The Validation of the Dai Nippon Medi·Ca SA Method for AOAC Research Institute Performance Tested MethodsSM Certification.

A ready-made dry medium method for Staphylococcus aureus count, the Medi·Ca SA method incubated at 35 or 37°C, was compared with the Baird-Parker method (AOAC Official MethodSM 975.55) for 11 food matrices: raw beef, raw ground beef, raw lamb, cooked ham, raw salmon, frozen prawn, fresh chilled pasta, pasteurized milk, natural cheese, cream puff, and potato salad. The mean difference between the two methods at each contamination level for each matrix was <0.5 log10, and the 95% confidence intervals on the mean differences fell within the range of -0.50 to 0.50. Standard deviation of repeatability and RSDr values of the Medi·Ca SA method were generally the same level as those of the Baird-Parker method, and r2 ranged from 0.98 to 1.00. Product consistency and stability studies showed little variability between productions lots and a shelf-life of 16 months. Incubation time within the range of 22-26 h and variations to the sample volume did not adversely affect the results. These results showed that the Medi·Ca SA method is a reasonable alternative to the reference method for selected food matrices and makes it possible to simultaneously detect and enumerate S. aureus in only 24 h.

Validation of Medi·Ca EC Method for AOAC Research Institute Performance Tested MethodsSM Certification.

A ready-made dry medium method for Escherichia coli and coliform count, the Medi·Ca EC method, was compared with the most probable number (MPN) method using Brilliant Green Lactose Bile broth and E. coli broth (AOAC INTERNATIONAL Official MethodSM 966.24) for seven food matrixes: raw beef, raw pork, raw frozen pork, raw lamb, raw salmon, frankfurter sausage, and cooked ham. The mean difference between the two methods at each contamination level for each matrix was <0.5 log10, and the 95% confidence intervals for the mean differences fell within the range of -0.5 to 0.5, with the exception of a few cases in the independent laboratory study. sr and RSDr values of the Medi·Ca EC method were generally lower than those of the MPN method, and r2 ranged from 0.91 to 0.99. Product consistency and stability studies showed little variability between production lots and the shelf-life of 20 months. An incubation time within the range of 22-26 h did not adversely affect the results; however, variations in sample volume did affect final counts. These results showed that the Medi·Ca EC method is a reasonable alternative to the reference method for the selected food matrixes and makes it possible to simultaneously detect and enumerate E. coli and coliform in only 24 h.

Inhibition of MEK1 Signaling Pathway in the Liver Ameliorates Insulin Resistance.

Although mitogen-activated protein kinase kinase (MEK) is a key signaling molecule and a negative regulator of insulin action, it is still uncertain whether MEK can be a therapeutic target for amelioration of insulin resistance (IR) in type 2 diabetes (T2D) in vivo. To clarify whether MEK inhibition improves T2D, we examined the effect of continuous MEK inhibition with two structurally different MEK inhibitors, RO5126766 and RO4987655, in mouse models of T2D. RO5126766 and RO4987655 were administered via dietary admixture. Both compounds decreased blood glucose and improved glucose tolerance in doses sufficient to sustain inhibition of extracellular signal-regulated kinase (ERK)1/2 phosphorylation downstream of MEK in insulin-responsive tissues in db/db mice. A hyperinsulinemic-euglycemic clamp test showed increased glucose infusion rate (GIR) in db/db mice treated with these compounds, and about 60% of the increase was attributed to the inhibition of endogenous glucose production, suggesting that the liver is responsible for the improvement of IR. By means of adenovirus-mediated Mek1 shRNA expression, we confirmed that blood glucose levels are reduced by suppression of MEK1 expression in the liver of db/db mice. Taken together, these results suggested that the MEK signaling pathway could be a novel therapeutic target for novel antidiabetic agents.

Dai Nippon Printing Co., Ltd Medi·Ca CC for Enumeration of Coliform Bacteria.

A ready-made dry medium method for coliform count, the Medi·Ca CC method, was compared to the Violet Red Bile Agar method (Bacteriological Analytical Manual, Chapter 4, Enumeration of Escherichia coli and the Coliform Bacteria, Section G) for nine raw foods from four food categories: raw ground pork, raw lamb, raw ground chicken, raw tuna fillet, raw salmon fillet, raw shrimp, fresh peeled banana, fresh cut pineapple, and fresh cut apple. The 95% confidence interval for the mean difference between the two methods at each contamination level for seven matrixes from all four categories fell within the range of -0.50 to 0.50, and no statistical difference was observed at all three contamination levels for four matrixes from three categories. These results demonstrated that the Medi·Ca CC method is a reasonable alternative to the reference method for raw meat, raw poultry, raw fish, and fresh fruits.

Automated selection of major arteries and veins for measurement of arteriolar-to-venular diameter ratio on retinal fundus images.

An automated method for measurement of arteriolar-to-venular diameter ratio (AVR) is presented. The method includes optic disc segmentation for the determination of the AVR measurement zone, retinal vessel segmentation, vessel classification into arteries and veins, selection of major vessel pairs, and measurement of AVRs. The sensitivity for the major vessels in the measurement zone was 87%, while 93% of them were classified correctly into arteries or veins. In 36 out of 40 vessel pairs, at least parts of the paired vessels were correctly identified. Although the average error in the AVRs with respect to those based on the manual vessel segmentation results was 0.11, the average error in vessel diameter was less than 1 pixel. The proposed method may be useful for objective evaluation of AVRs and has a potential for detecting focal arteriolar narrowing on macula-centered screening fundus images.