Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20
Filtrar
1.
Ann Hematol ; 103(6): 2013-2020, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38421404

RESUMO

Venetoclax is active in both frontline and relapsed/refractory settings for the treatment of chronic lymphocytic leukemia (CLL). Although the prevalence and severity of tumor lysis syndrome (TLS) are well characterized in clinical trials, laboratory and clinical TLS remain relatively unexplored in real-world clinical practice.In this prospective, real-world observational study, we aimed to determine the incidence and outcomes of TLS in patients with CLL receiving venetoclax outside a clinical trial. The study (VeRVe) was conducted in centers in Austria, Germany, and Switzerland.Two hundred and thirty-nine patients were treated according to local label with at least one dose of venetoclax. Patient demographics, baseline characteristics, and blood chemistry at baseline were documented, and descriptive statistical analyses were conducted.Seventy eight patients (33%) were treated with venetoclax monotherapy, 101 (42%) with venetoclax in combination with rituximab and 60 (25%) with venetoclax in combination with obinutuzumab. In all cases, the TLS risk mitigation strategy adhered to the ramp-up protocol. Median age was 73 years and 66% of patients were male. The majority of patients (75%) had relapsed/refractory CLL, 63/192 (32.8%) patients tested had a del(17p) and 93/134 (69.4%) patients tested had unmutated immunoglobulin heavy chain variable region gene (IGHV). Clinical TLS occurred in 5 patients (2.1%) and laboratory TLS occurred in 15 patients (6.3%). Ten patients received specific treatment, of which 6 were hospitalized. There were no deaths due to a TLS event and venetoclax was well-tolerated. Of the 5 clinical TLS events reported, none were fatal or resulted in renal failure (NCT03342144, registered on Nov 10, 2017).


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes , Leucemia Linfocítica Crônica de Células B , Sulfonamidas , Síndrome de Lise Tumoral , Humanos , Síndrome de Lise Tumoral/etiologia , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Idoso , Sulfonamidas/uso terapêutico , Sulfonamidas/efeitos adversos , Sulfonamidas/administração & dosagem , Masculino , Feminino , Compostos Bicíclicos Heterocíclicos com Pontes/uso terapêutico , Compostos Bicíclicos Heterocíclicos com Pontes/efeitos adversos , Compostos Bicíclicos Heterocíclicos com Pontes/administração & dosagem , Idoso de 80 Anos ou mais , Estudos Prospectivos , Incidência , Pessoa de Meia-Idade , Anticorpos Monoclonais Humanizados/uso terapêutico , Anticorpos Monoclonais Humanizados/efeitos adversos , Anticorpos Monoclonais Humanizados/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Alemanha/epidemiologia , Rituximab/administração & dosagem , Rituximab/efeitos adversos , Rituximab/uso terapêutico , Áustria/epidemiologia , Antineoplásicos/efeitos adversos , Antineoplásicos/uso terapêutico
2.
Front Pediatr ; 11: 1235877, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37941976

RESUMO

Background: Randomized controlled trials have indicated reduced mortality rates in very preterm infants assigned to high compared to low oxygen saturation (SpO2) target levels, accompanied by higher rates of retinopathy of prematurity and bronchopulmonary dysplasia. However, the benefit-to-harm ratio may depend on the local background mortality risk. We therefore aimed to quantify the risk-benefit ratios of different SpO2 target ranges in 10 tertiary newborn intensive care units (NICUs) in East Germany. Methods: In a retrospective multicenter study, 1,399 infants born between 2008 and 2012 at a gestational age between 24 0/7 and 27 6/7 weeks and with a birthweight below 1,250 g were grouped according to the hospital's target SpO2 range [high oxygen saturation group (HOSG) above 90%], low oxygen saturation group (LOSG) below 90%] and the compliance of units with their target SpO2 range. The association between neonatal morbidities, neurodevelopmental outcomes, selected treatment strategies, and target SpO2 ranges was calculated using chi-squared and Mann Whitney U tests. Results: Nine of the ten participating NICUs met their SpO2 target ranges. Five units were considered as HOSG, and five units were considered as LOSG. Necrotizing enterocolitis and intraventricular hemorrhage grade ≥ 2 occurred significantly more frequently in the HOSG than in the LOSG (8.4% vs. 5.1%, p = 0.02; and 26.6% vs. 17.7%, p < 0.001). No significant differences in the mortality rate and the rate of retinopathy of prematurity were found. Conclusion: In our patient population, a lower SpO2 target range was not associated with increased safety risks in extremely preterm infants. We cannot be sure that our outcome differences are associated with differences in oxygen saturations due to the retrospective study design and the differences in site practices.

3.
ACS Appl Bio Mater ; 4(5): 3739-3748, 2021 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-35006804

RESUMO

During infection, inflammation is an important contributor to tissue regeneration and healing, but it may also negatively affect these processes should chronic overstimulation take place. Similar issues arise in chronic inflammatory gastrointestinal diseases such as inflammatory bowel diseases or celiac disease, which show increasing incidences worldwide. For these dispositions, probiotic microorganisms, including lactobacilli, are studied as an adjuvant therapy to counterbalance gut dysbiosis. However, not all who are affected can benefit from the probiotic treatment, as immunosuppressed or hospitalized patients can suffer from bacteremia or sepsis when living microorganisms are administered. A promising alternative is the treatment with bacteria-derived membrane vesicles that confer similar beneficial effects as the progenitor strains themselves. Membrane vesicles from lactobacilli have shown anti-inflammatory therapeutic effects, but it remains unclear whether the stimulation of probiotics induces vesicles that are more efficient. Here, the influence of culture conditions on the anti-inflammatory characteristics of Lactobacillus membrane vesicles was investigated. We reveal that the culture conditions of two Lactobacillus strains, namely, L. casei and L. plantarum, can be optimized to increase the anti-inflammatory effect of their vesicles. Five different cultivation conditions were tested, including pH manipulation, agitation rate, and oxygen supply, and the produced membrane vesicles were characterized physico-chemically regarding size, yield, and zeta potential. We furthermore analyzed the anti-inflammatory effect of the purified vesicles in macrophage inflammation models. Compared to standard cultivation conditions, vesicles obtained from L. casei cultured at pH 6.5 and agitation induced the strongest interleukin-10 release and tumor necrosis factor-α reduction. For L. plantarum, medium adjusted to pH 5 had the most pronounced effect on the anti-inflammatory activity of their vesicles. Our results reveal that the anti-inflammatory effect of probiotic vesicles may be potentiated by expanding different cultivation conditions for lactobacilli. This study creates an important base for the utilization of probiotic membrane vesicles to treat inflammation.


Assuntos
Anti-Inflamatórios/farmacologia , Proteínas de Bactérias/metabolismo , Materiais Biocompatíveis/farmacologia , Lactobacillus/química , Probióticos/farmacologia , Anti-Inflamatórios/química , Proteínas de Bactérias/química , Materiais Biocompatíveis/química , Citocinas/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Teste de Materiais , Tamanho da Partícula , Probióticos/química , Células THP-1
4.
Cells ; 9(1)2020 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-31940898

RESUMO

In 2019, it was estimated that 2.5 million people die from lower tract respiratory infections annually. One of the main causes of these infections is Staphylococcus aureus, a bacterium that can invade and survive within mammalian cells. S. aureus intracellular infections are difficult to treat because several classes of antibiotics are unable to permeate through the cell wall and reach the pathogen. This condition increases the need for new therapeutic avenues, able to deliver antibiotics efficiently. In this work, we obtained outer membrane vesicles (OMVs) derived from the myxobacteria Cystobacter velatus strain Cbv34 and Cystobacter ferrugineus strain Cbfe23, that are naturally antimicrobial, to target intracellular infections, and investigated how they can affect the viability of epithelial and macrophage cell lines. We evaluated by cytometric bead array whether they induce the expression of proinflammatory cytokines in blood immune cells. Using confocal laser scanning microscopy and flow cytometry, we also investigated their interaction and uptake into mammalian cells. Finally, we studied the effect of OMVs on planktonic and intracellular S. aureus. We found that while Cbv34 OMVs were not cytotoxic to cells at any concentration tested, Cbfe23 OMVs affected the viability of macrophages, leading to a 50% decrease at a concentration of 125,000 OMVs/cell. We observed only little to moderate stimulation of release of TNF-alpha, IL-8, IL-6 and IL-1beta by both OMVs. Cbfe23 OMVs have better interaction with the cells than Cbv34 OMVs, being taken up faster by them, but both seem to remain mostly on the cell surface after 24 h of incubation. This, however, did not impair their bacteriostatic activity against intracellular S. aureus. In this study, we provide an important basis for implementing OMVs in the treatment of intracellular infections.


Assuntos
Antibacterianos/farmacologia , Membrana Externa Bacteriana/metabolismo , Vesículas Extracelulares/metabolismo , Myxococcales/química , Staphylococcus aureus/efeitos dos fármacos , Animais , Antibacterianos/biossíntese , Antibacterianos/química , Células Cultivadas , Células Epiteliais/metabolismo , Células Epiteliais/microbiologia , Vesículas Extracelulares/química , Humanos , Macrófagos/metabolismo , Macrófagos/microbiologia , Camundongos , Testes de Sensibilidade Microbiana , Myxococcales/metabolismo , Células RAW 264.7 , Células THP-1
5.
BMC Cancer ; 19(1): 611, 2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31227025

RESUMO

BACKGROUND: Treatment of postmenopausal, hormone receptor-positive metastatic breast cancer (MBC) patients varies despite clear therapy guidelines, favoring endocrine treatment (ET). Aim of this study was to analyze persistence of palliative aromatase inhibitor (AI) monotherapy in MBC patients. METHODS: EvAluate-TM is a prospective, multicenter, noninterventional study to evaluate treatment with letrozole in postmenopausal women with hormone receptor-positive breast cancer. To assess therapy persistence, defined as the time from therapy start to the end of the therapy (TTEOT), two pre-specified study visits took place after 6 and 12 months. Competing risk survival analyses were performed to identify patient and tumor characteristics that predict TTEOT. RESULTS: Out of 200 patients, 66 patients terminated treatment prematurely, 26 (13%) of them due to causes other than disease progression. Persistence rate for reasons other than progression at 12 months was 77.7%. Persistence was lower in patients who reported any adverse event (AE) in the first 30 days of ET (89.5% with no AE and 56% with AE). Furthermore, patients had a lower persistence if they reported compliance problems in the past before letrozole treatment. CONCLUSIONS: Despite suffering from a life-threatening disease, AEs of an AI will result in a relevant number of treatment terminations that are not related to progression. Some subgroups of patients have very low persistence rates. Especially with regard to novel endocrine combination therapies, these data imply that some groups of patients will need special attention to guide them through the therapy process. TRIAL REGISTRATION: Clinical Trials Number: CFEM345DDE19.


Assuntos
Inibidores da Aromatase/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Letrozol/uso terapêutico , Cooperação do Paciente , Pós-Menopausa , Idoso , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Pessoa de Meia-Idade , Pacientes Desistentes do Tratamento , Estudos Prospectivos , Resultado do Tratamento , Recusa do Paciente ao Tratamento
6.
Integr Cancer Ther ; 16(2): 165-175, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-27627986

RESUMO

BACKGROUND: Breast cancer patients often use complementary and alternative medicine, but few prospectively collected data on the topic are available specifically for postmenopausal breast cancer patients. A large prospective study was therefore conducted within a noninterventional study in order to identify the characteristics of patients interested in integrative medicine. METHODS: The EvAluate-TM study is a prospective, multicenter noninterventional study in which treatment with the aromatase inhibitor letrozole was evaluated in postmenopausal women with hormone receptor-positive primary breast cancer. Between 2008 and 2009, 5045 postmenopausal patients were enrolled at 339 certified breast centers in Germany. As part of the data collection process, patients were asked at the baseline about their interest in and information needs relating to integrative medicine. RESULTS: Of the 5045 patients recruited, 3411 responded to the questionnaire on integrative medicine and took part in the analysis, 1583 patients expressed an interest in integrative medicine, and 1828 patients declared no interest. Relevant predictors of interest in integrative medicine were age, body mass index, tumor size, previous chemotherapy, and use of concomitant medications for other medical conditions. Interest in integrative medicine declined highly significantly ( P < .001) with age (<50 years, 74.1%; 50-60 years, 54.1%; >65 years, 38.0%). Patients in favor of integrative medicine were significantly less satisfied with the information received about individual treatments and antihormonal therapy. Patients with interest in integrative medicine were more often interested in rehabilitation and fitness, nutritional counseling, and additional support from self-help organizations. These women were mostly interested in receiving information about their disease and integrative medicine from a physician, rather than from other sources. CONCLUSIONS: This study shows that a considerable proportion of postmenopausal breast cancer patients are interested in integrative medicine. Information about integrative medicine should therefore be provided as part of patient care for this group. It was found that receiving concomitant medication for other medical conditions is one of the main predictors for women not being interested in integrative medicine. This group of patients may need special attention and individualized information about integrative medicine. Additionally, most patients were interested in obtaining the relevant information from their doctor.


Assuntos
Antineoplásicos/uso terapêutico , Inibidores da Aromatase/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Nitrilas/uso terapêutico , Pós-Menopausa/efeitos dos fármacos , Triazóis/uso terapêutico , Idoso , Feminino , Alemanha , Humanos , Medicina Integrativa/métodos , Letrozol , Pessoa de Meia-Idade , Estudos Prospectivos
7.
Breast Care (Basel) ; 11(5): 315-322, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27920623

RESUMO

BACKGROUND: Decision-making for or against neoadjuvant or adjuvant chemotherapy in postmenopausal patients with hormone receptor-positive breast cancer does not follow any clear guidelines, and some patients may unnecessarily undergo chemotherapy and be exposed to the associated toxicity. The aim of this study was to identify the patient population for whom this issue may bear relevance. METHODS: Patients being treated with letrozole in the prospective multicenter noninterventional EvAluate-TM study were recruited. The percentage of patients receiving chemotherapy and factors associated with chemotherapy administration were identified. RESULTS: In all, 3,924 (37.4%) patients received chemotherapy before treatment with letrozole. Of these, 293 (20%) underwent neoadjuvant therapy. Younger age was predictive for both adjuvant and neoadjuvant therapy. Overall, decisions in favor of administering chemotherapy are more likely to be made in patients with a higher body mass index (BMI), and neoadjuvant chemotherapy is administered at a higher rate in women with a lower BMI. Concomitant medication influenced the overall decision-making regarding chemotherapy, irrespective of whether it was given on a neoadjuvant or adjuvant basis. CONCLUSION: There is an ongoing debate as to whether all of the many patients who receive chemotherapy actually benefit from it. Neoadjuvant chemotherapy is frequently administered in this patient population, and this should encourage further research to resolve current clinical and research issues.

8.
PLoS One ; 10(4): e0122564, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25856083

RESUMO

OBJECTIVE: It was the aim of our study to evaluate the independent effect of preterm prelabor rupture of membranes (PPROM) as a cause of preterm delivery on mortality during primary hospital stay and significant morbidities in very-low-birth-weight (VLBW) infants < 32 weeks of gestation. DESIGN: Observational, epidemiological study design. SETTING: Population-based cohort, German Neonatal Network (GNN). POPULATION: 6102 VLBW infants were enrolled in GNN from 2009-2012, n=4120 fulfilled criteria for primary analysis (< 32 gestational weeks, no pre-eclampsia, HELLP (highly elevated liver enzymes and low platelets syndrome) or placental abruption as cause of preterm birth). METHODS: Multivariable logistic regression analyses included PPROM as potential risk factors for adverse outcomes and well established items such as gestational age in weeks, birth weight, antenatal steroids, center, inborn delivery, multiple birth, gender and being small-for-gestational-age. RESULTS: PPROM as cause of preterm delivery had no independent effect on the risk of early-onset sepsis, clinical sepsis and blood-culture proven sepsis, while gestational age proved to be the most important contributor to sepsis risk. The diagnosis of PPROM was associated with an increased risk for bronchopulmonary dysplasia (BPD; OR: 1.25, 95% CI: 1.02-1.55, p=0.03) but not with other major outcomes. CONCLUSIONS: The diagnosis of PPROM per se is not associated with adverse outcome in VLBW infants < 32 weeks apart from a moderately increased risk for BPD. Randomized controlled trials with primary neonatal outcomes are needed to determine which subgroup of VLBW infants benefit from expectant or intentional management of PPROM.


Assuntos
Ruptura Prematura de Membranas Fetais/epidemiologia , Ruptura Prematura de Membranas Fetais/fisiopatologia , Recém-Nascido de muito Baixo Peso/fisiologia , Nascimento Prematuro/epidemiologia , Nascimento Prematuro/etiologia , Estudos de Coortes , Feminino , Alemanha/epidemiologia , Humanos , Recém-Nascido , Modelos Logísticos , Mortalidade , Gravidez
9.
Biomed Res Int ; 2014: 191767, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25050325

RESUMO

A persistent inflammatory and oxidative stress is a hallmark of most chronic CNS pathologies (Alzheimer's (ALS)) as well as the aging CNS orchestrated by the proinflammatory cytokines tumor necrosis factor alpha (TNFα) and interleukin-1 beta (IL-1ß). Loss of the integrity and plasticity of neuronal morphology and connectivity comprises an early step in neuronal degeneration and ultimate decline of cognitive function. We examined in vitro whether TNFα or IL-1ß impaired morphology and motility of growth cones in spinal cord neuron cultures. TNFα and IL-1ß paralyzed growth cone motility and induced growth cone collapse in a dose-dependent manner reflected by complete attenuation of neurite outgrowth. Scavenging reactive oxygen species (ROS) or inhibiting NADPH oxidase activity rescued loss of neuronal motility and morphology. TNFα and IL-1ß provoked rapid, NOX-mediated generation of ROS in advancing growth cones, which preceded paralysis of motility and collapse of morphology. Increases in ROS intermediates were accompanied by an aberrant, nonproductive reorganization of actin filaments. These findings suggest that NADPH oxidase serves as a pivotal source of oxidative stress in neurons and together with disruption of actin filament reorganization contributes to the progressive degeneration of neuronal morphology in the diseased or aging CNS.


Assuntos
Cones de Crescimento/patologia , Mediadores da Inflamação/toxicidade , Interleucina-1beta/toxicidade , Paralisia/patologia , Espécies Reativas de Oxigênio/toxicidade , Medula Espinal/patologia , Fator de Necrose Tumoral alfa/toxicidade , Citoesqueleto de Actina/efeitos dos fármacos , Citoesqueleto de Actina/metabolismo , Animais , Corpo Celular/efeitos dos fármacos , Corpo Celular/metabolismo , Embrião de Galinha , Cones de Crescimento/efeitos dos fármacos , Cones de Crescimento/enzimologia , Humanos , Modelos Biológicos , NADPH Oxidases/metabolismo , Neuritos/efeitos dos fármacos , Neuritos/metabolismo , Oxirredução/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Proteínas rac1 de Ligação ao GTP/metabolismo
10.
Psicol. saber soc ; 3(1): 132-137, jan.-jun. 2014.
Artigo em Inglês | LILACS | ID: lil-788786

RESUMO

The article discusses the question why and how social psychologists should research the impact of having been the host of the World Cup for the Brazilian society. It will be argued that social psychologist should focus on changing national narratives, social representations and social imaginaries of being Brazilian. This approach should be related to research on collectiveaction and collective emotions. Based on some qualitative projects conducted by the author in Germany and Brazil, the ambivalent character of modern national identity will be discussed. Thisambivalence is grounded on different national narratives that are essential for the selfunderstanding of members from a nation. Hosting the World Cup has impacted on these fundamental narratives, already in anticipation of the event. Whereas expectations regarding the upcoming event were broadly skeptical and linked to fears, the experience of the event by itself included some positively attributed surprises. For some, the fearful view of “imagina na copa” turned into a proud “copa das copas” – though critics in regard to large spendings maintained. Itcan be assumed that having been the host of the World Cup, in the future will be embedded in national narratives and therefore will have impacts for Brazilian national identity.


Assuntos
Humanos , Emoções , Comportamento de Massa , Narração , Psicologia Social , Autoimagem , Futebol , Grupos Populacionais
11.
PLoS One ; 9(4): e95995, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24760020

RESUMO

Neurites of neurons under acute or chronic stress form bundles of filaments (rods) containing 1∶1 cofilin∶actin, which impair transport and synaptic function. Rods contain disulfide cross-linked cofilin and are induced by treatments resulting in oxidative stress. Rods form rapidly (5-30 min) in >80% of cultured hippocampal or cortical neurons treated with excitotoxic levels of glutamate or energy depleted (hypoxia/ischemia or mitochondrial inhibitors). In contrast, slow rod formation (50% of maximum response in ∼6 h) occurs in a subpopulation (∼20%) of hippocampal neurons upon exposure to soluble human amyloid-ß dimer/trimer (Aßd/t) at subnanomolar concentrations. Here we show that proinflammatory cytokines (TNFα, IL-1ß, IL-6) also induce rods at the same rate and within the same neuronal population as Aßd/t. Neurons from prion (PrP(C))-null mice form rods in response to glutamate or antimycin A, but not in response to proinflammatory cytokines or Aßd/t. Two pathways inducing rod formation were confirmed by demonstrating that NADPH-oxidase (NOX) activity is required for prion-dependent rod formation, but not for rods induced by glutamate or energy depletion. Surprisingly, overexpression of PrP(C) is by itself sufficient to induce rods in over 40% of hippocampal neurons through the NOX-dependent pathway. Persistence of PrP(C)-dependent rods requires the continuous activity of NOX. Removing inducers or inhibiting NOX activity in cells containing PrP(C)-dependent rods causes rod disappearance with a half-life of about 36 min. Cofilin-actin rods provide a mechanism for synapse loss bridging the amyloid and cytokine hypotheses for Alzheimer disease, and may explain how functionally diverse Aß-binding membrane proteins induce synaptic dysfunction.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Hipocampo/citologia , Hipocampo/metabolismo , Neuritos/metabolismo , Proteínas PrPC/metabolismo , Transdução de Sinais , Fator de Necrose Tumoral alfa/metabolismo , Fatores de Despolimerização de Actina/metabolismo , Actinas/metabolismo , Animais , Células Cultivadas , Dactinomicina/farmacologia , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Ácido Glutâmico/farmacologia , Humanos , Inflamação/metabolismo , Camundongos , NADPH Oxidases/metabolismo , Proteínas PrPC/genética , Ratos , Transmissão Sináptica/efeitos dos fármacos
12.
PLoS One ; 8(12): e83609, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24391794

RESUMO

Filament bundles (rods) of cofilin and actin (1:1) form in neurites of stressed neurons where they inhibit synaptic function. Live-cell imaging of rod formation is hampered by the fact that overexpression of a chimera of wild type cofilin with a fluorescent protein causes formation of spontaneous and persistent rods, which is exacerbated by the photostress of imaging. The study of rod induction in living cells calls for a rod reporter that does not cause spontaneous rods. From a study in which single cofilin surface residues were mutated, we identified a mutant, cofilinR21Q, which when fused with monomeric Red Fluorescent Protein (mRFP) and expressed several fold above endogenous cofilin, does not induce spontaneous rods even during the photostress of imaging. CofilinR21Q-mRFP only incorporates into rods when they form from endogenous proteins in stressed cells. In neurons, cofilinR21Q-mRFP reports on rods formed from endogenous cofilin and induced by all modes tested thus far. Rods have a half-life of 30-60 min upon removal of the inducer. Vesicle transport in neurites is arrested upon treatments that form rods and recovers as rods disappear. CofilinR21Q-mRFP is a genetically encoded rod reporter that is useful in live cell imaging studies of induced rod formation, including rod dynamics, and kinetics of rod elimination.


Assuntos
Fatores de Despolimerização de Actina/metabolismo , Actinas/metabolismo , Neurônios/metabolismo , Fatores de Despolimerização de Actina/química , Fatores de Despolimerização de Actina/genética , Actinas/química , Actinas/genética , Animais , Linhagem Celular Tumoral , Sistemas Computacionais , Genes Reporter , Células HeLa , Humanos , Células LLC-PK1 , Proteínas Luminescentes/química , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Modelos Moleculares , Complexos Multiproteicos/química , Complexos Multiproteicos/genética , Complexos Multiproteicos/metabolismo , Mutagênese Sítio-Dirigida , Estrutura Quaternária de Proteína , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Análise de Célula Única , Suínos , Sinapses/metabolismo , Proteína Vermelha Fluorescente
13.
Oxid Med Cell Longev ; 2012: 768101, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22530077

RESUMO

Inflammation and oxidative stress are key to the progressive neuronal degeneration common to chronic pathologies, traumatic injuries, and aging processes in the CNS. The proinflammatory cytokine tumor necrosis factor-alpha (TNF-α) orchestrates cellular stress by stimulating the production and release of neurotoxic mediators including reactive oxygen species (ROS). NADPH oxidases (NOX), ubiquitously expressed in all cells, have recently emerged as pivotal ROS sources in aging and disease. We demonstrated the presence of potent NOX inhibitors in wild Alaska bog blueberries partitioning discretely into a nonpolar fraction with minimal antioxidant capacity and largely devoid of polyphenols. Incubation of SH-SY5Y human neuroblastoma cells with nonpolar blueberry fractions obstructed the coalescing of lipid rafts into large domains disrupting NOX assembly therein and abolishing ROS production characteristic for TNF-α exposure. These findings illuminate nutrition-derived lipid raft modulation as a novel therapeutic approach to blunt inflammatory and oxidative stress in the aging or diseased CNS.


Assuntos
Mirtilos Azuis (Planta)/química , NADPH Oxidases/metabolismo , Neurônios/efeitos dos fármacos , Extratos Vegetais/farmacologia , Fator de Necrose Tumoral alfa/farmacologia , Linhagem Celular Tumoral , Humanos , Neurônios/citologia , Neurônios/enzimologia , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/química , Espécies Reativas de Oxigênio/metabolismo
14.
Cell Signal ; 24(6): 1126-33, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22230689

RESUMO

A persistent inflammatory reaction is a hallmark of chronic and acute pathologies in the central nervous system (CNS) and greatly exacerbates neuronal degeneration. The proinflammatory cytokine tumor necrosis factor alpha (TNFα) plays a pivotal role in the initiation and progression of inflammatory processes provoking oxidative stress, eicosanoid biosynthesis, and the production of bioactive lipids. We established in neuronal cells that TNFα exposure dramatically increased Mg(2+)-dependent neutral sphingomyelinase (nSMase) activity thus generating the bioactive lipid mediator ceramide essential for subsequent NADPH oxidase (NOX) activation and oxidative stress. Since many of the pleiotropic effects of ceramide are attributable to its metabolites, we examined whether ceramide kinase (CerK), converting ceramide to ceramide-1-phosphate, is implicated both in NOX activation and enhanced eicosanoid production in neuronal cells. In the present study, we demonstrated that TNFα exposure of human SH-SY5Y neuroblastoma caused a profound increase in CerK activity. Depleting CerK activity using either siRNA or pharmacology completely negated NOX activation and eicosanoid biosynthesis yet, more importantly, rescued neuronal viability in the presence of TNFα. These findings provided evidence for a critical function of ceramide-1-phospate and thus CerK activity in directly linking sphingolipid metabolism to oxidative stress. This vital role of CerK in CNS inflammation could provide a novel therapeutic approach to intervene with the adverse consequences of a progressive CNS inflammation.


Assuntos
NADPH Oxidases/imunologia , Neuroblastoma/imunologia , Fosfotransferases (Aceptor do Grupo Álcool)/imunologia , Fator de Necrose Tumoral alfa/imunologia , Linhagem Celular Tumoral , Ceramidas/imunologia , Ceramidas/metabolismo , Eicosanoides/imunologia , Eicosanoides/metabolismo , Humanos , NADPH Oxidases/metabolismo , Neuroblastoma/metabolismo , Estresse Oxidativo , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Espécies Reativas de Oxigênio/imunologia , Espécies Reativas de Oxigênio/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
15.
J Neurosci Res ; 90(1): 229-42, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21932365

RESUMO

Inflammation accompanied by severe oxidative stress plays a vital role in the orchestration and progression of neurodegeneration prevalent in chronic and acute central nervous system pathologies as well as in aging. The proinflammatory cytokine tumor necrosis factor-α (TNFα) elicits the formation of the bioactive ceramide by stimulating the hydrolysis of the membrane lipid sphingomyelin by sphingomyelinase activities. Ceramide stimulates the formation of reactive oxygen species (ROS) and apoptotic mechanisms in both neurons and nonneuronal cells, establishing a link between sphingolipid metabolism and oxidative stress. We demonstrated in SH-SY5Y human neuroblastoma cells and primary cortical neurons that TNFα is a potent stimulator of Mg(2+) -dependent neutral sphingomyelinase (Mg(2+) -nSMase) activity, and sphingomyelin hydrolysis, rather than de novo synthesis, was the predominant source of ceramide increases. Mg(2+) -nSMase activity preceded an accumulation of ROS by a neuronal NADPH oxidase (NOX). Notably, TNFα provoked an NOX-dependent oxidative damage to sphingosine kinase-1, which generates sphingosine-1-phosphate, a ceramide metabolite associated with neurite outgrowth. Indeed, ceramide and ROS inhibited neurite outgrowth of dorsal root ganglion neurons by disrupting growth cone motility. Blunting ceramide and ROS formation both rescued sphingosine kinase-1 activity and neurite outgrowth. Our studies suggest that TNFα-mediated activation of Mg(2+) -nSMase and NOX in neuronal cells not only produced the neurotoxic intermediates ceramide and ROS but also directly antagonized neuronal survival mechanisms, thus accelerating neurodegeneration.


Assuntos
NADPH Oxidases/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/enzimologia , Esfingomielina Fosfodiesterase/metabolismo , Fator de Necrose Tumoral alfa/toxicidade , Animais , Apoptose/efeitos dos fármacos , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Ceramidas , Córtex Cerebral/citologia , Embrião de Galinha , Interações Medicamentosas , Inibidores Enzimáticos/farmacologia , Cones de Crescimento/efeitos dos fármacos , Cones de Crescimento/fisiologia , Humanos , Magnésio/metabolismo , Neuritos/efeitos dos fármacos , Neuritos/fisiologia , Neuroblastoma/patologia , Neurônios/citologia , Palmitatos/farmacologia , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , RNA Interferente Pequeno/farmacologia , Espécies Reativas de Oxigênio
16.
PLoS One ; 6(12): e28642, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22180787

RESUMO

Parasites of the nematode genus Anisakis are associated with aquatic organisms. They can be found in a variety of marine hosts including whales, crustaceans, fish and cephalopods and are known to be the cause of the zoonotic disease anisakiasis, a painful inflammation of the gastro-intestinal tract caused by the accidental consumptions of infectious larvae raw or semi-raw fishery products. Since the demand on fish as dietary protein source and the export rates of seafood products in general is rapidly increasing worldwide, the knowledge about the distribution of potential foodborne human pathogens in seafood is of major significance for human health. Studies have provided evidence that a few Anisakis species can cause clinical symptoms in humans. The aim of our study was to interpolate the species range for every described Anisakis species on the basis of the existing occurrence data. We used sequence data of 373 Anisakis larvae from 30 different hosts worldwide and previously published molecular data (n = 584) from 53 field-specific publications to model the species range of Anisakis spp., using a interpolation method that combines aspects of the alpha hull interpolation algorithm as well as the conditional interpolation approach. The results of our approach strongly indicate the existence of species-specific distribution patterns of Anisakis spp. within different climate zones and oceans that are in principle congruent with those of their respective final hosts. Our results support preceding studies that propose anisakid nematodes as useful biological indicators for their final host distribution and abundance as they closely follow the trophic relationships among their successive hosts. The modeling might although be helpful for predicting the likelihood of infection in order to reduce the risk of anisakiasis cases in a given area.


Assuntos
Anisakis/genética , Anisakis/isolamento & purificação , Organismos Aquáticos/parasitologia , Biodiversidade , Evolução Molecular , Geografia , Zoonoses/parasitologia , Algoritmos , Animais , Anisakis/classificação , Organismos Aquáticos/genética , Organismos Aquáticos/isolamento & purificação , Humanos , Modelos Teóricos , Especificidade da Espécie
17.
Cancer Biol Ther ; 10(11): 1126-36, 2010 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-20935456

RESUMO

The bioactive sphingolipid ceramide induces oxidative stress by disrupting mitochondrial function and stimulating NADPH oxidase (NOX) activity, both implicated in cell death mechanisms. Many anticancer chemotherapeutics (anthracyclines, Vinca alkaloids, paclitaxel, and fenretinide), as well as physiological stimuli such as tumor necrosis factor α (TNFα), stimulate ceramide accumulation and increase oxidative stress in malignant cells. Consequently, ceramide metabolism in malignant cells and, in particular the up-regulation of glucosylceramide synthase (GCS), has gained considerable interest in contributing to chemoresistance. We hypothesized that increases in GCS activity and thus glucosylceramide, the product of GCS activity, represents an important resistance mechanism in glioblastoma. In our study, we determined that increased GCS activity effectively blocked reactive oxygen species formation by NOX. We further showed, in both glioblastoma and neuroblastoma cells that glucosylceramide directly interfered with NOX assembly, hence delineating a direct resistance mechanism. Collectively, our findings indicated that pharmacological or molecular targeting of GCS, using non-toxic nanoliposome delivery systems, successfully augmented NOX activity, and improved the efficacy of known chemotherapeutic agents.


Assuntos
Glioblastoma/tratamento farmacológico , Glioblastoma/enzimologia , Glucosilceramidas/farmacologia , NADPH Oxidases/antagonistas & inibidores , Neuroblastoma/tratamento farmacológico , Neuroblastoma/enzimologia , Catalase/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Doxorrubicina/farmacologia , Resistencia a Medicamentos Antineoplásicos , Glioblastoma/patologia , Glucosilceramidas/metabolismo , Glucosiltransferases/antagonistas & inibidores , Glucosiltransferases/genética , Glucosiltransferases/metabolismo , Humanos , NADPH Oxidases/genética , NADPH Oxidases/metabolismo , Neuroblastoma/patologia , Estresse Oxidativo/efeitos dos fármacos , RNA Interferente Pequeno/administração & dosagem , RNA Interferente Pequeno/genética , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo , Fator de Necrose Tumoral alfa/farmacologia
18.
Mol Cell Neurosci ; 41(2): 274-85, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19344766

RESUMO

The proinflammatory cytokines TNFalpha and Il-1beta orchestrate the progression of CNS inflammation, which substantially contributes to neurodegeneration in many CNS pathologies. TNFalpha and Il-1beta stimulate actin filament reorganization in non-neuronal cells often accompanied by the formation of reactive oxygen species (ROS). Actin filament dynamics is vital for cellular plasticity, mitochondrial function, and gene expression despite being highly susceptible to oxidative damage. We demonstrated that, in neuronal cells, TNFalpha and Il-1beta stimulate a transient, redox-dependent reorganization of the actin cytoskeleton into lamellipodia under the regulation of Rac1 and a neuronal NADPH oxidase as the source of ROS. The persistent presence of intracellular ROS provoked oxidative damage (carbonylation) to actin coinciding with the loss of lamellipodia and arrest of cellular plasticity. Inhibition of NADPH oxidase activity or Rac1 abolished the adverse effects of cytokines. These findings suggest that oxidative damage to the neuronal actin cytoskeleton could represent a key step in CNS neurodegeneration.


Assuntos
Actinas/metabolismo , Citocinas , NADPH Oxidases/metabolismo , Neurônios , Estresse Oxidativo , Proteínas rac1 de Ligação ao GTP/metabolismo , Animais , Linhagem Celular , Citocinas/metabolismo , Citocinas/farmacologia , Citoesqueleto/metabolismo , Humanos , Inflamação/metabolismo , Interleucina-1beta/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Oxirredução , Espécies Reativas de Oxigênio/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
19.
Adv Exp Med Biol ; 644: 232-49, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19209826

RESUMO

Dynamics of actin filaments is pivotal to many fundamental cellular processes such as Dcytokinesis, motility, morphology, vesicle and organelle transport, gene transcription and senescence. In vivo kinetics of actin filament dynamics is far from the equilibrium in vitro and these profound differences are attributed to large number of regulatory proteins. In particular, proteins of the ADF/cofilin family greatly increase actin filament dynamics by severing filaments and enhancing depolymerization of ADP-actin monomers from their pointed ends. Cofilin binds cooperatively to a minor conformer of F-actin in which the subunits are slightly under rotated along the filament helical axis. At high stoichiometry of cofilin to actin subunits, cofilin actually stabilizes actin filaments. Many isoforms oftropomyosin appear to compete with ADF/cofilin proteins for binding to actin filaments. Tropomyosin isoforms studied to date prefer binding to the "untwisted" conformer of F-actin and through their protection and stabilization of F-actin, recruit myosin II and assemble different actin superstructures from the cofilin-actin filaments. However, some tropomyosin isoforms may synergize with ADF/cofilin to enhance filament dynamics, suggesting that the different isoforms of tropomyosins, many of which show developmental or tissue specific expression profiles, play major roles in the assembly and turnover of actin superstructures. Different actin superstructures can overlap both spatially and temporally within a cell, but can be differentiated from each other based upon their kinetic and kinematic properties. Furthermore, local regulation of ADF/cofilin activity through signal transduction pathways could be one mechanism to alter the dynamic balance in F-actin-binding of certain tropomyosin isoforms in subcellular domains.


Assuntos
Fatores de Despolimerização de Actina/química , Cofilina 1/química , Tropomiosina/fisiologia , Fatores de Despolimerização de Actina/metabolismo , Actinas/química , Trifosfato de Adenosina/química , Animais , Ligação Competitiva , Citoesqueleto/metabolismo , Humanos , Proteínas dos Microfilamentos/química , Modelos Biológicos , Miosina Tipo II/química , Ligação Proteica , Isoformas de Proteínas , Tropomiosina/química
20.
São Paulo; Perspectiva; 8 ed; 2003. 260 p. (Debates, 115).
Monografia em Português | LILACS, EMS-Acervo | ID: lil-622118
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA