RESUMO
Modern bacteriophage encapsulation methods based on polymers such as alginate have been developed recently for their use in phage therapy for veterinary purposes. In birds, it has been proven that using this delivery system allows the release of the bacteriophage in the small intestine, the site of infection by Salmonella spp. This work designed an approach for phage therapy using encapsulation by ionotropic gelation of the lytic bacteriophage S1 for Salmonella enterica in 2% w/v alginate beads using 2% w/v calcium chloride as crosslinking agent. This formulation resulted in beads with an average size of 3.73 ± 0.04 mm and an encapsulation efficiency of 70%. In vitro, the beads protected the bacteriophages from pH 3 and released them at higher pH. To confirm that this would protect the bacteriophages from gastrointestinal pH changes, we tested the phage infectivity in vivo assay. Using a model chicken (Gallus gallus domesticus) infected with Salmonella Enteritidis, we confirmed that after 3 h of the beads delivery, infective phages were present in the chicken's duodenal and caecal sections. This study demonstrates that our phage formulation is an effective system for release and delivery of bacteriophage S1 against Salmonella Enteritidis with potential use in the poultry sector.
Assuntos
Terapia por Fagos/métodos , Fagos de Salmonella/metabolismo , Alginatos/química , Animais , Bacteriófagos , Ceco/metabolismo , Encapsulamento de Células/métodos , Galinhas/microbiologia , Trato Gastrointestinal/metabolismo , Microesferas , Aves Domésticas/virologia , Fagos de Salmonella/genética , Salmonella enterica/metabolismo , Salmonella enterica/virologiaRESUMO
INTRODUCTION: splenomegaly and/or focal splenic lesions (FSL) have limited histopathologic studies due to the risk posed by splenic punctures. Percutaneous biopsies with a fine needle are difficult, especially due to interposition of gases, ascites, obesity or a history of abdominal surgery. On the other hand, endoscopic ultrasound (EUS) takes advantage of the proximity of the gastric wall to the spleen in order to puncture and visualize the needle and its movements in real time. OBJECTIVE: to describe the initial experience and results obtained with EUS-FNA in patients with splenomegaly or FSL. MATERIALS AND METHODS: this was a descriptive observational study. EUS-FNA of the spleen was performed with a slow-pull technique, which avoided fanning with an average of 3 needle passes. Biopsies were sent in Cytorich RedTM solution for analysis by cytology and cell block. RESULTS: punctures were performed in 15 patients (9 females) and the median age was 67 years (range 44-86). Patients studied due to an enlarged spleen or splenic FSL, in the context of fever of an unknown origin, adenopathies and abnormal weight loss were included. A conclusive diagnosis was achieved by EUS-FNA in 10 patients (66.7 %), 4 were large cell type B non-Hodgkin's lymphoma and one Hodgkin's lymphoma. There were no immediate or delayed complications related to the procedure. CONCLUSIONS: EUS-guided splenic punctures appear to be safe, effective and may be necessary in some clinical settings in order to complete the etiologic filiation of splenomegaly of an uncertain origin or FSL and to rule out malignancy.
Assuntos
Aspiração por Agulha Fina Guiada por Ultrassom Endoscópico , Esplenopatias , Adulto , Idoso , Idoso de 80 Anos ou mais , Endossonografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Agulhas , Esplenopatias/diagnóstico por imagem , Esplenomegalia/diagnóstico por imagemRESUMO
In our search for new antiamoebic agents, a new series of ethyl and methyl quinoxaline-7-carboxylate 1,4-di-N-oxide derivatives have been synthesized using the Beirut reaction. All compounds were characterized by spectroscopic techniques and elemental analysis. Antiamoebic activity was evaluated in vitro against Entamoeba histolytica strain HM1:IMSS by the microdilution method, and the structure-activity relationship was analyzed. We found that eleven quinoxaline derivatives showed greater activity than metronidazole and nitazoxanide with IC50 values in the range 1.99-0.35 µM. Compounds T-001 and T-016 shows IC50 values of 1.41 and 1.47 µM, respectively, with a value of selectivity index >60.
Assuntos
Antiprotozoários/química , Antiprotozoários/farmacologia , Entamoeba histolytica/efeitos dos fármacos , Quinoxalinas/química , Quinoxalinas/farmacologia , Antiprotozoários/síntese química , Óxidos N-Cíclicos/síntese química , Óxidos N-Cíclicos/química , Óxidos N-Cíclicos/farmacologia , Modelos Moleculares , Estrutura Molecular , Quinoxalinas/síntese química , Análise Espectral , Relação Estrutura-AtividadeRESUMO
In Mexico, Q fever is considered a rare disease among humans and animals. From March to May of 2008, three patients were referred, from the state of Hidalgo to a tertiary-care center in Mexico City, with an acute febrile illness that was diagnosed as Q fever. We decided to undertake a cross sectional pilot study to identify cases of acute disease in this particular region and to determine the seroprevalence of Coxiella burnetii among healthy individuals with known risk factors for infection with this bacteria. Q fever was defined according to the Centers for Disease Control and Prevention criteria. All subjects were interviewed for signs and symptoms of the disease, demographic and household characteristics and occupational exposure to cattle. Blood samples were taken from hospitalized and outpatients with symptoms suggestive of Q fever, as well as from asymptomatic individuals with direct and daily exposure to cattle (slaughterers, butchers, farmers, shepherds and veterinarians) in the five municipalities. We report the occurrence of 17 cases with positive antibodies against C. burnetii in a rural area of central Mexico; eight cases had clinical criteria of acute Q fever disease. Results from this pilot study underscore the need for active surveillance programs and comprehensive studies to further define the prevalence and risk factors associated with the disease in Mexico, to know more about its clinical presentation and to characterize bacterial factors involved in its pathogenesis.