Blood Heparin Research Articles

The Impact of Anticoagulation Agent on the Composition and Phenotype of Blood Leukocytes in Dromedary Camels.

For the analysis of several cellular biomarkers, blood samples are anticoagulated using different agents with different modes of action. However, for the most commonly used anticoagulants, EDTA and heparin, varying effects on blood components have been reported in different species. As little is known about the impact of anticoagulants on the immunological evaluation of camel leukocytes, the present study analyzed the leukogram, the immunophenotype, and the cell vitality of camel leukocytes separated from blood samples anticoagulated with EDTA or lithium heparin. Using flow cytometry and staining with monoclonal antibodies to several cell surface markers, the composition and immunophenotype of camel leukocytes separated from blood anticoagulated with EDTA or heparin were analyzed. In comparison to EDTA-anticoagulated blood, using lithium heparin as an anticoagulant resulted in reduced numbers of total leukocytes and reduced numbers of neutrophils, which led to a reduced neutrophil to lymphocyte ratio. The analysis of cell necrosis and apoptosis after the staining of leukocytes with the DNA-sensitive dye propidium iodide and the mitochondrial membrane potential probe JC1 revealed a higher fraction of necrotic neutrophils and higher fractions of apoptotic neutrophils and monocytes in heparin blood than in EDTA blood. In addition, monocytes from heparin blood showed higher expression levels of the cell surface markers CD14, CD163, and MHCII when compared to cells from EDTA blood. Similarly, in heparin blood, CD44 and CD172a were expressed higher on neutrophils, while CD11a was expressed higher on lymphocytes in comparison to cells from EDTA blood. The results of the current study indicate the importance of considering the type of anticoagulant when investigating the composition, vitality, and immunophenotype of camel leukocytes.

Effect of different storage solutions on oxidative stress in human saphenous vein grafts

BackgroundIschemia–reperfusion injury of saphenous vein grafts (SVG) during coronary artery bypass grafting surgery negatively impacts endothelial integrity and functionality and is associated with vein graft failure. The aim of this study was to evaluate the level of oxidative stress in human SVG segments following ischemic storage in three intraoperative graft storage solutions: saline (S), autologous heparinized blood (HB) and DuraGraft (DG).Methods3 mm tissue rings derived from surplus SVG segments from 50 patients were stored at room temperature for 30 min in DG, S or HB. Total oxidative status (TOS) and total antioxidant status (TAS) levels were determined from which the oxidative stress index (OSI: TOS/TAS ratio) was calculated. A p-value < 0.017 was considered significant implementing a Bonferroni correction.ResultsTOS values were significantly lower for DG stored samples in comparison to both S and HB; there was no difference between S and HB (DG: 32.6 ± 1.8, S: 39.6 ± 2.8 and HB: 40.6 ± 2.4 µmol H2O2 eqv.; DG vs. S and DG vs. HB p < 0.0001, S vs. HB p = 0.047). TAS was higher for both DG and HB in comparison to S (DG: 8.9 ± 0.9, S: 6.9 ± 1.0 and HB: 8.6 ± 0.9 mmol Trolox eqv.; DG vs S p < 0.0001, DG vs. HB p = 0.263, S vs. HB p < 0.0001). OSI differed between all groups with the lowest value for DG (DG: 3.7 ± 0.2, S: 5.8 ± 0.4 and HB: 4.7 ± 0.2 µmol H2O2 eqv./mmol Trolox eqv.; all p < 0.0001).ConclusionsSaphenous veins grafts stored in DuraGraft had a lower oxidative level, higher antioxidant level and a lower oxidative stress index in comparison to saphenous vein grafts stored in saline or heparinized blood.ClinicalTrials.gov Identifier NCT02922088.

Application Value of Blood Heparin-Binding Protein in the Diagnosis of Acute Exacerbation of Chronic Obstructive Pulmonary Disease.

Objective To investigate the expression and clinical significance of serum heparin-binding protein (HBP), C-reactive protein (CRP), and white blood cell count (WBC) in an acute exacerbation of chronic obstructive pulmonary disease (COPD). Methods A prospective research model was used to select 63 patients with acute exacerbation of chronic obstructive pulmonary disease who were hospitalized in Xuzhou First People's Hospital from January 2020 to June 2020, and among the chronic obstructive pulmonary disease patients who were followed up in our hospital during the same period, 18 patients were in the stable phase, and 43 healthy patients in our hospital during the same period were selected as the healthy control group. 18 patients with stable chronic obstructive pulmonary disease were selected as the observation group, and 43 healthy people who underwent examination at the same time as the control group. For patients with acute COPD recombination, 5 ml of venous blood was collected according to whether the condition of COPD patients with acute exacerbation was stable or not. 5 ml of venous blood was collected for acute exacerbation. According to their clinical symptoms (such as cough, sputum, and asthma), dyspnea score (MRC score), and pulmonary function (FEV1 and FEV1/FVC), it is determined whether the patient's condition is stable. Patients in the stable COPD group will collect 5 ml of venous blood during the outpatient follow-up, and those in the healthy physical examination group will collect veins on the day of the physical examination. In 5 ml of blood, the levels of HBP and CRP in the blood were measured by the enzyme-linked immunosorbent method and the immunoturbidimetric method, respectively, and the peripheral blood WBC was measured by a blood cell analyzer and its supporting reagents. The differences of the three indicators in each group were statistically analyzed. Normally distributed measurement data were compared using t-test, homogeneity of variance of nonnormally distributed measurement data were compared using one-way analysis of variance, uneven variance of nonnormally distributed measurement data were compared using a rank-sum test, and Pearson linear analysis was used for correlation test. Subject working characteristic curve (ROC) was drawn, P < 0.05 means the difference is statistically significant, the receiver working characteristic curve was established, and the area under the curve (AUC) was calculated to analyze blood HBP. The value of blood CRP and peripheral blood WBC counts alone or in combination in the diagnosis of acute exacerbations of chronic obstructive pulmonary disease. Results The level of blood heparin-binding protein in the acute exacerbation phase was significantly higher than that in the stable phase and healthy controls (P < 0.05). In the acute exacerbation stage and stable stage group, the blood heparin binding protein, the percentage of leukocytes, neutrophils, and CRP were detected. There is a correlation between (P < 0.05) and a correlation with lung function (FEV1) (P < 0.05). The predictive value of heparin-binding protein, white blood cells, neutrophil percentage, CRP, etc. for the acute exacerbation of chronic obstructive pulmonary disease, with the area under the heparin-binding protein curve, is the largest, and compared with the stable phase, the comparison of heparin-binding protein, white blood cells, and CRP is statistically significant (P < 0.05). Conclusion Heparin-binding protein increases in the stable phase and acute exacerbation phase and is related to other inflammatory factors. It is one of the important inflammatory factors in chronic obstructive pulmonary disease. Heparin-binding protein, white blood cells, CRP, etc. have diagnostic and predictive value for acute exacerbation of chronic obstructive pulmonary disease. Heparin-binding protein has the best predictive result, and the combined index test has a better diagnostic predictive value, which is better than single index detection.

PLASMA SEPARATOR TUBES DO NOT HAVE ANY OVERT EFFECTS ON ROUTINE PLASMA CHEMISTRY DATA OF GREEN SEA TURTLES (CHELONIA MYDAS).

Plasma separator tubes (PSTs) are a variant of lithium heparin blood tube containing a polymer gel, which, when centrifuged, creates a physical barrier between plasma and blood cells. Their use is common in laboratory procedures of reptilian species. This study aimed to determine whether the use of plasma separator tubes impacts plasma biochemistry data in green sea turtles (Chelonia mydas) at time of collection and after 24 hr of contact time with the separator gel after centrifugation at refrigerator temperature. A single blood sample was collected from 42 rehabilitating green sea turtles at the Sea Turtle Healing Center, Brevard Zoo, Melbourne, Florida, USA and divided into one lithium heparin tube [LHT (0 hr)] and two PSTs. After immediate centrifugation of all three tubes, plasma was transferred from the LHT (0 hr) and one PST (0 hr) into tubes without additive. The plasma was left in contact with the separator gel in the second PST (24 hr). After 24 hr of refrigeration, all three plasma aliquots were analyzed for the following 23 analytes: sodium, potassium, chloride, carbon dioxide, calcium, phosphorus, magnesium, iron, total protein, albumin, globulin (calculated), aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, lactate dehydrogenase, gamma-glutamyltransferase, creatine kinase, glucose, urea nitrogen, creatinine, uric acid, triglyceride, and cholesterol. No statistically significant differences were found for any biochemical analytes between LHT (0 hr), PST (0 hr), and PST (24 hr). The use of PST does not appear to impact routine plasma biochemical analytes in green sea turtles and analytes appear stable in refrigerated plasma for up to 24 hr after centrifugation when using PSTs.

Heparin time and blood clotting during surgery

Among the many complications in surgical patients, thromboembolic processes continue to be the most formidable. Despite significant progress in the study of the blood coagulation system, reliable and accessible methods for detecting prethrombotic conditions have not yet been found.

Bacterial phagocytosis and reactive oxygen species production by camel neutrophils and monocytes are influenced by the type of anticoagulation agent.

Background and Aim:Anticoagulants with different modes of action are used in the collection of camel blood samples. In the innate immune response, camel neutrophils and monocytes can play several roles during infection and inflammation. For anticoagulants ethylenediaminetetraacetic acid (EDTA) and heparin, research has described their effects on different parameters of the immune system. However, to date, no research has examined the effects of anticoagulants on the functional activity of camel phagocytes. Therefore, this study analyzed the influence of K3EDTA and lithium heparin on the antimicrobial activity of camel neutrophils and monocytes.Materials and Methods:Camel leukocytes were separated from blood collected in EDTA or heparin tubes, and their phagocytosis and reactive oxygen species (ROS) production activity were analyzed by flow cytometry after stimulation with Staphylococcus aureus or Escherichia coli bacteria.Results:In comparison to the cells collected from the EDTA blood, the camel neutrophils and monocytes separated from the heparin blood showed higher phagocytosis activity of S. aureus and E. coli. In addition, the neutrophils and monocytes produced significantly more ROS when the blood was collected in the heparin tubes.Conclusion:The antimicrobial functions of camel neutrophils and monocytes are significantly affected by the type of anticoagulation agent. Therefore, using heparin rather than EDTA as an anticoagulant is recommended when performing the functional analysis of phagocytosis and ROS production of camel phagocytes.

Plasma-based S100B testing for management of traumatic brain injury in emergency setting

BackgroundSerum biomarker S100B has been explored for its potential benefit to improve clinical decision-making in the management of patients suffering from traumatic brain injury (TBI), especially as a pre-head computed-tomography screening test for patients with mild TBI. Although being already included into some guidelines, its implementation into standard care is still lacking. This might be explained by a turnaround time (TAT) too long for serum S100B to be used in clinical decision-making in emergency settings. MethodsS100B concentrations were determined in 136 matching pairs of serum and lithium heparin blood samples. The concordance of the test results was assessed by linear regression, Passing Pablok regression and Bland-Altman analysis. Bias and within- and between-run imprecision were determined by a 5 × 4 model using pooled patient samples. CT scans were performed as clinically indicated. ResultsOverall, S100B levels between both blood constituents correlated very well. The suitability of S100B testing from plasma was verified according to ISO15189 requirements. Using a cut-off of 0.105 ng/ml, a sensitivity and negative predictive value of 100% were obtained for identifying patients with pathologic CT scans. Importantly, plasma-based testing reduced the TAT to 26 min allowing for quicker clinical decision-making. The clinical utility of integrating S100B in TBI management is highlighted by two case reports. ConclusionsPlasma-based S100B testing compares favorably with serum-based testing, substantially reducing processing times as the prerequisite for integrating S100B level into management of TBI patients. The proposed new clinical decision algorithm for TBI management needs to be validated in further prospective large-scale studies.

Corrigendum to “Blood heparin sensor made from a paste electrode of graphite particles grafted with molecularly imprinted polymer” [Sens. Actuators B: Chem. 259 (2018) 455–462

Corrigendum to “Blood heparin sensor made from a paste electrode of graphite particles grafted with molecularly imprinted polymer” [Sens. Actuators B: Chem. 259 (2018) 455–462

Using blood calprotectin as a measure of blood neutrophils

Presently, bed-side or at home quantification of neutrophils in blood (b-neutrophils) is not practical, because cytometric methods are too expensive and technically demanding. We have explored whether calprotectin concentration in whole blood (b-calprotectin) might be a valid measure of b-neutrophils because this principle might be used in a simple and robust immunoassay device. We obtained heparin blood samples from 77 patients with possible neutropenia, most of them cancer patients treated with cytostatic drugs, and compared b-calprotectin with their b-neutrophils in a simultaneously taken EDTA-blood sample. The Spearman rank correlation coefficient between b-calprotectin and b-neutrophils was 0.986 (p < .0001). In a regression model of b-neutrophils as a function of age, gender, type of hematology instrument, total leukocyte count minus neutrophils, b-calprotectin, and plasma calprotectin (p-calprotectin), only b-calprotectin was a statistically significant predictor. B-neutrophils below 1 × 109/L was unlikely if b-calprotectin was above 50 mg/L. In conclusion, b-calprotectin, without adjusting for p-calprotectin, correlates closely with b-neutrophils and could be used to detect b-neutrophils below 1 × 109/L.

Antiphospholipid Syndrome and Cardiac Bypass: The Careful Balance between Clotting and Bleeding

Antiphospholipid syndrome (APS) is an acquired autoimmune condition characterized by the presence of antiphospholipid antibodies (lupus anticoagulant, anticardiolipin antibody, and anti-β2 glycoprotein-I antibody) which leads to clinical thrombosis via a multifactorial mechanism of action. Despite the propensity to form clot in vivo, these antibodies interfere with the assembly of the prothrombinase complex on phospholipids in in vitro assays, leading to prolongation of activated clotting time and activated partial thromboplastin time. This disconnect between what occurs in vivo and in vitro makes monitoring anticoagulation during cardiac surgery particularly complex. We present a patient with APS undergoing coronary artery bypass grafting with cardiopulmonary bypass. We delineate our strategy for managing anticoagulation in the presence of this syndrome using the Hepcon Hemostasis Management System Plus (Medtronic, Inc. Minneapolis, MN) device by targeting whole blood heparin concentration to monitor anticoagulation.

Abstract 13359: Acute Phase Predictors for In-hospital Mortality and Chronic Thromboembolic Pulmonary Hypertension in Acute Pulmonary Embolism Patients

Background: Various predictors in patients with acute pulmonary embolism (PE) have been reported for in-hospital mortality and chronic thromboembolic pulmonary hypertension (CTEPH), but none have been established conclusively. Methods and Results: We retrospectively analyzed data that might be associated with in-hospital mortality and CTEPH from patients with acute PE who were admitted to our hospital. Among 163 patients (aged 69.3± 14.6 years) with acute PE, 11 patients (6.7%) died in the hospital. We examined the following acute and chronic-phase data: vital signs, echocardiography values, medications, laboratory test results, blood gas data and heparin infusion time. Multivariate logistic regression analysis showed that the acute-phase levels of plasma B-type natriuretic peptide (BNP) (odds ratio (OR), 1.003; 95% confidence interval (CI), 1.0004-1.0053; P = 0.034,) and arterial blood gas lactate (OR, 1.306; 95% CI, 1.056-1.615; P = 0.014) were significant independent predictors of in-hospital mortality. The area under the receiver operating characteristic (AUROC) curves of BNP and arterial blood lactate levels for in-hospital mortality were 0.846 and 0.921, respectively. (BNP, 400.65 pg/mL [sensitivity 77.8%, specificity 84.6%]; lactate 7.9 mmol/L [sensitivity 81.8%, specificity 89.5%]). In univariate logistic regression analysis, the plasma BNP level &gt; 400.65 pg/mL and lactate level &gt; 7.9 mmol/L on admission were significant predictors for in-hospital mortality (OR 62.5, 95% CI 10.0-390.3; P = 0.0001). Among 152 patients (aged 68.9±14.6 years) with acute PE who did not die in-hospital, 15 (9.8%) patients progressed to CTEPH. Multivariate logistic regression analysis showed that right ventricular systolic pressure (RVSP) at admission was an independent and significant predictor for CTEPH (OR, 1.183; 95% CI, 1.090-1.285; P = 0.0001). The AUROC curve of RVSP for developing CTEPH was 0.944. (RVSP, 51.4 mm Hg [sensitivity 86.7%, specificity 83.8%]). Conclusions: In patients with acute PE, the acute-phase BNP and arterial blood lactate levels are effective predictors of in-hospital mortality. And RVSP during the acute phase, but not during the chronic phase is an effective predictor of progression to CTEPH.

A highly active heparinase I from Bacteroides cellulosilyticus: Cloning, high level expression, and molecular characterization.

As one of the most extensively studied glycosaminoglycan lyases, heparinase I has been used in producing low or ultra-low molecular weight heparin. Its’ important applications are to neutralize the heparin in human blood and analyze heparin structure in the clinic. However, the low productivity and activity of the enzyme have greatly hindered its applications. In this study, a novel Hep-I from Bacteroides cellulosilyticus (BcHep-I) was successfully cloned and heterologously expressed in E. coli BL21 (DE3) as a soluble protein. The molecular mass and isoelectric point (pI) of the enzyme are 44.42 kDa and 9.02, respectively. And the characterization of BcHep-I after purified with Ni-NTA affinity chromatography suggested that it is a mesophilic enzyme. BcHep-I can be activated by 1 mM Ca2+, Mg2+, and Mn2+, while severely inhibited by Zn2+, Co2+, and EDTA. The specific activity of the enzyme was 738.3 U·mg-1 which is the highest activity ever reported. The Km and Vmax were calculated as 0.17 mg·mL-1 and 740.58 U·mg-1, respectively. Besides, the half-life of 300 min at 30°C showed BcHep-I has practical applications. Homology modeling and substrate docking revealed that Gln15, Lys74, Arg76, Lys104, Arg149, Gln208, Tyr336, Tyr342, and Lys338 were mainly involved in the substrate binding of Hep-I, and 11 hydrogen bonds were formed between heparin and the enzyme. These results indicated that BcHep-I with high activity has great potential applications in the industrial production of heparin, especially in the clinic to neutralize heparin.

The effect of tranexamic acid on the values of activated clotting time in patients undergoing cardiac surgery: A PRISMA-compliant systematic review and meta-analysis

Study objectiveActivated clotting time (ACT) is a non-specific test to evaluate the adequacy of systemic heparinization whose value could be influenced by many factors. Tranexamic acid (TXA) is a widely used antifibrinolytic agent worldwide and whether TXA influences ACT value in cardiac surgical patients remains unknown. Current study was performed to address this question. DesignSystematic review and meta-analysis. PUBMED, Cochrane Library, EMBASE, OVID and Chinese BioMedical Literature & Retrieval System were searched using search terms “tranexamic acid”, “activated clotting time”, “cardiac surgery”, “randomized controlled trial” till May 7th, 2020, to identify all relevant randomized controlled trials (RCTs). SettingOperating room. PatientsCardiac surgical patients. InterventionsTXA or placebo. MeasurementsPrimary outcomes of interest included peri-operative ACT values. Secondary outcomes of interest include heparin dosage, protamine dosage, postoperative bleeding and blood transfusion. Main resultsSearch yielded 13 studies including 1168 patients, and 619 patients were allocated into Group TXA and 549 into Group Control (placebo). Meta-analysis suggested that, ACT values after heparinization [(WMD = −1.45; 95%CI: −12.52 to 15.43; P = 0.84)] and after protamine [(WMD = −1.18; 95%CI: −2.81 to 0.46; P = 0.16)] were comparable between Group TXA and Group Control, and that TXA did not influence heparin dose in adult patients [(WMD = 0.38; 95%CI: 0.30 to 0.46; P<0.00001) with no heterogeneity (I2 = 4%, P = 0.35)] and protamine dose for heparin reversal [(WMD = 5.23; 95%CI: −0.33 to 10.80; P = 0.07) with no heterogeneity (I2 = 0, P = 0.58)]. Meta-analysis also demonstrated that, TXA administration significantly reduced post-operative bleeding volume [(WMD = −126.33; 95%CI: −177.46 to −75.19; P < 0.0001), post-operative red blood cell (RBC) transfusion volume [(WMD = −71.86; 95% CI: −88.22 to −55.50; P < 0.00001), fresh frozen plasma (FFP) transfusion volume [(WMD = −13.83; 95% CI: −23.67 to −4.00; P = 0.006) and platelet concentrate (PC) transfusion volume [(WMD = −0.20; 95% CI: −0.29 to −0.10; P < 0.0001). ConclusionThis meta-analysis suggested that, TXA administration did not influence ACT value, heparin and protamine doses, but significantly reduced post-operative blood loss and transfusion requirement in cardiac surgical patients.

Dried blood spot versus venous blood sampling for phenylalanine and tyrosine

BackgroundThis study investigated the agreement between various dried blood spot (DBS) and venous blood sample measurements of phenylalanine and tyrosine concentrations in Phenylketonuria (PKU) and Tyrosinemia type 1 (TT1) patients.Study designPhenylalanine and tyrosine concentrations were studied in 45 PKU/TT1 patients in plasma from venous blood in lithium heparin (LH) and EDTA tubes; venous blood from LH and EDTA tubes on a DBS card; venous blood directly on a DBS card; and capillary blood on a DBS card. Plasma was analyzed with an amino acid analyzer and DBS were analyzed with liquid chromatography-mass spectrometry. Agreement between different methods was assessed using Passing and Bablok fit and Bland Altman analyses.ResultsIn general, phenylalanine concentrations in LH plasma were comparable to capillary DBS, whereas tyrosine concentrations were slightly higher in LH plasma (constant bias of 6.4 μmol/L). However, in the low phenylalanine range, most samples had higher phenylalanine concentrations in DBS compared to LH plasma. Remarkably, phenylalanine and tyrosine in EDTA plasma were higher compared to all other samples (slopes ranging from 7 to 12%). No differences were observed when comparing capillary DBS to other DBS.ConclusionsOverall agreement between plasma and DBS is good. However, bias is specimen- (LH vs EDTA), and possibly concentration- (low phenylalanine) dependent. Because of the overall good agreement, we recommend the use of a DBS-plasma correction factor for DBS measurement. Each laboratory should determine their own factor dependent on filter card type, extraction and calibration protocols taking the LH plasma values as gold standard.

The relationship between plasma albumin, alkaline phosphatase and pyridoxal phosphate concentrations in plasma and red cells: Implications for assessing vitamin B6 status.

Plasma concentrations of most vitamins decrease as part of the systemic inflammatory response (SIR). Thus low plasma values do not necessarily indicate deficiency. Vitamin B6 status is usually assessed by measurement of pyridoxal phosphate (PLP) in plasma, although vitamin concentrations in blood cells tend to be better markers of cellular stores. In health, plasma PLP appears to be determined primarily by intake, its binding to albumin, and its hydrolysis by alkaline phosphatase (ALP). To examine, using invitro studies, the effect of albumin concentration and ALP activity on PLP concentration in plasma and red blood cells of healthy subjects (HS) and critically ill patients (CI). Heparin and EDTA (ALP inhibited) whole blood samples from HS (n=8) and CI (n=26) were incubated with PLP. Concentration of PLP in plasma and red cells was measured. Albumin and ALP levels were determined in plasma. In PLP incubated heparin samples, there was a strong direct relationship between albumin in the concentration range 10-44g/L and increase in plasma PLP concentration (rs=0.93, P<0.001) and an inverse relationship with increase in red cell PLP concentration (rs=-0.90, P<0.001). In contrast, ALP activity was inversely associated with increase in plasma PLP concentration (rs=-0.42; P=0.013) and directly associated with red cell PLP concentration (rs=0.49; P=0.003). Plasma albumin concentration and to a lesser extent ALP activity influences PLP concentration in plasma and red cells. In conditions associated with low albumin (e.g. SIR) or altered ALP activity, red cell PLP measurements are more likely to be reliable than plasma measurements in differentiating true from apparent vitamin B6 deficiency and to guide vitamin B6 supplementation.

Leukocytosis interference in clinical chemistry: Shall we still interpret test results without hematological data?

Extreme leukocytosis is known to induce remarkable variations of some clinical chemistry tests, thus leading to possible clinical misinterpretation. This study aimed to define whether also moderate leukocytosis may influence the stability of glucose and blood gases. Blood samples are sent to the local laboratory through a pneumatic tube system. Clinical chemistry testing is routinely performed using Lithium-heparin tubes (for glucose) and heparin blood gases syringes (for blood gas analysis). Stability of glucose (in uncentrifuged blood tubes) and blood gases (in syringes) was hence evaluated in samples maintained at room temperature. Results were also analyzed in 2 subgroups of samples with different leukocyte counts, i.e., those with leukocytes <15 × 109/L and those with leukocytes >15 × 109/L. An accelerated decrease of pH was observed in blood gases syringes with leukocytosis (i.e., >15 × 109/L), while no difference was noted for other blood gases parameters (PCO2, PO2). Spurious and time-dependent hypoglycemia was noted in uncentrifuged blood tubes of patients with leukocytosis. The results of our study suggest that even modest leukocytosis (i.e., around 15 × 109/L), which is frequently encountered in clinical and laboratory practice, may be associated with significant variations of both glucose and pH. This would lead us to conclude that results of these parameters shall be accompanied by those of hematologic testing to prevent clinical misinterpretation, namely with leukocyte counts.

Relationship between free hemoglobin (hemolysis), potassium and ionized calcium in lithium heparin blood gas samples collected intraoperatively

ObjectiveDevelop sample acceptability rules by determining the relationship between free hemoglobin level (hemolysis) and potassium or ionized calcium in blood gas samples collected intraoperatively. Design and methodsHemolysis was assessed visually or by H index for lithium heparin blood gas samples collected intraoperatively. During periods one and three this was done using two different rules for visual assessment of centrifuged lithium heparin plasma. During period two H index was measured for all visually hemolyzed samples on a Roche Cobas c501 analyzer to determine acceptability. Potassium and ionized calcium were measured in 75 lithium heparin whole blood samples on a Radiometer ABL90 to correlate H index and potassium or ionized calcium. ResultsDuring period one 35 of 5808 (0.6%) blood gas samples had visual hemolysis levels exceeding tolerance for reporting of potassium. By switching to measured H index using a laboratory-established threshold, during period 2 we estimate that 171 of 5396 (3.2%) blood gas samples exceeded the H index threshold for reporting of potassium. In 75 intraoperative blood gas samples with H index and whole blood potassium and ionized calcium measured; we observed no relationship between H index and potassium or ionized calcium. During period 3 we switched to visual assessment of hemolysis with a greater tolerance for hemolysis; with only 3 of 5345 (0.06%) samples exceeding the new visual hemolysis threshold. ConclusionFor blood gas samples collected intraoperatively, there is no relationship between hemolysis and measured potassium or ionized calcium. The results suggest that only grossly hemolyzed intraoperative blood gas samples should be rejected for measurement of whole blood potassium and ionized calcium.

Heparin as an anticoagulant for the dielectric measurement of blood

Testing blood ex-vivo allows physicians to gain an understanding of what is happening within the human body. Once blood is extracted from the body, it begins to clot. This process can affect the outcome of blood tests, particularly for dielectric measurements. As a result, the dielectric measurements recorded are dependent on time after extraction. To solve the clotting problem, and to allow measurements at any time, anticoagulants are employed. However, a number of anticoagulants have been shown to greatly alter the dielectric properties of fresh blood. In this paper, we analyze the anticoagulant heparin, which works by a different mechanism to stop coagulation than other previously studied anticoagulants. Specifically, heparin acts as a cofactor, accelerating the natural anticoagulation process by several orders of magnitude rather than chelating with clotting factors. We compare intra-individually the dielectric measurements of pure and heparin blood samples at 37°C, taken from four healthy adult volunteers. We also compare the heparin results to previous data on other anticoagulants, specifically, ethylene diamene tetra acetic acid (EDTA) and sodium citrate. In this exploratory study, we found that the effects of heparin on blood are 2.66% or less for the relative permittivity and conductivity, and that heparin has the least effect on dielectric measurements when compared to the other commonly used anticoagulants. These results suggest heparin as the anticoagulant of choice for dielectric measurement.

Chitosan-heparin nanoparticle coating on anodized NiTi for improvement of blood compatibility and biocompatibility.

The aim of this study was to simultaneously improve blood compatibility and corrosion resistance of nitinol via two-step process; anodizing and consequently coating with chitosans-heparin nanoparticles. Moreover, the role of these surface modification processes on the heparin release kinetic and blood compatibility was investigated. Finally, the interaction between human umbilical vein endothelial cells (HUVECs) and surface modified samples was investigated. Electrochemical characterization revealed that while Ni ions released from the anodized sample (9 ppb), chitosan-heparin nanoparticle coatings prohibited from Ni ion release form NiTi substrate. Moreover, the controlled release of heparin was found from chitosan-heparin nanoparticle coating deposited on the nanotubes, leading to significant improvement of blood compatibility. Finally, HUVECs were attached and proliferated on the chitosan-heparin nanoparticle coated samples confirming the cell compatibility of samples. In summary, results proved that two-step anodizing process and heparin release could promote both endothelial cell compatibility and blood compatibility to nitinol surface which might be appropriate for coronary stent application.

Evaluation of a filter system to harvest plasma for identification of failure of passive transfer in newborn calves

The objective of this study was to evaluate a filter system to harvest plasma to assess failure of passive transfer (FPT) in newborn calves. Blood samples (n = 227) for serum and plasma harvesting were collected via jugular vein puncture from Holstein calves aged 1 to 7 d from 4 commercial dairy herds in Northeast Germany. Serum IgG concentrations were determined using a sandwich ELISA. Failure of passive transfer was defined as IgG concentrations <10 mg/mL and used as a gold standard. One handheld optical refractometer (Euromex Holland, Arnhem, the Netherlands) and 2 digital Brix refractometers (device 1: HI 96801 digital refractometer, Hanna Instruments, Woonsocket, RI; device 2: Misco PA201, Misco, Solon, OH) were used to analyze total proteins in serum or plasma. The colostrum uptake of the calf can thus be monitored and calves with FPT can be identified. Serum was obtained through centrifugation. Plasma was obtained through either a filter system or centrifugation. For plasma filtration, approximately 2 mL of lithium heparin blood was injected into the inlet reservoir of a plasma filter (2-Drop-Filter, Pharmadoc, Lübeck, Germany) using a disposable syringe. Receiver operating characteristic curve analyses were used to determine optimum thresholds for each of the 3 devices using different media. Sixty-seven (30%) calves had FPT. For the handheld optical refractometer, the optimum threshold was 5.6 g/dL [sensitivity 70.1%; specificity 80.0%; positive predictive value (PPV) 60.1%; negative predictive value (NPV) 86.2%; area under the curve (AUC) 0.85] using serum. For centrifuged plasma, the optimum threshold was 6.3 g/dL (sensitivity 82.1%; specificity 68.1%; PPV 52.5%; NPV 89.9%; AUC 0.84), and for filtered plasma, the threshold was 6.0 g/dL (sensitivity 56.7%; specificity 90.0%; PPV 70.9%; NPV 82.9%; AUC 0.80). For device 1, the optimum threshold was 8.9% Brix (sensitivity 82.1%; specificity 63.8%; PPV 48.7%; NPV 89.5%; AUC 0.81), 9.4% Brix (sensitivity 76.1%; specificity 73.7%; PPV 55.4%; NPV 87.8%; AUC 0.80), using serum and centrifuged plasma, respectively. For device 2, the optimum threshold was 8.7% Brix (sensitivity 74.6%; specificity 76.2%; PPV 57.4%; NPV 87.5%; AUC 0.83), 9.5% Brix (sensitivity 80.6%; specificity 70.6%; PPV 54.0%; NPV 89.5%; AUC 0.83), and 9.2% Brix (sensitivity 58.2%; specificity 87.5%; PPV 66.6%; NPV 83.0%; AUC 0.80) using serum, centrifuged plasma, and filtered plasma, respectively. Based on the AUC, the 3 devices yielded comparable test characteristics to identify calves with FPT. In conclusion, a filter system can be used to facilitate the evaluation of FPT as a point of care technique in calves without the need for serum centrifugation.