134 research outputs found

    Patients’ use of information about medicine side effects in relation to experiences of suspected adverse drug reactions

    Get PDF
    Background Adverse drug reactions (ADRs) are common, and information about medicines is increasingly widely available to the public. However, relatively little work has explored how people use medicines information to help them assess symptoms that may be suspected ADRs. Objective Our objective was to determine how patients use patient information leaflets (PILs) or other medicines information sources and whether information use differs depending on experiences of suspected ADRs. Method This was a cross-sectional survey conducted in six National Health Service (NHS) hospitals in North West England involving medical in-patients taking at least two regular medicines prior to admission. The survey was administered via a questionnaire and covered use of the PIL and other medicines information sources, perceived knowledge about medicines risks/ADRs, experiences of suspected ADRs, plus demographic information. Results Of the 1,218 respondents to the survey, 18.8 % never read the PIL, whilst 6.5 % only do so if something unexpected happens. Educational level was related to perceived knowledge about medicines risks, but not to reading the PIL or seeking further information about medicines risks. Over half the respondents (56.0 %) never sought more information about possible side effects of medicines. A total of 57.2 % claimed they had experienced a suspected ADR. Of these 85.9 % were either very sure or fairly sure this was a reaction to a medicine. Over half of those experiencing a suspected ADR (53.8 %) had read the PIL, of whom 36.2 % did so before the suspected ADR occurred, the remainder afterwards. Reading the PIL helped 84.8 % of these respondents to decide they had experienced an ADR. Educational level, general knowledge of medicines risks and number of regular medicines used all increased the likelihood of experiencing an ADR. Conclusion More patients should be encouraged to read the PIL supplied with medicines. The results support the view that most patients feel knowledgeable about medicines risks and suspected ADRs and value information about side effects, but that reading about side effects in PILs or other medicines information sources does not lead to experiences of suspected ADRs

    GDNF Secreting Human Neural Progenitor Cells Protect Dying Motor Neurons, but Not Their Projection to Muscle, in a Rat Model of Familial ALS

    Get PDF
    Amyotrophic lateral sclerosis (ALS) is a fatal, progressive neurodegenerative disease characterized by rapid loss of muscle control and eventual paralysis due to the death of large motor neurons in the brain and spinal cord. Growth factors such as glial cell line derived neurotrophic factor (GDNF) are known to protect motor neurons from damage in a range of models. However, penetrance through the blood brain barrier and delivery to the spinal cord remains a serious challenge. Although there may be a primary dysfunction in the motor neuron itself, there is also increasing evidence that excitotoxicity due to glial dysfunction plays a crucial role in disease progression. Clearly it would be of great interest if wild type glial cells could ameliorate motor neuron loss in these models, perhaps in combination with the release of growth factors such as GDNF.Human neural progenitor cells can be expanded in culture for long periods and survive transplantation into the adult rodent central nervous system, in some cases making large numbers of GFAP positive astrocytes. They can also be genetically modified to release GDNF (hNPC(GDNF)) and thus act as long-term 'mini pumps' in specific regions of the rodent and primate brain. In the current study we genetically modified human neural stem cells to release GDNF and transplanted them into the spinal cord of rats over-expressing mutant SOD1 (SOD1(G93A)). Following unilateral transplantation into the spinal cord of SOD1(G93A) rats there was robust cellular migration into degenerating areas, efficient delivery of GDNF and remarkable preservation of motor neurons at early and end stages of the disease within chimeric regions. The progenitors retained immature markers, and those not secreting GDNF had no effect on motor neuron survival. Interestingly, this robust motor neuron survival was not accompanied by continued innervation of muscle end plates and thus resulted in no improvement in ipsilateral limb use.The potential to maintain dying motor neurons by delivering GDNF using neural progenitor cells represents a novel and powerful treatment strategy for ALS. While this approach represents a unique way to prevent motor neuron loss, our data also suggest that additional strategies may also be required for maintenance of neuromuscular connections and full functional recovery. However, simply maintaining motor neurons in patients would be the first step of a therapeutic advance for this devastating and incurable disease, while future strategies focus on the maintenance of the neuromuscular junction

    Genetic Knock-Down of Hdac3 Does Not Modify Disease-Related Phenotypes in a Mouse Model of Huntington's Disease

    Get PDF
    Huntington's disease (HD) is an autosomal dominant progressive neurodegenerative disorder caused by an expansion of a CAG/polyglutamine repeat for which there are no disease modifying treatments. In recent years, transcriptional dysregulation has emerged as a pathogenic process that appears early in disease progression and has been recapitulated across multiple HD models. Altered histone acetylation has been proposed to underlie this transcriptional dysregulation and histone deacetylase (HDAC) inhibitors, such as suberoylanilide hydroxamic acid (SAHA), have been shown to improve polyglutamine-dependent phenotypes in numerous HD models. However potent pan-HDAC inhibitors such as SAHA display toxic side-effects. To better understand the mechanism underlying this potential therapeutic benefit and to dissociate the beneficial and toxic effects of SAHA, we set out to identify the specific HDAC(s) involved in this process. For this purpose, we are exploring the effect of the genetic reduction of specific HDACs on HD-related phenotypes in the R6/2 mouse model of HD. The study presented here focuses on HDAC3, which, as a class I HDAC, is one of the preferred targets of SAHA and is directly involved in histone deacetylation. To evaluate a potential benefit of Hdac3 genetic reduction in R6/2, we generated a mouse carrying a critical deletion in the Hdac3 gene. We confirmed that the complete knock-out of Hdac3 is embryonic lethal. To test the effects of HDAC3 inhibition, we used Hdac3+/− heterozygotes to reduce nuclear HDAC3 levels in R6/2 mice. We found that Hdac3 knock-down does not ameliorate physiological or behavioural phenotypes and has no effect on molecular changes including dysregulated transcripts. We conclude that HDAC3 should not be considered as the major mediator of the beneficial effect induced by SAHA and other HDAC inhibitors in HD

    Modulation of Astrocytic Mitochondrial Function by Dichloroacetate Improves Survival and Motor Performance in Inherited Amyotrophic Lateral Sclerosis

    Get PDF
    Mitochondrial dysfunction is one of the pathogenic mechanisms that lead to neurodegeneration in Amyotrophic Lateral Sclerosis (ALS). Astrocytes expressing the ALS-linked SOD1G93A mutation display a decreased mitochondrial respiratory capacity associated to phenotypic changes that cause them to induce motor neuron death. Astrocyte-mediated toxicity can be prevented by mitochondria-targeted antioxidants, indicating a critical role of mitochondria in the neurotoxic phenotype. However, it is presently unknown whether drugs currently used to stimulate mitochondrial metabolism can also modulate ALS progression. Here, we tested the disease-modifying effect of dichloroacetate (DCA), an orphan drug that improves the functional status of mitochondria through the stimulation of the pyruvate dehydrogenase complex activity (PDH). Applied to astrocyte cultures isolated from rats expressing the SOD1G93A mutation, DCA reduced phosphorylation of PDH and improved mitochondrial coupling as expressed by the respiratory control ratio (RCR). Notably, DCA completely prevented the toxicity of SOD1G93A astrocytes to motor neurons in coculture conditions. Chronic administration of DCA (500 mg/L) in the drinking water of mice expressing the SOD1G93A mutation increased survival by 2 weeks compared to untreated mice. Systemic DCA also normalized the reduced RCR value measured in lumbar spinal cord tissue of diseased SOD1G93A mice. A remarkable effect of DCA was the improvement of grip strength performance at the end stage of the disease, which correlated with a recovery of the neuromuscular junction area in extensor digitorum longus muscles. Systemic DCA also decreased astrocyte reactivity and prevented motor neuron loss in SOD1G93A mice. Taken together, our results indicate that improvement of the mitochondrial redox status by DCA leads to a disease-modifying effect, further supporting the therapeutic potential of mitochondria-targeted drugs in ALS

    Optimised and Rapid Pre-clinical Screening in the SOD1G93A Transgenic Mouse Model of Amyotrophic Lateral Sclerosis (ALS)

    Get PDF
    The human SOD1G93A transgenic mouse has been used extensively since its development in 1994 as a model for amyotrophic lateral sclerosis (ALS). In that time, a great many insights into the toxicity of mutant SOD1 have been gained using this and other mutant SOD transgenic mouse models. They all demonstrate a selective toxicity towards motor neurons and in some cases features of the pathology seen in the human disease. These models have two major drawbacks. Firstly the generation of robust preclinical data in these models has been highlighted as an area for concern. Secondly, the amount of time required for a single preclinical experiment in these models (3–4 months) is a hurdle to the development of new therapies. We have developed an inbred C57BL/6 mouse line from the original mixed background (SJLxC57BL/6) SOD1G93A transgenic line and show here that the disease course is remarkably consistent and much less prone to background noise, enabling reduced numbers of mice for testing of therapeutics. Secondly we have identified very early readouts showing a large decline in motor function compared to normal mice. This loss of motor function has allowed us to develop an early, sensitive and rapid screening protocol for the initial phases of denervation of muscle fibers, observed in this model. We describe multiple, quantitative readouts of motor function that can be used to interrogate this early mechanism. Such an approach will increase throughput for reduced costs, whilst reducing the severity of the experimental procedures involved

    Effects of circadian disruption on physiology and pathology: from bench to clinic (and back)

    Get PDF
    Nested within the hypothalamus, the suprachiasmatic nuclei (SCN) represent a central biological clock that regulates daily and circadian (i.e., close to 24 h) rhythms in mammals. Besides the SCN, a number of peripheral oscillators throughout the body control local rhythms and are usually kept in pace by the central clock. In order to represent an adaptive value, circadian rhythms must be entrained by environmental signals or zeitgebers, the main one being the daily light?dark (LD) cycle. The SCN adopt a stable phase relationship with the LD cycle that, when challenged, results in abrupt or chronic changes in overt rhythms and, in turn, in physiological, behavioral, and metabolic variables. Changes in entrainment, both acute and chronic, may have severe consequences in human performance and pathological outcome. Indeed, animal models of desynchronization have become a useful tool to understand such changes and to evaluate potential treatments in human subjects. Here we review a number of alterations in circadian entrainment, including jet lag, social jet lag (i.e., desynchronization between body rhythms and normal time schedules), shift work, and exposure to nocturnal light, both in human subjects and in laboratory animals. Finally, we focus on the health consequences related to circadian/entrainment disorders and propose a number of approaches for the management of circadian desynchronization.Fil: Chiesa, Juan José. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Duhart, José Manuel. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Casiraghi, Leandro Pablo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Paladino, Natalia. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bussi, Ivana Leda. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Golombek, Diego Andrés. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Defining novel functions for cerebrospinal fluid in ALS pathophysiology

    Get PDF

    External Learning Opportunities and the Diffusion of Process Innovations to Small Firms: The Case of Programmable Automation

    Get PDF
    In this chapter, we are concerned with explaining which types of firms have failed to adopt well-known improvements in process technology. This problem has, of course, been the underlying concern of all studies of diffusion “to rationalize why, if a new technology is superior, it is not taken up by all potential adopters” (Stoneman, 1983). Drawing on various theoretical perspectives, we identify a number of different barriers to adoption. With data collected from a 1987 nationally representative sample of US establishments in 21 metal-working and machinery manufacturing industries, we then construct a multivariate logistic regression model to empirically test for the effects of these factors on the likelihood of adoption of a particular process innovation, namely programmable automation (PA) machine tools
    corecore