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1.
Catheter Cardiovasc Interv ; 98(5): E687-E694, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34347935

RESUMO

OBJECTIVES: To investigate a novel suspended radiation shield (ZG), in reducing operator radiation exposure during cardiology interventions. BACKGROUND: Radiation exposure to the operator remains an occupational health hazard in the cardiac catheterization laboratory. METHODS: An anthropomorphic mannequin simulating an operator was placed near a phantom, simulating a patient. To measure the operator dose reduction, thermoluminescent detectors (TLDs) were inserted into the head and into the eye bulbs of the mannequin, while electronic dosimeters were positioned on the temple and at the level of the thyroid. Measurements were performed without and with the ZG system in place. Physician exposure was subsequently prospectively measured on the torso, on the left eye and on upper arm using the same electronic dosimeters, during clinical procedures (coronary angiography (CA) and percutaneous coronary intervention (PCI)). The physicians dose reduction was assessed by comparing operator dose when using traditional radioprotection garments (Phase 0) versus using the ZG system (Phase 1). RESULTS: Dose reductions as measured on the mannequin ranged from 66% to the head, to 100% to the torso. No dose was detected at the level of the torso and thyroid with ZG. When comparing CA and PCI procedures between Phase 0 and Phase 1, a significant difference (p < 0.001) was found for the left eye and the left wrist. Dose reduction as measured during clinical procedures for left eye/upper arm were on average 78.9%/95.6% for CA and 83.0%/93.0% for PCI, respectively (p < 0.001 for both). CONCLUSIONS: The ZG systems has a great potential to significantly reduce operator dose through the creation of a nearly zero-radiation work environment.


Assuntos
Cardiologia , Exposição Ocupacional , Intervenção Coronária Percutânea , Exposição à Radiação , Proteção Radiológica , Angiografia Coronária/efeitos adversos , Humanos , Exposição Ocupacional/efeitos adversos , Intervenção Coronária Percutânea/efeitos adversos , Doses de Radiação , Exposição à Radiação/efeitos adversos , Exposição à Radiação/prevenção & controle , Radiografia Intervencionista/efeitos adversos , Fatores de Risco , Resultado do Tratamento
2.
Food Environ Virol ; 11(1): 52-64, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30426392

RESUMO

Lack of wastewater treatment efficiency causes receiving seawaters and bivalve molluscan shellfish to become contaminated, which can lead to public health issues. Six wastewater samples, five seawater samples and three batches of giant clams from Tahiti (French Polynesia) were investigated for the presence of enteric viruses, but also if present, for the diversity, infectivity and integrity of human adenoviruses (HAdV). Enteroviruses (EV), sapoviruses (SaV) and human polyomaviruses (HPyV) were detected in all wastewater samples. In decreasing frequency, noroviruses (NoV) GII and HAdV, rotaviruses (RoV), astroviruses (AsV), NoV GI and finally hepatitis E viruses (HEV) were also observed. Nine types of infectious HAdV were identified. HPyV and EV were found in 80% of seawater samples, NoV GII in 60%, HAdV and SaV in 40% and AsV and RoV in 20%. NoV GI and HEV were not detected in seawater. Intact and infectious HAdV-41 were detected in one of the two seawater samples that gave a positive qPCR result. Hepatitis A viruses were never detected in any water types. Analysis of transcriptomic data from giant clams revealed homologues of fucosyltransferases (FUT genes) involved in ligand biosynthesis that strongly bind to certain NoV strains, supporting the giant clams ability to bioaccumulate NoV. This was confirmed by the presence of NoV GII in one of the three batches of giant clams placed in a contaminated marine area. Overall, all sample types were positive for at least one type of virus, some of which were infectious and therefore likely to cause public health concerns.


Assuntos
Bivalves/virologia , Água do Mar/virologia , Vírus/isolamento & purificação , Águas Residuárias/virologia , Animais , Reação em Cadeia da Polimerase , Polinésia , Alimentos Marinhos/virologia , Vírus/genética
3.
Oncotarget ; 9(45): 27809-27822, 2018 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-29963239

RESUMO

APOBEC3 are cytidine deaminases that convert cytidine to uridine residues. APOBEC3A and APOBEC3B enzymes able to target genomic DNA are involved in oncogenesis of a sizeable proportion of human cancers. While the APOBEC3 locus is conserved in mammals, it encodes from 1-7 genes. APOBEC3A is conserved in most mammals, although absent in pigs, cats and throughout Rodentia whereas APOBEC3B is restricted to the Primate order. Here we show that the rabbit APOBEC3 locus encodes two genes of which APOBEC3A enzyme is strictly orthologous to human APOBEC3A. The rabbit enzyme is expressed in the nucleus and the cytoplasm, it can deaminate cytidine, 5-methcytidine residues, nuclear DNA and induce double-strand DNA breaks. The rabbit APOBEC3A enzyme is negatively regulated by the rabbit TRIB3 pseudokinase protein which is guardian of genome integrity, just like its human counterpart. This indicates that the APOBEC3A/TRIB3 pair is conserved over approximately 100 million years. The rabbit APOBEC3A gene is widely expressed in rabbit tissues, unlike human APOBEC3A. These data demonstrate that rabbit could be used as a small animal model for studying APOBEC3 driven oncogenesis.

4.
Int J Mol Sci ; 19(6)2018 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-29914107

RESUMO

The assumption that cellulose degradation and assimilation can only be carried out by heterotrophic organisms was shattered in 2012 when it was discovered that the unicellular green alga, Chlamydomonas reinhardtii (Cr), can utilize cellulose for growth under CO2-limiting conditions. Publications of genomes/transcriptomes of the colonial microalgae, Gonium pectorale (Gp) and Volvox carteri (Vc), between 2010⁻2016 prompted us to look for cellulase genes in these algae and to compare them to cellulases from bacteria, fungi, lower/higher plants, and invertebrate metazoans. Interestingly, algal catalytic domains (CDs), belonging to the family GH9, clustered separately and showed the highest (33⁻42%) and lowest (17⁻36%) sequence identity with respect to cellulases from invertebrate metazoans and bacteria, respectively, whereas the identity with cellulases from plants was only 27⁻33%. Based on comparative multiple alignments and homology models, the domain arrangement and active-site architecture of algal cellulases are described in detail. It was found that all algal cellulases are modular, consisting of putative novel cysteine-rich carbohydrate-binding modules (CBMs) and proline/serine-(PS) rich linkers. Two genes were found to encode a protein with a putative Ig-like domain and a cellulase with an unknown domain, respectively. A feature observed in one cellulase homolog from Gp and shared by a spinach cellulase is the existence of two CDs separated by linkers and with a C-terminal CBM. Dockerin and Fn-3-like domains, typically found in bacterial cellulases, are absent in algal enzymes. The targeted gene expression analysis shows that two Gp cellulases consisting, respectively, of a single and two CDs were upregulated upon filter paper addition to the medium.


Assuntos
Celulase/química , Clorófitas/enzimologia , Proteínas de Plantas/química , Domínio Catalítico , Celulase/genética , Celulase/metabolismo , Clorófitas/genética , Evolução Molecular , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Homologia de Sequência
5.
Int J Environ Res Public Health ; 12(9): 11910-28, 2015 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-26404350

RESUMO

BACKGROUND: The occurrence of faecal pathogens in drinking water resources constitutes a threat to the supply of safe drinking water, even in industrialized nations. To efficiently assess and monitor the risk posed by these pathogens, sampling deserves careful design, based on preliminary knowledge on their distribution dynamics in water. For the protozoan pathogens Cryptosporidium and Giardia, only little is known about their spatial distribution within drinking water supplies, especially at fine scale. METHODS: Two-dimensional distribution maps were generated by sampling cross-sections at meter resolution in two different zones of a drinking water reservoir. Samples were analysed for protozoan pathogens as well as for E. coli, turbidity and physico-chemical parameters. RESULTS: Parasites displayed heterogeneous distribution patterns, as reflected by significant (oo)cyst density gradients along reservoir depth. Spatial correlations between parasites and E. coli were observed near the reservoir inlet but were absent in the downstream lacustrine zone. Measurements of surface and subsurface flow velocities suggest a role of local hydrodynamics on these spatial patterns. CONCLUSION: This fine-scale spatial study emphasizes the importance of sampling design (site, depth and position on the reservoir) for the acquisition of representative parasite data and for optimization of microbial risk assessment and monitoring. Such spatial information should prove useful to the modelling of pathogen transport dynamics in drinking water supplies.


Assuntos
Cryptosporidium/isolamento & purificação , Água Potável/parasitologia , Escherichia coli/isolamento & purificação , Giardia/isolamento & purificação , Qualidade da Água , Luxemburgo , Medição de Risco , Recursos Hídricos
6.
Food Environ Virol ; 2015 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-25917314

RESUMO

This study aims to establish a straightforward and original workflow for high-throughput typing of human adenoviruses (HAdVs) in environmental samples. Occurrence of HAdVs in water is well documented worldwide, but data on diversity of HAdV types circulating in water are scarcely available. Here, the characterisation of viral particles was performed by determination of amplicon sequences using a next-generation sequencing (NGS) approach. Adenoviral DNA was either directly isolated from wastewater or river water concentrates or after a cell culture passage. Genome amplification targeted a hyper variable region of the hexon gene, allowing the discrimination of the 54 human adenoviral types described until now. After read generation on the benchtop MiSeq platform (Illumina), data were analysed using the Mothur software for identification of all HAdV species and types simultaneously present in a unique sample. NGS results showed a relatively wide HAdV diversity of up to six types in one sample, whereas Sanger sequencing always only retrieved the dominant one. Detected types included HAdV-1, HAdV-2, HAdV-3, HAdV-6, HAdV-12, HAdV-31, HAdV-40 and HAdV-41, HAdV-41 being the most abundant in tested samples. In addition, the influence of the cell line (A549 vs 293A cells) on the infectious HAdV typing results was clearly determined. The 293A appeared to be the most suitable cell line allowing the detection of a larger diversity of infectious HAdVs and reflecting a more realistic initial species distribution than using the A549 cells. These findings demonstrated the feasibility of amplicon sequencing NGS approach to identify viruses in complex environmental water samples.

7.
Sci Total Environ ; 472: 1023-35, 2014 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-24345862

RESUMO

Because of their significant public health impact, waterborne Cryptosporidium and Giardia have been monitored in surface water in order to assess microbial quality of water bodies used for drinking water production and/or for recreational purposes. In this context, sampling strategy is of key importance and should be representative enough to appropriately assess the related microbial risk. This, however, requires sound knowledge on the behaviour of both pathogens in water. In the present study, the spatial and temporal distribution of Cryptosporidium and Giardia was explored in the rural Upper-Sûre watershed used for drinking water production in Luxembourg. By subdividing it into three compartments including (i) sub-catchments, (ii) the Sûre River fed by the sub-catchments and (iii) the Upper-Sûre reservoir fed by the Sûre River, parasite distribution was assessed using sampling designs adapted to the hydro-dynamic characteristics of the respective compartments. Results highlighted the high spatial and temporal variability in parasite distribution at watershed scale, as well as the prevalence of Giardia over Cryptosporidium. Besides land use features and catchment characteristics, hydro-climatology appeared to be a major driver of parasite behaviour in the watershed. It introduced a seasonal trend in their occurrence, highest densities being detected during the wet season. Peaks of contamination triggered out by rainfall-induced runoff were further observed in the three compartments. In the Sûre River, Cryptosporidium and Giardia fluxes peaked at 10(9) and 10(10) (oo)cysts.d(-1), respectively, and were discharged into the drinking water reservoir, where they underwent a 2 to 3 log10 removal rate. Despite this, parasite fluxes entering the drinking water treatment plant were still high (10(6) to 10(7) (oo)cysts.d(-1)) and stressed on the need for improved watershed management upstream the water treatment barrier. The catchment-wide analysis described here constitutes a valuable tool for assessment of catchment microbial dynamics, especially within the framework of Water Safety Plans.


Assuntos
Cryptosporidium/crescimento & desenvolvimento , Água Potável/parasitologia , Giardia/crescimento & desenvolvimento , Recursos Hídricos/estatística & dados numéricos , Abastecimento de Água/estatística & dados numéricos , Criptosporidiose/epidemiologia , Monitoramento Ambiental , Giardíase/epidemiologia , Medição de Risco , Análise Espaço-Temporal
8.
J Virol Methods ; 194(1-2): 235-41, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23850702

RESUMO

Development of rapid, sensitive and specific methods for detection of infectious enteric viruses in water is challenging but crucial for gaining reliable information for risk assessment. An immunocapture real-time PCR (IC-qPCR) was designed to detect jointly the two major viral particle components, i.e. the capsid protein and the viral genome. Targeting both constituents helps circumventing the technical limits of cell culture approaches and the inability of PCR based methods to predict the infectious status. Two waterborne pathogenic virus models, human adenovirus types 2 and 41, were chosen for this study. IC-qPCR showed a detection limit of 10MPNCU/reaction with a dynamic range from 10(2) to 10(6)MPNCU/reaction. Sensitivity was thus 100-fold higher compared to ELISA-based capture employing the same anti-hexon antibodies. After optimisation, application on environmental water samples was validated, and specificity towards the targeted virus types was obtained through the qPCR step. Heat-treated pure samples as well as surface water samples brought evidence that this method achieves detection of encapsidated viral genomes while excluding free viral genome amplification. As a consequence, adenovirus concentrations estimated by IC-qPCR were below those calculated by direct qPCR. The results demonstrate that the IC-qPCR method is a sensitive and rapid tool for detecting, in a single-tube assay, structurally intact and thus potentially infectious viral particles in environmental samples.


Assuntos
Adenovírus Humanos/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real/métodos , Manejo de Espécimes/métodos , Virologia/métodos , Microbiologia da Água , Adenovírus Humanos/genética , Adenovírus Humanos/imunologia , Proteínas do Capsídeo/imunologia , DNA Viral/genética , Sensibilidade e Especificidade , Fatores de Tempo
9.
Appl Microbiol Biotechnol ; 97(9): 4159-66, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23558583

RESUMO

In order to provide a more suitable response to public health concerns, we improved the detection of infectious human adenoviruses in water by optimising the commonly used integrated cell culture-PCR method. Risk evaluation studies seek for rapid detection of infectious adenoviruses, including the enteric types 40 and 41 that are considered as the second most common agents of gastroenteritis in children next to rotaviruses. The here-employed 293A cell line used for infectious status assessment showed its ability to multiply adenoviruses including type 41. Two modifications were moreover applied to the workflow for viral detection. The first occurred at the nucleic acid extraction step performed directly on all infected cells, while the second was the application of real-time quantitative PCR as detection tool. All adaptations led to a 3-day reduction of the response delay and an improved sensitivity especially for the enteric adenoviral types. The infectious status of laboratory strain types 2 and 41 was demonstrated by a more than 2-log10 increase in genome quantity. These conclusions were confirmed and reinforced by the analysis of water samples applying the improved assay. Naturally occurring infectious adenoviruses were detected in wastewater and river water, within 2 days. Types belonging to the species human adenoviruses C and type 31 were observed, but the most frequently identified type was 41 (71 % of identified sequences, n = 34). This highlights the usefulness of our method for a wide range of types, and especially for the most prevalent and public health-relevant enteric adenoviruses.


Assuntos
Infecções por Adenovirus Humanos/virologia , Adenovírus Humanos/genética , Adenovírus Humanos/patogenicidade , Linhagem Celular , Humanos , Reação em Cadeia da Polimerase
10.
J Endovasc Ther ; 19(1): 115-20, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22313211

RESUMO

PURPOSE: To describe a case of multiple thoracoabdominal aneurysms of tuberculous origin treated in an endovascular procedure with the Multilayer stent. CASE REPORT: A 16-year-old girl had been treated 4 years previously for a ruptured abdominal aortic aneurysm of tuberculous origin. Due to the presence of 4 rapidly evolving saccular aneurysms of the descending thoracic aorta and a fusiform aneurysm of the suprarenal aorta, an endovascular solution was chosen after the patient refused open surgery. Three uncovered Multilayer stents (16×40, 16×80, and 16×80 mm) were successively implanted with a 1-cm overlap from the left subclavian artery to cover the entire aneurysmal segment of the thoracoabdominal aorta to above the renal arteries. At 18 months, serial imaging studies have shown disappearance of some aneurysms and regression of others. CONCLUSION: In this young patient, the endovascular treatment of a thoracoabdominal aneurysm with an uncovered stent made it possible to stabilize the aneurysm process without exposing the patient to the high morbidity and mortality of open surgery.


Assuntos
Aneurisma Infectado/cirurgia , Aneurisma da Aorta Torácica/cirurgia , Implante de Prótese Vascular/instrumentação , Procedimentos Endovasculares/instrumentação , Stents , Tuberculose Cardiovascular/cirurgia , Adolescente , Aneurisma Infectado/diagnóstico por imagem , Aneurisma Infectado/microbiologia , Aneurisma da Aorta Torácica/diagnóstico por imagem , Aneurisma da Aorta Torácica/microbiologia , Aortografia/métodos , Feminino , Humanos , Mycobacterium tuberculosis/isolamento & purificação , Desenho de Prótese , Fatores de Tempo , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Tuberculose Cardiovascular/diagnóstico por imagem , Tuberculose Cardiovascular/microbiologia
11.
PLoS One ; 7(1): e30036, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22272271

RESUMO

The APOBEC3 gene cluster encodes six cytidine deaminases (A3A-C, A3DE, A3F-H) with single stranded DNA (ssDNA) substrate specificity. For the moment A3A is the only enzyme that can initiate catabolism of both mitochondrial and nuclear DNA. Human A3A expression is initiated from two different methionine codons M1 or M13, both of which are in adequate but sub-optimal Kozak environments. In the present study, we have analyzed the genetic diversity among A3A genes across a wide range of 12 primates including New World monkeys, Old World monkeys and Hominids. Sequence variation was observed in exons 1-4 in all primates with up to 31% overall amino acid variation. Importantly for 3 hominids codon M1 was mutated to a threonine codon or valine codon, while for 5/12 primates strong Kozak M1 or M13 codons were found. Positive selection was apparent along a few branches which differed compared to positive selection in the carboxy-terminal of A3G that clusters with A3A among human cytidine deaminases. In the course of analyses, two novel non-functional A3A-related fragments were identified on chromosome 4 and 8 kb upstream of the A3 locus. This qualitative and quantitative variation among primate A3A genes suggest that subtle differences in function might ensue as more light is shed on this increasingly important enzyme.


Assuntos
Códon/genética , Citidina Desaminase/genética , Evolução Molecular , Primatas/genética , Proteínas/genética , Desaminase APOBEC-3G , Sequência de Aminoácidos , Animais , Sequência de Bases , Linhagem Celular Tumoral , Cromossomos Humanos Par 4/genética , Citidina Desaminase/classificação , Citidina Desaminase/metabolismo , Variação Genética , Células HeLa , Humanos , Microscopia de Fluorescência , Dados de Sequência Molecular , Filogenia , Primatas/classificação , Primatas/metabolismo , Proteínas/classificação , Proteínas/metabolismo , Seleção Genética , Homologia de Sequência de Aminoácidos , Especificidade da Espécie
12.
Proc Natl Acad Sci U S A ; 108(12): 4858-63, 2011 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-21368204

RESUMO

The human APOBEC3 (A3A-A3H) locus encodes six cytidine deaminases that edit single-stranded DNA, the result being DNA peppered with uridine. Although several cytidine deaminases are clearly restriction factors for retroviruses and hepadnaviruses, it is not known if APOBEC3 enzymes have roles outside of these settings. It is shown here that both human mitochondrial and nuclear DNA are vulnerable to somatic hypermutation by A3 deaminases, with APOBEC3A standing out among them. The degree of editing is much greater in patients lacking the uracil DNA-glycolyase gene, indicating that the observed levels of editing reflect a dynamic composed of A3 editing and DNA catabolism involving uracil DNA-glycolyase. Nonetheless, hyper- and lightly mutated sequences went hand in hand, raising the hypothesis that recurrent low-level mutation by APOBEC3A could catalyze the transition from a healthy to a cancer genome.


Assuntos
Citosina Desaminase/metabolismo , DNA Mitocondrial/metabolismo , Loci Gênicos , Genoma Humano , Mutação , Desaminases APOBEC , Citidina Desaminase , Citosina Desaminase/genética , DNA Mitocondrial/genética , Feminino , Células HeLa , Hepadnaviridae/genética , Hepadnaviridae/metabolismo , Humanos , Masculino , Neoplasias/enzimologia , Neoplasias/genética , Retroviridae/genética , Retroviridae/metabolismo , Uracila-DNA Glicosidase/deficiência , Uracila-DNA Glicosidase/genética , Uracila-DNA Glicosidase/metabolismo
13.
Environ Monit Assess ; 179(1-4): 163-75, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20890786

RESUMO

Starting in 2006, a monitoring of Giardia lamblia and Cryptosporidium parvum occurrence was conducted for 2 years in the largest drinking water reservoir of Luxembourg (Esch-sur-Sûre reservoir) using microscopy and qPCR techniques. Parasite analyses were performed on water samples collected from three sites: site A located at the inlet of the reservoir, site B located 18 km downstream site A, at the inlet of the drinking water treatment plant near the dam of the reservoir and site C where the finished drinking water is injected in the distribution network. Results show that both parasites are present in the reservoir throughout the year with a higher occurrence of G. lamblia cysts compared to C. parvum oocysts. According to our results, only 25% of the samples positive by microscopy were confirmed by qPCR. (Oo)cyst concentrations were 10 to 100 times higher at site A compared to site B and they were positively correlated to the water turbidity and negatively correlated to the temperature. Highest (oo)cyst concentrations were observed in winter. In contrast, no relationship between the concentrations of (oo)cysts in the reservoir and rain events could be established. Though a correlation has been observed between both parasites and faecal indicators in the reservoir, some discrepancies highlight that the latter do not represent a reliable tool to predict the presence/absence of these pathogenic protozoa. In summer 2007, the maximal risk of parasite infection per exposure event for swimmers in the reservoir was estimated to be 0.0015% for C. parvum and 0.56% for G. lamblia. Finally, no (oo)cysts could be detected in large volumes of finished drinking water.


Assuntos
Cryptosporidium parvum/crescimento & desenvolvimento , Monitoramento Ambiental/métodos , Água Doce/parasitologia , Giardia lamblia/crescimento & desenvolvimento , Abastecimento de Água/análise , Cryptosporidium parvum/genética , Cryptosporidium parvum/isolamento & purificação , Giardia lamblia/genética , Giardia lamblia/isolamento & purificação , Microscopia de Fluorescência , Oocistos , Medição de Risco , Poluição da Água/análise , Poluição da Água/estatística & dados numéricos , Abastecimento de Água/estatística & dados numéricos
14.
J Virol ; 85(5): 2458-62, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21159878

RESUMO

We sought to examine ADAR-1 editing of measles and influenza virus genomes derived from inactivated seasonal influenza and live attenuated measles virus vaccines grown on chicken cells as the culture substrate. Using highly sensitive 3DI-PCR (R. Suspène et al., Nucleic Acids Res. 36:e72, 2008), it was possible to show that ADAR-1 could hyperdeaminate adenosine residues in both measles virus and influenza virus A genomes. Detailed analysis of the dinucleotide editing context showed preferences for 5'ArA and 5'UrA, which is typical of editing in mammalian cells. The hyperedited mutant frequency, including genomes and antigenomes, was a log greater for influenza virus compared to measles virus, suggesting a greater sensitivity to restriction by ADAR-1.


Assuntos
Adenosina Desaminase/metabolismo , Genoma Viral , Vírus da Influenza A/genética , Influenza Humana/enzimologia , Vírus do Sarampo/genética , Sarampo/enzimologia , Mutação , Adenosina Desaminase/genética , Animais , Sequência de Bases , Linhagem Celular , Chlorocebus aethiops , Humanos , Vacinas contra Influenza/genética , Influenza Humana/virologia , Sarampo/virologia , Vacina contra Sarampo/genética , Dados de Sequência Molecular , Proteínas de Ligação a RNA , Estações do Ano , Vacinas Atenuadas/genética , Células Vero
15.
Water Sci Technol ; 62(1): 196-201, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20595771

RESUMO

In this study, three methods commercialized by Pall (Envirochek HV), Idexx (FiltaMax) and Whatman (Cryptest) to concentrate Giardia cysts and Cryptosporidium oocysts from surface and drinking waters were compared according to the EPA standard protocol. Twenty litres of surface and 100 litres of drinking waters were inoculated with 10(3) (oo)cysts before being concentrated by filtration. Our results show that recovery rates of Giardia cysts from surface water was significantly higher using FiltaMax (91+/-12%) than Cryptest (57+/-9%) or Envirochek HV (60+/-4%) while recovery from drinking water was equivalent using FiltaMax (84+/-7%) or Cryptest (78+/-7%) but lower using Envirochek HV (34+/-29%). Recovery of Cryptosporidium oocysts from surface water was significantly higher using Envirochek HV (65+/-5%) than using FiltaMax (45+/-7%) or Cryptest (50+/-7%) while recovery rates from drinking water was equivalent using either FiltaMax (48+/-8%), Cryptest (57+/-4%) or Envirochek HV (64+/-22%). Finally, regardless of the water type, all methods tested allowed recovery rates superior to 24% complying with the EPA standard protocol. Timing, material and practicability associated with each method are discussed.


Assuntos
Cryptosporidium parvum/isolamento & purificação , Giardia lamblia/isolamento & purificação , Oocistos/citologia , Parasitologia/métodos , Água/parasitologia , Filtração , Abastecimento de Água
16.
PLoS Pathog ; 6(5): e1000928, 2010 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-20523896

RESUMO

DNA viruses, retroviruses and hepadnaviruses, such as hepatitis B virus (HBV), are vulnerable to genetic editing of single stranded DNA by host cell APOBEC3 (A3) cytidine deaminases. At least three A3 genes are up regulated by interferon-alpha in human hepatocytes while ectopic expression of activation induced deaminase (AICDA), an A3 paralog, has been noted in a variety of chronic inflammatory syndromes including hepatitis C virus infection. Yet virtually all studies of HBV editing have confined themselves to analyses of virions from culture supernatants or serum where the frequency of edited genomes is generally low (< or = 10(-2)). We decided to look at the nature and frequency of HBV editing in cirrhotic samples taken during removal of a primary hepatocellular carcinoma. Forty-one cirrhotic tissue samples (10 alcoholic, 10 HBV(+), 11 HBV(+)HCV(+) and 10 HCV(+)) as well as 4 normal livers were studied. Compared to normal liver, 5/7 APOBEC3 genes were significantly up regulated in the order: HCV+/-HBV>HBV>alcoholic cirrhosis. A3C and A3D were up regulated for all groups while the interferon inducible A3G was over expressed in virus associated cirrhosis, as was AICDA in approximately 50% of these HBV/HCV samples. While AICDA can indeed edit HBV DNA ex vivo, A3G is the dominant deaminase in vivo with up to 35% of HBV genomes being edited. Despite these highly deleterious mutant spectra, a small fraction of genomes survive and contribute to loss of HBeAg antigenemia and possibly HBsAg immune escape. In conclusion, the cytokine storm associated with chronic inflammatory responses to HBV and HCV clearly up regulates a number of A3 genes with A3G clearly being a major restriction factor for HBV. Although the mutant spectrum resulting from A3 editing is highly deleterious, a very small part, notably the lightly edited genomes, might help the virus evolve and even escape immune responses.


Assuntos
Citidina Desaminase/genética , DNA Viral/genética , Vírus da Hepatite B/genética , Hepatite B/imunologia , Hepatite B/virologia , Desaminase APOBEC-3G , Idoso , Citidina Desaminase/metabolismo , DNA de Cadeia Simples/genética , Evolução Molecular , Feminino , Regulação Viral da Expressão Gênica/imunologia , Genoma Viral , Antígenos do Núcleo do Vírus da Hepatite B/genética , Vacinas contra Hepatite B/genética , Vacinas contra Hepatite B/imunologia , Vírus da Hepatite B/imunologia , Humanos , Cirrose Hepática/virologia , Masculino , Pessoa de Meia-Idade , Mutação , Regulação para Cima/fisiologia
17.
Retrovirology ; 6: 96, 2009 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-19843348

RESUMO

Retroviruses, hepadnaviruses, and some other retroelements are vulnerable to editing by single stranded DNA cytidine deaminases. Of the eleven human genes encoding such enzymes, eight have demonstrable enzymatic activity. Six of seven human APOBEC3 are able to hyperedit HBV DNA, frequently on both strands. Although human APOBEC1 (hA1) is not generally expressed in normal liver, hA1 can edit single stranded DNA in a variety of experimental assays. The possibility of ectopic expression of hA1 in vivo cannot be ruled out and interestingly, transgenic mice with A1 expressed under a liver specific promoter develop hepatocellular carcinoma. The impact of hA1 on HBV in tissue culture is varied with reports noting either reduced DNA synthesis or not, with cytidine deamination taking a low profile. We sought to examine the hA1 editing activity on replicating HBV. Using highly sensitive 3DPCR it was possible to show that hA1 edits the HBV minus DNA strand as efficiently as hA3G, considered the reference deaminase for HIV and HBV. The dinucleotide specificity of editing was unique among human cytidine deaminases providing a hallmark of use in a posteriori analyses of in vivo edited genomes. Analysis of sequences derived from the serum of two chronic carriers, indicated that hA1 explained only a small fraction of edited HBV genomes. By contrast, several human APOBEC3 deaminases were active including hA3G.


Assuntos
Citidina Desaminase/metabolismo , DNA Viral/genética , DNA Viral/metabolismo , Vírus da Hepatite B/genética , Desaminase APOBEC-1 , Animais , DNA de Cadeia Simples/genética , DNA de Cadeia Simples/metabolismo , Vírus da Hepatite B/isolamento & purificação , Humanos , Camundongos
18.
Water Res ; 43(10): 2728-38, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19395061

RESUMO

The aim of the present study was to evaluate the potential of transcript quantification as an indicator of Giardia cyst viability. The variations of beta-giardin, EF1A and ADHE mRNAs were quantified during excystation by real-time RT-PCR assays and compared with the percentages of viability estimated using propidium iodide staining and in vitro excystation. The first experiments were performed with purified G. duodenalis assemblage B cysts. When 55% of excysting protozoa were observed, the increase of the selected transcripts ranged from 0.40+/-0.13 to 0.97+/-0.11 log10 after 1h of incubation in excystation medium. Purified cysts were also stored at 4 degrees C for up to 56 days and analysed at several sampling times. Significant correlations were observed between the variations of the selected mRNAs and the percentages of viability estimated with staining and excystation methods. Among the three transcripts, beta-giardin appeared to be the most appropriate to study the viability of Giardia cysts concentrated from wastewater samples.


Assuntos
Giardia/genética , Giardia/fisiologia , Animais , Proteínas do Citoesqueleto , Proteínas de Protozoários/genética , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa
19.
Expert Rev Med Devices ; 5(5): 591-603, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18803470

RESUMO

Carotid stenosis is responsible for approximately 30% of strokes, and carotid endarterectomy is considered to be the gold-standard treatment. Carotid angioplasty and stenting (CAS) has been proposed as an alternative to surgery but the risk of neurological complications and brain embolism remains the major drawback to this procedure. Embolic protection devices (EPDs), which retain particles and debris generated during the procedure, have been proposed to reduce the frequency of neurological complications. Three types of EPD have been developed: distal occlusion balloon, distal filters and proximal protection devices. Preliminary clinical results indicate that the routine use of an EPD along with specifically designed flexible stents, increasing skills of the interventionist and appropriate drugs combine to reduce ischemic neurological complications and can achieve similar results to the best surgical series, particularly in high surgical risk patients. Recent prospective, multicenter controlled trials and registries evaluating CAS with EPD have demonstrated that the CAS results are, at least, not inferior to surgery for patients at high risk for surgery (Stenting and Angioplasty with Protection in Patients at High Risk for Endarterectomy study) and in symptomatic patients (Stent Supported Percutaneous Angioplasty of the Carotid Artery versus Endarterectomy study). However, all protection devices are not equivalent and have some drawbacks. Advantages and disadvantages of each EPD will be analyzed in this review, allowing a good choice of the EPD depending on the patient and the lesion. Nevertheless, there is now a consensus among specialists to perform all CAS with EPD. EPDs have become an integral part of CAS and the routine use of EPDs seems beneficial, leading to a 60% reduction of brain embolisms.


Assuntos
Angioplastia/efeitos adversos , Estenose das Carótidas/terapia , Embolização Terapêutica/efeitos adversos , Embolização Terapêutica/instrumentação , Stents/efeitos adversos , Humanos , Resultado do Tratamento
20.
Nucleic Acids Res ; 36(12): e72, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18515351

RESUMO

DNA complementarity is expressed by way of three hydrogen bonds for a G:C base pair and two for A:T. As a result, careful control of the denaturation temperature of PCR allows selective amplification of AT-rich alleles. Yet for the same reason, the converse is not possible, selective amplification of GC-rich alleles. Inosine (I) hydrogen bonds to cytosine by two hydrogen bonds while diaminopurine (D) forms three hydrogen bonds with thymine. By substituting dATP by dDTP and dGTP by dITP in a PCR reaction, DNA is obtained in which the natural hydrogen bonding rule is inversed. When PCR is performed at limiting denaturation temperatures, it is possible to recover GC-rich viral genomes and inverted Alu elements embedded in cellular mRNAs resulting from editing by dsRNA dependent host cell adenosine deaminases. The editing of Alu elements in cellular mRNAs was strongly enhanced by type I interferon induction indicating a novel link mRNA metabolism and innate immunity.


Assuntos
Adenosina Desaminase/metabolismo , DNA/química , Sequência Rica em GC , Reação em Cadeia da Polimerase/métodos , Edição de RNA , 2-Aminopurina/análogos & derivados , 2-Aminopurina/química , Sequência Rica em At , Elementos Alu , Animais , Sequência de Bases , Linhagem Celular , Chlorocebus aethiops , Rearranjo Gênico do Linfócito B , Ligação de Hidrogênio , Região Variável de Imunoglobulina/genética , Inosina Trifosfato/química , Vírus do Sarampo/genética , Dados de Sequência Molecular , Desnaturação de Ácido Nucleico , RNA Mensageiro/química , Proteínas de Ligação a RNA , Células Vero
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