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Apixaban is a direct factor Xa inhibitor approved for the treatment and prevention of thromboembolic disease. There is a lack of data regarding its reversal in cases of acute bleeding or prior to emergency surgery that needs addressing.

Recombinant factor VIIa (rFVIIa) is approved for use in controlling bleeding episodes in people with hemophilia who have developed inhibitors to replacement therapy. Due to its short half‐life (t½), frequent injections are required, limiting its use as a prophylactic treatment. A novel, recombinant fusion protein linking coagulation factor VIIa with albumin (rVIIa‐FP) has been developed to extend the t½of rFVIIa.

Summary. Background:One limitation of the direct thrombin inhibitor dabigatran is the lack of specific antidotes that allow acute bleeding events to be managed or urgent interventional procedures performed. Prothrombin complex concentrates (PCCs) have served as a standard treatment for the reversal of coumarin anticoagulation.

Summary. Background:Prophylaxis of hemophilia B, at present, requires multiple infusions of human factor (F)IX concentrates per week. A FIX molecule with a prolonged half‐life has the potential to greatly improve the convenience of, and adherence to, prophylaxis.

This pre-clinical study was performed to investigate the ability of the haemostatic fleece TachoComb® to prevent adhesion formation following uterine surgery. Thirty rabbits were randomized to receive TachoComb® or no intervention following incision to the right uterine horn. After 14 days, the animals were killed and examined for the presence of adhesion. The lengths of any adhesions were measured and the severity was recorded as a score (0, no adhesion; 1, adhesion easy to lyse; 2, adhesion lysed with traction; 3, adhesion separated by sharp dissection). The incidence of adhesions was 100% in the control group compared with 33% in the TachoComb®-treated animals. The mean adhesion score was significantly lower (0.7 versus 2.2) and the mean adhesion length category was significantly shorter (0.4 versus 2.0) with TachoComb® than in the control group. This study indicates that TachoComb® is a well-tolerated and effective means of preventing adhesion following gynaecological surgery.

According to its immunopharmacological profile, 15-deoxyspergualin (15-DOS) has been investigated as to its disease-modifying activity on HgCl2-induced glomerulonephritis (GN) and on tubulointerstitial nephritis (TIN) in Brown-Norway rats. Both models are induced autoimmune disorders in which afflicted animals display high levels of serum autoantibodies directed against the glomerular or tubular basement membrane (GBM or TBM), respectively. The diseases are manifested by high serum creatinine and urea levels with severe proteinuria. In the model of HgCl2-GN, administration of 15-DOS clearly led to a reduction of proteinuria and decreased the amount of rat IgG attached to the GBM. Furthermore, a therapeutic effect could be demonstrated when 15-DOS was given after the appearance of clinical symptoms. Not only urine-protein values butalso anti-laminin antibodies returned to normal levels. Also in the experimental TIN-model, 15-DOS, either given during the induction phase, or even late in the onset of the disease, strongly prevented the proteinuria of this autoimmune disease and inhibited the formation of autoantibodies to TBN.

The effect of bestatin, a low-molecular-weight immunomodulating drug isolated from Streptomyces olivoreticuli, on Salmonella typhimurium infection was elaborated. Bestatin enhanced the delayed-type hypersensitivity reaction against S. typhimurium in a dose- and time-dependent manner. Parallel to the activation of delayed-type hypersensitivity reaction, bestatin reduced the amount of persistent bacteria in livers and spleens as well as the amount of necrotic foci found in these organs. This was shown when bestatin was given either prophylactically or therapeutically. The therapeutic effect of bestatin was even seen when the drug was given in the chronic phase of the infection, i.e., 6 days after inoculation of the animals with the infectious agent. No influence of bestatin, however, could be observed on the initial multiplication rate of S. typhimurium and concomitantly on the initial mortality rate of the infected mice. As bestatin has no direct antibiotic effect on S. typhimurium, it must be concluded that the therapeutic effects of the drug on chronic infection must be solely contributed to elevation of the host's own defense mechanisms.

To prevent r-hirudin induced excess bleeding an animal model was established in pigs for the investigation of an anti-bleeding strategy. We used the Simplate® device to monitor skin bleeding time (SBT) at the inner site of the ear. r-Hirudin infused in a dose of 0.3 mag per h induced a prominent increase of SBT. The aim of our studies was to reverse r-hirudin induced bleeding by enhancing platelet adhesion to the endothelium via the administration of von Willebrand Factor (vWF). Pigs were treated with vWF containing solutions (Haemate® and a vWF-concentrate) at 3h after the start of the r-hirudin infusion. Both compounds suppressed SBT 1h after administration and significantly prevented bleeding until the termination of the experiment. SBT values (given in times of baseline) in the placebo group were 3.32 ± 0.9, 1.51 ± 0.14 in the Haemate® and 1.85 ± 0.42 in the vWF concentrate group (P = 0.008 or 0.032, in a two-sided Kruskall-Wallis-test). Coagulation parameters (aPTT, PT) were unaltered by the treatment, as were the r-hirudin plasma levels suggesting that vWF is not an antidote in its strict sense. It is concluded that vWF reverses bleeding without altering the anticoagulant effect of r-hirudin. Addition of 20 mg/kg per h aspirin resulted in a further increase of SBT. Aspirin, moreover, suppressed platelet aggregation but did not alter platelet counts. In a further study, bleeding induced by r-hirudin and aspirin was antagonized by Haemate® (66 Ukg i.v. bolus + 187 Ukg per h for 2 h infusion) and a significant reduction of bleeding time occurred.

Due to its immunosuppressive mode of action we examined the therapeutic effects of 15-Deoxyspergualin (15-DOS) in the two models of acute and chronic relapsing experimental allergic encephalomyelitis (EAE) in Lewis rats. Treatment of myelin basic protein (MBP) immunized rats with 15-DOS was most effective in delaying and reducing the onset of clinical symptoms, and mortality was prevented in acute EAE. Similarly, in the chronic relapsing disease, inhibition of pathological signs and prevention of relapses were observed, even when 15-DOS treatment was started after the appearance of the first clinical symptoms. The drug was also effective in preventing the passive adoptive transfer of the disease to naive Lewis rats, and when encephalitogenic spleen cells from diseased animals were incubatedin vitro with 15-DOS their neuritogenicity was dose-dependent abrogated. All these results confirm that 15-DOS is a powerful immunosuppressant for the therapy of human multiple sclerosis (MS).

The effect of 15-Deoxyspergualin, a novel drug which has been described to have anti-tumour activity, on allogeneic graft survival (Dark Agouti ⇀ Lewis rats) after pancreatic islet transplantation was tested. A marked prolongation of graft survival could be shown using doses of 1.0, 2.5 and 5.0mg Deoxyspergualin/kg on day 0 until day +9 post transplantation. A maximum of 55.6 days (average) survival time was observed using 2.5mg/kg Deoxyspergualin compared to 5.2±0.6 days without immunosuppression. Using the chemiluminescence reaction of recipient monocytes after islet transplantation, a marked suppression of the monocyte system exceeding the treatment period could be observed. Since, in contrast to cyclosporin, B-cell toxicity could not be shown, the new drug seems to be a hopeful step towards successful allogeneic islet transplantation for treatment of diabetes.

As has been reported previously, models of chronic graft-versus-host (GvH) and systemic lupus erythematosus (SLE)-like diseases are characterized by high IgE and IgG1 immunoglobulin (Ig) levels in the serum. An IL-4 induced pathological expansion of Th2 helper cells has been described for both disease models. Due to the immunopharmacological profile of soluble recombinant interleukin-4 receptor (IL-4-R) to bind specifically the corresponding ligand IL-4 and thereby to modulate biological activity upon exogenous administration in various autoimmune disease models, we investigated the immunoregulatory activity of IL-4-R and anti-IL-4 monoclonal antibody (MAb) 11B11 on the development of SLE-like disease in MRL/lpr autoimmune mice and on chronic GvH reaction in BDF1 hybrid mice. Sensitized GvH-BDF1 hybrid mice and SLE in MRL/lpr autoimmune mice were treated in vivo with the IL-4 antagonists to alter the pattern of serum Ig production and to modulate the disease process. These animals were followed for proteinuria, autoantibody production (anti-dsDNA), serum IgE, IgG1 and IgG2a levels, and the survival was monitored. Treatment of these diseased animals resulted in an improved survival rate, lowered the percentage of animals with lymphadenopathy and hepatosplenomegaly, reduced the levels of autoantibodies and inhibited proteinuria of the developing glomerulonephritis in both mouse strains, even in the established diseases. In both models the increase in total IgE and IgG1 levels in serum was strongly inhibited by the IL-4 antagonists, even under therapeutic conditions. But there was no inhibitory activity observed on the IgG2a serum levels.