Reuven Rasooly

Docosahexaenoic Acid (DHA) But Not Eicosapentaenoic Acid (EPA) Prevents Trans-10, Cis-12 Conjugated Linoleic Acid (CLA)–Induced Insulin Resistance in Mice

BACKGROUND The objective of this study was to investigate if eicosapentaenoic acid (20:5n-3, EPA) or docosahexaenoic acid (22:6n-3, DHA) or both would prevent conjugated linoleic acid (CLA)-induced insulin resistance and fatty liver. METHODS Eight-week-old, pathogen-free C57BL/6N female mice (10 per group) were fed either a control diet or diets containing t10, c12-CLA (0.5 wt %), CLA + DHA (0.5% + 1.5 wt %), or CLA + EPA (0.5% + 1.5 wt %) for 8 weeks prior to sacrifice and tissue collection. RESULTS CLA supplementation caused an 8.9-fold increase in circulating insulin, a 2.6-fold increase in liver weight, and a 6.2-fold increase in the weight of total lipids in the liver as compared with the corresponding values in the control group. DHA prevented the CLA-induced insulin resistance, while EPA was ineffective. Both EPA and DHA prevented CLA-induced fatty liver and reduced weights of total liver lipids to the levels of the control group. CLA also reduced the plasma leptin and adiponectin concentrations to approximately 15% of those in the control group. Both EPA and DHA partially restored the CLA-induced decrease in leptin, but only DHA partially restored the plasma adiponectin. CONCLUSIONS Our results suggest that DHA but not EPA in fish oils may reduce insulin resistance which may be mediated through an increase in circulating adiponectin. These findings may have clinical implications in the dietary management of patients at risk of insulin resistance and diabetes.

Improving the Sensitivity and Functionality of Mobile Webcam-Based Fluorescence Detectors for Point-of-Care Diagnostics in Global Health

Resource-poor countries and regions require effective, low-cost diagnostic devices for accurate identification and diagnosis of health conditions. Optical detection technologies used for many types of biological and clinical analysis can play a significant role in addressing this need, but must be sufficiently affordable and portable for use in global health settings. Most current clinical optical imaging technologies are accurate and sensitive, but also expensive and difficult to adapt for use in these settings. These challenges can be mitigated by taking advantage of affordable consumer electronics mobile devices such as webcams, mobile phones, charge-coupled device (CCD) cameras, lasers, and LEDs. Low-cost, portable multi-wavelength fluorescence plate readers have been developed for many applications including detection of microbial toxins such as C. Botulinum A neurotoxin, Shiga toxin, and S. aureus enterotoxin B (SEB), and flow cytometry has been used to detect very low cell concentrations. However, the relatively low sensitivities of these devices limit their clinical utility. We have developed several approaches to improve their sensitivity presented here for webcam based fluorescence detectors, including (1) image stacking to improve signal-to-noise ratios; (2) lasers to enable fluorescence excitation for flow cytometry; and (3) streak imaging to capture the trajectory of a single cell, enabling imaging sensors with high noise levels to detect rare cell events. These approaches can also help to overcome some of the limitations of other low-cost optical detection technologies such as CCD or phone-based detectors (like high noise levels or low sensitivities), and provide for their use in low-cost medical diagnostics in resource-poor settings.