181 research outputs found

    Fractal and stereological analyses of insulin-induced rat exocrine pancreas remodelling

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    Background: The effect of insulin on the endocrine pancreas has been the subject of extensive study, but quantitative morphometric investigations of the exocrine pancreas are scarce. This study was therefore undertaken to investigate the effect of acute and chronic insulin administration (two doses, 0.4 IU and 4 IU) on the morphology of rat pancreas acini. Materials and methods: Semi-fine sections stained with methylene blue and basic fuchsine or haematoxylin and eosin-stained 5-micrometer thick paraffin sections were used for fractal and stereological analysis of exocrine acini. Acute insulin treatment, independent of applied doses increased fractal dimension in line with decreased lacunarity of pancreas acini. Chronic low dose insulin decreased fractal dimension and increased lacunarity of pancreas acini, but a high dose had the opposite effect. The volume densities (Vv) of cytoplasm, granules and nucleus are affected differently: acute low dose and high chronic dose significantly decreased granules Vv, and in line increased cytoplasmic Vv, whereas other examined structures showed slight changes without statistical significance. Results: The results obtained from this investigation indicate that insulin treatment induced structural remodelling of the exocrine pancreas suggesting a substantial role of insulin in its functioning. Conclusions: Additionally, we showed that fine architectural changes in acini could be detected by fractal analysis, suggesting this method as an alternative or addition to routine stereology

    Endothelial cell apoptosis in brown adipose tissue of rats induced by hyperinsulinaemia: the possible role of TNF-α

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    The aim of the present study was to investigate whether hyperinsulinaemia, which frequently precedes insulin resistance syndrome (obesity, diabetes), induces apoptosis of endothelial cells (ECs) in brown adipose tissue (BAT) and causes BAT atrophy and also, to investigate the possible mechanisms underlying ECs death. In order to induce hyperinsuli-naemia, adult male rats of Wistar strain were treated with high dose of insulin (4 U/kg, intraperitonely) for one or three days. Examinations at ultrastructural level showed apoptotic changes of ECs, allowing us to point out that changes mainly but not exclusively, occur in nuclei. Besides different stages of condensation and alterations of the chromatin, nuclear fragmentation was also observed. Higher number of ECs apoptotic nuclei in the BAT of hyperinsulinaemic rats was also confirmed by propidium iodide staining. Immunohistochemical localization of tumor necrosis factor-alpha (TNF-α) revealed increased expression in ECs of BAT of hyperinsulinaemic animals, indicating its possible role in insulin-induced apoptotic changes. These results suggest that BAT atrophy in hyperinsulinaemia is a result of endothelial and adipocyte apoptosis combined, rather than any of functional components alone

    Effect of activated charcoal, abscisic acid and polyethylene glycol on maturation, germination and conversion of Aesculus hippocastanum androgenic embryos

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    The influence of activated charcoal (AC), abscisic acid (ABA) and polyethylene glycol (PEG) on the maturation and conversion of horse chestnut (Aesculus hippocastanum L.) androgenic embryos weretested. Androgenic embryos originating from microspores and anther culture were maturated over 90 days. Androgenic embryos on media containing PEG (50 g l-1), in combination with AC (1 g l-1) showed arapid development of embryos in the cotyledonary stage and lowered percentage of abnormal structures. The best results of androgenic microspore embryo germination were observed on media supplemented with AC alone (99%) and in combination with PEG (100%). Also, the greatest number of androgenic microspore plants (18%) and androgenic anther plants (12%) were formed on media enriched with 1 % AC. Lowest germination percentages of 37 and 39% in microspore culture and 33 and38% in anther culture were obtained on maturation media with ABA 20 mg l-1 alone and in combination with AC 1g l-1. Flow cytometric analysis showed that most of the androgenic embryos were haploid, corresponding to their microspore origin, while half of these became diploid after maturation for 90 days. All regenerants originating from microspore culture were haploid immediately after germination, but only 10% embryos re ained haploidity after 3 years subculturing, while 10.5% were diploid, 73.5% tetraploid and 6% octaploid on hormone-free medium. Unlike those from anther culture, after 3 years of subculturing on hormone-free medium, there were no haploid regenerant from anther culture, while8.5% were diploid, 81% tetraploid and 10.5% octaploid

    Governance tools for board members : adapting strategy maps and balanced scorecards for directorial action

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    The accountability of members of the board of directors of publicly traded companies has increased over years. Corresponding to these developments, there has been an inadequate advancement of tools and frameworks to help directorial functioning. This paper provides an argument for design of the Balanced Scorecard and Strategy Maps made available to the directors as a means of influencing, monitoring, controlling and assisting managerial action. This paper examines how the Balanced Scorecard and Strategy Maps could be modified and used for this purpose. The paper suggests incorporating Balanced Scorecards in the Internal Process perspective, ‘internal’ implying here not just ‘internal to the firm’, but also ‘internal to the inter-organizational system’. We recommend that other such factors be introduced separately under a new ‘perspective’ depending upon what the board wants to emphasize without creating any unwieldy proliferation of measures. Tracking the Strategy Map over time by the board of directors is a way for the board to take responsibility for the firm’s performance. The paper makes a distinction between action variables and monitoring variables. Monitoring variables are further divided on the basis of two considerations: a) whether results have been met or not and b) whether causative factors have met the expected levels of performance or not. Based on directorial responsibilities and accountability, we take another look at how the variables could be specified more completely and accurately with directorial recommendations for executives

    A new model for the characterization of infection risk in gunshot injuries:Technology, principal consideration and clinical implementation

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    <p>Abstract</p> <p>Introduction</p> <p>The extent of wound contamination in gunshot injuries is still a topic of controversial debate. The purpose of the present study is to develop a model that illustrates the contamination of wounds with exogenous particles along the bullet path.</p> <p>Material and methods</p> <p>To simulate bacteria, radio-opaque barium titanate (3-6 μm in diameter) was atomized in a dust chamber. Full metal jacket or soft point bullets caliber .222 (n = 12, v<sub>0 </sub>= 1096 m/s) were fired through the chamber into a gelatin block directly behind it. After that, the gelatin block underwent multi-slice CT in order to analyze the permanent and temporary wound cavity.</p> <p>Results</p> <p>The permanent cavity caused by both types of projectiles showed deposits of barium titanate distributed over the entire bullet path. Full metal jacket bullets left only few traces of barium titanate in the temporary cavity. In contrast, the soft point bullets disintegrated completely, and barium titanate covered the entire wound cavity.</p> <p>Discussion</p> <p>Deep penetration of potential exogenous bacteria can be simulated easily and reproducibly with barium titanate particles shot into a gelatin block. Additionally, this procedure permits conclusions to be drawn about the distribution of possible contaminants and thus can yield essential findings in terms of necessary therapeutic procedures.</p

    Designing the ideal model for assessment of wound contamination after gunshot injuries: a comparative experimental study

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    <p>Abstract</p> <p>Background</p> <p>Modern high-velocity projectiles produce temporary cavities and can thus cause extensive tissue destruction along the bullet path. It is still unclear whether gelatin blocks, which are used as a well-accepted tissue simulant, allow the effects of projectiles to be adequately investigated and how these effects are influenced by caliber size.</p> <p>Method</p> <p>Barium titanate particles were distributed throughout a test chamber for an assessment of wound contamination. We fired .22-caliber Magnum bullets first into gelatin blocks and then into porcine hind limbs placed behind the chamber. Two other types of bullets (.222-caliber bullets and 6.5 × 57 mm cartridges) were then shot into porcine hind limbs. Permanent and temporary wound cavities as well as the spatial distribution of barium titanate particles in relation to the bullet path were evaluated radiologically.</p> <p>Results</p> <p>A comparison of the gelatin blocks and hind limbs showed significant differences (<it>p </it>< 0.05) in the mean results for all parameters. There were significant differences between the bullets of different calibers in the depth to which barium titanate particles penetrated the porcine hind limbs. Almost no particles, however, were found at a penetration depth of 10 cm or more. By contrast, gas cavities were detected along the entire bullet path.</p> <p>Conclusion</p> <p>Gelatin is only of limited value for evaluating the path of high-velocity projectiles and the contamination of wounds by exogenous particles. There is a direct relationship between the presence of gas cavities in the tissue along the bullet path and caliber size. These cavities, however, are only mildly contaminated by exogenous particles.</p

    Corrigendum to "European contribution to the study of ROS:A summary of the findings and prospects for the future from the COST action BM1203 (EU-ROS)" [Redox Biol. 13 (2017) 94-162]

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    The European Cooperation in Science and Technology (COST) provides an ideal framework to establish multi-disciplinary research networks. COST Action BM1203 (EU-ROS) represents a consortium of researchers from different disciplines who are dedicated to providing new insights and tools for better understanding redox biology and medicine and, in the long run, to finding new therapeutic strategies to target dysregulated redox processes in various diseases. This report highlights the major achievements of EU-ROS as well as research updates and new perspectives arising from its members. The EU-ROS consortium comprised more than 140 active members who worked together for four years on the topics briefly described below. The formation of reactive oxygen and nitrogen species (RONS) is an established hallmark of our aerobic environment and metabolism but RONS also act as messengers via redox regulation of essential cellular processes. The fact that many diseases have been found to be associated with oxidative stress established the theory of oxidative stress as a trigger of diseases that can be corrected by antioxidant therapy. However, while experimental studies support this thesis, clinical studies still generate controversial results, due to complex pathophysiology of oxidative stress in humans. For future improvement of antioxidant therapy and better understanding of redox-associated disease progression detailed knowledge on the sources and targets of RONS formation and discrimination of their detrimental or beneficial roles is required. In order to advance this important area of biology and medicine, highly synergistic approaches combining a variety of diverse and contrasting disciplines are needed

    Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease

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    Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.

    The motivations for the adoption of management innovation by local governments and its performance effects

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    This article analyses the economic, political and institutional antecedents and performance effects of the adoption of shared Senior Management Teams (SMTs) – a management innovation (MI) that occurs when a team of senior managers oversees two or more public organizations. Findings from statistical analysis of 201 English local governments and interviews with organizational leaders reveal that shared SMTs are adopted to develop organisational capacity in resource‐challenged, politically risk‐averse governments, and in response to coercive and mimetic institutional pressures. Importantly, sharing SMTs may reduce rather than enhance efficiency and effectiveness due to redundancy costs and the political transaction costs associated with diverting resources away from a high‐performing partner to support their lower‐performing counterpart
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