Measuring Ochratoxin A Concentrations in Coffee Beverages with Immunoaffinity Columns and Ultra-Performance Liquid Chromatography/Tandem Mass Spectrometry.

This study developed and validated a method for measuring concentrations of ochratoxin A (OTA) in coffee beverages, not coffee beans. The new method involved extraction using immunoaffinity columns and ultra-performance LC (UPLC)-MS/MS using isotope-dilution techniques. The combination of a fused-core column and UPLC significantly shortened chromatographic time to 3 min compared to reported UPLC methods. The method was sensitive, with an LOD and LOQ of 0.52 and 1.73 pg/mL, respectively. Quantitative intraday (n = 4) and interday (n = 4) biases and RSD were both below 15%. The OTA levels in 40 samples of freshly brewed coffee from chain stores, 24 samples of canned ready-to-drink coffee, and 6 beverages made from instant coffee granules ranged from 1.60 to 93.2 pg/mL (90% positive), 6.00 to 131 pg/mL (100% positive), and 21.8 to 59.0 pg/mL (100% positive), respectively. Based on published tolerable daily intake, men and women in Taiwan should consume no more than 6.3 and 5.1 fifteen gram packages of instant coffee per day, respectively. Specific suggestions were not made for brewed coffee and canned coffee because of their large variation in OTA concentrations. This study should be more relevant to actual human exposure than those studying OTA in green, roasted, and ground coffee beans alone.

Rapid identification and susceptibility testing of uropathogenic microbes via immunosorbent ATP-bioluminescence assay on a microfluidic simulator for antibiotic therapy.

The incorporation of pathogen identification with antimicrobial susceptibility testing (AST) was implemented on a concept microfluidic simulator, which is well suited for personalizing antibiotic treatment of urinary tract infections (UTIs). The microfluidic device employs a fiberglass membrane sandwiched between two polypropylene components, with capture antibodies immobilized on the membrane. The chambers in the microfluidic device share the same geometric distribution as the wells in a standard 384-well microplate, resulting in compatibility with common microplate readers. Thirteen types of common uropathogenic microbes were selected as the analytes in this study. The microbes can be specifically captured by various capture antibodies and then quantified via an ATP bioluminescence assay (ATP-BLA) either directly or after a variety of follow-up tests, including urine culture, antibiotic treatment, and personalized antibiotic therapy simulation. Owing to the design of the microfluidic device, as well as the antibody specificity and the ATP-BLA sensitivity, the simulator was proven to be able to identify UTI pathogen species in artificial urine samples within 20 min and to reliably and simultaneously verify the antiseptic effects of eight antibiotic drugs within 3-6 h. The measurement range of the device spreads from 1 × 10(3) to 1 × 10(5) cells/mL in urine samples. We envision that the medical simulator might be broadly employed in UTI treatment and could serve as a model for the diagnosis and treatment of other diseases.

Preliminary results concerning the presence of secretory immunoglobulin A (SIgA) in the serum of patients with IgA myeloma.

Using the immunosorbents realized by binding either antisecretory immunoglobulin A antibodies or antisecretory component ones to beads of cross-linked polyvinyl alcohol matrix, secretory immunoglobulin A, from the serum of patients with IgA myeloma was investigated. The related protein isolated with the same method from colostrum was comparatively studied. Studies were done by polyacrylamyde gel electrophoresis (PAGE) and SDS-PAGE, as well as by immunochemical methods. The two proteins obtained presented the same characteristics: a single fraction in PAGE and four fractions in SDS-PAGE. The determinations were carried out by immunoelectrophoresis and double diffusion using monospecific antisera proved the identity of the isolated proteins with secretory IgA.