AIM: Irritable bowel syndrome (IBS) is characterized by abdominal pain and changes in stool habits. Visceral hypersensitivity is a key factor in the pathophysiology of IBS. The aim of this study was to examine the eff...AIM: Irritable bowel syndrome (IBS) is characterized by abdominal pain and changes in stool habits. Visceral hypersensitivity is a key factor in the pathophysiology of IBS. The aim of this study was to examine the effect of rectal balloon-distention stimulus by blood oxygenation leveldependent functional magnetic resonance imaging (BOLDfMRI) in visceral pain center and to compare the distribution,extent, and intensity of activated areas between IBS patients and normal controls.
METHODS: Twenty-six patients with IBS and eleven normal controls were tested for rectal sensation, and the subjective pain intensity at 90 ml and 120 ml rectal balloon-distention was reported by using Visual Analogue Scale. Then, BOLDfMRI was performed at 30 ml, 60 ml, 90 ml, and 120 ml rectal balloon-distention in all subjects.
RESULTS: Rectal distention stimulation increased the activity of anterior cingulate cortex (35/37), insular cortex (37/37),prefrontal cortex (37/37), and thalamus (35/37) in most cases.At 120 ml of rectal balloon-distention, the activation area and percentage change in MR signal intensity of the regions of interest (ROI) at IC, PFC, and THAL were significantly greater in patients with IBS than that in controls. Score of pain sensation at 90 ml and 120 ml rectal balloon-distention was significantly higher in patients with IBS than that in controls.
CONCLUSION: Using fMRI, some patients with IBS can be detected having visceral hypersensitivity in response to painful rectal balloon-distention. fMRI is an objective brain imaging technique to measure the change in regional cerebral activation more precisely. In this study, IC and PFC of the IBS patients were the major loci of the CNS processing of visceral perception.展开更多
AIM: To investigate the change of immunological characteristics of HBsAg caused by the mutation at codon 145 of HBsAg using DNA-based immunization.METHODS: Plasmids expressing mutant and wild type envelope antigens we...AIM: To investigate the change of immunological characteristics of HBsAg caused by the mutation at codon 145 of HBsAg using DNA-based immunization.METHODS: Plasmids expressing mutant and wild type envelope antigens were transfected into human hepatocellular carcinoma cells via electrotransformation. The antigenicity of HBsAg was studied with EIA and immunocytochemical staining. Then plasmids were used to immunize 5 C57BL/6 mice. Sera of mice were detected for anti-HBs and anti-preS2with ELISA. RESULTS: The mutant HBsAg could be detected by native antibody in EIA and immunocytochemical study. But the A(450nm) value of the mutant HBsAg in the supernatant was apparently lower than that of the wild-type. Both mutant and native HBsAg expression plasmid could stimulate a strong humoral immune response to HBsAg and preS2 antigen in mice. Protective antibodies against HBsAg elicited by the native HBsAg occurred earlier than that elicited by the mutant HBsAg about one to two weeks. The occurrence of protective antibodies against preS2 antigen was one to two weeks earlier than that of anti-HBs.CONCLUSION: The amino acid substitution causes changes of the antigenicity and immunogenicity of HBsAg, but mutant HBsAg can still induce a protective humoral immune responsein mice.展开更多
文摘AIM: Irritable bowel syndrome (IBS) is characterized by abdominal pain and changes in stool habits. Visceral hypersensitivity is a key factor in the pathophysiology of IBS. The aim of this study was to examine the effect of rectal balloon-distention stimulus by blood oxygenation leveldependent functional magnetic resonance imaging (BOLDfMRI) in visceral pain center and to compare the distribution,extent, and intensity of activated areas between IBS patients and normal controls.
METHODS: Twenty-six patients with IBS and eleven normal controls were tested for rectal sensation, and the subjective pain intensity at 90 ml and 120 ml rectal balloon-distention was reported by using Visual Analogue Scale. Then, BOLDfMRI was performed at 30 ml, 60 ml, 90 ml, and 120 ml rectal balloon-distention in all subjects.
RESULTS: Rectal distention stimulation increased the activity of anterior cingulate cortex (35/37), insular cortex (37/37),prefrontal cortex (37/37), and thalamus (35/37) in most cases.At 120 ml of rectal balloon-distention, the activation area and percentage change in MR signal intensity of the regions of interest (ROI) at IC, PFC, and THAL were significantly greater in patients with IBS than that in controls. Score of pain sensation at 90 ml and 120 ml rectal balloon-distention was significantly higher in patients with IBS than that in controls.
CONCLUSION: Using fMRI, some patients with IBS can be detected having visceral hypersensitivity in response to painful rectal balloon-distention. fMRI is an objective brain imaging technique to measure the change in regional cerebral activation more precisely. In this study, IC and PFC of the IBS patients were the major loci of the CNS processing of visceral perception.
基金Supported by National Natural Science Foundation of China,No.39970676
文摘AIM: To investigate the change of immunological characteristics of HBsAg caused by the mutation at codon 145 of HBsAg using DNA-based immunization.METHODS: Plasmids expressing mutant and wild type envelope antigens were transfected into human hepatocellular carcinoma cells via electrotransformation. The antigenicity of HBsAg was studied with EIA and immunocytochemical staining. Then plasmids were used to immunize 5 C57BL/6 mice. Sera of mice were detected for anti-HBs and anti-preS2with ELISA. RESULTS: The mutant HBsAg could be detected by native antibody in EIA and immunocytochemical study. But the A(450nm) value of the mutant HBsAg in the supernatant was apparently lower than that of the wild-type. Both mutant and native HBsAg expression plasmid could stimulate a strong humoral immune response to HBsAg and preS2 antigen in mice. Protective antibodies against HBsAg elicited by the native HBsAg occurred earlier than that elicited by the mutant HBsAg about one to two weeks. The occurrence of protective antibodies against preS2 antigen was one to two weeks earlier than that of anti-HBs.CONCLUSION: The amino acid substitution causes changes of the antigenicity and immunogenicity of HBsAg, but mutant HBsAg can still induce a protective humoral immune responsein mice.
