Brunel University London

About: Brunel University London is a education organization based out in London, United Kingdom. It is known for research contribution in the topics: Large Hadron Collider & Population. The organization has 10918 authors who have published 29515 publications receiving 893330 citations. The organization is also known as: Brunel & University of Brunel.

Glucose autoxidation and protein modification. The potential role of 'autoxidative glycosylation' in diabetes.

Abstract: Monosaccharide autoxidation (a transition metal-catalysed process that generates H2O2 and ketoaldehydes) appears to contribute to protein modification by glucose in vitro The metal-chelating agent diethylenetriaminepenta-acetic acid (DETAPAC), which inhibits glucose autoxidation, also reduces the covalent attachment of glucose to bovine serum albumin A maximal 45% inhibition of covalent attachment was observed, but this varied with glucose and DETAPAC concentrations in a complex fashion, suggesting at least two modes of attachment The extent of inhibition of the metal-catalysed pathway correlated with the extent of inhibition of glycosylation-associated chromo- and fluorophore development DETAPAC also inhibited tryptophan fluorescence quenching associated with glycosylation Conversely, ketoaldehydes analogous to those produced by glucose autoxidation, but generated by 60Co irradiation, bound avidly to albumin and accelerated browning reactions It is therefore suggested that a component of protein glycosylation is dependent upon glucose autoxidation and subsequent covalent attachment of ketoaldehydes The process of glucose autoxidation, or ketoaldehydes derived therefrom, appear to be important in chromophoric and fluorophoric alterations It is noted, consistent with these observations, that the chemical evidence for the currently accepted ‘Amadori’ product derived from the reaction of glucose with protein amino groups is consistent also with the structure expected for the attachment of a glucose-derived ketoaldehyde to protein The concept of ‘autoxidative glycosylation’ is briefly discussed in relation to oxidative stress in diabetes mellitus

A variety of environmentally persistent chemicals, including some phthalate plasticizers, are weakly estrogenic.

Abstract: Sewage, a complex mixture of organic and inorganic chemicals, is considered to be a major source of environmental pollution. A random screen of 20 organic man-made chemicals present in liquid effluents revealed that half appeared able to interact with the estradiol receptor. This was demonstrated by their ability to inhibit binding of 17 beta-estradiol to the fish estrogen receptor. Further studies, using mammalian estrogen screens in vitro, revealed that the two phthalate esters butylbenzyl phthalate (BBP) and di-n-butylphthalate (DBP) and a food antioxidant, butylated hydroxyanisole (BHA) were estrogenic; however, they were all less estrogenic than the environmental estrogen octylphenol. Phthalate esters, used in the production of various plastics (including PVC), are among the most common industrial chemicals. Their ubiquity in the environment and tendency to bioconcentrate in animal fat are well known. Neither BBP nor DBP were able to act as antagonists, indicating that, in the presence of endogenous estrogens, their overall effect would be cumulative. Recently, it has been suggested that environmental estrogens may be etiological agents in several human diseases, including disorders of the male reproductive tract and breast and testicular cancers. The current finding that some phthalate compounds and some food additives are weakly estrogenic in vitro, needs to be supported by further studies on their effects in vivo before any conclusions can be made regarding their possible role in the development of these conditions.

Inhibition of testicular growth in rainbow trout (Oncorhynchus mykiss) exposed to estrogenic alkylphenolic chemicals

Abstract: It is becoming evident that an increasing number of widely used industrial and agricultural chemicals are estrogenic. The biodegradation products of a major group of nonionic surfactants, the alkylphenol polyethoxylates, are one such group. Some of these chemicals are widespread aquatic pollutants, and bioconcentrate in aquatic biota. Exposure of male rainbow trout (Oncorhynchus mykiss) to four different alkylphenolic chemicals caused synthesis of vitellogenin, a process normally dependent on endogenous estrogens, and a concomitant inhibition of testicular growth. The magnitude of these estrogenic effects was dependent on the estrogenic potency of the chemical, the stage of reproductive development of the fish, and the concentration of the chemical in the water. These results support the contention that exposure of wildlife to environmentally persistent estrogenic chemicals can result in deleterious reproductive consequences.