[Objective] The aim was to study on the effects of heavy metal stress on the growth curves of Escherichia coli and Bacillus subtili. [Method] Using traditional culture method,Escherichia coli and Bacillus subtili were...[Objective] The aim was to study on the effects of heavy metal stress on the growth curves of Escherichia coli and Bacillus subtili. [Method] Using traditional culture method,Escherichia coli and Bacillus subtili were cultured under heavy metal stress including Cu2＋,Hg2＋,Pb2＋,Cd2＋ and Cr6＋ in different concentrations. Then the growth curves of the bacteria were determined to investigate the effects of exogenous heavy metals on the growth of the two kinds of bacteria. [Result] The proliferation of the two bacteria was inhibited at high concentrations of Hg2＋ and Cd2＋ respectively,and G＋ is more sensitive to them than G-; when the heavy metal concentration was 50 mg/L,the toxicity of the five kinds of heavy metals on the two bacteria was Hg2＋Cd2＋Cu2＋Cr6＋≈Pb2＋. [Conclusion] The research will provide a basis to explore the effects of heavy metal on environment and ecological system.展开更多
OBJECTIVE To evaluate the Quality of Life of the patients who received a total gastrectomy with different kinds of reconstruction methods. METHODS Patients who received a total gastrectomy between May 1999 to May 2003...OBJECTIVE To evaluate the Quality of Life of the patients who received a total gastrectomy with different kinds of reconstruction methods. METHODS Patients who received a total gastrectomy between May 1999 to May 2003 were followed-up via questionnaires. Fifty-nine who were alive more than 2 years with no sigh of recurrence were enrolled in this study. The patients were divided into 2 groups as follows： a group treated with reconstruction with a duodenal passage after total gastrectomy （gastric substitute, GS）; and a group receiving reconstruction without duodenal passage after total gastrectomy （Jejenal pouch, JP）. Follow-up feedback data of 14 items from the patients were analyzed, comparing the Quality of Life （QOL） between the 2 groups. RESULTS Six months after operation, the most common symptoms of all patients were reflux and loss of body weight, but there was no statistically significant differences in the 14 items related to the special post-operation symptoms between the 2 groups. At 12 months after the operations, there were significant differences between the 2 groups in body weight （P=0.01）, eating time （P=0.034〈0.05）, and frequency of food intake （P= 0.040〈0.05）; At 24 months after the operations, the only difference between the 2 groups was body weight gain （P=0.025〈0.05）. The JP group was better than the GS group. CONCLUSION The JP reconstruction pattern is superior to a simple GS in gain of body weight, volume of food intake and frequency of food intake, soon after the operation.展开更多
Duodenal duplication,a rare congenital malformation,can also be observed in adulthood.Although it can be cystic or tubular,communicating or non-communicating,cystic and non-communicating forms are the most common.Seve...Duodenal duplication,a rare congenital malformation,can also be observed in adulthood.Although it can be cystic or tubular,communicating or non-communicating,cystic and non-communicating forms are the most common.Several complications,such as obstruction,bleeding,perforation and pancreatitis,may result.Optimal treatment is total excision,although endoscopic procedures have also been described in appropriate cases.If total excision is not possible,subtotal excision and internal derivation can be performed.The 38-year-old woman presented here had occasional attacks of abdominal pain and obstruction,and we considered the diagnosis of duodenal duplication by abdominal computerized tomography.As we confirmed the diagnosis with operative findings and histopathological signs,we treated her with subtotal excision and intraduodenal cystoduodenostomy.展开更多
Gastrointestinal duplication is a congenital rare disease entity. Gastric duplication cysts seem to appear even more rarely. Herein, two duplications cysts of the stomach in a 46 year-old female patient are presented....Gastrointestinal duplication is a congenital rare disease entity. Gastric duplication cysts seem to appear even more rarely. Herein, two duplications cysts of the stomach in a 46 year-old female patient are presented. Abdominal computed tomography demonstrated a cystic lesion attached to the posterior aspect of the gastric fundus, while upper gastrointestinal endoscopy was negative. An exploratory laparotomy revealed a non-communicating cyst and a smaller similar cyst embedded in the gastrosplenic ligament. Excision of both cysts along with the spleen was performed and pathology reported two smooth muscle coated cysts with a pseudostratified ciliated epithelial lining (respiratory type).展开更多
We documented the pattern of cell development in Euplotes charon. The ontogenesis of this species was similar to many of its congeners, except for the formation of the caudal cirri. In E. Charon, a caudal cirrus is fo...We documented the pattern of cell development in Euplotes charon. The ontogenesis of this species was similar to many of its congeners, except for the formation of the caudal cirri. In E. Charon, a caudal cirrus is formed posterior to each of the rightmost two or three dorsal kinety anlage in the proter, and the second rightmost dorsal kinety in the opisthe. In addition, two caudal cirri are formed posterior to the rightmost dorsal kinety in the opisthe. This pattern of development represents a completely new type. Based on our evaluation, and in comparison with previous studies, we also conclude that the pattern of cell development is variable among species in the Euplotes genera. The variation is particularly evident during the formation of frontoventral and caudal cirri. Based on the segmentation pattern of frontal-midventral transverse cirral anlagen, cirri reduction, and migration of frontoventral cirri, we identified five types: the affinis-type, the eurystomus-type, the charon-type, the raikovi-type and orientalis-type. Euplotes (s. l.) can also be divided into three types based on the formation of caudal cirri: focardii-type, vannus-type and charon-type. Indeed, we conclude that the number (one or two) of marginal cirri should be given as much consideration as the genetic separation. Given this, we reassessed the validity of using genetic separation to classify the group. Generally, the morphogenetic data disagreed with the molecular data (SSrRNA gene sequences). Given these discrepancies, it is too early to draw conclusions on the systematic arrangement of this species-rich taxon.展开更多
AIM： To evaluate the effect of perioperative parenteral nutrition on serum immunoglobulin, weight change, and post-operative outcome in severely malnourished patients with Crohn＇s disease. METHODS： Thirty-two sever...AIM： To evaluate the effect of perioperative parenteral nutrition on serum immunoglobulin, weight change, and post-operative outcome in severely malnourished patients with Crohn＇s disease. METHODS： Thirty-two severely malnourished patients with Crohn＇s disease who had undergone surgery in our hospital were reviewed. Sixteen patients who received perioperative parenteral nutrition were enrolled in the study group, and the other 16 patients who did not receive parenteral nutrition were enrolled in the control group. Serum immunoglobulin, body mass index （BMI）, liver function, weight change, and postoperative complications were evaluated. RESULTS： Serum IgM levels elevated 1 wk before surgery in both groups, and decreased to normal value （from 139±41 to 105±29 mg/dL, P = 0.04） 4 wk after operation in the study group, while no significant changes was noted in the control group （from 133±16 to 129±13 mg/dL, P = 0.34）. There were no significant changes in concentrations of IgG and IgA. The BMI of the study group increased from 13.9±0.6 to 15.3±0.7 kg/m^2 （P = 0.02） with no significant change in the control group （14.1±0.7 and 14.5±0.5, respectively, P = 0.81）. The percentage of resuming work was higher in the study group than in the control group. CONCLUSION： Perioperative parenteral nutrition possibly ameliorates the humoral immunity, reverses malnutrition, and facilitates rehabilitation. 2005 The WJG Press and Elsevier Inc. All rights reserved展开更多
The kinetics of batch and fed-batch cultures of recombinant Escherichia coli producing human-like collagen was investigated. In the batch culture, a kinetic model of a simple growth-association system was concluded wi...The kinetics of batch and fed-batch cultures of recombinant Escherichia coli producing human-like collagen was investigated. In the batch culture, a kinetic model of a simple growth-association system was concluded without consideration of cell endogeneous metabolism. The cell lag time, the maximum specific growth rate and Yx/s were determined as 1.75h, 0.65h^-1 and 0.51g·g^-1, respectively. In the fed-batch culture, different specific growth rates were set at （0.15, 0.2, 0.25h^-1） by the method of pseudo-exponential feeding, and the expressions for the specific rate of substrate consumption, the growth kinetics and the product formation kinetics of each phase were obtained. The result shows that the concentrations of cell and product can reach 77.5g·L^-1 and 10.2g·L^-1 respectively. The modal predictions are in good agreement with the experimental data.展开更多
A genetically engineered Escherichia coli JM109 harboring pLF3 was used to produce a hybrid ex-tracellular β-glucanase. Starting with enzyme production medium, glycerol and yeast extract combined with NaNO3 were scre...A genetically engineered Escherichia coli JM109 harboring pLF3 was used to produce a hybrid ex-tracellular β-glucanase. Starting with enzyme production medium, glycerol and yeast extract combined with NaNO3 were screened to be the most suitable carbon and nitrogen source, respectively. Analysis of six components of the enzyme production medium by employing statistical optimization methods such as Plackett-Burman design and steepest ascent showed that yeast extract was the only significant variable and its best concentration for enzyme production was 12g·L-1. After optimization of the medium, 297.71U·ml-1 of β-glucanase activity in the medium and 352350U·g-1 of β-glucanase selectivity could be obtained, which were 14 and 72 folds higher than those ob-tained from original medium, respectively. Even higher enzyme activities were achieved by batch cultivations in a conventional stirred bioreactor on the optimized medium.展开更多
Percutaneous endoscopic colostomy （PEC） is increasingly proposed as an alternative to surgery to treat various disorders, including acute colonic pseudo-obstruction, chronic intestinal pseudo-obstruction and relapsi...Percutaneous endoscopic colostomy （PEC） is increasingly proposed as an alternative to surgery to treat various disorders, including acute colonic pseudo-obstruction, chronic intestinal pseudo-obstruction and relapsing sigmoid volvulus. We report on a severe complication that occurred two months after PEC placement. A 74-year-old man with a history of chronic intestinal pseudo-obstruction evolving since 8 years was readmitted to our hospital and received PEC to provide long-standing relief. The procedure was uneventful and greatly improved the patient＇s quality of life. Two months later, the patient developed acute stercoral peritonitis. At laparotomy, the colostomy flange was embedded in the abdominal wall but no pressure necrosis was found at the level of the colonic wall. This complication was likely related to inadvertent traction of the colostomy tube. Subtotal colectomy with terminal ileostomy was performed. We review the major features of 60 cases of PEC reported to date, including indications and complications.展开更多
AIM: To kill CEA positive colorectal carcinoma cells specifically using the E coli cytosine deaminase (CD) suicide gene, a new replication-deficient recombinant adenoviral vector was constructed in which CD gene was c...AIM: To kill CEA positive colorectal carcinoma cells specifically using the E coli cytosine deaminase (CD) suicide gene, a new replication-deficient recombinant adenoviral vector was constructed in which CD gene was controlled under CEA promoter and its in vitro cytotoxic effects were evaluated. METHODS: Shuttle plasmid containing CD gene and regulatory sequence of the CEA gene was constructed and recombined with the right arm of adenovirus genome DNA in 293 cell strain. Dot blotting and PCR were used to identify positive plaques. The purification of adenovirus was performed with ultra-concentration in CsCl step gradients and the titration was measured with plaque formation assay. Cytotoxic effects were assayed with MTT method, The fifty percent inhibition concentration (IC(50)) of 5-FC was calculated using a curve-fitting parameter. The human colorectal carcinoma cell line, which was CEA-producing, and the CEA-nonproducing Hela cell line were applied in cytological tests. An established recombinant adenovirus vector AdCMVCD, in which the CD gene was controlled under CMV promoter, was used as virus control. Quantitative results were expressed as the mean +/- SD of the mean. Statistical analysis was performed using ANOVA test. RESULTS: The desired recombinant adenovirus vector was named AdCEACD. The results of dot blotting and PCR showed that the recombinant adenovirus contained CEA promoter and CD gene. Virus titer was about 5.0 X 10(14)pfu/L(-1) after purification. The CEA-producing Lovo cells were sensitive to 5-FC and had the same cytotoxic effect after infection with AdCEACD and AdCMVCD (The IC(50) values of 5-FC in parent Lovo cells, Lovo cells infected with 100 M.O.I AdCEACD and Lovo cells infected with 10 M.O.I AdCMVCD were 】15000, 216.5+/-38.1 and 128.8+/-25.4 micromol.L(-1), P【0.001, respectively), and the cytotoxicity of 5-FC increased accordingly when the m.o.i of adenoviruses were enhanced (The value of IC(50) of 5-FC was reduced to 27.9+/-4.2 micromol.L(-1) in 1000 M.O.I AdCEACD infected Lovo cells and 24.8+/-7.1 micromol.L(-1) in 100 M.O.I AdCMVCD infected Lovo cells, P【0.05, P【0.01, respectively). The CEA-nonproducing Hela cells had no effect after infection with AdCEACD, but Hela cells had the cytotoxic sensitivity to 5-FC after infection with AdCMVCD (The IC(50) of 5-FC in parent Hele cells and Hela cells infected with AdCMVCD at 10 M.O.I was 】15000 and 214.5+/-31.3 micromol.L(-1), P【0.001). AdCEACD/5-FC system also had bystander effect, and the viability was about 30 percent when the proportion of transfected cells was only 10 percent. CONCLUSION: The recombinant adenovirus vector AdCEACD has the character of cell type-specific gene delivery. The AdCEACD/5-FC system may become a new, potent and specific approach for the gene therapy of CEA-positive neoplasms, especially colon carcinoma.展开更多
A 48-year-old woman was admitted with 15-mo history of abdominal pain, diarrhea and hematochezia, and 5-mo history of defecation difficulty. She had been successively admitted to nine hospitals, with an initial diagno...A 48-year-old woman was admitted with 15-mo history of abdominal pain, diarrhea and hematochezia, and 5-mo history of defecation difficulty. She had been successively admitted to nine hospitals, with an initial diagnosis of inflammatory bowel disease with stenotic sigmoid colon. Findings from computed tomography virtual colonoscopy, radiography with meglumine diatrizoate, endoscopic balloon dilatation, metallic stent implantation and later overall colonoscopy, coupled with the newfound knowledge of compound Qingdai pill-taking, led to a subsequent diagnosis of ischemic or toxic bowel disease with sigmoid colon stenosis. The patient was successfully treated by laparoscopic sigmoid colectomy, and postoperative pathological examination revealed ischemic or toxic injury of the sigmoid colon, providing a final diagnosis of druginduced sigmoid colon stenosis. This case highlights that adequate awareness of drug-induced colon stenosis has a decisive role in avoiding misdiagnosis and mistreatment. The diagnostic and therapeutic experiences learnt from this case suggest that endoscopic balloon expansion and colonic metallic stent implantation as bridge treatments were demonstrated as crucial for the differential diagnosis of benign colonic stenosis. Skillful surgical technique and appropriate perioperative management helped to ensure the safety of our patient in subsequent surgery after long-term use of glucocorticoids.展开更多
To establish a rapid quantification method for heparinase I during its production in recombinant Escherichia coli, a translational fusion vector was constructed by fusing the N terminus of heparinase I to the C termin...To establish a rapid quantification method for heparinase I during its production in recombinant Escherichia coli, a translational fusion vector was constructed by fusing the N terminus of heparinase I to the C terminus of a green fluorescent protein mutant （GFPmutl）. As a result, not only was the functional recombinant expression of heparinase I in E. coli accomplished, but also a linear correlation was obtained between the GFP fluorescence intensity and heparinase I activity, allowing enzyme activity to be quantified rapidly during the fermentation.展开更多
基金Supported by Science Research Fund Project of Yunnan Provincial Education Department "Physiological Toxicity of Heavy Metal Stress on Several Microorganisms" (09Y0382)Yunnan Natural Science Foundation Project "Toxicity Mechanism of Three Aquatic Plants under Heavy Metal Pollution" (2008ZC161M)~~
文摘[Objective] The aim was to study on the effects of heavy metal stress on the growth curves of Escherichia coli and Bacillus subtili. [Method] Using traditional culture method,Escherichia coli and Bacillus subtili were cultured under heavy metal stress including Cu2＋,Hg2＋,Pb2＋,Cd2＋ and Cr6＋ in different concentrations. Then the growth curves of the bacteria were determined to investigate the effects of exogenous heavy metals on the growth of the two kinds of bacteria. [Result] The proliferation of the two bacteria was inhibited at high concentrations of Hg2＋ and Cd2＋ respectively,and G＋ is more sensitive to them than G-; when the heavy metal concentration was 50 mg/L,the toxicity of the five kinds of heavy metals on the two bacteria was Hg2＋Cd2＋Cu2＋Cr6＋≈Pb2＋. [Conclusion] The research will provide a basis to explore the effects of heavy metal on environment and ecological system.
文摘OBJECTIVE To evaluate the Quality of Life of the patients who received a total gastrectomy with different kinds of reconstruction methods. METHODS Patients who received a total gastrectomy between May 1999 to May 2003 were followed-up via questionnaires. Fifty-nine who were alive more than 2 years with no sigh of recurrence were enrolled in this study. The patients were divided into 2 groups as follows： a group treated with reconstruction with a duodenal passage after total gastrectomy （gastric substitute, GS）; and a group receiving reconstruction without duodenal passage after total gastrectomy （Jejenal pouch, JP）. Follow-up feedback data of 14 items from the patients were analyzed, comparing the Quality of Life （QOL） between the 2 groups. RESULTS Six months after operation, the most common symptoms of all patients were reflux and loss of body weight, but there was no statistically significant differences in the 14 items related to the special post-operation symptoms between the 2 groups. At 12 months after the operations, there were significant differences between the 2 groups in body weight （P=0.01）, eating time （P=0.034〈0.05）, and frequency of food intake （P= 0.040〈0.05）; At 24 months after the operations, the only difference between the 2 groups was body weight gain （P=0.025〈0.05）. The JP group was better than the GS group. CONCLUSION The JP reconstruction pattern is superior to a simple GS in gain of body weight, volume of food intake and frequency of food intake, soon after the operation.
文摘Duodenal duplication,a rare congenital malformation,can also be observed in adulthood.Although it can be cystic or tubular,communicating or non-communicating,cystic and non-communicating forms are the most common.Several complications,such as obstruction,bleeding,perforation and pancreatitis,may result.Optimal treatment is total excision,although endoscopic procedures have also been described in appropriate cases.If total excision is not possible,subtotal excision and internal derivation can be performed.The 38-year-old woman presented here had occasional attacks of abdominal pain and obstruction,and we considered the diagnosis of duodenal duplication by abdominal computerized tomography.As we confirmed the diagnosis with operative findings and histopathological signs,we treated her with subtotal excision and intraduodenal cystoduodenostomy.
文摘Gastrointestinal duplication is a congenital rare disease entity. Gastric duplication cysts seem to appear even more rarely. Herein, two duplications cysts of the stomach in a 46 year-old female patient are presented. Abdominal computed tomography demonstrated a cystic lesion attached to the posterior aspect of the gastric fundus, while upper gastrointestinal endoscopy was negative. An exploratory laparotomy revealed a non-communicating cyst and a smaller similar cyst embedded in the gastrosplenic ligament. Excision of both cysts along with the spleen was performed and pathology reported two smooth muscle coated cysts with a pseudostratified ciliated epithelial lining (respiratory type).
基金Supported by the Natural Science Foundation of China (No. 40906065)the China Postdoctoral Science Foundation (No. 20090451351)a grant from the Center of Excellence in Biodiversity, King Saud University
文摘We documented the pattern of cell development in Euplotes charon. The ontogenesis of this species was similar to many of its congeners, except for the formation of the caudal cirri. In E. Charon, a caudal cirrus is formed posterior to each of the rightmost two or three dorsal kinety anlage in the proter, and the second rightmost dorsal kinety in the opisthe. In addition, two caudal cirri are formed posterior to the rightmost dorsal kinety in the opisthe. This pattern of development represents a completely new type. Based on our evaluation, and in comparison with previous studies, we also conclude that the pattern of cell development is variable among species in the Euplotes genera. The variation is particularly evident during the formation of frontoventral and caudal cirri. Based on the segmentation pattern of frontal-midventral transverse cirral anlagen, cirri reduction, and migration of frontoventral cirri, we identified five types: the affinis-type, the eurystomus-type, the charon-type, the raikovi-type and orientalis-type. Euplotes (s. l.) can also be divided into three types based on the formation of caudal cirri: focardii-type, vannus-type and charon-type. Indeed, we conclude that the number (one or two) of marginal cirri should be given as much consideration as the genetic separation. Given this, we reassessed the validity of using genetic separation to classify the group. Generally, the morphogenetic data disagreed with the molecular data (SSrRNA gene sequences). Given these discrepancies, it is too early to draw conclusions on the systematic arrangement of this species-rich taxon.
文摘AIM： To evaluate the effect of perioperative parenteral nutrition on serum immunoglobulin, weight change, and post-operative outcome in severely malnourished patients with Crohn＇s disease. METHODS： Thirty-two severely malnourished patients with Crohn＇s disease who had undergone surgery in our hospital were reviewed. Sixteen patients who received perioperative parenteral nutrition were enrolled in the study group, and the other 16 patients who did not receive parenteral nutrition were enrolled in the control group. Serum immunoglobulin, body mass index （BMI）, liver function, weight change, and postoperative complications were evaluated. RESULTS： Serum IgM levels elevated 1 wk before surgery in both groups, and decreased to normal value （from 139±41 to 105±29 mg/dL, P = 0.04） 4 wk after operation in the study group, while no significant changes was noted in the control group （from 133±16 to 129±13 mg/dL, P = 0.34）. There were no significant changes in concentrations of IgG and IgA. The BMI of the study group increased from 13.9±0.6 to 15.3±0.7 kg/m^2 （P = 0.02） with no significant change in the control group （14.1±0.7 and 14.5±0.5, respectively, P = 0.81）. The percentage of resuming work was higher in the study group than in the control group. CONCLUSION： Perioperative parenteral nutrition possibly ameliorates the humoral immunity, reverses malnutrition, and facilitates rehabilitation. 2005 The WJG Press and Elsevier Inc. All rights reserved
基金Supported by the National Science and Technology Key Funds (2003DA901A32) and the National Natural Science Foundationof China (No.20476085).
文摘The kinetics of batch and fed-batch cultures of recombinant Escherichia coli producing human-like collagen was investigated. In the batch culture, a kinetic model of a simple growth-association system was concluded without consideration of cell endogeneous metabolism. The cell lag time, the maximum specific growth rate and Yx/s were determined as 1.75h, 0.65h^-1 and 0.51g·g^-1, respectively. In the fed-batch culture, different specific growth rates were set at （0.15, 0.2, 0.25h^-1） by the method of pseudo-exponential feeding, and the expressions for the specific rate of substrate consumption, the growth kinetics and the product formation kinetics of each phase were obtained. The result shows that the concentrations of cell and product can reach 77.5g·L^-1 and 10.2g·L^-1 respectively. The modal predictions are in good agreement with the experimental data.
基金Supported by the National Natural Science Foundation of China (No.20306025)the Xiamen Science and Technology Pro-ject (No.3502Z20055017).
文摘A genetically engineered Escherichia coli JM109 harboring pLF3 was used to produce a hybrid ex-tracellular β-glucanase. Starting with enzyme production medium, glycerol and yeast extract combined with NaNO3 were screened to be the most suitable carbon and nitrogen source, respectively. Analysis of six components of the enzyme production medium by employing statistical optimization methods such as Plackett-Burman design and steepest ascent showed that yeast extract was the only significant variable and its best concentration for enzyme production was 12g·L-1. After optimization of the medium, 297.71U·ml-1 of β-glucanase activity in the medium and 352350U·g-1 of β-glucanase selectivity could be obtained, which were 14 and 72 folds higher than those ob-tained from original medium, respectively. Even higher enzyme activities were achieved by batch cultivations in a conventional stirred bioreactor on the optimized medium.
文摘Percutaneous endoscopic colostomy （PEC） is increasingly proposed as an alternative to surgery to treat various disorders, including acute colonic pseudo-obstruction, chronic intestinal pseudo-obstruction and relapsing sigmoid volvulus. We report on a severe complication that occurred two months after PEC placement. A 74-year-old man with a history of chronic intestinal pseudo-obstruction evolving since 8 years was readmitted to our hospital and received PEC to provide long-standing relief. The procedure was uneventful and greatly improved the patient＇s quality of life. Two months later, the patient developed acute stercoral peritonitis. At laparotomy, the colostomy flange was embedded in the abdominal wall but no pressure necrosis was found at the level of the colonic wall. This complication was likely related to inadvertent traction of the colostomy tube. Subtotal colectomy with terminal ileostomy was performed. We review the major features of 60 cases of PEC reported to date, including indications and complications.
基金the Creation Foundation of Nanjing Medical University,No.Cx9905
文摘AIM: To kill CEA positive colorectal carcinoma cells specifically using the E coli cytosine deaminase (CD) suicide gene, a new replication-deficient recombinant adenoviral vector was constructed in which CD gene was controlled under CEA promoter and its in vitro cytotoxic effects were evaluated. METHODS: Shuttle plasmid containing CD gene and regulatory sequence of the CEA gene was constructed and recombined with the right arm of adenovirus genome DNA in 293 cell strain. Dot blotting and PCR were used to identify positive plaques. The purification of adenovirus was performed with ultra-concentration in CsCl step gradients and the titration was measured with plaque formation assay. Cytotoxic effects were assayed with MTT method, The fifty percent inhibition concentration (IC(50)) of 5-FC was calculated using a curve-fitting parameter. The human colorectal carcinoma cell line, which was CEA-producing, and the CEA-nonproducing Hela cell line were applied in cytological tests. An established recombinant adenovirus vector AdCMVCD, in which the CD gene was controlled under CMV promoter, was used as virus control. Quantitative results were expressed as the mean +/- SD of the mean. Statistical analysis was performed using ANOVA test. RESULTS: The desired recombinant adenovirus vector was named AdCEACD. The results of dot blotting and PCR showed that the recombinant adenovirus contained CEA promoter and CD gene. Virus titer was about 5.0 X 10(14)pfu/L(-1) after purification. The CEA-producing Lovo cells were sensitive to 5-FC and had the same cytotoxic effect after infection with AdCEACD and AdCMVCD (The IC(50) values of 5-FC in parent Lovo cells, Lovo cells infected with 100 M.O.I AdCEACD and Lovo cells infected with 10 M.O.I AdCMVCD were 】15000, 216.5+/-38.1 and 128.8+/-25.4 micromol.L(-1), P【0.001, respectively), and the cytotoxicity of 5-FC increased accordingly when the m.o.i of adenoviruses were enhanced (The value of IC(50) of 5-FC was reduced to 27.9+/-4.2 micromol.L(-1) in 1000 M.O.I AdCEACD infected Lovo cells and 24.8+/-7.1 micromol.L(-1) in 100 M.O.I AdCMVCD infected Lovo cells, P【0.05, P【0.01, respectively). The CEA-nonproducing Hela cells had no effect after infection with AdCEACD, but Hela cells had the cytotoxic sensitivity to 5-FC after infection with AdCMVCD (The IC(50) of 5-FC in parent Hele cells and Hela cells infected with AdCMVCD at 10 M.O.I was 】15000 and 214.5+/-31.3 micromol.L(-1), P【0.001). AdCEACD/5-FC system also had bystander effect, and the viability was about 30 percent when the proportion of transfected cells was only 10 percent. CONCLUSION: The recombinant adenovirus vector AdCEACD has the character of cell type-specific gene delivery. The AdCEACD/5-FC system may become a new, potent and specific approach for the gene therapy of CEA-positive neoplasms, especially colon carcinoma.
基金Supported by the Science and Technology Project of State Grid Corporation of China,No.SGHB0000AJJS1400182
文摘A 48-year-old woman was admitted with 15-mo history of abdominal pain, diarrhea and hematochezia, and 5-mo history of defecation difficulty. She had been successively admitted to nine hospitals, with an initial diagnosis of inflammatory bowel disease with stenotic sigmoid colon. Findings from computed tomography virtual colonoscopy, radiography with meglumine diatrizoate, endoscopic balloon dilatation, metallic stent implantation and later overall colonoscopy, coupled with the newfound knowledge of compound Qingdai pill-taking, led to a subsequent diagnosis of ischemic or toxic bowel disease with sigmoid colon stenosis. The patient was successfully treated by laparoscopic sigmoid colectomy, and postoperative pathological examination revealed ischemic or toxic injury of the sigmoid colon, providing a final diagnosis of druginduced sigmoid colon stenosis. This case highlights that adequate awareness of drug-induced colon stenosis has a decisive role in avoiding misdiagnosis and mistreatment. The diagnostic and therapeutic experiences learnt from this case suggest that endoscopic balloon expansion and colonic metallic stent implantation as bridge treatments were demonstrated as crucial for the differential diagnosis of benign colonic stenosis. Skillful surgical technique and appropriate perioperative management helped to ensure the safety of our patient in subsequent surgery after long-term use of glucocorticoids.
基金Supported by the National Natural Science Foundation of China (No.20336010 and No.20176025).
文摘To establish a rapid quantification method for heparinase I during its production in recombinant Escherichia coli, a translational fusion vector was constructed by fusing the N terminus of heparinase I to the C terminus of a green fluorescent protein mutant （GFPmutl）. As a result, not only was the functional recombinant expression of heparinase I in E. coli accomplished, but also a linear correlation was obtained between the GFP fluorescence intensity and heparinase I activity, allowing enzyme activity to be quantified rapidly during the fermentation.
