Heparin Concentration Research Articles

Cardiopulmonary Bypass Strategy to Facilitate Transfusion-Free Congenital Heart Surgery in Neonates and Infants.

Priming the cardiopulmonary bypass (CPB) circuit without the addition of homologous blood constitutes the basis of blood-saving strategies in open-heart surgery. For low-weight patients, in particular neonates and infants, this implies avoidance of excessive hemodilution during extracorporeal circulation. The circuit has to be miniaturized and tubing must be cut as short as possible to reduce the priming volume to prevent unacceptable hemodilution with initiating CPB. During perfusion, measures should be taken to prevent blood loss from the primary circuit to avoid replacement by additional volume. Favorable factors such as mild hypothermia/normothermia and high heparin concentrations during extracorporeal circulation promote earlier hemostasis after coming off bypass.Lower mortality score, first chest entry, higher hemoglobin concentration before going on bypass, and shorter CPB duration support transfusion-free CPB procedure. Reduced postoperative morbidity and mortality were observed when CPB was performed without blood transfusion. In our experience, this can be achieved in at least 70% of CPBs, even in low-weight patients.Bloodless CPB circuit priming should become a widespread reality, even in neonates and young infants, in any open-heart procedure.

Temperature-Induced Mechanomodulation of Interpenetrating Networks of Star Poly(ethylene glycol)-Heparin and Poly(N-isopropylacrylamide).

Thermoresponsive interpenetrating networks (IPNs) were prepared by sequential synthesis of a biohybrid network of star-shaped poly(ethylene glycol) [starPEG] and heparin and a poly(N-isopropylacrylamide)-polymer network. Amide bond formation was used for cross-linking of the starPEG-heparin network and photo-cross-linking with N,N'-methylenebis(acrylamide) was applied for the formation of the second polymer network. Both networks were linked by chain entanglements and hydrogen bonds only. The obtained sequential IPNs (seq-IPNs) showed temperature-dependent network properties as reflected by swelling and elasticity data as well as by the release of glycosaminoglycan-binding growth factors. The elastic modulus of the seq-IPNs was found to be amplified up to 50-fold upon temperature change from 22 to 37 °C compared to the intrinsic elastic moduli of the two combined networks. The heparin concentration (as well as the complexation of growth factors with the hydrogel-contained heparin) was demonstrated to be variably independent from the mechanical properties (elastic moduli) of the hydrogels. Illustrating the usability of the developed seq-IPN platform for cell fate control, the thermo-modulation of the release of vascular endothelial growth factor (VEGF) and bone morphogenetic protein 2 (BMP-2) is shown as well as the osteogenic differentiation of human mesenchymal stem cells exposed to stiff and BMP-2 releasing seq-IPNs.

Sample Dilution Is Not an Effective Mitigation for Hemolysis Interference in Anti-Xa Heparin Activity Assays

Abstract The presence of hemolysis or icterus can interfere with chromogenic anti-Xa assays for unfractionated heparin monitoring (heparin activity), resulting in falsely lower estimates of heparin activity. Dilution is a common method for mitigating interference in spectroscopic assays that measure a single analyte by endpoint analysis and has been proposed as a solution for hemolysis interference in heparin activity assays. Heparin activity assays measure heparin/antithrombin complex activity using a chromogenic rate of absorbance change method. Heparin activity is a complex equilibrium of heparin binding to multiple proteins, including antithrombin, heparin cofactor II, platelet factor 4, histidine-rich glycoprotein, vitronectin, fibronectin, and others; some enhance while others neutralize heparin activity. The objective of this study was to determine how dilution affects heparin activity with different starting levels of antithrombin. First samples were diluted without interference (no hemolysis). Samples with 1 U/mL heparin in pooled normal plasma (PNP) and 50% PNP (to simulate 50% antithrombin levels) were diluted 1:1 with PNP versus OK buffer. Dilution resulted in nonlinear changes. Samples with 100% antithrombin recovered 88% of expected activity with PNP versus 74% with OK buffer; samples with 50% antithrombin recovered 111% with PNP versus 77% with OK buffer. Samples were then spiked with varying concentrations of hemolysate and 1:1 dilutions with PNP demonstrated nonlinear recoveries ranging from 41% to 84%. We were unable to recover the original heparin activity with or without hemolysis due to the complex interaction of initial heparin, antithrombin, and other binding protein concentrations with diluent antithrombin and other diluent heparin binding protein levels. When PNP is used as the diluent, the recovery will be lower when the initial antithrombin level is normal due to the addition of other heparin binding proteins; when the initial antithrombin level is low, the recovery is higher due to the addition of antithrombin from the diluent plasma. The recovery is always lower when buffer is used due to dilution of sample antithrombin. Careful consideration should be taken in evaluating the utility of sample dilution to mitigate interference from hemolysis and icterus in heparin activity assays, particularly in patients with fluctuating levels of antithrombin, such as those on extracorporeal life support or with liver failure.

Microfluidics-based device for the measurement of blood viscosity and its modeling based on shear rate, temperature, and heparin concentration.

Blood viscosity measurements are crucial for the diagnosis and understanding of a range of hematological and cardiovascular diseases. Such measurements are heavily used in monitoring patients during and after surgeries, which necessitates the development of a highly accurate viscometer that uses a minimal amount of blood. In this work, we have designed and implemented a microfluidic device that was used to measure fluid viscosity with a high accuracy using less than 10μl of blood. The device was further used to construct a blood viscosity model based on temperature, shear rate, and anti-coagulant concentration. The model has an R-squared value of 0.950. Finally, blood protein content was changed to simulate diseased conditions andblood viscosity was measured using the device and estimated using the model constructed in this work. Simulated diseased conditions were clearly detected when comparing estimated viscosity values using the model and the measured values using the device, proving the applicability of the setup in the detection of rheological anomalies and in disease diagnosis.

Oligo-guanidyl targeted bioconjugates forming rod shaped polyplexes as a new nanoplatform for oligonucleotide delivery

Novel bioconjugates (Agm6-M-PEG-FA) for active oligonucleotide (ON) delivery have been developed by conjugating a cationic oligo-guanidyl star-like shaped “head” (Agm6-M) to a polymeric “tail” (PEG) terminating with folic acid (FA) as targeting agent or methoxy group (Agm6-M-PEG-FA and Agm6-M-PEG-OCH3, respectively). Gel electrophoresis showed that the bioconjugates completely associated with ONs at 3 nitrogen/phosphate (N/P) ratio. Studies performed with folate receptor (FR)-overexpressing HeLa cells, showed that optimal cell up-take was obtained with the 75:25 w/w Agm6-M-PEG-OCH3:Agm6-M-PEG-FA mixture. Dynamic light scattering and transmission electron microscopy showed that the polyplexes had size <80 nm with narrow polydispersity and rod-shaped morphology. The polyplexes were stable for several hours in plasma while ON was released in the presence of heparin concentration 16-times higher than the physiological one. The polyplexes displayed negligible cytotoxicity, hemolysis and low pro-inflammatory TNF-α release. Studies performed with FR-overexpressing HeLa and MDA-MB-231 cells using siRac1 revealed that the folated polyplexes caused significantly higher gene silencing (86.1 ± 9.6%) and inhibition of cell migration (40%) than the non-folated polyplexes obtained with Agm6-M-PEG-OCH3 only. Although cytofluorimetric analyses showed similar cell uptake for both folated and non-folated polyplexes, confocal, TEM and competition studies showed that the folated polyplexes were taken-up by lysosome escaping caveolin-mediated pathway with final polyplex localization within cytosol, while non-folated polyplexes were preferentially taken-up via clathrin-mediated pathway to localize in the lysosomes. Finally, preliminary in vivo studies carried out in mice revealed that the folated polyplexes dispose in the tumor mass.

Evaluation of in Vitro Fertilization Index by Caudal Spermatozoa Capacitation with Different Heparin Concentration in Iraqi Sheep

Sperm capacitation refers to the physiological changes in which spermatozoa must undergo in order to have its ability to penetrate and fertilize a mature oocyte. Recognition of the phenomenon was quite important to early in vitro fertilization (IVF) experiments as well as to the fields of embryology and reproductive biology. This initial study is designed to study the process of capacitation of ram sperm with three heparin levels (50,100,150 IU). 140 pairs of abattoir testicular samples (70 pairs each season), with 70 ewe genitalia specimens (35 each season). Spermatozoa sample were capacitated with heparin in CO2 incubator for 45 minutes, and evaluated by its total motility and its ability to penetrate oocytes zona pellucida for fertilization. Different heparin level for spermatozoa capacitation in relation to seasonal influences revealed that; in regarding to capacitation index there was an increased spermatozoa activity and motility significantly for the three levels within season, but capacitation index showed significant variations between the three heparin levels out of breeding season in which the highest heparin level gave the best capacitation index than the other two. Results of oocytes collection in relation to seasonal influences revealed to; total oocytes number was 2035 oocytes on both season in which 1039 oocytes were obtained within season while a number of 1006 oocytes was collected out of season. Oocytes maturity index within season time is about 40% for the oocytes grade V.good and good grade, fair and poor grade is 25%.Oocytes collected out of breeding time showed range between 25% for the v. good and good grade to 10% for the other. Fertilizable index for embryos development after capacitated spermatozoa adding to the medium containing matured oocytes is range from 35% for the v. good and good graded oocytes within a season to 10% out of season. In conclusion; heparin can induced spermatozoa capacitation in any levels through the breeding season while the high level of heparin gave better results, fertilizable index and embryo production are both gave best result via breeding season.

Chemoenzymatic quantification for monitoring unpurified polysaccharide in rich medium.

The heparosan polysaccharide serves as the starting carbon backbone for the chemoenzymatic synthesis of heparin, a widely used clinical anticoagulant drug. The previous quantification methods for heparosan rely on time-consuming purification or expensive instruments not readily available for many labs. Here, a chemoenzymatic approach is developed to monitor the production of heparosan in rich medium without purification. After removing the interfering small molecules by ultrafiltration, heparosan was decomposed into oligosaccharides using heparin lyase III. The oligosaccharides were separated from large molecules by ultrafiltration and quantitatively determined by the anthrone-sulfuric acid assay using a spectrophotometer. Based on the different substrate specificity of heparin lyases, the study showed that the concentration of heparosan and heparin in a mixture was discriminatively determined by the two-step chemoenzymatic assay. Furthermore, the anthrone-sulfuric acid assay was observed to be more reliable than the phenol-sulfuric acid assay under these conditions. Besides heparosan and heparin, the chemoenzymatic assay may be adapted to quantify other types of polysaccharides if the specific lyases were available.

Heparin‐Mediated Growth of Self‐Organized ZnO Quasi‐Microspheres with Twinned Donut‐Like Hierarchical Structures

AbstractThe insight into the rational design of nanostructure with complex functionality is a significant challenge for the advanced application of Zinc Oxide (ZnO) in various areas. Herein, heparin, as a biotemplate, was introduced to manipulate growth of ZnO nanoparticle into hierarchical structures with unusual morphology. The formation process of the morphology and microstructure of the as‐achieved products were investigated. The heparin could alter nucleation and growth rates during the primary nanocrystal formation of ZnO, and promote the formation of two‐dimensional nanoplates and subsequently self‐assembly into novel quasi‐microspherical ZnO superstructures with twinned donut‐like hemispheres. The self‐assembled quasi‐microspheres displayed well crystallinity with a hexagonal wurtzite structure and a nearly uniform size‐distribution with a value of 452.9 ± 51.2 nm. The concentrations of heparin and zinc precursor played a vital role in determining the morphology of the resulting products. The possible growth mechanism of the obtained spherical like ZnO microparticles was proposed and discussed in detail. Our results are of fundamental importance to understanding crystal growth, and beneficial to promote the potential applications of ZnO with novel hierarchical structures in nanoscale devices.

Cartridge-Based Thromboelastography Can Be Used to Monitor and Quantify the Activity of Unfractionated and Low-Molecular-Weight Heparins.

Thromboelastography is increasingly utilized in the management of bleeding and thrombotic complications where heparin management remains a cornerstone. This study assessed the feasibility of the cartridge-based TEG ® 6s system (Haemonetics Corp., Braintree, Massachusetts, United States) to monitor and quantify the effect of unfractionated and low-molecular-weight heparin (UFH and LMWH). Blood samples from healthy donors were spiked with UFH ( n = 23; 0–1.0 IU/mL) or LMWH (enoxaparin; n = 22; 0–1.5 IU/mL). Functional fibrinogen maximum amplitude (CFF.MA), RapidTEG activated clotting time (CRT.ACT), and kaolin and kaolin with heparinase reaction time (CK.R and CKH.R) were evaluated for their correlation with heparin concentrations, as well as the combination parameters ΔCK.R − CKH.R, ratio CK.R/CKH.R, and ratio CKH.R/CK.R. Nonlinear mixed-effect modelling was used to study the relationship between concentrations and parameters, and Bayesian classification modelling for the prediction of therapeutic ranges. CK.R and CRT.ACT strongly correlated with the activity of LMWH and UFH ( p < 0.001). Using combination parameters, heparin activity could be accurately quantified in the range of 0.05 to 0.8 IU/mL for UFH and 0.1 to 1.5 IU/mL for LMWH. CRT.ACT was able to quantify heparin activity at higher concentrations but was only different from the reference range ( p < 0.05) at >0.5 IU/mL for UFH and >1.5 IU/mL for LMWH. Combination parameters classified blood samples into subtherapeutic, therapeutic, and supratherapeutic heparin ranges, with an accuracy of >90% for UFH, and >78% for LMWH. This study suggests that TEG 6s can effectively monitor and quantify heparin activity for LMWH and UFH. Additionally, combination parameters can be used to classify blood samples into therapeutic ranges based on heparin activity.

Cholesterol removal from human plasma with biologically modified cryogels

In this study, low molecular weight heparin immobilized P(HEMA) cryogels were fabricated for the removal of LDL-C in hypercholesterolemic human plasma. After characterization studies for P(HEMA) cryogels, effects of the parameters including medium pH, CNBr concentration, heparin concentration and contact time on heparin immobilization were investigated. Blood compatibility and cell adhesion tests were also performed, and platelet and leucocyte loss for P(HEMA)-Hp cryogels were found to be 2.95% and 4.91%, respectively. Maximum adsorption capacity for LDL-C from hypercholesterolemic human plasma was found to be 26.7 mg/g for P(HEMA)-Hp cryogel while it was only 1.67 mg/g for bare P(HEMA) cryogel. The P(HEMA)-Hp cryogels exhibit high desorption ratios up to 96% after 10 adsorption-desorption cycles with no significant decrease in the adsorption capacity. The findings indicated that these reusable P(HEMA)-based cryogels proposed good alternative adsorbents for removal of LDL-C.

Single conical track-etched nanopore for a free-label detection of OSCS contaminants in heparin

The heparin contamination by oversulfated chondroitin (OSCS) was at the origin of one major sanitary problem of last decade. Here we propose a novel strategy to detect OSCS from heparin solution based on conical nanopore functionalized with poly-L-lysine deposition to ensure its re-usability. This sensor is an excellent to detect low heparin concentration (from 25 ng/ml to 3 μg/ml) using the modification of ionic current rectification. It also allows following the kinetic of heparin degradation by heparinase with a good correlation with results obtained by classical methods. The sensor is sensitive to the inhibition of heparinase by OSCS until a concentration of 200 pg/ml representing 0.01% in weight in a heparin. This resolution is one order of magnitude lower than the one obtained by chromatography. For the first time, it was reached without fluorescence labeling.

Fibrinogen levels measured by the dry hematology method are lower than those measured by the Clauss method under a high concentration of heparin.

ABSTRACTThe activity of fibrinogen has been reported to decrease soon after the onset of major bleeding and to be an important determinant of the final extent of bleeding and postoperative outcome. A device that measures the perioperative fibrinogen level using the dry hematology (DH) method has recently become available. The aim of this study was to compare perioperative fibrinogen levels measured by the DH method with those measured by the conventional Clauss method and to assess the effects of heparin on these measurements. The study included 206 samples from 36 patients undergoing major surgery who received high-dose heparin (HH group, 23 samples), low-dose heparin (LH group, 57 samples), or no heparin (C group, 126 control samples). Each sample was measured using the DH and Clauss methods. After excluding samples outside the effective measurement range, the three study groups (HH group, n=23; LH group, n=49; C group, n=115) were compared. The mean fibrinogen level measured by the DH method in the HH group (87.9 ± 3.1%) was significantly lower than that measured by the Clauss method. There were no significant differences between the fibrinogen measurements obtained by the two methods between the LH and C groups. In patients on high-dose heparin, the mean fibrinogen level measured by the DH method was significantly lower than that measured by the Clauss method. When hemorrhage requires emergency treatment, a method that can measure the fibrinogen level rapidly is important. The DH method may be useful for decision-making with regard to perioperative coagulation factor replacement.

The influence of grafted heparin on chitosan/poly (ethylene glycol) blend membrane and it’s application for creatinine and urea transport

Modification of membrane using grafting reaction between chitosan and heparin showed the functional group on grafting agent reduced the positive charge on the membran surface and increased the active carrier groups which lead to increasing the membrane transport. The optimum concentration of heparin modified chitosan was determined by creatinine and urea transport studies. With the optimum concentration, the membrane was used for the transports of creatinine, urea and as well as a mixture of 5 species (creatinine, urea, Vitamine B12, albumin, and mineral salts). Characterization of the membrane was done using FT-IR Spectrophotometer and SEM. The results showed that the best concentration of heparin at 100 iu in the percent transports of creatinine and urea were 31.83% and 41.99%, respectively, for 6 hours of transport times. The other species in the transport membrane were proposed to disturb the creatinine permeation through the membrane. Addition of polyethyleneglycol (PEG) also increased the mechanical and porosity of the membrane in transport process.

Heparin‐avidin interaction interferes with the XPerT permeability assay

The endothelium is a monolayer of cells that line the vasculature and act as a semi‐permeable barrier controlling what passes from the lumen of blood vessels into the interstitium. Acute changes in endothelial permeability are commonly seen during inflammation. There are several in vitro assays which allow the researcher to look at changes in endothelial permeability under various inflammatory conditions, one of which is known as the XPerT assay. In this assay, endothelial permeability is assessed using fluorescence microscopy and is based on high affinity interactions between ligand (Alexa fluor‐488‐conjugated avidin) added in the culture medium, which permeates cell monolayer to reach substrate‐bound acceptor (biotinylated gelatin). Interestingly, heparin is known to strongly bind avidin and is also commonly found in different formulations of endothelial media in wildly differing concentrations. From this, we hypothesized that media with high concentration of heparin would interfere with the XPerT assay. To test this, we added increasing amounts of heparin to the XPerT assay and found that high doses impeded the ability of the avidin to interact with the biotinylated gelatin. Furthermore, we found that when high doses of heparin were present, the avidin was more likely to bind directly to the endothelial cells and not the biotinylated gelatin. Taken together, our data suggests that using a low heparin containing endothelial medium is optimal for using the XPerT assay to test endothelial permeability.Support or Funding InformationThis work was supported in part through the Hartwick College Faculty Research Grants Program.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Heparin affects cytosolic glucose responses of hyperglycemic dividing mesangial cells

Mesangial expansion underlies diabetic nephropathy, leading to sclerosis and renal failure. The glycosaminoglycan heparin inhibits mesangial cell growth, but the molecular mechanism is unclear. Here, rat mesangial cells (RMCs) were growth-arrested in the G0/G1 phase of cell division, stimulated to divide in normal glucose (5.6 mm) or high glucose (25.6 mm) with or without heparin, and analyzed for glucose uptake. We observed that RMCs entering the G1 phase in normal glucose with or without heparin rapidly cease glucose uptake. RMCs entering G1 in high glucose sustained glucose uptake for the first 3 h, and high-glucose exposure of RMCs only in the first 8 h of G1 induced the formation of an extracellular monocyte-adhesive hyaluronan matrix after cell division was completed. Moreover, a low heparin concentration under high-glucose conditions blocked glucose uptake by 1 h into G1 Of note, glucose transporter 4 (glut4) localized on the RMC surface at G0/G1 and was internalized into G1 cells under normal glucose conditions with or without heparin within 30 min. We also noted that, under high-glucose conditions, glut4 remained on the RMC surface for at least 2 h into G1 and was internalized by 4 h without heparin and within 1 h with heparin. These results provide evidence that the influx of glucose in hyperglycemic dividing RMCs initiates intermediate glucose metabolism, leading to increased cytosolic UDP sugars, and induces abnormal intracellular hyaluronan synthesis during the S phase of cell division.

Pharmacokinetic and Pharmacodynamic Profiles of Potency‐Adjusted Doses of Bovine, Ovine and Porcine Heparin are Comparable in a Primates Model

BackgroundUnfractionated heparin remains to be the only parenteral anticoagulant for various indications. Currently heparin is mainly derived from porcine mucosal heparin tissues. The USFDA and other regulatory agencies have considered resourcing heparin from alternate sources. Currently sheep (ovine) and cow (bovine) mucosal heparins are being developed for clinical use. The purpose of this study was to compare commercially available porcine heparin with the heparins obtained from bovine and ovine mucosal sources.Materials and MethodsBovine, ovine and porcine heparins were obtained from various commercial sources. Potencies of each heparin were determined by an amidolytic anti‐Xa assay in relation to the USP heparin standard. Individual groups of primates (n=4) were administered 100 anti‐Xa U/kg dosage of bovine, ovine or porcine heparin via intravenous route. Blood samples were collected at baseline, 15, 30, 60 and 120 minutes post‐administration. Anti‐Xa and anti‐IIa activities were measured to determine circulating heparin concentrations using commercially available USP compliant kits (Aniara Diagnostica, West Chester, OH). These drug concentrations were used to determine pharmacokinetic parameters such as area under the curve (AUC), half‐life (t1/2), clearance (Cl) and volume of distribution (Vd) using the PKSolver add‐in for Excel. The tissue factor pathway inhibitor (TFPI) levels were measured at 15 minutes.ResultsThe concentration vs. time curves for the three heparins were almost superimposable. Peak drug levels of approximately 1.5 and 1.4 U/mL were measured using anti‐Xa and anti‐IIa assays, respectively. After 2 hours, circulating drug levels were decreased to approximately 0.4 U/mL for all heparins. Pharmacokinetic parameters calculated from plasma concentration‐time curves indicated that all three heparins behaved similarly. Mean half‐life based on anti‐Xa activity ranged from 44 ± 13 min for ovine heparin to 71 ± 18 min for bovine heparin. Slightly longer half‐lives were observed using plasma concentrations determined using anti‐IIa activity. Mean AUC values based on anti‐Xa or anti‐IIa activities were comparable for all heparins. Mean Vd (~60 ml/kg) and Cl (~0.75 ml/kg/min) were also comparable for all heparins. The TFPI levels were similar for the porcine and ovine heparin whereas the bovine heparin exhibited lower levels.ConclusionAt a gravimetric level the bovine heparin exhibits a lower anticoagulant potency (140 U/mg) than ovine or porcine heparins (200 U/mg). USP cross‐referenced anti‐Xa potency adjusted based dosing results in comparable pharmacokinetic profiles for all three heparins. Therefore such dosing may provide uniform levels of anticoagulation for the parenteral indications for heparins. These observations warrant clinical validations in the specific indications.Support or Funding InformationNone.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Recent achievements and future developments in neonatal cardiopulmonary bypass.

A primary goal of improving neonatal cardiopulmonary bypass has been making the circuit smaller and reduce the blood contacting surfaces. As bypass circuit size has decreased, bloodless surgery has become possible even in neonates. Since transfusion guidelines are difficult to construct based on existing literature, these technical advances should be taken advantage of in conjunction with an individualized transfusion scheme, based on monitoring of oxygen availability to the tissues. For the majority of neonatal heart operations, several centers have shifted toward normothermic bypass even for complex neonatal surgeries, in order to avoid the adverse effects of hypothermia. Deep hypothermic circulatory arrest is no longer a necessity but an option, and selective antegrade cerebral perfusion has become common practice; however, technical uncertainties with regard to this technique have to be addressed, based on reliable neurologic monitoring. Maintenance of patient-specific heparin concentrations during bypass is another key goal, since neonates have lower baseline antithrombin concentrations and, therefore, a higher risk for inadequate thrombin inhibition and postoperative bleeding. Due to the immaturity of their hemostatic system, the standard coagulation tests alone are inappropriate to guide hemostatic therapy in neonates. The use of indirect heparin concentration assays and global viscoelastic assays in the operating room is likely to represent the optimal strategy, and requires validation in neonates. Monitoring of global and regional indexes of oxygen availability and consumption on bypass have become possible; however, their use in neonates still has outstanding technical issues which should be addressed and hence needs further validation. Due to the immaturity of the neonatal myocardium, single-shot cold cardioplegia solutions are thought to confer the best myocardial protection; their superiority when compared to more conventional modalities, however, remains to be demonstrated.

Heparanase-1 activity and the early postnatal prostate development.

Ventral prostate (VP) morphogenesis starts during embryonic development and continues for the first three postnatal weeks. Heparan sulfate (HS) affects paracrine signaling. Heparanase-1 (HPSE) is the only enzyme capable of cleaving HS. HPSE releases the HS bioactive fragment and mobilizes growth factors. Little is known, however, about HS turnover and HPSE function during VP morphogenesis. In this study, we measured HSPG expression and analyzed the expression and distribution of HPSE in the rat VP. HPSE was predominantly expressed by the VP epithelium. The VP was treated with heparin in ex vivo cultures to interfere with HS and resulted in delayed epithelial growth. Hpse knockdown using siRNA delayed epithelial growth in the first postnatal week ex vivo, which was similar to treating with the lower concentration of heparin. Hpse silencing was related to changes in HS chain length (as determined by size-exclusion chromatography, up-regulation of Mmp9, and down-regulation of Mmp2 expression). It also down-modulated ERK1/2 phosphorylation, suggesting a reduction in signaling, likely due to decreased HS cleavage and growth factor bioavailability. Our results showed that HPSE played a role in early epithelial growth during the first week of VP postnatal development. Developmental Dynamics 248:211-220, 2019. © 2019 Wiley Periodicals, Inc.

An in vitro study to investigate the interference of enoxaparin on plasma levels of direct oral factor Xa inhibitors measured by chromogenic assays.

IntroductionCo‐administration of enoxaparin and a direct oral factor Xa inhibitor (xabans: apixaban, edoxaban, rivaroxaban) could give rise to the problem of overlapping the anti‐Xa activity when measuring direct oral anticoagulant (DOAC) levels. We aimed to evaluate in vitro the degree of the interference of increasing enoxaparin concentrations on xaban plasma levels measured by different chromogenic anti‐Xa assays with drug‐specific calibrators and controls.MethodsSeven plasma samples were spiked with apixaban, edoxaban, or rivaroxaban at fixed concentration, and enoxaparin at increasing concentrations (0, 0.125, 0.250, 0.50, 1.0, 1.50, and 2.0 IU/mL). The evaluated chromogenic assays were as follows: Biophen DiXaI and Biophen Heparin LRT (Hyphen BioMed), Berichrom Heparin and Innovance Heparin (Siemens), STA‐Liquid Anti‐Xa (Stago Diagnostics), Technochrom anti‐Xa (Technoclone), and HemosIL Liquid Anti‐Xa (Werfen).ResultsThe presence of enoxaparin caused increased DOAC levels, with over‐estimation depending on the anti‐Xa assay and on the heparin concentration in the sample. The smallest over‐estimation was in the sample with enoxaparin 0.125 IU/mL and the greatest in the sample with enoxaparin 2.0 IU/mL (0%, 3.1%, and 7.4% vs 583.8%, 526.1%, and 415.2% for apixaban, edoxaban, and rivaroxaban, respectively). Biophen DiXaI showed lower interference compared to other methods (maximum over‐estimation in the presence of enoxaparin 2.0 IU/mL: 56.4% dosing rivaroxaban by Biophen DIXaI vs 583.8% dosing apixaban by Berichrom Heparin).ConclusionThe presence of enoxaparin interferes with xabans measurement by chromogenic anti‐Xa assays causing falsely elevated DOAC levels, the over‐estimation being dependent on the anti‐Xa assay and on the heparin concentration in the sample.

Ultrasound-Assisted Synthesis and Characterization of Heparin-Coated Eu3+ Doped Hydroxyapatite Luminescent Nanoparticles

Herein, the heparin-coated Eu3+ doped hydroxyapatite luminescent nanoparticles were synthesized by an ultrasound-assisted coprecipitation method followed with steam sterilization at 121 °C. The effects of ultrasound treatment, steam sterilization, sodium heparin (SH) concentration and Eu doping content on the formation of heparin-coated Eu3+ doped hydroxyapatite nanoparticles (SH-Eu:nHAP) were investigated. The sterilized and suspended Eu-nHAP with improved luminescence and stability was simultaneously achieved in a process of about 2 h due to the combined effect of ultrasonic sonochemistry and stabilization function of SH. The obtained SH-Eu:nHAP suspension shows good stability in water and biological media. Moreover, the SH-Eu:nHAP shows no hemolysis and cytotoxicity, and can be ingested by cells and emit characteristic luminescence in cells. In summary, this study provides an improved method for the synthesis of SH-Eu:nHAP suspension that is helpful for promoting the application of rare earth doped nHAP as bioimaging agent.