2.Study on expression and functions of staphylococcal enterotoxin B mutants
Chinese Journal of Microbiology and Immunology 2001;21(2):200-203
Objective To obtain staphylococcal enterotoxin B (SEB) mutant with normal antigenicity but low toxicity. Methods Using PCR technique, normal SEB (SEB-N) gene which was amplified from S. aureus S6B. SEB mutant gene (SEB-M) was prepared from the same strain, but one nucleotide in SEB gene was changed from asparagine (N23) to serine (S23). SEB-N and SEB-M were cloned into procaryotic expression vector pTrc99A then and transferred into E. coli JM109. SEB-N and SEB-M which were cloned into plasmid were sequenced directly by dideoxynucleotide method. The crude expressed proteins were identified by double agar immunodiffusion. The level of IL-2 in supernatants of mouse splenocytes stimulated by crude expressed proteins was determined by ELISA. Results SEB-N and SEB-M were obtained through PCR. The sequence of SEB-N was changed with non site-directed mutagenesis, threonine at the residue 150 of SEB-N was replaced with alanine (ACT→GCT, T150A). As being expected, at the residue 23 of SEB-M, serine substituted for asparagine (AAT→AGT, N23S) with site-directed mutagenesis. Double agar immunodiffusion showed obvious precipitin line with anti-SEB by both crude SEB-N and SEB-M mutant proteins could produce, but not by non-recombinant strain. ELISA demonstrated that the level of IL-2 in supernatant of mouse splenocytes stimulated by natural SEB protein (containing equal amount of JM109P crude protein) was 40 times as much as that stimulated by SEB-M and 12.5 times as much as that stimulated by SEB-N. Conclusions We obtained two recombinant strains which produced T150A and N23S mutant SEB protein. The mutant proteins showed binding ability to anti-SEB as the normal protein. However, their biological activity as superantigen decreased sharply. We consider that it is promising for further study of molecular adjuvant or superantigen vaccine.
3.Risk evaluation and monitoring of prophylaxis and treatment in tumor-associated venous thromboembolism
Chinese Journal of Laboratory Medicine 2016;39(10):739-742
Being one of the most important complications and also one of the leading cavses of death, venous thromboembolism ( VTE) could significantly increase the morbidity and mortality of patients with tumor.Therefore, accurate assessment of VTE risk and early prophylaxis according to the risk level are important to reduce the incidence of VTE, as well as to improve the quality of life and disease prognosisin patients with cancer.In this paper, we introduced the laboratory indicators that could be used for risk assessment of tumor-associated VTE and monitoring of prophylaxis and treatment in tumor patients with VTE.We aimed to strengthen the awareness of tumor-associated VTE and expected to provide help for clinical practice.
4.RESEARCH ON SPONTANEOUS DIFFERENTIATION OF STEM CELLS AND RELATED GENE EXPRESSION PROFILE
Acta Anatomica Sinica 1953;0(01):-
Objective To investigate the expression of endometrial developing-related genes,the endometrium-like structure and cells during spontaneous differentiation of hESCs. Methods (1) Embryoid bodies were cultured in suspension for 14 days,fixed in 10% neutral-buffered formalin and embedded in paraffin.Estrogen receptor(ER) was detected by immunocytochemical staining.(2) hESCs were cultured in a 35 mm plastic dish and differentiated spontaneously for 10 days.The expression of ER and Vimentin/Keratin was detected by double immunofluorescence histochemistry.(3) hESCs were cultured in a 35 mm plastic dish and differentiated for 5 days.The expressions of endometrial developing-related genes including Wnt4,Wnt7a,Wnt5a,Hoxa10,Hoxa11 and ER were detected by RT-PCR. Results (1) The endometrium-like structures were detected in 14-day-old EBs and some were positive for ER staining.(2) Some spontaneously differentiated cells from hESCs for 10 days were positive for ER together with Vimentin/Keratin.(3)Wnt7a,Wnt4,Hoxa10,Hoxa11 and ER were detected by RT-PCR in hESCs which were differentiated spontaneously for 5 days.Conclusion During the spontaneous differentiation of hESCs,some cells are liable to differentiate into endometrial stem cells and endometrium-like cells.However,further identifications of the whole development process are needed to be done in the future.
6.Psychological Responses and Ethical Countermeasures of HIV Infection
Chinese Medical Ethics 1994;0(05):-
The infection of HIV is not only a simple medical issue,but also a complex issue related to many complication of society.This article dicussed the psychological responses to the infection of HIV and brought forward some ethical countemeasures in order to make people pay more attention to it and do research on it deeply.
7.Relationship between carotid artery stenosis and ischemic ocular diseases
International Eye Science 2015;(1):108-111
Abstract?AlM: To investigate the relationship between carotid artery stenosis and ischemic ocular diseases.?METHODS: The clinical data of 30 cases ( 37 eyes ) of patients with ischemic eye diseases were collected from November 2010 to May 2014, and they were accepted the fundus fluorescein angiography ( FFA ) , transcranial Doppler ( TCD) ultrasonic blood vessels of the eye, neck vascular color Doppler flow imaging ( CDFl) , the neck CT angiography ( CTA ) and carotid artery digital subtraction angiography ( DSA) examination, and then the ischemic eye disease patients with ocular symptoms were analyzed. The peak systolic velocity ( PSV) and resistance index ( Rl) of ophthalmic artery and central retinal artery were compared. Correlation between the internal carotid artery intima- media thickness ( lMT ) and ophthalmic artery, central retinal artery PSV and Rl correlation risk;ipsilateral internal carotid artery plaque and ophthalmic artery PSV and Rl; PSV and Rl associated ipsilateral internal carotid artery plaque and central retinal artery were analyzed.?RESULTS:Eye symptoms:a black dim, reduced vision, the eyes flash, and around the eye pain were 75. 7%, 83. 8%, 51. 4% and 32. 4%;The eye signs:the dilatation of retinal vein, retinal hemorrhage, arterial stenosis and cotton spot and the contralateral side were regarded as main signs. Ophthalmic artery PSV and Rl value of the differences were statistically significant ( P<0. 05 ); The contralateral side of the central retinal artery PSV and Rl value of the differences were statistically significant ( P<0. 05 ); The ipsilateral internal carotid artery lMT and ophthalmic artery, central retinal artery PSV and Rl were not correlated ( P>0. 05 ); The ipsilateral internal carotid artery plaque and ophthalmic artery PSV had no correlation with Rl values (P>0. 05); PSV and Rl and the ipsilateral internal carotid artery plaque and central retinal artery had no correlation (P>0. 05).?CONCLUSlON: The incidence of ischemic eye diseases and internal carotid artery stenosis is associated with very close, the clinical can regard the degree of internal carotid artery stenosis as an important basis for diagnosis and treatment of eye diseases.
8.Clinical Analysis of 9 Cases with Histiocytic Necrotizing Lymphadenitis in Children
Journal of Applied Clinical Pediatrics 1986;0(01):-
Objective To summary 9 cases of histiocytic necrotizing lymphadenitis(HNL) of children and discuss the diagnosis and therapy.Methods Reviewed clinical data and histological findings.Nine cases of HNL from 1999 to 2003 years.Results All patients had fever and swelling of lymph node on neck.They were diagnosed by lymph node excisional biopsy.Six cases were administrated of glucocorticoid and benefited significantly.Conclusions The etiological factor and pathogenesis is unknown,yet.The clinical situation is not characterful.The diagnosis is always established by histopathology. The effect of management using glucocorticoid is remarkable.A long course can probably decrease recurrence.
9.Biological characterization of cultured rabbit corneal endothelial cells
Chinese Journal of Experimental Ophthalmology 2011;29(2):107-112
Background How to harvest the purified corneal endothelial seed cells is very important for the corneal tissue engineering technology. Herein,to establish a good culture method and effective identification method of corneal endothelial cells ( CECs) is the key. Objective Present study wag to establish the cultivating and identifying approach of the rabbit CECs and detect the biological characteristics of passaged cells. Methods Rabbits CECs were isolated from Descemet's membrane peeled off completely in 30 New Zealand white rabbits and then digested with 0. 25% trypsin-0. 02% EDTA and primarily cultured in CECs medium containing 15% fetal bovine serum. The growth situate and cellular morphology of rabbit CECs were observed under the inverted phase-contrast microscope following the alizarin red staining. Rabbit CECs were identified by cellular morphology as well as in gene and protein level, including the detection of expressions of collagen type IV α2(COL4A2) ,vascular endothelial growth factor receptor 2 ( FLK1 ) , Na+-K+ ATPase alpha 1subunit ( ATP1 A1 ) , aquaporin 1( AQP1 ) , voltage-dependent anion channels ( VDACs) by reverse transcription-polymerase chain reaction ( RT-PCR ). The expression and distribution of neurone specific enolase ( NSE) , Na+-K+ ATPase, zonula occludens-1 ( ZO-1 ) were also detected by immunocytochemistry under the fluorescence microscope. The proliferation activity of the passage cells was dynamically observed by MTT assay,and Na+-K+ ATPase activity of different generations cells was detected by ATPase kit. Results Majority of the primarily cultured cells adhered in 24 hours, infused in 2-3 days with the hexagon shape in appearance. The morphology of the cells was very varied with passage. Alizarin red staining showed a well- defined and well-lined cellular morphology similar to the corneal cells in vivo. Target genes of C0L4A2, FLK1, ATPIAI ,AQPI and VDACs were positively expressed in the cells. However,the expression of CK12 was absent in the cells. NSE, Na+-K+ ATPase, ZO-1 positive cells were respectively observed under the laser confocal scanning microscopy. MTT results showed a gradually low growth curve with the passage. Quantitative results also revealed that the Na+-K+ ATPase activity was gradually declined in different generations of cells ( F = 77. 174, P = 0. 000 ). Conclusion The enzyme digestion is a better approach of isolating and culturing comeal endothelial cells. Cultured cells can be identified by cells staining, gene expression and protein level. Earlier generation of CECs are ideal seed cells for cornea tissue engineering.
10.Inhibitory effect of astragalus polysaccharide on the proliferation of human erythroleukemia K562 cells and its mechanisms
Chao LI ; Xinhua QIAN ; Xinlai QIAN ; Linlin FU ; Hong WANG
Chinese Journal of Applied Clinical Pediatrics 2014;29(12):936-939
Objective To explore the inhibitory effect of astragalus polysaccharide (APS) on the proliferation of human erythroleukemia K562 cells and its mechanisms.Methods After K562 cells (purchased from Shanghai cell bank of chinese academy of science) were treated with different concentrations (0 mg/L,100 mg/L,200 mg/L and 400 mg/L) of APS.The influences of APS on the growth rate,doubling time and cell cycle distribution of K562 cells were observed by methyl thiazolyl tetra-zolium assay (MTF) and flow cytometry,respectively.Furthermore,the reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting assay were used to detect the expressions of Cyclin A,Cyclin B,Cyclin E and p21 gene at the mRNA and protein levels,respectively.Results MTT assay findings showed that,compared to the control group (0 mg/L APS),growth rates of K562 cells treated with 100 mg/L,200 mg/L and 400 mg/L APS decreased significantly (all P < 0.01),and the doubling times lengthened significantly (all P < 0.01).Flow cytometry findings revealed that,compared to the control group,the G1 phase cells in K562 cells of APS group increased significantly (P <0.01),while the S and G2/M phase cells decreased significantly (all P < 0.01).RT-PCR and Western blotting results indicated that Cyclin B and Cyclin E expression of K562 cells at the mRNA and protein levels in the APS group were significantly lower than those of the control group(all P < 0.01),whereas p21 expression was significantly enhanced at mRNA and protein levels (P < 0.01),and Cyclin A expression was not significantly different at mRNA and protein levels between the 2 groups (all P > 0.05).Conclusions APS could inhibit the proliferation of human erythroleukemia K562 cells.APS could inhibit the proliferation of K562 cells by down-regulating the expression of Cyclin B and Cyclin E and up-regulating the expression of p21.