Red Cell Aggregation Research Articles

Effect of regular winter swimming on blood morphological, rheological, and biochemical indicators and activity of antioxidant enzymes in males

BackgroundExposure of the human body to cold water triggers numerous beneficial physiological changes. The study aimed to assess the impact of regular winter swimming on blood morphological, rheological, and biochemical indicators and activity of antioxidant enzymes in males.MethodsThe study involved 10 male winter swimmers (the same participants examined before the season and after the season) and 13 males (not winter swimming, leading a sedentary lifestyle) in the control group. Fasting blood was collected twice: in November and in March of the following year. Basic blood morphological indicators, red cell elongation index (EI) and aggregation index (AI), concentrations of testosterone, cortisol, urea, and creatinine, as well as plasma activity of antioxidant enzymes of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) were determined.ResultsThe data were collected from the same winter swimmers at the beginning and end of the season. Winter swimming resulted in a significant increase of EI values at a shear stress of 0.30 (p = 0.40), 0.58 (p < 0.001), 4.24 (p = 0.021), 8.23 (p = 0.001), 15.59 (p = 0.001), 30.94 (p = 0.004), and 60.00 Pa (p = 0.043); haemoglobin was lower than before the season (p < 0.027). No significant changes were observed in AI, AMP, T1/2, the levels of urea, creatinine, eGFR, testosterone, cortisol, or the activity of CAT or SOD. There was a statistically significant increase in GPx activity (p = 0.014) and increase in testosterone concentration (p = 0.035) in the group of winter swimmers examined before the season as compared with the control group. No statistically significant differences were found for the mean values of blood morphological indicators and other parameters.ConclusionsWinter swimming can prove to be a health-promoting factor in males, as indicated by a rise in the deformability of red blood cells in the blood vessel system after a full season of winter swimming, leading to better body oxygenation, and improves the antioxidant defence and testosterone concentration (within standard limits) in the group of winter swimmers examined before the season as compared with the control group. Winter swimming helps maintain appropriate levels of blood rheological indicators, urea, creatinine, eGFR, cortisol, testosterone, and activity of antioxidant enzymes.Trial registrationClinicalTrials.gov identifier NCT06223087, 15.01.2024.

The rheology of interactions between leukocytes, platelets and the vessel wall in thrombo-inflammation.

Leukocytes and platelets must adhere to the wall of blood vessels to carry out their protective functions in inflammation and haemostasis. Recruitment is critically dependent on rheological variables (wall shear rate and stress, red cell aggregation and haematocrit) which affect delivery to the vessel wall as well as velocities and forces experienced there. Leukocyte recruitment is efficient only up to wall shear rates of about 300s-1 and usually restricted to low-shear post-capillary venules in inflammation. Being smaller, platelets experience lower velocities and shear forces adjacent to the wall and can adhere at much higher shear rates for haemostasis in arteries. In addition, we found quite different effects of variations in haematocrit or red cell aggregation on attachment of neutrophils or platelets, which also assist their separate recruitment in venules or arteries. However, it has become increasingly evident that inflammatory and thrombotic responses may occur together, with platelets promoting the adhesion and activation of neutrophils and monocytes. Indeed, it is 30 years since we demonstrated that platelets could cause neutrophils to aggregate in suspension and, when attached to a surface, could support selectin-mediated rolling of all leukocytes. Thrombin-activated platelets could further induce neutrophil activation and immobilisation. In some conditions, platelets could bind to intact endothelial monolayers and capture neutrophils or monocytes. Subsequently, we found that extracellular vesicles released by activated platelets (PEV) fulfilled similar functions when deposited on surfaces or bound to endothelial cells. In murine models, platelets or PEV could act as bridges for monocytes in inflamed vessels. Thus, leukocytes and platelets are rheologically adapted for their separate functions, while novel thrombo-inflammatory pathways using platelets or PEV may underlie pathogenic leukocyte recruitment.

Antilisterial Effectiveness of Origanum vulgare var. hirtum and Coridothymus capitatus Essential Oils and Hydrolates Alone and in Combination.

The antimicrobial activity of Origanum vulgare var. hirtum (O) and Coridothymus capitatus (C) essential oils (EOs) and hydrolates (HYs) of the same botanical species was evaluated on sixteen L. monocytogenes strains from food and clinical origins. The antimicrobial activity was assessed by Minimum Inhibitory Concentration (MIC) determination, viable cell enumeration over time up to 60 min, and evaluation of the cellular damage through Confocal Laser Scanning Microscope (CLSM) analysis. EOs exhibited antimicrobial activity with MIC values ranging from 0.3125 to 10 µL/mL. In contrast, HYs demonstrated antimicrobial effectiveness at higher concentrations (125-500 µL/mL). The effect of HYs was rapid after the contact with the cells, and the cell count reduction over 60 min of HY treatment was about 1.2-1.7 Log CFU/mL. L. monocytogenes cells were stressed by HY treatment, and red cell aggregates were revealed through CLSM observation. Moreover, the combinations of EOs and HYs had an additive antilisterial effect in most cases and allowed the concentration of use to be reduced, while maintaining or improving the antimicrobial effectiveness. The combined use of EOs and HYs can offer novel opportunities for applications, thereby enhancing the antimicrobial effectiveness and diminishing the concentration of use. This provides the added benefit of reducing toxicity and mitigating any undesirable sensory effects.

Which sub-compartments of fat mass and fat-free mass are related to blood viscosity factors?

The size of body compartments is a determinant of several factors of blood viscosity. Red cell aggregation is proportional to fat mass while hematocrit is proportional to both fat-free mass and abdominal adiposity, but which parts of these body components are involved in this relationship is not known. Segmental bioelectrical impedance analysis (sBIA) provides a possibility to delineate the relationships more precisely between various subdivisions of the body and blood viscosity factors, going farther than preceding studies using non segmental BIA. In this study we investigated in 38 subjects undergoing a standardized breakfast test with mathematical modelling of glucose homeostasis and a segmental bioelectrical impedance analysis (sBIA) the relationships between the various compartments of the body and viscosity factors. Blood and plasma viscosity were measured with the Anton Paar rheometer and analyzed with Quemada's model. The parameters better correlated to hematocrit are fat free mass (r = 0.562) and its two components muscle mass (r = 0.516) and non-muscular fat-free mass (r = 0.452), and also trunk fat mass (r = 0.383) and waist-to hip ratio (r = 0.394). Red cell aggregation measurements were correlated with both truncal and appendicular fat mass (r ranging between 0.603 and 0.728). Weaker correlations of M and M1 are found with waist circumference and hip circumference. This study shows that the correlation between lean mass and hematocrit involves both muscle and non-muscle moieties of lean mass, and that both central and appendicular fat are determinants of red cell aggregation.

Aβ-Aggregation-Generated Blue Autofluorescence Illuminates Senile Plaques as well as Complex Blood and Vascular Pathologies in Alzheimer's Disease.

Senile plaque blue autofluorescence was discovered around 40 years ago, however, its impact on Alzheimer's disease (AD) pathology has not been fully examined. We analyzed senile plaques with immunohistochemistry and fluorescence imaging on AD brain sections and also Aβ aggregation in vitro. In DAPI or Hoechst staining, the nuclear blue fluorescence could only be correctly assigned after subtracting the blue plaque autofluorescence. The flower-like structures wrapping dense-core blue fluorescence formed by cathepsin D staining could not be considered central-nucleated neurons with defective lysosomes since there was no nuclear staining in the plaque core when the blue autofluorescence was subtracted. Both Aβ self-oligomers and Aβ/hemoglobin heterocomplexes generated blue autofluorescence. The Aβ amyloid blue autofluorescence not only labels senile plaques but also illustrates red cell aggregation, hemolysis, cerebral amyloid angiopathy, vascular plaques, vascular adhesions, and microaneurysms. In summary, we conclude that Aβ-aggregation-generated blue autofluorescence is an excellent multi-amyloidosis marker in Alzheimer's disease.

A-137 Performance Evaluation of an Automatic, Rapid and Non-Westergren Based Method for Erythrocyte Sedimentation Rate Measurement

Abstract The erythrocyte sedimentation rate (ESR) is widely used for the assessment of acute or chronic inflammation, especially for rheumatoid diseases. The gold standard for determining ESR is the Westergren method, which measures the distance in millimeters that red blood cells fall in one hour. However, this method needs to be performed manually, which increases the biohazard risk to laboratory personnel, and the results are often influenced by many preanalytical and analytical factors. Several automated ESR analyzers with different methodologies are now available to provide faster results directly from whole blood anticoagulated with K3EDTA. In this study, we evaluated the performance of an automatic ESR analyzer, Alifax TEST1, and compared it with that of another automatic analyzer, Diesse Cube 30 touch, and also the Westergren method. TEST1 extrapolates the ESR values by measuring the kinetics of red cells aggregation in 20 s, while Cube 30 is a modified Westergren method that could obtain the results in 20 min. A total of 75 clinical samples were analyzed for ESR using the three methods. The hematocrit (Hct) and C-reactive protein (CRP) values were also analyzed. The Spearman correlation coefficient between TEST1 and Westergren methods was 0.90 (P &amp;lt; 0.0001) with a mean difference of -5.45; the correlation between Cube 30 and Westergren methods was 0.80 (P &amp;lt; 0.0001) with a mean difference of 10.74; the correlation between TEST1 and Cube 30 was 0.69 (P &amp;lt; 0.0001) with a mean difference of -15.9. The precision values (CV %) of TEST1 in low-, medium- and high-level controls were 2.71%, 1.21% and 1.05% for inter-assay, and 3.70%, 1.66% and 0.86% for intra-assay. The normal range of TEST1 was also established by analyzing ESR values of 125 healthy individuals where it is 0–15 mm/hr for men ≤50years old, 0–20 mm/hr for men &amp;gt; 50 years old and for women ≤50 years old, and 0–30 mm/hr for women &amp;gt; 50years old. The ESR values obtained from the three methods all significantly correlated with plasma CRP levels. However, the ESR values from Cube 30 and Westergren methods negatively correlated with Hct values, while that from TEST1 did not. The present study demonstrates that 1) TEST1 has a better correlation and a lower difference to the Westergren method compared to Cube 30, suggesting that TEST1, the automatic, rapid and non-Westergren based method is an effective assay for clinical practice; 2) the Westergren based methods are more easily influenced by Hct; 3) the large mean difference between TEST1 and Cube 30 highlights a need for harmonization of the ESR values obtained from different automatic analyzers, especially when it is applied to monitor the disease activity score (DAS28) in rheumatoid arthritis patients.

Astragalus membranaceus Additive Improves Serum Biochemical Parameters and Reproductive Performance in Postpartum Dairy Cows.

The purpose of the study was to assess the recovery, immune function, and breeding efficiency of postpartum dairy cows fed Astragalus membranaceus (AM) as a feed additive. The experiment used a completely randomized design. Cows were randomly assigned to two groups: (1) Control group fed total mixed ration (TMR; CON group, n = 15); (2) AM group fed TMR and AM (AM group, n = 15). The AM group was fed 675 g/day. The experimental results showed that compared with the CON group. The breeding interval of the AM group of dairy cows had a tendency to shorten (0.05 < p < 0.1). Plasma viscosity (PV), Plasma fibrinogen (FIB), the red cell aggregation index (TRCAI), Calcitonin (CT), Immunoglobulin M (IgM), and Luteinizing hormone (LH) results of AM group showed a time-treatment interaction (p < 0.05). Furthermore, the result of the study revealed that feeding AM as feed additives to dairy cows during the postpartum period had positive effects on wound recovery, immune function, endocrine regulation, and breeding efficiency.

High-Pressure-Induced Sublethal Injuries of Food Pathogens-Microscopic Assessment.

High Hydrostatic Pressure (HHP) technology is considered an alternative method of food preservation. Nevertheless, the current dogma is that HHP might be insufficient to preserve food lastingly against some pathogens. Incompletely damaged cells can resuscitate under favorable conditions, and they may proliferate in food during storage. This study was undertaken to characterize the extent of sublethal injuries induced by HHP (300–500 MPa) on Escherichia coli and Listeria inncua strains. The morphological changes were evaluated using microscopy methods such as Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Epifluorescence Microscopy (EFM). The overall assessment of the physiological state of tested bacteria through TEM and SEM showed that the action of pressure on the structure of the bacterial membrane was almost minor or unnoticeable, beyond the L. innocua wild-type strain. However, alterations were observed in subcellular structures such as the cytoplasm and nucleoid for both L. innocua and E. coli strains. More significant changes after the HHP of internal structures were reported in the case of wild-type strains isolated from raw juice. Extreme condensation of the cytoplasm was observed, while the outline of cells was intact. The percentage ratio between alive and injured cells in the population was assessed by fluorescent microscopy. The results of HHP-treated samples showed a heterogeneous population, and red cell aggregates were observed. The percentage ratio of live and dead cells (L/D) in the L. innocua collection strain population was higher than in the case of the wild-type strain (69%/31% and 55%/45%, respectively). In turn, E. coli populations were characterized with a similar L/D ratio. Half of the cells in the populations were distinguished as visibly fluorescing red. The results obtained in this study confirmed sublethal HHP reaction on pathogens cells.

Assessment of morphological, biochemical and rheological blood indicators in men after a 24-hour stay in a thermo-climatic chamber -50°C

Purpose: The aim of the study was to evaluate morphological, biochemical, and rheological blood indicators in men staying in a cryochamber at a temperature of -50°C for 24 hours. In 2018, a scientific-survival project ‘Taming the Frost’ was conducted at the Technoclimatic Research and Working Machines Laboratory of the Cracow University of Technology, under the scientific patronage of the Rector of the Cracow University of Technology, Prof. Jan Kazior, PhD, as well as the Rector of the University of Physical Education in Krakow, the late Prof. Aleksander Tyka, PhD, and the Vice-Rector for Science, Prof. Anna Marchewka, PhD. Material and methods: The blood for the tests was collected from an ulnar vein in fasting participants by a qualified nurse, in the morning, before entering the cryochamber and after 24 hours, i.e. on leaving the cryochamber. Morphological, biochemical, and rheological blood indicators were evaluated. The study group of the scientific-survival project ‘Taming the Frost’ involved men (n=6) who stayed in a cryochamber at a temperature of -50°C for 24 hours. For each participant, a 5-ml blood sample was placed in a tube (BD Vacutainer) with EDTA K2 anticoagulant for blood morphology and blood rheological evaluations in the Blood Physiology Laboratory of the Central Research and Development Laboratory, University of Physical Education in Krakow. Another 5-ml blood sample was placed in a Vacuette tube with a clotting activator for the remaining biochemical analyses in the Department of Clinical Biochemistry of the Krakow Branch of Maria Skłodowska-Curie National Research Institute of Oncology. Results: After leaving the cryochamber with a temperature of –50°C, the participants presented statistically significant increases in monocyte count and high-density lipoprotein and creatine kinase values, as well as decreases in IgA, total cholesterol, and triglycerides. In the assessment of blood rheological indicators, statistically significant increases in the elongation index at the shear stress of 0.30, 0.58, 1.13, and 2.19 Pa and decreases in the elongation index at the shear stress of 31.03 and 60.3 Pa were observed. For red cell aggregation indicators, a statistically significant increase in total aggregation time was reported. The other indicators exhibited a significance level of p&gt;0.05. Conclusions: Staying in a cryochamber at a temperature of -50°C for 24 hours did not exert a negative impact on morphological, biochemical, or rheological blood indicators, which implies the subjects’ adaptation to the arranged conditions.

Cold antibodies association with cellulitis, deep vein thrombosis and abnormal red cells indices: A Case Report.

Objectives: To provide awareness to the pathologists and technologists all about the red cells parameters in cold antibodies concerned cases. Case Report Findings: A sixty seven-years-old male admitted in emergency department of our hospital, having clinical history of swelling and pain in both the lower limb and feet, on physical examination, provisionally diagnosed as a case of Cellulitis and deep vein thrombosis(DVT). Blood specimen was obtained for general hematological investigations. Full blood count (FBC) was performed on sysmex XP-100 hematological analyzer which showed invalid findings especially red cells indices which were not corresponding to the hemoglobin (Hb) concentration of the patient. Blood sample was repeated, to confirm invalid red cells indices which showed values as in the 1st blood specimen. Blood smears revealed aggregation of red cells. By warming the ethylenediamine tetra-acetic acid (EDTA) tube containing the blood specimen, in water bath at 37⁰C for one hour and repeated the FBC on hematological analyzer and found the corrected red cells indices. Conclusion: Basic knowledge of cold antibodies and warming the blood sample at 37⁰c for one hour helps the correct diagnosis.

Гистобиохимические признаки апоптоза в тканях сусликов при пробуждении после спячки

Histological preparations of ground squirrel liver, heart and brain tissues were studied in the middle of the hibernation bout (body temperature of 1–4 °C), at self-heating (body temperature of 6–29 °C) and upon complete awakening (body temperature of 37–38 °C). In the state of deep hibernation, no signs of apoptosis were identified in ground squirrel tissues. We observed microcirculatory dysfunction manifested in abnormal blood rheology: acute hyperaemia of brain and myocardial capillaries, central veins and sinusoids of the liver, as well as mild tissue oedema and aggregations of red blood cells (rouleaux) in microvasculature. At self-heating, signs of the initial stage of apoptosis were detected: mild granularity in cardiomyocyte cytoplasm as a sign of protein dystrophy, and mild cytoplasmic vacuolization in hepatocytes. Morphological signs of these processes were revealed upon the animal’s complete awakening. Shrinkage of individual hepatocytes was observed; cells with pyknotic nuclei appeared, which can be explained by the condensation of chromatin and intracellular organelles; cell fragments with karyorrhectic phenomena resembling apoptotic bodies were identified. Thus, no signs of apoptosis were found in ground squirrel tissues during deep hibernation. At self-heating, signs of the initial stage of apoptosis were detected, and only in the state of complete awakening were single hepatocytes and neurons similar to apoptotic bodies identified. In addition, the absence of an inflammatory reaction in the tissues under study allows us to suggest that we are observing the stages of apoptosis. Noteworthy, ground squirrel awakening was accompanied by a significant increase in the activity of lysosomal membrane markers cathepsin D and acid phosphatase.

Imaging relative stasis of the blood column in human retinal capillaries.

Capillary flow largely consists of alternating red cells and plasma whose speed oscillates predictably with the cardiac cycle. Superimposed on this regular background are sporadic events potentially disruptive to capillary exchange: the passage of white cells, aggregates of red cells, epochs of sparse haematocrit, or unusually slow flow. Such events are not readily differentiated with velocimetry or perfusion mapping. Here we propose a method to identify these phenomena in retinal capillaries imaged with high frame-rate adaptive optics, by calculating and representing pictorially the autocorrelation of intensity through time at each pixel during short epochs. The phenomena described above manifest as bright regions which transiently appear and propagate across an otherwise dark image. Drawing data from normal subjects and those with Type I diabetes, we demonstrate proof of concept and high sensitivity and specificity of this metric to variations in capillary contents and rate of flow in health and disease. The proposed metric offers a useful adjunct to velocimetry and perfusion mapping in the study of normal and abnormal capillary blood flow.

Shear-induced non-monotonic viscosity dependence for model red blood cell suspensions in microvessels.

The cell-free layer thickness of an aggregating red blood cell (RBC) suspension in a rectangular microchannel is investigated by hybrid fluid-particle numerical modeling. Several factors affect the suspension viscosity, cell-free layer thickness, and the cell aggregate distribution. These include the hematocrit, vessel size, red cell stiffness, aggregation interaction, and shear rate. In particular, the effect of the shear rate on the cell-free layer thickness is controversial. We found that the suspension viscosity increases along with a decrease in the cell-free layer thickness as the shear rate increases for aggregating model RBCs at low shear rates. At moderate to high shear rates, the cell-free layer thickness increases with the increasing shear rate from medium to strong shear flow for both 10% and 20% red blood cell suspensions.

Blood-compatible, stable micelles of sodium alginate – Curcumin bioconjugate for anti-cancer applications

The bioconjugate of alginate and curcumin (AA-CUR) was synthesized in a simple, one-step process and used to prepare the stable calcium cross-linked spherical micelles serving as a delivery vehicle for curcumin. Above its critical micelle concentration (0.6 mg/ml) AA-CUR forms colloidally stable micelles of ca. 200 nm. Prolonged, well controlled release of curcumin was observed from the AA-CUR micelles cross-linked with calcium ions for 5 h under the physiological conditions. To assess the safety of applying the bioconjugate into the bloodstream for possible anti-cancer applications, the interaction between AA-CUR and cells isolated from human blood was analyzed. No red cells aggregation or hemolysis was observed. AA-CUR was also shown to have no significant cytotoxicity to the human Peripheral Blood Mononuclear Cells (PBMC) isolated from peripheral blood of healthy donors and to the mouse primary brain endothelial cells. To evaluate the efficiency of the obtained bioconjugate in the anti-cancer therapy, the micellar solution of AA-CUR was tested against various cancer cells lines: mammary carcinoma 4T1, melanoma B16F10 and colon carcinoma CT26-CEA and MC38-CEA. The bioconjugate at the concentration of 0.7 mg/ml decreased the viability of cancer cells by ca. 80%. The cellular uptake of AA-CUR was rapid and the highest micelles accumulation was detected within 1 h after treatment. The AA-CUR micellar system can serve as an effective and safe delivery vehicle for curcumin.

Amlodipine alters hemorheological parameters: Increased efficacy at the cost of edema?

BackgroundDespite several decades of use of calcium channel blockers, the side effect of edema persists as a class effect, and its mechanism is unresolved. Amlodipine has effects on hemorheology (HR), and its hemodilutory property may partly contribute to its antihypertensive action. This aspect is not well studied, and the literature is sparse in this regard. ObjectiveThis experiment was planned to determine effect of a single-dose administration of amlodipine on HR parameters in normal human volunteers. Methods and resultsAmlodipine (5 mg) or S (-) amlodipine (2.5 mg) was administered to 27 normal human volunteers. Whole-blood viscosity (WBV) at different shear rates, plasma viscosity (PV), red cell rigidity (RCR), red cell aggregation (RCA), hematocrit (Hct), plasma hemoglobin, along with plasma drug concentration were determined at time intervals, t = 0, 4, 8, 12, and 24 h. Statistically significant reductions were observed at tmax = 4 h in WBV at shear rates of 0.512 s–1 (p < 0.005), WBV at shear rates of 5.26 s–1 (p < 0.01), PV (p < 0.05), and Hct (p < 0.01). At t = 8 h, as drug concentration reduced, some of the changes persisted and later slowly decreased with the decreasing drug concentration till t = 24 h. Red blood cell–related parameters such as RCA and RCR remained unaltered. WBV values at all shear rates, when corrected for Hct = 0.45, did not show deviation from their original values at any time. ConclusionsAmlodipine causes a reduction in Hct and blood viscosity, along with hemodilution. These effects persist as long as the drug remains in plasma. Edema resulting from chronic dosing may be explained by the aforementioned effects. It is possible that antihypertensive action of the drug may be due to a combination of vasodilatation and an improvement in the HR properties.

Bone Marrow Characterization in Sickle Cell Disease: Inflammation and Stress Erythropoiesis Lead to Suboptimal CD34 Recovery Compared to Normal Volunteer Bone Marrow

IntroductionGene therapy for sickle cell disease (SCD) requires modification of a high number of long term engrafting hematopoietic stem cells (LT-HSCs) sufficient to sustain production of the gene of interest at levels capable of overcoming the pathogenic HbSS phenotype. Unlike β-Thalassemia, the inflammatory bone marrow (BM) environment and stress erythropoiesis associated with SCD may have significant impacts on HSC quality and yield necessary for disease amelioration. Important work to optimize gene therapy through improvement in gene transfer efficiency, editing strategies, or transplant conditioning can only improve gene therapy in SCD if enough autologous HSCs are LT-HSCs, thus characterization of SCD BM and CD34+ HSCs is required. Collection type, storage, and delays in processing may further impact CD34+ recovery and should be investigated as a strategy to maximize LT-HSC recovery.MethodsTwenty milliliters of BM from subjects with SCD (HbSS genotype) and normal volunteers was collected in different anticoagulants (Heparin, ACD-A) and processed immediately(day 0) or stored at 40C and processed the following day(day 1). After isolation via Ficoll density gradient centrifugation, the mononuclear (MN) layer was stained with antibodies against inflammatory markers (CD36, CD35, CD11b, CD62L, CD62P), non-MN cells (GPA, CD66b, CD41/61), or processed for CD34+ selection using a magnetic microbead CD34+ selection kit and stained for CD34, CD45, and GPA expression. Data were analyzed by conventional and imaging flow cytometry, the latter confirming post-CD34+ selection flow data and demonstrating antibody intensity as a characterization of HSC heterogeneity and progenitor lineage. Complete blood count and hemoglobin (Hb) electrophoresis were obtained at the time of BM collection. Statistical analyses were performed using unpaired t-tests.ResultsBM was collected from 18 subjects (16 with SCD; 11M; age 21-41 years). Median Hb (8.6 vs. 13.5 gm/dL, p<0.01) and white blood cell count (8.8 vs. 4.2 K/mcL, p<0.05) differed significantly between SCD and non-SCD subjects. Median percent sickle Hb in SCD subjects was 62%. Inflammatory markers and contamination with red cell and platelet markers in the post-Ficoll MN layer were higher in SCD vs. non-SCD BM regardless of anticoagulant (CD35 24% vs. 13%, p<0.05; CD36 22% vs. 11%, p<0.05; CD62P 16% vs. 3%, p<0.05; GPA 16% vs. 4%, p<0.05; CD41/61 19% vs. 3%, p<0.05), and trended higher on day 1 in SCD BM in both anticoagulants, significantly in Heparin (GPA 23% vs. 33% on day 1, p<0.05). Total CD45 expression was lower in SCD vs. non-SCD BM in both anticoagulants (p<0.05) and on day 0 (p<0.05) and 1 (p<0.01), with Amnis data confirming a higher CD34+CD45- population in SCD BM (4 ± 2% vs. 0.5 ± 0.3%, p<0.05). While there was no significant difference in total CD34+ cell count between SCD and non-SCD BM after selection post-Ficoll, there was a trend for lower CD34+ count in SCD in both anticoagulants (2.6x10^5 vs. 4.7x10^5, p=0.1). SCD CD34+ cells were characterized by higher GPA expression (28 ± 5% vs. 13 ± 3% in non-SCD BM, p<0.01) that worsened in Heparin on day 1 (22 ± 6.3% vs. 35 ± 12.4%, p<0.05). Image cytometry confirmed a majority of GPA expression in SCD BM is from single cell CD34+CD45+GPA+ and CD34+CD45-GPA+ HSCs in addition to red cell aggregates, with an increase in CD34+CD45-GPA+ HSCs on day 1 (10 ± 5% vs. 0.6 ± 0.2 % on day 0, p<0.05). Furthermore, the percentage of CD34hi HSCs was lower in SCD vs. non-SCD BM, with >50% SCD HSCs characterized as CD34dim (56% vs. 4% in non-SCD BM, p<0.001). Lastly, the purity of CD34+ selection worsened from day 0 to day 1 in SCD BM in heparin (94% vs. 68 ± 8%, p<0.05) and ACD-A (88% vs. 68 ± 0.7%, p<0.05).ConclusionsSCD BM is characterized by increased inflammation and cell contamination in the MN layer regardless of anticoagulant that worsens over time in Heparin more significantly than in ACD-A. Compared to non-SCD BM, CD34+ HSC yield post-Ficoll is lower in SCD subjects, and is characterized by a larger proportion of CD34+CD45+GPA+ and CD34+CD45-GPA+ HSCs that rise with delays in processing. This indication of early differentiation along the erythroid lineage, with more than 50% of HSCs losing CD34+ intensity suggesting they are not LT-HSCs, suggests suppression of inflammation and stress erythropoiesis, combined with early cell processing may be critical for maximal HSC recovery necessary for successful gene therapy in SCD. [Display omitted] DisclosuresLuo:bluebird bio Inc.: Employment. Pierciey:bluebird bio: Employment.

Unsteady solute dispersion in small blood vessels using a two-phase Casson model

This study explores the transport of a solute in an unsteady blood flow in small arteries with and without absorption at the wall. The Casson fluid model is suitable for blood flow in small vessels. Owing to the aggregation of red cells in the central region of the small vessels, a two-phase model is considered in this investigation. Using the generalized dispersion model (Sankarasubramanian &amp; Gill 1973 Proc. R. Soc. Lond. A 333 , 115–132. (doi:10.1098/rspa.1973.0051)), the convection, dispersion and mean concentration of the solute are analysed at all times in small arteries of different radii. The effects of the yield stress, wall absorption, the amplitude of the fluctuating pressure gradient component, the peripheral layer thickness, the Womersley frequency parameter, the Schmidt number and the Peclet number on the dispersion process are discussed. A comparative study of solute dispersion among single- and two-phase fluid models is presented. For small vessels, a significant difference between these models is observed during the solute dispersion; however, this difference becomes insignificant for large vessels. The mean concentration of solute reduces with increasing radius of the vessels. The present investigation is more realistic for understanding the transportation process of drugs in blood flow in small arteries using the non-Newtonian fluid model.

Segmental bioelectrical impedance analysis (SBIA) and blood rheology: Reducing the gap between in vivo and in vitro?

Bioelectrical impedancemetry (BIA) has been used to evaluate hematocrit and red cell aggregability in vitro but whole body impedance measurements are also correlated to some hemorheologic factors, suggesting a relationship between viscosity factors and electric properties of blood. We repeatedly reported correlations with whole body BIA and hematocrit, whole blood viscosity and plasma viscosity, red cell rigidity and RBC aggregation. The SBIA Inbody 770 modelizes body as 5 cylinders and measures impedance at 1, 5, 50, 250, 500, and 1000 kHz. With the SBIA we found that hematocrit is best correlated to leg reactance at 50 kHz but also to leg impedance at 1 and 5 kHz and trunk reactance. RBC aggregation "M" is best correlated to arm reactance at 5 kHz but also to most measurements of segmental impedance (28 correlations found). RBC aggregation "M1" is best correlated to arm reactance at 5 kHz and to 19 other impedance measurements. A predictive equation for "M" from the mean between the two arm reactances at 5 kHz (maXc5) is found: M = 2.1845maXc5-23.958 (r = 0.665, p < 0.001) that provides a satisfactory Bland-Altman plot (mean difference: 0.000524 range [-1.6;+1.6]. This study suggests that previously reported correlations between BIA and viscosity factors were not spurious, and that in a narrow cylinder such as the arm the structure of circulating blood (hematocrit, red cell aggregation) may influence the passage of an electric current by increasing reactance.

One-year follow-up of blood viscosity factors and hematocrit/viscosity ratio inelite soccer players.

We investigated to what extent aprediction of the 'ideal' hematocrit based on individual hemorheological profile with an equation of viscosity is relevant in trained athletes, and how the agreement between theoretical and actual values is modified by changes in training volume and performance. Elite soccer players (national level: 18-32yr, weight 61-83 kg, body mass index 20.9-25.8 kg/m2) were seen twice at one year interval. Hemorheologic parameters were measured with the MT90 viscometer and the Myrenne aggregometer the theoretical bell-shaped curve of hematocrit/viscosity ratio as afunction of hematocrit was reconstructed with Quemada's equation using actual plasma viscosity and red cell rigidity to predict hematocrit/viscosity at various hematocrit levels. RBC aggregation is correlated at baseline with fat mass (M1 = 0.552 p < 0.02) and changes in aggregation are related to changes in fat mass (M = 0.652, p < 0.05; M1 = 0.647, p < 0.05). Predicted and actual hematocrit are correlated (r = 0.644, p < 0.05) but exhibit discrepancies (mean difference -1% range [3.24 to 1.24]) and those discrepancies are inversely correlated to the level of predicted hematocrit (r = -0.912, p < 0.01), to systolic blood pressure (r = -0.626, p < 0.05), and to the overtraining score (r = -0.693, p < 0.05). After one year changes in hematocrit are aclose reflect of the change in training volume (r = -0.877, p < 0.01) but are not correlated to fitness changes. Therefore in these athletes i) systemic hematocrit is close to its predicted 'ideal value", suggesting the accuracy of the prediction; ii) red cell aggregation is correlated to fat mass even in nonobese subjects; iii) hematocrit is lower than predicted by the model when markers of sympathetic tone (systolic blood pressure, overtraining score) are increased; iv) weekly training volume appears the main determinant of the reduction of hematocrit.

On changes in aggregation of red cells, blood viscosity and plasma viscosity during normal gestation

On changes in aggregation of red cells, blood viscosity and plasma viscosity during normal gestation