253 research outputs found

    Neurodegeneration progresses despite complete elimination of clinical relapses in a mouse model of multiple sclerosis.

    Get PDF
    BACKGROUND: [corrected] Multiple Sclerosis has two clinical phases reflecting distinct but inter-related pathological processes: focal inflammation drives the relapse-remitting stage and neurodegeneration represents the principal substrate of secondary progression. In contrast to the increasing number of effective anti-inflammatory disease modifying treatments for relapse-remitting disease, the absence of therapies for progressive disease represents a major unmet clinical need. This raises the unanswered question of whether elimination of clinical relapses will prevent subsequent progression and if so how early in the disease course should treatment be initiated. Experimental autoimmune encephalomyelitis in the Biozzi ABH mouse recapitulates the clinical and pathological features of multiple sclerosis including relapse-remitting episodes with inflammatory mediated demyelination and progressive disability with neurodegeneration. To address the relationship between inflammation and neurodegeneration we used an auto-immune tolerance strategy to eliminate clinical relapses in EAE in a manner analogous to the clinical effect of disease modifying treatments. RESULTS: By arresting clinical relapses in EAE at two distinct stages, early and late disease, we demonstrate that halting immune driven demyelination even after the first major clinical event is insufficient to prevent long-term neurodegeneration and associated gliosis. Nonetheless, early intervention is partially neuroprotective, whereas later interventions are not. Furthermore early tolerisation is also associated with increased remyelination. CONCLUSIONS: These findings are consistent with both a partial uncoupling of inflammation and neurodegeneration and that the regenerative response of remyelination is negatively correlated with inflammation. These findings strongly support the need for early combinatorial treatment of immunomodulatory therapies and neuroprotective treatments to prevent long-term neurodegeneration in multiple sclerosis

    Human Serum Metabolites Associate With Severity and Patient Outcomes in Traumatic Brain Injury.

    Get PDF
    Traumatic brain injury (TBI) is a major cause of death and disability worldwide, especially in children and young adults. TBI is an example of a medical condition where there are still major lacks in diagnostics and outcome prediction. Here we apply comprehensive metabolic profiling of serum samples from TBI patients and controls in two independent cohorts. The discovery study included 144 TBI patients, with the samples taken at the time of hospitalization. The patients were diagnosed as severe (sTBI; n=22), moderate (moTBI; n=14) or mild TBI (mTBI; n=108) according to Glasgow Coma Scale. The control group (n=28) comprised of acute orthopedic non-brain injuries. The validation study included sTBI (n=23), moTBI (n=7), mTBI (n=37) patients and controls (n=27). We show that two medium-chain fatty acids (decanoic and octanoic acids) and sugar derivatives including 2,3-bisphosphoglyceric acid are strongly associated with severity of TBI, and most of them are also detected at high concentrations in brain microdialysates of TBI patients. Based on metabolite concentrations from TBI patients at the time of hospitalization, an algorithm was developed that accurately predicted the patient outcomes (AUC=0.84 in validation cohort). Addition of the metabolites to the established clinical model (CRASH), comprising clinical and computed tomography data, significantly improved prediction of patient outcomes. The identified 'TBI metabotype' in serum, that may be indicative of disrupted blood-brain barrier, of protective physiological response and altered metabolism due to head trauma, offers a new avenue for the development of diagnostic and prognostic markers of broad spectrum of TBIs.European Union FP7 project TBIcare (Grant ID: 270259), GE-NFL Head Health Challenge I Award (Grant ID: 7620), EVO (Finland), Maire Taponen Foundation, National Institute for Health Research, National Institute for Health Research Biomedical Research Centre Cambridge (Neuroscience Theme; Brain Injury and Repair Theme)This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.ebiom.2016.07.01

    Holographic Vitrification

    Get PDF
    We establish the existence of stable and metastable stationary black hole bound states at finite temperature and chemical potentials in global and planar four-dimensional asymptotically anti-de Sitter space. We determine a number of features of their holographic duals and argue they represent structural glasses. We map out their thermodynamic landscape in the probe approximation, and show their relaxation dynamics exhibits logarithmic aging, with aging rates determined by the distribution of barriers.Comment: 100 pages, 25 figure

    Psychological morbidity, sources of stress and coping strategies among undergraduate medical students of Nepal

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>In recent years there has been a growing appreciation of the issues of quality of life and stresses involved medical training as this may affect their learning and academic performance. However, such studies are lacking in medical schools of Nepal. Therefore, we carried out this study to assess the prevalence of psychological morbidity, sources and severity of stress and coping strategies among medical students in our integrated problem-stimulated undergraduate medical curriculum.</p> <p>Methods</p> <p>A cross-sectional, questionnaire-based survey was carried out among the undergraduate medical students of Manipal College of Medical Sciences, Pokhara, Nepal during the time period August, 2005 to December, 2006. The psychological morbidity was assessed using General Health Questionnaire. A 24-item questionnaire was used to assess sources of stress and their severity. Coping strategies adopted was assessed using brief COPE inventory.</p> <p>Results</p> <p>The overall response rate was 75.8% (407 out of 525 students). The overall prevalence of psychological morbidity was 20.9% and was higher among students of basic sciences, Indian nationality and whose parents were medical doctors. By logistic regression analysis, GHQ-caseness was associated with occurrence of academic and health-related stressors. The most common sources of stress were related to academic and psychosocial concerns. The most important and severe sources of stress were staying in hostel, high parental expectations, vastness of syllabus, tests/exams, lack of time and facilities for entertainment. The students generally used active coping strategies and alcohol/drug was a least used coping strategy. The coping strategies commonly used by students in our institution were positive reframing, planning, acceptance, active coping, self-distraction and emotional support. The coping strategies showed variation by GHQ-caseness, year of study, gender and parents' occupation.</p> <p>Conclusion</p> <p>The higher level of psychological morbidity warrants need for interventions like social and psychological support to improve the quality of life for these medical students. Student advisors and counselors may train students about stress management. There is also need to bring about academic changes in quality of teaching and evaluation system. A prospective study is necessary to study the association of psychological morbidity with demographic variables, sources of stress and coping strategies.</p

    Zinc adjunct therapy reduces case fatality in severe childhood pneumonia: a randomized double blind placebo-controlled trial

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Pneumonia is a leading cause of children's deaths in developing countries and hinders achievement of the fourth Millennium Development Goal. This goal aims to reduce the under-five mortality rate, by two thirds, between 1990 and 2015.</p> <p>Few studies have examined the impact of zinc adjunct therapy on the outcome of childhood pneumonia. We determined the effect of zinc as adjunct therapy on time to normalization of respiratory rate, temperature and oxygen saturation. We also studied the effect of zinc adjunct therapy on case fatality of severe childhood pneumonia (as a secondary outcome) in Mulago Hospital, Uganda.</p> <p>Methods</p> <p>In this double blind, randomized, placebo-controlled clinical trial, 352 children aged 6 to 59 months, with severe pneumonia were randomized to zinc (20 mg for children ≥12 months, and 10 mg for those < 12 months) or a placebo once daily for seven days, in addition to standard antibiotics for severe pneumonia. Children were assessed every six hours. Oxygen saturation was normal if it was above 92% (breathing room air) for more than 15 minutes. The respiratory rate was normal if it was consistently (more than 24 hours) below 50 breaths per minute in infants and 40 breaths per minute in children above 12 months of age. Temperature was normal if consistently below 37.5°C. The difference in case fatality was expressed by the risk ratio between the two groups.</p> <p>Results</p> <p>Time to normalization of the respiratory rate, temperature and oxygen saturation was not significantly different between the two arms.</p> <p>Case fatality was 7/176 (4.0%) in the zinc group and 21/176 (11.9%) in the placebo group: Relative Risk 0.33 (95% CI 0.15 to 0.76). Relative Risk Reduction was 0.67 (95% CI 0.24 to 0.85), while the number needed to treat was 13. Among HIV infected children, case fatality was higher in the placebo (7/27) than in the zinc (0/28) group; RR 0.1 (95% CI 0.0, 1.0).</p> <p>Among 127 HIV uninfected children receiving the placebo, case fatality was 7/127 (5.5%); versus 5/129 (3.9%) among HIV uninfected group receiving zinc: RR 0.7 (95% CI 0.2, 2.2). The excess risk of death attributable to the placebo arm (Absolute Risk Reduction or ARR) was 8/100 (95% CI: 2/100, 14/100) children. This excess risk was substantially greater among HIV positive children than in HIV negative children (ARR: 26 (95% CI: 9, 42) per 100 versus 2 (95% CI: -4, 7) per 100); <it>P</it>-value for homogeneity of risk differences = 0.006.</p> <p>Conclusion</p> <p>Zinc adjunct therapy for severe pneumonia had no significant effect on time to normalization of the respiratory rate, temperature and oxygen saturation. However, zinc supplementation in these children significantly decreased case fatality.</p> <p>The difference in case fatality attributable to the protective effect of zinc therapy was greater among HIV infected than HIV uninfected children. Given these results, zinc could be considered for use as adjunct therapy for severe pneumonia, especially among Highly Active Antiretroviral Therapy</p> <p>naïve HIV infected children in our environment.</p> <p>Clinical trials registration number</p> <p>clinicaltrials.gov <a href="http://www.clinicaltrials.gov/ct2/show/NCT00373100">NCT00373100</a></p

    Using Magnetically Responsive Tea Waste to Remove Lead in Waters under Environmentally Relevant Conditions

    Get PDF
    We report the use of a simple yet highly effective magnetite-waste tea composite to remove lead(II) (Pb[superscript 2+]) ions from water. Magnetite-waste tea composites were dispersed in four different types of water–deionized (DI), artificial rainwater, artificial groundwater and artificial freshwater–that mimic actual environmental conditions. The water samples had varying initial concentrations (0.16–5.55 ppm) of Pb[superscript 2+] ions and were mixed with the magnetite-waste tea composite for at least 24 hours to allow adsorption of the Pb[superscript 2+] ions to reach equilibrium. The magnetite-waste tea composites were stable in all the water samples for at least 3 months and could be easily removed from the aqueous media via the use of permanent magnets. We detected no significant leaching of iron (Fe) ions into the water from the magnetite-waste tea composites. The percentage of Pb adsorbed onto the magnetite-waste tea composite ranged from ~70% to 100%; the composites were as effective as activated carbon (AC) in removing the Pb[superscript 2+] ions from water, depending on the initial Pb concentration. Our prepared magnetite-waste tea composites show promise as a green, inexpensive and highly effective sorbent for removal of Pb in water under environmentally realistic conditions.SUTD-MIT International Design Center (Research Grant IDG11200105/IDD11200109)Singapore-MIT Allianc

    Altered Trabecular Bone Structure and Delayed Cartilage Degeneration in the Knees of Collagen VI Null Mice

    Get PDF
    Mutation or loss of collagen VI has been linked to a variety of musculoskeletal abnormalities, particularly muscular dystrophies, tissue ossification and/or fibrosis, and hip osteoarthritis. However, the role of collagen VI in bone and cartilage structure and function in the knee is unknown. In this study, we examined the role of collagen VI in the morphology and physical properties of bone and cartilage in the knee joint of Col6a1−/− mice by micro-computed tomography (microCT), histology, atomic force microscopy (AFM), and scanning microphotolysis (SCAMP). Col6a1−/− mice showed significant differences in trabecular bone structure, with lower bone volume, connectivity density, trabecular number, and trabecular thickness but higher structure model index and trabecular separation compared to Col6a1+/+ mice. Subchondral bone thickness and mineral content increased significantly with age in Col6a1+/+ mice, but not in Col6a1−/− mice. Col6a1−/− mice had lower cartilage degradation scores, but developed early, severe osteophytes compared to Col6a1+/+mice. In both groups, cartilage roughness increased with age, but neither the frictional coefficient nor compressive modulus of the cartilage changed with age or genotype, as measured by AFM. Cartilage diffusivity, measured via SCAMP, varied minimally with age or genotype. The absence of type VI collagen has profound effects on knee joint structure and morphometry, yet minimal influences on the physical properties of the cartilage. Together with previous studies showing accelerated hip osteoarthritis in Col6a1−/− mice, these findings suggest different roles for collagen VI at different sites in the body, consistent with clinical data

    Pneumonia and poverty: a prospective population-based study among children in Brazil

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Children in developing country suffer the highest burden of pneumonia. However, few studies have evaluated associations between poverty and pneumonia.</p> <p>Methods</p> <p>A prospective population-based study on pneumonia was carried out as part of the Latin America Epidemiological Assessment of Pneumococcus (LEAP study). Chest x-rays were obtained for children one to 35 months old with suspected pneumonia presenting to emergency care centers and hospital emergency rooms in Goiania, Brazil. Chest radiographs were evaluated according to WHO guidelines. Clustering of radiologically-confirmed pneumonia were evaluated using a Poisson-based spatial scan statistic. Associations between census socioeconomic indicators and pneumonia incidence rates were analyzed using generalized linear models.</p> <p>Results</p> <p>From May, 2007 to May, 2009, chest radiographs were obtained from 11 521 children with clinical pneumonia; 3955 episodes were classified as radiologically-confirmed. Incidence rates were significantly higher in very low income areas (4825.2 per 10<sup>5</sup>) compared to high income areas (1637.3 per 10<sup>5</sup>). Spatial analysis identified clustering of confirmed pneumonia in Western (RR 1.78; p = 0.001) and Southeast (RR 1.46; p = 0.001) regions of the city, and clustering of hospitalized pneumonia in the Western region (RR 1.69; p = 0.001). Lower income households and illiteracy were associated with pneumonia incidence.</p> <p>Conclusions</p> <p>In infants the risk of developing pneumonia is inversely associated with the head of household income and with the woman educational level. Areas with deprived socioeconomic conditions had higher incidence of pneumonia and should be targeted for high vaccination coverage.</p
    corecore