Navegando por Palavras-chave "RFLP"

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    Characterization of isolates of the cucumovirus Cucumber mosaic virus present in Brazil
    (Edizioni Ets, 2004-03-01) Eiras, M.; Boari, A. J.; Colariccio, A.; Chaves, ALR; Briones, MRS [UNIFESP]; Figueira, A. R.; Harakava, R.; Universidade de São Paulo (USP); Universidade Federal de Lavras (UFLA); Universidade Federal de São Paulo (UNIFESP)
    Cucumber mosaic virus (CMV) is a naturally occurring virus that infects several crops in Brazil, although its economic and epidemiological impact has not been fully characterized. Samples of different host plant species from different regions of Brazil, including passion-fruit, sweet-pepper, black-pepper, Peperomia, melon, squash, tomato, pea, water-cress, zingiber, banana and Commelina sp., showing foliar symptoms of mosaic, deformations and chlorotic ringspots that resemble those induced by CMV, were collected for biological, serological and molecular analysis. DAS-ELISA, RT-PCR/RFLP, sequencing and phylogenetic analysis were used to characterize the isolates. Nicotiana glutinosa plants, that showed foliar mosaic after inoculation with extracts from the samples collected, were submitted to DAS-ELISA and total RNA extraction. RT-PCR, with specific primers for the 3' end of RNA 3 and part of the coat protein gene, yielded 486-499 base pair DNA fragments that were characterized by RFLP. ELISA and RT-PCR/RFLP results showed the isolates belong to CMV subgroup I. These results were confirmed by the sequences of the RT-PCR products, which were 92 to 99% identical to those of subgroup I CMV isolates. The multiple sequence alignment of the nucleotides and the translated amino acid sequences of these and other CMV strains, and phylogenetic analyses revealed three distinct clusters. Most of the Brazilian CMV isolates were closely related among themselves and clustered with other CMV subgroup IA isolates. One CMV isolate clustered together with CMV subgroup IB isolates. These results indicate the prevalence of the CMV subgroup I in Brazil.
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    Cystic fibrosis in the Brazilian population: DF508 mutation and KM-19/XV-2C haplotype distribution
    (Wayne State Univ Press, 1997-08-01) Raskin, S.; Phillips, J. A.; Krishnamani, MRS; VnencakJones, C.; Parker, R. A.; Rozov, T.; Cardieri, J. M.; Marostica, P.; Abreu, F.; Giugliani, R.; Reis, F.; Rosario, N. A.; Ludwig, N.; Culpi, L.; Universidade Federal de São Paulo (UNIFESP); UNIV FED RIO GRANDE SUL; Universidade Federal de Minas Gerais (UFMG); UNIV FED PARANA; HOSP JOANA GUSMAO
    We have used PCR amplification of DNA obtained from Guthrie cards to identify the DF508 mutation and correlate it with the allele frequencies at two polymorphic loci (XV-2C and KM-19) closely linked to the cystic fibrosis gene. The DNA came from 193 white Brazilian families affected by cystic fibrosis and living in five different states of Brazil. The distribution of the haplotypes derived from the DF508 and non-DF508 XV-2C/KM-19 genotypes indicates that 88% of the DF508 alleles are linked to haplotype B and suggests that high heterogeneity exists among the non-DF508 cystic fibrosis alleles occurring in different states. Our data can be used to compare linkage disequilibrium between Brazilians and other heterogeneous populations where the DF508 mutation frequency is low and where many different rare mutations account for the remaining recessive cystic fibrosis alleles.
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    Genotipagem do citomegalovírus humano para pesquisa de resistência primária aos antivirais em transplantados renais
    (Sociedade Brasileira de Patologia ClínicaSociedade Brasileira de PatologiaSociedade Brasileira de Citopatologia, 2004-02-01) Carraro, Emerson [UNIFESP]; Granato, Celso Francisco Hernandes [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    The aim of this study was to detect by PCR/RFLP HCMV strains containing specific UL97 or UL54 mutation in patients without previous therapy. Samples from 20 renal transplant recipients with HCMV infection at the moment of the diagnosis. From all the patients blood, saliva and urine samples were collected to investigate the possible occurrence of distinct mutations in different body sites. Although no HCMV strains with mutations conferring drug resistance were detected, the PCR/RFLP methodology was considered an adequate and practical tool to detect alterations in viral genes from different body fluids. The absence of drug resistant viral strains in the analyzed samples do not preclude its appearance in the near future, since the use of antiviral drugs in this setting is more widespread in the recent years. We suggest a periodic evaluation of the sensitivity pattern to antiviral drugs in order to monitor its occurrence.
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    Identification of new-world leishmania using ribosomal gene spacer probes
    (Elsevier B.V., 1992-11-01) Guevara, Palmira; Alonso, Guillermina; Silveira, Jose Franco da [UNIFESP]; Mello, Maricilda Palandi de [UNIFESP]; Scorza, José Vicente; Anez, Nestor; Ramirez, José Luis; UNIV CENT VENEZUELA; Universidade Federal de São Paulo (UNIFESP); NUCL UNIV RAFAEL RANGEL; UNIV LOS ANDES
    DNA probes from the nontranscribed ribosomal spacer (NTS), of Leishmania garnhami and Leishmania braziliensis were constructed and tested for sensitivity and specificity against different Leishmania isolates. the L. garnhami probes were species-specific under hybridization conditions of high stringency, but displayed specificity for the mexicana complex under conditions of intermediate stringency. the L. braziliensis probes showed 'complex' specificity. RFLP for the nontranscribed spacer within the braziliensis complex revealed very homogeneous patterns even for organisms currently accepted as different species. A PCR assay for the detection of Leishmania from the braziliensis complex is presented.
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    Single human cytomegalovirus gB genotype shed in multiple sites at the time of diagnosis in renal transplant recipients
    (Wiley-Blackwell, 2003-06-01) Carraro, E.; Granato, CFH; Universidade Federal de São Paulo (UNIFESP)
    Human cytomegalovirus (HCMV) is a major cause of morbidity and mortality in immunocompromised patients, such as renal transplant recipients. Analysis of the gene encoding the envelope glycoprotein B (gB) showed that clinical isolates adopted one of the sequence configurations, permitting the isolates to be assigned a gB genotype of 1-4. It has been suggested that HCMV gB genotypes could be correlated with tropism and pathogenesis. A number of reports in the literature refer to shedding of different gB strains, permitting follow-up of renal transplant recipients. Considering that a single strain might be responsible for the clinical expression of the disease in multiply exposed individuals, the frequency distribution of gB genotypes was examined by nested polymerase chain reaction and restriction fragment length polymorphism in 20 renal transplant recipients at the time of diagnosis. the association between gB genotypes and cellular tropism was determined using blood, saliva, and urine for each patient. HCMV gB genotype 2 was found more frequently than other genotypes (gB2, 40%; gB1, 30%; gB3, 25%; and gB4, 5%) in renal transplant recipients. the gB type did not correlate with tropism for different body sites. All the patients with HCMV infections presumably harbored a single HCMV strain at the time of diagnosis. in multiply exposed patients, the immunomodulation provided by acute HCMV infection could favor later shedding of different strains.