The gadolinium-based contrast agent Omniscan® promotes in vitro fibroblast survival through in situ precipitation.

The current study aims to explore how the gadolinium (Gd)-based contrast agent (GBCA) Omniscan® enhanced cell viability of murine fibroblasts. The results of scanning electron microscopy showed that Omniscan® can precipitate in cell culture media and deposit on cell membranes. Energy-dispersive X-ray analysis and Fourier-transform infrared spectroscopy demonstrated the presence of Gd and phosphates in the agglomerated particles. By filtering the Omniscan®-containing medium through a 220 nm filter, it can be clearly found that the increased cell viability should be mainly attributed to the insoluble species of gadolinium rather than to chelated gadolinium. Moreover, the effects of other gadolinium-based contrast agents, Magnevist® and Dotarem®, were compared with that of Omniscan®. It is noted that the three contrast agents differed in their ability to induce cell viability, which is possibly ascribed to the different chemical stabilities of gadolinium chelates as demonstrated by the attenuation in cell growth upon the addition of excess ligands to the compounds. The results of flow cytometry analysis also showed that Omniscan® can promote cell growth via an increase in the S-phase cell population as evidenced by the elevated levels of cell cycle associated proteins cyclin D, cyclin A and the phosphorylated Rb protein. Furthermore, our results revealed that integrin-mediated signaling may play an important role in both Omniscan® and Magnevist®-enhanced focal adhesion formation since the blockade of integrins decreased the level of ERK phosphorylation induced by the two GBCAs. Taken together, these data suggested that in situ gadolinium phosphate precipitation formation mediated Omniscan®-promoted fibroblast survival, which is similar to that of gadolinium chloride. It was demonstrated that the application of GBCAs with more stable thermodynamic stability may cause less dissociation of the gadolinium ion and thus resulted in less precipitation, finally leading to lower occurrence of nephrogenic systemic fibrosis. The obtained results would also be helpful for the development of safe gadolinium-based contrast agents.

[The application of integrated surveillance system for symptoms in surveillance of influenza among children].

OBJECTIVE: To explore the integrated application of sales of child-specific over-the-counter (OTC) cold related medications in retail pharmacies and healthcare visits of children for influenza-like illness (ILI) in surveillance and early warning of influenza among children. METHODS: An integrated surveillance system (ISS) was implemented since 2012 in Qianjiang County, a rural area in Hubei Province of China. The daily information from August 1, 2012 to February 28, 2013 of health care visits of children for ILI reported by 80 health facilities and sales of 14 child-specific over-the-counter (OTC) cold related medications reported by 11 pharmacies were extracted from ISS database. Cumulative sums (CUSUM) model was conducted to analyze the degree of fitting and the early warning signal generated; the correlationship was then analyzed further. RESULTS: In 212 days, 983 visits of children for ILI and 12 819 sales by person of child-specific OTC were reported. Conducting CUSUM model, the fitting degree was in the acceptable range, 31 warning signals were generated from ILI data series with 3 peak periods and 14 from OTC data series with 2 peak periods. A similar time trend of two data series was observed with a correlation(r = 0.497, P < 0.05), but without any spatial clustering. And the optimal correlation(r = 0.505, P < 0.05) appeared at a time offset of 4 days preceded by OTC sales. CONCLUSION: The availability of integrated surveillance system for symptoms could be applied for surveillance of influenza among children; while it could explore the possibility of real epidemic in the very early stage.