184 research outputs found

    Determining the extragalactic extinction law with SALT

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    We present CCD imaging observations of early-type galaxies with dark lanes obtained with the Southern African Large Telescope (SALT) during its performance-verification phase. We derive the extinction law by the extragalactic dust in the dark lanes in the spectral range 1.11mu m^{-1} < lambda^{-1} < 2.94 mu m^{-1} by fitting model galaxies to the unextinguished parts of the image, and subtracting from these the actual images. We find that the extinction curves run parallel to the Galactic extinction curve, which implies that the properties of dust in the extragalactic enviroment are similar to those of the Milky Way. The ratio of the total V band extinction to the selective extinction between the V and B bands is derived for each galaxy with an average of 2.82+-0.38, compared to a canonical value of 3.1 for the Milky Way. The similar values imply that galaxies with well-defined dark lanes have characteristic dust grain sizes similar to those of Galactic dust.Comment: 20 pages, 15 figures and 4 tables. Accepted for publication in MNRA

    Chronic non-specific low back pain - sub-groups or a single mechanism?

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    Copyright 2008 Wand and O'Connell; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background: Low back pain is a substantial health problem and has subsequently attracted a considerable amount of research. Clinical trials evaluating the efficacy of a variety of interventions for chronic non-specific low back pain indicate limited effectiveness for most commonly applied interventions and approaches. Discussion: Many clinicians challenge the results of clinical trials as they feel that this lack of effectiveness is at odds with their clinical experience of managing patients with back pain. A common explanation for this discrepancy is the perceived heterogeneity of patients with chronic non-specific low back pain. It is felt that the effects of treatment may be diluted by the application of a single intervention to a complex, heterogeneous group with diverse treatment needs. This argument presupposes that current treatment is effective when applied to the correct patient. An alternative perspective is that the clinical trials are correct and current treatments have limited efficacy. Preoccupation with sub-grouping may stifle engagement with this view and it is important that the sub-grouping paradigm is closely examined. This paper argues that there are numerous problems with the sub-grouping approach and that it may not be an important reason for the disappointing results of clinical trials. We propose instead that current treatment may be ineffective because it has been misdirected. Recent evidence that demonstrates changes within the brain in chronic low back pain sufferers raises the possibility that persistent back pain may be a problem of cortical reorganisation and degeneration. This perspective offers interesting insights into the chronic low back pain experience and suggests alternative models of intervention. Summary: The disappointing results of clinical research are commonly explained by the failure of researchers to adequately attend to sub-grouping of the chronic non-specific low back pain population. Alternatively, current approaches may be ineffective and clinicians and researchers may need to radically rethink the nature of the problem and how it should best be managed

    Substantial chest-wall deformity following tissue expansion after radiotherapy

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    We present the case of a 54-year-old woman who underwent a two-stage breast reconstruction with a tissue expander after sustaining a lumpectomy and local radiotherapy for breast cancer. During expansion, the woman developed an abnormal concave deformity of the chest wall. Although respiratory or aesthetic consequences were expected, our patient reported only pain and was satisfied with the end result. Osteoporosis or local recurrence was excluded as predisposing factors, and radiotherapy was considered to be the causal factor in our patient. On the basis of this finding, we advise surgeons to take the risk of chest-wall deformity into consideration when planning a reconstruction with tissue expanders, especially in patients with a history of radiotherapy, and we recommend an alternative reconstructive method in this group of patients

    Depression during pregnancy: views on antidepressant use and information sources of general practitioners and pharmacists

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    <p>Abstract</p> <p>Background</p> <p>The use of antidepressants during pregnancy has increased in recent years. In the Netherlands, almost 2% of all pregnant women are exposed to antidepressants. Although guidelines have been developed on considerations that should be taken into account, prescribing antidepressants during pregnancy is still a subject of debate. Physicians and pharmacists may have opposing views on using medication during pregnancy and may give contradictory advice on whether or not to take medication for depression and anxiety disorders during pregnancy. In this study, we investigated information sources used by general practitioners (GPs) and pharmacists and their common practices.</p> <p>Methods</p> <p>A questionnaire on the use of information sources and the general approach when managing depression during pregnancy was sent out to 1400 health care professionals to assess information sources on drug safety during pregnancy and also the factors that influence decision-making. The questionnaires consisted predominantly of closed multiple-choice questions.</p> <p>Results</p> <p>A total of 130 GPs (19%) and 144 pharmacists (21%) responded. The most popular source of information on the safety of drug use during pregnancy is the Dutch National Health Insurance System Formulary, while a minority of respondents contacts the Dutch national Teratology Information Service (TIS). The majority of GPs contact the pharmacy with questions concerning drug use during pregnancy. There is no clear line with regard to treatment or consensus between GPs on the best therapeutic strategy, nor do practitioners agree upon the drug of first choice. GPs have different views on stopping or continuing antidepressants during pregnancy or applying alternative treatment options. The debate appears to be ongoing as to whether or not specialised care for mother and child is indicated in cases of gestational antidepressant use.</p> <p>Conclusion</p> <p>Primary health care workers are not univocal concerning therapy for pregnant women with depression. Although more research is needed to account for all safety issues, local or national policies are indispensable in order to avoid undesirable practices, such as giving contradictory advice. GPs and pharmacists should address the subject during their regular pharmacotherapeutic consensus meetings, preferably in collaboration with the TIS or other professionals in the field.</p

    Activation and modulation of antiviral and apoptotic genes in pigs infected with classical swine fever viruses of high, moderate or low virulence

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    The immune response to CSFV and the strategies of this virus to evade and suppress the pigs’ immune system are still poorly understood. Therefore, we investigated the transcriptional response in the tonsils, median retropharyngeal lymph node (MRLN), and spleen of pigs infected with CSFV strains of similar origin with high, moderate, and low virulence. Using a porcine spleen/intestinal cDNA microarray, expression levels in RNA pools prepared from infected tissue at 3 dpi (three pigs per virus strain) were compared to levels in pools prepared from uninfected homologue tissues (nine pigs). A total of 44 genes were found to be differentially expressed. The genes were functionally clustered in six groups: innate and adaptive immune response, interferon-regulated genes, apoptosis, ubiquitin-mediated proteolysis, oxidative phosphorylation and cytoskeleton. Significant up-regulation of three IFN-γ-induced genes in the MRLNs of pigs infected with the low virulence strain was the only clear qualitative difference in gene expression observed between the strains with high, moderate and low virulence. Real-time PCR analysis of four response genes in all individual samples largely confirmed the microarray data at 3 dpi. Additional PCR analysis of infected tonsil, MRLN, and spleen samples collected at 7 and 10 dpi indicated that the strong induction of expression of the antiviral response genes chemokine CXCL10 and 2′–5′ oligoadenylate synthetase 2, and of the TNF-related apoptosis-inducing ligand (TRAIL) gene at 3 dpi, decreased to lower levels at 7 and 10 dpi. For the highly and moderately virulent strains, this decrease in antiviral and apoptotic gene expression coincided with higher levels of virus in these immune tissues

    Pain acceptance and personal control in pain relief in two maternity care models: a cross-national comparison of Belgium and the Netherlands

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    <p>Abstract</p> <p>Background</p> <p>A cross-national comparison of Belgian and Dutch childbearing women allows us to gain insight into the relative importance of pain acceptance and personal control in pain relief in 2 maternity care models. Although Belgium and the Netherlands are neighbouring countries sharing the same language, political system and geography, they are characterised by a different organisation of health care, particularly in maternity care. In Belgium the medical risks of childbirth are emphasised but neutralised by a strong belief in the merits of the medical model. Labour pain is perceived as a needless inconvenience easily resolved by means of pain medication. In the Netherlands the midwifery model of care defines childbirth as a normal physiological process and family event. Labour pain is perceived as an ally in the birth process.</p> <p>Methods</p> <p>Women were invited to participate in the study by independent midwives and obstetricians during antenatal visits in 2004-2005. Two questionnaires were filled out by 611 women, one at 30 weeks of pregnancy and one within the first 2 weeks after childbirth either at home or in a hospital. However, only women having a hospital birth without obstetric intervention (N = 327) were included in this analysis. A logistic regression analysis has been performed.</p> <p>Results</p> <p>Labour pain acceptance and personal control in pain relief render pain medication use during labour less likely, especially if they occur together. Apart from this general result, we also find large country differences. Dutch women with a normal hospital birth are six times less likely to use pain medication during labour, compared to their Belgian counterparts. This country difference cannot be explained by labour pain acceptance, since - in contrast to our working hypothesis - Dutch and Belgian women giving birth in a hospital setting are characterised by a similar labour pain acceptance. Our findings suggest that personal control in pain relief can partially explain the country differences in coping with labour pain. For Dutch women we find that the use of pain medication is lowest if women experience control over the reception of pain medication and have a positive attitude towards labour pain. In Belgium however, not personal control over the use of pain relief predicts the use of pain medication, but negative attitudes towards labour.</p> <p>Conclusions</p> <p>Apart from individual level determinants, such as length of labour or pain acceptance, our findings suggest that the maternity care context is of major importance in the study of the management of labour pain. The pain medication use in Belgian hospital maternity care is high and is very sensitive to negative attitudes towards labour pain. In the Netherlands, on the contrary, pain medication use is already low. This can partially be explained by a low degree of personal control in pain relief, especially when co-occurring with positive pain attitudes.</p

    Development of a best-practice clinical guideline for the use of bleomycin in the treatment of germ cell tumours in the UK

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    Bleomycin, a cytotoxic chemotherapy agent, forms a key component of curative regimens for lymphoma and germ cell tumours. It can be associated with severe toxicity, long-term complications and even death in extreme cases. There is a lack of evidence or consensus on how to prevent and monitor bleomycin toxicity. We surveyed 63 germ cell cancer physicians from 32 cancer centres across the UK to understand their approach to using bleomycin. Subsequent guideline development was based upon current practice, best available published evidence and expert consensus. We observed heterogeneity in practice in the following areas: monitoring; route of administration; contraindications to use; baseline and follow-up investigations performed, and advice given to patients. A best-practice clinical guideline for the use of bleomycin in the treatment of germ cell tumours has been developed and includes recommendations regarding baseline investigations, the use of pulmonary function tests, route of administration, monitoring and patient advice. It is likely that existing heterogeneity in clinical practice of bleomycin prescribing has significant economic, safety and patient experience implications. The development of an evidence-based consensus guideline was supported by 93% of survey participants and aims to address these issues and homogenise practice across the UK

    GABAergic signaling as therapeutic target for autism spectrum disorders

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    gamma-Aminobutyric acid (GABA), the main inhibitory neurotransmitter in the adult brain, early in postnatal life exerts a depolarizing and excitatory action. This depends on accumulation of chloride inside the cell via the cation chloride importer NKCC1, being the expression of the chloride exporter KCC2 very low at birth. The developmentally regulated expression of KCC2 results in extrusion of chloride with age and a shift of GABA from the depolarizing to the hyperpolarizing direction. The depolarizing action of GABA leads to intracellular calcium rise through voltage-dependent calcium channels and/or N-methyl-D-aspartate receptors. GABA-mediated calcium signals regulate a variety of developmental processes from cell proliferation migration, differentiation, synapse maturation, and neuronal wiring. Therefore, it is not surprising that some forms of neuro-developmental disorders such as autism spectrum disorders (ASDs) are associated with alterations of GABAergic signaling and impairment of the excitatory/inhibitory balance in selective neuronal circuits. In this review, we will discuss how changes of GABAA-mediated neurotransmission affect several forms of ASDs including the Fragile X, the Angelman, and Rett syndromes. Then, we will describe various animal models of ASDs with GABAergic dysfunctions, highlighting their behavioral deficits and the possibility to rescue them by targeting selective components of the GABAergic synapse. In particular, we will discuss how in some cases, reverting the polarity of GABA responses from the depolarizing to the hyperpolarizing direction with the diuretic bumetanide, a selective blocker of NKCC1, may have beneficial effects on ASDs, thus opening new therapeutic perspectives for the treatment of these devastating disorders

    On the application of scattering matrix measurements to detection and identification of major types of airborne aerosol particles: Volcanic ash, desert dust and pollen

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    This work has been funded by the excellence research program of the Andalusian Regional Government, grant number P18RT-1854, the National Plan of Scientific and Technical Research and Innovation of the Spanish Ministry of Science and Innovation, grant number RTI2018-095330-B-100 (LEONIDAS), and the "Center of Excellence Severo Ochoa" award to the Instituto de Astrofisica de Andalucia (SEV-2017-0709) by the Spanish State Agency for Research. J.C.G.M acknowledges financial support from the Ramon y Cajal Program of the Spanish Ministry of Science and Innovation (RYC-2016-19570). JoseLuis de la Rosa, JoseAntonio Ruiz and Shi Zongbo are acknowledged for collecting the Sahara-OSN and GobiBeijing desert dust samples.Atmospheric aerosols play key roles in climate and have important impacts on human activities and health. Hence, much effort is directed towards developing methods of improved detection and discrimina- tion of different types of aerosols. Among these, light scattering-based detection of aerosol offers several advantages including applications in both in situ and remote sensing devices. In this work, new scat- tering matrix measurements for two samples of airborne desert dust collected in Spain and China are reported. The average extrapolated scattering matrices of airborne desert dust and of volcanic ash at two wavelengths have been calculated and compared with the aim of finding criteria to distinguish these two types of aerosol. Additionally, the scattering matrix of cypress pollen has been measured and extrapo- lated to explore differences with mineral dust that can be exploited in atmospheric detection. Field mea- surements of the backscattering linear depolarization ratio δL (180 °) are used to obtain information about non-sphericity and discrimination between fine and coarse aerosol. However, the average δL (180 °) for the three types of aerosols considered in this work in the visible spectral range is δL (180 °) = 0.40 ±0.05. This shows that δL (180 °) is not informative about the composition or morphology of irregular particles. By contrast, measurements of scattering matrix elements or depolarization ratios at different scattering angles may provide information about the structural differences of particles, and in particular may en- able to differentiate airborne volcanic ash from desert dust, which are otherwise similar in terms of size and optical constants. Cypress pollen shows a characteristic degree of linear polarization curve that is very different from that of polydisperse irregular mineral dust. Light scattering field instruments and re- mote sensing methods could extract more information about the characteristics of aerosol particles if modifications were introduced to measure the phase curves of several scattering matrix elements or de- polarization ratios.excellence research program of the Andalusian Regional Government P18RT-1854National Plan of Scientific and Technical Research and Innovation of the Spanish Ministry of Science and Innovation RTI2018-095330-B-100Spanish State Agency for Research SEV-2017-0709Spanish Government RYC-2016-1957
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