Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
1.
Nature ; 618(7963): 144-150, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37165196

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) is lethal in 88% of patients1, yet harbours mutation-derived T cell neoantigens that are suitable for vaccines 2,3. Here in a phase I trial of adjuvant autogene cevumeran, an individualized neoantigen vaccine based on uridine mRNA-lipoplex nanoparticles, we synthesized mRNA neoantigen vaccines in real time from surgically resected PDAC tumours. After surgery, we sequentially administered atezolizumab (an anti-PD-L1 immunotherapy), autogene cevumeran (a maximum of 20 neoantigens per patient) and a modified version of a four-drug chemotherapy regimen (mFOLFIRINOX, comprising folinic acid, fluorouracil, irinotecan and oxaliplatin). The end points included vaccine-induced neoantigen-specific T cells by high-threshold assays, 18-month recurrence-free survival and oncologic feasibility. We treated 16 patients with atezolizumab and autogene cevumeran, then 15 patients with mFOLFIRINOX. Autogene cevumeran was administered within 3 days of benchmarked times, was tolerable and induced de novo high-magnitude neoantigen-specific T cells in 8 out of 16 patients, with half targeting more than one vaccine neoantigen. Using a new mathematical strategy to track T cell clones (CloneTrack) and functional assays, we found that vaccine-expanded T cells comprised up to 10% of all blood T cells, re-expanded with a vaccine booster and included long-lived polyfunctional neoantigen-specific effector CD8+ T cells. At 18-month median follow-up, patients with vaccine-expanded T cells (responders) had a longer median recurrence-free survival (not reached) compared with patients without vaccine-expanded T cells (non-responders; 13.4 months, P = 0.003). Differences in the immune fitness of the patients did not confound this correlation, as responders and non-responders mounted equivalent immunity to a concurrent unrelated mRNA vaccine against SARS-CoV-2. Thus, adjuvant atezolizumab, autogene cevumeran and mFOLFIRINOX induces substantial T cell activity that may correlate with delayed PDAC recurrence.


Assuntos
Antígenos de Neoplasias , Vacinas Anticâncer , Carcinoma Ductal Pancreático , Ativação Linfocitária , Neoplasias Pancreáticas , Linfócitos T , Humanos , Adjuvantes Imunológicos/uso terapêutico , Antígenos de Neoplasias/imunologia , Vacinas Anticâncer/imunologia , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/imunologia , Carcinoma Ductal Pancreático/terapia , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/imunologia , Imunoterapia , Ativação Linfocitária/imunologia , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/imunologia , Neoplasias Pancreáticas/terapia , Linfócitos T/citologia , Linfócitos T/imunologia , Vacinas de mRNA , Neoplasias Pancreáticas
2.
Nature ; 606(7913): 389-395, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35589842

RESUMO

Cancer immunoediting1 is a hallmark of cancer2 that predicts that lymphocytes kill more immunogenic cancer cells to cause less immunogenic clones to dominate a population. Although proven in mice1,3, whether immunoediting occurs naturally in human cancers remains unclear. Here, to address this, we investigate how 70 human pancreatic cancers evolved over 10 years. We find that, despite having more time to accumulate mutations, rare long-term survivors of pancreatic cancer who have stronger T cell activity in primary tumours develop genetically less heterogeneous recurrent tumours with fewer immunogenic mutations (neoantigens). To quantify whether immunoediting underlies these observations, we infer that a neoantigen is immunogenic (high-quality) by two features-'non-selfness'  based on neoantigen similarity to known antigens4,5, and 'selfness'  based on the antigenic distance required for a neoantigen to differentially bind to the MHC or activate a T cell compared with its wild-type peptide. Using these features, we estimate cancer clone fitness as the aggregate cost of T cells recognizing high-quality neoantigens offset by gains from oncogenic mutations. With this model, we predict the clonal evolution of tumours to reveal that long-term survivors of pancreatic cancer develop recurrent tumours with fewer high-quality neoantigens. Thus, we submit evidence that that the human immune system naturally edits neoantigens. Furthermore, we present a model to predict how immune pressure induces cancer cell populations to evolve over time. More broadly, our results argue that the immune system fundamentally surveils host genetic changes to suppress cancer.


Assuntos
Antígenos de Neoplasias , Sobreviventes de Câncer , Neoplasias Pancreáticas , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/imunologia , Humanos , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/imunologia , Neoplasias Pancreáticas/patologia , Linfócitos T/imunologia , Evasão Tumoral/imunologia
3.
Microorganisms ; 10(2)2022 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-35208938

RESUMO

Heavy metal co-contamination in crude oil-polluted environments may inhibit microbial bioremediation of hydrocarbons. The model heavy metal-resistant bacterium Cupriavidus metallidurans CH34 possesses cadmium and mercury resistance, as well as genes related to the catabolism of hazardous BTEX aromatic hydrocarbons. The aims of this study were to analyze the aromatic catabolic potential of C. metallidurans CH34 and to determine the functionality of the predicted benzene catabolic pathway and the influence of cadmium and mercury on benzene degradation. Three chromosome-encoded bacterial multicomponent monooxygenases (BMMs) are involved in benzene catabolic pathways. Growth assessment, intermediates identification, and gene expression analysis indicate the functionality of the benzene catabolic pathway. Strain CH34 degraded benzene via phenol and 2-hydroxymuconic semialdehyde. Transcriptional analyses revealed a transition from the expression of catechol 2,3-dioxygenase (tomB) in the early exponential phase to catechol 1,2-dioxygenase (catA1 and catA2) in the late exponential phase. The minimum inhibitory concentration to Hg (II) and Cd (II) was significantly lower in the presence of benzene, demonstrating the effect of co-contamination on bacterial growth. Notably, this study showed that C. metallidurans CH34 degraded benzene in the presence of Hg (II) or Cd (II).

5.
J Control Release ; 332: 517-528, 2021 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-33675877

RESUMO

Tumor targeting and intratumoral virus spreading are key features for successful oncolytic virotherapy. VCN-11 is a novel oncolytic adenovirus, genetically modified to express hyaluronidase (PH20) and display an albumin-binding domain (ABD) on the hexon. ABD allows the virus to self-coat with albumin when entering the bloodstream and evade neutralizing antibodies (NAbs). Here, we validate VCN-11 mechanism of action and characterize its toxicity. VCN-11 replication, hyaluronidase activity and binding to human albumin to evade NAbs was evaluated. Toxicity and efficacy of VCN-11 were assessed in mice and hamsters. Tumor targeting, and antitumor activity was analyzed in the presence of NAbs in several tumor models. VCN-11 induced 450 times more cytotoxicity in tumor cells than in normal cells. VCN-11 hyaluronidase production was confirmed by measuring PH20 activity in vitro and in virus-infected tumor areas in vivo. VCN-11 evaded NAbs from different sources and tumor targeting was demonstrated in the presence of high levels of NAbs in vivo, whereas the control virus without ABD was neutralized. VCN-11 showed a low toxicity profile in athymic nude mice and Syrian hamsters, allowing treatments with high doses and fractionated administrations without major toxicities (up to 1.2x1011vp/mouse and 7.5x1011vp/hamster). Fractionated intravenous administrations improved circulation kinetics and tumor targeting. VCN-11 antitumor efficacy was demonstrated in the presence of NAbs against Ad5 and itself. Oncolytic adenovirus VCN-11 disrupts tumor matrix and displays antitumor effects even in the presence of NAbs. These features make VCN-11 a safe promising candidate to test re-administration in clinical trials.


Assuntos
Terapia Viral Oncolítica , Vírus Oncolíticos , Adenoviridae , Animais , Anticorpos Neutralizantes , Linhagem Celular Tumoral , Cricetinae , Hialuronoglucosaminidase , Camundongos , Camundongos Nus , Vírus Oncolíticos/genética , Replicação Viral , Ensaios Antitumorais Modelo de Xenoenxerto
6.
Nature ; 579(7797): 130-135, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32076273

RESUMO

Group 2 innate lymphoid cells (ILC2s) regulate inflammation and immunity in mammalian tissues1,2. Although ILC2s are found in cancers of these tissues3, their roles in cancer immunity and immunotherapy are unclear. Here we show that ILC2s infiltrate pancreatic ductal adenocarcinomas (PDACs) to activate tissue-specific tumour immunity. Interleukin-33 (IL33) activates tumour ILC2s (TILC2s) and CD8+ T cells in orthotopic pancreatic tumours but not heterotopic skin tumours in mice to restrict pancreas-specific tumour growth. Resting and activated TILC2s express the inhibitory checkpoint receptor PD-1. Antibody-mediated PD-1 blockade relieves ILC2 cell-intrinsic PD-1 inhibition to expand TILC2s, augment anti-tumour immunity, and enhance tumour control, identifying activated TILC2s as targets of anti-PD-1 immunotherapy. Finally, both PD-1+ TILC2s and PD-1+ T cells are present in most human PDACs. Our results identify ILC2s as anti-cancer immune cells for PDAC immunotherapy. More broadly, ILC2s emerge as tissue-specific enhancers of cancer immunity that amplify the efficacy of anti-PD-1 immunotherapy. As ILC2s and T cells co-exist in human cancers and share stimulatory and inhibitory pathways, immunotherapeutic strategies to collectively target anti-cancer ILC2s and T cells may be broadly applicable.


Assuntos
Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/imunologia , Linfócitos/imunologia , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/imunologia , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Animais , Células Dendríticas/imunologia , Feminino , Humanos , Imunidade Inata/imunologia , Imunoterapia , Interleucina-33/imunologia , Ativação Linfocitária , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Linfócitos T/imunologia
8.
Front Microbiol ; 10: 1499, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31338076

RESUMO

Cadmium is a highly toxic heavy metal for biological systems. Cupriavidus metallidurans CH34 is a model strain to study heavy metal resistance and bioremediation as it is able to deal with high heavy metal concentrations. Biofilm formation by bacteria is mediated by the second messenger bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP). The aim of this study was to characterize the response of C. metallidurans CH34 planktonic and biofilm cells to cadmium including their c-di-GMP regulatory pathway. Inhibition of the initiation of biofilm formation and EPS production by C. metallidurans CH34 correlates with increased concentration of cadmium. Planktonic and biofilm cells showed similar tolerance to cadmium. During exposure to cadmium an acute decrease of c-di-GMP levels in planktonic and biofilm cells was observed. Transcription analysis by RT-qPCR showed that cadmium exposure to planktonic and biofilm cells induced the expression of the urf2 gene and the mercuric reductase encoding merA gene, which belong to the Tn501/Tn21 mer operon. After exposure to cadmium, the cadA gene involved in cadmium resistance was equally upregulated in both lifestyles. Bioinformatic analysis and complementation assays indicated that the protein encoded by the urf2 gene is a functional phosphodiesterase (PDE) involved in the c-di-GMP metabolism. We propose to rename the urf2 gene as mrp gene for metal regulated PDE. An increase of the second messenger c-di-GMP content by the heterologous expression of the constitutively active diguanylate cyclase PleD correlated with an increase in biofilm formation and cadmium susceptibility. These results indicate that the response to cadmium in C. metallidurans CH34 inhibits the initiation of biofilm lifestyle and involves a decrease in c-di-GMP levels and a novel metal regulated PDE.

9.
Genes (Basel) ; 9(11)2018 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-30428624

RESUMO

For the past three decades, Cupriavidus metallidurans has been one of the major model organisms for bacterial tolerance to heavy metals. Its type strain CH34 contains at least 24 gene clusters distributed over four replicons, allowing for intricate and multilayered metal responses. To gain organic mercury resistance in CH34, broad-spectrum mer genes were introduced in a previous work via conjugation of the IncP-1ß plasmid pTP6. However, we recently noted that this CH34-derived strain, MSR33, unexpectedly showed an increased resistance to other metals (i.e., Co2+, Ni2+, and Cd2+). To thoroughly investigate this phenomenon, we resequenced the entire genome of MSR33 and compared its DNA sequence and basal gene expression profile to those of its parental strain CH34. Genome comparison identified 11 insertions or deletions (INDELs) and nine single nucleotide polymorphisms (SNPs), whereas transcriptomic analysis displayed 107 differentially expressed genes. Sequence data implicated the transposition of IS1088 in higher Co2+ and Ni2+ resistances and altered gene expression, although the precise mechanisms of the augmented Cd2+ resistance in MSR33 remains elusive. Our work indicates that conjugation procedures involving large complex genomes and extensive mobilomes may pose a considerable risk toward the introduction of unwanted, undocumented genetic changes. Special efforts are needed for the applied use and further development of small nonconjugative broad-host plasmid vectors, ideally involving CRISPR-related and advanced biosynthetic technologies.

10.
J Environ Qual ; 47(4): 735-745, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30025051

RESUMO

Soil organic C (SOC) is the largest terrestrial C pool, and it influences diverse soil properties and processes in a landscape. At global scales, SOC is related to climate; as climate changes, we expect that SOC will change at broad scales as well, but how SOC will respond to climate change in diverse environments is complex and highly uncertain. To evaluate the potential impact of predicted changes in temperature and precipitation across central Chile, we first estimated current SOC content using pedon descriptions and environmental variables (temperature, rainfall, land use, topography, soil types, and geology) as predictors. A random forest statistical model was used to predict SOC content by pedon data. Maps were created for six standard depths of the GlobalSoilMap project. Results showed mean SOC of 54 g kg at a depth interval of 0 to 5 cm, 51 g kg at 5 to 15 cm, 42 g kg at 15 to 30 cm, 29 g kg at 30 to 60 cm, 17 g kg at 60 to 100 cm, and 11 g kg at 100 to 200 cm. Model validation, withholding 25% of pedons, showed values of 0.70, 0.73, 0.75, 0.65, 0.56, and 0.29 for six depths, respectively. Two future temperature and precipitation for climate change scenarios, representative concentration pathways RCP4.5 and RCP8.5 from the NASA GISS-E2-R models, were considered in predicting SOC in 2050 and 2080. We found that central Chile would experience a loss of SOC in the depth range of 0 to 30 cm, averaging 9.7% for RCP4.5 and 12.9% for the RCP8.5 scenarios by the year 2050, with additional decreases of 8% in the RCP4.5 scenario and 16.5% under RCP8.5 by 2080.


Assuntos
Carbono , Mudança Climática , Solo/química , Chile , Previsões , Modelos Teóricos
11.
Int J Pharm ; 479(2): 312-9, 2015 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-25550211

RESUMO

Ultrapure oligochitosans have been recently reported as efficient non-viral vectors for the delivery of pCMS-EGFP plasmid (5.5kbp) to the cornea and retina. However, the delivery of oncolytic adenoviral plasmids (40kbp) represents a unique challenge. In this work, we elaborated self assembled O15 and O25 UOC/pAdTLRGD polyplexes, and we studied the influence of the N/P ratio, the pH of the transfection medium and the salt concentration on the particle size and zeta potential by an orthogonal experimental design. All polyplexes showed a particle size lower than 200nm and a positive zeta potential. These parameters were influenced by the N/P ratio, salt concentration, and pH of the transfection medium. The selected polyplexes were able to bind, release, and protect the plasmid from DNase degradation. Transfection experiments in HEK293 and A549 cell lines demonstrated that UOC/pAdTLRGD polyplexes were able to deliver the plasmid and transfect both cell lines. These results suggest that O15 and O25 UOC based polyplexes are suitable for future in vivo applications.


Assuntos
Adenoviridae/genética , Quitina/análogos & derivados , DNA/administração & dosagem , Polímeros/administração & dosagem , Linhagem Celular Tumoral , Quitina/administração & dosagem , Quitosana , Vetores Genéticos , Células HEK293 , Humanos , Concentração de Íons de Hidrogênio , Oligossacarídeos , Tamanho da Partícula , Plasmídeos , Transfecção/métodos
12.
Pediatr Crit Care Med ; 14(3): 306-9, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23392362

RESUMO

OBJECTIVES: A catheter thrombosis and the presence of a catheter-associated bloodstream infection (CBSI) often occur simultaneously, but it is unclear if or to what degree the two complications relate. Several animal and adult studies indicate a relationship between fibrin sheaths and thrombi in the development of CBSIs. To date, there has been limited human investigation in the pediatric population to determine a clear link between the presence of a thrombus and bacteremia. The use of alteplase for malfunctioning central venous catheter may indicate the formation of intraluminal thrombus or fibrin sheath. A catheter that requires alteplase is at higher risk of a CBSI. DESIGN: A retrospective chart review from July 2008 to December 2010. SETTING: PICU. PATIENTS: All patients with central catheters admitted to the PICU. INTERVENTIONS: No interventions performed with the retrospective study. MEASUREMENTS: Number of total central venous catheters, number of central venous catheters that received treatment with alteplase, and number of CBSIs. MAIN RESULTS: Preliminary data during the study period identified 3,289 central venous catheters. Twelve percent of these catheters required at least one dose of alteplase. There were 40 CBSIs during this same time period of which 28% received alteplase during the 5 days preceding the positive blood culture. The odds ratio for getting a CBSI when alteplase is administered is 2.87 (confidence interval 1.42-5.80; p = 0.002). The average age of the central venous catheters at time of infection was not statistically different, 16.1 days in the alteplase catheters compared with 25.6 days for the catheters that did not receive alteplase (p = 0.6). CONCLUSIONS: There is a positive correlation between the use of alteplase for malfunctioning central venous catheters and the development of a CASBI. This is likely associated with the presence of an intraluminal fibrin sheath or thrombus. This study adds evidence linking thrombus formation to CBSI.


Assuntos
Obstrução do Cateter/etiologia , Infecções Relacionadas a Cateter/etiologia , Cateterismo Venoso Central , Fibrinolíticos/uso terapêutico , Ativador de Plasminogênio Tecidual/uso terapêutico , Trombose Venosa/complicações , Criança , Humanos , Unidades de Terapia Intensiva Pediátrica , Razão de Chances , Estudos Retrospectivos , Trombose Venosa/tratamento farmacológico
13.
BMC Microbiol ; 12: 193, 2012 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-22950448

RESUMO

BACKGROUND: Copper mining has led to Cu pollution in agricultural soils. In this report, the effects of Cu pollution on bacterial communities of agricultural soils from Valparaiso region, central Chile, were studied. Denaturing gradient gel electrophoresis (DGGE) of the 16S rRNA genes was used for the characterization of bacterial communities from Cu-polluted and non-polluted soils. Cu-resistant bacterial strains were isolated from Cu-polluted soils and characterized. RESULTS: DGGE showed a similar high number of bands and banding pattern of the bacterial communities from Cu-polluted and non-polluted soils. The presence of copA genes encoding the multi-copper oxidase that confers Cu-resistance in bacteria was detected by PCR in metagenomic DNA from the three Cu-polluted soils, but not in the non-polluted soil. The number of Cu-tolerant heterotrophic cultivable bacteria was significantly higher in Cu-polluted soils than in the non-polluted soil. Ninety two Cu-resistant bacterial strains were isolated from three Cu-polluted agricultural soils. Five isolated strains showed high resistance to copper (MIC ranged from 3.1 to 4.7 mM) and also resistance to other heavy metals. 16S rRNA gene sequence analyses indicate that these isolates belong to the genera Sphingomonas, Stenotrophomonas and Arthrobacter. The Sphingomonas sp. strains O12, A32 and A55 and Stenotrophomonas sp. C21 possess plasmids containing the Cu-resistance copA genes. Arthrobacter sp. O4 possesses the copA gene, but plasmids were not detected in this strain. The amino acid sequences of CopA from Sphingomonas isolates (O12, A32 and A55), Stenotrophomonas strain (C21) and Arthrobacter strain (O4) are closely related to CopA from Sphingomonas, Stenotrophomonas and Arthrobacter strains, respectively. CONCLUSIONS: This study suggests that bacterial communities of agricultural soils from central Chile exposed to long-term Cu-pollution have been adapted by acquiring Cu genetic determinants. Five bacterial isolates showed high copper resistance and additional resistance to other heavy metals. Detection of copA gene in plasmids of four Cu-resistant isolates indicates that mobile genetic elements are involved in the spreading of Cu genetic determinants in polluted environments.


Assuntos
Bactérias/classificação , Bactérias/efeitos dos fármacos , Biodiversidade , Cobre/metabolismo , Farmacorresistência Bacteriana , Microbiologia do Solo , Poluentes do Solo/metabolismo , Bactérias/genética , Bactérias/isolamento & purificação , Proteínas de Bactérias/genética , Chile , Análise por Conglomerados , Cobre/toxicidade , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Eletroforese em Gel de Gradiente Desnaturante , Dados de Sequência Molecular , Filogenia , Plasmídeos , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Poluentes do Solo/toxicidade
14.
PLoS One ; 6(3): e17555, 2011 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-21423734

RESUMO

BACKGROUND: Mercury-polluted environments are often contaminated with other heavy metals. Therefore, bacteria with resistance to several heavy metals may be useful for bioremediation. Cupriavidus metallidurans CH34 is a model heavy metal-resistant bacterium, but possesses a low resistance to mercury compounds. METHODOLOGY/PRINCIPAL FINDINGS: To improve inorganic and organic mercury resistance of strain CH34, the IncP-1ß plasmid pTP6 that provides novel merB, merG genes and additional other mer genes was introduced into the bacterium by biparental mating. The transconjugant Cupriavidus metallidurans strain MSR33 was genetically and biochemically characterized. Strain MSR33 maintained stably the plasmid pTP6 over 70 generations under non-selective conditions. The organomercurial lyase protein MerB and the mercuric reductase MerA of strain MSR33 were synthesized in presence of Hg(2+). The minimum inhibitory concentrations (mM) for strain MSR33 were: Hg(2+), 0.12 and CH(3)Hg(+), 0.08. The addition of Hg(2+) (0.04 mM) at exponential phase had not an effect on the growth rate of strain MSR33. In contrast, after Hg(2+) addition at exponential phase the parental strain CH34 showed an immediate cessation of cell growth. During exposure to Hg(2+) no effects in the morphology of MSR33 cells were observed, whereas CH34 cells exposed to Hg(2+) showed a fuzzy outer membrane. Bioremediation with strain MSR33 of two mercury-contaminated aqueous solutions was evaluated. Hg(2+) (0.10 and 0.15 mM) was completely volatilized by strain MSR33 from the polluted waters in presence of thioglycolate (5 mM) after 2 h. CONCLUSIONS/SIGNIFICANCE: A broad-spectrum mercury-resistant strain MSR33 was generated by incorporation of plasmid pTP6 that was directly isolated from the environment into C. metallidurans CH34. Strain MSR33 is capable to remove mercury from polluted waters. This is the first study to use an IncP-1ß plasmid directly isolated from the environment, to generate a novel and stable bacterial strain useful for mercury bioremediation.


Assuntos
Cupriavidus/efeitos dos fármacos , Cupriavidus/metabolismo , Mercúrio/isolamento & purificação , Mercúrio/toxicidade , Proteínas de Bactérias/metabolismo , Biodegradação Ambiental/efeitos dos fármacos , Conjugação Genética/efeitos dos fármacos , Cupriavidus/genética , Cupriavidus/crescimento & desenvolvimento , Genes Bacterianos/genética , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase , Poluentes Químicos da Água/isolamento & purificação
15.
J Virol Methods ; 163(2): 445-51, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19914293

RESUMO

At least 58 viruses have been reported to infect grapevines causing economic damage globally. Conventional detection strategies based on serological assays, biological indexing and RT-PCR targeting one or few viruses in each assay are widely used. Grapevines are prone to contain mixed infections of several viruses, making the use of these techniques time-consuming. A 70-mer oligonucleotide microarray able to detect simultaneously a broad spectrum of known viruses as well as new viruses by cross-hybridization to highly conserved probes is reported in the present study. The array contains 570 unique probes designed against highly conserved and species-specific regions of 44 plant viral genomes. In addition probes designed against plant housekeeping genes are also included. By using a random primed RT-PCR amplification strategy of grapevine double stranded RNA-enriched samples, viral agents were detected in single and mixed infections. The microarray accuracy to detect 10 grapevine viruses was compared with RT-PCR yielding consistent results. For this purpose, grapevine samples containing single or mixed infections of Grapevine leafroll-associated virus-1, -2, -3, -4, -7, -9, Grapevine fanleaf virus, Grapevine rupestris stem pitting-associated virus, Grapevine virus A, and Grapevine virus B were used. Genomic libraries containing complete viral genomes were also used as part of the validation process. The specific probe hybridization pattern obtained from each virus makes this approach a powerful tool for high throughput plant certification purposes and also for virus discovery if the new viral genomic sequences have partial similarity with the microarray probes. Three Closteroviridae members (Grapevine leafroll-associated virus -4, -7 and -9) were detected for the first time in Chilean grapevines using the microarray.


Assuntos
Análise de Sequência com Séries de Oligonucleotídeos/métodos , Doenças das Plantas/virologia , Vírus de Plantas/classificação , Vírus de Plantas/isolamento & purificação , Vitis/virologia , Dados de Sequência Molecular , Sondas de Oligonucleotídeos/genética , Vírus de Plantas/genética , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sensibilidade e Especificidade , Análise de Sequência de DNA
16.
Biol Res ; 42(2): 189-98, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19746264

RESUMO

We present the analysis of an intronic polymorphism of the nephrin gene and its relationship to the development of diabetic nephropathy in a study of diabetes type 1 and type 2 patients. The frequency of the single nucleotide polymorphism rs#466452 in the nephrin gene was determined in 231 patients and control subjects. The C/T status of the polymorphism was assessed using restriction enzyme digestions and the nephrin transcript from a kidney biopsy was examined. Association between the polymorphism and clinical parameters was evaluated using multivariate correspondence analysis. A bioinformatics analysis of the single nucleotide polymorphism rs#466452 suggested the appearance of a splicing enhancer sequence in intron 24 of the nephrin gene and a modification of proteins that bind to this sequence. However, no change in the splicing of a nephrin transcript from a renal biopsy was found. No association was found between the polymorphism and diabetes or degree of renal damage in diabetes type 1 or 2 patients. The single nucleotide polymorphism rs#466452 of the nephrin gene seems to be neutral in relation to diabetes and the development of diabetic nephropathy, and does not affect the splicing of a nephrin transcript, in spite of a splicing enhancer site.


Assuntos
Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 2/complicações , Nefropatias Diabéticas/genética , Proteínas de Membrana/genética , Polimorfismo de Nucleotídeo Único/genética , Adulto , Idoso , Biópsia , Estudos de Casos e Controles , Feminino , Genótipo , Humanos , Íntrons/genética , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Splicing de RNA/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transcrição Gênica/genética
17.
Biol. Res ; 42(2): 189-198, 2009. ilus, tab
Artigo em Inglês | LILACS | ID: lil-524889

RESUMO

We present the analysis of an intronic polymorphism of the nephrin gene and its relationship to the development of diabetic nephropathy in a study of diabetes type 1 and type 2 patients. The frequency of the single nucleotide polymorphism rs#466452 in the nephrin gene was determined in 231 patients and control subjects. The C/T status of the polymorphism was assessed using restriction enzyme digestions and the nephrin transcript from a kidney biopsy was examined. Association between the polymorphism and clinical parameters was evaluated using multivaríate correspondence analysis. A bioinformatics analysis of the single nucleotide polymorphism rs#466452 suggested the appearance of a splicing enhancer sequence in intron 24 of the nephrin gene and a modification of proteins that bind to this sequence. However, no change in the splicing of a nephrin transcript from a renal biopsy was found. No association was found between the polymorphism and diabetes or degree of renal damage in diabetes type 1 or 2 patients. The single nucleotide polymorphism rs#466452 of the nephrin gene seems to be neutral in relation to diabetes and the development of diabetic nephropathy, and does not affect the splicing of a nephrin transcript, in spite of a splicing enhancer site.


Assuntos
Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Diabetes Mellitus Tipo 1/complicações , /complicações , Nefropatias Diabéticas/genética , Proteínas de Membrana/genética , Polimorfismo de Nucleotídeo Único/genética , Biópsia , Estudos de Casos e Controles , Genótipo , Íntrons/genética , Análise Multivariada , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Splicing de RNA/genética , Transcrição Gênica/genética
18.
Rev. dent. Chile ; 86(1): 41-6, abr. 1995. ilus
Artigo em Espanhol | LILACS | ID: lil-156380

RESUMO

Se analizaron los fundamentos para la selección de imágenes en los estudios de las articulaciones temporomandibulares afectadas por malformaciones con especial énfasis en la reconstrucción tridimensional. Se analiza la importancia clínica del scanner en las malformaciones de las ATM, especialmente para el cirujano que debe tratar estas condiciones. Además las ventajas del trabajo en equipo entre radiólogo y cirujano y se correlacionan la imágenes obtenidas por reconstrucciones tridimensionales con los hallazgos quirúrgicos en el estudio articular del paciente afectado por alteraciones congénitas de sus ATM. Para los autores, el estudio con tomografía axial computarizada (TAC) realizado de la forma que se expone es un estudio actualmente imprescindible para estudiar, planificar y seguir pacientes portadores de una malformación congénita, que indepndiente de su tipo afecte las articulaciones temporomandibulares (ATM)


Assuntos
Humanos , Feminino , Articulação Temporomandibular/anormalidades , Articulação Temporomandibular , Diagnóstico por Imagem/métodos , Tomografia Computadorizada por Raios X/métodos
19.
Rev. dent. Chile ; 86(1): 55-9, abr. 1995. ilus
Artigo em Espanhol | LILACS | ID: lil-156382

RESUMO

Se presenta un análisis cefalométrico para radiografías panorámicas. Este análisis está basado en una línea de referencia horizontal traspasada a la radiografía, según fue descrito por los autores. En el diseño y posterior interpretación del análisis propuesto, se consideraron acusiosamente los problemas distorsionales y magnificaciones que están asociadas a este tipo de radiografías. El análisis no utiliza estándares de comparación, por cuanto su objetivo es de ser proporcional y comparativo de ambos lados mandibulares. Los autores han utilizado este análisis por más de tres años en la planificación terapéutica de más de 20 casos quirúrgicos de pacientes portadores de microsomía facial. Este trabajo está en proceso de ser publicado


Assuntos
Cefalometria , Radiografia Panorâmica/métodos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...