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21.
Based on the ability of bile acids to vectorialize the cytostatic activity of other agents, we have designed and synthesized a new series of platinum and gold complexes. These compounds were studied and characterized by elemental analysis, FT-IR, FAB(+)/MS, 1H, 13C and 195Pt NMR, UV-Vis spectroscopy and conductivity measurements in solution, among other techniques. Kinetic studies carried out in aqueous solution and in the presence of different NaCl concentrations: 4 mM (similar to cytoplasmic concentration), 150 mM (similar to plasmatic concentration). The effects on the electrophoretic mobility of the pUC18 plasmid, the DNA denaturation temperature, and ethidium bromide (EtBr) binding to DNA were studied. The complexes are able to inter-react with DNA to inhibit DNA synthesis and hence, to reduce cell proliferation. The complexes were evaluated for in vitro cytostatic activity against human colon adenocarcinoma, mouse hepatoma, human hepatoma, mouse leukemia, etc. The antitumor effect of some of the compounds prepared was similar to that of cisplatin. However, other compounds had lower cytostatic activity. This different behavior can be accounted for by the structure/activity relationship (SAR), although other factors, such as uptake and the different kinetic behavior in solution, may be responsible for these differences. 相似文献
22.
B30.2-like domain proteins: update and new insights into a rapidly expanding family of proteins 总被引:5,自引:0,他引:5
Henry J; Mather IH; McDermott MF; Pontarotti P 《Molecular biology and evolution》1998,15(12):1696-1705
The B30.2 domain is a conserved region of around 170 amino acids associated
with several different protein domains, including the immunoglobulin folds
of butyrophilin and the RING finger domain of ret finger protein. We
recently reported several novel members of this family as well as
previously undescribed protein families possessing the B30.2 domain. Many
proteins have subsequently been found to possess this domain, including
pyrin/marenostrin and the midline 1 (MID1) protein. Mutations in the B30.2
domain of pyrin/marenostrin are implicated in familial Mediterranean fever,
and partial loss of the B30.2 domain of MID1 is responsible for Opitz G/BBB
syndrome, characterized by developmental midline defects. In this study, we
scrutinized the available sequence data bases for the identification of
novel B30.2 domain proteins using highly sensitive database-searching
tools. In addition, we discuss the chromosomal localization of genes in the
B30.2 family, since the encoded proteins are likely to be involved in other
forms of periodic fever, autoimmune, and genetic diseases.
相似文献
23.
Out of Africa and back again: nested cladistic analysis of human Y chromosome variation 总被引:18,自引:3,他引:15
Hammer MF; Karafet T; Rasanayagam A; Wood ET; Altheide TK; Jenkins T; Griffiths RC; Templeton AR; Zegura SL 《Molecular biology and evolution》1998,15(4):427-441
We surveyed nine diallelic polymorphic sites on the Y chromosomes of 1,544
individuals from Africa, Asia, Europe, Oceania, and the New World.
Phylogenetic analyses of these nine sites resulted in a tree for 10
distinct Y haplotypes with a coalescence time of approximately 150,000
years. The 10 haplotypes were unevenly distributed among human populations:
5 were restricted to a particular continent, 2 were shared between Africa
and Europe, 1 was present only in the Old World, and 2 were found in all
geographic regions surveyed. The ancestral haplotype was limited to African
populations. Random permutation procedures revealed statistically
significant patterns of geographical structuring of this paternal genetic
variation. The results of a nested cladistic analysis indicated that these
geographical associations arose through a combination of processes,
including restricted, recurrent gene flow (isolation by distance) and range
expansions. We inferred that one of the oldest events in the nested
cladistic analysis was a range expansion out of Africa which resulted in
the complete replacement of Y chromosomes throughout the Old World, a
finding consistent with many versions of the Out of Africa Replacement
Model. A second and more recent range expansion brought Asian Y chromosomes
back to Africa without replacing the indigenous African male gene pool.
Thus, the previously observed high levels of Y chromosomal genetic
diversity in Africa may be due in part to bidirectional population
movements. Finally, a comparison of our results with those from nested
cladistic analyses of human mtDNA and beta-globin data revealed different
patterns of inferences for males and females concerning the relative roles
of population history (range expansions) and population structure
(recurrent gene flow), thereby adding a new sex-specific component to
models of human evolution.
相似文献
24.
Guillermo Rodríguez‐Hernández Inés González‐Herrero Carolin Walter Sara González de Tena‐Dávila Salma Parvin Oskar Haas Wilhelm Woessmann Martin Stanulla Martin Schrappe Martin Dugas Yasodha Natkunam Alberto Orfao Verónica Domínguez Belén Pintado Oscar Blanco Diego Alonso‐López Javier De Las Rivas Alberto Martín‐Lorenzo Rafael Jiménez Francisco Javier García Criado María Begoña García Cenador Izidore S Lossos Carolina Vicente‐Dueñas Arndt Borkhardt Julia Hauer Isidro Sánchez‐García 《The EMBO journal》2018,37(14)
25.
26.
Plant Growth Regulators and Induction of Leaf Senescence in Nitrogen-Deprived Wheat Plants 总被引:1,自引:0,他引:1
M. Victoria Criado Irma N. Roberts Mariela Echeverria Atilio J. Barneix 《Journal of Plant Growth Regulation》2007,26(4):301-307
The sequence of events and the signals that regulate the remobilization of nitrogen (N) reserves during senescence induced
by N starvation were studied in leaf 3, the last fully expanded leaf, in 17-day-old wheat (Triticum aestivum L.) plants. The first event observed was a rapid decrease in the isopentenyl adenosine (iPA) concentration during the first
24 h of N starvation. No differences in t-zeatin riboside and dihydrozeatin riboside concentrations were observed until the
end of the assay. During the following 6 days, a decrease in soluble amino acids, chlorophyll, and protein, as well as an
increase in soluble sugar concentration and endoproteolytic activity, could be observed. At day 3 of the experiment, the abscisic
acid (ABA) concentration in the leaves of N-deprived plants started to increase. After 6 days of N deprivation there was a
rise in oxidative stress, as indicated by the increase in malondialdehyde concentration, as well as a decrease in the activities
of antioxidant enzymes catalase and ascorbate peroxidase. To analyze interactions with leaf development, the first, second,
third, and fourth leaves were studied. iPA concentration decreased in all the leaf stages, including leaf 4, which was not
fully expanded. A linear correlation between iPA and protein concentration was determined. These results suggest that the
sharp fall in iPA could be the earliest event that induces protein degradation during the development of senescence induced
by N deficiency, and that only later is ABA accumulated and oxidative stress developed. 相似文献
27.
Vera MF da Silva Anthony M Carter Carlos E Ambrosio Ana F Carvalho Marina Bonatelli Marcelo C Lima Angelica Maria Miglino 《Reproductive biology and endocrinology : RB&E》2007,5(1):26-6
A recent reassessment of the phylogenetic affinities of cetaceans makes it timely to compare their placentation with that
of the artiodactyls. We studied the placentae of two sympatric species of dolphin from the Amazon River Basin, representing
two distinct families. The umbilical cord branched to supply a bilobed allantoic sac. Small blood vessels and smooth muscle
bundles were found within the stroma of the cord. Foci of squamous metaplasia occurred in the allanto-amnion and allantochorion.
The interhemal membrane of the placenta was of the epitheliochorial type. Two different types of trophoblastic epithelium
were seen. Most was of the simple columnar type and indented by fetal capillaries. However, there were also areolar regions
with tall columnar trophoblast and these were more sparsely supplied with capillaries. The endometrium was well vascularised
and richly supplied with actively secreting glands. These findings are consistent with the current view that Cetacea are nested
within Artiodactyla as sister group to the hippopotamids. 相似文献
28.
29.
Germano Siqueira Adriane MF Milagres Walter Carvalho Gerald Koch André Ferraz 《Biotechnology for biofuels》2011,4(1):7
Background
Lignin and hemicelluloses are the major components limiting enzyme infiltration into cell walls. Determination of the topochemical distribution of lignin and aromatics in sugar cane might provide important data on the recalcitrance of specific cells. We used cellular ultraviolet (UV) microspectrophotometry (UMSP) to topochemically detect lignin and hydroxycinnamic acids in individual fiber, vessel and parenchyma cell walls of untreated and chlorite-treated sugar cane. Internodes, presenting typical vascular bundles and sucrose-storing parenchyma cells, were divided into rind and pith fractions. 相似文献30.