Pre- and Postoperative Levels of Antithrombin III with Special Reference to Thromboembolism After Total Hip Replacement

A prospective study of antithrombin HI, determined by electroimmunochemical assay or an amidolytical method, was carried out with special reference to thromboembolism after total hip replacement. Two hundred and seven patients were randomly allocated to thromboembolic prophylaxis with dextran 70 or low dose heparin combined with dihydroergotamine. Deep vein thrombosis determined by phlebography of the operated leg or pulmonary embolism diagnosed with perfusion/ventilation scintigraphy developed in 51% of the total material and did not differ significantly between the two groups of prophylaxis or between patients with a preoperative At III below normal and those with a normal value. The correlation between the two assay methods for At HI was 0.61. An initial, postoperative decrease in At III was noted with a parallel fall in hematocrit and fibrinogen, later followed by an increase of the plasma proteins. It is concluded that the immediate postoperative decrease of At III is mostly due to hemodilution.

"Thinking about the future, what's gonna happen?"-How young people in Sweden who neither work nor study perceive life experiences in relation to health and well-being

Purpose: The aim of this study was to explore how young people in Sweden who neither work nor study perceive life experiences in relation to health and well-being.

Methods: A task-based interview technique was used and data was analysed with qualitative content analysis. Interviews were conducted with 16 participants aged 16-20 who were unemployed and not eligible for upper secondary school, or who had dropped out of school.

Results: Three themes emerged from the analysis illustrating how the young people perceive their life experiences in relation to health and well-being: Struggling with hardships in the absence of caring connections, Feeling good when closely connected to others, and Being forced to question what has been taken for granted. Each theme consists of 2-3 subthemes.

Conclusion: Based on the young people's narrated experiences health can be understood as: something that is created in relation to others and in relation to the social and cultural context; as something dynamic and changeable; as the ability to adapt and respond to challenges; and finally as something existing on a collective as well as an individual level. Implications for school, social services and health promotion initiatives are discussed, with an emphasis on working with young people.

Corrigendum: Effects on Subclinical Heart Failure in Type 2 Diabetic Subjects on Liraglutide Treatment vs. Glimepiride Both in Combination with Metformin: A Randomized Open Parallel-Group Study

[This corrects the article on p. 325 in vol. 8, PMID: 29184539.].

Titanium Is a Highly Thrombogenic Biomaterial: Possible Implications for Osteogenesis

Titanium has superior osteointegrating properties compared to other biomaterials. The mechanism for this is unknown. During the initial phase of bone implantation the biomaterial comes into direct contact with whole blood. In this study we use a newly developed in vitro chamber model to compare different commonly used biomaterials in contact with whole blood. These materials were selected with respect to their different osteointegrating properties in order to correlate these properties with the response to whole blood. In the presence of 3 IU/ml of heparin only titanium induced macroscopic clotting. This was reflected by the generation of thrombin-antithrombin which was much increased in blood in contact with titanium compared with steel and PVC. The coagulation activation caused by titanium was triggered by the intrinsic pathway because the generation of FXIIa-AT/C1 esterase inhibitor paralleled that of thrombin-antithrombin, and both thrombinantithrombin complex and FXIIa-AT/C1 esterase inhibitor generation were abrogated by corn trypsin inhibitor, which is a specific inhibitor of FXIIa. The binding of platelets was increased on the titanium surface compared to the other biomaterial surfaces and the state of platelet activation was much more pronounced as reflected by the levels of β-thromboglobulin and PDGF. This study indicates that titanium is unsuitable as a biomaterial in devices which are in direct contact with blood for a prolonged period. Furthermore, PDGF and other α-granule proteins e.g. TGF-β, are known to be potent promotors of osteogenesis which suggests that the pronounced thrombogenic properties of titanium might contribute to the good osteointegrating properties.

Phosphorylation of Coagulation Factor XI by a Casein Kinase Released by Activated Human Platelets Increases Its Susceptibility to Activation by Factor XIIa and Thrombin

Previous studies suggest that activated platelets facilitate the cleavage of factor XI by both factor XIIa and thrombin. Extracellular phosphorylation is a mechanism by which the function of plasma proteins can be regulated. Phosphorylation is mediated by a casein kinase which is released by activated platelets concomitant with large amounts of ATP and Ca2+. The purpose of this study was to investigate if factor XI is phosphorylated by a platelet casein kinase and whether phosphorylation may affect its activation properties. It was shown that supernatants from platelets which contain platelet casein kinase phosphorylated factor XI. By Western blot analysis it was shown that phosphorylation of factor XI substantially increased its susceptibility to cleavage by factor XIIa, and, to a lesser extent, by thrombin. The generated factor XIa was functionally active in that it cleaved the chromogenic substrate S2366, and in that factor XIa-antithrombin and thrombin-antithrombin complexes were generated when phosphorylated factor XI was added to blood plasma. The present study indicates that platelet-mediated phosphorylation of factor XI enhances the cleavage of factor XI into XIa and that the generated XIa possesses functional activity. Phosphorylation of factor XI might be an essential regulatory mechanism by which platelets mediate amplification of the coagulation cascade.

Dispersion of TiO2 nanoparticles improves burn wound healing and tissue regeneration through specific interaction with blood serum proteins

Burn wounds are one of the most important causes of mortality and especially morbidity around the world. Burn wound healing and skin tissue regeneration remain thus one of the most important challenges facing the mankind. In the present study we have addressed this challenge, applying a solution-stabilized dispersion TiO2 nanoparticles, hypothesizing that their ability to adsorb proteins will render them a strong capacity in inducing body fluid coagulation and create a protective hybrid material coating. The in vitro study of interaction between human blood and titania resulted at enhanced TiO2 concentrations in formation of rather dense gel composite materials and even at lower content revealed specific adsorption pattern initiating the cascade response, promising to facilitate the regrowth of the skin. The subsequent in vivo study of the healing of burn wounds in rats demonstrated formation of a strongly adherent crust of a nanocomposite, preventing infection and inflammation with quicker reduction of wound area compared to untreated control. The most important result in applying the TiO2 dispersion was the apparently improved regeneration of damaged tissues with appreciable decrease in scar formation and skin color anomalies.

Subsurface nitrate reduction under wetlands takes place in narrow superficial zones

This study aims to investigate the depth distribution of the Nitrate Reduction Potential (NRP) on a natural and a re-established wetland. The obtained NRP provides a valuable data of the driving factors affecting denitrification, the Dissimilatory Nitrate Reduction to Ammonium (DNRA) process and the performance of a re-established wetland. Intact soil cores were collected and divided in slices for the determination of Organic Matter (OM) through Loss of Ignition (LOI) as well as Dissolved Organic Carbon (DOC) and NRP spiking nitrate in batch tests. The Nitrate Reduction (NR) was fitted as a pseudo-first order rate constant (k) from where NRPs were obtained. NR took place in a narrow superficial zone showing a dropping natural logarithmic trend along depth. The main driving factor of denitrification, besides depth, was OM. Although, DOC and LOI could not express by themselves and absolute correlation with NRP, high amounts of DOC ensured enough quantity and quality of labile OM for NR. Besides, high concentration of LOI but a scarce abundance of DOC failed to drive NR. DNRA was only important in superficial samples with high contents of OM. Lastly, the high NRP of the re-established wetland confirms that wetlands can be restored satisfactorily.

Dangerous liaisons: complement, coagulation, and kallikrein/kinin cross-talk act as a linchpin in the events leading to thromboinflammation

Innate immunity is fundamental to our defense against microorganisms. Physiologically, the intravascular innate immune system acts as a purging system that identifies and removes foreign substances leading to thromboinflammatory responses, tissue remodeling, and repair. It is also a key contributor to the adverse effects observed in many diseases and therapies involving biomaterials and therapeutic cells/organs. The intravascular innate immune system consists of the cascade systems of the blood (the complement, contact, coagulation, and fibrinolytic systems), the blood cells (polymorphonuclear cells, monocytes, platelets), and the endothelial cell lining of the vessels. Activation of the intravascular innate immune system in vivo leads to thromboinflammation that can be activated by several of the system's pathways and that initiates repair after tissue damage and leads to adverse reactions in several disorders and treatment modalities. In this review, we summarize the current knowledge in the field and discuss the obstacles that exist in order to study the cross-talk between the components of the intravascular innate immune system. These include the use of purified in vitro systems, animal models and various types of anticoagulants. In order to avoid some of these obstacles we have developed specialized human whole blood models that allow investigation of the cross-talk between the various cascade systems and the blood cells. We in particular stress that platelets are involved in these interactions and that the lectin pathway of the complement system is an emerging part of innate immunity that interacts with the contact/coagulation system. Understanding the resulting thromboinflammation will allow development of new therapeutic modalities.

Adenovirus-Mediated Expression of the Anticoagulant Hirudin in Human Islets: A Tool to Make the Islets Biocompatible to Blood

Human islets induce an injurious clotting reaction at the time of transplantation. A potential strategy to counteract this reaction would be to allow the islets to express hirudin, a protein with direct anticoagulative activity. Human islets were transduced with an adenoviral vector encoding hirudin, an empty corresponding vector, or left untreated. Islet culture supernatants were analyzed for hirudin using an ELISA, a chromogenic substrate assay based on the thrombin-binding properties of hirudin and in a whole blood viscosimetry assay. Immunohistochemical evaluation and determination of hirudin content revealed an abundant expression of hirudin after transduction. Hirudin content in transduced islets was in the range of the insulin content levels. A delay in human whole blood clotting time could be observed after addition of supernatants taken from islet cultures expressing hirudin. However, transduced islets showed an impaired glucose-stimulated insulin release, but could readily be retrieved 6 weeks after transplantation to athymic mice. A marked expression and secretion of hirudin with functional capacity can be induced in human islets using an adenoviral vector. The impairment in glucose-stimulated insulin release in hirudin-secreting islets, compared to controls, indicates that the additional protein synthesis affects the functional capacity of the islets.

The link between morphology and complement in ocular disease

The complement system is a vital component of the immune-priveliged human eye that is always active at a low-grade level, preventing harmful intraocular injuries caused by accumulation of turnover products and controlling pathogens to preserve eye homeostasis and vision. The complement system is a double-edged sword that is essential for protection but may also become harmful and contribute to eye pathology. Here, we review the evidence for the involvement of complement system dysregulation in age-related macular degeneration, glaucoma, uveitis, and neuromyelitis optica, highlighting the relationship between morphogical changes and complement system protein expression and regulation in these diseases. The potential benefits of complement inhibition in age-related macular degeneration, glaucoma, uveitis, and neuromyelitis optica are abundant, as are those of further research to improve our understanding of complement-mediated injury in these diseases.

Complement C5a Functions as a Master Switch for the pH Balance in Neutrophils Exerting Fundamental Immunometabolic Effects

During sepsis, excessive activation of the complement system with generation of the anaphylatoxin C5a results in profound disturbances in crucial neutrophil functions. Moreover, because neutrophil activity is highly dependent on intracellular pH (pH_i), we propose a direct mechanistic link between complement activation and neutrophil pH_i In this article, we demonstrate that in vitro exposure of human neutrophils to C5a significantly increased pH_i by selective activation of the sodium/hydrogen exchanger. Upstream signaling of C5a-mediated intracellular alkalinization was dependent on C5aR1, intracellular calcium, protein kinase C, and calmodulin, and downstream signaling regulated the release of antibacterial myeloperoxidase and lactoferrin. Notably, the pH shift caused by C5a increased the glucose uptake and activated glycolytic flux in neutrophils, resulting in a significant release of lactate. Furthermore, C5a induced acidification of the extracellular micromilieu. In experimental murine sepsis, pH_i of blood neutrophils was analogously alkalinized, which could be normalized by C5aR1 inhibition. In the clinical setting of sepsis, neutrophils from patients with septic shock likewise exhibited a significantly increased pH_i These data suggest a novel role for the anaphylatoxin C5a as a master switch of the delicate pH_i balance in neutrophils resulting in profound inflammatory and metabolic changes that contribute to hyperlactatemia during sepsis.

Cardiovascular disease in haemodialysis: role of the intravascular innate immune system

Haemodialysis is a life-saving renal replacement modality for end-stage renal disease, but this therapy also represents a major challenge to the intravascular innate immune system, which is comprised of the complement, contact and coagulation systems. Chronic inflammation is strongly associated with cardiovascular disease (CVD) in patients on haemodialysis. Biomaterial-induced contact activation of proteins within the plasma cascade systems occurs during haemodialysis and initially leads to local generation of inflammatory mediators on the biomaterial surface. The inflammation is spread by soluble activation products and mediators that are generated during haemodialysis and transported in the extracorporeal circuit back into the patient together with activated leukocytes and platelets. The combined effect is activation of the endothelium of the cardiovascular system, which loses its anti-thrombotic and anti-inflammatory properties, leading to atherogenesis and arteriosclerosis. This concept suggests that maximum suppression of the intravascular innate immune system is needed to minimize the risk of CVD in patients on haemodialysis. A potential approach to achieve this goal is to treat patients with broad-specificity systemic drugs that target more than one of the intravascular cascade systems. Alternatively, 'stealth' biomaterials that cause minimal cascade system activation could be used in haemodialysis circuits.

Cell Adhesion Induced Using Surface Modification with Cell-Penetrating Peptide-Conjugated Poly(ethylene glycol)-Lipid: A New Cell Glue for 3D Cell-Based Structures

We synthesized a novel material, cell-penetrating peptide-conjugated poly(ethylene glycol)-lipid (CPP-PEG-lipid), that can induce the adhesion of floating cells. Firm cell adhesion with spreading could be induced by cell surface modification with the CPP-PEG-lipids. Cell adhesion was induced by CPPs but not by any other cationic short peptides we tested. Here, we demonstrated adherence using the floating cell line CCRF-CEM as well as primary human T cells, B cells, erythrocytes, and hepatocytes. As compared to cells grown in suspension, adherent cells were more rapidly induced to attach to substrates with the cell-surface modification. The critical factor for attachment was localization of CPPs at the cell membrane by PEG-lipids with PEG > 20 kDa. These cationic CPPs on PEG chains were able to interact with substrate surfaces such as polystyrene (PS) surfaces, glass surfaces, and PS microfibers that are negatively charged, inducing firm cell adhesion and cell spreading. Also, as opposed to normal cationic peptides that interact strongly with cell membranes, CPPs were less interactive with the cell surfaces because of their cell-penetrating property, making them more available for adhering cells to the substrate surface. No effects on cell viability or cell proliferation were observed after the induction of cell adhesion. With this technique, cells could be easily immobilized onto PS microfibers, an important step in fabricating 3D cell-based structures. Cells immobilized onto 3D PS microfibers were alive, and human hepatocytes showed normal production of urea and albumin on the microfibers. This method is novel in inducing firm cell adhesion via a one-step treatment.

Effects on Subclinical Heart Failure in Type 2 Diabetic Subjects on Liraglutide Treatment vs. Glimepiride Both in Combination with Metformin: A Randomized Open Parallel-Group Study

OBJECTIVE

We aimed to investigate the effect of liraglutide treatment on heart function in type 2 diabetes (T2D) patients with subclinical heart failure.

METHODS

Randomized open parallel-group trial. 62 T2D patients (45 male) with subclinical heart failure were randomized to either once daily liraglutide 1.8 mg, or glimepiride 4 mg, both add on to metformin 1 g twice a day. Mitral annular systolic (s') and early diastolic (e') velocities were measured at rest and during bicycle ergometer exercise, using tissue Doppler echocardiography. The primary endpoint was 18-week treatment changes in longitudinal functional reserve index (LFRI_{diastolic/systolic}).

RESULTS

Clinical characteristics between groups (liraglutide = 33 vs. glimepiride = 29) were well matched. At baseline left ventricle ejection fraction (53.7 vs. 53.6%) and global longitudinal strain (-15.3 vs. -16.5%) did not differ between groups. There were no significant differences in mitral flow velocities between groups. For the primary endpoint, there was no treatment change [95% confidence interval] for: LFRI_diastolic (-0.18 vs. -0.53 [-0.28, 2.59; p = 0.19]), or LFRI_systolic (-0.10 vs. -0.18 [-1.0, 1.7; p = 0.54]); for the secondary endpoints, there was a significant treatment change in respect of body weight (-3.7 vs. -0.2 kg [-5.5, -1.4; p = 0.001]), waist circumference (-3.1 vs. -0.8 cm [-4.2, -0.4; p = 0.019]), and heart rate (HR) (6.3 vs. -2.3 bpm [-3.0, 14.2; p = 0.003]), with no such treatment change in hemoglobin A1c levels (-11.0 vs. -9.2 mmol/mol [-7.0, 2.6; p = 0.37]), between groups.

CONCLUSION

18-week treatment of liraglutide compared with glimepiride did not improve LFRI_{diastolic/systolic}, but however increased HR. There was a significant treatment change in body weight reduction in favor for liraglutide treatment.

Method development and validation for the quantitation of the complement inhibitor Cp40 in human and cynomolgus monkey plasma by UPLC-ESI-MS

Cp40 is a 14-amino acid cyclic analog of the peptidic complement inhibitor compstatin that binds with sub-nanomolar affinity to complement component C3 and has already shown promise in various models of complement-related diseases. The preclinical and clinical development of this compound requires a robust, accurate, and sensitive method for quantitatively monitoring Cp40 in biological samples. In this study, we describe the development and validation of an ultra-high performance liquid chromatography electrospray mass spectrometry method for the quantitation of Cp40 in human and non-human primate (NHP) plasma. Isotope-labeled Cp40 was used as an internal standard, allowing for the accurate and absolute quantitation of Cp40. Labeled and non-labeled Cp40 were extracted from plasma using reversed phase-solid phase extraction, with recovery rates exceeding 80%, indicating minor matrix effects. The triply charged states of Cp40 and isotope-labeled Cp40 were detected at m/z 596.60 and 600.34, respectively, via a Q-TOF mass spectrometer and were used for quantitation. The method was linear in the range of 0.18-3.58μg/mL (r²≥0.99), with precision values below 0.71% in NHP and 0.77% in human plasma. The accuracy of the method ranged from -2.17% to 17.99% in NHP and from -0.26% to 15.75% in human plasma. The method was successfully applied to the quantitation of Cp40 in cynomolgus monkey plasma after an initial intravenous bolus of 2mg/kg followed by repetitive subcutaneous administration at 1mg/kg. The high reproducibility, accuracy, and robustness of the method developed here render it suitable for drug monitoring of Cp40, and potentially other compstatin analogs, in both human and NHP plasma samples during pharmacokinetic and pharmacodynamic studies.