■ AbstractIn the recent decades, oxidative stress has become focus of interest in most biomedical disciplines and many types of clinical research. Increasing evidence from research on several diseases show that oxidative stress is associated with the pathogenesis of diabetes, obesity, cancer, ageing, inflammation, neurodegenerative disorders, hypertension, apoptosis, cardiovascular diseases, and heart failure. Based on this research, the emerging concept is that oxidative stress is the "final common pathway", through which risk factors of several diseases exert their deleterious effects. Oxidative stress causes a complex dysregulation of cell metabolism and cell-cell homeostasis. In this review, we discuss the role of oxidative stress in the pathogenesis of insulin resistance and beta-cell dysfunction. These are the two most relevant mechanisms in the pathophysiology of type 2 diabetes, and in the pathogenesis of diabetic vascular complications, the leading cause of death in diabetic patients.

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The degradation of von Willebrand factor (VWF) depends on the activity of a zinc protease (referred to as ADAMTS-13), which cleaves VWF at the Tyr 1605 -Met 1606 peptide bond. Little information is available on the physiological mechanisms involved in regulation of AD-AMTS-13 activity. In this study, the role of ions on the ADAMTS-13/VWF interaction was investigated. In the presence of 1.5 M urea, the protease cleaved multimeric VWF in the absence of NaCl at pH 8.00 and 37°C, with an apparent k cat /K m Х 3.4 ؋ 10 4 M ؊1 s ؊1 , but this value decreased by ϳ10-fold in the presence of 0.15 M NaCl. Using several monovalent salts, the inhibitory effect was attributed mostly to anions, whose potency was inversely related to the corresponding Jones-Dole viscosity B coefficients (ClO 4 ؊ > Cl ؊ > F ؊ ). The specific inhibitory effect of anions was due to their binding to VWF, which caused a conformational change responsible for quenching the intrinsic fluorescence of the protein and reducing tyrosine exposition to bulk solvent. Ristocetin binding to VWF could reduce the apparent affinity and reverse the inhibitory effect of chloride. We hypothesize that, after secretion into the extracellular compartment, VWF is bound by chloride ions abundantly present in this milieu, becoming unavailable to proteolysis by AD-AMTS-13. Shear forces, which facilitate GpIb␣ binding (this effect being artificially obtained by ristocetin), can reverse the inhibitory effect of chloride, whose concentration gradient across the cell membrane may represent a simple but efficient strategy to regulate the enzymatic activity of ADAMTS-13.

These are the first data about phospholipase A2 in neonates. The enzyme plays a role in neonatal lung injury, especially in infection related respiratory failure. It is associated with lung stiffness, higher mean airway pressure and need for oxygen.

The results of this study indicate that alendronate/cholecalciferol increases BMD in postmenopausal women with NPHPT. Alendronate/cholecalciferol or vitamin D alone does not affect serum or urinary calcium.

Oxidative stress is already present in the early stages of type 1 diabetes. We conclude that the initial increase in oxidative stress could be linked to a reduction in plasmatic levels of uric acid, which is probably directly caused by an overproduction of NO.

Ultrasonography-guided fine needle aspiration (FNA) and fine needle non-aspiration (FNNA) biopsy were performed consecutively on 104 patients (mean age 50 +/- 15 years) affected by multinodular and uninodular goiter. Both techniques were executed on the same patients in the same clinical session beginning with the first (FNA) on half of the patients (randomly selected) and vice versa. The cytological findings on cell samples were divided into four groups: colloidal (benign), follicular (suspicious), malignant, and inadequate. The overall cytologic findings obtained with the two techniques were as follows (FNA % vs FNNA %): inadequate, 16.3% vs 5.8%; colloidal, 69.2% vs 76.9%; follicular, 9.6% vs 10.5%; and malignant, 4.8% vs 6.7%. A statistically significant difference between FNA and FNNA cytology was found only on the number of inadequate results (p = 0.015). Interestingly, the frequency of inadequate specimens for FNNA showed a significantly different distribution depending on the sequence (first or second) in which the technique was executed. In conclusion, FNA and FNNA are useful and cost-effective techniques for the pre-operative assessment of patients with thyroid nodules. However, due probably to its minimally invasive procedure, FNNA produces specimens of better quality and reduces inadequate results. For these reasons FNNA should be preferable to FNA for the cytological evaluation of thyroid nodules.

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