Affordable Method for Hematocrit Determination in Murine Models.

Hematocrit (Hct) is a powerful tool often used in a clinical setting for the diagnosis of blood conditions such as anemia. It is also used in the research field as a hematological parameter in both human and mouse models. Measuring Hct, however, involves the use of expensive standardized equipment (such as a CritSpin™ Microhematocrit Centrifuge). Here, we describe a novel, simple, and affordable method to determine the Hct in untreated wild-type (WT) mice and phenylhydrazine (PHZ)-induced anemic mice with reasonable accuracy, using a benchtop centrifuge commonly available in laboratories. Hct of murine samples processed with a benchtop centrifuge, when compared to the standardized method CritSpin™, showed comparable results. This approach for determining Hct of murine can prove useful to research laboratories that cannot afford specialized equipment for Hct studies. © 2024 Wiley Periodicals LLC. Basic Protocol 1: Affordable Method for Hematocrit Determination in Murine Models Basic Protocol 2: Murine Sample Validation Support Protocol: Phenylhydrazine-induced anemia in wild-type (WT) mice.

Music Box-Inspired Semi-Automatic Hematocrit Validation Device.

A high hematocrit (HCT) level is strongly associated with the risk of cardiovascular disease. For early diagnosis of cardiovascular disease, it is vital to regularly measure the HCT, which is typically achieved by centrifuging a blood sample to measure the percentage of red blood cells. However, the centrifugal modalities are usually bulky, expensive, and require a stable electric input, which restrict the availability. This research develops a semi-automatic and portable centrifugal device for HCT measurement. This torque-actuated semi-automatic centrifuge, which we call the tFuge, is inspired by a music box, allowing different operators to generate the same rhythm. It is electricity-free and can be controlled based on a constant torque mechanism. Repeatable test results can be received from among different users regardless of their age, sex, and activity. With the assistance of the Boycott effect on the tFuge, we proved that the HCT level is in high linearity to the length of the sedimentation of the blood cells in a tube (R2 = 0.99, sample HCT range 10-60%). The tFuge takes less than 4 min and requires no more than 10 µL of blood that can be obtained by a less-invasive finger prick to complete the testing procedure. Calibrated gradient numbers are printed onto the rotation disc for instant HCT results that can be read by the naked eye. We expect this proposed point-of-care testing device possesses the potential to replace the microhematocrit centrifuge in the regions with limited resources.

Characterization of a Novel Approach for Neonatal Hematocrit Screening Based on Penetration Velocity in Lateral Flow Test Strip.

Hematocrit (HCT) is a crucial parameter for both adult and pediatric patients, indicating potentially severe pathological conditions. Most common methods for HCT assessment are microhematocrit and automated analyzers; however, developing countries present specific needs often not addressed by these technologies. Paper-based devices can be suitable for those environments being inexpensive, rapid, easy to use, and portable. The aim of this study is to describe and validate against a reference method, a novel HCT estimation method based on penetration velocity in lateral flow test strips complying with the requirements in low- or middle-income country (LMIC) scenarios. To calibrate and test the proposed method, 145 blood samples of 105 healthy neonates with gestational age greater than 37 weeks were collected (29 calibration set, 116 test set) in the range of HCT values (31.6-72.5%). The time difference (Δt) from the whole blood sample loading into the test strip instant till the nitrocellulose membrane saturation instant was measured by a reflectance meter. A nonlinear relation was observed between HCT and Δt and was estimated by a third-degree polynomial equation (R2 = 0.91) valid in 30% to 70% HCT interval. The proposed model was subsequently used to estimate HCT values on the test set showing a good agreement between the estimated HCT and the HCT measured by the reference method (r = 0.87, p < 0.001), with a low mean difference of 0.53 ± 5.04% and a slight trend of overestimation for higher hematocrit values. The mean absolute error was 4.29%, while the maximum absolute error was 10.69%. Although the proposed method did not present a sufficient accuracy to be used for diagnostic purposes, it could be suitable as a fast, low-cost, easy-to-use screening tool especially in LMIC scenarios.

Relationship between blood viscosity and existence and severity of carotid artery plaque.

BACKGROUND: Accumulating evidence shows that the increase in blood viscosity (BV) is an independent risk factor for atherosclerosis and its related diseases, but as far as we know, there are few studies on the relationship between blood viscosity and carotid plaque severity. Therefore, we aimed to investigate the relationship between blood viscosity and the presence of carotid plaques, and further explore its relationship with the severity of carotid plaques. METHODS: We retrospectively analyzed the data of consecutive subjects in the physical examination center of the Affiliated Hospital of Ningbo University Medical College from January 2022 to May 2022.The parameters of blood viscosity include the whole blood viscosity (WBV) at high, middle, and low shear rate, plasma viscosity (PV), hematocrit (HCT), rigidity "k", rigidity index (RI), aggregation index (AI) and electrophoresis rate (ER), and standardized BV calculated by Quemada's equation were included in the study. Carotid plaque score (CPS) was used to measure the severity of carotid artery disease, and participants were divided into mild, moderate, and severe groups according to the quartile of the score. Independent samples t-test and one-way ANOVA were used to compare normally distributed continuous variables between two or more independent groups, respectively. Binary logistic regression was used to evaluate the risk factors of carotid plaque. RESULTS: 314 men were enrolled in the study, of which 165 participants were diagnosed with Carotid artery plaque (CAP) (66.9%). Compared with the CAP- group, the WBV and PV of the CAP+group decreased, but the difference only existed in the PV (p = 0.001). However, standardized BV values (HCT set at 0.45) were higher in the CAP+group than in the CAP- group (3.8643±0.35431vs 3.9542±0.64871, p = 0.188). Regarding the rigidity and aggregation of RBC, the parameters including rigidity "k", RI, AI and ER increased in the CAP+group compared with the CAP- group. The difference was statistically significant in k and ER (p = 0.04, p = 0.009). To assess the severity of carotid plaque, we divided the participants into mild, moderate, and severe groups by using the tertile of CPS value. The mild group was defined as CPS≤0.5 (n = 108), the moderate group as 0.5 < CPS≤1.7 (n = 105), and the severe group as CPS > 1.7 (n = 101). It was found that WBV and PV decreased with the increase of plaque severity, but the difference among the three groups was significant in PV (F = 8.073, p < 0.0001). In addition, with the severity of plaque from mild to severe, standardized BV gradually increased, which were 3.8611±0.34845, 3.8757±0.36637, 3.9007±0.38353 respectively. The difference between the groups was close to statistically significant (F = 2.438, p = 0.089). The values of parameters describing erythrocyte aggregation and rigidity increased among the mild, moderate, and severe groups. The difference was statistically significant in RBC rigidity "k" and ER of RBC (F = 3.863, p = 0.022; F = 5.897, p = 0.003, respectively). CONCLUSION: Increased blood viscosity is a risk factor for carotid plaque, but its increase may be hidden by decreased hematocrit. Therefore, it is necessary to comprehensively analyze various parameters of blood viscosity, such as the standardized BV calculated by Quemada's equation, which may provide more useful reference value.

Revisiting the impact of serial therapeutic phlebotomy in polycythaemia on laboratory and clinical parameters using a fixed interval and fixed volume protocol.

OBJECTIVES: Therapeutic phlebotomy allows for a controlled and gradual decrease in red cell mass leading to improved blood flow and symptomatic relief in polycythaemia. The present study was aimed to determine the impact of serial fixed volume and fixed interval therapeutic phlebotomy protocol on the laboratory and clinical parameters in patients of polycythaemia. MATERIAL AND METHODS: This prospective longitudinal study was conducted over 18 months. The desired haematocrit for polycythemia vera and secondary polycythemia was 45% and 52% respectively. A fixed volume of 350 ml phlebotomy was performed every-three days till the achievement of desired haematocrit. Complete blood count was performed before and after each procedure and iron studies were done at the time of enrolment and after the achievement of desired haematocrit. Post-procedure symptomatic relief was assessed by a 10-point visual analogue scale (VAS). RESULTS: Of the 29 patients enrolled in the study, 3 patients were lost to follow up and data of 26 patients was analyzed. Mean Hb declined from 17.84 ± 1.88 gdL-1 to 14.67 ± 1.14 gdL-1 (p < 0.001) and mean haematocrit decreased from a baseline of 57.11 ± 5.47% to 46.27 ± 3.763% (p < 0.001) upon achievement of desired haematocrit. There was a significant decline in serum iron from the baseline of 132.85 ± 94.136 µg dL-1 to 69.41 ± 58.643 µg dL-1 at desired haematocrit. A significant change in VAS score of almost all clinical parameters was observed. Post phlebotomy hematocrit correlated negatively with the number of procedures (p = 0.015). CONCLUSION: Our protocol yielded rapid and marked improvement in patients of primary and secondary polycythemia with minimal adverse events and significant amelioration of clinical parameters.

Application of a new volumetric microsampling device for quantitative bioanalysis of immunosuppression.

Background: Volumetric absorptive microsampling may reduce the blood collection burden associated with therapeutic drug monitoring of immunosuppression to prevent organ transplant rejection. This work describes the development of a laboratory and analytical technique for quantifying tacrolimus and mycophenolic acid (MPA) from the Tasso-M20™ in human whole blood using bead-based impact-assisted extraction. Results: The sampled blood volume was accurate with estimated volumes within <2% of the expected 20 µl. Recovery using impact-assisted extraction was 73-87% for MPA and 100% for tacrolimus and was hematocrit-independent for both analytes. The LC-MS/MS assay is precise and accurate within the acceptance criteria of 15%. Conclusion: The sampling and extraction procedures allowed for accurate quantification of tacrolimus and MPA. Exploration of abuse scenarios identified important education points for patients conducting home-based sample collections in the future.

A Corrective Method for Different Hematocrit Values of Whole Blood Samples on the Detection of Procalcitonin.

BACKGROUND: We have explored that quantitative PCT detection can be conducted in different sample types (whole blood and/or plasma samples) with good correlation and consistency in clinical use. These findings reduce the sample volume and turnover time of PCT detection in clinical labs. However, different hematocrit (HCT) percentages of whole blood samples may affect the final results, especially abnormal hematocrit (HCT) percentages. To overcome this problem, we established a mathematical model to modify the whole blood test results and evaluated the effects of HCT correction. METHODS: First, we prepared a preliminary experiment - various hematocrit (HCT) percentages (15% - 65%) of whole blood samples with different PCT concentrations and established a mathematic model to correct the effects of PCT detection. Then, in this paper, we evaluated the consistency with Pearson's correlation and Kappa analysis between whole bloods detected by the i-Reader S system and plasma detected by the Biomerieux system. Besides, we prepared different HCT values about 15%, 40%, 60% of 9 samples with different PCT concentrations to evaluate the effects of HCT correction Results and Conclusions: Pearson's correlative studies and Kappa analysis indicated that PCT levels measured by i-Reader S (plasma & whole blood samples) were comparable to results from the VIDAS system, and HCT correction could improve consistency of PCT detection between whole blood and plasma. Analysis of samples with abnormal HCT values showed that the mathematical correction model could offset the influences of various HCT values.

An evidence-based definition of anemia for singleton, uncomplicated pregnancies.

BACKGROUND: The definition for anemia in pregnancy is outdated, derived from Scandinavian studies in the 1970's to 1980's. To identity women at risk of blood transfusion, a common cause of Severe Maternal Morbidity, a standard definition of anemia in pregnancy in a modern, healthy United States cohort is needed. OBJECTIVE: To define anemia in pregnancy in a United States population including a large county vs. private hospital population using uncomplicated patients. MATERIALS AND METHODS: Inclusion criteria were healthy women with the first prenatal visit before 20 weeks. Exclusion criteria included preterm birth, preeclampsia, hypertension, diabetes, short interval pregnancy (<18 months), multiple gestation, abruption, and fetal demise. All women had iron fortification (Ferrous sulfate 325 mg daily) recommended. The presentation to care and pre-delivery hematocrits were obtained, and the percentiles determined. A total of 2000 patients were included, 1000 from the public county hospital and 1000 from the private hospital. Each cohort had 250 patients in each 2011, 2013, 2015, and 2018. The cohorts were compared for differences in the fifth percentile for each antepartum epoch. Student's t-test and chi-squared statistical tests were used for analysis, p-value of ≤0.05 was considered significant. RESULTS: In the public and private populations, 777 and 785 women presented in the first trimester while 223 and 215 presented in the second. The women at the private hospital were more likely to be older, Caucasian race, nulliparous, and present earlier to care. The fifth percentile was compared between the women in the private and public hospitals and were clinically indistinguishable. When combining the cohorts, the fifth percentile for hemoglobin/hematocrit was 11 g/dL/32.8% in the first trimester, 10.3 g/dL/30.6% in the second trimester, and 10.0 g/dL/30.2% pre-delivery. CONCLUSIONS: Fifth percentile determinations were made from a combined cohort of normal, uncomplicated pregnancies to define anemia in pregnancy. Comparison of two different cohorts confirms that the same definition for anemia is appropriate regardless of demographics or patient mix.

A General Model to Calculate the Spin-Lattice Relaxation Rate (R1) of Blood, Accounting for Hematocrit, Oxygen Saturation, Oxygen Partial Pressure, and Magnetic Field Strength Under Hyperoxic Conditions.

BACKGROUND: Under normal physiological conditions, the spin-lattice relaxation rate (R1) in blood is influenced by many factors, including hematocrit, field strength, and the paramagnetic effects of deoxyhemoglobin and dissolved oxygen. In addition, techniques such as oxygen-enhanced magnetic resonance imaging (MRI) require high fractions of inspired oxygen to induce hyperoxia, which complicates the R1 signal further. A quantitative model relating total blood oxygen content to R1 could help explain these effects. PURPOSE: To propose and assess a general model to estimate the R1 of blood, accounting for hematocrit, SO2 , PO2 , and B0 under both normal physiological and hyperoxic conditions. STUDY TYPE: Mathematical modeling. POPULATION: One hundred and twenty-six published values of R1 from phantoms and animal models. FIELD STRENGTH/SEQUENCE: 5-8.45 T. ASSESSMENT: We propose a two-compartment nonlinear model to calculate R1 as a function of hematocrit, PO2 , and B0. The Akaike Information Criterion (AIC) was used to select the best-performing model with the fewest parameters. A previous model of R1 as a function of hematocrit, SO2 , and B0 has been proposed by Hales et al, and our work builds upon this work to make the model applicable under hyperoxic conditions (SO2  > 0.99). Models were assessed using the AIC, mean squared error (MSE), coefficient of determination (R2 ), and Bland-Altman analysis. The effect of volume fraction constants WRBC and Wplasma was assessed by the SD of resulting R1. The range of the model was determined by the maximum and minimum B0, hematocrit, SO2 , and PO2 of the literature data points. STATISTICAL TESTS: Bland-Altman, AIC, MSE, coefficient of determination (R2 ), SD. RESULTS: The model estimates agreed well with the literature values of R1 of blood (R2  = 0.93, MSE = 0.0013 s-2 ), and its performance was consistent across the range of parameters: B0 = 1.5-8.45 T, SO2  = 0.40-1, PO2  = 30-700 mmHg. DATA CONCLUSION: Using the results from this model, we have quantified and explained the contradictory decrease in R1 reported in oxygen-enhanced MRI and oxygen-delivery experiments. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: Stage 1.

Influence of Classical Massage on Biochemical Markers of Oxidative Stress in Humans: Pilot Study.

Classical massage is one of the most popular forms of conservative treatment in various diseases. Despite the wide scope of research, the mechanisms of massage are not fully known and understood. Apart from the well-described effects on individual body systems, there are few scientific reports on the effects of massage on the human body at the subcellular level. The study was designed to assess changes in oxidative stress parameters in healthy volunteers after a single session of classical massage. 29 healthy volunteers aged 22.24 ± 3.64 participated in the study. Before and 30 minutes after the massage procedures, blood samples were taken by experienced personnel. Biochemical markers of oxidative homeostasis were assessed with highly specific methods for each parameter: oxidase ceruloplasmin, glutathione, malondialdehyde, glutathione peroxidase, glutathione S-transferase, and superoxide dismutase. The study demonstrates that massage therapy caused statistically significant decrease in the concentration of glutathione peroxidase (red blood cells) and increase in the level of glutathione peroxidase (plasma), superoxide dismutase, and malondialdehyde. In contrast, statistically significant changes in the hematocrit, glutathione, NO2-/NO3-, and oxidase ceruloplasmin were not observed. The results show that complex influence of classical massage therapy on human organism may be reflected in parameters of the oxidative stress. To understand this mechanism clearly, further research is needed.

Seasonal and geographic variation in packed cell volume and selected serum chemistry of platypuses.

Platypuses (Ornithorhynchus anatinus) inhabit the permanent rivers and creeks of eastern Australia, from north Queensland to Tasmania, but are experiencing multiple and synergistic anthropogenic threats. Baseline information of health is vital for effective monitoring of populations but is currently sparse for mainland platypuses. Focusing on seven hematology and serum chemistry metrics as indicators of health and nutrition (packed cell volume (PCV), total protein (TP), albumin, globulin, urea, creatinine, and triglycerides), we investigated their variation across the species' range and across seasons. We analyzed 249 unique samples collected from platypuses in three river catchments in New South Wales and Victoria. Health metrics significantly varied across the populations' range, with platypuses from the most northerly catchment, having lower PCV, and concentrations of albumin and triglycerides and higher levels of globulin, potentially reflecting geographic variation or thermal stress. The Snowy River showed significant seasonal patterns which varied between the sexes and coincided with differential reproductive stressors. Male creatinine and triglyceride levels were significantly lower than females, suggesting that reproduction is energetically more taxing on males. Age specific differences were also found, with juvenile PCV and TP levels significantly lower than adults. Additionally, the commonly used body condition index (tail volume index) was only negatively correlated with urea, and triglyceride levels. A meta-analysis of available literature revealed a significant latitudinal relationship with PCV, TP, albumin, and triglycerides but this was confounded by variation in sampling times and restraint methods. We expand understanding of mainland platypuses, providing reference intervals for PCV and six blood chemistry, while highlighting the importance of considering seasonal variation, to guide future assessments of individual and population condition.

Comparison between blood hemoglobin concentration determined by point-of-care device and complete blood count in adult patients with dengue.

BACKGROUND: Hematocrit measurement has been an indispensable tool for monitoring plasma leakage and bleeding in dengue patients. However, hematocrit measurement by automated methods is hampered by frequent venipunctures. Utility of point-of-care hemoglobin (POC-Hb) test for monitoring dengue patients has not been established. We evaluated the relationship between hemoglobin measured by POC-Hb testing and hematocrit measured by the automated method in adult dengue patients. METHODOLOGY AND PRINCIPAL FINDINGS: Adult dengue patients were recruited at two university hospitals in Thailand from October 2019 to December 2020. POC-Hb test was performed using capillary blood simultaneously with venipuncture to obtain whole blood for an automated complete blood count (CBC) analysis. The correlation of hemoglobin and hematocrit measurement was evaluated. A total of 44 dengue patients were enrolled. Twenty-nine patients (65.9%) were female, with a median age of 31 years (interquartile range 22-41). Of the enrolled patients, 30 (68.2%), 11 (25.0%), and 3 (6.8%) were classified as dengue without warning signs, with warning signs, and severe dengue, respectively. Seven patients (15.9%) had hemoconcentration, and five patients (11.3%) had bleeding. A total of 216 pairs of POC-Hb and CBC were evaluated. A significant positive correlation was observed between hemoglobin measured by POC-Hb testing and hematocrit measured by an automated CBC (r = 0.869, p <0.001). Bland-Altman analysis between hemoglobin measured by POC-Hb testing and an automated CBC showed a bias of -0.43 (95% limit of agreement of -1.81 and 0.95). Using the cutoff of POC-Hb ≥20% as a criteria for hemoconcentration, the sensitivity and specificity of hemoconcentration detected by POC-Hb device were 71.4% and 100.0%, respectively. CONCLUSIONS: Hemoglobin measurement by POC-Hb testing has a strong correlation with hematocrit in adult patients with dengue fever. However, the sensitivity in detecting hemoconcentration is fair. The adjunct use of capillary POC-Hb testing can decrease the frequency of venipuncture. Further study in children is encouraged.

Volumetric Absorptive Microsampling as an Alternative Tool for Biomonitoring of Multi-Mycotoxin Exposure in Resource-Limited Areas.

Biomonitoring of biological samples arises as an effective tool to evaluate the exposure to mycotoxins in the population. Owing to the wide range of advantages, there is a growing interest in the use of non- and minimally invasive alternative sampling strategies, such as dried blood spot sampling or volumetric absorptive microsampling (VAMS). A VAMS-based multi-mycotoxin method was developed and validated for 24 different mycotoxins. Method validation was based on the Bioanalytical Method Validation Guideline of the Food and Drug Administration from the United States and for most of the studied mycotoxins, the results of the performance characteristics were in agreement with the criteria of the European Commission Decision 2002/657/EC. The recovery for the different mycotoxins was not haematocrit dependent and remained acceptable after storing the VAMS for 7 and 21 days at refrigeration temperature (4 °C) and room temperature, demonstrating that VAMS could be applied to assess mycotoxin exposure in blood in resource-limited areas, where there may be a delay between sampling and analysis. Finally, a comparison between VAMS and a procedure for liquid whole blood analysis, performed on 20 different blood samples, did not result in missed exposed cases for VAMS. Moreover, both methods detected similar levels of ochratoxin A, ochratoxin alpha, zearalenone and aflatoxin B1. Given all the benefits associated with VAMS and the developed method, VAMS sampling may serve as an alternative to conventional venous sampling to evaluate multiple mycotoxin exposure.

Animal blood in translational research: How to adjust animal blood viscosity to the human standard.

Animal blood is used in mock circulations or in forensic bloodstain pattern analysis. Blood viscosity is important in these settings as it determines the driving pressure through biomedical devices and the shape of the bloodstain. However, animal blood can never exactly mimic human blood due to erythrocyte properties differing among species. This results in the species-specific shear thinning behavior of blood suspensions, and it is therefore not enough to adjust the hematocrit of an animal blood sample to mimic the behavior of human blood over the entire range of shear rates that are present in the body. In order to optimize experiments that require animal blood, we need models to adapt the blood samples. We here offer mathematical models derived for each species using a multi linear regression approach to describe the influence of shear rate, hematocrit, and temperature on blood viscosity. Results show that pig blood cannot be recommended for experiments at low flow conditions (<200 s-1 ) even though erythrocyte properties are similar in pigs and humans. However, pig blood mimics human blood excellently at high flow condition. Horse blood is unsuitable as experimental model in this regard. For several studied conditions, sheep blood was the closest match to human blood viscosity among the tested species.

Exploitation of blood non-Newtonian properties for ultrasonic measurement of hematocrit.

New processing techniques for manipulating blood and its components at a microfluidic scale are currently implemented. As for extracorporeal circulation, the in-line evaluation and monitoring of blood properties during these microfluidic techniques is a challenging task. Here, we show that the blood hematocrit can be measured non-invasively in a sub-millimeter medical tube using the non-Newtonian behavior of blood velocity profile. This hematocrit measurement is demonstrated on human blood with a simple Doppler ultrasound system. Results show a mean measurement error of 4.6 ± 1.3%Hct for hematocrit up to 52% and for 5 s-long ultrasonic signals. The simplicity and the measurement scale of the approach make it highly valuable for measuring hematocrit in new blood separation techniques. The approach may have an impact on in-vitro blood processing in general.

Hematocrit-Related Alterations of Circulating microRNA-21 Levels in Heart Failure Patients with Reduced Ejection Fraction: A Preliminary Study.

Aim: Circulating microRNA-21 (miR-21) has been utilized as a diagnostic tool in the assessment of heart failure (HF). Blood constitution may be altered when HF occurs and miR-21 may affect hematopoiesis. Sample hemolysis may influence the determination of circulating miRNAs, challenging the diagnostic use of miRNAs. Methods: We examined the relationship between blood measurements and miR-21 levels in ambulant chronic HF patients with reduced ejection fraction (HFrEF; n = 19). Healthy volunteers (n = 11) served as controls. Serum miR-21 levels were measured through quantitative reverse transcription polymerase chain reaction (RT-qPCR) and we calculated the hemolysis score (H-score). Study was approved by an Institutional Review Board (EK FaF UK 02/2018). Results: MiR-21 serum levels were reduced in HFrEF patients compared with the controls (p < 0.05), without relationship to New York Heart Association class, left ventricular ejection fraction or N-terminal prohormone of brain natriuretic peptide levels. MiR-21 levels decreased markedly in anemic patients, compared with those with normal hematocrits (p < 0.05). We found a significant relationship between miR-21 to hematocrit (p < 0.05) and hemoglobin concentration (p < 0.05). Importantly, we found a correlation between hematocrit and sample H-score (p < 0.05) in the cohort of HFrEF patients; however, there was no correlation between hemolysis and miR-21. Conclusion: Circulating miR-21 levels were decreased in HFrEF patients and hematocrit was identified as a factor associated with this abnormality. This suggests that miR-21 mirrors other characteristics of HFrEF patients rather than the standard identifiers of HF severity and progression.

Cerebrovascular reactivity measurements using simultaneous 15O-water PET and ASL MRI: Impacts of arterial transit time, labeling efficiency, and hematocrit.

Cerebrovascular reactivity (CVR) reflects the capacity of the brain to meet changing physiological demands and can predict the risk of cerebrovascular diseases. CVR can be obtained by measuring the change in cerebral blood flow (CBF) during a brain stress test where CBF is altered by a vasodilator such as acetazolamide. Although the gold standard to quantify CBF is PET imaging, the procedure is invasive and inaccessible to most patients. Arterial spin labeling (ASL) is a non-invasive and quantitative MRI method to measure CBF, and a consensus guideline has been published for the clinical application of ASL. Despite single post labeling delay (PLD) pseudo-continuous ASL (PCASL) being the recommended ASL technique for CBF quantification, it is sensitive to variations to the arterial transit time (ATT) and labeling efficiency induced by the vasodilator in CVR studies. Multi-PLD ASL controls for the changes in ATT, and velocity selective ASL is in theory insensitive to both ATT and labeling efficiency. Here we investigate CVR using simultaneous 15O-water PET and ASL MRI data from 19 healthy subjects. CVR and CBF measured by the ASL techniques were compared using PET as the reference technique. The impacts of blood T1 and labeling efficiency on ASL were assessed using individual measurements of hematocrit and flow velocity data of the carotid and vertebral arteries measured using phase-contrast MRI. We found that multi-PLD PCASL is the ASL technique most consistent with PET for CVR quantification (group mean CVR of the whole brain = 42±19% and 40±18% respectively). Single-PLD ASL underestimated the CVR of the whole brain significantly by 15±10% compared with PET (p<0.01, paired t-test). Changes in ATT pre- and post-acetazolamide was the principal factor affecting ASL-based CVR quantification. Variations in labeling efficiency and blood T1 had negligible effects.

Establishing hematological reference intervals in healthy adults: Ravansar non-communicable disease cohort study, Iran.

INTRODUCTION: It is necessary to establish hematological reference intervals (RIs) in each population to improve disease management and healthcare quality. This study aimed to establish age- and sex-specific hematological RIs in a healthy adult Kurdish population and evaluate the influence of select lifestyle factors. METHODS: Hematological parameters were studied in 6518 individuals (3006 females, 3512 males) from Ravansar Non-Communicable Disease (RaNCD) cohort study. Hematological parameters were measured by Beckman Coulter HmX Analyzer. After combined application of exclusion criteria and statistical outlier removal, RIs for all partitions were calculated using nonparametric methods. RESULTS: The present study established hematological RIs for 14 parameters in a healthy adult Iranian population. Reference values for some analytes demonstrated significant age- and sex-specific differences and were slightly different when compared to RIs determined in other populations. Furthermore, the current smokers had higher levels of white blood cells (WBCs), red blood cells (RBCs), hemoglobin, hematocrit, mean corpuscular hemoglobin (MCH), and mean corpuscular volume than ex- and nonsmokers. Also, in the presence of high physical activity, elevated levels of RBC, hemoglobin, hematocrit, monocytes, and MCH were observed, as well as lower WBC levels. Further, a significant positive association was observed between body mass index (BMI) and WBC, red cell distribution width, and plateletcrit levels. CONCLUSION: Our study suggests hematological parameters are influenced by age, sex, and lifestyle factors such as physical activity and BMI. Additionally, discrepancies when compared to other population studies suggest that ethnic-specific differences need to be considered when establishing RIs for hematological parameters.

Preoperative low hematocrit is an adverse prognostic biomarker in ovarian cancer.

OBJECTIVE: The study aimed to investigate the prognostic value of preoperative hematocrit (HCT) on the survival of epithelial ovarian cancer (EOC) patients. METHODS: Patients who underwent primary debulking surgery (PDS) in our institution, from January 2010 to December 2015, were enrolled. The preoperative HCT, hemoglobin (Hb), tumor stage, ascites volume, age, albumin, BMI, ASA score, diabetes and other factors were collected and analyzed to find the risk factors for poor prognosis of EOC patients using Cox regression. Survival analysis was conducted with Kaplan-Meier method and log-rank test. RESULTS: 192 patients met the inclusion criteria. HCT < 35% (P = 0.031, HR: 1.715, 95% CI 1.050-2.802) was an independent risk factor for poor overall survival in patients. The mean survival time was 83.7 months in patients with preoperative HCT ≥ 35% and 61.7 months in patients with HCT < 35% (P = 0.002). Patients with low HCT (< 35%) had a poor prognosis compared with patients with normal HCT, specifically in the patients of stage III/IV, age ≥ 65 years, BMI ≥ 25.0 kg/m2, ascites volume ≤ 500 mL, ASA score < 3, albumin ≥ 35 g/L and nondiabetic. Low HCT was more likely to occur in patients with advanced stage (III/IV), anemia (Hb < 110 g/mL), low albumin (< 35 g/L), high ASA score (≥ 3) and platelet > 400 × 109/L. CONCLUSIONS: Preoperative low HCT was a valuable predictor for EOC patients' poor prognosis, specifically in obese, nondiabetic, elder, advanced stage but having relatively good performance status patients.

Dried blood spots for anti-doping: Why just going volumetric may not be sufficient.

The perspective discusses quantitative DBS analysis for anti-doping testing in an athletic population and why only using volumetric sampling for this subgroup might not be enough. It presents examples to highlight where HCT variations occur, followed by a whole blood to plasma ratio and an HCT extraction bias discussion. Finally, options to correct for the HCT bias are presented.