Incidence and severity of postthrombotic syndrome after iliofemoral thrombosis - results of the Iliaca-PTS - Registry.

Background: Deep venous thrombosis (DVT) and in particular, iliofemoral thrombosis (IFT) can lead to recurrent thrombosis and postthrombotic syndrome (PTS). Data on the prevalence, predictors and outcome of IFT are scarce. Patients and methods: We retrospectively searched our database of outpatients who had presented with DVT and IFT including the iliac veins from 2014 until 2017. In addition, we performed a prospective registry in a subgroup of patients with IFT. These patients received duplex ultrasound, magnetic resonance venography and measurement of symptom-free walking distance using a standardized treadmill ergometry. The severity of PTS was analyzed using the Villalta-Scale (VS) and quality of life was assessed using the VEINES-QOL/Sym Questionnaire. Results: 847 patients were retrospectively identified with DVT and 19.7% (167/847) of these presented with IFT. 50.9% (85/167) of the IFT-patients agreed to participate in the prospective registry. The majority of these patients (76.5%: 65/85) presented with left-sided IFT. In 53.8% (35/65) May-Thurner syndrome was suspected. 27.1% (23/85) underwent invasive therapy. Moderate or severe PTS (VS ≥ 10) occurred in 10.6% (9/85). The severity of PTS is correlated with a reduced quality of life (ρ (CI 95%) = -0.63 (-0.76; -0.46); p < 0.01). None of the patients presented with a venous ulcer at any time. A high body mass index was a significant predictor (OR (CI 95%) = 1.18 (1.05; 1.33), p = 0.007) for the development of clinically relevant PTS (VS ≥ 10) and venous claudication. Conclusions: Every fifth patient with DVT presented with an IFT. The majority developed left sided IFT. Every 10th patient developed moderate or severe PTS (VS ≥ 10). A high body mass index was predictive for the development of PTS and venous claudication.

Pharmacokinetics of Direct Oral Anticoagulants in Emergency Situations: Results of the Prospective Observational RADOA-Registry.

BACKGROUND: Direct oral anticoagulants (DOACs) are increasingly used worldwide. Little is known so far about their pharmacokinetics in emergency situations. METHODS: A prospective, observational registry was performed to determine the clinical course in consecutive patients with major bleeding or urgent surgery treated with DOACs. In samples collected as part of routine care DOAC drug concentrations were measured using ultraperformance liquid chromatography-tandem mass spectrometry. Anticoagulant intensity at first presentation and drug half-life (t 1/2), tested in repeat samples, were evaluated. RESULTS: A total of 140 patients were prospectively included. Pharmacokinetic data were available in 94% (132/140) of patients. Note that 67% (89/132) experienced life-threatening bleeding and 33% (43/132) needed an urgent surgery. For pharmacokinetic analysis a total of 605 blood samples was available. Median concentration on admission was 205 ng/mL for rivaroxaban and 108 ng/mL for apixaban. All treatment groups showed a high variation of drug concentrations at baseline. In rivaroxaban-treated patients t ½ was 17.3 hours (95% confidence interval [CI]: 15.4-19.7) without significant difference in both groups (major bleeding: t ½ 16.7 hours, 95% CI: 14.7-19.3; urgent surgery: t ½ 19.7 hours, 95% CI: 15.2-27.9; p = 0.292). In apixaban-treated patients t ½ was 25.0 hours (95% CI: 22.9-27.6) with a longer t ½ after urgent surgery (t 1/2: 30.8 hours; 95% CI: 26.9-36.4) compared with severe bleeding (t 1/2: 20.8 hours; 95% CI: 18.8-23.2; p < 0.001). CONCLUSION: Emergency patients under DOAC treatment show a high variation of anticoagulant concentrations at baseline. Compared with rivaroxaban, apixaban showed a lower median concentration on admission and a longer t ½.

Pharmacokinetics of Phenprocoumon in Emergency Situations-Results of the Prospective Observational RADOA-Registry (Reversal Agent Use in Patients Treated with Direct Oral Anticoagulants or Vitamin K Antagonists Registry).

Background: Phenprocoumon has been used as an oral anticoagulant in patients with thromboembolic disease for more than 40 years. So far its pharmacokinetics have not been analyzed in emergency situations. Methods: Phenprocoumon-treated patients with major bleeding or urgent surgery were included in a prospective, observational registry. Phenprocoumon drug concentrations were analyzed in samples, collected as part of routine care using ultraperformance liquid chromatography tandem mass spectrometry. Moreover, anticoagulant intensity and drug half-life (t1/2) were calculated. Results: 115 patients were included. Phenprocoumon levels declined over time with a half-life of 5.27 and 5.29 days in patients with major bleedings (n = 82) and with urgent surgery (n = 33). Baseline phenprocoumon levels were 2.2 times higher in the bleeding group compared to the surgery group (1.92 vs. 0.87 ng/mL, p < 0.0001). International normalized ratio (INR) values decreased rapidly during the first 24 h. In 27.6% of patients a rebound of INR (recurrent increase > 1.5) was observed which was associated with significantly increased bleeding rates (22% vs. 4.2% in patients with or without INR rebound, p = 0.012). Conclusions: In emergency situations, the long half-life of phenprocoumon may cause INR rebound and associated recurrent bleedings. Optimal management may need to include repeated vitamin K supplementation over days.

Severe Hemorrhage Associated With Oral Anticoagulants.

BACKGROUND: Few data have been published to date on outcomes after the common clinical experience of severe hemorrhage in orally anticoagulated patients. METHODS: A prospective, multicenter observational study was carried out to investigate outcomes and management in a series of consecutive patients who sustained a severe hemorrhage under treatment with vitamin K antagonists (VKA) or direct oral anticoagulant drugs (DOAC). The primary endpoint was in-hospital death up to and including day 30 after hospital admission. The secondary endpoints were the duration of bleeding, in-hospital death due to hemorrhage (as defined by the study physician examining the patient's records), the use of antagonists, the extent of supportive measures used to stop the hemorrhage, and an assessment of causality. Consecutive patients were recruited until a predefined number of patients was reached in both groups. RESULTS: Among 193 patients with severe hemorrhage, 97 had been taking a VKA, and 96 had been taking a DOAC. 13.0 % (95% confidence interval [8.6; 18.5]; 25/193) of the overall group patients died in the first 30 days after hospital admission, including 17.5% ([10.6; 26.6]; 17/97) in the VKA group and 8.3% ([3.7; 15.8]; 8/96) in the DOAC group (p = 0.085). The median duration of bleeding was 19.8 hours in the VKA group and 27.8 hours in the DOAC group (p = 0.632). The in-hospital mortality due to hemorrhage was higher in the VKA group than in the DOAC group (15.5% [15/97] versus 4.2% [4/97]; p = 0.014). Only the use of prothrombin complex concentrates (PCCs) lowered the median duration of hemorrhage in the two patient groups. In 35% (68/193) of the patients, the hemorrhage was caused by an external influence, most commonly a fall. CONCLUSION: The in-hospital mortality was higher among patients treated with VKA than among patients treated with DOAC, although the difference failed to reach statistical significance.

Regulation of the heat stress response in Arabidopsis by MPK6-targeted phosphorylation of the heat stress factor HsfA2.

So far little is known on the functional role of phosphorylation in the heat stress response of plants. Here we present evidence that heat stress activates the Arabidopsis mitogen-activated protein kinase MPK6. In vitro and in vivo evidence is provided that MPK6 specifically targets the major heat stress transcription factor HsfA2. Activation of MPK6 results in complex formation with HsfA2. MPK6 phosphorylates HsfA2 on T249 and changes its intracellular localisation. Protein kinase and phosphatase inhibitor studies indicate that HsfA2 protein stability is regulated in a phosphorylation-dependent manner, but this mechanism is independent of MPK6. Overall, our data show that heat stress-induced targeting of HsfA2 by MPK6 participates in the complex regulatory mechanism how plants respond to heat stress.

The equilibrium between long and very long chain ceramides is important for the fate of the cell and can be influenced by co-expression of CerS.

Ceramides are synthesized by six different ceramide synthases (CerS1-6), which differ in their specificity to produce ceramides of distinct chain length. We investigated the impact of CerS-co-transfection on ceramide production and apoptosis and proliferation in HCT-116 cells. Over-expression of CerS4 and CerS6 enhanced the level of C(16:0)-Cer twofold, that of C(18:0)- and C(20:0)-Cer up to sevenfold, in comparison to vector control transfected cells, whereas over-expression of CerS2 had no effect on the level of very long chain ceramide C(24:0)- and C(24:1)-Cer. Instead over-expression of CerS2 together with CerS4 or CerS6 increased the activity of CerS2 against very-long-chain ceramides about twofold. In contrast, co-expression of CerS4 with CerS6 inhibited slightly the production of C20:0-ceramide in comparison to cells over-expressing CerS4 alone, whereas the activity of CerS6 seemed not to be affected by other CerS. Interestingly, down-regulation of ELOVL1 had a comprehensive effect on the synthesis of very long chain ceramides which possibly point to a requirement for ELOVL1 expression for full CerS2-activity. Co-expression of CerS2 with CerS4/CerS6 reversed the inhibitory effect of long chain ceramides on cell proliferation and the induction of apoptosis. Even though we observed a twofold increase in total ceramide levels after co-expression of CerS2 with CerS4/CerS6, we detected no effect on cell proliferation. These data indicate that an increase in ceramide production per se is not critical for cell survival, but the equilibrium between long and very long chain ceramides and possibly protein/protein interactions determine the fate of the cell.

Long chain ceramides and very long chain ceramides have opposite effects on human breast and colon cancer cell growth.

Ceramides are known to be key players in intracellular signaling and are involved in apoptosis, cell senescence, proliferation, cell growth and differentiation. They are synthesized by ceramide synthases (CerS). So far, six different mammalian CerS (CerS1-6) have been described. Recently, we demonstrated that human breast cancer tissue displays increased activity of CerS2, 4, and 6, together with enhanced generation of their products, ceramides C(16:0), C(24:0), and C(24:1). Moreover, these increases were significantly associated with tumor dignity. To clarify the impact of this observation, we manipulated cellular ceramide levels by overexpressing ceramide synthases 2, 4 or 6 in MCF-7 (breast cancer) and HCT-116 (colon cancer) cells, respectively. Overexpression of ceramide synthases 4 and 6 elevated generation of short chain ceramides C(16:0), C(18:0) and C(20:0), while overexpression of ceramide synthase 2 had no effect on ceramide production in vivo, presumably due to limited substrate availability, because external addition of very long chain acyl-CoAs resulted in a significant upregulation of very long chain ceramides. We also demonstrated that upregulation of CerS4 and 6 led to the inhibition of cell proliferation and induction of apoptosis, whereas upregulation of CerS2 increased cell proliferation. On the basis of our data, we propose that a disequilibrium between ceramides of various chain length is crucial for cancer progression, while normal cells require an equilibrium between very long and long chain ceramides for normal physiology.