1,720,967 research outputs found
Pathophysiology of neuropathic lysosomal storage disorders
No full textAlthough neurodegenerative diseases are most prevalent in the elderly, in rare cases, they can also affect children. Lysosomal storage diseases (LSDs) are a group of inherited metabolic neurodegenerative disorders due to deficiency of a specific protein integral to lysosomal function, such as enzymes or lysosomal components, or to errors in enzyme trafficking/targeting and defective function of nonenzymatic lysosomal proteins, all preventing the complete degradation and recycling of macromolecules. This primary metabolic event determines a cascade of secondary events, inducing LSD's pathology. The accumulation of intermediate degradation affects the function of lysosomes and other cellular organelles. Accumulation begins in infancy and progressively worsens, often affecting several organs, including the central nervous system (CNS). Affected neurons may die through apoptosis or necrosis, although neuronal loss usually does not occur before advanced stages of the disease. CNS pathology causes mental retardation, progressive neurodegeneration, and premature death. Many of these features are also found in adult neurodegenerative disorders, such as Alzheimer's, Parkinson's, and Huntington's diseases. However, the nature of the secondary events and their exact contribution to mental retardation and dementia remains largely unknown. Recently, lysosomal involvement in the pathogenesis of these disorders has been described. Improved knowledge of secondary events may have impact on diagnosis, staging, and follow-up of affected children. Importantly, new insights may provide indications about possible disease reversal upon treatment. A discussion about the CNS pathophysiology involvement in LSDs is the aim of this review. The lysosomal involvement in adult neurodegenerative diseases will also be briefly described
Inborn Errors of Metabolism Involving Complex Molecules: Lysosomal and Peroxisomal Storage Diseases
No full textExpression of programmed death-1 ligand (PD-L) 1, PD-L2, B7-H3, and inducible costimulator ligand on human respiratory tract epithelial cells and regulation by respiratory syncytial virus and type 1 and 2 cytokines
No full textBACKGROUND: Respiratory syncytial virus (RSV) is associated with wheezing illness, and infections can occur repeatedly throughout life. We hypothesized that RSV infection of respiratory tract epithelial cells up-regulates B7 molecules that regulate memory immune responses and that type 1 and 2 cytokines differentially modulate this induction. METHODS: We used flow-cytometric analysis to investigate programmed death-1 ligand (PD-L) 1, PD-L2, B7-H3, and inducible costimulatory ligand (ICOS-L) expression on tracheal (NCI-H292), bronchial (BEAS-2B), and alveolar (A549) epithelial cells; regulation of this expression by RSV, interferon (IFN)- gamma , and interleukin (IL)-4; and the effects of IFN-gamma and IL-4 on RSV-induced expression of these molecules. RESULTS: B7-H3 was strongly expressed, PD-L1 and ICOS-L were moderately expressed, and PD-L2 was weakly expressed on unstimulated tracheal, bronchial, and alveolar epithelial cells. RSV infection up-regulated PD-L1, PD-L2, and B7-H3 expression on all cells and ICOS-L expression on bronchial and alveolar epithelial cells. IL-4 treatment alone had no effect, whereas IFN-gamma treatment alone increased PD-L1 and PD-L2 expression on all cells and decreased B7-H3 expression on bronchial and alveolar epithelial cells. On RSV-infected alevolar epithelial cells, IFN-gamma treatment increased PD-L1 and PD-L2 expression and decreased B7-H3 and ICOS-L expression, and IL-4 treatment increased PD-L2 and B7-H3 expression and decreased ICOS-L expression. CONCLUSIONS: Respiratory tract epithelial cells express a wide range of B7 molecules. RSV infection increases their expression, and this expression is differentially regulated by IFN-gamma and IL-4. These processes may be involved in decreasing T cell antiviral immune responses to RSV and in RSV-associated wheezing
Reducing agents inhibit rhinovirus-induced up-regulation of the rhinovirus receptor intercellular adhesion molecule-1 (ICAM-1) in respiratory epithelial cells
No full textRhinoviruses are the major cause of common colds and of asthma exacerbations. Intercellular adhesion molecule-1 (ICAM-1) has a central role in airway inflammation and is the receptor for 90% of rhinoviruses. Rhinovirus infection of airway epithelium induces ICAM-1. Because redox state is directly implicated in inflammatory responses via molecular signaling mechanisms, here we studied the effects of reducing agents on rhinovirus-induced ICAM-1 expression, mRNA up-regulation, promoter activation, and nuclear factor activation. To investigate the effects of rhinovirus infection on the intracellular redox balance, we also studied whether rhinovirus infection triggers the production of reactive oxygen species. We found that reduced (GSH) but not oxidized (GSSG) glutathione (1-100 microM) inhibited in a dose-dependent manner rhinovirus-induced ICAM-1 up-regulation and mRNA induction in primary bronchial and A549 respiratory epithelial cells. GSH but not GSSG also inhibited rhinovirus-induced ICAM-1 promoter activation and rhinovirus-induced NF-kB activation. In parallel, we found that rhinovirus infection induced a rapid increase of intracellular superoxide anion that was maximal at the time of NF-kB activation. This oxidant generation was completely inhibited by GSH. We conclude that redox-mediated intracellular pathways represent an important target for the therapeutic control of rhinovirus-induced disease
Gene therapy approaches for lysosomal storage disorders, a good model for the treatment of mendelian diseases.
No full textIncreased proportion of CD8(+) T-lymphocytes in the paratracheal lymph nodes of smokers with mild COPD
No full textPrevious studies have shown an increased number of inflammatory cells and, in particular, of CD8+ T lymphocytes, in central airways, peripheral airways, lung parenchyma and pulmonary arteries of smokers with COPD. In this study we investigated whether this inflammatory process is restricted to the lung tissue or whether a similar process is also present in the lymph nodes of these subjects. We examined paratracheal lymph nodes obtained from 6 smokers with COPD (FEV1/VC 88% predicted and FEV1/FVC > 70%) undergoing lung resection for localised pulmonary lesions. By immunohistochemistry we quantified CD4+ and CD8+ T-lymphocytes in the lymph nodes. Smokers with COPD had a decreased ratio CD4/CD8 compared to smokers without COPD. When all subjects were considered together, the ratio CD4/CD8 showed a positive correlation with the values of FEV1/VC and a negative correlation with cigarette consumption. In conclusion, smokers with COPD have an increased proportion of CD8+ cells in the lymph nodes, indicating that a T-lymphocyte pattern similar to that present in the lung tissue is also present in the lymph nodes of these subjects. This finding suggests that, in COPD, the polarisation of the immune response may occur in the regional lymph nodes, possibly as a consequence of the presentation of an endogenous antigen that remains unknow
Increased proportion of CD8(+) T-lymphocytes in the paratracheal lymph nodes of smokers with mild COPD
No full textPrevious studies have shown an increased number of inflammatory cells and, in particular, of CD8+ T lymphocytes, in central airways, peripheral airways, lung parenchyma and pulmonary arteries of smokers with COPD. In this study we investigated whether this inflammatory process is restricted to the lung tissue or whether a similar process is also present in the lymph nodes of these subjects. We examined paratracheal lymph nodes obtained from 6 smokers with COPD (FEV1/VC 88% predicted and FEV1/FVC > 70%) undergoing lung resection for localised pulmonary lesions. By immunohistochemistry we quantified CD4+ and CD8+ T-lymphocytes in the lymph nodes. Smokers with COPD had a decreased ratio CD4/CD8 compared to smokers without COPD. When all subjects were considered together, the ratio CD4/CD8 showed a positive correlation with the values of FEV1/VC and a negative correlation with cigarette consumption. In conclusion, smokers with COPD have an increased proportion of CD8+ cells in the lymph nodes, indicating that a T-lymphocyte pattern similar to that present in the lung tissue is also present in the lymph nodes of these subjects. This finding suggests that, in COPD, the polarisation of the immune response may occur in the regional lymph nodes, possibly as a consequence of the presentation of an endogenous antigen that remains unknown
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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