In situ identification of CD44+/CD24- cancer cells in primary human breast carcinomas.

Breast cancer cells with the CD44+/CD24- phenotype have been reported to be tumourigenic due to their enhanced capacity for cancer development and their self-renewal potential. The identification of human tumourigenic breast cancer cells in surgical samples has recently received increased attention due to the implications for prognosis and treatment, although limitations exist in the interpretation of these studies. To better identify the CD44+/CD24- cells in routine surgical specimens, 56 primary breast carcinoma cases were analysed by immunofluorescence and confocal microscopy, and the results were compared using flow cytometry analysis to correlate the amount and distribution of the CD44+/CD24- population with clinicopathological features.

Friedreich's ataxia: oxidative stress and cytoskeletal abnormalities.

Friedreich's ataxia (FRDA) is an autosomal recessive disorder caused by mutations in the gene encoding frataxin, a mitochondrial protein implicated in iron metabolism. Current evidence suggests that loss of frataxin causes iron overload in tissues, and increase in free-radical production leading to oxidation and inactivation of mitochondrial respiratory chain enzymes, particularly Complexes I, II, III and aconitase. Glutathione plays an important role in the detoxification of ROS in the Central Nervous System (CNS), where it also provides regulation of protein function by glutathionylation.

Protein glutathionylation increases in the liver of patients with non-alcoholic fatty liver disease.

Background And Aim: Oxidative stress is an important pathophysiological mechanism in non-alcoholic steatohepatitis, where hepatocyte apoptosis is significantly increased correlating with disease severity. Protein glutathionylation occurs as a response to oxidative stress, where an increased concentration of oxidized glutathione modifies post-translational proteins by thiol disulfide exchange. In this study, we analyzed the protein glutathionylation in non-alcoholic fatty liver disease (NAFLD) and evaluated a potential association between glutathionylation, fibrosis, and vitamin E treatment.

Protein glutathionylation in human central nervous system: potential role in redox regulation of neuronal defense against free radicals.

Neuronal defense against free radicals is mediated primarily by the glutathione system. A cerebral defect of this system gives rise to the oxidative stress occurring in some neurological diseases. Glutathione provides a means of regulating protein function by glutathionylation, consisting of the formation of mixed disulfides between cysteines and glutathione.

Glutathione metabolism and antioxidant enzymes in patients affected by nonalcoholic steatohepatitis.

Background: Oxidative stress and accumulation of excessive fat in the liver may underlie the pathophysiology of nonalcoholic steatohepatitis (NASH). Given that glutathione blood metabolism may represent an indicator of tissue oxidative status, we analysed the blood profile of various forms of glutathione in children with NASH, and we evaluated the presence of systemic oxidative stress by calculating the oxidised/reduced glutathione ratio (GSSG/GSH). Furthermore, we analysed the catalytic activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione transferase (GST), and glutathione reductase (GR) in blood of patients.

Actin glutathionylation increases in fibroblasts of patients with Friedreich's ataxia: a potential role in the pathogenesis of the disease.

Increasing evidence suggests that iron-mediated oxidative stress might underlie the development of neurodegeneration in Friedreich's ataxia (FRDA), an autosomal recessive ataxia caused by decreased expression of frataxin, a protein implicated in iron metabolism. In this study, we demonstrate that, in fibroblasts of patients with FRDA, the cellular redox equilibrium is shifted toward more protein-bound glutathione. Furthermore, we found that actin is glutathionylated, probably as a result of the accumulation of reactive oxygen species, generated by iron overload in the disease.

Glutathione metabolism and antioxidant enzymes in children with Down syndrome.

Oxidative stress has been proposed as a pathogenic mechanism of atherosclerosis, cell aging, and neurologic disorders in Down syndrome. This study demonstrates a systemic decrease of all glutathione forms, including glutathionyl-hemoglobin, in the blood of children with Down syndrome. Furthermore, we obtained a disequilibrium, in vivo, between the antioxidant enzyme activities.

Determination of glutathionyl-hemoglobin in human erythrocytes by cation-exchange high-performance liquid chromatography.

Since glutathionyl-hemoglobin has been suggested to be a clinical marker of oxidative stress in human blood and given the growing biological relevance of oxidative stress as a pathogenic factor in several diseases, we describe a method to measure glutathionyl-hemoglobin concentration in erythrocytes, by using cation-exchange high-pressure liquid chromatography with UV detection. The glutathionyl-hemoglobin peak has been identified on the basis of the following findings: (a) the peak increased when the sample was incubated with oxidized glutathione; (b) the peak disappeared when the sample was reduced with dithiothreitol, with the simultaneous increase of that corresponding to hemoglobin A(0); (c) the peak could be detected by incubating hemoglobin A(0) with reduced glutathione; (e) deconvoluted mass spectrum of the glutathionyl-hemoglobin peak showed a 16172.0-Da molecular mass, corresponding to hemoglobin beta bound to glutathione.

Determination of superoxide dismutase and glutathione peroxidase activities in blood of healthy pediatric subjects.

Background: Given the growing requirement of antioxidant enzymes measurements in laboratory and the increasing role of SOD/GPx ratio in the balance of reactive oxygen species (ROS), the aim of our study was to contribute to define reference values of enzyme activities in Italian healthy children, by determining SOD in erythrocytes and GPx in whole blood.

Methods: SOD (E.C.