Adrenal cortex carcinomas with distant metastases in beef cattle at slaughter.

Ten cases of adrenal cortex carcinomas with distant metastases were collected as subclinical lesions at slaughter of approximately 14,000 adult cattle. The primary lesion in the adrenal gland and the distant metastases, to either the lung or liver, were characterized by light microscopy and immunohistochemistry. Carcinomas were usually detected by noting metastases in the lungs as polypoid, soft, red or red and yellow masses. All adrenal tumours were unilateral and none were seen in bulls. In six of 10 carcinomas there was gross evidence of invasion of the vena cava via the adrenal vein. Normal bovine adrenal cortex labelled positively with S100, calretinin, α inhibin and melan-A; however, adenomas and seven of 10 carcinomas were labelled best by melan-A and α inhibin. Three carcinomas, grossly identical to the other seven, had numerous calcific granules and a slightly different microscopical appearance. In addition to melan-A and α-inhibin, these variant carcinomas labelled with S100. This variant may be derived from a different layer of the adrenal cortex. Because of the similarity of the bovine and human adrenal cortices, cultures of spontaneously arising bovine adrenal tumours may be a useful resource for study of human neoplasia.

Structure-activity relationships for abiotic thiol reactivity and aquatic toxicity of halo-substituted carbonyl compounds.

Using abiotic thiol reactivity (EC50) and Tetrahymena pyriformis toxicity (IGC50) data for a group of halo-substituted ketones, esters and amides (i.e. SN2 electrophiles) and related compounds a series of structure-activity relationships are illustrated. Only the alpha-halo-carbonyl-containing compounds are observed to be thiol reactive with the order I > Br > Cl > F. Further comparisons disclose alpha-halo-carbonyl compounds to be more reactive than non-alpha-halo-carbonyl compounds; in addition, the reactivity is reduced when the number of C atoms between the carbonyl and halogen is greater than one. Comparing reactivity among alpha-halo-carbonyl-containing compounds with different beta-alkyl groups shows the greater the size of the beta-alkyl group the lesser the reactivity. A comparison of reactivity data for 2-bromoacetyl-containing compounds of differing dimensions reveals little difference in reactivity. Regression analysis demonstrates a linear relationship between toxicity and thiol reactivity: log (IGC(50)(-1)) = 0.848 log (EC(50)(-1)) + 1.40; n=19, s=0.250, r2=0.926, r2(pred)=0.905, F=199, Pr > F=0.0001.