Platelet-related cytokines among normal body mass index, overweight, and obese Malaysians.

BACKGROUND AND OBJECTIVES: Recent studies have reported that obesity is associated with platelet activation and systemic inflammation. Malaysia has the highest prevalence of obesity, hence, this research is performed to evaluate the development of low-grade inflammation and platelet activation, measured using soluble CD40 ligand (sCD40L) and soluble P-selectin (sP-sel), and to determine their association with obesity. In addition, we assessed the mean platelet volume (MPV) and platelet count (PLT), which are novel parameters consistently associated with obesity. METHODS AND STUDY DESIGN: A cross-sectional study was conducted on 112 healthy men and women from 3 main ethnic group (Malay, Chinese, and Indian) who were aged 18-60 years. The participants were categorized into normal body mass index (BMI), overweight and obese groups according to WHO criteria for BMI in Asian populations (18.5 kg/m2

A transmission electron microscopy study of anticoagulant-induced platelet vesiculation.

HIGHLIGHTS: EDTA induces platelet microparticles (PMPs) vesiculation.Sodium citrated tubes are better than EDTA tubes in PMPs analysis.Sodium citrate has a minor impact on platelet structure. ABSTRACT: Platelet microparticles (PMPs) are small membrane fragments released from activated platelets in response to various stimuli. PMPs serve as biomarkers for several diseases and conditions and are useful tools for prognostic, diagnostic, and therapeutic purposes. The objective of our study was to compare the direct effects of ethylenediaminetetraacetic acid (EDTA) and sodium citrate anticoagulants on platelet structure and PMP vesiculation using transmission electron microscopy to visualize the morphologic changes in platelets. Micrographs revealed that platelets in the EDTA-anticoagulated tube manifested with significant morphologic changes and induced PMP vesiculation. On the other hand, the sodium citrate-anticoagulated tube showed a normal platelet structure and minor modifications in some cases, with poor indication of PMP vesiculation. In conclusion, EDTA induced platelet activation and PMP vesiculation and represents a major source of artifacts during the pre-analysis steps of PMP vesiculation.

Attenuation of Thrombosis by Crude Rice (Oryza sativa) Bran Policosanol Extract: Ex Vivo Platelet Aggregation and Serum Levels of Arachidonic Acid Metabolites.

Background. Vascular occlusion or thrombosis was often attributed to uncontrolled platelet activation. Influence of sugarcane policosanol extract on platelet was reported but little was known of rice bran policosanol, particularly its mechanisms of actions on platelet activities. Objective. Antiplatelet mechanisms of rice bran policosanol extract (RBE) were studied using hyperlipidemic Sprague Dawley rats. Ex vivo platelet aggregation, platelet count (PC), bleeding time (BT), and coagulation time were assayed. Serum eicosanoids and other aggregation-related metabolites levels were quantified. Design. Rats were divided into 6 groups for comparisons (vehicle control Tween 20/H2O, high dose policosanol 500 mg/kg, middle dose policosanol 250 mg/kg, low dose policosanol 100 mg/kg, and positive control aspirin 30 mg/kg). Results. Low dose 100 mg/kg of RBE inhibited aggregation by 42.32 ± 4.31% and this was comparable with the effect of 30 mg/kg aspirin, 43.91 ± 5.27%. Results showed that there were no significant differences in PC, BT, and coagulation time among various groups after RBE treatment. Serum thromboxane A2 was attenuated while prostacyclin level increased upon RBE treatment. Conclusions. RBE reduced ex vivo ADP-induced platelet aggregation without giving adverse effects. No changes in full blood count suggested that rice bran policosanol did not disturb biological blood cell production and destruction yet it reduced aggregation through different mechanisms.

Bioassay-guided fractionation of Melastoma malabathricum Linn. leaf solid phase extraction fraction and its anticoagulant activity.

The aims of this study were to examine the bioactive component(s) responsible for the anticoagulant activity of M. malabathricum Linn. leaf hot water crude extract via bioassay-guided fractionation and to evaluate the effect of bioactive component(s) on the intrinsic blood coagulation pathway. The active anticoagulant fraction of F3 was subjected to a series of chromatographic separation and spectroscopic analyses. Furthermore, the effect of the bioactive component(s) on the intrinsic blood coagulation pathway was studied through immediate and time incubation mixing studies. Through Activated Partial Thromboplastin Time (APTT) assay-guided fractionation, Subfraction B was considered the most potent anticoagulant fraction. Characterisation of Subfraction B indicated that anticoagulant activity could partly be due to the presence of cinnamic acid and a cinnamic acid derivative. APTT assays for both the immediate and time incubation mixing were corrected back into normal clotting time range (35.4-56.3 s). In conclusion, cinnamic acid and cinnamic acid derivative from Subfraction B were the first such compounds to be discovered from M. malabathricum Linn. leaf hot water crude extract that possess anticoagulant activity. This active anticoagulant Subfraction B prolonged blood clotting time by causing factor(s) deficiency in the intrinsic blood coagulation pathway.

Gender effect on in vitro lymphocyte subset levels of healthy individuals.

Differences in gender immune response have resulted in differences in immune protection and susceptibility to inflammatory diseases. Cultured peripheral blood mononuclear cells (PBMC) are widely used in immunomodulation studies, yet the influence of gender is usually not considered. We examined the effect of in vitro culture and phytohaemagglutinin (PHA) stimulation on PBMC lymphocyte subsets using flowcytometry. Full blood counts of whole blood showed higher levels of lymphocyte in male subjects. Lymphocyte subsets enumeration revealed higher NK cell counts in males and higher B cells in females. Cultured PBMC resulted in significant increases in B and total T cell percentages among females and NK cells among males. PHA stimulated significantly increased percentages of NK and total T cells in males and total activated T cells (CD69+) in females. Our results showed significant gender differences in lymphocyte subsets in cultured conditions. This may affect experimental outcome.