Serum copper, zinc and selenium levels in Tunisian patients with Parkinson's disease.

BACKGROUND: Parkinson's disease (PD) is a progressive neurodegenerative disorder. The etiology of this disease is still not fully clear, but free radicals have been proposed to cause neuronal injury. Metals play a key role in the intracellular oxidative balance. However their implication in the degeneration process remains unknown. AIM: To assess Cu, Zn and Se concentrations in serum of a group of PD patients in order to determinate, in comparison with age-matched controls, whether alteration in their levels could be involved in PD. METHODS: A serum level of 3 trace elements (Cu, Zn and Se) was investigated in 48 patients with PD and 36 matched controls using plasma atomic absorption spectrometry. We compared these parameters in PD patients with controls, and we also compared the variations within the PD group according to age, illness duration, stage of the disease and levodopa intake. RESULTS: Patients with PD had significantly lower Cu levels compared to controls. The mean Zn and Se levels in PD patients did not differ significantly from those of controls. Levodopa therapy, age, stage, and illness duration did not significantly influence the measured parameters. CONCLUSION: These results suggest that a disturbance of the plasmatic rate of Cu could be a marker of PD or at least, a risk factor for the development of this disease. Although zinc participates to the reduction of oxidative stress and the antioxidant role of the selenium, their implication in the onset of PD is not clearly established. Perspectives for the future could include antioxidant therapy. For this reason, other prospective studies should be conducted on this subject to elucidate the implication of trace elements in PD.

[Central neurocytoma: Study of 32 cases and review of the literature]. / Le neurocytome central : étude de 32 cas et revue de la littérature.

Central neurocytoma is a rare benign neoplasm of the central nervous system. The intraventricular location close to the Monro foramina and the attachment to the septum pellucidum are characteristic for the diagnosis. However, atypical appearances may be encountered and confused with other neoplasms. The authors report the radiological findings of 32 surgically treated and pathologically confirmed neurocytomas.

[Mercury impregnation in dentists and dental assistants in Monastir city, Tunisia]. / L'imprégnation mercurielle des dentistes et de leurs assistants dans la ville de Monastir, Tunisie.

INTRODUCTION: The property of mercury to amalgamate with other metals is used to create a material for filling teeth. This material remains the cheapest and most efficient in tooth restoration. Mercurial toxicity has been documented since Antiquity but the metal remains widely used in some countries. This study compared mercury impregnation in dentists and dental assistants in Monastir (Tunisia) to another population not exposed professionally. SUBJECTS AND METHODS: A cross-sectional study was made on 52 dentists and dental assistants working in private offices and in the stomatology unit of the Monastir teaching hospital, with a control group of 52 physicians and nurses working in the Monastir Fattouma Bourguiba hospital. The groups were paired according to age and gender. The study lasted three months. A questionnaire investigated the socioprofessional features of the study population, non professional mercury exposure, work environment, the various amalgam handling and preparation techniques, and preventive hygiene measures. Urinary and salivary sampling was performed so as to prevent any accidental mercurial contamination. Mercury level was assessed by atomic absorption spectroscopy in an automatic sampler, urine creatinine with Jaffé's colorimetric reaction. The results of mercury level assessment were expressed in microg/g of creatinine, salivary mercury in mug/l. The statistical analysis was made with the Epi.info 6 software. Khi(2) and Fisher tests were used to compare qualitative variables. The ANOVA test was used to compare averages with a statistic significance threshold at 0.05. RESULTS: Sixty-one percent of individuals with risk exposure worked in a dental clinic. Bruxism and onychophagia were more important in the control group with a significant statistical difference (respectively, p=0.01 and p<0.0001). The urinary and salivary mercury levels were significantly increased in the exposed group, with respective values of 20.4+/-42.4microg/g of creatinine and 10.6+/-13.02microg/l versus 0.04+/-0.3microg/g of creatinine and 0microg/l in the control group. Disposing of amalgam waste was inadequate in 94% of the cases. The variation of mercury in urine was significantly influenced by the presence of fabric curtains (p=0.04). Eating lunch at meals at the work place was also linked to a significant increase of mercury levels in urine (p=0.04). The storage mode of mercury in open containers was a significant factor for variation of mercury level (p=0.03). DISCUSSION: Most dentists' private offices in Monastir do not comply or comply weakly with prevention measures linked to risk of mercury poisoning. Awareness campaigns were launched as well as actions for the improvement of work conditions: efficient aspiration of offices containing fixed sources of mercury, adequate storage of mercury and waste, and compliance to occupational hygiene rules.

Peripheral blood markers of oxidative stress in Parkinson's disease.

Oxidative stress and generation of reactive oxygen species are believed to be implicated in Parkinson's disease (PD). Erythrocyte activity of superoxide dismutase (SOD) and catalase, the blood glutathione system, and plasma levels of thiobarbituric-acid-reactive substances (TBARS) were measured in 80 PD patients. These biochemical parameters were also measured in 29 age-matched controls. Patients with PD had significantly higher red blood corpuscle (RBC) activity of SOD. The mean RBC activity of catalase in PD patients did not differ significantly from those of controls. RBC catalase activity was significantly lower in advanced cases of PD compared to early cases. Oxidized glutathione was significantly higher in RBCs of PD patients, although there were no changes in total glutathione and reduced glutathione compared to controls. TBARS content was increased in patients with PD. Levodopa therapy, age and duration of illness did not significantly influence the measured parameters. Our study supports the previous hypothesis that oxidative stress is implicated in the pathogenesis of PD. Perspectives for treatment of PD in the future could include antioxidant therapy.

[Oxidative stress involvement in schizophrenia pathophysiology: a review]. / Implication du stress oxydant dans la physiopathologie de la schizophrénie: revue de la littérature.

BACKGROUND: Schizophrenia is a devastating psychiatric disorder with a broad range of behavioural and biologic manifestations. There are several clinical characteristics of the illness that have been consistently associated with poor premorbid adjustment, long duration of psychosis prior to treatment and prominent negative symptoms. The etiopathogenic mechanisms of lack of insight in patients with schizophrenia are to date unknown, although several hypotheses have been suggested. A point of convergence for the theoretical models occurs with regard to the neuronal membrane. Neuronal membrane contains a high proportion of polyunsaturated fatty acid and is the site for oxidative stress. Oxidative stress is a state when there is unbalance between the generation of reactive oxygen species and antioxidant defence capacity of the body. It is closely associated with a number of diseases including Parkinson's disease, Alzheimer-type dementia and Huntington's chorea. Accumulating evidence points to many interrelated mechanisms that increase production of reactive oxygen or decrease antioxidant protection in schizophrenic patients. OBJECTIVES: This review aims to summarize the perturbations in antioxidant protection systems during schizophrenia, their interrelationships with the characteristic clinics and therapeutics and the implications of these observations in the pathophysiology of schizophrenia are discussed. LITERATURE FINDINGS: In schizophrenia there is evidence for deregulation of free radical metabolism, as detected by abnormal activity of critical antioxidant enzymes (superoxide dismutase, glutathione peroxidase and catalase). Many studies conclude in the decrease in the activity of key antioxidant enzymes in schizophrenia. A few studies have examined levels of non enzymatic antioxidants such as plasma antioxidant proteins (albumin, bilirubine, uric acid) and trace elements. How showed decreased levels in schizophrenic patients. Others studies have provided evidence of oxidative membrane damage by examining levels of lipid peroxidation products. Such abnormalities have been associated with certain clinical symptoms and therapeutic features. Negative symptoms have been associated with low levels of GSH-Px. Positive symptoms have been positively correlated with SOD activity. Plasma TAS was significantly lower in drug-free and haloperidol treated patients with schizophrenia. A low erythrocyte SOD activity has been found in never-treated patients, but with haloperidol treatment, SOD activity increased. DISCUSSION: These results demonstrate altered membrane dynamics and antioxidant enzyme activity in schizophrenia. Membrane dysfunction can be secondary to free a radical-mediated pathology, and may contribute to specific aspects of the schizophrenia symptomatology. Membrane defects can significantly alter a broad range of membrane functions and presumably modify behavior through multiple downstream biological effects. Phospholipid metabolism in the brain may be perturbed in schizophrenia, with reduced amounts of phosphatidylcholins and phosphatidylethanolamine in post-mortem brain tissue from schizophrenic patients, and large amounts of lipofuscin-like materiel in the oligodendrocytes. The existence of these products within cell membranes results in an unstable membrane structure, altered membrane fluidity and permeability and impaired signal transduction. Recent findings suggest that multiple neurotransmitter systems may be faulty. CNS cells are more vulnerable to the toxic effects of free radicals because they have a high rate of catecholamine oxidative metabolic activity. Neurotransmitters, like glutamate, can induce the same metabolic processes that increase free radical production and can lead to impaired dopamine-glutamate balance. These results question the role of this imbalance in the biochemical basis evoked in the etipathogenic mechanisms of schizophrenia, as well as the role of antioxidants in the therapeutic strategy and their implication in preventive and early intervention approaches in populations at risk for schizophrenia.

Potential antioxidant effects of zinc and chromium supplementation in people with type 2 diabetes mellitus.

OBJECTIVE: To determine the effects of combined zinc (Zn) and chromium (Cr) supplementation on oxidative stress and glucose homeostasis of people with type 2 diabetes. DESIGN: Tunisian adult subjects with HbA1C > 7.5% were supplemented for 6 months with 30 mg/d of Zn as Zn gluconate or 400 microg/d of Cr as Cr pidolate or combined Zn/Cr supplementation or placebo. The effects of supplementation on plasma zinc (Zn), copper (Cu), selenium (Se), urinary Zn, Cr, plasma thiobarbituric acid reactive substances (TBARS), Cu-Zn superoxide dismutase (SOD) and Se glutathione peroxidase (GPx) in red blood cells, blood lipids and lipoproteins, HbA1C and fasting glucose were measured at the beginning of the study and after six months. RESULTS: At the beginning of the study, more than 30% of the subjects may have been Zn deficient with plasma Zn values less than 10.7 mircomol/L, whereas levels of plasma Cu, Se and antioxidant RBC enzyme activities were in the normal ranges. Following supplementation, there were significant decreases of plasma TBARS in the Cr (13.6%), Zn (13.6%) and Zn/Cr (18.2%) groups with no significant changes in the placebo group. The value for the TBARS of the control healthy Tunisian subjects was 2.08 +/- 0.04 micromol/L and that of the Tunisian subjects with diabetes was 3.32 +/- 0.05 micromol/L. This difference of 1.24 micromol/L between the control group and the subjects with diabetes was reduced from 36% to 50% in the three supplemented groups. Supplementation did not modify significantly HbAIC nor glucose homeostasis. No adverse effects of Zn supplementation were observed on Cu status. HDL cholesterol nor interactions in Zn or Cr. CONCLUSIONS: These data suggest the potential beneficial antioxidant effects of the individual and combined supplementation of Zn and Cr in people with type 2 DM. These results are particularly important in light of the deleterious consequences of oxidative stress in people with diabetes.

[The pH, PCO2 and PO2 of pleural fluid. Variations and diagnostic value]. / Le pH, la PCO2, la PO2 du liquide pleural. Variations et intérêt diagnostique.

The pH, the PCO2 and the PO2 of pleural liquid in 100 patients in the pneumology unit of the Sfax Hospital been measured. Variations according to etiology have been noticed: 44 tubercular pleurisies have presented an acid pH, a high PCO2 and a low PO2, without variation according of the evolution; 34 cancerous pleurisies were divided as follow: recent pleurisies with alcaline pH, normal PO2 and PCO2; neoplastic pleurisies with developed degree with acid pH, low PO2 and high PCO2; 6 cases of cardiac pleurisies have presented a very high PO2; some other etiologies have been explored (bacterial, viral, cirrhotic, rheumatoid, pancreatic). Afterwards, we have tried to bring out some physio-pathological explanations. At the end of this study, the gazometry of pleural liquid, of easy execution and rapid result, seems to be a useful complementary biological test.