Simulations for epidemiology and public health education.

Recent and potential outbreaks of infectious diseases are triggering interest in predicting epidemic dynamics on a national scale and testing the efficacies of different combinations of public health policies. Network-based simulations are proving their worth as tools for addressing epidemiology and public health issues considered too complex for field investigations and questionnaire analyses. Universities and research centres are therefore using network-based simulations as teaching tools for epidemiology and public health education students, but instructors are discovering that constructing appropriate network models and epidemic simulations are difficult tasks in terms of individual movement and contact patterns. In this paper we will describe (a) a four-category framework (based on demographic and geographic properties) to discuss ways of applying network-based simulation approaches to undergraduate students and novice researchers; (b) our experiences simulating the transmission dynamics of two infectious disease scenarios in Taiwan (HIV and influenza); (c) evaluation results indicating significant improvement in student knowledge of epidemic transmission dynamics and the efficacies of various public health policy suites; and (d) a geospatial modelling approach that integrates a national commuting network as well as multi-scale contact structures.

[Effect of immunostimulatory DNA sequence on the production of Th1 and Th2 cytokines induced by Dermatophagoides farinae allergen in vitro].

OBJECTIVE: To investigate the immunoregulatory effect of immunostimulatory DNA sequence (ISS) on the production of Th1 and Th2 cytokines induced by mite allergen in PBMC of the patients with mite allergic asthma in vitro. METHODS: PBMC from the patients with allergic asthma and normal controls were isolated and cultured in vitro stimulated by ISS and Dermatophagoides farinae allergen (Df). IL-12, IFN-gamma and IL-5 in the cell supernatants were detected by ELISA. Df specific IgE in sera of patients were assayed by fluorescent enzyme immunoassay. RESULTS: PBMC from both the patients and normal controls stimulated by ISS plus Df produced a significant increase in the level of both IFN-gamma and IL-12 compared with non-ISS and Df stimulations, whereas IL-5 was decreased. Moreover, the levels of IFN-gamma, IL-12 produced were significantly higher in normal controls than in the patients, on the contrary, IL-5 was down regulated. It was also shown that the level of IL-12 produced by PBMC of the patients with ISS plus Df stimulation correlated positively with that of IFN-gamma. CONCLUSION: ISS not only promotes the expressions of Th1 cytokines but also downregulates the production of Th2 cytokines induced by Df in both allergic and non-allergic individuals, indicating its potential application in the immunotherapy of mite allergy.

[Purification and physicochemical characterization of allergen I from Dermatophagoides farinae].

Dermatophagoides farinae allergen I (Der f I) has been extracted and purified from spent culture medium of Dermatophagoides farinae by affinity chromatography coupled with anti-Der f I McAb for the first time in China. Furthermore, its physicochemical properties were analysed. By SDS-PAGE, Der f I was estimated to have a molecular weight of 24 kDa and appeared as only one protein band. By isoelectric focusing, it was revealed to have pIs of 4.8-7.5 with six protein bands, suggesting that Der f I is heterogeneous with complicated composition.

[Ultrastructure of metacercarial membrane and immunohistochemical localization of metacercarial membrane reaction of Paragonimus westermani].

The ultrastructure of the tegument of the early excysted P. westermani metacercariae was observed with transmission electron microscope. The tegument was fine and dense in texture, containing a lot of disk-like bodies and a few mitochondria. The outer-plasma membrane was clear and intact. After the metacercariae were incubated in rabbit anti-serum for 3 hours, metacercarial membrane reaction (MMR) appeared closely to the outer plasma membrane and the tegument was damaged. Indirect peroxidase-labelled immunohistochemical technique was used to identify the location of the MMR at ultrastructural level. The result showed that the antibody-antigen complex was localized on the tegumental surface of the worm. The data constituted the evidence that the MMR resulted from the antibody-antigen reaction and the tegumental surface was the reaction site for the MMR.