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Analytical Findings (analytical + finding)
Selected AbstractsTemporal indication of cannabis use by means of THC glucuronide determinationDRUG TESTING AND ANALYSIS, Issue 11-12 2009Ute Mareck Abstract According to the regulations of the World Anti-Doping Agency (WADA), the use of cannabinoids is forbidden in competition. In doping controls, the detection of cannabinoid misuse is based on the analysis of the non-psychoactive metabolite 11-nor-9-carboxy-delta-9-tetrahydrocannabinol (carboxy-THC). The determination of values greater than 15 ng/mL in urine represents an adverse analytical finding; however, no accurate prediction of the time of application is possible as the half-life of carboxy-THC ranges between three and four days. Consequently the detection of carboxy-THC in doping control urine samples collected in competition might also result from cannabis use in out-of-competition periods. The analysis of the glucuronide of the pharmacologically active delta 9-tetrahydrocannabinol (THC-gluc) may represent a complementary indicator for the detection of cannabis misuse in competition. An assay for the determination of THC-gluc in human urine was established. The sample preparation consisted of liquid-liquid extraction of urine specimens, and extracts were analysed by liquid chromatography/tandem mass spectrometry (LC-MS/MS). Authentic doping-control urine samples as well as specimens obtained from a controlled smoking study were analysed and assay characteristics such as specificity, detection limit (0.1 ng/mL), precision (>90%), recovery (,80%), and extraction efficiency (90%) were determined. Copyright © 2010 John Wiley & Sons, Ltd. [source] Self-care behaviour and related factors in older people with Type 2 diabetesJOURNAL OF CLINICAL NURSING, Issue 23 2009Yu-Ling Bai Aim., The present study examined the factors related to self-care behaviour in type 2 diabetic patients aged ,65 years. In addition, this study tested the effect of the important explanatory factors on self-care behaviour. Background., Along with the development of an ageing society, diabetes occurs frequently among older people. Diabetes requires continual medical treatment, with patients responsible for self-care. Although the relationships among social support, depression and self-care have been widely studied, little is know about older diabetic patients, especially in Taiwan. Design., A correlational design was adopted. In total, 165 patients recruited using convenience sampling were diabetic outpatients at three hospitals in southern Taiwan from January,March 2005. Methods., The participants were interviewed using the Personal Resource Questionnaire 2000 (PRQ 2000), Diabetes Self-Care Scale and Taiwan Geriatric Depression Scale (TGDS). Data were analysed using descriptive statistics and multiple regression analysis. Result., Self-care behaviour scores were significantly influenced by different gender, education level, economic status and religious beliefs of older diabetic patients. Depression and self-care behaviour were negatively correlated. Social support, education and duration of diabetes significantly affected self-care behaviour, accounting for 35·6% of total variance. Conclusions., Social support plays a vital factor in contributing to the facilitation of self-care behaviour. These analytical findings demonstrate the importance of social support, education and duration of diabetes in determining self-care behaviour for diabetic older diabetic patients and serve as references for future studies of self-care behaviour in type 2 older diabetic patients. Relevance to clinical practice., Implication for nurses highlights the significance of providing patients with social support that will enable them to have good support systems during their disease treatment to enhance self-care abilities and improve quality of life. [source] Intratracheal clenbuterol in the horse: its pharmacological efficacy and analytical detectionJOURNAL OF VETERINARY PHARMACOLOGY & THERAPEUTICS, Issue 4 2000J. D. HARKINS Clenbuterol, a ,2 agonist/antagonist, is the only bronchodilator approved by the US Food and Drug Administration for use in horses. The Association of Racing Commissioners International classifies clenbuterol as a class 3 agent, and, as such, its identification in post-race samples may lead to sanctions. Anecdotal reports suggest that clenbuterol may have been administered by intratracheal (IT) injection to obtain beneficial effects and avoid post-race detection. The objectives of this study were (1) to measure the pharmacological efficacy of IT dose of clenbuterol and (2) to determine the analytical findings in urine in the presence and absence of furosemide. When administered intratracheally (90,,g/horse) to horses suffering from chronic obstructive pulmonary disease (COPD), clenbuterol had effects that were not significantly different from those of saline. In parallel experiments using a behavior chamber, no significant effects of IT clenbuterol on heart rate or spontaneous locomotor activity were observed. Clenbuterol concentrations in the urine were also measured after IT dose in the presence and absence of furosemide. Four horses were administered i.v. furosemide (5,mg/kg), and four horses were administered saline (5,mL). Two hours later, all horses were administrated clenbuterol (IT, 90,,g), and the furosemide-treated horses received a second dose of furosemide (2.5 mg/kg, i.v.). Three hours after clenbuterol dose (1,h after hypothetical ,post-time'), the mean specific gravity of urine samples from furosemide-treated horses was 1.024, well above the 1.010 concentration at which furosemide is considered to interfere with drug detection. There was no interference by furosemide with ,enhanced' ELISA screening of clenbuterol equivalents in extracted and concentrated samples. Similarly, furosemide had no effect on mass spectral identification or quantification of clenbuterol in these samples. These results suggest that the IT dose of clenbuterol (90,,g) is, in pharmacological terms, indistinguishable from the dose of saline, and that, using extracted samples, clenbuterol dose is readily detectable at 3,h after dosing. Furthermore, concomitant dose of furosemide does not interfere with detection or confirmation of clenbuterol. [source] Classical predator,prey system with infection of prey population,a mathematical modelMATHEMATICAL METHODS IN THE APPLIED SCIENCES, Issue 14 2003J. Chattopadhyay Abstract The present paper deals with the problem of a classical predator,prey system with infection of prey population. A classical predator,prey system is split into three groups, namely susceptible prey, infected prey and predator. The relative removal rate of the susceptible prey due to infection is worked out. We observe the dynamical behaviour of this system around each of the equilibria and point out the exchange of stability. It is shown that local asymptotic stability of the system around the positive interior equilibrium ensures its global asymptotic stability. We prove that there is always a Hopf bifurcation for increasing transmission rate. To substantiate the analytical findings, numerical experiments have been carried out for hypothetical set of parameter values. Our analysis shows that there is a threshold level of infection below which all the three species will persist and above which the disease will be epidemic. Copyright © 2003 John Wiley & Sons, Ltd. [source] Measurement of xenobiotics in saliva: is saliva an attractive alternative matrix?BIOMEDICAL CHROMATOGRAPHY, Issue 1 2009Case studies, analytical perspectives Abstract The use of saliva for measuring xenobiotic concentrations has been practiced for a number of years. While the use of saliva has been generally reserved for the analysis of diagnostic and forensic/toxicology samples, attempts have been made to further enhance the value of saliva as an alternate matrix to those of plasma and serum. It is understood that saliva represents a handy tool for therapeutic drug monitoring (TDM) as it offers certain distinctive advantages. This scope of this review encompasses the following: (a) a comprehensive view of saliva as an alternate matrix for either plasma or serum to understand the pharmacokinetic/pharmacodynamic (PK/PD) characteristics; (b) an account of the factors contributing to the observed variability in salivary monitoring; (c) a tabular compilation of diverse case studies of xenobitoics belonging to different therapeutic classes with emphasis on assay methodology and applicable analytical/biopharmaceutical/pharmacokinetic findings; (d) relevant thoughts on assay procedures as they relate to salivary monitoring; and (e) some representative case studies highlighting the new thinking on the use of saliva outside of traditional TDM. Overall, based on the review, saliva represents a valuable TDM tool for a number of xenobiotics. While parent compound and phase I metabolite(s) for many xenobiotics have been generally quantifiable in saliva, phase II metabolites have not generally been detected in saliva. Therefore saliva samples could also be used to answer some specific PK/PD questions during the drug development process, if applicable. However, the development and validation of the assay in saliva needs to be carried out carefully with particular focus on proper sample collection, processing and storage to ensure the stability of the xenobiotics and with the same rigor as applied to plasma, serum and urine matrices. Copyright © 2008 John Wiley & Sons, Ltd. [source] | |||||||||||||