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871.
Erling Tjus Staffan Lindberg Møller Birger Scheller Henrik Vibe 《Photosynthesis research》1999,60(1):75-86
Photoinhibition of Photosystem I at chilling temperatures was investigated. Illumination of barley and cucumber leaves at 4°C induced a lowered Photosystem I activity. In barley, the reaction centre proteins PSI-A and PSI-B were both partially degraded as was the nuclear-encoded PSI-D polypeptide. Barley leaves infiltrated with KCN to increase oxidative stress, showed increased photoinhibition of Photosystem I, including reduced photochemical activity and marked degradation of several Photosystem I polypeptides. The most rapid and pronounced degradation was found in the PSI-D and PSI-E polypeptides exposed at the Photosystem I acceptor side. The PSI-A, -B, -C, -G, -H, -K and -L polypeptides were less extensively damaged. No damage of the lumenally oriented PSI-F and -N polypeptides was detected. The elevated photoinhibition of Photosystem I seen in KCN treated barley is most likely induced by a combination of increased active oxygen due to inhibited scavenging and increased accumulation of reducing power due to inhibition of the Calvin cycle. In barley, photo-inactivation of Photosystem I closely followed the degradation of PSI-A and PSI-B. Illumination of cucumber resulted in a pronounced loss of activity and appearance of specific PSI-A and PSI-B degradation products whereas the total PSI-A/B degradation was small. The PSI-A/B degradation identified in barley is interpreted to reflect a physiologically relevant process being part of a repair cycle, whereas the much smaller PSI-A/B degradation observed in cucumber is interpreted to represent an irreversible damage induced far below the temperature tolerance for cucumber. 相似文献
872.
Nicolas Barraud Michael V. Storey Zoe P. Moore Jeremy S. Webb Scott A. Rice Staffan Kjelleberg 《Microbial biotechnology》2009,2(3):370-378
Strategies to induce biofilm dispersal are of interest due to their potential to prevent biofilm formation and biofilm‐related infections. Nitric oxide (NO), an important messenger molecule in biological systems, was previously identified as a signal for dispersal in biofilms of the model organism Pseudomonas aeruginosa. In the present study, the use of NO as an anti‐biofilm agent more broadly was assessed. Various NO donors, at concentrations estimated to generate NO levels in the picomolar and low nanomolar range, were tested on single‐species biofilms of relevant microorganisms and on multi‐species biofilms from water distribution and treatment systems. Nitric oxide‐induced dispersal was observed in all biofilms assessed, and the average reduction of total biofilm surface was 63%. Moreover, biofilms exposed to low doses of NO were more susceptible to antimicrobial treatments than untreated biofilms. For example, the efficacy of conventional chlorine treatments at removing multi‐species biofilms from water systems was increased by 20‐fold in biofilms treated with NO compared with untreated biofilms. These data suggest that combined treatments with NO may allow for novel and improved strategies to control biofilms and have widespread applications in many environmental, industrial and clinical settings. 相似文献
873.
874.
Nikita Oskolkov Piret Arukuusk Dana-Maria Copolovici Staffan Lindberg Helerin Margus Kärt Padari Margus Pooga Ülo Langel 《International journal of peptide research and therapeutics》2011,17(2):147-157
Oligonucleotide-based gene regulation has a high potential in gene therapy, but the plasma membrane is impermeable for nucleic
acid polymers and, consequently, an efficient and non-toxic transfection agent is needed for their delivery into the cell.
In this study we present a novel series, NickFects, of chemically modified TP10 peptide-based delivery vectors used for the
cellular delivery of single-stranded oligonucleotides. These carriers, obtained by replacement of Ile8 by threonine in stearyl-TP10
and by modifying of tyrosine and/or threonine, respectively, by phosphorylation formed 300–500 nm in size peptide:oligonucleotide
nanocomplexes with negative surface charges. The highest splice-correcting effect was obtained when phosphorotiate 2′-O-methyl
oligonucleotides were transduced into cells by NickFect1 (NF1) or NickFect2 (NF2). In addition, we also show how a small modification
(one or two negative charges) in peptide sequence can affect its ability to deliver ONs into cells and increase their potency
in the splicing redirection assay. Our studies demonstrate that NF1 and NF2 have higher transfection efficacy for oligonucleotides
as compared to the most commonly used transfection agent Lipofectamine™ 2000 and lead to higher biological response in cells. 相似文献
875.
Humoral and cellular immune reactions against tumor cells in patients with urinary bladder carcinoma 总被引:1,自引:0,他引:1
Hansson Yngve Paulie Staffan Larsson Åke Lundblad Marie-Louise Perlmann Peter Näslund Ingemar 《Cancer immunology, immunotherapy : CII》1983,16(1):23-29
Serum IgG fractions from a large and homogeneous group of patients with transitional cell carcinoma of the urinary bladder (TCC) were tested for their capacity to induce antibody-dependent cellular cytotoxicity (ADCC) with lymphocytes from healthy donors against a TCC-derived target cell and one derived from adenocarcinoma of the colon. Both targets have previously been shown to be of comparable susceptibility to cell-mediated lysis in vitro. Some of the IgG preparations showed strong and dose-dependent ADCC against either one or both targets, while others gave weak reactions or none at all. Similar results were obtained with IgG from a matched group of patients with prostatic carcinoma who were used as clinical controls (CC). In parallel experiments, lymphocytes taken from the two donor groups at the same time as the serum samples were tested for their direct cytotoxicity (CMC) against the two targets. CMC gave similar results to ADCC. The differences in cytotoxicity displayed by either IgG or lymphocytes from individual donors were analysed statistically, using nonparametric statistics. To avoid introducing bias due to arbitrary data selection, the entire set of results, comprising both high and low reactors, was included in the statistical assessment. ADCC of the TCC donors' IgG against the TCC target was significantly stronger than against the colon carcinoma and also significantly stronger than that of the control donors. Similarly, the TCC patients' lymphocytes displayed a significantly higher CMC against the TCC target than against the control targets. This was not seen when the lymphocytes from the patients with prostatic carcinoma were tested. When CMC and ADCC of individual donors were compared, a statistically significant correlation between these activities was seen in three of the four donor/target combinations. These results support earlier findings and suggest that a significant fraction of both the disease-related and the 'non-selective' CMC (NK) displayed by cancer patients lymphocytes against allogeneic tumor cells in vitro reflects antibody-dependent reactions. 相似文献
876.
Hofgaard Annika Ols Clémentine Drobyshev Igor Kirchhefer Andreas J. Sandberg Staffan Söderström Lars 《Ecosystems》2019,22(2):434-451
Ecosystems - Climate change modulates cold-marginal forest ecosystems through changing growth constraints. Understanding spatiotemporal variations in climate–growth relationships is essential... 相似文献
877.
Dan Hauzenberger Nancy Martin Staffan Johansson Karl-Gösta Sundqvist 《Experimental cell research》1996,222(2):312
In vitrocultured “activated” peripheral blood lymphocytes and T-cell lines synthesized a high-molecular-weight gelatin binding molecule (MW 500 kDa), whereas resting lymphocytes showed poor or negligible synthesis of the same component. Concanavalin A-mediated anchorage of the lymphocytes to a substratum potentiated synthesis of the high-molecular-weight molecule. Western blotting of the gelatin-binding lymphocyte molecule demonstrated reactivity with antibodies specific for human fibronectin. Furthermore, immunocytochemistry showed reactivity of anti-fibronectin antibodies with T-lymphocytes at the single-cell level. The lymphocyte-derived fibronectin was preferentially cell associated and relatively small amounts were present in the culture medium. RT-PCR of total RNA from CD4+T-cells and the lymphoid T-cell line MOLT-4 showed that the most abundant species of fibronectin mRNA lacked the entire III CS exon encoding the α4β1binding region LDV. Amplification of the III CS region from other T-cell lines revealed that these cells expressed several fibronectin mRNA isoforms most of which were lacking the LDV coding sequence. In conclusion, synthesis of fibronectin is demonstrated to occur in T-lymphocytes and to be regulated by signals which activate the cells. 相似文献
878.
W R Bensch T S Ingebritsen E R Diller 《Biochemical and biophysical research communications》1978,82(1):247-254
The phospholipase-2 inhibitor, p-bromophenacyl bromide, has been shown to inhibit strongly the elongation of endogenous fatty acids in preparations of brain mitochondria and microsomes. On the other hand, it does not inhibit the elongation of added palmitic or linoleic acids. The implication is that the normal first step in alteration of membrane lipid fatty acids is their release to other membrane-bound enzyme systems by a membrane-bound phospholipase A. 相似文献
879.
Factors controlling the in vitro growth pattern of human microvascular endothelial cells 总被引:6,自引:0,他引:6
Monolayer cultures of endothelial cells of human dermal microvascular origin were exposed to a variety of culture conditions and in vitro differentiation of the cells assessed by light and electron microscopic examination. Restoration of a cytologic and fine structural appearance which resembled most closely that present in vivo was possible by raising the intracellular cAMP level. These cells formed junctional complexes seen in uncontracted microvessels and specialized attachment sites at their basal cell membrane, contained a complex network of bundled micro- and intermediate filaments and numerous Weibel-Palade bodies and accumulated electron-opaque deposits between the cells and the culture dish surface. 相似文献
880.
Saeed Ghafghazi Taraneh Sowlati Shahab Sokhansanj Xiaotao Bi Staffan Melin 《The International Journal of Life Cycle Assessment》2011,16(3):212-223