[Prevalence status and influencing factors of visual impairment in the elderly people in rural areas of Yugan County, Jiangxi Province].

Objective: To assess the prevalence of visual impairment and the influencing factors among rural residents aged 60 years and above in Yugan county, Jiangxi province. Researchers analyzed influencing factors and provided scientific rationale for blindness prevention and control. Methods: Stratified cluster random sampling was used in randomly selecting 3 789 rural residents aged ≥ 60 in Yugan county. Eligible residents were invited to receive ophthalmic examinations and epidemiological investigations. Multivariate logistic regression was performed to analyze any influencing factors. Results: Three thousand seven hundred and eighty-nine rural residents completed the ophthalmic examination and investigation. Based on presenting visual acuity, the prevalence of visual impairment was 24.1%(915), of which blindness and moderate and severe was 2.9%(108) and 21.3%(807). The top five causes ranked are (1) cataract (283, 30.9%), (2) Refractive error (81, 8.9%), (3) macular degeneration (29, 3.2%), (4) Corneal opacity (14, 1.5%). Multivariate logistic regression showed that age, gender, education, occupation, marital status, ophthalmic anamnesis, smoking situation, and daily fruit intake were the main factors that were the influencing factors of visual impairment. Conclusions: The prevalence of visual impairment in the elderly population in rural areas of Yugan County is quite high. Keep a healthy diet, timely correction of eye disease, could reduce the risk of visual impairment. (Chin J Ophthalmol, 2018, 54:605-610).

The role of chronic viral hepatitis on tuberculosis treatment interruption.

BACKGROUND: Tuberculosis (TB) drug-induced liver injury (TB-DILI) usually occurs within 8 weeks of anti-tuberculosis drug initiation. In Singapore, we suspected that the onset of TB drug-induced transaminitis may be confounded with hepatitis C virus (HCV) and hepatitis B (HBV) virus co-infection. OBJECTIVE: To determine the impact of HCV/HBV co-infection on the course of treatment in patients with TB treatment interrupted due to transaminitis. DESIGN: TB patients with treatment interruption during 2013-2014 were identified through the Singapore national TB registry. Case notes of those with transaminitis were perused. RESULTS: Of 3860 TB patients notified, 140 had suspected TB-DILI. Of these, respectively 20/140 (14.3%) and 16/140 (11.4%) were HCV- or HBV-positive. The median time to treatment interruption/transaminitis was 5 weeks vs. 9.9 weeks and 9.6 weeks for transaminitis patients without chronic liver disease and with HCV/HBV co-infection (P < 0.01). Multivariate logistic regression analysis revealed that having HCV/HBV co-infection was associated with treatment interruption occurring beyond 8 weeks (adjusted OR [aOR] 4.06, 95%CI 1.28-12.85); HCV transaminitis patients were more likely to take 10 months to complete anti-tuberculosis treatment (aOR 5.11, 95%CI 1.21-21.67) than those without chronic liver disease. CONCLUSION: TB treatment interruption due to transaminitis in HCV/HBV co-infected patients occurred later than in those without liver disease. Most had completed 2 months of pyrazinamide-containing intensive phase treatment before the onset of transaminitis.

A 15-year single centre retrospective study of antiphospholipid syndrome patients from Northern Malaysia.

BACKGROUND: Antiphospholipid syndrome (APS) is an autoimmune disorder characterised by thrombosis and/or pregnancy morbidity in the presence of antiphospholipid antibodies (aPLs) based on the Sydney criteria. We aimed to explore the clinico-laboratory features and treatment strategies of APS patients retrospectively. METHODOLOGY: The medical records of APS patients registered under Hospital Universiti Sains Malaysia (Kelantan state) between 2000 and 2015 were reviewed. RESULTS: A total of 17 APS subjects (age 40.7 ± 12.8 years) including 11 primary (64.7%) and six secondary APS (35.3%) patients were identified. The follow-up period was 9.5 ± 6.7 years with male:female ratio of 1.0:4.7. Pregnancy morbidity was the most common clinical manifestation (11/14; 78.6%) followed by recurrent venous thrombosis (10/17; 58.8%). For other clinical features, menorrhagia was the most frequently observed manifestation (4/14; 28.6%) followed by aPLs-associated thrombocytopenia (4/17; 23.5%) and ovarian cyst (3/14; 21.4%). LA and aCL were positive in 94.1% (16/17) and 81.8% (9/11) of the patients, respectively. APTT value (76.7 ± 17.0 sec) was significantly high (p < 0.05). Low intensity warfarin alone was successful to maintain target INR (2.0 - 3.0) and prevent recurrence of thrombosis. CONCLUSION: The tendency of pregnancy morbidity in this cohort of Malaysian Kelantanese APS patients was high compared to other previously reported APS cohorts. Low intensity warfarin was successful in preventing recurrence of thrombosis, however, APS women receiving long-term anticoagulants should be monitored for possible occurrence of menorrhagia and ovarian cysts.

Correlation of Serum Estradiol and Duration of Anastrazole Therapy with Treatment Related Adverse Effects Among Postmenopausal Breast Cancer Women: A Cross-sectional Study.

Although anastrozole (Anas) plays a key role in the management of endocrine sensitive post-menopausal (PM) breast cancer (BC), there is much variability in its efficacy and tolerability. Anas-associated musculoskeletal symptoms (MS) and other adverse reactions, such as hot flashes (HF) and vaginal dryness/dyspareunia (VDD), are common and can affect the quality of life of BC patients, even sometimes leading to treatment withdrawal. The aim of this study was to determine the clinical and demographic factors associated with these adverse events. This is a cross-sectional study in estrogen receptor (ER) positive PM women (n = 92) with stages I to III BC receiving Anas. Multivariate analyses were performed to investigate the factors associated with Anas-induced adverse effects such as MS, HF and VDD. A serum estradiol concentration was undetectable (< 36.7 pmol/L) in 68.1% of patients but was detectable within a normal range (>36.7-88.1 pmol/L) in the other 31.9% of patients, and this group was found to have a lower odds of having at least one adverse effect (AE) compared to those with undetectable levels [adjusted odds ratio (AOR) 0.12, 95% confidence interval (CI) 0.02 to 0.64, p = 0.013]. Women with grades II and III tumors and a family history of BC had a higher odds of AE (grade II: AOR 12.22, CI 1.48 to 100.80, p = 0.020; grade III: AOR 12.95, CI 1.25 to 134.33, p = 0.032) and VDD (AOR 5.99, CI 1.30 to 27.52, p = 0.021), respectively. Patients who received Anas treatment for more than one year had a higher odds of VDD (one to three years: AOR 34.57, CI 3.86, 309.50, p = 0.002; more than 3 years: AOR 27.90, CI 2.21 to 351.84, p = 0.010). Advanced age also lowered the odds of HF (AOR 0.90, CI 0.83 to 1.00, p = 0.049). In conclusion, patients' hormonal environments and durations of Anas treatment may play a role in developing Anas-induced adverse effects.

Anthropometric and Reproductive Factors among Newly- Diagnosed Breast Cancer Patients and Healthy Women: A Case-Control Study.

The objective of this case-control study was to determine anthropometric and reproductive factors associated with the development of breast cancer among women. Fifty-six newly diagnosed breast cancer patients were recruited from the Oncology Clinic, Universiti Sains Malaysia (USM), and 56 healthy female hospital employees were recruited as controls. Socio-demographic and reproductive data were obtained using a standard questionnaire. Anthropometric factors (body weight, height, body fat percentage, visceral fat and waist and hip circumference) were assessed. A high waist circumference (adjusted OR= 1.04, [95% CI: 1.00, 1.09]) and being more than 30 years of age at rst full-term pregnancy (adjusted OR=3.77, [95% CI: 1.10, 12.90]) were predictors of breast cancer development. The results of this study indicate that weight and reproductive health management should be emphasized for breast cancer prevention in Malaysia.

Phytochemical profiles and inhibitory effects of Tiger Milk mushroom (Lignosus rhinocerus) extract on ovalbumin-induced airway inflammation in a rodent model of asthma.

BACKGROUND: Lignosus rhinocerus (L. rhinocerus), which is known locally as Tiger Milk mushroom, is traditionally used in the treatment of asthma by indigenous communities in Malaysia. However, to date, its efficacy on asthma has not been confirmed by scientific studies and there is also sparse information available on its active constituents. In this study, the volatile constituent of L. rhinocerus hot water extract was investigated using gas chromatography mass spectrometry (GC-MS). The potential effects of L. rhinocerus extract for anti-asthmatic activity was further investigated on ovalbumin (OVA)-sensitized asthmatic Sprague Dawley rats. METHODS: Sequential extraction using five solvents (petroleum ether, diethyl ether, hexane, ethyl acetate and methanol) was conducted prior to GC-MS analysis. Male Sprague Dawley rats were divided into the following four groups of five animals each: 1) normal rats, 2) sensitization plus OVA-challenged rats 3) sensitization plus OVA-challenged with L. rhinocerus treatment and 4) sensitization plus OVA-challenged with dexamethasone treatment. The levels of immunoglobulin E (IgE) in the serum and T-helper 2 cytokines, including interleukin (IL)-4, IL-5 and IL-13, in bronchoalveolar lavage fluid (BALF), as well as eosinophil infiltration in the lungs, were investigated. RESULTS: GC-MS analysis revealed the presence of five main groups (alkane, fatty acids, benzene, phenol and dicarboxylic acid) with a total of 18 constituents. Linoleic acid (21.35 %), octadecane (11.82 %) and 2,3-dihydroxypropyl elaidate (10.47 %) were present in high amounts. The extract significantly ameliorated the increase in total IgE in serum and IL-4, IL-5 and IL-13 levels in BALF and also effectively suppressed eosinophils numbers in BALF while attenuating eosinophil infiltrations in the lungs. CONCLUSION: L. rhinocerus hot water extract has the potential to be used as an alternative for the treatment of acute asthma.

A model of chlorpyrifos distribution and its biochemical effects on the liver and kidneys of rats.

This study investigated the main target sites of chlorpyrifos (CPF), its effect on biochemical indices, and the pathological changes observed in rat liver and kidney function using gas chromatography/mass spectrometry. Adult female Wistar rats (n = 12) were randomly assigned into two groups (one control and one test group; n = 6 each). The test group received CPF via oral gavage for 21 days at 5 mg/kg daily. The distribution of CPF was determined in various organs (liver, brain, heart, lung, kidney, ovary, adipose tissue, and skeletal muscle), urine and stool samples using GCMS. Approximately 6.18% of CPF was distributed in the body tissues, and the highest CPF concentration (3.80%) was found in adipose tissue. CPF also accumulated in the liver (0.29%), brain (0.22%), kidney (0.10%), and ovary (0.03%). Approximately 83.60% of CPF was detected in the urine. CPF exposure resulted in a significant increase in plasma transaminases, alkaline phosphatase, and total bilirubin levels, a significant reduction in total protein levels and an altered lipid profile. Oxidative stress due to CPF administration was also evidenced by a significant increase in liver malondialdehyde levels. The detrimental effects of CPF on kidney function consisted of a significant increase in plasma urea and creatinine levels. Liver and kidney histology confirmed the observed biochemical changes. In conclusion, CPF bioaccumulates over time and exerts toxic effects on animals.

Signaling pathway genes for blood pressure, folate and cholesterol levels among hypertensives: an epistasis analysis.

Irregular atrial pressure, defective folate and cholesterol metabolism contribute to the pathogenesis of hypertension. However, little is known about the combined roles of the methylenetetrahydrofolate reductase (MTHFR), apolipoprotein-E (ApoE) and angiotensin-converting enzyme (ACE) genes, which are involved in metabolism and homeostasis. The objective of this study is to investigate the association of the MTHFR 677 C>T and 1298A>C, ACE insertion-deletion (I/D) and ApoE genetic polymorphisms with hypertension and to further explore the epistasis interactions that are involved in these mechanisms. A total of 594 subjects, including 348 normotensive and 246 hypertensive ischemic stroke subjects were recruited. The MTHFR 677 C>T and 1298A>C, ACE I/D and ApoEpolymorphisms were genotyped and the epistasis interaction were analyzed. The MTHFR 677 C>T and ApoE polymorphisms demonstrated significant associations with susceptibility to hypertension in multiple logistic regression models, multifactor dimensionality reduction and a classification and regression tree. In addition, the logistic regression model demonstrated that significant interactions between the ApoE E3E3, E2E4, E2E2 and MTHFR 677 C>T polymorphisms existed. In conclusion, the results of this epistasis study indicated significant association between the ApoE and MTHFR polymorphisms and hypertension.

Assessment of dispersive liquid-liquid microextraction conditions for gas chromatography time-of-flight mass spectrometry identification of organic compounds in honey.

The suitability of the dispersive liquid-liquid microextraction (DLLME) technique for gas chromatography (GC) characterization of minor organic compounds in honey samples is evaluated. Under optimized conditions, samples were pre-treated by liquid-liquid extraction with acetonitrile followed by DLLME using carbon tetrachloride (CCl4, 0.075 mL) as extractant. The yielded settled phase was analyzed by GC using high resolution time-of-flight (TOF) mass spectrometry (MS). The whole sample preparation process is completed in approximately 10 min, with a total consumption of organic solvents below 4 mL, relative standard deviations lower than 12% and with more than 70 organic compounds, displaying linear retention index in the range from 990 to 2900, identified in the obtained extracts. In comparison with HS SPME extraction, higher peak intensities were attained for most volatile and semi-volatile compounds amenable to both extraction techniques. Furthermore, other species such as highly polar and water soluble benzene acids, long chain fatty acids, esters and flavonoids, which are difficult to concentrate by HS SPME, could be identified in DLLME extracts. Some of the compounds identified in DLLME extracts have been proposed as useful for samples classification and/or they are recognized as markers of honeys from certain geographic areas.

Assessment of gas chromatography time-of-flight accurate mass spectrometry for identification of volatile and semi-volatile compounds in honey.

The performance of gas chromatography (GC) combined with a hybrid quadrupole time-of-flight (QTOF) mass spectrometry (MS) system for the determination of volatile and semi-volatile compounds in honey samples is evaluated. After headspace (HS) solid-phase microextraction (SPME) of samples, the accurate mass capabilities of the above system were evaluated for compounds identification. Accurate scan electron impact (EI) MS spectra allowed discriminating compounds displaying the same nominal masses, but having different empirical formulae. Moreover, the use of a mass window with a width of 0.005 Da provided highly specific chromatograms for selected ions, avoiding the contribution of interferences to their peak areas. Additional information derived from positive chemical ionization (PCI) MS spectra and ion product scan MS/MS spectra permitted confirming the identity of novel compounds. The above possibilities are illustrated with examples of honey aroma compounds, belonging to different chemical classes and containing different elements in their molecules. Examples of compounds whose structures could not be described are also provided. Overall, 84 compounds, from a total of 89 species, could be identified in 19 honey samples from 3 different geographic areas in the world. The suitability of responses measured for selected ions, corresponding to above species, for authentication purposes is assessed through principal components analysis.

Surveillance of tuberculosis treatment outcomes of Singapore citizens and permanent residents, 2002-2011.

SETTING: Singapore, which had a tuberculosis (TB) incidence rate of 41 per 100,000 resident population in 2011. OBJECTIVE: To report the outcomes of Singapore citizens and permanent residents treated for TB from 2002 to 2011. METHODS: A computerised treatment surveillance module (TSM) was launched in 2001 to track the progress and outcome of TB patients nationally. Physicians were required to submit an electronic or paper return for every patient at each clinic visit. Treatment adherence, drugs prescribed, treatment delivery mode and final outcome, specified as 'completed treatment', 'lost to follow-up', 'death', 'transferred out', 'permanent cessation of treatment' and 'still on treatment/no final outcome', were captured. Quarterly cohort outcomes at 12-15 months after starting treatment were combined to generate annual treatment outcomes. RESULTS: Treatment completion rates increased from 73.4% to 82.8%. The proportion of patients lost to follow-up decreased from 3.4% to 1.7%, while that of patients still on treatment or with no final outcome decreased from 10.5% to 4.4%. The death rate ranged between 10.2% and 11.7%; the majority were not attributed to TB. CONCLUSION: TB treatment completion among Singapore citizens and permanent residents has improved since 2002 as the likely result of the TSM and other initiatives introduced over the past decade.

Analysis of volatile compounds of Malaysian Tualang (Koompassia excelsa) honey using gas chromatography mass spectrometry.

The constituents of honey's volatile compounds depend on the nectar source and differ depending on the place of origin. To date, the volatile constituents of Tualang honey have never been investigated. The objective of this study was to analyze the volatile compounds in local Malaysian Tualang honey. A continuous extraction of Tualang honey using five organic solvents was carried out starting from non-polar to polar solvents and the extracted samples were analysed using gas chromatography-mass spectrometry (GC-MS). Overall, 35 volatile compounds were detected. Hydrocarbons constitute 58.5% of the composition of Tualang honey. Other classes of chemical compounds detected included acids, aldehydes, alcohols, ketones, terpenes, furans and a miscellaneous group. Methanol yielded the highest number of extracted compounds such as acids and 5-(Hydroxymethyl) furfural (HMF). This is the first study to describe the volatile compounds in Tualang honey. The use of a simple one tube, stepwise, non-thermal liquid-liquid extraction of honey is a advantageous as it prevents sample loss. Further research to test the clinical benefits of these volatile compounds is recommended.

Cytochrome P450 3A4 genetic polymorphisms and post-operative fentanyl requirements.

WHAT IS KNOWN AND OBJECTIVE: Interindividual variability in drug responses may be attributable to genetically determined alteration in enzyme activity. In this study, we investigated the association between cytochrome P450 3A4 (CYP3A4) genetic polymorphisms and post-operative fentanyl requirements. METHODS: Patients (n = 94) scheduled for gynaecological laparotomy received i.v. fentanyl infusion (3 µg/kg/h) after induction of general anaesthesia. Post-operative fentanyl requirements were quantified by using a patient-controlled analgesia and the number of i.v. fentanyl rescue analgesia required were recorded. Pain control was assessed using visual analogue scores (VAS) and fentanyl's adverse effects were documented. CYP3A4*4, CYP3A4*5 and CYP3A4*18 alleles of cytochrome P450 3A4 were identified by polymerase chain reaction-restriction fragment length polymorphism. Differences in fentanyl requirements, VAS scores and adverse effects among the various genotypes were compared. RESULTS AND DISCUSSION: No CYP3A4*4 and CYP3A4*5 alleles were detected. Eighty-nine patients (94·7%) were wild-type, five (5·3%) were heterozygous and none was homozygous. No significant difference was demonstrated between the genotype groups in terms of fentanyl consumption, pain control and adverse effects. WHAT IS NEW AND CONCLUSION: CYP3A4*4 and CYP3A4*5 are rare in the Malaysian Malay population. Genetic polymorphism of CYP3A4*18 may not play an important role in influencing postoperative fentanyl requirements.

Advances in the analytical methods for determining the antioxidant properties of honey: a review.

Free radicals and reactive oxygen species (ROS) have been implicated in contributing to the processes of aging and disease. In an effort to combat free radical activity, scientists are studying the effects of increasing individuals' antioxidant levels through diet and dietary supplements. Honey appears to act as an antioxidant in more ways than one. In the body, honey can mop up free radicals and contribute to better health. Various antioxidant activity methods have been used to measure and compare the antioxidant activity of honey. In recent years, DPPH (Diphenyl-1-picrylhydrazyl), FRAP (Ferric Reducing Antioxidant Power), ORAC (The Oxygen Radical Absorbance Capacity), ABTS [2, 2-azinobis (3ehtylbenzothiazoline-6-sulfonic acid) diamonium salt], TEAC [6-hydroxy-2, 5, 7, 8-tetramethylchroman-2-carboxylic acid (Trolox)-equivalent antioxidant capacity] assays have been used to evaluate antioxidant activity of honey. The antioxidant activity of honey is also measured by ascorbic acid content and different enzyme assays like Catalase (CAT), Glutathione Peroxidase (GPO), Superoxide Dismutase (SOD). Among the different methods available, methods that have been validated, standardized and widely reported are recommended.

Stereoselective method development and validation for determination of concentrations of amphetamine-type stimulants and metabolites in human urine using a simultaneous extraction-chiral derivatization approach.

Amphetamine-type stimulants (ATS) are a group of chiral amine drugs which are commonly abused for their sympathomimetic and stimulant properties. ATS are extensively metabolised by hepatic cytochrome P450 enzymes. As metabolism of ATS has been shown to be highly stereospecific, stereoselective analytical methods are essential for the quantitative determination of ATS concentrations for both in vivo and in vitro studies of ATS metabolism. This paper describes a new stereoselective method for the simultaneous determination of amphetamine (AM), methamphetamine (MA), 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA), 4-hydroxy-3-methoxymethamphetamine (HMMA), 4-hydroxy-3-methoxyamphetamine (HMA), 3,4-hydroxymethamphetamine (HHMA) and 3,4-hydroxyamphetamine (HHA) in human urine samples validated according to the United States Food and Drug Administration guidelines. In this method, analytes are simultaneously extracted and derivatized with R-(-)-α-methoxy-α-(trifluoromethyl)phenylacetyl chloride (R-MTPCl) as the chiral derivatization reagent. Following this, the analytes were subjected to a second derivatization with N-methyl-N-trimethylsilyltrifluoroacetamide (MSTFA) which targets the hydroxyl groups present in HMMA, HMA, HHMA and HHA. The derivatized analytes were separated and quantified using gas chromatography-mass spectrometry (GC-MS). The method was evaluated according to the established guidelines for specificity, linearity, precision, accuracy, recovery and stability using a five-day protocol. Intra-day precision ranged from 0.89 to 11.23% RSD whereas inter-day precision was between 1.03 and 12.95% RSD. Accuracy values for the analytes ranged from -5.29% to 13.75%. Limits of quantitation were 10 µg/L for AM, MA, MDMA, HMA and HMMA and 2µg/L for MDA, HMA and HHA. Recoveries and stability values were also within accepted values. The method was applied to authentic ATS-positive samples.

Phenolic acid composition and antioxidant properties of Malaysian honeys.

The phenolic acid and flavonoid contents of Malaysian Tualang, Gelam, and Borneo tropical honeys were compared to those of Manuka honey. Ferric reducing/antioxidant power assay (FRAP) and the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical-scavenging activities were also quantified. All honey extracts exhibited high phenolic contents (15.21 ± 0.51- 42.23 ± 0.64 mg/kg), flavonoid contents (11.52 ± 0.27- 25.31 ± 0.37 mg/kg), FRAP values (892.15 ± 4.97- 363.38 ± 10.57 µM Fe[II]/kg), and high IC50 of DPPH radical-scavenging activities (5.24 ± 0.40- 17.51 ± 0.51 mg/mL). Total of 6 phenolic acids (gallic, syringic, benzoic, trans-cinnamic, p-coumaric, and caffeic acids) and 5 flavonoids (catechin, kaempferol, naringenin, luteolin, and apigenin) were identified. Among the Malaysian honey samples, Tualang honey had the highest contents of phenolics, and flavonoids, and DPPH radical-scavenging activities. We conclude that among Malaysian honey samples, Tualang honey is the richest in phenolic acids, and flavonoid compounds, which have strong free radical-scavenging activities.

Modification of propranolol's bioavailability by Eurycoma longifolia water-based extract.

WHAT IS KNOWN AND BACKGROUND: Eurycoma longifolia (E. longifolia), a herb commonly consumed for its aphrodisiac properties, is widely used by Asian males. This may include hypertensive patients receiving propranolol which may cause sexual dysfunction as one of its side-effects. There is no published study of the potential pharmacokinetic interaction between propranolol and the herb. OBJECTIVE: To study propranolol's pharmacokinetics when E. longifolia is consumed, comparing volunteers given either propranolol or a placebo. METHODS: This is a placebo-controlled randomized single-blinded crossover study of the effect of a water-based extract of E. longifolia on the pharmacokinetics of a single dose of proporanolol (Inderal(®)) in 14 healthy non-smoker young males. Eighty milligram of propranonol was orally administered with (i) placebo (Lactose) or (ii) 200 mg of water-based extract of E. longifolia (0·0272 ± 0·0026%eurycomanone) following an overnight fasting. Blood samples were collected at 0, 0·5, 1, 1·5, 2, 3, 4, 6, 8 and 10 h for propranolol's plasma concentration determinations using a validated high-performance liquid chromatography (HPLC) method. RESULTS AND DISCUSSION: When propranolol was administered with E. longifolia, its bioavailability (AUC0-∞) decreased by 29% while C(max) was reduced by 42% and T(max) was significantly prolonged by almost 86%. The terminal elimination half-life, however, was not significantly affected. CONCLUSION: The bioavailability of propranolol is significantly decreased when consumed together with E. longifolia. The interaction is due to a reduction in absorption, rather than an increase in propranolol's metabolism. Although the pharmacodynamics of propranolol was not affected in healthy volunteers, caution is still advisable with co-administration of the drug and the herb.

HPLC method development and validation for simultaneous detection of Arabinoside-C and doxorubicin.

This paper describes a new validated high performance liquid chromatography (HPLC) method for the simultaneous determination of two anti-cancer drugs, Arabinoside-C (Ara-C) and doxorubicin hydrochloride (DOX). A simultaneous determination method saves cost and time as both drugs can be injected into a single HPLC system without the need to change or re-equilibrate with a new mobile phase. The objective of the study is to develop a simultaneous determination method of two anti-cancer drugs, Ara-C and DOX. The mobile phase consisted of a mixture (45:55) of acetonitrile:ammonium hydrogen phosphate aqueous solution (0.01 M) at pH 6.2 at a flow rate of 0.3 ml/min, with UV detection at 252 nm. Separation was achieved on a C-18 column (5 µm: 250 mm × 4.6 mm) maintained at 30°C in a column oven. The method was linear between 325 ng/ml and 10 µg/ml for Ara-C and 625 ng/ml and 20 µg/ml for DOX. The limit of detection (LOD) was 20 ng/ml for Ara-C and 60 ng/ml for DOX. The developed HPLC method achieved good precision and accuracy as well as limit of quantitations. The developed and validated method is suitable to be used for routine analysis of Ara-C and DOX.

High 5-hydroxymethylfurfural concentrations are found in Malaysian honey samples stored for more than one year.

5-Hydroxymethylfurfural (HMF) content is an indicator of the purity of honey. High concentrations of HMF in honey indicate overheating, poor storage conditions and old honey. This study investigated the HMF content of nine Malaysian honey samples, as well as the correlation of HMF formation with physicochemical properties of honey. Based on the recommendation by the International Honey Commission, three methods for the determination of HMF were used: (1) high performance liquid chromatography (HPLC), (2) White spectrophotometry and (3) Winkler spectrophotometry methods. HPLC and White spectrophotometric results yielded almost similar values, whereas the Winkler method showed higher readings. The physicochemical properties of honey (pH, free acids, lactones and total acids) showed significant correlation with HMF content and may provide parameters that could be used to make quick assessments of honey quality. The HMF content of fresh Malaysian honey samples stored for 3-6 months (at 2.80-24.87 mg/kg) was within the internationally recommended value (80 mg/kg for tropical honeys), while honey samples stored for longer periods (12-24 months) contained much higher HMF concentrations (128.19-1131.76 mg/kg). Therefore, it is recommended that honey should generally be consumed within one year, regardless of the type.

CYP3A4 genetic polymorphism influences repaglinide's pharmacokinetics.

AIM: To investigate the effects of CYP3A4 and CYP2C8 enzymes on repaglinide's pharmacokinetics in healthy Malaysian subjects. METHODS: Subjects (n = 121) received oral repaglinide (4 mg). Blood samples were taken at 0, 30, 60, 120, 180 and 240 min and serum concentrations of repaglinide were determined using high-performance liquid chromatography. Subjects were also genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) for CYP3A4*4, *5 and*18 and by an allele-specific multiplex PCR for CYP2C8*2, *3, *4 and *5 alleles. RESULTS: The allele frequencies of CYP2C8*1, *2, *3, *4 and *5 were 95.04, 0.40, 0.40, 0 and 4.13%, respectively. The frequencies of the CYP3A4*1, *4, *5 and *18 alleles were 97.93, 0, 0 and 2.07%, respectively. CYP2C8 and CYP3A4 genotypes were not significantly associated with repaglinide's blood glucose-lowering effect. However, the CYP3A4 genotype significantly influenced some of repaglinide's pharmacokinetics, where the mean elimination rate constant was 44.0% lower (p = 0.04) and the mean half-life was 33.8% higher (p = 0.04) in subjects with the CYP3A4*1/*18 genotype as compared to those with the normal CYP3A4*1/*1 genotype. This result confirms that CYP3A4 plays a large role in metabolizing repaglinide. CONCLUSION: Genetic polymorphisms of CYP3A4, specifically CYP3A4*18, play a major role in contributing to the interindividual variability in repaglinide's pharmacokinetics.