Cells are capable of sensing and responding to the extracellular mechanical microenvironment via the actin skeleton.In vivo,tissues are frequently subject to mechanical forces,such as the rapid and significant shear f...Cells are capable of sensing and responding to the extracellular mechanical microenvironment via the actin skeleton.In vivo,tissues are frequently subject to mechanical forces,such as the rapid and significant shear flow encountered by vascular endothelial cells.However,the investigations about the transient response of intracellular actin networks under these intense external mechanical forces,their intrinsic mechanisms,and potential implications are very limited.Here,we observe that when cells are subject to the shear flow,an actin ring structure could be rapidly assembled at the periphery of the nucleus.To gain insights into the mechanism underlying this perinuclear actin ring assembly,we develop a computational model of actin dynamics.We demonstrate that this perinuclear actin ring assembly is triggered by the depolymerization of cortical actin,Arp2/3-dependent actin filament polymerization,and myosin-mediated actin network contraction.Furthermore,we discover that the compressive stress generated by the perinuclear actin ring could lead to a reduction in the nuclear spreading area,an increase in the nuclear height,and a decrease in the nuclear volume.The present model thus explains the mechanism of the perinuclear actin ring assembly under external mechanical forces and suggests that the spontaneous contraction of this actin structure can significantly impact nuclear morphology.展开更多
AIM： To assess the prevalence and clinical value of p-ANCA in a sample of Mexican ulcerative colitis （UC） patients. METHODS： In a prospective, IRB-approved protocol, p-ANCA was determined in 80 patients with UC （...AIM： To assess the prevalence and clinical value of p-ANCA in a sample of Mexican ulcerative colitis （UC） patients. METHODS： In a prospective, IRB-approved protocol, p-ANCA was determined in 80 patients with UC （mean age, 32 ± 12.9 years）. The severity and extension of disease were determined by clinical methods, searching a statistical association with p-ANCA status. RESULTS： p-ANCA were detected in 41 （51%） patients. Severity of disease was the only clinical variable statistically associated with their presence （P 〈 0.0001; OR = 9; CI 95% = 3.2-24.7）. CONCLUSION： The prevalence of p-ANCA was similar to that reported in other countries. Their presence was associated to UC severity, but offered no more information than the obtained by clinical methods.展开更多
AIM:To study serological antibodies in Caucasians and Asians,in health and inflammatory bowel disease(IBD),in Australia and Hong Kong(HK).METHODS:Anti-glycan antibodies[anti-chitobioside(ACCA),anti-laminaribioside(ALC...AIM:To study serological antibodies in Caucasians and Asians,in health and inflammatory bowel disease(IBD),in Australia and Hong Kong(HK).METHODS:Anti-glycan antibodies[anti-chitobioside(ACCA),anti-laminaribioside(ALCA)],and anti-mannobioside(AMCA),anti-Saccharomyces cervisiae(gASCA);and atypical perinuclear anti-neutrophil cytoplasmic antibody(pANCA)were tested in IBD patients,their unaffected relatives,and healthy controls in Australia and HK(China).Antibody status(positive or negative)and titre was compared between subjects of different geography,ethnicity and disease state.RESULTS:Ninety subjects were evaluated:21 Crohn’s disease(CD),32 ulcerative colitis(UC),29 healthy controls,and 8 IBD patient relatives.Forty eight subjects were Australian(29 Caucasian and 19 ethnic Han Chinese)and 42 were from HK(all Han Chinese).Caucasian CD patients had a significantly higher antibody prevalence of gASCA(67%vs 3%,P<0.001),ALCA(44%vs 6%,P=0.005),and AMCA(67%vs 15%,P=0.002),whereas HK CD patients had a higher prevalence of only AMCA(58%vs 25%,P=0.035),when compared with UC and healthy subjects in both countries.Caucasian CD had significantly higher gASCA prevalence(67%vs 0%,P<0.001)and titre(median59 vs 9,P=0.002)than HK CD patients.Prevalence and titres of ALCA,ACCA and AMCA did not differ between CD in the two countries.Presence of at least one antibody was higher in Caucasian than HK CD patients(100%vs 58%,P=0.045).pANCA did not differ between countries or ethnicity.CONCLUSION:Serologic CD responses differ between HK Asian and Australian Caucasian patients.Different genetic,environmental or disease pathogenic factors may account for these differences.展开更多
Crohn's disease(CD) is a chronic idiopathic inflammatory disease of gastrointestinal tract characterizedby segmental and transmural involvement of gastrointestinal tract. Ileocolonic and colonic/anorectal is a mos...Crohn's disease(CD) is a chronic idiopathic inflammatory disease of gastrointestinal tract characterizedby segmental and transmural involvement of gastrointestinal tract. Ileocolonic and colonic/anorectal is a most common and account for 40% of cases and involvement of small intestine is about 30%. Isolated involvement of stomach is an extremely unusual presentation of the disease accounting for less than 0.07% of all gastrointestinal CD. To date there are only a few documented case reports of adults with isolated gastric CD and no reports in the pediatric population. The diagnosis is difficult to establish in such cases with atypical presentation. In the absence of any other source of disease and in the presence of nonspecific upper gastrointestinal endoscopy and histological findings, serological testing can play a vital role in the diagnosis of atypical CD. Recent studies have suggested that perinuclear anti-neutrophil cytoplasmic antibody and anti-Saccharomycescervisia antibody may be used as additional diagnostic tools. The effectiveness of infliximab in isolated gastric CD is limited to only a few case reports of adult patients and the long-term outcome is unknown.展开更多
The search for biologic markers that can assess the natural history and perhaps predict the course of individual's disease including response to treatments over time has become an important focus of inflammatory b...The search for biologic markers that can assess the natural history and perhaps predict the course of individual's disease including response to treatments over time has become an important focus of inflammatory bowel disease research.The knowledge of an individual's prognosis can help physicians and patients make important management decisions and aid communication on risk and benefits of disease and treatment.展开更多
基金Project supported by the National Natural Science Foundation of China (Nos. 12025207 and 11872357)the Fundamental Research Funds for the Central Universities。
文摘Cells are capable of sensing and responding to the extracellular mechanical microenvironment via the actin skeleton.In vivo,tissues are frequently subject to mechanical forces,such as the rapid and significant shear flow encountered by vascular endothelial cells.However,the investigations about the transient response of intracellular actin networks under these intense external mechanical forces,their intrinsic mechanisms,and potential implications are very limited.Here,we observe that when cells are subject to the shear flow,an actin ring structure could be rapidly assembled at the periphery of the nucleus.To gain insights into the mechanism underlying this perinuclear actin ring assembly,we develop a computational model of actin dynamics.We demonstrate that this perinuclear actin ring assembly is triggered by the depolymerization of cortical actin,Arp2/3-dependent actin filament polymerization,and myosin-mediated actin network contraction.Furthermore,we discover that the compressive stress generated by the perinuclear actin ring could lead to a reduction in the nuclear spreading area,an increase in the nuclear height,and a decrease in the nuclear volume.The present model thus explains the mechanism of the perinuclear actin ring assembly under external mechanical forces and suggests that the spontaneous contraction of this actin structure can significantly impact nuclear morphology.
基金Supported by the "Consejo Nacional de Ciencia y Tecnologia (CONACYT)", Mexico
文摘AIM： To assess the prevalence and clinical value of p-ANCA in a sample of Mexican ulcerative colitis （UC） patients. METHODS： In a prospective, IRB-approved protocol, p-ANCA was determined in 80 patients with UC （mean age, 32 ± 12.9 years）. The severity and extension of disease were determined by clinical methods, searching a statistical association with p-ANCA status. RESULTS： p-ANCA were detected in 41 （51%） patients. Severity of disease was the only clinical variable statistically associated with their presence （P 〈 0.0001; OR = 9; CI 95% = 3.2-24.7）. CONCLUSION： The prevalence of p-ANCA was similar to that reported in other countries. Their presence was associated to UC severity, but offered no more information than the obtained by clinical methods.
文摘AIM:To study serological antibodies in Caucasians and Asians,in health and inflammatory bowel disease(IBD),in Australia and Hong Kong(HK).METHODS:Anti-glycan antibodies[anti-chitobioside(ACCA),anti-laminaribioside(ALCA)],and anti-mannobioside(AMCA),anti-Saccharomyces cervisiae(gASCA);and atypical perinuclear anti-neutrophil cytoplasmic antibody(pANCA)were tested in IBD patients,their unaffected relatives,and healthy controls in Australia and HK(China).Antibody status(positive or negative)and titre was compared between subjects of different geography,ethnicity and disease state.RESULTS:Ninety subjects were evaluated:21 Crohn’s disease(CD),32 ulcerative colitis(UC),29 healthy controls,and 8 IBD patient relatives.Forty eight subjects were Australian(29 Caucasian and 19 ethnic Han Chinese)and 42 were from HK(all Han Chinese).Caucasian CD patients had a significantly higher antibody prevalence of gASCA(67%vs 3%,P<0.001),ALCA(44%vs 6%,P=0.005),and AMCA(67%vs 15%,P=0.002),whereas HK CD patients had a higher prevalence of only AMCA(58%vs 25%,P=0.035),when compared with UC and healthy subjects in both countries.Caucasian CD had significantly higher gASCA prevalence(67%vs 0%,P<0.001)and titre(median59 vs 9,P=0.002)than HK CD patients.Prevalence and titres of ALCA,ACCA and AMCA did not differ between CD in the two countries.Presence of at least one antibody was higher in Caucasian than HK CD patients(100%vs 58%,P=0.045).pANCA did not differ between countries or ethnicity.CONCLUSION:Serologic CD responses differ between HK Asian and Australian Caucasian patients.Different genetic,environmental or disease pathogenic factors may account for these differences.
文摘Crohn's disease(CD) is a chronic idiopathic inflammatory disease of gastrointestinal tract characterizedby segmental and transmural involvement of gastrointestinal tract. Ileocolonic and colonic/anorectal is a most common and account for 40% of cases and involvement of small intestine is about 30%. Isolated involvement of stomach is an extremely unusual presentation of the disease accounting for less than 0.07% of all gastrointestinal CD. To date there are only a few documented case reports of adults with isolated gastric CD and no reports in the pediatric population. The diagnosis is difficult to establish in such cases with atypical presentation. In the absence of any other source of disease and in the presence of nonspecific upper gastrointestinal endoscopy and histological findings, serological testing can play a vital role in the diagnosis of atypical CD. Recent studies have suggested that perinuclear anti-neutrophil cytoplasmic antibody and anti-Saccharomycescervisia antibody may be used as additional diagnostic tools. The effectiveness of infliximab in isolated gastric CD is limited to only a few case reports of adult patients and the long-term outcome is unknown.
文摘The search for biologic markers that can assess the natural history and perhaps predict the course of individual's disease including response to treatments over time has become an important focus of inflammatory bowel disease research.The knowledge of an individual's prognosis can help physicians and patients make important management decisions and aid communication on risk and benefits of disease and treatment.
