RESUMO
Interactions of bacteria with target molecules (e.g. antibiotics) or other microorganisms are of growing interest. The first barrier for targeting gram-negative bacteria is layer of a Lipopolysaccharides (LPS). Liquid crystal (LC) based sensors covered with LPS monolayers, as presented in this study, offer a simple model to study and make use of this type of interface for detection and screening. This work describes in detail the production and application of such sensors based on three different LPS that have been investigated regarding their potential to serve as sensing layer to detect bacteria. The LPS O127:B8 in combination with a LC based sensor was identified to be most useful as biomimetic sensing surface. This LPS/LC combination interacts with three different bacteria species, one gram-positive and two gram-negative species, allowing the detection of bacterial presence regardless from their viability. It could be shown that even very low bacterial cell numbers (minimum 500 cell ml(-1)) could be detected within minutes (maximum 15 min). The readout mechanism is the adsorption of bacterial entities on surface bond LPS molecules with the LC serving as an optical amplifier.
Assuntos
Antibacterianos/farmacologia , Técnicas Biossensoriais , Bactérias Gram-Negativas/isolamento & purificação , Cristais Líquidos/química , Adsorção , Antibacterianos/química , Bactérias Gram-Negativas/química , Bactérias Gram-Negativas/efeitos dos fármacos , Lipopolissacarídeos/química , Fenômenos ÓpticosRESUMO
We have used discriminant analysis of the results of clinical examination to study whether or not it is possible to presume the histological findings of the kidney within the limits of the screening tests (urinalysis and blood tests) presently conducted at the outpatient clinic. A retrospective analysis was made of the data for 42 children who were found in school urine tests to have urinary abnormalities. Two discriminant functional equations were made and the overall rates of correct discrimination were > or = 90%. Proteinuria, IgA and complement titer were selected. These results were considered useful in determining the indication for renal biopsy.
Assuntos
Programas de Rastreamento/métodos , Nefrite/patologia , Adolescente , Biópsia , Criança , Pré-Escolar , Complemento C3/análise , Complemento C4/análise , Diagnóstico Diferencial , Análise Discriminante , Feminino , Fibrinogênio/análise , Glomerulonefrite/sangue , Glomerulonefrite/epidemiologia , Glomerulonefrite/patologia , Glomerulonefrite/urina , Humanos , Imunoglobulina A/análise , Imunoglobulina G/análise , Imunoglobulina M/análise , Masculino , Nefrite/sangue , Nefrite/epidemiologia , Nefrite/urina , Estudos Retrospectivos , Serviços de Saúde Escolar , Sensibilidade e EspecificidadeRESUMO
An 11 5/12-year-old girl with pituitary dwarfism had intractable nocturnal enuresis. Magnetic resonance imaging revealed pituitary stalk transection and the formation of an ectopic posterior lobe. The results of responses to dehydration, infusion of hyperosmolar NaCl solution, and 1-desamino-8-D-arginine vasopressin showed that the nocturnal enuresis in the present case was due to a partial vasopressin deficiency. We suggest that the ectopic posterior lobe is one cause of nocturnal enuresis.