RABINOWITZ, LAWRENCE, AND ROBERT A. GUNTHER. Urea transport in elasmobranch erythrocytes. Am. J. Physiol. 224(5) : 11091115. 1973.-The postulated presence of carrier-mediated transport of urea in elasmobranch erythrocytes was examined using cells of the spiny dogfish Squalus suckleyi. Under steady-state conditions with no net solute or net water flux and the external medium urea concentration 2...

An objective of this work was to assess the biological activity of beetroot juice (Chrobry variety, Beta vulgaris L. ssp. vulgaris), which was lactofermented by probiotic bacteria Lactobacillus brevis 0944 and Lactobacillus paracasei 0920. The oxidative status of blood serum, kidneys, and liver of rats consuming the fermented beetroot juice were determined. The experimental rats were divided in...

Aim. To study the frequency and spectrum of cytogenetic disorders in Triticum aestivum L., induced by effect moderate high concentrations N-nitroso-N-methylurea. Methods. The seeds winter wheat cultivars Albatros odeskyi Zymoiarka were treated with water solution N-nitroso-N-methylurea such as 0.005 %, 0.01 0.025 %. A analysis cells a root meristem was made help an anatelophase method. Results....

A fluorometric method for the determination of N-nitroso-N-methylurea (NMU) has been developed. It is based on the N-methylation reaction of nicotinamide with NMU and a subsequent condensation reaction with acetophenone, followed by an acid treatment to form a fluorescent 2,7-naphthyridine derivative. This method enabled the determination of NMU in the range 0.05 - 2 nmol/200 microl with a rela...

Embryonal kidney cell tumors develop in rats given the alkylating agent N-nitroso-N'-methylurea as neonates. These tumors resemble the childhood Wilms tumors in their histopathology. Deletions and mutations in the Wilms tumor suppressor gene, WT1, are present in up to 6% of childhood nephroblastomas. To investigate the role of WT1 in rat kidney tumorigenesis, we studied the genetic alterations ...

The mechansim of the three-component Biginelli dihydropyrimidine synthesis was reinvestigated using (1)H and (13)C NMR spectroscopy. Condensation of benzaldehyde, ethyl acetoacetate, and urea (or N-methylurea) in CD(3)OH according to the procedure described by Biginelli produced the expected 6-methyl-2-oxo-4-phenyl-1,2,3,4-tetrahydropyrimidine-5-carboxylates. According to NMR measurements, ther...

The interactions of a-chymotrypsinogen A with urea, methyl-, N,N'-dimethyl-, ethyl-, N,N'-diethyl-, and propylurea were studied by means of calorimetry and circular dichroism. It has been found that the enthalpies of interaction of the alkylureas, with the exception of methylurea, with a-chymotrypsinogen A are distinctly from those of urea. Thus the transfer of the protein from water to aqueous...

Several asco-, basidio-, and zygomycetes isolated from an agricultural field were shown to be able to hydroxylate the phenylurea herbicide isoproturon [N-(4-isopropylphenyl)-N',N'-dimethylurea] to N-(4-(2-hydroxy-1-methylethyl)phenyl)-N',N'-dimethylurea and N-(4-(1-hydroxy-1-methylethyl)phenyl)-N',N'-dimethylurea. Bacterial metabolism of isoproturon has previously been shown to proceed by an in...