ObjectiveTo investigate the impact of clopidogrel resistance on the long-term prognosis in the elderly with acute coronary syndrome (ACS), as clopidogrel is widely used for secondary prevention in the patients with ACS, while studies on the relationship between clopidogrel resistance and long-term outcome in the elderly with ACS are limited. MethodsThree hundred elderly patients with ACS, aged from 70 to 95, with on average age of (81.3±6.4) years old, receiving clopidogrel (75 mg, once a day) over one month between January 2009 and December 2010 were followed up for major adverse cardiac events (MACE, including cardiac death, non-fatal re-myocardial infarction, angina, ischemia stroke/TIA, acute thrombosis and hemorrhage). Platelet aggregation was measured by light transmission aggregometry using adenosine diphosphate as a stimulus. According to the variation of platelet aggregation, the patients were divided into clopidogrel resistance group (<10%) and non-lopidogrel resistance group (≥10%). The median follow-up was 2 years. A Cox hazard proportional model was used to estimate time to outcome associated with clopidogrel resistance and MACE. ResultsThe incidence of clopidogrel resistance was 24.0% in our study population. Patients with diabetes, renal insufficiency, or a higher body mass index tended to have clopidogrel resistance. Compared with those patients without clopidogrel resistance, there was significantly increased MACE in patients with clopidogrel resistance (37.5%, 22.8%; P=0.032). Additionally, Cox hazard proportional model analysis demonstrated that clopidogrel resistance was an independently risk factor for MACE[HR=2.34, 95% CI (1.07, 4.57), P=0.016]. ConclusionDiabetes, renal insufficiency and high body max index are associated with clopidogrel resistance, which can predict the increased risk of MACE in elderly patients with ACS.
Recombinant protein SMBPRG4 containing two Somatomedin B domains and a small amount of glycosylation of repetitive sequences of proteoglycan 4 was cloned according to PGR4 gene polymorphism. Mature purification process was established and recombinant protein SMBPRG4, with high-level expression was purified. By using size-exclusion chromatogaraphy and dynamic light scattering, we found that the recombinant protein self-aggregate to dimeric form. Structure prediction and non-reducing electrophoresis revealed that SMBPRG4 was a non-covalently bonded dimer.
Platelets are non-nucleated blood effector cells, which plays an important role in coagulation, hemostasis, and thrombosis. However, platelets are extremely susceptible to activation by external stimuli, which in turn damages the platelet’s natural biological activity and affects its biological function. Platelet biological activity has become a hotspot in the field of vascular diseases. In this study, ultrasound parameters (ultrasound intensity and duration time) were used to intervene in the biological activity of platelets. The response of platelets to ultrasound energy was explored from the aspects of platelet morphology, aggregation ability and particle release (the expression of P-selectin and the number of particles). The results showed that the ultrasound intensity of 0.25 W/cm2 (1 MHz, 60 s) had no effect on the morphology, aggregation ability and particle release of platelets. When the ultrasonic intensity was increased to greater than 0.25 W/cm2, the generation of platelet pseudopods, morphological changes, increase of particle release, as well as effect on aggregation were observed. When the ultrasound duration time was 60 s (1 MHz, 0.25 W/cm2), it had no effect on the biological activity of platelets. However, when the ultrasound time was greater than 60 s, the morphology, aggregation ability and microparticles release would been induced with no effect on the secretion of CD62P and total protein components. Therefore, when the ultrasound parameters were 1 MHz and 0.25 W/cm2 with 60 s duration time, the ultrasound energy had no effect on the biological activity of platelets. The results in this study are of great significant for ultrasound energy intervention for the treatment of platelet-related diseases.