A murine MTEC_1 thymus epithelial cell line established by us has been characterized. The cells were polyhydral and closely packed each other as epithelial like cells. Using anti-keratin antibody, the keratin were shown in cytoplasm of all cells. Under electronmicroscope, bunches of tonofilaments were clearly shown in the cytoplasm, and desmosomes were seen between neighbouring cells. Using anti-mouse epithelial cell monoclonal antibodies for immunohistochemical study, nearly all of the MTEC_1 cells were MTS33 positive. It suggests that MTEC, cells were derived from the epithelial cells located in medulla. The majority of the MTEC_1 cells have normal mouse diploid chomosome number of 40. These results provide evidence that MTEC, cell line is normal murine thymus epithelial cells.

Fresh cryostat sections from the thymus of BALB/c adult mice were processed with semipermeable membrane technique for demonstration of non-specific esterase (NE). The various cell types and the pattern of their distribution may be showed, because this technique may preserve the total enzyme activity of cells. The NE activity of epithelial reticular cells (ERC), thymic nurse cells (TNC), and interdigitating cells (IDC) are lower, but macrophages (M?) show a high activity. Cortical ERCs appear as a sponge-like network. Medullary ERCs may be divided into two cell types, i. e. low and high activity cells. The distribution of the latter shows foci-like pattern. M? present in both the cortex and medulla, in the cortico-medullary border they are prominent and may form rosettes-like structure with thymocytes. The thymus was also studied with immunohistochemical method using the monoclonal antibody of rat-anti-mouse thymic stromal ceils (MTS-6). This observation enable studies on the type of thymic stromal cells formed thymic microenvironment under LM.

The ultrastructural localization of acid phosphatase in the cells of mouse thymic cortex was described by using Robinson and Karnovsky method with cerium chloride as capture agent. The results indicated that the enzyme activity was localized mainly on the plasma membrane of epithelial reticular cells and thymocytes, especially where both of them were in contact with each other. Acid phosphatase activity was also found in the invaginations of plasma membrane, the vesicles near the plasma membrane, the saccules of the Golgi zone, the lysosomes, and a part of the vacuoles of epitheleial reticular cells. The lysosomes and the dense granules of cytoplasm, as well as on the some area of plasma membrane of the macrophages showed the enzyme activity. The enzyme activity was demonstrated in the cytoplasm and on the plasma membrane of degenerated thymocytes. The role of acid phosphatase in thymic cortex cells was discussed.

The thymic cortex is the important site for thymocyte differentiation, maturation and selection. Direct cell-cell interactions between thymocytes and distinct stromal cells are an important pattern to demonstrate the essential role in T-cell development. In order to approach the mechanism of their interactions, ultrastructural cytochemical localization of 5'-nucleotidase activity in the thymic cortex of BALB/c mice were investigated by means of Robinson and Karnovsky method using 5'-AMP or 5'-IMP as the substrate, cerium as the capture agent, and levamisol (an inhibitor of nonspecific alkaline phosphatase) was also used. The cytochemical distribution of the reaction products from both the 5'-AMPase and 5'-IMPase activity was essentially similar. The enzyme activity was localized on the extracellular side of the plasma membrane of the epithelial reticular cells and some thymocytes, especially on their contact faces with each other. 5'-nucleotidase activity was also found in the lysosomes of macrophages and in the vacuoles, and vesicles near the plasma membrane and some lysosomes of epithelial reticular cells. The biological significance of the 5'-nucleotidase in thymic cortex was discussed.

OBJECTIVE To analyze resistance and detect plasmid-mediated AmpC genes in Klebsiella pneumoniae.METHODS The susceptibility of the K.pneumoniae to 13 antibiotics was tested by K-B method.Modified three-dimensional extract test was adopted to detect AmpC lactamases in K.pneumoniae.The genotypes of AmpC lactamases were determined by polymerase chain reaction and sequencing.RESULTS Among the 105 isolates,the rate of extended spectrum ?-lactamases(ESBLs) was 41.90%,the rate of AmpC ?-lactamases was 0.95% strains,and the rate of ESBLs and AmpC ?-lactamases was 2.86%.DNA sequence analysis conformed that AmpC lactamases positive isolates were DHA AmpC gene.The resistance rate to penicillins,cephalosporins,?-lactam/?-lactam inhibitors,monobactams,and fluoroquinolones was very high.The susceptibility rate to imipenem was 100.00%.CONCLUSIONS The plasmid-mediated AmpC gene is present in clinically isolated K.pneumoniae.The resistance can be transferred to homologous or different genera of bacteria.

Objective To discuss the mechanism of inhibition of platelet activation by tanshinone type ⅡA(TanⅡA) through G protein signal pathway.Methods Methylthiazolyldiphenyl-tetrazolium bromide(MTT) test was used to determine the optimum effective concentration and optimal time of thrombin and TanⅡA on platelet.Northern blot and Western blot were used to detect the transcription and expression levels of G protein and related signal molecules,including protease activated receptors(PARs),P2Y1 and P2Y12 receptors,α2A-adrenergic receptor and thromboxane A2(TXA2) receptor,in control group,thrombin treated group and TanⅡA treated group,and the platelet aggregation rate was also detected.Results Platelet aggregation rate,and the transcription and expression levels of G protein and related molecules in thrombin treated group were higher than control group(P<0.05).The transcription and expression levels of G protein and related molecules in different concentrations of TanⅡA treated groups were lower than thrombin treated group(P<0.05).Conclusion TanⅡA could inhibit the activation of platelet by inhibiting the transcription and expression of G protein and the related molecules.

Objective To analyze the clinical characteristics of pulmonary infection in patients with multiple myeloma for improving early prevention,diagnosis and treatment.Methods A retrospective analysis was conducted for 70 patients with multiple myeloma admitted to our hospital from January 2012 to April 2015.The clinical data of pulmonary infection were reviewed and analyzed in terms of radiological findings,pathogen distribution,and related risk factors.Results The peripheral white blood cell count and neutrophil percentage could be normal in pulmonary infection of patients with multiple myeloma.However,erythrocyte sedimentation rate increased significantly.Radiological study revealed that infection of bilateral lungs was common.The most frequently identified pathogens were gram negative bacteria,especially Pseudomonas aeruginosa.The main predisposing factors of pulmonary infection were agranulocytosis,stage Ⅲ multiple myeloma,and complications.Conclusions The clinical symptoms of pulmonary infection are diverse in patients with multiple myeloma.Poor immunity is the primary predisposing factor.The common pathogens are gram-negative bacteria.Beta-lactam/beta-lactamase inhibitor combinations or fluoroquinolones are effective empiric treatment for controlling the progression of pulmonary infection.

Objective To investigate the detection rate of malnutrition among post-stroke patients in community hospitals and unravel the relevant factors that precipitate malnutrition after stroke. Methods Based on 438 post-stroke patients who were admitted in community hospitals, we examined the demographic characteristics, the nutritional indices and the possible malnutrition related factors through a cross-sectional study.Results The detection rate of malnutrition among post-stroke patients was 52.7%. Group comparison through multivariate logistic regression analysis showed that there was a higher malnutrition detection rate in the post-stroke patients with multiple stroke attacks (three stroke attackes and above, OR = 11.00,95%CI 1. 14-106.34), higher NIHSS scores (group with NIHSS≥15, OR=7.09, 95% CI 2.90-17.36) , higher modified Rankin scales (group mRS 4-5, OR = 15. 77,95% CI 6.61-37.59) (trend test P<0.0001) .The risk of malnutrition was also correlated with the post-stroke depression, poorer family care, no early-stage rehabilitation, history of malignant tumors and severe alcoholism. Conclusions There is a high detection rate of malnutrition among post-stroke patients in community hospitals. There are many factors related to malnutrition among post-stroke patients in the community. More attention to controllable influencing factors would improve the prognosis of post-stroke patients.