[Influence of data quality on early warning sensitivity of syndromic surveillance system based on medical institutions].

Objective: To evaluate the influence of data quality on the sensitivity of early warning syndromic surveillance system based on medical institutions in Qianjiang, Hubei province and explore the relationship between data quality and sensitivity of early warning of the system. Methods: The delay reporting rate and underreporting rate were calculated for the evaluation of the data quality. Data obtained from semi-synthetic simulated outbreak and area under the curve (AUC) were used in combination to test the sensitivity of early warning of various models and select the optimal model. Time-series generalized additive model (GAM) was used to analyze the curve fitting and threshold effect between data quality and early warning sensitivity of the system. Results: A total of 179 905 cases were reported from April 1, 2012 to January 31, 2014, in which 8 744 were not reported timely (16.45%). Averagely 416 reporting were delayed in each month. There were 2 566 cases which were underreported (4.83%). Compared with other early warning models, i.e. Cumulative Sum (CUSUM), Shewhart, Exponentially Weighted Moving Average (EWMA), Early Aberration Reporting System (EARS-3C), the MA model had the maximum area under the curve (AUC=0.93), and the difference was significant (P<0.001). The early warning sensitivity ranged from 84.89% to 97.25% during the operation period of the syndromic surveillance system. Underreporting had influence on early warning sensitivity, when underreporting rate was over 2.78%, the sensitivity would decrease obviously. No obvious associations were observed between the delay reporting rate and early warning sensitivity of the system. Conclusion: The data quality had influence on the early warning sensitivity of the syndromic surveillance system based on medical institution in Qianjiang. In the context of this study, underreporting had the main influence on the sensitivity of early warning.

In vitro cell culture model for anti-cataract drug penetration studies.

Immortalized human corneal epithelial cells (HCECs) and human lens epithelial cells (HLECs) were cultured in vitro. Cells were observed under a phase-contrast microscope and the integrity of cell monolayers was assayed by transepithelial electrical resistance (TEER) determination. The permeability of disulfiram (DSF) through a HCECs monolayer was compared with that of DSF through an excised rabbit cornea. The permeability coefficients of DSF through a HCECs monolayer and excised rabbit cornea were 29.5 +/- 4.8 x 10(-6) cm/s and 34.7 +/- 5.2 x 10(-6) cm/s, respectively. Diethyldithiocarbamate (DDC) had high permeability through HLECs monolayer with a permeability coefficient of 44.6 +/- 7.1 x 10(-6) cm/s. The cytotoxicity of DDC against HLECs was investigated using the trypan blue exclusion test. For a DDC concentration of 5 mmol/l, more than 85% cells were viable. DH3a1 mRNA was expressed in cultured HLECs. The expression of aldehyde dehydrogenase 3a1 (ALDH3a1), which may be be responsible for DSF-DDC conversion, was detected using RT-PCR and agarose gels electrophoresis. These results demonstrate that the permeability of DSF can be detected and intra-ocular drug action may be predicted using the cultured HCEC and HLEC monolayers as model.

Evaluation of transdermal permeability of pentoxifylline gel: in vitro skin permeation and in vivo microdialysis using Wistar rats.

The aim of the present work was to evaluate the transdermal permeability of pentoxifylline gel in vitro and in vivo. Gel was prepared with carbomer 934 as the base, and the Wistar rat was chosen as an animal model. The effects of percutaneous enhancers on the transdermal permeability of pentoxifylline gel were investigated by in vitro permeation experiments. Cumulative permeation at different times was determined by HPLC. 3% Azone and 5% propylene glycol were used as collaborative enhancers in an optimal formulation. Topical concentrations at different times were measured by microdialysis in vivo. The transdermal process of pentoxifylline fits to a zero-order kinetic equation, and its release profile remains of the zero-order despite the addition of enhancers. In addition, a good in-vitro-in-vivo correlation was achieved.