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991.
Tanaka K Matsuda Y Masangkay JS Solis CD Anunciado RV Kuro-o M Namikawa T 《The Journal of heredity》2000,91(2):117-121
The karyotype of the tamaraw (Bubalus mindorensis, 2n = 46) was investigated by RBG-banding technique and compared with those of the river and the swamp cytotypes of domestic water buffalo (B. bubalis). The tamaraw karyotype consisted of 6 submetacentric and 16 acrocentric autosome pairs (NAA = 56), and X and Y chromosomes. The RBG-banded karyotype of the three taxa had a high degree of homology, and the tamaraw karyotype could be explained by a Robertsonian translocation between chromosomes 7 and 15 and by a telomere-centromere tandem fusion between chromosomes 4p and 12 of the standardized river buffalo cytotype (2n = 50, NAA = 58). The buffalo satellite I and II DNAs were localized to the centromeric regions of all the tamaraw chromosomes. The biarmed chromosome 2 of the tamaraw resulting from the fusion between chromosomes 7 and 15 of the standard contained much larger amounts of the satellite I DNA than the other biarmed chromosomes, suggesting that this chromosome was formed by a relatively recent Robertsonian fusion. The (TTAGGG)n telomeric sequence was specifically localized to the telomeric region of all the buffalo chromosomes. The 18S + 28S rDNA was localized to the telomeric regions of the chromosomes 5p, 7, 19, 21, and 22 of the tamaraw and of their homologous chromosomes in the river and swamp buffalo cytotypes. 相似文献
992.
In an effort to quantify loss of information in the processing of protein bioinformatic data, we examine how representations of amino acid sequence and backbone conformation affect the quantity of accessible structural information from local sequence. We propose a method to extract the maximum amount of peptide backbone structural information available in local sequence fragments, given a finite structural data set. Using methods of information theory, we develop an unbiased measure of local structural information that gauges changes in structural distributions when different representations of secondary structure and local sequence are used. We find that the manner in which backbone structure is represented affects the amount and quality of structural information that may be extracted from local sequence. Representations based on virtual bonds capture more structural information from local sequence than a three-state assignment scheme (helix/strand/loop). Furthermore, we find that amino acids show significant kinship with respect to the backbone structural information they carry, so that a collapse of the amino acid alphabet can be accomplished without severely affecting the amount of extractable information. This strategy is critical in optimizing the utility of a limited database of experimentally solved protein structures. Finally, we discuss the similarities within and differences between groups of amino acids in their roles in the local folding code and recognize specific amino acids critical in the formation of local structure. 相似文献
993.
994.
de Souza Dilailson Arajo Kraus Cleber Nunes Burliga Ana Luiza de Melo Srgio Couceiro Sheyla Dias-Silva Karina Simes Nadson Ressye Braga Tony Bonnet Marie Paule da Motta Marques David 《Limnology》2022,23(2):275-286
Limnology - The Amazon floodplains are complex systems influenced by the annual hydrological regime with an effect on the structuring of physical, chemical and biological processes. Thus, we... 相似文献
995.
Leandro R Solis Daniel P Hallihan Richard R E Uwiera Richard B Thompson Enid D Pehowich Vivian K Mushahwar 《Journal of applied physiology》2007,102(5):1992-2001
Pressure ulcers develop due to morphological and biochemical changes triggered by the combined effects of mechanical deformation, ischemia, and reperfusion that occur during extended periods of immobility. The goal of this study was to test the effectiveness of a novel electrical stimulation technique in the prevention of deep tissue injury (DTI). We propose that contractions elicited by intermittent electrical stimulation (IES) in muscles subjected to constant pressure would induce periodic relief in internal pressure; additionally, each contraction would also restore blood flow to the tissue. The application of constant pressure to the quadriceps muscles of rats generated a DTI that affected 60 +/- 15% of the compressed muscle as assessed by magnetic resonance imaging. In contrast, in the groups of rats that received IES at 10- and 5-min intervals, DTI of the muscle was limited to 16 +/- 16 and 25 +/- 13%, respectively. Injury to the muscle was corroborated by histology. In an experiment with a human volunteer, compression of the buttocks reduced the oxygenation level of the muscles by approximately 4%; after IES, oxygenation levels increased by approximately 6% beyond baseline. Concurrently, the surface pressure profiles of the loaded muscles were redistributed and the high-pressure points were reduced during each IES-induced contraction. The results of this study indicate that IES significantly reduces the amount of DTI by increasing the oxygen available to the tissue and by modifying the pressure profiles of the loaded muscles. This presents a promising technique for the prevention of pressure ulcers in immobilized and/or insensate individuals. 相似文献
996.
Evans JG Chavez-Rueda KA Eddaoudi A Meyer-Bahlburg A Rawlings DJ Ehrenstein MR Mauri C 《Journal of immunology (Baltimore, Md. : 1950)》2007,178(12):7868-7878
The immune system contains natural regulatory cells important in the maintenance of tolerance. Although this suppressive function is usually attributed to CD4 regulatory T cells, recent reports have revealed an immunoregulatory role for IL-10-producing B cells in the context of several autoimmune diseases including collagen-induced arthritis. In the present study, we attribute this suppressive function to a B cell subset expressing high levels of CD21, CD23, and IgM, previously identified as transitional 2-marginal zone precursor (T2-MZP) B cells. T2-MZP B cells are present in the spleens of naive mice and increase during the remission phase of arthritis. Following adoptive transfer to immunized DBA/1 mice, T2-MZP B cells significantly prevented new disease and ameliorated established disease. The suppressive effect on arthritis was paralleled by an inhibition of Ag-specific T cell activation and a reduction in cells exhibiting Th1-type functional responses. We also provide evidence that this regulatory subset mediates its suppression through the secretion of suppressive cytokines and not by cell-to-cell contact. The ability to regulate an established immune response by T2-MZP B cells endows this subset of B cells with a striking and previously unrecognized immunoregulatory potential. 相似文献
997.
Recent data suggest that hexokinase KlHxk1 (Rag5) represents the only glucose-phosphorylating enzyme of Kluyveromyces lactis, which also is required for glucose signalling. Long-term growth studies of a K. lactis rag5 mutant, however, reveal slow growth on glucose, but no growth on fructose. Isolation of the permissive glucose-phosphorylating enzyme, mass spectrometric tryptic peptide analysis and determination of basic kinetic data identify a novel glucokinase (KlGlk1) encoded by ORF KLLA0C01,155g. In accordance with the growth characteristics of the rag5 mutant, KlGlk1 phosphorylates glucose, but fails to act on fructose as a sugar substrate. Multiple sequence alignment indicates the presence of at least one glucokinase gene in all sequenced yeast genomes. 相似文献
998.
999.
Lettnin Aline Portantiolo Wagner Eduardo Felipe Carrett-Dias Michele dos Santos Machado Karina Werhli Adriano Cañedo Andrés Delgado Trindade Gilma Santos de Souza Votto Ana Paula 《Molecular biology reports》2019,46(2):1873-1884
Molecular Biology Reports - Cancer stem cells show epigenetic plasticity and intrinsic resistance to anti-cancer therapy, rendering capable of initiating cancer relapse and progression.... 相似文献
1000.
Heloisa Navarro Pantaroto Karina Pintaudi Amorim Jairo Matozinho Cordeiro João Gabriel S. Souza Antônio Pedro Ricomini-Filho Elidiane C. Rangel 《Biofouling》2019,35(2):173-186
The chemical composition of biomaterials can drive their biological responses; therefore, this in vitro study aimed to evaluate the proteomic profile of the salivary pellicle formed on titanium (Ti) alloys containing niobium (Nb) and zirconium (Zr). The experimental groups consisted of Ti35NbxZr (x?=?5 and 10?wt%) alloys, and commercially pure titanium (cpTi); titanium aluminium vanadium (Ti6Al4V) alloys were used as controls. The physical and chemical characteristics of the Ti materials were analysed. The proteomic profile was evaluated by liquid chromatography coupled with tandem mass spectrometry. Bacterial adhesion (2?h) of mixed species (Streptococcus sanguinis and Actinomyces naeslundii) was investigated as colony-forming units (n?=?6). This paper reports the finding that salivary pellicle composition can be modulated by the composition of the Ti material. The Ti35NbxZr group showed a significant ability to adsorb proteins from saliva, which can favour interactions with cells and compatibility with the body. 相似文献