Elevated levels of iron in groundwater in Prey Veng province in Cambodia : a possible factor contributing to high iron stores in women

This work was carried out with the aid of a grant from Canada’s International Development Research Centre (IDRC), and with financial support from the Government of Canada, provided through Global Affairs Canada (GAC)Iron is a natural element found in food, water and soil and is essential for human health. Our aim was to determine the levels of iron and 25 other metals and trace elements in groundwater from 22 households in Prey Veng, Cambodia. Water analyses were conducted using inductively coupled plasma–mass spectrometry and optical emission spectrometry. Compared to the 2011 World Health Organization guidelines for drinking water quality, aluminum, iron and manganese exceeded maximum levels (in 4.5, 72.7 and 40.9% of samples, respectively). Compared to the 2004 Cambodian drinking water quality standards, iron and manganese exceeded maximum levels (in 59.1 and 36.4% of samples, respectively). We found no evidence of arsenic contamination. Guidelines for iron were established primarily for esthetic reasons (e.g. taste), whereas other metals and elements have adverse effects associated with toxicity. Iron in groundwater ranged from 134 to 5,200 μg/L (mean ∼1,422 μg/L). Based on a daily consumption of 3 L groundwater, this equates to ∼0.4–15.6 mg iron (mean ∼4.3 mg/day), which may be contributing to high iron stores and the low prevalence of iron deficiency anemia in Prey Veng women. Elevated levels of manganese in groundwater are a concern and warrant further investigation

Evaluation of two methods to measure hemoglobin concentration among women with genetic hemoglobin disorders in Cambodia : a method-comparison study

Background: Genetic hemoglobin (Hb) E variants are common in Cambodia and result in an altered and unstable Hb molecule.We evaluated two methods to measure Hb concentration among individuals with and without Hb variants using a hemoglobinometer (HemoCue®) and a hematology analyzer (Sysmex XT-1800i). Methods: We determined the bias and concordance between the methods among 420 Cambodian women (18–45 y). Results: Bias and concordance appeared similar betweenmethods amongwomenwith no Hb disorders (n=195, bias= 2.5, ρc= 0.68), women with Hb E variants (n= 133, bias= 2.5, ρc =0.78), and women with other Hb variants (n=92, bias=2.7, ρc=0.73). The overall bias was 2.6 g/l, resulting in a difference in anemia prevalence of 11.5% (41% using HemoCue®and 29.5% using Sysmex, p b 0.001). Based on visual interpretation of the concordance plots, the HemoCue® device appears to underestimate Hb concentrations at lower Hb concentrations and to overestimate Hb concentrations at higher Hb concentrations (in comparison to the Sysmex analyzer). Conclusions: Bias and concordance were similar across groups, suggesting the two methods of Hb measurement were comparable.We caution field staff, researchers and policy makers in the interpretation of data and the impact that bias between methods can have on anemia prevalence rates

Karakochuk - BMC Public Health manuscript - Sept 2014 (annex 18a)

Background: Genetic hemoglobin (Hb) E variants are common in Cambodia and result in an altered and unstable Hb molecule. There are no known studies on the accuracy of Hb measurement among individuals with Hb E or other Hb variants. Methods: This method-comparison study evaluates two methods to measure Hb concentration in capillary blood using a hemoglobinometer (HemoCueÒ) and in venous blood using an automated hematology analyzer (Sysmex XT-1800i). We determined the bias and concordance between the two methods among 420 non-pregnant women (18-45 y) in Cambodia using secondary data from a separate trial. Results: Bias and concordance appeared similar between methods among women with no Hb disorders (n=195, bias=2.5, rc=0.68), women with Hb E variants (n=133, bias=2.5, rc=0.78), and women with other Hb variants (n=92, bias=2.7, rc=0.73). Overall, agreement was poor between methods. The overall bias was 2.6 g/L (difference in Hb means between methods), resulting in a difference in anemia prevalence of 11.5% (41% using HemoCueÒ and 29.5% using Sysmex, p<0.001). This changes the WHO anemia severity from a ‘moderate’ to a ‘severe’ public health problem. Based on concordance plots, the HemoCueÒ device appears to underestimate Hb concentrations in capillary blood as compared to Sysmex (venous blood) at lower Hb concentrations, and to overestimate Hb concentrations in capillary blood as compared to Sysmex at higher Hb concentrations. Conclusions: Bias and concordance were similar among all groups, suggesting the two methods of Hb measurement were comparable. We highlight the bias between the two methods to caution field staff, researchers and policy makers in the interpretation of data and the impact that even a small bias between methods can have on anemia prevalence rates

Prevalence of Vitamin D Deficiency Varies Widely by Season in Canadian Children and Adolescents with Sickle Cell Disease

Sickle cell disease (SCD) is an inherited disorder caused by a variant (rs334) in the β-globin gene encoding hemoglobin. Individuals with SCD are thought to be at risk of vitamin D deficiency. Our aim was to assess serum 25-hydroxyvitamin D (25OHD) concentrations, estimate deficiency prevalence, and investigate factors associated with 25OHD concentrations in children and adolescents with SCD attending BC Children’s Hospital in Vancouver, Canada. We conducted a retrospective chart review of SCD patients (2–19 y) from 2012 to 2017. Data were available for n = 45 patients with n = 142 25OHD measurements assessed using a EUROIMMUN analyzer (EUROIMMUN Medizinische Labordiagnostika AG, Lübeck, Germany). Additional data were recorded, including age, sex, and season of blood collection. Linear regression was used to measure associations between 25OHD concentration and predictor variables. Overall, mean ± SD 25OHD concentration was 79 ± 36 nmol/L; prevalence of low 25OHD concentrations (<30, <40, and <75 nmol/L) was 5%, 17% and 50%, respectively. Mean 25OHD concentrations measured during Jul–Sep were higher (28 (95% confidence interval CI: 16–40) nmol/L higher, P < 0.001) compared to Jan–Mar. Vitamin D deficiency rates varied widely by season: Based on 25OHD <30 nmol/L, prevalence was 0% in Oct–Dec and 6% in Jan–Mar; based on <40 nmol/L, prevalence was 0% in Oct–Dec and 26% in Jan–Mar.Medicine, Faculty ofOther UBCPathology and Laboratory Medicine, Department ofPediatrics, Department ofReviewedFacult

Folic acid supplementation in children with sickle cell disease: study protocol for a double-blind randomized cross-over trial

Background: Sickle cell disease (SCD) is a genetic disorder which causes dysfunctional red blood cells (RBC) and is thought to increase requirements for folate, an essential B vitamin, due to increased RBC production and turnover in the disease. High-dose supplementation with 1–5 mg/d folic acid, synthetic folate, has been the standard recommendation for children with SCD. There is concern about whether children with SCD need such high doses of folic acid, following mandatory folic acid fortification of enriched grains in Canada, and advancements in medical therapies which extend the average lifespan of RBCs. In animal and human studies, high folic acid intakes (1 mg/d) have been associated with accelerated growth of some cancers, and the biological effects of circulating unmetabolized folic acid (UMFA), which can occur with doses of folic acid ≥ 0.2 mg/d, are not fully understood. The objective of this study is to determine efficacy of, and alterations in folate metabolism from high-dose folic acid in children with SCD during periods of folic acid supplementation versus no supplementation. Methods: In this double-blind randomized controlled cross-over trial, children with SCD (n = 36, aged 2–19 years) will be randomized to either receive 1 mg/d folic acid, the current standard of care, or a placebo for 12 weeks. After a 12-week washout period, treatments will be reversed. Total folate concentrations (serum and RBC), different folate forms (including UMFA), folate-related metabolites, and clinical outcomes will be measured at baseline and after treatment periods. The sum of the values measured in the two periods will be calculated for each subject and compared across the two sequence groups by means of a test for independent samples for the primary (RBC folate concentrations) and secondary (UMFA) outcomes. Dietary intake will be measured at the beginning of each study period. Discussion: As the first rigorously designed clinical trial in children with SCD, this trial will inform and assess current clinical practice, with the ultimate goal of improving nutritional status of children with SCD. Trial registration: ClinicalTrials.gov NCT04011345 . Registered on July 8, 2019Land and Food Systems, Faculty ofMedicine, Faculty ofOther UBCNon UBCPathology and Laboratory Medicine, Department ofPediatrics, Department ofPopulation and Public Health (SPPH), School ofReviewedFacult

Alkaline phosphatase-positive colony formation is a sensitive, specific, and quantitative indicator of undifferentiated human embryonic stem cells

Human embryonic stem cells (hESCs) can be maintained in vitro as immortal pluripotent cells but remain responsive to many differentiation-inducing signals. Investigation of the initial critical events involved in differentiation induction would be greatly facilitated if a specific, robust, and quantitative assay for pluripotent hESCs with self-renewal potential were available. Here we describe the results of a series of experiments to determine whether the formation of adherent alkaline phosphatase-positive (AP+) colonies under conditions optimized for propagating undifferentiated hESCs would meet this need. The findings can be summarized as follows. (a) Most colonies obtained under these conditions consist of ≥30 AP+ cells that coexpress OCT4, NANOG, SSEA3, SSEA4, TRA-1-60, and TRA-1-81. (b) Most such colonies are derived from SSEA3+ cells. (c) Primary colonies contain cells that produce secondary colonies of the same composition, including cells that initiate multi-lineage differentiation in embryoid bodies (EBs). (d) Colony formation is independent of plating density or the colony-forming cell (CFC) content of the test population over a wide range of cell concentrations. (e) CFC frequencies decrease when differentiation is induced by exposure either to retinoic acid or to conditions that stimulate EB formation. Interestingly, this loss of AP+ clonogenic potential also occurs more rapidly than the loss of SSEA3 or OCT4 expression. The CFC assay thus provides a simple, reliable, broadly applicable, and highly specific functional assay for quantifying undifferentiated hESCs with self-renewal potential. Its use under standardized assay conditions should enhance future elucidation of the mechanisms that regulate hESC propagation and their early differentiation

Genetic hemoglobin disorders rather than iron deficiency are a major predictor of hemoglobin concentration in women of reproductive age in rural Prey Veng, Cambodia

Background: Anemia is common in Cambodian women. Potential causes include micronutrient deficiencies, genetic hemoglobin disorders, inflammation, and disease. Objectives: We aimed to investigate factors associated with anemia (low hemoglobin concentration) in rural Cambodian women (18–45 y) and to investigate the relations between hemoglobin disorders and other iron biomarkers. Methods: Blood samples were obtained from 450 women. A complete blood count was conducted, and serum and plasma were analyzed for ferritin, soluble transferrin receptor (sTfR), folate, vitamin B-12, retinol binding protein (RBP), C-reactive protein (CRP), and a1 acid glycoprotein (AGP). Hemoglobin electrophoresis and multiplex polymerase chain reaction were used to determine the prevalence and type of genetic hemoglobin disorders. Results: Overall, 54% of women had a genetic hemoglobin disorder, which included 25 different genotypes (most commonly, hemoglobin E variants and a3.7-thalassemia). Of the 420 nonpregnant women, 29.5% had anemia (hemoglobin 8.3 mg/L), 5 mg/L) and 26% (AGP >1 g/L) of nonpregnant women, respectively. By using an adjusted linear regression model, the strongest predictors of hemoglobin concentration were hemoglobin E homozygous disorder and pregnancy status. Other predictors were 2 other heterozygous traits (hemoglobin E and Constant Spring), parity, RBP, log ferritin, and vitamin B-12. Conclusions: Multiple biomarkers for anemia and iron deficiency were significantly influenced by the presence of hemoglobin disorders, hence reducing their diagnostic sensitivity. Further investigation of the unexpectedly low prevalence of IDA in Cambodian women is warranted