1.Bacterial Programmed Cell Death Mediated by mazEF System Under Stressful Conditions
Microbiology 1992;0(06):-
mazEF, which is a toxin-antitoxin system located in bacterial chromosome, can mediate programmed cell death induced by various stressful conditions. In this review, the genetic structure, physiological and biochemical function of mazEF system were outlined, cellular signals and the regulation of cell factors involved in the process of cell death were introduced, and the controversy on the theory of mazEF-mediated programmed cell death was discussed. Based on the present results, It is pointed out that some questions about bacterial programmed cell death should be taken into more consideration.
2.Research Summary About Evaluation System of Thermal Environment in Cabin(Room)
Degang WANG ; Xinxi XU ; Ning ZHANG
Chinese Medical Equipment Journal 1989;0(03):-
The domestic and foreign research status related to thermal environment in the cabin(room) is reviewed.Parameters which affect thermal environment and the index limits in the standards of the different cabin(room) are narrated overall.Measuring methods pertinent to parameters of thermal environment are introduced.Finally,the comprehensive evaluation indices of thermal comfort in the cabin(room) and their using fields are analyzed emphatically.It's essential to study thermal environment and it can establish theory foundation for research on thermal environment index system inside mobile medical equipments.
3.Surface display of GFP using CotX as a molecular vector on Bacillus subtilis spores.
Qian LI ; Degang NING ; Chundu WU
Chinese Journal of Biotechnology 2010;26(2):264-269
Spore coat proteins, such as CotB, CotC, CotG et al, are able to efficiently display exogenous protein on spore surface for preparing oral vaccines or enzymes. CotX is another structural protein of spore coats of Bacillus subtilis. To investigate whether CotX could carry target protein onto the spore surface, we constructed a recombinant integrative plasmid, designated as pJS749, which carries a recombinant cotX-gfp gene under the control of the cotX promoter. We transformed pJS749 into Bacillus subtilis 168(trp-), an alpha-amylase inactivated mutant DRJS749 was selected and confirmed to be a double crossover integrant, where cotX-gfp fragment was integrated into the chromosome. After induction of spore formation, significant green fluorescence was observed on spore surface of strain DRJS749 under fluorescent microcopy. This suggests that CotX is associated with the outer part of the coat. CotX can therefore be used as a molecular vehicle for spore surface display of exogenous proteins.
Bacillus subtilis
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genetics
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metabolism
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physiology
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Bacterial Proteins
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biosynthesis
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genetics
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Gene Expression Regulation, Bacterial
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Green Fluorescent Proteins
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biosynthesis
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genetics
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Recombinant Fusion Proteins
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biosynthesis
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genetics
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Spores, Bacterial
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genetics
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metabolism
4.Study on the comprehensive effect of splenectomy on liver cirrhosis
Degang KONG ; Shichun LU ; Jushan WU ; Daobing ZENG ; Binwei DUAN ; Qingliang GUO ; Dongdong LIN ; Huiguo DING ; Qinghua MENG ; Juan LI ; Ning LI
Chinese Journal of Hepatobiliary Surgery 2022;28(7):499-503
Objective:To study the impact and the mechanism of splenectomy combined with pericardial devascularization on cirrhotic livers.Methods:Serum samples and clinical data were collected preoperatively and postoperatively from 54 patients with cirrhosis who underwent splenectomy combined with pericardial devascularization from May 2013 to Oct 2014 at Beijing You’an Hospital, Capital Medical University. Changes in hepatic arterial and portal venous blood flow, liver function and fibroscan results were analyzed. The levels of nitric oxide (NO), endothelin-1 (ET-1), interleukin-6 (IL-6), hepatocyte growth factor (HGF), transforming growth factor-β1 (TGF-β1) and matrix metalloproteinase 1 (MMP1) were measured.Results:There were 31 males and 23 females, aged(45.48±10.21)years. Free portal vein pressure decreased significantly from (37.0±7.1) cmH 2O (1 cmH 2O=0.098 kPa) to (26.1±5.7) cmH 2O after surgery ( P<0.05). Significant increases in postoperative lumen diameter (4.0±1.0) mm vs (3.1±0.7) mm were observed, accompanied by increase in peak flow velocity and blood flow of the hepatic artery. Significant deductions in lumen diameter (11.9±2.0) mm vs (13.1±1.9) mm, accompanied by reduction of peak flow velocity and blood flow of the portal vein were observed following surgery (all P<0.05). The NO level was significantly elevated immediately after splenectomy and was subsequently remained at high levels. The ET-1 level decreased 2 days after surgery and became fluctuated at low levels. The IL-6 and HGF levels increased significantly 2 days after surgery and decreased gradually after 7 days and 1 month, respectively. The TGF-β1 and the MMP1 levels increased after surgery. The endotoxin level decreased significantly after surgery (all P<0.05). Conclusion:Splenectomy combined with pericardial devascularization induced hepatic blood flow restoration, hepatocyte regeneration and reversal of fibrosis in cirrhotic livers. Splenectomy has a protective effect on cirrhotic liver when combined with pericardial devascularization.