152 research outputs found

    The psychological burden of an initially unexplained illness: patients with sternocostoclavicular hyperostosis before and after delayed diagnosis

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    <p>Abstract</p> <p>Background</p> <p>Sternocostoclavicular hyperostosis (SCCH) is a rare, debilitating, chronic inflammatory disorder of the anterior chest wall due to a chronic sterile osteomyelitis of unknown origin. SCCH is largely underdiagnosed and often misdiagnosed. In individual cases it can remain unrecognized for years. The purpose of this study is twofold. Firstly, to evaluate the psychological condition of SCCH patients, both in the sometimes quite extended pre-diagnostic period between first manifestations and confirmed diagnosis of the disease, and in the current situation. Secondly, to investigate the relationships between the pre-diagnostic and the current psychological conditions of confirmed SCCH patients.</p> <p>Methods</p> <p>Structured interviews were held with 52 confirmed SCCH patients. Questionnaires were included to assess posttraumatic stress symptoms, social support, aspects of pain, illness perceptions, self-reported health status, and quality of life.</p> <p>Results</p> <p>SCCH patients reported stronger posttraumatic stress symptoms, more unfavorable illness perceptions, lower health status, and poorer quality of life than healthy individuals and patients with other diseases or traumatic experiences. Psychological distress in the pre-diagnostic period was associated with unfavorable conditions in the current situation.</p> <p>Conclusion</p> <p>SCCH is an illness with serious psychological consequences. Psychological monitoring of patients with unexplained complaints is recommended as long as a diagnosis has not been reached.</p

    High disease impact of myotonic dystrophy type 2 on physical and mental functioning

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    The aim of the study was to investigate health status in patients with myotonic dystrophy type 2 (DM2) and determine its relationship to pain and fatigue. Data on health status (SF-36), pain (MPQ) and fatigue (CIS-fatigue) were collected for the Dutch DM2 population (n = 32). Results were compared with those of sex- and age-matched adult-onset myotonic dystrophy type 1 (DM1) patients. In addition, we compared the obtained scores on health status of the DM2 group with normative data of the Dutch general population (n = 1742). Compared to DM1, the SF-36 score for bodily pain was significantly (p = 0.04) lower in DM2, indicating more body pain in DM2. DM2 did not differ from DM1 on any other SF-36 scales. In comparison to the Dutch population, DM2 patients reported lower scores (indicating worse clinical condition) on the physical functioning, role functioning-physical, bodily pain, general health, vitality, social functioning, and role functioning-emotional scales (p < 0.01 on all scales). The difference was most profound for the physical functioning scale. In the DM2 group the severity of pain was significantly correlated with SF-36 scores for bodily pain (p = 0.003). Fatigue was significantly correlated with the SF-36 scores for role functioning-physical (p = 0.001), general health (p = 0.02), and vitality (p = 0.02). The impact of DM2 on a patients’ physical, psychological and social functioning is significant and as high as in adult-onset DM1 patients. From the perspective of health-related quality of life, DM2 should not be considered a benign disease. Management of DM2 patients should include screening for pain and fatigue. Symptomatic treatment of pain and fatigue may decrease disease impact and help improve health status in DM2, even if the disease itself cannot be treated

    Fast Homeostatic Plasticity of Inhibition via Activity-Dependent Vesicular Filling

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    Synaptic activity in the central nervous system undergoes rapid state-dependent changes, requiring constant adaptation of the homeostasis between excitation and inhibition. The underlying mechanisms are, however, largely unclear. Chronic changes in network activity result in enhanced production of the inhibitory transmitter GABA, indicating that presynaptic GABA content is a variable parameter for homeostatic plasticity. Here we tested whether such changes in inhibitory transmitter content do also occur at the fast time scale required to ensure inhibition-excitation-homeostasis in dynamic cortical networks. We found that intense stimulation of afferent fibers in the CA1 region of mouse hippocampal slices yielded a rapid and lasting increase in quantal size of miniature inhibitory postsynaptic currents. This potentiation was mediated by the uptake of GABA and glutamate into presynaptic endings of inhibitory interneurons (the latter serving as precursor for the synthesis of GABA). Thus, enhanced release of inhibitory and excitatory transmitters from active networks leads to enhanced presynaptic GABA content. Thereby, inhibitory efficacy follows local neuronal activity, constituting a negative feedback loop and providing a mechanism for rapid homeostatic scaling in cortical circuits

    Evidence for inhibition of cholinesterases in insect and mammalian nervous systems by the insect repellent deet

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    <p>Abstract</p> <p>Background</p> <p>N,N-Diethyl-3-methylbenzamide (deet) remains the gold standard for insect repellents. About 200 million people use it every year and over 8 billion doses have been applied over the past 50 years. Despite the widespread and increased interest in the use of deet in public health programmes, controversies remain concerning both the identification of its target sites at the olfactory system and its mechanism of toxicity in insects, mammals and humans. Here, we investigated the molecular target site for deet and the consequences of its interactions with carbamate insecticides on the cholinergic system.</p> <p>Results</p> <p>By using toxicological, biochemical and electrophysiological techniques, we show that deet is not simply a behaviour-modifying chemical but that it also inhibits cholinesterase activity, in both insect and mammalian neuronal preparations. Deet is commonly used in combination with insecticides and we show that deet has the capacity to strengthen the toxicity of carbamates, a class of insecticides known to block acetylcholinesterase.</p> <p>Conclusion</p> <p>These findings question the safety of deet, particularly in combination with other chemicals, and they highlight the importance of a multidisciplinary approach to the development of safer insect repellents for use in public health.</p

    Reduced Expression of the Vesicular Acetylcholine Transporter and Neurotransmitter Content Affects Synaptic Vesicle Distribution and Shape in Mouse Neuromuscular Junction

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    In vertebrates, nerve muscle communication is mediated by the release of the neurotransmitter acetylcholine packed inside synaptic vesicles by a specific vesicular acetylcholine transporter (VAChT). Here we used a mouse model (VAChT KDHOM) with 70% reduction in the expression of VAChT to investigate the morphological and functional consequences of a decreased acetylcholine uptake and release in neuromuscular synapses. Upon hypertonic stimulation, VAChT KDHOM mice presented a reduction in the amplitude and frequency of miniature endplate potentials, FM 1-43 staining intensity, total number of synaptic vesicles and altered distribution of vesicles within the synaptic terminal. In contrast, under electrical stimulation or no stimulation, VAChT KDHOM neuromuscular junctions did not differ from WT on total number of vesicles but showed altered distribution. Additionally, motor nerve terminals in VAChT KDHOM exhibited small and flattened synaptic vesicles similar to that observed in WT mice treated with vesamicol that blocks acetylcholine uptake. Based on these results, we propose that decreased VAChT levels affect synaptic vesicle biogenesis and distribution whereas a lower ACh content affects vesicles shape

    Actin- and Dynamin-Dependent Maturation of Bulk Endocytosis Restores Neurotransmission following Synaptic Depletion

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    Bulk endocytosis contributes to the maintenance of neurotransmission at the amphibian neuromuscular junction by regenerating synaptic vesicles. How nerve terminals internalize adequate portions of the presynaptic membrane when bulk endocytosis is initiated before the end of a sustained stimulation is unknown. A maturation process, occurring at the end of the stimulation, is hypothesised to precisely restore the pools of synaptic vesicles. Using confocal time-lapse microscopy of FM1-43-labeled nerve terminals at the amphibian neuromuscular junction, we confirm that bulk endocytosis is initiated during a sustained tetanic stimulation and reveal that shortly after the end of the stimulation, nerve terminals undergo a maturation process. This includes a transient bulging of the plasma membrane, followed by the development of large intraterminal FM1-43-positive donut-like structures comprising large bulk membrane cisternae surrounded by recycling vesicles. The degree of bulging increased with stimulation frequency and the plasmalemma surface retrieved following the transient bulging correlated with the surface membrane internalized in bulk cisternae and recycling vesicles. Dyngo-4a, a potent dynamin inhibitor, did not block the initiation, but prevented the maturation of bulk endocytosis. In contrast, cytochalasin D, an inhibitor of actin polymerization, hindered both the initiation and maturation processes. Both inhibitors hampered the functional recovery of neurotransmission after synaptic depletion. Our data confirm that initiation of bulk endocytosis occurs during stimulation and demonstrates that a delayed maturation process controlled by actin and dynamin underpins the coupling between exocytosis and bulk endocytosis

    The role of economic evaluation in the decision-making process of family physicians: design and methods of a qualitative embedded multiple-case study

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    <p>Abstract</p> <p>Background</p> <p>A considerable amount of resource allocation decisions take place daily at the point of the clinical encounter; especially in primary care, where 80 percent of health problems are managed. Ignoring economic evaluation evidence in individual clinical decision-making may have a broad impact on the efficiency of health services. To date, almost all studies on the use of economic evaluation in decision-making used a quantitative approach, and few investigated decision-making at the clinical level. An important question is whether economic evaluations affect clinical practice. The project is an intervention research study designed to understand the role of economic evaluation in the decision-making process of family physicians (FPs). The contributions of the project will be from the perspective of Pierre Bourdieu's sociological theory.</p> <p>Methods/design</p> <p>A qualitative research strategy is proposed. We will conduct an embedded multiple-case study design. Ten case studies will be performed. The FPs will be the unit of analysis. The sampling strategies will be directed towards theoretical generalization. The 10 selected cases will be intended to reflect a diversity of FPs. There will be two embedded units of analysis: FPs (micro-level of analysis) and field of family medicine (macro-level of analysis). The division of the determinants of practice/behaviour into two groups, corresponding to the macro-structural level and the micro-individual level, is the basis for Bourdieu's mode of analysis. The sources of data collection for the micro-level analysis will be 10 life history interviews with FPs, documents and observational evidence. The sources of data collection for the macro-level analysis will be documents and 9 open-ended, focused interviews with key informants from medical associations and academic institutions. The analytic induction approach to data analysis will be used. A list of codes will be generated based on both the original framework and new themes introduced by the participants. We will conduct within-case and cross-case analyses of the data.</p> <p>Discussion</p> <p>The question of the role of economic evaluation in FPs' decision-making is of great interest to scientists, health care practitioners, managers and policy-makers, as well as to consultants, industry, and society. It is believed that the proposed research approach will make an original contribution to the development of knowledge, both empirical and theoretical.</p

    Management control systems in innovation companies: A literature based framework

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    Past research has traditionally argued that management control systems (MCSs) may present a hindrance to the creativity of innovation companies. This theoretical paper surveys the literature to focus an investigation on the MCSs of innovation companies. Within the object of control paradigm the paper develops and presents a theoretical model of the impact of eleven external, organisational and innovation related contingency factors on the MCSs in companies that engage in innovation activities. We also suggest measures for further empirical research. By formulating hypotheses on 43 potential interactions the model predicts contradictory influences on two direct control categories, results and action control, but stresses the importance of two indirect categories, personnel and cultural control. More specifically, the high levels of technological complexity and innovation capability in this type of company are expected to be negatively associated with the application of results and action control, whereas personnel and cultural seem to be more appropriate. Furthermore, important sources of finance, venture capital and public funding, are both hypothesised to be positively associated with the application of results, action and personnel control; whereas only public funding is predicted to be positively related to the application of cultural control. The principal contribution of this paper lies in synthesising the literature to provide a model of the impact of a unique set of eleven contingency factors for innovation companies on a broad scope of controls. In addition, the contingency model, if empirically validated, would add value by inferring the particular forms of management control which would be beneficial in innovative company settings. © 2014 Springer-Verlag Berlin Heidelberg

    Multidimensional Scaling of Sorting Data: A Comparison of Three Procedures

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    Dissimilarity measures (D) derived from sortings of stimuli can be submitted to multidimen­sional sealing (MDS) either directly, or after transforming them to profile distances (Delta) computed on the rows of the D matrix. The Jatter procedure was criticized by Drasgow and Jones (1979) who performed two simulation studies, which are criticized here in turn. In the present article two sets of real sorting data were used for comparing the results of MDS on D and Delta both with each other and with the results of two other procedures: multiple correspondence analysis (by means of HOMALS) on the raw sorting data, and MDS on the pairwise similarity ratings of the same stimuli by the same subjects. The three procedures were compared both with respect to the final configurations and with regard to the fit of the corresponding distances to the data. These comparisons suggested that MDS on D is slightly superior to MDS on Delta. The latter analysis, however, yields results that are similar to those of the much more efficient HOMALS program. The differences, however, are on the average very small
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