Protective effect of 17beta-estradiol on oxidative stress and liver dysfunction in aged male rats.

In aging liver oxidative stress increases due to the decrease in antioxidant bio-molecules such as estrogens which can be modified by hormonal replacement therapy (HRT). With this in mind, we hypothesized that age-related decline in steroidogenesis may be associated with the impairment of the antioxidant defense cells in liver, the increase in lipid peroxidation, hepatic dysfunction and histological changes; estrogens prevent all these changes induced by aging. 17beta-estradiol treatment was initiated in 12 month-old Wistar rats, and continued until 18 months of age. Our results showed that 17beta-estradiol (E2) level in the serum of the aged untreated rats was reduced by -32% in 18 month-old rats compared to the young animals (4-month-old). The superoxide dismutase (SOD), catalase (CAT), and gluthatione peroxidase (GPX) activities were reduced by -47, -46, and -29% respectively in old rat liver. In addition, the TBARs in liver and hepatic dysfunction parameters in plasma such as gamma-glutamyl transferase (GGT), phosphatase alkalin (PAL) as well as bilirubin level increased significantly in old rats, and histological changes were investigated. In E2-treated rats, protective effects were observed. Indeed, 17beta-estradiol attenuates all changes induced by aging. The 17beta-estradiol level was higher in old E2-treated rats compared to the control rats. Moreover, the SOD, CAT and GPX activities were higher by +28, +15, and +11% respectively. This anti-aging effect of estrogens was clarified by a lower level of lipid peroxidation and liver dysfunction parameters as well as by histological observation.

[Myelodysplastic syndrome / acute myeloid leukemia with t(8; 21) and bundle of Auer rods in neutrophils: an unusual hemopathy]. / Syndrome myélodysplasique / leucémie aiguë avec t(8;21) et polynucléaires à corps d'Auer en fagot: une hémopathie rare de présentation inhabituelle.

We report the case of a 8-year-old girl diagnosed with myelodysplastic syndrome. This case was morphologically characterized by the presence of bundle of Auer rods in the neutrophils. The evolution of the disease was marked by a quick transformation in a acute myeloid leukaemia with t(8;21) refractory to treatment. We reviewed the literature for clinical, biological and therapeutic features of this rare childhood hemopathy.

Ochratoxin A in human blood in relation to nephropathy in Tunisia.

The determination of ochratoxin A (OTA) in human blood in Tunisian populations is underway. The range of contamination is between 0.7 to 7.8 ng ml-1 for the general population and 12 to 55 ng ml-1 for people suffering from chronic renal failure. It appears that 21 to 64% of people suffering from nephropathy are OTA positive with a detection limit of 1ng ml-1. This situation prompted us to search for possible association of OTA contamination and nephropathy resembling Balkan endemic nephropathy. The classification of the ill population into chronic interstitial nephropathy (CIN), chronic glomerular nephropathy (CGN), chronic vascular nephropathy (CVN) and others, indicated that the largest is the CIN group which is significantly different from the other groups, and from the control (P < 0.005). Furthermore, it presented the highest OTA mean values (25 to 59 ng ml-1) compared with the control, CGN, CVN and other groups (6 to 18 ng ml-1) according to the designated region in Tunisia. The rural population seems to be more exposed to ochratoxins in Tunisia, as has been previously reported in the Balkans and Western Europe. Altogether, these results emphasise that in Tunisia an endemic ochratoxin-related nephropathy is probably occurring.

[Ochratoxin A genotoxicity, relation to renal tumors]. / Génotoxicité de l'ochratoxine A, relation avec la tumeur rénale.

Ochratoxin A (OTA) is a mycotoxin which has been implicated in Balkan Endemic Nephropathy (BEN), a disease characterized by tubulonephritis and may be involved in the high incidence of urinary tract tumors associated to BEN. The prevalence of human ochratoxicosis is being determined in Tunisia. 100% of people suffering from chronic interstitial nephropathy of unknown etiology were ochratoxin A positive. These nephropathies are similar to Balkan Endemic Nephropathy. We prove an OTA genotoxic effects in patient suffering from this kind of nephropathy. OTA-DNA adducts formation has been detected in DNA of kidney tissues (biopsy). DNA adducts which are covalent complex between OTA and DNA base (Guanine), constitute first steps of the carcinogenesis process.