95 research outputs found

    Recurrent Recruitment Manoeuvres Improve Lung Mechanics and Minimize Lung Injury during Mechanical Ventilation of Healthy Mice

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    INTRODUCTION: Mechanical ventilation (MV) of mice is increasingly required in experimental studies, but the conditions that allow stable ventilation of mice over several hours have not yet been fully defined. In addition, most previous studies documented vital parameters and lung mechanics only incompletely. The aim of the present study was to establish experimental conditions that keep these parameters within their physiological range over a period of 6 h. For this purpose, we also examined the effects of frequent short recruitment manoeuvres (RM) in healthy mice. METHODS: Mice were ventilated at low tidal volume V(T) = 8 mL/kg or high tidal volume V(T) = 16 mL/kg and a positive end-expiratory pressure (PEEP) of 2 or 6 cm H(2)O. RM were performed every 5 min, 60 min or not at all. Lung mechanics were followed by the forced oscillation technique. Blood pressure (BP), electrocardiogram (ECG), heart frequency (HF), oxygen saturation and body temperature were monitored. Blood gases, neutrophil-recruitment, microvascular permeability and pro-inflammatory cytokines in bronchoalveolar lavage (BAL) and blood serum as well as histopathology of the lung were examined. RESULTS: MV with repetitive RM every 5 min resulted in stable respiratory mechanics. Ventilation without RM worsened lung mechanics due to alveolar collapse, leading to impaired gas exchange. HF and BP were affected by anaesthesia, but not by ventilation. Microvascular permeability was highest in atelectatic lungs, whereas neutrophil-recruitment and structural changes were strongest in lungs ventilated with high tidal volume. The cytokines IL-6 and KC, but neither TNF nor IP-10, were elevated in the BAL and serum of all ventilated mice and were reduced by recurrent RM. Lung mechanics, oxygenation and pulmonary inflammation were improved by increased PEEP. CONCLUSIONS: Recurrent RM maintain lung mechanics in their physiological range during low tidal volume ventilation of healthy mice by preventing atelectasis and reduce the development of pulmonary inflammation

    High susceptibility of c-KIT+CD34+ precursors to prolonged doxorubicin exposure interferes with Langerhans cell differentiation in a human cell line model

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    As neoadjuvant and adjuvant chemotherapy schedules often consist of multiple treatment cycles over relatively long periods of time, it is important to know what effects protracted drug administration can have on the immune system. Here, we studied the long-term effects of doxorubicin on the capacity of dendritic cell (DC) precursors to differentiate into a particular DC subset, the Langerhans cells (LC). In order to achieve high telomerase activity as detected in hematological stem cells, precursor cells from the acute-myeloid leukemia (AML)-derived cell line MUTZ3 were stably transduced with human telomerase reverse transcriptase (hTERT) to facilitate their growth potential, while preventing growth, and drug-induced senescence, and preserving their unique capacity for cytokine-dependent DC and LC differentiation. The hTERT-MUTZ3 cells were selected with increasing concentrations of the anthracyclin doxorubicin. After 1–2 months of selection with 30–90 nM doxorubicin, the cells completely lost their capacity to differentiate into LC. This inhibition turned out to be reversible, as the cells slowly regained their capacity to differentiate after a 3- to 4-month drug-free period and with this became capable again of priming allogeneic T cells. Of note, the loss and gain of this capacity to differentiate coincided with the loss and gain of a subpopulation within the CD34+ proliferative compartment with surface expression of the stem cell factor receptor (SCF-R/CD117/c-Kit). These data are in favor of cytostatic drug-free intervals before applying autologous DC-based vaccination protocols, as specific DC precursors may need time to recover from protracted chemotherapy treatment and re-emerge among the circulating CD34+ hematopoietic stem and precursor cells

    Male/Female Is Not Enough: Adding Measures of Masculinity and Femininity to General Population Surveys

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    Survey research and sociological theory each provide insights into how and why people and groups act, think, and feel. Sociological theories identify what concepts are important for understanding and representing the social world. That is, sociological theories inform what to measure in surveys, and, to a certain extent, how to measure it. Survey research permits sociologists to carefully specify what is to be measured vis a vis sociological theory, setting surveys apart as a social research tool. It is this level of specification of concepts and measures that allow surveys to provide continued value at a time when “big data” proliferate. High quality survey measurement and estimation is necessary for sociologists to evaluate sociological theory among generalizable samples with well-developed questions, leading to further refinement and improvement of the theory and improved understanding of the social world. High quality surveys also provide insights into where sociological theories fail and where they must be adjusted for different subgroups, as well as basic insights into the prevalence of outcomes of interest. Together, sociological theory and survey methods produce insights about society that can inform decision-making and social policy. This mutually reinforcing relationship between sociological theory and survey methods requires sociological theory to evolve from insights obtained using survey methods and survey measurement to evolve with advances in in sociological theory. The measurement of sex and gender in surveys is one area where the development of survey measures has not kept pace with sociological theory and empirical, largely qualitative, findings. Contemporary gender theory sees sex and gender as separate concepts, both of which are important for understanding behaviors and outcomes. Yet, virtually all contemporary surveys measure sex as a binary “male” versus “female” categorization and fail to measure gender, ignoring important heterogeneity in gender identification that may exist within sex categories and any overlap that may occur across categories. Both gender scholars and survey researchers are potentially affected by this shortcoming of modern survey measurement. Gender scholars lose an important tool for assessing gender theories, especially on generalizable samples, risking conclusions that are specific to a small group of individuals rather than the population at large. Survey researchers risk producing theoretically obsolete data, limiting the utility of the data or potentially generating misleading conclusions. Survey data that fail to capture and reflect modern and complex understandings of our social realities also face increased risk of being replaced by “big data” such as administrative and social media data. Survey data that do reflect modern and complex understandings can bring value not available in administrative or other data and are therefore unlikely to be replaced. This paper is part of a growing chorus advocating for updates to how modern surveys measure sex and gender. We argue that the reliance on a single binary measure of sex (male or female) is out of step with current sociological understandings of sex and gender. In response, we propose and test a new theoretically-informed gradational measure of gender identification in a nationally representative mail survey. We evaluate whether respondents answer the gender measure and examine the reliability and predictive validity of the measure. In particular, we examine whether measuring gender gradationally adds explanatory value beyond sex on important social outcomes such as sexuality, childcare, grocery shopping, housework, working for pay, and military service. We also examine whether sex moderates the effect of gender identification in the ways that sociological theory would suggest on these outcomes

    Addressing risk factors for child abuse among high risk pregnant women: design of a randomised controlled trial of the nurse family partnership in Dutch preventive health care

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    <p>Abstract</p> <p>Background</p> <p>Low socio-economic status combined with other risk factors affects a person's physical and psychosocial health from childhood to adulthood. The societal impact of these problems is huge, and the consequences carry on into the next generation(s). Although several studies show these consequences, only a few actually intervene on these issues. In the United States, the Nurse Family Partnership focuses on high risk pregnant women and their children. The main goal of this program is primary prevention of child abuse. The Netherlands is the first country outside the United States allowed to translate and culturally adapt the Nurse Family Partnership into VoorZorg. The aim of the present study is to assess whether VoorZorg is as effective in the Netherland as in the United States.</p> <p>Methods</p> <p>The study consists of three partly overlapping phases. Phase 1 was the translation and cultural adaptation of Nurse Family Partnership and the design of a two-stage selection procedure. Phase 2 was a pilot study to examine the conditions for implementation. Phase 3 is the randomized controlled trial of VoorZorg compared to the care as usual. Primary outcome measures were smoking cessation during pregnancy and after birth, birth outcomes, child development, child abuse and domestic violence. The secondary outcome measure was the number of risk factors present.</p> <p>Discussion</p> <p>This study shows that the Nurse Family Partnership was successfully translated and culturally adapted into the Dutch health care system and that this program fulfills the needs of high-risk pregnant women. We hypothesize that this program will be effective in addressing risk factors that operate during pregnancy and childhood and compromise fetal and child development.</p> <p>Trial registration</p> <p>Current Controlled Trials <a href="http://www.controlled-trials.com/ISRCTN16131117">ISRCTN16131117</a></p

    Gender differences in the utilization of health-care services among the older adult population of Spain

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    BACKGROUND: Compared to men, women report greater morbidity and make greater use of health-care services. This study examines potential determinants of gender differences in the utilization of health-care services among the elderly. METHODS: Cross-sectional study covering 3030 subjects, representative of the non-institutionalized Spanish population aged 60 years and over. Potential determinants of gender differences in the utilization of health services were classified into predisposing factors (age and head-of-family status), need factors (lifestyles, chronic diseases, functional status, cognitive deficit and health-related quality of life (HRQL)) and enabling factors (educational level, marital status, head-of-family employment status and social network). Relative differences in the use of each service between women and men were summarized using odds ratios (OR), obtained from logistic regression. The contribution of the variables of interest to the gender differences in the use of such services was evaluated by comparing the OR before and after adjustment for such variables. RESULTS: As compared to men, a higher percentage of women visited a medical practitioner (OR: 1.24; 95% confidence limits (CL): 1.07–1.44), received home medical visits (OR: 1.67; 95% CL: 1.34–2.10) and took ≥3 medications (OR: 1.54; 95% CL: 1.34–1.79), but there were no gender differences in hospital admission or influenza vaccination. Adjustment for need or enabling factors led to a reduction in the OR of women compared to men for utilization of a number of services studied. On adjusting for the number of chronic diseases, the OR (95% CL) of women versus men for ingestion of ≥3 medications was 1.24 (1.06–1.45). After adjustment for HRQL, the OR was 1.03 (0.89–1.21) for visits to medical practitioners, 1.24 (0.98–1.58) for home medical visits, 0.71 (0.58–0.87) for hospitalization, and 1.14 (0.97–1.33) for intake of ≥3 medications. After adjustment for the number of chronic diseases and HRQL, the OR of hospitalization among women versus men was 0.68 (0.56–0.84). CONCLUSION: The factors that best explain the greater utilization of health-care services by elderly women versus men are the number of chronic diseases and HRQL. For equal need, certain inequality was observed in hospital admission, in that it proved less frequent among women

    Corvid Re-Caching without ‘Theory of Mind’: A Model

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    Scrub jays are thought to use many tactics to protect their caches. For instance, they predominantly bury food far away from conspecifics, and if they must cache while being watched, they often re-cache their worms later, once they are in private. Two explanations have been offered for such observations, and they are intensely debated. First, the birds may reason about their competitors' mental states, with a ‘theory of mind’; alternatively, they may apply behavioral rules learned in daily life. Although this second hypothesis is cognitively simpler, it does seem to require a different, ad-hoc behavioral rule for every caching and re-caching pattern exhibited by the birds. Our new theory avoids this drawback by explaining a large variety of patterns as side-effects of stress and the resulting memory errors. Inspired by experimental data, we assume that re-caching is not motivated by a deliberate effort to safeguard specific caches from theft, but by a general desire to cache more. This desire is brought on by stress, which is determined by the presence and dominance of onlookers, and by unsuccessful recovery attempts. We study this theory in two experiments similar to those done with real birds with a kind of ‘virtual bird’, whose behavior depends on a set of basic assumptions about corvid cognition, and a well-established model of human memory. Our results show that the ‘virtual bird’ acts as the real birds did; its re-caching reflects whether it has been watched, how dominant its onlooker was, and how close to that onlooker it has cached. This happens even though it cannot attribute mental states, and it has only a single behavioral rule assumed to be previously learned. Thus, our simulations indicate that corvid re-caching can be explained without sophisticated social cognition. Given our specific predictions, our theory can easily be tested empirically

    Trends in healthy life expectancy in Hong Kong SAR 1996–2008

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    Although Hong Kong has one of the best life expectancy (LE) records in the world, second only to Japan for women, we know very little about the changes in the health status of the older adult population. Our article aims to provide a better understanding of trends in both chronic morbidity and disability for older men and women. The authors compute chronic morbidity-free and disability-free life expectancy and the proportion of both in relation to total LE using the Sullivan method to examine whether Hong Kong older adults are experiencing a compression of morbidity and disability and whether there is any gender difference in relation to mortality and morbidity. The results of this study show that Hong Kong women tend to outlive Hong Kong men but are also more likely to suffer from a ‘double disadvantage’, namely more years of life with more chronic morbidity and disability. There has also been a significant expansion of chronic morbidity, as chronic morbidity-free life expectancy (CMFLE) decreased substantially for both genders from 1996 to 2008. Although disability-free life expectancy (DFLE) increased during this period, it increased at a slower pace compared to LE. The proportion of life without chronic morbidity also declined remarkably during these 12 years. Among the advanced ages, the proportion of remaining life in good health without disability has decreased since 1996, indicating a relative expansion of disability

    Conceptual Frameworks and Methods for Advancing Invasion Ecology

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    Invasion ecology has much advanced since its early beginnings. Nevertheless, explanation, prediction, and management of biological invasions remain difficult. We argue that progress in invasion research can be accelerated by, first, pointing out difficulties this field is currently facing and, second, looking for measures to overcome them. We see basic and applied research in invasion ecology confronted with difficulties arising from (A) societal issues, e.g., disparate perceptions of invasive species; (B) the peculiarity of the invasion process, e.g., its complexity and context dependency; and (C) the scientific methodology, e.g., imprecise hypotheses. To overcome these difficulties, we propose three key measures: (1) a checklist for definitions to encourage explicit definitions; (2) implementation of a hierarchy of hypotheses (HoH), where general hypotheses branch into specific and precisely testable hypotheses; and (3) platforms for improved communication. These measures may significantly increase conceptual clarity and enhance communication, thus advancing invasion ecology
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