Extracorporeal Blood Circulation Research Articles

HEMA-Lysine-Based Cryogels for Highly Selective Heparin Neutralization.

Unfractionated heparin (UFH) and its low-molecular-weight fragments (LMWH) are widely used as anticoagulants for surgical procedures and extracorporeal blood purification therapies such as cardiovascular surgery and dialysis. The anticoagulant effect of heparin is essential for the optimal execution of extracorporeal blood circulation. However, at the end of these procedures, to avoid the risk of bleeding, it is necessary to neutralize it. Currently, the only antidote for heparin neutralization is protamine sulphate, a highly basic protein which constitutes a further source of serious side events and is ineffective in neutralizing LMWH. Furthermore, dialysis patients, due to the routine administration of heparin, often experience serious adverse effects, among which HIT (heparin-induced thrombocytopenia) is one of the most severe. For this reason, the finding of new heparin antagonists or alternative methods for heparin removal from blood is of great interest. Here, we describe the synthesis and characterization of a set of biocompatible macroporous cryogels based on poly(2-hydroxyethyl methacrylate) (pHEMA) and L-lysine with strong filtering capability and remarkable neutralization performance with regard to UFH and LMWH. These properties could enable the design and creation of a filtering device to rapidly reverse heparin, protecting patients from the harmful consequences of the anticoagulant.

Mechanical-Enhanced and Durable Zwitterionic Hydrogel Coating for Inhibiting Coagulation and Reducing Bacterial Infection.

Blood-contact medical devices are indispensable for clinical interventions, yet their susceptibility to thrombosis and bacterial infections poses substantial risks to treatment efficacy and patient well-being. This study introduces a polysulfobetaine/alginate-CuII (SAC) zwitterionic hydrogel coating on polyurethane (PU) surfaces. This approach retains the superhydrophilic and antifouling nature of pSBMA while conferring the antibacterial effects of copper ions. Meanwhile, the copper alginate network intertwines with the polysulfobetaine (pSBMA) network, enhancing its mechanical properties and overcoming inherent weaknesses, thereby improving coating durability. Compared to the substrate, the SAC hydrogel coating significantly reduces thrombus adhesion mass by approximately 81.5% during extracorporeal blood circulation and effectively prevents bacterial biofilm formation even in a high-concentration bacterial milieu over 30 days. Moreover, the results from an isolated blood circulation model in New Zealand white rabbits affirm the impressive anticoagulant efficacy of the SAC hydrogel coating. The findings suggest that this hydrogel coating and its application method hold promise as a solution for blood-contact material surface modification to address thrombosis and bacterial biofilm formation simultaneously.

Observer‐based non‐fragile event‐triggered control of extra‐corporeal blood circulation process in finite‐time interval

AbstractAn observer‐based event‐triggered non‐fragile control problem for regulating the levels of oxygen and carbon dioxide (O and CO) in patients blood during the extra‐corporeal blood circulation (ECC) process with random communication packet losses is explored in this work. The main intention of this work is to design an observer‐based event‐triggered and non‐fragile controller for ensuring the finite‐time boundedness criterion for the resulting system with mixed and passivity performance index over a finite interval of time. In addition to the limited bandwidth of the channels, such random packet losses might occur simultaneously between the sensors and the controllers, and between the controllers and the actuators. Unlike most studies in the literature, we have found that, since the controller‐actuator link has packet dropouts, the observer's control input differs from that of the plant. The sufficient conditions derived are presented in a linear matrix inequalities frame work. Finally, simulation results are used to validate the efficacy of the proposed control method. The results show that the proposed observer‐based event‐triggered non‐fragile controller keeps the blood gases within physiological limits during a stable ECC process.

The Surface of a PMP Hollow Fiber Membrane Was Modified with a Diamond-like Carbon Film to Enhance the Blood Compatibility of an Artificial Lung Membrane.

The contact between the blood and the surface of medical materials causes a series of rejection reactions. In this process, the plasma protein is adsorbed to the surface of materials within seconds and binds to glycoprotein receptors on platelets, causing platelet activation, coagulation cascade, and complement activation to form thrombus, which greatly limits the application of medical materials. In our work, the surface of poly(4-methyl-1-pentene) hollow fiber membranes (PMP HFMs) was coated with a diamond-like carbon (DLC) film by the ion plating method. The blood compatibility of the DLC coating was evaluated by protein adsorption, platelet adhesion, clotting time, red blood cell (RBCs) hemolysis, dynamic coagulation, and extracorporeal blood circulation tests. Compared with the unmodified PMP membrane, the DLC film could effectively reduce protein adsorption and platelet adhesion and prolong the coagulation time. The DLC coating showed BSA adsorption of as low as 0.53 μg/cm2 as well as a long activated partial thromboplastin time (APTT) value of 71.84 s. Furthermore, the PMP membrane modified with the DLC coating was used for extracorporeal blood circulation without thrombosis forming within 28 days. The DLC coating is one of the most promising medical coatings as an artificial lung membrane in extracorporeal membrane oxygenation (ECMO) equipment.

Effects of hollow fiber packing density and housing shape on the albumin filtration performance of CRRT filters

Continuous renal replacement therapy (CRRT) has become the most commonly used acute blood purification therapy for critically ill patients. As a key point of extracorporeal blood circulation, the CRRT filter plays a decisive role in therapeutic efficacy. However, few in vitro studies have been conducted on CRRT filters, particularly concerning the effects of design factors on filter effectiveness and safety profile; no comprehensive evaluation system has been established. Here, we designed nine CRRT filters with various combinations of hollow fiber packing density (PD) and housing shape (effective hollow fiber length (L) and inner housing diameter (D) ratio (L/D ratio)) and introduced a high-frequency sampling pressure monitor to accurately monitor small changes in transmembrane pressure (TMP) and ultrafiltration rate (UFR) over time. We also used concentration polarization mass transfer resistance (Rc), change in sieving coefficient (S) of albumin over time, and amount of albumin removed (Mfld) to investigate the effects of two design factors on albumin filtration performance and analyze the mechanism of protein filtration performance over time, thereby establishing a comprehensive in vitro evaluation system to explore the safety profile of CRRT filters. Our results showed that the nine CRRT filters designed with different combinations of PD (50%, 55%, and 60%) and L/D ratio (2.9, 5.3, and 9.3) were able to maintain stability in terms of hemodynamics and water permeability; the lowest Mfld was PD = 60% and L/D ratio = 9.3, which indicates that design factor optimization can effectively control albumin filtration, thereby improving the safety profile of CRRT filters.

Entropy analysis on the bioconvective peristaltic flow of gyrotactic microbes in Eyring-Powell nanofluid through an asymmetric channel

The educational value of nanofluids in several industrial and biological sectors, particularly in fluid movement systems known as peristalsis, has piqued researchers' interest in studying the peristaltic movement of nanofluids. Additionally, nanoparticles have crucial roles in many engineering and manufacturing processes, including those involving heat exchangers, cooling systems, boilers, MEMS, chemical engineering, laser diode arrays, and cool automotive engines. Various studies have been conducted on this subject. This is done by looking at how migratory gyrotactic microorganisms migrate through an artery that is anisotropically narrowing in a blood-based nanofluid that is non-Newtonian. To comprehend, the Powell-Eyring fluid model is used how the blood's rheology differs from that of a Newtonian fluid. Both Newtonian fluid characteristics and non-Newtonian traits can be seen in this fluid pattern. Equations for continuity, temperature, motile microbes, momentum, and concentration are used to create the mathematical formulation. The series solutions, which are produced using perturbation theory solutions are discussed using graphs for all dominant parameters. Discussion also includes the distribution of temperature, velocity, and swimming microorganisms. Additionally, the effects of wall shear stress, the Nusselt and Sherwood numbers, as well as the phenomena of trapping, are all examined in detail and shown in the graphs. Entropy generation analyses have also been undertaken. The investigation also reveals a crucial behaviour in the use of the heart-lung engine for extracorporeal blood circulation in medicine that may have an impact on the damage of red blood cells as a result of the large fluctuation in wall shear stress. When liquids are transported using arthro pumps and roller pumps in living organs, the results are likewise of significant use. The results are very helpful for executing particle movements in cardiac surgery and may be applicable to the fluid peristaltic pump used in haemodialysis.

Pharmacokinetic Evaluation of New Drugs Using a Multi-Labelling Approach and PET Imaging: Application to a Drug Candidate with Potential Application in Neuromuscular Disorders.

The determination of pharmacokinetic properties of new chemical entities is a key step in the process of drug development. Positron emission tomography (PET) is an ideal technique to obtain both biodistribution and pharmacokinetic parameters of new compounds over a wide range of chemical modalities. Here, we use a multi-radionuclide/multi-position labelling approach to investigate distribution, elimination, and metabolism of a triazole-based FKBP12 ligand (AHK2) with potential application in neuromuscular disorders. Target engagement and stabilizing capacity of the drug candidate (AHK2) towards FKBP12-RyR was evaluated using competitive ligand binding and proximity ligation assays, respectively. Subsequently, AHK2 was labelled either with the positron emitter carbon-11 (11C) via 11C-methylation to yield both [11C]AHK2.1 and [11C]AHK2.2, or by palladium-catalysed reduction of the corresponding 5-iodotriazole derivative using 3H gas to yield [3H]AHK2. Metabolism was first investigated in vitro using liver microsomes. PET imaging studies in rats after intravenous (IV) administration at different doses (1 µg/Kg and 5 mg/Kg) were combined with determination of arterial blood time-activity curves (TACs) and analysis of plasma samples by high performance liquid chromatography (HPLC) to quantify radioactive metabolites. Arterial TACs were obtained in continuous mode by using an in-house developed system that enables extracorporeal blood circulation and continuous measurement of radioactivity in the blood. Pharmacokinetic parameters were determined by non-compartmental modelling of the TACs. In vitro studies indicate that AHK2 binds to FKBP12 at the rapamycin-binding pocket, presenting activity as a FKBP12/RyR stabilizer. [11C]AHK2.1, [11C]AHK2.2 and [3H]AHK2 could be obtained in overall non-decay corrected radiochemical yields of 14 ± 2%, 15 ± 2% and 0.05%, respectively. Molar activities were 60-110 GBq/µmol, 68-122 GBq/µmol and 0.4-0.5 GBq/μmol, respectively. In vitro results showed that oxidation of the thioether group into sulfoxide, demethylation of the CH3O-Ar residue and demethylation of -N(CH3)2 were the main metabolic pathways. Fast metabolism was observed in vivo. Pharmacokinetic parameters obtained from metabolite-corrected arterial blood TACs showed a short half-life (12.6 ± 3.3 min). Dynamic PET imaging showed elimination via urine when [11C]AHK2.2 was administered, probably reflecting the biodistribution of [11C]methanol as the major metabolite. Contrarily, accumulation in the gastrointestinal track was observed after administration of [11C]AKH2.1. AHK2 binds to FKBP12 at the rapamycin-binding pocket, presenting activity as a FKBP12/RyR stabilizer. Studies performed with the 3H- and 11C-labelled FKBP12/RyR stabilizer AHK2 confirm fast blood clearance, linear pharmacokinetics and rapid metabolism involving oxidation of the sulfide and amine moieties and oxidative demethylation of the CH3-O-Ar and tertiary amine groups as the main pathways. PET studies suggest that knowledge about metabolic pathways is paramount to interpret images.

K+ontrol rapidly and efficiently reduces potassium in donor blood during ex vivo circulation.

Patients with kidney failure are at risk for lethal complications from hyperkalemia. Resuscitation, medications, and hemodialysis are used to mitigate increased potassium (K+) levels in circulating blood; however, these approaches may not always be readily available or effective, especially in a resource limited environment. We tested a sorbent cartridge (KC, K+ontrol CytoSorbents Medical Inc., Monmouth Junction, New Jersey) which contains a resin adsorber for K+. The objective of this study was to test the utility of KC in an ex vivo circulation system. We hypothesized that KC reduces K+ levels in extracorporeal circulation of donor swine whole blood infused with KCl. A six-hour circulation study was carried out using KC, a NxStage (NxStage Medical, Inc., Lawrence, MA) membrane, blood bag containing heparinized whole blood with KCl infusion, 3/16-inch ID tubing, a peristaltic pump, and flow sensors. The NxStage permeate line was connected back to the main circuit in the Control group (n = 6), creating a recirculation loop. For KC group (n = 6), KC was added to the recirculation loop, and a continuous infusion of KCl at 10mEq/hour was administered for two hours. Blood samples were acquired at baseline and every hour for 6h. In the control group, K+ levels remained at ∼9mmol/L; 9.1 ± 0.4mmol/L at 6h. In the KC group, significant decreases in K+ at hour 1 (4.3 ± 0.3mmol/L) and were sustained for the experiment duration equilibrating at 4.6 ± 0.4mmol/L after 6h (p = 0.042). Main loop blood flow was maintained under 400mL/min; recirculation loop flow varied between 60 and 70mL/min in the control group and 45-55mL/min in the KC group. Decreases in recirculation loop flow in KC group required 7% increase of pump RPM. During ex-vivo extracorporeal circulation using donor swine blood, KC removed approximately 50% of K+, normalizing circulating levels.

Anticoagulant biomimetic consecutive gas exchange network for advanced artificial lung membrane

Artificial lung membrane as extracorporeal blood-gas barriers could execute similar functions as human alveoli, whereby accomplish blood gas exchange process, providing imperative life support for patients with cardiopulmonary failure. However, the gas exchange performance for current membranous modules is restrained to the dense polymer matrix with low CO2 permeability. Meanwhile, it has long been difficult to balance the contradiction between haemorrhagic risk generated by heparin systemic anticoagulation and thrombogenesis during extracorporeal blood circulation. Here, inspired by the natural mammalian alveoli, a biomimetic consecutive gas exchange network (CGEN) is constructed on porous PES substrate by using aperture-modulated UIO-66-NH2 nanoparticles and hydrophilic CO2-affinitive polymer matrix to simulate the physiological structures and gas exchange features of human alveoli in vitro. The porous MOF particles within CGEN establish the main gas exchange channels, which not only enhance the total gas permeation, but also improve the CO2/O2 permselectivity to 13.17, approaching to the level of natural alveoli. Additionally, the prepared composite membrane with good hemocompatibility could effectively inhibit the formation of thrombus and provide a reliable local self-anticoagulation state during extracorporeal blood circulation. Overall, this biomimetic thin film composite membrane could provide new ideals for the preparation of advanced artificial lung membrane.

Сongenital immunity dysfunction in patients with postoperative cognitive impairment after coronary artery bypass grafting

With regard of post-surgical cognitive disturbances, an active search for biological markers of these neurological complications is performed. We have studied the contents of NSE, IL-6, TGF-β1, MMP9 and TIMP1 in blood serum of these patients. The study included 110 patients after aortal-coronary bypass surgery using extracorporeal blood circulation. Splitting into separate groups was based on the test scores, according to Montreal Cognitive Assessment Scale prior to surgery and on day +7 after the intervention: (I) patients without complications ( 3 points); (II) patients with post-surgical cognitive impairment ( 3 points). The comparison group (III) included 35 healthy subjects. Evaluation of NSE, IL-6, TGF-β1, ММP9 and TIMP1 in blood serum was performed by means of ELISA technique (RD Systems, USA). The data were expressed as pg/ml, or ng/ml. Blood sampling was made at 4 terms: before surgery, just after intervention, 24 h later, and on day 7 after the surgery.The patients from group II showed higher NSE levels, except of 7 days after surgery when it became similar to other groups. Increased IL-6 levels were found in the patients from group II at all terms after surgery. Decreased concentration of TGF-β1 was found in the II group prior to operation, 24 h and 7 days after the surgery. However, just after surgery, this index was increased, and its values barely differed from results of groups I and III. Studies of MMP9 showed significant differences between groups I and II only on day +7 after. However, lower MMP9 content was detected in the patients from I and II groups before surgery compared to group III. TIMP1 values showed gradual increase over the observation period, but did not differ between groups I and II. In the patients from group II, an increased content of NSE and IL-6 was revealed, along with low TGF-β1 levels and decreased ММP9/TIMP1 ratio over early postsurgical period, thus suggesting possible role of innate immunity dysfunction in pathogenesis of postsurgical cognitive impairment.

The effect of ultrafiltration transmembrane permeation on the flow field in a surrogate system of an artificial kidney

Abstract Renal Replacement Therapies generally associated to the Artificial Kidney (AK) are membrane-based treatments that assure the separation functions of the failing kidney in extracorporeal blood circulation. Their progress from conventional hemodialysis towards high-flux hemodialysis (HFHD) through the introduction of ultrafiltration membranes characterized by high convective permeation fluxes intensified the need of elucidating the effect of the membrane fluid removal rates on the increase of the potentially blood-traumatizing shear stresses developed adjacently to the membrane. The AK surrogate consisting of two-compartments separated by an ultrafiltration membrane is set to have water circulation in the upper chamber mimicking the blood flow rates and the membrane fluid removal rates typical of HFHD. Pressure drop mirrors the shear stresses quantification and the modification of the velocities profiles. The increase on pressure drop when comparing flows in slits with a permeable membrane and an impermeable wall is ca. 512% and 576% for $ \mathrm{CA}22/5\%{\mathrm{SiO}}_2 $ and $ \mathrm{CA}30/5\%{\mathrm{SiO}}_2 $ membranes, respectively.

Nanomotor-based adsorbent for blood Lead(II) removal in vitro and in pig models

Blood lead (Pb(II)) removal is very important but challenging. The main difficulty of blood Pb(II) removal currently lies in the fact that blood Pb(II) is mainly complexed with hemoglobin (Hb) inside the red blood cells (RBCs). Traditional blood Pb(II) removers are mostly passive particles that do not have the motion ability, thus the efficiency of the contact between the adsorbent and the Pb(II)-contaminated Hb is relatively low. Herein, a kind of magnetic nanomotor adsorbent with movement ability under alternating magnetic field based on Fe3O4 nanoparticle modified with meso-2, 3-dimercaptosuccinic acid (DMSA) was prepared and a blood Pb(II) removal strategy was further proposed. During the removal process, the nanomotor adsorbent can enter the RBCs, then the contact probability between the nanomotor adsorbent and the Pb(II)-contaminated Hb can be increased by the active movement of nanomotor. Through the strong coordination of functional groups in DMSA, the nanomotor adsorbent can adsorb Pb(II), and finally be separated from blood by permanent magnetic field. The in vivo extracorporeal blood circulation experiment verifies the ability of the adsorbent to remove blood Pb(II) in pig models, which may provide innovative ideas for blood heavy metal removal in the future.

A Measuring Instrument for In-Line and Real-Time Measurement of Blood-pCO2in Extracorporeal-Circulation

Since the late 1950s, blood $p$ CO2 can be measured by using electrodes and, more recently, also by using point-of-care instruments such as blood gas and chemistry analyzers. Nevertheless, nowadays no measurement method has succeeded in providing an economic, reliable, and accurate estimate of the blood- $p$ CO2 to be routinely used for the monitoring of extracorporeal (blood) circulation (ECC) treatments. Indeed, blood is a very complex biological matrix composed of several different constituents, thus apart from a limited maximum-admitted measurement error (about some mmHg) and a quite wide measuring interval (about [20, 100] mmHg), the measuring systems have to provide significant selectivity taking hemocompatibility and safety for the patient as a primary concern. In this article, we propose and demonstrate a measuring instrument consisting of a low-cost and disposable fluorescent pco-sensor that can be inserted in series with the bloodline, and a nondisposable optical head that contactless reads the sensor. The proposed measuring system is intrinsically safe for the patient, has adequate metrological performance, avoids blood sampling and the related issues, and may allow to comply with cost requirements. Preliminary tests, conducted simulating a 6-h ECC treatment by using bovine blood, revealed deviations from the reference measuring instrument of less than ±4 mmHg, while the blood- $p$ CO2 was varied in the range [20, 100] mmHg.

Finite-time contractive boundedness of extracorporeal blood circulation process

This paper proposes, finite-time contractive stability for a state space model of extra-corporeal blood circulation (ECC). Firstly, by virtue of an appropriately chosen Lyapunov function some sufficient inequality-based conditions for the existence of an observer-based controller has been proposed. Secondly, a non-fragile observer-based control is designed in such a way that it will withstand the impacts of uncertainties in controller and observer gains and therein guarantees H∞ finite-time contractive boundedeness of the overall dynamics of the system. The sufficient conditions derived are presented in a LMI frame work. In simulation results we address the finite-time contractive boundedness of the ECC model. The numerical simulations are conducted and discussed which validates the performance of the proposed algorithm.

Performances and Robustness of a Fluorescent Sensor for Nearly Neutral pH Measurements in Healthcare

The capability to measure pH is fundamental in many fields ranging from healthcare and agrifood, to chemistry and industrial applications. In medicine, the possibility of in-line and real-time monitoring critical care analytes, such as pH, is recognized to provide relevant information for the diagnosis and treatment of a variety of disorders and would be of considerable support for the management of extracorporeal (blood) circulation (ECC). In this article, we theoretically and experimentally investigate the performances and the robustness of a fluorescent sensor that we recently proposed for the in-line and real-time monitoring of blood pH in ECC. Indeed, being low-cost and biocompatible, the proposed sensor can be advantageously exploited for the in-line and real-time monitoring of the pH of fluids, particularly in applications such as healthcare where safe and low-cost disposables are usually required for all parts which come into contact with the patient. The reported results demonstrate that the proposed sensor allows achieving significant robustness to unevennesses in the production process of the sensing element.

Anatomical Minutiae and Cannular Self-experimentation

This article focuses on anatomical minutiae: small physical processes or features, as seen through micro-scale interventions on the author’s body. These include the sprouting of a begonia seed inside a tear duct and the extracorporeal circulation of blood through non-mechanized processes. Drawing from self-experimentation as an embodied research practice, this article explains how ocular germination and autologous transfusion are possible via the use of standard stainless-steel cannula, such as hypodermic needles and ophthalmological applicators. The repurposing of these medical devices expands on French philosopher Gilbert Simondon’s formulation of ‘techno-aesthetic objects,’ a means from which to appraise the physical and physiological limits of a human body in relation to an external machine. In so doing, this article identifies how cannular self-experimentation holds subtle yet effective potential for intrabody repositioning in artistic and scientific contexts alike, all while occurring primarily in a space less than a millimetre in breadth.

BILATERAL PARACENTRAL ACUTE MIDDLE MACULOPATHY AFTER CARDIOPULMONARY BYPASS.

To report the first two observations of bilateral paracentral acute middle maculopathy in the early postoperative period after cardiopulmonary bypass procedures. Comprehensive ophthalmic examinations were performed, including best-corrected visual acuity, Humphrey visual field testing, dilated fundus examination, and optical coherence tomography. Two patients complained of unilateral vision loss after cardiac surgery involving cardiopulmonary bypass. Unilateral optic disc edema consistent with ischemic optic neuropathy was observed in the symptomatic eye of each patient, whereas scattered cotton-wool spots were identified bilaterally. In addition, optical coherence tomography imaging revealed bilateral paracentral acute middle maculopathy, correlating with visual field defects detected on automated perimetry in the asymptomatic eyes. Although symptomatic postoperative vision loss is a rare complication of cardiac surgery, intraoperative retinal microvascular nonperfusion as a consequence of extracorporeal circulation of blood may be a more common and under-recognized occurrence.

Hemodialysis in emergency situation in a Hemodialysis Center in Dakar : A prospective study about 81 cases

Introduction: Hemodialysis is a renal replacement technique that uses extracorporeal blood circulation (ECC) to purge the blood of patients with renal failure. It is used urgently in severe acute kidney injury (AKI) and complicated end stage renal disease (ESRD). The objective of this work was to determine the prevalence of each indication of emergency hemodialysis and its prognosis. Methods: We conducted a prospective, mono-centric study of descriptive and analytical type over a period of 6 months at the hemodialysis center of Aristide Le Dantec University Hospital. All patients with acute or chronic renal failure who underwent hemodialysis during an emergency were included. These emergencies were for the AKI or Chronic Kidney disease (CKD) the existence of one or more severity criteria: pulmonary œdema, hyperkalemia, severe metabolic acidosis, poorly tolerated uremia, persistent anuria and / or symptomatic hyponatraemia. Results: Eighty-one emergency hemodialysis patients were received during the study period out of a total of 660 hemodialysis patients serving a hospital prevalence of 12.2%. The mean age of the patients was 39.31 ± 18.78 years with a sex ratio of 1.02. The first indication of emergency hemodialysis was poorly tolerated uremia in 46 patients (56.7%) followed by threatening hyperkalemia with 43.2%. The evolution was highlighted by a complete recovery in 53% of patients with AKI whereas for patients with ESRD lifting the emergency was the rule. Fifteen patients (18.50%) had died, including 12 patients (14.80%) outside dialysis and 3 patients (3.75%) on dialysis. The occurrence of death was statistically correlated with hyperkalemia (p = 0.003) and metabolic acidosis (p = 0.001). Conclusion: Hemodialysis was performed urgently in 12.2% of cases. Poorly tolerated urine was the most common indication (56.7%). In the majority of cases we noted a good evolution with the emergency lifting. However we noted 15 deaths (18.5%).

Platelet Function Changes during Neonatal Cardiopulmonary Bypass Surgery: Mechanistic Basis and Lack of Correlation with Excessive Bleeding.

Thrombocytopenia and platelet dysfunction induced by extracorporeal blood circulation are thought to contribute to postsurgical bleeding complications in neonates undergoing cardiac surgery with cardiopulmonary bypass (CPB). In this study, we examined how changes in platelet function relate to changes in platelet count and to excessive bleeding in neonatal CPB surgery. Platelet counts and platelet P-selectin exposure in response to agonist stimulation were measured at four times before, during, and after CPB surgery in neonates with normal versus excessive levels of postsurgical bleeding. Relative to baseline, platelet counts were reduced in patients while on CPB, as was platelet activation by the thromboxane A2 analog U46619, thrombin receptor activating peptide (TRAP), and collagen-related peptide (CRP). Platelet activation by adenosine diphosphate (ADP) was instead reduced after platelet transfusion. We provide evidence that thrombocytopenia is a likely contributor to CPB-associated defects in platelet responsiveness to U46619 and TRAP, CPB-induced collagen receptor downregulation likely contributes to defective platelet responsiveness to CRP, and platelet transfusion may contribute to defective platelet responses to ADP. Platelet transfusion restored to baseline levels platelet counts and responsiveness to all agonists except ADP but did not prevent excessive bleeding in all patients. We conclude that platelet count and function defects are characteristic of neonatal CPB surgery and that platelet transfusion corrects these defects. However, since CPB-associated coagulopathy is multifactorial, platelet transfusion alone is insufficient to treat bleeding events in all patients. Therefore, platelet transfusion must be combined with treatment of other factors that contribute to the coagulopathy to prevent excessive bleeding.

Immortalization of porcine hepatocytes with a α-1,3-galactosyltransferase knockout background.

In vivo pig liver xenotransplantation preclinical trials appear to have poor efficiency compared to heart or kidney xenotransplantation because of xenogeneic rejection, including coagulopathy, and particularly thrombocytopenia. In contrast, ex vivo pig liver (wild type) perfusion systems have been proven to be effective in "bridging" liver failure patients until subsequent liver allotransplantation, and transgenic (human CD55/CD59) modifications have even prolonged the duration of pig liver perfusion. Despite the fact that hepatocyte cell lines have also been proposed for extracorporeal blood circulation in conditions of acute liver failure, porcine hepatocyte cell lines, and the GalT-KO background in particular, have not been developed and applied in this field. Herein, we established immortalized wild-type and GalT-KO porcine hepatocyte cell lines, which can be used for artificial liver support systems, cell transplantation, and even in vitro studies of xenotransplantation. Primary hepatocytes extracted from GalT-KO and wild-type pigs were transfected with SV40 LT lentivirus to establish immortalized GalT-KO porcine hepatocytes (GalT-KO-hep) and wild-type porcine hepatocytes (WT). Hepatocyte biomarkers and function-related genes were assessed by immunofluorescence, periodic acid-Schiff staining, indocyanine green (ICG) uptake, biochemical analysis, ELISA, and RT-PCR. Furthermore, the tumorigenicity of immortalized cells was detected. In addition, a complement-dependent cytotoxicity (CDC) assay was performed with GalT-KO-hep and WT cells. Cell death and viability rates were assessed by flow cytometry and CCK-8 assay. GalT-KO and wild-type porcine hepatocytes were successfully immortalized and maintained the characteristics of primary porcine hepatocytes, including albumin secretion, ICG uptake, urea and glycogen production, and expression of hepatocyte marker proteins and specific metabolic enzymes. GalT-KO-hep and WT cells were confirmed as having no tumorigenicity. In addition, GalT-KO-hep cells showed less apoptosis and more viability than WT cells when exposed to complement and xenogeneic serum. Two types of immortalized cell lines of porcine hepatocytes with GalT-KO and wild-type backgrounds were successfully established. GalT-KO-hep cells exhibited higher viability and injury resistance against a xenogeneic immune response.