Prothrombotic activity of cytokine-activated endothelial cells and shear-activated platelets in the setting of ventricular assist device support

BACKGROUND

We systematically analyzed the synergistic effect of: (i) cytokine-mediated inflammatory activation of endothelial cells (ECs) with and (ii) shear-mediated platelet activation (SMPA) as a potential contributory mechanism to intraventricular thrombus formation in the setting of left ventricular assist device (LVAD) support.

METHODS

Intact and shear-activated human platelets were exposed to non-activated and cytokine-activated ECs. To modulate the level of LVAD-related shear activation, platelets were exposed to shear stress patterns of varying magnitude (30, 50, and 70 dynes/cm², 10 minutes) via a hemodynamic shearing device. ECs were activated via exposure to inflammatory tumor necrosis factor-α (TNF-α 10 and 100 ng/ml, 24 hours), consistent with inflammatory activation recorded in patients on LVAD circulatory support.

RESULTS

Adhesivity of shear-activated platelets to ECs was significantly higher than that of intact/unactivated platelets, regardless of the initial activation level (70 dynes/cm² shear-activated platelets vs intact platelets: +80%, p < 0.001). Importantly, inflammatory activation of ECs amplified platelet prothrombinase activity progressively with increasing shear stress magnitude and TNF-α concentration: thrombin generation of 70 dynes/cm² shear-activated platelets was 2.6-fold higher after exposure and adhesion to 100 ng/ml TNF-α‒activated ECs (p < 0.0001).

CONCLUSIONS

We demonstrated synergistic effect of SMPA and cytokine-mediated EC inflammatory activation to enhance EC‒platelet adhesion and platelet prothrombotic function. These mechanisms may contribute to intraventricular thrombosis in the setting of mechanical circulatory support.

Evaluation of use of antibiotics without prescription among young adults in Albania case study: Tirana and Fier District

BACKGROUND

Self-medication is defined as the utilization of drugs to treat self-diagnosed disorders or symptoms, or the irregular or continuous use of a prescribed drug for chronic or repeated diseases or symptoms. The main problem with self-medication with antimicrobials is the emergence of pathogenic resistance. Antimicrobial resistance is an existing problem world-wide, mainly in developing countries. The aims and objectives of the study presented in this article are to evaluate the prevalence of purchase of antibiotics without prescription and appropriateness of use among adults and to determine the impact of the education level on the sensibility level over the use of antibiotics.

METHODS

This was a questionnaire based study of 3 month duration. The study includes data from 350 young adults (182 men/172 women, mean age ± SD: 34.72 ± 13.7 years), who visited ten different pharmacies located in the city of Tirana and the "Olympus" Private Medical Clinic in Fier between December 2012 and March 2013. Also a part of questionnaires was distributed by e-mail.

RESULTS

The results of this study showed that out of 350 young adults, 273 (78.14%) of them used antibiotics as self medication. The most common reasons for self administration of antibiotics were fever 171 (29.23%), sore throat 170 (29.06%) and cough 83 (14.19%). In this study we observed that the most common source of information regarding self-medication is the pharmacy (community pharmacists) 166 (36.40%) and most common antibiotic used as self-medication is amoxicillin 70 (19.39%). Authors also determined the impact of education level over the use of antibiotics. The results showed that adults with low and medium education level (7.986% and 43.056% respectively) were most likely to use antibiotics as self-medication.

CONCLUSIONS

The findings from this study highlight the striking prevalence of self-medication among young adults in Albania and the lack of awareness about the risks associating their use. We recommend that a holistic approach must be taken to prevent this problem from escalating which would involve awareness and education regarding the implications of self medication, strategies to prevent the supply of medicines without prescription by pharmacies and strict rules regarding pharmaceutical advertising.Hippokratia 2014; 18 (3): 217-220.