RESUMO
The development of multi-species biofilms in chronic wounds is a serious health problem that primarily generates strong resistance mechanisms to antimicrobial therapy. The use of silver nanoparticles (AgNPs) as a broad-spectrum antimicrobial agent has been studied previously. However, their cytotoxic effects limit its use within the medical area. The purpose of this study was to evaluate the anti-biofilm capacity of chitosan gel formulations loaded with AgNPs, using silver sulfadiazine (SSD) as a standard treatment, on strains of clinical isolates, as well as their cytotoxic effect on human primary fibroblasts. Multi-species biofilm of Staphylococcus aureus oxacillin resistant (MRSA) and Pseudomonas aeruginosa obtained from a patient with chronic wound infection were carried out using a standard Drip Flow Reactor (DFR) under conditions that mimic the flow of nutrients in the human skin. Anti-biofilm activity of chitosan gels and SSD showed a log-reduction of 6.0 for MRSA when chitosan gel with AgNPs at a concentration of 100 ppm was used, however it was necessary to increase the concentration of the chitosan gel with AgNPs to 1000 ppm to get a log-reduction of 3.3, while the SSD showed a total reduction of both bacteria in comparison with the negative control. The biocompatibility evaluation on primary fibroblasts showed better results when the chitosan gels with AgNPs were tested even in the high concentration, in contrast with SSD, which killed all the primary fibroblasts. In conclusion, chitosan gel formulations loaded with AgNPs effectively prevent the formation of biofilm and kill bacteria in established biofilm, which suggest that chitosan gels with AgNPs could be used for prevention and treatment of infections in chronic wounds. The statistic significance of the biocompatibility of chitosan gel formulations loaded with AgNPs represents an advance; however further research and development are necessary to translate this technology into therapeutic and preventive strategies.
Assuntos
Quitosana/química , Nanopartículas Metálicas/química , Prata/química , Biofilmes/efeitos dos fármacos , Células Cultivadas , Fibroblastos/efeitos dos fármacos , Géis , Humanos , Prata/toxicidadeRESUMO
PURPOSE: Phase-contrast mammography with synchrotron radiation is an innovative X-ray imaging practice that improves the identification of breast lesions. Previous studies have proven the superiority of the mammography images taken in the phase-contrast modality using synchrotron radiation beams as compared with images taken in conventional mammography by subjective analyses. However, to our knowledge, no previous study has compared different acquisition systems in order to quantify this improvement by means of objective robust indicators. In this research, we intend to quantify the superiority of phase-contrast imaging by means of objective metrics of image quality. METHODS: Images from the American College of Radiology Mammographic Accreditation Phantom were obtained at hospitals, in two digital mammography equipment and at the Elettra synchrotron radiation facility (Trieste, Italy), using free space propagation phase-contrast modality. Regions of interest were selected to analyze image quality at the fibers (phase object) and masses (area object) simulated on the phantom by means of the signal-to-noise ratio, the figure of merit, the contrast and the edge visibility. RESULTS: The image contrast and edge visibility were significantly higher at the phase-contrast modality as compared with digital mammography equipment. The figure of merit using phase-contrast modality was higher for the fibers and comparable for the masses. CONCLUSION: The results showed an improvement of the contrast and edge visibility in phase-contrast images. These improvements may be important in the detection of small lesions and details.
Assuntos
Doenças Mamárias/diagnóstico por imagem , Mamografia/métodos , Imagens de Fantasmas , Síncrotrons , Feminino , Humanos , Reprodutibilidade dos Testes , Razão Sinal-RuídoRESUMO
Gastrointestinal stromal tumors are the most frequent mesenchymal digestive tract neoplasms, but represent only 1 to3% of all GI tract neoplasms. We report an uncommon case of stromal rectal tumor because of its atypical location.
Assuntos
Hemorragia Gastrointestinal/etiologia , Tumores do Estroma Gastrointestinal/patologia , Neoplasias Retais/secundário , Hemorragia Gastrointestinal/terapia , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Neoplasias Retais/complicações , Neoplasias Retais/patologiaRESUMO
Este es un Informe dirigido al señor Presidente y demás miembros de la Liga Antituberculosa de los Hospitales, sobre el tratamiento antituberculoso aplicado a varios enfermos del Hospital Vargas. Los hombres han recibido cada uno, en el transcurso del mes de agosto: trece y catorce inyecciones hipodérmicas de suero de Maragliano, 1 centímetro cúbico por dosis, uno de los pacientes por segunda vez; al igual que las dos mujeres, quienes han estado sometidas por dos veces a la medicación por el suero: a una se le practicaron treinta y ocho inyecciones en el espacio de dos y medio meses, y a la otra solo cinco. Los seis enfermos se encontraban franca y decididamente tuberculosos; se describen los signos y manifestaciones clínicas de los enfermos. Se discute la opinión del Dr. Maragliano y la del profesor Robin y las teorías sobre tratamiento físico e higiénico. Nuestras conclusiones nos llevan a pensar que con tan escasos materiales todo juicio sería prematuro y tal vez aventurado. El veredicto final debe permanecer en reserva, en tanto se multiplican los casos y se ensancha y perfecciona la aplicación del tratamiento