Clustered regulatory interspaced short palindromic repeats (CRISPR) found in bacteria and archaea genome that contains multiple short repeats loci, provides acquired immunity against invading foreign DNA via RNA-guided DNA cleavage. The first inkling of this hot new genetic engineering tool turned up in 1987, when a research team observed an oddly repetitive sequence at one end of a bacterial gene. Now three types of CRISPR/Cas system have been identified: types I, II and III. In the type II CRISPR/Cas9 system, short segments of foreign DNA termed 'spacers' are integrated within the CRISPR genomic loci, transcribed and processed into short CRISPR RNA (crRNA). These crRNAs anneal to trans-activating crRNA (tracrRNA) and direct sequence-specific cleavage in that a double-strand break (DSB) is generated by Cas proteins. Based on these findings, various genetic methods, including gene targeting (Gene disruption), gene insertion, gene correction etc., are being designed to manipulate the genomes of different species at specific loci. Compared with zinc finger nucleases (ZFN) and transcription activator-like effector nucleases (TALEN), CRISPR/Cas9 is simpler with higher specificity and less toxicity. This review summarizes recent progress, discusses the prospects of CRISPR/Cas9 system, with an emphasis on its structure, principle, applications and potential challenges, and provides a useful reference for researchers who are interested in this new technique.
Bacteria ; CRISPR-Cas Systems ; DNA ; Genetic Engineering ; Genomics ; RNA

Objective This experiment was to identify the influence of recombinant human endostatin (rhES) combined with 5-FU on the growth of a xenografted gastric cancer in nude mouse. Methods After the establishment of the model, mice were divided into 4 groups (six in each) receiving respectively, for consecutive 10 days: NS, 5-FU (10 mg/kg) intraperitoneally; rhES (2 mg/kg); and 5-FU + rhES. On 15th day tumor volume was measured. The expression of VEGF, bFGF, VEGF-C, PCNA, bcl-2 and apoptosis index (AI) were examined. The tumor inhibition rate(TIR) and tumor shrinking rate(TSR) were calculated. Results Tumor volume was (43?2) mm 3 in 5 FU+rhES group,(169?45) mm 3 in 5 FU group, (95?28) mm 3 in rhES group, (1057?114) mm 3 in control group ( P

Objective To discuss whether potassium sensitivity test(PST) is correlated with PUF in Interstitial Cystitis (IC). Methods The data of 14 IC patients (female 13, male 1) were an-alyzed. The mean age was 48 years (range 35-67 years). The clinical symptoms included urinary fre-quency, urgency, pelvic and peritoneal region pain after bladder filling. All the patients met the diag-nostic criteria of NIDDK for IC. Dilatations by hyponome were performed, medicine including heparin-sodium, lidocaine, NaHCO3 were used by intravesical instillation. PST and the pelvic pain and urgen-cy/frequency patient symptom (PUF) were used for evaluation. The relationship of the PST and PUF was assessed by statistics. Results PST median decreased from 4.0 to 1.0 (P<0.01). PUF medi-an decreased from 27.5 to 13.5(P<0.01). PST was directly correlated with PUF (rs=0. 868, t= 4.418, P= 0.001 before treatment, rs = 0.779, t=4.300, P = 0.001 after treatment). Conclusions PST and PUF are correlated. Both can be used as index in diagnosis, differential diagno-sis, symptom severity and treatment effectiveness evaluation of IC.

Objective: To observe the therapeutic effect of extracorporeal shock wave combined with orthopaedic insole on plantar fasciitis. Methods: A total of 153 plantar with plantar fasciitis were randomly divided into a combined group (n=51), an extracorporeal shock wave group (n=53) and an orthopaedic group (n=49). The combined group received treatment of both extracorporeal shock wave and orthopaedic insole while the extracorporeal shock wave or the orthopaedic group only received the treatment of extracorporeal shock wave or orthopaedic insole. The therapeutic parameters such as visual analogue scale (VAS) scores, continued walking time and thickness of the plantar fascia were monitored before and atf er the treatment for 2 weeks, 1 month and 3 months, respectively. Results: The VAS scores in the 3 groups were all reduced after the treatment compared with the corresponding scores before the therapy (P<0.05). hTe VAS score in the extracorporeal shock wave group was greater than that in the orthopedic group atfer the treatment for 2 weeks. hTe VAS score in the combined group was smaller than that in the orthopedic group atfer the treatment for 2 weeks and 3 months (P<0.05). hTe VAS scores in the orthopedic group and the combined group were smaller than those in the extracorporeal shock wave group after the treatment for 1 month or 3 months (P<0.05). The continued walking time and thickness of the plantar fascia was improved after the treatment (P<0.05). hTe cure rate and total effective rate in the combination group were obviously greater than those in the two other groups. hTe cure rate in the orthopedic group was greater than that in the extracorporeal shock wave group (P<0.05). Conclusion: Extracorporeal shock wave combined with orthopaedic insole therapy is an effective method to treat plantar fasciitis. It is recommended to spread in clinic.

Objective To investigate the clinical management of Spontaneous rupture of hepatocellular carcinoma(SRHCC) . Methods This was a retrospective review of the clinical data of patients with SRHCC who underwent treated in the affiliate hospi‐tal of Luzhou medical college from January 2001 to December 2014 .Results Among 104 patients ,small hepatocellular carcinoma (<5 cm) were found in 11 cases ,and large hepatocellular carcinoma(>5 cm) in 93 cases .Thirty‐one cases which underwent surgi‐cal treatment ,were cured;44 underwent transcatheter arterial embolization (TAE) ,5 cases died of liver function failure;29 cases were treated conservatively ,11 cases died of huge bleeding ,18 cases gave up discharged .Twenty‐two small and medium‐sized SRH‐CC cases underwent hepatectomy survived 1to‐10 years ;8 huge sized SRHCC cases survived 5to‐13 months;one case who under‐went partial filling pressure hemostasis and hepatic artery ligation ,but died of tumor rupture again after 34 days .Sixteen cases un‐derwent TAE were followed up ,14 cases survived 3to‐10 moths ,the survival time of two cases were 3 years and 5 years ,respective‐ly .Conservative treatment group has not been followed up .Conclusion The tumours should be surgical resection as soon as possi‐ble in those whose lesions confined to the liver and may be removed ,systemic condition is good;TAE should be used for other pa‐tients .

OBJECTIVE:To study the mechanism of action of grape seed proanthocynidins extract(GSPE)in treating acetic acid-induced colitis gravis in rats.METHODS:Rats model with acetic acid-induced colitis was built,the animals were di-vided into normal control group,model group,positive control group and GSPE group(which were subdivided into low,medium and high dose subgroups by intragastric administration).On the8th day of administration of drugs,the changes of myeloperoxidase(MPO),superoxide dismutase(SOD),glutathione peroxidase(GSH-Px)and malonaldehyde(MDA)in colonic tissue were detected,respectively.RESULTS:The model group had a significantly higher level of MPO content than did the normal control group(P

AIM To study the effects of rh bFGF on healing quality of chronic gastric ulcer in rats. METHODS Ulcer model induced by acetic acid was established. Rats were treated with rh bFGF ig until ulcer healing and then continually treated for 10 days(30 total treatment days). The effects of rh bFGF on healing quality of chronic gastric ulcer was evaluated not only from gastric mucoal barrier tissue structure but also from gastric mucus barrier. RESULTS rh bFGF( 5 000 ～ 10 000 AU?kg -1 ) increased the thickness of regenerated gastric mucosa, lowed its abnormity degree and made its align state near to normal. rh bFGF( 2 500 ～ 10 000 AU?kg -1 ) increased collagen and capillary density in scar tissue, added mucus quantity, mucopolysaccharide layer's thickness and PGE 2 content on the surface of regenerated gastric mucosa. CONCLUSION rh bFGF has effects of promoting gastric mucosal barrier to mature, increasing the function of gastric mucus barrier and increasing the quality of ulcer healing.

OBJECTIVE:To investigate the long-term toxicity of repeated intramuscular injection of Escherichia coli O157∶H7 polysaccharide-conjugated vaccine(O157) in rats so as to provide safety evidence for clinical trials.METHODS:A total of 48 SD rats were randomly assigned to receive either 0.5 mL vaccine(containing 25 ?g polysaccharides) (immunization group,n=24) or phosphate buffered solution (PBS,control group,n=24) with the same volume for 3 times at a dose interval of two weeks.Sacrifice of 6 rats in each group were scheduled at 2 weeks after first immunization,and at 1,3,and 5 weeks after the third immunization,respectively for observation and determination of hematological and biochemical parameters,histopathology,specific antibody,myeloid tissue,the tissues in injection sites,etc.RESULTS:Compared with control group,immunization group showed no significant pathological change except the dynamic regular change of some hematological parameters induced by the immunization,and no immunologic system damage was observed.CONCLUSION:Repeated intramuscular injection with O157 vaccine in rats wouldn't cause overt toxicity and local irritation.

Objective To review the clinical presentation of patients with hepatobiliary stones (HS).Method 2 359 patients with HS were divided into group A and B according to the presentation of these patients before or after 2002.Their clinical data were retrospectively analyzed.Results The age,the percentage of patients with a case history ＞ 10 years,the admission rate for relapse,the intrahepatic to extrahepatic stone ratio,the number of patients complicated with liver cirrhosis/portal hypertension,the elective operation rate,the ratio of biliary drainage operation,or the ratio of biliary drainage combined with hepatic resection in group B were 54.02 ± 13.54 years,68.99％,53.07％,73.18％,13.41％,80.80％,83.81％,44.74％,respectively.The corresponding figures for group A were 48.65 ± 14.47 years,46.25％,32.0％,62.02％,4.63％,63.92％,41.45％,19.05％,all P ＜0.01.However,the rates of biliary ascariasis,acute cholangitis of severe type (ACST),hepatic abscess,bleeding or perforation of the biliary tract,non-operative mortality,emergency operation rate and stone residual rate in group B were 6.56％,6.15％,0.84％,0,0,1.71％,5.18％,18.70％,respectively.All these were significantly lower than those in group A (12.11％,33.72％,1.95％,0.37％,0.67％,25.62％,respectively,all P ＜ 0.01).Conclusions The popularization of medical insurance and the increase in hospital admission rate,but not the actual increase in HS,led to the increase in hospitalization of patients.There was a tendency of less patients presenting with severe disease due to delay in treatment.Routine choledochoscopic stone extraction intraoperatively or postoperatively and the increased liver resection rate had decreased the residual stone rate.There should be a strict restriction on the use of choledochojejunostomy.

AIM: To inverstigate the protective effects of procyanidin on myocardial ischemia reperfusion injury in rats. METHODS: Myocardial ischemia reperfusion injury models were established by the ligation of left desending coronary artery for 40 min and referfusion for 120 min in rats, and the influence of procyanidin on enzymes of myocardial, myocardial infarction size and lipid peroxide were observed. RESULTS: Procyanidin decreased myocardial creatine phosphokinase (CPK) and lactate dehydrogenase (LDH) release significantly diminished myocardial infarction size, raised the activity of superoxide dismutase (SOD), reduced malondialdehyde (MDA) content in myocardial and serum in comparison with the control. CONCLUSION: Procyanidin has a protective effect on myocardial ischemia reperfusion injury. The action is related to the inhibition of the free radical and subsequent lipid peroxidation.