Marina Muzza

Università degli Studi del Sannio, Benevento, Campania, Italy

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Publications (17)70.91 Total impact

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    ABSTRACT: Context: Mutations in DUOX2 gene have been associated with transient (tCH) or permanent congenital hypothyroidism (pCH) due to a dyshormonogenic defect. Objective: This study aimed to verify the prevalence of DUOX2 mutations and the associated clinical features in children selected by criteria supporting a partial iodide organification defect (PIOD). Patients and methods: Thirty children with PIOD-like criteria were enrolled and genotyped. A detailed clinical characterization was undertaken, together with the functional analysis of DUOX2 variations and the revision of the clinical and molecular data of the literature. Results: In this large selected series the prevalence of DUOX2 mutations was high (37%). We identified 12 missense variants, 1 splice-site, and 3 frameshift DUOX2 mutations. Functional analyses showed significant impairment of H2O2 generation with 5 missense variants. Stop-codon mutants were shown to totally abolish DUOX2 activity by nonsense-mediated RNA decay, exon skipping or protein truncation. DUOX2 mutations, either mono- or biallelic, were most frequently associated with permanent CH. Moreover, the present data suggested that, together with goiter and PIOD, the most significant features to select patients for DUOX2 analysis are the low fT4 and the high TSH concentrations at the first postnatal serum sampling, despite bordeline blood spot TSH. Interestingly, the analysis of previously described DUOX2 mutated cases confirmed the validity of these findings. Conclusions: The defects in the peroxide generation system are common among CH patients with PIOD. The most robust clinical parameters for selecting patients for DUOX2 analysis have been identified, and several DUOX2 variants have been functionally characterized.
    The Journal of Clinical Endocrinology and Metabolism 01/2013; · 6.31 Impact Factor
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    ABSTRACT: Background: Evidence for an increased prevalence of BRAF(V600E) mutations has been documented in recent decades. The aim of this study was to evaluate the prevalence of both RET/PTC rearrangements and BRAF(V600E) mutations in an Italian cohort of papillary thyroid carcinoma (PTC) patients followed at the Endocrine Units of Pisa, Milano, and Perugia from 1996-2010. Patients and Methods: In total, 401 PTC patients were examined and grouped according to the time of surgery: group 1, 1996-2000; group 2, 2001-2005; and group 3, 2006-2010. Patients were analyzed for clinical, pathological, and molecular features. In parallel, the molecular characteristics of 459 PTC from Sicily were studied. Results: The genetic profiles of the three groups were significantly different (P < 0.0001). In particular, the frequency of RET/PTC rearrangements decreased from 1996-2010, occurring in 33 of 100 (33%) of the patients in group 1, 26 of 148 (17%) in group 2, and 15 of 153 (9.8%) in group 3. The incidence of BRAF(V600E) mutations increased over the same period, from 28% in group 1 (28 of 100) to 48.9% in group 2 (73 of 148) and 58.1% in group 3 (89 of 153). A consistent increase in BRAF(V600E) prevalence was observed in the Sicilian group (P < 0.0001). Moreover, a statistically significant increase in the mean age at diagnosis and decrease in tumor size over the study period was observed. Conclusion: The genetic profile of PTC changed over the last 15 yr, with a significant decrease in the prevalence of RET/PTC rearrangements and an increase in BRAF(V600E) mutations. In addition, the mean age at diagnosis increased and tumor size decreased over the study period.
    The Journal of Clinical Endocrinology and Metabolism 06/2012; 97(9):E1758-65. · 6.31 Impact Factor
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    ABSTRACT: Patients with PS or non-syndromic deafness were submitted to genetic/functional analyzes of SLC26A4, of its binding domain for FOXI1 (FOXI1-DBD), of the transcription activator FOXI1, and of the potassium channel KCNJ10. SLC26A4 was the most frequently mutated gene. An altered intracellular localization with immunocytochemistry, and a hampered maturation process were demonstrated for two novel SLC26A4 variants. Biochemical and immunocytochemical analyzes led to the development of a more sensitive fluorometric functional assay able to reveal the partial loss-of-function of SLC26A4 mutations. A novel missense variant was found in FOXI1 gene, though functional analysis showed no significant impairment in the transcriptional activation of SLC26A4. Finally, 3 patients were found to harbor a variant in KCNJ10, which was classified as polymorphism. The novelty of the study resides in the analysis of all the 4 candidate genetic loci linked to PS/non-syndromic deafness, and in the precise definition of the thyroid phenotype. PS was invariably associated with biallelic mutations of SLC26A4, whereas the genetic origin of non-syndromic deafness remained largely undetermined, since monoallelic SLC26A4 variants accounted for one fourth of the cases and FOXI1 and KCNJ10 were not involved in this series.
    Molecular and Cellular Endocrinology 04/2012; 351(2):342-50. · 4.04 Impact Factor
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    ABSTRACT: Congenital hypothyroidism (CH) is the most common congenital endocrine disorder, accounting for up to 1:1500 newborns per year. CH can be related to defects in either formation and migration of the thyroid gland (dysgenesis) or thyroid hormone synthesis. The pathogenesis of dysgenetic CH is still largely unknown. On the contrary, several mutations have been found in different genes involved in thyroid dyshormonogenesis (such as pendrin, thyroperoxidase-TPO, thyroglobulin). Recently, new genes involved in the etiology of dyshormonogenesis have been identified: dual oxidase 2 (DUOX2) and dual oxidase maturation factor 2 (DUOXA2). They are the principal elements generating the hydrogen peroxide needed for TPO function. Mutations in these genes have been associated to transient or permanent CH, with a high intra and interfamilial phenotypic variability. Some hypotheses have been drawn to explain the variability of the DUOX2/A2 phenotype. Among them, the existence of other H(2)0(2) generating systems, the different requirements for thyroid hormones according to age, the ethnicity, the intake of iodine. In the present paper, the genetic and clinical features of CH caused by defects in the peroxide generator system will be revised.
    Annales d Endocrinologie 04/2011; 72(2):82-6. · 1.02 Impact Factor
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    Frontiers in Endocrinology 01/2011; 2:88.
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    ABSTRACT: To report a case of complete androgen insensitivity syndrome (CAIS) with Müllerian duct persistence. Case report. Academic hospital. A case of CAIS at 20 weeks' gestational age, and three male and one female 20-week-old fetuses for comparison. DNA screening for androgen receptor (AR), antimüllerian hormone (AMH), and AMH receptor type 2 (AMHR2) gene mutations, and morphologic examination of Wolffian and Müllerian derivatives and immunohistochemistry for AMH, AMHR2, and bone morphogenetic protein receptor type 1A (BMPR1A) in aborted fetuses. Histopathologic, genetic, and immunohistochemical studies. A novel mutation of AR (D767V) was identified in the index fetus. The CAIS case showed Wolffian duct degeneration, Leydig cell hyperplasia, and normally developed Sertoli cells. No AMH and AMHR2 gene sequence alterations were observed in the CAIS case, and the uterus and vagina were developed to a similar extent as found in the normal female 20-week-old fetus. The CAIS testes expressed more abundant AMH and showed fewer AMHR2-positive peritubular mesenchymal cells than the normal male testes, but BMPR1A stained similarly. Our study indicates that testes differentiation and development as well as the expression patterns of AMH, AMHR2, and BMPR1A are independent from AR function, at least up to the second trimester. The mechanisms by which the lack of functional androgen interferes with AMH action and Müllerian duct regression remain undefined.
    Fertility and sterility 10/2010; 95(3):1119.e9-14. · 3.97 Impact Factor
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    ABSTRACT: The recent concept that oncogenes responsible for thyroid neoplastic transformation are able to elicit an inflammatory protumourigenic microenvironment raises interest in further studies on papillary thyroid cancer (PTC) associated with thyroid autoimmunity. The clinical and molecular features, and the expression of inflammation-related genes, were investigated in a large series of PTCs with and without associated thyroiditis (groups A, n = 128 and B, n = 215). The two groups did not show significant differences in clinical and prognostic features, whereas they harboured a significantly different genetic background (P = 0.001), with RET/PTC1 being more represented in PTCs associated with autoimmunity, and BRAF(V600E) in patients with PTC alone. A RET/PTC rearrangement was also found in 41% of non-neoplastic thyroiditis tissues, contralateral to tumours harbouring either RET/PTC or BRAF mutations. The expression of genes encoding CCL20, CXCL8 and l-selectin was significantly higher in PTC specimens (either with RET/PTC, BRAF(V600E) or unknown genetic lesion) compared with normal thyroid samples. On the contrary, thyroiditis showed l-selectin expression levels even higher than PTCs, but CCL20 and CXCL8 levels comparable with normal tissues. The present data extend the knowledge about the tight relationships among oncogenes, thyroiditis and thyroid cancer. A different genetic background among PTCs with and without associated autoimmunity has been firstly demonstrated. The strong association between RET/PTC1 and thyroiditis points to a critical role of this oncoprotein in the modulation of the autoimmune response. Moreover, preliminary expression studies, indicating enhanced expression of inflammatory molecules in PTCs, suggest a proinflammatory, nonautoimmune relationship between thyroiditis and thyroid cancer.
    Clinical Endocrinology 05/2010; 72(5):702-8. · 3.40 Impact Factor
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    ABSTRACT: Most germline-activating mutations of the RET proto-oncogene associated with inherited medullary thyroid cancer (MTC) are localized in exons 10, 11 and 13-15. Four novel RET variants, located in the extracellular domain (p.A510V, p.E511K and p.C531R) coded by exon 8 and in the intracellular juxtamembrane region (p.K666N) coded by exon 11, were identified on the leukocyte DNA from apparently sporadic cases. Plasmids carrying Ret9-wild-type (Ret9-WT), Ret9-C634R and all Ret9 variants were transfected, and the phosphorylation levels of RET and ERK were evaluated by western blot analyses. The transforming potentials were assessed by the focus formation assay. The p.A510V, p.E511K and p.C531R variants were found to generate RET and ERK phosphorylation levels and to have a transforming activity higher than that of Ret9-WT variant, but lower than that of Ret9-C634R variant. Differently, the p.K666N variant, located immediately downstream of the transmembrane domain, and involving a conserved residue, displayed high kinase and transforming activities. Computational analysis predicted non-conservative alterations in the mutant proteins consistent with putative modifications of the receptor conformation. The molecular analyses revealed an oncogenic potential for all the novel germline RET variants. Therefore, the prevalence of exon 8 genomic variations with an oncogenic potential may be higher than previously thought, and the analysis of this exon should be considered after the exclusion of mutations in the classical hotspots. In addition, on the basis of these functional data, it is advisable to extend the genetic screening to all the first-degree relatives of the MTC patients, and to perform a strict follow-up of familial carriers.
    European Journal of Endocrinology 04/2010; 162(4):771-7. · 3.14 Impact Factor
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    ABSTRACT: Fetal cell microchimerism (FCM) is defined as the persistence, for decades after pregnancy, of fetal cells in maternal organs and circulation without any apparent rejection. We recently reported evidence, in papillary thyroid cancer (PTC) tissues, supporting a possible role of FCM in tumor damage and repair. To extend those data at the peripheral level, 106 women with a previous male pregnancy, comprising 57 with PTC and 49 healthy controls were enrolled. The presence of circulating male DNA was assessed by the amplification of the Y chromosome-specific gene SRY, with a sensitivity of 1 male cell per 1 million female cells. Moreover, to compare the microchimeric status in blood and in tumors, the neoplastic tissues of 19 women were studied. At the blood level, a significantly lower frequency of FCM was found in parous women with PTC with respect to controls (49.1% vs. 77.6%; p = 0.002). By PCR, male DNA was identified in the tumor tissues of 6 patients, and FISH analyses confirmed the presence of microchimeric cells (range 2.1-6.9 cells/section). In some patients, FCM was negative in the blood, whereas microchimeric cells were identified in the tumor. In conclusion, the prevalence of FCM in peripheral blood was found to be significantly lower in patients than in healthy controls. The presence of microchimeric cells in the tumors, but not at the peripheral level, supports the hypothesis that fetal cells could reside in maternal niches and could be recruited to diseased areas, where they could differentiate to regenerate damaged tissues.
    International Journal of Cancer 10/2009; 126(12):2874-8. · 6.20 Impact Factor
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    ABSTRACT: Objective:  The recent concept that oncogenes responsible for thyroid neoplastic transformation are able to elicit an inflammatory pro-tumourigenic microenvironment raises interest in further studies on papillary thyroid cancer (PTC) associated with thyroid autoimmunity.Patients:  The clinical and molecular features, and the expression of inflammation-related genes, were investigated in a large series of PTCs with and without associated thyroiditis (groups A, n=128 and B, n=215).Results:  The two groups did not show significant differences in clinical and prognostic features, whereas they harboured a significantly different genetic background (P=0.001), with RET/PTC1 being more represented in PTCs associated with autoimmunity, and BRAFV600E in patients with PTC alone. A RET/PTC rearrangement was also found in 41% of non-neoplastic thyroiditis tissues, contralateral to tumours harbouring either RET/PTC or BRAF mutations. The expression of genes encoding CCL20, CXCL8, and L-selectin was significantly higher in PTC specimens (either with RET/PTC, BRAFV600E or unknown genetic lesion) compared with normal thyroid samples. On the other hand, thyroiditis showed L-selectin expression levels even higher than PTCs, but CCL20 and CXCL8 levels comparable to normal tissues.Conclusions:  The present data extend the knowledge about the tight relationships between oncogenes, thyroiditis and thyroid cancer. A different genetic background among PTCs with and without associated autoimmunity has been firstly demonstrated. The strong association between RET/PTC1 and thyroiditis points to a critical role of this oncoprotein in the modulation of the autoimmune response. Moreover, preliminary expression studies, indicating enhanced expression of inflammatory molecules in PTCs, suggest a proinflammatory, non-autoimmune relationship between thyroiditis and thyroid cancer.
    Clinical Endocrinology 01/2009; · 3.40 Impact Factor
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    ABSTRACT: Fetal cells enter the maternal circulation during pregnancy and can persist in the maternal blood or tissues for decades, creating a physiologic microchimerism. Because papillary thyroid cancer (PTC) is more frequent in women, the role of persisting fetal male cells in this tumor has been investigated. Tumor tissue specimens were obtained from 63 women with PTC who had a male pregnancy before the diagnosis. Male cells, identified by PCR amplification of a male-specific gene, the sex-determining region Y, was detected in 47.5% of women. By fluorescence in situ hybridization (FISH) analyses, the total number of microchimeric cells was significantly higher in neoplastic tissue than in controlateral normal sections. By combined FISH and immunohistochemistry (immuno-FISH), male cells expressing thyroglobulin were found in tumor and normal tissues, whereas male microchimeric cells stained with the CD45 antigen were detected only in tumor sections. Microchimeric cells negative for either marker were detected both in tumor and normal tissues. Moreover, both CD45(+) and Tg(+) fetal cells did not express MHC II antigens. In conclusion, fetal microchimerism has been documented in a high proportion of women with PTC. The immuno-FISH studies indicate that CD45(+)/MHC II(-) male cells found in neoplastic tissues might be committed to destroy tumor cells, whereas Tg(+)/MHC II(-) cells could have a repair function. Finally, microchimeric cells negative for either CD45 or Tg could have "progenitor-like" properties able to transdifferentiate in different cellular types. Although a pathogenetic mechanism cannot be excluded, the whole of the present results indicates a protective role of microchimerism in thyroid cancer.
    Cancer Research 11/2008; 68(20):8482-8. · 9.28 Impact Factor
  • Clinical Endocrinology 05/2008; 69(5):828-9. · 3.40 Impact Factor
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    ABSTRACT: Highly discrepant data about the different distribution of RET germline single nucleotide polymorphisms (SNPs) among patients with sporadic medullary thyroid cancer (sMTC) and controls are available. In the present case-control study, a wide panel of seven RET SNPs has been tested in the largest sMTC series and in a matched control group. None of the investigated polymorphisms show a significantly different distribution in patients with sMTC when compared to controls. Twenty haplotypes and 57 genotypes were generated, and their association with the disease and with the clinical features were statistically evaluated. Interestingly, 14 genotypes were found to be unique to sMTC patients and 25 to controls. Two haplotypes and three genotypes, all including the intronic variants IVS1-126 and IVS14-24, were significantly associated with sMTC patients and with a higher tumour aggression. The functional activity of the only nonsynonymous RET variant (c.2071C > A, G691S) was tested for the first time. Interestingly, Western blot analyses showed that the fraction of Ret9-G691S protein located at the plasma membrane level was overrepresented when compared to Ret9-WT, suggesting facilitated targeting at the cell membrane for this variant. However, no transforming activity was shown in a focus formation assay on cells carrying the Ret9-G691S, against a possible oncogenic role of G691S variant. RET genotypes including two intronic RET variants were associated with the risk of developing sMTC and to more aggressive behaviour. Further studies are warranted to elucidate whether these RET genotypes are in linkage disequilibrium with another susceptibility gene or whether these variants could play a role in the genesis of sMTC per se.
    Clinical Endocrinology 03/2008; 69(3):418-25. · 3.40 Impact Factor
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    ABSTRACT: Pendred syndrome (PS) is characterized by the association of sensorineural hearing loss (SNHL) and a partial iodide organification defect at the thyroid level. It is caused by mutations in the SLC26A4 gene. The encoded transmembrane protein, called pendrin, has been found to be able to transport chloride and other anions. The aim of the present study was to characterize a family with PS, which shows a strong intrafamilial phenotypic variability, including kidney atrophy in one member. The age of disease-onset was significantly different in all three affected siblings, ranging from 2 to 21 years for thyroid alterations and from 1.5 to 11 years for SNHL. Clinical and genetic studies were carried out in affected siblings. The functional activity of the novel duplication found was studied by a fluorimetric method in a human renal cell line (HEK293 Phoenix) in which the protein was overexpressed. All three siblings were found to be compound heterozygotes for the missense mutation (1226G>A, R409H) and for a novel 11 bp duplication (1561_1571CTTGGAATGGC, S523fsX548). The latter mutation creates a frame shift leading to the loss of the entire carboxy-terminus domain. Functional studies of this mutant demonstrated impaired transport of chloride and iodide when expressed in HEK 293 Phoenix cells, when compared with wild type pendrin. A novel 11 bp duplication was found in a family with Pendred syndrome, showing a high intrafamilial phenotypic variability. An impaired transmembrane anionic transport of the mutated SLC26A4 protein was demonstrated in functional studies using a heterologous cell system.
    European Journal of Endocrinology 10/2007; 157(3):331-8. · 3.14 Impact Factor
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    ABSTRACT: The cut-off values able to differentiate between reactive or neoplastic C-cell hyperplasia (CCH) or to predict sporadic medullary thyroid cancer (MTC) are still debated both for basal and stimulated calcitonin (bCT and sCT). In the present study, the prevalence and the histological patterns of CCH in 15 patients with multinodular goiter (MNG), bCT>10 pg/ml and sCT levels >50 pg/ml were studied. As controls, 16 patients with MNG and bCT levels <10 pg/ml and 4 patients with familial (FMTC) were included. For each case, calcitonin (CT) immunoreactive cells were counted in 60 consecutive high-power fields (400x) and CCH classified as focal, diffuse, nodular, or neoplastic. RET genetic analyses were performed at the germline and tissue levels in MTC and CCH cases. In patients with MNG, sCT levels >50 pg/ml were associated with CCH or MTC, being the total number of C-cells/60 fields significantly higher than that found in MNG with normal bCT (P = 0.0008) and comparable with that detected in FMTCs. In the group with sCT>50 pg/ml, the C-cells displayed a neoplastic phenotype. Neither germline nor somatic RET mutations were found. In conclusion, sCT levels >50 pg/ml were always associated with CCH, without correlation between CT levels and the number of C-cells or the final diagnosis. The C-cells had a morphology and distribution pattern similar to those observed in FMTC. Thus, sCT levels >50 pg/ml indicate the presence of CCH with a possible preneoplastic potential, suggesting the opportunity to perform a prophylactic surgical treatment.
    Endocrine Related Cancer 07/2007; 14(2):393-403. · 5.26 Impact Factor
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    ABSTRACT: Activating mutations of the RET proto-oncogene are associated with inherited syndromes, multiple endocrine neoplasia (MEN2A/2B) and with familial and sporadic medullary thyroid cancer (MTC). Single base pair missense mutations in the extracellular Cys-rich domain are responsible for most MEN2A and familial MTC (FMTC) cases. Rarely, somatic deletions and germline duplications have been described in sporadic MTC and in FMTC. We report the detection and functional studies of a deletion/insertion in exon 11 (c.2646delGinsTTCT) associated with FMTC. This in-frame complex rearrangement leads to an Asn to Lys change (Lys666Asn) and to a Ser insertion. The mutation was found in the proband, who was diagnosed with metastatic MTC at 41 years, and in her son, who presented diffuse C-cells hyperplasia at 4 years of age. The mutation displayed a transforming activity stronger than Ret wild type (Ret-WT) at the focus formation assay and functional analyses after transient and stable transfection revealed an increased autophosphorylation, indicating the constitutive activation of the receptor. The transforming activity may be favoured by an increased stabilization of the fully mature form of the mutant receptor. Dimerization assay demonstrated that the activation mechanism of the complex mutation is not mediated by stable dimer formation. Computational analysis predicted nonconservative alterations in the mutant protein consistent with a possible modification of the conformation of the receptor. In conclusion, the first molecular studies on a complex germline RET mutation lying in the juxtamembrane region of the receptor are reported. Functional analyses showed that alterations at this level too can lead to a ligand independent Ret activation.
    Endocrine Related Cancer 10/2006; 13(3):945-53. · 5.26 Impact Factor
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    ABSTRACT: Recently, a somatic point mutation of the BRAF gene (V599E) has been identified as the most common genetic event in papillary thyroid carcinoma (PTC) with a variable frequency (about 25-70%) in different series from USA, Japan, Portugal and Ukraine. In the present study, the genetic analysis of BRAF in an Italian cohort of 65 thyroid tumours with corresponding normal tissues and 21 thyroid benign disorders is reported. For BRAF analysis, the somatic DNA was PCR amplified by means of specific intronic primers and PCR products were directly sequenced. Statistical analyses were obtained by means of Fisher's exact test. All mutations detected involved a T > A transversion at 1796 (V599E) and were heterozygous. Overall, BRAF(V599E) mutation was found in 18/56 (32.1%) PTCs. According to the histological type of the tumour, the mutation was present in 38.3% of cases of conventional PTC (18/47), in 0/6 follicular variant of PTC, in 0/3 oncocytic variant of PTC. No BRAF mutations were detected either in five follicular carcinomas, or in four poorly differentiated or undifferentiated cancers or in benign thyroid disorders. No statistically significant correlation of BRAF mutation with patient age and gender, with multicentricity of the tumour, with the lymphocytic infiltration of the tissue, with the stage and with the recurrence rate, was found. BRAF(V599E) tended to be associated, although not significantly, with a greater volume and extension of the tumour and with lymph-nodal metastases at surgery. In conclusion, the present study on the first Italian series of thyroid cancers shows a frequency of 38.3% of BRAF(V599E) in the classical variant of PTC, confirming the key role of this mutation in promoting tumourigenesis.
    Clinical Endocrinology 09/2004; 61(2):239-43. · 3.40 Impact Factor

Publication Stats

227 Citations
70.91 Total Impact Points

Institutions

  • 2012
    • Università degli Studi del Sannio
      Benevento, Campania, Italy
  • 2010–2012
    • Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico
      Milano, Lombardy, Italy
  • 2006–2011
    • University of Milan
      • • Department of Medical Sciences
      • • Department of Internal Medicine
      Milano, Lombardy, Italy