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11.
12.
Jacek?Siciński Krzysztof?PabisEmail author Krzysztof?Ja?d?ewski Alicja?Konopacka Magdalena?B?a?ewicz-Paszkowycz 《Polar Biology》2012,35(3):355-367
There are only few studies on shallow Antarctic benthic communities associated with habitats affected by intense mineral sedimentation
inflow. The analysis of macrofaunal communities associated with two shallow, isolated glacial coves was performed in Admiralty
Bay (King George Island) and compared with non-disturbed sites. Multivariate analyses (hierarchical classification, nMDS)
clearly separated glacial cove communities (two assemblages) from the sites situated outside both basins (two assemblages).
The community influenced by the streamflow of glacial discharge of meltwater situated in the area with sandy–clay–silt sediments
had a very low species richness, diversity and abundance. It was dominated by eurytopic, motile deposit feeding polychaetes
such as Mesospio
moorei, Tharyx
cincinnatus and Leitoscoloplos
kerguelensis as well as the bivalve Yoldia
eightsi. The second glacial community of the area located at a grater distance from the outlet of the stream was characterized by
sandy–clay–silt and clay–silt deposits and showed also a low diversity and species richness. The most abundant here were peracarid
crustaceans, with the dominant opportunistic feeder Cheirimedon
femoratus. Community from the non-disturbed area with silty–clay–sand, and silty–sand sediments had higher species richness and diversity.
The assemblage of fauna from the sandy bottom has values of those two indexes similar to those found in the disturbed areas. 相似文献
13.
Kowalewicz-Kulbat M Kaźmierczak D Donevski S Biet F Pestel J Rudnicka W 《Folia histochemica et cytobiologica / Polish Academy of Sciences, Polish Histochemical and Cytochemical Society》2008,46(2):153-157
Mycobacterium bovis bacillus Calmette-Guérin (BCG) is a live vaccine that has been used in routine vaccination against tuberculosis for nearly 80 years. However, its efficacy is controversial. The failure of BCG vaccination may be at least partially explained by the induction of poor or inappropriate host responses. Dendritic cells (DCs) are likely to play a key role in the induction of immune response to mycobacteria by polarizing the reactivity of T lymphocytes toward a Th1 profile, contributing to the generation of protective cellular immunity against mycobacteria. In this study we aimed to investigate the production of Th1 and Th2 cytokines by naive CD4+ T cells to mycobacterial antigen-pulsed DCs in the group of young, healthy BCG vaccinated volunteers. The response of naive helper T cells was compared with the response of total blood lymphocytes. Our present results clearly showed that circulating naive CD45RA+CD4+ lymphocytes from BCG-vaccinated subjects can become effector helper cells producing IFN-gamma and IL-5 under the stimulation by autologous dendritic cells presenting mycobacterial protein antigen-PPD or infected with live M. bovis BCG bacilli. 相似文献
14.
Our study focused on the relationship between amyloid β 1–42 (Aβ), sphingosine kinases (SphKs) and mitochondrial sirtuins in regulating cell fate. SphK1 is a key enzyme involved in maintaining sphingolipid rheostat in the brain. Deregulation of the sphingolipid metabolism may play a crucial role in the pathogenesis of Alzheimer’s disease (AD). Mitochondrial function and mitochondrial deacetylases, i.e. sirtuins (Sirt3,-4,-5), are also important for cell viability. In this study, we evaluated the interaction between Aβ1–42, SphKs and Sirts in cell survival/death, and we examined several compounds to indicate possible target(s) for a strategy protecting against cytotoxicity of Aβ1–42. PC12 cells were subjected to Aβ1–42 oligomers and SphK inhibitor SKI II for 24–96 h. Our data indicated that Aβ1–42 enhanced SphK1 expression and activity after 24 h, but down-regulated them after 96 h and had no effect on Sphk2. Aβ1–42 and SKI II induced free radical formation, disturbed the balance between pro- and anti-apoptotic proteins and evoked cell death. Simultaneously, up-regulation of anti-oxidative enzymes catalase and superoxide dismutase 2 was observed. Moreover, the total protein level of glycogen synthase kinase-3β was decreased. Aβ1–42 significantly increased the level of mitochondrial proteins: apoptosis-inducing factor AIF and Sirt3, -4, -5. By using several pharmacologically active compounds we showed that p53 protein plays a significant role at very early stages of Aβ1–42 toxicity. However, during prolonged exposure to Aβ1–42, the activation of caspases, MEK/ERK, and alterations in mitochondrial permeability transition pores were additional factors leading to cell death. Moreover, SphK product, sphingosine-1-phosphate (S1P), and Sirt activators and antioxidants, resveratrol and quercetin, significantly enhanced viability of cells subjected to Aβ1–42. Our data indicated that p53 protein and inhibition of SphKs may be early key events responsible for cell death evoked by Aβ1–42. We suggest that activation of S1P-dependent signalling and Sirts may offer a promising cytoprotective strategy. 相似文献
15.
Magdalena A. Gutowska F. Melzner M. Langenbuch C. Bock G. Claireaux H. O. Pörtner 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2010,180(3):323-335
Acidification of ocean surface waters by anthropogenic carbon dioxide (CO2) emissions is a currently developing scenario that warrants a broadening of research foci in the study of acid–base physiology.
Recent studies working with environmentally relevant CO2 levels, indicate that some echinoderms and molluscs reduce metabolic rates, soft tissue growth and calcification during hypercapnic
exposure. In contrast to all prior invertebrate species studied so far, growth trials with the cuttlefish Sepia officinalis found no indication of reduced growth or calcification performance during long-term exposure to 0.6 kPa CO2. It is hypothesized that the differing sensitivities to elevated seawater pCO2 could be explained by taxa specific differences in acid–base regulatory capacity. In this study, we examined the acid–base
regulatory ability of S. officinalis in vivo, using a specially modified cannulation technique as well as 31P NMR spectroscopy. During acute exposure to 0.6 kPa CO2, S. officinalis rapidly increased its blood [HCO3
−] to 10.4 mM through active ion-transport processes, and partially compensated the hypercapnia induced respiratory acidosis.
A minor decrease in intracellular pH (pHi) and stable intracellular phosphagen levels indicated efficient pHi regulation. We conclude that S. officinalis is not only an efficient acid–base regulator, but is also able to do so without disturbing metabolic equilibria in characteristic
tissues or compromising aerobic capacities. The cuttlefish did not exhibit acute intolerance to hypercapnia that has been
hypothesized for more active cephalopod species (squid). Even though blood pH (pHe) remained 0.18 pH units below control values,
arterial O2 saturation was not compromised in S. officinalis because of the comparatively lower pH sensitivity of oxygen binding to its blood pigment. This raises questions concerning
the potentially broad range of sensitivity to changes in acid–base status amongst invertebrates, as well as to the underlying
mechanistic origins. Further studies are needed to better characterize the connection between acid–base status and animal
fitness in various marine species. 相似文献
16.
17.
Magdalena Semla Pavol Schwarcz Ján Mezey Łukasz J. Binkowski Martyna Błaszczyk Grzegorz Formicki Agnieszka Greń Robert Stawarz Peter Massanyi 《Biological trace element research》2018,184(1):33-41
Wine consumption delivers macroelements and microelements necessary for the proper metabolism. On the other hand, wine can be an important source of toxic metals. The aim of this study was to estimate the concentrations of Ca, Cd, Cu, Fe, Hg, Mg, Ni, Pb, and Zn in the Slovak and non-Slovak wines. The concentration of metals was evaluated with respect to the type, the alcohol content, and the age of Slovak wine. The general scheme of concentrations found was as follows Ca > Mg > Fe > Zn > Pb > Cd > Ni > Cu > Hg. The type of wine and the alcohol content do not have a significant impact on metal concentrations. Also, the age of wine has no influence on the mean concentration of metals, except for Zn. Metal concentrations in Slovak and non-Slovak wines indicate similar contents of metals, except for Ni. The contribution to both dietary reference values (DRVs) and provisional tolerable weekly intake (PTWI) evaluations in the Slovak wine suggested low dietary exposure to Ca, Cu, Fe, Mg, Ni, Zn, Cd, Hg, and Pb, respectively. However, we do not suggest that the consumption of all Slovak wines is healthy. The maximum Pb concentrations in Slovak wines exceed the maximum permitted level proposed by the European Commission. This might be proved by the results of the margin of the exposure (MOE) value evaluation in the samples containing the maximum Pb concentrations, showing a high risk of CKD and SBP in high and extreme consumption groups. 相似文献
18.
Pullmann R Juhaszova M López de Silanes I Kawai T Mazan-Mamczarz K Halushka MK Gorospe M 《The Journal of biological chemistry》2005,280(24):22819-22826
In dividing cells, the RNA-binding protein HuR associates with and stabilizes labile mRNAs encoding proliferative proteins, events that are linked to the increased cytoplasmic presence of HuR. Here, assessment of HuR levels in various vascular pathologies (intimal hyperplasia, atherosclerosis and neointimal proliferation, sclerosis of arterialized saphenous venous graft, and fibromuscular dysplasia) revealed a distinct increase in HuR expression and cytoplasmic abundance within the intima and neointima layers. On the basis of these observations, we postulated a role for HuR in promoting the proliferation of vascular smooth muscle cells. To test this hypothesis directly, we investigated the expression, subcellular localization, and proliferative influence of HuR in human vascular smooth muscle cells (hVSMCs). Treatment of hVSMCs with platelet-derived growth factor increased HuR levels in the cytoplasm, thereby influencing the expression of metabolic, proliferative, and structural genes. Importantly, knockdown of HuR expression by using RNA interference caused a reduction of hVSMC proliferation, both basally and following platelet-derived growth factor treatment. We propose that HuR contributes to regulating hVSMC growth and homeostasis in pathologies associated with vascular smooth muscle proliferation. 相似文献
19.
We identified and isolated a monoclonal antibody (MAb 3G2) raised against extracellular proteins from microcluster cells of
orchard grass (Dactylis glomerata L.) embryogenic suspension culture. MAb 3G2 recognized with high specificity an antigen ionically bound within the primary
cell wall and in the culture medium of microcluster cells. Two-dimensional polyacrylamide gel analysis and blotting of proteins
on PVDF membrane showed that MAb 3G2 detected a single polypeptide of apparent molecular mass of 48 kDa and an isoelectric
point (pI) of 5.2, designated EP48. A transient expression during somatic embryogenesis was observed for EP48. Indirect immunofluorescence
showed that this protein highly accumulated in the cell walls of some single cells, microclusters and partly in proembryogenic
masses (PEMs), but not in globular embryos of the embryogenic cell line and microclusters from the non-embryogenic cell line.
Signal intensity varied between individual cells of the same population and in successive stages of somatic embryo development.
Screening of several D. glomerata L. embryogenic and non-embryogenic cell lines with MAb 3G2 indicated the presence of ECP48 in only embryogenic suspension
cultures at early stages of embryo development long before morphological changes have taken place and thus it could serve
as an early marker for embryogenic potential in D. glomerata L. suspension cultures. 相似文献
20.
Plant invasion is a major threat to the integrity of an ecosystem. Exceptionally successful invaders in Europe are the American species of Solidago genus. In this study we examined growth, reproduction, and phenology of Solidago species, of American origin, growing in central Europe (S. altissima, S. canadensis, S. gigantea, S. graminifolia). These taxa were compared with two native species: Solidago virgaurea and Tanacetum vulgare. We observed high differentiation in height, number of shoots, and biomass production between individuals within taxa. Generally, the invasive species produced substantially (two to five times) more biomass than the native ones, being statistically significant in the comparison of alien Solidago graminifolia and S. gigantea versus native S. virgaurea and T. vulgare. The ratio of biomass of reproductive parts to overall biomass varied considerably among years, but generally the lowest one was for Solidago altissima, and the highest for S. graminifolia. It shows a lack of a clear pattern of differentiation between alien and native species in terms of biomass investment in reproduction. We observed a general tendency of allocation of a major part of biomass in rhizomes by phalanx species (S. graminifolia and S. gigantea), while species with guerrilla strategy (S. altissima and S. canadensis) invested more biomass in stems and leaves. However, because of the high variability there was no clear, stable pattern of statistically significant differences between these two groups. The results suggest that S. graminifolia reveals a strong potential of invasion, in spite of its, so far limited, distribution in Europe. 相似文献