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71.
The role of histamine in implantation in the rabbit. 总被引:1,自引:0,他引:1
When disodium cromoglycate, an inhibitor of histamine release, was instilled into the uterine lumen on Days 5 or 6 of pregnancy, the number of blastocysts implanting was significantly (P less than 0.002) reduced. Simultaneous instillation of histamine and disodium cromoglycate prevented the effect. 相似文献
72.
Chacón MR Fernández-Real JM Richart C Megía A Gómez JM Miranda M Caubet E Pastor R Masdevall C Vilarrasa N Ricard W Vendrell J 《Obesity (Silver Spring, Md.)》2007,15(3):664-672
Objective: Our goal was to test any association between human plasma circulating levels of monocyte chemoattractant protein‐1 (cMCP‐1) and insulin resistance and to compare monocyte chemoattractant protein‐1 (MCP‐1) adipose tissue gene expression and cMCP‐1 in relation with inflammatory markers. Research Methods and Procedures: cMCP‐1 was measured in n = 116 consecutive control male subjects to whom an insulin sensitivity (Si) test was performed. Circulating levels of soluble CD14, soluble tumor necrosis factor receptor type 2 (sTNFR2), soluble interleukin‐6 (sIL‐6), and adiponectin also were measured. Subcutaneous adipose tissue samples were obtained from n = 107 non‐diabetic and type 2 diabetic subjects with different degrees of obesity. Real‐time polymerase chain reaction was used to measure gene expression of MCP‐1, CD68, tumor necrosis factor‐α (TNF‐α), and its receptor TNFR2. Results: In the Si study, no independent effect of cMCP‐1 levels on insulin sensitivity was observed. In the expression study, in non‐diabetic subjects, MCP‐1 mRNA had a positive correlation with BMI (r = 0.407, p = 0.003), TNF‐α mRNA (r = 0.419, p = 0.002), and TNFR2 mRNA (r = 0.410, p = 0.003). In these subjects, cMCP‐1 was found to correlate with waist‐to‐hip ratio (r = 0.322, p = 0.048). In patients with type 2 diabetes, MCP‐1 mRNA was up‐regulated compared with non‐diabetic subjects. TNF‐α mRNA was found to independently contribute to MCP‐1 mRNA expression. In this group, CD68 mRNA was found to correlate with BMI (r = 0.455, p = 0.001). Discussion: cMCP‐1 is not associated with insulin sensitivity in apparently healthy men. TNF‐α is the inflammatory cytokine associated with MCP‐1 expression in subcutaneous adipose tissue. 相似文献
73.
74.
RO Cristóvão SC Silvério AP Tavares AI Brígida JM Loureiro RA Boaventura EA Macedo MA Coelho 《World journal of microbiology & biotechnology》2012,28(9):2827-2838
Commercial laccase formulation was immobilized on modified green coconut fiber silanized with 3-glycidoxypropyltrimethoxysilane, aiming to achieve a cheap and effective biocatalyst. Two different strategies were followed: one point (pH 7.0) and multipoint (pH 10.0) covalent attachment. The influence of immobilization time on enzymatic activity and the final reduction with sodium borohydride were evaluated. The highest activities were achieved after 2?h of contact time in all situations. Commercial laccase immobilized at pH 7.0 was found to have higher activity and higher affinity to the substrate. However, the immobilization by multipoint covalent attachment improved the biocatalyst thermal stability at 50?°C, when compared to soluble enzyme and to the immobilized enzyme at pH 7.0. The Schiff's bases reduction by sodium borohydride, in spite of causing a decrease in enzyme activity, showed to contribute to the increase of operational stability through bonds stabilization. Finally, these immobilized enzymes showed high efficiency in the continuous decolourization of reactive textile dyes. In the first cycle, the decolourization is mainly due to dyes adsorption on the support. However, when working in successive cycles, the adsorption capacity of the support decreases (saturation) and the enzymatic action increases, indicating the applicability of this biocatalyst for textile wastewater treatment. 相似文献
75.
González-Robles A Castañón G Cristóbal-Ramos AR Lázaro-Haller A Omaña-Molina M Bonilla P Martínez-Palomo A 《Experimental parasitology》2006,114(3):133-140
In this study we report observations on the structural mechanisms of the cytopathic effect of Acanthamoeba castellanii trophozoites on cultured MDCK cell monolayers. Co-incubations were carried out for a maximum of 24h. The first evidence of damage to the cell monolayer was detected by measuring the transepithelial resistance of cell monolayers that interacted with the amoebae. At 6h, transepithelial resistance diminished to 51% and amoebae required 5-6h to produce evidence of structural injury at the light microscopy level. Following 12h of incubation, the cell monolayer was severely damaged. After making intimate contact with the surface of target cells, trophozoites detached cells from the substrate, lysed and by means of food-cups ingested the damaged cells. There was no morphological evidence of modifications in MDCK cell membranes, membrane fusion or junction formation between the amoeba and host plasma membrane. The lytic capacity of the amoebas appears to be the result of cytotoxic factors secreted by the amoebae since, when monolayers were incubated with conditioned medium, there was also a decrease in the transepithelial resistance. Besides, mechanical injury produced by the attachment and movement of the trophozoites may contribute to the disruption of the cell monolayer. As in other pathogenic amoebae, the cytopathic action of A. castellanii on the cell monolayers can subjectively be separated into four stages: adhesion, cytolysis, phagocytosis, and intracellular degradation. 相似文献
76.
Cristóbal-Azkarate J Chavira R Boeck L Rodríguez-Luna E Veàl JJ 《Hormones and behavior》2006,49(2):261-267
The challenge hypothesis asserts that testosterone levels and aggression in male adult animals are closely associated with one another in the context of intense reproductive competition, particularly when males challenge one another for the access to females. For mantled howler monkeys (Alouatta palliata), the presence of a solitary male in the vicinity of a social group can be considered a threat for the reproductive success of the resident males, as group takeovers by solitary males are followed by a reestablishment of the access to females among group males and sometimes by infanticide. Therefore, these episodes should be accompanied by an increase in testosterone secretion according to the challenge hypothesis. In order to test our prediction, we relate different group and subpopulation variables to the testosterone levels measured in feces collected from 10 groups living in 6 forest fragments, at Los Tuxtlas, Mexico. Our results suggest that resident A. palliata males regard solitary individuals as potential contesters for their reproductive success and that they respond to interactions with them with an increase in testosterone levels, that is increasing their aggressiveness. Our results also suggest that in the studied groups all males have at least certain access to mates and that the entrance of a new male would affect their reproductive success negatively. Finally, the negative effects of chronically high testosterone levels may be negatively affecting the fitness of our study groups living in high population densities and small fragments. 相似文献
77.
Chrysoula Vasileiou Kin Sing Stephen Lee Rachael M. Crist Soheila Vaezeslami Sarah M. Goins James H. Geiger Babak Borhan 《Proteins》2009,76(2):281-290
The binding of retinoic acid to mutants of Cellular Retinoic Acid Binding Protein II (CRABPII) was evaluated to better understand the importance of the direct protein/ligand interactions. The important role of Arg111 for the correct structure and function of the protein was verified and other residues that directly affect retinoic acid binding have been identified. Furthermore, retinoic acid binding to CRABPII mutants that lack all previously identified interacting amino acids was rescued by providing a carboxylic acid dimer partner in the form of a Glu residue. Proteins 2009. © 2008 Wiley‐Liss, Inc. 相似文献
78.
Manuel J. Díaz Encarnación Ruiz Inmaculada Romero Cristóbal Cara Manuel Moya Eulogio Castro 《World journal of microbiology & biotechnology》2009,25(5):891-899
The ethanolic fermentation of liquid fractions (hydrolysates) issued from dilute acid pre-treatment of olive tree biomass
by Pichia stipitis is reported for the first time. On the one side, P. stipitis has been reported as the most promising naturally occurring C5 fermenting microorganism; on the other side, olive tree biomass
is a renewable, low cost, and lacking of alternatives agricultural residue especially abundant in Mediterranean countries.
The study was performed in two steps. First, the fermentation performance of P. stipitis was evaluated on a fermentation medium also containing the main inhibitors found in these hydrolysates (acetic acid, formic
acid, and furfural), as well as glucose and xylose as carbon sources. The effect of inhibitors, individually or in a mixture,
on kinetic and yield parameters was calculated. In a second step, hydrolysates obtained from 1% (w/w) sulfuric acid pre-treatment
of olive tree biomass at 190°C for 10 min were used as a real fermentation medium with the same microorganism. Due to inhibition,
effective fermentation required dilution of the hydrolysate and either overliming or activated charcoal treatment. Results
show that ethanol yields obtained from hydrolysates, ranging from 0.35 to 0.42 g/g, are similar to those from synthetic medium,
although the process proceeds at lower rates. Inhibiting compounds affect the fermentation performance in a synergistic way.
Furfural is rapidly assimilated by the yeast; acetic acid and formic acid concentrations decrease slowly during the process.
Activated charcoal or overliming detoxification improve the fermentability of diluted hydrolysates. 相似文献
79.
Cristóvão RO Tavares AP Ferreira LA Loureiro JM Boaventura RA Macedo EA 《Bioresource technology》2009,100(3):1094-1099
Degradation of a mixture of three reactive textile dyes (Reactive Black 5, Reactive Yellow 15 and Reactive Red 239), simulating a real textile effluent, by commercial laccase, was investigated in a batch reactor. The discoloration was appraised as a percentage of the absorbance reduction at the wavelength of maximum absorbance for each dye and as total color removal based in all visible spectrum. A significantly high discoloration was achieved in both cases, indicating the applicability of this method for textile wastewater treatment. Mathematical models were developed to simulate the kinetics of laccase catalyzed degradation of reactive dyes in mixtures. Like in single dye degradation, some of the reactions present an unusual kinetic behavior, corresponding to the activation of the laccase-mediator system. The kinetic constants of the models were estimated by minimizing the difference between the predicted and the experimental time courses. Although not perfect, the ability of the models in representing the experimental results suggests that they could be used in design and simulation applications. 相似文献
80.
Richard C. Crist Jacquelyn J. Roth Amy A. Baran Benjamin J. McEntee Linda D. Siracusa Arthur M. Buchberg 《Mammalian genome》2010,21(9-10):450-457
The adenomatous polyposis coli (APC) gene is known to act as a tumor suppressor gene in both sporadic and hereditary colorectal cancer by negatively regulating WNT signaling. Familial adenomatous polyposis (FAP) patients develop intestinal polyps due to the presence of a single germline mutation in APC. The severity of the FAP phenotype is a function of the position of the APC mutation, indicating a complex role for APC that extends beyond the canonical WNT pathway. APC encodes a large protein with multiple functional domains, including an armadillo repeat domain that has been linked to protein–protein interactions. To determine the effect of the armadillo repeat domain on intestinal tumorigenesis, we generated a congenic mouse line (Apc Δ242 ) carrying a gene trap cassette between exons 7 and 8 of the murine Apc gene. Apc Δ242/+ mice express a truncated Apc product lacking the armadillo repeat domain as part of a fusion protein with β-geo. Expression of the fusion product was confirmed by X-gal staining, ensuring that Apc Δ242 is not a null allele. In contrast, Apc Min/+ mice produce a truncated Apc product that contains an intact armadillo repeat domain. On the C57BL/6J background, Apc Δ242/+ mice develop more polyps than do Apc Min/+ mice along the entire length of the small intestine; however, polyps were significantly smaller in Apc Δ242/+ mice. In addition, polyp multiplicity in Apc Δ242/+ mice is affected by polymorphisms between inbred strains. These data suggest that the armadillo repeat domain of the Apc protein suppresses tumor initiation in the murine intestine while also promoting tumor growth. 相似文献