a cluster of homogeneous adjacent pixels with variable size, shape and number. Features of super pixel map were extracted and used as inputs to machine classifier (LogitBoost adaptive boosting) to automatically identify diseased eyes. For discriminating performance assessment, area under the curve (AUC) of the receiver operating characteristics of the machine classifier outputs were compared with the conventional circumpapillary RNFL (cpRNFL) thickness measurements. Results: The super pixel analysis showed statistically significantly higher AUC than the cpRNFL (0.855 vs. 0.707, respectively, p = 0.031, Jackknife test) when glaucoma suspects were discriminated from healthy, while no significant difference was found when confirmed glaucoma eyes were discriminated from healthy eyes. Conclusions: A novel 3D OCT analysis technique performed at least as well as the cpRNFL in glaucoma discrimination and even better at glaucoma suspect discrimination. This new method has the potential to improve early detection of glaucomatous damage. © 2013 Xu et al

The evaluation of disability and its related factors among the elderly population in Kashan, Iran

<p>Abstract</p> <p>Background</p> <p>Recent literature indicates that developing countries in Asia are aging faster than other countries in the world and disability has become one of the greater public health concern in these countries. Pausity of published data on the elderly disability in Iran signifies the importance of this study designed to evaluate the disability and its related factors among the elderly population in Kashan, Iran during 2006–2007.</p> <p>Methods/Design</p> <p>A cross-sectional study is conducting on a multy-stage random sample of elderly people in Kashan ages 65 years and older. Volunteer participants were included by age 65 and older and excluded if they had the medical diagnosis of Alzhimer disease. The WHO DAS II was used as the generic disability measure in this survey. The original version of WHO DAS II was translated into Farsi according to the standardized guidelines for cross-cultural adaptation of health-related measures. Upon completion of data collection the descriptive statistics will compute all the variables. Chi-square, t-test analysis and ANOVA will be used to examine significant differences between the subgroups.</p> <p>Discussion</p> <p>This is the first research protocol to study disability among the Iranian elderly population. Presently, 80% of eligible subjects have been selected. The results of this study will help to develop more effective protocols to assist Iranian elderly population with disabilities.</p

Mathematical model of the dynamics of psychotherapy

The success of psychotherapy depends on the nature of the therapeutic relationship between a therapist and a client. We use dynamical systems theory to model the dynamics of the emotional interaction between a therapist and client. We determine how the therapeutic endpoint and the dynamics of getting there depend on the parameters of the model. Previously Gottman et al. used a very similar approach (physical-sciences paradigm) for modeling and making predictions about husband–wife relationships. Given that this novel approach shed light on the dyadic interaction between couples, we have applied it to the study of the relationship between therapist and client. The results of our computations provide a new perspective on the therapeutic relationship and a number of useful insights. Our goal is to create a model that is capable of making solid predictions about the dynamics of psychotherapy with the ultimate intention of using it to better train therapists

Assessment of severity and frequency of self-reported hypoglycemia on quality of life in patients with type 2 diabetes treated with oral antihyperglycemic agents: A survey study

<p>Abstract</p> <p>Background</p> <p>Some oral antihyperglycemic agents may increase risk of hypoglycemia and thereby reduce patient quality of life. Our objective was to assess the impact of the severity and frequency of self-reported hypoglycemia on health-related quality of life (HRQoL) among patients with type 2 diabetes treated with oral antihyperglycemic agents.</p> <p>Findings</p> <p>A follow-up survey was conducted in participants with self-reported type 2 diabetes treated with oral antihyperglycemic agents from the US National Health and Wellness Survey 2007. Data were collected on the severity and frequency of hypoglycemic episodes in the 6 months prior to the survey, with severity defined as mild (no interruption of activities), moderate (some interruption of activities), severe (needed assistance of others), or very severe (needed medical attention). HRQoL was assessed using the EuroQol-5D Questionnaire (EQ-5D) US weighted summary score (utility) and Worry subscale of the Hypoglycemia Fear Survey (HFS). Of the participants who completed the survey (N = 1,984), mean age was 58 years, 57% were male, 72% reported an HbA_1c<7.0%, and 50% reported treatment with a sulfonylurea-containing regimen. Hypoglycemic episodes were reported by 63% of patients (46% mild, 37% moderate, 13% severe and 4% very severe). For patients reporting hypoglycemia, mean utility score was significantly lower (0.78 versus 0.86, p < 0.0001) and mean HFS score was significantly higher (17.5 versus 6.2, p < 0.0001) compared to patients not reporting hypoglycemia. Differences in mean scores between those with and without hypoglycemia increased with the level of severity (mild, moderate, severe, very severe) for utility (0.03, 0.09, 0.18, 0.23) and HFS (6.1, 13.9, 20.1, 25.6), respectively. After adjusting for age, gender, weight gain, HbA_1c, microvascular complications, and selected cardiovascular conditions, the utility decrement was 0.045 (by level of severity: 0.009, 0.055, 0.131, 0.208), and the HFS increase was 9.6 (by severity: 5.3, 12.4, 17.6, 23.2). HRQoL further decreased with greater frequency of hypoglycemic episodes.</p> <p>Conclusions</p> <p>Self-reported hypoglycemia is independently associated with lower HRQoL, and the magnitude of this reduction increases with both severity and frequency of episodes in patients with type 2 diabetes treated with oral antihyperglycemic agents.</p

Electron ionization mass spectral fragmentation study of sulfation derivatives of polychlorinated biphenyls

<p>Abstract</p> <p>Background</p> <p>Polychlorinated biphenyls are persistent organic pollutants that can be metabolized via hydroxylated PCBs to PCB sulfate metabolites. The sensitive and selective analysis of PCB sulfate monoesters by gas chromatography-mass spectrometry (GC-MS) requires their derivatization, for example, as PCB 2,2,2-trichloroethyl (TCE) sulfate monoesters. To aid in the identification of unknown PCB sulfate metabolites isolated from biological samples, the electron impact MS fragmentation pathways of selected PCB TCE sulfate diesters were analyzed and compared to the fragmentation pathways of the corresponding methoxylated PCBs.</p> <p>Results</p> <p>The most abundant and characteristic fragment ions of PCB TCE sulfate diesters were formed by releasing CHCCl₃, SO₃, HCl₂and/or CCl₃from the TCE sulfate moiety and Cl₂, HCl, ethyne and chloroethyne from an intermediate phenylcyclopentadienyl cation. The fragmentation pattern depended on the degree of chlorination and the position of the TCE sulfate moiety (i.e., <it>ortho </it>vs. <it>meta/para </it>to the second phenyl ring), but were independent of the chlorine substitution pattern. These fragmentation pathways are similar to the fragmentation pathways of structurally related methoxylated PCBs.</p> <p>Conclusion</p> <p>Knowledge of the fragmentation patterns of PCB TCE sulfate diesters will greatly aid in determining the position of sulfate moiety (<it>ortho </it>vs. <it>meta/para</it>) of unknown PCB sulfate metabolites isolated from environmental or laboratory samples.</p

Care management for Type 2 diabetes in the United States: a systematic review and meta-analysis

<p>Abstract</p> <p>Background</p> <p>This systematic review and meta-analysis aims at assessing the composition and performance of care management models evaluated in the last decade and their impact on patient important outcomes.</p> <p>Methods</p> <p>A comprehensive literature search of electronic bibliographic databases was performed to identify care management trials in type 2 diabetes. Random effects meta-analysis was used when feasible to pool outcome measures.</p> <p>Results</p> <p>Fifty-two studies were eligible. Most commonly reported were surrogate outcomes (such as HbA1c and LDL), followed by process measures (clinic visit or testing frequency). Less frequently reported were quality of life, patient satisfaction, self-care, and healthcare utilization. Most care management modalities were carved out from primary care. Meta-analysis demonstrated a statistically significant but trivial reduction of HbA1c (weighted difference in means -0.21%, 95% confidence interval -0.40 to -0.03, p < .03) and LDL-cholesterol (weighted difference in means -3.38 mg/dL, 95% confidence interval -6.27 to -0.49, p < .02).</p> <p>Conclusions</p> <p>Most care management programs for patients with type 2 diabetes are 'carved-out', accomplish limited effects on metabolic outcomes, and have unknown effects on patient important outcomes. Comparative effectiveness research of different models of care management is needed to inform the design of medical homes for patients with chronic conditions.</p

Knowledge-to-action processes in SHRTN collaborative communities of practice: A study protocol

<p>Abstract</p> <p>Background</p> <p>The Seniors Health Research Transfer Network (SHRTN) Collaborative is a network of networks that work together to improve the health and health care of Ontario seniors. The collaborative facilitates knowledge exchange through a library service, knowledge brokers (KBs), local implementation teams, collaborative technology, and, most importantly, Communities of Practice (CoPs) whose members work together to identify innovations, translate evidence, and help implement changes.</p> <p>This project aims to increase our understanding of knowledge-to-action (KTA) processes mobilized through SHRTN CoPs that are working to improve the health of Ontario seniors. For this research, KTA refers to the movement of research and experience-based knowledge between social contexts, and the use of that knowledge to improve practice. We will examine the KTA processes themselves, as well as the role of human agents within those processes. The conceptual framework we have adopted to inform our research is the Promoting Action on Research Implementation in Health Services (PARIHS) framework.</p> <p>Methods/design</p> <p>This study will use a multiple case study design (minimum of nine cases over three years) to investigate how SHRTN CoPs work and pursue knowledge exchange in different situations. Each case will yield a unique narrative, framed around the three PARIHS dimensions: evidence, context, and facilitation. Together, the cases will shed light on how SHRTN CoPs approach their knowledge exchange initiatives, and how they respond to challenges and achieve their objectives. Data will be collected using interviews, document analysis, and ethnographic observation.</p> <p>Discussion</p> <p>This research will generate new knowledge about the defining characteristics of CoPs operating in the health system, on leadership roles in CoPs, and on the nature of interaction processes, relationships, and knowledge exchange mechanisms. Our work will yield a better understanding of the factors that contribute to the success or failure of KTA initiatives, and create a better understanding of how local caregiving contexts interact with specific initiatives. Our participatory design will allow stakeholders to influence the practical usefulness of our findings and contribute to improved health services delivery for seniors.</p

A Glial Variant of the Vesicular Monoamine Transporter Is Required To Store Histamine in the Drosophila Visual System

Unlike other monoamine neurotransmitters, the mechanism by which the brain's histamine content is regulated remains unclear. In mammals, vesicular monoamine transporters (VMATs) are expressed exclusively in neurons and mediate the storage of histamine and other monoamines. We have studied the visual system of Drosophila melanogaster in which histamine is the primary neurotransmitter released from photoreceptor cells. We report here that a novel mRNA splice variant of Drosophila VMAT (DVMAT-B) is expressed not in neurons but rather in a small subset of glia in the lamina of the fly's optic lobe. Histamine contents are reduced by mutation of dVMAT, but can be partially restored by specifically expressing DVMAT-B in glia. Our results suggest a novel role for a monoamine transporter in glia that may be relevant to histamine homeostasis in other systems