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排序方式: 共有267条查询结果,搜索用时 140 毫秒
41.
Gall Bernhard Ellervee Aleksandr Tars Märt Scheer Hugo Freiberg Arvi 《Photosynthesis research》1997,52(3):225-231
Absorption spectra of the D1-D2-cytochrom b559 complex at 4°C were investigated at pressures up to 300 MPa. Pressure effects were mostly reversible and independent of the detergent used (CHAPS or dodecyl--D-maltoside). Red-shifts were observed under pressure for the chlorophyll Qy- and the -carotene S0 S2 bands. The relatively small Qy-shift of approximately 0.15 cm-1/MPa is an indication for the absence of strongly coupled chlorophyll dimers within the reaction center and supports earlier reports from low-temperature measurements (Chang HC, Jankowiak R, Reddy NRS and Small GJ (1995) Chem Phys 197: 307–321). The carotene red-shift (seen in CHAPS) is much larger (0.5 – 0.6 cm-1/MPa) and within the range observed for excitonically coupled chlorophylls. However, since carotenes are more sensitive to changes of refractive index, we do not consider this evidence for excitonically coupled carotenes. Varying the pH and the detergent induced only small effects. Pigment exchange using high pressure instead of elevated temperature was not possible under the conditions tested. 相似文献
42.
Prudovsky I Tarantini F Landriscina M Neivandt D Soldi R Kirov A Small D Kathir KM Rajalingam D Kumar TK 《Journal of cellular biochemistry》2008,103(5):1327-1343
A growing number of proteins devoid of signal peptides have been demonstrated to be released through the non-classical pathways independent of endoplasmic reticulum and Golgi. Among them are two potent proangiogenic cytokines FGF1 and IL1alpha. Stress-induced transmembrane translocation of these proteins requires the assembly of copper-dependent multiprotein release complexes. It involves the interaction of exported proteins with the acidic phospholipids of the inner leaflet of the cell membrane and membrane destabilization. Not only stress, but also thrombin treatment and inhibition of Notch signaling stimulate the export of FGF1. Non-classical release of FGF1 and IL1alpha presents a promising target for treatment of cardiovascular, oncologic, and inflammatory disorders. 相似文献
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44.
Priit Adler Raivo Kolde Meelis Kull Aleksandr Tkachenko Hedi Peterson Jüri Reimand Jaak Vilo 《Genome biology》2009,10(12):R139-11
We present a web resource MEM (Multi-Experiment Matrix) for gene expression similarity searches across many datasets. MEM
features large collections of microarray datasets and utilizes rank aggregation to merge information from different datasets
into a single global ordering with simultaneous statistical significance estimation. Unique features of MEM include automatic
detection, characterization and visualization of datasets that includes the strongest coexpression patterns. MEM is freely
available at . 相似文献
45.
Leo Garcia Flores Susanna Bertolini Hsin Hsin Yeh Daniel Young Uday Mukhopadhyay Ashutosh Pal Yunming Ying Andrei Volgin Aleksandr Shavrin Suren Soghomonyan William Tong William Bornmann Mian M. Alauddin Craig Logsdon Juri G. Gelovani 《PloS one》2009,4(11)
Background
Early diagnosis of pancreatic carcinoma with highly sensitive diagnostic imaging methods could save lives of many thousands of patients, because early detection increases resectability and survival rates. Current non-invasive diagnostic imaging techniques have inadequate resolution and sensitivity for detection of small size (∼2–3 mm) early pancreatic carcinoma lesions. Therefore, we have assessed the efficacy of positron emission tomography and computer tomography (PET/CT) imaging with β-O-D-galactopyranosyl-(1,4′)-2′-deoxy-2′-[18F]fluoroethyl-D-glucopyranose ([18F]FEDL) for detection of less than 3 mm orthotopic xenografts of L3.6pl pancreatic carcinomas in mice. [18F]FEDL is a novel radioligand of hepatocarcinoma-intestine-pancreas/pancreatitis-associated protein (HIP/PAP), which is overexpressed in peritumoral pancreatic acinar cells.Methodology/Principal Findings
Dynamic PET/CT imaging demonstrated rapid accumulation of [18F]FEDL in peritumoral pancreatic tissue (4.04±2.06%ID/g), bi-exponential blood clearance with half-lives of 1.65±0.50 min and 14.14±3.60 min, and rapid elimination from other organs and tissues, predominantly by renal clearance. Using model-independent graphical analysis of dynamic PET data, the average distribution volume ratio (DVR) for [18F]FEDL in peritumoral pancreatic tissue was estimated as 3.57±0.60 and 0.94±0.72 in sham-operated control pancreas. Comparative analysis of quantitative autoradiographic images and densitometry of immunohistochemically stained and co-registered adjacent tissue sections demonstrated a strong linear correlation between the magnitude of [18F]FEDL binding and HIP/PAP expression in corresponding regions (r = 0.88). The in situ analysis demonstrated that at least a 2–4 fold apparent lesion size amplification was achieved for submillimeter tumors and to nearly half a murine pancreas for tumors larger than 3 mm.Conclusion/Significance
We have demonstrated the feasibility of detection of early pancreatic tumors by non-invasive imaging with [18F]FEDL PET/CT of tumor biomarker HIP/PAP over-expressed in peritumoral pancreatic tissue. Non-invasive non-invasive detection of early pancreatic carcinomas with [18F]FEDL PET/CT imaging should aid the guidance of biopsies and additional imaging procedures, facilitate the resectability and improve the overall prognosis. 相似文献46.
Sang-Moo Kang Dae-Goon Yoo Aleksandr S. Lipatov Jae-Min Song C. Todd Davis Fu-Shi Quan Li-Mei Chen Ruben O. Donis Richard W. Compans 《PloS one》2009,4(3)
Background
Recurrent outbreaks of highly pathogenic H5N1 avian influenza virus pose a threat of eventually causing a pandemic. Early vaccination of the population would be the single most effective measure for the control of an emerging influenza pandemic.Methodology/Principal Findings
Influenza virus-like particles (VLPs) produced in insect cell-culture substrates do not depend on the availability of fertile eggs for vaccine manufacturing. We produced VLPs containing influenza A/Viet Nam1203/04 (H5N1) hemagglutinin, neuraminidase, and matrix proteins, and investigated their preclinical immunogenicity and protective efficacy. Mice immunized intranasally with H5N1 VLPs developed high levels of H5N1 specific antibodies and were 100% protected against a high dose of homologous H5N1 virus infection at 30 weeks after immunization. Protection is likely to be correlated with humoral and cellular immunologic memory at systemic and mucosal sites as evidenced by rapid anamnestic responses to re-stimulation with viral antigen in vivo and in vitro.Conclusions/Significance
These results provide support for clinical evaluation of H5N1 VLP vaccination as a public health intervention to mitigate a possible pandemic of H5N1 influenza. 相似文献47.
Xu J Wei L Mathvink R Edmondson SD Mastracchio A Eiermann GJ He H Leone JF Leiting B Lyons KA Marsilio F Patel RA Petrov A Wu JK Thornberry NA Weber AE 《Bioorganic & medicinal chemistry letters》2006,16(5):1346-1349
anti-Substituted beta-methylphenylalanine derived amides have been shown to be potent DPP-IV inhibitors exhibiting excellent selectivity over both DPP8 and DPP9. The optimized compound exhibited good pharmacokinetic profiles in three preclinical species. 相似文献
48.
49.
Ishtiaque Rashid Michal Hammel Aleksandr Sverzhinsky Miaw-Sheue Tsai John M. Pascal John A. Tainer Alan E. Tomkinson 《The Journal of biological chemistry》2021,297(2)
Tyrosyl DNA phosphodiesterase 1 (TDP1) and DNA Ligase IIIα (LigIIIα) are key enzymes in single-strand break (SSB) repair. TDP1 removes 3′-tyrosine residues remaining after degradation of DNA topoisomerase (TOP) 1 cleavage complexes trapped by either DNA lesions or TOP1 inhibitors. It is not known how TDP1 is linked to subsequent processing and LigIIIα-catalyzed joining of the SSB. Here we define a direct interaction between the TDP1 catalytic domain and the LigIII DNA-binding domain (DBD) regulated by conformational changes in the unstructured TDP1 N-terminal region induced by phosphorylation and/or alterations in amino acid sequence. Full-length and N-terminally truncated TDP1 are more effective at correcting SSB repair defects in TDP1 null cells compared with full-length TDP1 with amino acid substitutions of an N-terminal serine residue phosphorylated in response to DNA damage. TDP1 forms a stable complex with LigIII170–755, as well as full-length LigIIIα alone or in complex with the DNA repair scaffold protein XRCC1. Small-angle X-ray scattering and negative stain electron microscopy combined with mapping of the interacting regions identified a TDP1/LigIIIα compact dimer of heterodimers in which the two LigIII catalytic cores are positioned in the center, whereas the two TDP1 molecules are located at the edges of the core complex flanked by highly flexible regions that can interact with other repair proteins and SSBs. As TDP1and LigIIIα together repair adducts caused by TOP1 cancer chemotherapy inhibitors, the defined interaction architecture and regulation of this enzyme complex provide insights into a key repair pathway in nonmalignant and cancer cells. 相似文献
50.
Alfonso Timoneda Temur Yunusov Clement Quan Aleksandr Gavrin Samuel F. Brockington Sebastian Schornack 《PLoS biology》2021,19(7)
Arbuscular mycorrhiza (AM) are mutualistic interactions formed between soil fungi and plant roots. AM symbiosis is a fundamental and widespread trait in plants with the potential to sustainably enhance future crop yields. However, improving AM fungal association in crop species requires a fundamental understanding of host colonisation dynamics across varying agronomic and ecological contexts. To this end, we demonstrate the use of betalain pigments as in vivo visual markers for the occurrence and distribution of AM fungal colonisation by Rhizophagus irregularis in Medicago truncatula and Nicotiana benthamiana roots. Using established and novel AM-responsive promoters, we assembled multigene reporter constructs that enable the AM-controlled expression of the core betalain synthesis genes. We show that betalain colouration is specifically induced in root tissues and cells where fungal colonisation has occurred. In a rhizotron setup, we also demonstrate that betalain staining allows for the noninvasive tracing of fungal colonisation along the root system over time. We present MycoRed, a useful innovative method that will expand and complement currently used fungal visualisation techniques to advance knowledge in the field of AM symbiosis.Arbuscular mycorrhiza are mutualistic interactions formed between soil fungi and plant roots. This study presents the MycoRed system, which uses red plant pigments derived from beetroot to reveal how fungi establish symbiosis with living legume and wild tobacco roots. 相似文献