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1.
中国麻鸡中发现禽J亚群白血病   总被引:44,自引:0,他引:44       下载免费PDF全文
成子强  张利  刘思当  张玲娟  崔治中 《微生物学报》2005,45(4):584-587,i002
首次报道了中国特有鸡种——麻鸡J亚群白血病的发病情况。山东某种鸡场饲养的中国麻鸡,于开产前出现消瘦、贫血、瘫痪等症状,死亡率达10%。经大体剖检发现,病鸡的内脏器官均弥漫性肿大,色彩斑驳,质度较硬;在胸骨内侧、小肠浆膜面和气管粘膜面出现大小不等的肿瘤结节,呈灰白色。组织学检查发现,增生的肿瘤细胞为均一的髓细胞。用禽白血病病毒J亚群(ALV_J)的特异性引物进行PCR检测,阳性率为89%(15/17);PCR产物测序,其基因序列、预期氨基酸序列与ALV_J原型株HPRS_103的同源性分别为98.05%和97.4%。用ALV_J单克隆抗体,经免疫组织化学检测发现,在肿瘤组织、肝、脾、肾、骨髓、腺胃中呈现强特异性染色。上述检测表明此髓细胞肿瘤是由ALV_J感染引起的。ALV_J麻鸡病例的发现警示:应注意中国地方种鸡的白血病净化工作。  相似文献
2.
A designed ankyrin repeat protein evolved to picomolar affinity to Her2   总被引:4,自引:0,他引:4  
Designed ankyrin repeat proteins (DARPins) are a novel class of binding molecules, which can be selected to recognize specifically a wide variety of target proteins. DARPins were previously selected against human epidermal growth factor receptor 2 (Her2) with low nanomolar affinities. We describe here their affinity maturation by error-prone PCR and ribosome display yielding clones with zero to seven (average 2.5) amino acid substitutions in framework positions. The DARPin with highest affinity (90 pM) carried four mutations at framework positions, leading to a 3000-fold affinity increase compared to the consensus framework variant, mainly coming from a 500-fold increase of the on-rate. This DARPin was found to be highly sensitive in detecting Her2 in human carcinoma extracts. We have determined the crystal structure of this DARPin at 1.7 A, and found that a His to Tyr mutation at the framework position 52 alters the inter-repeat H-bonding pattern and causes a significant conformational change in the relative disposition of the repeat subdomains. These changes are thought to be the reason for the enhanced on-rate of the mutated DARPin. The DARPin not bearing the residue 52 mutation has an unusually slow on-rate, suggesting that binding occurred via conformational selection of a relatively rare state, which was stabilized by this His52Tyr mutation, increasing the on-rate again to typical values. An analysis of the structural location of the framework mutations suggests that randomization of some framework residues either by error-prone PCR or by design in a future library could increase affinities and the target binding spectrum.  相似文献
3.
Livin蛋白在乳腺癌中的表达及与Bcl-2的关系   总被引:2,自引:0,他引:2  
目的 探讨凋亡抑制基因Livin和Bel-2蛋白在乳腺癌组织中表达及与临床病理参数的关系。方法应用western blot和免疫组织化学SP法检测90例乳腺癌、30例乳腺良性病变和15例乳腺癌旁组织中Livin和Bcl-2蛋白的表达情况,分析两种蛋白表达的相关性。结果Livin蛋白在乳腺癌组织中的阳性表达率及蛋白表达量明显高于癌旁组织和乳腺良性病变,差异有显著性(P〈0.05)。Livin蛋白在乳腺癌中的阳性表达与肿瘤大小,组织学类型,组织学分级及淋巴结转移无关(P〉0.05),但随临床分期的增加而升高(P〈0.05);Livin和Bel-2蛋白在乳腺癌组织中的表达显著相关(P〈0.05)。结论Livin蛋白在乳腺癌组织中表达上调,且与病理分期有关,提示Livin蛋白可通过抑制细胞凋亡促进乳腺癌的发生、发展,Livin与Bel-2蛋白可能在乳腺癌的演进中起着协同作用。  相似文献
4.
5.
Sha K  Conner WC  Choi DY  Park JH 《Gene》2012,497(2):191-199
In this article, we characterized structure and expression of genes encoding the neuropeptide Corazonin (MdCrz) and its putative receptor (MdCrzR) in the House Fly, Musca domestica. The MdCrz gene contains two introns, one within the 5' untranslated region and the other within the open reading frame. The 150-amino-acid precursor consists of an N-terminal signal peptide, and mature Crz followed by Crz-associated peptide (CAP). The CAP region is highly diverged from those of other insect precursors, whereas the mature Crz is identical in other dipteran members. In situ hybridization and immunohistochemistry consistently found a group of three MdCrz-producing neurons in the dorso-lateral protocerebrum, and eight pairs of bi-lateral neurons in the ventral nerve cord in the larvae. In adults, the expression was found exclusively in a cluster of five to seven neurons per brain lobe. Comparable expression patterns observed in other dipteran species suggest conserved regulatory mechanisms of Crz expression and functions during the course of evolution. MdCrzR deduced from the full-length cDNA sequence is a 655-amino acid polypeptide that contains seven trans-membrane (TM) domains and other motifs that are characteristics of Class-A G-protein coupled receptors. Although the TMs and loops between the TMs are conserved in other CrzRs, N-terminal extracellular domain is quite dissimilar. Tissue-specific RT-PCR revealed a high level of MdCrzR expression in the larval salivary glands and a moderate level in the CNS. In adults, the receptor was expressed both in the head and body, suggesting multifunctionality of the Crz signaling system.  相似文献
6.
Doublecortin is expressed in articular chondrocytes   总被引:1,自引:0,他引:1  
Articular cartilage and cartilage in the embryonic cartilaginous anlagen and growth plates are both hyaline cartilages. In this study, we found that doublecortin (DCX) was expressed in articular chondrocytes but not in chondrocytes from the cartilaginous anlagen or growth plates. DCX was expressed by the cells in the chondrogenous layers but not intermediate layer of joint interzone. Furthermore, the synovium and cruciate ligaments were DCX-negative. DCX-positive chondrocytes were very rare in tissue engineered cartilage derived from in vitro pellet culture of rat chondrosarcoma, ATDC5, and C3H10T1/2 cells. However, the new hyaline cartilage formed in rabbit knee defect contained mostly DCX-positive chondrocytes. Our results demonstrate that DCX can be used as a marker to distinguish articular chondrocytes from other chondrocytes and to evaluate the quality of tissue engineered or regenerated cartilage in terms of their "articular" or "non-articular" nature.  相似文献
7.
It has been demonstrated that expression of cyclooxygenase-2 (COX-2) isoform is induced by Entamoeba histolytica in macrophages and polymorphonuclear cells during amoebic liver abscess (ALA) formation in hamsters. Trophozoites present in the lesion were also positive for COX-2 signal. However, no cross reactivity of the anti-COX-2 antibody with protein extract of cultivated trophozoites was found. To clarify if trophozoites are involved in PGE(2) production during ALA development, COX-2 expression was detected by in situ hybridization and RT-PCR in liver tissue from intrahepatically infected hamsters. COX-2 mRNA was in polymorphonuclear cells since 4h postinfection, and subsequently, local macrophages expressed COX-2 mRNA in a similar way. Additionally, a positive signal for COX-2 mRNA expression was detected in E. histolytica trophozoites, suggesting that, in vivo, parasite COX expression may be an important mechanism to promote inflammation.  相似文献
8.
Breast cancer is a heterogeneous disease that encompasses a wide range of histopathological types including: invasive ductal carcinoma, lobular carcinoma, medullary carcinoma, mucinous carcinoma, tubular carcinoma, and apocrine carcinoma among others. Pure apocrine carcinomas represent about 0.5% of all invasive breast cancers according to the Danish Breast Cancer Cooperative Group Registry, and despite the fact that they are morphologically distinct from other breast lesions, there are at present no standard molecular criteria available for their diagnosis. In addition, the relationship between benign apocrine changes and breast carcinoma is unclear and has been a matter of discussion for many years. Recent proteome expression profiling studies of breast apocrine macrocysts, normal breast tissue, and breast tumours have identified specific apocrine biomarkers [15-hydroxyprostaglandin dehydrogenase (15-PGDH) and hydroxymethylglutaryl coenzyme A reductase (HMG-CoA reductase)] present in early and advanced apocrine lesions. These biomarkers in combination with proteins found to be characteristically upregulated in pure apocrine carcinomas (psoriasin, S100A9, and p53) provide a protein expression signature distinctive for benign apocrine metaplasias and apocrine cystic lesions. These studies have also presented compelling evidence for a direct link, through the expression of the prostaglandin degrading enzyme 15-PGDH, between early apocrine lesions and pure apocrine carcinomas. Moreover, specific antibodies against the components of the expression signature have identified precursor lesions in the linear histological progression to apocrine carcinoma. Finally, the identification of proteins that characterize the early stages of mammary apocrine differentiation such as 15-PGDH, HMG-CoA reductase, and cyclooxygenase 2 (COX-2) has opened a window of opportunity for pharmacological intervention, not only in a therapeutic manner but also in a chemopreventive setting. Here we review published and recent results in the context of the current state of research on breast apocrine cancer.  相似文献
9.
The present study characterized the immunohistochemical localization of beta-catenin protein in hepatocellular neoplasms and hepatoblastomas in B6C3F(1) mice exposed to diethanolamine (DEA) for 2 years and evaluated genetic alterations in the Catnb and H-ras genes which are known to play important roles in the pathogenesis of liver malignancies. Genomic DNA was isolated from paraffin sections of each liver tumor. Catnb exon 2 (corresponds to exon 3 in human) genetic alterations were identified in 18/18 (100%) hepatoblastomas from DEA exposed mice. Deletion mutations (15/18, 83%) were identified more frequently than point mutations (6/18, 33%) in hepatoblastomas. Eleven of 34 (32%) hepatocellular adenomas and carcinomas from DEA treated mice had mutations in exon 2 of the beta-catenin gene, while only 1 of 10 spontaneous neoplasms had a deletion mutation of codon 5-6. Common to all liver neoplasms (hepatocellular adenomas, carcinomas and hepatoblastomas) was membrane staining for the beta-catenin protein, while cytoplasmic and nuclear staining was observed only in hepatoblastomas. The lack of H-ras mutations in hepatocellular neoplasms and hepatoblastomas suggests that the ras signal transduction pathway is not involved in the development of liver tumors following DEA exposure which is different from that of spontaneous liver tumors that often contain H-ras mutations.  相似文献
10.
BRCA1 is a tumour suppressor gene (TSG), which predisposes cancer to both breast and ovary. The primary objective of the present study is to ascertain the involvement of BRCA1 gene in the pathogenesis of sporadic breast cancer women in Chennai (South India) by analysing its protein expression by immunohistochemistry (IHC) and loss of heterozygosity (LOH) for confirmation of the involvement of TSG in the study population. We found down regulation of BRCA1 protein (54%) in IHC and it was correlated with the clinicopathological parameters of the patients. We found near significant correlation (P < 0.063) between BRCA1 protein expression and clinicopathological parameters. We found 30% LOH in our study and it was also correlated with the clinicopathological parameters. No correlation was found between LOH and clinicopathological parameters. Though we found no correlation, the results revealed in this study support the involvement of BRCA1 TSG in the pathogenesis of sporadic breast cancer women in Chennai (South India).  相似文献
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