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G Verleye

Publications and source records attributed to G Verleye.

6 recordsLinked to original sources

Cognitive ability and occupational status in a British cohort.

The relation between individual trait differences, social mobility and social structure is central to social biology. Because genetic variance underlies phenotypic variance in some of these traits, for example IQ, several mechanisms determine the population variance. Polygenic inheritance is the basic mechanism. Social mobility and assortative partner choice distribute the trait variance within generations. This feedback circle is constrained by sociological conditions at several levels of analysis. Fundamental to this theory of social assortment is the relation between social-biological traits and social class on the one hand, and these traits and social mobility on the other hand. The focus here is on the relation between social class, social mobility and cognitive ability. The National Child Development Study is drawn upon, including the last follow-up (1999-2000). By approaching this relationship through various methods, both social-biological and sociological aspects of this research question can be assessed.

Achievement↗

Variation in nutrient intake with dental status, age and odour perception.

OBJECTIVES: Since the proportion of elderly people with an insufficient intake of nutrients is high and many of the elderly have poor odour perception or poor dental state, in this study, the relation between age, odour perception, dental state and nutrient intake is explored. DESIGN: Single centre cross sectional study. SETTING: Independently living elderly were tested at their homes in 4 locations in Belgium, ranging in ages 60-90 y. SUBJECTS: 200 elderly participated in a 7 d food record study, resulting in 119 complete records. INTERVENTIONS: Food quantities were converted to nutrient intake levels. For all people, odour detection threshold was determined of isoamylacetate and dental status was noted. Path analysis was used and the separate effects of age, dental state, odour perception and gender were tested on macronutrient intake and micronutrient intake respectively. MAIN OUTCOME MEASURES: For all nutrients, no significant correlation was observed between nutrient intake and odour perception, except for energy, water, Fe and niacin (P < 0.05). A significant separate effect of odour perception was observed for water intake (CR = 2.09). Significant separate effects of dental state were observed for animal protein (CR = 2.29), niacine (CR = 2.04) and mono-unsaturated fats (CR = 2.32). CONCLUSIONS: Although odour perception and dental state can not fully explain variability in nutrient intake, our results show that people with poor odour perception have lower nutrient intake levels than people with good odour perception. Dental state may not be a direct cause of poor nutrition but a contribution factor in those elderly who have other risk factors.

Aged↗

Effect of the aging process on the gender and phenobarbital dependent expression of glutathione S-transferase subunits in brown Norway rat liver.

The effect of age, gender and phenobarbital treatment on the hepatic cytosolic glutathione S-transferase subunit composition was studied in Brown Norway rats. Affinity chromatography followed by reversed phase HPLC was used in order to separate the various glutathione S-transferase subunits. Corresponding steady-state mRNA levels were measured by Northern Blot analysis using cDNA clones hybridizing to mRNA encoding glutathione S-transferase subunits 1/2, 3/4 and 7, respectively. In all the age groups studied (15, 25, 53, 99, 112 and 136 weeks) the total amount of glutathione S-transferase protein was in untreated rats significantly higher in males (132 micrograms/mg cytosolic protein) than in females (91 micrograms/mg cytosolic protein) and significant gender dependent differences in the subunit composition were demonstrated. Aging seemed to be of minor importance in untreated as well as in phenobarbital treated rats. Under control conditions, the subunit composition of male rats between 15 and 136 weeks old consisted of 28, 12, 11 and 49% of subunits 1, 2, 3 and 4 respectively and of female animals of the same age groups of 38, 26, 7 and 30%, respectively. In all the age groups studied phenobarbital administration (45 mg/kg body weight, i.p., once a day for 7 days) doubled total glutathione S-transferase protein in both genders and affected the subunit composition in a significant way, emphasizing the already existing differences between genders. Subunits 1, 2 and 3, especially, were increased in male rats in comparison to females resulting in the observation that levels of glutathione S-transferase subunits studied became higher in males than in their female counterparts. The HPLC results were confirmed by steady-state mRNA analysis. In untreated rats, higher levels of mRNA encoding glutathione S-transferase subunits 1/2 and 3/4 were present in male than in female livers. Phenobarbital treatment increased mRNA levels in both genders. Subunit 7 was never detected. These effects were demonstrated in both young and old rats.

Aging↗

Phase I and phase II xenobiotic biotransformation in cultures and co-cultures of adult rat hepatocytes.

The aim of this study was to measure the activity of phase I and II key enzymes in the biotransformation of xenobiotics and their inducibility by phenobarbital (2 mM) in two currently used in vitro models, namely adult rat hepatocytes, conventionally cultured or co-cultured with rat epithelial cells derived from primitive biliary duct cells. For phase I, the cytochrome P450 content and the enzymic activities of 7-ethoxycoumarin O-deethylase and aldrin epoxidase have been determined, for phase II glutathione S-transferase activity was measured. In conventional cultures, all phase I parameters investigated declined continuously as a function of culture time. Two mM phenobarbital had inducing effects on 7-ethoxycoumarin O-deethylase and glutathione S-transferases but not on aldrin epoxidase. In co-cultures, after an initial decrease, a steady state situation developed for all the parameters measured, lasting for at least 10 days. The cytochrome P450 content, the 7-ethoxycoumarin O-deethylase, aldrin epoxidase and glutathione S-transferase activities were maintained from 3 to 4 days on at 25, 100, 15 and 50%, respectively, of their corresponding value obtained for freshly isolated hepatocytes. After phenobarbital treatment, the parameters mentioned were significantly increased with the exception of the aldrin epoxidase activity of which the inducibility was nearly completely lost.

7-Alkoxycoumarin O-Dealkylase↗

Hepatic cytosolic glutathione S-transferase activities in ageing brown Norway rats--importance of sex differences and phenobarbital treatment for studies of ageing.

Age-associated alterations of hepatic cytosolic glutathione S-transferase activities towards 1-chloro-2,4-dinitrobenzene and 1,2-dichloro-4-nitrobenzene were investigated in Brown Norway rats of both sexes (11-144 weeks old), under control conditions and after administration of phenobarbital. With both substrates, small changes in glutathione S-transferase activities are observed for the control rats (15-53 weeks old). For these specific age groups, male glutathione S-transferase activities are significantly higher than those of their female counterparts, with sex-related differences being most pronounced after 1,2-dichloro-4-nitrobenzene conjugation. Using 1-chloro-2,4-dinitrobenzene as a 'general' substrate, the sex-differences tend to decrease from the age of 53 weeks onwards to become non-significant at the age of 112 weeks. Phenobarbital administration significantly increases the total and the isoenzymes 3-3 and 3-4 activities in both sexes, with the highest and the lowest increase being observed in the youngest and oldest animals, respectively. It therefore can be concluded that some age-related variations exist as far as the glutathione S-transferase activity of both control and phenobarbital-treated rats are concerned, but that the changes observed are rather small. On the contrary, the parameters 'Sex' and 'Phenobarbital treatment' are found to be responsible for the major activity changes observed.

Aging↗