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991.
Thomas Josef Vogl Thaddäus T. Wissniowski Nagy N. N. Naguib Renate M. Hammerstingl Martin G. Mack Sabine Münch Matthias Ocker Deike Strobel Eckhart G. Hahn Johannes Hänsler 《Cancer immunology, immunotherapy : CII》2009,58(10):1557-1563
Purpose To asses if laser-induced thermotherapy (LITT) induces a specific cytotoxic T cell response in patients treated with LITT
for colorectal cancer liver metastases.
Methods Eleven patients with liver metastases of colorectal cancer underwent LITT. Blood was sampled before and after LITT. Peripheral
T cell activation was assessed by an interferon gamma (IFNg) secretion assay and flow cytometry. Test antigens were autologous
liver and tumor lysate obtained from each patient by biopsy. T cells were stained for CD3/CD4/CD8 and IFNg to detect activated
T cells. The ratio of IFNg positive to IFNg negative T cells was determined as the stimulation index (SI). To assess cytolytic
activity, T cells were co-incubated with human colorectal cancer cells (CaCo) and cytosolic adenylate kinase release was measured
by a luciferase assay.
Results IFNg secretion assay: before LITT SI was 12.73 (±4.83) for CD3+, 4.36 (±3.32) for CD4+ and 3.64 (±1.77) for CD8+ T cells against
autologous tumor tissue. Four weeks after LITT SI had increased to 92.09 (±12.04) for CD3+ (P < 0.001), 42.92 (±16.68) for CD4+ (P < 0.001) and 47.54 (±15.68) for CD8+ T cells (P < 0.001) against autologous tumor tissue. No increased SI was observed with normal liver tissue at any time point. Cytotoxicity
assay: before LITT activity against the respective cancer cells was low, with RLU = 1,493 (±1,954.68), whereas after LITT
cytolytic activity had increased to RLU = 7,260 [±3,929.76 (P < 0.001)].
Conclusion Patients with liver metastases of colorectal cancer show a tumor-specific cytotoxic T cell stimulation and a significantly
increased cytolytic activity of CD3+, CD4+ and CD8+ T cells after LITT against an allogenic tumor (CaCo cell line). 相似文献
992.
Susann Müller Carsten Vogt Mandy Laube Hauke Harms & Sabine Kleinsteuber 《FEMS microbiology ecology》2009,70(3):254-264
A sulfate-reducing bacterial consortium was enriched from an anoxic aquifer contaminated with BTEX compounds, using toluene as a growth substrate. Total cell counts, protein contents and sulfide production were determined to follow growth at the in situ temperature (14 °C) and at 25 °C, respectively. Community members were identified by 16S rRNA gene cloning and sequencing. Phylogenetic analysis revealed 12 sequence types belonging to Deltaproteobacteria (several groups) , Epsilonproteobacteria, Bacteroidetes, Spirochaetaceae and an unclassified bacterial clade. The most prominent phylotype comprising 34% of all clones was affiliated to the Desulfobulbaceae and closely related to environmental clones retrieved from hydrocarbon-contaminated aquifers. Flow-cytometric methods were applied to analyze the community dynamics and to identify key organisms involved in toluene assimilation. Flow-cytometric measurement of DNA contents and scatter behavior served to detect and quantify dominant and newly emerging clusters of subcommunities. Up to seven subcommunities, two of them dominant, were distinguished. Cell sorting was used to facilitate the analysis of conspicuous clusters for phylogenetic identity by terminal restriction fragment length polymorphism profiling of the 16S rRNA genes. The Desulfobulbaceae phylotype accounted for up to 87% in proliferating subcommunities, indicating that it represents the key organism of toluene degradation within this complex anaerobic consortium. 相似文献
993.
Lai Hong Fu Yansong Miao Sze Wan Lo Tai Chi Seto Samuel S.M. Sun Zeng-Fu Xu Sabine Clemens Lorne A. Clarke Allison R. Kermode Liwen Jiang 《Plant science》2009,177(6):668-675
Lysosomal storage diseases (LSDs), that collectively represent over 50 disorders, are amenable to enzyme replacement therapies. However, the current methods used to commercially produce recombinant lysosomal enzymes for this purpose, most commonly Chinese Hamster Ovary cells and human fibroblasts, are prohibitively costly. Plant bioreactors hold great promise for economic production of functional human α-l-iduronidase (hIDUA; glycosaminoglycan α-l-iduronohydrolase; EC 3.2.1.76), the enzyme deficient in the human LSD, Mucopolysaccharidosis I. We have developed and tested an expression system using transgenic tobacco BY-2 cells to produce high amounts of active hIDUA. A plant signal peptide was essential for proper expression and secretion of the 78 kDa glycosylated hIDUA into the cultured media of transgenic BY-2 cells. The yield and activity of the secreted hIDUA from long-term cultures of transgenic BY-2 cell lines were as high as 10 μg/mL media and 53,000 pmol/min/mg proteins, respectively. Thus, this transgenic BY-2 cell line presents an attractive platform for economic production and easy downstream purification of hIDUA for enzyme replacement therapy. Furthermore, this system can be used for the production and purification of other human lysosomal enzymes or pharmaceuticals. 相似文献
994.
Justyna Wolinska Sabine Giessler Henrike Koerner 《Applied and environmental microbiology》2009,75(22):7051-7059
Parasites play important roles in local population dynamics and genetic structure. However, due to insufficient diagnostic tools, detailed host-parasite interactions may remain concealed by hidden parasite diversity in natural systems. Microscopic examination of 19 European lake Daphnia populations revealed the presence of three groups of parasites: fungi, microsporidia, and oomycetes. For most of these parasites no genetic markers have been described so far. Based on sequence similarities of the nuclear small-subunit and internal transcribed spacer (ITS) rRNA gene regions, one fungus, four microsporidian, and nine oomycete taxa were discovered in 147 infected Daphnia (and/or three other zooplankton crustaceans). Additionally, cloning of rRNA gene regions revealed parasite sequence variation within host individuals. This was most pronounced in the ITS region of one microsporidian taxon, where the within-host sequence variation ranged from 1.7% to 5.3% polymorphic sites for parasite isolates from 14 different geographical locations. Interestingly, the parasite isolates from close locations grouped together based on sequence similarities, suggesting that there was parasite dispersal. Taken together, the data obtained in this study revealed hidden diversity of parasite communities in Daphnia lake populations. Moreover, a higher level of resolution for identifying parasite strains makes it possible to test new hypotheses with respect to parasite dispersal, transmission routes, and coinfection.During the last decade, microparasites of Daphnia species, which are small zooplankton crustaceans, have become a popular study system in ecological and evolutionary research (for a review, see reference 15). It has been shown both in the field and under controlled laboratory conditions that parasites have a substantial impact on Daphnia fitness (7, 21, 52). Parasite-induced reductions in Daphnia population density (11, 12) or even population crashes (17) might result in disruptions of aquatic food webs, as daphnids play important roles as main phytoplankton grazers and as a major food of planktivorous fish (27). Moreover, as infections are often genotype specific (6, 8), they can lead to changes in the gene pool of a Daphnia population (7, 14), sometimes significantly increasing the genetic diversity of the host population (12, 54). Thus, Daphnia parasites cause not only ecological but also evolutionary changes in aquatic systems.Conclusions regarding the importance of parasites in natural systems require powerful tools to detect and properly identify parasite taxa. Thus far, few species-specific molecular markers have been developed for Daphnia parasites (33, 38, 39, 41) and then used in experimental studies (3). In surveys of natural Daphnia populations, parasite identification has been based primarily on microscopic examination (4, 5, 29, 52), with only one exception (32). The parasites recorded in natural populations of Daphnia are thus considered members of certain taxa, or even species, without genetic confirmation. The fact that molecular markers are not used to characterize Daphnia infections makes it difficult to compare epidemic patterns across different habitats and/or various field surveys, as parasites cannot be unambiguously identified by microscopic examination alone. Even if microscopic identification is theoretically possible (for example, by examining ultrastructural morphology by electron microscopy [37]), this approach is not feasible for routine analysis. Consequently, classification of parasites that actually belong to different taxa in the same group might introduce noise into field surveys, as parasite taxa differ widely in virulence and host range (for a review, see reference 15).Most of the known Daphnia parasites that have been described were obtained from small temporary ponds and rock pools (4, 16, 43). In permanent lakes, lower parasite diversity was assumed, mainly because increased fish predation reduces the population density of potential hosts (18), whereas high host density is a crucial determinant of epidemic spread (1, 2, 45). In addition, infected Daphnia spp. are more vulnerable to fish that hunt visually due to loss of their transparent appearance (11, 13). On the other hand, it was recently shown that even if Daphnia host density was reduced by selective fish predation, the prevalence of infection did not decline, probably due to the very high rates of transmission of the parasite that was observed (11). In contrast, we expected that the highly heterogeneous biotic and abiotic conditions in permanent lakes (27) would provide a variety of niches (for a review, see reference 47), which also favor a high level of parasite diversity. Therefore, Czech canyon-shaped reservoirs were chosen as our main study systems, because in these lakes environmental gradients are particularly pronounced in both the horizontal and vertical dimensions (42). Moreover, the Daphnia communities of these reservoirs are dominated by members of the Daphnia longispina complex (35), taxa which have previously been shown to be infected by a variety of parasites (52).The results of our study revealed a high level of diversity of Daphnia parasites in permanent lakes. Fourteen different parasite taxa were detected using nuclear small-subunit (SSU) and internal transcribed spacer (ITS) rRNA gene sequence information. In addition, a high level of sequence variation was observed in the ITS region of one microsporidian taxon. Thus, molecular markers are now available which allow discrimination with high resolution among and within parasite taxa and provide tools to address more detailed questions concerning lake Daphnia-microparasite systems. 相似文献
995.
Júlio César Bicca-Marques Carina Barboza Muhle Helissandra Mattjie Prates Sabine Garcia de Oliveira Cláudia Calegaro-Marques 《International journal of primatology》2009,30(5):743-748
Species response to habitat loss, fragmentation, or alteration ranges from intolerance and extinction to tolerance and population
growth. An ability to increase trophic niche breadth is likely to play a key role in promoting tolerance to habitat change
in many species. Howlers (Alouatta spp.) are good examples of these tolerant species. Researchers have related their capacity to thrive well in disturbed habitats
to their ability to exploit an eclectic vegetarian diet. Despite >50,000 h of observation of habituated free-ranging groups
throughout the distribution of Alouatta, no case of intentional ingestion of animal matter has ever been observed. Here, we report an unexpected trophic niche broadening
for free-ranging groups of black-and-gold howlers (Alouatta caraya) living in small (≤2 ha) impoverished habitat islands in the State of Rio Grande do Sul, Brazil. We studied 3 isolated social
groups (15–17, 12–14, and 5 individuals) and observed 1 of them preying on birds’ nests. We recorded 19 events of egg-eating
during 2274 h of observation in 1 group and 2 suspected cases in another. Our findings highlight the dietary flexibility that
characterize howlers and contrast with the widely held view that they observe a strictly vegetarian diet. 相似文献
996.
997.
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999.
Nathan H. Lents Virginia Irintcheva Reema Goel Leroy W. Wheeler Joseph J. Baldassare 《Cellular signalling》2009,21(6):1007-1014
α-thrombin is a potent mitogen for fibroblasts and initiates a rapid signal transduction pathway leading to the activation of Ras and the stimulation of cell cycle progression. While the signaling events downstream of Ras have been studied in significant detail and appear well conserved across many species and cell types, the precise molecular events beginning with thrombin receptor activation and leading to the activation of Ras are not as well understood. In this study, we examined the immediate events in the rapid response to α-thrombin, in a single cell type, and found that an unexpected degree of specificity exists in the pathway linking α-thrombin to Ras activation. Specifically, although IIC9 cells express all three Ras isoforms, only N-Ras is rapidly activated by α-thrombin. Further, although several Gα subunits associate with PAR1 and are released following stimulation, only Gαi2 couples to the rapid activation of Ras. Similarly, although IIC9 cells express many Gβ and Gγ subunits, only a subset associates with Gαi2, and of those, only a single Gβγ dimer, Gβ1γ5, participates in the rapid activation of N-Ras. We then hypothesized that co-localization into membrane microdomains called lipid rafts, or caveolae, is at least partially responsible for this degree of specificity. Accordingly, we found that all components localize to lipid rafts and that disruption of caveolae abolishes the rapid activation of N-Ras by α-thrombin. We thus report the molecular elucidation of an extremely specific and rapid signal transduction pathway linking α-thrombin stimulation to the activation of Ras. 相似文献