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Biomedical subjects

C L Teng

Publications and source records attributed to C L Teng.

At least 19 recordsLinked to original sources

Antibiotic prescribing for childhood febrile illness by primary care doctors in Malaysia.

AIM: Fever in children, a mostly benign and self-limiting illness, is often viewed with consternation by the care givers. It results in early consultation and excessive use of antipyretics and antibiotics. In this study, we document the prescribing practice of doctors from three primary care settings in Malaysia and identify the predictors of antibiotic prescription. METHODS: Interview of care givers bringing febrile children (age </= 12 years) to three primary care settings: public primary care clinics, private general practice clinics and a university-based primary care clinic. RESULTS: Data from 649 children were analysed. Mean age of children 4.1 years and 55% were boys. One-third of the children had prior consultation for the same episode of fever. About 80% of the febrile children were diagnosed to have upper respiratory tract infection, viral fever and gastroenteritis. Overall antibiotic prescribing rate was 36.6% (public primary care clinic 26.8%, private general practice clinic 70.0% and university-based primary care clinic 32.2%). Independent predictors of antibiotic prescription were: clinic setting, longer duration of fever (>7 days), higher temperature (>38 degrees C) and the diagnosis of upper respiratory tract infections. After controlling for demographic and clinical factors, antibiotic prescription in private general practice clinic was seven times higher than public primary care clinic (odds ratio 7.1, 95% confidence interval 4.0-12.7), and 1.6 times higher than university-based primary care clinic (odds ratio 1.6, 95% confidence interval 1.0-2.5). CONCLUSION: Differences in the patients' demographic and clinical characteristics could not adequately explain the high antibiotic prescribing rate in private general practice clinics. This inappropriately high antibiotic prescribing for febrile children in private general practice clinics is a suitable target for future intervention.

Anti-Bacterial Agents↗

Pain morbidity in primary care - preliminary observations from two different primary care settings.

The prevalence of pain complaints as a reason for patient-doctor encounters in the local primary care setting is unknown. We performed a cross-sectional survey of such encounters in one public primary care clinic (KK) and 17 general practice clinics (GP), from the city of Seremban, Negeri Sembilan, Malaysia. Reasons for visits were recorded by doctors in KK and medical students in GP using a structured questionnaire. Morbidity data was coded using the International Classification of Primary Care (ICPC-2). A total of 2234 encounters were recorded (80.9% from KK, 19.1% from GP). The overall prevalence of pain complaints was 31.9% with a significant difference between the two cohorts (KK 28.7% and GP 45.2%, p<0.001). Musculoskeletal pain complaints were more common in KK than GP (40.9% versus 29.7%, p<0.05). Of the 3 main ethnic groups in Malaysia (Malay, Chinese and Indian) the Indian patients at KK had the highest prevalence of pain complaints and the Chinese at the GP had the lowest. Thus pain was a common complaint in the two different primary care settings studied. Some of the differences observed are probably due to the differences in the healthcare seeking behaviour of patients consulting at these two settings as well as differences in the payment systems.

Adolescent↗

Primary care doctors' perceptions towards evidence-based medicine in Melaka State: a questionnaire study.

A cross sectional study using a self-administered questionnaire to determine the perceptions of primary care doctors towards evidence-based medicine (EBM) was conclucted in Melaka state. About 78% of the primary care doctors were aware of EBM and agreed it could improve patient care. Only 6.7% of them had ever conducted a Medline literature search. They had a low level of awareness of review publications and databases relevant to EBM; only about 33% of them were aware of the Cochrane Database of Systemic Reviews. Over half of the respondents had at least some understanding of the technical terms used in EBM. Ninety percent of the respondents had Internet access and the majority of them used it at home. The main barriers to practicing EBM were lack of personal time and lack of Internet access in the primary care clinics.

Adult↗

General and URTI-specific antibiotic prescription rates in a Malaysian primary care setting.

Antibiotic prescribing by primary care doctors has received renewed interest due to the continuing emergence of antibiotic resistance and the attendant cost to healthcare. We examined the antibiotic prescribing rate in relation to selected socio-demographic characteristics of the prescribers at the Seremban Health Clinic, a large public primary care clinic, designated for teaching, in the state of Negeri Sembilan, Malaysia. Data were obtained from: (1) retrospective review of prescriptions for the month of June 2002 and (2) a questionnaire survey of prescribers. A total of 10667 prescriptions were reviewed. The overall antibiotic prescribing rate was 15%; the rate (16%) was higher for the general Outpatient Department (OPD) than the 3% for the Maternal & Child Health Clinic (MCH). The antibiotic prescription rates for upper respiratory tract infection (URTI) were 26% and 16%, respectively, for the OPD and MCH. Half of all the antibiotic prescriptions were for URTI making prescribing for URTI an appropriate target for educational intervention. The URTI-specific antibiotic prescription rate did not correlate with the prescribers' intention to specialise, patient load, perceived patient's expectation for an antibiotic, or the score for knowledge of streptococcal tonsillitis. Prescribing behaviours and record-keeping practices requiring correction were identified.

Adult↗

Metered-dose inhaler technique in asthmatic patients--a revisit of the Malaysian scene.

Inefficient metered-dose inhaler (MDI) technique results in poor drug delivery, suboptimal disease control a possibility of inhaled medication overuse. The MDI technique of 134 government hospital and clinic followed-up adult asthmatic patients followed-up in a government hospital and a heath clinic was pragmatically assessed based on the 3 obligatory steps of adequate lip seal, appropriate hand-breath coordination and sufficient breath holding after inhalation. The relationship between technique efficiency and frequency of daily short-acting beta2-agonist (SABA) use via the MDI and asthma exacerbations over a 12-month period was also assessed. Fifty-six patients (42%) had inefficient MDI technique. All demographic and asthma-related variables between the 'efficient' and 'inefficient' technique groups of patients were comparable except for significantly longer mean years of MDI use in the 'efficient' technique group [mean (SD): 10 (7) vs. 7 (5); p=0.003]. There were no significant differences between the two groups in relation to frequency of daily SABA use or asthma exacerbations over the past 12 months. Despite having been available in Malaysia for a considerable period of time, the MDI device is still poorly handled by a large proportion of adult asthmatic patients. Changing to other more user-friendly devices or use of spacer devices to facilitate delivery should be considered for these patients.

Adolescent↗

Upper respiratory tract infections: to what extent is the management evidence-based?

Over a 2-week period, the management of upper respiratory tract infection by 24 medical officers and medical assistants in Seremban District was studied. Each practitioner recorded clinical data and prescription for twenty consecutive patients using a structured questionnaire. The extent to which the practitioners used "predictive features" (fever, absence of cough, cervical adenopathy, enlarged tonsils and exudates on tonsils) in clinical decision-making was analysed. The mean antibiotic prescription rate was 28.7% (95% CI: 24.6%, 33.0%). The antibiotic prescription rate of medical officers and medical assistants were similar. Five features were independently associated with antibiotic prescription (phlegm, fever, cervical adenopathy, red throat and tonsillar exudates). Antibiotics were prescribed for 22.1% of patients with 0-1 predictive features. High prescribers were 5 times more likely to prescribe antibiotics in this group of patients than low prescribers. To a large extent the clinical decision-making of practitioners in this study was evidence based. However, they were unduly influenced by purulent manifestation (phlegm) and redness of throat. The antibiotic prescription rate in these government health clinics is potentially reducible by means of educational intervention.

Adolescent↗

Morbidity and process of care in urban Malaysian general practice: the impact of payment system.

BACKGROUND: The majority of primary care consultations in Malaysia occur in the general practice clinics. To date, there is no comprehensive documentation of the morbidity and practice activities in this setting. OBJECTIVES: We reported the reasons for encounter, diagnoses and process of care in urban general practice and the influence of payment system on the morbidity and practice activities. METHODS: 115 clinics in Kuala Lumpur, Ipoh and Penang participated in this study. General practitioners in these clinics completed a 2-page questionnaire for each of the 30 consecutive patients. The questionnaire requested for the following information: demographic data, reasons for encounter, important physical findings, diagnoses, investigations ordered, outpatient procedures performed, medical certificate given, medication prescribed and referral made. The morbidity (reasons for encounter and diagnoses) was coded using ICPC-2 and the medication data was coded using MIMS Classification Index. RESULTS: During 3481 encounters, 5300 RFEs (152 RFEs per 100 encounters) and 3342 diagnoses (96 diagnoses per 100 encounters) were recorded. The majority of the RFEs and diagnoses are in the following ICPC Chapters: Respiratory, General and unspecified, Digestive, Neurological, Musculoskeletal and Skin. The frequencies of selected aspects of the process of care (rate per 100 encounters) were: laboratory investigations 14.7, outpatient procedures 2.4, sick certification 26.9, referral 2.4, and medication prescription 244. Consultation for chronic diseases and acute infections were influenced more by demographic variables (age, employment) rather than payment system. Cash-paying patients were more likely to receive laboratory investigations and injections. CONCLUSION: This study demonstrated the breadth of clinical care in the general practice. Relatively fewer patients consulted specifically for preventive care and treatment of chronic diseases. The frequencies of outpatient procedures and referrals appeared to be low. Payment system results in important differences in patient mix and influences some types of practice activities.

Adolescent↗

The prevalence of diabetic peripheral neuropathy in an outpatient setting.

This study was undertaken to clinically estimate the prevalence of diabetic peripheral neuropathy amongst patients attending an outpatient clinic and to evaluate their risk factors for developing peripheral neuropathy. It was a cross-sectional study of 134 diabetes mellitus patients who attended the Primary Care Clinic, University Hospital, Kuala Lumpur. The patients were interviewed for their demographic data, past and present medical/surgical history, social history, personal habits and symptoms of peripheral neuropathy. Foot examination and clinical neurological tests were conducted and the presence of peripheral neuropathy was assessed. The main outcome measures were the Neuropathy Symptom Score and the Neuropathy Disability Score. The prevalence of diabetic peripheral neuropathy was found to be 50.7%. Peripheral neuropathy was related to the age of the patient and the duration of diabetes but did not seem to be significantly related to diabetic control. To conclude, there was a high prevalence of peripheral neuropathy amongst the diabetics in this study. These patients developed peripheral neuropathy at a younger age and shorter duration of diabetes compared to a similar study that was done in the UK.

Adolescent↗

DNA microarray reveals changes in gene expression of shear stressed human umbilical vein endothelial cells.

Using DNA microarray screening (GeneFilter 211, Research Genetics, Huntsville, AL) of mRNA from primary human umbilical vein endothelial cells (HUVEC), we identified 52 genes with significantly altered expression under shear stress [25 dynes/cm(2) for 6 or 24 h (1 dyne = 10 microN), compared with matched stationary controls]; including several genes not heretofore recognized to be shear stress responsive. We examined mRNA expression of nine genes by Northern blot analysis, which confirmed the results obtained on DNA microarrays. Thirty-two genes were up-regulated (by more than 2-fold), the most enhanced being cytochromes P450 1A1 and 1B1, zinc finger protein EZF/GKLF, glucocorticoid-induced leucine zipper protein, argininosuccinate synthase, and human prostaglandin transporter. Most dramatically decreased (by more than 2-fold) were connective tissue growth factor, endothelin-1, monocyte chemotactic protein-1, and spermidine/spermine N1-acetyltransferase. The changes observed suggest several potential mechanisms for increased NO production under shear stress in endothelial cells.

Blotting, Northern↗

Iontophoretic transport of oligonucleotides across human epidermal membrane: a study of the Nernst-Planck model.

The objective of this study was to investigate the transport behavior of a series of oligonucleotides with human epidermal membrane (HEM) and to examine the applicability of the modified NERNST-PLANCK model to transdermal iontophoresis of these macromolecules. Iontophoretic transport experiments were first carried out in a synthetic model membrane system (Nuclepore membranes) with a four-electrode potentiostat to examine the baseline modified NERNST-PLANCK model. The modified NERNST-PLANCK model derived from the Einstein relation and the Stokes-Einstein equation taken from previous work did not hold for the oligonucleotides. Results obtained in the Nuclepore studies were, however, consistent with predictions of the modified NERNST-PLANCK model using the experimentally determined electromobilities and diffusion coefficients. The electromobilities of the oligonucleotides (determined by capillary electrophoresis) were found to be more than a factor of two smaller than expected from the Einstein relation between electromobilities and diffusion coefficients (the latter determined in diffusion cell experiments). A correlation between these electromobilities and the theoretical electromobilities estimated by considering the effects of counterion binding and the effects of mobility reduction according to colloid theory was also observed. These results suggest that the modified NERNST-PLANCK model predictions are satisfactory only when the electromobilities and the effective molecular size of the oligonucleotides are known and are used directly to predict the iontophoretically enhanced transport. Results with the HEM experiments generally agreed with model predictions based on the experimental electromobilities. The oligonucleotide HEM flux data also suggest the existence of pores with effective pore radii greater than the effective radii estimated in previous studies with small molecular weight model permeants.

Biological Transport↗

Molecular oxygen spin-lattice relaxation in solutions measured by proton magnetic relaxation dispersion.

Proton spin-lattice relaxation rate constants have been measured as a function of magnetic field strength for water, water-glycerol solution, cyclohexane, methanol, benzene, acetone, acetonitrile, and dimethyl sulfoxide. The magnetic relaxation dispersion is well approximated by a Lorentzian shape. The origin of the relaxation dispersion is identified with the paramagnetic contribution from molecular oxygen. In the small molecule cases studied here, the effective correlation time for the electron-nuclear coupling may include contributions from both translational diffusion and the electron T(1). The electron T(1) for molecular oxygen dissolved in several solvents was found to be approximately 7.5 ps and nearly independent of solvent or viscosity.

Algorithms↗

The management of upper respiratory tract infections.

Upper respiratory tract infections are the commonest reason for consultation in primary care. Group A beta-haemolytic Streptococcus (GABHS), the most important bacterial pathogen in this condition, can be cultured from about 30% of patients, more so in children than adults. Clinical features that are predictive of positive GABHS culture are absence of cough, fever, cervical adenopathy, tonsillar enlargement and tonsillar exudate. Use of a sore throat score can help in the detection of streptococcal throat infection. Symptomatic therapies which are useful include anticholinergic, antihistamine, decongestant, humified hot air and Vitamin C. Antibiotics are universally over-prescribed in this condition as a result of high patient expectation and faulty clinical decision making. Oral Penicillin V for 10 days is the drug of choice. Effective intervention to reduce inappropriate antibiotic prescription probably require a multifaceted approach targeted at both the patients and the prescribers.

Adult↗

A study of clinical questions in primary care.

This is a prospective study of clinical questions generated in primary care consultations and a comparison of two approaches to answering those clinical questions. Twenty-one doctors in a university-based primary care clinic submitted 78 clinical questions arising from patient consultations during 24 clinic days (0.01 question per patient encounter). These doctors subsequently found answers to 40% of their questions but were satisfied with only 67% of these answers. The investigators were able to provide answers for 95% of the questions asked and the doctors rated these answers as satisfactory in 86% of instances. Answers obtained by investigators had significantly higher satisfaction score than those obtained by doctors' search (p = 0.002). The two main findings of this study are (1) almost all questions arising in clinic setting could be answered by intensive search; (2) answers found by intensive searches were judged to be more satisfactory than those found routinely by doctors. Provision of an information retrieval service in addition to training in the searching and appraisal of medical literature are possible solutions to the information needs of busy clinicians.

Adult↗

A method for the quantitation of protamine in plasma.

A unique and simple colorimetric method for the quantitation of plasma protamine levels has been developed. The method is established on the competitive binding displacement mechanism between protamine and heparin-azure A dye complex, and the metachromatic color change of azure A dye in the presence of heparin. Because the method is based on the clinical specificity of protamine as the heparin antagonist, it is specific for protamine quantitation. Plasma protamine levels determined by this method are within 94% of accuracy when compared with their aqueous counterparts determined by the conventional Lowry protein assay. Since the method measures the protamine excess after heparin neutralization, it potentially could be employed during clinical heparin reversal with protamine to monitor protamine excess. In addition, the method may provide a useful means to identify the mechanism of the so-called "heparin rebound".

Azure Stains↗

The use of immobilized protamine in removing heparin and preventing protamine-induced complications during extracorporeal blood circulation.

Heparin, currently used in extracorporeal blood circulation procedures, may lead to hemorrhagic complications. Protamine, used for reversal of heparin-induced anticoagulation at the end of such procedures, can cause adverse hemodynamic responses. To prevent both types of complications, we have developed a reactor device containing immobilized protamine (i.e., a protamine bio-reactor) that can be placed at the distal end of the circuit, thus providing simultaneous extracorporeal heparin removal and protamine treatment. In preliminary in vivo studies involving dogs at a blood flow of 100 ml/min, the bio-reactor removed about 50% of the administered dose of heparin (i.e., 100 units/kg) in 10 min. While rapid injection of protamine in dogs anticoagulated with heparin produced a transient and significant (P less than 0.005) decreases in systemic arterial blood pressure (-39.5 +/- 9.2 mmHg), cardiac output (-1.59 +/- 0.23 L/min), and mixed venous oxygen saturation (-7.5 +/- 1.3%) and increases in pulmonary artery systolic (+12.7 +/- 4.4 mmHg) and diastolic pressures (+10.0 +/- 3.6 mmHg), the use of the protamine bio-reactor did not elicit any statistically significant change in any of the variables measured. Hemolysis was not significant, as reflected by a statistically insignificant change of the animals' red blood cell counts, hematocrits, and total hemoglobin values. In addition, hemolytic complement was found to be reduced only by 10% in animals with the protamine bio-reactor, whereas it was reduced rapidly by 20% in animals receiving intravenous protamine administration and progressively by 20% in control animals with a sham reactor that contained no protamine. Furthermore, the use of the protamine bio-reactor also significantly reduced the protamine-induced transient thrombocytopenic and granulocytopenic responses. The white blood cell counts and platelet counts decreased to 87.7 +/- 7.5 and 83.3 +/- 5.0% of baseline, respectively, in dogs with the protamine bio-reactor compared to 35.5 +/- 14.3 and 32.1 +/- 8.1% of baseline in dogs receiving intravenous protamine. The protamine bio-reactor may provide a unique means to simultaneously control both heparin- and protamine-induced complications.

Animals↗

A facile colorimetric protamine titration method.

On the basis of the reversible, competitive binding of protamine and azure A dye to heparin, a facile, colorimetric protamine titration method was developed. The method uses azure A dye as the titration indicator and has thus replaced the time-consuming clotting assay in the traditional protamine titration method with a rapid colorimetric assay. It offers the same accuracy in estimating the titration end point as the traditional titration method but allows the processing time to be significantly shortened. With the use of a premade diagnostic kit containing a fixed amount of azure A dye and various amounts of protamine, the titration end point can be determined in less than 5 minutes. This new colorimetric protamine titration method should provide clinicians with an easy and reliable means to accurately estimate the protamine dose required for heparin neutralization. It should also assist medical laboratories in preparing plasma samples that are free of heparin interference for routine coagulation tests. In a reverse manner, the colorimetric assay can also be used with a heparin titration procedure to quickly assess the heparin dose required for protamine reversal. For patients who have received overdoses of protamine, the availability of a facile heparin titration method may offer the prospect of exercising a heparin "back titration."

Azure Stains↗