scholarly journals THE RHEOLOGY OF THE BLOOD

1944 ◽  
Vol 28 (2) ◽  
pp. 131-149 ◽  
Author(s):  
Eugene C. Bingham ◽  
Raymond R. Roepke
Keyword(s):  
Human Blood ◽  
Whole Blood ◽  
Blood Cells ◽  
Volume Concentration ◽  
Preceding Paper ◽  
Barometric Pressure ◽  
The State ◽  
Hemoglobin Content ◽  
Healthy Human ◽  
Similar Formula

In the preceding paper (1b) a formula was developed for the lowering of the fluidity of a medium by a mixture of proteins, given the volume concentration of each and its fluidity-lowering constant. Whole blood is now shown to follow an essentially similar formula, except that the hemoglobin content is taken from the literature as the best available measure of the volume of the blood cells Δ Φ = 0.24H, assuming the fluidity of the medium to be 53 rhes. Age, sex, diet, barometric pressure affect the hemoglobin content of the blood, but the formula may apply to any healthy human blood to about 3 per cent. The shape, number, and size of the blood cells, if known, might help to explain discrepancies as well as the state of oxidation of the blood. In disease the discrepancy becomes much greater, suggesting the possible use of rheology in diagnosis.

Abstract WP287: Deterioration in Recombinant Tissue Plasminogen Activator After Repeated Freezing and Thawing Cycles for Thromboelastography

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Sean Calo ◽  
Anja-Kathrin Jaehne ◽  
Kelly A Keenan ◽  
Jun Xu ◽  
Baruch Tawil ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Human Blood ◽  
Whole Blood ◽  
Recombinant Tissue Plasminogen Activator ◽  
Healthy Human ◽  
Clot Strength ◽  
Blood Samples ◽  
Freeze Dried ◽  
Tissue Plasminogen

Background and Purpose: Thromboelastography (TEG) is often used to measure coagulation dynamics in the setting of acute ischemic stroke and thrombolytic therapy. The stability of thrombolytics has not been investigated in TEG. We conducted an experimental series to test the effects of recombinant tissue plasminogen activator (rtPA) on fibrinolysis in normal blood samples using TEG. Methods: Freeze dried rtPA powder was reconstituted in normal saline containing 0.2% bovine serum albumin (100 mg/24 mL), divided into 1 mL aliquots, and diluted to enable using a relatively large volume for complete mixing with blood samples. Aliquots and dilutions were frozen at -20°C. The same rtPA dilution was thawed to ambient temperature before each use and refrozen until the next use over 4 testing days. Blood was drawn into 3.2% sodium citrated collection tubes. rtPA (100 μL) was added to 1 mL whole blood to achieve a 636 ng/mL rtPA TEG sample concentration. Control-whole blood and rtPA-whole blood TEG was performed for 3 h on 4 healthy human blood samples. Maximum clot amplitude (mm) and absolute clot strength (dynes/cm 2 ) were measured. Data (mean±SD) were analyzed by t-tests and significance inferred at p <0.05. Results: Clot amplitude increased with thawing and refreezing (28±3, p=0.004; 35±2 p=0.01; 50±3, p=0.02; and 55±3, p=0.30; for testing cycles 1, 2, 3 and 4, respectively) compared to untreated samples (63±4). Clot strength also increased over the 4 cycles (2±0.3, p=0.007; 3±0.2, p=0.02; 5±05, p=0.01 and 6±0.7, p=0.30) compared to untreated (9±1.4). Lysis initiation time was gradually longer over the 4 tests (red arrows, Figure 1) suggesting delayed fibrinolysis. Conclusions: One repeatedly thawed and refrozen rtPA stock showed a delay in fibrinolysis in healthy human blood, suggesting a loss of potency. Thus, rtPA should be aliquoted for 1-time use for experiments using TEG. Further investigation into rtPA potency deterioration with storage after reconstitution is warranted.

Combined Platelet and Erythrocyte Salvage: Evaluation of a New Filtration-based Autotransfusion Device

2021 ◽  
Author(s):  
Alexandre Mansour ◽  
Benoit Decouture ◽  
Mikaël Roussel ◽  
Charles Lefevre ◽  
Lucie Skreko ◽  
...  
Keyword(s):  
Red Blood Cells ◽  
Whole Blood ◽  
Blood Cells ◽  
Plasma Proteins ◽  
Complete Blood Count ◽  
Cell Recovery ◽  
Healthy Human ◽  
Platelet Recovery ◽  
Human Whole Blood ◽  
And Function

Background The SAME device (i-SEP, France) is an innovative filtration-based autotransfusion device able to salvage and wash both red blood cells and platelets. This study evaluated the device performances using human whole blood with the hypothesis that the device will be able to salvage platelets while achieving a erythrocyte yield of 80% and removal ratios of 90% for heparin and 80% for major plasma proteins without inducing signification activation of salvaged cells. Methods Thirty healthy human whole blood units (median volume, 478 ml) were diluted, heparinized, and processed by the device in two consecutive treatment cycles. Samples from the collection reservoir and the concentrated blood were analyzed. Complete blood count was performed to measure blood cell recovery rates. Flow cytometry evaluated the activation state and function of platelets and leukocytes. Heparin and plasma proteins were measured to assess washing performance. Results The global erythrocyte yield was 88.1% (84.1 to 91.1%; median [25th to 75th]) with posttreatment hematocrits of 48.9% (44.8 to 51.4%) and 51.4% (48.4 to 53.2%) for the first and second cycles, respectively. Ektacytometry did not show evidence of erythrocyte alteration. Platelet recovery was 36.8% (26.3 to 43.4%), with posttreatment counts of 88 × 109/l (73 to 101 × 109/l) and 115 × 109/l (95 to 135 × 109/l) for the first and second cycles, respectively. Recovered platelets showed a low basal P-selectin expression at 10.8% (8.1 to 15.2%) and a strong response to thrombin-activating peptide. Leukocyte yield was 93.0% (90.1 to 95.7%) with no activation or cell death. Global removal ratios were 98.3% (97.8 to 98.9%), 98.2% (96.9 to 98.8%), and 88.3% (86.6 to 90.7%) for heparin, albumin, and fibrinogen, respectively. The processing times were 4.4 min (4.2 to 4.6 min) and 4.4 min (4.2 to 4.7 min) for the first and second cycles, respectively. Conclusions This study demonstrated the performance of the SAME device. Platelets and red blood cells were salvaged without significant impact on cell integrity and function. In the meantime, leukocytes were not activated, and the washing quality of the device prevented reinfusion of high concentrations of heparin and plasma proteins. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

Meeting Requirements of the California Cholinesterase Monitoring Program

2004 ◽  
Vol 23 (2) ◽  
pp. 97-100 ◽  
Author(s):  
Barry W. Wilson ◽  
John D. Henderson ◽  
Daniel E. Arrieta ◽  
Michael A. O’Malley
Keyword(s):  
Human Blood ◽  
Whole Blood ◽  
Blood Cells ◽  
Conversion Factor ◽  
Monitoring Program ◽  
Plasma Samples ◽  
Comparison Study ◽  
Clinical Laboratories ◽  
Pesticide Regulation ◽  
Current List

California (CA) has a long-standing formal blood cholinesterase (ChE) monitoring program for mixers, loaders, and applicators of pesticides. When the authors found commercial clinical kits were not optimal for assaying blood ChEs, CA regulations were revised to specify use of the Ellman ChE assay or to demonstrate a conversion factor with a correlation ( r2) of 0.9 or better. The authors were enlisted to work with the clinical laboratories. Only two of seven participating laboratories generated an acceptable correlation for red blood cells (RBCs), whereas four of five laboratories had an acceptable correlation for plasma ChE. Subsequently, the CA Department of Pesticide Regulation (DPR) restated the need to meet this requirement and the authors worked with several of the clinical laboratories using a bovine ghost RBC ChE as a reference. Unfortunately, only 3 of 10 laboratories had acceptable correlations. Next, the authors provided all interested laboratories with human blood and plasma samples to perform the comparison study outlined in the regulation (Section 6728f). Fourteen laboratories participated; 9 met the ChE criteria for whole blood, 14 for plasma, and 6 for RBCs. Based on such data, on July 8, 2003, DPR notified the CA Agricultural Commissioners that nine of the participating laboratories were approved for ChE testing. Later work resulted in acceptable RBC values for two of the laboratories and their approval. The authors continue to work with laboratories interested in being on the approved list. The current list may be seen at www.cdpr.ca.gov/docs/whs/lablist.htm .

scholarly journals Isolation of Human Platelets (Thrombocytes)

2002 ◽  
Vol 2 ◽  
pp. 1607-1609 ◽  
Author(s):  
John Graham
Keyword(s):  
Human Blood ◽  
Whole Blood ◽  
Blood Cells ◽  
Human Platelets ◽  
Sedimentation Velocity ◽  
High Yield ◽  
Density Barrier

Platelets from human blood can be isolated in high yield by centrifugation of whole blood over an iodixanol density barrier of 1.063 g/ml. The separation from all of the blood cells (which form a pellet) is based on the slower sedimentation velocity of the smaller platelets.

Abstract WP108: Novel Human Acute Ischemic Stroke Blood Clot Analogues for in-vitro Testing

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Seán Fitzgerald ◽  
Daying Dai ◽  
Andrew S Douglas ◽  
Oana M Mereuta ◽  
Thomas Caracena ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Red Blood Cells ◽  
Acute Ischemic Stroke ◽  
Human Blood ◽  
Whole Blood ◽  
Blood Cells ◽  
Blood Clot ◽  
Buffy Coat

Introduction: Previous studies have successfully created blood clot analogues for In-vitro testing using animal blood. Blood components vary greatly among species and thus, creating clot analogues with human blood is likely a more accurate representation of thrombi formed in the human vasculature. We present a novel method of creating clot analogues from human blood and platelets that mimic the process by which clots form In-vivo . Methods: Following IRB approval from Mayo Clinic, human whole blood and platelets donations were obtained from the Blood Transfusion service. The whole blood was centrifuged at 1,200RPM for 20 minutes to separate it into its constituents. Plasma was removed and the remaining Red Blood Cells and Buffy Coat were mixed together by inverting. A total of 12 clot analogues were created with varying concentrations of components; Red Blood cells/Buffy Coat, Plasma and Platelets. Thrombin was added first to stimulate platelets activation for a total of 5 mins whilst continuously mixing by inversion. The RBC/WBC mixture was added next followed by CaCl2. The mixture was then quickly drawn into a 3cc syringe and spun overnight at 20RPM at room temperature to mimic dynamic flow conditions. Macro-photographs were taken to display the variation in texture and color between different clot analogue types. The clots were then fixed in 10% neutral buffered formalin for 24 hours prior to being processed. Histopathological analysis was performed using Hematoxylin and Eosin (H&E) and Martius Scarlet Blue (MSB) staining to confirm clot composition. Results: Red Blood cell-rich, Fibrin-rich, Platelet-rich and mixed clot analogues that accurately mimic clots retrieved from Acute Ischemic Stroke Patients were created. The range of histopathological compositions of the clot analogues is similar to that of the clinical samples. Conclusions: The addition and activation of platelets is key to creating accurate clot analogues for In-vitro testing. Spinning the clots is important to prevent natural sedimentation and mimic the In-vivo situation.

scholarly journals Spectroscopic Studies of in Vitro Exposure to Low-Dose Gamma Rays from 137Cs Radioactivity on Some Human Blood Components (Plasma and Red Blood Cells)

2021 ◽  
Author(s):  
Benjamaporn Supawat ◽  
Watcharit Vorasiripreecha ◽  
Sakornniya Wattanapongpitak ◽  
Suchart Kothan ◽  
Montree Tungjai
Keyword(s):  
Red Blood Cells ◽  
Gamma Rays ◽  
Human Blood ◽  
Whole Blood ◽  
Blood Cells ◽  
Low Dose ◽  
Radioactive Cesium ◽  
Blood Components ◽  
Blood Samples

Abstract This current study was to determine the effects of in vitro exposure to radioactive cesium-137 on some human blood components (Plasma and red blood cells). Blood samples were given a radiation dose of 0.02, 0.05, 0.1, 0.2, and 0.3 mGy of gamma rays using a 137Cs radioactive standard source. The blood samples that were exposed to 0 mGy served as sham-controls. The spectrofluoroscopic technique was used to determine the autofluorescence spectrum of protein in plasma or red blood cells by using excitation wavelength and range of emission wavelengths at 280 nm and 300-550 nm, respectively. The spectrophotometric technique was used to determine the release of hemoglobin from the red blood cells to the supernatant. This data indicated no change in the ratio of fluorescence emission intensity at 340 nm of wavelength of protein extract from irradiated whole blood or red blood cells compared to the corresponding non-irradiated control. The results did not change in the absorption intensity at 415 nm of wavelength of hemoglobin leakage from in vitro irradiated red blood cells when compared to the corresponding non-irradiated red blood cells. These current results suggested that there were no harmful effects of the low-dose gamma rays from radioactive 137Cs on some blood components when human whole blood was exposed to gamma rays in an in vitro condition.

Plasma Thromboplastin Component (Christmas Factor, Factor IX) Levels in Stored Human Blood and Plasma

1960 ◽  
Vol 04 (03) ◽  
pp. 376-388 ◽  
Author(s):  
J Dieter Geratz ◽  
John B. Graham
Keyword(s):  
Human Plasma ◽  
Human Blood ◽  
Whole Blood ◽  
Room Temperature ◽  
Close Agreement ◽  
Factor Ix ◽  
Deficient Patient ◽  
Glass Tubes ◽  
Disodium Hydrogen Citrate ◽  
Bank Blood

Summary1. PTC activity was assayed in 26 units of human plasma prepared from whole blood stored for 3 weeks at 4° C. The plasma had been frozen and stored at — 20° C for additional periods ranging from a few days to 4 months. High PTC activity was still present in the plasma at the end of this period, the activity averaging 95% of normal.2. The PTC activity of 19 samples of “reclaimed“ plasma stored for an additional 6 months at — 20° C decreased by an average of 23%. This decrease was statistically significant.3. Liquid plasma kept at room temperature for 5½—7½ months contained no PTC activity.4. Lyophilized plasma stored at room temperature for 6—8 years contained an average of 30% PTC activity. Lyophilized plasma stored at — 20° C for 4 years contained 68% PTC activity.5. ACD and disodium hydrogen citrate anticoagulant solutions served equally well in preserving PTC activity in whole blood stored in glass tubes over a period of 3 weeks at 4° C.6. “Reclaimed“ plasma from outdated bank blood provided effective hemostasis in two operations for the removal of 20 teeth from a severely PTC-deficient patient.7. The high PTC activity of “reclaimed“ plasma was confirmed by the close agreement between the PTC level expected in a PTC deficient patient after transfusion of such plasma and that observed.

Mechanism of the Antiplatelet Action of Dipyridamole in Whole Blood: Modulation of Adenosine Concentration and Activity

1986 ◽  
Vol 55 (01) ◽  
pp. 012-018 ◽  
Author(s):  
Paolo Gresele ◽  
Jef Arnout ◽  
Hans Deckmyn ◽  
Jos Vermylen
Keyword(s):  
Platelet Aggregation ◽  
Adenosine Receptor ◽  
Whole Blood ◽  
Blood Cells ◽  
Inhibitory Action ◽  
Phosphodiesterase Inhibitor ◽  
Inhibitory Effect ◽  
Adenosine Concentration ◽  
Pharmacological Studies

SummaryDipyridamole inhibits platelet aggregation in whole blood at lower concentrations than in plasma. The blood cells responsible for increased effectiveness in blood are the erythrocytes. Using the impedance aggregometer we have carried out a series of pharmacological studies in vitro to elucidate the mechanism of action of dipyridamole in whole blood. Adenosine deaminase, an enzyme breaking down adenosine, reverses the inhibitory action of dipyridamole. Two different adenosine receptor antagonists, 5’-deoxy-5’-methylthioadenosine and theophylline, also partially neutralize the activity of dipyridamole in blood. Enprofylline, a phosphodiesterase inhibitor with almost no adenosine receptor antagonistic properties, potentiates the inhibition of platelet aggregation by dipyridamole. An inhibitory effect similar to that of dipyridamole can be obtained combining a pure adenosine uptake inhibitor (RE 102 BS) with a pure phosphodiesterase inhibitor (MX-MB 82 or enprofylline). Mixing the blood during preincubation with dipyridamole increases the degree of inhibition. Lowering the haematocrit slightly reduces the effectiveness.Although we did not carry out direct measurements of adenosine levels, the results of our pharmacological studies clearly show that dipyridamole inhibits platelet aggregation in whole blood by blocking the reuptake of adenosine formed from precursors released by red blood cells following microtrauma. Its slight phosphodiesterase inhibitory action potentiates the effects of adenosine on platelets.

DETERMINATION OF WHITE BLOOD CELLS USING FOLDSCOPE WITH SMARTPHONE

2019 ◽  
pp. 10-13
Author(s):  
Ranu Kumar ◽  
Prasad Kapildeo
Keyword(s):  
Human Blood ◽  
Blood Cells ◽  
Blood Smear ◽  
Clinical Laboratory ◽  
White Blood Cells ◽  
Healthcare Services ◽  
Field Level ◽  
Morphology Analysis

We are traditionally used Microscope in clinical laboratory for determination of white blood cells of human blood smear. Now, in this study we were used Foldscope with Smartphone in the place of Microscope and examine many samples of human blood smear which was collected from local diagnostic centers. We were very easily quantity & morphology analysis of all types of WBC cells such as Neutrophils, Lymphocytes, Monocytes, Eosionophils, Basophils in blood smear with the help of Foldscope & image taken by Smartphone. The main objective of this study is to use Foldscope for quantity & morphology analysis of human WBCs at field level especially poor resource area where healthcare services or centers is not available & where carry of microscope is not possible.

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