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Enhanced production of insecticidal proteins in Bacillus thuringiensis strains carrying an additional crystal protein gene in their chromosomes. 总被引:4,自引:1,他引:3 下载免费PDF全文
A two-step procedure was used to place a cryIC crystal protein gene from Bacillus thuringiensis subsp. aizawai into the chromosomes of two B. thuringiensis subsp. kurstaki strains containing multiple crystal protein genes. The B. thuringiensis aizawai cryIC gene, which encodes an insecticidal protein highly specific to Spodoptera exigua (beet armyworm), has not been found in any B. thuringiensis subsp. kurstaki strains. The cryIC gene was cloned into an integration vector which contained a B. thuringiensis chromosomal fragment encoding a phosphatidylinositol-specific phospholipase C, allowing the B. thuringiensis subsp. aizawai cryIC to be targeted to the homologous region of the B. thuringiensis subsp. kurstaki chromosome. First, to minimize the possibility of homologous recombination between cryIC and the resident crystal protein genes, B. thuringiensis subsp. kurstaki HD73, which contained only one crystal gene, was chosen as a recipient and transformed by electroporation. Second, a generalized transducing bacteriophage, CP-51, was used to transfer the integrated cryIC gene from HD73 to two other B. thuringiensis subsp. kurstaki stains. The integrated cryIC gene was expressed at a significant level in all three host strains, and the expression of cryIC did not appear to reduce the expression of the endogenous crystal protein genes. Because of the newly acquired ability to produce the CryIC protein, the recombinant strains showed a higher level of activity against S. exigua than did the parent strains. This two-step procedure should therefore be generally useful for the introduction of an additional crystal protein gene into B. thuringiensis strains which have multiple crystal protein genes and which show a low level of transformation efficiency. 相似文献
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中国的炭疽杆菌DNA分型及其地理分布 总被引:7,自引:1,他引:6
炭疽广泛分布于中国各地,特别是西部地区,并经常造成人畜疾病,在一项合作研究中,用多位点VNTR分析(MLVA)对从1952-1998年自中国主要地理流行区域分离的病人,病畜和土壤等来源的炭疽杆菌进行了基因分型,MLVA分析结果揭示了21种新的基因型,其等位基因组合在以前世界范围分离物的研究中未曾发现,此外,分离物的分群显示,A3b组是地理上最广泛分布的基因组,说明该组可能是中国的“地方流行株”。而来自古丝绸之路重要贸易中心新疆的大量分离株其基因型特别分散。 相似文献
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Otte JM Schwenger M Brunke G Schmitz F Otte C Kiehne K Kloehn S Mönig H Schmidt WE Herzig KH 《Regulatory peptides》2007,144(1-3):82-90
BACKGROUND AND AIM: Immunomodulatory and protective properties have been identified for the keratinocyte growth factor (KGF). For hepatocytes, pro-proliferative and anti-apoptotic effects of this growth factor have been reported in vitro. This study was designed to characterize a putative role of KGF in observed histomorphological changes in both, human and experimental liver fibrosis. METHODS: Liver fibrosis and cirrhosis was induced in rats by repetitive exposure to phenobarbitone and increasing doses of carbon tetrachloride. Human samples were obtained from patients undergoing surgery for partial hepatectomy or transplantation. Organ samples were scored for inflammation and morphological changes. Expression of KGF and its receptor (KGFR) mRNA was quantified by real-time RT-PCR. Protein expression and receptor phosphorylation was determined by Western blot analysis. In-situ hybridization and immunohistochemistry were utilized to determine distribution of KGF and KGFR in the liver. RESULTS: Expression of KGF was significantly increased in damaged liver tissue in correlation to the degree of fibrosis, whereas expression of the receptor was up-regulated in early stages of liver fibrosis and down-regulated in cirrhotic organs. Protein expression of this growth factor and its receptor correlated with the alterations in mRNA. KGF expression was restricted to mesenchymal cells, whereas expression of KGFR was detected on hepatocytes only. CONCLUSION: The expression of KGF and KGFR is differentially and significantly regulated in damaged liver tissue. This growth factor might therefore not only contribute to morphological alterations but also regeneration of liver parenchyma most likely mediated by indirect mechanisms of action. 相似文献
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Ceribelli A Yao B Dominguez-Gutierrez PR Nahid MA Satoh M Chan EK 《Arthritis research & therapy》2011,13(4):229
MicroRNAs (miRNAs) are endogenous, non-coding, single-stranded RNAs about 21 nucleotides in length. miRNAs have been shown
to regulate gene expression and thus influence a wide range of physiological and pathological processes. Moreover, they are
detected in a variety of sources, including tissues, serum, and other body fluids, such as saliva. The role of miRNAs is evident
in various malignant and nonmalignant diseases, and there is accumulating evidence also for an important role of miRNAs in
systemic rheumatic diseases. Abnormal expression of miRNAs has been reported in autoimmune diseases, mainly in systemic lupus
erythematosus and rheumatoid arthritis. miRNAs can be aberrantly expressed even in the different stages of disease progression,
allowing miRNAs to be important biomarkers, to help understand the pathogenesis of the disease, and to monitor disease activity
and effects of treatment. Different groups have demonstrated a link between miRNA expression and disease activity, as in the
case of renal flares in lupus patients. Moreover, miRNAs are emerging as potential targets for new therapeutic strategies
of autoimmune disorders. Taken together, recent data demonstrate that miRNAs can influence mechanisms involved in the pathogenesis,
relapse, and specific organ involvement of autoimmune diseases. The ultimate goal is the identification of a miRNA target
or targets that could be manipulated through specific therapies, aiming at activation or inhibition of specific miRNAs responsible
for the development of disease. 相似文献
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Satoh M Krzyszczak ME Li Y Ceribelli A Ross SJ Chan EK Segal MS Bubb MR Sobel ES Reeves WH 《Arthritis research & therapy》2011,13(3):R73
Introduction
The presence of anti-topoisomerase I (topo I) antibodies is a classic scleroderma (SSc) marker presumably associated with a unique clinical subset. Here the clinical association of anti-topo I was reevaluated in unselected patients seen in a rheumatology clinic setting. 相似文献7.
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JINDŘIŠKA BOJKOVÁ KLÁRA KOMPRDOVÁ TOMÁŠ SOLDÁN SVĚTLANA ZAHRÁDKOVÁ 《Freshwater Biology》2012,57(12):2550-2567
1. Rapid expansion and intensification of anthropogenic activities in the 20th century has caused profound changes in freshwater assemblages. Unfortunately, knowledge of the extent and causes of species loss (SL) is limited due to the lack of reliable historical data. An unusual data set allows us to compare changes in the most sensitive of aquatic insect orders, the Plecoptera, at some 170 locations in the Czech Republic between two time periods, 1955–1960 and 2006–2010. Historical data (1890–1911) on assemblages of six lowland rivers allow us to infer even earlier changes. 2. Regional stonefly diversity decreased in the first half of the 20th century. Streams at lower altitudes lost a substantial number of species, which were never recovered. In the second half of the century, large‐scale anthropogenic pressure caused SL in all habitats, leading to a dissimilarity of contemporary and previous assemblages. The greatest changes were found at sites affected by organic pollution and a mixture of organic pollution and channelisation or impoundment. Colonisation of new habitats was observed in only three of the 80 species evaluated. 3. Species of moderate habitat specialisation and tolerance to organic pollution were most likely to be lost. Those with narrow specialisations in protected habitats were present in both historical and contemporary collections. 4. Contemporary assemblages are the consequence of more than a 100 years of anthropogenic impacts. In particular, streams at lower altitude and draining intensively exploited landscapes host a mere fragment of the original species complement. Most stonefly species are less frequently present than before, although their assemblages remain almost intact in near‐natural mountain streams. Our analyses demonstrate dramatic restriction of species ranges and, in some cases, apparent changes in altitudinal preference throughout the area. 相似文献
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Steve Horvath Abu NM Nazmul-Hossain Rodney PE Pollard Frans GM Kroese Arjan Vissink Cees GM Kallenberg Fred KL Spijkervet Hendrika Bootsma Sara A Michie Sven U Gorr Ammon B Peck Chaochao Cai Hui Zhou David TW Wong 《Arthritis research & therapy》2012,14(6):1-13
Bone tissue has an exceptional quality to regenerate to native tissue in response to injury. However, the fracture repair process requires mechanical stability or a viable biological microenvironment or both to ensure successful healing to native tissue. An improved understanding of the molecular and cellular events that occur during bone repair and remodeling has led to the development of biologic agents that can augment the biological microenvironment and enhance bone repair. Orthobiologics, including stem cells, osteoinductive growth factors, osteoconductive matrices, and anabolic agents, are available clinically for accelerating fracture repair and treatment of compromised bone repair situations like delayed unions and nonunions. Preclinical and clinical studies using biologic agents like recombinant bone morphogenetic proteins have demonstrated an efficacy similar or better than that of autologous bone graft in acute fracture healing. A lack of standardized outcome measures for comparison of biologic agents in clinical fracture repair trials, frequent off-label use, and a limited understanding of the biological activity of these agents at the bone repair site have limited their efficacy in clinical applications. 相似文献
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Activation of hypothalamic RIP‐Cre neurons promotes beiging of WAT via sympathetic nervous system 下载免费PDF全文
Baile Wang Ang Li Xiaomu Li Philip WL Ho Donghai Wu Xiaoqi Wang Zhuohao Liu Kelvin KL Wu Sonata SY Yau Aimin Xu Kenneth KY Cheng 《EMBO reports》2018,19(4)
Activation of brown adipose tissue (BAT) and beige fat by cold increases energy expenditure. Although their activation is known to be differentially regulated in part by hypothalamus, the underlying neural pathways and populations remain poorly characterized. Here, we show that activation of rat‐insulin‐promoter‐Cre (RIP‐Cre) neurons in ventromedial hypothalamus (VMH) preferentially promotes recruitment of beige fat via a selective control of sympathetic nervous system (SNS) outflow to subcutaneous white adipose tissue (sWAT), but has no effect on BAT. Genetic ablation of APPL2 in RIP‐Cre neurons diminishes beiging in sWAT without affecting BAT, leading to cold intolerance and obesity in mice. Such defects are reversed by activation of RIP‐Cre neurons, inactivation of VMH AMPK, or treatment with a β3‐adrenergic receptor agonist. Hypothalamic APPL2 enhances neuronal activation in VMH RIP‐Cre neurons and raphe pallidus, thereby eliciting SNS outflow to sWAT and subsequent beiging. These data suggest that beige fat can be selectively activated by VMH RIP‐Cre neurons, in which the APPL2–AMPK signaling axis is crucial for this defending mechanism to cold and obesity. 相似文献