Carbamylation of Integrin α IIb ß 3: The Mechanistic Link to Platelet Dysfunction in ESKD.

BACKGROUND: Bleeding diatheses, common among patients with ESKD, can lead to serious complications, particularly during invasive procedures. Chronic urea overload significantly increases cyanate concentrations in patients with ESKD, leading to carbamylation, an irreversible modification of proteins and peptides. METHODS: To investigate carbamylation as a potential mechanistic link between uremia and platelet dysfunction in ESKD, we used liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) to quantify total homocitrulline, and biotin-conjugated phenylglyoxal labeling and Western blot to detect carbamylated integrin α IIb ß 3 (a receptor required for platelet aggregation). Flow cytometry was used to study activation of isolated platelets and platelet-rich plasma. In a transient transfection system, we tested activity and fibrinogen binding of different mutated forms of the receptor. We assessed platelet adhesion and aggregation in microplate assays. RESULTS: Carbamylation inhibited platelet activation, adhesion, and aggregation. Patients on hemodialysis exhibited significantly reduced activation of α IIb ß 3 compared with healthy controls. We found significant carbamylation of both subunits of α IIb ß 3 on platelets from patients receiving hemodialysis versus only minor modification in controls. In the transient transfection system, modification of lysine 185 in the ß 3 subunit was associated with loss of receptor activity and fibrinogen binding. Supplementation of free amino acids, which was shown to protect plasma proteins from carbamylation-induced damage in patients on hemodialysis, prevented loss of α IIb ß 3 activity in vitro. CONCLUSIONS: Carbamylation of α IIb ß 3-specifically modification of the K185 residue-might represent a mechanistic link between uremia and dysfunctional primary hemostasis in patients on hemodialysis. The observation that free amino acids prevented the carbamylation-induced loss of α IIb ß 3 activity suggests amino acid administration during dialysis may help to normalize platelet function.

Influence of platelet storage time on human platelet lysates and platelet lysate-expanded mesenchymal stromal cells for bone tissue engineering.

BACKGROUND: Human platelet lysate (HPL) is emerging as the preferred xeno-free supplement for the expansion of mesenchymal stromal cells (MSCs) for bone tissue engineering (BTE) applications. Due to a growing demand, the need for standardization and scaling-up of HPL has been highlighted. However, the optimal storage time of the source material, i.e., outdated platelet concentrates (PCs), remains to be determined. The present study aimed to determine the optimal storage time of PCs in terms of the cytokine content and biological efficacy of HPL. METHODS: Donor-matched bone marrow (BMSCs) and adipose-derived MSCs (ASCs) expanded in HPL or fetal bovine serum (FBS) were characterized based on in vitro proliferation, immunophenotype, and multi-lineage differentiation. Osteogenic differentiation was assessed at early (gene expression), intermediate [alkaline phosphatase (ALP) activity], and terminal stages (mineralization). Using a multiplex immunoassay, the cytokine contents of HPLs produced from PCs stored for 1-9 months were screened and a preliminary threshold of 4 months was identified. Next, HPLs were produced from PCs stored for controlled durations of 0, 1, 2, 3, and 4 months, and their efficacy was compared in terms of cytokine content and BMSCs' proliferation and osteogenic differentiation. RESULTS: BMSCs and ASCs in both HPL and FBS demonstrated a characteristic immunophenotype and multi-lineage differentiation; osteogenic differentiation of BMSCs and ASCs was significantly enhanced in HPL vs. FBS. Multiplex network analysis of HPL revealed several interacting growth factors, chemokines, and inflammatory cytokines. Notably, stem cell growth factor (SCGF) was detected in high concentrations. A majority of cytokines were elevated in HPLs produced from PCs stored for ≤ 4 months vs. > 4 months. However, no further differences in PC storage times between 0 and 4 months were identified in terms of HPLs' cytokine content or their effects on the proliferation, ALP activity, and mineralization of BMSCs from multiple donors. CONCLUSIONS: MSCs expanded in HPL demonstrate enhanced osteogenic differentiation, albeit with considerable donor variation. HPLs produced from outdated PCs stored for up to 4 months efficiently supported the proliferation and osteogenic differentiation of MSCs. These findings may facilitate the standardization and scaling-up of HPL from outdated PCs for BTE applications.

Staff officers as blood suppliers: Effects of repeated donations and autologous reinfusions of untransfused units.

BACKGROUND: Limited blood inventory and resupply chains in combat settings can result in preventable deaths from traumatic hemorrhage. One way of mitigating this could be to establish donor pools where blood is collected in advance of high-risk missions and then reinfused back to the donor if not needed to treat casualties. METHODS: Four hundred fifty milliliters plus 56 mL of blood was collected, rested for 2 hours in room temperature, and stored at 4°C. The blood was reinfused 22 to 24 hours after donation and the donor observed for adverse reactions. Samples were collected before and 20 minutes after each donation for hematology, immunoglobulin G, ferritin, C-reactive protein, total protein, lactate dehydrogenase, bilirubin, haptoglobin, and activated partial thromboplastin time. RESULTS: Nine participants went through a total of 36 donation and reinfusion procedures. Four donors participated in five rounds, two in four rounds, two in three rounds, and one in two rounds. A significant drop was seen in hemoglobin (14.6 ± 0.9 to 13.9 ± 0.9) and ferritin (179 ± 70 to 149 ± 78) from before the first donation to after the last reinfusion (p < 0.05). Other parameters were unaffected. CONCLUSION: This small pilot study suggests that repeated donations and reinfusions may be both feasible and safe. Blood collected in this way should be labeled with the donor's full name and social security number (or similar) and the identity visually verified by the donor immediately before both donation and reinfusion. To further reduce risk, this form of donation should be restricted to scenarios where there is no other option for making blood available. LEVEL OF EVIDENCE: Therapeutic/Care management study, level V.

The Simons Genome Diversity Project: 300 genomes from 142 diverse populations.

Here we report the Simons Genome Diversity Project data set: high quality genomes from 300 individuals from 142 diverse populations. These genomes include at least 5.8 million base pairs that are not present in the human reference genome. Our analysis reveals key features of the landscape of human genome variation, including that the rate of accumulation of mutations has accelerated by about 5% in non-Africans compared to Africans since divergence. We show that the ancestors of some pairs of present-day human populations were substantially separated by 100,000 years ago, well before the archaeologically attested onset of behavioural modernity. We also demonstrate that indigenous Australians, New Guineans and Andamanese do not derive substantial ancestry from an early dispersal of modern humans; instead, their modern human ancestry is consistent with coming from the same source as that of other non-Africans.

Effects of the Sangvia blood collection system on patients undergoing elective hip surgery.

We have conducted a randomized controlled study where 164 patients were randomized to receive autologous salvaged blood collected by Sangvia™ Blood Salvage System or allogeneic red cell concentrates if transfusion was indicated by clinical judgement. The study was powered to detect if transfusion of autologous blood reduced the occurrence of postoperative infections. We found no statistical significant difference in postoperative infection rate between the groups, but this may be due to the fact that postoperative infections were diagnosed in only five patients. Increased C-reactive protein concentrations slightly above level of significance indicate that autologous blood transfusions stimulate the patient's immune system. However, there was no indication of increased transfusion reaction rate, including febrile reactions, in the autologous group. Transfusion of autologous blood did not reduce the use of allogeneic red cell concentrates. The mean use of allogeneic red cell concentrates was 0.93 units (both groups combined), indicating that the transfusion policy may have been too liberal. There was a highly significant inverse correlation between pre-operative haemoglobin concentration and transfusion of allogeneic blood. In a patient population with a low frequency of postoperative infection, a larger study is needed to clarify if autologous salvaged blood protects against postoperative infections.

Blood doping: the flip side of transfusion and transfusion alternatives.

Blood doping in sports has been a hot topic of present. Longitudinal follow up of hematological parameters in different endurance sports, during the 1990s and early 2000s, has provided considerable suspicions about extensive blood manipulation, with performance enhancing effects. Recent doping revelations in the media also prove that blood doping is not an anticipated myth but it is, in fact, real. Erythropoiesis stimulating agents and autologous blood transfusions are used in synergy with substantial effect on the maximum oxygen uptake and delivery to muscles. Whilst both methods of blood manipulation represent a potential health hazard, in the context of an elevated hematocrit, nevertheless despite a number of suspicious deaths amongst athletes, this has not yet been fully documented. A reliable test for detection of recombinant human erythropoietin was implemented in 2000, but this is probably circumvented by microdose regimens. The Athlete's Biological Passport represents the progeny of the idea of an indirect approach based on long term monitoring of hematological parameters, thus making it possible to detect autologous blood doping and erythropoietin use after the substance is excreted. Nevertheless with advances in anti-doping measures it is possible that the levels of excretion of substances used can be masked. Clearly more sensitive and specific diagnostic tools and research/development in these areas of major concern are warranted, which, combined with changes in the athlete's attitude, will help in reaching the vision of fair play.

[Dietary supplement of iron for iron deficiency]. / Kosttilskudd med jern ved jernmangel.

BACKGROUND: A low supply of iron in the diet may result in iron deficiency and mild iron-deficiency anaemia in healthy individuals. Women are more susceptible than men because of menstrual iron loss. We compared the effect of a low dose of iron, administered as a dietary supplement, with a high pharmacological dose of iron to otherwise healthy individuals with iron deficiency and mild iron deficiency anaemia. MATERIAL AND METHOD: In a randomised, double-blind trial conducted in 2000-2001, 73 women and three men with iron deficiency received either 27.6 mg of iron consisting of ferrous fumarate enriched with 13% haem iron, or 100 mg ferrosulphate daily for 12 weeks. Blood samples were analysed four times in the course of the treatment. RESULTS: The median ferritin value rose by 13 and 7 µg/l in the high-dose and low-dose group, respectively. The increase in ferritin was significantly higher in the high-dose than in the low dose group ( < 0.001). There was no statistically significant difference between the groups in the change in Hb, serum-iron or serum-iron binding capacity. The median haemoglobin value increased by 0.4 g/100 ml in both groups. Gastrointestinal side effects were experienced by 58% in the high-dose group and 35% in the low-dose group. Four subjects in the high-dose group and one in the low-dose group broke off the treatment because of side effects. INTERPRETATION: A supplement of low-dose iron is enough to increase iron stores in cases of nutritional iron deficiency in healthy individuals and to optimise haemoglobin. High-dose iron caused the largest increase in iron stores. Low-dose iron resulted in the least side effects.

Anemia treatment of lymphoproliferative malignancies with erypoiesis: an overview of state of the art.

Anemia is a common comorbidity of lymphoproliferative malignancies, especially in multiple myeloma. Blood transfusions and ESAs (erythropoiesis stimulating agents) are both possible treatment options, but the latter is often preferred because of the potential risks of unwanted side effects related to blood transfusions. Evidence is accumulating that the use of ESAs in above clinical conditions is safe and effective and not associated with an increase in mortality or serious adverse events. 69.1% of patients achieved a hemoglobin response defined as an increase in hemoglobin of>2g/dl while receiving ESAs and concomitant chemotherapy. If supplemented with iron the hemoglobin response rate can be increased and hence the total dosage and financial cost reduced. A hemoglobin response is often accompanied by an increase in quality of life. HYPO% (hypochromic erythrocytes<5%) is believed to be both a significant positive predictor for the Hb response and also an indicator for iron supplementation if⩾5%. Conventional biochemical markers like serum ferritin concentration and transferrin saturation are not reliable for this use. The effect of EPO stimulating agents as the predictor of the Hb response, quality of life, mortality and the potential adverse events are discussed.