METHODS: Serum and urine samples were collected from healthy human subjects. The experiment was divided into two parts, part one to evaluate 2,2,2,2-tetradeutero-4,4-dimethyl-4-silapentanoic acid (TSP) and 4,4-dimethyl-4-silapentane-1-ammonium trifluoroacetate (DSA) as the optimal internal standard for the serum and urine samples. The second part investigated the effects of preservatives in the serum and urine samples on extended storage.
RESULTS: Overall, TSP and DSA are suitable to be used as an internal standard in human urine samples. However, DSA is a superior internal standard in serum samples for NMR analysis. For the effect of preservative, the results indicated that human serum and urine samples could be stored without addition of preservative in -80 °C, as no changes in NMR fingerprinting have been observed during storage in the absence or presence of the preservative.
CONCLUSIONS: The findings suggest the use of DSA and TSP as an internal standard in serum and urine samples, respectively. Storage of serum and urine samples without any addition of preservative for an extended period has no effect on the metabolites changes. By having a standardised method, it will offer a considerable saving in both operator and spectrometer time and most importantly produce reproducible and reliable data.
METHODS: In this study, a grounded theory approach was used to develop a substantive theoretical model with the aim of investigating the decision-making process of consumers when purchasing health supplements and natural products online. Malaysian adult consumers who had purchased these products via the Internet were either purposively or theoretically sampled. A total of 18 virtual in-depth interviews (IDIs) were conducted to elicit participants' experiences and priorities in relation to this activity. All the IDIs were audio-recorded and transcribed verbatim. The data were analysed using open coding, focus coding and theoretical coding. The analytical interpretations and theoretical concepts were recorded in research memos.
RESULTS: Consumers' decisions to purchase a health supplement or natural product over the Internet are based on a series of assessments regarding the perceived benefits and risks of this activity, which may be related to the product or the process. In the online marketplace, consumers attempt to choose products, online sellers, sales platforms and/or purchase mechanisms with lower perceived risk, which ultimately enhances their confidence in five elements related to the purchase: (1) product effectiveness, (2) product safety, (3) purchase convenience, (4) fair purchase and (5) online security. Consumers take an acceptable level of risk to purchase these products online, and this acceptable level is unique to each individual and is based on their perception of having control over the potential consequences if the worst-case scenario occurs.
CONCLUSIONS: In this study, a substantive theoretical model is developed to demonstrate how consumers decide to purchase online health supplements and natural products by accepting an acceptable level of risk associated with the product or process. The emerging model is potentially transferable to other populations in similar contexts.
METHODS: Serum and urine samples were collected from healthy human subjects. The experiment was divided into two parts, part one to evaluate 2,2,2,2-tetradeutero-4,4-dimethyl-4-silapentanoic acid (TSP) and 4,4-dimethyl-4-silapentane-1-ammonium trifluoroacetate (DSA) as the optimal internal standard for the serum and urine samples. The second part investigated the effects of preservatives in the serum and urine samples on extended storage.
RESULTS: Overall, TSP and DSA are suitable to be used as an internal standard in human urine samples. However, DSA is a superior internal standard in serum samples for NMR analysis. For the effect of preservative, the results indicated that human serum and urine samples could be stored without addition of preservative in -80 °C, as no changes in NMR fingerprinting have been observed during storage in the absence or presence of the preservative.
CONCLUSIONS: The findings suggest the use of DSA and TSP as an internal standard in serum and urine samples, respectively. Storage of serum and urine samples without any addition of preservative for an extended period has no effect on the metabolites changes. By having a standardised method, it will offer a considerable saving in both operator and spectrometer time and most importantly produce reproducible and reliable data.
STUDY DESIGN: A review of articles was performed.
METHODS: A search strategy was used by using electronic bibliographic databases including PubMed, Embase and CENTRAL for published studies and reference list of published studies. The articles were exported to a bibliographic database for further screening process. Two reviewers worked independently to screen results and extract data from the included studies. Any discrepancies were resolved and confirmed by the consensus of all authors.
RESULTS: There were three screening approaches for detecting MCI and dementia - screening by a healthcare provider, screening by a self-administered questionnaire and caretaker informant screening. Montreal Cognitive Assessment (MoCA) was the most common and preferable tool for MCI screening (sensitivity [Sn]: 81-97%; specificity [Sp]: 60-86%), whereas Addenbrooke's Cognitive Examination (ACE) was the preferable tool for dementia screening (Sn: 79-100%; Sp: 86%).
CONCLUSION: This systematic review found that there are three screening approaches for detecting early dementia and MCI at primary health care. ACE and MoCA are recommended tools for screening of dementia and MCI, respectively.
METHODS: Pre-dosed urine samples were collected from male Sprague-Dawley rats. The rats were treated with either LDA (10 mg/kg) or 1% methylcellulose (10 mL/kg) per oral for 28 days. The rats' stomachs were examined for gastric toxicity using a stereomicroscope. The urine samples were analyzed using a proton nuclear magnetic resonance spectroscopy. Metabolites were systematically identified by exploring established databases and multivariate analyses to determine the spectral pattern of metabolites related to LDA-induced gastric toxicity.
RESULTS: Treatment with LDA resulted in gastric toxicity in 20/32 rats (62.5%). The orthogonal projections to latent structures discriminant analysis (OPLS-DA) model displayed a goodness-of-fit (R2Y) value of 0.947, suggesting near-perfect reproducibility and a goodness-of-prediction (Q2Y) of -0.185 with perfect sensitivity, specificity and accuracy (100%). Furthermore, the area under the receiver operating characteristic (AUROC) displayed was 1. The final OPLS-DA model had an R2Y value of 0.726 and Q2Y of 0.142 with sensitivity (100%), specificity (95.0%) and accuracy (96.9%). Citrate, hippurate, methylamine, trimethylamine N-oxide and alpha-keto-glutarate were identified as the possible metabolites implicated in the LDA-induced gastric toxicity.
CONCLUSION: The study identified metabolic signatures that correlated with the development of a low-dose Aspirin-induced gastric toxicity in rats. This pharmacometabolomic approach could further be validated to predict LDA-induced gastric toxicity in patients with coronary artery disease.