992 resultados para aggregative-like adherence pattern
Resumo:
Toll-like receptors (TLRs) are pattern recognition receptors playing a fundamental role in sensing microbial invasion and initiating innate and adaptive immune responses. TLRs are also triggered by danger signals released by injured or stressed cells during sepsis. Here we focus on studies developing TLR agonists and antagonists for the treatment of infectious diseases and sepsis. Positioned at the cell surface, TLR4 is essential for sensing lipopolysaccharide of Gram-negative bacteria, TLR2 is involved in the recognition of a large panel of microbial ligands, while TLR5 recognizes flagellin. Endosomal TLR3, TLR7, TLR8, TLR9 are specialized in the sensing of nucleic acids produced notably during viral infections. TLR4 and TLR2 are favorite targets for developing anti-sepsis drugs, and antagonistic compounds have shown efficient protection from septic shock in pre-clinical models. Results from clinical trials evaluating anti-TLR4 and anti-TLR2 approaches are presented, discussing the challenges of study design in sepsis and future exploitation of these agents in infectious diseases. We also report results from studies suggesting that the TLR5 agonist flagellin may protect from infections of the gastrointestinal tract and that agonists of endosomal TLRs are very promising for treating chronic viral infections. Altogether, TLR-targeted therapies have a strong potential for prevention and intervention in infectious diseases, notably sepsis.
Resumo:
PURPOSE Our purpose was development and assessment of a BRAF-mutant gene expression signature for colon cancer (CC) and the study of its prognostic implications. Materials and METHODS A set of 668 stage II and III CC samples from the PETACC-3 (Pan-European Trails in Alimentary Tract Cancers) clinical trial were used to assess differential gene expression between c.1799T>A (p.V600E) BRAF mutant and non-BRAF, non-KRAS mutant cancers (double wild type) and to construct a gene expression-based classifier for detecting BRAF mutant samples with high sensitivity. The classifier was validated in independent data sets, and survival rates were compared between classifier positive and negative tumors. Results A 64 gene-based classifier was developed with 96% sensitivity and 86% specificity for detecting BRAF mutant tumors in PETACC-3 and independent samples. A subpopulation of BRAF wild-type patients (30% of KRAS mutants, 13% of double wild type) showed a gene expression pattern and had poor overall survival and survival after relapse, similar to those observed in BRAF-mutant patients. Thus they form a distinct prognostic subgroup within their mutation class. CONCLUSION A characteristic pattern of gene expression is associated with and accurately predicts BRAF mutation status and, in addition, identifies a population of BRAF mutated-like KRAS mutants and double wild-type patients with similarly poor prognosis. This suggests a common biology between these tumors and provides a novel classification tool for cancers, adding prognostic and biologic information that is not captured by the mutation status alone. These results may guide therapeutic strategies for this patient segment and may help in population stratification for clinical trials.
Resumo:
Background: In the course of evolution butterflies and moths developed two different reproductive behaviors. Whereas butterflies rely on visual stimuli for mate location, moths use the"female calling plus male seduction" system, in which females release long-range sex pheromones to attract conspecific males. There are few exceptions from this pattern but in all cases known female moths possess sex pheromone glands which apparently have been lost in female butterflies. In the day-flying moth family Castniidae ("butterfly-moths"), which includes some important crop pests, no pheromones have been found so far. Methodology/Principal Findings: Using a multidisciplinary approach we described the steps involved in the courtship of P. archon, showing that visual cues are the only ones used for mate location; showed that the morphology and fine structure of the antennae of this moth are strikingly similar to those of butterflies, with male sensilla apparently not suited to detect female-released long range pheromones; showed that its females lack pheromone-producing glands, and identified three compounds as putative male sex pheromone (MSP) components of P. archon, released from the proximal halves of male forewings and hindwings. Conclusions/Significance: This study provides evidence for the first time in Lepidoptera that females of a moth do not produce any pheromone to attract males, and that mate location is achieved only visually by patrolling males, which may release a pheromone at short distance, putatively a mixture of Z,E-farnesal, E,E-farnesal, and (E,Z)-2,13-octadecadienol. The outlined behavior, long thought to be unique to butterflies, is likely to be widespread in Castniidae implying a novel, unparalleled butterfly-like reproductive behavior in moths. This will also have practical implications in applied entomology since it signifies that the monitoring/control of castniid pests should not be based on the use of female-produced pheromones, as it is usually done in many moths.
Resumo:
Adherence to aMediterranean diet (MD) is associated with a reduced risk of coronary heart disease. However, themolecular mechanisms involved are not fully understood. The aim of this studywas to compare the effects of 2MD with those of a lowfat- diet (LFD) on circulating inflammatory biomarkers related to atherogenesis. A total of 516 participants included in the PreventionwithMediterraneanDiet Studywere randomized into 3 intervention groups [MD supplementedwith virgin olive oil (MD-VOO); MD supplemented with mixed nuts (MD-Nuts); and LFD]. At baseline and after 1 y, participants completed FFQ and adherence to MD questionnaires, and plasma concentrations of inflammatory markers including intercellular adhesion molecule-1(ICAM-1), IL-6, and 2 TNF receptors (TNFR60 and TNFR80) were measured by ELISA. At 1 y, the MD groups had lower plasma concentrations of IL-6, TNFR60, and TNFR80 (P , 0.05), whereas ICAM-1, TNFR60, and TNFR80 concentrations increased in the LFD group (P , 0.002). Due to between-group differences, participants in the 2 MD groups had lower plasma concentrations of ICAM-1, IL-6, TNFR60, and TNFR80 compared to those in the LFD group (P # 0.028). When participants were categorized in tertiles of 1-y changes in the consumption of selected foods, those in the highest tertile of virgin olive oil (VOO) and vegetable consumption had a lower plasma TNFR60 concentration compared with those in tertile 1 (P,0.02).Moreover, the only changes in consumption thatwere associated with 1-y changes in the geometricmean TNFR60 concentrations were those of VOO and vegetables (P = 0.01). This study suggests that a MD reduces TNFR concentrations in patients at high cardiovascular risk.
Resumo:
BACKGROUND: An inverse correlation between expression of the aldehyde dehydrogenase 1 subfamily A2 (ALDH1A2) and gene promoter methylation has been identified as a common feature of oropharyngeal squamous cell carcinoma (OPSCC). Moreover, low ALDH1A2 expression was associated with an unfavorable prognosis of OPSCC patients, however the causal link between reduced ALDH1A2 function and treatment failure has not been addressed so far. METHODS: Serial sections from tissue microarrays of patients with primary OPSCC (n = 101) were stained by immunohistochemistry for key regulators of retinoic acid (RA) signaling, including ALDH1A2. Survival with respect to these regulators was investigated by univariate Kaplan-Meier analysis and multivariate Cox regression proportional hazard models. The impact of ALDH1A2-RAR signaling on tumor-relevant processes was addressed in established tumor cell lines and in an orthotopic mouse xenograft model. RESULTS: Immunohistochemical analysis showed an improved prognosis of ALDH1A2(high) OPSCC only in the presence of CRABP2, an intracellular RA transporter. Moreover, an ALDH1A2(high)CRABP2(high) staining pattern served as an independent predictor for progression-free (HR: 0.395, p = 0.007) and overall survival (HR: 0.303, p = 0.002), suggesting a critical impact of RA metabolism and signaling on clinical outcome. Functionally, ALDH1A2 expression and activity in tumor cell lines were related to RA levels. While administration of retinoids inhibited clonogenic growth and proliferation, the pharmacological inhibition of ALDH1A2-RAR signaling resulted in loss of cell-cell adhesion and a mesenchymal-like phenotype. Xenograft tumors derived from FaDu cells with stable silencing of ALDH1A2 and primary tumors from OPSCC patients with low ALDH1A2 expression exhibited a mesenchymal-like phenotype characterized by vimentin expression. CONCLUSIONS: This study has unraveled a critical role of ALDH1A2-RAR signaling in the pathogenesis of head and neck cancer and our data implicate that patients with ALDH1A2(low) tumors might benefit from adjuvant treatment with retinoids.
Resumo:
The synthesis of 1-deoxy-D-xylulose 5-phosphate (DXP), catalyzed by the enzyme DXP synthase (DXS), represents a key regulatory step of the 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway for isoprenoid biosynthesis. In plants DXS is encoded by small multigene families that can be classified into, at least, three specialized subfamilies. Arabidopsis thaliana contains three genes encoding proteins with similarity to DXS, including the well-known DXS1/CLA1 gene, which clusters within subfamily I. The remaining proteins, initially named DXS2 and DXS3, have not yet been characterized. Here we report the expression and functional analysis of A. thaliana DXS2. Unexpectedly, the expression of DXS2 failed to rescue Escherichia coli and A. thaliana mutants defective in DXS activity. Coherently, we found that DXS activity was negligible in vitro, being renamed as DXL1 following recent nomenclature recommendation. DXL1 is targeted to plastids as DXS1, but shows a distinct expression pattern. The phenotypic analysis of a DXL1 defective mutant revealed that the function of the encoded protein is not essential for growth and development. Evolutionary analyses indicated that DXL1 emerged from DXS1 through a recent duplication apparently specific of the Brassicaceae lineage. Divergent selective constraints would have affected a significant fraction of sites after diversification of the paralogues. Furthermore, amino acids subjected to divergent selection and likely critical for functional divergence through the acquisition of a novel, although not yet known, biochemical function, were identified. Our results provide with the first evidences of functional specialization at both the regulatory and biochemical level within the plant DXS family.
Resumo:
Pancreatic adenocarcinoma is associated with a very poor prognosis, characterized with a 5-year survival rate of only 5%. Surgery is the only curative treatment for selected patients. Nevertheless, recurrence is very frequent. Identifying prognostic factors is thus warranted. Like numerous other tumors, adenocarcinomas are preceded by preneoplastic lesions. The role and the impact of these lesions remain unclear. This study aimed to assess the impact of the preneoplastic lesion pattern and histo-morphological features, on survival after pancreatic resection. Thirty-five patients who underwent pancreatic resection for pancreatic adenocarcinoma were identified from a prospective database of a single center, between 2003 and 2008. We considered demographics, tumor characteristics and type of treatment. The major outcome was survival. Analyzes were separated into two groups, according to the preneoplastic lesions: Pancreatic intraepithelial neoplasia (PanIN)-related carcinomas and intracanalar papillary mucinous neoplasia (IPMN)-related carcinomas. The former were more frequent, accounting for 63% (22/35). Moreover, they displayed more aggressive features, with a higher tumor stage (p = 0.01) and higher rate of positive lymph nodes (p = 0.019). Lymphatic (p = 0.009) and perinervous (p = 0.019) invasions were also more frequent. Survival was negatively influenced by PanIN preneoplastic lesions (p = 0.015), T3-4 tumor stage (p = 0.038), positive lymph nodes (p = 0.044), lymphatic (p = 0.019) and vascular (p = 0.029) invasions. Pancreatic adenocarcinoma displays different behavior according to its preneoplastic lesion. Indeed, PanIN-related adenocarcinoma showed more aggressive features and lower survival rate. Preneoplastic lesions may represent predictive factors for survival. Their role and predictive value should be investigated more thoroughly.
Resumo:
Non-typable Haemophilus influenzae (NTHi) is a Gram negative pathogen that causes acute respiratory infections and is associated with the progression of chronic respiratory diseases. Previous studies have established the existence of a remarkable genetic variability among NTHi strains. In this study we show that, in spite of a high level of genetic heterogeneity, NTHi clinical isolates display a prevalent molecular feature, which could confer fitness during infectious processes. A total of 111 non-isogenic NTHi strains from an identical number of patients, isolated in two distinct geographical locations in the same period of time, were used to analyse nine genes encoding bacterial surface molecules, and revealed the existence of one highly prevalent molecular pattern (lgtF+, lic2A+, lic1D+, lic3A+, lic3B+, siaA−, lic2C+, ompP5+, oapA+) displayed by 94.6% of isolates. Such a genetic profile was associated with a higher bacterial resistance to serum mediated killing and enhanced adherence to human respiratory epithelial cells.
Resumo:
BACKGROUND: Simulation techniques are spreading rapidly in medicine. Suc h resources are increasingly concentrated in Simulation Laboratories. The MSRP-USP is structuring such a laboratory and is interested in the prevalence of individual initiatives that could be centralized there. The MSRP-USP currently has five full-curriculum courses in the health sciences: Medicine, Speech Therapy, Physical Therapy, Nutrition, and Occupational Therapy, all consisting of core disciplines. GOAL: To determine the prevalence of simulation techniques in the regular courses at MSRP-USP. METHODS: Coordinators of disciplines in the various courses were interviewed using a specifically designed semi-structured questionnaire, and all the collected data were stored in a dedicated database. The disciplines were grouped according to whether they used (GI) or did not use (GII) simulation resources. RESULTS AND DISCUSSION: 256 disciplines were analyzed, of which only 18.3% used simulation techniques, varying according to course: Medicine (24.7.3%), Occupational Therapy (23.0%), Nutrition (15.9%), Physical Therapy (9.8%), and Speech Therapy (9.1%). Computer simulation programs predominated (42.5%) in all five courses. The resources were provided mainly by MSRP-USP (56.3%), with additional funding coming from other sources based on individual initiatives. The same pattern was observed for maintenance. There was great interest in centralizing the resources in the new Simulation Laboratory in order to facilitate maintenance, but there was concern about training and access to the material. CONCLUSIONS: 1) The MSRP-USP simulation resources show low complexity and are mainly limited to computer programs; 2) Use of simulation varies according to course, and is most prevalent in Medicine; 3) Resources are scattered across several locations, and their acquisition and maintenance depend on individual initiatives rather than central coordination or curricular guidelines
Resumo:
This work established the adequate temperature and the period of exposition for the accelerated ageing test with diasporas of Myracrodruon urundeuva from an area of the Cerrado in the state of Mato Grosso, Brazil. Before and after the ageing, at the temperatures of 40ºC, 41ºC, 42ºC and 45ºC combined with periods of 12, 18, 24, 30 and 36 hours, the water content and germination were evaluated. For each treatment, 12g of diasporas in mini chambers with 40 mL of distilled water were submitted to the accelerated ageing test. A total of 100 diasporas, divided into four replications, in plastic boxes, on two sheets of blotting paper, in germinator at 25ºC and 8 hours of photoperiod were germinated. In all treatments the content of water of the aged diasporas was superior to 20% and this value stabilized itself between 25% and 28%, from the 18 hours of exposition. Independently of the tested periods, the ageing at the temperatures of 40ºC, 41ºC and 42ºC did not affect the germination. After the ageing at 45ºC, the germination did not differ among the periods of 12, 18 and 24 hours of exposition, but in all these periods it was inferior to the control and superior to the periods of 30 and 36 hours. In these last two periods, fungi were observed. The accelerated ageing of diasporas of Myracrodruon urundeuva should be conducted at the temperature of 45ºC, during the exposition periods of 12 to 24 hours.
Resumo:
This study focuses on work commitment creation on rhetorical level, that is to say, the rhetorical and linguistic means that are used to construct or elicit worker commitment. The commitment of the worker is one of the most important objectives of all business communication. There is a strong demand for commitment, identification, or adherence to work in various walks of life, although the actual circumstances are often somewhat insecure and shortsighted. The analysis demonstrates that the actual object of commitment may vary from work itself or work organization to one’s career or professional development. The ideal pattern for commitment appears as comprehensive: it contains affective and rational as well as ideological dimensions. This thesis is a rhetorical discourse analysis, or rhetorical analysis with discourse-analytic influences. Primarily it is a rhetorical analysis in which discourses are observed mainly as tools of a rhetorician. The study also draws on various findings of sociology of work and organizational studies. Research material consists of magazines from three and web pages from six different companies. This study explores repeated discourses in commitment rhetoric, mainly through pointing core concepts and recurrent patterns of argumentation. In this analysis section, a semantic and concept-analytic approach is also employed. Companies talk about ideas, values, feelings and attitudes thus constructing a united and unanimous group and an ideal model of commitment. Probably the most important domain of commitment rhetoric is the construction of group and community. Collective identity is constructed through shared meanings, values and goals, and these rhetorical group constructs that can be used and modified in various ways. Every now and then business communication also focuses on the individual, employing different speakers, positions and discourses associated to them. Constructing and using these positions also paints the picture of an ideal worker and ideal work orientation. For example, the so called entrepreneurship model is frequently used here. Commitment talk and the rhetorical situation it constructs are full of tensions and contradictions; the presence of seemingly contradictory values, goals or identities is constant. This study demonstrates tensions like self-fulfilment and individuality versus conformity, and constant change and development versus dependable establishment, and analyses how they are used, processed and dealt with. An important dimension in commitment rhetoric is the way companies define themselves in respect of current social issues, and how they define themselves as responsible social actors, and how they, in this sense, seek to appear as attractive workplaces. This point of view gives rise to problematic questions as companies process the tensions between, for example, rhetoric and action, ethical ideals and business conditions and so on. For its part, the commitment talk also defines the meaning of waged work in human life. Changing society, changing working life, and changing business environments set new claims and standards for workers and contents of work. In this point of view this research contributes to the study of working life and takes part in current public discussion concerning the meaning, role and future of waged work.
Resumo:
This study reports on changes in the number of somatostatin-like immunoreactive (SOM-LI) endocrine cells in the porcine descending colon, caused by chemically driven inflammation, axotomy and proliferative enteropathy (PE). The distribution pattern of SOM-LI endocrine cells has been studied using the routine single-labelling immunofluorescence technique. Semi-quantitative evaluation of the number of the SOM-immunostained endocrine cells within the mucosal layer of the porcine descending colon has been based on counting of all endocrine cells immunoreactive to SOM per unit area (0,1 mm²). Under physiological conditions the number of SOM-LI endocrine cells has been shown to constitute 3,30±0,22. All applied pathological processes resulted in changes in the SOM-like immunoreactivity, which varied in particular processes studied. The number of SOM-LI endocrine cells increased to 6,28±0,31 and 4,43±0,35 during chemically driven inflammation and proliferative enteropathy, respectively, and decreased to 1,17%±0,16 after axotomy. The obtained results suggest that SOM-LI endocrine cells may participate in various pathological states within porcine descending colon and their functions probably depend on the type of pathological factor.
Resumo:
This study evaluated the expression of CD14, toll-like receptor (TLR) 2 and TLR4 on the surface of milk neutrophils in bovine mammary glands infected with Corynebacterium bovis. Here, we used 23 culture-negative control quarters with no abnormal secretion on the strip cup test and milk somatic cell count lower than 1x105 cells/mL, and 14 C. bovis infected quarters. The identification of neutrophils, as well as, the percentage of neutrophils that expressed CD14, TLR2 and TLR4 were analyzed by flow cytometry using monoclonal antibodies. The present study encountered no significant difference in the percentages of milk neutrophils that expressed TLR2 and TLR4 or in the expression of TLR4 by milk neutrophils. Conversely, a lower median fluorescence intensity of TLR2 in milk neutrophils was observed in C. bovis-infected quarters. The percentage of neutrophils that expressed CD14 and the median fluorescence intensity of CD14 in milk neutrophils was also lower in C. bovis-infected quarters.
Resumo:
The sleep-wake cycle of students is characterized by delayed onset, partial sleep deprivation and poor sleep quality. Like other circadian rhythms, the sleep-wake cycle is influenced by endogenous and environmental factors. The aim of the present study was to determine the effects of different class starting times on the sleep-wake pattern of 27 medical students. The data were collected during two medical school semesters having different class starting times. All subjects answered the Portuguese version of the Horne and Östberg Morningness/Eveningness Questionnaire, the Pittsburgh Sleep Quality Index (PSQI) and kept a sleep diary for two weeks during each semester. Better sleep quality (PSQI = 5.3 vs 3.4), delayed sleep onset (23:59 vs 0:54 h) and longer sleep duration (6 h and 55 min vs 7 h and 25 min) were observed with the late schedule. We also found reduced sleep durations during weekdays and extended sleep durations during weekends. This pattern was more pronounced during the semester with the early class schedule, indicating that the students were more sleep deprived when their classes began earlier in the morning. These results require further investigation regarding the temporal organization of our institutions.
Resumo:
Head dipping (HD) is a behavioral pattern considered to have a risk assessment or an exploratory role and is used as a complementary parameter to evaluate anxiety in experimental animals. Since rats with electrolytic lesion in the area of the median raphe nucleus displayed high frequencies of HD in a previous study, the present investigation was undertaken to confirm this observation and to determine its anxiety-related origin. HD episodes were counted in adult male Wistar rats (270-350 g) with electrolytic lesion (N = 11) and sham-lesioned controls (N = 12). When HD was measured for 60 min on an elevated open platform, lesioned rats emitted 13 times more HD than controls (264.7 ± 93.3 vs 20.3 ± 7.6 episodes), with the difference being statistically significant (P < 0.05). HD counts during 10-min sessions held 7, 14, 21, 27, and 63 days after lesion showed significantly higher means (range: 28.14 ± 5.38 to 62.85 ± 9.48) compared to sham-lesioned controls (range: 7.37 ± 1.13 to 8.5 ± 1.45). Normal rats stepped down into their home cages when the vertical distance between them and the cage was short (16 cm), and the step-down latencies increased with increasing depths (36.7 ± 7.92 to 185.87 ± 35.44 s). Lesioned rats showed a similar behavior when facing the shortest depth, but had a significantly increased number (23.28 ± 2.35 episodes) and latency (300 ± 0.00 s) of HD compared to normal rats (9.25 ± 1.37 episodes and 185.87 ± 35.44 s) when facing the greatest depth (30 cm). This suggests that HD may be a depth-measuring behavior related to risk assessment.