Homology modeling and epitope prediction of Der f 33

Dermatophagoides farinae (Der f), one of the main species of house dust mites, produces more than 30 allergens. A recently identified allergen belonging to the alpha-tubulin protein family, Der f 33, has not been characterized in detail. In this study, we used bioinformatics tools to construct the secondary and tertiary structures and predict the B and T cell epitopes of Der f 33. First, protein attribution, protein patterns, and physicochemical properties were predicted. Then, a reasonable tertiary structure was constructed by homology modeling. In addition, six B cell epitopes (amino acid positions 34-45, 63-67, 103-108, 224-230, 308-316, and 365-377) and four T cell epitopes (positions 178-186, 241-249, 335-343, and 402-410) were predicted. These results established a theoretical basis for further studies and eventual epitope-based vaccine design against Der f 33.

Morphology of Rat Testis Preserved in Three Different Fixatives / 华中科技大学学报（医学）（英德文版）

Histopathological examination of testes is important in assessing spermatogenesis and testicular function.Modified Davidson's fluid (mDF) has been proposed as a superior substitute for Bouin's fluid (BF) for fixation of adult animal testes.Besides,4％ paraformaldehyde (PFA) has been commonly used to fix testes with convenience.We compared the morphology of the rat testis fixed in 4％ PFA,mDF,or BF using hematoxylin and eosin (HE)-stained sections.Fixation in 4％ PFA resulted in obvious tissue shrinkage artifacts,especially between seminiferous epithelium cells.Shrinkage artifacts were also observed in the central area of the testes fixed in BF.Use of mDF did not cause shrinkage artifacts between seminiferous tubules,though a small amount can be observed in seminiferous tubules between germ cells.Clarity of nuclear detail in testes fixed in mDF and BF is better compared to 4％ PFA.Our study demonstrated that fixation in mDF provided better morphologic details in the rat testis as compared with 4％ PFA and BF.

Effects of Livin Gene RNA Interference on Apoptosis of Cervical Cancer Hela Cells and Enhanced Sensitivity to Cisplatin / 华中科技大学学报（医学）（英德文版）

The recombinant plasmids pGenesii-1-BIRC71 and pGenesil-1-BIRC72 were transfected into Hela cells and cisplatin was added with different concentrations in order to study the inhibitory ef-fects of Livin gene, increase the apoptosis induced by cisplatin, and detect the expression of Bcl-2, Bax,caspase-3, and survivin genes. The pGenesil-1-BIRC71 and pGenesil-1-BIRC72 were transfected into Hela cells, and the expression levels of Livin, Bcl-2, Bax, caspase-3, and survivin genes were detected by using fluorescence quantitative real-time PCR. Then cisplatin at different concentrations (3.0, 6.0 and 9.9 μg/mL) was added into the transfected Hela cells, and 24, and 48 h later, the apoptosis rate was measured by flow cytometry. After transfection of pGenesil-1-BIRC71 and pGenesil-1-BIRC72 into Hela cells, the expression level of Livin gene was obviously reduced, and the apoptosis rate was sig-nificantly increased in transfection group as compared with control group (P<0.05). Cisplatin could in-crease the apoptosis rate in a dose- and time-dependent manner. After cisplatin was added, the expres-sion levels of Bcl-2 mRNA were reduced, and those of Bax, caspase-3, and survivin mRNA were in-creased in transfection group as compared with those in control group (P<0.05). It was concluded that shRNA expression vector targeting Livin gene could inhibit the expression of Livin gene in Hela cells and enhance the apoptosis induced by cisplatin, which was related to the decreased expression of Bcl-2and activation of Bax and caspase-3. Survivin might play an important role as an antagonist in the proc-ess of apoptosis induction.