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A reversed-phase HPLC method to determine total plasma warfarin was developed and validated. Warfarin was extracted from human plasma using a two-step liquid-liquid extraction method. The residue was reconstituted with a phenylbutazone standard solution, which was used as the internal standard. The analytical column was a Purospher STAR RP-18e (4 x 4mm I.D., 5m particle size). The mobile phase consisted of acetonitrile: potassium dihydrogen orthophosphate buffer solution at pH 6.5 [30:70 (v/v)] with a flow rate of 1mL/min. Both warfarin and phenylbutazone were detected using a photodiode array detector. The lower limit of quantification was 100ng/mL, while the limit of detection was 20ng/mL. The linearity of the assay was good (r2=0.992) in the concentration range from 0.1 - 6.0µg/mL. The extraction recovery of warfarin was 93.53 ± 12.40%. Both the intraday and interday quality control assay for warfarin demonstrated good precision and accuracy, with all of the percentage coefficients of variation being less than 15%. Warfarin was stable in human plasma for up to three months of storage. The validated method was successfully applied to four human samples for a pharmacokinetics study.

Background Differential polarization of macrophage into M1 and M2 mediates atherosclerotic plaque clearance through efferocytosis. Higher expression of Mer proto-oncogene tyrosine kinase (MerTK) on M2 macrophage helps in maintaining macrophage efferocytic efficiency. In healthy individuals, macrophage polarization into M1 and M2 occurs in tissues in concomitance with the acquisition of functional phenotypes depending on specific microenvironment stimuli. However, whether the macrophage differential polarization and MerTK expression vary in coronary artery disease (CAD) patients remain unknown. Objective This study aimed to elucidate the polarization of M1 and M2 macrophage from CAD patients as well as to investigate the expression of MerTK in these macrophage phenotypes. Methods A total of 14 (n) CAD patients were recruited and subsequently grouped into “no apparent CAD”, “non-obstructive CAD” and “obstructive CAD” according to the degree of stenosis. Thirty ml of venous blood was withdrawn to obtain monocyte from the patients. The M1 macrophage was generated by treating the monocyte with GMCSF, LPS and IFN-γ while MCSF, IL-4 and IL-13 were employed to differentiate monocyte into M2 macrophage. After 7 days of polarization, analysis of cell surface differentiation markers (CD86+/CD80+ for M1 and CD206+/CD200R+ for M2) and measurement of MerTK expression were performed using flow cytometry. Results Both M1 and M2 macrophage expressed similar level of CD86, CD80 and CD206 in all groups of CAD patients. MerTK expression in no apparent CAD patients was significantly higher in M2 macrophage compared to M1 macrophage [12.58 ± 4.40 vs. 6.58 ± 1.37, p = 0.040]. Conclusion Differential polarization of macrophage into M1 and M2 was highly dynamic and can be varied due to the microenvironment stimuli in atherosclerotic plaque. Besides, higher expression of MerTK in patients with the least coronary obstructive suggest its vital involvement in efferocytosis.

Background: Treatment of the left ventricular thrombus (LVT) with Vitamin K antagonists (VKAs) such as warfarin may lead to longer hospitalization. Thus, the potential of non-VKA oral anticoagulants as alternative to warfarin need to be explored. This study aims to investigate the size reduction or resolution of LVT with apixaban compared to conventional warfarin. Materials and Methods: This is a pilot, prospective, single-center, randomized, single-blinded outcome study with patients diagnosed with LVT. Patients diagnosed with LVT by echocardiography were randomized into two treatment groups: apixaban or warfarin, with target international normalized ratio 2–3. Echocardiography was repeated at weeks 6 and 12 to assess the LVT size. The percentage of reduction or total resolution during the first 12 weeks was the primary endpoint. Repeated measure ANCOVA was used to evaluate the differences in left ventricular (LV) thrombus size between treatment groups. Results: Twenty-seven patients were recruited: 14 were treated with apixaban and 13 patients with warfarin. Thirteen patients completed treatment in the apixaban arm with one patient lost to follow-up, and one death observed. In the warfarin arm, nine patients completed the study follow-up, and four died during the follow-up. The mean (standard deviation [SD]) reduction in LV thrombus size in apixaban arm was 65.1% (SD 31.3) versus warfarin arm, 61.5% (SD 44.0) at the 12th week follow-up (P = 0.816). Safety outcomes were similar with both treatment arms. Conclusions: This pilot study suggests that apixaban may have similar effectiveness and safety to warfarin for LVT resolution.

A 47-year-old Malay man who presented with fever, poor oral intake and loss of weight for 1 month duration. Further work-up revealed evidence of disseminated Salmonella infection that was further complicated with pericardial and pleural empyema. Cultures from pericardial and pleural fluids grew Salmonella species with negative serial blood cultures. Contrast enhanced CT thorax showed pleural effusion with large pericardial effusion. The patient was treated with antibiotics and drainage of pericardial and pleural empyema was done and he was discharged well.

Introduction Leptospirosis is an important worldwide zoonotic disease caused by pathogenic leptospires. Human infection results when leptospires penetrate through abrasions in mucous membranes and skin, after which they enter the bloodstream and rapidly disseminate to various tissues. Leptospirosis presents with a wide range of clinical manifestations, ranging from a mild flu-like illness to very severe disease with hemorrhagic manifestations and multiorgan failure [1]. Unusual clinical manifestations may result from pulmonary, cardiovascular, neural, gastrointestinal, ocular, and other organ system involvement. Cardiac involvement, producing electrocardiographic (ECG) changes and myocarditis, is a known clinical finding [2].

The selection of stable endogenous control genes is critical for normalization of quantitative realtime PCR (qPCR) data. In this study, we aimed to identify a suitable set of control genes to be used as endogenous references for gene expression evaluation in human peripheral blood samples among coronary artery disease patients. The expression levels of 12 endogenous control genes procured from TATAA Biocenter (Goteborg, Sweden) were measured in five acute coronary syndrome patients and five chronic stable angina patients. Gene expression stability was analyzed using two different software applications i.e geNorm and NormFinder. Results suggested that beta-glucuronidase is the most stable endogenous control, followed by hypoxanthine-guanine phosphoribosyltransferase. The NormFinder analysis further confirmed that betaglucuronidase and hypoxanthine-guanine phosphoribosyltransferase were on the first rank order with the most stable expression among endogenous control genes analyzed and 60S acidic ribosomal protein P0. Besides, the expression levels of 18S rRNA were revealed to be highly variable between coronary heart disease patients. We thus recommend the use of beta-glucuronidase and hypoxanthine-guanine phosphoribosyltransferase as reference genes for accurate normalization of relative quantities of gene expression levels in coronary artery disease patients using qPCR. Also the use of 18S rRNA as a control gene should be avoided.

Objective: Assessment on platelet responsiveness to aspirin may be required in selected clinical conditions. So far, no standardization in laboratory practices for aspirin assessment using whole blood (WB) platelet aggregation based test. A study for method validation was performed to investigate the aspirin effects on platelets by comparing with a reference method. Methods: Forty patients taking aspirin were analyzed using WB by conventional platelet aggregometer (Chrono-Log Model 500CA/560CA). Among these patients, nine of them had their platelet rich plasma (PRP) tested by the same analyzer (reference method). Another WB specimens from 25 patients were tested on both ChronoLog and Multiplate® (Dynabyte GmbH), which is a newer generation platelet function analyzer. Results: There were good and moderate agreements between WB on the Chronolog analyzer vs the reference method and WB on Chronolog vs WB on Multiplate® analyzers respectively. Conclusions: There are agreements between PRP and WB aggregation (WBA) methods in detecting aspirin effects on platelets. It is recommended that the test validation for the assessment of platelet responsiveness to aspirin is interpreted and correlated with the reference method preferably PRP.

A b s t r ac t Background To assess potentially elevated cardiovascular risk related to new antihyperglycemic drugs in patients with type 2 diabetes, regulatory agencies require a comprehensive evaluation of the cardiovascular safety profile of new antidiabetic therapies. We assessed cardiovascular outcomes with alogliptin, a new inhibitor of dipeptidyl peptidase 4 (DPP-4), as compared with placebo in patients with type 2 diabetes who had had a recent acute coronary syndrome. Methods We randomly assigned patients with type 2 diabetes and either an acute myocardial infarction or unstable angina requiring hospitalization within the previous 15 to 90 days to receive alogliptin or placebo in addition to existing antihyperglycemic and cardiovascular drug therapy. The study design was a double-blind, noninferiority trial with a prespecified noninferiority margin of 1.3 for the hazard ratio for the primary end point of a composite of death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke. Results A total of 5380 patients underwent randomization and were followed for up to 40 months (median, 18 months). A primary end-point event occurred in 305 patients assigned to alogliptin (11.3%) and in 316 patients assigned to placebo (11.8%) (hazard ratio, 0.96; upper boundary of the one-sided repeated confidence interval, 1.16; P

To determine whether pulse wave velocity (PWV) as a measure of arterial stiffness is a marker of coronary artery diseases (CAD), the authors did a cross-sectional study in 92 patients undergoing coronary angiography for suspected CAD. Arterial stiffness was assessed through recording PWV from the left carotid-right femoral arteries using an automated machine. The mean PWV was higher in patients with CAD than in those without CAD (11.13+/-0.91 vs 8.14+/-1.25 m/sec; P

Background/aim: VKORC1 and CYP2C9 genetic polymorphisms may not accurately predict warfarin dose requirements. We evaluated an existing warfarin dosing algorithm developed for Malaysian patients that was based only on VKORC1 and CYP2C9 genes. Materials and methods: Five Malay patients receiving warfarin maintenance therapy were investigated for their CYP2C9*2, CYP2C9*3, and VKORC1-1639G>A genotypes and their vitamin K-dependent (VKD) clotting factor activities. The records of their daily warfarin doses and international normalized ratio (INR) 2 years prior to and after the measurement of VKD clotting factors activities were acquired. The mean warfarin doses were compared with predicted warfarin doses calculated from a genotypic-based dosing model developed for Asians. Results: A patient with the VKORC1-1639 GA genotype, who was supposed to have higher dose requirements, had a lower mean warfarin dose similar to those having the VKORC1-1639 AA genotype. This discrepancy may be due to the coadministration of celecoxib, which has the potential to decrease warfarin's metabolism. Not all patients' predicted mean warfarin doses based on a previously developed dosing algorithm for Asians were similar to the actual mean warfarin dose, with the worst predicted dose being 54.34% higher than the required warfarin dose. Conclusion: Multiple clinical factors can significantly change the actual required dose from the predicted dose from time to time. The additions of other dynamic variables, especially INR, VKD clotting factors, and concomitant drug use, into the dosing model are important in order to improve its accuracy.

Background Familial hypercholesterolemia is a genetic disorder mainly caused by defects in the low-density lipoprotein receptor gene. Few and limited analyses of familial hypercholesterolemia have been performed in Malaysia, and the underlying mutations therefore remain largely unknown. We studied a group of 154 unrelated FH patients from a northern area of Malaysia (Kelantan). The promoter region and exons 2-15 of the LDLR gene were screened by denaturing high-performance liquid chromatography to detect short deletions and nucleotide substitutions, and by multiplex ligation-dependent probe amplification to detect large rearrangements. Results A total of 29 gene sequence variants were reported in 117(76.0%) of the studied subjects. Eight different mutations (1 large rearrangement, 1 short deletion, 5 missense mutations, and 1 splice site mutation), and 21 variants. Eight gene sequence variants were reported for the first time and they were noticed in familial hypercholesterolemic patients, but not in controls (p.Asp100Asp, p.Asp139His, p.Arg471Gly, c.1705+117 T>G, c.1186+41T>A, 1705+112C>G, Dup exon 12 and p.Trp666ProfsX45). The incidence of the p.Arg471Gly variant was 11%. Patients with pathogenic mutations were younger, had significantly higher incidences of cardiovascular disease, xanthomas, and family history of hyperlipidemia, together with significantly higher total cholesterol and low density lipoprotein levels than patients with non-pathogenic variants. Conclusions Twenty-nine gene sequence variants occurred among FH patients; those with predicted pathogenicity were associated with higher incidences of cardiovascular diseases, tendon xanthomas, and higher total and low density lipoprotein levels compared to the rest. These results provide preliminary information on the mutation spectrum of this gene among patients with FH in Malaysia.

Various factors may contribute to a hypercoagulable state and acute vascular thrombosis. A prospective study was conducted involving 165 coronary heart disease (CHD) patients from the Cardiology Unit, Hospital Universiti Sains Malaysia. The purpose of this study was to investigate the relationship among factor VIII (FVIII), prothrombin time (PT), activated partial thromboplastin time (APTT), and activated protein C resistance (APC-R) state among CHD patients and to look for potential clinical applications from these laboratory findings. There were 110 cases diagnosed as acute coronary syndrome (ACS), whereas another 55 were stable coronary artery disease (SCAD) patients. PT, APTT, FVIII, and APC-R assays were performed on all subjects. There was a significant difference between the FVIII level and the APTT results (P value0.0001). A negative relationship was found between the FVIII level and the APTT from linear regression analysis (R(2) = 10%, P value0.0001). For each 1% increase in the FVIII level, the APTT was reduced by 0.013 s (95% confidence interval (CI) between -0.019 and -0.007). Interestingly, none of the SCAD patients had abnormally short APTT. Approximately 68.4% of cases with a positive APC-R assay were found to have a high FVIII level. In conclusion, the APTT test is a potential hemostatic marker for hypercoagulable state including in arterial thrombosis.

Background Biomarkers play a pivotal role in the diagnosis and management of patients with acute coronary syndrome. This study aimed to investigate the differences in level of several biomarkers, i.e. C-reactive protein, myeloperoxidase, soluble CD40 ligand and placental growth factor, between acute coronary syndrome and chronic stable angina patients. The relationship between these biomarkers in the coronary circulation and systemic circulation was also investigated. Methods A total of 79 patients were recruited in this study. The coronary blood was sampled from occluded coronary artery, while the peripheral venous blood was withdrawn from antecubital fossa. The serum concentrations of C-reactive protein, soluble CD40 ligand and placental growth factor and plasma concentration of myeloperoxidase were measured using ELISA method. Results The systemic level of the markers measured in the peripheral venous blood was significantly increased in acute coronary syndrome compared to chronic stable angina patients. The concentrations of the C-reactive protein, myeloperoxidase and soluble CD40 ligand taken from peripheral vein were closely similar to the concentration found in coronary blood of ACS patients. The level of placental growth factor was significantly higher in coronary circulation than its systemic level. Conclusion The concentration of these C-reactive protein, myeloperoxidase, soluble CD40 ligand and placental growth factor were significantly increased in acute coronary syndrome patients. The concentration of the markers measured in the systemic circulation directly reflected those in the local coronary circulation. Thus, these markers have potential to become a useful tool in predicting plaque vulnerability in the future.