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551.
Autoimmune pancreatitis(AIP) is a distinct type of chronic pancreatitis with unique clinical,pathological,serological,and imaging features.AIP usually presents with obstructive jaundice.Imaging studies often reveal enlargement of the pancreas with a pancreatic mass and strictures of the main pancreatic duct.Two subtypes of AIP have recently been identified.Type I AIP is more prevalent in elderly Asian males and is characterized by lymphoplasmacytic sclerosing pancreatitis,obliterative phlebitis,and infiltration of large numbers of IgG4-positive plasma cells.Type II AIP is more prevalent in Caucasians and is characterized by granulocyte epithelial lesions.Most patients with type I AIP have a significantly elevated serum IgG4 concentration,which is an important feature for diagnosis and for differentiating between AIP and other conditions such as pancreatic cancer.Extrapancreatic complications are common,such as sclerosing cholangitis,sclerosing sialadenitis,retroperitoneal fibrosis in type I AIP,and ulcerative colitis in type II AIP.A rapid response to glucocorticoids treatment is suggestive of AIP,but the relapse rate is high,warranting the use of immunosuppressant treatment.B-cell depletion with rituximab may be a promising therapy.The prognosis of AIP is generally benign if treated promptly,and spontaneous remission occurs in a proportion of patients. 相似文献
552.
553.
长春花叶片发育过程中气孔密度和气孔指数的动态变化 总被引:1,自引:0,他引:1
对长春花叶片近轴面和远轴面上的气孔密度和气孔指数在不同发育阶段的动态变化进行了研究.结果表明:在各个发育阶段,近轴面上的气孔以叶脉两侧居多,远轴面上的气孔则在整个叶片上均匀分布.将一个枝条上的10对真叶按发育顺序界定为10个发育阶段,即从枝条的顶端到基部,分别将第10、第9、第8……第1节位的叶片定义为第1、第2、第3... 相似文献
554.
Frequencies of ABO, Rh and Kell phenotypes in couples from Han, Kazak, Uyghur and Hui in Xinjiang: an inheritance simulation model for blood group incompatibility in new-born
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Wei Chen Jun Wen Fei Li Changmin Wang Qing Li Gang Zhao 《Asia-Pacific Journal of Blood Types and Genes》2018,2(1):39-44
The Xinjiang region with residents from more than 13 minorities represents an area of many diverse ethnicities. This ethnic diversity in relation to their blood groups and immune status may have a consequential impact on the clinical status of married couples. To evaluate the risks of haemolytic disease in new-born infants, we investigated the rate of blood-group incompatibility among 487 married couples from four ethnic minorities, namely the Han, Hui, Uyghur and Kazak populations. Han minority married couples showed significantly different ABO, Rh and K phenotype frequencies between marrial relationship, whereas there was no significant difference in ABO, Rh and K phenotypes between the Uyghur, Hui and Kazak .There was a significant difference between ABO blood types in Han married couples, in the Kazak Rh-C phenotype and in the Uyghur Rh-D phenotype. The Hui married couples only demonstrated ABO, Rh and K phenotypes. The Hui minority showed the highest incompatibility rate for Rh-C and Rh-E phenotypes between mothers and their new-born infants. The highest incompatibility rate for the ABO phenotype occurred in the Kazak group. These results particularly demonstrate the clinical issues relating to ABO and Rh incompatibility, in the Kazak and Hui minorities, respectively. 相似文献
555.
大麦种子经5种不同剂量γ射线辐照后, M1植株的花粉母细胞出现多种染色体畸变类型,例如后Ⅰ、后Ⅱ中出现桥、落后,后Ⅰ中出现不对称分裂,后Ⅱ中出现不同步分裂,中期Ⅰ出现环状四价体,末期Ⅰ中有三极分裂和微核,四分体中出现微核且有的微核独立于四分体,从而形成多分体。花粉母细胞的染色体畸变率随剂量的增高而升高,二者呈极显著直线相关关系。 M1花粉母细胞的染色体畸变率与M2的叶绿素突变率及农艺性状变异率呈显著或极显著指数函数关系。 M2花粉母细胞的染色体畸变率低于M1。
Abstract:Barley seeds were irradiated with five different doses of 60 Co-γ ray.There were many kinds of chromosome aberration in pollen mother cells,such as bridge,laggards in anaphase I and anaphase II,asymmetrical division in anaphase I and asynchronous division in anaphase II,ring quadrivalent in metaphase I,three pole division and micro-nuclei in telophase I,micro-nuclei in tetrad and some micro-nucleus separates from the tetrad to form polyad.The frequency of chromosome aberration in pollen mother cells of M1 increased with the increase of dose.There was a significant linear relationship between them.The frequencies of agronomic character mutation and chlorophyll mutation in M2 significantly correlated with the frequencies of chromosome aberration in pollen mother cells of M1 and showed an exponential function.The chromosome aberration frequency in pollen mother cells of M2 was lower than that of M1. 相似文献
556.
为了研究枯水期鄱阳湖子湖泊轮虫休眠卵空间分布的差异, 于2015年1月份, 在鄱阳湖南矶山湿地自然保护区的南深湖和白沙湖2个子湖泊进行取样调查。研究发现, 不同生境类型中轮虫休眠卵的密度具有显著差异(P<0.05), 轮虫休眠卵的分布具有明显的梯度性, 在洲滩植被区、泥滩区和积水区中轮虫休眠卵的密度逐渐减少。南深湖植被区中轮虫休眠卵的密度最高, 为(3.34±1.28) ind./cm3, 茭白中密度高达5.45 ind./cm3。不同水生植被生境中轮虫休眠卵的密度趋势为: 挺水植物>洲滩植物>浮叶植物>沉水植物。不同水深区轮虫休眠卵的分布不具有明确的规律性。此外, 研究还发现轮虫休眠卵的密度与底泥的软硬程度具有一定相关性, 泥质越软, 轮虫休眠卵的密度越低。 相似文献
557.
栓菌420(Trametes sp. 420)漆酶基因lacD以两种方式在巴斯德毕赤酵母(Pichia pastoris)进行异源表达,产生两种重组漆酶:rLacDx(具有天然N-末端)和rLacDe(N-末端带有8个额外的氨基酸残基)。摇瓶发酵18d,rLacDx和rLacDe的产量分别为1.21×105u/L、7.38×104u/L [以2,2′-连氮-3-乙苯-二噻唑-6磺酸(ABTS)为底物]。在高密度发酵条件下,rLacDx的产量增加到2.39×105u/L,同时其生产周期降至7.5 d。两种重组酶对愈创木酚底物的氧化特性相似,且在50℃和pH3~10的范围内均稳定。然而,rLacDx对底物ABTS的比活力(1761u/mg)高于rLacDe (1122u/mg),其表观Km值(427μmol/L)低于rLacDe (604μmol/L)。 相似文献
558.
Lin-ding WANG 《Virologica Sinica》2007,22(3):248-255
Kaposi's sarcoma-associated herpesvirus (KSHV) is the primary,etiological agent of Kaposi's sarcoma, primary effusion lymphoma and muticentric Castleman's disease. In common with the other herpesviruses, KSHV exhibits both latent and lyric life cycles, both of which are characterized by distinct gene expression profiles and programs. KSHV encodes proteins which play essential roles in the inhibition of host adaptive and innate immunity, the inhibition of apoptosis, and the regulation of the cell cycle. KSHV also encodes several proteins which have transforming and intrcellular signalling activity. 相似文献
559.
Jun-liang FU Fu-biao KANG Yan-mei JIAO Shao-jun XING Bao-yun FU Chun-bao ZHOU Xi-cheng WANG Hao WU Fu-Sheng WANG 《Virologica Sinica》2007,22(6):501-508
CD4 CD25 Regulatory T cells (Treg) have been found to down-regulate immune activation in HIV-1 infection. However,whether the depletion of Treg benefits to the disease status of HIV infection remains undefined. To address this issue,we enumerated the Treg absolute counts and frequency in 75 antiviral-nave HIV-1-infected individuals in this study. It was found that HIV-infected patients displayed a significant decline in Treg absolute counts but a significant increase in Treg frequency. In addition,with disease progression indicated by CD4 T-cell absolute counts,circulating Treg frequency gradually increased; while Treg absolute counts were gradually decreased,suggesting that the alteration of Treg number closely correlated with disease progression in HIV infection. Functional analysis further showed that Treg efficiently inhibit both CD4 and CD8 T cell proliferation in vitro. Thus,our findings indicates that Treg actively participate in pathogenesis of chronic HIV infection,influencing the disease progression. 相似文献
560.
Yi ZHANG Wei WANG Jin-rong GAO Li YE Xiao-nan FANG Ying-chun ZENG Zheng-hui WU Ying-long SHE Lin-bai YE 《Virologica Sinica》2007,22(1):1-7
SARS-CoV is a newly discovery pathogen causing severe acute respiratory problems. It has been established that the S protein in this pathogen plays an important rule in the adsorption and penetration of SARS-CoV into the host cell by interaction with the ACE2 receptor. To determinant which functional motif of the S protein was involved in the interaction with ACE2, seven truncated S proteins deleted from the N or C terminal were obtained by an E.coli expression system and purified by column chroma-tography to homogeneity. Each truncated S protein was fixed on to the well of an ELISA plate and an interaction was initiated with the ACE2 protein. The adsorption were quantified by ELISA, and the results indicated that amino acids from 388 to 496 of the S protein was responsible for the interaction with the ACE2 receptor, and the interaction could be completely disrupted by an antibody specific to these amino acids. Deletions adjacent to this domain did not appear to have a significant impact on the interaction with ACE2, suggesting that the S protein of SARS-CoV could be developed as a vaccine to prevent the spread of SARS-CoV. 相似文献