Search results for "MUTATION"

A selective medium for the isolation of malolactic mutants of Leuconostoc oenos

1994

We have developed a selective medium for the isolation of Leuconostoc oenos mutants defective in malolactic fermentation. Forty per cent of colonies isolated directly on selective plates after UV mutagenesis had lost their ability to degrade malate. None of the tested mutants showed any detectable malolactic activity and all lacked a protein band corresponding in size to that of the malolactic enzyme. The availability of such mutants provides a valuable tool both for physiological and genetic research on malolactic fermentation.

2020

The efficiency of chemotherapy drugs can be affected by ATP-binding cassette (ABC) transporter expression or by their mutation status. Multidrug resistance is linked with ABC transporter overexpression. In the present study, we performed rare mutation analyses for 12 ABC transporters related to drug resistance (ABCA2, -A3, -B1, -B2, -B5, -C1, -C2, -C3, -C4, -C5, -C6, -G2) in a dataset of 18 cancer patients. We focused on rare mutations resembling tumor heterogeneity of ABC transporters in small tumor subpopulations. Novel rare mutations were found in ABCC1, but not in the other ABC transporters investigated. Diverse ABCC1 mutations were found, including nonsense mutations causing premature …

P58 Differential molecular diagnosis of uterine leiomyomas and leiomyosarcomas using DNA and RNA sequencing

2019

Introduction/Background Nowadays, the absence of standardized criteria to identify and differentiate uterine leiomyomas (LM) and leiomyosarcomas (LMS) prior to surgery, cause a significant stress in the patient, leading to unnecessary invasive procedures and additional costs to the National Health System. As consequence, the development of an accurate and non-invasive differential diagnostic methods in patients with surgical indication is needed to avoid the potential dissemination of hidden LMS from morcellation. We aim to identify differential genetic targets in LMS vs LM using Next Generation Sequencing to advance our knowledge in their differential diagnosis. Methodology A total of 13 L…

Havep53gene mutations and protein expression a different biological significance in colorectal cancer?*

2002

p53 alterations are considered the most common genetic events in many types of neoplasms, including colorectal carcinoma (CRC). These alterations include mutations of the gene and/or overexpression of the protein. The aim of our study was to assess whether in 160 patients undergoing resective surgery for primary operable CRC there was an association between p53 mutations and protein overexpression and between these and other biological variables, such as cell DNA content (DNA-ploidy) and S-phase fraction (SPF), and the traditional clinicopathological variables. p53 mutations, identified by PCR-SSCP-sequencing analysis, were found in 68/160 patients (43%) and positive staining for p53 protei…

Impact of Clinical Features, Cytogenetics, Genetic Mutations and Methylation of CDKN2B and DLC-1 Promoters on Treatment Response to Azacitidine

2019

Introduction : Azacitidine (AZA) is a DNA hypomethylating agent used in myeloid neoplasms, however approximately half of patients show treatment failure or relapse. Last years, several studies have showed that genetic mutations may influence on response and survival of the treated patients. Other biomarkers that have traditionally been associated with the response to AZA are the recovery of the platelet count and the presence of abnormalities in the chromosome 7. Finally, the methylation dynamics of genes promoters could be a useful tool to predict the clinical response. Aim: To assess the predictive value on response to AZA of clinical features, cytogenetics, genetic mutations and the meth…

Frequency of Fabry disease in patients with small-fibre neuropathy of unknown aetiology: a pilot study

2010

Background:  Early occurrence of small-fibre neuropathy (SFN) is a common feature of Fabry disease (FD) – an X-linked storage disorder caused by reduced activity of the α-galactosidase A (α-GAL). Although SFN may result from different disorders, the cause is often unclear. Therefore, we investigated the frequency of FD in patients with SFN of unknown aetiology. Methods:  Patients with idiopathic SFN, established by sensory quantitative testing and/or skin biopsy, were examined for mutations in the α-GAL gene. Where mutations in the α-GAL gene were identified, levels of globotriaosylceramide (Gb3) were measured in urine and blood and the α-GAL activity was evaluated. When new mutations were …

A Novel CCT5 Missense Variant Associated with Early Onset Motor Neuropathy

2020

Diseases associated with acquired or genetic defects in members of the chaperoning system (CS) are increasingly found and have been collectively termed chaperonopathies. Illustrative instances of genetic chaperonopathies involve the genes for chaperonins of Groups I (e.g., Heat shock protein 60, Hsp60) and II (e.g., Chaperonin Containing T-Complex polypeptide 1, CCT). Examples of the former are hypomyelinating leukodystrophy 4 (HLD4 or MitCHAP60) and hereditary spastic paraplegia (SPG13). A distal sensory mutilating neuropathy has been linked to a mutation [p.(His147Arg)] in subunit 5 of the CCT5 gene. Here, we describe a new possibly pathogenic variant [p.(Leu224Val)] of the same subunit b…

Genetic lesions associated with Muller's ratchet in an RNA virus

1996

The molecular basis of Muller's ratchet has been investigated using the important animal pathogen foot-and-mouth disease virus (FMDV). Clones from two FMDV populations were subjected to serial plaque transfers (repeated bottleneck events) on host BHK-21 cells. Relative fitness losses were documented in 11 out of 19 clones tested. Small fitness gains were observed in three clones. One viral clone attained an extremely low plating efficiency, suggesting that accumulation of deleterious mutations had driven the virus near extinction. Nucleotide sequence analysis revealed unique genetic lesions in multiply transferred clones that had never been seen in FMDVs isolated in nature or subjected to m…

An

2020

Intracellular acid stress inhibits plant growth by unknown mechanisms and it occurs in acidic soils and as consequence of other stresses. In order to identify mechanisms of acid toxicity, we screened activation-tagging lines of Arabidopsis thaliana for tolerance to intracellular acidification induced by organic acids. A dominant mutant, sbt4.13-1D, was isolated twice and shown to over-express subtilase SBT4.13, a protease secreted into endoplasmic reticulum. Activity measurements and immuno-detection indicate that the mutant contains less plasma membrane H+-ATPase (PMA) than wild type, explaining the small size, electrical depolarization and decreased cytosolic pH of the mutant but not orga…

2-(2,6-Dihalophenyl)-3-(pyrimidin-2-yl)-1,3-thiazolidin-4-ones as non-nucleoside HIV-1 reverse transcriptase inhibitors.

2004

Several 1,3-thiazolidin-4-ones bearing a 2,6-dihalophenyl group at C-2 and a substituted pyrimidin-2-yl ring at the N-3 were synthesised and evaluated as anti-HIV agents. The results of the in vitro tests showed that some of them were highly effective inhibitors of human immunodeficiency virus type-1 (HIV-1) replication at 10–40 nM concentrations with minimal cytotoxicity. Structure–activity relationship studies revealed that the nature of the substituents at the 2 and 3 positions of the thiazolidinone nucleus had a significant impact on the in vitro anti-HIV activity of this class of potent antiretroviral agents. The compounds had significantly reduced activity against the characteristic N…