679 research outputs found
Can children withhold consent to treatment
A dilemma exists when a doctor is faced with a child or young person who refuses medically indicated treatment. The Gillick case has been interpreted by many to mean that a child of sufficient age and intelligence could validly consent or refuse consent to treatment. Recent decisions of the Court of Appeal on a child's refusal of medical treatment have clouded the issue and undermined the spirit of the Gillick decision and the Children Act 1989. It is now the case that a child patient whose competence is in doubt will be found rational if he or she accepts the proposal to treat but may be found incompetent if he or she disagrees. Practitioners are alerted to the anomalies now exhibited by the law on the issue of children's consent and refusal. The impact of the decisions from the perspectives of medicine, ethics, and the law are examined. Practitioners should review each case of child care carefully and in cases of doubt seek legal advice
Achieving diffraction-limited performance on the Berkeley MET5
The Berkeley MET5, funded by EUREKA, is a 0.5-NA EUV projection lithography tool located at the Advanced Light Source at Berkeley National Lab. Wavefront measurements of the MET5 optic have been performed using a custom in-situ lateral shearing interferometer suitable for high-NA interferometry. In this paper, we report on the most recent characterization of the MET5 optic demonstrating an RMS wavefront 0.31 nm, and discuss the specialized mask patterns, gratings, and illumination geometries that were employed to accommodate the many challenges associated with high-NA EUV interferometry
Formalin-induced behavioural hypersensitivity and neuronal hyperexcitability are mediated by rapid protein synthesis at the spinal level
Background: The mammalian target of rapamycin ( mTOR) is a key regulator of mRNA translation whose action can be inhibited by the drug rapamycin. Forms of long-term plasticity require protein synthesis and evidence indicates that mRNA in dendrites, axon terminals and cell bodies is essential for long-term synaptic plasticity. Specific to pain, shifts in pain thresholds and responsiveness are an expression of neuronal plasticity and this likely contributes to persistent pain. We investigated this by inhibiting the activity of mTOR with rapamycin at the spinal level, of rats that were subjected to the formalin test, using both behavioural and electrophysiological techniques.Results: For in vivo electrophysiology, Sprague Dawley rats were fully anaesthetised and single-unit extracellular recordings were obtained from lamina V wide dynamic range (WDR) dorsal horn spinal neurones at the region where input is received from the hind paw. Neuronal responses from naive rats showed that rapamycin-sensitive pathways were important in nociceptive-specific C-fibre mediated transmission onto WDR neurones as well mechanically-evoked responses since rapamycin was effective in attenuating these measures. Formalin solution was injected into the hind paw prior to which, rapamycin or vehicle was applied directly onto the exposed spinal cord. When rapamycin was applied to the spinal cord prior to hind paw formalin injection, there was a significant attenuation of the prolonged second phase of the formalin test, which comprises continuing afferent input to the spinal cord, neuronal hyperexcitability and an activated descending facilitatory drive from the brainstem acting on spinal neurones. In accordance with electrophysiological data, behavioural studies showed that rapamycin attenuated behavioural hypersensitivity elicited by formalin injection into the hind paw.Conclusion: We conclude that mTOR has a role in maintaining persistent pain states via mRNA translation and thus protein synthesis. We hypothesise that mTOR may be activated by excitatory neurotransmitter release acting on sensory afferent terminals as well as dorsal horn spinal neurones, which may be further amplified by descending facilitatory systems originating from higher centres in the brain
Capsaicin 8% dermal patch in clinical practice: an expert opinion
Introduction: Neuropathic pain (NP) is caused by a lesion or disease of the somatosensory system, which can severely impact patientsâ quality of life. The current-approved treatments for NP comprise of both centrally acting agents and topical drugs, including capsaicin 8% dermal patches, which is approved for the treatment of peripheral NP. /
Areas covered: The authors summarize literature data regarding capsaicin use in patients who suffer from NP and discuss the clinical applications of this topical approach. /
Expert opinion: Overall, the capsaicin 8% dermal patch is as effective in reducing pain intensity as other centrally active agents (i.e. pregabalin). Some studies have also reported fewer systemic side effects, a faster onset of action and superior treatment satisfaction compared with systemic agents. In our opinion, capsaicin 8% dermal patches also present additional advantages, such as a good systemic tolerability, the scarcity of adverse events, the possibility to combine it with other agents, and a good cost-effective profile. It is important to note that, as the mechanism of action of capsaicin 8% is the âdefunctionalizationâ of small afferent fibers through interaction with TRPV1 receptors, the peripheral expression of this receptor on nociceptor fibers, is crucial to predict patientâs response to treatment
Behavioural and electrophysiological characterisation of experimentally induced osteoarthritis and neuropathy in C57Bl/6 mice
Background: Osteoarthritis is a widespread condition affecting the elderly where similar to 70-90% of over 75 year olds are affected, representing one of the largest cost burdens to healthcare in the western world. The monosodium iodoacetate (MIA) osteoarthritis model has been well described in the rat especially in terms of the pathological progression of the disease and more recently pain behaviour. In this study, we characterise, for the first time, MIA induced osteoarthritis in mice and compare it with nerve-injured mice (partial sciatic nerve injury), using both behavioural and in vivo electrophysiological measurements. These approaches uniquely allow the threshold and suprathreshold measures to many modalities to be quantified and so form a basis for improving and expanding transgenic studies.Results: Significant mechanical hypersensitivity was observed in the ipsilateral hindpaw in MIA injected mice at all observed time points following infrapetellar MIA injection (p < 0.05). The mechanical hypersensitivity exhibited a partial biphasic temporal pattern, but thermal hypersensitivity was absent. Electrically-evoked dorsal horn neuronal responses in MIA injected mice were significantly elevated (p < 0.05) with respect to A- and C-fibre firing, input, pinch and noxious von Frey (26 and 60 g). No significant changes in A- or C-fibre thresholds were observed. Nerve-injured mice displayed significant behavioural thermal and mechanical hypersensitivity (p < 0.05) and evoked dorsal horn responses were significantly increased with respect to C-fibre firing, pinch and wind-up (p < 0.05).Conclusion: The MIA model of osteoarthritic pain in mice displays behavioural characteristics similar to those observed in rats. Changes in both behavioural measures and neuronal activity from the paw, suggest that central changes are involved in this pain state, although a role for peripheral drives is also likely. Moreover, the behavioural and neuronal measures in these two pain models showed overlapping alterations in terms of certain neuronal measures and mechanical sensitivity despite their very different pathologies and a loss of input in neuropathy, suggesting some commonalities in the central processing of different peripheral pain states. This murine model of osteoarthritis will allow the exploitation of knock out animals to better understand underlying mechanisms and identify novel molecular targets
Pharmacological rationale for tapentadol therapy: a review of new evidence
Chronic pain could be considered as a neurological disorder. Therefore, appropriate selection of the therapy, which should consider the pathophysiological mechanisms of pain, can result in a successful analgesic outcome. Tapentadol is an analgesic drug which acts both as a ÎŒ-opioid receptor (MOR) agonist and as a noradrenaline reuptake inhibitor (NRI), thereby generating a synergistic action in terms of analgesic efficacy, but not for the burden of adverse effects. Therefore, tapentadol can be defined as the first âMOR-NRIâ drug. This molecule holds the potential to address at least some of the current limitations of analgesic therapy due to its unique mechanism of action and has shown to be safe and effective in the treatment of chronic pain of cancer and noncancer etiologies including nociceptive, neuropathic and mixed pain. In particular, the MOR component of tapentadol activity predominantly allows for analgesia in nociceptive pain; on the other hand, the NRI component contributes, now in a predominant manner, for analgesic efficacy in cases of neuropathic pain states. This paper will discuss recent pieces of evidence on the pathophysiology of pain, the background on tapentadol and then present some new studies on how the unique mechanism of action of tapentadol provides a key role in its analgesic efficacy in a number of pain states and with a favorable safety profile
Calibrating the discrete boundary conditions of a dynamic simulation: a combinatorial approximate Bayesian computation sequential Monte Carlo (ABC-SMC) approach
This paper presents a novel adaptation of the conventional approximate Bayesian computation sequential Monte Carlo (ABC-SMC) sampling algorithm for parameter estimation in the presence of uncertainties, coined combinatorial ABC-SMC. Inference of this type is used in situations where there does not exist a closed form of the associated likelihood function, which is replaced by a simulating model capable of producing artificial data. In the literature, conventional ABC-SMC is utilised to perform inference on continuous parameters. The novel scheme presented here has been developed to perform inference on parameters that are high-dimensional binary, rather than continuous. By altering the form of the proposal distribution from which to sample candidates in subsequent iterations (referred to as waves), high-dimensional binary variables may be targeted and inferred by the scheme. The efficacy of the proposed scheme is demonstrated through application to vibration data obtained in a structural dynamics experiment on a fibre-optic sensor simulated as a finite plate with uncertain boundary conditions at its edges. Results indicate that the method provides sound inference on the plate boundary conditions, which is validated through subsequent application of the method to multiple vibration datasets. Comparisons between appropriate forms of the metric function used in the scheme are also developed to highlight the effect of this element in the schemes convergence
Propulsion Systems Panel
Topics addressed are: (1) cryogenic tankage; (2) launch vehicle TPS/insulation; (3) durable passive thermal control devices and/or coatings; (4) development and characterization of processing methods to reduce anisotropy of material properties in Al-Li; (5) durable thermal protection system (TPS); (6) unpressurized Al-Li structures (interstages, thrust structures); (7) near net shape sections; (8) pressurized structures; (9) welding and joining; (10) micrometeoroid and debris hypervelocity shields; (11) state-of-the-art shell buckling structure optimizer program to serve as a rapid design tool; (12) test philosophy; (13) reduced load cycle time; (14) structural analysis methods; (15) optimization of structural criteria; and (16) develop an engineering approach to properly trade material and structural concepts selection, fabrication, facilities, and cost
Phenyl Saligenin Phosphate Induced Caspase-3 and c-Jun N-Terminal Kinase Activation in Cardiomyocyte-Like Cells
At present, little is known about the effect(s) of organophosphorous compounds (OPs) on cardiomyocytes. In this study we have investigated the effects of phenyl saligenin phosphate (PSP), two organophosphorothioate insecticides (diazinon and chlorpyrifos) and their acutely toxic metabolites (diazoxon and chlorpyrifos oxon) on mitotic and differentiated H9c2 cardiomyoblasts. OP-induced cytotoxicity was assessed by monitoring MTT reduction, LDH release and caspase-3 activity. Cytotoxicity was not observed with diazinon, diazoxon or chlorpyrifos oxon (48 h exposure; 200 ÎŒM). Chlorpyrifos-induced cytotoxicity was only evident at concentrations >100 ÎŒM. In marked contrast, PSP displayed pronounced cytotoxicity towards mitotic and differentiated H9c2 cells. PSP triggered the activation of JNK1/2, but not ERK1/2, p38 MAPK or PKB, suggesting a role for this pro-apoptotic protein kinase in PSP-induced cell death. The JNK1/2 inhibitor SP 600125 attenuated PSP-induced caspase-3 and JNK1/2 activation, confirming the role of JNK1/2 in PSP-induced cytotoxicity. Fluorescently labelled PSP (dansylated PSP) was used to identify novel PSP binding proteins. Dansylated PSP displayed cytotoxicity towards differentiated H9c2 cells. 2D-gel electrophoresis profiles of cells treated with dansylated PSP (25 ÎŒM) were used to identify proteins fluorescently labelled with dansylated PSP. Proteomic analysis identified tropomyosin, heat shock protein ÎČ-1 and nucleolar protein 58 as novel protein targets for PSP. In summary, PSP triggers cytotoxicity in differentiated H9c2 cardiomyoblasts via JNK1/2-mediated activation of caspase-3. Further studies are required to investigate whether the identified novel protein targets of PSP play a role in the cytotoxicity of this OP, which is usually associated with the development of OP-induced delayed neuropathy
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