Biomedical subjects

D Djuric

Publications and source records attributed to D Djuric.

12 recordsLinked to original sources

PubMed2000

Homocysteine and arteriosclerosis: established risk factor or new illusion?

Homocysteine is an amino acid and a product of methionine metabolism that is metabolized through two different enzymatic pathways: transsulfuration and remethylation. Vitamin B6 is important in homocysteine transsulfuration, whereas folate and vitamin B12 play significant roles in homocysteine remethylation. The hyperhomocysteinemia offers an explanation for observations on human arteriosclerosis that are difficult to explain by the cholesterol/fat approach. However, hyperhomocysteinemia can influence cognitive functions in the elderly. The causes of hyperhomocysteinemia are inherited and acquired. The treatment of hyperhomocysteinemia varies with underlying cause; generally, vitamin supplementation (with folic acid and vitamins B6 and B12) is effective in reducing homocysteine concentrations. Also, specific recommendations, food fortification with folic acid, and preventive strategies in European countries (as in United States) are necessary to decrease cardiovascular morbidity and mortality.

Arteriosclerosis↗

PubMed1999

Age-related progressive brachial artery endothelial dysfunction precedes the changed carotid and left ventricular geometry in healthy humans.

In this study the authors evaluated correlation between aging and brachial endothelial and vascular smooth muscle dysfunction, changes in carotid geometry, and left ventricular remodeling. Vasomotor influences of brachial endothelium and brachial smooth muscle function to reactive hyperemia and nitroglycerin (400 microg, sublingual spray) were assessed by noninvasive ultrasound in 66 healthy subjects of different ages (20-82 years). Carotid intima-media thickness and left ventricular mass index were also assessed by ultrasound and compared with brachial hemodynamic parameters. All results were analyzed by linear regression analysis. The response of brachial artery diastolic diameter to reactive hyperemia decreased with aging (p<0.0001). Also, the response of brachial artery diastolic diameter to nitroglycerin increased relative to aging (p<0.004). Age-related correlations between increased carotid intima-media thickness and brachial artery diastolic diameter response to reactive hyperemia (p<0.01) as well as between increased carotid intima-media thickness and increased left ventricular mass index (p<0.001) were found. However, there was no correlation between brachial artery diastolic diameter response to reactive hyperemia and increased left ventricular mass index (p>0.05). The study showed that aging influences not only brachial endothelial vasomotor properties but also vascular and cardiac geometry. The authors believe that modern therapeutic approach should take these results into consideration to establish new vasculo-protective and cardioprotective strategies.

Adult↗

PubMed1991

The effects of (R) alpha-methyl histamine on the isolated guinea pig aorta.

The effects of the H3 agonist (R) alpha-methyl histamine ( (R) alpha-MeHA) on the isolated guinea pig aorta were investigated. At all the concentrations of (R) alpha-MeHA used, a relaxation of the aorta, which had been preconstricted with KC1 (50mM), was produced. This response was abolished by the H3 antagonist mixture of cimetidine (100 microM) and impromidine (10 microM). In contrast the same concentrations of histamine produced vasoconstriction which could be abolished by the H1 antagonist pyrilamine (3 microM). The results show that (R) alpha-MeHA produces a vasodilation response which is most probably mediated by H3 receptors and provides further evidence of a functional role for H3 receptors in the control of the cardiovascular system.

Animals↗

PubMed1988