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排序方式: 共有327条查询结果,搜索用时 15 毫秒
81.
Apoptosis and the loss of chondrocyte survival signals contribute to articular cartilage degradation in osteoarthritis 总被引:6,自引:0,他引:6
Goggs R Carter SD Schulze-Tanzil G Shakibaei M Mobasheri A 《Veterinary journal (London, England : 1997)》2003,166(2):140-158
Apoptotic death of articular chondrocytes has been implicated in the pathogenesis of osteoarthritis (OA). Apoptotic pathways in chondrocytes are multi-faceted, although some cascades appear to play a greater in vivo role than others. Various catabolic processes are linked to apoptosis in OA cartilage, contributing to the reduction in cartilage integrity. Recent studies suggest that beta1-integrin mediated cell-matrix interactions provide survival signals for chondrocytes. The loss of such interactions and the inability to respond to IGF-1 stimulation may be partly responsible for the hypocellularity and matrix degradation that characterises OA. Here we have reviewed the literature in this area of cartilage cell biology in an effort to consolidate the existing information into a plausible hypothesis regarding the involvement of apoptosis in the pathogenesis of OA. Understanding of the interactions that promote chondrocyte apoptosis and cartilage hypocellularity is essential for developing appropriately targeted therapies for inhibition of chondrocyte apoptosis and the treatment of OA. 相似文献
82.
K99 fimbriae are important for intestinal colonisation by bovine strains of enterotoxigenic Escherichia coli. The mode of action of this colonisation factor is well understood and specific immune responses are protective. K99 was therefore chosen for this study as a model to test if antibodies with anti-adhesion activity could be isolated from recombinant libraries using phage display techniques. Potentially, this strategy could be used to understand better the action of bacterial colonisation factors and aid the design of therapies (e.g. vaccines, purified protein products or bacteria bearing colonisation-blocking antibodies) to inhibit bacterial adherence. The major fimbrial subunit from K99, FanC, was purified from a clinical E. coli isolate. The protein was coated to plastic immunotubes and used as a target for selection of antibodies from the Tomlinson I and J libraries of single chain (scFv) antibodies. Clones able to recognise K99 were isolated by iterative rounds of binding, elution and amplification. scFv antibodies chosen from the resulting panel were purified and their specificity confirmed by ELISA. Pre-incubation of several scFvs with bacteria expressing K99 fimbriae inhibited the agglutination of erythrocytes. Further investigation by microscopy confirmed that when E. coli expressing K99 were exposed to scFv antibodies, the binding of bacteria to erythrocytes was blocked with high efficiency. The study showed that recombinant antibodies were able to block the action of a bacterial colonisation factor and hence that phage display techniques might be applied to the identification of less well-characterised virulence factors and the analysis of their structure and function. 相似文献
83.
Nakhaee A Taheri T Taghikhani M Mohebali M Salmanian AH Fasel N Rafati S 《Veterinary parasitology》2004,119(2-3):107-123
Canids are natural reservoirs of Leishmania infantum and have been promoted as experimental hosts to decipher the pathogenesis of human visceral leishmaniasis (VL). In this study, the presence of IgG antibodies as well as the presence of mononuclear leukocytes reactive to different cysteine proteinases (CPs) were examined in 13 L. infantum-infected dogs (six with symptoms, seven asymptomatic). Cysteine proteinases which belong to papain-like enzymes known as clan CA are the most studied CPs of parasite protozoa. These molecules are expressed by the intracellular stages of the parasite and could be immunogenic. We studied Type II CP (CPA) and Type I CP (CPB) with its long C-terminal extension (CTE) which could be highly immunogenic. We showed that the level of antibodies reactive to rCPA is low in both symptomatic and asymptomatic dogs. In contrast, when CPB and CTE were used as antigens, the level of total IgG (with IgG2 superior to IgG1) reached higher values in asymptomatic dogs than in dogs with VL. While the peripheral blood mononuclear cell (PBMC) reactivity was significant when cultured in the presence of freezed/thawed (F/T) lysate, it remained low in presence of CP although always higher for PBMC recovered from asymptomatic dogs. We showed the importance of CPB and CTE in particular as a target of immune response and their potential use for serodiagnosis in asymptomatic dogs. 相似文献
84.
Three factors were examined to determine their effect on the reproduction and sex-ratio in the predacious miteAmblyseius zaheri Yousef & El-Borolossy in the laboratory. The factors studied included multiple matings, disturbed mating and age of mating females. Fecundity of females mated more than once was 3 times higher than in females mated only once. Artificial curtailment of copulation to 120, 60 and SO min resulted in reduction of fecundity and oviposition period. The Age of mated females has an influence also on fecundity, old females produce fewer eggs compared with young females under constant condition of abundant prey. All 3 factors studied have no influence on the sex-ratio of the progeny. 相似文献
85.
Mehdi Rasoli Swee Keong Yeap Sheau Wei Tan Hassan Moeini Aini Ideris Mohd Hair Bejo Noorjahan Banu Mohamed Alitheen Pete Kaiser Abdul Rahman Omar 《Comparative immunology, microbiology and infectious diseases》2014
Newcastle disease (ND) is a highly contagious avian disease and one of the major causes of economic losses in the poultry industry. The emergence of virulent NDV genotypes and repeated outbreaks of NDV in vaccinated chickens have raised the need for fundamental studies on the virus–host interactions. In this study, the profiles of B and T lymphocytes and macrophages and differential expression of 26 immune-related genes in the spleen of specific-pathogen-free (SPF) chickens, infected with either the velogenic genotype VII NDV strain IBS002 or the genotype VIII NDV strain AF2240, were evaluated. A significant reduction in T lymphocyte population and an increase in the infiltration of IgM+ B cells and KUL01+ macrophages were detected in the infected spleens at 1, 3 and 4 days post-infection (dpi) (P < 0.05). The gene expression profiles showed an up-regulation of CCLi3, CXCLi1, CXCLi2 (IL-8), IFN-γ, IL-12α, IL-18, IL-1β, IL-6, iNOS, TLR7, MHCI, IL-17F and TNFSF13B (P < 0.05). However, these two genotypes showed different cytokine expression patterns and viral load. IBS002 showed higher viral load than AF2240 in spleen at 3 and 4 dpi and caused a more rapid up-regulation of CXCLi2, IFN-γ, IL-12α, IL-18, IL-1β, iNOS and IL-10 at 3 dpi. Meanwhile, the expression levels of CCLI3, CXCLi1, IFN-γ, IL-12α, IL-1β and iNOS genes were significantly higher in AF2240 at 4 dpi. In addition, the expression levels of IL-10 were significantly higher in the IBS002-infected chickens at 3 and 4 dpi. Hence, infection with velogenic genotype VII and VIII NDV induced different viral load and production of cytokines and chemokines associated with inflammatory reactions. 相似文献
86.
Mohamed Boukharta Nadia Touil Elmostafa El Fahim Meriame Terta Bachir Kissi Chafiqua Loutfi Mehdi El Harrak My Mustapha Ennaji 《Journal of Equine Veterinary Science》2014
Reported here are the results of antigenic and genetic characterization of equine influenza strains causing local outbreaks reported in Morocco, respectively, in 1997 and 2004. The antigenic and genetic characterizations of the equine influenza virus H3N8 are reported here. The highest similarity between the HA1 nucleotide sequences of A/equine/Nador/1/1997 and those of A/equine/Rome/5/1991 and A/equine/Italy/1199/1992 demonstrate that A/equine/Nador/1/1997 belongs to the European lineage. On the other hand, A/equine/Essaouira/2/2004 and A/equine/Essaouira/3/2004 were classified in the predivergent lineage. The present work emphasizes the importance of a national influenza survey program, which requires a collaborative laboratory network to promote the collection and characterization (antigenic and genetic) of equine influenza viruses in real time. 相似文献
87.
Cann HM de Toma C Cazes L Legrand MF Morel V Piouffre L Bodmer J Bodmer WF Bonne-Tamir B Cambon-Thomsen A Chen Z Chu J Carcassi C Contu L Du R Excoffier L Ferrara GB Friedlaender JS Groot H Gurwitz D Jenkins T Herrera RJ Huang X Kidd J Kidd KK Langaney A Lin AA Mehdi SQ Parham P Piazza A Pistillo MP Qian Y Shu Q Xu J Zhu S Weber JL Greely HT Feldman MW Thomas G Dausset J Cavalli-Sforza LL 《Science (New York, N.Y.)》2002,296(5566):261-262
88.
Basalt Weathering and Soil Development since the Middle Tertiary on Lanzarote, Canary Islands - The Profile Malaya Chica A polygenetic soil on tertiary (miocene) basalt in the north of Lanzarote (Canary Islands, Spain) was examined. Soil development was reconstructed, which took place in a semiarid climate since the end of the tertiary period. The interpretation of field and laboratory results (carbonate, grainsize distribution, oxalate and dithionithe soluble oxides, CEC, clay minerals, micromorphology) explained the history of development. Since the miocene at least seven consecutive phases of soil development took place induced by erosion, volcanic and colluvial sedimentation and/or climatic changes. 相似文献
89.
This paper reports on an experiment to determine growth and survival of blacklip pearl oyster, Pinctada margaritifera (L.), larvae fed a 1:1 mixture of Isochrysis aff. galbana clone T-ISO and Pavlova salina at six different densities (1, 2, 5, 10, 20 and 30 × 103 cells ml-1. Larval growth and survival were assessed every four days over a 20–day period. Exponential and logistic regression models were fitted to the growth and survival responses, respectively. Overall growth of larvae fed 5 × 103 cells ml-1 was significantly greater (p > 0.01) than growth of larvae reared at other algal densities. The optimal food ration for maximum larval growth was 20 × 103 cells ml-1, which resulted in larvae with antero-posterior shell length of 230 m after 20 days. These larvae were significantly larger (p > 0.05) than those in all other treatments at the end of the experiment. Survival of larvae fed 0, 1 and 2 × 103 cells ml-1 was significantly lower than that of larvae in all other treatments at the end of 15 days (p > 0.01). Maximal survival (8%) over the 20 day period was shown by larvae fed 10 × 103 cells ml-1, while lower survival was shown by larvae fed 2 × 103 cells ml-1 (2%) and 1 × 103 cells ml-1 (0%). 相似文献
90.
Partitioning of the genotypes by environment interaction (GEI) is important in order to determine the nature of the GEI. The
objectives of this study were to assess the presence and nature of GEI for nine agronomic traits of rapeseed cultivars, and
to identify cultivars with favorable levels of stable oil production. Nine rapeseed cultivars, including seven open pollinated
and two hybrids, Hyola308 and Hyola401, were grown in ten environments under rain-fed warm areas of Iran. The GEI was significant
for all traits and was partitioned into components representing heterogeneity due to environmental index and the remainder
of the GEI. Among the all traits with a highly significant heterogeneity, the largest amount of heterogeneity removed from
the GEI was for seeds per pod and seed weight. We found GEIs for both oil content and seed yield were largely influenced by
differences in correlations among pairs of cultivars (86.8 and 71.4% of the GEI sum of squares, respectively), suggesting
that crossover GEIs (i.e., change in genotype rankings among environments) are present. The mean correlation of each cultivar
with all other cultivars ([`(r)]ii¢ \bar{r}_{{ii^{\prime}}} ) ranged from 0.53 to 0.83 for oil content and 0.86 to 0.96 for seed yield. A comparison was done of the significance of Sh-σi2 (stability variance derived from total GEI) and Sh-Si2 (adjusted stability variance derived from residual GEI) assignable to each genotype for oil content and seed and oil yield.
Based on Sh-σi2, three cultivars were unstable for oil content, whereas six cultivars were unstable for seed and oil yield. The removal of
heterogeneity revealed that one unstable cultivar for oil content and three unstable cultivars for oil yield were judged to
be stable. All cultivars with [`(r)]ii¢ \bar{r}_{{ii^{\prime } }} ≤ 0.63 were labeled unstable for oil content, whereas all with [`(r)]ii¢ \bar{r}_{{ii^{\prime } }} ≤ 0.94 were considered unstable for seed yield. The relationships between [`(r)]ii¢ \bar{r}_{{ii^{\prime } }} and Sh-σi2 were significant (P < 0.01) for oil content and seed yield. The results of rank correlation coefficients showed significant positive correlations
of Yield-Stability statistic (YSi) with oil content and oil yield. Cultivars such as Option500 and Hyola401 were identified as having stable, high levels to
seed yield and oil content. 相似文献