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Background: The aim of our study was to measure reactive oxygen metabolites (ROMs) in chronic hemodialysis (HD) patients and evaluate the possible association with cardiovascular disease (CVD) and mortality., Methods: We measured ROMs in 76 HD patients and correlated with CVD, cardiovascular (CV) events in the follow-up and all-cause and CVD-related mortality., Results: The levels of ROMs presented a median value of 270 (238.2-303.2) CARR U (interquartile range). We created a ROC curve (ROMs levels vs. CVD) and we identified a cut-off point of 273 CARR U. Patients with ROMs levels ≥273 CARR U were significantly older, had higher C-reactive protein levels and lower creatinine concentrations. The prevalence of CVD was higher in patients with ROMs levels ≥273 (87.1%) than in those with ROMs levels <273 CARR U (17.7%; p<0.0001). ROMs levels were significantly higher in patients with CVD (317±63.8) than in those without (242.7±49.1; p<0.0001). At multiple regression analysis, age, creatinine and C-reactive protein were independent factors associated with ROMs. At multiple logistic regression analysis the association between ROMs and CVD was independent (OR: 1.02, 95% CI: 1.00-1.05; p=0.03). Twenty six patients developed cardiovascular (CV) events during the follow-up. Of these, seven were in the group with ROMs levels <273 CARR U and 19 in the group with ROMs levels ≥273 CARR U. The logistic regression analysis showed that both age (OR: 1.06, 95% CI: 1.01-1.12; p=0.013) and ROMs levels (OR: 1.10, 95% CI: 1.00-1.02; p=0.045) were independently associated with CV events in the follow-up., Conclusions: ROMs are independently associated with CVD and predict CV events in chronic HD patients.

Background: Age-related macular degeneration (AMD) is a complex disorder causing irreversible central vision loss. Complement Factor H (CFH) and age-related maculopathy susceptibility 2 (ARMS2) are now widely accepted as important AMD susceptibility genes. In particular, two specific variants, CFH p.Y402H and ARMS2 p.A69S, have been reported as strongly AMD associated. In order to perform the genetic screening of these single nucleotide polymorphisms (SNPs), we describe a high resolution melting analysis (HRM) as a rapid closed tube mutation scanning assay., Methods: To validate HRM genotyping, 94 DNA samples from AMD patients (previously genotyped by sequence analysis) were analyzed. PCR amplification and melting curve analysis were performed in the LightCycler 480 Real-Time PCR System. In order to evaluate the accuracy of the HRM assay, we performed a blinded study of 20 unknown independent samples., Results: We correctly genotyped all samples. In fact, all samples corresponded to the previous genotype assignments., Conclusions: Early identification of individuals with genetic risk variants CFH p.Y402H and ARMS2 p.A69S is clinically important for the definition of AMD status. High-resolution DNA melting is homogenous, accurate and rapid method for CFH and ARMS2 genotyping.

Background: Recent studies strongly suggest the use of oncofetal fibronectin (onfFN) mRNA in diagnostic follow-up and staging due to its very high specificity for thyroid cancers. Since the use of this marker has not been well established yet, particularly in the monitoring of minimal residual disease, we have tried to verify the diagnostic power of onfFN and its usefulness as a prognostic molecular marker. For this reason, we evaluated (by RT-PCR) the presence of onfFN mRNAs, not only in blood samples and thyroid tissues (both normal and neoplastic), but also in different biological fluids (such as K3-EDTA blood samples, saliva and urine) belonging to healthy individuals., Methods: Molecular investigations, such as RT-PCR protocol, and sequencing of onfFN cDNAs evaluation of the above-mentioned samples were performed., Results: The onfFN transcript was largely expressed in all benign and malignant thyroid tissues [differentiated thyroid carcinomas (DTCs)] tested as well as in a large number of biological fluids; in particular, 100% urine samples were positive for onfFN transcript as compared to the thyroglobulin (Tg) mRNA (75%), while saliva was always positive for onfFN and never for Tg. These findings indicate that onfFN cannot be considered a marker specific for thyroid cancer presence. Finally, Tg results were positive in a large part of the samples, but not always in concomitance with onfFN., Conclusions: We underline how the complexity of onfFN transcripts could affect the RT-PCR procedure. In addition, the presence of onfFN transcripts in several normal and cancer tissues, along with non-thyroid biological fluids or cells, does not allow the use of this marker for cancer monitoring.

Background: Asymmetric dimethylarginine (ADMA), an endogenous competitive inhibitor of nitric oxide synthase plays an important role in endothelial dysfunction processes. Recent studies have linked high ADMA levels with several pathological conditions. The interest as a marker of endothelial dysfunction has increased in the last few years. In this paper, a method for serum ADMA quantification by liquid chromatography tandem mass spectrometry has been described. To test the utility in a pathological condition ADMA levels in hypertensive subjects have been measured., Methods: HPLC separation was performed by hydrophilic interaction chromatography using acetonitrile/water containing 0.1% formic acid and 20 mmol/L ammonium formate. Selected reaction monitoring was performed following the transitions m/z 203.1→46.4 for ADMA and 210.1→46.3 for the internal standard [2H7]ADMA., Results: The method was linear up to 10 μmol/L, limit of detection and limit of quantification were 0.005 μmol/L and 0.01 μmol/L, respectively. Recovery was higher than 96%. Intra- and inter-assay imprecision were lower than 6%. The accuracy, expressed as bias %, was <2.5. ADMA in "healthy" subjects ranged from 0.343 to 0.608 μmol/L and resulted significantly lower than that measured in hypertensive subjects (p<0.001)., Conclusions: The method developed is selective and sensitive, thus suitable not only for research purposes, but also for routinely work.

Background: The poor comparability of growth hormone (GH) results obtained using commercially available methods, is partly due to standard preparations used in calibration. The system relies on the use of the International Reference Preparation (IRP) international standard (IS) 80/505, of human pituitary origin, containing all GH isoforms. Recently, a 22K recombinant GH isoform IRP IS 98/574 was commercialized. Our aim was to evaluate the influence of both calibrators on GH results., Methods: GH concentration in 97 serum samples from children undergoing a growth hormone releasing hormone+arginine stimulation test was measured using Siemens IMMULITE electro-chemiluminescence method, calibrated with both IS 80/505 and IS 98/574 (GRH Growth hormone-Recombinant 98/574-kit)., Results: Comparison of our results obtained with the two sets of calibrators showed good correlation, although we found higher percentage variation (var%) than that stated by Siemens. The mean var% value was confirmed when all results were sub-divided into subgroups based on both high and low GH concentrations., Conclusions: Since the GH assay is influenced by a variety of binding proteins, isoforms and conversion factors, standardization of the assay is strongly required. In Italy, the Agenzia Italiana del Farmaco 39 note provides GH laboratory values which are useful for therapy. On the basis of our results, we therefore propose to adjourn these GH values in order to ensure better management of patients with GH-related disorders.

Background: The best index of adrenal dysfunction is urinary free cortisol (UFC) measurements performed using a 24-h urine collection. This measurement is also useful in the investigation of Cushing's syndrome. In this paper, we report a simple and selective method for the analysis of UFC by liquid chromatography-tandem mass spectrometry (LC-MS/MS) suitable for use in a high-volume clinical laboratory routine. The results were compared to those obtained using a commercial immunoassay method used in our laboratory., Methods: Urine samples containing 50 ng of internal standard (Cortisol-9,11,12,12-d(4)) were deproteinized using centrifugal filters with a molecular weight 10,000 Da cut-off and injected on a reversed phase column. Cortisol was analyzed in highly selective reaction monitoring in positive atmospheric pressure chemical ionization mode, at a resolution of 0.4 amu full width half maximum, and following the transitions related to the precursor 363.2 for cortisol and 367.2 for deuterated cortisol. The method validation included analysis of precision, linearity, sensitivity, recovery and interference from structurally similar steroids. UFC from 230 subjects was measured using LC-MS/MS and electrochemiluminescence immunoassay (ECLIA) methods., Results: The calibration curves exhibited linearity and reproducibility in the range 7-10,000 nmol/L. Total imprecision was lower than 10%. The limit of detection and limit of quantification were 2 and 7 nmol/L, respectively. Mean recovery was higher than 90%. Structurally similar steroids do not interfere in the proposed method, but cause a significant change in the ECLIA results. Cortisol values obtained using the ECLIA method were always higher than those obtained using the LC-MS/MS method, with the bias directly proportional to cortisol concentrations. The reference values calculated using 180 normal subjects were 11-70 μg/day., Conclusions: The proposed method is sensitive, simple, free from interferences and reliable for routine use.

Steroid 21-hydroxylase deficiency is present in more than 90% of patients with congenital adrenal hyperplasia, an inherited metabolic disorder of adrenal steroidogenesis. Impaired enzymatic activity leads to the accumulation of metabolic intermediates (progesterone and 17-hydroxyprogesterone), which results in excessive androgen production and varied signs of virilisation. CYP21A2 is an active gene and encodes for the steroid 21-hydroxylase enzyme, whereas CYP21A1P is an inactive pseudogene that contains a series of deleterious mutations. The major part of disease-causing mutations in CYP21A2 alleles are CYP21A1P-derived sequence transferred to the active gene by macro or microconversion events. Approximately 5% of all disease-causing CYP21A2 alleles harbour rare mutations that do not originate from the pseudogene. A list of all reported CYP21A2 mutations can be found in the CYP21A2 database created by the Human Cytochrome P450 (CYP) Allele Nomenclature Committee (http:www.imm.Ki.se/CYPalleles/cyp21.htm). Unfortunately, the last update of this database was in 2006. However, over the last 4 years many other novel CYP21A2 mutations have been reported in PubMed. The aim of this review is to provide a focus on the molecular and genetic aspects of the diagnosis of 21-hydroxylase deficiency. In addition, an updated list of the last new CYP21A2 mutations is included.

Congenital adrenal hyperplasia (CAH) is an autosomal recessive disorder caused primarily by defects in the steroid 21-hydroxylase gene (CYP21A2). The CYP21A2 gene is located in the HLA class III region on the short arm of chromosome 6p21.3, along with an inactive pseudogene, CYP21A1P, that is 98% homologous with CYP21A2 in its coding sequence. Most mutations found in the CYP21A2 gene are normally present in the pseudogene, implying that recombination events (microconversion) between these two genes may lead to the transfer of mutations from the pseudogene to the functional gene. Approximately only 5% of all CYP21A2 alleles causing disease harbour rare mutations not originating from the pseudogene. However, detection of these rare and spontaneous mutations has continued to expand worldwide. In this report, we describe the clinical and genetic findings in a Romanian newborn suffering from classic salt wasting form of CAH due to severe 21-hydroxylase deficiency.

Background: This report describes clinical, biochemical and molecular findings regarding two Italian monozygotic twins carrying a novel multiple endocrine neoplasia type 1 (MEN1) mutation inherited from their mother., Methods: Clinical, biochemical and genetic evaluations of the above-mentioned family members were performed., Results: All three members were heterozygous for a deletion involving the first nucleotide at codon 98 in exon 2 of the MEN1 gene, which results in early termination of the protein. The clinical phenotypes were as follows: one out of the two twins suffered from insulinoma and hyperparathyroidism, while the second one was asymptomatic. Furthermore, the mother suffered from hyperparathyroidism, as well as from hypergastrinemia for several years before the daughter was diagnosed of MEN-1., Conclusions: We describe a family with a new heterozygous mutation (g.292delC) in the MEN1 gene not described previously. The mutation leads to a truncated protein without activity, explaining the clinical picture of this family.

At least four premature newborn complications have been reported to be associated with low serum insulin-like growth factor-I (IGF-I) levels: bronchopulmonary dysplasia, retinopathy of prematurity, necrotizing enterocolitis and brain damage. Local IGF-I concentrations have only been reported for bronchopulmonary dysplasia and these findings show that lung IGF-I levels are clearly increased (epithelial lining fluid levels), emphasizing the fact that IGF-I is differently regulated in the general circulation or at local level. The present review discusses the meaning of the association between serum IGF-I amounts and development of complications in premature newborns. Finally, some methodological indications are reported regarding the IGF-I assay procedures. It is important to establish what are the possible relationships between blood levels and those of different compartments involved in the diseases.