Combined plasma biomarkers for diagnosing mild cognition impairment and Alzheimer's disease.

A highly sensitive immunoassay, the immunomagnetic reduction, is used to measure several biomarkers for plasma that is related to Alzheimer's disease (AD). These biomarkers include Aß-40, Aß-42, and tau proteins. The samples are composed of four groups: healthy controls (n=66), mild cognitive impairment (MCI, n=22), very mild dementia (n=23), and mild-to-serve dementia, all due to AD (n=22). It is found that the concentrations of both Aß-42 and tau protein for the healthy controls are significantly lower than those of all of the other groups. The sensitivity and the specificity of plasma Aß-42 and tau protein in differentiating MCI from AD are all around 0.9 (0.88-0.97). However, neither plasma Aß-42 nor tau-protein concentration is an adequate parameter to distinguish MCI from AD. A parameter is proposed, which is the product of plasma Aß-42 and tau-protein levels, to differentiate MCI from AD. The sensitivity and specificity are found to be 0.80 and 0.82, respectively. It is concluded that the use of combined plasma biomarkers not only allows the differentiation of the healthy controls and patients with AD in both the prodromal phase and the dementia phase, but it also allows AD in the prodromal phase to be distinguished from that in the dementia phase.

Assessing the quality of Bionime self-monitoring blood glucose system Rightest GM110: a critical evaluation of interference and ambient circumstances.

BACKGROUND: The key issue in preventing chronic diabetic complications is to maintain near-normoglycemia. Analytical evaluation of Bionime self-monitoring blood glucose (SMBG) Rightest GM110 was carried out in this study. METHODS: The evaluation was executed according to the Standards for Reporting Diagnostic Accuracy (STARD) and the Clinical and Laboratory Standards Institute (CLSI). The evaluation procedure mainly focused on analytical performance. The accuracy tests included hematocrit, interferants, temperature, humidity, altitude and clinical evaluations. RESULTS: Good linearity response (R(2)>0.99) and satisfactory precision (CVs: 1.1-2.8%) were observed in glucose concentrations of 0.6-30.5 mmol/l. In hematocrit test, the Rightest GM110 was suitable for use in sample containing hematocrit in the range of 30-55%. Interfering test indicated that almost all substances tested were insignificant, with bias <10% in medium- and hyper-glycemia samples. Satisfactory stability was also found under various ambient circumstances, with bias within +/-10%. In clinical trials, values within the acceptable zone (A+B) were 100% and values within zone A exceed 95% in error grid analysis. CONCLUSIONS: The Bionime Rightest GM110 is reliable to display accurate glucose concentrations in specimens with irresistible interfering factors.