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1.
J Cyst Fibros ; 22(1): 172-178, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35842291

RESUMO

The Dutch CF Foundation (NCFS) developed a quality improvement program, to assess and improve quality of care in all CF centers in The Netherlands. Criteria to assess quality of care from the patient perspective were defined, and quality of care was assessed by patients via online surveys and site visits. Recommendations were addressed to all centers to improve quality of care. Most recommendations were related to communicational issues. All centers were given the quality mark of the patient organisation, although two of them needed extra time to meet the lower limit of the core set of criteria. After two years, over 75 % of the recommendations given to the centers were fully or partly implemented, showing a high efficacy of the program.


Assuntos
Fibrose Cística , Humanos , Melhoria de Qualidade , Inquéritos e Questionários , Países Baixos
2.
ERJ Open Res ; 8(4)2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36382237

RESUMO

Background: Although short-term efficacy of lumacaftor/ivacaftor and tezacaftor/ivacaftor is clearly established in clinical trials, data on long-term effectiveness is limited. This registry-based cohort study assessed real-world longitudinal outcomes of F508del-homozygous people with cystic fibrosis (pwCF) ≥12 years, up to 3 years after the introduction of dual cystic fibrosis transmembrane conductance regulator (CFTR) modulators. Methods: Annual data (2010-2019) were retrieved from the Dutch Cystic Fibrosis Registry. Longitudinal trends of per cent predicted forced expiratory volume in 1 s (FEV1 % pred) decline, body mass index (BMI), BMI Z-score and intravenous antibiotic treatment duration before and after CFTR modulator initiation were assessed with linear and negative binomial mixed models. Results: We included 401 participants (41.9% female, baseline age 24.5 years (IQR 18.0-31.5 years), baseline mean±sd FEV1 70.5±23.4% pred). FEV1 decline improved from -1.36% pred per year to -0.48% pred per year after modulator initiation (change: 0.88% pred, 95% CI: 0.35-1.39%, p=0.001). This change was even 1.40% pred per year (95% CI: -0.0001-2.82%, p=0.050) higher in participants with baseline FEV1 <40% pred. In adults, annual BMI trend was not altered (change: 0.10 kg·m-2·year-1, 95% CI:-0.01-0.21, p=0.079). Annual BMI Z-score in children reversed from -0.08 per year before modulator treatment to 0.06 per year afterwards (change: 0.14 per year, 95% CI: 0.06-0.22, p<0.001). Intravenous antibiotic treatment duration showed a three-fold reduction in the first year after modulator initiation (incidence rate ratios (IRR): 0.28, 95% CI: 0.19-0.40, p<0.001), but the annual trend did not change in the subsequent years (IRR: 1.19, 95% CI: 0.94-1.50, p=0.153). Conclusion: Long-term effectiveness of dual CFTR modulator therapies on FEV1 decline, BMI and intravenous antibiotic treatment duration is less pronounced in a real-world setting than in clinical trials and varies considerably between pwCF and different baseline FEV1 levels.

3.
J Small Anim Pract ; 62(10): 866-873, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34029383

RESUMO

OBJECTIVES: To evaluate biomarkers of oxidative stress in dogs with copper-associated hepatitis (CAH) as compared with healthy controls, and to evaluate if these markers correlate with hepatic copper concentrations and hepatic histopathologic features. MATERIALS AND METHODS: Prospective study. Plasma reactive metabolite concentrations, plasma antioxidant potential, and plasma and urine isoprostane concentrations were determined in Labrador retrievers with copper-associated hepatitis (n=9) as well as in breed- and sex-matched (n=9) and age- and sex-matched (n=9) healthy control populations. Possible correlations between markers of oxidative stress and hepatic histopathological features also were investigated. RESULTS: Reactive metabolites (median, range) were over twofold greater in dogs with copper-associated hepatitis (87.2 RFU/µL, 60.9 to 185.6 RFU/µL) as compared to breed- and sex-matched (38.2 RFU/µL, 22.4 to 116.8 RFU/µL) and age- and sex-matched controls (32.0 RFU/µL, 18.5 to 127.4 RFU/µL). Antioxidant potential was decreased in copper-associated hepatitis dogs (6.5 TE/µL, 5.1 to 7.7 TE/µL) as compared to breed- and sex-matched controls (8.2 TE/µL, 5.3 to 11.8 TE/µL). Both reactive metabolite concentrations and the reactive metabolite to antioxidant potential ratio were positively correlated with hepatic copper concentrations. Plasma and urine isoprostanes were variable and not significantly different between populations. CLINICAL SIGNIFICANCE: Labrador retrievers with copper-associated hepatitis have altered oxidant status. Plasma reactive metabolite concentrations and the reactive metabolite to antioxidant potential ratio could be useful biomarkers. However, neither plasma nor urine isoprostanes were useful biomarkers for copper-associated hepatitis.


Assuntos
Doenças do Cão , Hepatite , Animais , Biomarcadores , Cobre , Cães , Estresse Oxidativo , Estudos Prospectivos
4.
J Cyst Fibros ; 18(3): 382-384, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30926323

RESUMO

The Dutch CF Foundation started to focus on scientific research thirteen years ago. The patient organization defined the patients perspective and unmet needs bottom-up, and through a structured process. The patients research priorities were matched with the research priorities of Dutch basic scientists and clinicians. The Dutch patient organization facilitated the process, in which mutual dependency between patients, scientists and clinicians is the keyword. The, at that time initiated dialogue, maintained. Subsequently a research program called "HIT CF" was composed and executed over five years. HIT CF was financially supported mainly by the patient community and some other stakeholders.


Assuntos
Atitude do Pessoal de Saúde , Atitude Frente a Saúde , Pesquisa Biomédica , Fibrose Cística/epidemiologia , Pesquisa/organização & administração , Pesquisa Biomédica/métodos , Pesquisa Biomédica/organização & administração , Pesquisa Biomédica/normas , Humanos , Avaliação das Necessidades , Países Baixos/epidemiologia , Avaliação de Resultados da Assistência ao Paciente , Participação do Paciente , Avaliação de Programas e Projetos de Saúde , Pesquisa Translacional Biomédica
5.
J Cyst Fibros ; 18(1): 54-63, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30146269

RESUMO

BACKGROUND: Newborn screening for cystic fibrosis (NBSCF) was introduced in the Dutch NBS program in 2011 with a novel strategy. METHODS: Dutch NBSCF consisted of four steps: immuno-reactive trypsin (IRT), Pancreatitis-associated Protein (PAP), DNA analysis by Inno-LiPa (35 mutations), extended gene analysis (EGA) as fourth step and as safety net. Only samples with two CFTR-variants were considered screen-positive, but samples with one disease-causing variant were considered also screen-positive from April 2013. The first 5 years of NBSCF were evaluated during a follow-up ranging from 2 to 6.8 years for sensitivity, specificity, positive predictive value (PPV), ratio of CF/Cystic Fibrosis Screen Positive infants with an Inconclusive Diagnosis (CFSPID) and median age at diagnosis, and were compared to other novel strategies for NBSCF and European Cystic Fibrosis Society (ECFS) Best Practice Standards of Care. RESULTS: NBSCF achieved a sensitivity of 90% (95% CI 82%-94%), specificity of 99.991% (95% CI 99.989%-99.993%), PPV of 63% (95% CI 55%-69%), CF/CFSPID ratio of 4/1, and median age at diagnosis of 22 days, if samples with two variants as well as samples with one disease-causing variant were considered screen-positive. CONCLUSION: The program achieved the goal to minimize the number of false positives and showed a favourable performance but sensitivity and CF/CFSPID ratio did not meet criteria of EFCS Best Standards of Care. Changed cut-off values for PAP and IRT and classification of R117H-7T/9T to non-pathogenic may improve sensitivity to ≥95% and CF/CFSPID ratio to 10/1. PPV is estimated to be around 60%.


Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística/genética , Fibrose Cística/diagnóstico , Triagem de Portadores Genéticos/métodos , Guias como Assunto , Mutação , Triagem Neonatal/normas , Sistema de Registros , Biomarcadores/sangue , Fibrose Cística/sangue , Fibrose Cística/epidemiologia , Regulador de Condutância Transmembrana em Fibrose Cística/análise , Análise Mutacional de DNA , Feminino , Humanos , Recém-Nascido , Masculino , Países Baixos/epidemiologia , Curva ROC , Reprodutibilidade dos Testes
6.
Int J Infect Dis ; 76: 35-37, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30201506

RESUMO

A 75-year-old woman with a history of immunosuppressive treatment for rheumatoid arthritis and non-Hodgkin lymphoma, was referred to our reference centre for treatment of tenosynovitis caused by Mycobacterium malmoense, which had disseminated due to immunosuppressive therapy. This rare diagnosis was made after years of treatment for supposed rheumatoid arthritis. The patient presented with relapsing tenosynovitis with wounds on her right middle finger and wounds on her left lower leg, despite 3 months of adequate therapy (rifampicin+ethambutol+clarithromycin). Therapy was intensified with amikacin, clofazimine, moxifloxacin, and interferon-gamma due to the lack of response. Amputation of the right middle finger was necessary due to advanced disease. Treatment was further complicated by a paradoxical reaction, requiring prednisone treatment, which ultimately led to cure.


Assuntos
Hospedeiro Imunocomprometido , Infecções por Mycobacterium não Tuberculosas/diagnóstico por imagem , Infecções por Mycobacterium não Tuberculosas/imunologia , Idoso , Antibacterianos/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Feminino , Dedos/microbiologia , Dedos/cirurgia , Humanos , Imunossupressores/uso terapêutico , Linfoma não Hodgkin/tratamento farmacológico , Micobactérias não Tuberculosas/isolamento & purificação
8.
Nutr Clin Pract ; 32(1): 130-132, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27094687

RESUMO

BACKGROUND: Height evaluation is an integral part of cystic fibrosis (CF) care. Height is compared with reference values by converting it to height-for-age (HFA) z scores. However, HFA z scores do not adjust for genetic potential (ie, target height [TH]), which could result in an incorrect estimation of the height. MATERIALS AND METHODS: To evaluate the magnitude of this potential problem, we assessed the agreement between HFA and HFA-adjusted-for-TH (HFA/TH) z scores in 474 Dutch children with CF. RESULTS: In this study sample, HFA z scores were -0.07 (95% confidence interval, -0.02 to -0.12) lower than HFA/TH z scores. When HFA and HFA/TH z scores were subdivided into 4 categories (≥0, <0 and ≥-1, <-1 and ≥-2, and ≤-2), a moderate agreement was found. HFA z scores were classified lower than HFA/TH z scores in 21% of the measurements and higher in 15% of the measurements. CONCLUSION: In clinical routine, height evaluation based on HFA may result in underestimation or overestimation of height growth, which may induce inappropriate nutrition interventions.


Assuntos
Fenômenos Fisiológicos da Nutrição do Adolescente , Fenômenos Fisiológicos da Nutrição Infantil , Fibrose Cística/fisiopatologia , Erros de Diagnóstico/prevenção & controle , Transtornos do Crescimento/diagnóstico , Desnutrição/diagnóstico , Estado Nutricional , Adolescente , Desenvolvimento do Adolescente , Fatores Etários , Estatura , Criança , Desenvolvimento Infantil , Pré-Escolar , Estudos Transversais , Transtornos do Crescimento/etiologia , Transtornos do Crescimento/fisiopatologia , Humanos , Desnutrição/etiologia , Desnutrição/fisiopatologia , Países Baixos , Avaliação Nutricional , Sistema de Registros , Índice de Gravidade de Doença
9.
Acta Anaesthesiol Scand ; 60(2): 158-65, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26346761

RESUMO

BACKGROUND: Severe blood loss is a common complication of craniofacial reconstruction surgery. The antifibrinolytic ε-aminocaproic acid (EACA) reduces transfusion requirements in children undergoing cardiac surgery and in older children undergoing spine surgery. Tranexamic acid (TXA), another antifibrinolytic with a similar mechanism of action, has been shown to reduce blood loss and transfusion requirements in children undergoing craniofacial surgery. However, TXA has been associated with an increase in post-operative seizures and is more expensive than EACA. There is currently little published data evaluating the efficacy of EACA in children undergoing craniofacial surgery. METHODS: This is a retrospective study of prospectively collected data from our craniofacial perioperative registries for children under 6 years of age who underwent anterior or posterior cranial vault reconstruction. We compared calculated blood loss, blood donor exposures, and post-operative drain output between subjects who received EACA and those who did not. RESULTS: The registry queries returned data from 152 subjects. Eighty-six did not receive EACA and 66 received EACA. The EACA group had significantly lower calculated blood loss (82 ± 43 vs. 106 ± 63 ml/kg, P = 0.01), fewer intraoperative blood donor exposures (median 2, interquartile range 1-2 vs. median 2, interquartile range 1-3; P = 0.02) and lower surgical drain output in the first post-operative 24 h (28 ml/kg vs. 37 ml/kg, P = 0.001) than the non-EACA group. CONCLUSION: In this analysis of prospectively captured observational data, EACA administration was associated with less calculated blood loss, intraoperative blood donor exposures, and post-operative surgical drain output.


Assuntos
Ácido Aminocaproico/administração & dosagem , Antifibrinolíticos/administração & dosagem , Perda Sanguínea Cirúrgica/prevenção & controle , Transfusão de Sangue , Craniotomia , Procedimentos de Cirurgia Plástica , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Estudos Retrospectivos
10.
J Electromyogr Kinesiol ; 24(4): 465-72, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24845169

RESUMO

This study compares muscle fiber conduction velocities estimated using surface electromyography during isometric maximal voluntary contraction in different stages of diabetic neuropathy. Eighty-five adults were studied: 16 non-diabetic individuals and 69 diabetic patients classified into four neuropathy stages, defined by a fuzzy expert system: absent (n=26), mild (n=21), moderate (n=11) and severe (n=11). Average muscle fiber conduction velocities of gastrocnemius medialis, tibialis anterior, vastus lateralis and biceps femoris were assessed using linear array electrodes, and were compared by ANOVA. Conduction velocities were significantly decreased in the moderate neuropathy group for the vastus lateralis compared to other groups (from 18% to 21% decrease), and were also decreased in all diabetic groups for the tibialis anterior (from 15% to 20% from control group). Not only the distal anatomical localization of the muscle affects the conduction velocity, but also the proportion of muscle fiber type, where the tibialis anterior with greater type I fiber proportion is affected earlier while the vastus lateralis with greater type II fiber proportion is affected in later stages of the disease. Generally, the muscles of the lower limb have different responsiveness to the effects of diabetes mellitus and show a reduction in the conduction velocity as neuropathy progresses.


Assuntos
Neuropatias Diabéticas/fisiopatologia , Eletromiografia/métodos , Contração Isométrica/fisiologia , Músculo Esquelético/fisiologia , Idoso , Estudos de Casos e Controles , Progressão da Doença , Eletrodos , Feminino , Lógica Fuzzy , Humanos , Extremidade Inferior/fisiopatologia , Masculino , Pessoa de Meia-Idade , Doenças do Sistema Nervoso Periférico/fisiopatologia , Músculo Quadríceps/fisiopatologia , Coxa da Perna/fisiologia
13.
J Thorac Cardiovasc Surg ; 134(3): 608-12, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17723806

RESUMO

OBJECTIVE: Mediastinal shift and rotation after pneumonectomy can lead to severe symptomatic airway compression. Historically, a variety of treatments, such as muscle-flap transposition, pericardial fixation, and plombage, have been used. In this study we retrospectively evaluated the effectiveness of intrathoracic tissue expansion in postpneumonectomy syndrome. METHODS: Since 1990, our center has used tissue expanders as plombage in patients with postpneumonectomy syndrome. Between 1990 and 2005, a total of 20 patients were treated. The outcome was evaluated by using preoperative, perioperative, and postoperative bronchoscopy and imaging studies. Patient satisfaction was determined with a validated questionnaire. RESULTS: In 19 of the 20 patients, up to 3 tissue expanders were placed and filled within the pleural cavity. Access to the pleural cavity could not be obtained in 1 patient because of adhesions. Perioperative and postoperative bronchoscopic scans demonstrated decompression of the left main bronchus in 16 (84%) of 19 patients. On discharge, all patients reported improvement of their respiratory symptoms. Six (32%) patients required reoperation because of herniation (n = 2), luxation (n = 1), inadequate positioning (n = 2), and leakage of the tissue expander (n = 4). In 4 patients additional filling was performed in the outpatient clinic, with immediate improvement of respiratory distress. CONCLUSION: Use of tissue expanders in adults with postpneumonectomy syndrome is an effective means of decompressing the remaining bronchus, thereby leading to a significant improvement in respiratory symptoms. Although 32% of patients required reoperation for complications, each complication was readily correctable.


Assuntos
Mediastino/anormalidades , Pneumonectomia/efeitos adversos , Transtornos Respiratórios/etiologia , Transtornos Respiratórios/cirurgia , Dispositivos para Expansão de Tecidos , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Síndrome
14.
Eur J Cardiothorac Surg ; 26(1): 202-8, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15201002

RESUMO

Due to its localisation in the apex of the lung with invasion of the lower part of the brachial plexus, first ribs, vertebrae, subclavian vessels or stellate ganglion, a superior sulcus tumour causes characteristic symptoms, like arm or shoulder pain or Horner's syndrome. If rib invasion is the only feature, lysis of the rib must be evident on the chest radiograph; otherwise the tumour cannot be defined as a Pancoast tumour. It is important to adequately stage the tumour, because staging significantly influences survival. Survival is better for T3 than T4 tumours and mediastinal lymph node involvement has been found to be a negative prognostic factor. Also Horner's syndrome and incompleteness of resection worsen survival. The management of superior sulcus tumours has evolved over the past 50 years. Before 1950 it was considered to be inoperable and uniformly fatal. Shaw and Paulson introduced combined modality treatment and for many years, this combination of radiotherapy and surgery was the treatment of choice with a mean 5-year survival of approximately 30%. Postoperative radiotherapy or brachytherapy does not improve survival in patients with complete or incomplete resection. The tumour can be resected through the classic posterior Shaw-Paulson approach or the newer anterior transcervical approach, introduced by Dartevelle. This method facilitates better exposure of the extreme apex of the lung, brachial plexus and subclavian vessels. Regarding the extent of pulmonary resection, en bloc resection of the involved ribs with a lobectomy is recommended. Recent multimodality studies, involving chemoradiotherapy and surgical resection, show promising results regarding completeness of resection, local recurrence and survival, provided that appropriate staging has been carried out. However, careful patient selection and adequate perioperative management with protection of the bronchial stump or anastomosis are important to achieve reasonable rates of morbidity and mortality. As brain metastases remain one of the most common forms of relapse, further studies are needed to examine the role of prophylactic cranial irradiation in patients with complete resection. Also the addition of other chemotherapy agents or biologic agents such as angiogenesis inhibitors or tyrosine kinase inhibitors gives a new perspective in the treatment of Pancoast tumours.


Assuntos
Síndrome de Pancoast/cirurgia , Terapia Combinada , Humanos , Recidiva Local de Neoplasia , Estadiamento de Neoplasias , Síndrome de Pancoast/diagnóstico , Síndrome de Pancoast/patologia , Prognóstico , Análise de Sobrevida , Resultado do Tratamento
15.
Exp Neurol ; 166(1): 65-82, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11031084

RESUMO

Activation of the metabotropic glutamate receptor (mGluR) system can prevent free radical, nitric oxide (NO)-induced programmed cell death (PCD). To investigate the mechanisms utilized by the mGluR system to regulate the induction of PCD, we examined the course of PCD in real time in individual, living, primary hippocampal neurons. We assessed both phosphatidylserine (PS) externalization, an early event in PCD, and DNA fragmentation during NO toxicity and mGluR modulation to determine the individual contributions of PS externalization and genomic DNA fragmentation during neuronal PCD. Exposure to the NO donors (300 microM SNP or 300 microM NOC-9) induced PCD in approximately 75% of neurons over a 24-h period. The externalization of PS in neurons increased to 21 +/- 2% as early as 3 h following NO exposure and then increased to 80 +/- 2% over a 24-h period. The externalization of PS was independent of the loss of membrane integrity. Agonists for individual mGluR subgroups were equally able to prevent NO-induced neuronal death and DNA degradation, yet they possessed differential abilities to regulate PS externalization. The group I agonist DHPG (750 microM) and the group III agonist L-AP4 (750 microM) both prevented and reversed NO-induced PS externalization. In contrast, activation of group II subtypes using L-CCG-I (750 microM) did not prevent PS externalization. Employing an experimental model that independently led to the externalization of PS residues, we demonstrated that PS externalization does not immediately impact on neuronal survival. Yet, subsequent neuronal survival may ultimately depend upon preventing PS externalization to avoid neuronal tagging for phagocytosis. Since group I and III mGluR subtypes possess the unique ability to maintain genomic integrity and membrane PS asymmetry, these agents may provide superior overall protection against NO-induced neuronal injury.


Assuntos
Apoptose/fisiologia , Sobrevivência Celular/fisiologia , Degeneração Neural/induzido quimicamente , Neurônios/metabolismo , Fármacos Neuroprotetores/metabolismo , Receptores de Glutamato Metabotrópico/metabolismo , Animais , Animais Recém-Nascidos , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Agonistas de Aminoácidos Excitatórios/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Hipocampo/patologia , Degeneração Neural/tratamento farmacológico , Degeneração Neural/fisiopatologia , Neurônios/efeitos dos fármacos , Neurônios/patologia , Fosfatidilserinas/genética , Fosfatidilserinas/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores de Glutamato Metabotrópico/agonistas , Receptores de Glutamato Metabotrópico/antagonistas & inibidores , Recuperação de Função Fisiológica/efeitos dos fármacos , Recuperação de Função Fisiológica/fisiologia
16.
Cell Mol Neurobiol ; 20(3): 383-400, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10789835

RESUMO

1. As a free radical, nitric oxide (NO) may be toxic to neurons through mechanisms that directly involve DNA damage. Lubeluzole, a novel benzothiazole compound, has recently been demonstrated to be neuroprotective through the signal transduction pathways of NO. We therefore examined whether neuroprotection by lubeluzole was dependent upon the molecular pathways of programmed cell death (PCD). 2. In primary hippocampal neurons, evidence of PCD was determined by hematoxylin and eosin (H&E) stain, transmission electron microscopy, and annexin-V binding. NO administration with the NO generators sodium nitroprusside (300 microM) or SIN-1 (300 microM) directly induced PCD. 3. Neurons positive for PCD increased from 22+/-3% (untreated) to 72+/-3% (NO) over a 24-hr period. Coadministration of NO and lubeluzole (750 nM), a neuroprotective concentration, actively decreased PCD expression on H&E stain from 72+/-3% (NO only) to 25+/-3% (NO and lubeluzole). Significant reduction in DNA fragmentation by lubeluzole also was evident on electron microscopy. Application of lubeluzole in concentrations that were not neuroprotective or administration of the biologically inactive R-isomer did not significantly alter NO-induced PCD, suggesting that neuroprotection by lubeluzole was intimately linked to the modulation of PCD. Lubeluzole also was able to prevent the initial stages of cellular membrane inversion labeled with annexin-V binding, an early and sensitive indicator of PCD. Interestingly, the critical period for lubeluzole to reverse PCD induction appeared to be within the first 4 hr following NO exposure. 4. Further investigation into the neuroprotective pathways that alter PCD may provide greater insight into the molecular mechanisms that ultimately determine neuronal injury.


Assuntos
Apoptose/fisiologia , Hipocampo/citologia , Neurônios/citologia , Animais , Anexina A5/análise , Apoptose/efeitos dos fármacos , Biomarcadores , Membrana Celular/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Fragmentação do DNA , Molsidomina/análogos & derivados , Molsidomina/farmacologia , Neurônios/química , Fármacos Neuroprotetores/farmacologia , Óxido Nítrico/metabolismo , Doadores de Óxido Nítrico/farmacologia , Nitroprussiato/farmacologia , Fosfatidilserinas/metabolismo , Piperidinas/farmacologia , Ratos , Ratos Sprague-Dawley , Tiazóis/farmacologia , Vasodilatadores/farmacologia
17.
J Neurosci Res ; 59(4): 568-80, 2000 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-10679797

RESUMO

The ability to elucidate the molecular mechanisms that modulate programmed cell death (PCD) may provide the crucial clues to unravel the cellular basis of neurodegenerative disorders. Employing both a novel assay to follow serially PCD in individual living neurons and the neuroprotective agent lubeluzole as an investigative tool, we examined the development of nitric oxide (NO)-induced PCD over time through the reversible annexin V labelling of membrane phosphatidylserine (PS) exposure and the electron microscopy of genomic DNA in primary rat hippocampal neurons. Exposure to the NO generators SNP (300 microM) or NOC-9 (300 microM) alone increased annexin V-positive neurons in the population from 7% +/- 4% in untreated cultures to 13% +/- 4% at 1 hr and to 61% +/- 5% at 24 hr. Administration of a neuroprotective concentration of lubeluzole (750 nM) at the time of NO exposure initially prevented the exposure of PS residues, but consistently maintained DNA integrity over a 24 hr period. During posttreatment paradigms of lubeluzole (750 nM) at 2, 4, and 6 hr following NO exposure, progression of membrane PS inversion was reversed and subsequently suppressed over a 24 hr course. Our work illustrates that neuronal PCD is composed of at least two physiologically distinct and separate pathways that consist of the externalization of membrane PS residues and the independent maintenance of genomic DNA integrity. In addition, neuronal injury is fluid and reversible in nature, suggesting a "window of opportunity" for the repair and reversal of neurons yet to be committed to PCD.


Assuntos
Apoptose/fisiologia , DNA/metabolismo , Neurônios/fisiologia , Fármacos Neuroprotetores/farmacologia , Fosfatidilserinas/metabolismo , Piperidinas/farmacologia , Tiazóis/farmacologia , Animais , Animais Recém-Nascidos , Anexina A5/farmacologia , Apoptose/efeitos dos fármacos , Biomarcadores , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Núcleo Celular/efeitos dos fármacos , DNA/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Sequestradores de Radicais Livres/farmacologia , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/ultraestrutura , Óxido Nítrico/farmacologia , Óxido Nítrico/fisiologia , Ratos , Ratos Sprague-Dawley , Triazenos/farmacologia
18.
J Neurobiol ; 40(2): 171-84, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10413448

RESUMO

Neuronal injury is intricately linked to the activation of three distinct neuronal endonucleases. Since these endonucleases are exquisitely pH dependent, we investigated in primary rat hippocampal neurons the role of intracellular pH (pH(i)) regulation during nitric oxide (NO)-induced toxicity. Neuronal injury was assessed by both a 0.4% Trypan blue dye exclusion survival assay and programmed cell death (PCD) with terminal deoxynucleotidyl transferase nick-end labeling (TUNEL) 24 h following treatment with the NO generators sodium nitroprusside (300 microM), 3-morpholinosydnonimine (300 microM), or 6-(2-hyrdroxy-1-methyl-2-nitrosohydrazino)-N-methyl-1-hex anamine (300 microM). The pH(i) was measured using the fluorescent probe BCECF. NO exposure yielded a rapid intracellular acidification during the initial 30 min from pH(i) 7.36 +/- 0.01 to approximately 7.00 (p <.0001). Within 45 min, a biphasic alkaline response was evident, with pH(i) reaching 7.40 +/- 0.02, that was persistent for a 6-h period. To mimic the effect of NO-induced acidification, neurons were acid-loaded with ammonium ions to yield a pH(i) of 7.09 +/- 0.02 for 30 min. Similar to NO toxicity, neuronal survival decreased to 45 +/- 2% (24 h) and DNA fragmentation increased to 58 +/- 8% (24 h) (p <.0001). Although neuronal caspases did not play a dominant role, neuronal injury and the induction of PCD during intracellular acidification were dependent upon enhanced endonuclease activity. Furthermore, maintenance of an alkaline pH(i) of 7.60 +/- 0.02 during the initial 30 min of NO exposure prevented neuronal injury, suggesting the necessity for the rapid but transient induction of intracellular acidification during NO toxicity. Through the identification of the critical role of both NO-induced intracellular acidification and the induction of the neuronal endonuclease activity, our work suggests a potential regulatory trigger for the prevention of neuronal degeneration.


Assuntos
Apoptose/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Líquido Intracelular/fisiologia , Neurônios/química , Ácido Nítrico/toxicidade , Triazenos , Animais , Apoptose/fisiologia , Caspases/fisiologia , Fragmentação do DNA , Endonucleases/antagonistas & inibidores , Endonucleases/fisiologia , Fluoresceínas , Corantes Fluorescentes , Hipocampo/citologia , Hidrazinas/farmacologia , Molsidomina/análogos & derivados , Molsidomina/farmacologia , Proteínas do Tecido Nervoso/antagonistas & inibidores , Proteínas do Tecido Nervoso/fisiologia , Neurônios/citologia , Doadores de Óxido Nítrico/toxicidade , Nitroprussiato/toxicidade , Compostos Nitrosos/farmacologia , Compostos de Amônio Quaternário/farmacologia , Ratos , Ratos Sprague-Dawley
19.
Neurosci Lett ; 264(1-3): 17-20, 1999 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-10320003

RESUMO

Invoking the modulation of parallel cellular pathways, the G-protein metabotropic glutamate receptors (mGluRs) and nitric oxide (NO) have been shown to require a host of signal transduction pathways to modulate neuronal programmed cell death (PCD). Since the cysteine protease caspase-3 (CPP32) is one of the principal mediators of PCD in several nonneuronal cell systems, we investigated whether CPP32 activity was linked to both NO induced PCD and mGluR neuroprotection. We demonstrate that NO directly increases the activity of CPP32 by approximately 400% over a 6 h period that is necessary, at least in part, for the generation of neuronal PCD. Activation of only Group I mGluRs completely ameliorates the induction of CPP32 activity by NO and prevents the induction of PCD.


Assuntos
Inibidores de Caspase , Hipocampo/enzimologia , Neurônios/enzimologia , Óxido Nítrico/farmacologia , Receptores de Glutamato Metabotrópico/fisiologia , Animais , Apoptose/fisiologia , Caspase 3 , Caspases/metabolismo , Indução Enzimática/fisiologia , Hipocampo/citologia , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Ratos , Ratos Sprague-Dawley
20.
J Histochem Cytochem ; 47(5): 661-72, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10219058

RESUMO

Destruction of neurons through the genetically directed process of programmed cell death (PCD) is an area of intense interest because this is the underlying mechanism in a variety of developmental and neurodegenerative diseases. The ability to identify and track viable neurons subjected to PCD could be invaluable in development of strategies to prevent or reverse the downstream mechanisms of neuronal PCD. We have developed a novel assay for PCD in viable, adherent cells using annexin V labeling. Annexin V binds to the highly negatively charged plasma membrane phosphatidylserine residues that undergo membrane translocation during PCD. Current annexin V techniques are almost exclusively restricted to flow cytometric analysis. Our unique technique permits repeated examination of individual viable neurons without altering their survival. Correlation with electron microscopy and dye exclusion assays demonstrate both sensitivity and specificity for our method to detect PCD. To our knowledge, this is the first account of a technique that positively identifies PCD in viable, adherent cells.


Assuntos
Apoptose , Neurônios/citologia , Animais , Animais Recém-Nascidos , Anexina A5/metabolismo , Núcleo Celular/ultraestrutura , Sobrevivência Celular , Microscopia Eletrônica , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neurônios/ultraestrutura , Óxido Nítrico/farmacologia , Fosfatidilserinas/metabolismo , Ratos , Ratos Sprague-Dawley , Fatores de Tempo
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