Discrimination between possible sarcopenia and metabolic syndrome using the arterial pulse spectrum and machine-learning analysis.

Sarcopenia is defined as decreased skeletal muscle mass and function, and is an important cause of frailty in the elderly, also being associated with vascular lesions and poor microcirculation. The present study aimed to combine noninvasive pulse measurements, frequency-domain analysis, and machine learning (ML) analysis (1) to determine the effects on the pulse waveform induced by sarcopenia and (2) to develop discriminating models for patients with possible sarcopenia. Radial blood pressure waveform (BPW) signals were measured noninvasively for 1 min in 133 subjects who visited Tri-Service General Hospital for geriatric health checkups. They were assigned to a robust group and a possible-sarcopenia group that combined dynapenia, presarcopenia, and sarcopenia. Two classification methods were used: ML analysis and a self-developed scoring system that used 40 harmonic pulse indices as features: amplitude proportions and their coefficients of variation, and phase angles and their standard deviations. Significant differences were found in several spectral indices of the BPW between possible-sarcopenia and robust subjects. Threefold cross-validation results indicated excellent discrimination performance, with AUC equaling 0.77 when using LDA and 0.83 when using our scoring system. The present noninvasive and easy-to-use measurement and analysis method for detecting sarcopenia-induced changes in the arterial pulse transmission condition could aid the discrimination of possible sarcopenia.

The bioactivity of 2,5-dimethoxy-4-ethylthiophenethylamine (2C-T-2) and its detection in rat urine by capillary electrophoresis combined with an on-line sample concentration technique.

The bioactivity of 2,5-dimethoxy-4-ethylthiophenethylamine (2C-T-2) on nitric oxide (NO) production and the proliferation of spleen and thymus lymphocytes to mitogen stimulation in mice are reported for the first time. NO production by T and B lymphocytes in spleen and T cells in the thymus of mice decreased after the oral administration of 2C-T-2. This indicates that 2C-T-2 intake may perturb both neural and immune activity since a decrease in NO production is indicative of a weakened defense function. 2C-T-2 (the parent drug) in rat urine samples was detected by means of capillary electrophoresis/UV absorbance combined with an on-line sample concentration technique. When the CZE and MEKC modes were employed, the detection limit was found to be 4.5 and 5.0 microg/mL (at a 92.1% confidence level); whereas when on-line sample concentration methods, including stacking and sweeping-micellar electrokinetic chromatography were used, the detection limits were improved to 19.2 and 9.1 ng/mL, respectively. In an analysis of some actual samples from animal experiments, three male rats were administered 20 microg/g of body weight of 2C-T-2 by intra-peritoneal injection. The first- and second-day urine fractions were collected after the administration, for use in the analysis. As a result, 2.9 microg/mL and 0.25 microg/mL of 2C-T-2, respectively, were detected after ingestion of the doses.

Optimization of a simple method for the chiral separation of methamphetamine and related compounds in clandestine tablets and urine samples by beta-cyclodextrine modified capillary electrophoresis: a complementary method to GC-MS.

The chiral separation of (+/-)-methamphetamine, (+/-)-methcathinone, (+/-)-ephedrine and (+/-)-pseudoephedrine by means of beta-cyclodextrine modified capillary electrophoresis is described. The distribution of enantiomers in clandestine tablets and urine samples were identified. Several electrophoretic parameters such as the concentration of beta-cyclodextrin, temperature, the applied voltage and the amount of organic solvent required for successful separation were optimized. The method, as described herein, represents a good complementary method to GC-MS for use in forensic and clinical analysis.