Inactivation radiation

Thayer et al. (26) reported the results of nutritional, genetic, and toxicological studies of enzyme-inactivated, radiation-sterilized chicken meat. The study included four enzyme-inactivated chicken meat products 1) a frozen control, 2) a thermally processed product (llS.b C), 3) a gamma-sterilized product, and 4)... 

Irradiation. Although no irradiation systems for pasteurization have been approved by the U.S. Food and Dmg Administration, milk can be pasteurized or sterilized by P tays produced by an electron accelerator or y-rays produced by cobalt-60. Bacteria and enzymes in milk are more resistant to irradiation than higher life forms. For pasteurization, 5000—7500 Gy (500,000—750,000 tad) are requited, and for inactivating enzymes at least 20,000 Gy (2,000,000 rad). Much lower radiation, about 70 Gy (7000 tad), causes an off-flavor. A combination of heat treatment and irradiation may prove to be the most acceptable approach. 

Although freeze-fracture experiments have demonstrated that monomers are assembled into stable tetramers in the membranes, radiation inactivation studies and, later, expression studies revealed that each monomer is a functional water channel (Fig. lc). 

RODRIGUEZ LOPEZ J, FENOLL L G, TUDELA J, DEVECE C, SANCHEZ HERNANDEZ D, DE LOS REYES E and GARCIA CANOVAS F (1999) Thermal inactivation of mushroom polyphenol oxidase employing 2450 MHz microwave radiation , J Agric Food Chem, 47 (8) 3028-35. 

Adams, G.E., Bisby, RH., Cundall, R.B., Redpath, J.L. and Willson, RL (1972). Selective free radical reactions with proteins and enzymes. The inactivation of ribonuclease. Radiat. Res. 49, 290-298. 

Thurston-Enriquez, J. A., Haas, C. N., Jacangelo, J., Riley, K., and Gerba, C. P. (2003b). Inactivation of feline calicivirus and adenovirus type 40 by UV radiation. Appl. Environ. 

Incorporation of downstream processing steps known to inactivate a wide variety of viral types provides further assurance that the final product is unlikely to harbour active virus. Heating and irradiation are amongst the two most popular such approaches. Heating the product to between 40 and 60°C for several hours inactivates a broad range of viruses. Many biopharmaceuticals can be heated to such temperatures without being denatured themselves. Such an approach has been used extensively to inactivate blood-borne viruses in blood products. Exposure of product to controlled levels of UV radiation can also be quite effective, while having no adverse effect on the product itself. 

Milner, H. E., Beliveau, R., and Jarvis, S. M. (1994) The in situ size of the dopamine transporter is a tetramer as estimated by radiation inactivation. Biochim. Biophys. Acta 1190,185-187. 

Irradiate WT and CD 154 NIH3T3 using an appropriate source of y radiation and follow all the health and safety procedures of your institution. Lfsually a dose of 30 Gray is sufficient to block cell proliferation (see Note 6). Cells can be used immediately after irradiation or frozen in 90% heat/inactivated FBS supplemented with 10% DMSO and stored at -80°C or in liquid nitrogen for short- and long-term storage, respectively. 

Hemotoxic activity. Seed oil, administered orally to human adults, produced thrombocytosis in children, the effect was inactivated by ultraviolet radiation . Hypercholesterolemic activity. Seed oil, administered by gastric intubation to rabbits at a dose of 0.4 g/kg, was inactive " . Male Wistar rats fed 12 or 24% sesame oil in the diet for 4 weeks were investigated. The rats on the 24% sesame oil diet had significantly lower lymphatic cholesterol and fatty acids . 

Munakata, N. Hieda, K. Kobayashi, K. Ito, A. Ito, T. Action spectra in ultraviolet wavelengths (150-250 nm) for inactivation and mutagenesis of Bacillus subtilis spores obtained with synchrotron radiation. Photochem. Photobiol. 1986, 44 (3), 385-390. 

---