Low-cost microphysiological systems: feasibility study of a tape-based barrier-on-chip for small intestine modeling.

We see affordability as a key challenge in making organs-on-chips accessible to a wider range of users, particularly outside the highest-resource environments. Here, we present an approach to barrier-on-a-chip fabrication based on double-sided pressure-sensitive adhesive tape and off-the-shelf polycarbonate. Besides a low materials cost, common also to PDMS or thermoplastics, it requires minimal (€100) investment in laboratory equipment, yet at the same time is suitable for upscaling to industrial roll-to-roll manufacture. We evaluate our microphysiological system with an epithelial (Caco-2/BBe1) barrier model of the small intestine, studying the biological effects of permeable support pore size, as well as stimulation with a common food compound (chili pepper-derived capsaicinoids). The cells form tight and continuous barrier layers inside our systems, with comparable permeability but superior epithelial polarization compared to Transwell culture, in line with other perfused microphysiological models. Permeable support pore size is shown to weakly impact barrier layer integrity as well as the metabolic cell profile. Capsaicinoid response proves distinct between culture systems, but we show that impacted metabolic pathways are partly conserved, and that cytoskeletal changes align with previous studies. Overall, our tape-based microphysiological system proves to be a robust and reproducible approach to studying physiological barriers, in spite of its low cost.

Microbiological Testing Results of Cooked Diced Chicken and Pasteurized Egg Products Purchased for United States Federal Nutrition Assistance Programs, 2012-2018.

The Agricultural Marketing Service (AMS) purchases cooked diced chicken, pasteurized liquid whole eggs, and pasteurized dried egg mix for federal nutrition assistance programs. Purchases are made from establishments that have met the financial and technical requirements to become AMS-approved vendors. Cooked diced chicken is tested for the presence of Salmonella and Listeria monocytogenes, and for levels of aerobic plate count (APC) organisms, coliforms, and generic Escherichia coli (GEC). Of 3668 samples collected from October 2012 through September 2018, none were positive for Salmonella, 3 (0.8%) were positive for L. monocytogenes, 8 (0.22%) exceeded the APC critical limit (CL) of 1000 colony-forming units (CFUs)/mL, 15 (0.41%) exceeded the coliform CL of 50 CFU/mL, and 5 (0.14%) exceeded the GEC CL of 10 CFU/mL. Pasteurized liquid whole egg and pasteurized dried egg mix are tested for the presence of Salmonella and for levels of APC and CL. Of 984 pasteurized liquid whole egg samples collected from October 2012 through September 2018, 1 (0.10%) was positive for Salmonella, 29 (2.5%) exceeded the APC CL, and 4 (0.41%) exceeded the coliform CL. Of 380 pasteurized dried egg mix samples collected during this period, none was positive for Salmonella, none exceeded the APC CL, and 3 (0.79%) exceeded the coliform CL. All production lots from which samples found to contain pathogens or to exceed indicator organism CLs were identified and rejected for purchase by AMS. These data suggest that cooked diced chicken and pasteurized egg products produced for federal nutrition assistance programs are done so under effective food safety systems.

National trends in concomitant psychotropic medication with stimulants in pediatric visits: practice versus knowledge.

OBJECTIVES: (1) To examine U.S. national trends in the use of concomitant pharmacotherapy with the stimulant class of psychotropic drugs in youth; and (2) to present these trends in the context of (a) extant safety and efficacy data, and (b) overall trends in concomitant pharmacotherapy with psychotropic drugs for youth. METHODS: Prescribing data for youths under age 18 years from National Ambulatory Medical Surveys from 1993 to 1998 were analyzed. The visits were categorized into monotherapy (only one psychotropic prescribed) and concomitant pharmacotherapy (>1 psychotropic prescribed). The proportions of these groups were computed as a percentage of all visits during which a psychotropic medication was prescribed. Differences in proportions between surveys were analyzed to determine trends. RESULTS: Between 1993--94 and 1997--98, the proportions of visits for concomitant pharmacotherapy in association with the stimulant class increased nearly five-fold. This increase paralleled an overall increase in the proportion of visits involving prescription of more than one psychotropic medication among youth. CONCLUSIONS: The growth in concomitant pharmacotherapy with the stimulants class has out-paced the increase in safety/efficacy data to inform the use of this practice, resulting in a mismatch between trends in prescribing and growth in knowledge. A simultaneous trend of note is the overall increase in the use of concomitant pharmacotherapy with all psychotropic drugs in youth. Controlled trials are particularly needed to support commonly used combinations of stimulants with antidepressants in youth. In the absence of definitive data, clinical guidelines based on expert consensus and limited data are available and are useful.