Epidemiology and diagnostics of primary Sjögren's syndrome

This review paper contains selected aspects of Sj?gren's syndrome. It consists of epidemiology, ultrasound of salivary glands and antimuscarinic antibodies. The first part present studies aimed to determine the prevalence and the incidence of the disease with special emphasize on epidemiological studies performed in Slovenia. This is followed by the demonstration of the role of ultrasound of salivary glands in the diagnosis of Sj?gren's syndrome and the value of antimuscarinic antibodies in global assesment of the secretory failure.     

Influence of food restriction on dopamine receptor densities, catecholamine concentrations and dopamine turnover in chicken brain

To investigate further a putative role of dopamine in control of food restriction-induced behavioural stereotypies, chickens were fed during rearing on either a daily restricted ration recommended by a breeding company, twice the recommended restricted ration, or ad libitum food. They were killed at 60 days of age and their excised brains were dissected into six regions and homogenized. Densities of dopamine D1 and D2 receptors were assessed, after first estimating binding parameters for [3H]SCH 23390 (D1) and [3H]spiperone (D2) in chicken brain homogenates. Specific binding of both ligands was highest in basal telencephalon. Concentrations of dopamine and its metabolites 3,4-dihydroxyphenylacetic acid and homovanillic acid were also highest in basal telencephalon, whereas noradrenaline and adrenaline levels were highest in diencephalon. Dopamine concentration in basal telencephalon and noradrenaline concentration in diencephalon were increased significantly in response to food restriction, but no effect of feeding treatment was found in dopamine turnover, adrenaline levels, or D1 and D2 receptor densities in any brain region studied. The observed changes in brain catecholamine levels are consistent with roles for dopaminergic and adrenergic mechanisms in the control of food restriction-induced behavioural stereotypies in chickens.     

Urinary catecholamines in children with attention deficit hyperactivity disorder (ADHD): modulation by a polyphenolic extract from pine bark (pycnogenol)

Our study tested the hypothesis that treatment with a potent polyphenol complex not only reduces hyperactivity of children, but also catecholamine excretion and oxidative stress. Urine catecholamine concentrations were measured in attention deficit hyperactivity disorder (ADHD) children and healthy controls. ADHD children received either placebo (PL) or Pycnogenol (Pyc), a bioflavonoid extract from the pine bark, for one month. The study was performed in a randomized, double-blind, PL controlled design. Concentrations of catecholamines were higher in urine of ADHD patients compared to those of healthy children. Moreover, noradrenaline (NA) concentrations positively correlated with degree of hyperactivity of ADHD children. In ADHD patients, adrenaline (A) and NA concentrations positively correlated with plasma levels of oxidized glutathione. The treatment of ADHD children with Pyc caused decrease of dopamine (D) and trend of A and NA decrase and increased GSH/GSSG ratio. In conclusion, the data provide further evidence for the overactivity of the noradrenergic system in ADHD and demonstrate that A release may be increased, as well. Treatment of ADHD children with Pyc normalized catecholamine concentrations, leading to less hyperactivity, and, consequently, to reduced oxidative stress.     

Reduced plasma homocysteine levels in levodopa/entacapone treated Parkinson patients

Hyperhomocysteinemia is not only a major risk factor for atherothrombotic disease, but is also strongly associated with an increased risk of dementia and cognitive impairment, both of which are common in the course of Parkinson's disease (PD). Previous work has found that levodopa increases plasma homocysteine concentrations. Animal studies have indicated that the catechol-O-methyltransferase (COMT) inhibitors can prevent levodopa-induced elevation of homocysteine concentrations by reducing the O-methylation of levodopa. The objective of our study was to assess the impact of entacapone, a COMT inhibitor, on plasma levels of homocysteine, serum folate, and vitamin B12 in levodopa-treated PD patients. Nineteen PD patients receiving only levodopa and 21 PD patients on a combination of levodopa and entacapone participated in the cross-sectional study. The control group consisted of 17 subjects on dopamine agonists. The mean plasma homocysteine concentration in the subjects on only levodopa was higher than that in the subjects on a combination of levodopa and entacapone (P=0.001) or in the control group (P=0.0001). Concentrations of serum vitamin B12 and serum folate were on average normal in all groups, but levodopa-treated subjects (with or without entacapone therapy) were more prone to have hypovitaminosis B12 (45%) than controls on dopamine agonists (6%). We suggest that the COMT inhibition may play a promising role in successfully controlling levodopa-induced hyperhomocysteinemia and in reducing the risk of pathologies probably linked to it. These preliminary findings and postulated hypotheses must now be confirmed in prospective studies.