[Comparison of application effects of colonoscopy, fecal immunochemical test and a novel risk-adapted screening approach in colorectal cancer screening in Xuzhou population].

Objective: To compare the application effect of the colonoscopy, fecal immunochemical test (FIT) and novel risk-adapted screening approach in colorectal cancer screening in Xuzhou population. Methods: From May 2018 to April 2019, 4 280 subjects aged 50-74 were recruited from Gulou district, Yunlong district and Quanshan district of Xuzhou. They were randomly assigned to the colonoscopy group (n=863), FIT group (n=1 723) and novel risk-adapted screening approach group (n=1 694) according to the ratio of 1∶2∶2. For the novel risk-adapted screening approach group, after the risk assessment, high-risk subjects were invited to undergo colonoscopy and low-risk subjects were invited to undergo FIT examination. All FIT positive subjects were invited to undergo colonoscopy. Colonoscopy participation rate [(the number of colonoscopies completed/the number of colonoscopies invited to participate)×100%], detection rate of colorectal lesions [(the number of diagnosed patients/the number of colonoscopies completed)×100%], colonoscopy resource load (the number of colonoscopies completed/the number of diagnosed advanced tumors) and FIT resource load in each group were calculated and compared. Results: The age of all subjects was (61±6) years old, including 1 816 males (42.43%). There was no statistically significant difference in the socio-demographic characteristics of the subjects in different screening groups. The colonoscopy participation rate was 22.60% (195/863) in the colonoscopy group, 57.04% (77/135) in the FIT group, and 33.94% (149/439) in the novel risk-adapted screening approach group, respectively. The colonoscopy participation rate was higher in the FIT group than in the colonoscopy group and the novel risk-adapted screening approach group (P<0.001). The colonoscopy participation rate of novel risk-adapted screening group was significantly higher than the colonoscopy group (P<0.001). The detection rates of advanced tumors were 6.67% (13/195), 9.09% (7/77) and 8.72% (13/149), respectively, and the difference was not statistically significant (P>0.05). The colonoscopy resource load (95%CI) was 15 (13-17) in the colonoscopy group, 11 (9-14) in the FIT group and 11 (10-13) in the novel risk-adapted screening approach group, respectively. Among them, the colonoscopy resource load of high-risk individuals in the novel risk-adapted screening approach group was 12 (9-15). FIT resource loads (95%CI) were 207 (196-218) and 88 (83-94) in the FIT group and the novel risk-adapted screening approach group. Conclusion: The combined application of risk-adapted screening approach and FIT may have a good application effect in colorectal cancer screening.

[Changes of intermediate filament during mitosis in two epithelial cell lines].

Immunofluorescence microscopy was used to follow the rearrangement of keratin filaments and vimentin filaments during mitosis in Vero and HeLa cell lines. The experiment results showed that the three dimensional organization and structure of intermediate filaments changed drastically during mitosis. The behavior of intermediate filaments was different in these two epithelial cell lines. In mitotic Vero cells the keratin filaments and vimentin filaments maintained their filamentous structure and formed a cage around the mitotic apparatus. In mitotic HeLa cells the keratin filaments and vimentin filaments reorganized extensively and formed granular cytoplasmic bodies. The ratio of granular cytoplasmic body formation changed in different mitotic phase. The interphase intermediate filament network was reconstructed after mitosis. It is proposed that the state of intermediate filament network in these cells is cell cycle-dependent and intermediate filaments may have some skeletal role in mitosis.

[Investigation of nuclear lamina in Tetrahymena thermophila].

The nuclear lamina in the nuclei of Tetrahymena thermophila was investigated using the techniques of selective extraction and embedment-free electron microscopy, as well as immunofluorescence staining. By means of immunoblotting and protein isolating, the lamina was found to consist mainly of a 66 KD polypeptide. While rabbit-anti-lamins polyclonal antibodies crossreacted with this protein, neither murine-anti-lamin A&C mAB C23 nor murine-anti-lamin III mAB 223 showed positive reaction with it. It was also demonstrated that the lamin is not so rich as that in mammalian cells. The existence of lamina in T. thermophila, a unicellular organism, seems to show that the lamina is a basic characteristic structure of eukaryotic cells, and that the function of the lamina may not be limited to the process of breakdown and reconstitution of nuclear envelope during mitosis.

[Vimentin and Nup 180 in vitro binding assay].

In order to investigate relationship between vimentin and nuclear pore complex, we examined binding ability of vimentin, expressed in E. coli, with nucleoporin, isolated from rat liver nuclei, in vitro. Negative staining electron microscopy showed that the vimentin expressed in bacteria assembled 10 nm filament in vitro. SDS-PAGE and western blotting showed that Nup 180 bind to vimentin in binding assay in vitro. Combining immunogold labeling and negative staining electron microscopy techniques, we showed that Nup 180 bind on the 10 nm vimentin filaments. The experiment results indicated that vimentin filament may be anchored on nuclear pore complex in vivo by binding with Nup 180.

Chronic treatment with (-)-stepholidine alters density and turnover of D1 and D2 receptors in striatum.

AIM: To study the effects of chronic administration of SPD on the density and turnover of striatal D1 and D2 dopamine (DA) receptors. METHODS: Receptor density was monitored by radio-receptor binding assay. The receptor recovery and turnover were studied after irreversible inactivation by N-ethoxycarbonyl-2-ethoxy-1, 2-dihydro-quinoline (EEDQ). RESULTS: Chronic SPD treatment (sc, 20 mg.kg-1.d-1 x 21 d) upregulated both striatal D1 and D2 receptor density. As compared to vehicle-treated rats, SPD increased D1 and D2 receptors by 41.5% and 43.7%, respectively SPD also altered the turnover of both D1 and D2 receptors. The degradation rate constant (k = 0.0082.h-1) and the synthesis rate (r = 2.65 pmol.h-1/g protein) of D2 receptors in SPD-treated rats were significantly increased vs vehicle-treated rats (k = 0.0049.h-1; r = 1.10 pmol.h-1/g protein). The degradation rate constant (k = 0.0059.h-1) and the synthesis rate (r = 3.1 pmol.h-1/g protein) of D1 receptors was also increased in SPD-treated rats vs vehicle-treated rats (k = 0.0048.h-1; r = 1.8 pmol.h-1/g protein), but the alteration of degradation rate constant missed significance (P > 0.05). As a result, receptor recovery following EEDQ was accelerated. The half time for D1 and D2 receptors recovery in SPD group were 117.5 h and 84.5 h, respectively, shorter than 144.4 h and 141.4 h in vehicle-treated rats. CONCLUSION: Chronic SPD treatment upregulated D1 and D2 receptors, and accelerated DA receptor turnover and recovery mainly by increasing receptor synthesis.

[Immunogold labeling electron microscopy showing vimentin filament anchored on nuclear pore complex].

The relationship between intermediate filament and nucleus is an important question to be solved. By combining sequential cell fractionation with immunoblotting, we showed that the intermediate filament protein in turkey erythrocyte is vimentin. Using pre-embedment immunogold labeling techniques together with sequential cell fractionation, we showed that cytoplasmic intermediate filaments in turkey erythrocyte are labeled specifically by rabbit anti-vimentin antibody-protein A-gold. Moreover, we showed that the cytoplasmic filaments anchored on nuclear pore complex were also labeled by rabbit anti-vimentin antibody-protein A-gold specifically. Our results demonstrated that cytoplasmic filaments anchored on nuclear pore complex was vimentin filament. The experiments indicated that vimentin filament may be anchored on nuclear pore complex by binding with Nup 180 and intermediate filament may be involved in nuclear transportation.

[Detection of nuclear matrix and intermediate filament scaffold in Crypthecodinium cohnii].

Nuclear matrix (NM) and intermediate filament (IF) scaffold in primitive eukaryote Crypthecodinium cohnii were shown using selective extraction together with embedment-free electron microscopy, whole mount cell preparation and immunoblot techniques. There exists a delicate NM-IF network spreading over cytoplasm and nucleus in dinoflagellate cells, however, nuclear lamina is undeveloped. The diameter of NM fiber is about 3-5 nm and IF is 10 nm. Chromosomes are connected with NM filament network. Immunoblot analysis showed that dinoflagellate contained keratin-like polypeptides (63 kD and 67 kD) while mammalian lamin antibodies did not crossreact with dinoflagellate total protein. Our experiment results demonstrated that a framework similar to NM-IF scaffold in mammalian cell appeared in primitive eukaryote. We propose that: (1) NM-IF scaffold is not restrict to vertebrate cell, and it may be originated from early stages of eukaryote evolution; (2) Keratin is probably very conservative; (3) Compared with IF, lamina might appear late in evolution, and some of primitive characteristics of dinoflagellate nucleus may be related to the lack of lamina.

Immunogold labelling of the intermediate filament-lamina-nuclear matrix system in HeLa and BHK-21 cells.

Whole-mount, sequentially extracted cells combined with immunogold electron microscopy were developed to demonstrate the intermediate filaments, lamina, and nuclear matrix (IF-L-NM) and to identify their protein components. The IFs of HeLa cells were reacted both with keratin and vimentin monoclonal antibodies; meanwhile, the IF network of BHK-21 cell was reacted only with vimentin monoclonal antibody. The lamina and nuclear matrices of both HeLa and BHK-21 cell were labelled, respectively, with lamin monoclonal antibody-gold complex and 280 Kd nuclear matrix protein monoclonal antibody-gold complex. The monoclonal antibody to keratin could cross-react with the lamina both of HeLa and BHK-21 cells.