Finger-prick Samples Research Articles

Intervals to Plasmodium falciparum recurrence after anti-malarial treatment in pregnancy: a longitudinal prospective cohort.

BackgroundPlasmodium falciparum infections adversely affect pregnancy. Anti-malarial treatment failure is common. The objective of this study was to examine the duration of persistent parasite carriage following anti-malarial treatment in pregnancy.MethodsThe data presented here are a collation from previous studies carried out since 1994 in the Shoklo Malaria Research Unit (SMRU) on the Thailand-Myanmar border and performed using the same unique methodology detailed in the Materials and Methods section. Screening for malaria by microscopy is a routine part of weekly antenatal care (ANC) visits and therapeutic responses to anti-malarials were assessed in P. falciparum malaria cases. Women with microscopy confirmed P. falciparum malaria had a PCR blood spot from a finger-prick sample collected. Parasite DNA was extracted from the blood-spot samples using saponin lysis/Chelex extraction method and genotyped using polymorphic segments of MSP1, MSP2 and GLURP. Recurrent infections were classified by genotyping as novel, recrudescent or indeterminate. Factors associated with time to microscopy-detected recrudescence were analysed using multivariable regression techniques.ResultsFrom December 1994 to November 2009, 700 women were treated for P. falciparum and there were 909 recurrent episodes (481 novel and 428 recrudescent) confirmed by PCR genotyping. Most of the recurrences, 85 % (770/909), occurred after treatment with quinine monotherapy, artesunate monotherapy or artesunate-clindamycin. The geometric mean number of days to recurrence was significantly shorter in women with recrudescent infection, 24.5 (95 %: 23.4-25.8), compared to re-infection, 49.7 (95 %: 46.9-52.7), P <0.001. The proportion of recrudescent P. falciparum infections that occurred after days 28, 42 and 63 from the start of treatment was 29.1 % (124/428), 13.3 % (57/428) and 5.6 % (24/428). Recrudescent infections ≥100 days after treatment occurred with quinine and mefloquine monotherapy, and quinine + clindamycin and artesunate + atovaquone-proguanil combination therapy. Treatments containing an artemisinin derivative or an intercalated Plasmodium vivax infection increased the geometric mean interval to recrudescence by 1.28-fold (95 % CI: 1.09-1.51) and 2.19-fold (1.77-2.72), respectively. Intervals to recrudescence were decreased 0.83-fold (0.73-0.95) if treatment was not fully supervised (suggesting incomplete adherence) and 0.98-fold (0.96-0.99) for each doubling in baseline parasitaemia.ConclusionsProlonged time to recrudescence may occur in pregnancy, regardless of anti-malarial treatment. Long intervals to recrudescence are more likely with the use of artemisinin-containing treatments and also observed with intercalated P. vivax infections treated with chloroquine. Accurate determination of drug efficacy in pregnancy requires longer duration of follow-up, preferably until delivery or day 63, whichever occurs last.

Blood Lactate Levels Measured Using Finger Prick vs. Venous Blood Draw Methods

Audriana Mooth, Paul Hafen, Andy Larsen, Kurtis Rosengreene, Gregory Savio, Sean Catlett, Parker Wood, Mark McKay, Pat Vehrs, FACSM. Brigham Young University, Provo, UT. (Sponsor: Pat Vehrs, FACSM) (No relationships reported) Blood lactate measurements can be a useful tool in developing endurance training programs, and is used in different settings by athletes hoping to improve their performance. In most cases, handheld blood lactate meters are the most practical way to measure blood lactate, and can take measurements from a finger prick or sample of blood drawn intravenously. PURPOSE: The purpose of this study was to compare the blood lactate measurements taken from a finger prick versus an intravenous blood draw during steady-state aerobic exercise using the NOVA Lactate Plus handheld meter. METHODS: Seven male runners, ages 18-39, with a weekly training mileage of 25-60 miles and 5K run times of less than 18:25 participated in this study. Exercise testing determined lactate threshold and VO2max for all six volunteers, and maximal lactate steady-state (MLSS) was found for each participant as they completed multiple submaximal steady-state runs. An intravenous catheter positioned in the antecubital vein was used to obtain blood samples during the submaximal steady-state runs. Finger prick samples were taken simultaneously. The NOVA Lactate Plus was used to determine blood lactate levels using the intravenously drawn blood and finger prick samples. Lactate was measured twice from the intravenously drawn blood and once from the finger prick. RESULTS: The lactate values from the two samples of intravenously drawn blood were not significantly different (0.009 mmol/L; p=0.790) and were highly correlated (R=0.995). The lactate values from the finger prick blood samples were significantly different (p=0.0001) than the intravenous blood samples. On average, the lactate values measured from the finger prick samples were 1.41 mmol/L greater than the lactate values measured from the intravenous blood samples. CONCLUSIONS: Compared to intravenous blood samples, finger prick samples tend to overestimate blood lactate levels. Use caution when using lactate measurements from finger prick blood samples to develop endurance.

The Chhattisgarh state screening programme for the sickle cell gene: a cost-effective approach to a public health problem.

In India, the Chhattisgarh State screening programme for sickle haemoglobin focuses on children aged 3-15years and has screened over 1,050,440 subjects over the last 6years. Commencing in the District around the capital Raipur, this programme has now completed screening in 7 of the 27 Districts of Chhattisgarh State. Screening is initially performed by solubility tests on fingerprick samples in the field and those with positive tests have venipunctures for haemoglobin electrophoresis. The frequency of the sickle cell trait was 9.64% and of the SS phenotype 0.29% with only two Districts in Hardy-Weinberg equilibrium, most Districts showing an excess of the SS 'phenotype' most readily explained by symptomatic selection. The estimated costs were US$0.28 (solubility tests alone) and US$0.60 (haemoglobin electrophoresis). Of the social groupings commonly used in India, the OBC's (other backward classes) had the highest frequencies of the sickle cell gene mutations, followed by the Scheduled Tribes and the Scheduled Castes. The objectives of the programme were the detection of sickle cell disease for prospective clinical management and of the sickle cell trait for purposes of genetic counselling. The former objective is being met for diagnosis although the success of referral to clinic services requires audit. The objective of genetic counselling is compromised by the failure of the screening test to detect other genes of potential clinical significance such as HbD Punjab and the beta thalassaemia trait. Despite these exceptions, the detection of HbS appears relatively robust and could be another condition factored into the traditions of partner selection amongst the underprivileged communities of this state. Overall, the Chhattisgarh programme seeks to address the daunting challenges of large populations carrying the sickle cell gene and maybe a useful model for elsewhere.

Therapeutic drug monitoring of carbamazepine and its metabolite in children from dried blood spots using liquid chromatography and tandem mass spectrometry

Carbamazepine (CBZ) is a first-line drug for the treatment of different forms of epilepsy and the first choice drug for trigeminal neuralgia. CBZ is metabolized in the liver by oxidation into carbamazepine-10,11-epoxide (CBZE), its major metabolite which is equipotent and known to contribute to the pharmacological activity of CBZ. The aim of the present study was to develop and validate a reliable, selective and sensitive liquid chromatography–tandem mass spectrometry method for the simultaneous quantification of CBZ and its active metabolite in dried blood spots (DBS). The extraction process was carried out from DBS using methanol–water–formic acid (80:20:0.1, v/v/v). Chromatographic elution was achieved by using a linear gradient with a mobile phase consisting of acetonitrile–water–0.1% formic acid at a flow rate of 0.50mL/min. The method was linear over the range 1–40mg/L and 0.25–20mg/L for CBZ and CBZE, respectively. The limit of quantification was 0.75mg/L and 0.25mg/L for CBZ and CBZE. Intra-day and inter-day assay precisions were found to be lower than 5.13%, 6.46% and 11.76%, 4.72% with mean percentage accuracies of 102.1%, 97.5% and 99.2%, 97.8% for CBZ and CBZE. We successfully applied the method for determining DBS finger-prick samples in paediatric patients and confirmed the results with concentrations measured in matched plasma samples. This novel approach allows quantification of CBZ and its metabolite from only one 3.2mm DBS disc by LC–MS/MS thus combining advantages of DBS technique and LC–MS/MS in clinical practice.

Effect of a low dose whey/guar preload on glycemic control in people with type 2 diabetes--a randomised controlled trial.

ObjectiveLarge preloads of protein and fat have been shown to lower glucose after a carbohydrate-rich meal in people with type 2 diabetes but add a considerable energy burden. Low calorie preloads [<5% of daily energy intake] have been tested in this study in people with prediabetes and with type 2 diabetes.Research design and methodsThis was an unblinded randomised crossover study with two placebo days and two active treatment days. Glucose was measured for 3 hours with fingerprick samples as well as continuous glucose monitoring [CGMS]. Twenty-four subjects with pre-diabetes or moderately controlled type 2 diabetes [fasting glucose < 10 and HbA1c < 8.5%] were recruited. The preload contained 17 g whey protein plus 3 g lactose and 5 g guar, and 1 g flavour material [including sucralose] dissolved in 150 ml cold water or 150 ml cold water with no additives. The breakfast test meal consisted of 2 slices of bread, margarine and jam [3 slices for men] with the test drink 15 minutes beforehand.ResultsPeak fingerprick glucose was reduced by 2.1 mmol/L at 45 min [p < 0.0001]. Average fingerprick glucose over 3 hours was reduced by 0.8 mmol/L [p = 0.0003]. There was no difference between those with diabetes or prediabetes or those on medication or not on medication.ConclusionsAn 80 kcal whey protein/fibre preload can lower average glucose over 3 hours by 0.8 mmol/L. If used long term before at least two carbohydrate-rich meals/day this preload could lower HbA1c by up to 1%.Trial registrationThe trial was registered with the Australian New Zealand Clinical Trials Registry number ACTRN12612001251819.

THE DIFFERENCES IN CHD RISK FACTORS AND LIFESTYLE PARAMETERS BETWEEN ARAB AND MALAYSIAN ADOLESCENTS IN KUALA LUMPUR

Studying Arab and Malaysian students at international schools appears new to the research field, as there is little in the way of data or literature review that has been obtained to date.The purpose of this study is to compare lifestyle parameters (physical activity, body composition, fitness level and Coronary Heart Disease (CHD) risk factors) of Arab and Malaysian adolescents Method:a total of 190 adolescents students, 96 Malaysian and 94 Arab, both male and female aged 14-16 years old, participated in this research.A questionnaire was used to obtain details of physical activity levels (PAL) in Metabolic Equivalents. A 20m shuttle-run test was used to estimate the fitness level (VO2max). A finger prick sample of fasting blood was obtained to measure high-density (HDL) lipoprotein, low-density lipoprotein (LDL), total cholesterol (TC), glucose (GLU) and triglycerides (TRG) in mmoll and identify CHD risk factors, by using the Cholestch LDX analyzer. BMI and %fat used for the body compositions. Conclusion:males were more physically active than females.Arab students had lower BMI, GLU, and TC and participated more in physical activities, and their fitness level was higher than Malaysian students at international schools.Malaysian adolescents had higher triglycerides levels than Arab adolescents.

The postprandial glucose response to some varieties of commercially available gluten-free pasta: a comparison between healthy and celiac subjects.

The objective of the present paper is to evaluate the post-prandial response to some varieties of gluten free (GF) pasta that are commonly consumed in Italy. The glycaemic responses were compared with a glucose standard in healthy subjects and gluten-free diet celiac subjects. Subjects were served portions of the test foods and a standard food (glucose), on separate occasions, each containing 50 g available carbohydrates. Capillary blood glucose was measured from finger-prick samples in fasted subjects and at 15, 30, 45, 60, 90 and 120 minutes after the consumption of each test food. For each type of pasta, the glycaemic index (GI) was calculated by expressing the incremental area under the blood glucose curve as a percentage of each subject's average incremental area under the blood glucose curve (AUC) for the standard food. Gluten free pasta exhibited a range of GI values from 46 to 66. The glycaemic load (GL) and glycaemic profile (GP) were also calculated. A higher GI value was observed in pasta containing rice flour as the main ingredient. Lower values were observed in pasta obtained using corn or a mixture of corn and rice flour as the main ingredients. The results were confirmed in celiac subjects. The information presented in this paper may be useful in helping celiac people to select low-GI pasta.

Human Finger-Prick Induced Pluripotent Stem Cells Facilitate the Development of Stem Cell Banking

Induced pluripotent stem cells (iPSCs) derived from somatic cells of patients can be a good model for studying human diseases and for future therapeutic regenerative medicine. Current initiatives to establish human iPSC (hiPSC) banking face challenges in recruiting large numbers of donors with diverse diseased, genetic, and phenotypic representations. In this study, we describe the efficient derivation of transgene-free hiPSCs from human finger-prick blood. Finger-prick sample collection can be performed on a "do-it-yourself" basis by donors and sent to the hiPSC facility for reprogramming. We show that single-drop volumes of finger-prick samples are sufficient for performing cellular reprogramming, DNA sequencing, and blood serotyping in parallel. Our novel strategy has the potential to facilitate the development of large-scale hiPSC banking worldwide.

Gamma-H2AX biodosimetry for use in large scale radiation incidents: comparison of a rapid ‘96 well lyse/fix’ protocol with a routine method

Following a radiation incident, preliminary dose estimates made by γ-H2AX foci analysis can supplement the early triage of casualties based on clinical symptoms. Sample processing time is important when many individuals need to be rapidly assessed. A protocol was therefore developed for high sample throughput that requires less than 0.1 ml blood, thus potentially enabling finger prick sampling. The technique combines red blood cell lysis and leukocyte fixation in one step on a 96 well plate, in contrast to the routine protocol, where lymphocytes in larger blood volumes are typically separated by Ficoll density gradient centrifugation with subsequent washing and fixation steps. The rapid ‘96 well lyse/fix’ method reduced the estimated sample processing time for 96 samples to about 4 h compared to 15 h using the routine protocol. However, scoring 20 cells in 96 samples prepared by the rapid protocol took longer than for the routine method (3.1 versus 1.5 h at zero dose; 7.0 versus 6.1 h for irradiated samples). Similar foci yields were scored for both protocols and consistent dose estimates were obtained for samples exposed to 0, 0.2, 0.6, 1.1, 1.2, 2.1 and 4.3 Gy of 250 kVp X-rays at 0.5 Gy/min and incubated for 2 h. Linear regression coefficients were 0.87 ± 0.06 (R2 = 97.6%) and 0.85 ± 0.05 (R2 = 98.3%) for estimated versus actual doses for the routine and lyse/fix method, respectively. The lyse/fix protocol can therefore facilitate high throughput processing for γ-H2AX biodosimetry for use in large scale radiation incidents, at the cost of somewhat longer foci scoring times.

A Novel Dried Blood Spot-LCMS Method for the Quantification of Methotrexate Polyglutamates as a Potential Marker for Methotrexate Use in Children

ObjectiveDevelopment and validation of a selective and sensitive LCMS method for the determination of methotrexate polyglutamates in dried blood spots (DBS).MethodsDBS samples [spiked or patient samples] were prepared by applying blood to Guthrie cards which was then dried at room temperature. The method utilised 6-mm disks punched from the DBS samples (equivalent to approximately 12 µl of whole blood). The simple treatment procedure was based on protein precipitation using perchloric acid followed by solid phase extraction using MAX cartridges. The extracted sample was chromatographed using a reversed phase system involving an Atlantis T3-C18 column (3 µm, 2.1×150 mm) preceded by Atlantis guard column of matching chemistry. Analytes were subjected to LCMS analysis using positive electrospray ionization.Key ResultsThe method was linear over the range 5–400 nmol/L. The limits of detection and quantification were 1.6 and 5 nmol/L for individual polyglutamates and 1.5 and 4.5 nmol/L for total polyglutamates, respectively. The method has been applied successfully to the determination of DBS finger-prick samples from 47 paediatric patients and results confirmed with concentrations measured in matched RBC samples using conventional HPLC-UV technique.Conclusions and Clinical RelevanceThe methodology has a potential for application in a range of clinical studies (e.g. pharmacokinetic evaluations or medication adherence assessment) since it is minimally invasive and easy to perform, potentially allowing parents to take blood samples at home. The feasibility of using DBS sampling can be of major value for future clinical trials or clinical care in paediatric rheumatology.

Prospective Evaluation of Diagnostic Accuracy of Dried Blood Spots from Finger Prick Samples for Determination of HIV-1 Load with the NucliSENS Easy-Q HIV-1 Version 2.0 Assay in Malawi

HIV-1 viral load (VL) testing is not widely available in resource-limited settings. The use of finger prick dried blood spot (FP-DBS) samples could remove barriers related to sample collection and transport. Measurement of VL using DBS from EDTA venous blood (VB-DBS) in place of plasma has previously been validated using the NucliSENS Easy-Q HIV-1 v2.0 assay, but information on the accuracy of FP-DBS samples for measuring VL is limited. This prospective study, conducted at Thyolo District Hospital in southern Malawi, compared VL levels measured on FP-DBS samples and plasma using the NucliSENS Easy-Q HIV-1 v2.0 assay. Comparability was assessed by means of agreement and correlation (131 patients with VLs of ≥100 copies/ml), sensitivity, and specificity (612 patients on antiretroviral treatment [ART]). Samples of EDTA venous blood and FP-DBS from 1,009 HIV-infected individuals were collected and prepared in the laboratory. Bland-Altman analysis found good agreement between plasma and FP-DBS VL levels, with a mean difference of -0.35 log10, and 95% limits of agreement from -1.26 to 0.55 log10. FP-DBS had a sensitivity of 88.7% (95% confidence interval [CI], 81.1 to 94.4%) and a specificity of 97.8% (95% CI, 96.1 to 98.9%) using a 1,000-copies/ml cut point and a sensitivity of 83.0% (95% CI, 73.4 to 90.1%) and a specificity of 100% (95% CI, 99.3 to 100%) using a 5,000-copies/ml cut point. This study shows that FP-DBS is an acceptable alternative to plasma for measuring VL using the NucliSENS Easy-Q HIV-1 v2.0. We are conducting a second study to assess the proficiency of health workers at preparing FP-DBS in primary health care clinics.

The routine paediatric human immunodeficiency virus visit as an intervention opportunity for failed maternal care, and use of point-of-care CD4 testing as an adjunct in determining antiretroviral therapy eligibility

South African women and children remain at the centre of the human immunodeficiency virus (HIV) pandemic, and maternal well-being plays a critical role in child health. In this study, we evaluated the impact of the paediatric visit on the determination of antiretroviral therapy (ART) eligibility in mothers using Alere Pima™ Analyser (Pima™) testing as an adjunct to routine care. Fifty-two mothers who had failed to obtain routine CD4 screening were enrolled during the paediatric visit at Tygerberg Children’s Hospital between November 2011 and May 2012. Clinical staging assessments and parallel standard CD4 cell count testing were performed. Finger-prick samples for the Pima™, and simultaneous venous samples for reference flow cytometry, were obtained. The Pima™ identified 37% of mothers as meeting ART eligibility versus 35% using the reference flow cytometry method. An additional 4% of mothers were identified using World Health Organization clinical staging only. The sensitivity of the Pima™ was 89%, speci...

Evaluation of Plasmodium falciparum gametocyte detection in different patient material

BackgroundFor future eradication strategies of malaria it is important to control the transmission of gametocytes from humans to the anopheline vector which causes the spread of the disease. Sensitive, non-invasive methods to detect gametocytes under field conditions can play a role in monitoring transmission potential.MethodsMicroscopically Plasmodium falciparum-positive patients from Jimma, Ethiopia donated finger-prick blood, venous blood, saliva, oral mucosa and urine samples that were spotted on filter paper or swabs. All samples were taken and stored under equal, standardized conditions. RNA was extracted from the filter paper and detected by real-time QT-NASBA. Pfs16-mRNA and Pfs25-mRNA were measured with a time to positivity to detect gametocyte specific mRNA in different gametocyte stages. They were compared to 18S-rRNA, which is expressed in all parasite stages. Results were quantified via a known dilution series of artificial RNA copies.ResultsNinety-six samples of 16 uncomplicated malaria patients were investigated. 10 (66.7%) of the slides showed gametocyte densities between 0.3-2.9 gametocytes/μl. For all RNA-targets, molecular detection in blood samples was most sensitive; finger-prick sampling required significantly smaller amounts of blood than venous blood collection. Detection of asexual 18S-rRNA in saliva and urine showed sensitivities of 80 and 67%, respectively. Non-invasive methods to count gametocytes proved insensitive. Pfs16-mRNA was detectable in 20% of urine samples, sensitivities for other materials were lower. Pfs25-mRNA was not detectable in any sample.ConclusionsThe sensitivity of non-invasively collected material such as urine, saliva or mucosa seems unsuitable for the detection of gametocyte-specific mRNA. Sensitivity in asymptomatic carriers might be generally even lower. Finger-prick testing revealed the highest absolute count of RNA copies per μL, especially for Pfs25-mRNA copies. The method proved to be the most effective and should preferably be applied in future transmission control and eradication plans. A rapid test for gametocyte targets would simplify efforts.

Evaluation of PIMA analyzer detecting CD4 cell count of venous and capillary blood in HIV-infected individuals

This study is aimed at evaluating the utility of the portable CD4 analyzers (PIMA). The paired finger prick blood (25 µl) and 5 ml venous blood samples were collected from 196 HIV infected patients, who came to Yunnan CDC voluntary counseling and testing (VCT) clinic for CD4 test services, from May to August, 2012. The absolute CD4 cell counts were measured by PIMA (using venous and finger-prick blood) and by Calibur (using venous blood) as the reference. The PIMA and Calibur CD4 results were compared using the Wilcoxon matched-pairs test, and the Spearman's rank correlation coefficients were estimated. The Bland-Altman plots were used to assess the consistency of the two methods. The median absolute CD4 counts of 196 venous blood samples obtained by PIMA and by Calibur were 268 (range:169-403) cells/µl and 302 (range:181-474) cells/µl respectively, which showed significant difference (Z = -7.31, P < 0.01). The median absolute CD4 counts measured by PIMA and by Calibur (using 188 finger-prick and venous blood samples respectively) were 271 (range: 165-450) cells/µl and 304 (range:188-476) cells/µl, which also showed significant difference (Z = -7.60, P < 0.01). The CD4 counts obtained by PIMA CD4 analyzer (using venous and finger-prick blood) showed strong positive correlation with the CD4 counts obtained by the reference method (using venous blood), and the r values were 0.94 and 0.92 respectively (P < 0.01) . The mean biases (limit of agreement) were -38.7 (-210.9-133.5)cells/µl and -45.4 (-221.8-131.0) cells/µl, respectively.Using 350 CD4 counts as the threshold for ART treatment initiation, the sensitivity and specificity of PIMA were 99.1% and 79.3% for venous blood samples, and 97.2%and 78.5% for finger-prick blood samples, respectively. The CD4 counts obtained by PIMA are lower than that obtained by Calibur, while the sensitivity is high.

Therapeutic drug monitoring of ciclosporin A and tacrolimus in heart lung transplant patients using dried blood spots

Therapeutic drug monitoring of ciclosporin A (CsA) and tacrolimus is traditionally performed using venous whole blood sampling. A number of reports have described development of ultra high-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) methods for the quantitation of CsA and tacrolimus from dried blood spots (DBS), which may offer a convenient alternative. As yet, no such reports have validated this methodology using fingerprick capillary DBS samples collected from transplant patients. Capillary fingerprick DBS were collected from heart and lung transplant patients in a specialist cardiothoracic transplant centre. We utilized our previously published method for the extraction and simultaneous quantitation of CsA and tacrolimus from DBS using UPLC-MS/MS. Drug concentrations measured from DBS were compared to concentrations measured in venous whole blood by our routine clinical UPLC-MS/MS assay. In total, 91 heart or lung transplant patients were enrolled onto the study; 46 patients were on CsA therapy and 45 on tacrolimus therapy. Passing-Bablock analysis demonstrated excellent agreement between capillary fingerprick DBS samples and venous whole blood samples. There was a mean positive bias of 2.6 µg/L (95% confidence interval (CI) -2.2 to 7.5 µg/L) for CsA (n = 45) and mean negative bias of -0.7 µg/L (95% CI -1.1 to -0.3 µg/L) for tacrolimus (n = 42). We demonstrate utility of DBS for serial monitoring of CsA and tacrolimus using UPLC-MS/MS in heart and lung transplant patients. This may offer significant advantages for these patients including the ability to take capillary DBS samples in the community prior to clinic visits.

Microfluidic analysis of cellular deformability of normal and oxidatively damaged red blood cells

Microfluidic analysis of blood has potential clinical value for determining normal and abnormal erythrocyte deformability. To determine if a microfluidic device could reliably measure intra- and inter-personal variations of normal and oxidized human red blood cell (RBC), venous blood samples were collected from repeat donors over time. RBC deformability was defined by the cortical tension (pN/µm), as determined from the threshold pressure required to deform RBC through 2-2.5 μm funnel-shaped constrictions. Oxidized RBC were prepared by treatment with phenazine methosulphate (PMS; 50 µM). Analysis of the control and oxidized RBC demonstrated that the microfluidic device could clearly differentiate between normal and mildly oxidized (20.13 ± 1.47 versus 27.51 ± 3.64 pN/µm) RBC. In vivo murine studies further established that the PMS-mediated loss of deformability correlated with premature clearance. Deformability variation within an individual over three independent samplings (over 21 days) demonstrated minimal changes in the mean pN/µm. Moreover, inter-individual variation in mean control RBC deformability was similarly small (range: 19.37-21.40 pN/µm). In contrast, PMS-oxidized cells demonstrated a greater inter-individual range (range: 25.97-29.90 pN/µm) reflecting the differential oxidant sensitivity of an individual's RBC. Importantly, similar deformability profiles (mean and distribution width; 20.49 ± 1.67 pN/µm) were obtained from whole blood via finger prick sampling. These studies demonstrated that a low cost microfluidic device could be used to reproducibly discriminate between normal and oxidized RBC. Advanced microfluidic devices could be of clinical value in analyzing populations for hemoglobinopathies or in evaluating donor RBC products post-storage to assess transfusion suitability.

Flow cytometric comparison of platelets from a whole blood and finger-prick sample: impact of 24 hours storage

In this study, we investigate the validity and laboratory utility of flow cytometry when analyzing platelet activation by studying CD41, CD42b, CD62P and CD63. We compare flow cytometry results from citrated whole-blood and finger-prick samples directly after collection and also after storing both a finger-prick and whole-blood sample for 24 hours. Citrated whole-blood and finger-prick samples were taken from three healthy individuals on two occasions, and a total of 60 000 cells were analyzed for each of the four phycoerythrin-labeled monoclonal antibodies. Half of each sample was analyzed immediately after sampling while the other half was kept in the fridge at 6°C for 24 hours before analysis. No significant difference was found between the sampling methods or the period of time before analysis. Results therefore suggest that an appropriately prepared finger-prick sample can be used for platelet function analysis, and samples can be stored for 24 hours in the fridge at 6°C before analysis.

Asymptomatic malaria and intestinal helminth co-infection among children in a rural community in Southwest Nigeria.

Malaria is prevalent in sub-Saharan Africa, where other concomitant parasitic infections, including intestinal helminths, are common. However, little is known about how concurrent infections affect the expression or pathogenesis of each other. This study aimed to document the prevalence rates of malaria and intestinal helminths individually and as co-infection among asymptomatic children in a rural community in southwest Nigeria. Apparently healthy children aged 1-17 years, who were enrolled into a larger study that evaluated the efficacy and safety of two anti-helminthic drugs, were evaluated for intestinal helminths by stool examination using the saline wet mount and Kato-Katz methods. Capillary blood from finger prick samples was used for haematocrit determination and malaria screening by microscopy. Data analysis was conducted using SPSS and significance levels were set at p < 0.05. Eighty-nine of 178 (50%) enrolees were male. One hundred and fifteen of the 178 (64.6%) children had at least one intestinal helminthic infection while 69 (60%) thereof harboured multiple helminthic infections. Malaria parasites were encountered in 35/178 (19.7%) of the enrolees. Parasite density was ≤500/μl in 51.4% (18/35), 501-1,000/μl in 9 (25.7%) and 1,000-4,720/μl in 8 (22.9%) of the children. Malaria-helminth co-infection was detected in 24/115 (20.9%) of the children. The prevalence [60/115 (52.2%) versus 8/63 (12.7%) p<0.0001] and severity of anaemia were significantly higher among children with worms compared to those without worms. For mild anaemia this was 53/115 (46.8%; with worms) versus 7/63 (11.1%; no worms p<0.0001); for moderate anaemia 2/115 (1.74%; with worms) versus 1/63 (1.59%; without worms; p<0.271). Malaria and helminths co-infection is common among apparently asymptomatic children in the rural community studied. Co-infections increase the problems associated with anaemia and aggravate the burden of disease in Nigerian children.

The Glycemic Index of Traditional Types of Bread in UAE

Background: The Glycemic Index (GI) of traditional bread has not been measured previously. Objective: To determine the GIs of 3 traditional breads and 3 commercial breads widely consumed in the United Arab Emirates (UAE). Design: The study was conducted at the Rashid Center for Diabetes and Research in the UAE. Subjects (n=14) were served 50 g glucose (reference) on 3 occasions, followed by a selection of 50 g of available carbohydrates in the breads. Each bread was tested by 7 subjects, and these breads were 3 traditional breads (rigag, chbab, and khameer) and 3 commercial breads widely consumed in the UAE (white pita bread, khobuz; white bread roll, summon; whole-meal bread). After an 8- to 10-hour overnight fast, the subjects’ capillary blood glucose was measured via finger-prick samples over 120 min. The GI (%) of a specific bread for each subject was measured geometrically (trapezoids rule) by calculating the incremental area under the blood glucose response curve (IAUC) divided by the average IAUC for the reference (in triplicate) multiplied by 100. Then, the GI of the bread was calculated as the mean value across all subjects who consumed that bread. Results: Compared to the control (50 g glucose), the GIs of the traditional UAE bread ranged between low and medium; the GIs for rigag, chbab, and khameer were 48.21(15.6), 63.95 (7.06), and 63.91 (11.49), respectively. AllGIs exhibited a significant difference (P 0.05), and 66.71 (14.68) (P<0.05), respectively. The correlation between the GI value in the studied portion and fat (r=0.04) and protein (r=0.18) was weak, but that with insoluble fiber was moderate (r=0.48). Conclusion: The GI values of these traditional UAE breads provide valuable information to healthcare providers, researchers, and the public. The difference between our GI values and that of previously tested food proves the importance of testing the food consumed in a particular country.

Which point-of-care creatinine analyser for radiology: direct comparison of the i-Stat and StatStrip creatinine methods with different sample types

Availability of whole blood creatinine estimation for patients scheduled to undergo radiological contrast investigations can provide information to aid patient care by reducing adverse effects and improving departmental efficiencies. We performed imprecision studies, different patient sample type comparison in 40 participants, and a limited interference study with dopamine and dobutamine on the i-Stat and StatStrip point-of-care enzymatic analysers with the Beckman DxC800 Jaffe assay. Imprecision results showed that the i-Stat performed better. Patient comparison data indicated that the i-Stat provided better correlation than the StatStrip for all the different sample types with correlation coefficients (r(2)) being 0.995-0.996 and 0.918-0.995, respectively. The i-Stat results had a small positive bias of 6-9% for the three different sample types, which required different reference intervals. The StatStrip method showed greater scatter and overall small negative bias of -6% for the whole blood samples and a 10% positive bias with the plasma samples. Dopamine caused significant positive interference with the i-Stat only while dobutamine caused a small negative bias with the StatStrip method only. The findings indicated there are differences offered by the two systems. The StatStrip requires a very small finger prick capillary sample, calculates estimation of the glomerular filtration rate and has an adjustment option to improve correlation with the local method. The i-Stat offers better analytical imprecision and patient comparison with the laboratory method with the three sample types but showed significant interference from dopamine. A final consideration was the availability of middleware to capture patient results with the i-Stat. Based on all the study data, the i-Stat was recommended.