RESUMO
According to TWGDAM guideline 4.5 (1), prior to implementing a new DNA analysis procedure or an existing DNA analysis procedure developed by another laboratory, the forensic laboratory must first demonstrate reliability of the procedure in-house. Seven phases were designed to validate the use of the AmpFlSTR Profiler Plus PCR Amplification Kit, as well as the PE Applied Biosystems 310 Genetic Analyzer. This report summarizes the results obtained for each of the seven phases of the validation study which included the following evaluations: polymer, reproducibility, sensitivity, stutter, precision, mixtures and nonprobative casework.
Assuntos
Impressões Digitais de DNA/métodos , Reação em Cadeia da Polimerase/métodos , Sequências de Repetição em Tandem/genética , Medicina Legal/métodos , Genética Populacional , Humanos , Polímeros , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
The immunomodulator Betafectin(R) PGG-glucan is a homopolymer of glucose derived from yeast cell walls which has been demonstrated to enhance leukocyte anti-infective activity in vitro and in vivo, without the induction of proinflammatory cytokines. We report here the purification of a PGG-glucan-binding element from human leukocytes and its identification as lactosylceramide, a major glycosphingolipid of neutrophils, which includes the CDw17 epitope. The binding of radiolabeled PGG-glucan to purified lactosylceramide was saturable, specific, and time- and temperature-dependent. Lactosylceramides from human leukocytes were fractionated by high performance liquid chromatography in order to analyze the effect of ceramide structure on binding. A variety of fatty acid chain lengths with varying degrees of unsaturation were found to support binding to radiolabeled PGG-glucan. However, DL-lactosylceramides containing dihydrosphingosine did not bind. Radiolabeled PGG-glucan bound several other neutral glycosphingolipids with a terminal galactose, including galactosylceramide, globotriaosylceramide, and gangliotetraosylceramide. The binding of radiolabeled PGG-glucan to lactosylceramide was not inhibited by glycogen, dextran, mannan, pustulan, laminarin, or a low molecular weight beta-(1-3)-glucan, but was inhibited by high molecular weight beta-(1-3)-glucans and by a monoclonal antibody to lactosylceramide. Although this glycosphingolipid has been shown in numerous reports to bind various microorganisms, this represents the first report of lactosylceramide binding to a macromolecular carbohydrate.
