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Background: Choroidal neovascularization (CNV) is a major cause of blindness in patients with age-related macular degeneration. CNV is characterized by new blood vessel growth and subretinal fluid accumulation, which results in mechanical pressure on retinal pigment epithelial (RPE) cells. The overexpression of RPE-derived angiogenic factors plays an important role in inducing CNV. In this work, we investigated the effect of mechanical stress on the expression of angiogenic factors in porcine RPE cells and determined the impact of conditioned medium on in-vitro angiogenesis. Results: The goal of this study was to determine whether low levels of acute mechanical stress during early CNV can induce the expression of angiogenic factors in RPE cells and accelerate angiogenesis. Using a novel device, acute mechanical stress was applied to primary porcine RPE cells and the resulting changes in the expression of major angiogenic factors, VEGF, ANG2, HIF-1α, IL6, IL8 and TNF-α, were examined using immunocytochemistry, qRT-PCR, and ELISA. An in vitro tube formation assay was used to determine the effect of secreted angiogenic proteins due to mechanical stress on endothelial tube formation by human umbilical vein endothelial cells (HUVECs). Our results showed an increase in the expression of VEGF, ANG2, IL-6 and IL-8 in response to mechanical stress, resulting in increased in vitro angiogenesis. Abnormal epithelial-mesenchymal transition (EMT) in RPE cells is also associated with CNV and further retinal degeneration. Our qRT-PCR results verified an increase in the expression of EMT genes, CDH2, VIM and FN1, in RPE cells. Conclusions: In conclusion, we showed that acute mechanical stress induces the expression of major angiogenic and EMT factors and promotes in vitro angiogenesis, suggesting that mechanical stress plays a role in promoting aberrant angiogenesis in AMD. [ABSTRACT FROM AUTHOR]

Background: Cavity effusion is common in patients with infectious diseases. However, the incidence rate and characteristics of serous cavity effusions (SCE) in septic patients are not clear to date. The objective of this study was to investigate the incidence and characteristics of SCE in septic patients and to explore the correlations between the bloody effusions and the illness severity/prognosis in septic patients. Methods: From January 2010 to January 2015, a total of 214 patients with severe sepsis and septic shock were enrolled in this retrospective observational study. Thoracentesis or abdominal paracentesis was performed in 45 septic patients because of massive pleural effusions or ascites. The serum concentrations of VEGF, VEGFR, Ang, sICAM-1, sVCAM-1, E-selectin, Serpine1 and VE-cadherin in 45 septic patients underwent paracentesis were measured by enzyme-linked immunosorbent assay (ELISA). Results: Of the 214 septic patients, 155 (72.4%) had SCE according to imaging or ultrasound manifestations. 45 subjects with SCE underwent therapeutic thoracentesis or abdominal paracentesis. Effusion laboratory analysis showed that exudates were predominant when compared with transudates (95.6% vs. 4.4%), and 16 (35.6%) patients suffered bloody effusions. Compared with patients with non-bloody effusions, those with bloody effusions showed higher critical illness scores (13 vs. 17 for APACHE II; 7 vs. 9 for SOFA), and higher mortality (6.9% vs. 62.5%). Moreover, patients with bloody effusions had delayed TT and APTT, increased D-dimer concentration, and higher serum levels of CRP and PCT (P < 0.05). In addition, the serum levels of Ang2, sVCAM-1 and E-selectin were significantly higher in patients with bloody effusions than in those with non-bloody effusions (P < 0.05). However, the serum level of VEGFR2 was lower in patients with bloody fluids (P = 0.025). Conclusions: The incidence of serous cavity effusion is high in patients with sepsis. The septic patients with bloody effusions suffer a more inflammatory burden and a worse prognosis compared to septic patients with non-bloody effusions. [ABSTRACT FROM AUTHOR]