Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Lett Appl Microbiol ; 77(1)2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38211976

RESUMO

Acinetobacter baumannii is a relevant bacterium due to its high-resistance profile. It is well known that antimicrobial resistance is primarily linked to mutations and the acquisition of external genomic material, such as plasmids or phages, to which the Clustered Regularly Interspaced Short Palindromic Repeats associated with Cas proteins, or CRISPR-Cas, system is related. It is known that the system can influence the acquisition of foreign genetic material and play a role in various physiological pathways. In this study, we conducted an in-silico analysis using 91 fully assembled genomes of clinical strains obtained from the NCBI database. Among the analyzed genomes, the I-F1 subtype of the CRISPR-Cas system was detected showcasing variations in architecture and phylogeny. Using bioinformatic tools, we determined the presence, distribution, and specific characteristics of the CRISPR-Cas system. We found a possible association of the system with resistance genes but not with virulence determinants. Analysis of the system's components, including spacer sequences, suggests its potential role in protecting against phage infections, highlighting its protective function.


Assuntos
Acinetobacter baumannii , Bacteriófagos , Acinetobacter baumannii/genética , Sistemas CRISPR-Cas , Plasmídeos/genética , Genômica , Filogenia , Bacteriófagos/genética
2.
GE Port J Gastroenterol ; 30(1): 49-56, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36743991

RESUMO

Background: Tissue sampling using endoscopic ultrasound-guided fine-needle aspiration is the gold standard for diagnosing malignant pancreatic tumors; however, its sensitivity and specificity are highly variable. Thus, fine-needle biopsy using cutting needles has been developed to overcome current limitations and improve diagnostic yield. Our study compared two fine-needle biopsy needles for tissue sampling for pancreatic solid lesions. Materials and Methods: Samples obtained from patients with pancreatic solid lesions using the 22-gauge fine-needle biopsy needles (Franseen needle or reverse bevel needle) were retrospectively analyzed. The primary outcomes were diagnostic yield and sample adequacy. The secondary outcome was diagnostic performance. The analysis was performed using 2 × 2 tables to calculate sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy for each needle type. Proportions were compared using the Z test. For quantitative variables, a comparative analysis was performed using Student's t test. Qualitative and unpaired outcome variables were described using Fisher's exact test. Results: Sixty-three patients with pancreatic lesions were included in the analysis. The fine-needle biopsy Franseen and reverse bevel groups included 33 and 30 patients, respectively. An adequate sample was obtained in 97% of patients in the Franseen needle group versus 80% in the reverse bevel needle group; the diagnostic yields in these groups were 93.9 and 66.7%, respectively. Neither differences between needle passes nor complications were noted. The sensitivity and specificity were 93.5 and 100%, respectively, in the fine-needle biopsy Franseen group, versus 71 and 100%, respectively, in the reverse bevel needle group. Conclusions: The Franseen needle was more effective for sampling pancreatic tumors than the reverse bevel needle.


Introdução: A aquisição de tecido através de punção com agulha fina guiada por ecoendoscopia é o padrão para o diagnóstico de neoplasias pancreáticas malignas; contudo, a sua sensibilidade e especificidade é altamente variável. A biópsia por agulha fina (FNB) usando agulhas cortantes foi desenvolvida para ultrapassar as limitações atuais. Este estudo comparou duas agulhas de FNB na aquisição de tecido de lesões pancreáticas sólidas. Métodos: Amostras obtidas de doentes com lesões pancreáticas sólidas utilizando agulha de FND de 22 gauge (Franseen ou reverse bevel) foram avaliadas retrospetivamente. Os outcomes primárias foram a rentabilidade diagnóstica e a adequabilidade das amostras. O outcome secundário foi a performance diagnóstica. A análise estatística foi realizada através de tabelas de contingência 2 × 2 para cálculo da sensibilidade, especificidade, valor preditivo positivo e negativo e acuidade para cada tipo de agulha. As proporções foram calculadas utilizando o teste-Z. Para variáveis quantitativas foi realizada análise comparativa com teste t-Student. Variáveis qualitativas e não pareadas foram comparadas com teste exato de Fisher. Resultados: Foram incluídos 63 doentes com lesões pancreáticas (33 no grupo FNB Franseen e 30 no grupo reverse bevel). Foram obtidas amostras adequadas em 97% do grupo Franseen vs 80% no grupo reverse bevel, sendo a rentabilidade diagnóstica de 93.9 e 66.7%, respetivamente. Não houve diferenças no número de passagens nem nas complicações. A sensibilidade e especificidade foram, respetivamente, de 93.5 e 100% no grupo Franseen versus 71 e 100% no grupo reverse bevel. Conclusões: A agulha Franseen foi mais efetiva na aquisição de amostras de lesões pancreáticas do que a agulha reverse bevel.

3.
PLoS One ; 11(9): e0162199, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27611077

RESUMO

BACKGROUND: The nucleotide analogue brincidofovir was developed to prevent and treat infections caused by double-stranded DNA viruses. Based on in vitro data suggesting an antiviral effect against Ebola virus, brincidofovir was included in the World Health Organisation list of agents that should be prioritised for clinical evaluation in patients with Ebola virus disease (EVD) during the West African epidemic. METHODS AND FINDINGS: In this single-arm phase 2 trial conducted in Liberia, patients with laboratory-confirmed EVD (two months of age or older, enrolment bodyweight ≥50 kg) received oral brincidofovir 200 mg as a loading dose on day 0, followed by 100 mg brincidofovir on days 3, 7, 10, and 14. Bodyweight-adjusted dosing was used for patients weighing <50 kg at enrolment. The primary outcome was survival at Day 14 after the first dose of brincidofovir. Four patients were enrolled between 01 January 2015 and 31 January 2015. The trial was stopped following the decision by the manufacturer to terminate their program of development of brincidofovir for EVD. No Serious Adverse Reactions or Suspected Unexpected Serious Adverse Reactions were identified. All enrolled subjects died of an illness consistent with EVD. CONCLUSIONS: Due to the small sample size it was not possible to determine the efficacy of brincidofovir for the treatment of EVD. The premature termination of the trial highlights the need to establish better practices for preclinical in-vitro and animal screening of therapeutics for potentially emerging epidemic infectious diseases prior to their use in patients. TRIAL REGISTRATION: Pan African Clinical Trials Registry PACTR201411000939962.


Assuntos
Antivirais/uso terapêutico , Citosina/análogos & derivados , Ebolavirus/fisiologia , Doença pelo Vírus Ebola/tratamento farmacológico , Organofosfonatos/uso terapêutico , Adulto , Antivirais/farmacologia , Citosina/farmacologia , Citosina/uso terapêutico , Ebolavirus/efeitos dos fármacos , Feminino , Doença pelo Vírus Ebola/virologia , Humanos , Libéria , Masculino , Pessoa de Meia-Idade , Organofosfonatos/farmacologia , Resultado do Tratamento , Adulto Jovem
4.
PLoS Med ; 13(4): e1001997, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27093560

RESUMO

BACKGROUND: TKM-130803, a small interfering RNA lipid nanoparticle product, has been developed for the treatment of Ebola virus disease (EVD), but its efficacy and safety in humans has not been evaluated. METHODS AND FINDINGS: In this single-arm phase 2 trial, adults with laboratory-confirmed EVD received 0.3 mg/kg of TKM-130803 by intravenous infusion once daily for up to 7 d. On days when trial enrolment capacity was reached, patients were enrolled into a concurrent observational cohort. The primary outcome was survival to day 14 after admission, excluding patients who died within 48 h of admission. After 14 adults with EVD had received TKM-130803, the pre-specified futility boundary was reached, indicating a probability of survival to day 14 of ≤0.55, and enrolment was stopped. Pre-treatment geometric mean Ebola virus load in the 14 TKM-130803 recipients was 2.24 × 109 RNA copies/ml plasma (95% CI 7.52 × 108, 6.66 × 109). Two of the TKM-130803 recipients died within 48 h of admission and were therefore excluded from the primary outcome analysis. Of the remaining 12 TKM-130803 recipients, nine died and three survived. The probability that a TKM-130803 recipient who survived for 48 h will subsequently survive to day 14 was estimated to be 0.27 (95% CI 0.06, 0.58). TKM-130803 infusions were well tolerated, with 56 doses administered and only one possible infusion-related reaction observed. Three patients were enrolled in the observational cohort, of whom two died. CONCLUSIONS: Administration of TKM-130803 at a dose of 0.3 mg/kg/d by intravenous infusion to adult patients with severe EVD was not shown to improve survival when compared to historic controls. TRIAL REGISTRATION: Pan African Clinical Trials Registry PACTR201501000997429.


Assuntos
Antivirais/uso terapêutico , Ebolavirus/genética , Doença pelo Vírus Ebola/tratamento farmacológico , RNA Interferente Pequeno/uso terapêutico , RNA Viral/genética , Terapêutica com RNAi/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Ebolavirus/patogenicidade , Feminino , Doença pelo Vírus Ebola/diagnóstico , Doença pelo Vírus Ebola/genética , Doença pelo Vírus Ebola/mortalidade , Doença pelo Vírus Ebola/virologia , Interações Hospedeiro-Patógeno , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Nanopartículas , RNA Interferente Pequeno/administração & dosagem , RNA Viral/sangue , Terapêutica com RNAi/efeitos adversos , Serra Leoa , Análise de Sobrevida , Fatores de Tempo , Resultado do Tratamento , Carga Viral/efeitos dos fármacos , Carga Viral/genética , Adulto Jovem
5.
Acta Biomater ; 23: 103-115, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26022967

RESUMO

The article deals with the design, preparation, and evaluation of a new bilayered dressing for application in the healing of compromised wounds. The system is based on the sequential release of two complementary bioactive components to enhance the activation of the regeneration of dermal tissue. The internal layer is a highly hydrophilic and biodegradable film of gelatin and hyaluronic acid (HG), crosslinked with the natural compound genipin, which reacts with the amine groups of gelatin. This film is loaded with the proangiogenic, anti-inflammatory, and antibacterial peptide, proadrenomedullin N-terminal 20 peptide (PAMP), that is released slowly in the wound site. The external layer, more stable and less hydrophilic, is constituted by a biodegradable polyurethane derived from poly(caprolactone) and pluronic L61. This layer is loaded with resorbable nanoparticles of bemiparin (a fractionated low molecular weight heparin), which promotes the activation of growth factors, FGF and VEGF, and provides a good biomechanical stability and controlled permeability of the bilayered dressing. Experiments carried out in mice demonstrate the excellent angiogenic effect of the HG film in the dermal tissue. Application of the bilayered dressing in the wound healing rabbit ear model shows an improved cicatrization of the wound in both ischemic and non-ischemic defects, favoring epithelialization and reducing noticeably the contraction and the inflammation.


Assuntos
Adrenomedulina/administração & dosagem , Bandagens , Heparina de Baixo Peso Molecular/administração & dosagem , Regeneração/efeitos dos fármacos , Pele/crescimento & desenvolvimento , Pele/lesões , Implantes Absorvíveis , Animais , Preparações de Ação Retardada/administração & dosagem , Preparações de Ação Retardada/síntese química , Combinação de Medicamentos , Heparina de Baixo Peso Molecular/química , Masculino , Camundongos , Coelhos , Regeneração/fisiologia , Pele/efeitos dos fármacos , Adesivo Transdérmico , Resultado do Tratamento , Cicatrização/efeitos dos fármacos
6.
J Biomed Mater Res A ; 102(4): 1110-20, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23766296

RESUMO

This study aimed to analyze the in vitro and in vivo release kinetics and evaluate the grades of repair induced by either the release of 50 ng of transforming growth factor-ß1 or 2.5 or 5 µg of bone morphogenetic protein-2 (BMP-2) from a bilayer scaffold of segmented polyurethane/polylactic-co-glycolic (SPU/PLGA) in osteochondral defects, in a rabbit model. The scaffold consisted of a porous, bone-directed PLGA layer, overlaid with a cartilage-directed layer of growth factor (GF)-loaded PLGA microspheres, dispersed in a matrix of SPU. The PLGA porous layer was fabricated by gas foaming. Microspheres were prepared by a double emulsion method. SPU was synthesized by following the two-step method. GF release kinetics were assessed using iodinated ((125)I) GFs. The in vivo release profiles of both GFs fitted to zero-order kinetics, demonstrating a consistently good control of their release rates by SPU. Cartilage-like tissue, characterized by histological analysis, scoring, and immunolabeling of chondrogenic differentiation markers, was observed only after 12 weeks, maintaining integrity up to at least 24 weeks, independently of the GF and the dose of BMP-2. The biocompatibility and the resulting good quality, hyaline repair cartilage convert this system into a promising candidate for future applications in osteochondral lesions.


Assuntos
Proteína Morfogenética Óssea 2/farmacologia , Cartilagem/patologia , Ácido Láctico/química , Ácido Poliglicólico/química , Poliuretanos/química , Alicerces Teciduais/química , Cicatrização/efeitos dos fármacos , Agrecanas/metabolismo , Animais , Proteína Morfogenética Óssea 2/administração & dosagem , Cartilagem/efeitos dos fármacos , Contagem de Células , Colágeno/metabolismo , Fêmur/efeitos dos fármacos , Fêmur/patologia , Masculino , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Implantação de Prótese , Coelhos , Ratos , Distribuição Tecidual/efeitos dos fármacos , Fator de Crescimento Transformador beta1/administração & dosagem , Fator de Crescimento Transformador beta1/farmacologia
7.
J Res Natl Inst Stand Technol ; 116(2): 557-72, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-26989584

RESUMO

The Sistema Interamericano de Metrologia (SIM) is a regional metrology organization (RMO) whose members are the national metrology institutes (NMIs) located in the 34 nations of the Organization of American States (OAS). The SIM/OAS region extends throughout North, Central, and South America and the Caribbean Islands. About half of the SIM NMIs maintain national standards of time and frequency and must participate in international comparisons in order to establish metrological traceability to the International System (SI) of units. The SIM time network (SIMTN) was developed as a practical, cost effective, and technically sound way to automate these comparisons. The SIMTN continuously compares the time standards of SIM NMIs and produces measurement results in near real-time by utilizing the Internet and the Global Positioning System (GPS). Fifteen SIM NMIs have joined the network as of December 2010. This paper provides a brief overview of SIM and a technical description of the SIMTN. It presents international comparison results and examines the measurement uncertainties. It also discusses the metrological benefits that the network provides to its participants.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...