Preliminary insight on diarylpentanoids as potential antimalarials: In silico, in vitro pLDH and in vivo zebrafish toxicity assessment

Malaria remains a major public health problem worldwide, including in Southeast Asia. Chemotherapeutic agents such as chloroquine (CQ) are effective, but problems with drug resistance and toxicity have necessitated a continuous search for new effective antimalarial agents. Here we report on a virtual screening of ∼300 diarylpentanoids and derivatives, in search of potential Plasmodium falciparum lactate dehydrogenase (PfLDH) inhibitors with acceptable drug-like properties. Several molecules with binding affinities comparable to CQ were chosen for in vitro validation of antimalarial efficacy. Among them, MS33A, MS33C and MS34C are the most promising against CQ-sensitive (3D7) with EC50 values of 1.6, 2.5 and 3.1 μM, respectively. Meanwhile, MS87 (EC50 of 1.85 μM) shown the most active against the CQ-resistant Gombak A strain, and MS33A and MS33C the most effective P. knowlesi inhibitors (EC50 of 3.6 and 5.1 μM, respectively). The in vitro cytotoxicity of selected diarylpentanoids (MS33A, MS33C, MS34C and MS87) was tested on Vero mammalian cells to evaluate parasite selectivity (SI), showing moderate to low cytotoxicity (CC50 > 82 μM). In addition, MS87 exhibited a high SI and the lowest resistance index (RI), suggesting that MS87 may exert effective parasite inhibition with low resistance potential in the CQ-resistant P. falciparum strain. Furthermore, the in vivo toxicity of the molecules on early embryonic development, the cardiovascular system, heart rate, motor activity and apoptosis were assessed in a zebrafish animal model. The overall results indicate the preliminary potential of diarylpentanoids, which need further investigation for their development as new antimalarial agents.

Public Knowledge and Attitudes Regarding the Use of Antibiotics and Resistance: Findings from a Cross-Sectional Study Among Palestinian Adults

Antibiotics are considered to be among the most commonly sold drug classes in Palestine. Resistance to antibiotics has increased for reasons relating to the use and misuse of antibiotics. The aim of this study was to evaluate the knowledge, and attitudes regarding antibiotic use and awareness about resistance among adults visiting the emergency departments at hospitals in North Palestine. A self-administered cross-sectional questionnaire survey involving participants aged 18 or over was conducted from June 2012 to February 2013. Adults who visited the emergency departments at hospitals in North Palestine were included. Demographic characteristics, knowledge and attitudes towards antibiotic use were included in the questionnaire. Poor and good knowledge were defined as a total knowledge score of 0-7 and 8-15 of 15 questions, respectively. Attitude scores of 0-3 and 4-7 of 7 questions were considered poor and good, respectively. A total of 375 questionnaires were included in the study. A response rate of 83.3% was attained. About 55.0% of the participants had a good knowledge and 56.5% had a good attitude towards rational antibiotic use. A significant positive correlation was shown between participants' knowledge scores and participants' attitude scores towards antibiotic use (R = 0.344, P = 0.001. Participants with a high family income were more likely to be aware of appropriate antibiotic use than participants with a low family income (P-value <0.001). Participants with a higher educational level (university) had a good attitude towards rational antibiotic use than those with a lower education level (P-value <0.001). This study has documented important knowledge and attitude gaps in antibiotic use. These findings will help health policymakers in Palestine to implement intervention programmes to rationalize antibiotic use. Continuing medical education, professional development and training workshops for healthcare professionals regarding rational use of antibiotics and health risks associated with the spread of antibiotic resistance are needed. In addition, minimizing non-prescription use of antibiotics and increasing the public awareness about the health and economic hazards of antibiotic resistance are also required.

Profile of poisoning admissions in Malaysia

We retrospectively reviewed poisoning admissions to all government health facilities from 1999 to 2001, in an effort to expand our current knowledge on poisoning in Malaysia to a level that better reflects a nationwide burden. There were 21 714 admissions reported with 779 deaths. The case-fatality rate was 35.88/1000 admissions. The majority of admissions (89.7%) and deaths (98.9%) occurred in adults. Some 55.1% of all admissions were female, mostly involving pharmaceutical agents. Male poisoning admissions were more often due to chemical substances. The prevalence of poisoning and death was highest among Indians compared to all other races in Malaysia. Overall, the majority of poisoning admissions were due to pharmaceutical agents, with agents classified as non-opioid analgesics, antipyretics and anti-rheumatics the most common. Pesticides accounted for the largest number of fatalities. It was also the commonest substance reported in cases of intentional self-harm. Most cases of poisoning admissions occurred due to accidental exposure (47%), followed by cases of intentional self-harm (20.7%). Overall, this study has managed to contribute substantial additional information regarding the epidemiology of poisoning in Malaysia, highlighting important issues, such as the rampant poisonings involving pesticides and analgesics, as well as the high prevalence of poisoning among Indians in Malaysia. Human & Experimental Toxicology (2007) 26, 73- 81

A Randomised Single-Blinded Controlled Trial on the Effectiveness of Brief Advice on Smoking Cessation among Tertiary Students in Malaysia

INTRODUCTION

Tobacco smoking, a habitual behavior, is addictive and detrimental to health. Quitting requires personal abilities and environmental opportunities and therefore, improving these abilities and opportunities will undoubtedly act on smokers' motivation to quit.

METHODS

A prospective single-blinded randomized controlled interventional study was conducted among first year undergraduate students in Malaysia. A total of eighty smokers were randomly allocated to a control or intervention groups (40/40). Randomization remained concealed from research personnel. All participants were followed up for six months to evaluate abstinence.

RESULTS

Quit line enrolment rate of the intervention group was 55% (22) compared to 7.5% (3) in the control (P < 0.001 95% CI 30.1 - 64.9). In the intervention group 27% (6) sustained quitting for six months compared to none in the control group.

CONCLUSION

This study has shown that brief advice for smoking cessation is more effective than an information leaflet alone to promote quitting and that to maintain abstinence quit line follow up is necessary. Larger samples size and longer follow up studies are needed to further confirm these findings.

Global research productivity of N-acetylcysteine use in paracetamol overdose: A bibliometric analysis (1976-2012)

PURPOSE

The main objective of this study was to examine the publication pattern of N-acetylcysteine (NAC) research output for paracetamol overdose at the global level.

METHODS

Data were searched for documents that contained specific words regarding NAC and paracetamol as keywords in the title and/or abstract and/or keywords. Scientific output was evaluated based on a methodology developed and used in other bibliometric studies. Research productivity was adjusted to the national population and nominal gross domestic product per capita.

RESULTS

The criteria were met by 367 publications from 33 countries. The highest number of articles associated with the use of NAC in paracetamol overdose was from the United States of America (USA; 39.78%), followed by the United Kingdom (UK; 11.99%). After adjusting for economy and population power, USA (2.822), Iran (1.784) and UK (1.125) had the highest research productivity. The total number of citations at the time of data analysis (14 March 2014) was 8785 with an average of 23.9 citations per document and a median (interquartile range) of 6 (1-22). The h-index of the retrieved documents was 48. The highest h-index was 32 for USA, followed by 20 for UK. Furthermore, the highest number of collaborations with international authors for each country was held by USA with 11 countries, followed by Canada with 7 countries.

CONCLUSION

The amount of NAC-based research activity was low in some countries, and more effort is needed to bridge this gap and to promote better evaluation of NAC use worldwide. Our findings demonstrate that NAC use for paracetamol overdose remains a hot issue in scientific research and may have a larger audience compared with other toxicological aspects. Editors and authors in the field of toxicology might usefully promote the submission of work on NAC in future to improve their journal's impact.

A bibliometric analysis of research productivity of Malaysian publications in leading toxicology journals during a 10-year period (2003-2012)

BACKGROUND

Toxicology in Malaysia has experienced rapid development and made great progress in education and research in conjunction with economic development in Malaysia over the past two decades.

OBJECTIVES

The main objectives of this study were to analyse the research originating from Malaysia and published in toxicology journals and to examine the authorship pattern and the citations retrieved from the Scopus database.

METHODS

Data from 1 January 2003 till 31 December 2012 were searched for documents with specific words in the toxicology field as a 'source title' and Malaysia as an affiliation country. Research productivity was evaluated based on a methodology we developed and used in other bibliometric studies by analysing: (a) total and trends of contributions in toxicology fields between 2003 and 2012; (b) Malaysian authorship pattern and productivity; (c) collaboration patterns; (d) journals in which Malaysian researchers publish; (e) the classification of journals to Institute for Scientific Information (ISI) or non-ISI; (f) impact factors (IFs) of all publications; and (g) citations received by the publications.

RESULTS

In total, 290 documents were retrieved from 55 international peer-reviewed toxicology journals. The quantity of publication increased by around 10-fold from 2003 to 2012. The h-index of the retrieved documents was 20. Of the 55 journal titles, 42 (76.4%) have their IF listed in the journal citation reports 2012. Forty-two documents (14.5%) were published in journals that had no official IF. The total number of citations, at the time of manuscript writing (5 August 2013), was 1707, with a median (interquartile range) of 3 (0-7). Malaysia collaborated mostly with countries in the Asia-Pacific regions (18.3%), especially India and Japan, followed by the Middle East and Africa (10.0%), especially Palestine and Yemen.

CONCLUSION

The present data show a promising rise and a good start for toxicology research activity in Malaysia. The sharing of relevant research questions by developed and developing countries can lead to research opportunities in the field of toxicology.

Clinically important drug-drug interactions in primary care

WHAT IS KNOWN AND OBJECTIVE

Drug-drug interactions (DDIs) cause considerable morbidity and mortality worldwide and may lead to hospital admission. Sophisticated computerized drug information and monitoring systems, more recently established in many of the emerging economies, including Malaysia, are capturing useful information on prescribing. Our aim is to report on an investigation of potentially serious DDIs, using a university primary care-based system capturing prescription records from its primary care services.

METHODS

We retrospectively collected data from two academic years over 20 months from computerized databases at the Universiti Sains Malaysia (USM) from users of the USM primary care services.

RESULTS AND DISCUSSION

Three hundred and eighty-six DDI events were observed in a cohort of 208 exposed patients from a total of 23,733 patients, representing a 2-year period prevalence of 876·4 per 100,000 patients. Of the 208 exposed patients, 138 (66·3%) were exposed to one DDI event, 29 (13·9%) to two DDI events, 15 (7·2%) to three DDI events, 6 (2·9%) to four DDI events and 20 (9·6%) to more than five DDI events. Overall, an increasing mean number of episodes of DDIs was noted among exposed patients within the age category ≥70 years (P=0·01), an increasing trend in the number of medications prescribed (P<0·001) and an increasing trend in the number of long-term therapeutic groups (P<0·001).

WHAT IS NEW AND CONCLUSION

We describe the prevalence of clinically important DDIs in an emerging economy setting and identify the more common potentially serious DDIs. In line with the observations in developed economies, a higher number of episodes of DDIs were seen in patients aged ≥70 years and with more medications prescribed. The easiest method to reduce the frequency of DDIs is to reduce the number of medications prescribed. Therapeutic alternatives should be selected cautiously.

Pharmaco-epidemiologic study of the prescription of contraindicated drugs in a primary care setting of a university: a retrospective review of drug prescription

BACKGROUND

The prescription of contraindicated drugs is a preventable medication error, which can cause morbidity and mortality. Recent data on the factors associated with drug contraindications (DCIs) is limited world-wide, especially in Malaysia.

AIMS

The objectives of this study are 1) to quantify the prevalence of DCIs in a primary care setting at a Malaysian University; 2) to identify patient characteristics associated with increased DCI episodes, and 3) to identify associated factors for these DCIs.

METHODS

We retrospectively collected data from 1 academic year using computerized databases at the Universiti Sains Malaysia (USM) from patients of USM's primary care. Descriptive and comparative statistics were used to characterize DCIs.

RESULTS

There were 1,317 DCIs during the study period. These were observed in a cohort of 923 patients, out of a total of 17,288 patients, representing 5,339 DCIs per 100,000 patients, or 5.3% of all patients over a 1-year period. Of the 923 exposed patients, 745 (80.7%) were exposed to 1 DCI event, 92 (10%) to 2 DCI events, 35 (3.8%) to 3 DCI events, 18 (2%) to 4 DCI events, and 33 patients (3.6%) were exposed to 5 or more DCI events. The average age of the exposed patients was 30.7 ± 15 y, and 51.5% were male. Multivariate logistic regression analysis revealed that being male (OR = 1.3; 95% CI = 1.1 - 1.5; p < 0.001), being a member of the staff (OR = 3; 95% CI = 2.5 - 3.7; p < 0.001), having 4 or more prescribers (OR = 2.8; 95% CI = 2.2 - 3.6; p < 0.001), and having 4 or more longterm therapeutic groups (OR = 2.3; 95%CI = 1.7 - 3.1; p < 0.001), were significantly associated with increased chance of exposure to DCIs.

DISCUSSION AND CONCLUSIONS

This is the first study in Malaysia that presents data on the prevalence of DCIs. The prescription of contraindicated drugs was found to be frequent in this primary care setting. Exposure to DCI events was associated with specific socio-demographic and health status factors. Further research is needed to evaluate the relationship between health outcomes and the exposure to DCIs.

Identification of psychosocial factors of noncompliance in hypertensive patients

This cross-sectional study was aimed to identify the predictors of medication noncompliance in hypertensive patients. The study was conducted at the Family Medicine Clinic, Hospital Universiti Sains Malaysia, Kelantan, Malaysia, which is a university-based teaching hospital. All hypertensive patients aged 40 or over-registered from January to June 2004, who had been on treatment for at least 3 months, were screened. Previously validated self-administered questionnaires were used to assess the compliance and psychosocial factors. A total of 240 hypertensive patients were recruited in the study. Of these, 55.8% were noncompliant to medication. Logistic regression showed that age (adjusted odds ratio (OR): 0.96; 95% confidence interval (CI): 0.92-0.997; P: 0.035), patient satisfaction (adjusted OR: 0.97; 95% CI: 0.93-0.998; P: 0.036) and medication barrier (adjusted OR: 0.95; 95% CI: 0.91-0.987; P: 0.009) were significant predictors of medication noncompliance. Therefore, younger age, poor patient satisfaction and medication barrier were identified as independent psychosocial predictors of medication noncompliant in hypertensive patients.

Community-acquired vancomycin-resistant Enterococcus faecium: a case report from Malaysia

Vancomycin-resistant enterococci (VRE) are formidable organisms renowned for their ability to cause infections with limited treatment options and their potential for transferring resistance genes to other Gram-positive bacteria. Usually associated with nosocomial infections, VRE are rarely reported as a cause of community-acquired infection. Presented here is a case of community-acquired infection due to vancomycin-resistant Enterococcus faecium. The patient had been applying herbal leaves topically to his cheek to treat a buccal space abscess, resulting in a burn of the overlying skin. From pus aspirated via the skin a pure culture of E. faecium was grown that was resistant to vancomycin with a MIC of >256 microg ml-1 by the E test and resistant to teicoplanin by disc diffusion, consistent with the VanA phenotype. The organism was suspected of contaminating the leaf and infecting the patient via the burnt skin. This case highlights the need for further studies on the community prevalence of VRE among humans and animals to define unrecognized silent reservoirs for VRE, which may pose a threat to public health.

Lipase-catalyzed esterification of palm-based 9,10-dihydroxystearic acid and 1-octanol in hexane – a kinetic study

The esterification of palm-based 9,10-dihydroxystearic acid (DHSA) and 1-octanol in hexane as catalyzed by lipase from Rhizomucor meihei (Lipozyme IM) followed Michaelis-Menten kinetics. The esterification reaction follows a Ping-Pong, Bi-Bi mechanism. The maximum rate was estimated to be 1 micromol min(-1) mg(-1) catalyst in hexane at 50 degrees C, and the Michaelis-Menten constants for DHSA and 1-octanol were 1.3 M and 0.7 M, respectively.

Trends in inquiries on poisoning: a five-year report from the National Poison Centre, Malaysia

This report describes inquiries relating to poisoning cases which were received by the National Poison Centre of Malaysia from the years 1996 to 2000. The study utilized data from the NPC report forms. Only data relating to patient contact with a poison or chemical were included in the analysis. The poison centre received an average of 186 poisoning inquiries per year. Doctors remained the highest group of caller to the poison centre throughout the five-year period. Nearly 50% of all inquiries was regarding pesticide poisoning and this trend remained constant during the five-year period. Overall, the findings showed that poisoning inquiries relating to patient care were lower than in Japan and the United States.

Altered aminoglycoside pharmacokinetics in critically ill patients with sepsis

The pharmacokinetic disposition of aminoglycosides in critically ill patients with sepsis was studied. In an open-label study of the disposition of gentamicin and tobramycin, individualized pharmacokinetic values of 100 critically ill patients in the surgical intensive-care unit were compared with those of a concurrently monitored group of 100 surgery patients who were not critically ill. The a priori computer-predicted dosage requirements of the critically ill patients were also compared with the dosages derived from their individualized pharmacokinetic values, and intrapatient variation in the critically ill patients was studied. Serum concentration-time data were analyzed using a one-compartment model and the DataMed Clinical Support Services system to provide individualized dosage requirements. Initial dosing guidelines were also generated for the critically ill patients using the a priori model of the DataMed Clinical Support Services program and patient demographic information. The critically ill patients were significantly older, had higher serum creatinine concentrations (SCr), and had lower elimination rate constants (k) and total body clearances (CL) than the surgery patients who were not critically ill. The volume of distribution (V) was not significantly different. The a priori computer predictions for the critically ill patients were significantly lower than the individualized values for V, CL, dose, and amount of drug per 24 hours. The dosing regimen from the a priori model was the same as the individualized regimen in only 2/100 patients. In the 76 critically ill patients who had a second pharmacokinetic analysis performed, there was a significant decrease in k and CL from the first analysis.(ABSTRACT TRUNCATED AT 250 WORDS)