A global benchmark study using affinity-based biosensors.

To explore the variability in biosensor studies, 150 participants from 20 countries were given the same protein samples and asked to determine kinetic rate constants for the interaction. We chose a protein system that was amenable to analysis using different biosensor platforms as well as by users of different expertise levels. The two proteins (a 50-kDa Fab and a 60-kDa glutathione S-transferase [GST] antigen) form a relatively high-affinity complex, so participants needed to optimize several experimental parameters, including ligand immobilization and regeneration conditions as well as analyte concentrations and injection/dissociation times.

Reproducibility and accuracy of body composition assessments in mice by dual energy x-ray absorptiometry and time domain nuclear magnetic resonance.

OBJECTIVE: To assess the accuracy and reproducibility of dual-energy absorptiometry (DXA; PIXImus(™)) and time domain nuclear magnetic resonance (TD-NMR; Bruker Optics) for the measurement of body composition of lean and obese mice. SUBJECTS AND MEASUREMENTS: Thirty lean and obese mice (body weight range 19-67 g) were studied. Coefficients of variation for repeated (x 4) DXA and NMR scans of mice were calculated to assess reproducibility.

Harris-Benedict equation estimations of energy needs as compared to measured 24-h energy expenditure by indirect calorimetry in people with early to mid-stage Huntington's disease.

Weight loss and energy metabolism are important clinical research areas in understanding the disease mechanisms in Huntington's disease. Having an accurate method to estimate expected total energy expenditure would likely facilitate the development of studies about these features of the disease. The Harris-Benedict equation is a formula commonly used to estimate basal energy expenditure of individuals, adjusted for height, weight, age and gender.

Leptin levels and luteinizing hormone pulsatility in normal cycling women and their relationship to daily changes in metabolic rate.

Objective: To determine whether leptin and LH secretion in normal women is related to changes in metabolic rate.

Setting: Academic medical center. PATIENT(S) AND DESIGN: Ten young women with normal weight and menses were studied during the early follicular phase.

Higher post-absorptive skeletal muscle LPL activity in African American vs. non-Hispanic White pre-menopausal women.

Objective: Higher post-absorptive post-heparin plasma lipoprotein lipase (LPL) activity has been reported in African Americans as compared to non-Hispanic whites but differences in tissue-specific LPL activity are unclear.

Methods And Procedures: Post-absorptive skeletal muscle (SM)-LPL (vastus lateralis ) and subcutaneous abdominal adipose tissue (AT)-LPL activity was measured in overweight, sedentary African American females (n = 11) as well as in their non-Hispanic white counterparts (n = 6) during a period of controlled low fat (30%) diet (for 10 days) combined with physical activity (for days 8-10). Post-absorptive substrate utilization was measured on day 10; fasting blood levels and SM and AT biopsies were obtained on day 11.