196 research outputs found

    Braking of the overhead cranes by pneumohydraulic buffers in the accidents

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    The majority of the numerous animal studies of the effects of estrogens on cerebral ischemia have reported neuroprotective results, but a few have shown increased damage. Differences in hormone administration methods, resulting in highly different 17 beta-estradiol levels, may explain the discrepancies in previously reported effects. The objective of the present study was to test the hypothesis that it is the delivered dose per se, and not the route and method of administration, that determines the effect, and that high doses are damaging while lower doses are protective. One hundred and twenty ovariectomized female Wistar rats (n = 40 per group) were randomized into three groups, subcutaneously administered different doses of 17 beta-estradiol and subjected to transient middle cerebral artery occlusion. The modified sticky tape test was performed after 24 h and the rats were subsequently sacrificed for infarct size measurements. In contrast to our hypothesis, a significant negative correlation between 17 beta-estradiol dose and infarct size was found (p = 0.018). Thus, no support was found for the hypothesis that 17 beta-estradiol can be both neuroprotective and neurotoxic merely depending on dose. In fact, on the contrary, the findings indicate that the higher the dose of 17 beta-estradiol, the smaller the infarct.Funding Agencies|County Council of Ostergotland, Sweden</p

    Different methods for administering 17β-estradiol to ovariectomized rats result in opposite effects on ischemic brain damage

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    <p>Abstract</p> <p>Background</p> <p>Numerous stroke studies have controversially shown estrogens to be either neuroprotective or neurodamaging. The discordant results observed in rat brain ischemia models may be a consequence of discrepancies in estrogen administration modes resulting in plasma concentration profiles far from those intended. To test this hypothesis we reproduced in detail and extended an earlier study from our lab using a different mode of 17β-estradiol administration; home-made silastic capsules instead of commercial slow-release 17β-estradiol pellets. Four groups of female rats (n = 12) were ovariectomized and administered 17β-estradiol or placebo via silastic capsules. All animals underwent MCAo fourteen days after ovariectomy and were sacrificed three days later.</p> <p>Results</p> <p>In contrast to our earlier results using the commercial pellets, the group receiving 17β-estradiol during the entire experiment had significantly smaller lesions than the group receiving placebo (mean ± SEM: 3.85 ± 0.70% versus 7.15 ± 0.27% of total slice area, respectively; p = 0.015). No significant neuroprotection was found when the 17β-estradiol was administered only during the two weeks before or the three days immediately after MCAo.</p> <p>Conclusions</p> <p>The results indicate that different estrogen treatment regimens result in diametrically different effects on cerebral ischemia. Thus the effects of estrogens on ischemic damage seem to be concentration-related, with a biphasic, or even more complex, dose-response relation. These findings have implications for the design of animal experiments and also have a bearing on the estrogen doses used for peri-menopausal hormone replacement therapy.</p

    Risk of myocardial infarction at specific troponin T levels using the parameter predictive value among lookalikes (PAL)

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    AbstractBackgroundMyocardial infarction is more likely if the heart damage biomarker cardiac troponin T (cTnT) is elevated in a blood sample, indicating that cardiac damage has occurred. No method allows the clinician to estimate the risk of myocardial infarction at a specific cTnT level in a given patient.MethodsPredictive value among lookalikes (PAL) uses pre-test prevalence, sensitivity and specificity at adjacent cTnT limits based on percentiles. PAL is the pre-test prevalence-adjusted probability of disease between two adjacent cTnT limits. If a chest pain patient's cTnT level is between these limits, the risk of myocardial infarction can be estimated.ResultsThe PAL based on percentiles had an acceptable sampling error when using 100 bootstrapped data of 18 different biomarkers from 38,945 authentic lab measurements. A PAL analysis of an emergency room cohort (n=11,020) revealed that the diagnostic precision of a high-sensitive cTnT assay was similar among chest pain patients at different ages. The higher incidence of false positive results due to non-specific increases in cTnT in the high-age group was counterbalanced by a higher pre-test prevalence of myocardial infarction among older patients, a finding that was missed when using a conventional ROC plot analysis.ConclusionsThe PAL was able to calculate the risk of myocardial infarction at specific cTnT levels and could complement decision limits

    Автоматизированное рабочее место мастера участка тяговых подстанций КУП «Горэлектротранспорт»

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    Background: The elevated body swing test (EBST) is a behavioral test used to evaluate experimental stroke in rodents. The basic idea is that when the animal is suspended vertically by the tail, it will swing its head laterally to the left or right depending on lesion side. In a previous study from our lab using the EBST after middle cerebral artery occlusion (MCAo), rats swung contralateral to the infarct day 1 post-MCAo, but ipsilateral day 3 post-MCAo. This shift was unexpected and prompted us to perform the present study. First, the literature was systematically reviewed to elucidate whether a similar shift had been noticed before, and if consensus existed regarding swing direction. Secondly, an experiment was conducted to systematically investigate the suggested behavior. Eighty-three adult male and female Sprague-Dawley rats were subjected to MCAo or sham surgery and the EBST was performed up to 7 days after the lesion. Results: Both experimentally and through systematic literature review, the present study shows that the direction of biased swing activity in the EBST for rodents after cerebral ischemia can differ and even shift over time in some situations. The EBST curve for females was significantly different from that of males after the same occlusion time (p = 0.023). Conclusions: This study highlights the importance of adequate reporting of behavioral tests for lateralization and it is concluded that the EBST cannot be recommended as a test for motor asymmetry after MCAo in rats.Funding Agencies|Region Ostergotland/Linkoping University, Sweden</p

    Система экономического стимулирования персонала предприятия» (на примере ООО «МозырьПромТехМонтаж»)

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    Background The prevalence of mental strain and stress has increased in modern societies, resulting in increased public health problems. Stress can be measured either by biomarkers or by self-reports. A new biomarker that measures long-term biological stress is cortisol measured in timed hair extracts. Hair grows at approximately 1 cm per month, and retrospectively reflects average stress levels. However, the plausible relationship between perceived stress and self-reported health and this novel biomarker is yet not firmly established. The objective of this study was to investigate the possible relationship between perceived stress, self-reported health, and cortisol in hair extracts in healthy middle-aged women from two different occupations. Method A cross-sectional study was conducted in 112 middle-aged women working as nurses or librarians in a county in southeast Sweden. The women were invited to fill in a questionnaire covering stress, health, and life situation. The questionnaire included questions on health and disease symptoms, the Perceived Stress Scale (PSS), and the Hospital Anxiety and Depression (HAD) scale. A piece of hair was cut from the vertex posterior area of the head an analysed by a competitive radioimmunoassay method. Results Middle-aged women who reported high perceived stress (p = 0.031) or lower health (p = 0.029), or had signs of depressiveness (p = 0.016) had significantly higher cortisol concentrations adjusted for age. There were no significant differences in cortisol in hair concentrations or perceived stress between nurses and librarians. Two women with extremely high cortisol concentrations were considered as outliers, but during the interview at follow-up they reported experiences of serious life events in their work or social life during the retrospective time of the sample taken for cortisol measurement. Conclusions Higher cortisol concentrations measured in the hair of healthy and working middle-aged women were associated with higher perceived stress and generally poorer health and with depressiveness. These findings lend support to the general applicability of cortisol measured in hair extracts as a biomarker in population-based epidemiological studies

    Lack of association in acne and salivary testosterone

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    The pathogenesis of acne vulgaris has only been partially elucidated. Various hormones, especially androgens, are likely to play a role, but results of studies are still inconclusive. The objective of the current study was to investigate whether day to day variation in salivary testosterone correlates with acne in males. Saliva samples were collected for 120 consecutive days from each of the 40 males. Salivary testosterone concentrations were measured by enzyme-linked immunosorbent assay (ELISA). Facial acne lesions were assessed on a daily basis by photography by the participating males. Potential confounders’ (sexual intercourse, masturbation, physical exercise and disease) were also registered every day by the participants. A significant but weak association between salivary testosterone and acne was found (n = 4602, r = 0.031, P = 0.034). Elevated testosterone concentrations were associated with an increase in acne, but when testosterone concentrations were above twice the individual average, acne lesions paradoxically decreased. The current results indicate that daily fluctuations in salivary testosterone levels in males are associated with acne patterns, but the weak correlation suggests that the effect is too small to be of clinical significance. The analysis in the current study was complicated by a large number of days on which the participants had no acne, as well as the seemingly non-monotonic relation between testosterone and acne. This may indicate that the actual relation is stronger than concluded here

    The LEAP checklist for laboratory evaluation and analytical performance characteristics reporting of clinical measurement procedures

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    Reporting a measurement procedure and its analytical performance following method evaluation in a peer-reviewed journal is an important means for clinical laboratory practitioners to share their findings. It also represents an important source of evidence base to help others make informed decisions about their practice. At present, there are significant variations in the information reported in laboratory medicine journal publications describing the analytical performance of measurement procedures. These variations also challenge authors, readers, reviewers, and editors in deciding the quality of a submitted manuscript. The International Federation of Clinical Chemistry and Laboratory Medicine Working Group on Method Evaluation Protocols (IFCC WG-MEP) developed a checklist and recommends its adoption to enable a consistent approach to reporting method evaluation and analytical performance characteristics of measurement procedures in laboratory medicine journals. It is envisioned that the Laboratory Evaluation and Analytical Performance Characteristics (LEAP) checklist will improve the standardisation of journal publications describing method evaluation and analytical performance characteristics, improving the quality of the evidence base that is relied upon by practitioners
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