[Oxidative stress in end stage renal disease: evidence and association with cardiovascular events in Tunisian patients]. / Stress oxydant chez les insuffisants rénaux chroniques: evidence et association avec les maladies cardiovasculaires chez des urémiques Tunisiens.

We assessed oxidative stress in 35 chronic renal failure under conservative treatment (CRF), 50 hemodialysed (HD) and 30 renal transplant (RT) patients, and 31 age- and sex-matched healthy subjects. Compared to controls, CRF patients exhibited significantly higher conjugated dienes (139 +/- 37 versus 121 +/- 22 micromol/l) and LDL oxidation (126 +/- 65 versus 99 +/- 46 micromol/l). Glutathione peroxidase activity was decreased in CRF and HD (5.31 +/- 2.46 and 5.39 +/- 2.32 versus 7.42 +/- 2.72 U/ml in healthy subjects). Superoxide dismutase activity was lower in HD (91 +/- 38 U/ml) and higher in RT patients (132 +/- 33 U/ml) than controls (116 +/- 30 U/ml). Plasma zinc concentrations were significantly decreased in CRF and HD patients and copper concentrations were significantly decreased in TPR. Plasma selenium levels were normal in the three groups of patients. Vitamin A was significantly increased, whereas vitamin E was normal in the 3 groups of patients compared to healthy controls. Total antioxidant status was increased in CRF and HD, but not in RT patients. Patients with cardiovascular disease showed increased serum copper, and significantly decreased glutathione peroxidase activity. This study revealed an oxidative stress in CRF and HD patients that may favour the development of cardiovascular diseases.

Health Risk Assessment of Heavy Metals in Traditional Cosmetics Sold in Tunisian Local Markets.

This study was undertaken in order to determine heavy metal contents in twelve (n = 12) henna brands and eleven (n = 11) kohl products. An analytical test was performed for Pb, Cd, Cu, and Zn in henna and kohl products using atomic absorption spectrophotometery. The overall mean concentrations of heavy metals in henna varied between 1.2 and 8.9 µg g(-1) for Pb; 0.8 and 18.6 µg g(-1) for Cd; 0.5 µg g(-1) and 3.3 µg g(-1) for Cu; and 3.7 µg g(-1) and 90.0 µg g(-1) for Zn. As for kohl products, Pb concentrations ranged between 51.1 µg g(-1) and 4839.5 µg g(-1), Cd concentrations ranged between 1.0 µg g(-1) and 158.6 µg g(-1), Cu concentrations ranged between 2.5 µg g(-1) and 162.5 µg g(-1), and Zn concentrations ranged between 0.7 µg g(-1) and 185.0 µg g(-1). The results of our study revealed that Pb, Cd, Cu, and Zn contents in investigated samples were high, making from the prolonged use of such products a potential threat to human health. Therefore, major quality controls are recommended in order to enforce acceptable limits of potential contaminants in cosmetics and good manufacturing practice.

Risk of female breast cancer and serum concentrations of organochlorine pesticides and polychlorinated biphenyls: a case-control study in Tunisia.

The aim of this study was to investigate the association between serum concentrations of a group of organochlorine pesticides/polychlorinated biphenyls with xenoestrogenic potential and the risk of breast cancer in a female population from Tunisia. The relationship between serum levels of the pollutants and the risk of cancer was assessed using logistic regression analyses. In the unadjusted models, ß-hexachlorocyclohexane (ß-HCH), hexachlorobenzene, heptachlor, polychlorinated biphenyl congeners 138, 153, and 180, and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) were positively associated with breast cancer risk. However, when the models were further adjusted for the selected covariates, only ß-HCH and p,p'-DDE remained statistically significant, and heptachlor was borderline significant. In addition, analyses using POP concentration tertiles corroborated a positive dose-response relationship that was significant for p,p'-DDE (p-trend=0.020) and borderline significant for heptachlor (p-trend=0.078). A similar trend was also confirmed for ß-HCH, in which concentrations≥limit of detection were positively associated with breast cancer risk (vs. concentrations

[Apport of serum vitamin B12 determination in the diagnosis of deficiency: about 95 cases]. / Apport du dosage de la vitamine B12 serique dans le diagnostic d'une carence: a propos de 95 cas.

Vitamin B12 belong a group of cobalamins. It's known to be an enzymatic cofactor of many metabolic reactions essentially in the synthesis of DNA. Damage of deficiency are various essentially hematologic and neurologic. Macrocytic anaemia constitute the main disorder of vitamin B12 deficiency. However, Vitamin B12 deficiency is common in the elderly with neuropsychiatric disorders whether macrocytic anaemia is present or not as its development may come later. In a study we investigate 95 patients aged 21 to 85 years (29 men, 20 women) with symptoms of vitamin B12 deficiency. First, vitamin B12 serum were measured by immuno enzymatic method (MEIA Abbott). Values were classified among 4 categories characterised on manufacture norms; low: 41 cases, unspecified: 19 cases, normal: 13 cases and high: 22 cases. Secondly, the concordance between Vitamin B12 serum, clinical history and evolution were evaluated. The Kappa index established showed a satisfactory result (= 0.97).

Potential Toxic Levels of Cyanide in Almonds (Prunus amygdalus), Apricot Kernels (Prunus armeniaca), and Almond Syrup.

Under normal environmental conditions, many plants synthesize cyanogenic glycosides, which are able to release hydrogen cyanide upon hydrolysis. Each year, there are frequent livestock and occasional human victims of cyanogenic plants consumption. The present work aims to determine the hydrocyanic acid content in different samples of cyanogenic plants, selected from the Tunisian flora, and in the almond syrup. In order to evaluate their toxicity and their impact on the consumer health in the short term as well as in the long term, using the ISO 2164-1975 NT standard, relating to the determination of cyanogenic heterosides in leguminous plants.

Fumonisin determination in tunisian foods and feeds. ELISA and HPLC methods comparison.

A survey for fumonisins B1 and B2 (FB1 and FB2, respectively) was performed on 180 samples of high-consumption food commodities and 15 feed samples randomly collected from various regions of Tunisia. The determination of fumonisin level was performed by an in-house validated high-performance liquid chromatography and an enzyme-linked immunosorbent assay (ELISA) methods. Detection limit by ELISA for fumonisins sum was 25 microg/kg, and those by HPLC were 50 microg/kg for FB1 and 70 microg/kg for FB2. Recoveries of fumonisins spiked at 130 microg/kg ranged from 68.5 to 75.6% by ELISA, whereas those by HPLC for FB1 at 400 microg/kg and for FB2 at 300 microg/kg varied from 75.2 to 90.5%. Naturally occurring fumonisins were found in 10.5% of food samples with levels ranging from 70 to 2130 microg/kg. All contaminated samples contained FB1, and 31.5% of them contained FB2. In addition, the most contaminated commodities were corn foods and sorghum, whereas no fumonisin contamination was found in any nut or rice samples. For analyzed feed samples, fumonisins were detected in 86.6% of them with concentrations ranging from 50 to 2800 microg/kg. In addition, the performance of analytical methods was investigated in a comparison between ELISA and HPLC results for samples analyzed by both methods.

Prognostic value of human erythrocyte acetyl cholinesterase in acute organophosphate poisoning.

Acute organophosphate poisoning (OPP) such as dichlorvos may be monitored by the measurement of the erythrocyte acetyl cholinesterase (EAChE) and the serum cholinesterase (SChE) activities. The aim of this study was to look at correlation between the severity of the OPP judged by certain parameters such as coma, hemodynamic disturbances, respiratory failure, and the decrease of cholinesterases enzymes including EAChE and SChE at admission. Cholinesterase activity was determined upon admission and then on days 3 and 15 in the morning. Clinical effects, EAChE, and SChE activities data were investigated in 42 patients with OPP aged of 29.6 +/- 11.8 years with acute cholinergic crisis in all cases. They were comatose in 29% of cases, presenting both hypotension or shock and hypoxemia in 17% of cases. Fifteen of them (36%) required mechanical ventilation. The mean EAChE activity at admission was 24.3 +/- 11.6 micromol/mL per hour at 37 degrees C; it was 1260 +/- 2204 IU/L for SChE. There were no correlations between the EAChE and the SChE activities. The EAChE was decreased only in comatose patients and those presenting hypotension, hypoxemia, and bradycardia with a cutoff of 23.5 micromol/mL per hour at 37 degrees C. Death was observed in 2 patients with a deep decrease of the EAChE at 5 micromol/mL per hour at 37 degrees C in 1 case and 9 micromol/mL per hour at 37 degrees C in another. The kinetics of improvement of the EAChE activity below the cutoff showed the absence of statistical improvement of the EAChE activity on day 3 (16.6 +/- 9 vs 19.5 +/- 5.7 micromol/mL per hour at 37 degrees C); this improvement was remarkable on day 15 (16.6 +/- 9 vs 27.5 +/- 6.5micromol/mL per hour at 37 degrees C, P = .0004). In summary, the marked decrease of EAChE activity appears in this study as prognostic factor in acute OPP, and coma, respiratory failure, hemodynamic disturbances, and death are associated with a decrease of the EAChE of less than 23.5 micromol/mL per hour at 37 degrees C.