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61.
Dev Karan Neena Dahiya Ashok K. Munjal Patricia Gibert Brigitte Moreteau Ravi Parkash Jean R. David 《Evolution; international journal of organic evolution》1998,52(3):825-831
Desiccation and starvation tolerance were measured along latitudinal transects in three Drosophilid species (Drosophila ananassae, D. melanogaster, and Zaprionus indianus) of the Indian subcontinent. In each case, significant latitudinal clines were observed; desiccation tolerance increased with latitude while starvation tolerance decreased. Such field observations suggest that desiccation and starvation tolerance are fitness related traits that are independently selected in nature and genetically independent. It was, however, difficult to relate these genetic changes with precise climatic variables, except winter temperature. The overall negative correlation between the two traits, which was evidenced in natural populations, contrasts with a positive correlation generally observed in various laboratory selection experiments and that also seems to exist between different species. These observations point to the difficulty of interpreting correlations among fitness-related traits when different evolutionary levels are compared, and also different sets of data, that is, field versus laboratory studies. 相似文献
62.
We examined the effects of the conversion of tropical forest to pasture on soil organic matter (SOM) origin and quality along
a chronosequence of sites, including a primary forest and six pastures. Bulk soil samples received a physical size-fractionation
treatment to assess the contribution of each compartment to total SOM pool. Besides a general increase in total C and N stocks
along the chronosequence, we observed a reduction of the relative contribution of the coarser fractions to total soil C content,
and an increased concentration in the finer fractions. The origin of the C in each size fraction was established from measurements
of13C abundance. After 80 years about 93% of the C in the least humified fraction of the top 10 cm of soil was of pasture origin,
while in the most humified it was 82%. Chemical analyses indicated that the fine silt and coarse clay fractions contained
the most refractory carbon. 相似文献
63.
An up-date of Verster's (1969) `Taxonomic revision of the genus Taenia Linnaeus' (Cestoda) in table format 总被引:3,自引:0,他引:3
Loos-Frank B 《Systematic parasitology》2000,45(3):155-184
The paper `A taxonomic revision of the genus Taenia Linnaeus, 1758 s. str.' (Verster, 1969) gives concise characterisations, together with drawings of rostellar hooks and the terminal genital organs, of the 32 Taenia species and three subspecies which this author found to be valid. Yet, it is hardly possible to quickly identify a questionable species or to readily access information on their hosts, geographical range and synonyms. The present paper compiles these data and additional information on larval characteristics into tables. Measurements and numbers of hooks are shown using a graph. Additional data are included from authors not mentioned by Verster and for seven new species (T. dinniki, T. jaipurensis, T. kotlani, T. madoquae, T. saigoni and T. simbae), two re-validated species (T. krepkogorski, T. retracta) and two subspecies (T. polyacantha arctica and T. saginata asiatica) described since 1969. Reasons for rejecting one new species and one new subspecies are given. A table of definitive hosts and the Taenia species occurring in them is also included, as is one of synonyms from 1850 onwards. A good procedure for the staining and mounting of cestodes is described. 相似文献
64.
Duc M. Vu Albert Tai Jeffrey B. Tatro Richard H. Karas Brigitte T. Huber Debbie Beasley 《PloS one》2014,9(10)
Unique innate immunity-linked γδT cells have been seen in early human artery lesions, but their role in lesion development has received little attention. Here we investigated whether γδT cells modulate atherogenesis in apolipoprotein E-deficient (ApoE KO) mice. We found that γδT cell numbers were markedly increased in the proximal aorta of ApoE-deficient vs. wild-type mice during early atherogenesis, particularly in the aortic root and arch, where they comprised most of the T cells and lesion progression is most rapid. γδT cells infiltrated intimal lesions in ApoE KO mice, but only the adventitia in wild-type mice, and were more prevalent than CD4+ T cells in early nascent lesions, as evaluated by en face confocal microscopy. These aortic γδT cells produced IL-17, but not IFN-γ, analyzed by ex vivo FACS. Furthermore, aortic arch lipid accumulation correlated strongly with abundance of IL-17-expressing splenic γδT cells in individual ApoE KO mice. To investigate the role of these γδT cells in early atherogenesis, we analyzed ApoE/γδT double knockout (DKO) compared to ApoE KO mice. We observed reduced early intimal lipid accumulation at sites of nascent lesion formation, both in chow-fed (by 40%) and Western diet-fed (by 44%) ApoE/γδT DKO mice. In addition, circulating neutrophils were drastically reduced in these DKO mice on Western diet, while expansion of inflammatory monocytes and splenic Th1 or Th17 lymphocytes was not affected. These data reveal, for the first time, a pathogenic role of γδT cells in early atherogenesis in ApoE KO mice, by mechanisms likely to involve their IL-17 production and induction of neutrophilia. Targeting γδT cells thus might offer therapeutic benefit in atherosclerosis or other inflammatory vascular diseases. 相似文献
65.
Held B Tsvilovskyy V Meissner M Kaestner L Ludwig A Mossmang S Lipp P Freichel M Flockerzi V 《Cell calcium》2007,42(4-5):477-487
Voltage activated L-type Ca(2+) channels are the principal Ca(2+) channels in intestinal smooth muscle cells. They comprise the ion conducting Ca(V)1 pore and the ancillary subunits alpha(2)delta and beta. Of the four Ca(V)beta subunits Ca(V)beta(3) is assumed to be the relevant Ca(V)beta protein in smooth muscle. In protein lysates isolated from mouse ileum longitudinal smooth muscle we could identify the Ca(V)1.2, Ca(V)alpha(2), Ca(V)beta(2) and Ca(V)beta(3) proteins, but not the Ca(V)beta(1) and Ca(V)beta(4) proteins. Protein levels of Ca(V)1.2, Ca(V)alpha(2) and Ca(V)beta(2) are not altered in ileum smooth muscle obtained from Ca(V)beta(3)-deficient mice indicating that there is no compensatory increase of the expression of these channel proteins. Neither the Ca(V)beta(2) nor the other Ca(V)beta proteins appear to substitute for the lacking Ca(V)beta(3). L-type Ca(2+) channel properties including current density, inactivation kinetics as well as Cd(2+)- and dihydropyridine sensitivity were identical in cells of both genotypes suggesting that they do not require the presence of a Ca(V)beta(3) protein. However, a key hallmark of the Ca(V)beta modulation of Ca(2+) current, the hyperpolarisation of channel activation is slightly but significantly reduced by 4 mV. In addition to L-type Ca(2+) currents T-type Ca(2+) currents could be recorded in the murine ileum smooth muscle cells, but T-type currents were not affected by the lack of Ca(V)beta(3). Both proteins, Ca(V)beta(2) and Ca(V)beta(3) are localized near the plasma membrane and the localization of Ca(V)beta(2) is not altered in Ca(V)beta(3) deficient cells. Spontaneous contractions and potassium and carbachol induced contractions are not significantly different between ileum longitudinal smooth muscle strips from mice of both genotypes. In summary the data show that in ileum smooth muscle cells, Ca(V)beta(3) has only subtle effects on L-type Ca(2+) currents, appears not to be required for spontaneous and potassium induced contraction but might have a function beyond being a Ca(2+) channel subunit. 相似文献
66.
Păunescu V Deak E Herman D Siska IR Tănasie G Bunu C Anghel S Tatu CA Oprea TI Henschler R Rüster B Bistrian R Seifried E 《Journal of cellular and molecular medicine》2007,11(3):502-508
Our study examined whether human bone marrow-derived MSCs are able to differentiate, in vitro, into functional epithelial-like cells. MSCs were isolated from the sternum of 8 patients with different hematological disorders. The surface phenotype of these cells was characterized.To induce epithelial differentiation, MSCs were cultured using Epidermal Growth Factor, Keratinocyte Growth Factor, Hepatocyte Growth Factor and Insulin-like growth Factor-II. Differentiated cells were further characterized both morphologically and functionally by their capacity to express markers with specificity for epithelial lineage. The expression of cytokeratin 19 was assessed by immunocytochemistry, and cytokeratin 18 was evaluated by quantitative RT-PCR (Taq-man). The data demonstrate that human MSCs isolated from human bone marrow can differentiate into epithelial-like cells and may thus serve as a cell source for tissue engineering and cell therapy of epithelial tissue. 相似文献
67.
Gubbins MJ Berry JD Corbett CR Mogridge J Yuan XY Schmidt L Nicolas B Kabani A Tsang RS 《FEMS immunology and medical microbiology》2006,47(3):436-443
Antibodies against the protective antigen (PA) of Bacillus anthracis play a key role in response to infection by this important pathogen. The aim of this study was to produce and characterize monoclonal antibodies (mAbs) specific for PA and to identify novel neutralizing epitopes. Three murine mAbs with high specificity and nanomolar affinity for B. anthracis recombinant protective antigen (rPA) were produced and characterized. Western immunoblot analysis, coupled with epitope mapping using overlapping synthetic peptides, revealed that these mAbs recognize a linear epitope within domain 2 of rPA. Neutralization assays demonstrate that these mAbs effectively neutralize lethal toxin in vitro. 相似文献
68.
69.
Thanos Tsaktanis Heidi Kremling Miha Pav?i? Ricarda von Stackelberg Brigitte Mack Akio Fukumori Harald Steiner Franziska Vielmuth Volker Spindler Zhe Huang Jasmine Jakubowski Nikolas H. Stoecklein Elke Luxenburger Kirsten Lauber Brigita Lenar?i? Olivier Gires 《The Journal of biological chemistry》2016,291(1):425
70.
Fiori LM Wanner B Jomphe V Croteau J Vitaro F Tremblay RE Bureau A Turecki G 《PloS one》2010,5(11):e15146