To date,the clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 system has been widely used to edit the genome in many species and cells.The system is the third generation of artificial endonuclease,which can edit DNA by recognizing short DNA sequences.This paper reviews the structural features of the system and its application in virus research,such as the functional studies of virus-related genes and the exploration of antiviral therapies (including HIV,HBV,and EB virus),looking forward to the future direc-tion of virus research.

Hepatitis C, Chronic ; Humans

Objective To evaluate total laparoscopic splenectomy combined with pericardial devascularization. Methods In this study,40 patients with portal hypertension and hypersplenism underwent total laparoscopic splenectomy combined with pericardial devascularization,in which 26 cases had a history of up-GI bleeding. Results Procedures were successful in 36 patients.There was four conversions to open surgery.The operations were completed in a mean time of (224 ± 54) min,with a mean estimated blood loss of (296 ± 209) ml and with no serious complication. Conclusion Total laparoscopic splenectomy combined with pericardial devascularization is a safe and effective available minimally invasive procedure in patients with portal hypertension and hypersplenism.

Objective To develop a rapid method based on ARMS, named four primers allele-specific PCR(4p-AS PCR), to detect the most common non-deletional ?-thalassemia mutation Hb Constant Spring(Hb CS) by PCR technique. Methods The 4p-ASPCR was used to detect the Hb CS mutation of ?-thalassemia in 38 DNA samples of Hb H disease patients and using PCR-RE and DNA sequencing to confirm the results. Results Among the 38 Hb H disease patients 15 cases was revealed to carry Hb CS, 16 cases were deletional Hb H, and 7 cases need to be defined.Conclusion A simple, rapid and reliable method, named 4P-ASPCR, to detect Hb CS mutation have been developed. It is also may be useful in screen other point mutations such as Hb Quong Sze.

Objective To review our clinical experience on 12 patients with retroperitoneal infection who were treated with retroperitoneal laparoscopic debridement.Method This retrospective study included 12 patients with retroperitoneal infection who were treated with retroperitoneal laparoscopic dehridement and drainage.Results All the 12 patients recovered well and were finally discharged home.Conclusions Retroperitoneal laparoscopic debridement and drainage for retroperitoneal infection is a mini-invasive procedure.It was found to be safe,produced minimal bleeding and resulted in rapid postoperative recovery.It can be used as the first choice treatment in properly selected patients.

Purpose To evaluate the value of multi-slice spiral computed tomography (MSCT) scan in the diagnosis of papillary renal cell carcinoma. Materials and Methods A retrospective study was conducted on the findings of plain CT scan and triphasic dynamic contrast enhanced CT scan of 23 patients with papillary renal cell confirmed pathologically, and further contrasted with the findings of 96 patients with clear cell renal cell carcinoma at corresponding phases in such aspects as cystic degeneration, enhancement degree and pattern (homogeneous, peripheral or heterogeneous) and tumor spreading pattern (perinephric invasion, lymphadenopathy or venous invasion). Results The degree of enhancement CT value for both diseases showed statistical significance in corticomedullary phase, parenchymal phase and excretory phase (t=9.70, 8.08, 5.92;P<0.01), but papillary renal cell carcinoma was lower than clear cell renal cell carcinoma. In terms of cystic degeneration, papillary renal cell carcinoma was significantly lower than clear cell renal cell carcinoma (21.7%vs 54.2%,χ2=7.54, P<0.01). Papillary renal cell carcinoma mainly showed homogeneous enhancement (60.9%) whereas clear cell renal cell carcinoma mainly presented heterogeneous enhancement (68.8%) with statistical difference (χ2=30.40, P<0.01). The tumor spreading patterns like perinephric invasion, lymphadenopathy and venous invasion had no significant difference (χ2=0.51, 0.11, 0.03;P>0.05). Conclusion Papillary renal cell carcinoma shows homogeneous enhancement, seldom cystic degeneration or necrosis on MSCT scan, which is helpful for the differential diagnosis from clear cell renal cell carcinoma.

ObjectiveTo evaluate the killing effects of MMC,5-Fu and TAM on human breast cancer cell lines (MCF-7 and MDA-MB-435S). MethodsThe MTT method and median-effect principle were used. ResultsKilling effects of drugs were enhanced as drug concentration increased while they were used alone or in combination. The median-effect concentration of TAM in conjunction with MMC was 1.65?10 -5 mmol/L,and that of TAM in conjunction with 5-Fu was 0.032 6 mmol/L. MMC was synergetic with 5-Fu at high concentration(CI1). The ratios of drug concentration and the sequence of administration were not related with the killing effects. ConclusionsA combination of MMC, 5-Fu and TAM has an increased killing effect on MCF-7 cell lines and questionable enhanced effect on MDA-MB-435S cell lines.

AIM: The purpose of this study was to explore the expression of estrogen receptor(ER) and progesterone receptor(PR) mRNA in endometrium of rats with endometriosis. METHODS: The rat model of endometriosis was established, and the expression of ER, PR mRNA in the endometrium was examined by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: The expression of ER and PR mRNA in ectopic endometrium was significantly lower than that in eutopic and normal endometrium (P

Objective To investigate the effects of deletion of adenosine A2A receptors on peripheral leukocytes on cerebral white matter lesions induced by chronic cerebral hypoperfusion.Methods Twenty-four wild type(WT) male mice were given a ? irradiation of 12.5Gy,followed by receiving bone marrow cells tail vein from female A2A receptor knocked out(KO) mice via tail vein,were assigned as KO→WT group,while those received bone marrow cells from WT female mice were assigned as WT→WT group(n=20).The efficiency of reconstitution of bone marrow cells in recipient mice was assessed 7 weeks after transplantation by PCR and immunofluorescent technique.Then,the recipient mice were subjected to bilateral common carotid artery stenosis with internal diameter of 0.18mm by external banding using microcoils at 8 weeks after transplantation.On 7d,14d and 30d after the surgery,corpus callosum,fiber bundles of Caudoputamen and optic tract were harvested from the cerebral white matter,and stained with Kluver-Barrera staining for observing the changes in nerve fibers,and with GFAP and CD11b immunohistochemistry staining for observing the proliferation of microglia and astrocytes.Results At 7 weeks after successful transplantation,the genotype of sex chromosome in peripheral leukocytes of the male recipient mice was changed into female pattern.The expression rate of A2A receptor was 9.73%?2.05% in KO→WT group and 93.82%?11.24% in WT→WT group,with significant difference between the two groups(P

Objective To observe behavioral characteristics and pathologic changes of chronic cerebral hypoperfusion in mice. MethodsTotally 62 adult C57BL/6 mice were subjected to either sham-operation (n=31) or bilateral common carotid artery stenosis using external microcoils with an inner diameter of 0.18 mm(n=31). At 30 d after the stenosis, the animals of the 2 groups (8 mice for each group) underwent behavioral test of 8-arm radial maze. In 7, 14 and 30 d, the rest mice were sacrificed for their brain tissue samples which were examined with Kluver-Barrera staining and immunohistochemical assay for markers of microglia and astroglia, glial fibrillary acidic protein (GFAP) and CD11b. In 14 d after the model establishment, Evans blue dye extravasation test was performed for the blood-brain barrier function. ResultsThe model group made significantly more errors than sham-operated group in 8-arm radial maze test at 30 d after the surgery. White matter lesions occurred and the proliferation of activated microglia and astroglia were observed in white matter in model mice after 14 and 30 d bilateral common carotid artery stenosis. The disruption of blood-brain barrier function of model mice was indicated in the evans blue extravasation test at 14 d after bilateral common carotid artery stenosis. ConclusionCognitive impairment, white matter lesions and glial activation are successfully induced after bilateral common carotid artery stenosis in mice model of chronic cerebral hypoperfusion.