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461.
462.
Pirkka V. Kirjavainen Hani S. El-Nezami Seppo J. Salminen Jorma T. Ahokas Paul F.A. Wright 《FEMS immunology and medical microbiology》1999,26(2):131-135
Four common Lactobacillus strains were screened for their effects on proliferation of mouse splenic lymphocytes. Mice received perorally 10(9) viable bacteria kg(-1) body weight for 7 days. Lactobacillus acidophilus treatment enhanced ex vivo basal proliferation (by 43%) and B-cell response at suboptimal and optimal concentrations of lipopolysaccharide (LPS) (by 27-28%). Conversely, Lactobacillus casei, Lactobacillus gasseri and Lactobacillus rhamnosus inhibited both basal proliferation (by 14-51%) and mitogen-stimulated lymphoproliferation, particularly at supra-optimal concentrations of concanavalin A (by 43-68%) and LPS (by 23-62%). Therefore, these Lactobacillus strains demonstrate strain-specific effects on B- and T-cells and may also alter the splenocyte sensitivity to the cytotoxic effects of mitogens. 相似文献
463.
Deane F. Mosher Olli Saksela Jorma Keski-Oja Antti Vaheri 《Journal of cellular biochemistry》1977,6(4):551-557
Fibronectin was present in media and cell layers of cultures of adherent cells from human skin, kidney, lung, chest wall, liver, and heart. Cell-surface fibronectin, visualized by immunofluorescence, was in dense fibrillar (cultures from lung), discrete fibrillar (e.g., cultures from skin), or punctate (some cultures from kidney) structures. The subunit sizes of cell-surface fibronectin and fibronectin soluble in medium appeared identical in sodium dodecyl sulfate-polyacrylamide gels. To explain the polymorphism of cell-surface fibronectin, there must be chemical differences among the fibronectins synthesized by different cell strains or factors in the cell layer which influence fibronectin binding and aggregation. 相似文献
464.
465.
In order to provide guidelines for conservationand management of the severely declining LakeSaimaa (eastern Finland) European grayling(Thymallus thymallus, Salmonidae), weinvestigated the microgeographic geneticstructure of three populations from the watersystem using 17 microsatellite loci andmitochondrial DNA polymerase chainreaction-restriction fragment lengthpolymorphism analysis. Microsatellites revealedlow levels of intrapopulation genetic diversityand substantial divergence between populationssampled from spawning sites separated by aslittle as 55 kilometers. Mitochondrial analysisindicated the occurrence of two compositehaplotypes within Lake Saimaa. The nucleotidesubstitution estimates between the haplotypessuggested their separation to markedly predatethe late Pleistocene period. The populationsexhibited marked frequency differences for thetwo mitochondrial haplotypes, reinforcing theview of limited interpopulation gene flowwithin Lake Saimaa. An individual basedmicrosatellite Neighbor-Joining dendrogramdemonstrated clustering of all the specimensaccording to their sampling origin. Individualassignment tests revealed 100% assignmentsuccess of individuals into their population oforigin and 100% exclusion (p <0.05) from all alternative referencepopulations. These findings exemplify that T. thymallus populations may be genetically highly structured over small geographical scales and provide a good starting point for the development of appropriate conservation strategies for Lake Saimaa grayling. 相似文献
466.
Benthic processes were measured at a coastal deposition area in the northern Baltic Sea, covering all seasons. The N2 production rates, 90–400 μmol N m−2 d−1, were highest in autumn-early winter and lowest in spring. Heterotrophic bacterial production peaked unexpectedly late in
the year, indicating that in addition to the temperature, the availability of carbon compounds suitable for the heterotrophic
bacteria also plays a major role in regulating the denitrification rate. Anaerobic ammonium oxidation (anammox) was measured
in spring and autumn and contributed 10% and 15%, respectively, to the total N2 production. The low percentage did, however, result in a significant error in the total N2 production rate estimate, calculated using the isotope pairing technique. Anammox must be taken into account in the Gulf
of Finland in future sediment nitrogen cycling research.
Handling editor: J. Cole 相似文献
467.
A simplified technique to trap respired carbon dioxide in a closed bottle system was developed from the technique introduced by Hobbie & Crawford in 1969. In this technique carbon dioxide was trapped in ethanolamine in a glass cup without the use of chromatographic paper. The results show that there is no need to enlarge the absorption surface with filter paper as practically complete recovery was achieved with ethanolamine alone in the cup. 相似文献
468.
Intramuscular pressure and muscle blood flow in supraspinatus 总被引:2,自引:0,他引:2
Ulf J?rvholm Jorma Styf Madis Suurkula Peter Herberts 《European journal of applied physiology and occupational physiology》1988,58(3):219-224
Intramuscular pressure and muscle blood flow was measured in the supraspinatus muscle in 6 healthy subjects. The recordings were performed at rest, during isometric exercise, during an isometric muscle contraction of 5.6 kPa (42 mm Hg) and 10.4 kPa (78 mm Hg) and at rest after the contraction. Intramuscular pressure was measured by the microcapillary infusion technique, and muscle blood flow by the Xenon-133 washout technique. Intramuscular pressure was 38.2 kPa (SD 12.0) (287 mm Hg) during maximal voluntary contraction. A muscle contraction pressure of 5.6 kPa (42 mm Hg), which is 16% of maximal voluntary contraction, reduces local muscle blood flow significantly. It is concluded that the high intramuscular pressures found in supraspinatus during work with the arms elevated impedes local muscle blood flow. 相似文献
469.
Green-tree retention is a relatively new forestry application, which aims at decreasing the negative effects of clear-cut
logging on forest biodiversity. In this study, the value of retained aspens in maintaining diverse assemblages of wood-decaying
fungi (polypores; Basidiomycota) on clear-cuts was investigated, after the retention trees had died, fallen and started to
decay. A total of 110 fallen aspen trunks were investigated on clear-cuts and within old-growth forests in eastern Finland,
southern boreal zone; and 499 records of polypores belonging to 46 species were made. The intermediately decayed trunks on
a clear-cut area hosted more species and more red-listed species than did trunks within forests. Most of the polypore species
with more than two records were found in both habitats. These results suggest that many aspen-associated polypores are able
to live and reproduce in sun-exposed habitats, if the quality and quantity of dead wood fulfill the species-specific requirements.
This unexpected result, however, may be partly due to the exceptionally great abundance of aspen in the study area. Furthermore,
in the long term, the local benefits of fallen retention trees can be limited, unless the local continuity of large aspens,
both living and dead, is ensured. 相似文献