Large Number Of Blood Samples Research Articles

Investigation of different methods in rapid microbial identification directly from positive blood culture bottles by MALDI-TOF MS.

Sepsis is a life-threatening condition, and rapid and accurate identification of the causative microorganisms from blood cultures is crucial for timely and effective treatment. Although there are many studies on direct identification from blood cultures with MALDI-TOF MS, further standardization is still needed. In our study, we analyzed the performance of three different preparation methods and compared by using two analysis modules of the Bruker Biotyper MALDI-TOF MS for direct identification of bacteria from numerous positive blood culture bottles. The literature reports a limited number of studies that compare different preparation methods for direct blood culture identification, processing a large number of blood samples concurrently and evaluating the same samples as in our study. Moreover, although SDS is used very frequently in medical laboratories, there are few studies on direct identification from blood culture bottles. In our study, the highest correct identification rate was observed with the SDS method.

A simple and accurate LC‑MS/MS method for monitoring cyclosporinA that is suitable for high throughput analysis.

With time, the number of samples in clinical laboratories from therapeutic drug monitoring has increased. Existing analytical methods for blood cyclosporin A (CSA) monitoring, such as high-performance liquid chromatography (HPLC) and immunoassays, have limitations including cross-reactivity, time consumption, and the complicated procedures involved. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) has long been considered the reference standard owing to its high accuracy, specificity, and sensitivity. However, large numbers of blood samples, multi-step preparation procedures, and longer analytical times (2.5-20 min) are required as a consequence of the different technical strategies, to ensure good analytical performance and routine quality assurance. A stable, reliable, and high throughput detection method will save personnel time and reduce laboratory costs. Therefore, a high throughput and simple LC-MS/MS method was developed and validated for the detection of whole-blood CSA with CSA-d12 as the internal standard in the present study. Whole blood samples were prepared through a modified one-step protein precipitation method. A C18 column (50x2.1 mm, 2.7 µm) with a mobile phase flow rate of 0.5 ml/min was used for chromatographic separation with a total running time of 4.3 min to avoid the matrix effect. To protect the mass spectrometer, only part of the sample after LC separation was allowed to enter the mass spectrum, using two HPLC systems coupled to one mass spectrometry. In this way, throughput was improved with detection of two samples possible within 4.3 min using a shorter analytical time for each sample of 2.15 min. This modified LC-MS/MS method showed excellent analytical performance and demonstrated less matrix effect and a wide linear range. The design of multi-LC systems coupled with one mass spectrometry may play a notable role in the improvement of daily detection throughput, speeding up LC-MS/MS, and allowing it to be an integral part of continuous diagnostics in the near future.

Efficient and Simple Paper-Based Assay for Plasma Separation Using Universal Anti-H Agglutinating Antibody.

Conventional laboratory tests require plasma separation using centrifugation by skilled personnel in well-equipped lab. Development of a simple, reliable, and cheap point-of-care (POC) test for plasma separation will overcome these limitations. Plasma separation was achieved in filter paper using the anti-H agglutinating antibody. Hydrophobic channels were created using a solid ink printer. The reproducibility, efficiency, recovery, and applicability of the assay were validated on a large number of blood samples. A simple, fast, cheap, and direct paper-based assay for plasma separation from whole blood using universal anti-H agglutinating antibody was developed without equipment or pretreatment requirements. The purity of plasma separation using anti-H treated paper was confirmed by microscopy and biuret test for plasma albumin detection. Plasma separation was affected by paper structure, antibody concentration, donor gender, and hematocrit. The efficiency of the assay was 72% and the reproducibility was about 90% with minimal interassay and intra-assay variabilities. The assay successfully separated plasma from 116/119 samples, indicating high sensitivity (97.5%). Furthermore, the assay accurately recovers thyroid stimulating hormone from samples compared to standard methods with 107% recovery rate. Paper-based plasma separation using anti-H agglutinating antibodies would have numerous applications in paper-based POC tests and in resource limited areas.

Evaluation of a haemozoin-based rapid diagnostic test for diagnosis of imported malaria during the phase of prevention of reestablishment in Sri Lanka

BackgroundSri Lanka, an island nation, has eliminated endemic malaria transmission. Maintaining elimination in the continued presence of vectors requires vigilance in screening people travelling from high malaria-risk areas and a rapid response with focal screening for infections identified in the community. Such screening requires accurate and very rapid assays that enable an immediate response. Both microscopy and rapid diagnostic tests (RDTs) have limitations including sensitivity and speed in screening large numbers, while polymerase chain reaction (PCR) is practical only as laboratory confirmation. This study assessed the utility of ‘Gazelle’, a novel rapid malaria assay based on magneto-optical detection of haemozoin, a by-product of malaria parasite metabolism.MethodsBetween October 2020 and March 2021, two groups of individuals were screened for malaria by four methods, namely, microscopy, Rapid Diagnostic Test (RDT), Gazelle and PCR. Passive case detection was carried out for confirmation of diagnosis amongst individuals suspected of having malaria. Individuals at high-risk of acquiring malaria, namely persons returning from malaria endemic countries, were screened by active case detection.ResultsOf the 440 individuals screened for malaria, nine malaria positives were diagnosed by PCR, microscopy and the HRP2 band of RDT, which included five Plasmodium falciparum infections, two Plasmodium ovale, and one each of Plasmodium vivax and Plasmodium malariae. Gazelle correctly detected the P. vivax, P. ovale and P. malariae infections within the 2 min test time, but did not detect two P. falciparum infections giving a sensitivity of 77.8%. Specificity was 100%.DiscussionThe Gazelle, a portable bench top device proved useful to screen a large number of blood samples for non-falciparum parasites within 5 minutes of sample input. Species differentiation, and improvement in P. falciparum detection, will be important to broaden utility.

Data mining of pediatric reference intervals

Abstract Laboratory tests are essential to assess the health status and to guide patient care in individuals of all ages. The interpretation of quantitative test results requires availability of appropriate reference intervals, and reference intervals in children have to account for the extensive physiological dynamics with age in many biomarkers. Creation of reference intervals using conventional approaches requires the sampling of healthy individuals, which is opposed by ethical and practical considerations in children, due to the need for a large number of blood samples from healthy children of all ages, including neonates and young infants. This limits the availability and quality of pediatric reference intervals, and ultimately negatively impacts pediatric clinical decision-making. Data mining approaches use laboratory test results and clinical information from hospital information systems to create reference intervals. The extensive number of available test results from laboratory information systems and advanced statistical methods enable the creation of pediatric reference intervals with an unprecedented age-related accuracy for children of all ages. Ongoing developments regarding the availability and standardization of electronic medical records and of indirect statistical methods will further improve the benefit of data mining for pediatric reference intervals.

A Survey on Identification of Blood Group Types and its Hemoglobin Estimation Using Image Processing

It is very crucial to determine human blood groups in an emergency situation. But according to current system, the detection procedure is very slow. At present, human blood groups are determined manually through plate test procedure. It consists of blood collection and mixing with specific reagents in order to determine the blood agglutination. Blood typing is system which basically used to detect specific blood group of human. Investigation of appropriate blood type within short interval of time plays vital role in blood transfusion, donation, accident and other emergency situations. Currently, blood typing tests are performed by technicians in laboratories. But it is monotonous to do with large number of blood samples, require more time to diagnosis and, as these tests carried out manually, it may introduce human error which will be harmful. Hemoglobin (Hb), a very significant parameter for the human body and deficiency of it causes anemia. During pregnancy, menstruation and ICU deficiency of it can be very risky and even caused death. So, it is important to diagnose it continuously. Usually, physicians examine it by conducting a blood test to confirm it is painful, time-consuming and costly. The major concept of this study is to screen Hb levels within a short period of time. This paper focused on recent advances in detection of blood group with hemoglobin, which can classify different blood group within short period of time with great accuracy and calculate its hemoglobin level.

Ellipsoidal mirror dark-field scanning for detection of circulating tumor cells

The detection of circulating tumor cells (CTCs) plays a very important role in the prevention and treatment of cancer. However, because of the low content of tumor cells in peripheral blood, these cells have always been difficult to detect. An efficient and accurate imaging method, the dark-field scanning imaging method, was innovatively proposed for the detection of CTCs in filtered and colored peripheral blood specimens. Here, the original dark-field scanning system was improved. By introducing an ellipsoidal mirror system, the noise in the sampling process is greatly reduced, and the sampling accuracy is significantly improved. Meanwhile, an automatic identification algorithm was developed to identify and screen CTCs in a large number of blood samples. Comparing with the other CTC detection methods, this method does not require a complex biological enrichment process, which may cause loss and destruction of CTCs.

Increasing DNA Isolation Performance from Blood Cells Using a Modified Commercial Low-Cost Reagent.

Genomic studies facilitate comprehension of the pathophysiology, diagnosis, and treatment of chronic diseases. Such studies require sufficient and good quality DNA isolated from a large number of blood samples. This study attempts to obtain a high-quality genomic DNA isolated from a large number of blood samples using a simple and cheap method. The EasyPure® Genomic DNA Kit (Transgen Biotech) was modified to increase the amount of DNA recovery: a few steps and two additional column elutions were added to the original manufacturer´s procedure. The amount of DNA isolated from frozen blood samples increased by an average of 56%. Its 260/280 ratio and electrophoretic mobility properties make it suitable for genomic studies. A relatively low-cost commercial column and a simple modification of the manufacturer´s protocol, provided a simple and cheap procedure to isolate high-quality DNA from a large number of blood samples suitable for genomic studies.

Cloning, expression & evaluation of potential immunogenic recombinant capsid premembrane protein of West Nile virus.

Background & objectives:West Nile virus (WNV) is a neurotropic flavivirus that has emerged globally as a significant cause of viral encephalitis. The early confirmatory diagnosis of WNV infections is important for timely clinical management and in areas where multiple flaviviruses are endemic. Diagnosis of WNV infection is primarily based on serodiagnosis, followed by virus isolation and identification. The aim of this study was to develop and evaluate a highly sensitive and specific immunoglobulin M (IgM) ELISA using the recombinant CprM protein (rWNV-CprM) for rapid, early and accurate diagnosis of WNV.Methods:The gene coding for the CprM protein of WNV was cloned and expressed in pET 28a vector followed by purification. An indirect IgM microplate ELISA using purified rWNV-CprM protein was optimized having no cross-reactivity with healthy human serum and serum samples obtained from patients with dengue and Japanese encephalitis viruses infection.Results:The comparative evaluation of this rWNV-CprM protein-specific IgM ELISA with plaque reduction neutralization test using 105 blood samples collected from patients suspected to have acute WNV infection revealed 98 per cent concordance with sensitivity and specificity of 100 and 97 per cent, respectively.Interpretation & conclusions:The recombinant CprM protein-based WNV-specific ELISA reported in this study may be useful for rapid screening of large numbers of blood samples in endemic areas during outbreaks.

The Differences Result Of Platelets Count In K3edta Blood At Room Temperature (24-29°C) And Refrigerator (2-8°C) For 2 Hours

Examination of platelets count is one of hematological examinations. This examination used K3EDTA blood samples which is better to be examined directly. The large number of blood samples in hospital causes nurses who take the sample do not directly bring them to laboratory and process of changing shifts on laboratory workers allows for a delay, causing platelets count decrease, so the K3EDTA blood sample should be stored at the refigerator (2-8°C) when examination delays. This study was aimed to find out the differences result of platelets count in the K3EDTA blood stored at room temperature (24-29ºC) and refigerator (2-8oC) for 2 hours. This study is a quantitative approach to the design of observational analytic with cross-sectional study, where K3EDTA blood tests stored at room temperature (24-29ºC) and refigerator (2-8º C) at the same time. The subjects of this research were 30 blood samples were taken using vein puncture from Health Analyst students aged around 18-21 years old and had no history of blood disorders, especially abnormalities of platelet count. The result of platelets count examination of K3EDTA blood stored in refigerator (2-8°C) for 2 hours tend to be higher than in K3EDTA blood samples stored at room temperature (24-29°C), with p value 0.046 (p <0,05). The average number of platelets in the K3EDTA blood stored at room temperature (24-29°C) was 276,000 cells/mm3 and stored in refrigerator (2-8°C) was 304 000 cells/mm3. The conclusion is there are significant differences in the result of platelets count in the K3EDTA blood stored at room temperature (24-29ºC) and refigerator (2-8°C) for 2 hours.

The small molecule NSM00191 specifically represses the TNF-α/NF-кB axis in foot and ankle rheumatoid arthritis.

The activation of TNF-α/NF-кB signaling is involved in the regulation of a wide range of biological processes, such as cell proliferation, differentiation and apoptosis, eventually causing a number of diseases, such as cancer and inflammation. Here, we found that TNF-α/NF-кB signaling was activated in a large number of blood samples taken from foot and ankle rheumatoid arthritis (RA) patients. By applying a microarray assay to the human synovial sarcoma cell line SW982 and the human fibroblast-like synoviocyte cell line HFLS-RA, as well as in their corresponding p65 knockdown and -overexpressing cells, we identified and verified the activation of many p65 targets, including cytokines (e.g., TNF-α and IL-6), chemokines (e.g., MCP-1 and PANTES), protein receptors (e.g., CD-40 and MHC-1), and inducible enzymes (e.g., COX2). In addition, we subjected microRNAs from foot and ankle RA patients to a microRNA-specific microarray and found that miR-7-5p targeted the 3'-UTR of p65, negatively regulating its expression. By applying an in vitro screen to identify small molecules that specifically inhibited the interaction between TRADD and TNFR2, we found that NSM00191 strongly inhibited the activation of TNF-α/NF-кB signaling in vitro and in vivo, causing the downregulation of NF-кB targets and the decrease of arthritis scores. Collectively, our findings shed new light on the regulation of the TNF-α/NF-кB axis and might provide a new avenue for RA treatment.

Stability of Proteins in Dried Blood Spot Biobanks.

An important motivation for the construction of biobanks is to discover biomarkers that identify diseases at early, potentially curable stages. This will require biobanks from large numbers of individuals, preferably sampled repeatedly, where the samples are collected and stored under conditions that preserve potential biomarkers. Dried blood samples are attractive for biobanking because of the ease and low cost of collection and storage. Here we have investigated their suitability for protein measurements. Ninety-two proteins with relevance for oncology were analyzed using multiplex proximity extension assays (PEA) in dried blood spots collected on paper and stored for up to 30 years at either +4 °C or −24 °C.Our main findings were that (1) the act of drying only slightly influenced detection of blood proteins (average correlation of 0.970), and in a reproducible manner (correlation of 0.999), (2) detection of some proteins was not significantly affected by storage over the full range of three decades (34 and 76% of the analyzed proteins at +4 °C and −24 °C, respectively), whereas levels of others decreased slowly during storage with half-lives in the range of 10 to 50 years, and (3) detectability of proteins was less affected in dried samples stored at −24 °C compared with at +4 °C, as the median protein abundance had decreased to 80 and 93% of starting levels after 10 years of storage at +4 °C or −24 °C, respectively. The results of our study are encouraging as they suggest an inexpensive means to collect large numbers of blood samples, even by the donors themselves, and to transport, and store biobanked samples as spots of whole blood dried on paper. Combined with emerging means to measure hundreds or thousands of protein, such biobanks could prove of great medical value by greatly enhancing discovery as well as routine analysis of blood biomarkers.

Prevalence of tick-borne haemoparasites in small ruminants in Turkey and diagnostic sensitivity of single-PCR and RLB

BackgroundTick-borne haemoparasitic diseases (TBHDs), caused by Theileria, Babesia, Anaplasma and Ehrlichia, are common in regions of the world where the distributions of host, pathogen and vector overlap. Many of these diseases threaten livestock production and some also represent a concern to human public health. The primary aim of this study was to determine the prevalence of the above-mentioned pathogens in a large number of blood samples (n = 1979) collected from sheep (n = 1727) and goats (n = 252) in Turkey. A secondary aim was to assess the diagnostic sensitivity of a number of species-specific polymerase chain reaction (PCR) tests and the reverse line blotting (RLB) assay. DNA samples were screened using species-specific PCR for the presence of Theileria ovis, Theileria sp. MK, T. lestoquardi, T. uilenbergi, T. luwenshuni, Babesia ovis, Anaplasma ovis and A. phagocytophilum while RLB was undertaken to test for the presence of all known Theileria, Babesia, Anaplasma and Ehrlichia species. The diagnostic sensitivity of these two approaches was then compared in terms of their ability to detect single species and mixed infections.ResultsOverall, 84 and 74.43% of the small ruminants sampled were identified as hosting one or more pathogen(s) by species-specific PCR and RLB respectively. The presence of Theileria sp. OT1, T. luwenshuni and T. uilenbergi in Turkey was revealed for the first time while the presence of Babesia motasi, B. crassa and T. separata in Turkish small ruminants was confirmed using molecular methods. A high prevalence of mixed infection was evident, with PCR and RLB approaches indicating that 52.24 and 35.42% of animals were co-infected with multiple species, respectively. More than 80% of the mixed infections contained T. ovis and/or A. ovis. The RLB approach was found to be capable of detecting mixed infections with species such as Theileria sp. OT1, Theileria sp. OT3, T. separata, B. crassa and Babesia spp.ConclusionThe results indicated that pathogens causing TBHDs are highly prevalent in sheep and goats in Turkey. The diagnostic sensitivity of species-specific single PCR was generally higher than that of RLB. However, the latter approach was still capable of identifying a high proportion of individuals containing mixed-species infections. The use of species-specific single PCR is recommended to accurately estimate pathogen prevalence and to identify co-infected hosts.

The Isolation, Differentiation, and Quantification of Human Antibody-secreting B Cells from Blood: ELISpot as a Functional Readout of Humoral Immunity.

The hallmark of humoral immunity is to generate functional ASCs, which synthesize and secrete Abs specific to an antigen (Ag), such as a pathogen, and are used for host defense. For the quantitative determination of the functional status of the humoral immune response of an individual, both serum Abs and circulating ASCs are commonly measured as functional readouts. In humans, peripheral blood is the most convenient and readily accessible sample that can be used for the determination of the humoral immune response elicited by host B cells. Distinct B-cell subsets, including ASCs, can be isolated directly from peripheral blood via selection with lineage-specific Ab-conjugated microbeads or via cell sorting with flow cytometry. Moreover, purified naïve and memory B cells can be activated and differentiated into ASCs in culture. The functional activities of ASCs to contribute to Ab secretion can be quantified by ELISpot, which is an assay that converges enzyme-linked immunoabsorbance assay (ELISA) and western blotting technologies to enable the enumeration of individual ASCs at the single-cell level. In practice, the ELISpot assay has been increasingly used to evaluate vaccine efficacy because of the ease of handling of a large number of blood samples. The methods of isolating human B cells from peripheral blood, the differentiation of B cells into ASCs in vitro, and the employment of ELISpot for the quantification of total IgM- and IgG-ASCs will be described here.

Strong Relationships in Acid-Base Chemistry - Modeling Protons Based on Predictable Concentrations of Strong Ions, Total Weak Acid Concentrations, and pCO2.

Understanding acid-base regulation is often reduced to pigeonholing clinical states into categories of disorders based on arterial blood sampling. An earlier ambition to quantitatively explain disorders by measuring production and elimination of acid has not become standard clinical practice. Seeking back to classical physical chemistry we propose that in any compartment, the requirement of electroneutrality leads to a strong relationship between charged moieties. This relationship is derived in the form of a general equation stating charge balance, making it possible to calculate [H+] and pH based on all other charged moieties. Therefore, to validate this construct we investigated a large number of blood samples from intensive care patients, where both data and pathology is plentiful, by comparing the measured pH to the modeled pH. We were able to predict both the mean pattern and the individual fluctuation in pH based on all other measured charges with a correlation of approximately 90% in individual patient series. However, there was a shift in pH so that fitted pH in general is overestimated (95% confidence interval -0.072–0.210) and we examine some explanations for this shift. Having confirmed the relationship between charged species we then examine some of the classical and recent literature concerning the importance of charge balance. We conclude that focusing on the charges which are predictable such as strong ions and total concentrations of weak acids leads to new insights with important implications for medicine and physiology. Importantly this construct should pave the way for quantitative acid-base models looking into the underlying mechanisms of disorders rather than just classifying them.

A broad spectrum screening of Schmallenberg virus antibodies in wildlife animals in Germany.

To identify native wildlife species possibly susceptible to infection with Schmallenberg virus (SBV), a midge-transmitted orthobunyavirus that predominantly infects domestic ruminants, samples from various free-living ruminants, but also carnivores, small mammals and wild boar were analyzed serologically. Before 2011, no SBV-specific antibodies were detectable in any of the tested species, thereafter, a large proportion of the ruminant population became seropositive, while every sample taken from carnivores or small mammals tested negative. Surprisingly, SBV-specific-antibodies were also present in a large number of blood samples from wild boar during the 2011/2012 and 2012/2013 hunting seasons. Hence, free-ranging artiodactyls may play a role as wildlife host.

Donor verification using Short Tandem Repeat (STR) analysis directly from blood collected in PAXgene RNA tubes.

Biorepository processing includes nucleic acid extractions in batch mode from a large number of blood samples from many different donors. Handling such a large number of biospecimens presents the challenge of ensuring that samples are not switched or mislabeled during processing. One approach for confirming donor identity from DNA samples is the use of multiplexed fluorescent PCR for detecting Short Tandem Repeat (STR) allelic-size polymorphisms for a set of common autosomal loci. While donor identity of DNA extracted directly from blood collected in standard tubes containing anticoagulants can be easily verified by generating STR profiles, RNA from blood collected in PAXgene Blood RNA tubes (PAXgene RNA tubes) is depleted of DNA and is not amenable to STR fingerprinting for donor identity verification. We investigated the feasibility of isolating DNA directly from blood collected in PAXgene RNA tubes for use as template for STR DNA fingerprinting for blood donor identity verification. We determined that DNA extraction can be performed manually with the QIAamp DNA Blood Minikit or on the QIAxtractor instrument with minimal pre-processing protocol additions, and that DNA isolated from blood collected in PAXgene RNA tubes is of sufficient quantity and quality for successful STR fingerprint analysis. Adaptation of quality assurance methods such as the PAXgene RNA tube DNA extraction/STR fingerprinting assay described here is a good practice that ensures that biobanking collections provide scientists with high quality, donor-verified biomaterial.

Clinical Evaluation and Cross-Validation of the Point-of-Care System iStat at the Emergency Department Versus Central Laboratory Analysis

BACKGROUND: In the emergency department (ED), large numbers of blood samples are taken on a daily basis. Owing to their ability to produce rapid results, point-of-care (POC) analysis systems are applied increasingly in the ED. In the current study, we cross validated the quality of the POC iSTAT (Abbott point of care) against the central laboratory for the most common blood samples taken at the ED of a tertiary care university hospital. METHODS: Forty-one patients older than 18 years presenting to the ED owing to shortness of breath or chest pain were enrolled in the study. In all patients, the following tests were performed on venous blood: iSTAT Chem8 + (sodium, Na; potassium, K; chloride, Cl; ionized Ca; glucose; serum urea nitrogen, BUN; creatinine; hematocrit; hemoglobin), and CG4 + (venous blood gas [VBG] + lactate). Similar tests were performed parallel to the central laboratory of the hospital. Troponin testing was performed but omitted for clinical consideration owing to the routine use of high-sensitivity troponin by our central laboratory. Statistical analysis was performed using the Pearson correlation coefficient on each analyte. RESULTS: The results of the POC analysis were available at a mean ± SD of 48.5 minutes earlier than the central laboratory results. The Chem8 + results between iSTAT and central laboratory correlated to a high degree, with the least correlation relating to K (κ = 0.77), Cl (κ = 0.82), and ionized Ca (κ = 0.86). All other items ranged between κ = 0.9 (Na) and κ andgt; 0.95 (glucose, BUN, creatinine, hematocrit, and hemoglobin). For the CG4 +, pH revealed a κ = 0.87, pCO2 κ = 0.9, base excess κ = 0.9, HCO3 κ = 0.72, pO2 κ = 0.62, and SpO2 (saturation) κ = 0.77. Lactate analysis showed a κ = 0.94. The results from the central analysis testing showed lower pH, base excess, and HCO3 values than the POC, whereas the pCO2 and lactate values were higher in the central laboratory. The discrepant values might have resulted in inadequate treatment in the clinical context. When an arterial blood gas was simultaneously analyzed by POC and the central laboratory (20 samples), we found the following results: HCO3 κ = 0.9, SpO2 κ = 0.93, and all other κ andgt; 0.95. CONCLUSION: The electrolyte analyses performed by the POC-system iSTAT correlate to a very high degree with the analysis provided by our central laboratory. The POC iSTAT system might be considered as a potential POC device for use in the ED. Furthermore, our findings suggest that POC might serve as independent control system for the clinician to find potential problems in the process of blood sample analysis.

FPGA implementation of image processing technique for blood samples characterization

This work presents a hardware implementation of an image processing algorithm for blood type determination. The image processing technique proposed in this paper uses the appearance of agglutination to determine blood type by detecting edges and contrast within the agglutinated sample. An FPGA implementation and parallel processing algorithms are used in conjugation with image processing techniques to make this system reliable for the characterization of large numbers of blood samples. The program was developed using Matlab software then transferred and implemented on a Vertex 6 FPGA from Xilinx employing ISE software. Hardware implementation of the proposed algorithm on FPGA demonstrates a power consumption of 770mW from a 2.5V power supply. Blood type characterization using our FPGA implementation requires only 6.6s, while a desktop computer-based algorithm with Matlab implementation on a Pentium 4 processor with a 3GHz clock takes 90s. The presented device is faster, more portable, less expensive, and consumes less power than conventional instruments. The proposed hardware solution achieved accuracy of 99.5% when tested with over 500 different blood samples.

Effect of blood storage conditions on DNA repair capacity measurements in peripheral blood mononuclear cells

Due to the great number of genes involved in DNA repair and the interactions among the pathways responsible for the repair of different types of DNA damage, there is an increasing need for simple and reliable approaches to phenotypically assess DNA repair capacity (DRC). The use of peripheral blood mononuclear cells (PBMCs) in DRC assays is particularly useful for human monitoring studies. However, in such studies it is not always possible to collect and process samples on the same day as the blood is taken.We performed a genotype–phenotype correlation study on DRC on 225 healthy subjects. Due to the large number of blood samples to be processed, PBMCs were either isolated and cryopreserved on the same day of blood collection (day 1) or on the following day after 24h blood storage at room temperature (day 2-RT). Samples processed in different days showed a significant difference in the DRC evaluated as 8-oxoguanine glycosylase activity (OGG assay) in cell extracts (p<0.0001) and as benzo[a]pyrene diol epoxide (BPDE)-induced damage repair by the comet assay (p=0.05). No apparent effect of the blood storage conditions on the outcome of γ-ray induced H2AX phosphorylation assay was reported.These results prompted us to further analyze the effects of blood storage conditions by performing a validation study. Three blood samples were simultaneously taken from ten healthy donors, PBMCs were isolated and cryopreserved as follows: immediately after blood collection (day 1); on the following day, after blood storage at RT (day 2-RT); or after blood storage at 4°C (day 2-4°C). DRC was then evaluated using phenotypic assays. The γ-ray induced H2AX phosphorylation assay has been confirmed as the only assay that showed good reproducibility independently of the blood storage conditions. The measurement of OGG assay was most affected by the blood storage conditions.