A possible role for selenoprotein glutathione peroxidase (GPx1) and thioredoxin reductases (TrxR1) in thyroid cancer. Our experience in thyroid surgery

Abstract Background: Oxidative stress is responsible for some alterations in the chemical structure and, consequently, in the function of proteins, lipids, and DNA. Recent studies have linked oxidative stress to cancers, particularly thyroid cancer, but the mechanisms remain unclear. Here, we further characterize the role of oxidative stress in thyroid cancer by analyzing the expression of two selenium antioxidant molecules, glutathione peroxidase (GPx1) and thioredoxin reductase (TrxR1) in thyroid cancer cells. Methods: Samples of both healthy thyroid tissue and thyroid tumor were taken for analysis after total thyroidectomy. The expression of GPx1 and TrxR1 was revealed by Western blot analysis and quantified by densitometric analyses, while the evaluation of free radicals was performed by Electron Paramagnetic Resonance (EPR)-spin trapping technique. Results: Our results show a decrease in the expression of GPx1 and TrxR1 (− 45.7 and − 43.2% respectively, p < 0.01) in the thyroid cancer cells compared to the healthy cells. In addition, the EPR technique shows an increase of free radicals in tumor tissue, significantly higher than that found in healthy thyroid tissue (+ 116.3%, p < 0.01). Conclusions: Our findings underscore the relationship between thyroid cancer and oxidative stress, showing the imbalance of the oxidant/antioxidant system in thyroid cancer tissue. These results suggest that either the inability to produce adequate antioxidant defense or an increased consumption of antioxidants, due to the hyper-production of free radicals, may play a crucial role in thyroid cancer. Keywords: Oxidative stress, Thyroid cancer, Glutathione peroxidase (GPx1), Thioredoxin reductases (TrxR1), Selenium enzyme

Optineurin gene is not involved in the common high-tension form of primary open-angle glaucoma

Purpose: To assess the influence of optineurin in the more common high-tension, primary open-angle glaucoma (POAG). Methods: Eighteen sporadic cases and 35 probands from 35 familial cases, including three families with one member having normal-tension glaucoma (NTG), were enrolled. Using transgenomic WAVE denaturing high-performance liquid chromatography (DHPLC), all coding portion of the optineurin gene (from exon 4 to exon 16) was analyzed. Samples displaying an altered elution profile were sequenced to confirm and identify sequence variants. Exon 4 containing the previously reported p.E50K (Glu50Lys) recurrent mutation (covering 13% of normotensive cases) was entirely sequenced. Results: We did not detect the mutation p.E50K, and we did not find any other pathogenic mutation. A putative splice-site mutation was detected in one family. Extension of segregation analysis to additional family members and mRNA investigation failed to establish a certain involvement of this mutation with the disease. We detected a number of common polymorphisms, including the previously reported p.M98K (Met98Lys) variant. Conclusions: In this population, mutations in the optineurin gene are not associated with adult-onset primary POAG. \ua9 Springer-Verlag 2006

True aneurysm of the proximal occipital artery. Case report

INTRODUCTION: True aneurysms of the proximal occipital artery are rare, may cause neurological symptoms due to compression of the hypoglossal nerve and their resection may be technically demanding. PRESENTATION OF CASE: The case of an aneurysm of the proximal occipital artery causing discomfort and tongue deviation by compression on the hypoglossal nerve is reported. Postoperative course after resection was followed by complete regression of symptoms. CONCLUSION: Surgical resection, as standard treatment of aneurysms of the occipital artery, with the eventual technical adjunct of intubation by the nose is effective in durably relieving symptoms and preventing aneurysm-related complicatio

Snow accumulation rates in northern Victoria Land, Antarctica, by firn-core analysis

AbstractA multiparametric (chemical, isotopic and physical) study on three shallow firn cores sampled in northern Victoria Land was carried out to obtain glaciological information and climatic data in this Antarctic region. Sampling areas were accurately prospected to identify sites, located at different altitudes and distances from the sea, where the snow accumulation was not influenced by katabatic wind redistribution or summer melting. Stratigraphic, isotopic (δl8O) and chemical (H2O2, MSA and nssSO42−) profiles were mutually examined for dating purposes and to determine the mean snow-accumulation rates at three different stations. Annual accumulation rates of 85–420 kg m−2 a−1 were determined in the period 1971–92. An inverse pattern between accumulation rate and altitude was shown by the progression of the mean annual rates of 160, 203 and 260 kg m−2 a−1, respectively, in the highest, medium and lowest stations. The mean accumulation value of all northern Victoria Land data available, 170 kg m−2 a−1, represents a decrease of up to 35% with respect to the estimated value most widely used until now. Our accumulation value is very close to that required for a zero net surface mass balance according to ice discharge. A linear relationship with a gradient of 0.81‰ °C−1 has been found between mean δ18O values and mean annual surface temperature for different ice cores drilled in northern Victoria Land