Phage display technology is improved in recent years.LoxP-cre system based in vivo recombination is the most important one. From double recombination system to single recombination system,from large scale sample sequencing to visual judgement, in vivo recombination makes it feasible to construct large natural antibody library, and it is favorable to get high affinity antibody. This review introduces the important improvement of in vivo recombination system.

Objective To investigate the effect of hydrogen on radiation-induced acute injury in rat brain.Methods Forty-five mature Sprague-Dawley rats were randomly divided into three groups:saline therapy group,hydrogen therapy group and healthy control group.The whole brain of SD rat was irradiated with single dose of 20 Gy by 4 MeV electrons.Rats in therapy group were injected with hydrogen-rich saline after irradiation and were sacrificed at 1,3,7,14 d post-irradiation.The changes of malonaldehyde (MDA),superoxidase dismutase (SOD) and 8-hydroxydeoxygunosine (8-OHdG) in brain homogenate and the pathological changes in brain hippocampus were observed.Results The brain water content (t=3.78,3.18,P＜0.05) and the contents of 8-OHdG (t=2.33,2.71,2.33,P＜0.05) in the therapy group was lower than the control group at 7 d and 14 d post-irradiation.The contents of SOD were significantly higher(t =2.41-2.92,P ＜ 0.05) from 1 to 7 day,while the contents of MDA were significantly lower in therapy group than those in the control group from 1 to 14 day post-irradiation (t =4.01-6.20,P ＜ 0.05).Moreover,the damage degree in the nerve cells of hippocampus was less compared to the control group.Conclusions The hydrogen-rich saline could have protection role in irradiation-induced acute brain injury in rats.

Objective To explore a new method for one-stage repair of the intestinal leakage based on the principle of magnetic compression anastomosis. Methods Twenty-four dogs were randomly divided into experimental group (n = 12) and control group (n = 12) according to random number table. The model of upper and multiple intestinal leakages was established by making transverse incisions of 1 cm in length on the jejunum wall about 50 cm and 100 cm away from the Treitz ligament. Forty-eight hours later, two NdFeB magnetic rings with the magnetic flux of 2500 G were put into the intestine from the leak sites. The leak sites were pressed between the two rings. The ventages in the control group were sutured. The condition of the dogs was observed after the repair of the leakage. The excreting time was recorded, and the leakage pressures of the anastomotic stoma were detected.The positions of the magnetic rings in the experimental group were detected by X ray. Tissues of the anastomotic stoma were processed by hematoxylin eosin and Masson staining. All data were analyzed using the two-sample t test. Results Severe abdominal infection occurred 48 hours after the establishment of the model. All the intestinal leakages in the experimental group were successfully repaired and the dogs survived for a long time. The magnetic rings were excreted six or seven days after the repair. Eight dogs of the control group survived. The leakage pressure of the anastomotic stoma seven days after the repair was (134 ±23)mm Hg (1 mm Hg =0. 133 kPa) in the experimental group and (91 ± 18)mm Hg in the control group, respectively, with a significant difference between the two groups (t = 3.225, P ＜ 0.05). The leakage pressure of the anastomotic stoma 14 days after the repair was (281 ±7)mm Hg in the experimental group and (271 ±21) mm Hg in the control group, respectively, with no significant difference between the two groups (t =0. 988, P ＞ 0.05). Histological observation showed that after the magnetic compression anastomosis, the intestinal muscle and mucosa recovered well, inflammatory reaction was slight and less collagen fiber and scar was formed. Conclusions Application of magnetic ring with the magnetic flux of 2500 G in one-stage repair of the intestinal leakage in the state of severe abdominal infection is safe and reliable.

OBJECTIVE: To explore the regulatory mechanism of human hepatocyte apoptosis induced by lysosomal membrane protein Sidt2 knockout. METHODS: The Sidt2 knockout (Sidt2^-/-) cell model was constructed in human hepatocyte HL7702 cells using Crispr-Cas9 technology.The protein levels of Sidt2 and key autophagy proteins LC3-II/I and P62 in the cell model were detected using Western blotting, and the formation of autophagosomes was observed with MDC staining.EdU incorporation assay and flow cytometry were performed to observe the effect of Sidt2 knockout on cell proliferation and apoptosis.The effect of chloroquine at the saturating concentration on autophagic flux, proliferation and apoptosis of Sidt2 knockout cells were observed. RESULTS: Sidt2^-/- HL7702 cells were successfully constructed.Sidt2 knockout significantly inhibited the proliferation and increased apoptosis of the cells, causing also increased protein expressions of LC3-II/I and P62(P < 0.05) and increased number of autophagosomes.Autophagy of the cells reached a saturated state following treatment with 50 μmol/L chloroquine, and at this concentration, chloroquine significantly increased the expressions of LC3B and P62 in Sidt2^-/- HL7702 cells. CONCLUSION Sidt2 gene knockout causes dysregulation of the autophagy pathway and induces apoptosis of HL7702 cells, and the latter effect is not mediated by inhibiting the autophagy-lysosomal pathway.
Humans ; Lysosome-Associated Membrane Glycoproteins/metabolism* ; Autophagy ; Apoptosis ; Hepatocytes ; Lysosomes/metabolism* ; Chloroquine/pharmacology* ; Nucleotide Transport Proteins/metabolism*