Urea is the principal nitrogenous waste product of metabolism and is generated from protein breakdown. It is eliminated from the body almost exclusively by the kidneys in urine, and measurement of its concentration, first in urine and later in blood, has had clinical application in the assessment of kidney (renal) function for well over 150 years. This is the first of two articles that together...

The effects of lesions rostral to the brain stem on breathing responses to hypoxia were determined in chronically catheterized fetal sheep (>0.8 term). These studies were designed to test the hypothesis that the diencephalon is involved in hypoxic inhibition of fetal breathing. As in normal fetuses, hypoxia inhibited breathing with transection rostral to the thalamus or transection resulting in...

A simple and inexpensive procedure involving saponification and methylation in wet biomass, winterization and urea complexation in a sequential way has been developed in order to concentrate docosahexaenoic acid (DHA) from Crypthecodinium cohnii CCMP 316 biomass. Different urea/fatty acid ratios and crystallization temperatures were tested in the urea complexation method. ANOVA test revealed th...

The purpose of this study was to evaluate sternocleidomastoideus (SCM) and trapezius (superior fibers) muscle activity patterns in mouth-breathing children, and to compare them with nasal-breathing children. Forty-six children, of both sexes, ranging from 8 to 12 years old, were evaluated through electromyography. The selected children were divided into two groups; Group I, was made up of 26 mo...