1. The mechanical and pharmacological properties of small pulmonary arteries (100–300 μm normalized lumen diameter) were directly compared with those the left main artery (1–2 mm) from rat. active passive length-tension characteristics responses to a variety agonists antagonists dependent on arterial diameter. 2. Maximum contractile function was obtained in both groups vessels when stretched so as give an equivalent transmural pressure 30 mmHg. This is substantially lower than that found for...

Manganese deficiency in the laying hen results decreased egg production and eggshell thickness. Eggshells from deficient hens show specific changes appearance characterized by translucent areas. Examination of these areas with scanning electron microscope revealed ultrastructure shell. The most prominent feature was large irregular mammillary knobs probably due to fusion several cores during early phases formation. Chemical analysis organic matrix showed a decrease hexosamine hexuronic acid...

A CHOLINE deficiency is readily produced in chicks by feeding a diet low choline or certain precursors. The effect of laying hens, however, less clear. McCollum et al. (1912) fed containing 70 parts ground polished rice previously extracted with hot alcohol and 30 dried skimmed milk to hens found that more lecithin was present eggs these than had been consumed the diet. Therefore, investigators concluded large amounts were synthesized hens. Abbott DeMasters (1940), using similar McCollum's...

EARLY experiments by Titus (1932), Insko, Lyons and Martin (1938) Lyons, Insko failed to show zinc be a dietary essential for the chick. More recently, Mehring, Brumbaugh (1956) observed no beneficial effect upon growth of chicks from increasing amount consumed 42 820 mg. per kg. diet. In studies on perosis, Wilgus, Norris Heuser (1937), found that as well manganese had incidence but under conditions their was shown primary deficiency. Therefore, it not until 1957, result O’Dell Savage, true...

The objective of this presentation is to relate the abundance and mobility Cd in components terrestrial ecosystems with implications for land utilization sewage sludge. uptake by crop plants a function quantity element soil plus other factors affecting ion activity or electrochemical potential at plant root surface. natural soils has been reported as 0.5 μg/g which higher than background level 0.2 found studied Pennsylvania. Experimental results indicate that availability increases each...

Nickel toxicity was studied in young chicks fed a semi-purified diet. Dietary nickel concentrations of 300 mg/kg and higher resulted significant reduction growth rate. Mortality anemia were observed receiving 1100 nickel. content increase kidney while dietary levels required to affect the other body tissues. Supplementation toxic diets (500 mg/kg) with 100 cobalt, iron, copper, zinc did not alleviate symptoms or consistently tissue accumulation. The addition cobalt further depression rate...

The effects of long-term consumption 1 and 5 ppm Cd on Cd, Cu, Fe, Zn concentrations in milk a variety tissues first-lactation dairy cows was investigated. Thirty-six Holstein heifers were allocated to three groups fed similar diets differing only the concentration (.25, 1, ppm) for 394-d period before calving. One- 5-ppm achieved using CdCl2. Liver, kidney cortex, muscle biopsied from one-half each group supplementation again same within d after parturition. Colostrum sampled throughout 150...