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51.
CP/MAS 13C NMR spectroscopy was used in combination with spectral fitting to examine the surface structure of hydrated cellulose I fibrils from Halocynthia and Gluconoacetobacter xylinus. To increase the spectral intensities and minimize signal overlap, G. xylinus celluloses site-specifically enriched in 13C either on C4 or on both C1 and C6 were examined. The experimental data showed multiple C4 and C6 signals for the water accessible fibril surfaces in the highly crystalline celluloses. These signal multiplicities were attributed to structural features in the surface layers induced by the fibril interior, and could not be extracted by spectral fitting in celluloses with a lower degree of crystallinity such as cellulose from cotton. 相似文献
52.
Borge BA Iversen VV Reed RK 《American journal of physiology. Heart and circulatory physiology》2006,290(5):H2108-H2115
Docetaxel and prostaglandin E1 (PGE1) increase transcapillary albumin extravasation and reduce interstitial fluid pressure in the skin. In this study the microdialysate concentration (Cm) of 125I-labeled human serum albumin (125I-HSA) and different-sized endogenous plasma proteins (EPP) was compared to evaluate changes in transcapillary extravasation of plasma proteins. 125I-HSA was also used to estimate changes in the specific activity of albumin. Extravasation of 125I-HSA and EPP from plasma to interstitium in the rat skin was compared during continuous administration of docetaxel and PGE1 by using microdialysis in anesthetized rats. Also, 20 ml of Ringer solution (RS) were injected intravenously during 10 min in a separate group. Two hollow plasmapheresis fibers (3 cm, cut off 3,000 kDa), one acting as control, were placed subcutaneously on the back skin and perfused with RS (5 microl/min, 140 min, collected every 10 min). The size of the different EPP was estimated to be 73, 65, 56, 47, and 39 A, separated by a size-exclusion high-performance liquid chromatography column and quantified by UV detection (280 nm). Docetaxel (0.5 mg/ml, n = 5) increased Cm of 125I-HSA and EPP of sizes 73, 65, 56, and 39 A significantly (P < 0.05) compared with control. PGE1 (20 microg/ml, n = 6) increased Cm of 125I-HSA significantly (P < 0.05) but none of the different-sized EPP was increased compared with control. Intravenous RS (20 ml, n = 6) increased Cm of 125I-HSA and increased all the different-sized EPP significantly (P < 0.05) compared with control. Although the microdialysis method is able to monitor qualitative changes in capillary permeability, a quantitative determination of the capillary reflection coefficient or permeability-surface area product was not possible, because steady state between plasma and dialysate was not achieved during the measurement period. The different pattern of extravasation of EPP and 125I-HSA after docetaxel, PGE1, and RS indicates increased interstitial transport rate and/or increased capillary permeability after docetaxel and RS, whereas PGE1 seems to increase transcapillary fluid flux without altering the permeability. 相似文献
53.
54.
Grethe Skretting Nina Iversen Christiane F. Myklebust Anders E. Dahm Per Morten Sandset 《Molecular biology reports》2012,39(12):10089-10096
There is now circumstantial evidence that tissue factor pathway inhibitor (TFPI) is not only a major anticoagulant, but also has proapoptotic properties. The current study was designed to address the role of TFPI on signalling pathways and apoptosis. The non-TFPI expressing cell line CHO-K1 was stably transfected with pcDNA3.1/V5-His-TOPO-TFPI and control cells were established by transfecting the CHO-K1 cells with pcDNA3.1/V5-His-TOPO. Sodium butyrate (NaBut) has been shown to induce the expression of recombinant proteins. Here we have used NaBut to increase the expression of TFPI as assessed by qRT-PCR and ELISA. Compared to the control cells, TFPI induced apoptosis in a concentration dependent manner as measured by a cell death detection assay. Independent of caspase-3 activation an increased cleavage of PARP was detected in the TFPI expressing cells. This was accompanied by downregulation of Bcl-XL, elevated levels of Bax, and increased translocation of the apoptosis initiating factor. Increased DNA binding activity of NF-κB was revealed by electrophoretic mobility shift assay when the TFPI level was elevated by NaBut together with an increased translocation of the NF-κB subunit p65. The results indicate that TFPI affected the apoptotic activity through a process independent of caspase-3, and was also able to increase the activation of the NF- κB pathway. 相似文献
55.
Boon H Kostovski E Pirkmajer S Song M Lubarski I Iversen PO Hjeltnes N Widegren U Chibalin AV 《American journal of physiology. Endocrinology and metabolism》2012,302(7):E864-E871
Na(+)-K(+)-ATPase is an integral membrane protein crucial for the maintenance of ion homeostasis and skeletal muscle contractibility. Skeletal muscle Na(+)-K(+)-ATPase content displays remarkable plasticity in response to long-term increase in physiological demand, such as exercise training. However, the adaptations in Na(+)-K(+)-ATPase function in response to a suddenly decreased and/or habitually low level of physical activity, especially after a spinal cord injury (SCI), are incompletely known. We tested the hypothesis that skeletal muscle content of Na(+)-K(+)-ATPase and the associated regulatory proteins from the FXYD family is altered in SCI patients in a manner dependent on the severity of the spinal cord lesion and postinjury level of physical activity. Three different groups were studied: 1) six subjects with chronic complete cervical SCI, 2) seven subjects with acute, complete cervical SCI, and 3) six subjects with acute, incomplete cervical SCI. The individuals in groups 2 and 3 were studied at months 1, 3, and 12 postinjury, whereas individuals with chronic SCI were compared with an able-bodied control group. Chronic complete SCI was associated with a marked decrease in [(3)H]ouabain binding site concentration in skeletal muscle as well as reduced protein content of the α(1)-, α(2)-, and β(1)-subunit of the Na(+)-K(+)-ATPase. In line with this finding, expression of the Na(+)-K(+)-ATPase α(1)- and α(2)-subunits progressively decreased during the first year after complete but not after incomplete SCI. The expression of the regulatory protein phospholemman (PLM or FXYD1) was attenuated after complete, but not incomplete, cervical SCI. In contrast, FXYD5 was substantially upregulated in patients with complete SCI. In conclusion, the severity of the spinal cord lesion and the level of postinjury physical activity in patients with SCI are important factors controlling the expression of Na(+)-K(+)-ATPase and its regulatory proteins PLM and FXYD5. 相似文献
56.
I Bjurhager H Halonen EL Lindfors T Iversen G Almkvist EK Gamstedt LA Berglund 《Biomacromolecules》2012,13(8):2521-2527
In 1628, the Swedish warship Vasa capsized on her maiden voyage and sank in the Stockholm harbor. The ship was recovered in 1961 and, after polyethylene glycol (PEG) impregnation, it was displayed in the Vasa museum. Chemical investigations of the Vasa were undertaken in 2000, and extensive holocellulose degradation was reported at numerous locations in the hull. We have now studied the longitudinal tensile strength of Vasa oak as a function of distance from the surface. The PEG-content, wood density, and cellulose microfibril angle were determined. The molar mass distribution of holocellulose was determined as well as the acid and iron content. A good correlation was found between the tensile strength of the Vasa oak and the average molecular weight of the holocellulose, where the load-bearing cellulose microfibril is the critical constituent. The mean tensile strength is reduced by approximately 40%, and the most affected areas show a reduction of up to 80%. A methodology is developed where variations in density, cellulose microfibril angle, and PEG content are taken into account, so that cell wall effects can be evaluated in wood samples with different rate of impregnation and morphologies. 相似文献
57.
Hultström M Leh S Paliege A Bachmann S Skogstrand T Iversen BM 《Physiological genomics》2012,44(10):576-586
Aging is associated with progressive structural and functional deterioration of the kidney. Among the morphological changes associated with renal aging is an accumulation of extracellular matrix (ECM) in the glomeruli and tubuloinsterstitium, which may ultimately lead to the development of renal fibrosis. The mechanisms governing the regulation of ECM metabolism during renal aging are only incompletely defined. We present data from a genome-wide mRNA expression study on renal tissue from 90 wk old male Wistar rats and 10 wk old controls using Illumina BeadArray cDNA microarray. Regulation of candidate gene products was verified by real-time PCR. Morphological changes were evaluated by routine histological methods. Activated fibroblasts were identified by their expression of alpha-smooth muscle actin and collagen I. Morphological analysis demonstrated an expansion of the tubulointerstitial compartment with increased amounts of fibrous collagen but no overt glomerular or tubular damage in the aged rats. Activated fibroblasts were readily detectable in the adventitial layer of large renal vessels in controls and were not found in the old animals. In agreement with this finding, gene expression analysis revealed significant downregulation of collagen I mRNA along with numerous other ECM components. Concomitantly, collagen-stabilizing proteins were induced, whereas matrix metalloproteinase 9, an enzyme involved in collagen breakdown, was reduced. In conclusion, our results suggest that ECM expansion during renal aging results from an augmented stabilization in conjunction with a reduced breakdown of collagen fibers. Collagen stabilizing proteins may be essential for the control of renal ECM turnover and the pathogenesis of kidney fibrosis. 相似文献
58.
To evaluate the impact of mass vaccination with adjuvanted vaccines (eventually 40% population coverage) and antivirals during the 2009 influenza pandemic in Norway, we fitted an age-structured SEIR model using data on vaccinations and sales of antivirals in 2009/10 in Norway to Norwegian ILI surveillance data from 5 October 2009 to 4 January 2010. We estimate a clinical attack rate of approximately 30% (28.7-29.8%), with highest disease rates among children 0-14 years (43-44%). Vaccination started in week 43 and came too late to have a strong influence on the pandemic in Norway. Our results indicate that the countermeasures prevented approximately 11-12% of potential cases relative to an unmitigated pandemic. Vaccination was found responsible for roughly 3 in 4 of the avoided infections. An estimated 50% reduction in the clinical attack rate would have resulted from vaccination alone, had the campaign started 6 weeks earlier. Had vaccination been prioritized for children first, the intervention should have commenced approximately 5 weeks earlier in order to achieve the same 50% reduction. In comparison, we estimate that a non-adjuvanted vaccination program should have started 8 weeks earlier to lower the clinical attack rate by 50%. In conclusion, vaccination timing was a critical factor in relation to the spread of the 2009 A(H1N1) influenza. Our results also corroborate the central role of children for the transmission of A(H1N1) pandemic influenza. 相似文献
59.
60.
Ahlehoff O Skov L Gislason G Lindhardsen J Kristensen SL Iversen L Lasthein S Gniadecki R Dam TN Torp-Pedersen C Hansen PR 《PloS one》2012,7(4):e36342