Blood coagulation & fibrinolysis : an international journal in haemostasis and thrombosis
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Blood Coagul. Fibrinolysis · Dec 2011
Redox-based thrombelastographic method to detect carboxyhemefibrinogen-mediated hypercoagulability.
Cigarette smoking is associated with plasmatic hypercoagulability, and carbon monoxide has been demonstrated to enhance coagulation by binding to a fibrinogen-bound heme. Our objective was to design and test a redox-based method to detect carboxyhemefibrinogen. Normal, pooled, citrated plasma was exposed to 0-100 μmol/l carbon monoxide releasing molecule-2 (tricarbonyldichlororuthenium (II) dimer; CORM-2) before or after exposure to the organic reductant phenylhydroxylamine (PHA, 0-30 mmol/l), a compound that rapidly converts Fe(+2) to Fe(+3) in heme. ⋯ Conversion of fibrinogen-bound to the metheme state alone decreased G by 34.3-38.9% following exposure to 10-30 mmol/l PHA. Conversion of fibrinogen-bound heme Fe(+2) to Fe(+3) with PHA abrogated carbon monoxide-mediated increases in clot strength. Clinical trials are planned to investigate smoking individuals to mechanistically link carboxyhemefibrinogen formation with in-vitro hypercoagulability.
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Blood Coagul. Fibrinolysis · Dec 2011
Intrarater and interrater variability of point of care coagulation testing using the ROTEM delta.
This study aimed to assess intrarater and interrater variability of coagulation point-of-care testing (POCT) using ROTEM delta operated by trained staff. Arterial blood samples were taken from 43 anesthetized piglets aged up to 6 weeks and weighing 4-6 kg. The following clotting measurements were recorded: clotting time, clot formation time (CFT), maximum clot firmness (MCF) and alpha angle using ROTEM delta assays ExTEM, InTEM, FibTEM and ApTEM. ⋯ Variability was significantly lower in MCF and angle alpha compared with clotting time and CFT. No further variability was added by a second user. Based on these data, ROTEM delta appears to be suitable as POCT.
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Blood Coagul. Fibrinolysis · Dec 2011
Multicenter StudyObservational study of fibrinogen concentrate in massive hemorrhage: evaluation of a multicenter register.
In acute hemorrhage, a critical decrease in fibrinogen often induces acquired coagulopathy. Fibrinogen concentrate has been used to supplement fibrinogen during massive hemorrhage. However, there are limited data on the utilization of fibrinogen concentrate in this setting. ⋯ Clinical application of fibrinogen concentrate in bleeding patients is included within a multimodal therapeutic concept. High levels of fibrinogen are necessary in order to reach therapeutic goals. In bleeding patients, higher plasma fibrinogen might be associated with higher rates of survival.
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Blood Coagul. Fibrinolysis · Dec 2011
Egyptian experience of reliability of 4T's score in diagnosis of heparin induced thrombocytopenia syndrome.
To evaluate the utility of the 4Ts clinical scoring system as a pretest probability method for detection of heparin-induced thrombocytopenia (HIT). Medical and surgical inpatients and outpatients at Kasr El Eini hospital. This single-centre series of 50 HIT testing referrals assessed combination of clinical score (thrombocytopenia, timing, thrombosis, other causes of thrombocytopenia not evident; 4T's), Heparin platelet factor 4 (H-PF4) rapid particle gel immunoassay (PaGIA) and 14C serotonin release assay (SRA) to develop a practical and well tolerated diagnostic strategy for HIT. ⋯ The negative predictive value of a low 4T's score was 100%, effectively ruling out HIT. A low 4Ts score supports low probability of HIT based on the results of the PaGIA and SRA. Overall, the interrater reliability of the scoring system was fair.
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Blood Coagul. Fibrinolysis · Dec 2011
Carbon monoxide and nitric oxide modulate α₂-antiplasmin and plasmin activity: role of heme.
Cigarette smoke and carbon monoxide (CO) released from tricarbonyldichlororuthenium (II) dimer (CORM-2) attenuate fibrinolysis. The purpose of the present study was to determine whether CO diminished fibrinolysis by enhancement of α₂-antiplasmin via a putative heme group. Plasma, isolated α₂-antiplasmin and isolated plasmin were exposed to CO released from CORM-2 and nitric oxide (NO) via a NO donor to induce carboxyheme and metheme states, respectively. ⋯ CO elicits hypofibrinolysis by enhancing α₂-antiplasmin activity and decreasing plasmin activity. On the basis of the responses to NO and LC-MS/MS data, it is highly likely that both enzymes are modulated by attached heme groups. Efforts to develop methods to detect CO-mediated hypercoagulability are ongoing, with the goal of identifying populations at risk of thrombotic morbidity secondary to cigarette smoking.