RESUMO
Blue green microalgae have been identified as one of the promising groups of organism from which biochemically active natural products have been isolated. Aqueous and organic extracts of nine blue green microalgae strains were screened against in vitro generated vancomycin intermediate resistant Staphylococcus aureus (VISA) strains. Aqueous extracts of all the blue green microalgae cultures were found to be inactive, while all the organic (hexane, chloroform and methanolic) extracts of Anabaena virabilis and Anabaena sp. showed activity against VISA strains with MIC of 32-64 mug/ml.
Assuntos
Anti-Infecciosos/farmacologia , Cianobactérias/química , Staphylococcus aureus/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Compostos Orgânicos/química , Resistência a VancomicinaRESUMO
Scatter and veiling glare are predominant sources of error in videodensitometric iodine quantification. Standard beam stop techniques such as lead strips or an array of lead discs, placed before the patients, have previously been used to measure scatter and veiling glare in digital radiographic images. However, these techniques significantly increase patient x-ray exposure. In order to overcome this limitation, a scatter measurement technique based on sampled primary intensity has been investigated. This technique uses an array of apertures in a lead sheet to sample the primary x-ray intensity. The scatter-glare intensity in these locations is calculated by subtracting the sampled primary intensity from an open field image which contains both primary and scatter-glare. The calculated scatter-glare values can be interpolated or combined with digital filtration to estimate the scatter-glare intensity on a pixel by pixel basis. The technique was evaluated using a Lucite step phantom and an anthropomorphic chest phantom. The average rms percentage errors of scatter and veiling glare estimation using bi-cubic interpolation and digital filtration techniques were 8.02% and 7.53%, respectively. The average rms percentage errors of primary intensity estimation using bi-cubic interpolation and digital filtration techniques were 10.01% and 8.91%, respectively. The x-ray exposure-area product (EAP) from the aperture array was only 4.38% of the EAP from the open field. These results indicate that the scatter-glare intensity can be accurately estimated with minimal x-ray exposure using sampled primary intensity.
Assuntos
Densitometria/instrumentação , Densitometria/métodos , Ofuscação , Processamento de Imagem Assistida por Computador , Desenho de Equipamento , Chumbo , Modelos Teóricos , Imagens de Fantasmas , Espalhamento de Radiação , Raios XRESUMO
PIP: Agglutination and immobilization tests were performed to detect the presence of sperm antibodies in the sera of 100 vasectomized men. Overall, 52% of subjects had sperm antibodies. 50% showed agglutinating antibodies, while immobilizing antibodies were present in 40%. Of the 52 positive cases, 23 showed agglutinating antibody alone in their sera. 73 had both agglutinating and immobilizing antibodies, and 3.8% had sperm immobilizing activity alone. The age incidence of the presence of sperm antibodies was as follows: under 35 years, 66%; 36-40 years, 50%; 41-45 years, 50%; and 46 years and above, 33.3%. The highest percentage of presence of sperm antibodies was recorded in men who had been vasectomized less than 1 year previously (75%). Significantly high titers of sperm agglutinating activity were found in 20% of the positive cases, while high titers of sperm immobilizing activity were noted in 40% of positive cases. It has been suggested that the development of sperm antibodies after vasectomy may prevent subsequent successful restoration of fertility by reanastomosis.^ieng