AIM:To examine the feasibility of predicting the flareup of ulcerative colitis (UC) before symptoms emerge using the immunochemical fecal occult blood test (IFOBT).METHODS:We prospectively measured fecal hemoglobin co...AIM:To examine the feasibility of predicting the flareup of ulcerative colitis (UC) before symptoms emerge using the immunochemical fecal occult blood test (IFOBT).METHODS:We prospectively measured fecal hemoglobin concentrations in 78 UC patients using the I-FOBT every 1 or 2 mo.RESULTS:During a 20 mo-period,823 fecal samples from 78 patients were submitted.The median concentration of fecal hemoglobin was 41 ng/mL (range:0-392 500 ng/mL).There were three types of patients with regard to the correlation between I-FOBT and patient symptoms;the synchronous transition type with symptoms (44 patients),the unrelated type withsymptoms (19 patients),and the flare-up predictive type (15 patients).In patients with the flare-up predictive type,the values of I-FOBT were generally low during the study period with stable symptoms.Two to four weeks before the flare-up of symptoms,the I-FOBT values were high.Thus,in these patients,I-FOBT could predict the flare-up before symptoms emerged.CONCLUSION:Flare-up could be predicted by I-FOBT in approximately 20% of UC patients.These results warrant periodical I-FOBT in UC patients.展开更多
Magmatic periodicity is recognized in continental arcs worldwide,but the mechanism responsible for punctuated arc magmatism is controversial.Continental arcs in the Trans-Himalayan orogenic system display episodic mag...Magmatic periodicity is recognized in continental arcs worldwide,but the mechanism responsible for punctuated arc magmatism is controversial.Continental arcs in the Trans-Himalayan orogenic system display episodic magmatism and the most voluminous flare-up in this system was in early Eocene during the transition from subduction to collision.The close association of the flare-up with collision is intriguing.Our study employs zircon Lu-Hf and bulk rock Sr-Nd isotopes,along with mineral geochemistry,to track the melt sources of the Nymo intrusive complex and the role of mantle magma during the early Eocene flare-up of the Gangdese arc,Xizang.The Nymo intrusive complex is composed of gabbronorite,diorite,quartz diorite,and granodiorite which define an arc-related calc-alkaline suite.Zircon U-Pb ages reveal that the complex was emplaced between~50–47 Ma.Zircon Hf isotopes yieldεHf(t)values of 8.2–13.1,while whole-rock Sr and Nd isotopes yieldεNd(t)values of 2.7–6.5 indicative of magmatism dominated by melting of a juvenile mantle source with only minor crustal assimilation(~15%–25%)as indicated by assimilation and fractional crystallization modeling.Together with published data,the early Eocene magmatic flare-up was likely triggered by slab breakoff of subducted oceanic lithosphere at depths shallower than the overriding plate.The early Eocene magmatic flare-up may have contributed to crustal thickening of the Gangdese arc.This study provides important insights into the magmatic flare-up and its significant role in the generation of large batholiths during the transition from subduction to collision.展开更多
The link between cytomegalovirus(CMV) infection and inflammatory bowel diseases remains an important subject of debate. CMV infection is frequent in ulcerative colitis(UC) and has been shown to be potentially harmful....The link between cytomegalovirus(CMV) infection and inflammatory bowel diseases remains an important subject of debate. CMV infection is frequent in ulcerative colitis(UC) and has been shown to be potentially harmful. CMV reactivation needs to be diagnosed using methods that include in situ detection of viral markers by immunohistochemistry or by nucleic acid amplification techniques. Determination of the density of infection using quantitative tools(numbers of infected cells or copies of the genome) is particularly important. Although CMV reactivation can be considered as an innocent bystander in active flareups of refractory UC, an increasing number of studies suggest a deleterious role of CMV in this situation. The presence of colonic CMV infection is possibly linked to a decreased response to steroids and other immunosuppressive agents. Some treatments, notably steroids and cyclosporine A, have been shown to favor CMV reactivation, which seems not to be the case for therapies using anti-tumor necrosis factor drugs. According to these findings, in flare-ups of refractory UC, it is now recommended to look for the presence of CMV reactivation by using quantitative tools in colonic biopsies and to treat them with ganciclovir in cases of high viral load or severe disease.展开更多
Northeast Asian continental margins contain the products of magma emplacement driven by prolonged subduction of the(paleo-)Pacific plate.As observed in many Cordilleran arcs,magmatic evolution in this area was punctua...Northeast Asian continental margins contain the products of magma emplacement driven by prolonged subduction of the(paleo-)Pacific plate.As observed in many Cordilleran arcs,magmatic evolution in this area was punctuated by high-volume pulses amid background periods.The present study investigates the early evolution of the Cretaceous magmatic flare-up using new and published geochronological,geochemical,and O-Hf isotope data from plutonic rocks in the southern Korean Peninsula.After a long(~50 m.y.)magmatic hiatus and the development of the Honam Shear Zone through flat-slab subduction,the Cretaceous flare-up began with the intrusion of monzonites,granodiorites,and granites in the inboard Gyeonggi Massif and the intervening Okcheon Belt.Compared to Jurassic granitoids formed during the former flare-up,Albian(~111 Ma)monzonites found in the Eopyeong area of the Okcheon Belt have distinctly higher zirconε_(Hf)(t)(-7.5±1.3)andδ^(18)O(7.78‰±0.25‰)values and lower wholerock La/Yb and Sr/Y ratios.The voluminous coeval granodiorite and granite plutons in the Gyeonggi Massif are further reduced in Sr/Y and to a lesser extent,in La/Yb,and have higher zirconε_(Hf)(t)values(-13 to-19)than the Precambrian basement(ca.-30).These chemical and isotopic features indicate that Early Cretaceous lithospheric thinning,most likely resulting from delamination of tectonically and magmatically overthickened lithospheric keel that was metasomatized during prior subduction episodes,and consequent asthenospheric upwelling played vital roles in igniting the magmatic flare-up.The O-Hf isotopic ranges of synmagmatic zircons from the Albian plutons and their Paleoproterozoic and Jurassic inheritance attest to the involvement of lithospheric mantle and crustal basement in magma generation during this decratonization event.Arc magmatism then migrated trenchward and culminated in the Late Cretaceous,yielding widespread granitoid rocks emplaced at shallow crustal levels.The early Late Cretaceous(94-85 Ma)granites now prevalent in Seoraksan-Woraksan-Sokrisan National Parks are highly silicic and display flat chondrite-normalized rare earth element patterns with deep Eu anomalies.Synmagmatic zircons in these granites mimic their host rock's chemistry.Delamination-related rejuvenation of crustal protoliths is indicated by zirconε_(Hf)(t)values of granites(-6 to-20)that are consistently higher than the Precambrian basement value.Concomitant core-to-rim variation in zircon O-Hf isotopic compositions reflects a typical sequence of crustal assimilation and fresh input into the magma chamber.展开更多
文摘AIM:To examine the feasibility of predicting the flareup of ulcerative colitis (UC) before symptoms emerge using the immunochemical fecal occult blood test (IFOBT).METHODS:We prospectively measured fecal hemoglobin concentrations in 78 UC patients using the I-FOBT every 1 or 2 mo.RESULTS:During a 20 mo-period,823 fecal samples from 78 patients were submitted.The median concentration of fecal hemoglobin was 41 ng/mL (range:0-392 500 ng/mL).There were three types of patients with regard to the correlation between I-FOBT and patient symptoms;the synchronous transition type with symptoms (44 patients),the unrelated type withsymptoms (19 patients),and the flare-up predictive type (15 patients).In patients with the flare-up predictive type,the values of I-FOBT were generally low during the study period with stable symptoms.Two to four weeks before the flare-up of symptoms,the I-FOBT values were high.Thus,in these patients,I-FOBT could predict the flare-up before symptoms emerged.CONCLUSION:Flare-up could be predicted by I-FOBT in approximately 20% of UC patients.These results warrant periodical I-FOBT in UC patients.
基金co-supported by the National Natural Science Foundation of China(Grant No.42272267)the Research Grants of Chinese Academy of Geological Sciences(Grant No.JKYQN202309)+3 种基金the National Key Research and Development Project"Key scientific issues of transformative technology"(Grant No.2019YFA0708604)the second Tibetan Plateau Scientific Expedition and Research Program(STEP)Grant(Grant Nos.2019QZKK0802,2019QZKK0901)the Scientific Investigation on Basic Resources of Ministry of Science and Technology(Grant No.2021FY100101)the Geological Survey of China(Grant Nos.DD20221630,DD20242126)。
文摘Magmatic periodicity is recognized in continental arcs worldwide,but the mechanism responsible for punctuated arc magmatism is controversial.Continental arcs in the Trans-Himalayan orogenic system display episodic magmatism and the most voluminous flare-up in this system was in early Eocene during the transition from subduction to collision.The close association of the flare-up with collision is intriguing.Our study employs zircon Lu-Hf and bulk rock Sr-Nd isotopes,along with mineral geochemistry,to track the melt sources of the Nymo intrusive complex and the role of mantle magma during the early Eocene flare-up of the Gangdese arc,Xizang.The Nymo intrusive complex is composed of gabbronorite,diorite,quartz diorite,and granodiorite which define an arc-related calc-alkaline suite.Zircon U-Pb ages reveal that the complex was emplaced between~50–47 Ma.Zircon Hf isotopes yieldεHf(t)values of 8.2–13.1,while whole-rock Sr and Nd isotopes yieldεNd(t)values of 2.7–6.5 indicative of magmatism dominated by melting of a juvenile mantle source with only minor crustal assimilation(~15%–25%)as indicated by assimilation and fractional crystallization modeling.Together with published data,the early Eocene magmatic flare-up was likely triggered by slab breakoff of subducted oceanic lithosphere at depths shallower than the overriding plate.The early Eocene magmatic flare-up may have contributed to crustal thickening of the Gangdese arc.This study provides important insights into the magmatic flare-up and its significant role in the generation of large batholiths during the transition from subduction to collision.
文摘The link between cytomegalovirus(CMV) infection and inflammatory bowel diseases remains an important subject of debate. CMV infection is frequent in ulcerative colitis(UC) and has been shown to be potentially harmful. CMV reactivation needs to be diagnosed using methods that include in situ detection of viral markers by immunohistochemistry or by nucleic acid amplification techniques. Determination of the density of infection using quantitative tools(numbers of infected cells or copies of the genome) is particularly important. Although CMV reactivation can be considered as an innocent bystander in active flareups of refractory UC, an increasing number of studies suggest a deleterious role of CMV in this situation. The presence of colonic CMV infection is possibly linked to a decreased response to steroids and other immunosuppressive agents. Some treatments, notably steroids and cyclosporine A, have been shown to favor CMV reactivation, which seems not to be the case for therapies using anti-tumor necrosis factor drugs. According to these findings, in flare-ups of refractory UC, it is now recommended to look for the presence of CMV reactivation by using quantitative tools in colonic biopsies and to treat them with ganciclovir in cases of high viral load or severe disease.
基金the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(2021R1 A2C1003363)research grants from the Korea Basic Science Institute(C280100 and C230120).
文摘Northeast Asian continental margins contain the products of magma emplacement driven by prolonged subduction of the(paleo-)Pacific plate.As observed in many Cordilleran arcs,magmatic evolution in this area was punctuated by high-volume pulses amid background periods.The present study investigates the early evolution of the Cretaceous magmatic flare-up using new and published geochronological,geochemical,and O-Hf isotope data from plutonic rocks in the southern Korean Peninsula.After a long(~50 m.y.)magmatic hiatus and the development of the Honam Shear Zone through flat-slab subduction,the Cretaceous flare-up began with the intrusion of monzonites,granodiorites,and granites in the inboard Gyeonggi Massif and the intervening Okcheon Belt.Compared to Jurassic granitoids formed during the former flare-up,Albian(~111 Ma)monzonites found in the Eopyeong area of the Okcheon Belt have distinctly higher zirconε_(Hf)(t)(-7.5±1.3)andδ^(18)O(7.78‰±0.25‰)values and lower wholerock La/Yb and Sr/Y ratios.The voluminous coeval granodiorite and granite plutons in the Gyeonggi Massif are further reduced in Sr/Y and to a lesser extent,in La/Yb,and have higher zirconε_(Hf)(t)values(-13 to-19)than the Precambrian basement(ca.-30).These chemical and isotopic features indicate that Early Cretaceous lithospheric thinning,most likely resulting from delamination of tectonically and magmatically overthickened lithospheric keel that was metasomatized during prior subduction episodes,and consequent asthenospheric upwelling played vital roles in igniting the magmatic flare-up.The O-Hf isotopic ranges of synmagmatic zircons from the Albian plutons and their Paleoproterozoic and Jurassic inheritance attest to the involvement of lithospheric mantle and crustal basement in magma generation during this decratonization event.Arc magmatism then migrated trenchward and culminated in the Late Cretaceous,yielding widespread granitoid rocks emplaced at shallow crustal levels.The early Late Cretaceous(94-85 Ma)granites now prevalent in Seoraksan-Woraksan-Sokrisan National Parks are highly silicic and display flat chondrite-normalized rare earth element patterns with deep Eu anomalies.Synmagmatic zircons in these granites mimic their host rock's chemistry.Delamination-related rejuvenation of crustal protoliths is indicated by zirconε_(Hf)(t)values of granites(-6 to-20)that are consistently higher than the Precambrian basement value.Concomitant core-to-rim variation in zircon O-Hf isotopic compositions reflects a typical sequence of crustal assimilation and fresh input into the magma chamber.
