Celiac disease (CD) is a common autoimmune disorder characterized by an immune response to ingested gluten and has a strong HLA association with HLA- DQ2 and HLA-DQ8 molecules, but human HLA-DQ risk factors do not exp...Celiac disease (CD) is a common autoimmune disorder characterized by an immune response to ingested gluten and has a strong HLA association with HLA- DQ2 and HLA-DQ8 molecules, but human HLA-DQ risk factors do not explain the entire genetic susceptibility to gluten intolerance. CD is caused by the lack of immune tolerance (oral tolerance) to wheat gluten. In this sense, the expression of soluble HLA-G in CD is of special interest because the molecule plays an important role in the induction of immune tolerance. The enhanced expression of soluble HLA-G found in CD may be part of a mechanism to restore the gluten intolerance. In this editorial, we review recent progress in understanding CD in relation to its prevalence, diagnosis and possible mechanisms of pathogenesis.展开更多
AIM: To review the risk of proximal colon cancer in patients undergoing colonoscopy.METHODS: We estimated the risk of advanced proximal adenomas and cancers in 6 196 consecutive patients that underwent colonoscopy (me...AIM: To review the risk of proximal colon cancer in patients undergoing colonoscopy.METHODS: We estimated the risk of advanced proximal adenomas and cancers in 6 196 consecutive patients that underwent colonoscopy (mean age 60 years, 65% males,without prior history of colorectal examination). Neoplasms were classified as diminutive adenoma (5 mm or less),small adenoma (6-9 mm), advanced adenoma (10 mm or more, with villous component or high-grade dysplasia)and cancer (invasive adenocarcinoma). The sites of neoplasms were defined as rectosigmoid (rectum and sigmoid colon) and proximal colon (from cecum to descending colon).RESULTS: The trend of the prevalence of advanced proximal adenoma was to increase with severe rectosigmoid findings, while the prevalence of proximal colon cancer did not increase with severe rectosigmoid findings. Among the 157 patients with proximal colon cancer, 74% had no neoplasm in the rectosigmoid colon. Multivariate logisticregression analysis revealed that age was the main predictor of proximal colon cancer and existence of rectosigmoid adenoma was not a predictor of proximal colon cancer.CONCLUSION: Sigmoidoscopy is inadequate for colorectal cancer screening, especially in older populations.展开更多
AIM： To characterize changes in ghrelin levels in response to oral glucose tolerance test （OGTT） and to correlate changes in ghrelin levels with changes in insulin and glucose following OGTT in Chinese obese childr...AIM： To characterize changes in ghrelin levels in response to oral glucose tolerance test （OGTT） and to correlate changes in ghrelin levels with changes in insulin and glucose following OGTT in Chinese obese children of Tanner Ⅰ and Ⅱ stage with insulin resistance. METHODS： 22 obese children with insulin resistance state were divided into four groups according to their Tanner stage and gender： boys of Tanner Ⅰ （fir- Ⅰ ）, boys of Tanner Ⅱ（BT-Ⅱ ）, girls of Tanner Ⅰ （GT- Ⅰ ）, girls of Tanner Ⅱ （GT-Ⅱ）. Ghrelin, insulin and glucose were measured at 0, 30, 60 and 120 rain following OGTT. The control children with normal BMI were divided into control boys of Tanner Ⅰ （CBT- Ⅰ, n = 6）, control boys of Tanner Ⅱ （CBT-Ⅱ, n = 5）, control girls of Tanner Ⅰ （CGT- Ⅰ, n = 6）, control girls of Tanner Ⅱ （CGT-Ⅱ, n = 5）. Fasting serum ghrelin levels were analyzed. RESULTS： Ghrelin levels were lower in obese groups. Ghrelin levels of control group decreased in Tanner Ⅱ stage （CGT- Ⅰ vs CGT-Ⅱ t = -4.703, P = 0.001; CBT- Ⅰ vs CBT- Ⅱ t = -4.794, P = 0.001）. Basal ghrelin levels in fir-Ⅱ decreased more significantly than that in BT- Ⅰ group （t = 2.547, P = 0.029）. Ghrelin levels expressed a downward trend after OGTT among obese children. The decrease in ghrelin levels at 60 min with respect to basal values was 56.9% in BT- Ⅰ. Ghrelin concentrations at 0 min correlated directly with glucose level at 0 min in fir- Ⅰ （r = 0.898, P = 0.015）. There wasn＇t a significant correlation of ghrelin changes with glucose changes and insulin changes during OGTT in obese children with insulin resistance. CONCLUSION： In conclusion, in obese children with insulin resistance, ghrelin levels decreased with advancing pubertal stage. Ghrelin secretion suppression following OGTT was influenced by gender and pubertal stage. Baseline ghrelin levels and ghrelin suppression after OGTT did not significantly correlate with the degree of insulin resistance and insulin sensitivity.展开更多
Objective： To investigate the mechanism of carbapenem resistance and the occurrence ofplasmid-mediated quinolone resistance determinants qnr and aac（6＇）-Ib-cr in a clinical isolate of Enterobacter cloacae. Methods...Objective： To investigate the mechanism of carbapenem resistance and the occurrence ofplasmid-mediated quinolone resistance determinants qnr and aac（6＇）-Ib-cr in a clinical isolate of Enterobacter cloacae. Methods： An ertapenem-resistant E. cloacae ZY106, which was isolated from liquor puris of a female gastric cancer patient in a Chinese hospital, was investigated. Antibiotic susceptibilities were determined by agar dilution method. Conjugation experiments, isoelectric focusing, polymerase chain reaction （PCR）, and DNA sequence analyses of plasmid-mediated carbapenemases and quinolone resistance determinants were preformed to confirm the genotype. Outer membrane proteins （OMPs） were examined by urea-sodium dodecyl sulfate- polyacrylamide gel electrophoresis （Urea-SDS-PAGE）. Results： Minimum inhibitory concentrations （MICs） of imipenem, mer- openem, and ertapenem for ZY 106 were 2, 4, and 16 pg/ml, respectively. Conjugation studies with Escherichia coli resulted in the transfer of significantly reduced carbapenem susceptibility. ZY106 produced IMP-1 metallo-β-lactamase and CTX-M-3 extended-spectrum β-1actamase, and E. coli transconjugant produced IMP-1. Plasrnid-mediated quinolone resistance determinant qnrS1 was detected in ZY106. Transfer of the qnrSl-encoding-plasmid into E. coli by conjugation resulted in intermediate resistance to ciprofloxacin in E. coli transconjugant. Urea-SDS-PAGE analysis of OMPs showed that ZYI06 lacked an OMP of approximately 38 kDa. Conclusion： It is the first IMP-l-producing Enterobacteriaceae in China and the first report of a clinical isolate that harbors both blalMP and qnrS genes as well. The blalMP-1, blaCTX-M-3, and qnrS1 are encoded at three different plasmids. IMP-1 combined with the loss of an OMP possibly resulted in ertapenem resistance and reduced imipenem and mero- penern susceptibility in E. cloacae.展开更多
The dynamics of a bacterial population exposed to the minimum inhibitory concentration （MIC） of an antibiotic is an important issue in pharmacological research. Therefore, a novel antibiotic susceptibility test is u...The dynamics of a bacterial population exposed to the minimum inhibitory concentration （MIC） of an antibiotic is an important issue in pharmacological research. Therefore, a novel antibiotic susceptibility test is urgently needed that can both precisely determine the MIC and accurately select antibiotic-resistant strains from clinical bacterial populations. For this purpose, we developed a method based on Fick＇s laws of diffusion using agar plates containing a linear gradient of antibiotic. The gradient plate contained two layers. The bottom layer consisted of 15 mL agar containing the appropriate concentration of enrofloxacin and allowed to harden in the form of a wedge with the plate slanted such that the entire bottom was just covered. The upper layer consisted of 15 mL plain nutrient agar added with the plate held in the horizontal position. After allowing vertical diffusion of the drug from the bottom agar layer for 12 h, the enrofloxacin concentration was diluted in proportion to the ratio of the agar layer thicknesses. The uniform linear concentration gradient was verified by measuring the enrofloxacin concentration on the agar surface. When heavy bacterial suspensions were spread on the agar surface and incubated for more than 12 h, only resistant cells were able to form colonies beyond the boundary of confluent growth of susceptible cells. In this way, the true MIC of enrofloxacin was determined. The MICs obtained using this linear gradient plate were consistent with those obtained using conventional antibiotic susceptibility tests. Discrete colonies were then spread onto a gradient plate with higher antibiotic concentrations; the boundary line increased significantly, and gene mutations conferring resistance were identified. This new method enables the rapid identification of resistant strains in the bacterial population. Use of the linear gradient plate can easily identify the precise MIC and reveal the dynamic differentiation of bacteria near the MIC. This method allows the study of genetic and physiological characteristics of individual strains, and may be useful for early warning of antibiotic resistance that may occur after use of certain antirnicrobial agents, and guide clinical treatment.展开更多
文摘Celiac disease (CD) is a common autoimmune disorder characterized by an immune response to ingested gluten and has a strong HLA association with HLA- DQ2 and HLA-DQ8 molecules, but human HLA-DQ risk factors do not explain the entire genetic susceptibility to gluten intolerance. CD is caused by the lack of immune tolerance (oral tolerance) to wheat gluten. In this sense, the expression of soluble HLA-G in CD is of special interest because the molecule plays an important role in the induction of immune tolerance. The enhanced expression of soluble HLA-G found in CD may be part of a mechanism to restore the gluten intolerance. In this editorial, we review recent progress in understanding CD in relation to its prevalence, diagnosis and possible mechanisms of pathogenesis.
文摘AIM: To review the risk of proximal colon cancer in patients undergoing colonoscopy.METHODS: We estimated the risk of advanced proximal adenomas and cancers in 6 196 consecutive patients that underwent colonoscopy (mean age 60 years, 65% males,without prior history of colorectal examination). Neoplasms were classified as diminutive adenoma (5 mm or less),small adenoma (6-9 mm), advanced adenoma (10 mm or more, with villous component or high-grade dysplasia)and cancer (invasive adenocarcinoma). The sites of neoplasms were defined as rectosigmoid (rectum and sigmoid colon) and proximal colon (from cecum to descending colon).RESULTS: The trend of the prevalence of advanced proximal adenoma was to increase with severe rectosigmoid findings, while the prevalence of proximal colon cancer did not increase with severe rectosigmoid findings. Among the 157 patients with proximal colon cancer, 74% had no neoplasm in the rectosigmoid colon. Multivariate logisticregression analysis revealed that age was the main predictor of proximal colon cancer and existence of rectosigmoid adenoma was not a predictor of proximal colon cancer.CONCLUSION: Sigmoidoscopy is inadequate for colorectal cancer screening, especially in older populations.
基金Supported by Research Award (2005c24001) from Department of Science and Technology, Zhejiang Province, China
文摘AIM： To characterize changes in ghrelin levels in response to oral glucose tolerance test （OGTT） and to correlate changes in ghrelin levels with changes in insulin and glucose following OGTT in Chinese obese children of Tanner Ⅰ and Ⅱ stage with insulin resistance. METHODS： 22 obese children with insulin resistance state were divided into four groups according to their Tanner stage and gender： boys of Tanner Ⅰ （fir- Ⅰ ）, boys of Tanner Ⅱ（BT-Ⅱ ）, girls of Tanner Ⅰ （GT- Ⅰ ）, girls of Tanner Ⅱ （GT-Ⅱ）. Ghrelin, insulin and glucose were measured at 0, 30, 60 and 120 rain following OGTT. The control children with normal BMI were divided into control boys of Tanner Ⅰ （CBT- Ⅰ, n = 6）, control boys of Tanner Ⅱ （CBT-Ⅱ, n = 5）, control girls of Tanner Ⅰ （CGT- Ⅰ, n = 6）, control girls of Tanner Ⅱ （CGT-Ⅱ, n = 5）. Fasting serum ghrelin levels were analyzed. RESULTS： Ghrelin levels were lower in obese groups. Ghrelin levels of control group decreased in Tanner Ⅱ stage （CGT- Ⅰ vs CGT-Ⅱ t = -4.703, P = 0.001; CBT- Ⅰ vs CBT- Ⅱ t = -4.794, P = 0.001）. Basal ghrelin levels in fir-Ⅱ decreased more significantly than that in BT- Ⅰ group （t = 2.547, P = 0.029）. Ghrelin levels expressed a downward trend after OGTT among obese children. The decrease in ghrelin levels at 60 min with respect to basal values was 56.9% in BT- Ⅰ. Ghrelin concentrations at 0 min correlated directly with glucose level at 0 min in fir- Ⅰ （r = 0.898, P = 0.015）. There wasn＇t a significant correlation of ghrelin changes with glucose changes and insulin changes during OGTT in obese children with insulin resistance. CONCLUSION： In conclusion, in obese children with insulin resistance, ghrelin levels decreased with advancing pubertal stage. Ghrelin secretion suppression following OGTT was influenced by gender and pubertal stage. Baseline ghrelin levels and ghrelin suppression after OGTT did not significantly correlate with the degree of insulin resistance and insulin sensitivity.
文摘Objective： To investigate the mechanism of carbapenem resistance and the occurrence ofplasmid-mediated quinolone resistance determinants qnr and aac（6＇）-Ib-cr in a clinical isolate of Enterobacter cloacae. Methods： An ertapenem-resistant E. cloacae ZY106, which was isolated from liquor puris of a female gastric cancer patient in a Chinese hospital, was investigated. Antibiotic susceptibilities were determined by agar dilution method. Conjugation experiments, isoelectric focusing, polymerase chain reaction （PCR）, and DNA sequence analyses of plasmid-mediated carbapenemases and quinolone resistance determinants were preformed to confirm the genotype. Outer membrane proteins （OMPs） were examined by urea-sodium dodecyl sulfate- polyacrylamide gel electrophoresis （Urea-SDS-PAGE）. Results： Minimum inhibitory concentrations （MICs） of imipenem, mer- openem, and ertapenem for ZY 106 were 2, 4, and 16 pg/ml, respectively. Conjugation studies with Escherichia coli resulted in the transfer of significantly reduced carbapenem susceptibility. ZY106 produced IMP-1 metallo-β-lactamase and CTX-M-3 extended-spectrum β-1actamase, and E. coli transconjugant produced IMP-1. Plasrnid-mediated quinolone resistance determinant qnrS1 was detected in ZY106. Transfer of the qnrSl-encoding-plasmid into E. coli by conjugation resulted in intermediate resistance to ciprofloxacin in E. coli transconjugant. Urea-SDS-PAGE analysis of OMPs showed that ZYI06 lacked an OMP of approximately 38 kDa. Conclusion： It is the first IMP-l-producing Enterobacteriaceae in China and the first report of a clinical isolate that harbors both blalMP and qnrS genes as well. The blalMP-1, blaCTX-M-3, and qnrS1 are encoded at three different plasmids. IMP-1 combined with the loss of an OMP possibly resulted in ertapenem resistance and reduced imipenem and mero- penern susceptibility in E. cloacae.
基金supported by the National Natural Science Foundation of China (Grant No.81171621)Shandong Province Young and Middle-Aged Scientists Research Awards Fund (Grant No.2006BS02008)China Postdoctoral Science Foundation Funded Project (Grant No.20080440451)
文摘The dynamics of a bacterial population exposed to the minimum inhibitory concentration （MIC） of an antibiotic is an important issue in pharmacological research. Therefore, a novel antibiotic susceptibility test is urgently needed that can both precisely determine the MIC and accurately select antibiotic-resistant strains from clinical bacterial populations. For this purpose, we developed a method based on Fick＇s laws of diffusion using agar plates containing a linear gradient of antibiotic. The gradient plate contained two layers. The bottom layer consisted of 15 mL agar containing the appropriate concentration of enrofloxacin and allowed to harden in the form of a wedge with the plate slanted such that the entire bottom was just covered. The upper layer consisted of 15 mL plain nutrient agar added with the plate held in the horizontal position. After allowing vertical diffusion of the drug from the bottom agar layer for 12 h, the enrofloxacin concentration was diluted in proportion to the ratio of the agar layer thicknesses. The uniform linear concentration gradient was verified by measuring the enrofloxacin concentration on the agar surface. When heavy bacterial suspensions were spread on the agar surface and incubated for more than 12 h, only resistant cells were able to form colonies beyond the boundary of confluent growth of susceptible cells. In this way, the true MIC of enrofloxacin was determined. The MICs obtained using this linear gradient plate were consistent with those obtained using conventional antibiotic susceptibility tests. Discrete colonies were then spread onto a gradient plate with higher antibiotic concentrations; the boundary line increased significantly, and gene mutations conferring resistance were identified. This new method enables the rapid identification of resistant strains in the bacterial population. Use of the linear gradient plate can easily identify the precise MIC and reveal the dynamic differentiation of bacteria near the MIC. This method allows the study of genetic and physiological characteristics of individual strains, and may be useful for early warning of antibiotic resistance that may occur after use of certain antirnicrobial agents, and guide clinical treatment.
