191 research outputs found
An assessment of the court’s role in the withdrawal of clinically assisted nutrition and hydration from patients in the permanent vegetative state
In this article, we reassess the court's role in the withdrawal of clinically assisted nutrition and hydration from patients in the permanent vegetative state (PVS), focussing on cases where health-care teams and families agree that such is in the patient's best interest. As well as including a doctrinal analysis, the reassessment draws on empirical data from the families of patients with prolonged disorders of consciousness, on economic data about the costs of the declaratory relief process to the National Health Service (NHS), and on comparative legal data about the comparable procedural requirements in other jurisdictions. We show that, following the decision in the Bland case, the role of the Court of Protection is now restricted to the direct supervision of the PVS diagnosis as a matter of proof. We argue that this is an inappropriate role for the court, and one that sits in some tension with the best interests of patients. The blanket requirement of declaratory relief for all cases is economically expensive for the NHS and thus deprives other NHS patients from health care. We demonstrate that many of the ancillary benefits currently offered by declaratory relief could be achieved by other means. Ultimately, we suggest that reform to the declaratory relief requirement is called for
In-cell NMR characterization of the secondary structure populations of a disordered conformation of α-Synuclein within E. coli cells
α-Synuclein is a small protein strongly implicated in the pathogenesis of Parkinson’s disease and related neurodegenerative disorders. We report here the use of in-cell NMR spectroscopy to observe directly the structure and dynamics of this protein within E. coli cells. To improve the accuracy in the measurement of backbone chemical shifts within crowded in-cell NMR spectra, we have developed a deconvolution method to reduce inhomogeneous line broadening within cellular samples. The resulting chemical shift values were then used to evaluate the distribution of secondary structure populations which, in the absence of stable tertiary contacts, are a most effective way to describe the conformational fluctuations of disordered proteins. The results indicate that, at least within the bacterial cytosol, α-synuclein populates a highly dynamic state that, despite the highly crowded environment, has the same characteristics as the disordered monomeric form observed in aqueous solution
Airway mucins promote immunopathology in virus-exacerbated chronic obstructive pulmonary disease.
The respiratory tract surface is protected from inhaled pathogens by a secreted layer of mucus rich in mucin glycoproteins. Abnormal mucus accumulation is a cardinal feature of chronic respiratory diseases but the relationship between mucus and pathogens during exacerbations is poorly understood. We identified elevations in airway MUC5AC and MUC5B concentrations during spontaneous and experimentally-induced chronic obstructive pulmonary disease (COPD) exacerbations. MUC5AC was more sensitive to changes in expression during exacerbation and was therefore more predictably associated with virus load, inflammation, symptom severity, decrements in lung function, and secondary bacterial infections. MUC5AC was functionally related to inflammation as Muc5ac-deficient (Muc5ac-/-) mice had attenuated rhinovirus (RV)-induced airway inflammation and exogenous MUC5AC glycoprotein administration augmented inflammatory responses and increased release of extracellular adenosine triphosphate (ATP) in mice and human airway epithelial cell cultures. Hydrolysis of ATP suppressed MUC5AC augmentation of rhinovirus-induced inflammation in mice. Therapeutic suppression of mucin production using an epidermal growth factor receptor (EGFR) antagonist ameliorated immunopathology in a mouse COPD exacerbation model. The coordinated virus induction of MUC5AC and MUC5B suggests that non-Th2 mechanisms trigger mucin hypersecretion during exacerbations. Our data identifies a pro-inflammatory role for MUC5AC during viral infection and suggest that MUC5AC inhibition may ameliorate COPD exacerbations
ADAM33, a New Candidate for Psoriasis Susceptibility
Psoriasis is a chronic skin disorder with multifactorial etiology. In a recent study, we reported results of a genome-wide scan on 46 French extended families presenting with plaque psoriasis. In addition to unambiguous linkage to the major susceptibility locus PSORS1 on Chromosome 6p21, we provided evidence for a susceptibility locus on Chromosome 20p13. To follow up this novel psoriasis susceptibility locus we used a family-based association test (FBAT) for an association scan over the 17 Mb candidate region. A total of 85 uncorrelated SNP markers located in 65 genes of the region were initially investigated in the same set of large families used for the genome wide search, which consisted of 295 nuclear families. When positive association was obtained for a SNP, candidate genes nearby were explored more in detail using a denser set of SNPs. Thus, the gene ADAM33 was found to be significantly associated with psoriasis in this family set (The best association was on a 3-SNP haplotype P = 0.00004, based on 1,000,000 permutations). This association was independent of PSORS1. ADAM33 has been previously associated with asthma, which demonstrates that immune system diseases may be controlled by common susceptibility genes with general effects on dermal inflammation and immunity. The identification of ADAM33 as a psoriasis susceptibility gene identified by positional cloning in an outbred population should provide insights into the pathogenesis and natural history of this common disease
Predictive criteria of insignificant prostate cancer: what is the correspondence of linear extent to percentage of cancer in a single core?
Pros and cons of a prion-like pathogenesis in Parkinson's disease
Background: Parkinson's disease (PD) is a slowly progressive neurodegenerative disorder which affects widespread areas of the brainstem, basal ganglia and cerebral cortex. A number of proteins are known to accumulate in parkinsonian brains including ubiquitin and alpha-synuclein. Prion diseases are sporadic, genetic or infectious disorders with various clinical and histopathological features caused by prion proteins as infectious proteinaceous particles transmitting a misfolded protein configuration through brain tissue. The most important form is Creutzfeldt-Jakob disease which is associated with a self-propagating pathological precursor form of the prion protein that is physiologically widely distributed in the central nervous system. Discussion: It has recently been found that alpha-synuclein may behave similarly to the prion precursor and propagate between cells. The post-mortem proof of alpha-synuclein containing Lewy bodies in embryonic dopamine cells transplants in PD patient suggests that the misfolded protein might be transmitted from the diseased host to donor neurons reminiscent of prion behavior. The involvement of the basal ganglia and brainstem in the degenerative process are other congruencies between Parkinson's and Creutzfeldt-Jakob disease. However, a number of issues advise caution before categorizing Parkinson's disease as a prion disorder, because clinical appearance, brain imaging, cerebrospinal fluid and neuropathological findings exhibit fundamental differences between both disease entities. Most of all, infectiousness, a crucial hallmark of prion diseases, has never been observed in PD so far. Moreover, the cellular propagation of the prion protein has not been clearly defined and it is, therefore, difficult to assess the molecular similarities between the two disease entities. Summary: At the current state of knowledge, the molecular pathways of transmissible pathogenic proteins are not yet fully understood. Their exact involvement in the pathophysiology of prion disorders and neurodegenerative diseases has to be further investigated in order to elucidate a possible overlap between both disease categories that are currently regarded as distinct entities
Brugia malayi Excreted/Secreted Proteins at the Host/Parasite Interface: Stage- and Gender-Specific Proteomic Profiling
Relatively little is known about the filarial proteins that interact with the human host. Although the filarial genome has recently been completed, protein profiles have been limited to only a few recombinants or purified proteins of interest. Here, we describe a large-scale proteomic analysis using microcapillary reverse-phase liquid chromatography-tandem-mass spectrometry to identify the excretory-secretory (ES) products of the L3, L3 to L4 molting ES, adult male, adult female, and microfilarial stages of the filarial parasite Brugia malayi. The analysis of the ES products from adult male, adult female, microfilariae (Mf), L3, and molting L3 larvae identified 852 proteins. Annotation suggests that the functional and component distribution was very similar across each of the stages studied; however, the Mf contributed a higher proportion to the total number of identified proteins than the other stages. Of the 852 proteins identified in the ES, only 229 had previous confirmatory expressed sequence tags (ESTs) in the available databases. Moreover, this analysis was able to confirm the presence of 274 “hypothetical” proteins inferred from gene prediction algorithms applied to the B. malayi (Bm) genome. Not surprisingly, the majority (160/274) of these “hypothetical” proteins were predicted to be secreted by Signal IP and/or SecretomeP 2.0 analysis. Of major interest is the abundance of previously characterized immunomodulatory proteins such as ES-62 (leucyl aminopeptidase), MIF-1, SERPIN, glutathione peroxidase, and galectin in the ES of microfilariae (and Mf-containing adult females) compared to the adult males. In addition, searching the ES protein spectra against the Wolbachia database resulted in the identification of 90 Wolbachia-specific proteins, most of which were metabolic enzymes that have not been shown to be immunogenic. This proteomic analysis extends our knowledge of the ES and provides insight into the host–parasite interaction
Serum IgE Reactivity Profiling in an Asthma Affected Cohort
BACKGROUND: Epidemiological evidence indicates that atopic asthma correlates with high serum IgE levels though the contribution of allergen specific IgE to the pathogenesis and the severity of the disease is still unclear. METHODS: We developed a microarray immunoassay containing 103 allergens to study the IgE reactivity profiles of 485 asthmatic and 342 non-asthmatic individuals belonging to families whose members have a documented history of asthma and atopy. We employed k-means clustering, to investigate whether a particular IgE reactivity profile correlated with asthma and other atopic conditions such as rhinitis, conjunctivitis and eczema. RESULTS: Both case-control and parent-to-siblings analyses demonstrated that while the presence of specific IgE against individual allergens correlated poorly with pathological conditions, particular reactivity profiles were significantly associated with asthma (p<10E-09). An artificial neural network (ANN)-based algorithm, calibrated with the profile reactivity data, correctly classified as asthmatic or non-asthmatic 78% of the individual examined. Multivariate statistical analysis demonstrated that the familiar relationships of the study population did not affect the observed correlations. CONCLUSIONS: These findings indicate that asthma is a higher-order phenomenon related to patterns of IgE reactivity rather than to single antibody reactions. This notion sheds new light on the pathogenesis of the disease and can be readily employed to distinguish asthmatic and non-asthmatic individuals on the basis of their serum reactivity profile
Abeta42-Induced Neurodegeneration via an Age-Dependent Autophagic-Lysosomal Injury in Drosophila
The mechanism of widespread neuronal death occurring in Alzheimer's disease (AD) remains enigmatic even after extensive investigation during the last two decades. Amyloid beta 42 peptide (Aβ1–42) is believed to play a causative role in the development of AD. Here we expressed human Aβ1–42 and amyloid beta 40 (Aβ1–40) in Drosophila neurons. Aβ1–42 but not Aβ1–40 causes an extensive accumulation of autophagic vesicles that become increasingly dysfunctional with age. Aβ1–42-induced impairment of the degradative function, as well as the structural integrity, of post-lysosomal autophagic vesicles triggers a neurodegenerative cascade that can be enhanced by autophagy activation or partially rescued by autophagy inhibition. Compromise and leakage from post-lysosomal vesicles result in cytosolic acidification, additional damage to membranes and organelles, and erosive destruction of cytoplasm leading to eventual neuron death. Neuronal autophagy initially appears to play a pro-survival role that changes in an age-dependent way to a pro-death role in the context of Aβ1–42 expression. Our in vivo observations provide a mechanistic understanding for the differential neurotoxicity of Aβ1–42 and Aβ1–40, and reveal an Aβ1–42-induced death execution pathway mediated by an age-dependent autophagic-lysosomal injury
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