Chronic diseases develop in susceptible individuals following exposure to environmental conditions including high fat diets. Inbred strains of mice differing in susceptibility to atherosclerosis, diabetes, obesity and certain cancers are models for understanding the genetic basis and molecular mechanisms whereby diet influences these polygenic and multifactorial disorders. Expression sequence tags (EST) and disease quantitative trait loci (QTL) are also being identified with these strains. Reported here are comparisons of food intake, growth, nonfasting serum lipids and expression of mRNA for hepatic apolipoprotein E (ApoE), hepatic stearoyl CoA desaturase (Scd1) and heart lipoprotein lipase (Lpl) in a 2 x 2 x 2 design with C57BL/6J and BALB/cByJ mice fed semipurified diets with 4 or 20% saturated (coconut) or unsaturated (corn) oils for 4 mo. Histological studies of aortas and coronary arteries are also reported for these animals. After 4 mo, BALB/cByJ mice were significantly heavier and had significantly higher total serum cholesterol, HDL cholesterol and triglyceride concentrations in the fed state than C57BL/6J mice. Efficiency of utilizing dietary energy did not differ consistently between strains. Oil level affected serum total cholesterol, triglycerides and HDL cholesterol, which were significantly greater in mice fed high fat diets. Lpl and ApoE mRNA expression levels were not significantly affected by mouse strain, oil source or oil level. Scd1 mRNA expression, however, was significantly higher in C57BL/6J than in BALB/cByJ mice and was lower in all mice fed 20% compared with those fed 4% fat diets. Genes regulated differently by diet among strains with distinct susceptibility to diet-influenced disease may be associated with molecular pathways contributing to incidence or severity.

Recent functional evidence has indicated that ureteric obstruction for three or more days in dogs causes a diversion of renal lymph from the hilar to the capsular system. The present study was concerned with the structural correlate of this functional evidence, having special reference to communications between the two systems. Within three days of ureteric occlusion the capsular lymphatic system became dilated. On histological examination two types of tributaries were found. One (termed a perforating lymphatic) served as a primary pathway for superficial cortical lymph from the subcapsular plexus, and penetrated the capsule either alone or in company with a small vein. The other (termed a communicating lymphatic) was closely associated with the occasional penetrating interlobular blood vessel which traversed the capsule to ramify in the perirenal tissue. Approximately 60% of the penetrating arteries in eight dog kidneys had associated communicating lymphatics. On the renal surface the perforating and communicating lymphatics formed the primary collecting vessels of the capsular system. Within the renal substance the communicating lymphatics were directly continuous with lymphatics which surrounded the interlobular blood vessels and which have been shown to drain into the hilar network. Thus the communicating lymphatics formed direct connections between the hilar and capsular systems. It was concluded that these communications, although dilated by hydronephrosis, existed under control conditions. Functionally they are probably of importance only under special circumstances when intrarenal lymph may be diverted from one to the other system.

The clinical value of the fine needle aspiration of thyroid nodules was evaluated by comparing preoperative cytology to subsequent pathology in 109 patients undergoing thyroidectomy. Preoperative cytology was reported as insufficient cellular material (31 patients), benign goiter (27 patients), follicular neoplasm (22 patients), thyroiditis (12 patients), suspicious for papillary carcinoma (nine patients), Hurthle cell neoplasm (five patients), medullary carcinoma (one patient), lymphoma (one patient), and metastatic adenocarcinoma (one patient). Operative findings demonstrated that the overall sensitivity of fine needle aspiration in diagnosing thyroid neoplasia (carcinoma or adenoma) was 88% and its specificity was 80%. Operation verified the cytologic diagnosis of medullary carcinoma, lymphoma, metastatic adenocarcinoma, and seven of nine papillary carcinomas. Of the five patients with an aspiration biopsy diagnosis of Hurthle cell neoplasm, three patients had carcinoma and one had an adenoma. Four carcinomas and 12 follicular adenomas were found in patients with a cytologic diagnosis of follicular neoplasm. Thyroiditis was confirmed at operation in all 12 patients with this diagnosis on fine needle aspiration. One carcinoma was found in the 27 patients with benign goiter diagnosed on cytology. Fine needle aspiration is a valuable tool that can lead to earlier diagnosis and treatment of thyroid cancer. However, a negative aspiration does not supplant good clinical judgement in determining the need for thyroidectomy.