DEVELOPMENT OF MICROCHIP ELECTROPHORESIS BASED METHODS TO PROFILE CELLULAR NITROSATIVE STRESS

Nitric oxide (NO) is the main reactive nitrogen species (RNS) produced by immune cells. NO reacts with superoxide to produce peroxynitrite (ONOO-). These two RNS are capable of nitration, nitrosylation and oxidation of intracellular biomolecules that can alter various biochemical processes. To help maintain cellular redox homeostasis in nitrosative and oxidative stress, antioxidant molecules are present in the cells. However, excessive nitrosative stress can alter the balance between antioxidants and prooxidants and therefore it plays an important role in cancer, cardiovascular and neurodegenerative diseases. A method for the simultaneous detection of prooxidants and antioxidants associated with nitrosative stress in biological samples would be beneficial for better understanding of their role in disease states. Therefore, in this dissertation a separation-based approach is described that makes it possible to detect and quantify cellular antioxidants and prooxidants such as NO, ONOO-, glutathione and ascorbic acid. Microchip electrophoresis (ME) was selected as the separation method due to its fast analysis times, compatibility with low sample volumes and potential future application to chemical cytometry. Most prooxidants and antioxidants are electrochemically active and therefore, electrochemical detection was used as the primary detection mode. First, a ME method with in-channel amperometric detection that employed an isolated potentiostat was developed for the detection of NO, ONOO-, and other biologically important molecules associated nitrosative stress. Separation of these species was achieved in less than 35 s, which made it possible to detect prooxidants before they significantly degraded. Following this, two dual electrode configurations were developed and evaluated for better identification of reactive species in standard mixtures and cell lysates using voltammetric characterization. The ME-amperometric method was then used for detection and quantification of NO2- and NO in macrophage cells under native and LPS stimulated conditions. Glutathione, a cellular antioxidant, was also measured in these studies and compared with the prooxidant levels in the cells. For further confirmation of NO production in these cells, ME with laser induced fluorescence detection was used for the determination of NO using diaminofluorofluorescein. This same probe and separation was also used to investigate the heterogeneity of NO production in single cells using a cytometric device in collaboration with the Culbertson group. The main future goal of this project is to monitor macrophage cellular heterogeneity during nitrosative stress using an electrochemical cytometric device

Managing health information in New Zealand: An analysis of the health information privacy principles

The New Zealand Health Information Service has recently established a national health register. At the heart of this development are three national databases. These applications and their functions are presented. Other initiatives currently being explored are also discussed. The paper contends that these initiatives under the guise of advancing the nation\u27s health may instead be infringing the privacy of the nation\u27s citizens. An analysis of New Zealand\u27s privacy legislation to the development of such a centralized health system is detailed. The paper concludes by considering the possibility of hidden agendas despite the provisions of the nation\u27s privacy rules

THE IMPACT OF ORGANIZATIONAL CULTURE ON BUSINESS PERFORMANCE IN STAR CLASS HOTELS OF SRI LANKA

The purpose of this study is to investigate the relationship between the organizational culture and business performance in star class hotels of Sri Lanka. The study has utilized data collected from 215 senior managers employed in star class hotel sector using self-administered questionnaire. CFA SEM analysis has performed using AMOS 21 to identify the relationship between the variables examined. The quantitative data analysis revealed there is a significant relationship between all four elements of organizational culture and business performance. The organizational culture was reflected through four dimensions organizational climate, flexibility or the support to change, team work and employee empowerment. This study develops a better understanding of elements of organizational culture and their influence on business performance. JEL: D23; L80; L83  Article visualizations

THE EFFECT OF ORGANIZATIONAL CULTURE TOWARDS ENTREPRENEURIAL ORIENTATION IN SRI LANKAN HOSPITALITY OPERATIONS

The article examines the relationship between the organizational culture and the entrepreneurial orientation in the Sri Lankan hospitality sector. The data for the study was collected from 215 managers occupying senior positions star class hotel sector. The analysis was performed based on CFA SEM techniques using AMOS 21 software to identify the relationship. The quantitative data analysis revealed there is a significant relationship between organizational culture and entrepreneurial orientation. In the research entrepreneurial orientation was reflected with three dimensions proactiveness, risk taking and innovativeness. The organizational culture was reflected with four dimensions organizational climate, flexibility or the support to change, team work and employee empowerment. This study develops a better understanding of elements of organizational culture and entrepreneurial orientation.  Article visualizations

Development of Arrayed Colonic Organoids for Screening of Secretagogues Associated with Enterotoxins

Enterotoxins increase intestinal fluid secretion through modulation of ion channels as well as activation of the enteric nervous and immune systems. Colonic organoids, also known as colonoids, are functionally and phenotypically similar to in vivo colonic epithelium and have been used to study intestinal ion transport and subsequent water flux in physiology and disease models. In conventional cultures, organoids exist as spheroids embedded within a hydrogel patty of extracellular matrix, and they form at multiple depths, impairing efficient imaging necessary to capture data from statistically relevant sample sizes. To overcome these limitations, an analytical platform with colonic organoids localized to the planar surface of a hydrogel layer was developed. The arrays of densely packed colonoids (140 μm average diameter, 4 colonoids/mm2) were generated in a 96-well plate, enabling assay of the response of hundreds of organoids so that organoid subpopulations with distinct behaviors were identifiable. Organoid cell types, monolayer polarity, and growth were similar to those embedded in hydrogel. An automated imaging and analysis platform efficiently tracked over time swelling due to forskolin and fluid movement across the cell monolayer stimulated by cholera toxin. The platform was used to screen compounds associated with the enteric nervous and immune systems for their effect on fluid movement across epithelial cells. Prostaglandin E2 promoted increased water flux in a subset of organoids that resulted in organoid swelling, confirming a role for this inflammatory mediator in diarrheal conditions but also illustrating organoid differences in response to an identical stimulus. By allowing sampling of a large number of organoids, the arrayed organoid platform permits identification of organoid subpopulations intermixed within a larger group of nonresponding organoids. This technique will enable automated, large-scale screening of the impact of drugs, toxins, and other compounds on colonic physiology

Microchip Electrophoresis with Amperometric Detection Method for Profiling Cellular Nitrosative Stress Markers

The overproduction of nitric oxide (NO) in cells results in nitrosative stress due to the generation of highly reactive species such as peroxynitrite and N2O3. These species disrupt the cellular redox processes through the oxidation, nitration, and nitrosylation of important biomolecules. Microchip electrophoresis (ME) is a fast separation method that can be used to profile cellular nitrosative stress through the separation of NO and nitrite from other redox-active intracellular components such as cellular antioxidants. This paper describes a ME method with electrochemical detection (ME-EC) for the separation of intracellular nitrosative stress markers in macrophage cells. The separation of nitrite, azide (interference), iodide (internal standard), tyrosine, glutathione, and hydrogen peroxide (neutral marker) was achieved in under 40 s using a run buffer consisting of 7.5 to 10 mM NaCl, 10 mM boric acid, and 2 mM TTAC at pH 10.3 to 10.7. Initially, NO production was monitored by the detection of nitrite (NO2−) in cell lysates. There was a 2.5- to 4-fold increase in NO2− production in lipopolysaccharide (LPS)-stimulated cells. The concentration of NO2− inside a single unstimulated macrophage cell was estimatedto be 1.41 mM using the method of standard additions. ME-EC was then used for the direct detection of NO and glutathione in stimulated and native macrophage cell lysates. NO was identified in these studies based on its migration time and rapid degradation kinetics. The intracellular levels of glutathione in native and stimulated macrophages were also compared, and no significant difference was observed between the two conditions

Microchip electrophoresis with amperometric detection for the study of the generation of nitric oxide by NONOate salts

Microchip electrophoresis (ME) with electrochemical detection was used to monitor nitric oxide (NO) production from diethylammonium (Z)-1-(N,N-diethylamino)diazen-1-ium-1,2-diolate (DEA/NO) and 1-(hydroxyl-NNO-azoxy)-L-proline disodium salt (PROLI/NO). NO was generated through acid hydrolysis of these NONOate salts. The products of acid hydrolysis were introduced into a 5-cm separation channel using gated injection. The separation was accomplished using reverse polarity and a background electrolyte consisting of 10 mM boric acid and 2 mM tetradecyltrimethylammonium bromide, pH 11. Electrochemical detection was performed using an isolated potentiostat in an in-channel configuration. Potentials applied to the working electrode, typically higher than +1.0 V vs. Ag/AgCl, allowed the direct detection of nitrite, NO, DEA/NO, and PROLI/NO. Baseline resolution was achieved for the separation of PROLI/NO and NO while resolution between DEA/NO and NO was poor (1.0±0.2). Nitrite was present in all samples tested

Community-based interventions for the prevention and control of cutaneous leishmaniasis: A systematic review

We reviewed the evidence on community-based interventions for the prevention and control of cutaneous leishmaniasis (CL). Community initiatives tailored towards awareness and mobilisation are regarded as a priority area in the Neglected Tropical Disease Roadmap 2021–2030 by the World Health Organization. We searched nine electronic databases for intervention-based studies. Two independent reviewers screened and assessed the articles for methodological quality using predefined criteria. We conducted a meta-analysis using a random effects model, along with narrative synthesis. Thirteen articles were eligible for inclusion, of which 12 were quantitative studies (quasi-experimental with control group and pre-post interventions) and one qualitative study. All articles reported on health education interventions aimed at changing people’s knowledge, attitudes, and practices (KAP) in relation to CL. Participant groups included students, mothers, housewives, volunteer health workers, and residents in general. An increased score was recorded for all outcomes across all interventions: knowledge (SMD: 1.85, 95% CI: 1.23, 2.47), attitudes (SMD: 1.36, 95% CI: 0.56, 2.15), and practices (SMD: 1.73, 95% CI: 0.99, 2.47). Whilst our findings show that educational interventions improved people’s knowledge, attitudes, and practices about CL, we argue that this approach is not sufficient for the prevention and control of this disease. Knowledge does not always translate into action, particularly where other structural barriers exist. Therefore, we recommend the design of more innovative community-based interventions with a broader focus (e.g., stigma, financial barriers, and healthcare access)

The Impact of Entrepreneurial Orientation on Business Performance in Star Class Hotels of Sri Lanka

The article studies the relationship between the Entrepreneurial Orientation and Business Performance in star class hotels of Sri Lanka The study has utilized data collected from 215 senior managers employed in the star class hotel sector CFA SEM analysis was performed using AMOS 21 to identify the relationship The quantitative data analysis revealed there is a significant relationship between Entrepreneurial Orientation and Business performance Further it was found Proactiveness Risk Taking Innovativeness Autonomy and Competitor Aggressiveness are dimensions of Entrepreneurial Orientatio