Maria Laura De Feo

Two Novel Mutations at Exon 8 of the Sequestosome 1 (SQSTM1) Gene in an Italian Series of Patients Affected by Paget's Disease of Bone (PDB)†

PDB is genetically heterogeneous. Mutations of the sequestosome1 gene have been reported in sporadic and familial forms of Pagets in patients of French Canadian and British descent. Mutational analyses in different ethnic groups are needed to accurately investigate hereditary diseases. We describe two novel mutations of sequestosome1 in 62 Italian sporadic patients, confirming the role of the encoded protein in this disorder.

Systemic hemodynamics and renal function during brain natriuretic peptide infusion in patients with essential hypertension

We assessed the cardiovascular and renal effects of human brain natriuretic peptide (BNP) infused at a dose inducing an increase in plasma BNP to pathophysiologic levels, in eight hypertensive patients in a randomized, placebo-controlled, cross-over study. Left ventricular performance, cardiac output (echocardiography), heart rate, arterial pressure, glomerular filtration rate (GFR; creatinine clearance), sodium excretion, intrarenal sodium handling (lithium clearance method), and urine flow rate were measured in the infusion and postinfusion periods (1 h each), together with plasma BNP and the urinary excretion rate of cGMP. Plasma BNP levels increased from 2.90 +/- 0.74 to 36.43 +/- 5.51 pmol/L (P < .01) at the end of the infusion and were still elevated at the end of the postinfusion period (7.03 +/- 1.41 pmol/L, P < .05). The urinary excretion of cGMP was also significantly higher during BNP infusion. Left ventricular performance, cardiac output, arterial pressure, and peripheral vascular resistance were not affected by BNP. Peptide infusion induced a significant increase in GFR (placebo, 115 +/- 24; BNP, 147 +/- 19 mL/min), sodium excretion (placebo, 129 +/- 40; BNP, 243 +/- 60 mumol/min), and urine flow rate. All these effects were observed also in the postinfusion period. The natriuretic effect of BNP was attributable to both an increase in filtered sodium load and a reduction of distal sodium reabsorption. These results suggest that BNP may contribute to maintain renal function and sodium excretion in patients with essential hypertension.

Thromboxane-Receptor Blockade Increases Water Diuresis in Cirrhotic Patients With Ascites

This study was undertaken to investigate the role of increased renal thromboxane (TX) A2 production in modulating renal hemodynamics and sodium and water retention in cirrhotic patients with ascites. In a randomized, double-blind, placebo-controlled, crossover trial, 15 nonazotemic cirrhotic patients with ascites and elevated urinary TXB2 excretion received the thromboxane-receptor antagonist ONO-3708 (3 micrograms.kg-1.min-1) in a 4-hour continuous infusion. Administration of ONO-3708 significantly blocked TXA2 receptors; bleeding time showed a twofold increase (432 +/- 65 vs. 131 +/- 17 seconds; P less than 0.005), and platelet aggregation to U-46619 (an agonist of TXA2 receptors) was abolished in all patients studied. The drug induced a significant increase in free water clearance (3.06 +/- 0.70 vs. 1.72 +/- 0.57 mL/min; P less than 0.001) and diuresis (4.74 +/- 0.79 vs. 3.94 +/- 0.66 mL/min; P less than 0.05) compared with placebo, as well as a significant (14%) increase in renal plasma flow. The increases in both free water clearance and diuresis induced by ONO-3708 were directly related to basal urinary TXB2 excretion. These results suggest a role for renal TXA2 as a modulator of water handling in cirrhotic patients with ascites.

A high-resolution melting protocol for rapid and accurate differential diagnosis of thyroid nodules.

A large majority of thyroid nodules are benign, and only 5% have malignant features on cytological examination. Unfortunately, fine-needle aspiration is inconclusive in approximately 30% of all thyroid biopsies, because the cytological features are indeterminate (suspicious for malignancy but not completely diagnostic or nondiagnostic). Wide panels of somatic mutations have been identified in thyroid cancers, and detection of genetic alterations in fine-needle aspirate has been demonstrated to improve diagnostic accuracy. Nevertheless, the relatively high number of genetic targets to be investigated, in comparison with the low percentage of malignant samples, makes the usual diagnostic protocol both time-consuming and expensive. We developed a reliable and sensitive protocol based on high-resolution melting analysis for the rapid screening of mutations of KRAS, HRAS, NRAS, and BRAF oncogenes in thyroid fine-needle aspirations. The entire procedure can be completed in approximately 48 hours, with a dramatic reduction in costs. The proposed protocol was applied to the analysis of 260 consecutive fine-needle aspiration biopsy (FNAB) samples. In 35 of 252 samples, 36 sequence variants were detected for BRAF (17 samples), NRAS (6 samples), HRAS (3 samples), KRAS codon 12 (9 samples), and KRAS codon 61 (1 sample).

Urinary Endothelin-1 Excretion Is Enhanced by Low-Dose Infusion of Brain Natriuretic Peptide in Normal Humans

To evaluate the functional relationship between cardiac natriuretic peptides and endothelin-1 within the human kidney, we studied the effects exerted by infusion of brain natriuretic peptide on urinary endothelin-1 excretion. We studied twice in a single-blind manner five normal volunteers who received a constant infusion of 5% dextrose (250 mL/h) or human brain natriuretic peptide-32 at a dose of 4 pmol/kg per minute. Blood samples were drawn at intervals for measurement of hematocrit and concentrations of creatinine, electrolytes, brain natriuretic peptide, and endothelin-1. Urine was collected an intervals for measurement of flow rate and concentrations of creatinine, sodium, cGMP, and endothelin-1. Blood pressure and heart rate were measured every 15 minutes. Placebo administration did not change blood pressure, heart rate, or any of the other parameters measured in plasma and urine. As expected, brain natriuretic peptide infusion caused significant increases in its own plasma levels (basal versus peak levels [mean +/- SD], 1.45 +/- 0.20 versus 50.5 +/- 6.0 pmol/L, P < .01), in urinary cGMP (0.75 +/- 0.16 versus 1.92 +/- 0.81 fmol/min, P < .05), and in urinary sodium excretion (140.0 +/- 38.7 versus 624.2 +/- 181.6 mumol/min, P < .01). In addition, it caused an increase in urinary endothelin-1 excretion (4.32 +/- 2.11 versus 19.67 +/- 9.52 fmol/min, P < .05), without modifying plasma endothelin-1, blood pressure, heart rate, creatinine clearance, and urinary flow rate. Our data indicate that brain natriuretic peptide, at plasma levels comparable to those observed in patients with heart failure, causes a significant increase in urinary but not plasma endothelin-1, thus demonstrating a functional link between cardiac natriuretic peptides and renal release of endothelin-1.

Synchronous Occurrence of Medullary and Papillary Carcinoma of the Thyroid in a Patient with Cutaneous Melanoma: Determination of BRAFV600E in Peripheral Blood and Tissues. Report of a Case and Review of the Literature

The purpose of this study is to describe a case of concurrent medullary and papillary thyroid carcinoma (MTC and PTC) and cutaneous melanoma and to analyze BRAFV600E mutation in plasma and tissues. We report the clinical history and the laboratory, imaging, and histopathological findings of a 47-year-old man affected by multinodular goiter. BRAFV600E-mutated DNA was quantified in plasma samples and in cancer sections by quantitative real-time polymerase chain reaction (qPCR). At ultrasound examination, the dominant right nodule of the thyroid was weakly hyperechoic and hypervascularized, while the left one was hypoechoic without internal vascularization. Regional lymphadenomegalia was not detected. Basal plasma calcitonin was elevated, and the patient underwent total thyroidectomy and resection of central cervical lymph nodes. Histopathological examination identified two distinct foci of MTC and PTC and micrometastasis of well-differentiated carcinoma in one of the six resected lymph nodes. RET proto-oncogene germline mutations were not detected. Cutaneous melanoma of the thorax was subsequently diagnosed. BRAFV600E tissue DNA was detected in PTC and melanoma but not in MTC. The cell-free plasma percentage of BRAFV600E DNA was detected in pre-thyroidectomy peripheral blood and was drastically reduced after cancer treatments. This study confirms the occurrence of synchronous MTC and PTC and is the first evidence of the co-existence of melanoma and distinct thyroid cancers of different origin. BRAFV600E allele was detected in PTC and melanoma but not in MTC tissues. BRAFV600E molecular quantification in pre- and post-treatment blood supports our previous data, suggesting its possible role in diagnosis and follow-up of BRAF-positive tumors.

HypoparaNet: A Database of Chronic Hypoparathyroidism Based on Expert Medical-Surgical Centers in Italy

Hypoparathyroidism is a rare disease characterized by low serum calcium levels and absent or deficient parathyroid hormone level. Regarding the epidemiology of chronic hypoparathyroidism, there are limited data in Italy and worldwide. Therefore, the purpose of this study was to build a unique database of patients with chronic hypoparathyroidism, derived from the databases of 16 referral centers for endocrinological diseases, affiliated with the Italian Society of Endocrinology, and four centers for endocrine surgery with expertise in hypoparathyroidism, to conduct an epidemiological analysis of chronic hypoparathyroidism in Italy. The study was approved by the Institutional Review Board. A total of 537 patients with chronic hypoparathyroidism were identified. The leading etiology was represented by postsurgical hypoparathyroidism (67.6%), followed by idiopathic hypoparathyroidism (14.6%), syndromic forms of genetic hypoparathyroidism (11%), forms of defective PTH action (5.2%), non-syndromic forms of genetic hypoparathyroidism (0.9%), and, finally, other forms of acquired hypoparathyroidism, due to infiltrative diseases, copper or iron overload, or ionizing radiation exposure (0.7%). This study represents one of the first large-scale epidemiological assessments of chronic hypoparathyroidism based on data collected at medical and/or surgical centers with expertise in hypoparathyroidism in Italy. Although the study presents some limitations, it introduces the possibility of a large-scale national survey, with the final aim of defining not only the prevalence of chronic hypoparathyroidism in Italy, but also standards for clinical and therapeutic approaches.