RESUMO
OBJECTIVES: Anti-inflammatory functions of antibiotics may counteract deleterious hyperinflammation in pneumonia. Moxifloxacin reportedly exhibits immunomodulatory properties, but experimental evidence in pneumonia is lacking. Therefore, we investigated moxifloxacin in comparison with ampicillin regarding pneumonia-associated pulmonary and systemic inflammation and lung injury. METHODS: Ex vivo infected human lung tissue and mice with pneumococcal pneumonia were examined regarding local inflammatory response and bacterial growth. In vivo, clinical course of the disease, leucocyte dynamics, pulmonary vascular permeability, lung pathology and systemic inflammation were investigated. In addition, transcellular electrical resistance of thrombin-stimulated endothelial cell monolayers was quantified. RESULTS: Moxifloxacin reduced cytokine production in TNF-α-stimulated, but not in pneumococci-infected, human lung tissue. In vivo, moxifloxacin treatment resulted in reduced bacterial load as compared with ampicillin, whereas inflammatory parameters and lung pathology were not different. Moxifloxacin-treated mice developed less pulmonary vascular permeability during pneumonia, but neither combination therapy with moxifloxacin and ampicillin in vivo nor examination of endothelial monolayer integrity in vitro supported direct barrier-stabilizing effects of moxifloxacin. CONCLUSIONS: The current experimental data do not support the hypothesis that moxifloxacin exhibits potent anti-inflammatory properties in pneumococcal pneumonia.
Assuntos
Anti-Inflamatórios/uso terapêutico , Fluoroquinolonas/uso terapêutico , Pneumonia Pneumocócica/tratamento farmacológico , Animais , Modelos Animais de Doenças , Feminino , Humanos , Pulmão/patologia , Camundongos Endogâmicos C57BL , Moxifloxacina , Pneumonia Pneumocócica/microbiologia , Pneumonia Pneumocócica/patologia , Streptococcus pneumoniae/crescimento & desenvolvimento , Resultado do TratamentoRESUMO
Severe community- and hospital-acquired pneumonia is caused by Legionella pneumophila. Lung airway and alveolar epithelial cells comprise an important sentinel system in airborne infections. Although interleukin (IL)-6 is known as a central regulator of the immune response in pneumonia, its regulation in the lung is widely unknown. Herein, we demonstrate that different L. pneumophila strains induce delayed expression of IL-6 in comparison with IL-8 by human lung epithelial cells. IL-6 expression depended, at early time points, on flagellin recognition by Toll-like receptor (TLR)5, activity of mitogen-activated protein kinase/extracellular signal-regulated kinase kinase (MEK)1 and p38 mitogen-activated protein (MAP) kinase, and, at later time points, on the type-IV secretion system. In the same manner, but more rapidly, the recently described transcription factor IκBζ was induced by Legionella infection and, binding to the nuclear factor (NF)-κB subunit p50 - recruited to the il6 promoter together with CCAAT-enhancer-binding protein ß and phosphorylated activator protein-1 subunit cJun. Similarly, histone modifications and NF-κB subunit p65/RelA appeared at the iκbζ and subsequently at the il6 gene promoter, thereby initiating gene expression. Gene silencing of IκBζ reduced Legionella-related IL-6 expression by 41%. Overall, these data indicate a sequence of flagellin/TLR5- and type IV-dependent IκBζ expression, recruitment of IκBζ/p50 to the il6 promoter, chromatin remodelling and subsequent IL-6 transcription in L. pneumophila-infected lung epithelial cells.
Assuntos
Células Epiteliais/microbiologia , Regulação da Expressão Gênica , Quinase I-kappa B/metabolismo , Legionella pneumophila/metabolismo , Legionelose/microbiologia , Pulmão/microbiologia , Linhagem Celular Tumoral , Cromatina/metabolismo , Células Epiteliais/imunologia , Células Epiteliais/metabolismo , Flagelina/metabolismo , Humanos , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Legionelose/metabolismo , Pulmão/metabolismo , NF-kappa B/metabolismo , Pneumonia/metabolismo , Regiões Promotoras GenéticasRESUMO
Legionella pneumophila is an important causative agent of severe pneumonia in humans. The human alveolar epithelium is an effective barrier for inhaled microorganisms and actively participates in the initiation of innate host defense. Although secretion of granulocyte-macrophage colony-stimulating factor (GM-CSF) is essential for the elimination of invading Legionella spp., mechanisms of Legionella pneumophila-induced release of this cytokine are widely unknown. In this study, we have demonstrated a toll-like receptor (TLR)2- and TLR5-dependent release of GM-CSF in L. pneumophila-infected human alveolar epithelial cells. GM-CSF secretion was not dependent on the bacteria type II or type IV secretion system. Furthermore, an increase in protein kinase C (PKC) activity, particularly PKC(alpha) and PKC(epsilon), was noted. Blocking of PKC(alpha) and PKC(epsilon) activity or expression, but not of PKC(beta), PKC(delta), PKC(eta), PKC(theta), and PKC(zeta), significantly reduced the synthesis of GM-CSF in infected cells. While PKC(alpha) was critical for the initiation of a nuclear factor-kappaB-mediated GM-CSF expression, PKC(epsilon) regulated GM-CSF production via activator protein 1. Thus, differential regulation of GM-CSF, production by PKC isoforms, contributes to the host response in Legionnaires' disease.
Assuntos
Epitélio/microbiologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Legionella pneumophila/metabolismo , Proteína Quinase C-alfa/metabolismo , Proteína Quinase C-épsilon/metabolismo , Alvéolos Pulmonares/microbiologia , Linhagem Celular Tumoral , Citocinas/metabolismo , Regulação Bacteriana da Expressão Gênica , Regulação Enzimológica da Expressão Gênica , Humanos , Isoformas de Proteínas , Receptor 2 Toll-Like/metabolismo , Receptor 5 Toll-Like/metabolismo , Fatores de Transcrição/metabolismoRESUMO
Moraxella catarrhalis is a major cause of infectious exacerbations of chronic obstructive lung disease. In pulmonary epithelial cells, M. catarrhalis induces release of the pro-inflammatory cytokine interleukin (IL)-8, which plays a pivotal role in orchestrating airway inflammation. The present study demonstrated that protein kinase (PK)C was activated by Moraxella infection and positively regulated M. catarrhalis-triggered nuclear factor (NF)-kappaB activation and subsequent IL-8 release. Activation of the PKC/NF-kappaB signalling pathway was found to be dependent on expression of the Moraxella-specific ubiquitous surface protein A2. In addition, it was shown that specific isoforms of PKC play differential roles in the fine-tuning of the M. catarrhalis-induced NF-kappaB-dependent gene expression through controlling il8 promoter activity. Inhibition of PKCalpha and epsilon with chemical inhibitors or using short interfering RNA-mediated gene silencing significantly suppressed, whereas inhibition of PKCtheta increased, the M. catarrhalis-induced IL-8 transcription and cytokine release. In conclusion, it was shown that Moraxella catarrhalis infection activates protein kinase C and its isoforms alpha, epsilon and theta, which differentially regulate interleukin-8 transcription in human pulmonary epithelial cells.
Assuntos
Brônquios/imunologia , Células Epiteliais/imunologia , Interleucina-8/metabolismo , Isoenzimas/imunologia , Infecções por Moraxellaceae/imunologia , Proteína Quinase C-alfa/imunologia , Proteína Quinase C-épsilon/imunologia , Proteína Quinase C/imunologia , Brônquios/citologia , Linhagem Celular , Regulação da Expressão Gênica/imunologia , Humanos , Moraxella catarrhalis/patogenicidade , Regiões Promotoras Genéticas , Proteína Quinase C-theta , Transdução de Sinais/imunologiaRESUMO
Studies of phonological processes during language comprehension consistently report activation of the superior portion of Broca's area. In the domain of language production, however, there is no unequivocal evidence for the contribution of Broca's area to phonological processing. The present event-related fMRI study investigated the existence of a common neural network for phonological decisions in comprehension and production by using production tasks most comparable to those previously used in comprehension. Subjects performed two decision tasks on the initial phoneme of German picture names (/b/ or not? Vowel or not?). A semantic decision task served as a baseline for both phonological tasks. The contrasts between each phonological task and the semantic task were calculated, and a conjunction analysis was performed. There was significant activation in the superior portion of Broca's area (Brodmann's area (BA) 44) in the conjunction analysis, also present in each single contrast. In addition, further left frontal (BA 45/46) and temporal (posterior superior temporal gyrus) areas known to support phonological processing in both production and comprehension were activated. The results suggest the existence of a shared fronto-temporal neural network engaged in the processing of phonological information in both perception and production.
Assuntos
Idioma , Rede Nervosa/fisiologia , Fala/fisiologia , Percepção Visual/fisiologia , Adulto , Mapeamento Encefálico , Córtex Cerebral/fisiologia , Tomada de Decisões/fisiologia , Feminino , Lobo Frontal/fisiologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Tempo de Reação , LeituraRESUMO
On day 2 after delivery, dams of the DBA/1 mouse inbred strain (n = 20/group) with their litter were allocated to one of the following groups: NH21, nonhandling, housed 1 litter/cage, weaned on postnatal day (PND) 21;H21, handling, housed 1 litter/cage, weaned on PND 21; NH30, nonhandling, group-housed (5 litters/cage), weaned on PND 30; H30, handling, group-housed (5 litters/cage), weaned on PND 30. Two male pups of each litter were color marked on PND 2. From PND 8-21 they were removed from their cage, gently held in the experimenter's hand for 5 min/day. The two marked males of each litter were housed together after weaning, and tested in the open-field on PNDs 51-53, and one of each of these siblings was tested for hot-plate latencies on PND 54. Being raised in group-housing and weaned on PND 30 resulted in offspring exhibiting shorter latencies to initiate behavior and higher percentages of centerfield entries in the open field, hot-plate latencies, however, remained unaffected. Preweaning handling increased hot-plate latencies and the number of grooming episodes in the open field, and it decreased defecation, percent centerfield entries and open-field activity in general. It is concluded that the two forms of early experience have different effects on neurobehavioral endpoints 8 weeks after birth.
Assuntos
Comportamento Animal/fisiologia , Manobra Psicológica , Tempo de Reação/fisiologia , Meio Social , Animais , Química Encefálica/fisiologia , Defecação , Feminino , Asseio Animal , Masculino , Camundongos , Camundongos Endogâmicos DBA , Medição da DorRESUMO
The neural correlates of the selection of grammatical gender during overt picture naming were investigated by event-related functional magnetic resonance imaging in the left hemisphere. Relative to simply naming a picture, the production of the definite determiner of the picture name (requiring gender selection) resulted exclusively in pronounced activation of a single region in the superior portion of Broca's area. This activation was not present in contrasts reflecting lexical access (naming a picture vs. saying "jaja" to a smiley) or articulation (saying "jaja" vs. rest). Rather, lexical access activated other inferior frontal regions, insula, fusiform and inferior temporal gyrus. Articulation involved insula, Rolandic operculum, motor and premotor cortex and superior temporal gyrus. The results are discussed with respect to data from studies investigating gender processing during language comprehension.
Assuntos
Lobo Frontal/fisiologia , Lateralidade Funcional/fisiologia , Idioma , Rede Nervosa/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Sexo , Fala/fisiologia , Adulto , Mapeamento Encefálico , Feminino , Lobo Frontal/anatomia & histologia , Humanos , Testes de Linguagem , Imageamento por Ressonância Magnética , Masculino , Vias Neurais/fisiologiaRESUMO
The ability to detect unusual and novel events is an important prerequisite for storage of information in memory. Non-tonal novel sounds that deviate from an ongoing auditory environment elicit a positive event-related potential (ERP) component, the so-called novel P3. Though there is converging evidence on the neuronal network engaged in novelty detection, little attention has been paid to the properties of novel sounds, such as their typicality or relationship to mental concepts. Here we report the ERPs evoked by two types of generically novel stimuli, namely identifiable (meaningful) and non-identifiable (non-meaningful) novel sounds. The ERP analysis revealed a novel P3 for both types of sounds. However, when subjects actively attended to the stimuli only identifiable novel sounds evoked a right-lateralized negativity (N4) that peaked shortly after the novel P3. We conclude that novelty detection not only includes the registration of deviancy but also fast access and identification of related semantic concepts.
Assuntos
Atenção/fisiologia , Memória/fisiologia , Semântica , Som , Adulto , Análise de Variância , Córtex Cerebral/fisiologia , Potenciais Evocados P300 , Potenciais Evocados Auditivos , Feminino , Humanos , Masculino , Neurônios Aferentes/fisiologiaRESUMO
C57BL/6 mice were intubated on gestational days 14-18 twice daily with 1.58 g/kg ethanol, 4.2 g/kg sucrose, or remained untreated. Offspring of ethanol-treated or lab chow control groups were raised either by group-housed dams and weaned on postnatal day (PND) 28 (enriched condition), or by individually housed dams and weaned on PND 21 (standard condition). Offspring of the sucrose control group were raised by individually housed dams and weaned on PND 21. Groups did not differ in pup weight or litter size. Male and female offspring were assessed for performance in an unbaited radial maze (PND 45-52) and male offspring only were tested for conditioned taste aversion (PND 54-59). As hypothesized, mice prenatally exposed to ethanol and raised under standard conditions failed to develop the conditioned taste aversion response. In contrast, subjects with in utero ethanol exposure that were raised under enriched preweaning conditions developed the taste aversion response. Maze performance improved significantly over days, but no significant effects were detected for either prenatal treatment or preweaning rearing conditions. In conclusion, enriched preweaning rearing conditions abolished the detrimental effects of prenatal ethanol exposure on conditioned taste aversion, but radial maze performance remained unaffected by any treatment in this study.
Assuntos
Aprendizagem da Esquiva/efeitos dos fármacos , Condicionamento Operante/efeitos dos fármacos , Etanol/efeitos adversos , Aprendizagem em Labirinto/efeitos dos fármacos , Efeitos Tardios da Exposição Pré-Natal , Análise de Variância , Animais , Relação Dose-Resposta a Droga , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , GravidezRESUMO
The effects of preweaning experience in rats and mice on neuroendocrine and behavioral end points and their implications for prenatal drug effects are reviewed. The hypothalamo-pituitary-adrenal axis and the dopaminergic system were shown to be affected. Behavior related to hippocampal, adrenocortical functions and to the benzodiazepine receptor system was also modified. Other paradigms (nociception, conditioned taste aversion) exhibited susceptibility to such preweaning manipulations also. The effects of these early experiences seem to be mediated through complex factors including neuroendocrine responses of the pup to hypothermia and a permanent alteration of mother-infant interactions, with subsequent effects on neuroendocrine functions that are important for postnatal brain organization. Studies of interactions between prenatal drug effects and preweaning manipulations have been performed only with ethanol. When extending this work to other compounds, the systems and functions described above may provide some guidance in looking for possible interactions. In most cases the preweaning manipulations alleviated the effects of prenatal ethanol exposure. These findings may have important implications regarding the controversy about environmental influences affecting the outcome of exposure to neurobehavioral teratogens.
Assuntos
Encéfalo/efeitos dos fármacos , Animais , Animais Lactentes , Comportamento Animal/efeitos dos fármacos , Encéfalo/fisiopatologia , Meio Ambiente , Feminino , Masculino , Camundongos , Sistema Hipófise-Suprarrenal/efeitos dos fármacos , Sistema Hipófise-Suprarrenal/fisiologia , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Ratos , Receptores de GABA-A/efeitos dos fármacos , Receptores de GABA-A/fisiologiaRESUMO
-C57BL/6 mice were intubated from gestational day 14-18 twice daily with 1.58 g/kg ethanol, 4.2 g/kg sucrose, or remained untreated. Offspring of ethanol treated or lab chow control groups were raised either by group-housed dams and weaned on postnatal day (PND) 28 or by individually housed dams and weaned on PND 21. Offspring of the sucrose control group were raised by individually housed dams and weaned on PND 21. Groups did not differ in pup weight or litter size. Offspring were assessed for home-cage activity (PND 36-38) and open-field behavior (PND 40-42). Mice prenatally exposed to ethanol showed increased activity in their home cages, whereas open-field behavior was generally not different from that of control groups. Conversely, different preweaning rearing conditions had affected open-field behavior, but not home-cage activity. In conclusion, home-cage behavior was a sensitive paradigm for detecting hyperactivity subsequent to a relatively low dose of prenatal ethanol in mice, and communal nesting/late weaning vs. individual nesting/ standard weaning may be a useful preweaning environmental manipulation to study possible modifications of prenatal neurobehavioral effects.
Assuntos
Animais Recém-Nascidos/psicologia , Comportamento Animal/efeitos dos fármacos , Depressores do Sistema Nervoso Central/toxicidade , Etanol/toxicidade , Efeitos Tardios da Exposição Pré-Natal , Animais , Peso ao Nascer/efeitos dos fármacos , Depressores do Sistema Nervoso Central/sangue , Meio Ambiente , Etanol/sangue , Comportamento Exploratório/efeitos dos fármacos , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Atividade Motora/efeitos dos fármacos , GravidezRESUMO
Different types of syntactic information (word category, grammatical gender) are processed at different times during word recognition. However, it is an open issue which brain systems support these processes. In the present event-related fMRI study, subjects performed either a syntactic gender decision task on German nouns (GEN), a word category decision task (WC, nouns vs. prepositions), or a physical baseline task (BASE). Reaction times in WC were faster than in GEN, supporting earlier electrophysiological results. Relative to BASE, both syntactic tasks activated the inferior tip of BA 44. In addition, BA 45 showed activation in GEN, whereas BA 47 was activated in WC. The imaging data indicate that the inferior portion of BA 44 together with type-specific prefrontal areas supports both initial word category related and later syntactic processes.
Assuntos
Córtex Cerebral/fisiologia , Lobo Frontal/fisiologia , Linguística , Rede Nervosa/fisiologia , Adulto , Feminino , Humanos , Masculino , Distribuição Aleatória , Tempo de Reação , Análise e Desempenho de TarefasRESUMO
In accordance with the communist ideology of the GDR, interventions in the private domain of citizens were made without any compunction. Notwithstanding, Section 136 of the Penal Code of the GDR made it a punishable offence to divulge in professional secrets. However, this regulation only simulated the right and obligation to respect professional secrets. Organs of the state continually disregarded medical confidentiality. Besides this, there were numerous statutory medical notifications which were also a severe burden to the relationship of trust between the physician and patient. The State Security Service of the GDR also constantly infringed medical confidentiality. In "research work" carried out at the "Juridical University" of the State Security Service, a thorough strategy of procuring information actually protected by medical confidentiality was ceveloped. The physician has sole responsibility in maintaining medical confidentiality. This also applies to the period of the GDR. There are examples of physicians resisting the State Security Service.
Assuntos
Confidencialidade/legislação & jurisprudência , Notificação de Doenças/legislação & jurisprudência , Alemanha Ocidental , HumanosAssuntos
Nitrato de Prata/uso terapêutico , Pele/lesões , Sulfanilamidas/uso terapêutico , Cicatrização , Animais , Anti-Infecciosos Locais , Tecido de Granulação/efeitos dos fármacos , Coelhos , Regeneração/efeitos dos fármacos , Infecção dos Ferimentos/prevenção & controle , Ferimentos e Lesões/tratamento farmacológicoRESUMO
Pneumonia can lead to the critical impairment of gas exchange in the lung. Due to the great variability of pneumonia causing pathogens, a large variety of diverse virulence factors act on the lung. Besides stimulation of unspecific defense mechanisms, activation of receptor-dependent cell-mediated innate immune defense mechanisms are critical for the pulmonary immune defense. Pathogen-associated molecules are detected via transmembraneous and cytosolic receptors of the host. This interaction stimulates the expression of immunomodulatory molecules via signal cascades. Of particular importance, in addition to direct pathogen-caused lung damage, is the overwhelming activation of the inflammatory response which can result in lung barrier failure and impairment of pulmonary gas exchange. In addition to the design of new antibiotics, innovative therapeutic strategies should therefore concentrate on the enhancement of antimicrobial mechanisms by concurrent limitation of inflammation.
Assuntos
Pneumonia Bacteriana/imunologia , Toxinas Bacterianas/imunologia , Humanos , Imunidade Ativa/imunologia , Imunidade Celular/imunologia , Imunidade Inata/imunologia , Pulmão/imunologia , Macrófagos Alveolares/imunologia , Neutrófilos/imunologia , Pneumonia Pneumocócica/imunologia , Edema Pulmonar/imunologia , Troca Gasosa Pulmonar/fisiologia , Receptores Imunológicos/imunologia , Transdução de Sinais/imunologia , Síndrome de Resposta Inflamatória Sistêmica/imunologiaRESUMO
Legionella pneumophila causes community-acquired pneumonia with high mortality, but little is known about its interaction with the alveolar epithelium. The aim of this study was to investigate whether L. pneumophila infection of lung epithelial cells (A549) resulted in pro-inflammatory activation. L. pneumophila infection induced liberation of interleukin (IL)-2, -4, -6, -8 and -17, monocyte chemoattractant protein-1, tumour necrosis factor-alpha, IL-1beta, interferon-gamma and granulocyte colony-stimulating factor, but not of IL-5, -7, -10, -12 (p70) or -13 or granulocyte-macrophage colony-stimulating factor. The present study focused on IL-8 and found induction by L. pneumophila strains 130b, Philadelphia 1, Corby and, to a lesser extent, JR32. Knockout of dotA, a central gene involved in type IVB secretion, did not alter IL-8 induction, whereas lack of flagellin significantly reduced IL-8 release by Legionella. Moreover, p38 mitogen-activated protein kinase (MAPK) was activated and kinase inhibition reduced secretion of induced cytokines, with the exception of IL-2 and granulocyte colony-stimulating factor. In contrast, inhibition of the MAPK kinase 1/extracellular signal-regulated kinase pathway only reduced the expression of a few cytokines. L. pneumophila also induced binding of nuclear factor-kappaB subunit RelA/p65 and RNA polymerase II to the il8 promoter, and a specific inhibitor of the inhibitor of nuclear factor-kappaB complex dose-dependently lowered IL-8 expression. Taken together, Legionella pneumophila activated p38 mitogen-activated protein kinase- and nuclear factor-kappaB/RelA pathway-dependent expression of a complex pattern of cytokines by human alveolar epithelial cells, presumably contributing to the immune response in legionellosis.
Assuntos
Citocinas/metabolismo , Células Epiteliais/metabolismo , Legionella pneumophila/fisiologia , Pulmão/patologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Técnicas de Cultura de Células , Células Cultivadas , Citocinas/genética , Gliceraldeído-3-Fosfato Desidrogenases/genética , Gliceraldeído-3-Fosfato Desidrogenases/metabolismo , Humanos , Pulmão/metabolismo , RNA Mensageiro/metabolismo , Quinase Induzida por NF-kappaBRESUMO
Moraxella catarrhalis is a major cause of infectious exacerbations of chronic obstructive lung disease. Cyclooxygenase (COX)-derived prostaglandins, such as prostaglandin E(2) (PGE(2)), are considered to be important regulators of lung function. The present authors tested the hypothesis that M. catarrhalis induces COX-2-dependent PGE(2) production in pulmonary epithelial cells. In the present study, the authors demonstrate that M. catarrhalis specifically induces COX-2 expression and subsequent PGE(2) release in pulmonary epithelial cells. Furthermore, the prostanoid receptor subtypes EP2 and EP4 were also upregulated in these cells. The M. catarrhalis-specific ubiquitous cell surface protein A1 was important for the induction of COX-2 and PGE(2). Moreover, M. catarrhalis-induced COX-2 and PGE(2) expression was dependent on extracellular signal-regulated kinase 1/2-driven activation of nuclear factor-kappaB, but not on the activation of p38 mitogen-activated protein kinase. In conclusion, the present data suggest that ubiquitous cell surface protein A1 of Moraxella catarrhalis, extracellular signal-regulated kinase 1/2 and nuclear factor-kappaB control cyclooxygenase-2 expression and subsequent prostaglandin E(2) release by lung epithelial cells. Moraxella catarrhalis-induced prostaglandin E(2) expression might counteract lung inflammation promoting colonisation of the respiratory tract in chronic obstructive pulmonary disease patients.