Search results for "Single-strand conformation polymorphism"
showing 7 items of 27 documents
Direct Identification of Each Specific Mutation in Codon 12 and 13 of ci-ki-ras2 by SSCP Analysis
1998
We compared the SSCP behaviour of the DNA fragments containing c-ki-ras 2 wild type 12 and 13 codons or each of the 12 possible point mutated sequences in these two codons. We found that a single electrophoresis condition was sufficient to distinguish each specific mutation from the other 11 and from the wild type sequence. This observation makes it possible to identify each specific mutation directly by SSCP without any need for reamplification and sequencing.
Prognostic significance of p16INK4a alterations and 9p21 loss of heterozigosity in locally advanced laryngeal squamous cell carcinoma
2002
The p16INK4a gene, localized within chromosome 9p21, has been identified as a cyclin-dependent kinase inhibitor and may negatively regulate the cell cycle acting as a tumor suppressor. Genetic alterations involving the 9p21 region are common in human cancers. A consecutive series of 64 untreated patients (median of follow up 53 months) undergoing surgical resection for locally advanced laryngeal squamous-cell carcinomas (LSCCs) has been studied prospectively. Our purpose was to investigate p16 alterations (9p21 allelic loss, hypermethylation and point mutations) and their possible association with clinico-pathological data and flow cytometric variables (DNA-ploidy and S-phase fraction (SPF)…
Analysis of p53 and mdm2 proteins in malignant fibrous histiocytoma in absence of gene alteration: prognostic significance.
2000
TP53 and MDM2 genes and their protein expression were evaluated in frozen and paraffin-embedded tissue from 27 patients with malignant fibrous histiocytoma to elucidate the relationship between them, their implication in tumor progression mechanisms and their possible diagnostic-prognostic value in malignant fibrous histiocytoma. Single-strand conformation polymorphism analysis and direct sequencing of polymerase chain reaction-amplified DNA were used to establish two TP53 mutations (7.4%): a point mutation and a 63-bp duplication. Amplification of the MDM2 gene was observed in two tumors (7.4%) by means of Southern-blot analysis, one of them also carrying the TP53 point mutation. Immunohis…
Analysis of the p53 and MDM-2 gene in acute myeloid leukemia
1996
The MDM-2 (murine double minute 2) gene codes for a cellular protein that can bind to the p53 tumor suppressor gene product, thereby functioning as a negative regulator of p53. In order to define the role of the MDM-2 gene in the pathogenesis of human acute myeloid leukemia, the expression and the sequence of the MDM-2 gene were examined in samples of bone marrow and/or peripheral mononuclear cells of 38 patients by using immunostaining, polymerase chain reaction (PCR), single strand conformation polymorphism, and sequencing. Immunohistochemical staining detected a weak accumulation of the MDM-2 protein in AML patients of FAB classification M4 and M5. RT-PCR analysis revealed a heterogeneou…
Molecular analysis suggests that recent Citrus tristeza virus outbreaks in Italy were originated by at least two independent introductions
2005
Citrus tristeza virus (CTV) is the causal agent of the most important virus disease of citrus. Numerous CTV isolates differing in biological and molecular characteristics have been reported worldwide. Recently, CTV was detected in Italy in several citrus crops from three separate areas: (1) Cassibile, province of Syracuse; (2) Massafra, province of Taranto; and (3) Belpasso, province of Catania. CTV isolates from Massafra and Cassibile were mild, whereas isolates from Belpasso induced severe symptoms. To study the genetic variation of CTV populations of these areas, 150 samples per area were examined by single strand conformation polymorphism (SSCP) and nucleotide sequence analysis of CTV g…
Globularia nudicaulis, a new host of Cucumber mosaic virus
2006
) is a perennial, foundnaturally on European mountains at altitudes between 900 and 2000 m.In June 2004, G. nudicaulis plants, with a yellow mosaic and/or variega-tion on malformed leaves, were noted among plant species cultivated in theBotanical Garden at Bologna University, Italy. No elongated virus-likeparticles were observed in affected-leaf extracts by transmission electronmicroscopy using a leaf dip method. By applying a protein A sandwichenzyme-linked immunosorbent assay (PAS-ELISA) technique ( Edwards Csystemic symptoms were observed in Nicotiana tabacum , N. benthamiana ,N. glutinosa, N. clevelandii and Capsicum annuum, and Cucumis sativusand C. melo. Reverse transcription-polymera…
Absence of mutation at the GAP-related domain of the neurofibromatosis type 1 gene in sporadic neurofibrosarcomas and other bone and soft tissue sarc…
1995
The NF1 gene encodes neurofibromin, a GTPase-activating protein containing a GAP-related domain (NF1-GRD) that is capable of downregulating ras by stimulating ras intrinsic GTPase activity. We tested 44 sarcomas, nine of which corresponded to sporadic neurofibrosarcomas, for mutations at the NF1-GRD by the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) technique, finding no mutation in every sample tested. We suggest that inactivation of the NF1-GRD by gene mutation seems not to be an important event in the tumorigenesis of sarcomas.