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451.
Ewa Chodurek Arkadiusz Orchel Joanna Orchel S?awomir Kurkiewicz Natalia Gawlik Zofia Dzier?ewicz Krystyna St?pień 《Cellular & molecular biology letters》2012,17(4):616-632
Malignant melanoma (melanoma malignum) is one of the most dangerous types of tumor. It is very difficult to cure. In recent years, a lot of attention has been given to chemoprevention. This method uses natural and synthetic compounds to interfere with and inhibit the process of carcinogenesis. In this study, a new treatment strategy was proposed consisting of a combination of 5,7-dimethoxycoumarin (DMC), an activator of melanogenesis, and valproic acid (VPA), a well-known drug that is one of the histone deacetylase inhibitors (HDACis). In conjunction with 1 mM VPA, all of the tested concentrations of DMC (10?C150 ??M) significantly decreased the proliferation of A-375 cells. VPA and DMC also induced the synthesis of melanin and the formation of dendrite and star-shaped cells. Tyrosinase gene expression and tyrosinase activity significantly increased in response to VPA treatment. Pyrolysis with gas chromatography and mass spectrometry (Py-GC/MS) was used to investigate the structure of the isolated melanin. This showed that the quantitative and qualitative components of melanin degradation products are dependent on the type of applied melanogenesis inductor. Products derived from eumelanin were detected in the pyrolytic profile of melanin isolated from A-375 cells stimulated with DMC. Thermal degradation of melanin isolated from melanoma cells after exposure to VPA or a mixture of VPA and DMC revealed the additional presence of products derived from pheomelanin. 相似文献
452.
Felipe Figueroa Werner E. Mayer Akie Sato Zofia Zaleska-Rutczynska Beate Hess Herbert Tichy Jan Klein 《Immunogenetics》2001,53(8):695-708
Swordtail fishes and platies in the genus Xiphophorus (order Cyprinodontiformes, Teleostei) encompass 22 closely related species which are the products of a recent adaptive radiation in the streams of Central America. To investigate the evolution of the major histocompatibility complex (Mhc) genes in the period immediately following speciation, the class I genes from 20 of the 22 species were cloned and characterized by sequencing. The analysis revealed the existence of multiple loci (at least seven in some individuals) whose numbers vary among the different species and probably also among individuals of the same species. The variation does not seem to bear any relationship to the taxonomy of the genus. Genes at the different loci are distinguished by their intron sequences and by the presence of characteristic motifs in exons 2 and 3. The variation in copy number of loci may have been effected in part by unequal crossing over occurring between introns of misaligned closely related genes. The sequences of the genes fall into two groups, A and B, which represent ancient lineages. The groups define two families of loci, which diverged from each other an estimated 85 million years ago, before the separation of the Acanthopterygii from the Paracanthopterygii of the advanced bony fishes. Evolution of the genes within each family can be explained by the birth-and-death process driven by gene duplications and mutational differentiation. 相似文献
453.
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455.
Biochar physicochemical properties: pyrolysis temperature and feedstock kind effects 总被引:4,自引:0,他引:4
Tomczyk Agnieszka Sokołowska Zofia Boguta Patrycja 《Reviews in Environmental Science and Biotechnology》2020,19(1):191-215
Reviews in Environmental Science and Bio/Technology - Biochar is a pyrogenous, organic material synthesized through pyrolysis of different biomass (plant or animal waste). The potential biochar... 相似文献
456.
457.
It has been shown that germinating seeds of Calendula officinalis possess the ability to synthetize triterpene compounds of the oleanane, ursane and lupane groups. The biosynthesis of the various triterpenes occur in different parts of the seed. In the embryo, only oleanane derivatives are formed, but cotyledons also synthetize compounds belonging to ursane and lupane groups. 相似文献
458.
Using thin-layer chromatography for separation and colorimetric test with CoClj for determination, qualitative and quantitative composition of triterpenoids was estimated in Calendula officinalis dining vegetation. It was found that sterols and oleanolic acid as well as trace amounts of triterpenic monols occur in all organs of the plant during the whole vegetative period. Triterpenic diols and greater quantities of triterpenic monols appear in flowers. The biosynthesis rate of triterpcnoids is highest in young organs of the plant that is in seedlings, young leaves and flower buds. During flowering the content of sterols and oleanolic acid increases in all plant organs except of old leaves. A high level of oleanolic acid in the root during the flowering period implies that oleanolic acid glycosides can be transported from older leaves to underground parts of the plant. Biosynthesis of triterpenic monols, Ψ-taraxasterol and taraxasterol, precedes the formation of the diols faradiol and arnidiol. It can be inferred from the course of accumulation of these compounds that monols are the precursors of diols and that hydroxylation occurs in flowers. 相似文献
459.
Zofia Nehr Bernard Billoud Aude Le Bail Bénédicte Charrier 《Plant signaling & behavior》2011,6(12):1889-1892
Ectocarpus siliculosus is being developed as a model organism for brown algal genetics and genomics.1,2 Brown algae are phylogenetically distant from the other multicellular phyla (green lineage, red algae, fungi and metazoan)3 and therefore might offer the opportunity to study novel and alternative developmental processes that lead to the establishment of multicellularity. E. siliculosus develops as uniseriate filaments, thereby displaying one of the simplest architectures among multicellular organisms.4 The young sporophyte grows as a primary filament and then branching occurs, preferentially at the center of the filament. We recently described the first morphogenetic mutant étoile (etl) in a brown alga, produced by UVB mutagenesis in E. siliculosus.5 We showed that a single recessive mutation was responsible for a defect in both cell differentiation and the very early branching pattern (first and second branch emergences). Here, we supplement this study by reporting the branching defects observed subsequently, i.e. for the later stages corresponding to the emergence of up to the first six secondary filaments, and we show that the branching process is composed of at least two distinct components: time and position.
The developmental pattern of E. siliculosus is characterized by a very high level of morphological plasticity.6 Observations followed by statistical analyses allowed analyzing the morphometric features accompanying the establishment of the branching pattern in the mutant étoile, compared with the wild type (WT) organism (strain Ec32). The branching pattern can be deciphered in two main components: (1) the timing of branching and (2) the position of branching. 相似文献
460.
Tomasz Jagielski Henryk Krukowski Mariola Bochniarz Tomasz Piech Katarzyna Roeske Zofia Bakuła Łukasz Wlazło Piotr Woch 《Microbial biotechnology》2019,12(3):556-566
The Prototheca algae have recently emerged as an important cause of bovine mastitis globally. Here, we present results of a first large-scale, cross-country survey on the prevalence of Prototheca spp. in dairy cows, and their environment in Poland. A total of 1211 samples were collected and microbiologically analysed. Included within this number were milk (n = 638), body swabs (n = 374) and environmental samples (n = 199), originating from 400 dairy cows and their surroundings, on 16 dairy farms, based in all major provinces of the country. Prototheca spp. were the third, after Streptococcus and Staphylococcus spp., most common mastitis pathogens. The overall prevalence of protothecal mastitis was 8.3% (33/400), with the majority (75.8%) of cases having a subclinical course, and all but one attributable to P. zopfii genotype 2. Prototheca spp. were cultured from body swabs of both healthy and mastitic cows, yet the isolation rate among the latter was conspicuously lower (12.3% vs. 17.8%). Forty-two (21.2%) environmental samples yielded growth of Prototheca spp. However, no clear association between Prototheca mastitis in dairy cows and the algal isolation from the herd environment was found. Nor was there any association between the environmental recovery of the algae and farm management practices. 相似文献