977 resultados para Standard Mouse Neutralization Test
Resumo:
Mice show urinary scent marking behavior as a form of social communication. Marking to a conspecific stimulus mouse or odor varies with stimulus familiarity, indicating discrimination of novel and familiar animals. This study investigated Fos immunoreactivity in inbred C57BL/6J (C57) males following scent marking behavior in response to detection of a social stimulus, or discrimination between a familiar and an unfamiliar conspecific. In Experiment 1 C57 mice were exposed for four daily trials to an empty chamber; on a test day they were exposed to the same chamber or to a male CD-1 mouse in that chamber. Increased scent marking to the CD-1 mouse was associated with increased Fos-immunoreactive cells in the basolateral amygdala, medial amygdala, and dorsal and ventral premammillary nuclei. In Experiment 2 C57 mice were habituated to a CD-1 male for 4 consecutive days and, on the 5th day, exposed to the same CD-1 male, or to a novel CD-1 male. Mice exposed to a novel CD-1 displayed a significant increase in scent marking compared to their last exposure to the familiar stimulus, indicating discrimination of the novelty of this social stimulus. Marking to the novel stimulus was associated with enhanced activation of several telencephalic, as well as hypothalamic and midbrain, structures in which activation had not been seen in the detection paradigm (Experiment 1). These included medial prefrontal and piriform cortices, and lateral septum; the paraventricular nuclei, ventromedial nuclei, and lateral area of the hypothalamus, and the ventrolateral column of the periaqueductal gray. These data suggest that a circumscribed group of structures largely concerned with olfaction is involved in detection of a conspecific olfactory stimulus, whereas discrimination of a novel vs. a familiar conspecific stimulus engages a wider range of forebrain structures encompassing higher-order processes and potentially providing an interface between cognitions and emotions. (C) 2009 IBRO. Published by Elsevier Ltd. All rights reserved.
Resumo:
The inferior colliculus (IC) together with the dorsal periaqueductal gray (dPAG), the amygdala and the medial hypothalamus make part of the brain aversion system, which has mainly been related to the organization of unconditioned fear. However, the involvement of the IC and dPAG in the conditioned fear is still unclear. It is certain that GABA has a regulatory role on the aversive states generated and elaborated in these midbrain structures. In this study, we evaluated the effects of injections of the GABA-A receptor agonist muscimol (1.0 and 2.0 nmol/0.2 mu L) into the IC or dPAG on the freezing and fear-potentiated startle (FPS) responses of rats submitted to a context fear conditioning. Intra-IC injections of muscimol did not cause any significant effect on the FPS or conditioned freezing but enhanced the startle reflex in non-conditioned animals. In contrast, intra-dPAG injections of muscimol caused significant reduction in FPS and conditioned freezing without changing the startle reflex in non-conditioned animals. Thus, intra-dPAG injections of muscimol produced the expected inhibitory effects on the anxiety-related responses, the FPS and the freezing whereas these injections into the IC produced quite opposite effects suggesting that descending inhibitory pathways from the IC, probably mediated by GABA-A mechanisms, exert a regulatory role on the lower brainstem circuits responsible for the startle reflex. (C) 2008 Elsevier Inc. All rights reserved.
Resumo:
Establishment of the left-right axis is a fundamental process of vertebrate embryogenesis. Failure to develop left-right asymmetry leads to incorrect positioning and morphogenesis of numerous internal organs, and is proposed to underlie the etiology of several common cardiac malformations. The transcriptional modulator Cited2 is essential for embryonic development: Cited2-null embryos die during gestation with profound developmental abnormalities, including cardiac malformations, exencephaly and adrenal agenesis. Cited2 is also required for normal establishment of the left-right axis; we demonstrate that abnormal heart looping and right atrial and pulmonary isomerism are consistent features of the left-right-patterning defect. We show by gene expression analysis that Cited2 acts upstream of Nodal, Lefty2 and Pitx2 in the lateral mesoderm, and of Lefty1 in the presumptive floor plate. Although abnormal left-right patterning has a major impact on the cardiac phenotype in Cited2-null embryos, laterality defects are only observed in a proportion of these embryos. We have therefore used a combination of high-resolution imaging and three-dimensional (3D) modeling to systematically document the full spectrum of Cited2-associated cardiac defects. Previous studies have focused on the role of Cited2 in cardiac neural crest cell development, as Cited2 can bind the transcription factor Tfap2, and thus affect the expression of Erbb3 in neural crest cells. However, we have identified Cited2-associated cardiac defects that cannot be explained by laterality or neural crest abnormalities. In particular, muscular ventricular septal defects and reduced cell density in the atrioventricular (AV) endocardial cushions are evident in Cited2-null embryos. As we found that Cited2 expression tightly correlated with these sites, we believe that Cited2 plays a direct role in development of the AV canal and cardiac septa. We therefore propose that, in addition to the previously described reduction of cardiac neural crest cells, two other distinct mechanisms contribute to the spectrum of complex cardiac defects in Cited2-null mice; disruption of normal left-right patterning and direct loss of Cited2 expression in cardiac tissues.
Resumo:
A central tenet of life-history theory is the presence of a trade-off between the size and number of offspring that a female can produce for a given clutch. A crucial assumption of this trade-off is that larger offspring perform better than smaller offspring. Despite the importance of this assumption empirical, field-based tests are rare, especially for marine organisms. We tested this assumption for the marine invertebrate, Diplosoma listerianum, a colonial ascidian that commonly occurs in temperate marine communities. Colonies that came from larger larvae had larger feeding structures than colonies that came from smaller larvae. Colonies that came from larger larvae also had higher survival and growth after 2 weeks in the field than colonies that came from smaller larvae. However, after 3 weeks in the field the colonies began to fragment and we could not detect an effect of larval size. We suggest that offspring size can have strong effects on the initial recruitment of D. listerianum but because of the tendency of this species to fragment, offspring size effects are less persistent in this species than in others.
Resumo:
PURPOSE: Many guidelines advocate measurement of total or low density lipoprotein cholesterol (LDL), high density lipoprotein cholesterol (HDL), and triglycerides (TG) to determine treatment recommendations for preventing coronary heart disease (CHD) and cardiovascular disease (CVD). This analysis is a comparison of lipid variables as predictors of cardiovascular disease. METHODS: Hazard ratios for coronary and cardiovascular deaths by fourths of total cholesterol (TC), LDL, HDL, TG, non-HDL, TC/HDL, and TG/HDL values, and for a one standard deviation change in these variables, were derived in an individual participant data meta-analysis of 32 cohort studies conducted in the Asia-Pacific region. The predictive value of each lipid variable was assessed using the likelihood ratio statistic. RESULTS: Adjusting for confounders and regression dilution, each lipid variable had a positive (negative for HDL) log-linear association with fatal CHD and CVD. Individuals in the highest fourth of each lipid variable had approximately twice the risk of CHD compared with those with lowest levels. TG and HDL were each better predictors of CHD and CVD risk compared with TC alone, with test statistics similar to TC/HDL and TG/HDL ratios. Calculated LDL was a relatively poor predictor. CONCLUSIONS: While LDL reduction remains the main target of intervention for lipid-lowering, these data support the potential use of TG or lipid ratios for CHD risk prediction. (c) 2005 Elsevier Inc. All rights reserved.
Resumo:
PREDBALB/c is a computational system that predicts peptides binding to the major histocompatibility complex-2 (H2(d)) of the BALB/c mouse, an important laboratory model organism. The predictions include the complete set of H2(d) class I ( H2-K-d, H2-L-d and H2-D-d) and class II (I-E-d and I-A(d)) molecules. The prediction system utilizes quantitative matrices, which were rigorously validated using experimentally determined binders and non-binders and also by in vivo studies using viral proteins. The prediction performance of PREDBALB/c is of very high accuracy. To our knowledge, this is the first online server for the prediction of peptides binding to a complete set of major histocompatibility complex molecules in a model organism (H2(d) haplotype). PREDBALB/c is available at http://antigen.i2r.a-star.edu.sg/predBalbc/.
Resumo:
The present study aimed to determine the richness, occurrence constancy, reproductive modes. standard of abundance distribution, season of vocalization and to test correlation among climatic variables and activity of vocalization of anurans in a region of the Pampa Biome, Santa Maria, Rio Grande do Sul State. During the period of Novernber/2001 to October/2002 monthly collections were carried out utilizing the `survey at breeding site` method and examination of specimens kept in the Colecao Herpetologica do Setor de Zoologia da Universidade Federal de Santa Maria (ZUFSM). Tire Occurrence of 25 species of anurans was recorded. The anurofauna recorded represents 30% of the species known to Occur in Rio Grande do Sul, and comprises species generally associated with grasslands in this state and neighboring countries. Four reproductive modes were recorded: mode 1 (14 species: 58.3%) mode 11 and 30 (9 species` 37.5%) and mode 24 (1 species; 4.2%). The low diversification of reproductive modes is likely related to the homogeneity of the grassland habitat. Most species were constant or accessory in the Study area and the species abundance distribution patterns fit in the Broken Stick and Log-normal models. characterized by homogeneity of species abundance distribution. Most species showed great plasticity in habitat. but few were plastic in vocalization sites use. There was a weak positive correlation between species richness and precipitation. There was also a weak positive correlation between the abundance of species calling activity and maximum average temperatures. These correlations indicated that, in the study area. the abundance of calling males is more affected by the temperature, and species richness is more affected by precipitation, despite the fact that significantly higher species richness occurs during the hottest period of the year. These results showed that the climatological variables examined were not enough to explain the seasonal occurrence of species, thus the influence of other environmental variables merit to be tested in future studies.
5-HT1A receptors of the lateral septum regulate inhibitory avoidance but not escape behavior in rats
Resumo:
Serotonin in the lateral septum (LS) has been implicated in the modulation of defensive behaviors and in anxiety. However, it is currently unknown whether changes in 5-HT mechanisms in this brain area may selectively affect defensive responses associated with specific subtypes of anxiety disorders recognized in clinical settings. To address this question, we evaluated the effect of the intra-LS injection of the 5-HT1A/7 receptor agonist 8-CH-DPAT (0.6, 3.0, 15.0 nmol) in male Wistar rats exposed to the elevated T-maze animal model of anxiety. This test allows the measurement of two behavioral defensive responses in the same rat: inhibitory avoidance and escape behavior. In clinical terms, these responses have been respectively related to generalized anxiety and panic disorder. The effects of 8-OH-DPAT were compared to those caused by a standard anxiolytic compound, the benzodiazepine receptor agonist midazolam (MDZ, 20 nmol). We also investigated whether the intra-LS injection of the 5-HT1A receptor antagonist WAY-100635 (0.37 nmol) was able to block the effects of 8-OH-DPAT. All animals were also tested in an open field for locomotor activity assessments. Results showed that whereas intra-LS administration of MDZ decreased avoidance latencies, suggesting an anxiolytic action, 8-OH-DPAT caused the opposite effect. Neither drug affected the escape performance. Intra-LS administration of WAY-100635 blocked the anxiogenic effect caused by 8-OH-DPAT. No changes to locomotion were detected in the open field. The data suggests that LS 5-HT1A receptors are involved in the control of inhibitory avoidance behavior and that a failure in this regulatory mechanism may be of importance to the physiopathology of generalized anxiety disorder. (c) 2008 Elsevier Inc. All rights reserved.
Resumo:
The object of this study is to assess informative possibilities of some technical indicators of the Test of Photos of Professions (BBT - Berufsbilder test), a projective method to clarify professional inclination, proposed by Martin Achtnich. This psychological evaluation technique is composed of 96 photos of professionals, performing various types of activities. The test subject classifies the photos into three groups: positive (agreeable), negative (disagreeable) and indifferent (neutral). Among those chosen positively, five preferences are chosen and a story is developed that includes them, an activity that is requested two times during the Vocational Guidance process: in the beginning (or middle) and at the end of the intervention. In this study, 160 stories were created by 80 youths, between 15 and 20 years of age, in public and private schools in a mid-sized Brazilian city. The stories were compared in three analytical categories: protagonist, professional conflict and resolution. The results were submitted to Wilcoxon nonparametric statistical analysis (p < .05), significant and relevant indicators of resolution being found in the process of occupational choice. This technical resource was shown, from this empirical evidence, to be promising for use in evaluation of intervention processes of Vocational Guidance.
Resumo:
Tuberculosis, a polymorphic disease, is a diagnostic challenge, particularly when arises concomitantly to an autoimmune disease such as rheumatoid arthritis (RA). Herein, the authors describe a 33-year-old woman with nodular RA who was being treated with methotrexate, sulfasalazine and corticosteroids and presented with subcutaneous nodules simultaneously with aseptic meningitis. Mycobacterium tuberculosis was identified in cultures from a biopsy of an axillary nodule. The patient also developed polyuria and polydipsia with normal glycemia; antidiuretic hormone (ADH) treatment before and after a 3% saline infusion test was performed and diabetes insipidus was diagnosed. An encephalic MRI showed sellar and suprasellar masses, suggesting central diabetes insipidus (CDI). The patient received standard tuberculosis (TB) treatment for 6 months and also DDAVP (desmopressin acetate) during this period. Control of CDI was observed. A pre-surgical magnetic resonance imaging (MRI) showed no pituitary mass. It is known that intrasellar tuberculoma occurs in only 1% of TB patients. TB should be considered in the differential diagnosis of CDI, especially in immunosupressed patients and in countries where this infection is a serious public health problem.
Resumo:
Considering that mycobacterial heat-shock protein 65 (hsp65) gene transfer can elicit a profound antitumoral effect, this study aimed to establish the safety, maximum-tolerated dose (MTD) and preliminary efficacy of DNA-hsp65 immunotherapy in patients with advanced head and neck squamous cell carcinoma (HNSCC). For this purpose, 21 patients with unresectable and recurrent HNSCC were studied. Each patient received three ultrasound-guided injections at 21-day intervals of: 150, 600 or 400 mu g of DNA-hsp65. Toxicity was graded according to CTCAE directions. Tumor volume was measured before and after treatment using computed tomography scan. The evaluation included tumor mass variation, delayed-type hypersensitivity response and spontaneous peripheral blood mononuclear cell proliferation before and after treatment. The MTD was 400 mg per dose. DNA-hsp65 immunotherapy was well tolerated with moderate pain, edema and infections as the most frequent adverse effects. None of the patients showed clinical or laboratory alterations compatible with autoimmune reactions. Partial response was observed in 4 out of 14 patients who completed treatment, 2 of which are still alive more than 3 years after the completion of the trial. Therefore, DNA-hsp65 immunotherapy is a feasible and safe approach at the dose of 400 mg per injection in patients with HNSCC refractory to standard treatment. Further studies in a larger number of patients are needed to confirm the efficacy of this novel strategy.