Investigation on MMACHC-R161Q pathological mutant from cblC disease

The cblC disease is a rare inborn disorder of the vitamin B12 (cobalamin, Cbl) metabolism characterized by combined methylmalonic aciduria and homocystinuria. The clinical consequences are devastating and, even when early treated with current therapies, the affected children manifest symptoms involving vision, growth, and learning. The molecular genetic cause of the disease was found in the mutations of the gene coding for MMACHC, a 282 amino acid protein that transports and processes the various forms of Cbl. Here we present the biophysical characterization of wild type MMACHC and a variant, p.R161Q, resulting from the most common missense pathological mutation found in cblC patients. By using a biophysical approach we investigated the stability of the two proteins and their ability to bind and transform the vitamin B12, and to assemble in a dimeric structure. Moreover, interesting indications about the behaviour of the proteins resulted from the Molecular Dynamics (MD) simulations. Overall, our results reveal how a biophysical approach based on the complementarity of computational and experimental methods can offer new insights in the study of the specific effects of the pathological cblC mutation and help prospecting new routes for the cblC treatment

TP53 and p16INK4A, but not H-KI-Ras, are involved in tumorigenesis and progression of pleomorphic adenomas.

The putative role of TP53 and p16INK4A tumor suppressor genes and Ras oncogenes in the development and progression of salivary gland neoplasias was studied in 28 cases of pleomorphic adenomas (PA), 4 cases of cystic adenocarcinomas, and 1 case of carcinoma ex-PA. Genetic and epigenetic alterations in the above genes were analyzed by Polymerase Chain Reaction/Single Strand Conformational Polymorphism (PCR/SSCP) and sequencing and by Methylation Specific-PCR (MS-PCR). Mutations in TP53 were found in 14% (4/28) of PAs and in 60% (3/5) of carcinomas. Mutations in H-Ras and K-Ras were identified in4%(1/28) and7% (2/28) of PAs, respectively. Only 20% (1/5) of carcinomas screened displayed mutations in K-Ras. p16INK4A promoter hypermethylation was found in 14% (4/28) of PAs and 100% (5/5) carcinomas. All genetic and epigenetic alterations were detected exclusively in the epithelial and transitional tumor components, and were absent in the mesenchymal parts. Our analysis suggests that TP53 mutations and p16INK4A promoter methylation, but not alterations in the H-Ras and K-Ras genes, might be involved in the malignant progression of PA into carcinoma. J. Cell. Physiol. 207: 654–659, 2006. 2006 Wiley-Liss, Inc

TP53 mutations and S-Phase fraction are independent prognostic indicators in locally advanced laryngeal squamous cell carcinoma

Larynx tumor is a rare neoplasia that represent only the 2% of all human tumor. In particular, the 90% of tumor that occur in this organ correspond to the laryngeal squamous cell carcinoma (LSCC). From the biomolecular point of view, it was shown that the TP53 gene mutations are the most common events observed in the early phases of LSCC carcinogenesis. However, them prognostic significance remains controversial. Besides, the prognostic significance of DNA ploidy has been well established for other solid tumors, but its role in LSCC is still controversial. The aim of this study was, therefore, to prospectively evaluate the prognostic significance of TP53 mutations, DNA-ploidy and S-phase fraction (SPF) in LSCC patients. Prospective analysis of 81 patients who underwent resective surgery for primary operable locally advanced LSCC patients (stages III and IV) was performed. Tumor DNA was screened for TP53 mutations by PCR/SSCP and sequencing; DNA flow cytometry was performed on mechanically disaggregated sample of frozen tumor tissue. The median follow-up time in our study group was 71 months (range 11-137 months). Fourthy-four percent of patients (36/81) have, at least, a mutation in the TP53 gene. Of them, 22% (8/36) have double mutations and 6% (2/36) have triple mutations. In total, 47 TP53 mutations were observed. The majority (42%) of these occur in exon 5 (20/47), while the mutations in exons 6, 7 and 8 are represented in 14, 7 and 6 patients respectively (30%, 15% and 13%). The flow cytometry analysis showed that sixty-three percent of the cases (51/81) were DNA aneuploidy and 14% of these (7/51) were multiclonal. LSCC patients were divided into two groups using median SPF level as cut-off point: low SPF 15.1 % and high SPF >15.1 %, Even though it seems that TP53 mutations promotes the LSCC carcinogenesis in young people (p< 0.05), there was not any association between this variable and the clinicopathological or the other biomolecular variables. At univariate analysis, the Kaplan and Meier text show that DNA aneuploidy, high SPF, any TP53 mutations and, in particular, the mutations that occur in exons 5 and 8 proved to be significantly related to quicker disease relapse and short OS. At multivariate analysis, the Cox proportional hazards model show that the major significant predictors for both disease relapse and death were high SPF and any TP53 mutations. In conclusion, any TP53 mutations, more than specific mutations in exon 5 and 8, are important biological indicators to predict the outcome of patients indicating these mutations have biological relevance in terms of LSCC disease course. Our study has also identify high SPF as independent prognostic factors in locally advanced LSCC patients

LINEE GUIDA NAZIONALI PER LE AUTOPSIE A SCOPO FORENSE IN MEDICINA VETERINARIA

Vedi Prefazione nel testo

LINEE GUIDA NAZIONALI PER LE AUTOPSIE A SCOPO FORENSE IN MEDICINA VETERINARIA

Vedi Prefazione nel testo

Clinical and Histological Features in Wegener Granulomatosis

Abstract Wegener Granulomatosis is a systemic ANCA-associated Vasculitis, affecting small-to-medium vessels. Clinical presentation with simultaneous involvement of kidney and upper and lower respiratory tract is unusual. There are few histological reports regarding lung biopsy in WG because clinical and radiologic features are diagnostic. Sometimes radiologic findings can be unusual. We detected an instructive case of WG, analyzing clinical course, laboratory and radiological features, kidney, lung and larynx histological pictures. Besides renal biopsy, nephrology team performed larynx and lung biopsies because of unusual clinical presentation, computed tomography chest examination and relevant malignancy risk regarding following immunosuppressant therapy. WG is a point of interest for clinical multidisciplinary activity. Diagnosis of WG is a combination of clinical, laboratory and pathologic features. Collaboration between different specialities help to improve current diagnostic activity

Acute kidney injury in a patient with metabolic syndrome

Introduction: The metabolic syndrome (MS) encompasses many metabolic abnormalities and the insulin resistance is considered as one of the most significant denominators. The chronic kidney disease (CKD) is an emerging health problem but only few patients would reach the end stage renal disease. There exists an increasing strong association between MS and CKD, but up until now the link between MS and CKD is unclear and there are few studies regarding the renal histology in MS. Methods: We describe an acute tubulointerstitial nephritis case, due to both infective and pharmacological aetiology, overlapping relevant histological changes (focal segmental glomerulosclerosis [FSG], hyaline arteriosclerosis) in a patient with MS and previously normal renal function. Despite the severe vascular finding (elevated renal arterial resistive index), the patient recovered a normal renal function. Results: We reviewed the kidney pathological studies in MS and analyzed the principal renal histological images of glomerulomegaly, segmental glomerulosclerosis, and obesity-related glomerulopathy. Conclusion: Despite the strong association, the renal involvement in MS has not been proven. A greater knowledge of the combination of histological renal changes in MS can help to understand the pathophysiological mechanism(s) of MS