Oxidative stress, nitric oxide, and diabetes.

In 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.

Role of asymmetric-dimethyl-L-arginine (ADMA) and nitrite/nitrate (NOx) in the pathogenesis of oxidative stress in female subjects with uncomplicated type 1 diabetes mellitus.

AIMS: To explore the role of asymmetric-dimethyl-L-arginine (ADMA), an endogenous nitric oxide synthetases (NOS) inhibitor, and nitrite/nitrate (NOx) in the pathogenesis of oxidative stress in early stages of type 1 diabetes mellitus. METHODS: We measured in 99 female subjects with uncomplicated type 1 diabetes (duration disease <10 years) and in 44 sex-matched controls (comparable for age, smoking habit, diet and physical activity) plasma levels of NOx, glycosylated haemoglobin (HbA1c), glucose, uric acid, total cholesterol, high density lipoprotein (HDL) cholesterol, triglycerides and serum ADMA. RESULTS: Type 1 diabetic subjects have higher levels of glycemia, HbA1c, LDL cholesterol and NOx, but lower ADMA and serum uric acid (UA), compared with the control group; no further differences were found. A significant linear and inverse correlation was found between NOx and ADMA levels (R(2)=0.237, p<0.001). CONCLUSIONS: This study suggests a reduced ADMA inhibition of NOS as possible mechanism involved in the pathogenesis of oxidative stress in female subjects with a short duration and uncomplicated type 1 diabetes.

A new standardized absolute quantitative RT-PCR method for detection of tyrosinase mRNAs in melanoma patients: technical and operative instructions.

BACKGROUND: To develop a new absolute quantitative real-time PCR method for blood mRNA tyrosinase assay and to compare this new method with standard RT-PCR nested. METHODS: Ten blood of melanoma patients (stages I-III), 5 tissue samples, 2 surgical fresh metastatic skin and 3 lymph nodes paraffin-embedded slices were analysed, and 10 negative controls were used. Ten millilitres of blood was analysed for each individual. Three different protocols for RNA extraction and two reverse transcription methods were used. Specific human tyrosinase cDNA fragment was cloned into pcDNA3+ vector and then titrated for the standard curve construction (from 10(6) to 10(1)copies/microl). Recovery assays for RNA and cells were also performed. RESULTS: Our method was able to detect less than 5 cells/10(8) WBC and about 100 fg of tyrosinase RNA. Very low CVs (<1.5%) were obtained on all samples run in triplicate. Sensitivity and specificity were of 100%. The amount of starting volume of blood was crucial for the determination of copy number since large volumes are necessary for patient's monitoring. CONCLUSIONS: Our absolute qRT-PCR assay could be proposed as a new standardized molecular method for the management of melanoma patients, particularly for the follow up of the highest AJCC stages.

A comparative study of fine needle aspiration and fine needle non-aspiration biopsy on suspected thyroid nodules.

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.

Effects of rehabilitation treatment on thyroid function.

OBJECTIVE: The aim of the study was to evaluate the effects of an intensive rehabilitation programme on thyroid metabolism, the relationship between disability and thyroid hormone level, and the occurrence of nonthyroidal illness syndrome (NTIS) before and after rehabilitation. DESIGN, SUBJECTS AND MEASUREMENTS: This was a clinical prospective study. Orthopaedic surgery patients (n = 82) were classified into two groups: patients in whom early active mobilization and walking were possible (walking group, WG, n = 45), and patients in whom these were not recommended (nonwalking group, NWG, n = 37). Levels of free T3 (fT3), fT4, TSH and rT3 were measured before and after surgery, and then at 1, 3, 7, 14 and 30 days from the beginning of rehabilitation. Personal, nutritional and clinical data were acquired for all patients. The Barthel Index (BI) was used to assess disability before and after rehabilitation. RESULTS: Immediately after surgery, both groups of patients showed a significant decrease in mean fT3 concentrations and a significant increase in rT3; mean fT4 values decreased significantly only in NWG patients. Once rehabilitation had been completed, fT3 and rT3 levels returned to baseline values in WG patients. In NWG patients mean fT3 and fT4 levels continued to decrease significantly and rT3 values remained significantly high until the end of rehabilitation. NTIS occurred in 38% of the NWG patients. No significant changes in TSH levels were observed in either group. Finally, we observed a direct correlation between fT3 levels and the BI in WG patients. CONCLUSIONS: Our data suggest that early patient mobilization and physical activity during an active and intensive rehabilitation programme induce recovery of thyroid function and avoid occurrence of NTIS.