Prevalence of glucose-6-phosphate dehydrogenase deficiency in Cameroonian blood donors.

OBJECTIVE: Deficiency in G6PD is the most common enzymopathy worldwide. It is frequently found in individuals of African descent in whom it can lead to hemolytic crises triggered by the use of certain antimalarial medications and infection. The prevalence of G6PD deficiency and its contribution to morbidity in West Africa is under-studied. To understand the prevalence of glucose-6-phosphate dehydrogenase (G6PD) deficiency in West African blood donors. RESULTS: We evaluated the G6PD status and infectious disease screening tests of 1001 adult male Cameroonian blood donors (mean age 31.7 ± 9.8 years). The prevalence of G6PD deficiency was 7.9%. There was no difference in levels of hemoglobin or ABO subtype between those who were G6PD-normal compared to those that were deficient. Interestingly, G6PD-normal vs. deficient blood donors were less likely to have screened positive for hepatitis C virus (p = 0.02) and rapid plasma reagin (indicative of syphilis, p = 0.03). There was no significant difference in hepatitis B sAg, HIV-1, or HIV-2 reactivity between those with vs. without G6PD sufficiency. These data suggest that G6PD deficiency is common among West African male blood donors and may be associated with specific infectious disease exposure.

Subdissociative intranasal ketamine plus standard pain therapy versus standard pain therapy in the treatment of paediatric sickle cell disease vaso-occlusive crises in resource-limited settings: study protocol for a randomised controlled trial.

INTRODUCTION: Pediatric sickle cell disease, highly prevalent in sub-Saharan Africa, carries great morbidity and mortality risk. Limited resources and monitoring make management of acute vaso-occlusive crises challenging. This study aims to evaluate the efficacy and safety of subdissociative intranasal ketamine as a cheap, readily available and easily administered adjunct to standard pain therapy. We hypothesise that subdissociative, intranasal ketamine may significantly augment current approaches to pain management in resource-limited settings in a safe and cost-effective manner. METHODS AND ANALYSIS: This is a multicentred, randomised, double-blind, placebo-controlled trial enrolling children 4-16 years of age with sickle cell disease and painful vaso-occlusive pain crises. Study sites include two sub-Saharan teaching and referral hospitals with acute intake areas. All patients receive standard analgesic therapy during evaluation. Patients randomised to the treatment arm receive 1 mg/kg intranasal ketamine at onset of therapy, while placebo arm participants receive volume-matched intranasal normal saline. All participants and clinical staff are blinded to the treatment allocation. Data will be analysed on an intention-to-treat basis. Primary endpoints are changes in self-report pain scales (Faces Pain Scale-Revised) at 30, 60 and 120 minutes and rates of adverse events. Secondary endpoints include hospital length of stay, total analgesia use and quality of life assessment 2-3 weeks postintervention. ETHICS AND DISSEMINATION: The research methods for this study have been approved by the Cameroon Baptist Convention Health Board Institutional Review Board (IRB2015-07), the Tanzanian National Institute for Medical Research (NIMR/HQ/R.8a/Vol. IX/2299), Muhimbili National Hospital IRB (MNH/IRB/I/2015/14) and the Tanzanian Food and Drugs Authority (TFDA0015/CTR/0015/9). Data reports will be provided to the Data and Safety Monitoring Board (DSMB) periodically throughout the study as well as all reports of adverse events. All protocol amendments will also be reviewed by the DSMB. Study results, regardless of direction or amplitude, will be submitted for publication in relevant peer-reviewed journals. TRIAL REGISTRATION: ClinicalTrials.Gov, NCT02573714. Date of registration: 8 October 2015. Pre-results.

Regulatory volume response following hypotonic stress in Atlantic salmon erythrocytes.

The purpose of this study was to examine regulatory volume decrease (RVD) in Atlantic salmon red blood cells (RBCs). Osmotic fragility was determined optically, mean cell volume was measured electronically, and changes in intracellular Ca(2+) concentration were visualized using fluorescence microscopy and fluo-4-AM. Cells displayed an increase in osmotic fragility and an inhibition of volume recovery following hypotonic shock when they were exposed to a high taurine Ringer or when placed in a high K(+) medium. Interestingly, RVD in cells from fish collected during the summer depended more on taurine efflux, whereas fall cells relied more on the loss of K(+). In addition, RVD in fall cells was prevented with the K(+) channel inhibitor quinine, whereas the ionophore gramicidin decreased osmotic fragility and potentiated volume recovery. Further, hypotonic shock (0.5X Ringer) for both summer and fall cells caused an increase in cytosolic Ca(2+), which resulted from influx of this ion because it was not observed when extracellular Ca(2+) was chelated with EGTA (10 nM free Ca(2+)). Cells exposed to a low Ca(2+) hypotonic Ringer also had a greater osmotic fragility and failed to recover from hypotonic swelling. Finally, inhibition of phospholipase A(2) with ONO-RS-082 blocked volume recovery. In conclusion, Atlantic salmon RBCs displayed volume decrease in response to hypotonic shock, which depended on a swelling-induced influx of Ca(2+) and an increase in the efflux of K(+) and taurine.