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We review two algorithmic advances that bring us closer to reliable quantum simulations of model systems in high-energy physics and beyond on noisy intermediate-scale quantum (NISQ) devices. The first method is the dimensional expressivity analysis of quantum circuits, which allows for constructing minimal but maximally expressive quantum circuits. The second method is an efficient mitigation of readout errors on quantum devices. Both methods can lead to significant improvements in quantum simulations, e.g. when variational quantum eigensolvers are used. This article is part of the theme issue 'Quantum technologies in particle physics'.
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Advances in the biological sciences have led to an ongoing paradigm shift in toxicity testing based on expanded application of high-throughput in vitro screening and in silico methods to assess potential health risks of environmental agents. This review examines progress on the vision for toxicity testing elaborated by the US National Research Council (NRC) during the decade that has passed since the 2007 NRC report on Toxicity Testing in the 21st Century (TT21C). Concomitant advances in exposure assessment, including computational approaches and high-throughput exposomics, are also documented. A vision for the next generation of risk science, incorporating risk assessment methodologies suitable for the analysis of new toxicological and exposure data, resulting in human exposure guidelines is described. Case study prototypes indicating how these new approaches to toxicity testing, exposure measurement, and risk assessment are beginning to be applied in practice are presented. Overall, progress on the 20-year transition plan laid out by the US NRC in 2007 has been substantial. Importantly, government agencies within the United States and internationally are beginning to incorporate the new approach methodologies envisaged in the original TT21C vision into regulatory practice. Future perspectives on the continued evolution of toxicity testing to strengthen regulatory risk assessment are provided.
Assuntos
Rotas de Resultados Adversos , Medição de Risco/métodos , Testes de Toxicidade/métodos , Animais , Carcinógenos/química , Carcinógenos/toxicidade , Biologia Computacional/métodos , Mineração de Dados , Exposição Ambiental/efeitos adversos , Exposição Ambiental/análise , Ensaios de Triagem em Larga Escala , Humanos , National Academy of Sciences, U.S. , Relação Estrutura-Atividade , Testes de Toxicidade/tendências , Toxicogenética/métodos , Toxicologia/métodos , Estados UnidosRESUMO
OBJECTIVE: Psychological distress is common in cancer patients, and awareness of its indicators is essential. We aimed to assess the prevalence of psychological distress and to identify problems indicative of high distress. METHODS: We used the distress thermometer (DT) and its 34-item problem list to measure psychological distress in 3724 cancer patients (mean age 58 years; 57% women) across major tumor entities, enrolled in an epidemiological multicenter study. To identify distress-related problems, we conducted monothetic analyses. RESULTS: We found high levels of psychological distress (DT ≥ 5) in 52% of patients. The most prevalent problems were fatigue (56%), sleep problems (51%), and problems getting around (47%). Sadness, fatigue, and sleep problems were most strongly associated with the presence of other problems. High distress was present in 81.4% of patients reporting all 3 of these problems (DT M = 6.4). When analyzing only the subset of physical problems, fatigue, problems getting around, and indigestion showed the strongest association with the remaining problems and 76.3% of patients with all 3 problems were highly distressed (DT M = 6.1). CONCLUSIONS: Our results show a high prevalence of psychological distress in cancer patients, as well as a set of problems that indicate the likely presence of other problems and high distress and can help clinicians identify distressed patients even if no routine distress screening is available.
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Depressão/diagnóstico , Fadiga/diagnóstico , Programas de Rastreamento/métodos , Neoplasias/psicologia , Estresse Psicológico/diagnóstico , Adulto , Idoso , Depressão/epidemiologia , Depressão/psicologia , Emoções , Fadiga/epidemiologia , Fadiga/etiologia , Fadiga/psicologia , Feminino , Inquéritos Epidemiológicos , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/complicações , Prevalência , Escalas de Graduação Psiquiátrica , Estresse Psicológico/epidemiologia , Estresse Psicológico/etiologia , Estresse Psicológico/psicologiaRESUMO
This longitudinal study was designed to assess patients' desire for early retirement and investigate which cancer-related and psychosocial characteristics are associated with early retirement. We assessed 750 cancer patients at the beginning (t0 ) and end (t1 ) of, and 12 months after (t2 ) inpatient cancer rehabilitation. At t0 , 22% had a desire to retire early. These patients reported significantly longer sick leave periods, less favourable workplace environments, lower work ability, higher psychological distress and lower quality of life than other patients. At t2 , 12.5% of patients received temporary or permanent early retirement pensions. Of all patients with a desire for early retirement at t0 , 43% had returned to work at t2 . This subgroup had a significantly lower physical quality of life than other patients returning to work. The most influential predictors of early retirement were being on sick leave (OR = 6.50, 95% CI = 1.97-21.47) and a desire for early retirement (OR = 5.61, 95% CI = 2.73-11.52). Inverse predictors of early retirement were cancer remission (OR = 0.23, 95% CI = 0.10-0.53), perceived productivity (OR = 0.38, 95% CI = 0.18-0.83), work satisfaction (OR = 0.36, 95% CI = 0.17-0.77) and mental quality of life (OR = 0.94, 95% CI = 0.91-0.98). This underlines the need for cancer-specific multi-professional rehabilitation and occupational therapy programmes.
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Neoplasias/reabilitação , Qualidade de Vida , Aposentadoria/estatística & dados numéricos , Retorno ao Trabalho/estatística & dados numéricos , Estresse Psicológico/epidemiologia , Local de Trabalho , Adulto , Fatores Etários , Atitude , Eficiência , Feminino , Humanos , Satisfação no Emprego , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Neoplasias/psicologia , Razão de Chances , Pensões , Aposentadoria/psicologia , Retorno ao Trabalho/psicologia , Fatores de Risco , Licença Médica/estatística & dados numéricos , Estresse Psicológico/psicologia , Adulto JovemRESUMO
The Threshold Toxicological Concern (TTC) is based on the concept that in absence of experimental data reasonable assurance of safety can be given if exposure is sufficiently low. Using the REACH database the low 5th percentile of the NO(A)EL distribution, for prenatal developmental toxicity (OECD guideline 414) was determined. For rats, (434 NO(A)ELs values) for maternal toxicity, this value was 10 mg/kg-bw/day. For developmental toxicity (469 NO(A)ELs): 13 mg/kg-bw/day. For rabbits, (100 NO(A)ELs), the value for maternal toxicity was 4 mg/kg-bw/day, for developmental toxicity, (112 NO(A)EL values): 10 mg/kg-bw/day. The maternal organism may thus be slightly more sensitive than the fetus. Combining REACH- (industrial chemicals) and published BASF-data (mostly agrochemicals), 537 unique compounds with NO(A)EL values for developmental toxicity in rats and 150 in rabbits were evaluated. The low 5th percentile NO(A)EL for developmental toxicity in rats was 10 mg/kg-bw/day and 9.5 mg/kg-bw/day for rabbits. Using an assessment factor of 100, a TTC value for developmental toxicity of 100 µg/kg-bw/day for rats and 95 µg/kg-bw/day for rabbits is calculated. These values could serve as guidance whether or not to perform an animal experiment, if exposure is sufficiently low. In emergency situations this value may be useful for a first tier risk assessment.
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Agroquímicos/toxicidade , Desenvolvimento Fetal/efeitos dos fármacos , Feto/efeitos dos fármacos , Animais , Bases de Dados Factuais , Feminino , Nível de Efeito Adverso não Observado , Coelhos , Ratos , Medição de Risco , Testes de ToxicidadeRESUMO
Several shortcomings of current Parkinson's disease (PD) models limit progress in identification of environmental contributions to disease pathogenesis. The conditionally immortalized cell line LUHMES promises to make human dopaminergic neuronal cultures more easily available, but these cells are difficult to culture for extended periods of time. We overcame this problem by culturing them in 3D with minor medium modifications. The 3D neuronal aggregates allowed penetration by small molecules and sufficient oxygen and nutrient supply for survival of the innermost cells. Using confocal microscopy, gene expression, and flow cytometry, we characterized the 3D model and observed a highly reproducible differentiation process. Visualization and quantification of neurites in aggregates was achieved by adding 2 % red fluorescent protein-transfected LUHMES cells. The mitochondrial toxicants and established experimental PD agents, rotenone and MPP+, perturbed genes involved in one-carbon metabolism and transsulfuration pathways (ASS1, CTH, and SHTM2) as in 2D cultures. We showed, for the first time in LUHMES, down-regulation of mir-7, a miRNA known to target alpha-synuclein and to be involved in PD. This was observed as early as 12 h after rotenone exposure, when pro-apoptotic mir-16 and rotenone-sensitive mir-210 were not yet significantly perturbed. Finally, washout experiments demonstrated that withdrawal of rotenone led to counter-regulation of mir-7 and ASS1, CTH, and SHTM2 genes. This suggests a possible role of these genes in direct cellular response to the toxicant, and the model appears to be suitable to address the processes of resilience and recovery in neurotoxicology and Parkinson's disease in future studies.
Assuntos
Antiparkinsonianos/farmacologia , Neurônios Dopaminérgicos/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos/métodos , Fármacos Neuroprotetores/farmacologia , Neurotoxinas/toxicidade , Testes de Toxicidade Aguda/métodos , Testes de Toxicidade Crônica/métodos , Agregação Celular , Técnicas de Cultura de Células , Diferenciação Celular , Linhagem Celular Transformada , Sobrevivência Celular/efeitos dos fármacos , Neurônios Dopaminérgicos/citologia , Neurônios Dopaminérgicos/metabolismo , Resistência a Medicamentos , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Imageamento Tridimensional , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Microscopia Confocal , Microscopia de Fluorescência , Proteínas do Tecido Nervoso/agonistas , Proteínas do Tecido Nervoso/antagonistas & inibidores , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Neuritos/efeitos dos fármacos , Neuritos/metabolismo , Proteínas Recombinantes/metabolismoRESUMO
Given the increasing incidence of cancer and improved diagnostics and cancer treatments, the number of cancer patients in industrialized nations is increasing worldwide. Multimodal treatment regimens, which contribute to a tumor-free survival or extend patients life expectancy can, however, alone or in combination increase the risk of physical and psychosocial long-term problems or late complications. For many patients cancer has become a chronic disease and is associated with significant physical and psychosocial problems that affect the quality of life in the medium and longer-term perspective. Common problems of cancer patients in the longer course of the disease include chronic and post-cancer pain, cancer-specific fatigue, psychosocial distress and impairment in self-management and activities of daily living, work participation and quality of life. Current developments with respect to both curative and palliative oncological care have various implications for health services research in psycho-oncology. These questions relate to issues of care needs, service provision and the appropriateness of care, issues of development, implementation and scientific evaluation of patient-centered and affordable support programs for different groups of cancer patients with different supportive care needs, issues of access and utilization of supportive care services, as well as questions of appropriate outcome criteria of health services research.
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Pesquisa sobre Serviços de Saúde/organização & administração , Oncologia/organização & administração , Transtornos Mentais/terapia , Neoplasias/terapia , Psicologia/organização & administração , Alemanha , Humanos , Transtornos Mentais/psicologia , Neoplasias/psicologia , Cuidados Paliativos/organização & administração , Equipe de Assistência ao Paciente/organização & administraçãoRESUMO
Amyotrophic lateral sclerosis (ALS) is a rapidly progressive disease leading to degeneration of motor neurons (MNs). Epigenetic modification of gene expression is increasingly recognized as potential disease mechanism. In the present study we generated motor neurons from induced pluripotent stem cells from ALS patients carrying a mutation in the fused in sarcoma gene (FUS) and analyzed expression and promoter methylation of the FUS gene and expression of DNA methyltransferases (DNMTs) compared to healthy control cell lines. While mutant FUS neural progenitor cells (NPCs) did not show a difference in FUS and DNMT expression compared to healthy controls, differentiated mutant FUS motor neurons showed significantly lower FUS expression, higher DNMT expression and higher methylation of the proximal FUS gene promoter. Immunofluorescence revealed perceived proximity of cytoplasmic FUS aggregates in ALS MNs together with 5-methylcytosin (5-mC). Targeting disturbed methylation in ALS may therefore restore transcriptional alterations and represent a novel therapeutic strategy.
RESUMO
Lipoteichoic acids (LTAs) have been proposed as putative Gram-positive immunostimulatory counterparts to Gram-negative lipopolysaccharides. However, LTA from Staphylococcus aureus, the clinically most frequent Gram-positive pathogen, was inactive after purification. Here, a novel isolation procedure to prepare pure (>99%) biologically active LTA, allowing the first structural analysis by nuclear magnetic resonance and mass spectrometry, is described. A comparison with LTA purified by standard techniques revealed that alanine substituents are lost during standard purification, resulting in attenuated cytokine induction activity. In line with this finding, hydrolysis of alanine substituents of active LTA decimated cytokine induction. LTA represents a major immunostimulatory component of S. aureus.
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Lipopolissacarídeos/imunologia , Staphylococcus aureus/imunologia , Ácidos Teicoicos/imunologia , Fator de Necrose Tumoral alfa/biossíntese , Acetilglucosamina/química , Acetilglucosamina/imunologia , Alanina/química , Alanina/imunologia , Humanos , Lipopolissacarídeos/química , Lipopolissacarídeos/isolamento & purificação , Espectrometria de Massas/métodos , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular/métodos , Staphylococcus aureus/química , Relação Estrutura-Atividade , Ácidos Teicoicos/química , Ácidos Teicoicos/isolamento & purificaçãoRESUMO
Hexavalent chromium raises high concern because of its wide industrial applications and reported toxicity. Long-term (135 days) oral exposure of Wistar rats to chromium in the form of K2Cr2O7 (exposed group~20â¯mg/kg/day) led to a decrease in thymus mass and thymocytes' number and caused structural and functional changes in the lymph nodes and spleen, namely lymphoreticular hyperplasia and plasmocytic macrophage transformation. Programmed cell death was increased in both thymocytes and splenocytes and decreased in lymphocytes in the T-zones of spleen and lymph nodes. Moreover, Cr (VI) administration decreased myeloid cells' and neutrophils' number, while it increased lymphoid and erythroid cells' number in bone marrow. Cr (VI) immune system effects seem to be related to oxidative stress induction, as depicted by the increased levels of diene conjugates and malondialdehyde in the spleen and liver and by the decreased activity of catalase and superoxide dismutase in rats' erythrocytes. In addition, exposure to Cr (VI) decreased copper, nickel and iron concentrations in blood and liver, while Cr levels in blood, spleen and liver were increased, as expected. The observed changes in the series of immunological parameters studied contribute to the development of new approaches for the prevention of low level Cr exposure toxicity.
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Cromo/toxicidade , Linfonodos/efeitos dos fármacos , Baço/efeitos dos fármacos , Timo/efeitos dos fármacos , Animais , Peso Corporal/efeitos dos fármacos , Imuno-Histoquímica , Linfonodos/metabolismo , Contagem de Linfócitos , Masculino , Tamanho do Órgão/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Ratos Wistar , Baço/metabolismo , Linfócitos T/metabolismo , Timócitos/metabolismo , Timo/metabolismo , Timo/patologiaRESUMO
Lipoteichoic acid (LTA) of Gram-positive bacteria initiates innate immune responses via Toll-like receptor-2 (TLR2), resulting in the activation of intracellular signaling and production of inflammatory cytokines in macrophages. Although Bruton's tyrosine kinase (Btk) is biologically important molecule implicated in immune regulation and recently in TLR signaling its importance for LTA-TLR2 mediated responses has not been evaluated. In this study, we detected Btk in the LTA signaling complex with TLR2 and PI 3-kinase (PI3K). The constitutive interaction of these proteins was mediated via PI3K Src homology (SH3) -domain. Both Btk and PI3K were activated by LTA stimulation and the LTA induced cytokine expression was differentially modulated by these kinases. LTA induced the activation of nuclear factor kappaB (NFkappaB), however, only Btk inhibition affected the LTA induced Ser536 phosphorylation and DNA-binding of NFkappaB. In conclusion, our results demonstrate that Btk and PI3K occupy important roles in TLR2-induced activation of macrophages, resulting in selective regulation of cytokines.
Assuntos
Lipopolissacarídeos/farmacologia , Macrófagos/fisiologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Tirosina Quinases/metabolismo , Ácidos Teicoicos/farmacologia , Receptor 2 Toll-Like/metabolismo , Tirosina Quinase da Agamaglobulinemia , Animais , Linhagem Celular , Genes Reporter , Glutationa Transferase/metabolismo , Luciferases/metabolismo , Macrófagos/efeitos dos fármacos , Camundongos , Fosfatidilinositol 3-Quinases/análise , Fosfatidilinositol 3-Quinases/genética , Proteínas Recombinantes de Fusão/metabolismo , Transdução de SinaisRESUMO
The implementation of Registration, Evaluation and Authorisation of new and existing Chemicals (REACH) will increase the number of laboratory animals used, if alternative methods will not be available. In the meantime, REACH promotes the use of in vitro tests and, therefore, a set of appropriated alternative testing methods and assessment strategies are needed. The immune system can be a target for many chemicals including environmental contaminants and drugs with potential adverse effects on human health. The aim of this study was to evaluate the predictivity of a set of in vitro assays to detect immunosuppression. The tests have been performed on human, rat and murine cells. Different endpoints have been assessed: cytotoxicity, cytokine release, myelotoxicity and mitogen responsiveness. For each of these endpoints IC50s values have been calculated. Six chemical substances, representative of the full range of in vivo responses and for which good human and/or animal data are available either from databases or literature, have been selected: two chemicals classified as not immunotoxic (Urethane and Furosemide), and four (tributyltin chloride (TBTC), Verapamil, Cyclosporin A, Benzo(a)pyrene) with different effect on immune system. All the tests confirmed the strong immunotoxic effect of TBTC as well as they confirmed the negative controls. For one chemical (Verapamil) the IC50 is similar through the different tests. The IC50s obtained with the other chemicals depend on the endpoints and on the animal species. The clonogenic test (CFU-GM) and the mitogen responsiveness showed similar IC50s between human and rodent cells except for Cyclosporin A and TBTC. All different tests classified the compounds analyzed in the same way.
Assuntos
Proliferação de Células/efeitos dos fármacos , Imunotoxinas/toxicidade , Animais , Benzo(a)pireno/toxicidade , Complexo CD3/imunologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/imunologia , Ciclosporina/toxicidade , Citocinas/biossíntese , Citocinas/imunologia , Citocinas/metabolismo , Relação Dose-Resposta a Droga , Furosemida/toxicidade , Humanos , Concentração Inibidora 50 , Lipopolissacarídeos/toxicidade , Camundongos , Camundongos Endogâmicos BALB C , Fito-Hemaglutininas/toxicidade , Ratos , Reprodutibilidade dos Testes , Baço/citologia , Baço/imunologia , Linfócitos T/citologia , Linfócitos T/efeitos dos fármacos , Testes de Toxicidade/métodos , Compostos de Trialquitina/toxicidade , Uretana/toxicidade , Verapamil/toxicidadeRESUMO
BACKGROUND: Depression is a common co-morbidity of cancer that has a detrimental effect on quality of life, treatment adherence and potentially survival. We conducted an epidemiological multi-center study including a population-based random comparison sample and estimated the prevalence of depressive symptoms by cancer site, thereby identifying cancer patients with the highest prevalence of depression. PATIENTS AND METHODS: We included 4020 adult cancer inpatients and outpatients from five distinct regions across Germany in a proportional stratified random sample based on the nationwide cancer incidence and a comparison group consisting of 5018 participants. Both groups reported depressive symptoms by filling in the Patient Health Questionnaire (PHQ-9). In multivariate analyses adjusted for age and sex, we calculated the odds of being depressed. RESULTS: Out of 5818 eligible patients, 69% participated (51% women, mean age = 58 years). We estimated that one in four cancer patients (24%) is depressed (PHQ-9 ≥ 10). The odds of being depressed among cancer patients were more than five times higher than in the general population (OR, 5.4; 95% CI, 4.6-6.2). Patients with pancreatic (M = 8.0, SD = 5.0), thyroid (M = 7.8, SD = 6.3) and brain tumours (M = 7.6, SD = 4.9) showed the highest prevalence, whereas patients with prostate cancer (M = 4.3, SD = 3.8) and malignant melanoma (M = 5.3, SD = 4.3) had the lowest levels of depressive symptoms. CONCLUSION: Our results help clinicians identify cancer patients in need of psychosocial support when navigating in the growing survivor population.
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Transtorno Depressivo/epidemiologia , Neoplasias/psicologia , Adolescente , Adulto , Idoso , Transtorno Depressivo/etiologia , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Prevalência , Escalas de Graduação Psiquiátrica , Adulto JovemRESUMO
The co-culture of bovine brain capillary endothelial cells and rat primary glial cells was established as an in vitro blood-brain barrier model to investigate the mechanisms by which the Gram-positive bacterial cell wall components lipoteichoic acid and muramyl dipeptide induced injury of blood-brain barrier structure and function. We found that highly purified lipoteichoic acid disrupted blood-brain barrier integrity in a concentration- and time-dependent manner indirectly, through glia activation. Low trans-endothelial electrical resistance and high permeability to fluorescein isothiocyanate-inulin observed in the presence of lipoteichoic acid-activated glial cells were potentiated by muramyl dipeptide and could be reversed only when glial cells were activated by lipoteichoic acid at 10 microg/ml but not with a higher lipoteichoic acid concentration (30 microg/ml). Immunocytochemistry analysis revealed no evident changes in the distribution of the cytoskeleton protein F-actin and tight junction proteins occludin and claudin after lipoteichoic acid treatment. However, the tight junction associated protein AHNAK clearly revealed the morphological alteration of the endothelial cells induced by lipoteichoic acid. Lipoteichoic acid-activated glial cells produced nitric oxide and pro-inflammatory cytokines (tumor necrosis factor-alpha and interleukin-1beta) that contributed to lipoteichoic acid-induced blood-brain barrier disruption, since the direct treatment of the endothelial monolayer with tumor necrosis factor-alpha or interleukin-1beta increased blood-brain barrier permeability, whereas the pre-treatment of lipoteichoic acid-activated glial cells with antibodies against these two cytokines blocked lipoteichoic acid effects. Additionally, nitric oxide was also involved in blood-brain barrier damage, since the nitric oxide donor itself (diethylenetriamine-nitric oxide adduct) increased blood-brain barrier permeability and inducible nitric oxide synthase inhibitor (1400W) partially reversed lipoteichoic acid-induced trans-endothelial electrical resistance decrease.
Assuntos
Barreira Hematoencefálica/fisiologia , Córtex Cerebral/irrigação sanguínea , Citocinas/fisiologia , Endotélio Vascular/fisiologia , Lipopolissacarídeos/farmacologia , Neuroglia/fisiologia , Óxido Nítrico/fisiologia , Ácidos Teicoicos/farmacologia , Actinas/metabolismo , Animais , Barreira Hematoencefálica/efeitos dos fármacos , Capilares , Bovinos , Permeabilidade da Membrana Celular , Células Cultivadas , Citoesqueleto/efeitos dos fármacos , Citoesqueleto/fisiologia , Endotélio Vascular/efeitos dos fármacos , Bactérias Gram-Positivas/química , Lipopolissacarídeos/isolamento & purificação , Neuroglia/citologia , Neuroglia/efeitos dos fármacos , Ácidos Teicoicos/isolamento & purificação , Junções Íntimas/efeitos dos fármacos , Junções Íntimas/fisiologiaRESUMO
Dimethyl sulfoxide (DMSO) and ethanol are common organic solvents used for dissolving lipophilic substances for in vitro testing. However, DMSO is known to induce differentiation in embryonic stem (ES) and embryonic teratocarcinoma (EC) cells. In order to clarify if solvents like DMSO and ethanol have an influence on in vitro developmental toxicity test systems, the presented study has evaluated their effects on differentiation by using different test systems. ES and EC cells were transfected with a construct containing the mTert promoter combined with the green fluorescent protein gene (GFP). A down-regulation of mTert, a marker for undifferentiated cells, results in a lower expression of GFP, which could be measured by flow cytometry. Taking the specific characteristics of ES and EC cells into account this effect could be a hint for the interaction of DMSO with embryonic development. Additionally, the effects of the solvents ethanol and DMSO on Oct-4 expression, another marker for undifferentiated cells, were measured in wild-type ES cells. Both selected molecular markers demonstrated an induction of differentiation after exposure to DMSO; in wild-type ES cells at a concentration of 0.125% and in transgenic EC cells at a concentration of 0.25% DMSO. All other differences from controls, including those which attained a level of statistical significance, were minor or not dosage related in degree, or were not consistent over time and are, therefore, considered to be of little toxicological importance. In addition, a cytotoxicity test demonstrated that the solvents affected the employed molecular markers in non-cytotoxic concentrations. The ES cells were the most sensitive towards the cytotoxic effects of the solvent DMSO while the EC cells were more sensitive when treated with the solvent ethanol.
Assuntos
Diferenciação Celular/efeitos dos fármacos , Solventes/toxicidade , Células-Tronco/efeitos dos fármacos , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Dimetil Sulfóxido/farmacologia , Dimetil Sulfóxido/toxicidade , Relação Dose-Resposta a Droga , Etanol/farmacologia , Etanol/toxicidade , Citometria de Fluxo , Genes Reporter , Proteínas de Fluorescência Verde/genética , Camundongos , Camundongos Endogâmicos BALB C , Fator 3 de Transcrição de Octâmero/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Solventes/farmacologia , Sais de Tetrazólio , Tiazóis , TransfecçãoRESUMO
The increasing demands on toxicology of large-scale risk assessment programmes for chemicals and emerging or expanding areas of chemical use suggest it is timely to review the toxicological toolbox. Like in clinical medicine, where an evidence-based medicine (EBM) is critically reviewing traditional approaches, toxicology has the opportunity to reshape and enlarge its methodology and approaches on the basis of compounded scientific knowledge. Such revision would have to be based on structured reviews of current practice, ie, assessment of test performance characteristics, mechanistic understanding, extended quality assurance, formal validation and the use of integrated testing strategies. This form of revision could optimize the balance between safety, costs and animal welfare, explicitly stating and, where possible, quantifying uncertainties. After a self-critical reassessment of current practices and evaluation of the thus generated information, such an evidence-based toxicology (EBT) promises to make better use of resources and to increase the quality of results, facilitating their interpretation. It shall open up hazard and also risk assessments to new technologies, flexibly accommodating current and future mechanistic understanding. An EBT will be better prepared to answer the continuously growing safety demands of modern societies.
Assuntos
Medicina Baseada em Evidências/métodos , Modelos Estatísticos , Testes de Toxicidade/métodos , Toxicologia/métodos , Animais , Simulação por Computador , Previsões , Humanos , Controle de Qualidade , Reprodutibilidade dos Testes , Medição de Risco , Testes de Toxicidade/normas , Toxicologia/tendênciasRESUMO
In primary cultures of Kupffer cells and hepatocytes, human granulocytes potentiated toxicity of endotoxin about 1000-fold. Granulocyte elastase activity was found to correlate with toxicity. The serine protease inhibitors alpha1-antitrypsin, eglin C, and aprotinin protected against toxicity. Tumor necrosis factor-alpha (TNF-alpha) induced cytotoxicity and elastase release, whereas neutralization of TNF-alpha blocked both events. We conclude that TNF-alpha formed by Kupffer cells activates granulocytes. Experiments in cultures where cells were separated by membranes permeable to mediators indicated that cell contact is needed for toxicity. Scanning electron microscopy showed granulocytes adhering to and interdigitating with hepatocytes. Using liver cells from ICAM-1-deficient mice had no effect on toxicity. However, neutralizing CD31 inhibited toxicity and elastase release but not granulocyte adhesion. Our findings demonstrate that adhesion of granulocytes is a necessary but not sufficient condition for the synergistic interaction of endotoxin-stimulated liver macrophages and granulocytes in the proteolytic killing of hepatocytes.
Assuntos
Doença Hepática Induzida por Substâncias e Drogas/fisiopatologia , Endotoxinas/toxicidade , Granulócitos/efeitos dos fármacos , Células de Kupffer/metabolismo , Falência Hepática/induzido quimicamente , Fígado/efeitos dos fármacos , Elastase Pancreática/metabolismo , Serina Endopeptidases/metabolismo , Fator de Necrose Tumoral alfa/fisiologia , Androstadienos/farmacologia , Animais , Aprotinina/farmacologia , Antígenos CD18/análise , Adesão Celular , Comunicação Celular , Permeabilidade da Membrana Celular , Células Cultivadas , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Técnicas de Cocultura , Endotoxinas/farmacologia , Granulócitos/enzimologia , Granulócitos/metabolismo , Granulócitos/ultraestrutura , Humanos , Molécula 1 de Adesão Intercelular/fisiologia , Fígado/citologia , Falência Hepática/etiologia , Falência Hepática/fisiopatologia , Masculino , Camundongos , Microscopia Eletrônica de Varredura , Elastase Pancreática/antagonistas & inibidores , Molécula-1 de Adesão Celular Endotelial a Plaquetas/análise , Proteínas , Ratos , Ratos Endogâmicos F344 , Serpinas/farmacologia , Choque Séptico/complicações , Fator de Necrose Tumoral alfa/metabolismo , Wortmanina , alfa 1-Antitripsina/farmacologiaRESUMO
In contrast to the anticipation that in sepsis granulocyte colony-stimulating factor (G-CSF) would overactivate the nonspecific immune system by recruiting and priming leukocytes with consequent aggravation of inflammatory tissue lesions, recombinant (r) G-CSF pretreatment was protective in various experimental non-neutropenic models of inflammation. The mechanisms of protection, however, are not fully understood. Using intravital fluorescence microscopy, we show that rG-CSF enhances leukocyte endothelial cell interaction within the microvasculature of normal rat livers, whereas rG-CSF pretreatment of animals exposed to lipopolysaccharide (LPS) attenuates the LPS-induced leukocytic response, including stasis in sinusoids as well as rolling and adherence in postsinusoidal venules with subsequent tissue infiltration. Moreover, rG-CSF, which did not affect Kupffer cell activity in normal rat livers, reduced the immediate activation of Kupffer cells on LPS exposure, as indicated in vivo by the delayed adherence/phagocytosis of intra-arterially administered latex particles associated with attenuation of proinflammatory cytokine release (tumor necrosis factor alpha and interleukin-6). Finally, rG-CSF reduced LPS-induced nutritive perfusion failure and hepatocellular excretory dysfunction. This study provides evidence for a distinct, possibly tumor necrosis factor alpha-dependent modulation of LPS-induced cellular response within the liver by rG-CSF, thereby achieving protection against microcirculatory perfusion failure and hepatic dysfunction.
Assuntos
Adjuvantes Imunológicos/farmacologia , Comunicação Celular/imunologia , Movimento Celular/imunologia , Fator Estimulador de Colônias de Granulócitos/farmacologia , Células de Kupffer/patologia , Leucócitos/patologia , Fígado/imunologia , Fígado/patologia , Animais , Adesão Celular/efeitos dos fármacos , Adesão Celular/imunologia , Comunicação Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Fator Estimulador de Colônias de Granulócitos/imunologia , Células de Kupffer/efeitos dos fármacos , Células de Kupffer/imunologia , Leucócitos/efeitos dos fármacos , Leucócitos/imunologia , Masculino , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/farmacologiaRESUMO
Studies on the role of endogenous granulocyte colony-stimulating factor (G-CSF) in host defense indicate that, in addition to its anti-infectious role, this cytokine has an immunomodulatory function and also augments antibiotic efficacy. Pre-clinical and clinical trials with Filgrastim, recombinant-methionyl human G-CSF, in neutropenic and non-neutropenic infections demonstrate a reduction in morbidity and mortality. This is attributed to Filgrastim's ability to control infectious complications and permit continuation of immunosuppressive therapies.
Assuntos
Doenças Transmissíveis/imunologia , Fator Estimulador de Colônias de Granulócitos/imunologia , Síndrome da Imunodeficiência Adquirida/complicações , Síndrome da Imunodeficiência Adquirida/imunologia , Adjuvantes Imunológicos/uso terapêutico , Antibacterianos/uso terapêutico , Doenças Transmissíveis/complicações , Doenças Transmissíveis/tratamento farmacológico , Doenças Transmissíveis/metabolismo , Filgrastim , Fator Estimulador de Colônias de Granulócitos/metabolismo , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , HIV-1/imunologia , Humanos , Neutropenia/tratamento farmacológico , Neutropenia/etiologia , Neutropenia/imunologia , Neutrófilos/imunologia , Neutrófilos/metabolismo , Proteínas RecombinantesRESUMO
TNF-alpha has been implicated as a potentially detrimental cytokine in autoimmune disorders of the nervous system and has been reported to be elevated in antigen-specific therapy of experimental autoimmune neuritis (EAN) in vivo. To investigate the role of TNF-alpha in EAN in rats that had been subjected to antigen-specific therapy with human P2 protein, animals were cotreated with an anti-TNF-alpha neutralizing antibody and the effects of the antibody on disease determined. Using this strategy in adoptive transfer (AT-) EAN, antigen-induced T-cell apoptosis in inflamed sciatic nerve and in liver was reduced to levels observed in control animals indicating that TNF-alpha mediates antigen-induced apoptosis of inflammatory T-cells. Focal liver necrosis, which had been observed in earlier studies after antigen therapy in AT-EAN, was prevented by passive immunization with neutralizing anti-TNF-alpha antibody. Unexpectedly, neutralization of TNF-alpha only partly abolished the protective effect of antigen therapy on the overall disease course. This may indicate that inhibition of TNF-alpha exerts beneficial effects other than through T-cell apoptosis, or that some of the benefit of antigen therapy is mediated by other pathways. These results indicate that secretion of TNF-alpha during antigen therapy has the dual potential to mediate beneficial apoptosis of inflammatory T-cells in the inflammatory lesion and to induce liver damage as a severe side effect.