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1.
Nat Commun ; 14(1): 3754, 2023 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-37365181

RESUMO

Dopaminergic cell loss due to the accumulation of α-syn is a core feature of the pathogenesis of Parkinson disease. Neuroinflammation specifically induced by α-synuclein has been shown to exacerbate neurodegeneration, yet the role of central nervous system (CNS) resident macrophages in this process remains unclear. We found that a specific subset of CNS resident macrophages, border-associated macrophages (BAMs), play an essential role in mediating α-synuclein related neuroinflammation due to their unique role as the antigen presenting cells necessary to initiate a CD4 T cell response whereas the loss of MHCII antigen presentation on microglia had no effect on neuroinflammation. Furthermore, α-synuclein expression led to an expansion in border-associated macrophage numbers and a unique damage-associated activation state. Through a combinatorial approach of single-cell RNA sequencing and depletion experiments, we found that border-associated macrophages played an essential role in immune cell recruitment, infiltration, and antigen presentation. Furthermore, border-associated macrophages were identified in post-mortem PD brain in close proximity to T cells. These results point to a role for border-associated macrophages in mediating the pathogenesis of Parkinson disease through their role in the orchestration of the α-synuclein-mediated neuroinflammatory response.


Assuntos
Doença de Parkinson , Humanos , Doença de Parkinson/metabolismo , alfa-Sinucleína/metabolismo , Doenças Neuroinflamatórias , Macrófagos/metabolismo , Inflamação/patologia , Microglia/metabolismo
2.
J Geophys Res Space Phys ; 127(7): e2022JA030408, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36248013

RESUMO

We present observations in Earth's magnetotail by the Magnetospheric Multiscale spacecraft that are consistent with magnetic field annihilation, rather than magnetic topology change, causing fast magnetic-to-electron energy conversion in an electron-scale current sheet. Multi-spacecraft analysis for the magnetic field reconstruction shows that an electron-scale magnetic island was embedded in the observed electron diffusion region (EDR), suggesting an elongated shape of the EDR. Evidence for the annihilation was revealed in the form of the island growing at a rate much lower than expected for the standard X-type geometry of the EDR, which indicates that magnetic flux injected into the EDR was not ejected from the X-point or accumulated in the island, but was dissipated in the EDR. This energy conversion process is in contrast to that in the standard EDR of a reconnecting current sheet where the energy of antiparallel magnetic fields is mostly converted to electron bulk-flow energy. Fully kinetic simulation also demonstrates that an elongated EDR is subject to the formation of electron-scale magnetic islands in which fast but transient annihilation can occur. Consistent with the observations and simulation, theoretical analysis shows that fast magnetic diffusion can occur in an elongated EDR in the presence of nongyrotropic electron effects. We suggest that the annihilation in elongated EDRs may contribute to the dissipation of magnetic energy in a turbulent collisionless plasma.

3.
Arthritis Res Ther ; 21(1): 182, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31370858

RESUMO

BACKGROUND: Patients with rheumatoid arthritis (RA) experience extra-articular manifestations including osteoporosis and muscle wasting, which closely associate with severity of disease. Whilst therapeutic glucocorticoids (GCs) reduce inflammation in RA, their actions on muscle and bone metabolism in the context of chronic inflammation remain unclear. We utilised the TNF-tg model of chronic polyarthritis to ascertain the impact of therapeutic GCs on bone and muscle homeostasis in the context of systemic inflammation. METHODS: TNF-tg and wild-type (WT) animals received either vehicle or the GC corticosterone (100 µg/ml) in drinking water at onset of arthritis. Arthritis severity and clinical parameters were measured, serum collected for ELISA and muscle and bone biopsies collected for µCT, histology and mRNA analysis. In vivo findings were examined in primary cultures of osteoblasts, osteoclasts and myotubes. RESULTS: TNF-tg mice receiving GCs showed protection from inflammatory bone loss, characterised by a reduction in serum markers of bone resorption, osteoclast numbers and osteoclast activity. In contrast, muscle wasting was markedly increased in WT and TNF-tg animals receiving GCs, independently of inflammation. This was characterised by a reduction in muscle weight and fibre size, and an induction in anti-anabolic and catabolic signalling. CONCLUSIONS: This study demonstrates that when given in early onset chronic polyarthritis, oral GCs partially protect against inflammatory bone loss, but induce marked muscle wasting. These results suggest that in patients with inflammatory arthritis receiving GCs, the development of interventions to manage deleterious side effects in muscle should be prioritised.


Assuntos
Artrite/tratamento farmacológico , Reabsorção Óssea/prevenção & controle , Corticosterona/uso terapêutico , Células Musculares/patologia , Atrofia Muscular/prevenção & controle , Osteoblastos/patologia , Osteoclastos/patologia , Animais , Artrite/diagnóstico , Artrite/metabolismo , Biópsia , Reabsorção Óssea/metabolismo , Reabsorção Óssea/patologia , Células Cultivadas , Doença Crônica , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Glucocorticoides/uso terapêutico , Camundongos , Camundongos Endogâmicos C57BL , Células Musculares/efeitos dos fármacos , Células Musculares/metabolismo , Atrofia Muscular/metabolismo , Atrofia Muscular/patologia , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Osteoclastos/efeitos dos fármacos , Osteoclastos/metabolismo
4.
J Geophys Res Space Phys ; 123(2): 1118-1133, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29938153

RESUMO

This paper reports on Magnetospheric Multiscale observations of whistler mode chorus and higher-frequency electrostatic waves near and within a reconnection diffusion region on 23 November 2016. The diffusion region is bounded by crescent-shaped electron distributions and associated dissipation just upstream of the X-line and by magnetic field-aligned currents and electric fields leading to dissipation near the electron stagnation point. Measurements were made southward of the X-line as determined by southward directed ion and electron jets. We show that electrostatic wave generation is due to magnetosheath electron beams formed by the electron jets as they interact with a cold background plasma and more energetic population of magnetospheric electrons. On the magnetosphere side of the X-line the electron beams are accompanied by a strong perpendicular electron temperature anisotropy, which is shown to be the source of an observed rising-tone whistler mode chorus event. We show that the apex of the chorus event and the onset of electrostatic waves coincide with the opening of magnetic field lines at the electron stagnation point.

5.
Phys Rev Lett ; 119(2): 025101, 2017 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-28753352

RESUMO

During a magnetopause crossing the Magnetospheric Multiscale spacecraft encountered an electron diffusion region (EDR) of asymmetric reconnection. The EDR is characterized by agyrotropic beam and crescent electron distributions perpendicular to the magnetic field. Intense upper-hybrid (UH) waves are found at the boundary between the EDR and magnetosheath inflow region. The UH waves are generated by the agyrotropic electron beams. The UH waves are sufficiently large to contribute to electron diffusion and scattering, and are a potential source of radio emission near the EDR. These results provide observational evidence of wave-particle interactions at an EDR, and suggest that waves play an important role in determining the electron dynamics.

6.
J Eur Acad Dermatol Venereol ; 26(12): 1516-21, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22077962

RESUMO

BACKGROUND: There is a need for the development of novel non-steroidal topical drugs for the treatment of psoriasis. OBJECTIVE: To assess the efficacy and safety of topical 1.0% WBI-1001 in patients with mild to moderate plaque psoriasis. METHODS: A total of 61 patients with 1-10% body surface area (BSA) covered with plaque psoriasis and a physician's global assessment score (PGA) of 2-4 were randomized (2:1) to receive either 1% WBI-1001 in a cream formulation or placebo, applied twice daily for 12 weeks. Efficacy was evaluated using PGA, BSA and Psoriasis Area and Severity Index (PASI). The primary endpoint was the change from baseline (Day 0) in PGA at week 12. RESULTS: The improvement in PGA at week 12 was 62.8% for patients randomized to WBI-1001 when compared with 13.0% for patients randomized to placebo (P<0.0001). At week 12, the proportion of patients who achieved a PGA of clear or almost clear and the mean improvement in BSA were 67.5% and 79.1%, respectively, for patients randomized to WBI-1001, when compared with 4.8% (P<0.0001) and an increase of 9.4% (P<0.0001), respectively, for patients randomized to placebo. More application site adverse drug reactions were observed in patients randomized to WBI-1001 than in those randomized to placebo. These adverse drug reactions were all mild or moderate in intensity. CONCLUSION: Topical WBI-1001 induces rapid and significant improvement in patients with plaque psoriasis.


Assuntos
Fármacos Dermatológicos/uso terapêutico , Psoríase/tratamento farmacológico , Resorcinóis/uso terapêutico , Estilbenos/uso terapêutico , Administração Tópica , Fármacos Dermatológicos/administração & dosagem , Fármacos Dermatológicos/efeitos adversos , Método Duplo-Cego , Humanos , Placebos , Resorcinóis/administração & dosagem , Resorcinóis/efeitos adversos , Índice de Gravidade de Doença , Estilbenos/administração & dosagem , Estilbenos/efeitos adversos
7.
AIDS Care ; 18(4): 339-44, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16809111

RESUMO

Individuals involved in the criminal justice system are at substantial risk for HIV infection and have elevated rates of AIDS. Offenders under community supervision, such as probationers, have substantially more opportunities to engage in high-risk behaviors than prisoners. Furthermore, probationers in rural areas are at risk because rural areas may be slower to adopt HIV risk-reduction approaches. Consequently, the primary goal of this study is to describe the HIV risk behaviors and level of HIV knowledge of 800 rural felony probationers. Bivariate results indicate that males have substantially greater criminal histories and engage in more substance use risk behaviors than females. Overall, there was minimal and inconsistent use of condoms, but there were no significant differences by gender. Gender differences prevailed in perceived HIV knowledge, with females reporting high levels of perceived HIV knowledge. Multivariate models did not support the hypothesis that perceived knowledge would be a more robust correlate of scores on the HIV Risk Behavior Knowledge Test for males than females. Results suggest that rural residents are not protected from engaging in HIV risk behaviors and future studies should examine gender discrepancies between perceived and actual HIV knowledge among offenders under community supervision.


Assuntos
Infecções por HIV/psicologia , Adulto , Idoso , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Kentucky , Masculino , Pessoa de Meia-Idade , Assunção de Riscos , Saúde da População Rural , Controle Social Formal
8.
J Nematol ; 38(4): 466-73, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19259465

RESUMO

To assess the effect of an inundative release of entomopathogenic nematodes on soil organisms, population densities of soil-dwelling organisms were monitored before and after an application of an aqueous suspension of Heterorhabditis megidis to field plots in mown grassland (Exp. I) at a level of 0.38 million/m(2) and to plots (Exp. II) situated in a forested area, a grass sports field and an orchard at a level of 1.5 million/m(2). At the forested site, heat-killed H. megidis (1.5 million/m(2)) also were applied to two plots to compare the impact on soil organisms of a large introduction of living and dead nematodes. Post-treatment, temporary changes in natural population densities of several nematode genera and other organisms were detected in H. megidis-treated plots in both experiments. Temporary changes in the nematode trophic structure occurred in the percentages of nematode omnivores, herbivores and predators in both experiments. Evidence from all sites suggests that the changes were temporary and that the presence of decaying H. megidis following treatment contributed to nutrient enrichment of the soil and to direct and indirect effects on the nematode community.

9.
J Invertebr Pathol ; 79(3): 146-53, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12133703

RESUMO

Galleria mellonella larvae infected with Steinernema riobrave soon showed (after 24 h) the typical growth of its Xenorhabdus sp. RIO symbiont and, in parallel, the growth of another Gram negative bacterial species in the body cavity. A population of Entercoccus sp. in the nematode infected larvae collapsed to zero by 96 h. The level of antibiotic and antimycotic activity followed a pattern similar to that of the growth curve to stationary phase of the Xenorhabdus sp. RIO symbiont, over a period of 168 h. The antimycotic activity was composed of exo- and endochitinases as well as other proteinaceous and some small molecule compounds. The changing pH, relatively high growth rate of Xenorhabdus sp. RIO compared with that of other Gram negative bacterial species and of collapse of the Enterococcus sp. population enabled Xenorhabdus sp. RIO to out-compete other species.


Assuntos
Mariposas/parasitologia , Rabditídios/microbiologia , Simbiose/fisiologia , Xenorhabdus/fisiologia , Animais , Proteínas de Bactérias/análise , Quitinases/análise , Meios de Cultura , Larva/microbiologia , Larva/parasitologia , Mariposas/microbiologia , Xenorhabdus/crescimento & desenvolvimento , Xenorhabdus/metabolismo
10.
Pac Symp Biocomput ; : 297-309, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-11928484

RESUMO

GlycoSuiteDB, a database of glycan structures, has been constructed with an emphasis on quality, consistency and data integrity. Importance has been placed on making the database a reliable and useful resource for all researchers. This database can help researchers to identify what glycan structures are known to be attached to certain glycoproteins, as well as more generally identifying what types of glycan structures are associated with different states, for example, different species, tissues and diseases. To achieve this, a major effort has gone into data standardisation. Many rules and standards have been adopted, especially for representing glycan structure and biological source information. This paper describes some of the challenges faced during the continuous development of GlycoSuiteDB.


Assuntos
Configuração de Carboidratos , Oligossacarídeos/química , Polissacarídeos/química , Animais , Sequência de Carboidratos , Galinhas , Glicoproteínas/genética , Humanos , Antígenos CD15/química , Antígenos CD15/classificação , Dados de Sequência Molecular , Oligossacarídeos/classificação , Ovalbumina/química , Polissacarídeos/classificação , Proteínas Recombinantes/química , Reprodutibilidade dos Testes , Antígeno Sialil Lewis X
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