Chemoprevention is the use of natural or synthetic substances to prevent、suppress or to reverse the development of colorectal cancer.Aspirin and cox-2 inhibitor are the most effective preventive agents.However,the gastrointestinal and cardiovascular adverse effects limit the application.Recurrent adenomas can be markedly reduced by a combination of difluoromethylornithine and sulinclac and with few side effects.5-aminosalicylate and ursodeoxycholic acid have become the focus of inflammatory bowel disease.The double roles of folate need further study.Statins and EGFR inhibitors have some effects,which are in early clinical studies.The article reviews the new progress of chemoprevention of colorectal cancer.

Objective To observe the effects of the different serum uric acid levels on expression of Alzheimer’s disease biomarkers (APP and BACE1) in rats. Methods Intraperitoneal injection of oxygen of oxazine acid potassium was used to produce HUA models in rats. H&E staining was used to detect the morphological changes of the hippocampus. Western blot was used to detect the protein levels of APP and BACE1 of the hippocampus. Results Compared with nor-mal control group, the serum uric acid and the protein levels of APP and BACE1 in the hippocampus was obviously in-creased at OAPS treatment group (P<0.01). Compared with low dose OAPS treatment group, the serum uric acid level was significantly increased whereas the protein levels of APP and BACE1 in the hippocampus were significantly decreased at the middle and high dose group (P<0.01). Compared with middle dose group, the serum uric acid level was increased at high dose group (P<0.05) and the expression of APP were decreased in the hippocampus rats but the expression of BACE1 remained unchanged (P>0.05). Conclusion The higher level of serum uric acid may be a protective factor of AD. The higher serum uric acid levels, the lower the risk of AD.

In physiological property and growing environment aspects, there are some similarities between Acidthiobacillus ferrooxidans(ATF) and magnetotactic bacteria. ATF shows magnetotacxis under the microscope. The magnetosome can be extracted from ATF by using the extracting method of magnetosome from magnetotactic bacteria. The membrane of ATF was crushed by ultrasonic wave and the magnetosomes in the ATF which mainly contains Fe through chemical detection were attracted by using magnetite. After purifing with sucrose density gradient centrifugation and washing by PBS, the magnetosomes can be seen clearly through a transmission electron microscope. The results indicate there are a small amount of intracellular magnetosomes which made the ATF be magnetotactic under the applied magnetic field. It is the first time to find that ATF was magnetotactic. The magnetotaxis of ATF can be utilized and isolated by the magnetotactic properties to gain the high-performance ATF strains of mineral leaching, which have high activity and different magnetism.

Objective To investigate the efficacy of foramen magnum decompression alone and foramen magnum decompression + Syrinx-shunt in the treatment of Chiari anomalies with syringomyelia.Methods Forty-nine Chiari anomalies with syringomyelia patients were selected,28 patients performed foramen magnum decompression alone (surgical method Ⅰ group),21 patients performed foramen magnum decompression + Syrinx-shunt (surgical method Ⅱ group).The treatment efficacy was evaluated by postoperative clinical effect and MRI review.Results In surgical method Ⅰ group,effective in 18 cases,invalid in 10 cases,the effective rate was 64.3％ (18/28).In surgical method Ⅱ group,effective in 19 cases,invalid in 2 cases,the effective rate was 90.5％(19/21).There was statistical difference (x2 =4.45,P =0.034).Conclusion Foramen magnum decompression + Syrinx-shunt is effective in the treatment of Chiari anomalies with syringomyelia,which is applicable for these patients and has a more precise consequence than foramen magnum decompression alone.

Objective To observe the influence of p53-upregulated modulator of apoptosis (PUMA) on the growth of human brain glioma cell lines U251 (p53 mutant) and SHG-44 (p53 wild type),and to explore its possible mechanism.Methods Construct the adenovirus PUMA (Ad-PUMA) and vector of adenovirus (AdDsRed) which were respectively transfected into glioma cell lines U251 and SHG-44.Cells proliferation rates were measured with cell counting kit-8 (CCK-8).The apoptotic ratios were detected by flow cytometry.The expression of PUMA and apoptosis associated proteins (bcl-2,Bax) were determined with Western blot analysis.Caspase-3,Caspase-8,Caspase-9 activity were measured by Caspase activity assay kit.Results Compared with vector group and blank control group,Ad-PUMA transfected group showed strong cell proliferating inhibition effects [the inhibition rates were (50.89±4.73) ％ and (44.45±5.33) ％ respectively,P ＜0.05] and pro-apoptotic effects [apoptotic rates were (44.89±5.08) ％ and (31.67±7.32) ％,P ＜ 0.05] in different p53 glioma cell lines U251 and SHG-44.Western blot analysis showed that PUMA protein expression increased after Ad-PUMA transfection,accompanied by the reduced expression of the anti-apoptotic protein bcl-2 and the increased expression of pro-apoptotic protein Bax.The activity of Caspase testing results showed that the Caspase-3,Caspase-9 activity increased significantly,while the Caspase-8 activity changed little.Conclusion No matter how p53 phenotype,PUMA can inhibit glioma proliferation,promote apoptosis,and its mechanism may be through the mitochondrial apoptotic pathways,upregulation of Bax and inhibition of bcl-2 expression,which activated Caspase-9.Ad-PUMA is expected to become a new target for gene therapy of gliomas.

Objective To analyze the complications ofventriculoperitoneal shunt in the treatment of pediatric hydrocephalus,and improve operative method,in order to reduce postoperative complications and improve the clinical curative effect.Methods A total of 39 infants with hydrocephalus who underwent adjustable shunt were retrospectively analyzed,including surgical methods,results,and complications,and put forward counter measures.Results Thirty cases of postoperative clinical symptoms obviously improved compared with preoperative,head CT review were clearly seen with ventricle retraction.Nine cases suffered with complications after operation.Obstruction of shunt tube was found in 4 cases,shunt exposed in 3 cases,and postoperative infection in 2 cases.Conclusions Ventriculoperitoneal shunt complications related to surgery itself.Improved surgical techniques,and taking appropriate treatment measures can effectively reduce the incidence of complications.

Hepatitis B virus (HBV)-specific cytotoxic T lymphocytes (CTLs) are believed to play a major role in viral clearance and disease pathogenesis during HBV infection. To clarify the differences in host immune responses between self-limited and chronic HBV infections, we constructed three HLA-A*0201/HBV tetramers with immunodominant epitopes of core18-27, polymerase 575-583 and envelope 335-343, and analyzed the HBV-specific CTLs in peripheral blood mononuclear cells (PBMCs) from patients infected with HBV. The frequencies and expansion ability of HBV-specific CD8(+) T cells in most self-limited HBV infected individuals were higher than those in chronic HBV-infected patients. HBV-specific CD8(+) T cells could be induced by in vitro peptide stimulation from chronic patients with a low level of serum HBV-DNA but not from those with a high level of serum HBV-DNA. In chronic infection, no significant correlation was found either between the frequencies of HBV-specific CD8(+) T cells and the viral load, or between the frequencies and the levels of alanine transaminase. Our results suggested that the frequencies of HBV-specific CTLs are not the main determinant of immune-mediated protection in chronic HBV infection and immunotherapeutic approaches should be aimed at not only boosting a HBV-specific CD8(+) T response but also improving its function.

A new mutant human papiUomavirus type 16 E7 gene, termed HPV16 HBE7, was isolated from cervical carcinoma biopsy samples from patients in an area with high incidence of cervical cancer (Hubei province, China). A previous study showed that the HPVI6 HBE7 protein was primarily cytoplasmic while wild-type HPV16 E7 protein, termed HPV16 WET, was concentrated in the nucleus. With the aim of studying the biological functions of HPV16 HBE7, the transforming potential of HPV16 HBE7 in NIH/3T3 cells was detected through observation of cell morphology, cell proliferation assay and anchorage-independent growth assay. The effect of HPVI6 HBE7 on cell cycle was examined by flow cytometry. Dual-luciferase reporter assay and RT-PCR were used to investigate the influence of HPVI6 HBE7 protein on the expression of regulation factors associated with GI/S checkpoint. The results showed that HPV16 HBE7 protein, as well as HPV16 WE7 protein, held transformation activity. NIH/3T3 cells expressing HPV16 HBE7 could easily transition from G1 phase into S phase and expressed high level of cyclin A and cdc25A. These results indicated HPV16 mutant E7 protein, located in the cytoplasm, induces oncogenic transformation of NIH/3T3 cells via up-regulation of cyclin A and cdc25A.

Objective To explore the computed tomography (CT)manifestations of adrenocortical oncocytoma (ACO)for better understanding the disease and improving its diagnosis accuracy.Methods The CT manifestations of 9 cases with adrenocortical onco-cytomas confirmed by surgery were retrospectively reviewed and compared with pathological results.Results Five of cases were lo-cated in left side while 4 cases were in right side.Well defined and round or oval border could be found in all the cases.Of all the ca-ses,3 cases were solid lesions with equal density,< 3 cm in diameter,and mild consistent intensification after enhancement.Cystic lesion was detectd in 6 cases with > 3 cm in diameter.The mixed cystic and solid components with polycystic changes could be found on CT image,and remarkable intensification on solid lesion while no intensification on cystic lesion after the enhancement. Moreover,patchy or cotton-like shape could be found on solid lesion in 4 cases and 1 case with island like intensification;reticular pattern could be found in the central of lesion in 3 cases and 1 case with stellate shape.Pathological observation showed that the on-cotytomas were comprised of cells with abundant eosinophilic cytoplasm and necrotic and fibrous capsule without pathological mitosis could be found in some of lesion.Conclusion The characteristic CT features of adrenocortical oncotytoma has a worse specificity,its diagnosis was dependent on pathologic examination.

Objective: To explore the dynamic regulation of histone acetylases p300 and p300/CBP associated factor (PCAF) on cardiac development gene NKX2.5 during cardio-genesis and to provide the new theoretical basis to clarify the regulatory mechanism for cardio-genesis in fetal mice.
Methods: Our research included 4 groups of cardiac tissues: Embryo (EB) 14.5 days group,n=10, EB 16.5 days group, n=10 and Neonatal 0.5 day group,n=5, Neonatal 7 days group,n=3. Immunoprecipitation was performed in myocardial tissues using anti-p300, anti-PCAF and anti-H3K9ac antibodies to retrieve p300, PCAF and H3K9ac binding DNA, the speciifc DNA sequences were ampliifed by real-time PCR to detect and the binding levels of p300, PCAF and the acetylation level of H3K9ac in NKX2.5 promoter sequence. In addition, the mRNA expression of NKX2.5 was examined by RT-PCR.
Results: The binding levels of p300 and PCAF had the timing consequence at different stage of cardio-genesis. The binding level of p300 in EB 16.5 days group (0.063 ± 0.021), Neonatal 0.5 day group (0.019 ± 0.008), Neonatal 7 days group (0.011 ± 0.003) were all lower than that in EB 14.5 days group (0.231 ± 0.033), and in Neonatal 0.5 day group and Neonatal 7 days group were lower than EB 16.5 days group, allP<0.05. The binding level of PCAF in EB 16.5 days group (0.063 ± 0.021), Neonatal 0.5 day group (0.019 ± 0.008), Neonatal 7 days group (0.011 ± 0.003) were all lower than that in EB 14.5 days group (0.185 ± 0.023), allP<0.05. The H3K9ac acetylation level and NKX2.5 mRNA expression level had the timing consequence at different stage of cardio-genesis. H3K9ac acetylation level in EB 16.5 days group (0.098 ± 0.014), Neonatal 0.5 day group (0.074 ± 0.010), Neonatal 7 days group (0.045 ± 0.014) were all lower than that in EB 14.5 days group (0.119 ± 0.020), and in Neonatal 7 days group was lower than EB 16.5 days group, allP<0.05. The NKX2.5 mRNA expression level in EB 16.5 days group (0.701 ± 0.181), Neonatal 0.5 day group (0.502 ± 0.159), Neonatal 7 days group (0.529 ± 0.13) were all lower than that in EB 14.5 days group (1.000 ± 0.130), allP<0.05.
Conclusion: Histone acetylases p300 and PCAF may dynamically regulate H3K9ac acetylation in NKX2.5 promoter sequence, and the mRNA of NKX2.5 was dynamically expressed during cardio-genesis in experimental fetal mice.