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1.
2.
Most adult Barbus haasi , at a 1950 m-long site in Vallvidrera creek, were highly sedentary and resided within a home range <20 m (32 m2 ), while a small group were more mobile. On successive sampling occasions, between 52·3 and 64·9% of fish were recaptured in the same 10-m-long section in which they had previously been captured. Movements over long distances were infrequent, and only 5·6% of the fish moved >100 m. The movement pattern of the population was seasonally stable, although the mean distances were slightly greater in summer because of the medium-range movements of a few individuals. Overall, upstream and downstream movements were equally common but a significant downstream movement occurred in spring. The size of the fish did not influence the movement rate. Fish inhabiting those sections of the stream with greater depth, slower current and more cover had a lower movement rate than fish occupying shallower, exposed sections. The restricted movement of B. haasi could increase the survival of fish by increasing the probability of staying in the remaining pools during summer dry-out, and may therefore be of adaptive significance. 相似文献
3.
S Rojo P Aparicio S Y Choo J A Hansen J A López de Castro 《Journal of immunology (Baltimore, Md. : 1950)》1987,139(3):831-836
The structure of a new HLA-B27 variant, B27f, distinguishable from other HLA-B27 subtypes by isoelectric focusing and serologic criteria, has been established by comparative peptide mapping and radiochemical sequence analysis. HLA-B27f differs from the major B27.1 subtype in three clustered amino acid replacements: Asp74, Asp77, and Leu81 in B27.1 are changed to Tyr74, Asn77, and Ala81, respectively in B27f. This pattern of differences is analogous to that of HLA-B27.2 in that this subtype also differs from B27.1 in multiple clustered substitutions within the same segment. Thus, polymorphism within the HLA-B27 system is being achieved by introducing different sets of amino acid changes within a particular short segment of the alpha 1 domain. The most likely mechanism for the introduction of multiple changes within this segment is a nonreciprocal recombination event, such as gene conversion. The structural analogies and ethnic distribution of B27f and B27.2 as compared with those of B27.3, and B27.4 support a dynamic model of HLA-B27 evolution in which polymorphism has been created after the separation of the major ethnic groups. In this model, a Caucasian branch would be characterized by subtypes differing from B27.1 in a few changes within the alpha 1 domain, which were probably generated by single genetic steps. An Oriental branch would include those subtypes which differ from B27.1 by changes in both alpha 1 and alpha 2, involving multiple genetic steps for their generation. 相似文献
4.
B Gonzalez-Yanes R B Mandell M Girard S Henry O Aparicio M Gritzali R D Brown G W Erdos C M West 《Developmental biology》1989,133(2):576-587
Strain HL250 of Dictyostelium discoideum cannot convert GDP-mannose to GDP-fucose, resulting in an inability to fucosylate protein. This affects a group of proteins which are normally fucosylated intracellularly and then secreted via prespore vesicles to become part of the outer lamina of the spore coat. We have found that strain HL250 nevertheless accumulates typical amounts of these proteins, stores them normally in prespore vesicles, and secretes them normally to become a part of the spore coat. However, affected proteins are proteolyzed after germination, the spore coat is more accessible to penetration by a macromolecular probe, and germination is inefficient in older spores. These findings can be explained by a dependence of the integrity of the outer layer of the spore coat on protein-linked fucose. 相似文献
5.
Juan M. R. Aparicio Akemi Wakisaka Akio Takada Nobuo Matsuura Miki Aizawa 《Immunogenetics》1988,28(4):240-246
Fifty-six unrelated Japanese patients with insulin-dependent diabetes mellitus (IDDM) were HLA-typed, and restriction fragment length polymorphism (RFLP) analysis was performed after enzyme digestion with Bam HI and Taq I by using both DR and DQ probes. As previously reported, increased frequencies of Bw54, Cw1, DR4, and DRw53, which are in strong linkage disequilibrium in the Japanese population and make the characteristic Japanese haplotype, were confirmed. DQw4, a new allele of the DQ system recognized by the monoclonal antibody HU-46 and in linkage disequilibrium with this haplotype, presented the highest IDDM association. The RFLP analysis also showed the strongest correlation to IDDM when the DQ probe was applied. These results indicate that HLA-DQ might play the most important role in the development of IDDM in Japanese as well as in Caucasians. The correlation of DQ amino acid sequences strongly associated with IDDM in Japanese are discussed in this study, and contrasting results were found when such sequences were compared with those of Caucasians.Abbreviations used in this paper IDDM
insulin-dependent diabetes mellitus
- RFLP
restriction fragment length polymorphism
- Asp
aspartic acid
- Asp-57
aspartic acid at the 57th residue of the DQ chain
- non-Asp-57
nonaspartic acid at the 57th residue of the DQ chain
- R.R.
relative risk of Woolf and Haldane 相似文献
6.
Aparicio Enric Rocaspana Rafel Palau-Ibars Antoni de Sostoa Adolfo Alcaraz Carles 《Ichthyological Research》2023,70(1):101-109
Ichthyological Research - The Mediterranean brown trout (Salmo trutta complex) is native to basins draining to the Western Mediterranean Sea, and natural populations are currently declining in... 相似文献
7.
David Julian Arias-Chávez Patrick Mailloux-Salinas Jessica Ledesma Aparicio Elihu Campos-Pérez Omar Noel Medina-Campos José Pedraza-Chaverri Guadalupe Bravo 《Journal of cellular and molecular medicine》2023,27(20):3147-3156
Benign prostatic hyperplasia (BPH) is the most common adenoma in old men. Tomatoes are a rich source of bioactive compounds that, as well as selenium (Se), possess antioxidant and antiproliferative activity. The aim was to evaluate the therapeutic effect of Se in combination with a tomato extract in aged rats with BPH. Aged male Wistar rats were divided in the following groups (n = 10 rats/group): Control (C), BPH, BPH + Finasteride (BPH + F), BPH + Tomato Lipidic Extract (BPH + E), BPH + Selenium (BPH + S) and BPH plus E plus S (BPH + E + S). After 4 weeks of treatment, prostate weight, diuresis, antioxidants enzymes, prooxidants and inflammatory markers, growth factors and androgens were determined. BPH + E + S reduced prostate weight by 59.29% and inhibited growth by 99.35% compared to BPH + F which only decreased weight and inhibited growth by 15.31% and 57.54%, respectively. Prooxidant markers were higher with BPH + F (49.4% higher vs. BPH), but BPH + E + S decreased these markers (94.27% vs. BPH) and increased antioxidant activity. Finally, diuresis was higher with the BPH + E + S combination and markers of inflammation and growth factors were significantly lower with respect to BPH + F. Our findings provide a beneficial and protective therapeutic option of E + S directed against androgens, oxidative stress and inflammation that regulates cell proliferation in the prostate gland. 相似文献
8.
The blue light dependent utilization of nitrate by green algae under common air and high irradiances, besides its assimilatory nature, is associated with the release of NO2
– and NH4
+ to the culture medium. If the CO2 content of the sparging air was increased up to 2%, previously excreted NO2
– and NH4
+ were rapidly assimilated. When under air and high irradiances the cell density in the culture reached values corresponding to 25 g Ch 1.ml-1, no further growth was observed and the highest values of NO3
– consumption and NO2
– and NH4
+ release were attained. Besides low CO2 tensions, increasing NO3
– concentrations in the medium stimulated the release of NO3
– and NH4
+. Under CO2-free air the consumption of NO3
– and the release of NO2
– and NH4
+ on a total N bases were almost stoichiometric and their rates saturated at much lower irradiances than under air. Under CO2-free air high rates of NO2
– release were only observed under the blue radiations that were effectively absorbed by photosynthetically active pigments, i.e. 460 nm, but not under 404 and 630 nm radiations. However, the simultaneous illumination of the cells with 404 and 630 nm monochromatic light showed a remarkable synergistic effect on NO2
– release.The results are discussed in terms of the close relationship between C and N metabolism, the photosynthetic reducing power required to convert NO
inf3
sup±
-N into R – NH2-N and the blue light activation of nitrate reductase. 相似文献
9.
F. J. Lopez Aparicio F. Zorrilla Benitez F. Santoyo Gonzalez 《Carbohydrate research》1981,90(2):315-318
The homogeneous, neutral polysaccharide isolated from the crude polysaccharide of the fruit pulp from bael (Aegle marmelos) contains arabinose, galactose, and glucose in the molar ratios of 2:3:14. The linkages among the different monosaccharide residues were established through methylation analysis and Smith-degradation studies of the polysaccharide. The anomeric configurations of the different glycosyl groups were determined by study of the chromium trioxide oxidation of the acetylated polysaccharide. Results of these experiments have been discussed in order to assess the structure of the neutral polysaccharide. 相似文献
10.
Purified spinach nitrite reductase, a protein that contains siroheme, is characterized by absorption maxima in the visible region at 385 and 573 nm. On addition of the substrate nitrite, the bands shift to 360 and 570 nm. Dithionite also causes shifts in the maxima of the visible absorption region. Electron paramagnetic resonance studies show that the untreated enzyme contains a high-spin Fe3+ heme and that the addition of cyanide, an inhibitor that is competitive with nitrite, results in a spin-state change of the heme. Electron paramagnetic resonance analysis of the enzyme in the presence of dithionite or dithionite plus cyanide indicates the presence of a reduced iron-sulfur center with rhombic symmetry (g-values of 2.03, 1.94, and 1.91). In contrast, when the enzyme is treated with dithionite plus nitrite, the EPR spectrum of an NO-heme complex (g-values of 2.07 and 2.00) is observed. The presence of an iron-sulfur center has also been confirmed by chemical analyses of the nonheme iron and acid-labile sulfide in nitrite reductase. These results are discussed in terms of a mechanism for nitrite reduction that involves electron transfer between the iron-sulfur center and siroheme. 相似文献