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To study the effect of Sorbaria Sorbifolia extract on anti-oxidative activities in rats with precancerosis induced by diethylnitrosamine.

Traditional recombination technology of bacteria chromosome and its limitation were introduced. The definition of Red recombination technology is put forward: a method of homologous recombination between foreign linear DNA and the target gene in chromosomes mediated by ? phage Red system. The linear DNA referred here is general PCR product or oligonucleotide, which has a 36~50bp homologous sequence with the target gene in chromosome at both flanking. Red recombination technology leaves out the in vitro DNA restriction enzyme digestion and link process, which makes the knockout and alternation of target gene in bacteria chromosome relatively easier, and becomes an effective method to exploring genes and constructing new strains gradually. The gene inactivation and alternation method aiming at bacteria chromosome applied to Red recombination system was summarized by the structure element, action mechanism, and strategy of recombination, advantage and developing prospect. The Red system includes three genes: bet (aka?), exo and gam (aka ?). Exo is a 5′→3′ exonuclease, which degrades the 5′ ends of linear DNA molecules. Bet is a single-stranded DNA binding protein that binds to the single stranded 3′ ends generated by Exo and promotes annealing to complementary DNA. Gam binds to the host RecBCD complex and inhibits its exonuclease activity. Red recombination system may be constructed in such plasmids as pKD20 and pKD46 or in chromosome of bacteria. Most bacteria are not readily transformable with linear DNA because of the presence of intracellular exonucleases that degrade linear DNA. But when bacteria cells are transformed with pKD20 or pKD46 plasmid, or integrated with a detective ? prophage, Red recombination enzymes may be expressed in host cells, which make linear DNA with 36~50bp extensions that are homologous to both flanking of target genes transform E.coli readily and knock-out or alternate target gene. The Red recombination method is not only useful in chromosomal gene inactivation in E.coli, but also in other bacteria or virus, such as Salmonella, Shigella flexneri and virus HaSNPV. With the proceeding research, Red system will be applied for more and more purposes, and contribute a lot for gene improvement and gene function investigation in the coming Postgenome Era.

ObjectiveTo investigate the mechanisms of neonatal transplantation tolerance,especially the role of immature immune system and chimerism in tolerance.MethodsF1 ( or GFP-F1 ) mice were bred by crossing male C57BL/6 (or GPF transgenic C57BL/6) and female BALB/c mice. Within 24 h,newborn C57BL/6 mice were inoculated with different doses of splenocytes from F1 or GFP-F1 mice,irradiated spleen cells were used as control.Six weeks later,the mice were subjected to F1 skin grafting,and mixed-lymphocyte reaction was performed to determine their tolerance.Flow analysis was used to detect chimerism.ResultsLiving F1 spleen cells could induce chimerism and neonatal transplantation tolerance,but irradiated cells not.The chimerism in long-term tolerant mice is higher than that in chronic rejected mice,with 6.48％ ±4.02％ vs 1.57％ ±0.89％,the difference is significant in statistical analysis.The degree of neonatal transplantation tolerance is determined by the dosage of donor cells,the mice induced with 3 × 107 F1 spleen cells have 80％ long-term tolerance,but the dose of0.7×107 F1 spleen cells could only prolong allografts survival.ConclusionNeonatal transplantation tolerance is dependent on chimerism,the chimerism of donor cells leads to clonal deletion of alloreactive T cells.

Objective To evaluate the safety and accuracy of CT-guided cutting needle biopsy for the hepatic lesions near diaphragmatic dome.Methods A total of 25 cases with hepatic lesions near the diaphragmatic dome were undertaken CT-guided cutting needle biopsy using 16 gauge or 18 gauge core biopsy needles.Results Histological examination showed malignancy in 17 cases and benign in 8 with 2 false negative results(8%),and there were no false positive results.The specificities of malignant and benign lesions were 100% and 75%,respectively.Overall accuracy was 92%.Pneumothorax,needle tract hemorrhage,and subcapsular hepatic hemorrhage occurred in 2(8%),1(4%)and 1(4%),respectively.Conclusion CT-guided cutting needle biopsy for the hepatic lesions near diaphragmatic dome is a reliable and relatively safe diagnostic method.(J Intervent Radiol,2007,16:838-840)

Objective To explore the effect of protoporphyrin Ⅸ zinc(Znpp) on hyperoxic lung injury in preterm rats.Methods Three-day-old preterm SD rats were randomly assigned to room air control group(group Ⅰ)hyperoxia control group(oxygen≥900 mL/L)(group Ⅱ),room air plus Znpp group(group Ⅲ),hyperoxia plus Znpp group(group Ⅳ).Group Ⅲ and group Ⅳ were injected intraperitoneally with ZnPP 45 ?mol/kg each day.After the third day and the 7th day of exposure,the activity of heme oxygenase-1(HO-1) and the percent of carboxyhemoglobin(HbCO) in the lungs,the lung wet weight /dry weight ratio(W/D),tumor necrosis factor-?(TNF-?),total protein and malondialdehyde(MDA) in bronchoalveolar lavage fluid were determined and lung histophathological changes were examined in all groups.Results On the third day,compared with group Ⅰ the activity of HO-1 and the percent of HbCO in the lungs,W/D,TNF-?,total protein and MDA,all greatly rised in group Ⅱ(Pa

Adolescent ; Adult ; Child ; Child, Preschool ; Female ; Humans ; Hypothalamic Neoplasms ; pathology ; radiotherapy ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Pituitary Neoplasms ; pathology ; radiotherapy

Objective:Osteoprotegerin (OPG) is a key molecule negatively regulating osteoclast differentiation and activation; and the conserved mycobacterial heat shock 70 (HSP70) peptide p111-125 has also been found to inhibit inflammation reactions in chronic arthritis. BaculoDirectTM baculovirus expression system was selected to express recombinant OPG-HSP70 in insect cells.Methods:The human functional fragment (p22-194) of OPG and functional fragment (p111-125) of mycobacterial HSP70 gene were cloned into the transfer vector pENTRTM/SD/D-TOPO. The recombinant plasmid was performed an LR reaction with the BaculoDirectTM Linear DNA to generate recombinant baculovirus DNA. The cultured Sf9 insect cells were directly transferred with the recombinant baculovirus DNA,and the pure recombinant baculovirus was obtained. Then recombinant baculovirus was infected Sf9 insect cells again to express the OPG-HSP70 gene.Results:The target protein was detected at the time of 48h post infection,reached at highest yield at the time of 72h post-infection. A 28kDa protein immunostaining band was detected by Western blotting from lysate of those cells.And the purified protein was obtained by using Ni-NTA system. Functional stuies on the fusion protein showed it significantly reduce osteoclast cell number[(3.10?0.640) cells under each microscope field in treatment group by comparing to (10.70?0.817)cells in the control group] in the osteoclast inhibition test,and reduce the inflammation reaction in a delayed type hypersensitivity (DTH) mice model (P

Objective To observe the changes of expression and activity of heme oxygenase-1(HO-1) in lung tissue of preterm rats exposed to hyperoxia,and explore the role of HO-1 in hyperexia-induced lung injury of preterm rats.Methods Three-day-old preterm rats of standard SD were randomly assigned to hyperoxia group and air group.At the third and 7th day of exposure,the expressions of HO-1 mRNA were detected by means of reverse transcription polymerase chain reaction and the cellular distribution and expressions of HO-1 protein in the lung were measured by immunohistochemical techniques,respectivesly,and the active of HO-1 was determined also.Results On the third day,in air group,the expressions of HO-1 mRNA(0.17 ?0.08),HO-1(7.23?4.63)were mildly expressed and the activity of HO-1 was(4.32?1.57) nmol/(mg?h);compared with those of air group,the expression of HO-1 mRNA in hyperoxia group(0.72?0.33) was significantly increased(Pa

Objective To investigate the aging-related changes in gap junction protein-connexin 43 (Cx 43) in rats and their effect on the high incidence rate of ventricular arrhythmia in aged rats. Methods The 64 healthy male Fischer 344 (F344) rats were randomly divided into four age groups (n=16,each): 3-6 months (juvenile), 9-12 months (young-adult), 18-21 months (middle-aged) and 24-26 months (aged). The incidence rate of ventricular arrhythmia was recorded by monitoring their limb-lead Electroa rdiogram(ECG). Morphological changes of ventricular myocardium were observed under optical microscope in Hematoxylin (HE) and Masson's stain. The distribution of connexins 43 (Cx43) and deophosphatase (NP) Cx43 was observed by confocal immunofluorescence microscopy and the Cx43 and NP-Cx43 protein expression was assessed by Western-Blot. Results The incidence rate of ventricular arrhythmia was much higher in aged group (75.0%) than in other three groups (0%,0%,12.5%), all P＜0.05, and the aged group showed that ventricular muscle cells were hypertrophy and arrayed sparsely and disorderly with hyperplasia of connective tissues. The distribution of Cx43 changed from end-to-end to disordered arrangement and the total expression amount of Cx43 decreased as age increased (P＜0.05). The expression amount of NP-Cx43 in middle-aged rats was notably decreased than in juvenile and aged rats (P＜0.05). Conclusions For aged rats, the high incidence rate of ventricular arrhythmia may be associated with ventricular myocardium reconstruction, disarrangement of ventricular muscle cells and gap junction proteins, decreased expression amount of Cx43 and relatively increased NP-Cx43.