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AIMS: Amyotrophic lateral sclerosis (ALS) is characterized by degeneration of motoneurons and progressive muscle wasting. Inflammatory processes, mediated by non-neuronal cells, such as glial cells, are known to contribute to disease progression. Inflammasomes consist of pattern recognition receptors (PRRs), apoptosis-associated speck-like protein (ASC) and caspase 1 and are essential for interleukin (IL) processing and a rapid immune response after tissue damage. Recently, we described inflammasome activation in the spinal cord of ALS patients and in SOD1(G93A) ALS mice. Since pathological changes in the skeletal muscle are early events in ALS, we hypothesized that PRRs might be abnormally expressed in muscle fibre degeneration. METHODS: Western blot analysis, real-time PCR and immunohistochemistry were performed with muscle tissue from presymptomatic and early-symptomatic male SOD1(G93A) mice and with muscle biopsies of control and sporadic ALS (sALS) patients. Analysed PRRs include nucleotide-binding oligomerization domain-like (NOD-like) receptor protein 1 (NLRP1), NLR protein 3 (NLRP3), NLR family CARD domain-containing 4 (NLRC4) and absent in melanoma 2. Additionally, expression levels of ASC, caspase 1, interleukin 1 beta (IL1ß) and interleukin 18 (IL18) were evaluated. RESULTS: Expression of PRRs and ASC was detected in murine and human tissue. The PRR NLRC4, caspase 1 and IL1ß were significantly elevated in denervated muscle of SOD1(G93A) mice and sALS patients. Furthermore, levels of caspase 1 and IL1ß were already increased in presymptomatic animals. CONCLUSION: Our findings suggest that increased inflammasome activation may be involved in skeletal muscle pathology in ALS. Furthermore, elevated levels of NLRC4, caspase 1 and IL1ß reflect early changes in the skeletal muscle and may contribute to the denervation process.
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Esclerose Lateral Amiotrófica/metabolismo , Inflamassomos/metabolismo , Músculo Esquelético/metabolismo , Receptores de Reconhecimento de Padrão/metabolismo , Esclerose Lateral Amiotrófica/patologia , Animais , Humanos , Camundongos , Músculo Esquelético/patologia , Superóxido Dismutase-1/metabolismoRESUMO
Dynamic characteristics of strongly coupled classical one-component Coulomb and Yukawa plasmas are obtained within the nonperturbative model-free moment approach without any data input from simulations so that the dynamic structure factor (DSF) satisfies the first three nonvanishing sum rules automatically. The DSF, dispersion, decay, sound speed, and other characteristics of the collective modes are determined using exclusively the static structure factor calculated from various theoretical approaches including the hypernetted chain approximation. A good quantitative agreement with molecular dynamics simulation data is achieved.
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BACKGROUND: Femoral nerve blocks have been the gold standard approach for post-operative analgesia following total knee arthroplasty; however, the adductor canal block has recently gained popularity due to less block-induced motor weakness. The primary aim of this time-series analysis was to identify whether regional anesthesia practice changes have occurred for total knee arthroplasty. Our secondary aim was to assess for possible associated changes in safety and quality. METHODS: Using a 20-member clinical registry, we examined the practice patterns and safety around the performance of adductor canal blocks for all total knee arthroplasties between 18 July 2011 to 9 October 2015. To obtain more information about changes in quality associated with this practice transition, we analyzed clinical outcomes data surrounding all primary total knee arthroplasties from the largest contributing institution. RESULTS: A total of 6921 blocks were performed for 4822 primary and revision total knee arthroplasties (TKAs). Across the registry, adductor canal block utilization for TKA increased. This was not associated with any increase in immediate or recovery room-related complications. When analyzing unilateral primary TKAs from the largest surgical volume center (n = 766), there were no statistically significant changes in numeric rating scale scores (5.4 to 4.6, P value = 0.004), length of stay (3.0 to 2.8 days, P value = 0.3), or 30-day hospital re-evaluations for pain (2.8-4.9%, P value = 0.1). CONCLUSION: There was a large increase in the utilization of adductor canal blockade for TKAs among participating registry members. This change in practice was not associated with significant changes in safety or quality.
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Artroplastia do Joelho , Bloqueio Nervoso/métodos , Dor Pós-Operatória/prevenção & controle , Idoso , Humanos , Tempo de Internação , Pessoa de Meia-Idade , Padrões de Prática MédicaRESUMO
Nontuberculous mycobacterial (NTM) are found ubiquitously in the environment and are usually of low pathogenicity. Infection occurs via inhalation of aerosols, and some species may cause severe infections. The incidence of NTM infections is rising worldwide. The risk of developing NTM disease depends on the susceptibility of the host as well as the frequency and duration of exposure. In addition to congenital immune deficiencies and immunosuppressive therapy, structural lung and systemic diseases, including rheumatoid arthritis (RA), are associated with an increased risk for NTM infections. The immune response to NTM is complex and relies on the interplay between professional phagocytes and lymphoid cells. This interplay is concerted by three key cytokines: interleukin-12 (IL-12), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ). Targeted immunotherapies, e. g., treatment with TNF inhibitors, interfere with these essential pathways and increase the risk of NTM infection significantly. This review focuses on the relationship between the immune response to NTM and intrinsic and iatrogenic dispositions for NTM infection, with an emphasis on RA.
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Artrite Reumatoide/complicações , Síndromes de Imunodeficiência/complicações , Imunossupressores/efeitos adversos , Infecções por Mycobacterium não Tuberculosas/diagnóstico , Infecções Oportunistas/diagnóstico , Artrite Reumatoide/imunologia , Artrite Reumatoide/terapia , Humanos , Doença Iatrogênica , Síndromes de Imunodeficiência/imunologia , Síndromes de Imunodeficiência/terapia , Imunoterapia , Interferon gama/sangue , Interleucina-12/sangue , Linfócitos/imunologia , Infecções por Mycobacterium não Tuberculosas/epidemiologia , Infecções por Mycobacterium não Tuberculosas/imunologia , Infecções por Mycobacterium não Tuberculosas/terapia , Infecções Oportunistas/epidemiologia , Infecções Oportunistas/imunologia , Infecções Oportunistas/terapia , Fagócitos/imunologia , Fatores de Risco , Fator de Necrose Tumoral alfa/sangueRESUMO
Recently, epidemiological data shows an increase of childhood tuberculosis in Germany. In addition to this, drug resistant tuberculosis becomes more frequent. Therefore, diagnosis, prevention and therapy in childhood and adolescence remain a challenge. Adult guidelines do not work for children, as there are age specific differences in manifestation, risk of progression and diagnostic as well as therapeutic pathways.The German Society for Pediatric Infectious Diseases (DGPI) has initiated a consensus-based (S2k) process and completed a paediatric guideline in order to improve and standardize care for children and adolescents with tuberculosis exposure, infection or disease.Updated dosage recommendations take age dependant pharmacokinetics in the treatment of drug sensitive but also drug resistant tuberculosis in account. In addition to this, there is a detailed chapter on perinatal exposure and disease as well as extrapulmonary manifestations.
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Antituberculosos/uso terapêutico , Infectologia , Pediatria , Sociedades Médicas , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/tratamento farmacológico , Adolescente , Áustria , Criança , Pré-Escolar , Estudos Transversais , Feminino , Alemanha , Humanos , Lactente , Recém-Nascido , Masculino , Suíça , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/prevenção & controle , Tuberculose Pulmonar/epidemiologia , Tuberculose Pulmonar/prevenção & controleRESUMO
Infections with Mycobacterium tuberculosis (MTB) induce complex immune responses involving an orchestrated interplay of innate and adaptive immune mechanisms. Why the immune system fails to eradicate the pathogen and at best achieves control of infection in the latent stage, still remains an unsolved mystery even more than 100 years after the discovery of MTB by Robert Koch. This article provides an overview of the current state of the art in the constantly evolving field of tuberculosis (TB) immunology. This review focuses on a change of paradigm proposing that in the latent stage MTB is anything but dormant and that latent TB is not merely a state of bacterial stasis but a state of dynamic bacterial and immunological equilibrium. The understanding of these dynamics is crucial for the development of new drugs against MTB as well as vaccines that aim to provide effective protection against the disease.
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Imunidade Adaptativa/imunologia , Imunidade Inata/imunologia , Tuberculose Latente/imunologia , Tuberculose Latente/microbiologia , Modelos Imunológicos , Mycobacterium tuberculosis/imunologia , Animais , HumanosRESUMO
BACKGROUND: Glycerol is known to possess anti-irritant and hydrating properties and previous studies suggested that xylitol may also have similar effects. OBJECTIVE: Our aim was to study whether different concentrations of these polyols restore skin barrier function and soothe inflammation in sodium lauryl sulphate (SLS)-induced acute irritation. METHODS: The experiments were performed on male SKH-1 hairless mice. The skin of the dorsal region was exposed to SLS (5%) for 3 h alone or together with 5% or 10% of glycerol respectively. Further two groups received xylitol solutions (8.26% and 16.52% respectively) using the same osmolarities, which were equivalent to those of the glycerol treatments. The control group was treated with purified water. Transepidermal water loss (TEWL) and skin hydration were determined. Microcirculatory parameters of inflammation were observed by means of intravital videomicroscopy (IVM). Furthermore, accumulation of neutrophil granulocytes and lymphocytes, the expression of inflammatory cytokines and SLS penetration were assessed, as well. RESULTS: Treatment with the 10% of glycerol and both concentrations of xylitol inhibited the SLS-induced elevation of TEWL and moderated the irritant-induced increase in dermal blood flow and in the number of leucocyte-endothelial interactions. All concentrations of the applied polyols improved hydration and prevented the accumulation of lymphocytes near the treatment site. At the mRNA level, neither glycerol nor xylitol influenced the expression of interleukin-1 alpha. However, expression of interleukin-1 beta was significantly decreased by the 10% glycerol treatment, while expression of tumour necrosis factor-alpha decreased upon the same treatment, as well as in response to xylitol. Higher polyol treatments decreased the SLS penetration to the deeper layers of the stratum corneum. CONCLUSION: Both of the analysed polyols exert considerable anti-irritant and anti-inflammatory properties, but the effective concentration of xylitol is lower than that of glycerol.
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Dermatite Irritante/tratamento farmacológico , Emolientes/uso terapêutico , Glicerol/uso terapêutico , Fenômenos Fisiológicos da Pele/efeitos dos fármacos , Pele/metabolismo , Xilitol/uso terapêutico , Animais , Dermatite Irritante/etiologia , Dermatite Irritante/patologia , Emolientes/farmacologia , Expressão Gênica/efeitos dos fármacos , Glicerol/farmacologia , Interleucina-1alfa/genética , Interleucina-1beta/genética , Microscopia Intravital , Masculino , Camundongos , Camundongos Pelados , Permeabilidade/efeitos dos fármacos , Fluxo Sanguíneo Regional/efeitos dos fármacos , Pele/irrigação sanguínea , Pele/química , Dodecilsulfato de Sódio/farmacocinética , Fator de Necrose Tumoral alfa/genética , Água/análise , Perda Insensível de Água/efeitos dos fármacos , Xilitol/farmacologiaRESUMO
PURPOSE: Identifying factors that determine concentrations of antiretroviral drugs in CD4 cells are important for improving therapeutic efficacy. Experimental models indicate that the nucleoside reverse transcriptase inhibitor lamivudine is transported by the organic cation transporters 1 and 2 (OCT1 and OCT2, respectively). Here, we tested whether OCT1 and OCT2 contribute to the uptake of lamivudine into native CD4 cells of human immunodeficiency virus (HIV)-infected individuals. METHODS: CD4 cells obtained by non-activated cell sorting from 35 individuals with HIV-1 infection were incubated with lamivudine (10 µM, 30 min), and intracellular concentrations of lamivudine and its active metabolite lamivudine triphosphate were determined by liquid chromatography tandem mass spectrometry. The expression of OCT1 and OCT2 mRNA was measured by quantitative real-time polymerase chain reaction (PCR). A model of OCT2-transfected CD4 cells was established for mechanistic investigations. RESULTS: Intracellular concentrations of lamivudine and its active metabolite lamivudine triphosphate showed strong linear correlations with each other and with the CD4 mRNA expression of OCT1 and OCT2 (r > 0.80). Coincubation with protease inhibitors (ritonavir, nelfinavir) that inhibit OCT1 and OCT2 yielded decreased intracellular concentrations of lamivudine and lamivudine triphosphate. Incubation of CD4 cells from healthy donors transfected with an OCT2 expression vector yielded increased concentrations of lamivudine and lamivudine triphosphate. CONCLUSION: Our studies indicate a role of OCT1 and OCT2 for the cellular accumulation of lamivudine in HIV-infected individuals.
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Linfócitos T CD4-Positivos/efeitos dos fármacos , Citidina Trifosfato/análogos & derivados , Didesoxinucleotídeos/farmacocinética , Infecções por HIV/tratamento farmacológico , Lamivudina/análogos & derivados , Proteínas de Transporte de Cátions Orgânicos/metabolismo , Transportador 1 de Cátions Orgânicos/metabolismo , Adulto , Terapia Antirretroviral de Alta Atividade , Linfócitos T CD4-Positivos/metabolismo , Citidina Trifosfato/administração & dosagem , Citidina Trifosfato/farmacocinética , Didesoxinucleotídeos/administração & dosagem , Feminino , Inibidores da Protease de HIV/administração & dosagem , Inibidores da Protease de HIV/farmacocinética , HIV-1/efeitos dos fármacos , Humanos , Lamivudina/administração & dosagem , Lamivudina/farmacocinética , Masculino , Pessoa de Meia-Idade , Nelfinavir/farmacologia , Proteínas de Transporte de Cátions Orgânicos/genética , Transportador 1 de Cátions Orgânicos/genética , Transportador 2 de Cátion Orgânico , Fosforilação , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Ritonavir/farmacologia , Espectrometria de Massas em Tandem , Transfecção , Adulto JovemRESUMO
PURPOSE: To evaluate a newly implemented infectious disease (ID) consultation service in terms of patient care, outcome and antibiotic prescription and to describe factors influencing adherence to recommendations. METHODS: Data from consultations during the first 6 months of the ID consultation program were collected and evaluated. Consultation requests, diagnostic results, treatment outcomes and antibiotic recommendations were categorised. Diagnostic and therapeutic recommendations were assessed and rated for adherence and outcome. Statistical analysis was performed to identify factors influencing adherence and treatment outcome. RESULTS: A total of 251 consultations were assessed. In most cases, ID specialists were asked for further advice regarding a previously initiated anti-infective treatment (N = 131, 52 %). In 54 of 195 (28 %) first consultations, the ID specialist proposed a differential diagnosis that differed from that of the working diagnoses submitted with the consultation request, and which was subsequently confirmed in 80 % of these cases. Diagnostic and therapeutic recommendations were made in 190 (76 %) and 240 (96 %) of the consultations, respectively. A change in the current treatment was recommended in 66 % of consultations; 37 % of recommendations were cost-saving and 26 % were cost-neutral. Compliance with diagnostic and therapeutic recommendations was rated as good by pre-specified criteria in 65 and 86 % of consultations, respectively. Treatment outcome was correlated with adherence to diagnostic recommendations (P = 0.012). Twenty-nine patients (16 %) died during the same hospital stay. CONCLUSION: Infectious disease consultations may help to establish the correct diagnosis, resulting in the appropriate treatment being provided to a severely sick patient population. Treatment outcome was improved in cases of good diagnostic adherence to the recommendations of the ID specialist.
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Doenças Transmissíveis/diagnóstico , Encaminhamento e Consulta/normas , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anti-Infecciosos/uso terapêutico , Criança , Pré-Escolar , Doenças Transmissíveis/tratamento farmacológico , Feminino , Alemanha , Fidelidade a Diretrizes , Departamentos Hospitalares/normas , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Atenção Terciária à Saúde , Resultado do Tratamento , Adulto JovemRESUMO
The luminal composition of the auditory tube influences its function. The mechanisms involved in the monitoring are currently not known. For the lower respiratory epithelium, such a sentinel role is carried out by cholinergic brush cells. Here, using two different mouse strains expressing eGFP under the control of the promoter of choline acetyltransferase (ChAT), we show the presence of solitary cholinergic villin-positive brush cells also in the mouse auditory tube epithelium. They express the vesicular acetylcholine (ACh) transporter and proteins of the taste transduction pathway such as α-gustducin, phospholipase C beta 2 (PLC(ß2)) and transient receptor potential cation channel subfamily M member 5 (TRPM5). Immunoreactivity for TRPM5 and PLCß2 was found regularly, whereas α-gustducin was absent in approximately 15% of the brush cells. Messenger RNA for the umami taste receptors (TasR), Tas1R1 and 3, and for the bitter receptors, Tas2R105 and Tas2R108, involved in perception of cycloheximide and denatonium were detected in the auditory tube. Using a transgenic mouse that expresses eGFP under the promotor of the nicotinic ACh receptor α3-subunit, we identified cholinoceptive nerve fibers that establish direct contacts to brush cells in the auditory tube. A subpopulation of these fibers displayed also CGRP immunoreactivity. Collectively, we show for the first time the presence of brush cells in the auditory tube. These cells are equipped with all proteins essential for sensing the composition of the luminal microenvironment and for communication of the changes to the CNS via attached sensory nerve fibers.
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Células Quimiorreceptoras/citologia , Neurônios Colinérgicos/citologia , Tuba Auditiva/citologia , Animais , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Língua/citologiaRESUMO
BACKGROUND: Viral suppression by antiretroviral therapy (ART) inhibits HIV-induced apoptosis and CD4 T-cell loss. It has been suggested that protease inhibitors (PIs) have nonviral antiapoptotic effects by maintaining mitochondrial integrity. Long-term clinical effects of PI-based ART on mitochondrial toxicity and lymphocyte apoptosis beyond viral suppression have not been exploited to date. METHODS: We conducted a 7-year study on HIV-1-infected patients from the Cologne HIV cohort with sufficient viral suppression under either a PI-based or nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimen. Eight patients on PI and eight on NNRTI were eligible for inclusion in the analysis. The primary outcome measure was defined as a change in the mitochondrial-to-nuclear DNA ratio in PBMCs. Further key molecules involved in extrinsic [tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), Fas ligand (FasL) and caspase 8], intrinsic [B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), caspase 9 and lactate-to-pyruvate ratio] and overall apoptosis [Annexin+/7-aminoactinomycin D (7-AAD)- and caspase 3/7] and viral activity [negative regulatory factor (Nef), interferon-α (IFN-α) and myxovirus resistance protein A (MxA)] were measured. RESULTS: Demographic and baseline clinical parameters were similar in the two groups, except that patients in the PI group had a higher mean age. After 7 years of treatment, CD4 T-cell count increased and the expression of genes encoding the proapoptotic viral protein Nef and HIV-induced cytokine IFN-α and its downstream effector MxA decreased in both groups. Focusing on the different pathways of apoptosis, only in the PI group intrinsic apoptosis decreased significant and in the inter-group comparison the decrease was significantly higher than in the NNRTI group. CONCLUSIONS: Our study provides evidence that long-term therapy with a PI-based regimen may be superior to that with a NNRTI-based regimen with regard to its intrinsic antiapoptotic effect.
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Apoptose/efeitos dos fármacos , Infecções por HIV/tratamento farmacológico , HIV-1 , Leucócitos Mononucleares/efeitos dos fármacos , Inibidores de Proteases/uso terapêutico , Adulto , Apoptose/fisiologia , Biomarcadores/análise , Núcleo Celular/genética , Estudos de Coortes , DNA Mitocondrial/análise , Feminino , Humanos , Leucócitos Mononucleares/metabolismo , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/metabolismo , Análise de RegressãoRESUMO
QUESTION: Back pain is a challenge for case management but is a health insurance fund (HIF) that identifies high risk patients and includes them in a back pain assessment and a multimodal program cost-effective? METHODS: Case managers of a HIF contacted selected patients and requested information on pain and current perspectives. Patients in the intervention group were offered a multimodal assessment and, if applicable, a multimodal treatment program. Control group patients received verbal or written (back book) information. Cost data were evaluated with respect to the interview data 1 year prior and 1 year afterwards. FINDINGS: Of the 800 insured persons contacted 621 were nationwide, 88 were regional controls and 91 were intervention patients. Inability to work was still rising in all groups but less in the intervention group versus both control groups. Drugs, hospital as well as cure/adjuvant costs were less for intervention patients than in both control groups. The investment for the program was thus more than refinanced. INTERPRETATION: Case management was well accepted but the intervention was in need of training for case managers and the specific diagnostic and treatment option regionally. FUNDING: The HIF was responsible for the study investment and project partners shared the training of the HIF regional case managers.
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Dor nas Costas/economia , Dor nas Costas/terapia , Administração de Caso/economia , Programas Nacionais de Saúde/economia , Equipe de Assistência ao Paciente/economia , Apoio Social , Adulto , Dor nas Costas/psicologia , Terapia Combinada/economia , Análise Custo-Benefício , Avaliação da Deficiência , Feminino , Alemanha , Humanos , Entrevistas como Assunto , Masculino , Pessoa de Meia-Idade , Medição da Dor , Folhetos , Educação de Pacientes como Assunto/economia , Licença Médica/economiaRESUMO
We investigate the Ar(+)-Fe asymmetric charge transfer (ACT) reaction using a combination of plasma diagnostics methods and a kinetic model of the afterglow plasma, which allow monitoring of the temporal evolution of the densities of different species. The iron vapor is created inside a discharge cell by cathode sputtering; its density is measured by atomic absorption spectroscopy. The rate coefficient of the reaction is evaluated from the emission intensity decay of Fe(+)∗ lines pumped by the ACT process in the He-Ar-Fe and Ar-Fe afterglow plasmas. The measurements yield a rate coefficient k = 7.6( ± 3.0) × 10(-9) cm(3) s(-1) at T = 300 K.
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Argônio/química , Ferro/química , Hélio/química , Íons/química , Cinética , Espectrofotometria Atômica , VácuoRESUMO
The existence of plasma oscillations at multiples of the magnetoplasmon frequency in a strongly coupled two-dimensional magnetized Yukawa plasma is reported, based on extensive molecular dynamics simulations. These modes are the analogues of Bernstein modes which are renormalized by strong interparticle correlations. Their properties are theoretically explained by a dielectric function incorporating the combined effect of a magnetic field, strong correlations and finite temperature.
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Ciliary beating of airway epithelial cells drives the removal of mucus and particles from the airways. Mucociliary transport and possibly airway epithelial development are governed by muscarinic acetylcholine receptors but the precise roles of the subtypes involved are unknown. This issue was addressed by determining cilia-driven particle transport, ciliary beat frequency, and the composition and ultrastructural morphology of the tracheal epithelium in M1-M5 muscarinic receptor gene-deficient mice. Knockout of M3 muscarinic receptors prevented an increase in particle transport speed and ciliary beat frequency in response to muscarine. Furthermore, the ATP response after application of muscarine was blunted. Pretreatment with atropine before application of muscarine restored the response to ATP. Additional knockout of the M2 receptor in these mice partially restored the muscarine effect, most likely through the M1 receptor, and normalised the ATP response. M1, M4 and M5 receptor-deficient mice exhibited normal responses to muscarine. None of the investigated mutant mouse strains had any impairment of epithelial cellular structure or composition. In conclusion, M3 receptors stimulate whereas M2 receptors inhibit cilia-driven particle transport. The M1 receptor increases cilia-driven particle transport if the M3 and M2 receptors are missing. None of the receptors is necessary for epithelial development.
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Cílios/fisiologia , Receptores Muscarínicos/deficiência , Traqueia/fisiologia , Trifosfato de Adenosina/farmacologia , Animais , Cílios/ultraestrutura , Imuno-Histoquímica , Camundongos , Camundongos Knockout , Depuração Mucociliar , Muscarina/farmacologia , Receptores Muscarínicos/genética , Receptores Muscarínicos/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Estatísticas não ParamétricasRESUMO
A classical dusty plasma experiment was performed using two different dust grain sizes to form a strongly coupled asymmetric bilayer (two closely spaced interacting monolayers) of two species of charged dust particles. The observation and analysis of the thermally excited particle oscillations revealed the collective mode structure and dispersion (wave propagation) in this system; in particular, the existence of the theoretically predicted k=0 energy (frequency) gap was verified. Equilibrium molecular-dynamics simulations were performed to emulate the experiment, assuming Yukawa-type interparticle interaction. The simulations and analytic calculations based both on lattice summation and on the quasilocalized charge approximation approach are in good agreement with the experimental findings and help in identifying and characterizing the observed phenomena.
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The existence of coefficients for diffusion, viscosity, and thermal conductivity is examined for two-dimensional (2D) liquids. Equilibrium molecular dynamics simulations are performed using a Yukawa potential and the long-time behavior of autocorrelation functions is tested. Advances reported here as compared to previous 2D Yukawa liquid simulations include an assessment of the thermal conductivity, using a larger system size to allow meaningful examination of longer times, and development of improved analysis methods. We find that the transport coefficient exists for diffusion at high temperature and viscosity at low temperature, but not in the opposite limits. The thermal conductivity coefficient does not appear to exist at high temperature. Further advances in computing power could improve these assessments by allowing even larger system sizes and longer time series.
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OBJECTIVE: To investigate if early treatment of primary HIV-1 infection (PHI) reduces viral set point and/or increases CD4 lymphocytes. METHODS: Analysis of two prospective multi-centre PHI cohorts. HIV-1 RNA and CD4 lymphocytes in patients with transient treatment were compared to those in untreated patients. Time to CD4 lymphocyte decrease below 350/ microl after treatment stop or seroconversion was calculated using Kaplan-Meier and Cox-PH-regression analyses. RESULTS: 156 cases of PHI were included, of which 100 had received transient HAART (median treatment time 9.5 months) and 56 remained untreated. Median viral load (563000 cop/ml vs 240000 cop/ml; p<0.001) and median CD4 lymphocyte (449/ microl vs. 613/ microl; p<0.01) differed significantly between treated and untreated patients. Median viral load was 38056 copies/ml in treated patients (12 months after treatment stop) and 52880 copies/ml in untreated patients (12 months after seroconversion; ns). Median CD4 lymphocyte change was +60/ microl vs. -86/ microl (p = 0.01). Median time until CD4 lymphocytes decreased to <350/ microl (including all patients with CD4 lymphocytes <500/ microl during seroconversion) was 20.7 months in treated patients after treatment stop and 8.3 months in untreated patents after seroconversion (p<0.01). Cox-PH analyses adjusting for baseline VL, CD4 lymphocytes, stage of early infection and symptoms confirmed these differences. CONCLUSIONS: Treatment during PHI did not lower viral set point. However, patients treated during seroconversion had an increase in CD4 lymphocytes, whereas untreated patients experienced a decrease in CD4 lymphocytes. Time until reaching CD4 lymphocytes <350/ microl was significantly shorter in untreated than in treated patients including patients with CD4 lymphocytes <500/ microl during seroconversion.
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Terapia Antirretroviral de Alta Atividade/métodos , Contagem de Linfócito CD4 , Infecções por HIV/tratamento farmacológico , HIV-1/efeitos dos fármacos , Adolescente , Adulto , Estudos de Coortes , Feminino , Infecções por HIV/imunologia , Infecções por HIV/virologia , Soropositividade para HIV/tratamento farmacológico , Soropositividade para HIV/imunologia , Soropositividade para HIV/virologia , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Estudos Multicêntricos como Assunto , Avaliação de Resultados em Cuidados de Saúde/métodos , Avaliação de Resultados em Cuidados de Saúde/estatística & dados numéricos , Modelos de Riscos Proporcionais , Fatores de Tempo , Carga Viral , Adulto JovemRESUMO
The self-diffusion phenomenon in a two-dimensional dusty plasma at extremely strong (effective) magnetic fields is studied experimentally and by means of molecular dynamics simulations. In the experiment the high magnetic field is introduced by rotating the particle cloud and observing the particle trajectories in a corotating frame, which allows reaching effective magnetic fields up to 3000 T. The experimental results confirm the predictions of the simulations: (i) superdiffusive behavior is found at intermediate timescales and (ii) the dependence of the self-diffusion coefficient on the magnetic field is well reproduced.
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We present molecular-dynamics calculations of the shear viscosity of three-dimensional strongly coupled Yukawa liquids which are frequently used as a model system of complex plasmas. The results obtained using two independent nonequilibrium simulation methods are critically compared with each other and with earlier published data for a wide range of plasma coupling (Gamma) and screening (kappa) parameters. The non-Newtonian behavior of the liquid, manifested as a decrease of the shear viscosity with increasing shear rate (shear thinning), and the validity of the Stokes-Einstein relation at high coupling strength are also demonstrated.