Background Cataract was directly associated with the damage to the structure and function of lens epithelial cells (LECs).In those patients who suffer from cataracts,morphologic changes of LECs is the most compelling evidence confirming loss of cellular structure and function of LECs.So,learning about the morphological changes of LECs of the different types of cataracts is very important for study on biological behaviors of LECs in different environments or diseases.Objective This study was to evaluate the morphological and ultrastructural changes of the LECs in different types of cataracts.Methods Anterior capsular member from age-related cataracts,diabetic cataracts and high myopia complicated cataract were obtained during the cataract surgery and 15 pieces for each.Trypan blue and alizarin red (TB-AR) stain,haematoxylin and eosin stain were performed in the samples to assess the viability and morphology of LECs.The ultrastructural change of LECs was observed under the transmission electron microscope.The features of the LECs were compared among the different types of cataract.Results TB-AR stain showed that LECs were polygon in shape with the mosaic arrangement and round cell nucleus,and a few dead cells were seen in the samples age-related cataract.In the diabetic samples,LECs largened from swelling with different sizes.More dead cells were found in the high myopia complicated cataract.Haematoxylin and eosin stain exhibited that the anterior capsular membrane presented a homogeneuous membrane,and monolayer LECs attached firmly anterior capsular membrane in the samples of related cataract.Majority of the cells had the intact structure.However,the interspaces between cells and capsular membrane were found in diabetic cataract.Also,smaller LECs were seen in high myopia complicated cataract with the irregular cell morphology.Under the transmission electron microscope,LECs presented the normal shape,intact intercellular tight junction and well attachment between cells and capsular membrane in the samples of the age-related cataract.In the samples of the diabetic cataract,edema of LECs and large intercellular spaces were seen.In addition,the jogged pump and vacuolar degeneration of cytoplasm were revealed in the high myopia complicated cataract.Conclusions The degeneration,necrosis and apoptosis was a common pathological basis of age-related cataract,diabetic cataract and high myopia complicated cataract.However,the damage of LECs was more serious in diabetic cataract and high myopia complicated cataract than that of agerelated cataract.

OBJECTIVETo study the risk classification of animal plague in Spermophilus Dauricus Focus, using the Best Subsets Regression (BSR) model.

METHODSMatlab, BSR and exponential smoothing were employed to develop and evaluate a model for risk classification as well as to forecast plague epidemics at the Spermophilus Dauricus Focus. Data was based upon the Inner Mongolia surveillance programs. This model involved 7 risk factors, including density of Spermophilus dauricus, percentage of hosts infested, host flea index, percentage of nests infested, nest flea index, percentage of runways infested, and runway flea index.

RESULTSForecasting values of the classification model(CM)were calculated and grouped into 3 risk levels. Values that over 2/3 of the CM would indicate the existence of potential epidemics while those below 1/3 would indicate that there were no risk for epidemics but when values that were in between would indicate that there exist for high risk. Annually, during the observation period in the Inner Mongolia Spermophilus Dauricus Foci, the detection of Yersinia pestis gave a risk rating value of 1 which stood for existing epidemics, while nil detection rate generated a 'zero' value which representing the situation of non-epidemic. The overall plague epidemics forecasting surveillance programs in 2012 at the Spermophilus Dauricus Foci indicated that no active plague was observed. When the forecasting values became over 2/3, combinations of all the risk factors would achieve the consistency rates of 100%. When the forecasting values were below 1/3, combinations of at least the first 4 factors could also achieve the consistency rates of 100%. However, when the forecasting values fell in between, combinations of at least the first 4 factors would achieve the consistency rates of around 50%.

CONCLUSIONResults from our study showed that plague would not be active to become epidemic, in 2012.

Animals ; China ; epidemiology ; Plague ; epidemiology ; prevention & control ; Risk Assessment ; Rodent Diseases ; epidemiology ; Sciuridae ; Yersinia pestis