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991.
de Souza AP de Jesus Borges T Pillat MM Bonorino C 《Cancer immunology, immunotherapy : CII》2011,60(1):145-151
The tumor microenvironment is complex and creates an immunosuppressive network to tolerize tumor-specific immune responses;
however, little information is available regarding the response against non-tumor antigens in tumor-bearing individuals. The
goal of the present study was to evaluate if tumor burden could influence a CD4+ T cell response against a soluble protein, not expressed by the tumor, in the absence of in vitro stimulation. Using an experimental
system in which we can compare CD4+ T cell responses to the Ea antigen when it is either expressed by B16F10 melanoma cells (B16EaRFP cells) or is an exogenous,
non-tumor antigen (soluble EaRFP protein), in immunizations of B16F10 tumor-bearing mice, we observed that the tumor can modulate
the CD4+ T cell-specific response to the antigen when it is expressed by the tumor cells. TEa cells proliferated poorly and produced
less IFN-γ in mice bearing B16F10 melanoma expressing Ea peptide, and tumor growth was impervious to this response. However,
in mice bearing 7 days B16F10 tumors, not expressing the Ea antigen, priming of TEa cells was similar to that observed in
tumor-free mice, based on the total number of cells recovered and proliferation assessed by CFSE dilution after EaRFP immunization.
We also investigated if tumor burden could influence recall responses of already differentiated effector cells. We immunized
mice with EaRFP antigen and after a few days injected B16F10 cells. After 10 days of tumor growth, we challenged the mice
with the non-tumor antigen. We found that the number of TEa cells producing IFN-γ in tumor-bearing mice was not different
compared to tumor-free mice. No differences in antigen presentation, assessed by YAe antibody staining, were verified in the
draining lymph node of these two groups. Collectively, our data indicate that tumor burden does not affect immune responses
to non-tumor antigens. These results have important implications in the design of anti-cancer therapy. 相似文献
992.
Domínguez-Escobar J Beltrán Y Bergman B Díez B Ininbergs K Souza V Falcón LI 《FEMS microbiology letters》2011,316(2):90-99
Heterocyst-forming cyanobacteria are important players at both evolutionary and ecological scales, but to date it has been difficult to establish their phylogenetic affiliations. We present data from a phylogenetic and molecular clock analysis of heterocystous cyanobacteria within the family Rivulariaceae, including the genera Calothrix, Rivularia, Gloeotrichia and Tolypothrix. The strains were isolated from distant geographic regions including fresh and brackish water bodies, microbial mats from beach rock, microbialites, pebble beaches, plus PCC strains 7103 and 7504. Phylogenetic inferences (distance, likelihood and Bayesian) suggested the monophyly of genera Calothrix and Rivularia. Molecular clock estimates indicate that Calothrix and Rivularia originated ~1500 million years ago (MYA) ago and species date back to 400-300 MYA while Tolypothrix and Gloeotrichia are younger genera (600-400 MYA). 相似文献
993.
Beatriz Candida Silva Eldamária de Vargas Wolfgramm Vitor Resende da Costa Aguiar Frederico Scott Varela Malta Amanda Mafia de Castro Alessandro Clayton de Souza Ferreira Flavia de Paula Iúri Drumond Louro 《Molecular biology reports》2011,38(5):3013-3016
Allelic frequencies and other population data analysis are reported for the 15 autosomal Short Tandem Repeats (STR) loci included in the PowerPlex®16 kit (CSF1PO, D13S317, D16S539, D18S51, D21S11, D3S1358, D5S818, D7S820, D8S1179, FGA, Penta D, Penta E, TPOX, TH01 and vWA) in Pomeranian’s descendants from the Espirito Santo State (ES), Brazil, third largest population of Pomeranian’s descendants in the world. They chose the mountain region of the state for their preferred geographic location, and they have a very peculiar lifestyle with a selective mating behavior which has maintained their characteristics as a relatively pure subpopulation. Blood samples were obtained from 82 unrelated volunteers from 11 different cities of Espirito Santo State, where there are the Pomeranian’s descendants. All 15 loci analyzed showed Power of Discrimination (PD) values > 0.75. Except the TPOX locus, all analyzed loci were at Hardy–Weinberg equilibrium. This subpopulation has not yet been characterized for STR allelic frequencies used for forensic and genetic identification studies. 相似文献
994.
The present study was conducted to evaluate testis size, spermatogenesis and hormone concentrations before and when peripheral testosterone reached 1 ng/ml as related to further gonad development of beef bulls (n=28). Blood samples were taken weekly starting at 10 weeks (wk) and when testosterone reached 1 ng/ml (AGE1), the left testis was surgically excised. From AGE1 until 54 wk, blood samples were collected to follow basal and GnRH-stimulated hormone profiles. At 54 wk, the second testis was removed. Testosterone reached 1 ng/ml at 20±0.6 wk and, at this developmental state, the seminiferous tubules occupied 57±1.1% of the testis parenchyma. At this phase, 79.3±1.4% of tubule sections had no germ cells and only 2.4±0.3% of the remaining tubules had spermatocytes as the most advanced germ cell type. Also at AGE1, testis size was correlated with the number of Sertoli cells per testis (r=0.67; P<0.05), but not (P>0.05) with the percentage of tubules with germ cells. There was a consistent increase in body weight and testis size throughout the study showing that hemicastration did not impair the development of the bulls. At 54 wk, seminiferous tubules represented 76±0.7% of the testis parenchyma and 72.3±1.7% of tubule sections were found with either round or elongated spermatids. Quantitative criteria of spermatogenesis in the second testis (excised at 54 wk) were not correlated (P>0.05) with the percentage of seminiferous tubules with germ cells in the first testis (excised at AGE1). As determined by regression analysis, testis diameter measured between 30 and 44 wk (AVTD) was associated with AGE1 and testis diameter averaged at 12 wk and AGE1 (R(2)=0.77; P<0.01). Also, AVTD was related to AGE1, testis diameter at 12 wk and concentrations of 17β-estradiol (estradiol; basal+GnRH-stimulated) averaged between 10 wk and AGE1 (R(2)=0.79; P<0.01). Yearling testis weight, in turn, was linked to AGE1 and testis weight at AGE1 (R(2)=0.49, P<0.01). In conclusion, early detection of 1 ng of testosterone/ml, larger testis size and greater estradiol before and at that developmental period positively relate to future testis attributes. When testosterone reached 1 ng/ml, the seminiferous tubules had Sertoli cells, spermatogonia and a few spermatocytes and events occurring before and at that phase are potential markers of testis growth and sperm-producing capacity of sires. 相似文献
995.
996.
de Souza WR Vessecchi R Dorta DJ Uyemura SA Curti C Vargas-Rechia CG 《Journal of bioenergetics and biomembranes》2011,43(3):237-246
In addition to adenosine triphosphate (ATP) production, mitochondria have been implicated in the regulation of several physiological
responses in plants, such as programmed cell death (PCD) activation. Salicylic acid (SA) and reactive oxygen species (ROS)
are essential signaling molecules involved in such physiological responses; however, the mechanisms by which they act remain
unknown. In non-photosynthesizing tissues, mitochondria appear to serve as the main source of ROS generation. Evidence suggests
that SA and ROS could regulate plant PCD through a synergistic mechanism that involves mitochondria. Herein, we isolate and
characterize the mitochondria from non-photosynthesizing cell suspension cultures of Rubus fruticosus. Furthermore, we assess the primary site of ROS generation and the effects of SA on isolated organelles. Mitochondrial Complex
III was found to be the major source of ROS generation in this model. In addition, we discovered that SA inhibits the electron
transport chain by inactivating the semiquinone radical during the Q cycle. Computational analyses confirmed the experimental
data, and a mechanism for this action is proposed. 相似文献
997.
Costa-e-Sousa RH Souza LL Calviño C Cabanelas A Almeida NA Oliveira KJ Pazos-Moura CC 《Regulatory peptides》2011,171(1-3):43-47
Neuropeptide Y (NPY) inhibits TRH neurons in fed state, and hypothalamic NPY higher expression during fasting has been proposed to be involved in fasting-induced suppression of the hypothalamus-pituitary-thyroid (HPT) axis. We investigated the role of central Y5 receptors in the control of thyrotropin (TSH) and thyroid hormone (TH) secretion. Fed and fasting rats received twice daily central injections (3rd ventricle) of Y5 receptor antagonist (CGP71683; 15nmol/rat) for 72h. Fasted rats also received a single central injection of CGP71683 (15nmol/rat) at the end of 72h of fasting. In fed rats, Y5 receptor blockade reduced total food intake by 32% and body mass by almost 10% (p<0.01), corroborating the role of this receptor in food intake control. 72h-fasted rats exhibited a 4-fold increase in serum TSH (p<0.001), 1h after a single injection of Y5 antagonist. Also with multiple injections during 72h of fasting, Y5 blockade resulted in activation of thyroid axis, as demonstrated by a 3-times rise in serum T4 (p<0.001), accompanied by unchanged TSH and T3. In fed rats, the chronic central administration of CGP71683 resulted in reduced total serum T4 without changes in free T4 and TSH. Serum leptin and PYY were not altered by the NPY central blockade in both fed and fasted rats, suggesting no role of these hormones in the alterations observed. Therefore, the inhibition of central Y5 neurotransmission resulted in activation of thyroid axis during fasting suggesting that NPY-Y5 receptors contribute to fasting-induced TSH and TH suppression. 相似文献
998.
Camilios-Neto D Bugay C de Santana-Filho AP Joslin T de Souza LM Sassaki GL Mitchell DA Krieger N 《Applied microbiology and biotechnology》2011,89(5):1395-1403
Rhamnolipid biosurfactants are attracting attention due to their low toxicity, high biodegradability, and good ecological
acceptability. However, production in submerged culture is made difficult by severe foaming problems. Solid-state cultivation
(SSC) is a promising alternative production method. In the current work, we report the optimization of rhamnolipid production
by Pseudomonas aeruginosa UFPEDA 614 on a solid substrate containing sugarcane bagasse and corn bran. The best rhamnolipid production, 45 g/l of impregnating
solution used, was obtained with a 50:50 (m/m) mixture of sugarcane bagasse and corn bran supplemented with an impregnating
solution containing 6% (v/v) of each of glycerol and soybean oil. This level is comparable with those of previous studies
undertaken in solid-state cultivation; the composition of the biosurfactant is similar, but our medium is cheaper. Our work
therefore provides a suitable basis for future studies of the development of an SSC-based process for rhamnolipid production. 相似文献
999.
Fabrícia de Souza Predes Juliana Castro Monteiro Sérgio Luis Pinto Matta Márcia C. Garcia Heidi Dolder 《Biological trace element research》2011,140(3):330-341
The aim of this study is to investigate the association of a single low dose of Cd and daily doses of Ginkgo biloba extract (GbE) on the testis and accessory glands of rats. The animals were treated with a single dose of 3 µmol/kg body weight of cadmium chloride (CdCl2) and/or 100 mg/kg body weight of GbE. The plasma testosterone levels; corporal, testicular, and accessory glands weight; gonadosomatic index, volumetric proportion; and absolute volume of testicular components did not change after the treatments. CdCl2 caused significant reduction in Leydig cells volume and altered Leydig cell morphology, as well as vacuolated Sertoli cells cytoplasm, irregular chromatin condensation of late spermatids, and modified acrosome formation. However, animals that received GbE did not show these alterations. The reversal of Cd-induced alterations by the extract is a strong indication that G. biloba is helpful in diminishing the effect of Cd toxicity. 相似文献
1000.
Siqueira IR Elsner VR Leite MC Vanzella C Moysés Fdos S Spindler C Godinho G Battú C Wofchuk S Souza DO Gonçalves CA Netto CA 《Neurochemistry international》2011,58(4):527-532
Ascorbate, an intracellular antioxidant, has been considered critical for neuronal protection against oxidant stress, which is supported especially by in vitro studies. Besides, it has been demonstrated an age-related decrease in brain ascorbate levels. The aims of the present study were to investigate ascorbate uptake in hippocampal slices from old Wistar rats, as well as its neuroprotective effects in in vitro and in vivo assays. Hippocampal slices from male Wistar rats aged 4, 11 and 24 months were incubated with radiolabeled ascorbate and incorporated radioactivity was measured. Hippocampal slices from rats were incubated with different concentrations of ascorbate and submitted to H(2)O(2)-induced injury, cellular damage and S100B protein levels were evaluated. The effect of chronic administration of ascorbate on cellular oxidative state and astrocyte biochemical parameters in the hippocampus from 18-months-old Wistar rats was also studied. The ascorbate uptake was decreased in hippocampal slices from old-aged rats, while supplementation with ascorbate (2 weeks) did not modify any tested oxidative status in the hippocampus and the incubation was unable to protect hippocampal slices submitted to oxidative damage (H(2)O(2)) from old rats. Our data suggest that the decline of ascorbate uptake might be involved in the brain greater susceptibility to oxidative damage with advancing age and both in vitro and vivo assays suggest that ascorbate supplementation did not protect hippocampal cells. 相似文献