Repolarisation descriptors and heart rate variability in hemodialysed patients

T wave morphology (TWM) descriptors derived from Holter electrocardiograms during hemodialysis (HD) are of potential value for cardiac risk assessment in HD patients. Our knowledge on autonomic regulation of TWM descriptors is limited. The purpose of this study was to investigate the association between TWM parameters and heart rate variability (HRV) during intradialytic monitoring. In each of 81 patients on maintenance HD, continuous electrocardiograms were recorded 5 times during HD on alternate weeks. TWM descriptors were calculated every 5 s in overlapping 10-s ECG segments and Low Frequency (LF) (0.04 Hz to 0.15 Hz), High Frequency (HF) (0.15 Hz to 0.40 Hz) powers of the spectrum of HRV were calculated every five min. The calculated values of TWM and HRV were averaged during the first hour of the recordings and subsequently over all recordings in each subject. Analyzable data for HRV and TWM were available in 71 HD patients (aged 61+/-15, 36 % diabetics, 32 % females). LF in normalized units correlated positively with Total Cosine R to T (r=0.374, p=0.001) and negatively with T wave morphology dispersion (r=-0.253, p=0.033) after adjusting for heart rate. A heart rate independent association between repolarisation descriptors and HRV exists in HD patients. Autonomic modulation needs to be considered when using TWM characteristics for risk profiling of HD patients.

Haematology patients and the Internet--the use of on-line health information and the impact on the patient-doctor relationship

OBJECTIVE

Patients access on-line health information (OHI) to better understand their health. We aimed to determine which demographic factors influence OHI use. We also explored how OHI is used and subsequent implications to the patient-doctor relationship.

METHODS

We distributed a self-administered questionnaire to 202 haematology out-patients.

RESULTS

62.3% used the internet and 54.3% used OHI. Higher education, (P<0.001, OR 34.62, 95% CI 5.20-230.66) and household incomes of £15000-25000 (P=0.023 OR 4.8 95% CI 1.236-18.59) were positively associated with OHI use. Those reassured after reading OHI had improved trust in their specialist (P<0.001, OR 52.1, 95% CI 12.3-221.1), improved confidence during consultations, (P<0.001, OR 23.0, 95% CI 2.8-188.2) and were improved decisions makers (P=0.008, OR 13.6, 95% CI 4.1-45.7). Those with increased trust in their haematologist also had improved confidence (P<0.001, OR 6.2, 95% CI 2.2-17.3) and improved decision making ability (P<0.001, OR 13.6, 95% CI 4.7-39.4). 74.6% of patients did not share OHI with their haematologist.

CONCLUSIONS

Two-thirds of participants were exposed directly or indirectly to OHI. OHI affects patients' view of their health and influences behaviour during consultations.

PRACTICE IMPLICATIONS

Haematologists could facilitate patients using OHI by recommending high quality websites and act supportively when patients share OHI.

In vitro evaluation of combination of polyenes with EDTA against Aspergillus spp. by different methods (FICI and CI Model)

AIMS

We investigated in vitro activity of polyene drugs (amphotericin B, Amp B; and nystatin, NYS;) in combination with ethylene diamine tetra acetic acid (EDTA) against 8 pathogenic isolates of Aspergillus spp.

METHODS AND RESULTS

The intensity of the drug interactions was assessed using Fractional Inhibitory Concentration Index (FICI) model and Combination Index (CI) model. The interactions were further confirmed by time-kill curve study. The best combination ratio was subjected for toxicity analysis by MTT and haemolytic assay. A significant synergy was found between each of two polyenes with EDTA against Aspergillus fumigatus and Aspergillus flavus at one ratio four. The FICI ranged from 0·29 to 0·38 against A. fumigatus and A. flavus. The FICI value ranged from 0·78 to 1·26 showed no interaction against Aspergillus niger. The CI value (0·21-0·30) and time-kill curve analysis also confirmed synergistic interaction. Antagonism was not detected. There was reduction in toxicity of Amp B and NYS when used with EDTA.

CONCLUSIONS

Subsequently, the chelating agent (EDTA) can be used in combination with Amp B and NYS with increased antifungal potential and reduced toxicity.

SIGNIFICANCE AND IMPACT OF THE STUDY

To emphasize new development in antifungal drug discovery, combination therapy can be used as a tool box to expand drug development.

Knowledge and perceptions of prescribers regarding adherence to standard treatment guidelines for malaria: a comparative cross-sectional study from Pakistan

Despite the availability of standard treatment guidelines for malaria in Pakistan adherence to protocols by prescribers is poor. This descriptive, cross-sectional study aimed to explore the perceptions and knowledge of prescribers in Islamabad and Rawalpindi cities towards adherence to standard treatment guidelines for malaria. A questionnaire was distributed to a random sample of 360 prescribers; 64.7% were satisfied with the available antimalarial drugs and 41.3% agreed that antimalarial drugs should only be prescribed after diagnostic testing. Only half the prescribers had the guidelines available in their health facility. Almost all the prescribers (97.7%) agreed that there was a need for more educational programmes about the guidelines. Most prescribers were unaware of the correct standard treatment regimen for Plasmodium falciparum and P. vivax malaria. There were no differences in knowledge between males and females, but prescribers having more experience, practising as general practitioners and working in private health-care facilities possessed significantly better knowledge than their counterparts.

Simulation of Co-Rotating Twin Screw Extrusion Process Subject to Pressure-Dependent Wall Slip at Barrel and Screw Surfaces: 3D FEM Analysis for Combinations of Forward- and Reverse-Conveying Screw Elements

Mathematical modeling and simulation of the coupled flow, deformation, heat and mass transfer, and rate of reactions occurring in the twin screw extruder allow the optimization of process parameters and the screw and barrel geometries. In mathematical modeling of the twin screw extrusion process the conventional flow boundary condition at the screw and barrel walls is the no-slip condition. However, most complex fluids, including polymers, polymeric suspensions and blends, exhibit wall slip, with the slip behavior depending on the intrinsic properties of the materials being processed, the operating conditions, the geometries of the barrel, screw and the die, and the properties of the solid surfaces. Typically, the slip velocity is specified to be a function of temperature, stress condition at the wall and the materials of construction. However, recent investigations have further revealed that the wall slip behavior can also be significantly affected by pressure. With an objective of considering the effects of wall slip on the dynamics of twin screw extrusion, fully-intermeshing co-rotating twin screw extrusion of a concentrated suspension is analyzed using three-dimensional finite element method, FEM, subject to the wall slip boundary condition. The wall slip boundary condition is first applied systematically to barrel and screw surfaces individually followed by the application of wall slip to both surfaces simultaneously. In an integrated fashion both the forward-conveying (pressure-generating) and reverse-conveying (pressure-losing) screw sections are considered. The effects of pressure on wall slip are also analyzed and elucidated.

The challenges of publishing on health informatics in developing countries

The Journal of Health Informatics in Developing Countries was established to meet a perceived need for Health Informaticians in developing countries to be able to share the results of their research in an affordable and easy-to-access online publication. The journal was developed using the open source platform "Open Journal System," and has now published 67 articles across 13 issues. A collaborative editorial approach has been established to address the problems of limited research budgets, difficulties with translating to English and other problems specific to authors from developing countries. The journal faces many challenges including ensuring future financial sustainability and inclusion in journal indexing systems. However, the continuing support of an international body of Associate Editors and Editorial Board Members has enabled a wide range of useful and informative health informatics research to be disseminated across the developing world.

Reproducibility and validity of a quantitative food frequency questionnaire in an urban and rural area of northern India

Background. Food frequency questionnaires (FFQs) have been used in epidemiological studies across the world to capture the usual food intake of individuals. As food habits vary in different population groups, FFQs should be validated before use. Hence, we determined the reproducibility and validity of FFQs designed for urban and rural populations of northern India. Methods. Separate FFQs, designed for urban and rural populations using standard methods, were administered to a sample of 200 subjects (100 urban and 100 rural) in the age group of 35-70 years in the beginning (baseline FFQ) of the study and after an interval of 1 year (1-year FFQ) to assess their reproducibility. Six 24-hour dietary-recalls, taken at an interval of 2 months over a period of 1 year, were used as a reference method to test the validity. Crude and energy- adjusted nutrient intakes estimated from FFQs and 24-hour dietary-recalls were compared using Pearson correlation coefficients. Bland and Altman plots were also used to test the agreement between the two methods. Results. Nutrient intakes were found to be similar at the baseline and 1-year FFQs in urban and rural areas. The unadjusted Pearson correlation between 24-hour dietary- recalls and 1-year FFQ ranged from 0.22 for vitamin C to 0.63 for iron in the urban area. It ranged from 0.06 for vitamin C to 0.74 for energy in the rural area. The correlations lowered after adjusting for energy and there was a minimal increase after de-attenuation. Conclusion. The FFQs were reproducible and valid for assessing nutrient intakes except for some micronutrients.

The state of hepatitis B and C in the Mediterranean and Balkan countries: report from a summit conference

The burden of disease due to chronic viral hepatitis constitutes a global threat. In many Balkan and Mediterranean countries, the disease burden due to viral hepatitis remains largely unrecognized, including in high-risk groups and migrants, because of a lack of reliable epidemiological data, suggesting the need for better and targeted surveillance for public health gains. In many countries, the burden of chronic liver disease due to hepatitis B and C is increasing due to ageing of unvaccinated populations and migration, and a probable increase in drug injecting. Targeted vaccination strategies for hepatitis B virus (HBV) among risk groups and harm reduction interventions at adequate scale and coverage for injecting drug users are needed. Transmission of HBV and hepatitis C virus (HCV) in healthcare settings and a higher prevalence of HBV and HCV among recipients of blood and blood products in the Balkan and North African countries highlight the need to implement and monitor universal precautions in these settings and use voluntary, nonremunerated, repeat donors. Progress in drug discovery has improved outcomes of treatment for both HBV and HCV, although access is limited by the high costs of these drugs and resources available for health care. Egypt, with the highest burden of hepatitis C in the world, provides treatment through its National Control Strategy. Addressing the burden of viral hepatitis in the Balkan and Mediterranean regions will require national commitments in the form of strategic plans, financial and human resources, normative guidance and technical support from regional agencies and research.

An Integrated Approach for Numerical Analysis of Coupled Flow and Heat Transfer in Co-rotating Twin Screw Extruders

The co-rotating twin screw extrusion process is widely employed in chemical industries for the processing of complex fluids including various polymers, suspensions, emulsions and gels. Here we propose a new integrated modeling strategy that is based on the numerical analysis of pressure-generating extrusion elements concomitantly with the pressure-losing extrusion elements of the co-rotating twin screw extrusion process for non-Newtonian fluids under nonisothermal conditions. The numerical analysis undertakes three-dimensional (3-D) finite element simulations of any multiple combinations of forwarding and reversing fully-flighted screw elements with other types of elements including kneading discs staggered in the forward or reverse configurations and the die. The abilities of the methodologies in simulating the coupled flow and heat transfer in industrially-relevant mixing sections or pressurization/die shaping are demonstrated with predictions of the degree of fill and typical velocity, deformation rate, stress magnitude, pressure distributions as functions of various operating parameters and basic twin screw extrusion geometries for a viscoplastic type generalized Newtonian fluid.

Infection prevention and control measures for acute respiratory infections in healthcare settings: an update

Viruses account for the majority of the acute respiratory tract infections (ARIs) globally with a mortality exceeding 4 million deaths per year. The most commonly encountered viruses, in order of frequency, include influenza, respiratory syncytial virus, parainfluenza and adenovirus. Current evidence suggests that the major mode of transmission of ARls is through large droplets, but transmission through contact (including hand contamination with subsequent self-inoculation) and infectious respiratory aerosols of various sizes and at short range (coined as "opportunistic" airborne transmission) may also occur for some pathogens. Opportunistic airborne transmission may occur when conducting highrisk aerosol generating procedures and airborne precautions will be required in this setting. General infection control measures effective for all respiratory viral infections are reviewed and followed by discussion on some of the common viruses, including severe acute respiratory syndrome (SARS) coronavirus and the recently discovered novel coronavirus.