1,397 research outputs found

    Complement activation in the Parkinson's disease substantia nigra: an immunocytochemical study

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    BACKGROUND: Inflammatory processes are increased in the Parkinson's disease (PD) brain. The long-term use of nonsteroidal anti-inflammatory drugs has been associated, in retrospective studies, with decreased risk for PD, suggesting that inflammation may contribute to development of this disorder. The objective of this study was to determine the extent of complement activation, a major inflammatory mechanism, in PD. METHODS: Substantia nigra specimens from young normal subjects (n = 11–13), aged normal subjects (n = 24–28), and subjects with PD (n = 19–20), Alzheimer's disease (AD; n = 12–13), and dementia with Lewy bodies (DLB; n = 9) were stained for iC3b and C9, representing early- and late-stage complement activation, respectively. Numbers of iC3b(+), C9(+), and total melanized neurons in each section were counted in a blinded fashion. Nonparametric analyses were used to evaluate differences between groups and to evaluate correlations between complement staining, numbers of melanized neurons, and the duration of PD. RESULTS: Lewy bodies in both PD and DLB specimens stained for iC3b and C9. Staining was also prominent on melanized neurons. The percentage of iC3b(+ )neurons was significantly increased in PD vs. aged normal and AD specimens, and in young normal vs. aged normal specimens. C9 immunoreactivity was significantly increased in PD vs. AD specimens, but unlike iC3b, the increased C9 staining in PD and young normal specimens did not achieve statistical significance vs. aged normal specimens. iC3b and C9 staining in PD specimens was not correlated with the numbers of remaining melanized neurons, nor with the duration of PD. CONCLUSION: Complement activation occurs on Lewy bodies and melanized neurons in the PD substantia nigra. Early complement activation (iC3b) is increased on melanized neurons in PD vs. aged normal specimens, and late-stage complement activation (C9) also tends to increase. This latter finding suggests that complement activation may contribute to loss of dopaminergic neurons in some individuals with PD. Complement activation on melanized neurons appears to decrease with normal aging, suggesting a possible neuroprotective role for this process in the normal substantia nigra

    Genomic insights into the rapid emergence and evolution of MDR in Staphylococcus pseudintermedius.

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    OBJECTIVES: MDR methicillin-resistant Staphylococcus pseudintermedius (MRSP) strains have emerged rapidly as major canine pathogens and present serious treatment issues and concerns to public health due to their, albeit low, zoonotic potential. A further understanding of the genetics of resistance arising from a broadly susceptible background of S. pseudintermedius is needed. METHODS: We sequenced the genomes of 12 S. pseudintermedius isolates of varied STs and resistance phenotypes. RESULTS: Nine distinct clonal lineages had acquired either staphylococcal cassette chromosome (SCC) mec elements and/or Tn5405-like elements carrying up to five resistance genes [aphA3, sat, aadE, erm(B), dfrG] to generate MRSP, MDR methicillin-susceptible S. pseudintermedius and MDR MRSP populations. The most successful and clinically problematic MDR MRSP clones, ST68 SCCmecV(T) and ST71 SCCmecII-III, have further accumulated mutations in gyrA and grlA conferring resistance to fluoroquinolones. The carriage of additional mobile genetic elements (MGEs) was highly variable, suggesting that horizontal gene transfer is frequent in S. pseudintermedius populations. CONCLUSIONS: Importantly, the data suggest that MDR MRSP evolved rapidly by the acquisition of a very limited number of MGEs and mutations, and that the use of many classes of antimicrobials may co-select for the spread and emergence of MDR and XDR strains. Antimicrobial stewardship will need to be comprehensive, encompassing human medicine and veterinary disciplines to successfully preserve antimicrobial efficacy

    Social cognition in individuals with 22q11.2 deletion syndrome and its link with psychopathology and social outcomes: a review

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    Background: The 22q11.2 deletion syndrome (22q11DS) is a genetic syndrome that results in a highly variable profile of affected individuals of which impairments in the social domain and increased psychopathology are the most prominent. Notably, 25–30% of affected individuals eventually develop schizophrenia/psychosis, predisposing persons with the syndrome to increased risk for this disorder. Because social cognition is considered to underlie social behavior and to be related to psychopathology, this systematic review investigated social cognition in individuals with 22q11DS and examined reported links across its domains with psychopathology and social outcomes. This can provide the basis for a closer understanding of the path from risk to disorder and will inform on the specific domains that can be targeted with preventive intervention strategies. Method: Systematic literature review of studies that reported the links between social cognitive domains and psychopathology and/or social outcomes in individuals with 22q11DS. Electronic databases searched were PubMed and PsycINFO. Results: Defined eligibility criteria identified a total of ten studies to be included in the present review. Selected studies investigated links between two domains of social cognition (emotion processing and theory of mind (ToM)) and psychopathology and/or social outcomes. With respect to the links to psychopathology, two aspects of social cognition were related primarily to negative symptoms. Results regarding the associations to positive and emotional symptoms (anxiety/depression) are limited and require further investigation. Even though both aspects of social cognition were associated with social outcomes, several studies also found no links between these two domains. Both reports invite for an additional examination of reported results and specific considerations regarding chosen constructs. Conclusion: Although equivocal, results of the present review provide sufficient evidence that social cognition is a useful domain for the closer elucidation of clinical outcomes and social difficulties in this population. At the same time, longitudinal studies and consideration of other variables are also necessary for a timely understanding of affected persons in this respect

    Mechanisms of transient nitric oxide and nitrous oxide production in a complex biofilm

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    Nitric oxide (NO) and nitrous oxide (N2O) are formed during N-cycling in complex microbial communities in response to fluctuating molecular oxygen (O2) and nitrite (NO2−) concentrations. Until now, the formation of NO and N2O in microbial communities has been measured with low spatial and temporal resolution, which hampered elucidation of the turnover pathways and their regulation. In this study, we combined microsensor measurements with metabolic modeling to investigate the functional response of a complex biofilm with nitrifying and denitrifying activity to variations in O2 and NO2−. In steady state, NO and N2O formation was detected if ammonium (NH4+) was present under oxic conditions and if NO2− was present under anoxic conditions. Thus, NO and N2O are produced by ammonia-oxidizing bacteria (AOB) under oxic conditions and by heterotrophic denitrifiers under anoxic conditions. NO and N2O formation by AOB occurred at fully oxic conditions if NO2− concentrations were high. Modeling showed that steady-state NO concentrations are controlled by the affinity of NO-consuming processes to NO. Transient accumulation of NO and N2O occurred upon O2 removal from, or NO2− addition to, the medium only if NH4+ was present under oxic conditions or if NO2− was already present under anoxic conditions. This showed that AOB and heterotrophic denitrifiers need to be metabolically active to respond with instantaneous NO and N2O production upon perturbations. Transiently accumulated NO and N2O decreased rapidly after their formation, indicating a direct effect of NO on the metabolism. By fitting model results to measurements, the kinetic relationships in the model were extended with dynamic parameters to predict transient NO release from perturbed ecosystems

    Ionic Liquid Electrolytes for Safer Lithium Batteries – I. Investigation around Optimal Formulation

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    In this paper we report on the investigation of ionic liquid-based electrolytes with enhanced characteristics. In particular, we have studied ternary mixtures based on the lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt and two ionic liquids sharing the same cation (N-methyl-N-propyl pyrrolidinium, PYR13), but different anions, bis(trifluoromethanesulfonyl)imide (TFSI) and bis(fluorosulfonyl)imide (FSI). The LiTFSI-PYR13TFSI-PYR13FSI mixtures, found to be ionically dissociated, exhibit better ion transport properties (about 10−3 S cm−1 at −20°C) with respect to similar ionic liquid electrolytes till reported in literature. An electrochemical stability window of 5 V is observed in carbon working electrodes. Preliminary battery tests confirm the good performance of these ternary electrolytes with high-voltage NMC cathodes and graphite anodes

    Trained laser-patterned carbon as high-performance mechanical sensors

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    We describe the mechanical properties of turbostratically graphitized carbon films obtained by carbon laser-patterning (CLaP) and their application as bending or mechanical pressure sensors. Stable conductive carbonized films were imprinted on a flexible polyethylene terephthalate (PET) substrate by laser-induced carbonization. After initial gentle bending, i.e. training, these sponge-like porous films show a quantitative and reversible change in resistance upon bending or application of pressure in normal loading direction. Maximum response values of ΔR/R0 = 388% upon positive bending (tensile stress) and −22.9% upon negative bending (compression) are implicit for their high sensitivity towards mechanical deformation. Normal mechanical loading in a range between 0 and 500 kPa causes a response between ΔR/R0 = 0 and −15%. The reversible increase or decrease in resistance is attributed to compression or tension of the turbostratically graphitized domains, respectively. This mechanism is supported by a detailed microstructural and chemical high-resolution transmission electron microscopic analysis of the cross-section of the laser-patterned carbon

    Dilute ferrimagnetic semiconductors in Fe-substituted spinel ZnGa2_2O4_4

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    Solid solutions of nominal composition [ZnGa2_2O4_4]1−x_{1-x}[Fe3_3O4_4]x_x, of the semiconducting spinel ZnGa2_2O4_4 with the ferrimagnetic spinel Fe3_3O4_4 have been prepared with xx = 0.05, 0.10, and 0.15. All samples show evidence for long-range magnetic ordering with ferromagnetic hysteresis at low temperatures. Magnetization as a function of field for the xx = 0.15 sample is S-shaped at temperatures as high as 200 K. M\"ossbauer spectroscopy on the xx = 0.15 sample confirms the presence of Fe3+^{3+}, and spontaneous magnetization at 4.2 K. The magnetic behavior is obtained without greatly affecting the semiconducting properties of the host; diffuse reflectance optical spectroscopy indicates that Fe substitution up to xx = 0.15 does not affect the position of the band edge absorption. These promising results motivate the possibility of dilute ferrimagnetic semiconductors which do not require carrier mediation of the magnetic moment.Comment: 9 pages and 6 figure

    Standard and increased-dose BEACOPP chemotherapy compared with COPP-ABVD for advanced Hodgkins disease

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    BACKGROUND: Faced with unsatisfactory results of treatment for advanced Hodgkin's disease, we investigated three combinations of chemotherapy. METHODS: From 1993 to 1998, 1201 eligible patients 15 to 65 years of age who had newly diagnosed Hodgkin's disease in unfavorable stage IIB or IIIA or stage IIIB or IV were randomly assigned to receive eight cycles of cyclophosphamide, vincristine, procarbazine, and prednisone alternating with doxorubicin, bleomycin, vinblastine, and dacarbazine (COPP-ABVD); bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone (BEACOPP); or increased-dose BEACOPP, each followed by local radiotherapy when indicated. Enrollment in the COPP-ABVD group was stopped in 1996 owing to inferior results. RESULTS: For the final analysis, 1195 of 1201 patients could be evaluated: 260 in the COPP-ABVD group, 469 in the BEACOPP group, and 466 in the increased-dose BEACOPP group; the median follow-up was 72, 54, and 51 months, respectively. The rate of freedom from treatment failure at five years was 69 percent in the COPP-ABVD group, 76 percent in the BEACOPP group, and 87 percent in the increased-dose BEACOPP group (P=0.04 for the comparison of the COPP-ABVD group with the BEACOPP group and P<0.001 for the comparison of the increased-dose BEACOPP group with the COPP-ABVD group and with the BEACOPP group), and the five-year rates of overall survival were 83 percent, 88 percent, and 91 percent, respectively (P=0.16 for the comparison of the COPP-ABVD group with the BEACOPP group, P=0.06 for the comparison of the BEACOPP group with the increased-dose BEACOPP group, and P=0.002 for the comparison of the COPP-ABVD group with the increased-dose BEACOPP group). Rates of early progression were significantly lower with increased-dose BEACOPP than with COPP-ABVD or standard BEACOPP. CONCLUSIONS: Increased-dose BEACOPP resulted in better tumor control and overall survival than did COPP-ABVD
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