排序方式: 共有158条查询结果,搜索用时 46 毫秒
21.
Ait-Oufella H Salomon BL Potteaux S Robertson AK Gourdy P Zoll J Merval R Esposito B Cohen JL Fisson S Flavell RA Hansson GK Klatzmann D Tedgui A Mallat Z 《Nature medicine》2006,12(2):178-180
Atherosclerosis is an immunoinflammatory disease elicited by accumulation of lipids in the artery wall and leads to myocardial infarction and stroke. Here, we show that naturally arising CD4(+)CD25(+) regulatory T cells, which actively maintain immunological tolerance to self and nonself antigens, are powerful inhibitors of atherosclerosis in several mouse models. These results provide new insights into the immunopathogenesis of atherosclerosis and could lead to new therapeutic approaches that involve immune modulation using regulatory T cells. 相似文献
22.
Hedvig E. L?fdahl Juan Du Anders N?sman Emilia Andersson Carlos A. Rubio Yunxia Lu Torbj?rn Ramqvist Tina Dalianis Jesper Lagergren Hanna Dahlstrand 《PloS one》2012,7(10)
Background
The prevalence and role of human papillomavirus (HPV) in the aetiology of oesophageal squamous cell carcinoma is uncertain. Based on the presence of HPV in the oral cavity and its causal association with squamous cell carcinoma of the oropharynx, we hypothesised that HPV is more strongly associated with proximal than distal oesophageal squamous cell carcinoma.Methods
A population-based study comparing HPV infection in relation to tumour site in patients diagnosed with oesophageal squamous cell carcinomas in the Stockholm County in 1999–2006. Multiplex polymerase chain reaction genotyping (PCR) with Luminex was conducted on pre-treatment endoscopic biopsies to identify type specify HPV. Carcinogenic activity of HPV was assessed by p16INK4a expression. Multivariable logistic regression was used to calculate odds ratios and 95% confidence intervals.Results
Among 204 patients, 20 (10%) had tumours harbouring HPV DNA, almost all (90%) of HPV high-risk type, mainly HPV16. Tumours containing HPV were not overrepresented in the upper compared to the middle or lower third of the oesophagus (odds ratio 0.6, 95% confidence interval 0.2–1.9). P16INK4a expression was similarly common (24% and 16%) in the HPV-positive and HPV-negative groups.Conclusion
This study found a limited presence of HPV in oesophageal squamous cell carcinoma of uncertain oncogenic relevance and did not demonstrate that HPV was more strongly associated with proximal than distal tumours. 相似文献23.
Tobacco etch virus (TEV) protease is generally used to remove affinity tags from target proteins. It has been reported that some detergents inhibit the activity of this protease, and therefore should be avoided when removing affinity tags from membrane proteins. The aim of this study was to explore and evaluate this further. Hence, affinity tag removal with TEV protease was tested from three membrane proteins (a Pgp synthase and two CorA homologs) in the presence of 16 different detergents commonly used in membrane protein purification and crystallization. We observed that in the presence of the same detergent (Triton X-100), TEV protease could remove the affinity tag completely from one protein (CorA) but not from another protein (Pgp synthase). There was also a large variation in yield of cleaved membrane protein in different detergents, which probably depends on features of the protein-detergent complex. These observations show that, contrary to an earlier report, detergents do not inhibit the enzymatic activity of the TEV protease. 相似文献
24.
The causes of rheumatoid arthritis (RA) are largely unknown. However, RA is most probably a multifactorial disease with contributions from genetic and environmental factors. Searches for genes that influence RA have been conducted in both human and experimental model materials. Both types of study have confirmed the polygenic inheritance of the disease. It has become clear that the features of RA complicate the human genetic studies. Animal models are therefore valuable tools for identifying genes and determining their pathogenic role in the disease. This is probably the fastest route towards unravelling the pathogenesisis of RA and developing new therapies. 相似文献
25.
Anna-Karin H. Hultg?rd-Ekwall Vincent Couloigner Kristofer Rubin Helge Rask-Andersen 《The journal of histochemistry and cytochemistry》2003,51(11):1491-1500
The human endolymphatic duct (ED) and sac of the inner ear have been suggested to control endolymph volume and pressure. However, the physiological mechanisms for these processes remain obscure. We investigated the organization of the periductal interstitial connective tissue cells and extracellular matrix (ECM) in four freshly fixed human EDs by transmission electron microscopy and by immunohistochemistry. The unique surgical material allowed a greatly improved structural and epitopic preservation of tissue. Periductal connective tissue cells formed frequent intercellular contacts and focally occurring electron-dense contacts to ECM structures, creating a complex tissue network. The connective tissue cells also formed contacts with the basal lamina of the ED epithelium and the bone matrix, connecting the ED with the surrounding bone of the vestibular aqueduct. The interstitial connective tissue cells were non-endothelial and non-smooth muscle fibroblastoid cells. We suggest that the ED tissue network forms a functional mechanical entity that takes part in the control of inner ear fluid pressure and endolymph resorption. 相似文献
26.
Atle Wibe Anna-Karin Borg-Karlson Torbjörn Norin Hanna Mustaparta 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1997,180(6):585-595
Naturally produced plant volatiles, eliciting responses of single olfactory receptor neurons in the pine weevil, have been
identified by gas chromatography linked with mass spectrometry. The receptor neurons (n = 72) were classified in 30 types, according to the compound which elicited the strongest response in each neuron, 20 of
which compounds were identified. Most potent for 14 types of neurons (n = 50) were monoterpenes, including bicyclic (e.g. α-pinene, camphor and myrtenal) for 8 types (n = 32), monocyclic (limonene, carvone, α-terpinene) for 3 types (n = 12) and acyclic (e.g. β-myrcene and linalool) for 3 types (n = 6). Other compounds eliciting strongest responses of a neuron were five sesquiterpenes, including α-copaene and a farnesene-isomer,
and an anethole type which has no biosynthetic relationship with terpenes. Within one type, receptor neurons with quite selective
responses to the most potent compound as well as neurons with additional responses to several, structurally similar compounds
were found, indicating that the neurons may have the same functional types of membrane receptors, but different sensitivities.
Response spectra of neurons within the bicyclic-, mono-cyclic and acyclic types showed more overlapping than across the neuron
types. Minimal overlapping response spectra was found between monoterpene and sesquiterpene neurons. The results suggest that
this structure-activity relationship is significant for encoding plant odour information in the pipe weevil.
Accepted: 6 January 1997 相似文献
27.
Chromosomal localization of three human genes encoding bone morphogenetic protein receptors 总被引:7,自引:0,他引:7
Anna-Karin Åström Donald Jin Takeshi Imamura Eva Röijer Bradley Rosenzweig Kohei Miyazono Peter ten Dijke Göran Stenman 《Mammalian genome》1999,10(3):299-302
Bone morphogenetic proteins (BMPs) are members of the TGF-β superfamily that play a pivotal role in bone formation during
embryogenesis and fracture repair. BMP signaling occurs via hetero-oligomeric serine/threonine kinase complexes of BMP type
I (BMPR-IA or BMPR-IB) and type II receptors (BMPR-II). BMPR-IA and IB are closely related receptors, with sequence differences
conserved between different species, suggesting that they serve distinct functions. Here we report the cDNA cloning of human
BMPR1B and the chromosomal localization of all three BMPR genes. Using somatic cell hybrid and FISH analyses, the BMPR1A,
BMPR1B, and BMPR2 genes were assigned to 10q23, 4q22-24, and 2q33-34, respectively. A processed BMPR1A pseudogene was mapped
to 6q23.
Received: 17 February 1997 / Accepted: 15 October 1998 相似文献
28.
Martinez Molina D Lundbäck AK Niegowski D Eshaghi S 《Protein expression and purification》2008,62(1):49-52
YidC is an inner membrane protein from Escherichia coli and is an essential component in insertion, translocation and assembly of membrane proteins in the membranes. Previous purification attempts resulted in heavy aggregates and precipitated protein at later stages of purification. Here we present a rapid and straightforward stability screening strategy based on gel filtration chromatography, which requires as little as 10 microg of protein and takes less than 15 min to perform. With this technique, we could rapidly screen several buffers in order to identify an optimum condition that stabilizes purified YidC. After optimization we could obtain several milligrams of purified YidC that could be easily prepared at high concentrations and that was stable for weeks at +4 degrees C. The isolated protein is thus well suited for structural studies. 相似文献
29.
Géraldine Giraud Torbj?rn Ramqvist Diana V. Pastrana Vincent Pavot Cecilia Lindau Per Kogner Abiel Orrego Christopher B. Buck Tobias Allander Stefan Holm Bengt Gustavsson Tina Dalianis 《PloS one》2009,4(12)
Background
BK and JC polyomaviruses (BKV and JCV) are potentially oncogenic and have in the past inconclusively been associated with tumours of the central nervous system (CNS), while BKV has been hinted, but not confirmed to be associated with neuroblastomas. Recently three new polyomaviruses (KIPyV, WUPyV and MCPyV) were identified in humans. So far KIPyV and WUPyV have not been associated to human diseases, while MCPyV was discovered in Merkel Cell carcinomas and may have neuroepithelial cell tropism. However, all three viruses can be potentially oncogenic and this compelled us to investigate for their presence in childhood CNS and neuroblastomas.Methodology
The presence of KI, WU and MCPyV DNA was analysed, by a joint WU and KI specific PCR (covering part of VP1) and by a MCPyV specific regular and real time quantitative PCR (covering part of Large T) in 25 CNS tumour biopsies and 31 neuroblastoma biopsies from the Karolinska University Hospital, Sweden. None of the three new human polyomaviruses were found to be associated with any of the tumours, despite the presence of PCR amplifiable DNA assayed by a S14 housekeeping gene PCR.Conclusion
In this pilot study, the presence of MCPyV, KI and WU was not observed in childhood CNS tumours and neuroblastomas. Nonetheless, we suggest that additional data are warranted in tumours of the central and peripheral nervous systems and we do not exclude that other still not yet detected polyomaviruses could be present in these tumours. 相似文献30.
We treated Norway spruce (Picea abies) stems with methyl jasmonate (MeJA) to determine possible quantitative and qualitative effects of induced tree defenses on pheromone emission by the spruce bark beetle Ips typographus. We measured the amounts of 2-methyl-3-buten-2-ol and (S)-cis-verbenol, the two main components of the beetle's aggregation pheromone, released from beetle entrance holes, along with phloem terpene content and beetle performance in MeJA-treated and untreated Norway spruce logs. As expected, phloem terpene levels were higher and beetle tunnel length was shorter (an indication of poor performance) in MeJA-treated logs relative to untreated logs. Parallel to the higher phloem terpene content and poorer beetle performance, beetles in MeJA-treated logs released significantly less 2-methyl-3-buten-2-ol and (S)-cis-verbenol, and the ratio between the two pheromone components was significantly altered. These results suggest that host resistance elicited by MeJA application reduces pheromone emission by I. typographus and alters the critical ratio between the two main pheromone components needed to elicit aggregation. The results also provide a mechanistic explanation for the reduced performance and attractivity observed in earlier studies when bark beetles colonize trees with elicited host defenses, and extend our understanding of the ecological functions of conifer resistance against bark beetles. 相似文献