14C and 15N isotopes of urea were infused intravenously into rabbits for 6-8 h in order to measure urea synthesis and the extent of degradation in the digestive tract. The results indicate that 0.62 of the urea flux was excreted in the urine and that re-incorporation of urea-N following hydrolysis in the gut represented 0.3 of the urea synthesis rate. Sampling of metabolites from the caecum by ...

We studied the effects of supplementing N as distillers dried grains with solubles (DDGS) or urea to steers consuming corn-based diets. Six ruminally and duodenally cannulated steers (244 kg) were used in 2 concurrent 3 x 3 Latin squares and fed 1 of 3 corn-based diets: control (10.2% CP), urea (13.3% CP), or DDGS (14.9% CP). Periods were 14 d, with 9 d for adaptation and 5 d for collection of ...

The data shown in this article are related to the subject of an article in Carbohydrate Polymers, entitled "Synthesis and characterization of chitosan alkyl urea" [1]. 1H NMR and 13C NMR spectra of chitosan n-octyl urea, chitosan n-dodecyl urea and chitosan cyclohexyl urea are displayed. The chemical shifts of proton and carbon of glucose skeleton in these chitosan derivatives are designated in...

Urea herbicides form, together with phenoxy derivatives and triazines, the most important agricultural herbicide group. The urea-derivatives are typical pre-emergence herbicides applied usually as aqueous emulsions to the surface of soil. Almost all of the urea compounds with good herbicidal action are trisubstituted ureas, containing a free iminohydrogen. According to the receptor theory, this...

Modified brucella broth medium was used to study the growth of Helicobacter pylori at varied pHs and partial pressures of oxygen and to determine the effect of urea on culture pH. Our findings suggested that the pHs of the media remained stable with or without urea and that H. pylori showed facultative acidophilism and obligate microaerophilism.

Acute dehydration biochemically manifests itself with mild uremia and a normal creatinine concentration. The reason for this, as quoted in popular medical textbooks, is that there is increased reabsorption of urea by the kidneys (1). This explanation is rarely taken further by clinical tutors or lectures on laboratory medicine. However, an appreciation of the physiology of the renal tubules all...

Five ruminally cannulated steers (initial BW = 375 ± 34 kg; ADG = 1.16 ± 0.13 kg) were used in a 5 x 5 Latin square design experiment to determine the effects of increasing urea level on intake, nutrient digestion, nitrogen balance and ruminal kinetics. Isocaloric (NEm = 2.11 Mcal/kg; NEg = 1.35 Mcal/kg) and isonitrogenous (2.24% N) steam-flaked corn-based diets with urea concentrations of 0.0,...

The branchial mechanism of urea retention in elasmobranchs was investigated using an in vitro isolated-perfused head preparation, as well as in vivo samples, in the spiny dogfish shark. Both in vivo and in control saline perfusions containing 350 mmol L(-1) urea, calculated intracellular urea concentrations in gill epithelial cells were close to extracellular concentrations. Urea efflux to the ...

previous work by other investigators indicates a direct relation between the amount of protein in the diet and the level of urea in the blood . however, the present report shows that the type of protein , apart from its level in the ration , also has an effect on blood urea concentrations. when adult male or female rats of two strains were fed a ration in which the only source of protein was wh...

The survival of clinical isolates of H pylori at two cultural ages (two and four days) at pH 2, in the presence of different buffers, with and without urea, was investigated. It was found that the morphological changes which occur with longer incubation of H pylori have an inverse correlation with its resistance to an acidic environment. The finding that the addition of urea almost reversed thi...