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1.
Human cytomegalovirus (HCMV) induces morphological changes in infected cells that are remarkably similar to those seen in oncogenically transformed cells. The molecular bases of these phenotypic alterations are not known but their occurrence in some transformed cells can be associated with abnormal fibronectin (FN) expression. In this report, we have compared FN levels in normal and HCMV-infected cells. In these studies, the HCMV-infected fibroblasts exhibited a progressive loss of cellular FN. Northern (RNA) blot analysis revealed that the decrease in FN levels resulted from a lowering of FN mRNA levels in HCMV-infected cells. We detected an initial decrease in FN mRNA of 25 to 30% at immediate-early and early times, whereas at late times after infection the levels of FN mRNA were lowered by greater than 80%. These results indicated that the HCMV-induced decrease in FN expression is due to a decrease in the quantity of FN mRNA and suggested that HCMV-encoded and/or -induced functions may be involved in producing these alterations.  相似文献   
2.
The peptide galanin (GAL), when injected into the rat hypothalamus, is known to stimulate feeding behavior and affect the secretion of various hormones, including insulin and the adrenal steroid, corticosterone. To determine whether endogenous peptide levels shift in relation to natural rhythms of feeding and circulating hormone levels, rats were sacrificed at different times of the light/dark cycle, and their GAL levels were measured, via radioimmunoassay, in medial hypothalamic dissections and micropunched hypothalamic areas. The results suggest the existence of two distinct diurnal rhythms for hypothalamic GAL. One rhythm, detected exclusively in the area of the SCN, is characterized by bimodal peaks of GAL, threefold higher than basal peptide levels, around the onset of the dark and light periods. The second rhythm shows a single peak of GAL towards the middle of the nocturnal feeding cycle, specifically between the third and sixth hour. This latter rhythm is evident in the dorsal region of the medial hypothalamus, localized specifically to the lateral portion of the PVN. Moreover, it is inversely related to circulating insulin but unrelated to the adrenal steroids, suggesting a possible association between this pancreatic hormone and GAL in the PVN.  相似文献   
3.
This is the first record of seed transmission of turnip yellow mosaic virus (TYMV) in oilseed and turnip rapes. The seed transmission of TYMV in a naturally infected winter turnip rape (Brassica napus var. silvestris) cultivar Perko PVH was investigated. By ELISA 1.6%, 3.2% and 8.3% seed transmission of the virus was found in seed of plants from three localities. The proportion of infected seeds produced by artificially infected plants of winter oilseed rape (Brassica napus ssp. oleifera) and winter turnip rape cultivars was determined. The virus transmission rate, expressed as the proportion of virus-infected plants which germinated from the seed was for the oilseed rape cvs Jet Neuf 0.1%, Solida 0.4%, Silesia 0.8%, Darmor 1.2%, SL-507 0.2%, SL-509 0.0% and for the winter turnip rape cv. Perko 1.5%. ELISA cannot be used in direct tests on bulk seed lots to estimate proportion of infected seed, but must be used on germinated seedlings.  相似文献   
4.
Massanori Takaki  V. M. Zaia 《Planta》1984,160(2):190-192
A short period (15–30 min) at 30° C promotes germination of seeds of Lactuca sativa L. cv. Repolhuda in darkness. Far-red light reverses this stimulation, and the escape curves for phytochrome and high-temperature action are quite similar, indicating that the two factors act at a common point in the chain of events leading to germination. It is suggested that high temperature acts by decreasing the threshold of the active, far-red absorbing, form of phytochrome (Pfr) needed to promote germination.Abbreviations FR far-red light - Pfr far-red-absorbing form of phytochrome - R red light  相似文献   
5.
Supraorbital bones in Saurolophus angustirostris are described, and their presence in all hadrosaurs is suggested. Frontal-nasal and premaxillar-nasal fontanellae are distinguished in hadrosaurs; their presence is explained as connected with growth and considered to he responsible for the variability of crest structures. New data indicating the presence of a cartilaginous diverticulum nasi within the circumnarial depression in Saurobphus ongustirostris are presented. A physiological (respiratory and/or thermoregulatory) function of the nasal diverticulum is proposed.  相似文献   
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Heparan sulfate (HS) represents a large class of linear polysaccharides that are required for the function of all mammalian physiological systems. HS is characterized by a repeating disaccharide backbone that is subject to a wide range of modifications, making this class of macromolecules arguably the most information dense in all of biology. The majority of HS functions are associated with the ability to bind and regulate a wide range of proteins. Indeed, recent years have seen an explosion in the discovery of new activities for HS where it is now recognized that this class of glycans functions as co-receptors for growth factors and cytokines, modulates cellular uptake of lipoproteins, regulates protease activity, is critical to amyloid plaque formation, is used by opportunistic pathogens to enter cells, and may even participate in epigenetic regulation. This review will discuss the current state of understanding regarding the specificity of HS-protein binding and will describe the concept that protein binding to HS depends on the overall organization of domains within HS rather than fine structure.  相似文献   
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The paper presents multiplex panels of polymorphic microsatellites for two closely related cryptic species Pipistrellus pipistrellus and Pipistrellus pygmaeus. We tested the cross‐species amplification of 34 microsatellite loci, originally developed for five vespertilionid bat species. Ten and nine polymorphic loci in P. pipistrellus (mean number of alleles per locus = 10.5) and P. pygmaeus (8.1), respectively, in three multiplex polymerase chain reactions per species were amplified. All loci can be analysed in a single fragment analysis and can be used as markers to the study of evolution and the ecology of structured populations of socially living bats.  相似文献   
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