Effect of phytate in soy protein on the serum and liver cholesterol levels and liver fatty acid profile in rats.

Dietary soy protein, in comparison with casein, generally lowers the serum cholesterol concentration in rats fed on a cholesterol-enriched diet, while mixed results were observed in rats fed on a diet free of cholesterol. Soy protein also suppresses the conversion of linoleic acid to arachidonic acid in the rat liver. The present study examines whether phytate, a minor component of a soy protein isolate, is responsible for these beneficial effects of soy protein. Weanling male rats were fed for 4 weeks on a purified diet containing a 20% level of protein (either casein (CAS), soy protein (SOY), phytate-depleted SOY (PDSOY) or phytate-replenished PDSOY (PRSOY)) and cholesterol (0 or 0.5%). The dietary protein source and phytate level only affected the serum and liver cholesterol concentrations when the animals were fed on the cholesterol-enriched diet, being significantly lower in those rats fed on the SOY and PRSOY diets than in those fed on the CAS diet, while the concentrations in the rats fed on the PDSOY diet were intermediate. When the animals were fed on the cholesterol-free diet, the ratio of (20:3n-6 + 20:4n-6)/18:2n-6 in liver phosphatidylcholine, a delta6 desaturation index, was significantly lower in the SOY diet group than in the CAS, PDSOY and PRSOY diet groups. Dietary cholesterol significantly depressed the ratio, but neither depletion nor replenishment of phytate affected the ratio. These results suggest that phytate in soy protein played a limited role in the cholesterol-lowering effect of soy protein and was not involved in the metabolism of linoleic acid.

Core functions and capabilities of state public health laboratories: a report of the Association of Public Health Laboratories.

Emerging natural and man-made threats to the health of the nations population require development of a seamless laboratory network to address preventable health risks; this can be achieved only by defining the role of public health laboratories in public and private laboratory service delivery. Establishing defined core functions and capabilities for state public health laboratories will provide a basis for assessing and improving quality laboratory activities. Defining public health laboratory functions in support of public health programs is the beginning of the process of developing performance standards for laboratories, against which state public health laboratories, and eventually local public health and clinical laboratories, will establish and implement best laboratory practices. Public health is changing, and as apart of that change, public health laboratories must advocate for and implement improvements for public health testing and surveillance. These changes are outlined also in the Association of Public Health Laboratories consensus report (Association of Public Health Laboratories. Core functions and capabilities of state public health laboratories: a white paper for use in understanding the role and value of public health laboratories in protecting our nation's health. Washington, DC: Association of Public Health Laboratories, 2000).