Post-collection, pre-measurement variables affecting VEGF levels in urine biospecimens.

摘要: Angiogenesis, the development and recruitment of new blood vessels, plays an important role in tumour growth metastasis.Vascular endothelial factor (VEGF) is stimulator angiogenesis.Circulating urinary VEGF levels have been suggested as clinically useful predictors behaviour, investigations into these associations are ongoing.Despite recent interest measuring patients, little known about factors that influence biospecimens. To begin to address this question, urine samples were collected from patients with solid tumours undergoing radiotherapy healthy volunteers.Four examined for their effects on concentrations measured by chemiluminescent immunoassay: time sample collection freezing, number specimen freeze–thaw cycles, storage tube type inclusion or exclusion sediment. The results study indicate freeze up 4 hrs, cycles between one five, different types polypropylene tubes did not statistically significant levels. Urinary sediment had higher than supernatant five six patients.It clear whether there active agent causing increase if particles themselves affecting accuracy assay.Therefore, we recommend centrifuging urine, isolating supernatant, freezing microcentrifuge cryogenic vials within hrs collection.In addition, use cycles.