Journal de bioanalyse et de biomédecine

Background: The stability of viral load in a patient blood sample during storage and shipping is an important pre-analytical variable that affects the accuracy of viral pathogen quantitation. Therefore, there is a need for developing a blood collection tube with stabilizing reagents which can not only inactivate the viral agent but also stabilize the viral nucleic acids for accurate viral load determination in blood samples post blood draw. This study was undertaken to investigate the ability of Cyto-Chex® BCT (BCT) blood collection device to stabilize the nucleic acids of the Mason-Pfizer monkey virus, an RNA virus, in collected blood specimens during storage and shipping for viral load determination at a later time point.

Findings: Blood was drawn from each donor into K3EDTA and BCT tubes, spiked with Mason-Pfizer monkey virus particles and stored at room temperature. Viral RNA was extracted using RNeasy® FFPE Kit. Our results demonstrate that the viral RNA was stable in blood drawn into BCT after storage at 22°C for 7 days. Virus stored in blood drawn into K3EDTA tubes showed a decrease in viral load over time and a statistically significant decrease was observed at day 7. Shipping blood samples which took 3 days did not have adverse effect on viral load measurements for blood samples collected in BCT.

Conclusion: Our results demonstrate that BCT can stabilize viral load in blood during shipping and storage at 22°C for 7 days.

Different beer brands produced in Ethiopia were surveyed for the presence of Cd, Cu, Pb, Mn and Zn. The samples were digested in nitric acid and hydrogen peroxide, and analysed by atomic absorption spectrometry equipped with deuterium arc background corrector. The mean concentrations of metals in beer were as follows: Cd, 0.0014 mg/l; Cu, 0.0368 mg/l; Mn, 0.0954 mg/l; Pb, 0.006 mg/l; Zn, 1.5206 mg/l. The estimated daily intakes were calculated based on Ethiopian annual per capita beer consumption of 8.75 liters. The mean intakes of Cd, Cu, Pb, Mn and Zn through beer were estimated to be 0.0006, 0.0232, 0.0024, 0.0378 and 0.6076 μg/kg bw/day, respectively. The risk assessment of mean levels indicated that health risk associated with these heavy metals through consumption of beer was absent.

Background: Non-adherence to tuberculosis (TB) treatment in TB/human immunodeficiency virus (HIV) coinfected patients greatly affect treatment outcome. It can lead to an increased risk of drug resistance which is difficult to treat and contribute to increased mortality. Therefore, this study was aimed to determine the prevalence and factors associated with non-adherence to anti-TB drugs among TB/HIV co-infected patients in Mekelle, Ethiopia.

Methods: A health institution based cross-sectional study was conducted in Mekelle from March to April 2013. Consecutive sampling was used to select respondents. Data were collected with the help of a structured questionnaire and analyzed using the Statistical Package for Social Sciences (SPSS) version 20.0 software.

Results: The prevalence of non-adherence to anti-TB medications among TB/HIV co-infected patients was 55.8% in a 5-day period prior to the interview. From logistic regression models, patients who had no caregivers (Adjusted Odds Ratio (AOR)=3.73, 95% CI=1.15-12.11) and people to remind them to take their medications (AOR=11.15, 95% CI=1.66-74.91) were more likely to be non-adherent. The major reasons cited for missing medicines were forgetting to take medications, felt sick when take the medications and far away from health facilities.

Conclusions: The prevalence of non-adherence was high. TB/HIV co-infected patients should be targeted with interventions to improve medication adherence, particularly by supporting them to continue their treatment.

Due to high affinity between biotin and avidin, biotinylation is widely used in ligand-binding-assay development for large-molecule bioanalysis. However, biotinylation adds biotin/spacer moiety onto the molecule and may affect the functional activity of the labeled molecule. The current Gyrolab™ immunoassay system requires the capture reagent to be biotinylated as the solid phase comprises a streptavidin-coated-bead column. During method development of a Gyrolab assay for quantification of otelixizumab, we discovered that the response and assay sensitivity was affected by freeze-thaw, which might be related to the type of spacers used between the biotin and the labeled antibody. The hydrophilic Polyethylene Glycol (PEG) spacer enhances water solubility but might be more liable to freeze-thaw compared to antibodies labeled with reagents having only hydrocarbon spacers. The overall response increased 10 fold after 8-hour incubation of the PEG-reagent at benchtop after thaw. The signal-to-background increased 8 fold for the same treatment. In contrast, no significant change upon freeze-thaw was observed for reagents with hydrocarbon spacers. Since Gyrolab assays do not require prolonged incubation, it provides an effective tool for assessing critical reagents in assay development and optimization, especially for evaluating time-dependent parameters for immunoassays

The CRISPR-Cas9 (clustered regularly interspaced short palindromic repeats with CRISPR-associated protein 9) system is a genome editing system that is easy to design, highly specific, efficient, robust, and well suited for highthroughput and multiplexed gene editing for a variety of cell types and organisms. In this review we describe current applications of this new system, which is growing in popularity and is increasingly being employed to selectively control gene expression on a genome-wide scale.

Orexin A is a hypothalamic neuropeptide produced in the dorsal and lateral hypothalamus, and orexin-producing cell have widespread anatomical projections within the central nervous system. Orexin A is involved in multiple physiological functions, including eating behavior, thermoregulation, and sleep-regulation. The aim of this work was to study the thermal preference induced by orexin A. A thermal preference task with floor thermal gradient from 16°C to 25°C, divided into 10 equal segments, was designed to evaluate the thermal preferences in rats. Male rats (n=10, divided into two groups of five animals) received an intracerebroventricular injection of 1.5 nmol of orexin A or vehicle and were subsequently tested for thermal preference for 4 h. The results showed that the rats injected with orexin A had increased motor activity compared to the control group, particularly after the second hour of the test. Moreover the group treated with orexin A preferred hotter temperatures ranging from 24 to 25°C compared to the control group that preferred temperature of 22°C, which is near room temperature for rat housing (22 ± 1°C). No significant correlation was seen between thermal preference and time (hours). Since orexin A induces thermal preference, this study indicates that this neuropeptide plays a key role in the thermoregulation.