Consulta: subjectFacets:"Mutation"
Registros recuperados: 50
Data/hora: 11/06/2024 01:12:42

Factor 9 de crecimiento y diferenciación asociado al índice de prolificidad en la oveja pelibuey.
Provedor de dados: 32
Autores: Pérez Ruíz, Elizabeth.
El Factor 9 de Crecimiento y Diferenciación (GDF9) es miembro de la súperfamilia β de factores de crecimiento (TGFβ) y su expresión en el ovocito es esencial para el desarrollo y crecimiento folicular. Diferentes mutaciones en el gen GDF9 han sido asociadas con el incremento de tasa de ovulación y/o prolificidad en algunas razas de ovejas, por lo que el objetivo de este estudio fue la búsqueda de polimorfismos de una sola base (SNPs) en el gen GDF9, así como la asociación entre polimorfismos del gen GDF9 y el índice de prolificidad en ovejas de la raza Pelibuey. Se tomaron muestras sanguíneas de la vena yugular de 16 ovejas y fueron conservadas en papel FTA® (Whatman Mini Card). El exón dos del gen fue amplificado mediante la técnica de Polimerase Chain...
Palavras-chave: Análisis de secuencias; GDF9; Mutación; Polimorfismo; PCR; SNP; Sequence analysis; Mutation; Polymorphism; Maestría; Ganadería.
Ano: 2012
URL: http://hdl.handle.net/10521/1712

Enzyme activity and thermostability of a non-specific nuclease from Yersinia enterocolitica subsp. palearctica by site-directed mutagenesis
Provedor de dados: 69
Autores: Zhang,Yu; Li,Zhen-Hua; Zheng,Wei; Tang,Zhen-Xing; Zhang,Zhi-Liang; Shi,Lu-E.
Background: To identify the critical amino acid residues that contribute to the high enzyme activity and good thermostability of Yersinia enterocolitica subsp. palearctica (Y. NSN), 15 mutants of Y. NSN were obtained by site-directed mutagenesis in this study. And their enzyme activity and thermostability were assayed. Effect of several factors on the enzyme activity and thermostability of Y. NSN, was also investigated. Results: The results showed that the I203F and D264E mutants retained approximately 75% and 70% enzyme activity, respectively, compared to the wild-type enzyme. In addition to the I203F and D264E mutants, the mutant E202A had an obvious influence on the thermostability of Y. NSN. According to the analysis of enzyme activity and...
Tipo: Journal article
Palavras-chave: Factors affecting enzyme activity; Nuclease; Mutation; Mutagenesis; Nucleases without sequence specificity.
Ano: 2016
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582016000600005

Physiological, morphological, and mannanase production studies on Aspergillus niger uam-gs1 mutants
Provedor de dados: 69
Autores: De Nicolás-Santiago,Soledad; Regalado-González,Carlos; García-Almendárez,Blanca; Fernández,Francisco J; Téllez-Jurado,Alejandro; Huerta-Ochoa,Sergio.
Mutant strains from Aspergillus niger UAM-GS1 were produced by UV radiation to increase their hemicellulolytic and cellulolytic activity production. The mutant strains showing more enzymatic activity were those labelled GS1-S059 and GS1-S067. These strains also showed the largest relationship between diameter of hydrolysis zone and colony diameter. The mutant GS1-S067 showed a colony radial extension rate and a biomass growth rate g biomass/(cm² h), 1.17 times higher than that achieved by strain UAM-GS1. The high invasive capacity makes this mutant strain a promising alternative for its use in solid substrate fermentation (SSF). The morphological properties of the two mutant strains were evaluated by using scanning electron microscopy. The diameter of the...
Tipo: Journal article
Palavras-chave: Aspergillus niger; Mutation; Mannanase production.
Ano: 2006
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582006000100008

Performance of probe polymerization-conjunction-agarose gel electrophoresis in the rapid detection of KRAS gene mutation
Provedor de dados: 74
Autores: Xiao,Na; Tang,Yi-Tong; Li,Zhi-Shan; Cao,Rui; Wang,Rong; Zou,Jiu-Ming; Pei,Jiao.
Abstract This study aimed to develop a simple and rapid method to detect KRAS gene mutations for conventional clinical applications under laboratory conditions. The genotype of mutation sites was determined based on the occurrence of target bands in the corresponding lanes of the reaction tubes through polymerization-conjunction of the probes, probe purification and amplification, and agarose gel electrophoresis. Circulating DNA samples were obtained from the plasma of 72 patients with lung cancer, which were identified based on six mutation sites (G12S, G12R, G12C, G12D, G12A, and G12V) of codon 12 of the KRAS gene. The detection results were compared with direct sequencing data. The proposed detection method is characterized by simple operation, high...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Mutation; Circulating DNA; Polymerization-conjunction reaction; Agarose gel electrophoresis; K-ras.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572018000400555

Three novel α-L-iduronidase mutations in 10 unrelated Chinese mucopolysaccharidosis type I families
Provedor de dados: 74
Autores: Sun,Luning; Li,Chunyi; Song,Xiaoyu; Zheng,Ningning; Zhang,Haipeng; Dong,Guizhang.
Mucopolysaccharidosis type I (MPS I) arises from a deficiency in the α-L-iduronidase (IDUA) enzyme. Although the clinical spectrum in MPS I patients is continuous, it was possible to recognize 3 phenotypes reflecting the severity of symptoms, viz., the Hurler, Scheie and Hurler/Scheie syndromes. In this study, 10 unrelated Chinese MPS I families (nine Hurler and one Hurler/Scheie) were investigated, and 16 mutant alleles were identified. Three novel mutations in IDUA genes, one missense p.R363H (c.1088G &gt; A) and two splice-site mutations (c.1190-1G &gt; A and c.792+1G &gt; T), were found. Notably, 45% (nine out of 20) and 30% (six out of 20) of the mutant alleles in the 10 families studied were c.1190-1G &gt; A and c.792+1G &gt; T, respectively. The...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Mucopolysaccharidosis type I; Α-L-iduronidase; Mutation; Polymorphism.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572011000200004

A novel nonsense mutation, E150X, in the SOX9 gene underlying campomelic dysplasia
Provedor de dados: 74
Autores: Shotelersuk,Vorasuk; Jaruratanasirikul,Somchit; Sinthuwiwat,Thivaratana; Janjindamai,Waricha.
Campomelic dysplasia (CD) is an autosomal dominant skeletal malformation syndrome with features including bowed lower limbs with pretibial skin dimpling, hypoplastic scapulae and pelvic bones, and 11 pairs of ribs. Mutations in the SOX9 gene have been identified to cause CD. The gene encodes a transcription factor containing a dimerization, a high mobility group, and a C-terminal transactivation (TA) domain. Up to now, 35 SOX9 mutations have been published. In the present study, we describe a Thai girl with clinically and radiologically typical CD. Direct sequencing analysis of the PCR products for the entire coding region of SOX9 revealed that she was heterozygous for a novel 448G &gt; T in exon 2 of SOX9. The DNA change was expected to result in E150X...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: SOX9; Campomelic dysplasia; Mutation.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572006000400007

Prevalence of 185delAG and 5382insC mutations in BRCA1, and 6174delT in BRCA2 in women of Ashkenazi Jewish origin in southern Brazil
Provedor de dados: 74
Autores: Dillenburg,Crisle Vignol; Bandeira,Isabel Cristina; Tubino,Taiana Valente; Rossato,Luciana Grazziotin; Dias,Eleonora Souza; Bittelbrunn,Ana Cristina; Leistner-Segal,Sandra.
Certain mutations in BRCA1 and BRCA2 genes are frequent in the Ashkenazi Jewish population. Several factors contribute to this increased frequency, including consanguineous marriages and an event known as a "bottleneck', which occurred in the past and caused a drastic reduction in the genetic variability of this population. Several studies were performed over the years in an attempt to elucidate the role of BRCA1 and BRCA2 genes in susceptibility to breast cancer. The aim of this study was to estimate the carrier frequency of certain common mutations in the BRCA1 (185delAG and 5382insC) and BRCA2 (6174delT) genes in an Ashkenazi Jewish population from Porto Alegre, Brazil. Molecular analyses were done by PCR followed by RFLP (ACRS). The carrier frequencies...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ashkenazi Jews; Breast cancer; BRCA1; BRCA2; Mutation.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572012000400009

Determining mutations in G6PC and SLC37A4 genes in a sample of Brazilian patients with glycogen storage disease types Ia and Ib
Provedor de dados: 74
Autores: Carlin,Marcelo Paschoalete; Scherrer,Daniel Zanetti; Tommaso,Adriana Maria Alves De; Bertuzzo,Carmen Silvia; Steiner,Carlos Eduardo.
Glycogen storage disease (GSD) comprises a group of autosomal recessive disorders characterized by deficiency of the enzymes that regulate the synthesis or degradation of glycogen. Types Ia and Ib are the most prevalent; while the former is caused by deficiency of glucose-6-phosphatase (G6Pase), the latter is associated with impaired glucose-6-phosphate transporter, where the catalytic unit of G6Pase is located. Over 85 mutations have been reported since the cloning of G6PC and SLC37A4 genes. In this study, twelve unrelated patients with clinical symptoms suggestive of GSDIa and Ib were investigated by using genetic sequencing of G6PC and SLC37A4 genes, being three confirmed as having GSD Ia, and two with GSD Ib. In seven of these patients no mutations...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: DNA-based diagnosis; Glycogen storage disease; G6PC; SLC37A4; Mutation.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572013000400007

Mutation and association analysis of the PVR and PVRL2 genes in patients with non-syndromic cleft lip and palate
Provedor de dados: 74
Autores: Sözen,Mehmet A.; Hecht,Jacqueline T.; Spritz,Richard A.
Orofacial clefts (OFC; MIM 119530) are among the most common major birth defects. Here, we carried out mutation screening of the PVR and PVRL2 genes, which are both located at an OFC linkage region at 19q13 (OFC3) and are closely related to PVRL1, which has been associated with both syndromic and non-syndromic cleft lip and palate (nsCLP). We screened a total of 73 nsCLP patients and 105 non-cleft controls from the USA for variants in PVR and PVRL2, including all exons and encompassing all isoforms. We identified four variants in PVR and five in PVRL2. One non-synonymous PVR variant, A67T, was more frequent among nsCLP patients than among normal controls, but this difference did not achieve statistical significance.
Tipo: Info:eu-repo/semantics/other
Palavras-chave: PVR; PVRL2; Cleft lip and palate; Mutation; SSCP.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572009000300007

Novel splice-affecting variants in CYP27A1 gene in two Chilean patients with Cerebrotendinous Xanthomatosis
Provedor de dados: 74
Autores: Smalley,Susan V.; Preiss,Yudith; Suazo,José; Vega,Javier Andrés; Angellotti,Isidora; Lagos,Carlos F.; Rivera,Enzo; Kleinsteuber,Karin; Campion,Javier; Martínez,J. Alfredo; Maiz,Alberto; Santos,José Luis.
Cerebrotendinous Xanthomatosis (CTX), a rare lipid storage disorder, is caused by recessive loss-of-function mutations of the 27-sterol hydroxylase (CYP27A1), producing an alteration of the synthesis of bile acids, with an accumulation of cholestanol. Clinical characteristics include juvenile cataracts, diarrhea, tendon xanthomas, cognitive impairment and other neurological manifestations. Early diagnosis is critical, because treatment with chenodeoxycholic acid may prevent neurological damage. We studied the CYP27A1 gene in two Chilean CTX patients by sequencing its nine exons, exon-intron boundaries, and cDNA from peripheral blood mononuclear cells. Patient 1 is a compound heterozygote for the novel substitution c.256-1G &gt; T that causes exon 2...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cerebrotendinous Xanthomatosis; Splicing; Mutation; Exon skipping.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572015000100030

Identification of a novel mutation in ARSA gene in three patients of an Iranian family with metachromatic leukodystrophy disorder
Provedor de dados: 74
Autores: Golchin,Neda; Hajjari,Mohammadreza; Malamiri,Reza Azizi; Aminzadeh,Majid; Mohammadi-asl,Javad.
Abstract Metachromatic leukodystrophy disorder (MLD) is an autosomal recessive and lysosomal storage disease. The disease is caused by the deficiency of the enzyme arylsulfatase A (ARSA) which is encoded by the ARSA gene. Different mutations have been reported in different populations. The present study was aimed to detect the mutation type of the ARSA gene in three relative Iranian patients. We found a novel homozygous missense mutation c.1070 G &gt; T (p.Gly357Val) in exon 6 of these patients. The mutation was found to be reported for the first time in MLD patients. The data can update the mutation profile and contribute toward improved clinical management and counseling of MLD patients.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Metachromatic leukodystrophy disorder; ARSA gene; Mutation; Arylsulfatase A.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572017000500759

Effects of β-glucan polysaccharide revealed by the dominant lethal assay and micronucleus assays, and reproductive performance of male mice exposed to cyclophosphamide
Provedor de dados: 74
Autores: Oliveira,Rodrigo Juliano; Pesarini,João Renato; Salles,Maria José Sparça; Kanno,Tatiane Yumi Nakamura; Lourenço,Ana Carolina dos Santos; Leite,Véssia da Silva; Silva,Ariane Fernanda da; Matiazi,Hevenilton José; Ribeiro,Lúcia Regina; Mantovani,Mário Sérgio.
β-glucan is a well-known polysaccharide for its chemopreventive effect. This study aimed to evaluate the chemopreventive ability of β-glucan in somatic and germ cells through the dominant lethal and micronucleus assays, and its influence on the reproductive performance of male mice exposed to cyclophosphamide. The results indicate that β-glucan is capable of preventing changes in DNA in both germ cells and somatic ones. Changes in germ cells were evaluated by the dominant lethal assay and showed damage reduction percentages of 46.46% and 43.79% for the doses of 100 and 150 mg/kg. For the somatic changes, evaluated by micronucleus assay in peripheral blood cells in the first week of treatment, damage reduction percentages from 80.63-116.32% were found. In...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Mutation; Post-implantation losses; Chemoprevention; Micronucleus; Nulliparous females.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572014000100017

Molecular Basis for Resistance to Fluazifop-P-Butyl in Itchgrass (Rottboellia cochinchinensis) from Costa Rica
Provedor de dados: 87
Autores: CASTILLO-MATAMOROS,R.; BRENES-ANGULO,A.; HERRERA-MURILLO,F.; GÓMEZ ALPÍZAR.,L.
Rottboellia cochinchinensis is an annual grass weed species known as itchgrass, or "caminadora" in America´s Spanish speaking countries, and has become a major and troublesome weed in several crops. The application of fluazifop-P-butyl at recommended rates (125 g a.i. ha-1) was observed to be failing to control itchgrass in a field in San José, Upala county, Alajuela province, Costa Rica. Plants from the putative resistant R. cochinchinensis population survived fluazifop-P-butyl when treated with 250 g a.i. ha-1 (2X label rate) at the three- to four-leaf stage under greenhouse conditions. PCR amplification and sequencing of partial carboxyl transferase domain (CT) of the acetyl-CoA carboxylase (ACCase) gene were used to determine the molecular mechanism of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Herbicide; Mutation; Acetyl-CoA carboxylase.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582016000100143

Sourgrass Resistance Mechanism to the Herbicide Glyphosate
Provedor de dados: 87
Autores: MELO,M.S.C.; ROCHA,L.J.F.N.; BRUNHARO,C.A.C.G.; NICOLAI,M.; TORNISIELLO,V.L.; NISSEN,S.J.; CHRISTOFFOLETI,P.J.
ABSTRACT: The knowledge on the mechanism that gives a weed resistance to a particular herbicide is essential regarding scientific, academic, and practical aspects because it determines the recommendations for prevention and management of resistance in the field. Studies on the sourgrass (Digitaria insularis) glyphosate resistance mechanism in the literature have not been conclusive. Thus, the aim of this research was to study and evaluate the putative resistance mechanisms whichgives sourgrass biotypes, the ability to survive after glyphosate application. For this, 14C-glyphosate leaf absorption and translocation were compared in the biotypes Matão (R), Campo Florido (MG), Diamantino (MT), and Iracemápolis (S) as a function of the time after its...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Absorption; Translocation; Mutation; 14C-glyphosate; Digitaria insularis.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582019000100232

Antimicrobial Resistance in Campylobacter jejuni Isolated from Brazilian Poultry Slaughterhouses
Provedor de dados: 89
Autores: Paravisi,M; Laviniki,V; Bassani,J; Kunert Filho,HC; Carvalho,D; Wilsmann,DE; Borges,KA; Furian,TQ; Salle,CTP; Moraes,HLS; Nascimento,VP.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antimicrobial resistance; Campylobacter jejuni; GyrA; Mutation; Poultry; TetO.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2020000200323

Molecular epidemiology and evolution of avian infectious bronchitis virus
Provedor de dados: 89
Autores: Montassier,HJ.
Mutation and recombination processes are involved in the genetic and phenotypic variations of RNA viruses, leading to the emergence of new variant strains, and give rise to virus population diversity to be modeled by the host, particularly by the immune system, as occurred with infectious bronchitis virus (IBV) in chickens. The consequence is a continuous emergence of new IBV variants with regard to pathotypes, serotypes, and protectotypes. Nucleotide sequencing and subsequent genetic analysis of the S1 and N protein gene sequences provide a fast and accurate method to classify and predict IBV genotype, and a powerful instrument to monitor phylogenetic and epidemiological evolution of IBV variants. Despite the use of vaccination programmes, infectious...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chicken; Coronavirus; Genetic evolution; Mutation; Prophylaxis; Recombination; Variant strains.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2010000200003

In vitro sensivity of fig plantlets to gamma rays
Provedor de dados: 63
Autores: Ferreira,Ester Alice; Pasqual,Moacir; Tulmann Neto,Augusto.
Fig breeding programs through conventional methods are rare in many countries, e.g. Brazil, since the wasp Blastophaga psenes, which is responsible for the natural pollination, is not present. For these cases a low cost alternative for the breeding program is the induction of physical mutagenesis by radiation. The sensivity of fig explant buds of different sizes to gamma radiation were evaluated. Fig plantlets "Roxo de Valinhos" already established in vitro were classified by size in 2.5 to 4.5 cm, 5 to 9 7 cm and 8 to 10 cm long, and irradiated with: 10, 20, 30, 40 and 50 Gy doses. After irradiation each plantlet was cut in pieces containing one-bud and transferred to WPM culture medium, according to the bud position: medium and apical. Explants were...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Mutation; Breeding; Tissue culture.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162009000400017

การปฏิวัติยีน กับการปรับปรุงพันธุ์พืช
Provedor de dados: 106
Palavras-chave: Gene revolution; Plant improvement; Biodiversity; Genetic diversity; Species diversity; Eco-system diversity; Mutation; Genome research; การปรับปรุงพันธุ์พืช; การปฏิวัติยีน; การแสดงออกของยีน; พันธุวิศวกกรม; การตัดต่อยีน; จีเอ็มโอ; ไลเปส; ความปลอดภัยทางชีวภาพ; การติดฉลาก.
Ano: 2001
URL: http://anchan.lib.ku.ac.th/agnet/handle/001/4156

Nutritional characteristics of bmr mutant and normal sorghum genotypes used for cutting and grazing
Provedor de dados: 2
Autores: Aguilar, Poliana Batista de; Universidade Estadual de Montes Claros; Pires, Daniel Ananias de Assis; Universidade Estadual de Montes Claros; Frota, Benara Carla Barros; Universidade Estadual de Montes Claros; Rodrigues, José Avelino Santos; Empresa Brasileira de Pesquisa Agropecuária; Reis, Sidnei Tavares; Universidade Estadual de Montes Claros; Rocha Júnior, Vicente Ribeiro; Universidade Estadual de Montes Claros.
This study evaluated the nutritional characteristics of BMR mutant and normal sorghum genotypes, eleven BMR mutants and nine normal. Seeds were sown in a randomized block design with three blocks, in which each genotype was a treatment. The nutritional characteristics were analyzed at 42 days of regrowth after the first cut, determined for DM, EE, ash, CP, NDIN, NIDA, NDF, ADF, NFC, CT, HCEL, CEL and NGLs. Regarding DM, EE, ash, NDIN, NIDA, NDF, FDA and HCEL, there were no differences between genotypes. As for CP, there were differences, with mean levels ranging from 9.77% for BR001AXTX2785bmr to 16.45% for BR001AxTX2784. Considering CT and NFC, there were differences in the mean levels that ranged from 75.21 to 83.28% for BR007AxTX2785bmr and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Forage; Isogenic; Mutation; Brown midrib.
Ano: 2014
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAnimSci/article/view/21284

Simulated self-organization of death by inherited mutations
Provedor de dados: 42
Autores: Martins,Jorge S. Sá; Stauffer,Dietrich; Oliveira,Paulo M.C. de; Oliveira,Suzana Moss de.
An agent-based computer simulation of death by inheritable mutations in a changing environment shows a maximal population, or avoids extinction, at some intermediate mutation rate of the individuals. Our results indicate that death seems needed to allow for evolution of the fittest, as required by a changing environment.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Changing environment; Computer modeling; Evolution; Mutation; Selection.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652009000400010

Germline mutation analysis of Tpit in Poodle dogs with ACTH-dependent hyperadrenocorticism
Provedor de dados: 45
Autores: De Marco,V.; Carvalho,L.R.; Billerbeck,A.E.C.; Mendonça,B.B.
There is a high incidence of pituitary-dependent hyperadrenocorticism (PDH) in Poodle dogs, with family members being affected by the disease, suggesting a genetic involvement. Tpit is an obligate transcription factor for the expression of pro-opiomelanocortingene and for corticotroph terminal differentiation. The aim of the present study was to screen the Tpit gene for germline mutations in Poodles with PDH. Fifty Poodle dogs (33 female, 8.71±2.8 years) with PDH and 50 healthy Poodle dogs (32 females, 9.4241 2.8 years) were studied. Genomic DNA was isolated from peripheral blood, amplified by PCR and submitted to automatic sequence. No mutation in the coding region of Tpit was found, whereas the new single nucleotide polymorphism p.S343G, in heterozygous...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Dog; ACTH-dependent hyperadrenocorticism; Tpit; Mutation.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-09352012000400010

Molecular and pathological basis of aceruloplasminemia
Provedor de dados: 48
Autores: KONO,SATOSHI; MIYAJIMA,HIROAKI.
Aceruloplasminemia is an autosomal recessive neurodegenerative disease characterized by iron accumulation in the brain as well as visceral organs. It is a loss-of-function disorder caused by mutations in the ceruloplasmin gene. Clinically, this disease consists of the triad of adult-onset neurological disease, retinal degeneration and diabetes mellitus. Massive iron accumulation and extensive loss of neurons are observed in the basal ganglia. The elevated iron concentration is associated with increased lipid peroxidation in the brains of aceruloplasminemia patients. Enlarged or deformed astrocytes and spheroid-like globular structures are characteristic neuropathological findings in aceruloplasminemia. Moreover, deformed astrocytes and globular structures...
Tipo: Journal article
Palavras-chave: Ceruloplasmin; Iron; Lipid peroxidation; Mutation.
Ano: 2006
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602006000100003

Mutation breeding of lipase-producing strain Flavobacterium sp. by supercritical CO2 with hydrazine hydrate
Provedor de dados: 52
Autores: Zhang,Qiaoyan; Qian,Junqing; Ma,Lingzhi.
This work aimed to obtain an ideal mutant strain with higher lipase yield using hydrazine hydrate (HZH) as a novel additive to treat Flavobacterium sp. strain YY25 by supercritical CO2. The survival rate and the positive mutation rate of the tested strain were strongly dependent on the dose of HZH. The treatment by 0.5% HZH in supercritical CO2 (8 MPa, 35°C) for 30 min provided 58.3% of positive mutation rate and an expected mutant strain with about 76.7% increase in lipase yield compared with the wild strain. Possible mutagenesis mechanisms were further explored. The analysis on pH drop of the treated seed liquid was performed to better understand the interaction. Results proved that the induced mutation with enhanced yield of lipase could be achieved by...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Supercritical CO2; Mutation; PH Drop; Lipase; Flavobacterium sp.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132013000400003

Hepatitis B virus genotypes, precore mutations, and basal core promoter mutations in HBV-infected Chinese patients with persistently normal alanine aminotransferase and low serum HBV-DNA levels
Provedor de dados: 55
Autores: Shi,Ming; Zhang,Yong; Zhang,Jing; Liu,Wei; Xing,Lu.
Hepatitis B virus (HBV) genotype and precore and basal core promoter (BCP) mutants in the patients with persistently normal alanine aminotransferase (ALT) and low serum HBV-DNA levels are unclear. The aim of this study was to determine HBV genotypes, precore and BCP mutations, and their association with chronic hepatitis and liver fibrosis in HBV-infected patients with persistently normal ALT, and low serum HBV-DNA levels in northeast China. Patients (n = 89) with normal ALT and serum HBV-DNA levels below 20000 IU/mL but detectable with real-time PCR were included in this study. HBV genotypes were determined by real-time PCR. The precore and BCP mutations were detected by sequencing. All the patients had biopsy results. Of the 89 patients, 11 (12.4%) were...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hepatitis B virus; Genotype; Mutation; Alanine transaminase.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702012000100009

Characteristics of hospitalized children infected with macrolide-resistant Mycoplasma pneumoniae
Provedor de dados: 55
Autores: Komatsu,Haruki; Tsunoda,Tomoyuki; Inui,Ayano; Sogo,Tsuyoshi; Fujisawa,Tomoo.
BACKGROUND: The aim of this study was to clarify retrospectively the characteristics of children hospitalized for respiratory tract infection caused by macrolide-resistant Mycoplasma pneumoniae (M. pneumoniae).METHODS: Children who were hospitalized for respiratory tract infection due to M. pneumoniae were enrolled in this study. The diagnosis of M. pneumoniae infection was made on the grounds of polymerase chain reaction results.RESULTS: Thirty-three children were hospitalized due to lower respiratory tract infection with M. pneumoniae. Of the 33 children, 31 (median age five years) were identified as being infected with macrolide-resistant M. pneumoniae (A2063G:30, A2064G:1) by sequence analysis. Of the 31 children infected with macrolide-resistant M....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antibiotics; Minocycline; Mutation; Young children.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702014000300294

Simultaneous detection of hepatitis B virus genotypes and mutations associated with resistance to lamivudine, adefovir, and telbivudine by the polymerase chain reaction-ligase detection reaction
Provedor de dados: 55
Autores: Wang,Yong-Zhong; Xiao,Jun-Hua; Liu,Long-Gen; Ye,Chun-Yan; Shen,Hong-Yu; Xu,Tian-Min; Zhu,Ke-Zhuan.
OBJECTIVES: Detection of mutations associated to nucleos(t)ide analogs and hepatitis B virus (HBV) genotyping are essential for monitoring treatment of HBV infection. We developed a multiplex polymerase chain reaction-ligase detection reaction (PCR-LDR) assay for the rapid detection of HBV genotypes and mutations associated with lamivudine, adefovir, and telbivudine resistance in HBV-infected patients. METHODS: HBV templates were amplified by PCR, followed by LDR and electrophoresis on a sequencer. The assay was evaluated using plasmids that contained wild-type or mutant HBV sequences and 216 clinical samples. RESULTS: The PCR-LDR assay and sequencing gave comparable results for 158 of the 216 samples (73.1%) with respect to mutation detection and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hepatitis B; Drug resistance; Mutation; Genotype.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702011000600010

Impact of the number of failed therapeutic regimes on the development of resistance mutations to HIV-1 in northeast Brazil
Provedor de dados: 55
Autores: Medeiros,Melissa Soares; Arruda,Érico Antônio Gomes; Guerrant,Richard Littleton; Brown,Christopher Cooley; Lima,Aldo Ângelo Moreira.
Highly-potent antiretroviral therapy is necessary to avoid viral replication in HIV patients; however, it can favor the appearance of resistance mutations. The mutations 41L, 67N, 70R, 210W, 215Y/F, 219E/Q, 44D and 118I are defined as nucleoside analogous mutations (NAMs), because they affect the efficacy of all nucleoside reverse transcriptase inhibitors (NRTI). The mutation most frequently associated with non-nucleoside reverse transcriptase inhibitors (NNRTIs) is 103N. 33W/F, 82A/F/L/T, 84V and 90M are called protease inhibitor resistance-associated mutations (PRAM), because they are associated with resistance to several protease inhibitors (PI). This study evaluated the development of resistance mutations and examine the susceptibility of HIV with...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Mutation; HIV-1; Failure therapy; Antiretrovirals; Resistance.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702007000500002

Mini-Mu insertions in the tetracycline resistance determinant from Proteus mirabilis
Provedor de dados: 56
The inducible tetracycline resistance determinant isolated from Proteus mirabilis cloned into the plasmid pACYC177 was mutagenized by insertion of a mini-Mu-lac phage in order to define the regions in the cloned sequences encoding the structural and regulatory proteins. Three different types of mutants were obtained: one lost the resistance phenotype and became Lac+; another expressed the resistance at lower levels and constitutively; the third was still dependent on induction but showed a lower minimal inhibitory concentration. The mutant phenotypes and the locations of the insertions indicate that the determinant is composed of a repressor gene and a structural gene which are not transcribed divergently as are other known tetracycline determinants...
Palavras-chave: Tetracycline; Mutation; LacZ-fusion; Proteus mirabilis; Bacteriophage Mu.
Ano: 1997
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997000300009

Infrequent p53 gene alterations in ulcerative colitis
Provedor de dados: 56
Autores: Mattar,R.; Alexandrino,A.M.; Laudanna,A.A.
The purpose of this study was to determine whether point mutations and loss of the p53 gene take place in ulcerative colitis which is histologically negative for dysplasia. DNA was extracted from 13 frozen rectal or colon biopsies and blood samples. Ulcerative colitis was classified histologically as active (10 cases) and inactive (3 cases). Exons 5-8 were amplified by PCR, treated with exonuclease and shrimp alkaline phosphatase and sequenced by the dideoxy chain termination method with the Sequenase Version 2.0 DNA sequencing kit. PCR products of intron 6 and exon 4 were digested with MspI and AccII, respectively, for RFLP analysis. No p53 gene mutation was detected in these cases. The number of informative patients for loss of heterozygosity (LOH) at...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: P53 gene; Ulcerative colitis; LOH; Mutation.
Ano: 1999
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999000900005

A case of severe glutathione synthetase deficiency with novel GSS mutations
Provedor de dados: 56
Autores: Xia,H.; Ye,J.; Wang,L.; Zhu,J.; He,Z.
Glutathione synthetase deficiency (GSSD) is a rare inborn error of glutathione metabolism with autosomal recessive inheritance. The severe form of the disease is characterized by acute metabolic acidosis, usually present in the neonatal period with hemolytic anemia and progressive encephalopathy. A case of a male newborn infant who had severe metabolic acidosis with high anion gap, hemolytic anemia, and hyperbilirubinemia is reported. A high level of 5-oxoproline was detected in his urine and a diagnosis of generalized GSSD was made. DNA sequence analysis revealed the infant to be compound heterozygous with two mutations, c.738dupG in exon 8 of GSS gene resulting in p.S247fs and a repetitive sequence in exon 3 of GSS gene. Treatment after diagnosis of GSSD...
Tipo: Info:eu-repo/semantics/report
Palavras-chave: Glutathione synthetase; 5-oxoprolinuria; Newborn; Metabolism; Mutation.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2018000300501

Multigenerational Brazilian family with malignant hyperthermia and a novel mutation in the RYR1 gene
Provedor de dados: 56
Autores: Matos,A.R.; Sambuughin,N.; Rumjanek,F.D.; Amoedo,N.D.; Cunha,L.B.P.; Zapata-Sudo,G.; Sudo,R.T.
Malignant hyperthermia (MH) is a pharmacogenetic disease triggered in susceptible individuals by the administration of volatile halogenated anesthetics and/or succinylcholine, leading to the development of a hypermetabolic crisis, which is caused by abnormal release of Ca2+ from the sarcoplasmic reticulum, through the Ca2+ release channel ryanodine receptor 1 (RyR1). Mutations in the RYR1 gene are associated with MH in the majority of susceptible families. Genetic screening of a 5-generation Brazilian family with a history of MH-related deaths and a previous MH diagnosis by the caffeine halothane contracture test (CHCT) in some individuals was performed using restriction and sequencing analysis. A novel missense mutation, Gly4935Ser, was found in an...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Malignant hyperthermia; Mutation; Ryanodine receptor; Calcium channel.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2009001200016

The expression of the ACTH receptor
Provedor de dados: 56
Autores: Elias,L.L.K.; Clark,A.J.L.
Adrenal glucocorticoid secretion is regulated by adrenocorticotropic hormone (ACTH) acting through a specific cell membrane receptor (ACTH-R). The ACTH-R is a member of the G protein superfamily-coupled receptors and belongs to the subfamily of melanocortin receptors. The ACTH-R is mainly expressed in the adrenocortical cells showing a restricted tissue specificity, although ACTH is recognized by the other four melanocortin receptors. The cloning of the ACTH-R was followed by the study of this gene in human diseases such as familial glucocorticoid deficiency (FGD) and adrenocortical tumors. FGD is a rare autosomal recessive disease characterized by glucocorticoid deficiency, elevated plasma ACTH levels and preserved renin/aldosterone secretion. This...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: ACTH receptor; Resistance; Mutation; Transfection.
Ano: 2000
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000001000015

Phenotype and genotype correlation of the microconversion from the CYP21A1P to the CYP21A2 gene in congenital adrenal hyperplasia
Provedor de dados: 56
Autores: Torres,N.; Mello,M.P.; Germano,C.M.R.; Elias,L.L.K.; Moreira,A.C.; Castro,M.
Deficiency of 21-hydroxylase is the most common form of congenital adrenal hyperplasia (CAH-21OH). We determined by allele-specific PCR the frequency of microconversion in the CYP21A2 gene in 50 Brazilian patients with the classical (salt wasting: SW and simple virilizing: SV) forms and nonclassical (NC) form of CAH-21OH and correlated genotype with phenotype. Genotypes were classified into three mutation groups (A, B, and C) based on the amount of enzymatic activity in in vitro studies using adrenal cells. In 94 unrelated alleles, we diagnosed 76% of the affected alleles after screening for 7 microconversions. The most frequent point mutations observed in this series were I172N (19%), V281L (18%), and IVS2,A/C&gt;G,-12 (15%). In the SW form, the most...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: 21-Hydroxylase; Mutation; Microconversion; Genotype; Phenotype; Congenital adrenal hyperplasia.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003001000006

Detection of somatic mutations of the PIG-A gene in Brazilian patients with paroxysmal nocturnal hemoglobinuria
Provedor de dados: 56
Autores: Franco de Carvalho,R.; Arruda,V.R.; Saad,S.T.O.; Costa,F.F.
Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal syndrome characterized by intravascular hemolysis mediated by complement, thrombotic events and alterations in hematopoiesis. Basically, the molecular events which underlie the complexity of the syndrome consist of the absence of the glycosylphosphatidylinositol (GPI) anchor as a consequence of somatic mutations in the PIG-A gene, located on the X chromosome. The GPI group is responsible for the attachment of many proteins to the cytoplasmic membrane. Two of them, CD55 and CD59, have a major role in the inhibition of the action of complement on the cellular membrane of blood cells. The absence of GPI biosynthesis can lead to PNH. Since mutations in the PIG-A gene are always present in patients...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Paroxysmal nocturnal hemoglobinuria; Intravascular hemolysis; Complement PIG-A; Mutation.
Ano: 2001
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2001000600010

No evidence for mutations in exons 1, 8 and 18 of the patched gene in sporadic skin lesions of Brazilian patients
Provedor de dados: 56
Autores: Granja,F.; Santarosa,P.L.; Leite,J.L.A.A.P.; Ward,L.S.
There is strong evidence that the patched (PTCH) gene is a gene for susceptibility to the nevoid basal cell carcinoma syndrome. PTCH has also been shown to mutate in both familial and sporadic basal cell carcinomas. However, mutations of the gene seem to be rare in squamous cell carcinomas. In order to characterize the role of the gene in the broader spectrum of sporadic skin malignant and pre-malignant lesions, we performed a polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) analysis of genomic DNA extracted from 105 adult patients (46 females and 59 males). There were 66 patients with basal cell carcinomas, 30 with squamous cell carcinomas, 2 with malignant melanomas and 7 patients with precancerous lesions. Two tissue samples...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Skin; Cancer; PTCH; Mutation.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003000400006

Epidermal growth factor receptor (EGFR) mutations in lung cancer: preclinical and clinical data
Provedor de dados: 56
Autores: Jorge,S.E.D.C.; Kobayashi,S.S.; Costa,D.B.
Lung cancer leads cancer-related mortality worldwide. Non-small-cell lung cancer (NSCLC), the most prevalent subtype of this recalcitrant cancer, is usually diagnosed at advanced stages, and available systemic therapies are mostly palliative. The probing of the NSCLC kinome has identified numerous nonoverlapping driver genomic events, including epidermal growth factor receptor (EGFR) gene mutations. This review provides a synopsis of preclinical and clinical data on EGFR mutated NSCLC and EGFR tyrosine kinase inhibitors (TKIs). Classic somatic EGFR kinase domain mutations (such as L858R and exon 19 deletions) make tumors addicted to their signaling cascades and generate a therapeutic window for the use of ATP-mimetic EGFR TKIs. The latter inhibit these...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Mutation; Lung cancer; Non-small-cell lung cancer; EGFR; EGFR inhibitor; Precision therapies; Resistance.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2014001100929

Hepatitis B virus subgenotype C2- and B2-associated mutation patterns may be responsible for liver cirrhosis and hepatocellular carcinoma, respectively
Provedor de dados: 56
Autores: Chen,Y.M.; Wu,S.H.; Qiu,C.N.; Yu,D.J.; Wang,X.J.
The objective of this study was to examine hepatitis B virus (HBV) subgenotypes and mutations in enhancer II, basal core promoter, and precore regions of HBV in relation to risks of liver cirrhosis (LC) and hepatocellular carcinoma (HCC) in Southeast China. A case-control study was performed, including chronic hepatitis B (CHB; n=125), LC (n=120), and HCC (n=136). HBV was genotyped by multiplex polymerase chain reaction and subgenotyped by restriction fragment length polymorphism. HBV mutations were measured by DNA sequencing. HBV genotype C (68.2%) predominated and genotype B (30.2%) was the second most common. Of these, C2 (67.5%) was the most prevalent subgenotype, and B2 (30.2%) ranked second. Thirteen mutations with a frequency &gt;5% were detected....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hepatitis B virus; Genotype; Core promoter; Precore; Mutation; Advanced liver disease.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2013000700614

Lack of evidence for mutations or deletions in the CDKN2A/p16 and CDKN2B/p15 genes of Brazilian neuroblastoma patients
Provedor de dados: 56
Autores: Bassi,C.L.; Martelli,L.; Cipolotti,R.; Scrideli,C.A.; Defávery,R.; Tone,L.G.
Neuroblastoma, the most common extracranial tumor in childhood, has a wide spectrum of clinical and biological features. The loss of heterozygosity within the 9p21 region has been reported as a prognostic factor. Two tumor suppressor genes located in this region, the CDKN2B/p15 and CDKN2A/p16 (cyclin-dependent kinase inhibitors 2B and 2A, respectively) genes, play a critical role in cell cycle progression and are considered to be targets for tumor inactivation. We analyzed CDKN2B/p15 and CDKN2A/p16 gene alterations in 11 patients, who ranged in age from 4 months to 13 years (male/female ratio was 1.2:1). The most frequent stage of the tumor was stage IV (50%), followed by stages II and III (20%) and stage I (10%). The samples were submitted to the...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: P15 gene; P16 gene; Deletion; Mutation; Neuroblastoma.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2004001100014

ß-Spectrin São PauloII, a novel frameshift mutation of the ß-spectrin gene associated with hereditary spherocytosis and instability of the mutant mRNA
Provedor de dados: 56
Autores: Bassères,D.S.; Tavares,A.C.; Costa,F.F.; Saad,S.T.O.
Hereditary spherocytosis (HS) is a common inherited anemia characterized by the presence of spherocytic red cells. Defects in several membrane protein genes have been involved in the pathogenesis of HS. ß-Spectrin-related HS seems to be common. We report here a new mutation in the ß-spectrin gene coding region in a patient with hereditary spherocytosis. The patient presented acanthocytosis and spectrin deficiency and, at the DNA level, a novel frameshift mutation leading to HS, i.e., a C deletion at codon 1392 (ß-spectrin São PauloII), exon 20. The mRNA encoding ß-spectrin São PauloII was very unstable and the mutant protein was not detected in the membrane or in other cellular compartments. It is interesting to note that frameshift mutations of the...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: SS-Spectrin; Red cell membrane; Spherocytosis; Acanthocytes; Mutation.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002000800009

The P48T germline mutation and polymorphism in the CDKN2A gene of patients with melanoma
Provedor de dados: 56
Autores: Huber,J.; Ramos,E.S.
CDKN2A has been implicated as a melanoma susceptibility gene in some kindreds with a family history of this disease. Mutations in CDKN2A may produce an imbalance between functional p16ink4a and cyclin D causing abnormal cell growth. We searched for germline mutations in this gene in 22 patients with clinical criteria of hereditary cancer (early onset, presence of multiple primary melanoma or 1 or more first- or second-degree relatives affected) by secondary structural content prediction, a mutation scanning method that relies on the propensity for single-strand DNA to take on a three-dimensional structure that is highly sequence dependent, and sequencing the samples with alterations in the electrophoretic mobility. The prevalence of CDKN2A mutation in our...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: CDKN2A; Familial melanoma; Mutation; P48T; Polymorphism.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2006000200010

Inducing mutations in the mouse genome with the chemical mutagen ethylnitrosourea
Provedor de dados: 56
Autores: Massironi,S.M.G.; Reis,B.L.F.S.; Carneiro,J.G.; Barbosa,L.B.S.; Ariza,C.B.; Santos,G.C.; Guénet,J.L.; Godard,A.L.B.
When compared to other model organisms whose genome is sequenced, the number of mutations identified in the mouse appears extremely reduced and this situation seriously hampers our understanding of mammalian gene function(s). Another important consequence of this shortage is that a majority of human genetic diseases still await an animal model. To improve the situation, two strategies are currently used: the first makes use of embryonic stem cells, in which one can induce knockout mutations almost at will; the second consists of a genome-wide random chemical mutagenesis, followed by screening for mutant phenotypes and subsequent identification of the genetic alteration(s). Several projects are now in progress making use of one or the other of these...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Mouse; Ethylnitrosourea; Mutation; Co-isogenic mutations; Mutagenesis.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2006000900009

Amplification of 9q34 in childhood adrenocortical tumors: a specific feature unrelated to ethnic origin or living conditions
Provedor de dados: 56
Autores: Figueiredo,B.C.; Ribeiro,R.C.; Zambetti,G.; Haddad,B.; Pianovsky,M.D.; Pereira,R.M.; DeLacerda,L.; Sandrini,R.
Adrenocortical tumors (ACT) in children under 15 years of age exhibit some clinical and biological features distinct from ACT in adults. Cell proliferation, hypertrophy and cell death in adrenal cortex during the last months of gestation and the immediate postnatal period seem to be critical for the origin of ACT in children. Studies with large numbers of patients with childhood ACT have indicated a median age at diagnosis of about 4 years. In our institution, the median age was 3 years and 5 months, while the median age for first signs and symptoms was 2 years and 5 months (N = 72). Using the comparative genomic hybridization technique, we have reported a high frequency of 9q34 amplification in adenomas and carcinomas. This finding has been confirmed more...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Adrenocortical carcinoma; Cancer; Mutation; 9q34 amplification.
Ano: 2000
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000001000012

Inactivation of phoPQ genes attenuates Salmonella Gallinarum biovar Gallinarum to susceptible chickens
Provedor de dados: 58
Autores: Alves,Lucas Bocchini Rodrigues; Freitas Neto,Oliveiro Caetano de; Batista,Diego Felipe Alves; Barbosa,Fernanda de Oliveira; Rubio,Marcela da Silva; Souza,Andrei Itajahy Secundo de; Almeida,Adriana Maria de; Barrow,Paul Andrew; Berchieri Junior,Angelo.
Abstract Salmonella Gallinarum is a host-restrict pathogen that causes fowl typhoid, a severe systemic disease that is one of the major concerns to the poultry industry worldwide. When infecting the bird, SG makes use of evasion mechanisms to survive and to replicate within macrophages. In this context, phoPQ genes encode a two-component regulatory system (PhoPQ) that regulates virulence genes responsible for adaptation of Salmonella spp. to antimicrobial factors such as low pH, antimicrobial peptides and deprivation of bivalent cations. The role of the mentioned genes to SG remains to be investigated. In the present study a phoPQ-depleted SG strain (SG ΔphoPQ) was constructed and its virulence assessed in twenty-day-old laying hens susceptible to fowl...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Mutation; Virulence; Fowl typhoid; Adaptation; Chickens.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822018000300601

Molecular mechanism of fluoroquinolones resistance in Mycoplasma hominis clinical isolates
Provedor de dados: 58
Autores: Dong-Ya,Meng; Chang-Jian,Sun; Jing-Bo,Yu; Jun,Ma; Wen-Cheng,Xue.
To evaluate the molecular mechanism of fluoroquinolones resistance in Mycoplasma hominis (MH) clinical strains isolated from urogenital specimens. 15 MH clinical isolates with different phenotypes of resistance to fluoroquinolones antibiotics were screened for mutations in the quinolone resistance-determining regions (QRDRs) of DNA gyrase (gyrA and gyrB) and topoisomerase IV (parC and parE) in comparison with the reference strain PG21, which is susceptible to fluoroquinolones antibiotics. 15 MH isolates with three kinds of quinolone resistance phenotypes were obtained. Thirteen out of these quinolone-resistant isolates were found to carry nucleotide substitutions in either gyrA or parC. There were no alterations in gyrB and no mutations were found in the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Mycoplasma hominis; Quinolones; Drug resistance; Mutation.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822014000100034

Identification of a mutation in the spike protein cleavage site in Brazilian strains of wild-type bovine coronavirus
Provedor de dados: 58
Autores: Takiuchi,Elisabete; Barreiros,Marco Antônio Bacellar; Alfieri,Alice Fernandes; Alfieri,Amauri Alcindo.
The spike (S) protein of coronaviruses, a type I membrane glycoprotein, is primarily responsible for entry into susceptible cells by binding with specific receptors on cells and mediating subsequent virus-cell fusion. The bovine coronavirus (BCoV) S protein is cleaved into two subunits, the N-terminal S1 and the C-terminal S2. The proteolytic cleavage site of S protein is highly conserved among BCoV strains and is located between amino acids 763 and 768 (KRRSRR). This study describes a single mutation in the S protein cleavage site of three Brazilian strains of BCoV detected in diarrheic fecal samples from calves naturally infected. The sequenced PCR products revealed that amino acid sequence of the cleavage site of our strains was KRRSSR, indicating a...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: BCoV; Sequencing; Spike protein; Cleavage site; Mutation.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822007000400021

Isolation and partial characterization of a mutant of Bacillus thuringiensis producing melanin
Provedor de dados: 58
Autores: Vilas-Bôas,Gislayne T.; Vilas-Bôas,Laurival A.; Braz,Veridiana T.; Saridakis,Halha O.; Santos,Clelton A.; Arantes,Olívia M. N.
A mutant (407-P) of Bacillus thuringiensis subsp. thuringiensis strain 407 producing a melanin was obtained after treatment with the mutagenic agent ethyl-methane-sulfonate. Several microbiological and biochemical properties of the two strains were analyzed and the results were similar. The mutant 407-P was also incorporated into non-sterilized soil samples, recovered, easily identified, and quantified, what enables its use in ecology of B. thuringiensis.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bacillus thuringiensis; Melanin; Mutation; Ecol.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822005000300012

Improvement of penicillin G acylase expression in Escherichia coli through UV induced mutations
Provedor de dados: 58
Autores: Arshad,Rubina; Farooq,Shafqat; Ali,Syed Shahid.
We used ultraviolet (UV) radiation to induce mutation in three locally isolated strains of Escherichia coli. Different dilutions of bacterial cultures were exposed to UV lamp of 254 nm wavelength for different time intervals at varied distances ranging from 5 to 210 sec and 5 to 100 cm. Viable colonies were screened for mutants with an increased production of penicillin G acylase (PGA) and a reduced production of β-lactamase, which are the desired properties of PGA producing industrial strains. A survival curve was made to get optimum exposure time and distance. The survival percentage for each exposure period was calculated and 1-5% survival was found useful for obtaining mutants with desired change. Screening for PGA and β-lactamase constitutive and/or...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Escherichia coli; Mutation; Penicillin G acylase expression; UV irradiation.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822010000400035

Contribution of flagella and motility to gut colonisation and pathogenicity of Salmonella Enteritidis in the chicken
Provedor de dados: 58
Autores: Barbosa,Fernanda de Oliveira; Freitas Neto,Oliveiro Caetano de; Batista,Diego Felipe Alves; Almeida,Adriana Maria de; Rubio,Marcela da Silva; Alves,Lucas Bocchini Rodrigues; Vasconcelos,Rosemeire de Oliveira; Barrow,Paul Andrew; Berchieri Junior,Angelo.
ABSTRACT Salmonella Enteritidis causes fowl paratyphoid in poultry and is frequently associated to outbreaks of food-borne diseases in humans. The role of flagella and flagella-mediated motility into host-pathogen interplay is not fully understood and requires further investigation. In this study, one-day-old chickens were challenged orally with a wild-type strain Salmonella Enteritidis, a non-motile but fully flagellated (SE ΔmotB) or non-flagellated (SE ΔfliC) strain to evaluate their ability to colonise the intestine and spread systemically and also of eliciting gross and histopathological changes. SE ΔmotB and SE ΔfliC were recovered in significantly lower numbers from caecal contents in comparison with Salmonella Enteritidis at early stages of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Mutation; Flagellum; Virulence factors; Poultry; Gut colonisation.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822017000400754

Production of actinomycin-D by the mutant of a new isolate of Streptomyces sindenensis
Provedor de dados: 58
Autores: Praveen,Vandana; Tripathi,C.K.M.; Bihari,Vinod; Srivastava,S.C.
An actinomycin-D producing strain was isolated from soil and characterized as Streptomyces sindenensis. The culture was subjected to UV irradiation and a mutant with 400% higher actinomycin-D production was isolated (400 mg/l-1 as compared to 80 mg/l-1 produced by the parent). Production medium was optimized and antibiotic yield with the mutant was enhanced to 850 mg/l-1 which is 963% higher as compared with the parent.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Actinomycin-D; Antibiotics; Streptomyces; Mutation.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822008000400017

Clavulanic acid production by the MMS 150 mutant obtained from wild type Streptomyces clavuligerus ATCC 27064
Provedor de dados: 58
Autores: Vasconcelos,Eliton da Silva; Lima,Vanderlei Aparecido de; Goto,Leandro Seiji; Cruz-Hernández,Isara Lourdes; Hokka,Carlos Osamu.
Clavulanic acid (CA) is a powerful inhibitor of the beta-lactamases, enzymes produced by bacteria resistants to penicillin and cefalosporin. This molecule is produced industrially by strains of Streptomyces clavuligerus in complex media which carbon and nitrogen resources are supplied by inexpensive compounds still providing high productivity. The genetic production improvement using physical and chemical mutagenic agents is an important strategy in programs of industrial production development of bioactive metabolites. However, parental strains are susceptible to loss of their original productivity due genetic instability phenomenona. In this work, some S. clavuligerus mutant strains obtained by treatment with UV light and with MMS are compared with the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Clavulanic acid; Streptomyces clavuligerus; Mutation; Lipase.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822013000400005