Rodents

The separation of cells from the culture media or fermentation broth is the first step in a bioproduct recovery sequence. Whereas centrifugation is common for recombinant bacterial cells (see Centrifugal separation), the final removal of CHO cells utilizes sterile-filtration techniques. Safety concerns with respect to contamination of the product with CHO cells were addressed by confirming the absence of cells in the product, and their relative noninfectivity with respect to immune competent rodents injected with a large number of CHO cells. 

In 1983 the National Toxicology Program (NTP) reported that ethyl acrylate produced tumors in the rodent forestomach after gavage (forced... 

Mutagenic and later carciaogenic properties were found for tris(2,3-dibromopropyl) phosphate (148—150), a flame retardant used on polyester fabric ia the 1970s. This product is no longer on the market. The chemically somewhat-related tris(dichloroisopropyl) phosphate has been intensively studied and found not to display mutagenic activity (148,149,151). Tris(2-chloroethyl) phosphate appears to be a weak tumor-iaducer ia a susceptible rodent strain (150). 

Laboratory experiments using rodents, or the use of gas analysis, tend to be confused by the dominant variable of fuel—air ratio as well as important effects of burning configuration, heat input, equipment design, and toxicity criteria used, ie, death vs incapacitation, time to death, lethal concentration, etc (154,155). Some comparisons of polyurethane foam combustion toxicity with and without phosphoms flame retardants show no consistent positive or negative effect. Moreover, data from small-scale tests have doubtful relevance to real fine ha2ards. 

More and more raw spices are converted to finished products near the growing sites. This saves shipping costs of bulk vs concentrate. Rapid processing also assures less loss of flavor volatiles resulting from evaporation, reduction of colored components due to oxidation or isomeri2ation, and reduction of losses due to insect and rodent infestation. 

Toxicity. Sodium fluoroacetate is one of the most effective all-purpose rodenticides known (18). It is highly toxic to all species of rats tested and can be used either in water solution or in bait preparations. Its absence of objectionable taste and odor and its delayed effects lead to its excellent acceptance by rodents. It is nonvolatile, chemically stable, and not toxic or irritating to the unbroken skin of workers. Rats do not appear to develop any significant tolerance to this compound from nonlethal doses. However, it is extremely dangerous to humans, to common household pets, and to farm animals, and should only be used by experienced personnel. The rodent carcasses should be collected and destroyed since they remain poisonous for a long period of time to any animal that eats them. 

The extension of the useful storage life of plant and animal products beyond a few days at room temperature presents a series of complex biochemical, physical, microbial, and economic challenges. Respiratory enzyme systems and other enzymes ia these foods continue to function. Their reaction products can cause off-davors, darkening, and softening. Microbes contaminating the surface of plants or animals can grow ia cell exudates produced by bmises, peeling, or size reduction. Fresh plant and animal tissue can be contaminated by odors, dust, iasects, rodents, and microbes. 

Formaldehyde is classified as a probable human carcinogen by the International Agency for Research on Cancer (lARC) and as a suspected human carcinogen by the American Conference of Governmental Industrial Hygienists (ACGIH). This is based on limited human evidence and on sufficient evidence in experimental animals (136). Lifetime inhalation studies with rodents have shown nasal cancer at formaldehyde concentrations that overwhelmed cellular defense mechanisms, ie, 6 to 15 ppm. No nasal cancer was seen at 2 ppm or lower levels (137). 

Chorionic Somatomammotropin. Three genes encode human chorionic somatomammotropin [11085-36-2] (hCS). These are located within a cluster of genes on human chromosome 17 which code for pituitary growth hormone [12629-01 -5] (GH-N), placental GH [109675-94-7J (GH-V), and three hCS molecules, ie, hCS-A, hCS-B, and hCS-V (1 3), also referred to as human placental lactogens. All of these molecules ate closely related to GH in stmcture (Fig. 1). Placental lactogens also exist in rodents and mminants however, these hormones are more closely related to prolactin than GH. 

Prolactin-Like Proteins. A number of prolactin-like proteins (PLPs), which ate distinct from the PLs, have been identified in mminants and rodents (11,23). Several cDNA transcripts coding for PLPs in catde have been identified (23). These transcripts code for proteins which possess about 40% sequence homology with bovine PRL 60% if conservative substitutions ate considered. Three glycosylated PLPs, ie, PLP-A, -B, and -C, ate produced during pregnancy in the rat (11). Two additional prolactin-related molecules have been identified in the mouse (24,25), ie, proliferin [92769-12-5] (PLF) and PLF-related protein [98724-27-7]. These ate not found in other rodents and may be unique to the mouse. The functional roles of PLPs remain to be deterrnined. 

Fig. 4. FSH receptor-binding potencies of equine FSH ( ), eCG purified from pregnant mate s semm (O), and endometrial cups (A). Receptor-binding in ceU membrane fractions, B/Bq from (a) horse, (b) calf, and (c) rodent testes (40). Courtesy of Butterworth-Heinemaim.

IL-l radiation/cytotoxic injury bacterial infection rodent... 

IL-2+ LAK cell or tumor infiltrating lymphocyte tumor destmction rodent and human... 

Microwaves are also used for the rapid inactivation of brain enzymes in rodents (160). Microwave power at high levels of kilowatts is appHed by means of a waveguide appHcator to achieve a rapid sacrifice of the rodent. 

Transport Equipment insects and rodents carried by tmcks, trains, ships, aircraft... 

Vector Control and Plagues rodents, mosquitoes, tsetse flies, grasshoppers, locusts... 

Whereas the agreement between the values in humans and guinea pig is close, this is not always so. For example, in human and rodent 5-HT p receptors, significant pharmacological differences are conferred by a single amino acid residue. 

On the basis of these differences in species response it was concluded that phthalates do not pose a significant health hazard to humans. This view is home out by the EU Commission decision of July 25, 1990 which states that DEHP shall not be classified or labeled as a carcinogenic or an irritant substance (42). This has been reaffirmed in a comprehensive review (43) which concludes that "peroxisome proliferators constitute a discrete class of nongenotoxic rodent hepatocarcinogens and that the relevance of thek hepatocarcinogenic effects for human hazard assessment is considered to be negligible."... 

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