RESUMO A infecção por parvovírus de ganso (GPV) é uma doença infecciosa altamente patogênica em gansinhos e patinhos de Muscovy. Para detectar o antígeno GPV, desenvolvemos um novo ensaio imunoenzimático (ELISA) sanduíche usando um anticorpo de domínio único de cadeia pesada específico contra a proteína GPV NS1 como anticorpo de detecção. Os limites de detecção da proteína GST-NS1 e do título do vírus da cepa GPV H1 foram 5 ng/mL e 102,9 TCID50/mL, respectivamente. O ELISA sanduíche foi específico para GPV sem reatividade cruzada com outros vírus comuns de ganso, incluindo vírus Tembusu, circovírus de ganso, adenovírus de aves, vírus Newcastle ou vírus H9 da gripe aviária. Um total de 118 amostras de swab cloacal foram usadas para detectar o antígeno GPV usando o ELISA sanduíche e reação em cadeia da polimerase com uma taxa de coincidência de 91,5%. A sensibilidade e especificidade do ELISA sanduíche foram de 91,6% e 91,4%, respectivamente. Esses resultados sugerem que este ELISA sanduíche pode ser aplicado para detectar GPV.

Notch signaling plays a vital role in tumorigenicity and tumor progression by regulating proliferation, invasion, and the tumor microenvironment. Previous research by our group indicated that Notch ligand Delta-like 1 (Dll1) is involved in angiogenesis in melanoma, and we noticed that it took a longer time to trypsinize Dll1-expressing B16 melanoma cells than the control cells. In this article, we extended our study to investigate the effects of Dll1 on tumor cell adhesion and metastasis. Dll1 overexpression activated Notch signaling in B16 tumor cells and significantly enhanced the adhering capacity of B16 tumor cells both in vitro and in vivo. B16-Dll1 cells also had a higher metastatic potential than their counterpart in the mouse model of lung metastasis. Along with increased Dll1 expression, N-cadherin, but not E-cadherin, was upregulated in B16-Dll1 cells. These data suggested that Notch ligand Dll1 may enhance the adhesion and metastasis of melanoma cells by upregulation of N-cadherin.

Angiopoietin (Ang)-1 and Ang-2 interact in angiogenesis to activate the Tie-2 receptor, which may be involved in new vessel maturation and regression. Mast cells (MCs) are also involved in formation of new blood vessels and angiogenesis. The present study was designed to test whether MCs can mediate angiogenesis in myocardial microvascular endothelial cells (MMVECs). Using a rat MMVEC and MC co-culture system, we observed that Ang-1 protein levels were very low even though its mRNA levels were increased by MCs. Interestingly, MCs were able to enhance migration, proliferation, and capillary-like tube formation, which were associated with suppressed Ang-2 protein expression, but not Tie-2 expression levels. These MCs induced effects that could be reversed by either tryptase inhibitor [N-tosyl-L-lysine chloromethyl ketone (TLCK)] or chymase inhibitor (N-tosyl-L-phenylalanyl chloromethyl ketone), with TLCK showing greater effects. In conclusion, our data indicated that MCs can interrupt neovessel maturation via suppression of the Ang-2/Tie-2 signaling pathway.