[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.

Left ventricular deformation associated with cardiomyocyte Ca(2+) transients delay in early stage of low-dose of STZ and high-fat diet induced type 2 diabetic rats

Background

In the early stage of diabetes, the cardiac ejection fraction is preserved, despite the existence of the subclinical cardiac dysfunction to some extent. However, the detailed phenotype of this dysfunction and the underlying mechanism remain unclear. To improve our understanding of this issue, we used low-dose STZ and high-fat diet to induce type 2 diabetic models in rats. The effects and the mechanism associated with the early stages of the disease were analyzed.

Methods

The type 2 diabetic mellitus (T2DM) in SD rats were induced through 30 mg/kg STZ and high-fat diet. Two-dimensional spackle-tracking echocardiography (STE) and the dobutamine test were performed to examine the cardiac function. Calcium transients of left ventricular myocytes were detected and the related intracellular signalling factors were analyzed by western blotting.

Results

After 6-weeks, T2DM rats in left ventricular (LV) diastole showed decreased global and segment strain(S) levels (P < 0.05), both in the radial and circumferential directions. Strain rate (Sr) abatement occurred in three segments in the radial and circumferential directions (P < 0.05), and the radial global Sr also decreased (P < 0.05). In the systolic LV, radial Sr was reduced, except the segment of the anterior septum, and the Sr of the lateral wall and post septum decreased in the circumferential direction (P < 0.05). Conventional M-mode echocardiography failed to detect significant alterations of cardiac performance between the two groups even after 12 weeks, and the decreased ejection fraction (EF%), fractional shortening (FS%) and end-systolic diameters (ESD) could be detected only under stress conditions induced by dobutamine (P < 0.05). In terms of calcium transients in cardiac myocytes, the T_peak in model rats at 6 weeks was not affected, while the T_decay1/2 was higher than that of the controls (P < 0.05), and both showed a dose-dependent delay after isoproterenol treatment (P < 0.05). Western blot analysis showed that in 6-week T2DM rats, myocardial p-PLB expression was elevated, whereas p-CaMKII, p-AMPK and Sirt1 were significantly down-regulated (P < 0.05).

Conclusion

A rat model of T2DM was established by low dose STZ and a high-fat diet. LV deformation was observed in the early stages of T2DM in association with the delay of Ca²⁺ transients in cardiomyocytes due to the decreased phosphorylation of CaMKII. Myocardial metabolism remodeling might contribute to the early LV function and calcium transportation abnormalities.

[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.

[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.

[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.

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.