As a protein originally found in plant pathogenic bacteria, transcription activator-like effectors (TALEs) can be fused with the cleaving domain of restriction endonuclease (For example Fok I) to form artificial nucleases named TALENs. These proteins are dependent on variable numbers of tandem Repeats of TALEs to recognize and bind DNA sequences. Each of these repeats consists of a set of approximately 34 amino acids, composed of about 32 conserved amino acids and 2 highly variable amino acids called repeat variant di-residues (RVDs). RVDs distinguish one TALE from another and can make TALEs have a simple cipher for the one-to-one recognition for proteins and DNA bases. Based on this, in theory, artificially constructed TALENs could recognize and break DNA sites specifically and arbitrarily to perform gene knockout, insertion or modification. We reviewed the development of this technology in multi-level and multi species, and its advantages and disadvantages compared with ZFNs and CRISPR/Cas technology. We also address its special advantages in industrial microbe breeding, vector construction, targeting precision, high efficiency of editing and biological safety.
Amino Acid Motifs ; Biotechnology ; DNA ; chemistry ; Endonucleases ; chemistry ; Tandem Repeat Sequences ; Trans-Activators ; chemistry

Objective To investigate the effect of natural killer (NK) cells treated by serum of severe preeclampsia patient on the function of endothelial cells.Methods Fifteen patients with severe preeclampsia and 15 normal pregnant women from the Obstetrics department,Shengjing Hospital,China Medical University were admitted into this case-control study from January 1,2006 to December 31,2008.NK cells from healthy non-pregnant woman were incubated with 20% serum from severe preeclampsia patients or normal pregnant women for 20 hours.Then,human umbilical vein endothelial cells ( HUVEC) and serum-treated NK cells were co-incubated for 24 hours.Apoptosis of HUVEC was checked by flow cytometry and electronic microscope.Endothelin-1 (ET-1) levels in the supernatants of HUVEC and NK cells were examined by radioimmunologic method.Results In severe preeclampsia group,the percentage of early apoptosis cell (Annexin V-FITC+ /PI+ ) was (23.81±4.79)%,that of late apoptosis cell (AnnexinV-FITC+/PI+ ) was (3.29±1.04) %,while those were (16.59±5.13)% and (2.24±0.72)% respectively in normal pregnant group (P＜0.01).There was no significant difference in dead cells (Annexin V-FITC- /PI+ ).Under electronic microscope,typical morphologic changes of apoptosis were shown in severe preeclampsia group.Level of ET-1 in

Objectives To investigate the possible role of perforin (PFN) in the pathogenesis of severe preeclampsia.Methods Thirty-two cases of severe preeclampsia were included in the study.Thirtytwo cases of normal pregnancy were selected as control group in random.The expression of PFN mRNA in the peripheral blood mononuclear cells (PBMC) was detected by reverse transcription (RT)-PCR, and its correlation with mean arterial pressure was analyzed in severe preeclamptic patients.The expression of PFN protein in the decidua was detected by immunohistochemistry.Results ( 1 ) The expression of PFN mRNA in PBMC:the PFN mRNA level in severe preeclamptic group was 1.19 ± 0.31, and that in normal pregnancy group is 0.82 ± 0.28.The PFN mRNA level in severe preeclamptic group was significantly higher than that of control group (P ＜ 0.0l ).(2)Correlation analysis:the mean blood pressure in severe preeclampsia group was (133 ±5) mm Hg( 1 mm Hg =0.133 kPa).There was significant positive correlation between level of PFN mRNA in PBMC and mean blood pressure in severe preeclamptic patients ( r = 0.701, P = 0.000).(3)Decidual PFN protein expression:PFN protein was mainly expressed in lymphocytes and the cytoplasm of decidual stromal cells.The positive ratio of PFN in the decidua of severe preeclamptic patients was 84% ( 27/32), significantly higher than that of control group (53%, 17/32, P ＜ 0.01 ).Conclusions Expression of PFN was significantly increased in severe preeclampsia, and it was of significant positive correlation with mean blood pressure.PFN may participate in the pathogenesis of severe preeclampsia.

The reproduction of Helicoverpa armigera nucleopolyhedrovirus in the midgut epithelia cells and the other sensitive tissues was observed by electron microscopy. The reproducing viruses in the midgut epithelia cells were mostly without envelopes, and thte polyhedrons were seldom formed. The reproduciing viruses in the other sensitive cells were with envelopes, and packed in polyhedrons.

BACKGROUND: Compound antitumor coral hydroxyapatite (CCHA) has a good delayed-release and anti-tumor effect. However, whether the high-dose drug contained in the CCHA influences normal induction, conduction and growth of bone tissues at the implant site is unclear.OBJECTIVE: To establish an osteogenesis model of CCHA and to investigate the osteogensis effect and rule of self-made CCHA in vivo. METHODS: Implants of CCHA (20%CDDP-CHA w/w) and CHA(control, 0% CDDP w/w) were implanted into the metaphyseal holes of rabbit femur. X-rays and decalcified histological section of rabbit femoral bone with hematoxylin and eosin staining were used regularly to investigate the degradation of CCHA and CHA, and how bone tissues grow at the implant site. RESULTS AND CONCLUSION: After implantation, CHA crystals were faster than CCHA in connecting with surrounding bone tissues and forming bone bridges. The borderlines of implanted CHA became obscure in 4 weeks. Loose connective tissues were found in pores of the CHA and osteoblasts were growing on the surface. Bone tissues of the surrounding gradually grew into the CHA, finally repaired the bone defects. At the beginning of implantation, CCHA mainly inhibited the growth of surrounding tissues until 6-12 weeks later, normal bone tissues gradually grew into pores of CCHAs, and healed bone defects at 26 weeks. CCHA can inhibit the osteogenesis effects at early stage; however, it can achieve bone healing with surrounding bone defect ultimately.

There are multimechanism and multipathogens in the course of the progress and the metastasis of hepatocarcinoma. Growth factors play an important role in the process. In this review, the relationship between growth factors and hepatocarcinoma are summarized.

0.05).Conclusion Long-term inhaled glucocorticosteroids has no obvious effect on GH and height growth of asthmatic children.

As one of the risk factors for atherosclerosis,human cytomegalovirus infection has received increasing attention,while cytomegalovirus infection of vascular endothelial cells is considered as the initial stage of causing atherosclerosis.Therefore,elucidating the mechanism of human cytomegalovirus infection of vascular endothelial cells will help further confirm the viral and etiological theories of atherosclerosis,and may block its occurrence and development from the initial stage of infection.

A solid-phase cell enzyme-linked immunoassay is described for screeningand analyzing monoclonal antibodies against the cell surface antigensof human colorectal adenocarcinoma.Horse-radish peroxidase conjugatedProtein A was used to detect the binding of mouse monoclonal antibodiesto human colorectal adenocarcinoma.HR_(8348) cells which had been cultured inand then fixed to the wells of microtiter plates by using glutaraldehyde.Thismethod was found to be specific,reproducible and practical,and especiallyto be advantageous for the large scale screening and analyzing of monoclo-nal antibodies with a panel of cell types.

AIM To testify the special cytotoxicity of TGF? SAP on proliferating vascular smooth muscle cells and endothelial cells. METHODS Conjugation of saporin to TGF? was accomplished after derivatization of saporin and TGF? with N succinimidyl 3 (2 pyridyldithio) proprionate. Cytotoxicity assays were measured by cell count. The studies of influence of TGF? SAP on values of thymidine and leucine incorporation into SMCs and ECs were measured by 3H thymidine uptake and 3H leucine uptake, respectively. RESULTS Cytotoxicity assays testified TGF? SAP conjugate could inhibit remarkably proliferation of SMCs in culture. The values of thymidine of TGF? SAP group (1?10 -9 mol?L -1 and 1?10 -7 mol?L -1 ) in comparison significantly decreased to 60 9% and 56 0% of the control group respectively, suggesting that cellular DNA synthesis obviously decreased as TGF? SAP was added. But saporin did not affect cellular DNA synthesis at higher level. The rate of 3H leucine incorporation of TGF? SAP group significantly decreased to 47 3% of the control group, suggesting that SMCs protein synthesis obviously decreased as TGF? SAP was added. But TGF? SAP at the same level did not affect DNA synthesis and protein synthesis of ECs compared with the control group. CONCLUSION TGF? SAP possesses the more effective cytotoxicity than saporin and the more specific citotoxicity on proliferating vascular smooth muscle cells than on proliferating endothelial cells.