Plasma Sequestration Research Articles

Acitretin-Induced Systemic Capillary Leak Syndrome

Systemic capillary leak syndrome (SCLS) is a potentially life-threatening condition characterized by recurrent episodes of massive plasma sequestration into the interstitial space causing vascular collapse. SCLS is a rare syndrome where only a few cases are published in literature. The etiology being either idiopathic (Clarkson’s disease) or secondary to underlying causes such as sepsis and drugs and diagnosis is often missed due to nonspecific presentation. We hereby present a case of pustular psoriasis on acitretin who developed SCLS after increasing the dose and eventually succumbed. Acitretin is considered the drug of choice in extensive psoriasis despite having side effect profiles. Although most of them are dose dependent and not life threatening. This is one of the rare complications where early detection of the condition, withdrawal of the drug, and appropriate management can be lifesaving.

Platelet Function during Platelet-Rich Plasma Sequestration in Complex Cardiac Surgical Procedures - Prospective Controlled Study

Platelet Function during Platelet-Rich Plasma Sequestration in Complex Cardiac Surgical Procedures - Prospective Controlled Study

Vitamin D receptor is a novel transcriptional regulator for Axin1

BackgroundAxin1 is a scaffold protein in the β-catenin destruction complex, which, if disrupted, contributes to pathogenesis of various human diseases, including colorectal carcinogenesis and inflammatory bowel diseases (IBD). We have previously demonstrated that Salmonella infection promotes the degradation and plasma sequestration of Axin1, leading to bacterial invasiveness and inflammatory responses. Vitamin D and the vitamin D receptor (VDR) appear to be important regulators of IBD and colon cancer. Although VDR and Axin1 are all involved in intestinal inflammation, it remains unclear whether these processes are related or function independently. In the current study, we hypothesize that VDR is an important regulator for the maintenance of physiological level of Axin1. MethodsUsing the intestinal epithelial conditional VDR knockout mouse model (VDRΔIEC) and cultured cell lines, influences of VDR status on the expression of Axin1 was evaluated by Western blots and real-time PCR. Loss- and gain-of-function assays were used to investigate the regulation of VDR on Axin1 at the transcriptional and translational levels. Cells were treated with cycloheximide or actinomycin for molecular mechanistic studies. Candidate genomic VDR binding sites for Axin1 were tested by chromatin immunoprecipitation (ChIP) assay. Physical interactions among VDR, Axin1, and β-catenin were tested by immunoprecipitation. Cellular localization of Axin1 with different VDR status was determined by fractionation and immunohistochemistry. ResultsWe found that VDR deletion led to lower protein and mRNA levels of Axin1, whereas knockdown of Axin1 did not change the expression level of VDR protein. Immunoprecipitation data did not support physical interaction between VDR and Axin1. The VDR regulation of Axin1 was through a VDR genomic binding site for Axin1 gene on the regulatory region. Fractionation data showed that cytosolic Axin1 was significantly reduced due to VDR deletion, leaving the nuclear fraction unchanged. In ileum, Axin1 was distributed in the cytosol of apical epithelium and crypts. ConclusionVDR is important for the maintenance of physiological level of Axin1. The discovery of Axin1 as a VDR target gene provides novel and fundamental insights into the interactions between the VDR and β-catenin signaling pathways.

Plasma sequestration: a good therapy to prevent the deleterious effect of clopidogrel when clopidogrel is used within one to four days of coronary bypass surgery

Clopidogrel (Plavix) is an inhibitor of ADP-induced platelet aggregation, acting by direct inhibition of adenosine diphosphate (ADP) binding to its receptor and of the subsequent ADP-mediated activation of the glycoprotein GPIIb/IIIa complex. A common recommendation for coronary artery bypass surgery is to stop clopidogrel five to seven days before surgery.(1) Patients taking clopidogrel within five days of surgery are more likely to show an increase in post-operative bleeding, an increase need for blood products, and an increased chance for secondary operations to control bleeding. This paper presents an option which appears to decrease the adverse effects of clopidogrel for patients undergoing coronary artery bypass surgery within one to four days of stopping the use of clopidogrel. This option is autologous plasma sequestration. The process of plasma sequestration collection prior to the administration of heparin during surgery offers a significant therapy to minimize bleeding post bypass. Twelve consecutive patients are included in this study (one a REDO) each receiving clopidogrel within one to four days of surgery. Throughout their hospital stay, three patients required packed red blood cell (RBC) transfusions (two received 2 units, one received 1 unit). No other donor blood products were required. Post-operative bleeding was minimal, and the need for a secondary operation due to bleeding was eliminated. The average stay in the cardiovascular intensive care unit(CICU) was 2.8 days, with an average hospital stay of 7.25 days.

Bloodless aortic valve and ascending aorta replacement surgery requiring circulatory arrest: two case studies

Blood and/or blood product transfusions are common during and after complicated cardiac procedures. Replacement of the aortic valve, ascending aorta, and coronary implantation requiring circulatory arrest are high-risk procedures. Blood product transfusions only add to the morbidity and mortality rates associated with these types of procedures. Perfusion strategies must be incorporated to decrease the effects of hemodiluton due to cardiopulmonary bypass (CPB), and preserve platelets and clotting factors needed for hemostasis, post-operatively. We are reporting two consecutive cases where the patients presented with aortic valve stenosis accompanying an ascending aortic aneurysm requiring surgical correction using circulatory arrest. Neither patient required any blood or blood product donation throughout their hospital stay. Our strategies included minimizing our bypass circuit, utilization vacuum-assisted venous drainage, plasma sequestration, total circuit retrograde autologous priming (RAP), and cell salvage.

P3-098: Proteomic analysis of amyloid beta binding proteins in human plasma

Amyloid–β peptide (Aβ) circulates in plasma and interacts extensively with plasma proteins. Several plasma proteins have been identified which can interact with Aβ in purified form; however, a paucity of studies examine Aβ–protein binding relationships in the intact plasma milieu. Published studies suggest that plasma sequestration of Aβ by protein interaction can alter brain levels of Aβ. Aβ–protein interactions could also interfere with removal of Aβ from the plasma. The present study uses affinity–purification with Aβ followed by mass spectrometric identification of proteins to identify endogenous Aβ binding proteins in human plasma. The affinity purified proteins were separated by denaturing electrophoresis and identified after in–gel trypsin digests by peptide map fingerprint analysis using matrix–assisted laser desorption/ionization–time of flight mass spectrometry (MALDI–TOF MS) and subsequently verified using tandem analysis (MALDI–TOF/TOF MS) of the digested samples. All identified proteins were identified from three different plasma samples. Aβ binding proteins identified in this study include proteins involved in coagulation processes such as fibrinogen β, fibrinogen γ, coagulation factor V and vitronectin. Several lipoprotein–associated proteins were also identified suggesting lipoprotein association of Aβ. These proteins include apolipoprotein (apo) A–I, apoC–II, apoE, apoJ, and serum paraoxonase. The pattern of apolipoproteins identified suggests that the Aβ is interacting predominately with high density lipoprotein (HDL). Interestingly, apoE and apoJ were enriched relative to apo A–I suggesting that the Aβ may interact with a subset of lipoprotein particles. Additional proteins identified by Aβ binding include the protease inhibitor α–2–macroglobulin, the thyroid binding protein transthyretin, and complement C3. The nature of these Aβ–protein interactions has implications in both Aβ clearance and Aβ equilibrium across the blood–brain barrier.

Platelet-Rich Plasma and Platelet Gel: A Review

Strategies to reduce blood loss and transfusion of allogeneic blood products during surgical procedures are important in modern times. The most important and well-known autologous techniques are preoperative autologous predonation, hemodilution, perioperative red cell salvage, postoperative wound blood autotransfusion, and pharmacologic modulation of the hemostatic process. At present, new developments in the preparation of preoperative autologous blood component therapy by whole blood platelet-rich plasma (PRP) and platelet-poor plasma (PPP) sequestration have evolved. This technique has been proven to reduce the number of allogeneic blood transfusions during open heart surgery and orthopedic operations. Moreover, platelet gel and fibrin sealant derived from PRP and PPP mixed with thrombin, respectively, can be exogenously applied to tissues to promote wound healing, bone growth, and tissue sealing. However, to our disappointment, not many well-designed scientific studies are available, and many anecdotic stories exist, whereas questions remain to be answered. We therefore decided to study perioperative blood management in more detail with emphasis on the application and production of autologous platelet gel and the use of fibrin sealant. This review addresses a large variety of aspects relevant to platelets, platelet-rich plasma, and the application of platelet gel. In addition, an overview of recent animal and human studies is presented.

Autologous Platelet Gel Applications During Cardiovascular Surgery: Effect on Wound Healing

Abstract: Autologous platelet gel (APG) was developed in the early 1990s as a byproduct of platelet-rich plasma sequestration during cardiac surgery. Although APG has been approved for postoperative healing, there have been no published studies that evaluate the effects of APG on sternal healing postcardiopulmonary bypass. The purpose for this study was to examine the effects of APG on postoperative sternal wound healing evidenced by subjective reports of chest and leg pain, the amount of measurable bruising incurred, and platelet indices both preoperatively and postoperatively.

Database Review of Possible Factors Influencing Point-of-Care Platelet Gel Manufacture

The application of autologous platelet gel (APG) to surgical wounds has been advocated during the last 10 years to speed bone and wound healing, minimize infection, and modify postoperative pain. There are few data available to confirm these claims. Prior to organized study, consistency and agreement in manufacture of the APG is needed. In this study, an attempt is made to isolate factors that are important in developing a consistent gel. A database review was performed to determine factors that affect PG quality and function. Quality was assessed by platelet count and fibrinogen concentration, whereas function was assessed by an arbitrary scale of gelling, in which a “1” was equal to a soup texture, “3” equal to a “Jell-O” consistency, whereas a grade of “2” was somewhere in between. Data specific to the blood draw and platelet-rich plasma sequestration were collected. Two hundred and sixty cases of APG production were reviewed. The volume of blood drawn was dependent on the machine used. Gelling of the APG was independent of platelet count and fibrinogen concentration. Gels that were rated soupy had an average platelet count of 540 K/μL ± 327 K/μL and a fibrinogen concentration of 225 mg/dL ± 76 mg/dL whereas a firm gel had an average platelet count of 486 K/μL ± 264 K/μL and a fibrinogen concentration of 229 mg/dL ± 78 mg/dL. The manner in which the blood was drawn along with the site from which the blood was drawn influenced the platelet concentration of the platelet-rich plasma. Optimal platelet counts were obtained when blood was drawn from a peripheral vein and sequestration was performed with the Medtronic Sequestra or the Medtronic Magellan. Ultimate gelling of PG is independent of fibrinogen and platelet concentrations. This work suggests a need for further research into the manufacture of APG.

Plasma sequestration before cardiopulmonary bypass and cell saving contribute to improved outcome in high-risk cardiac surgical patients

Plasma sequestration before cardiopulmonary bypass and cell saving contribute to improved outcome in high-risk cardiac surgical patients

Determination of Platelet Yields from Platelet Rich Plasma for Five Autotransfusion Machines

Introduction: A significant advance in perioperative autologous blood therapy over the last decade has been the introduction of autotransfusion machines which are capable of both cell salvage and the production of platelet concentrates [1]. Five autotransfusion machines with differing techniques for producing platelet concentrate were evaluated for their platelet yields. The machines were the Sequestra 1000 (Medtronic), and the Compact Advanced (Sorin), which use a conventional bell-shaped Lathem processing bowl with a dual-spin separation technique (5600 rpm, followed by 2400 rpm to separate the platelet rich buffy coat from the red cell pack); the Cell Saver 5 (Haemonetics), also a Lathem bowl but employing a single-spin separation technique (4750 rpm), the BRAT II (Cobe), which employs a cylindrical bowl using a dual-spin technique; and the C.A.T.S.(Fresenius) which utilizes a continuous disk-shaped chamber, also with a dual-spin technique. Methods: Fresh human whole blood was warmed, oxygenated, pooled and mixed. The pool was equally divided into 5 parts, which were then processed simultaneously on the five autotransfusion machines using the manufacturers' recommended protocols for platelet rich plasma sequestration. A total of 10 blood pools were produced and processed. Platelet yields were calculated as follows: platelet yield (PRP)= platelet count * PRP volume (1 unit platelets = 5.0 x 1010 platelets); platelets processed = platelet count of pooled blood sample * volume of blood processed; % platelet yield = (platelet yield (PRP)/platelets processed)*100. Results: (Table 1)Table 1Discussion: The Sequestra and Compact Advance performed similarly with high platelet counts and low PRP volumes. The Cell Saver 5 had low platelet counts but high PRP volumes. This resulted in similar platelet yields for these machines. The Brat II had a high platelet count and a high PRP volume resulting in the greatest platelet yield. But, it had the slowest processing time. The CATS was intermediate in most areas, except for the slowest platelet units per minute. The decision to use one of these machines over the other for platelet sequestration depends on the relative importance of the various processing parameters.

Gonadotropins and reproductive function in the anuran amphibian, Rana esculenta.

In this study, the measurement both of peripheral gonadotropins (FSH and LH) and of sex steroids in male and female wild anuran, Rana esculenta, was performed during the annual reproductive cycle; moreover, the role of gonadotropins in the vitellogenic process and in ovarian steroidogenesis was investigated through in vitro experiments. LH plasma changes in males showed high values during autumn-winter months and during the mating period, when high androgen levels were found. Conversely, for the first time in male vertebrates, a clear correspondence between plasma FSH and estradiol-17beta (E2) was shown. In females, FSH peak values were found at the beginning of the mating period in parallel with those of plasma vitellogenin (VTG) and E2; in contrast, high LH levels went together with ovarian weight (gonadosomatic index), which is considered a good marker for the plasma sequestration of VTG by growing oocytes. The in vivo results are corroborated by in vitro studies showing the direct effects of both FSH and LH in inducing hepatic VTG synthesis and release in the culture media. Lastly, although it is not yet known whether or not FSH and LH have separate functions in amphibians, it was clearly shown that they induce ovarian steroid production. These results are discussed in terms of the high seasonality previously demonstrated in this wild frog.

A risk-benefit assessment of aprotinin in cardiac surgical procedures.

Aprotinin, a naturally occurring serine protease inhibitor, has found widespread application during cardiac surgical procedures as a consequence of its ability to decrease blood loss and transfusion requirements. While its efficacy in a variety of clinical situations associated with increased risk of blood loss has been well established, at the same time, various complications including anaphylaxis, renal insufficiency, graft closure and arterial thromboses have been reported in association with aprotinin administration. In order to more fully evaluate the risks and benefits associated with aprotinin usage, this review first of all examines the hazards associated with transfusion of blood and blood products. Consideration is then given to various alternatives to allogeneic transfusion, including autologous predonation, acute normovolemic hemodilution, perioperative cell salvage and intraoperative plasma sequestration. A critique of other available pharmacological therapies, specifically desmopressin, aminocaproic acid and tranexamic acid, reviewing their modes of action, efficacy and associated complications, is then made. The role of aprotinin in cardiac surgery is then discussed and its pharmacology, including consideration of its antifibrinolytic, platelet preserving and anti-inflammatory effects is reviewed. Finally, an analysis of potential complications associated with aprotinin administration is undertaken. Issues involving its influence on specific measures of anticoagulation, namely partial thromboplastin time and activated clotting time, and issues relating to graft patency, hypothermic circulatory arrest, renal function, and allergic reactions are analysed and interpreted. In summary, this review concludes that most of the risks associated with aprotinin administration primarily involve inadequate anticoagulation and those of developing an allergic reaction, particularly upon aproptinin re-exposure. The benefits of aproptinin to decrease blood loss and transfusion requirements are confirmed, and there is evidence pointing to the intriguing possibility of a potential salutary effect on perioperative central nervous system complications.

Autogolous plasma sequestration: A further improvement in blood conservation?

Autogolous plasma sequestration: A further improvement in blood conservation?

Platelet Rich Plasma (PRP) Sequestration Why, When, How?

Reduction in the amount of blood products transfused during and following any surgery is vitally important because of the risk of blood-transmitted diseases and the increasing costs associated with any transfusion. During the 1970s, a technique of sequestering (drawing off and storing) a patient's blood in the operating room evolved in cardiac surgery. This procedure involved the removal of one or two units of whole blood into anticoagulated storage bags prior to going on cardiopulmonary bypass. This autologous blood was stored in the operating room at room temperature until the patient was brought off cardiopulmonary bypass and stabilized. The blood was then reinfused into the patient. It was theorized that the blood withdrawn contained fresh platelets, red cells, and coagulation factors required to help restore hemostasis rapidly. Furthermore, oxygen carrying capacity following the operation was improved, thereby reducing the need for homologous blood product transfusions following the operation. An entirely new approach to reduction in the use of blood products involves the preoperative collection of Platelet Rich Plasma (PRP) and the subsequent reinfusion of the PRP containing fresh, undamaged platelets and clotting factors following the operation. This paper will document why the technique of utilizing Platelet Rich Plasma Sequestration is beneficial for the patient, when and where platelet rich plasma sequestration can be performed and, how the PRP procedure is technically performed.

Platelet-rich plasma reduces postoperative blood loss after cardiopulmonary bypass

To study the effect of plasma sequestration and reinfusion of platelet-rich plasma on blood loss after cardiopulmonary bypass, 18 patients undergoing heart operations were randomly selected either to have collected or not to have collected approximately 250 ml of platelet-rich plasma before initiating cardiopulmonary bypass with the use of the Haemonetics Plasma Saving System (Haemonetics Corporation, Braintree, Mass.). All patients had standardized anesthesia and cardiopulmonary bypass. After reversal of heparin, autologous platelet-rich plasma was reinfused in nine patients. Thrombocyte counts, hemoglobin, and hematocrit were calculated before, during, and after cardiopulmonary bypass, and 24 and 48 hours postoperatively. Blood loss and total number of transfusions were recorded. Although 9% of the total platelet volume was removed, there were no hemodynamic complications related to the use of the Haemonetics Plasma Saving System. In both groups, significant low levels of thrombocytes, hemoglobin, and hematocrit were seen after cardiopulmonary bypass. Platelet-rich plasma-reinfused patients had a significantly higher number of platelets after heparin reversal. They also had significantly less blood loss after the operation, necessitating 65% less banked blood products (p less than 0.05). We concluded that reinfusion of autologous platelet-rich plasma may serve as an effective and safe way to restore some of the hematologic derangements after cardiopulmonary bypass.

Does Plasma Sequestration Reduce Post-Operative Bleeding?

Hematologic profiles, postoperative blood loss and transfusion requirements were studied in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) in order to determine the effect of sequestration and reinfusion of platelet-rich plasma (PRP). Eighteen patients were randomly selected to have approximately one unit of PRP collected or not prior to CPB. Autologous PRP was reinfused in nine patients after reversal of anticoagulation. Evaluation of results was based upon thrombocyte counts, Hgb, Hct, and platelet index readings pre- and post-PRP reinfusion, amount of blood loss and volumes of homologous blood and banked blood products required postoperatively. There were no hemodynamic complications related to the sequestration process. PRP reinfused patients had significantly higher thrombocyte counts after reversal of anticoagulation (p < 0.05). Patients receiving PRP required approximately 2/3 less banked blood products, their bleeding being significantly reduced 24 hours postoperatively (p < 0.05). We concluded that plasma sequestration and reinfusion of autologous PRP post-bypass may serve as an effective and safe way in decreasing blood loss after cardiac operations necessitating extracorporeal circulation.

Acetaminophen-induced hepatotoxic congestion in mice.

Acetaminophen-induced (750 mg per kg p.o.) hepatotoxicity in mice is characterized by hepatomegaly and massive centrilobular congestion which precede the appearance of necrosis. The vascular changes are correlated with the morphologic features using liver hemoglobin content to quantitate erythrocyte sequestration, and hematocrit measurements and 125I-albumin injections to determine plasma and blood volume. The initial increase in liver size was a result of plasma accumulation due to endocytic vacuolation of hepatocytes and Disse space enlargement in centrilobular regions. Further increases in liver size after 3 hr were a consequence of erythrocyte and additional plasma sequestration within the damaged liver. These events occurred without any increase in intrahepatic or portal venous pressure. Hepatic hemoglobin and plasma levels increased 10- and 5-fold, respectively, by 4.5 to 6 hr after administration of acetaminophen. There are two major consequences of acetaminophen-induced hepatotoxic congestion. First, blood and plasma volumes fell significantly, and we suggest that hypovolemic shock contributes to early mortality after acetaminophen. Second, impaired circulation within the congested liver, as manifested by reduced 125I-albumin entry into the liver when 125I-albumin was injected after congestion had developed, probably aggravates the initial injury. Early lesions were always evenly distributed around central veins. However, the pattern of damage at 24 hr could be variable. Occasional large confluent areas of necrosis were always congested, which is consistent with the concept that secondary ischemic damage can develop. Congestion and hypovolemia are reversible and can be largely prevented by administration of the protective compound N-acetylcysteine (1,200 mg per kg p.o.) 3 hr after acetaminophen.

Plasma sequestration produced by acute changes in body temperature in turtles.

Plasma sequestration produced by acute changes in body temperature in turtles.

Sites of plasma sequestration induced by body cooling in turtles.

Sites of plasma sequestration induced by body cooling in turtles.