<i>In Vitro</i>Whole Blood Clot Lysis for Fibrinolytic Activity Study Using D-Dimer and Confocal Microscopy

Elnager, Abuzar; Abdullah, Wan Zaidah; Hassan, Rosline; Idris, Zulkarnain Md; Arfah, Nadiah Wan; Sulaiman, Siti Amrah; Mustafa, Mohd Zulkifli

doi:10.1155/2014/814684

Cited by 23 publications

(35 citation statements)

References 20 publications

(38 reference statements)

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“…Similar methods using microscopy to quantify fibrin degradation have been previously described by other investigators 18–21 . Results obtained from analysis of fibrinolysis using microscopy correlate with fibrinolytic activity measured using quantification of D-dimer 20 . A device consisting of a single major and minor channel, which lies perpendicular to the main channel, was utilized for fibrinolysis assays.…”

Section: Methodsmentioning

confidence: 79%

Fibrin Network Changes in Neonates after Cardiopulmonary Bypass

et al. 2016

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Background Quantitative and qualitative differences in the hemostatic systems exist between neonates and adults, including the presence of “fetal” fibrinogen, a qualitatively dysfunctional form of fibrinogen that exists until 1 yr of age. The consequences of “fetal” fibrinogen on clot structure in neonates, particularly in the context of surgery-associated bleeding, have not been well characterized. Here, the authors examine the sequential changes in clotting components and resultant clot structure in a small sample of neonates undergoing cardiac surgery and cardiopulmonary bypass (CPB). Methods Blood samples were collected from neonates (n = 10) before surgery, immediately after CPB, and after the transfusion of cryoprecipitate (i.e., adult fibrinogen component). Clots were formed from patient samples or purified neonatal and adult fibrinogen. Clot structure was analyzed using confocal microscopy. Results Clots formed from plasma obtained after CPB and after transfusion were more porous than baseline clots. Analysis of clots formed from purified neonatal and adult fibrinogen demonstrated that at equivalent fibrinogen concentrations, neonatal clots lack three-dimensional structure, whereas adult clots were denser with significant three-dimensional structure. Clots formed from a combination of purified neonatal and adult fibrinogen were less homogenous than those formed from either purified adult or neonatal fibrinogen. Conclusions The results of this study confirm that significant differences exist in clot structure between neonates and adults and that neonatal and adult fibrinogen may not integrate well. These findings suggest that differential treatment strategies for neonates should be pursued to reduce the demonstrated morbidity of blood product transfusion.

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Section: Methodsmentioning

confidence: 79%

Fibrin Network Changes in Neonates after Cardiopulmonary Bypass

et al. 2016

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“…While clot weight was not altered, a significant change in D-dimer concentration was detected that suggested a positive effect on clot lysis activity. 31 D-dimer, one of the final products of complete fibrinolysis, is a specific fibrin degradation product created from two adjacent fibrin monomers that indicates cross-linked fibrin-specific clot degradation by plasmin. [32][33][34] Of the coagulation assays available for diagnosis and prognosis of thromboembolic events such as deep vein thrombosis (DVT), PE, or infarction, the D-dimer is the most widely used.…”

Section: Discussionmentioning

confidence: 99%

The Effect of High Storage Temperature on the Stability and Efficacy of Lyophilized Tenecteplase

Henkel

Vella

Fenning

2020

Prehosp. Disaster med.

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Introduction: Tenecteplase is a thrombolytic protein drug used by paramedics, emergency responders, and critical care medical personnel for the prehospital treatment of blood clotting diseases. Minimizing the time between symptom onset and the initiation of thrombolytic treatment is important for reducing mortality and improving patient outcomes. However, the structure of protein drug molecules makes them susceptible to physical and chemical degradation that could potentially result in considerable adverse effects. In locations that experience extreme temperatures, lyophilized tenecteplase transported in emergency service vehicles (ESVs) may be subjected to conditions that exceed the manufacturer’s recommendations, particularly when access to the ambulance station is limited. Study Objective: This study evaluated the impact of heat exposure (based on temperatures experienced in an emergency vehicle during summer in a regional Australian city) on the stability and efficacy of lyophilized tenecteplase. Methods: Vials containing 50mg lyophilized tenecteplase were stored at 4.0°C (39.2°F), 35.5°C (95.9°F), or 44.9°C (112.8°F) for a continuous period of eight hours prior to reconstitution. Stability and efficacy were determined through assessment of: optical clarity and pH; analyte concentration using UV spectrometry; percent protein monomer and single chain protein using size-exclusion chromatography; and in vitro bioactivity using whole blood clot weight and fibrin degradation product (D-dimer) development. Results: Heat treatment, particularly at 44.9°C, was found to have the greatest impact on tenecteplase solubility; the amount of protein monomer and single chain protein lost (suggesting structural vulnerability); and the capacity for clot lysis in the form of decreased D-dimer production. Meanwhile, storage at 4.0°C preserved tenecteplase stability and in vitro bioactivity. Conclusion: The findings indicate that, in its lyophilized form, even relatively short exposure to high temperature can negatively affect tenecteplase stability and pharmacological efficacy. It is therefore important that measures are implemented to ensure the storage temperature is kept below 30.0°C (86.0°F), as recommended by manufacturers, and that repeated refrigeration-heat cycling is avoided. This will ensure drug administration provides more replicable thrombolysis upon reaching critical care facilities.

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“…[13] This model is a reliable and sensitive technique. From the results it is evident that the drug has significant thrombolytic activity.…”

Section: Discussionmentioning

confidence: 99%