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 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 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 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 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 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 effects of tumor necrosis factor-α(TNF-α)and interleukin-6(IL-6)on acute myocardial functional lesion after severe craniocerebral injury.Methods Sixty five examples with severe craniocerebral injury are collected in the 253th hospital of PLA from February in 2009 to May in 2012,of whom glasgow coma scale was low or equal to 8 points.They are examined creatine kinase-MB(CK-MB),cardiac troponin T(cTnT),TNF-αand IL-6 for correlative analysis while they are emer-gency treated at the same time.Results The myocardial function of the observe group examined results:CK-MB(198.63±37.72) U/L,cTnT(548.17±49.58)pg/mL;injury factors examined results:TNF-α(39.93± 18.88)ng/mL,IL-6(469.61 ±73.66)ng/mL.It both has evidently difference between the control group and the observe group and has obviously correlation between the my-ocardial function and injury factors of the observe group (P <0.01),and they were positively correlated.Compared TNF-α,IL-6 in observe group,CK-MB(r>0.911 4)and cTnT(r>0.942 1)had statistically significant difference.Conclusion TNF-αand IL-6 all participate in the process of the acute myocardial functional lesion after severe craniocerebral injury.The inchoate interference and treatment against TNF-αand IL-6 are possible to have inhibited the high expression of TNF-αand IL-6 in the blood and to improve the myocardial functional lesion after severe craniocerebral injury.

To explain how to ensure and improve the quality of the clinical practice teaching for the clinical institutes,we expatiate on the practical experience in the hospital from enhancing the practice teaching management,improving the teaching consciousness,meliorating the teaching environment and reforming the method.