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

Translational medicine is a new term recently which aims to eliminate the barrier between preclinical and clinical medicine,to efficiendy and effectively translate basic scientific findings into drugs and medical devices that benefits patients.This article discussed the meaning of translational medicine in cultivating postgraduates of neurology.According to the preliminary attempt,it is beneficial for postgraduates to form translational medicine philosophy and be high-quality medical talents.

Objective To study the effect of different dialysis modalities on pruritus in uremic patients .Methods Patients with maintenance hemodialysis who were suffered with severe cutaneous pruritus were randomly divided into hemodialysis group (HD group) ,hemodialysis combined with hemodiafiltration group (HD+ HDF group) ,hemodialysis and hemodiafiltration combined with hemoperfusion group (HD+ HDF+ HP group) .Plasma P3+ ,parathyroid hormone (PTH) and β2-microglobulin (β2-MG) were measured at pre-dialysis ,1 weeks ,4 weeks and 12 weeks after dialysis ,cutaneous pruritus was scored too .Results Compared with pre-dialysis ,the level of plasma P3+ ,PTH ,β2-MG and the scores of cutaneous pruritus were significantly lower at 4 weeks and 12 weeks after dialysis in HD+ HDF+ HP group (P<0 .05) .The were statistically significant difference in P3+ ,PTH ,β2-MG and cu-taneous pruritus scores among 3 groups after 12 weeks (P<0 .05) .Conclusion HD+ HDF+ HP is superior to HD+ HDF in effi-ciently clear P3+ ,PT H andβ2-M G ,and relief cutaneous pruritus and itching .

Based on the research of risk assessment of medical equipment safety and operation to formulate evaluation criteria and methods of how to use the practical management work. Objective to evaluate the practical method is to use and the risk of adverse events of medical equipment in operation risk in order to find the risk, control risk, ensure safety in time, so that Improve the level of risk management of medical equipment.
Equipment Safety ; Humans ; Risk Assessment ; Risk Management

Objective To explore the characteristics of approach and avoidance behaviors among subthreshold depressed adolescents. Methods 27 subthreshold depressed adolescents and 29 healthy con?trol teenagers completed the approach?avoidance task,and the reaction time at approach and avoidance task of the two groups was compared. At the same time,their differences were analyzed between the two groups on the Behavioral Inhibition/Activation System Scale scores. Results ( 1 ) Subthreshold depression group (1208.18±338.92)ms) had significantly longer reaction time than those in healthy control group((1058.40 ±204.22)ms) when approaching happy expression ( t=2.02, P<0.05). (2) Subthreshold depression group (37.33±4.46) had significantly lower behavioral activation system scale scores than those in healthy control group ((39.76±3.75), t=-2.21, P<0.05); and the score of reward responsiveness was marginally signifi?cant lower in subthreshold depression group (12.63±1.67) than that in healthy control group ((13.41± 1.30), t=-1.97, P=0.054). Conclusion To activate the approach behaviors of subthreshold depression adolescents may be helpful for reducing the symptoms of depression.

Focal adhesion kinase (FAK), a type of protein tyrosine kinase in the cytoplasm, is highly expressed in many types of malignant tumors. FAK is named as such because of its close relationship with the cell adhesion function. Recent studies show that FAK is expressed in many tumor cells and has a definite relationship with cancer progress, metastasis, and prognosis. Accordingly, FAK has become one of the new tumor therapeutic targets that will bring new methods for tumor therapy.

The clinical classification of metastatic spinal tumors is based on the degree of malignancy, nervous system function, osteoclasia, and prognosis of patients. The application of this classification system is relatively simple. The assessment and evaluation of patients to estimate the period of survival can guide the individualized treatment of patients. Patients with clear surgical indications can choose to undergo a palliative operation, tumor resection, or total spondylectomy. Alternatively, other patients can opt to have mini-mally invasive surgery aside from the normal surgical approach. Stereotactic radiotherapy and intensity-modulated radiation therapy combined with the use of radiofrequency ablation, radiation, and other therapies can achieve local tumor control, relieve pain, and main-tain normal neurological function. Thus, the quality of life of the patient is improved. Percutaneous vertebroplasty, radiofrequency abla-tion, spinal endoscopy, and other modern forms of minimally invasive surgery will have more applications in the treatment of spinal metastatic tumors.

10.3969/j.issn.2095-4344.2013.26.018

Objective To explore the significance of thyroid function determination at the first and second trimesters of pregnan‐cy .Methods Electrochemiluminescence immunoassay was used to detect the levels of TSH ,FT3 and FT4 in first trimester women (T1 group) ,second trimester women (T2 group) and non‐pregnant women (control group) ,respectively .And the results were an‐alyzed .Results There were significant difference in the levels of TSH ,FT3 and FT4 between T1 group and control group (P<0 .05) .The total prevalence rate of thyroid diseases in pregnant women was 28 .85% ,which was significantly higher than that in control group(15 .00% ) ,P<0 .05 .Hypothyroidism and subclinical hypothyroidism were the main forms of thyroid dysfunction in pregnant women .Conclusion The determination of thyroid function at the first and second trimesters of pregnancy will benefit pre‐natal and post‐natal care .