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1.
Braz J Biol ; 83: e275603, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37729317

RESUMO

Foodborne diseases are common illnesses caused by the consumption of food contaminated with microorganisms, such as viruses, fungi, bacteria, and protozoa. Every year, 600 million people become ill and 420,000 people die as a result of consuming contaminated food. Therefore, food safety is an important issue. In this study, samples of homemade spiced mayonnaise and self-serve acai sold in the city of Araguaína, Tocantins, Brazil were analyzed for microbiological contaminants. Acai was collected from 10 stores, one sample from each store, and tested for mold, yeast, and coliforms, as well as coliform identification and total and thermotolerant coliform counts. Mayonnaise was collected from 20 snack bars, one sample from each. These samples were inoculated on MacConkey and Salmonella Shigella agar plates, and the plates were analyzed for growth. Salmonella spp. were detected in some Mayonnaise samples, and coliforms were detected in all acai samples; 60% of samples had thermotolerant coliforms, and only 40% were within the limits established by ANVISA. The collected samples of mayonnaise and acai were contaminated with molds and yeasts above the established limit of 103 CFU/g. Thus, the analyzed mayonnaise and acai samples were contaminated and unfit for consumption, demonstrating the importance of hygienic-sanitary measures in food handling.


Assuntos
Alimentos , Humanos , Brasil , Ágar
2.
J Bioenerg Biomembr ; 53(2): 109-118, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33585958

RESUMO

Microglial activation involves both fragmentation of the mitochondrial network and changes in cellular Ca2+ homeostasis, but possible modifications in mitochondrial calcium uptake have never been described in this context. Here we report that activated microglial BV-2 cells have impaired mitochondrial calcium uptake, including lower calcium retention capacity and calcium uptake rates. These changes were not dependent on altered expression of the mitochondrial calcium uniporter. Respiratory capacity and the inner membrane potential, key determinants of mitochondrial calcium uptake, are both decreased in activated microglial BV-2 cells. Modified mitochondrial calcium uptake correlates with impaired cellular calcium signaling, including reduced ER calcium stores, and decreased replenishment by store operated calcium entry (SOCE). Induction of mitochondrial fragmentation through Mfn2 knockdown in control cells mimicked this effect, while inhibiting LPS-induced mitochondrial fragmentation by a dominant negative form of Drp1 prevented it. Overall, our results show that mitochondrial fragmentation induced by LPS promotes altered Ca2+ homeostasis in microglial cells, a new aspect of microglial activation that could be a key feature in the inflammatory role of these cells.


Assuntos
Cálcio/metabolismo , Homeostase/imunologia , Lipopolissacarídeos/metabolismo , Microglia/metabolismo , Mitocôndrias/metabolismo , Humanos
3.
Braz J Biol ; 81(2): 343-350, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32491062

RESUMO

The composition of the diet of two species of characids (Knodus heteresthes and Moenkhausia lepidura) was evaluated in the Teles Pires and Juruena Rivers, sampled in September and October 2016. We analyzed 226 stomachs of K. heteresthes and 425 of M. lepidura. The analysis of the stomach contents was based on volumetric and frequency of occurrence methods, applying the food importance index. For the similarity of the diets between the species we calculated the niche overlap with Pianka's index. Both species in the Juruena River have a dietary preference for arthropods (IAi > 0.95). In the Teles Pires River the diet is concentrated in three sources for both species: arthropods (IAi > 0.52), vegetables (IAi > 0.33) and fish (IAi > 0.12). The diet was dissimilar when compared to environments (ANOSIM, R ≥ 0.57, p < 0.001) with high trophic niche overlap (α > 0.97), regardless of the sampled environment. In the Teles Pires River, both species were classified as omnivorous with an insectivorous tendency and in the Juruena River the insectivorous behaviour occurs.


Assuntos
Artrópodes , Characidae , Caraciformes , Animais , Brasil , Rios , Verduras
4.
Braz. j. biol ; 81(2): 343-350, 2021. tab, graf, mapas, ilus
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1153352

RESUMO

The composition of the diet of two species of characids (Knodus heteresthes and Moenkhausia lepidura) was evaluated in the Teles Pires and Juruena Rivers, sampled in September and October 2016. We analyzed 226 stomachs of K. heteresthes and 425 of M. lepidura. The analysis of the stomach contents was based on volumetric and frequency of occurrence methods, applying the food importance index. For the similarity of the diets between the species we calculated the niche overlap with Pianka's index. Both species in the Juruena River have a dietary preference for arthropods (IAi > 0.95). In the Teles Pires River the diet is concentrated in three sources for both species: arthropods (IAi > 0.52), vegetables (IAi > 0.33) and fish (IAi > 0.12). The diet was dissimilar when compared to environments (ANOSIM, R ≥ 0.57, p < 0.001) with high trophic niche overlap (α > 0.97), regardless of the sampled environment. In the Teles Pires River, both species were classified as omnivorous with an insectivorous tendency and in the Juruena River the insectivorous behaviour occurs.


Foram avaliadas a composição da dieta de duas espécies de Characideos (Knodus heteresthes e Moenkhausia lepidura) nos rios Teles Pires e Juruena, amostrados em setembro e outubro de 2016. Analisamos 226 estômagos de K. heteresthes e 425 de M. lepidura, sendo utilizados os métodos volumétrico e frequência de ocorrência, aplicando-se o índice de importância alimentar. Para a similaridade das dietas entre as espécies calculamos a sobreposição de nicho com índice de Pianka. Ambas as espécies no rio Juruena têm preferência alimentar por artrópodes (IAi > 0,95), no rio Teles Pires a dieta concentra-se em três fontes para ambas espécies: artrópodes (IAi > 0,52), vegetais (IAi > 0,33) e peixes (IAi > 0,12). A dieta é dissimilar quando comparados os ambientes (ANOSIM, R ≥ 0,57; p < 0,001), com alta sobreposição de nicho trófico (α > 0,97), independente do ambiente amostrado. No rio Teles Pires, ambas as espécies foram classificadas como onívoras com tendência insetívora e no rio Juruena ocorre o comportamento insetívoro.


Assuntos
Animais , Artrópodes , Caraciformes , Characidae , Insetos , Verduras , Brasil , Rios , Ingestão de Alimentos
5.
Mol Aspects Med ; 71: 100826, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31630771

RESUMO

The brain is highly dependent on mitochondrial energy metabolism. As a result, mitochondrial dysfunction is a central aspect of many adult-onset neurological diseases, including stroke, ALS, Alzheimer's, Huntington's, and Parkinson's diseases. We review here how different mitochondrial functions, including oxidative phosphorylation, mitochondrial dynamics, oxidant generation, cell death regulation, Ca2+ homeostasis, and proteostasis are involved in these disorders.


Assuntos
Mitocôndrias/metabolismo , Doenças Neurodegenerativas/metabolismo , Sinalização do Cálcio , Metabolismo Energético , Humanos , Dinâmica Mitocondrial , Doenças Neurodegenerativas/patologia , Fosforilação Oxidativa , Estresse Oxidativo , Proteostase , Espécies Reativas de Oxigênio/metabolismo
6.
Biomed Phys Eng Express ; 6(1): 015009, 2019 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-33438597

RESUMO

Recent epidemiological studies suggested to lower the threshold dose for radiation induced cataract in the eye lens. Therefore, eye lens radiation protection became to play a more important role in personal dosimetry. The main objective of this work is to propose a new methodology for prototyping and benchmarking of an eye lens dosimter based on the equivalent dose to the sensitive part of the eye lens, using CAD Software and Geant4 Monte Carlo simulations with mesh modelling and 3D printing. A 3D printed dosemeter was type tested based on IEC 62387:2012, in terms of energy and angular dependence for the measurements of Hp(3). The results show that the methodology employed is suitable for the development of new eye lens dosemeters.


Assuntos
Cristalino/efeitos da radiação , Impressão Tridimensional , Algoritmos , Simulação por Computador , Humanos , Método de Monte Carlo , Doses de Radiação , Monitoramento de Radiação/métodos , Proteção Radiológica/métodos
7.
Sci Rep ; 8(1): 8595, 2018 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-29872062

RESUMO

Phosphatase and tensin homolog (PTEN) is an important protein with key modulatory functions in cell growth and survival. PTEN is crucial during embryogenesis and plays a key role in the central nervous system (CNS), where it directly modulates neuronal development and synaptic plasticity. Loss of PTEN signaling function is associated with cognitive deficits and synaptic plasticity impairment. Accordingly, Pten mutations have a strong link with autism spectrum disorder. In this study, neuronal Pten haploinsufficient male mice were subjected to a long-term environmental intervention - intermittent fasting (IF) - and then evaluated for alterations in exploratory, anxiety and learning and memory behaviors. Although no significant effects on spatial memory were observed, mutant mice showed impaired contextual fear memory in the passive avoidance test - an outcome that was effectively rescued by IF. In this study, we demonstrated that IF modulation, in addition to its rescue of the memory deficit, was also required to uncover behavioral phenotypes otherwise hidden in this neuronal Pten haploinsufficiency model.


Assuntos
Disfunção Cognitiva/terapia , Jejum , Haploinsuficiência , PTEN Fosfo-Hidrolase/deficiência , Animais , Transtornos de Ansiedade/terapia , Comportamento Animal , Deficiências da Aprendizagem/terapia , Masculino , Transtornos da Memória/terapia , Camundongos
8.
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1467425

RESUMO

Abstract The composition of the diet of two species of characids (Knodus heteresthes and Moenkhausia lepidura) was evaluated in the Teles Pires and Juruena Rivers, sampled in September and October 2016. We analyzed 226 stomachs of K. heteresthes and 425 of M. lepidura. The analysis of the stomach contents was based on volumetric and frequency of occurrence methods, applying the food importance index. For the similarity of the diets between the species we calculated the niche overlap with Piankas index. Both species in the Juruena River have a dietary preference for arthropods (IAi > 0.95). In the Teles Pires River the diet is concentrated in three sources for both species: arthropods (IAi > 0.52), vegetables (IAi > 0.33) and fish (IAi > 0.12). The diet was dissimilar when compared to environments (ANOSIM, R 0.57, p 0.001) with high trophic niche overlap ( > 0.97), regardless of the sampled environment. In the Teles Pires River, both species were classified as omnivorous with an insectivorous tendency and in the Juruena River the insectivorous behaviour occurs.


Resumo Foram avaliadas a composição da dieta de duas espécies de Characideos (Knodus heteresthes e Moenkhausia lepidura) nos rios Teles Pires e Juruena, amostrados em setembro e outubro de 2016. Analisamos 226 estômagos de K. heteresthes e 425 de M. lepidura, sendo utilizados os métodos volumétrico e frequência de ocorrência, aplicando-se o índice de importância alimentar. Para a similaridade das dietas entre as espécies calculamos a sobreposição de nicho com índice de Pianka. Ambas as espécies no rio Juruena têm preferência alimentar por artrópodes (IAi > 0,95), no rio Teles Pires a dieta concentra-se em três fontes para ambas espécies: artrópodes (IAi > 0,52), vegetais (IAi > 0,33) e peixes (IAi > 0,12). A dieta é dissimilar quando comparados os ambientes (ANOSIM, R 0,57; p 0,001), com alta sobreposição de nicho trófico ( > 0,97), independente do ambiente amostrado. No rio Teles Pires, ambas as espécies foram classificadas como onívoras com tendência insetívora e no rio Juruena ocorre o comportamento insetívoro.

9.
J Obstet Gynaecol ; 32(3): 230-6, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22369394

RESUMO

The objective was to determine the cross-sectional area of the umbilical cord, its diameter and the diameter of its vessels to establish a reference curve for these parameters during pregnancy, through a prospective cross-sectional study, including 2,310 low-risk pregnancies between 12 and 40 weeks' gestation. Means and standard deviations (SDs), plus the 10th, 50th and 90th percentiles for each measurement were calculated using polynomial regression analysis. Mann-Whitney, Kruskal-Wallis and Wilcoxon tests were used for statistical analysis. These parameters increased significantly with gestational age. The area of the cord also varied significantly with parity. Their new reference curves for low risk pregnancies were calculated using polynomial regression, and an almost linear increase in values was found up to 32 weeks of pregnancy, tending to stabilise from then onwards. The regression equation of the umbilical cord area according to gestational age (GA) was: -1.417 + 0.3026*GA-0.008*GA(2) + 0.000007*GA(3) and the degree of adjustment (R(2)) was 0.89.


Assuntos
Ultrassonografia Pré-Natal/normas , Cordão Umbilical/diagnóstico por imagem , Adulto , Brasil , Estudos Transversais , Feminino , Idade Gestacional , Humanos , Gravidez , Estudos Prospectivos , Padrões de Referência , Valores de Referência , Análise de Regressão , Artérias Umbilicais/anatomia & histologia , Artérias Umbilicais/diagnóstico por imagem , Cordão Umbilical/anatomia & histologia , Cordão Umbilical/irrigação sanguínea , Veias Umbilicais/anatomia & histologia , Veias Umbilicais/diagnóstico por imagem
10.
Maturitas ; 57(4): 415-21, 2007 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-17587515

RESUMO

OBJECTIVE: To evaluate the prevalence of premalignant and malignant polyps and their association with menopausal status, hormone therapy and clinical characteristics in perimenopausal and postmenopausal women. METHODS: A surgical database was used to select pre- and postmenopausal women >or=40 years of age, submitted to hysteroscopic resection of endometrial polyps. The medical records of 475 women were reviewed and clinical characteristics and histological diagnosis of resected polyps were assessed. RESULTS: The majority of women had benign endometrial lesions, 78.53% of which were endometrial polyps and 13.47% polyps with simple or complex endometrial hyperplasia without atypia. Polyps with endometrial hyperplasia with atypia comprised 1.05% of cases, while 2.74% were carcinomatous polyps. Analysis using prevalence ratios showed that premalignant and malignant lesions were associated with age and postmenopausal bleeding. Women >60 years of age had a prevalence ratio 3.28 times greater (95%CI: 1.19-9.07) of premalignant or malignant polyps. When only postmenopausal women were evaluated for the effect of age, those over 60 years of age had a prevalence 5.31 times greater (95%CI: 1.22-23.09), while those with postmenopausal bleeding had an age-adjusted prevalence ratio of 3.71 (95%CI: 1.21-11.34) compared to asymptomatic women. No significant association was found between arterial hypertension, diabetes mellitus, obesity, use of hormone therapy or tamoxifen and premalignancy or malignancy. CONCLUSIONS: There was a low prevalence of premalignant and malignant lesions in endometrial polyps. Older women and those with postmenopausal bleeding had a greater prevalence of malignancy and in these cases hysteroscopic resection of endometrial polyps is mandatory.


Assuntos
Neoplasias do Endométrio/epidemiologia , Pólipos/epidemiologia , Pós-Menopausa , Pré-Menopausa , Doenças Uterinas/epidemiologia , Idoso , Neoplasias do Endométrio/etiologia , Neoplasias do Endométrio/patologia , Feminino , Terapia de Reposição Hormonal , Humanos , Histeroscopia , Pessoa de Meia-Idade , Pólipos/complicações , Pólipos/patologia , Prevalência , Estudos Retrospectivos , Doenças Uterinas/complicações , Doenças Uterinas/patologia
11.
Biochim Biophys Acta ; 1413(1): 55-61, 1999 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-10524262

RESUMO

Cytochrome c" from Methylophilus methylotrophus is an unusual monohaem protein that undergoes a major redox-linked spin-state transition: one of the two axial histidines bound to the iron in the oxidised form is detached upon reduction and a proton is taken up. A 3.5-kb DNA fragment, containing the gene encoding cytochrome c" (cycA), has been cloned and sequenced. The cytochrome c" gene codes for a pre-protein with a typical prokaryotic 20-residue signal sequence, suggesting that the protein is synthesised as a precursor which is processed during its secretion into the periplasm. The C-terminus of cytochrome c" has homology with the corresponding region of an oxygen-binding haem protein (SHP) from phototrophically grown Rhodobacter sphaeroides. SHP is similar in size and in the location of its haem-binding site. Immediately downstream from cytochrome c" a second open reading frame (ORF) codes for a 23-kDa protein with similarity to the cytochrome b-type subunit of Ni-Fe hydrogenase. The possibility of coordinated expression of cycA and this ORF is discussed.


Assuntos
Grupo dos Citocromos c/genética , Genes Bacterianos , Bactérias Aeróbias Gram-Negativas/genética , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , Grupo dos Citocromos c/química , DNA Antissenso/química , DNA Bacteriano/química , Dados de Sequência Molecular , Fases de Leitura Aberta , Óperon , Alinhamento de Sequência
12.
J Virol Methods ; 66(2): 211-8, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9255732

RESUMO

An improved solid-phase enzyme linked immunosorbent assay (ELISA) using monoclonal antibodies was developed to detect an African swine fever virus protein (VP73) in pig samples. The use of monoclonal antibodies against VP73 allowed a sensitive and specific sandwich ELISA. This assay detected a limiting antigen concentration of 0.05 microgram/ml of VP73, lower than the detection limit of 0.6 microgram/ml obtained by using polyclonal antibodies by the same ELISA. The whole virus particle was detected with this method to a limit of 2.3 x 10(2) PFU/ml. At the same time, an indirect ELISA was developed to detect ASFV antibodies. The results also indicate that this method may be a useful technique for epidemiological surveys.


Assuntos
Vírus da Febre Suína Africana/imunologia , Febre Suína Africana/diagnóstico , Anticorpos Antivirais/sangue , Antígenos Virais/sangue , Ensaio de Imunoadsorção Enzimática/métodos , Vírus da Febre Suína Africana/isolamento & purificação , Animais , Anticorpos Monoclonais , Antígenos Virais/isolamento & purificação , Sensibilidade e Especificidade , Suínos , Proteínas Estruturais Virais/sangue , Proteínas Estruturais Virais/isolamento & purificação
13.
Virus Genes ; 15(3): 271-4, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9482593

RESUMO

Sequencing of the left variable region of the L60V Vero cell-adapted strain of African swine fever virus (ASFV) showed the presence of three genes belonging to multigene family 110 (MGF110) and of a fourth unrelated gene. This gene was separated from the MGF110 genes by a region rich in direct repeats. The first MGF110 gene, V1L, with 104 codons, was only moderately related to the other two, W1L and W2L, with 124 and 80 codons, respectively. These two genes were closely related, W2L being a truncated duplication of W1L. Homology matrix analysis of the sequence against itself showed the existence of a repeated block corresponding to the central conserved domain of the three genes, flanked by two other repeated blocks in W1L and W2L. The comparison of the organization of the left variable region of ASFV L60V with that of field isolates and other adapted viruses revealed that adaptation of unrelated viruses resulted in similar large deletions that map, in their right boundaries, exactly at the same positions in the intergenic repeat-rich region.


Assuntos
Vírus da Febre Suína Africana/genética , Genes Virais , Família Multigênica , Adaptação Biológica , Vírus da Febre Suína Africana/fisiologia , Animais , Sequência de Bases , Chlorocebus aethiops , DNA Viral , Dados de Sequência Molecular , Sequências Repetitivas de Ácido Nucleico , Células Vero
14.
Virology ; 214(1): 72-81, 1995 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-8525640

RESUMO

African swine fever virus (ASFV) growth and plaque formation were inhibited by phosphonoacetic acid (PAA) concentrations of 200 micrograms/ml or more. One spontaneous mutant and two mutants isolated from mutagenized virus were resistant to PAA inhibition and showed practically normal viral DNA synthesis in the presence of PAA. DNA polymerase activity present in the cytoplasmic fraction from cells infected with the mutants required 10-fold higher concentrations of PAA for inhibition compared to equivalent inhibition of the wild-type enzyme. Like wild-type virus, the PAA-resistant mutants were resistant to inhibition by aphidicolin. Marker rescue analysis with mutant DNA fragments covering different regions of the ASFV DNA polymerase gene mapped the mutations within a fragment which was cloned and sequenced. A single nucleotide and amino acid change was assigned to each mutant. Two of the PAA-resistant mutations lie within the highly conserved region II common to alpha-like DNA polymerases, which has been implicated in pyrophosphate binding and probably also in dNTP binding. The other mutation was localized to within a region of moderate homology among viral DNA polymerases close to one of the motifs allegedly considered as constituting the 3'-5' exonuclease active site.


Assuntos
Vírus da Febre Suína Africana/efeitos dos fármacos , Vírus da Febre Suína Africana/genética , Antivirais/farmacologia , Ácido Fosfonoacéticos/farmacologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Chlorocebus aethiops , DNA Viral , DNA Polimerase Dirigida por DNA/genética , Resistência Microbiana a Medicamentos/genética , Genes Virais , Marcadores Genéticos , Humanos , Dados de Sequência Molecular , Mutação , Homologia de Sequência de Aminoácidos , Células Vero
15.
Biochim Biophys Acta ; 1256(3): 396-402, 1995 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-7786905

RESUMO

Previous purification of a commercial lipolytic preparation from Chromobacterium viscosum using gel filtration chromatography yielded two enzymatically active fractions, named lipases A and B. Characterization of these fractions by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that lipase A consisted of a high molecular weight aggregate of lipase protein with lipopolysaccharides. This complex could be dissociated by treatment with EDTA-Tris buffer containing the non-ionic detergent n-octyl-beta-D-glucopyranoside and subsequent isoelectric focusing in an agarose gel containing the same detergent. Both lipases A and B revealed a major peak corresponding to an isoelectric point of 7.1. SDS-PAGE analysis of lipases A and B after purification by gel filtration or by IEF revealed one major protein band of M(r) of 33 K. Determination of N-terminal amino acid sequences confirmed that both fractions A and B contained the same lipase protein. Furthermore, the N-terminal amino acid sequence of the C. viscosum lipase was identical to the one of Pseudomonas glumae lipase.


Assuntos
Chromobacterium/enzimologia , Lipase/isolamento & purificação , Pseudomonas/enzimologia , Sequência de Aminoácidos , Eletroforese em Gel de Poliacrilamida , Immunoblotting , Focalização Isoelétrica , Ponto Isoelétrico , Lipase/química , Lipopolissacarídeos/química , Dados de Sequência Molecular , Peso Molecular , Homologia de Sequência de Aminoácidos
16.
Virology ; 207(2): 392-9, 1995 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-7886943

RESUMO

Recombinant plasmids containing African swine fever virus (ASFV) DNA fragments covering all the virus genome were transfected into infected cells in order to detect viral origins of DNA replication. Plasmid replication was monitored by sensitivity to MboI, which cleaves only replicated, unmethylated DNA, and resistance to DpnI, which cleaves only the same methylated sequence. All the recombinants replicated to a similar extent, indicating that ASFV does not use a preferred origin for DNA replication. Circular plasmids without viral inserts were also replicated, but linearized plasmids or lambda bacteriophage DNA were not replicated. Replicated plasmid DNA began to accumulate with a time course similar to viral DNA, starting between 6 and 12 hr p.i. and increasing steadily for about 18 hr. This apparent dependence on viral functions was confirmed by the sensitivity of plasmid replication to phosphonoacetic acid and resistance to aphidicolin and by the reduction of replication in cells infected with a mutant defective in DNA replication. Replicated plasmid DNA present as unit length circles and as large dimension forms, probably head-to-tail concatemers. The results of two-dimensional electrophoresis (neutral/alkaline) favor a rolling-circle mechanism for plasmid DNA replication.


Assuntos
Vírus da Febre Suína Africana/genética , Replicação do DNA , DNA Viral/biossíntese , DNA Viral/genética , Plasmídeos/genética , Vírus da Febre Suína Africana/metabolismo , Animais , Chlorocebus aethiops , DNA Viral/química , Eletroforese em Gel Bidimensional , Amplificação de Genes , Cinética , Conformação de Ácido Nucleico , Recombinação Genética , Transfecção , Células Vero
17.
Virology ; 203(1): 193-6, 1994 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-8030278

RESUMO

The 4-kb terminal BclI fragment of African swine fever virus (ASFV) DNA, including the inverted terminal repetition (ITR), was cloned and sequenced. The sequence showed that the 2.1-kb ITR is composed of a 301-nucleotide-long unique sequence immediately adjacent to the terminal hairpin loop, a set of 38 tandem direct repeats of a 34-nucleotide degenerate sequence, another unique intervening sequence with no remarkable features, and a set of 5 tandem repeats of a 27-nucleotide unit unrelated in sequence to the 34-nucleotide repeat unit. Several short repeats were found scattered along the most distal unique sequence. The proximal half of the terminal fragment possesses one complete and one interrupted copy of genes belonging to multigene family 360.


Assuntos
Vírus da Febre Suína Africana/genética , Genoma Viral , Telômero/química , Animais , Sequência de Bases , Dados de Sequência Molecular , Fases de Leitura Aberta , Sequências Repetitivas de Ácido Nucleico , Células Vero
18.
Nucleic Acids Res ; 22(2): 208-13, 1994 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-8121806

RESUMO

The DNA polymerase gene of African swine fever virus (ASFV) was mapped by marker rescue experiments using a phosphonoacetic acid-resistant mutant and hybridization with an oligonucleotide probe designed from the most conserved motif of family B DNA polymerases. Viral DNA fragments mapping in this region were cloned and sequenced. An open reading frame coding for a 1244 amino acid long peptide with a molecular mass of 142.5 kDa was determined from the sequence. A unique feature of ASFV DNA polymerase is the presence of 13 tandem repeats of the sequence Ala-Gly-Asp-Pro near the carboxyl end of the molecule. Comparison with 30 sequences of alpha-like DNA polymerases of cellular and viral origin showed that ASFV DNA polymerase has all the conserved motifs of family B DNA polymerases. A 3.9 kb transcript was detected by Northern hybridization and the transcription initiation and termination sites were mapped by S1 analysis and primer extension. Late transcription was initiated at a site different from the early transcription initiation site. A 145 kDa protein, consistent with the size of the gene, was identified by an in situ enzyme assay after gel electrophoresis of infected cell extracts.


Assuntos
Vírus da Febre Suína Africana/genética , DNA Polimerase Dirigida por DNA/genética , Vírus da Febre Suína Africana/enzimologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Chlorocebus aethiops , Sequência Conservada , DNA Polimerase Dirigida por DNA/química , Dados de Sequência Molecular , Mapeamento por Restrição , Homologia de Sequência de Aminoácidos , Transcrição Gênica , Células Vero
19.
Virology ; 191(1): 498-501, 1992 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1413523

RESUMO

African swine fever virus (ASFV) induces the synthesis of a virus-specific DNA polymerase, which is inhibited by phosphonoacetic acid and cytosine arabinoside. In contrast to all other alpha-like DNA polymerases of DNA viruses, ASFV-specific DNA polymerase is resistant to aphidicolin. Concentrations of the drug as high as 160 microM had no effect on virus production or plaquing efficiency. The resistance of ASFV DNA polymerase to aphidicolin was confirmed by analyzing the effect of the drug on viral DNA synthesis. A moderate inhibition of viral DNA synthesis was observed when aphidicolin was added immediately after virus adsorption but normal synthesis occurred, with a peak at 10 hr p.i., when the drug was added at 2 or 4 hr p.i. This suggests that a very early phase of ASFV DNA replication is sensitive to aphidicolin and is probably catalyzed by a different enzyme. An in vitro assay of DNA polymerase activity was used to assay the sensitivity of the virus-specific DNA polymerase to inhibitors. In correspondence to the results observed in vivo, phosphonoacetic acid strongly inhibited the enzyme activity, whereas aphidicolin had no effect. Resistance to aphidicolin was independent of the concentration of dCTP used in the assay. Three independent ASFV mutants resistant to phosphonoacetic acid showed the same resistance to aphidicolin as wild type virus.


Assuntos
Vírus da Febre Suína Africana/enzimologia , Afidicolina/farmacologia , DNA Polimerase Dirigida por DNA/efeitos dos fármacos , Vírus da Febre Suína Africana/efeitos dos fármacos , Citarabina/farmacologia , DNA Viral/biossíntese , DNA Polimerase Dirigida por DNA/metabolismo , Resistência Microbiana a Medicamentos , Cinética , Ácido Fosfonoacéticos/farmacologia
20.
Virology ; 187(1): 73-83, 1992 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-1736545

RESUMO

Infection of Vero cells with African swine fever virus (ASFV) resulted in a marked increase in ribonucleotide reductase activity. The induction of ribonucleotide reductase was detected early after infection and was proportional to the multiplicity of infection. Inhibition of viral DNA replication did not affect the induction of the enzyme. Several characteristics could distinguish the virus-induced from the normal cell enzyme. ASFV-induced ribonucleotide reductase was inhibited by magnesium, was more strongly inhibited by hydroxyurea, and had a fourfold lower Km. The virus-induced enzyme was inhibited by deoxyribonucleoside triphosphates and by ATP. The isolation of hydroxyurea-resistant ASFV mutants provided genetic evidence for the viral origin of the induced ribonucleotide reductase. The resistance to hydroxyurea was due to a threefold overproduction of ribonucleotide reductase, as compared to enzyme induction by wild-type ASFV. Hydroxyurea had similar effect in vitro on ribonucleotide reductases induced by wild-type or mutant virus. The gene for the small subunit of the viral enzyme was mapped within a 2.3-kb fragment by hybridization with an oligonucleotide probe designed from a conserved aminoacid sequence of eukaryotic and viral ribonucleotide reductases.


Assuntos
Vírus da Febre Suína Africana/enzimologia , Ribonucleotídeo Redutases/biossíntese , Vírus da Febre Suína Africana/genética , Vírus da Febre Suína Africana/fisiologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Southern Blotting , DNA Viral/biossíntese , Indução Enzimática , Hidroxiureia/farmacologia , Cinética , Dados de Sequência Molecular , Mutação/genética , Ribonucleotídeo Redutases/genética , Ribonucleotídeo Redutases/isolamento & purificação , Ribonucleotídeo Redutases/metabolismo , Células Vero , Replicação Viral
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