375 research outputs found

    Endothelium-dependent relaxation of rat aorta to a histamine H3 agonist is reduced by inhibitors of nitric oxide synthase, guanylate cyclase and Na+,K+-ATPase

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    The possible involvement of different effector systems (nitric oxide synthase, guanylate cyclase, β-adrenergic and muscarinic cholinergic receptors, cyclooxygenase and lipoxygenase, and Na+,K+-ATPase) was evaluated in a histamine H3 receptor agonist-induced ((R)α-methylhistamine, (R)α-MeHA) endothelium-dependent rat aorta relaxation assay. (R)α-MeHA (0.1 nM – 0.01 mM) relaxed endothelium-dependent rat aorta, with a pD2 value of 8.22 ± 0.06, compared with a pD2 value of 7.98 ± 0.02 caused by histamine (50% and 70% relaxation, respectively). The effect of (R)α-MeHA (0.1 nM – 0.01 mM) was competitively antagonized by thioperamide (1, 10 and 30 nM) (pA2 = 9.21 ± 0.40; slope = 1.03 ± 0.35) but it was unaffected by pyrilamine (100 nM), cimetidine (1 μM), atropine (10 μM), propranolol (1 μM), indomethacin (10 μM) or nordthydroguaiaretic acid (0.1 mM). Inhibitors of nitric oxide synthase, L-NG-monomethylarginine (L-NMMA, 10 μM) and NG-nitro-L-arginine methylester (L-NOARG, 10 μM) inhibited the relaxation effect of (R)α-MeHA, by approximately 52% and 70%, respectively). This inhibitory effect of L-NMMA was partially reversed by L-arginine (10 μM). Methylene blue (10 μM) and ouabain (10 μM) inhibited relaxation (R)α-MeHA-induced by approximately 50% and 90%, respectively. The products of cyclooxygenase and lipoxygenase are not involved in (R)α-MeHA-induced endothelium-dependent rat aorta relaxation nor are the muscarinic cholinergic and β-adrenergic receptors. The results also suggest the involvement of NO synthase, guanylate cyclase and Na+,K+-ATPase in (R)α-MeHA-induced endothelium-dependent rat aorta relaxation

    Co-overexpression of bcl-2 and c-myc in uterine cervix carcinomas and premalignant lesions

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    To establish the role of co-overexpression of bcl-2 and c-myc protooncogenes in uterine cervix carcinogenesis, we examined 138 tissue samples of low grade cervical squamous intraepithelial lesions (SIL), high grade SIL, portio vaginalis uteri (PVU) carcinoma in situ and PVU invasive carcinoma, stage IA-IIA (study group) and 36 samples without SIL or malignancy (control group). The expression of bcl-2 and c-myc was detected immunohistochemically using a monoclonal antibody. Fisher's exact test (P<0.05) was used to assess statistical significance. Overexpression of bcl-2 was found to increase in direct relation to the grade of the cervical lesions. High sensitivity was of great diagnostic significance for the detection of these types of changes in the uterine cervix. On the basis of high predictive values it can be said that in patients with bcl-2 overexpression there is a great possibility that they have premalignant or malignant changes in the uterine cervix. Co-overexpression of bcl-2 and c-myc oncogenes was found only in patients with PVU invasive carcinoma (6/26-23.0%). Statistically significant difference was not found in the frequency of co-overexpression in patients with PVU invasive carcinoma in relation to the control group (Fisher's test; P=0.064). The method's sensitivity of determining these oncogenes with the aim of detecting PVU invasive carcinoma was 23%, while specificity was 72.2%. On the basis of high predictive values (100%), speaking in statistical terms, it can be concluded that all patients with co-overexpression of bcl-2 and c-myc oncogenes will have PVU invasive carcinoma. We confirmed in our research that co-overexpression of bcl-2 and c-myc oncogenes was increased only in PVU invasive carcinoma. However, a more extensive series of samples and additional tests are required to establish the prognostic significance of bcl-2 and c-myc co-overexpression in cervical carcinogenesis

    Breeding progress in grain yield of winter wheat cultivars grown at different nitrogen levels in semiarid conditions

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    The objectives of this study were to estimate the progress in wheat genetic yield potential, associated with changes in some agronomic traits, under different N rates. Twenty-four cultivars of winter wheat (T. aestivtum L.) representing most of the cultivars released in Serbia from 1955 to 2006 were analyzed. The cultivars were grown for four years (2005-2008) in field trails with two levels of agronomic inputs (low nitrogen-N-45 and high nitrogen-N-110). Data were collected on 1000-kernel weight, kernels per spike, kernels per square meter, spikes per square meter, plant height, harvest index, heading time and grain yield. Mean difference between the two fertilization levels was 0.44 t ha(-1). The average rate of increase in yield potential per year of release, estimated from the slope, was 41 kg ha(-1) year(-1) and it was significantly different from zero (P lt = 0.01). It was 35 kg ha(-1) year(-1) or 0.55% at the low level of N input, and 46 kg ha(-1) year(-1) or 0.68% at the high level of N input. This suggests that modern cultivars are better adapted to high N input. Our results suggested that individual contribution of the most of analyzed traits may vary depending on the genotype as well as environmental conditions

    From model-driven software development processes to problem diagnoses at runtime

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    Following the “convention over configuration” paradigm, model-driven software development (MDSD) generates code to implement the “default” behaviour that has been specified by a template separate from the input model. On the one hand, developers can produce end-products without a full understanding of the templates; on the other hand, the tacit knowledge in the templates is subtle to diagnose when a runtime software failure occurs. Therefore, there is a gap between templates and runtime adapted models. Generalising from the concrete problematic examples in MDSD processes to a model-based problem diagnosis, the chapter presents a procedure to separate the automated fixes from those runtime gaps that require human judgments

    A population Monte Carlo scheme with transformed weights and its application to stochastic kinetic models

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    This paper addresses the problem of Monte Carlo approximation of posterior probability distributions. In particular, we have considered a recently proposed technique known as population Monte Carlo (PMC), which is based on an iterative importance sampling approach. An important drawback of this methodology is the degeneracy of the importance weights when the dimension of either the observations or the variables of interest is high. To alleviate this difficulty, we propose a novel method that performs a nonlinear transformation on the importance weights. This operation reduces the weight variation, hence it avoids their degeneracy and increases the efficiency of the importance sampling scheme, specially when drawing from a proposal functions which are poorly adapted to the true posterior. For the sake of illustration, we have applied the proposed algorithm to the estimation of the parameters of a Gaussian mixture model. This is a very simple problem that enables us to clearly show and discuss the main features of the proposed technique. As a practical application, we have also considered the popular (and challenging) problem of estimating the rate parameters of stochastic kinetic models (SKM). SKMs are highly multivariate systems that model molecular interactions in biological and chemical problems. We introduce a particularization of the proposed algorithm to SKMs and present numerical results.Comment: 35 pages, 8 figure

    Development of exchange lists for M editerranean and H ealthy E ating D iets: implementation in an intervention trial

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    Background There has been little research published on the adaptation of diabetic exchange list diet approaches for the design of intervention diets in health research despite their clinical utility. The exchange list approach can provide clear and precise guidance on multiple dietary changes simultaneously. The present study aimed to develop exchange list diets for M editerranean and H ealthy E ating, and to evaluate adherence, dietary intakes and markers of health risks with each counselling approach in 120 subjects at increased risk for developing colon cancer. Methods A randomised clinical trial was implemented in the USA involving telephone counselling. The M editerranean diet had 10 dietary goals targeting increases in mono‐unsaturated fats, n ‐3 fats, whole grains and the amount and variety of fruits and vegetables. The Healthy Eating diet had five dietary goals that were based on the US H ealthy P eople 2010 recommendations. Results Dietary compliance was similar in both diet arms, with 82–88% of goals being met at 6 months, although subjects took more time to achieve the M editerranean goals than the H ealthy E ating goals. The relatively modest fruit and vegetable goals in the Healthy Eating arm were exceeded, resulting in fruit and vegetable intakes of approximately eight servings per day in each arm after 6 months. A significant ( P  < 0.05) weight loss and a decrease in serum C ‐reactive protein concentrations were observed in the overweight/obese subgroup of subjects in the M editerranean arm in the absence of weight loss goals. Conclusions Counselling for the M editerranean diet may be useful for both improving diet quality and for achieving a modest weight loss in overweight or obese individuals.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108685/1/jhn12158.pd

    Enhanced cosmic-ray flux toward zeta Persei inferred from laboratory study of H3+ - e- recombination rate

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    The H3+ molecular ion plays a fundamental role in interstellar chemistry, as it initiates a network of chemical reactions that produce many interstellar molecules. In dense clouds, the H3+ abundance is understood using a simple chemical model, from which observations of H3+ yield valuable estimates of cloud path length, density, and temperature. On the other hand, observations of diffuse clouds have suggested that H3+ is considerably more abundant than expected from the chemical models. However, diffuse cloud models have been hampered by the uncertain values of three key parameters: the rate of H3+ destruction by electrons, the electron fraction, and the cosmic-ray ionisation rate. Here we report a direct experimental measurement of the H3+ destruction rate under nearly interstellar conditions. We also report the observation of H3+ in a diffuse cloud (towards zeta Persei) where the electron fraction is already known. Taken together, these results allow us to derive the value of the third uncertain model parameter: we find that the cosmic-ray ionisation rate in this sightline is forty times faster than previously assumed. If such a high cosmic-ray flux is indeed ubiquitous in diffuse clouds, the discrepancy between chemical models and the previous observations of H3+ can be resolved.Comment: 6 pages, Nature, in pres

    Philosophical aspects of personal branding in the context of informationculture and social nets (through the example of Instagram platform)

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    The article reveals the issue of the concept of personal branding in the context of information culture, social nets and social media. The relevance of the article is reasoned by the growing interest towardspersonal branding and people’s tendency to turn to commodity their personality, knowledge and experience in digital world. The general definitions of the process of commodification and personal branding aregiven. The due consideration is given to the manifestation of personal branding on the platform of Instagram. The author emphasizes the role of personal branding under the modern market conditions,created with the help of smart and digital technologies in the context of globalized world
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