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1.
Exp Lung Res ; 46(1-2): 32-43, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31941389

RESUMO

Airway inflammation (assessed by exhaled nitric oxide (eNO)) increases after a single high-fat meal (HFM), yet this response may be modified by airway stretch and baseline eNO level.Purpose: The purpose of this study was to investigate whether deep inspirations (DIs) would attenuate airway inflammation post-HFM and whether this is modulated by baseline eNO level.Methods: A total of sixteen healthy college-aged participants completed a randomized cross-over study with 8 lower eNO (14.8 ± 2.0 ppb: 3 M/5F; age: 22.0 ± 2.2 yrs) and 8 higher eNO (29.3 ± 11.6 ppb 5 M/3F; age: 22.5 ± 2.6 yrs) participants. All participants completed a control (CON) condition (no DIs pre-HFM) and DI condition (60 DI's to total lung capacity immediately pre-HFM) after an overnight fast. The primary outcome was eNO. Participants had 20 minutes to consume the HFM (1 g fat/1 kg body weight) and eNO was performed at 2- and 4- hours post-HFM. To determine whether baseline eNO levels impacted the effect of DI's, a median split was performed on their baseline eNO level.Results: There was a significant increase in eNO as a main effect of time (p < 0.001). However when analyzing the potential effect of baseline eNO, there was no significant increase in eNO post-HFM in the higher eNO group in the DI condition (p = 0.54). DIs modified the eNO response to a HFM in the group with a higher baseline eNO value.Conclusions: These data display a possible bronchoprotective protect of DIs against postprandial airway inflammation in participants with higher initial eNO level.


Assuntos
Inalação/fisiologia , Óxido Nítrico/metabolismo , Pneumonia/metabolismo , Pneumonia/fisiopatologia , Período Pós-Prandial/fisiologia , Adulto , Testes Respiratórios/métodos , Estudos Cross-Over , Feminino , Humanos , Masculino , Projetos Piloto , Sistema Respiratório/metabolismo , Sistema Respiratório/fisiopatologia , Adulto Jovem
2.
J Vet Pharmacol Ther ; 41(2): 340-348, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29057479

RESUMO

Ketoprofen is a nonsteroidal anti-inflammatory and analgesic agent that nonselectively inhibits cyclooxygenase, with both COX-1 and COX-2 inhibition. Recent studies on COX receptor expression in reptiles suggest that nonselective COX inhibitors may be more appropriate than more selective inhibitors in some reptiles, but few pharmacokinetic studies are available. The goal of this study was to determine single- and multidose (three consecutive days) pharmacokinetics of racemic ketoprofen administered intravenously and intramuscularly at 2 mg/kg in healthy juvenile loggerhead turtles (Caretta caretta). The S-isomer is the predominant isomer in loggerhead sea turtles, similar to most mammals, despite administration of a 50:50 racemic mixture. Multidose ketoprofen administration demonstrated no bioaccumulation; therefore, once-daily dosing will not require dose adjustment over time. S-isomer pharmacokinetic parameters determined in this study were Cmax of 10.1 µg/ml by IM injection, C0 of 13.4 µg/ml by IV injection, AUC of 44.7 or 69.4 µg*hr/ml by IM or IV injection, respectively, and T½ of 2.8 or 3.6 hr by IM or IV injection, respectively. Total ketoprofen plasma concentrations were maintained for at least 12 hr above concentrations determined to be effective for rats and humans. A dose of 2 mg/kg either IM or IV every 24 hr is likely appropriate for loggerhead turtles.


Assuntos
Anti-Inflamatórios não Esteroides/farmacocinética , Cetoprofeno/farmacocinética , Tartarugas/metabolismo , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Esquema de Medicação/veterinária , Feminino , Injeções Intramusculares/veterinária , Injeções Intravenosas/veterinária , Cetoprofeno/administração & dosagem
3.
J Fish Dis ; 39(3): 277-83, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25864868

RESUMO

Monogenean parasite infestations are common in captive marine teleosts, and are generally found on the skin and gills. This report describes an unusual pathological presentation of exuberant granulation tissue of the gills, suspected to be related to Neobenedenia infestation in two cobia housed together at a North Carolina aquarium.


Assuntos
Animais de Zoológico/parasitologia , Doenças dos Peixes/parasitologia , Tecido de Granulação/parasitologia , Trematódeos/fisiologia , Infecções por Trematódeos/veterinária , Animais , Brânquias/parasitologia , Perciformes/parasitologia , Infecções por Trematódeos/parasitologia
4.
Eur J Cancer Care (Engl) ; 24(6): 812-7, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26094701

RESUMO

This pilot study investigated feasibility and preliminary efficacy of a high-intensity functional training (HIFT) group-exercise programme among adult cancer survivors within 5 years of last cancer treatment. Eight participants were assigned to a 5-week, 3 days/week HIFT intervention with four testing sessions and 12 workouts along with mobility and stretching exercises. Feasibility was assessed by initiation, adherence, and acceptability. Efficacy was determined by changes from baseline to post-test in health-related quality of life, body composition and functional movement. The recruitment rate was 80% and the adherence rate was 75%. Significant improvements were found for emotional functioning (P = 0.042) and body composition (lean mass +3.8 ± 2.1 kg, P = 0.008; fat mass -3.3 ± 1.0 kg, P = 0.001; body fat percentage -4.7 ± 1.2%, P < 0.001). Participants also significantly improved on five of seven functional movements: balance (P = 0.032), carrying a weighted object (P = 0.004), lower body strength and power (P = 0.009), aerobic capacity and endurance (P = 0.039), and perceived difficulty for flexibility (P = 0.012). Five weeks of HIFT training was well-received and feasible for most cancer survivors, and effective for improving emotional functioning, body composition and functional movement.


Assuntos
Composição Corporal , Terapia por Exercício/métodos , Força Muscular , Neoplasias/reabilitação , Sobreviventes , Tecido Adiposo , Estudos de Viabilidade , Feminino , Nível de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Resistência Física , Projetos Piloto , Equilíbrio Postural , Qualidade de Vida , Resultado do Tratamento
5.
Eur J Appl Physiol ; 114(4): 675-82, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24368552

RESUMO

INTRODUCTION: Many environmental and dietary influences can cause immune cells to produce biological mediators that increase airway inflammation. A high-fat meal (HFM) is one stimulus that increases airway inflammation in healthy individuals. Supplementation with omega-3 fatty acids can reduce inflammation systemically and may be beneficial to the airways. PURPOSE: To determine if omega-3 fatty acid supplementation via fish oil would mitigate the airway inflammatory response induced by a single HFM. METHODS: Seventeen non-asthmatic men (22 ± 2 years.) were supplemented with 3,000 mg × day(-1) fish oil or a placebo for 3 weeks. Fractional exhaled nitric oxide (FENO; a marker of airway inflammation), impulse oscillometry (a measure of respiratory impedance), pulmonary function, and triglycerides were measured prior to and 2 h following a HFM. RESULTS: Following a HFM, triglycerides increased in both fish oil and placebo groups compared to pre-HFM (~59 and ~49 %, respectively, p < 0.05). The percent increase in FENO was greater in the placebo group compared to the fish oil group (25.7 ± 16.7 vs. -1.99 ± 10.5 %, respectively, p < 0.05). A significant correlation was observed between blood triglycerides and FENO in the placebo group (r = 0.61; p < 0.05), but not the fish oil group (p = 0.21). CONCLUSION: A single HFM increases airway inflammation and omega-3 fatty acid supplementation via fish oil protects against HFM associated changes in airway health.


Assuntos
Anti-Inflamatórios/uso terapêutico , Gorduras na Dieta/efeitos adversos , Ácidos Graxos Ômega-3/uso terapêutico , Fenômenos Fisiológicos Respiratórios/efeitos dos fármacos , Sistema Respiratório/metabolismo , Anti-Inflamatórios/administração & dosagem , Gorduras na Dieta/administração & dosagem , Suplementos Nutricionais , Ácidos Graxos Ômega-3/administração & dosagem , Humanos , Inflamação/etiologia , Inflamação/metabolismo , Inflamação/prevenção & controle , Masculino , Refeições , Óxido Nítrico/metabolismo , Sistema Respiratório/patologia , Método Simples-Cego , Triglicerídeos/sangue , Adulto Jovem
7.
J Vet Pharmacol Ther ; 37(4): 382-7, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24483951

RESUMO

This study was designed to investigate the pharmacokinetics of meloxicam, an oxicam class, nonsteroidal anti-inflammatory drug (NSAID), in ferrets. We determined the pharmacokinetic properties of a single subcutaneous dose of meloxicam (0.2 mg/kg) in nine male and nine female ferrets. Blood samples were collected by venipuncture of the cranial vena cava into heparinized syringes. Plasma meloxicam concentrations were determined by high-pressure liquid chromatography (HPLC). Pharmacokinetic variables were calculated using nonlinear mixed-effects modeling to take advantage of the population-based sampling scheme and to minimize sample volume collected per animal. Maximum plasma concentration, volume of distribution per absorption, and elimination half-life were 0.663 µg/mL, 0.21 L, and 11.4 h, respectively, for females and 0.920 µg/mL, 0.35 L, and 17.8 h, respectively, for males. Significant differences were found in each of the above parameters between male and female ferrets. Systemic clearance per absorption was not affected by gender and was 13.4 mL/h. Analgesic efficacy was not evaluated, but plasma meloxicam concentrations achieved in these animals are considered effective in other species. Sex differences in the pharmacokinetic behavior of meloxicam should be taken into consideration when treating ferrets.


Assuntos
Anti-Inflamatórios não Esteroides/farmacocinética , Furões/metabolismo , Tiazinas/farmacocinética , Tiazóis/farmacocinética , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Feminino , Furões/sangue , Meia-Vida , Injeções Subcutâneas , Masculino , Meloxicam , Fatores Sexuais , Tiazinas/administração & dosagem , Tiazóis/administração & dosagem
8.
J Fish Dis ; 36(4): 389-99, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23134071

RESUMO

Rapid changes in salinity, as with other environmental stressors, can have detrimental effects on fish and may trigger increased susceptibility to disease. However, the precise mechanisms of these effects are not well understood. We examined the effects of sudden increases or decreases in salinity on teleost immune function using Nile tilapia, Oreochromis niloticus (L.), as the fish model in a battery of bioassays of increasing immune system specificity. Two different salinity experiments were performed: one of increasing salinity (0 to 5, 10 and 20 g L(-1) ) and one of decreasing salinity (20 to 15, 10 and 5 g L(-1) ). Histopathology of anterior kidney, gills, gonads, intestines and liver of exposed fish was performed, but no remarkable lesions were found that were attributable to the salinity treatment regimes. The spleen was removed from each fish for analysis of cytokine expression, and peripheral blood was used for haematology, cortisol and phagocytosis assays. In the increasing salinity experiments, no significant changes were observed in any immune system assays. However, in the decreasing salinity experiments, lymphopenia, neutrophilia and monocytosis were observed in the peripheral blood without modification of the packed cell volume, plasma protein or plasma cortisol levels. Phagocytosis was increased in response to decreases in salinity from 20 g L(-1) to 15 g L(-1) , 10 g L(-1) and 5 g L(-1) , whereas phagocytic index was not significantly altered. Transforming growth factor-ß (TGF-ß) transcription increased during the same decreases in salinity. However, the TGF-ß value at 5 g L(-1) was less than those in the 15 and 10 g L(-1) salinity treatments. Interleukin-1ß (IL-1ß) transcription did not significantly respond to either salinity regime. In total, acute salinity changes appeared to trigger reactive dysregulation of the immune response in tilapia, a situation which, when combined with additional co-occurring stressors such as sudden changes in temperature and/or dissolved oxygen, could make fish more susceptible to infectious diseases. Accordingly, these findings may help to explain how sudden environmental changes may initiate disease outbreaks and lead to critical declines in cultured or wild fish populations.


Assuntos
Ciclídeos/imunologia , Salinidade , Cloreto de Sódio/toxicidade , Água/química , Animais , Citocinas , Relação Dose-Resposta a Droga , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/imunologia , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Cloreto de Sódio/administração & dosagem , Fatores de Tempo , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo
9.
J Fish Dis ; 35(9): 683-93, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22631876

RESUMO

Ocular lipid deposition and its surgical management and possible association with systemic hyperlipidaemia in captive moray eels are described. Ophthalmologic examinations, haematology and plasma biochemistry analyses were performed on an initial population of captive moray eels (n=10): green moray, Gymnothorax funebris Ranzani; spotted moray, Gymnothorax morninga (Cuvier) and reticulated moray, Muraena retifera Goode and Bean. Recently captured green moray eels comprised the control group (n=9). Clinical signs compatible with ocular lipid deposition were identified in six of ten captive eels (60%) vs. none of the controls. Green moray eels in the initial captive population (n=5) had significantly higher total protein, triglyceride, cholesterol and aspartate amino transferase values than the control eels. Dietary management was attempted in all captive eels, and surgical intervention was performed in three eels, including two from a separate population, with improved ocular clarity within 1month post-operatively. Histopathological evaluation of surgical specimens and two eyes from an additional affected eel that died suggested ocular lipid deposition. Eels in captivity have an apparent predisposition for hyperlipidaemia and ocular lipid deposition. Although limited in this study and complicated by exhibit restraints, dietary management was minimally effective, while surgery improved ocular clarity.


Assuntos
Enguias , Oftalmopatias/veterinária , Doenças dos Peixes/patologia , Hiperlipidemias/veterinária , Animais , Análise Química do Sangue , Dieta , Oftalmopatias/fisiopatologia , Oftalmopatias/cirurgia , Doenças dos Peixes/prevenção & controle , Doenças dos Peixes/cirurgia , Pesqueiros , Hiperlipidemias/patologia , Hiperlipidemias/prevenção & controle , Hiperlipidemias/cirurgia , Lipídeos
10.
J Cogn ; 2(1): 3, 2019 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-31517223

RESUMO

The antisaccade (AS) task is considered a prominent measure of inhibitory control, but it is still unclear which cognitive processes are used for successful performance of the task. Previous results have provided evidence for the involvement of several processes, including working memory (WM), inhibition and attention. Thus, the aim of this study was to explore, using a range of neuropsychological tests, which cognitive factors predict individual differences in AS performance. To do so, 143 healthy participants underwent a battery including tests measuring inhibition, working memory, cognitive flexibility, sustained attention, IQ and fluency. Hierarchical stepwise regression analyses were conducted to assess the association with AS performance. Performance on the Trail-Making-Test, version B (TMT-B), a test measuring flexibility, divided attention and WM, was found to significantly predict AS latency. Rapid Visual Information Processing (RVIP), used to assess sustained attention and WM, significantly predicted AS error rate. Other cognitive measures, however, did not significantly predict AS performance. Bayesian Model Averaging supported these conclusions and showed that non-significant predictors are unlikely to be associated with AS outcomes. Several explanations are provided for the associations of TMT-B and RVIP with AS performance; as the tests measure a range of different cognitive processes, interpretation of these results remains less clear. For a better understanding of the cognitive mechanisms underlying AS performance, future research should make use of a wider range of attention and WM tests.

13.
Vet Rec ; 161(1): 15-21, 2007 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-17617540

RESUMO

Ten nesting leatherback sea turtles on Trinidad were anaesthetised for electroretinogram (ERG) measurements, using ketamine and medetomidine, reversed with atipamezole. They weighed 242 to 324 kg and were given initial doses of 3 to 8 mg/kg ketamine and 30 to 80 microg/kg medetomidine administered into an external jugular vein; six of the turtles received supplementary doses of 2.6 to 3.9 mg/kg ketamine combined with 0 to 39 microg/kg medetomidine. The lower doses were used initially to ensure against overdosage and reduce the chances of residual effects after the turtles returned to the water, but successful ergs called for step-wise dose increases to the required level of anaesthesia. Respiratory rate, heart rate, electrocardiogram, cloacal temperature, and venous blood gases were monitored, and blood was collected for plasma biochemistry. At the end of the erg procedure, atipamezole was administered at 150 to 420 microg/kg (five times the dose of medetomidine), half intramuscularly and half intravascularly. The turtles were monitored and prevented from re-entering the water until their behaviour was normal. No apparent mortalities or serious anaesthetic complications occurred. The observed within-season return nesting rate of the anaesthetised turtles was comparable with that of unanaesthetised turtles.


Assuntos
Anestesia/veterinária , Anestésicos Combinados/administração & dosagem , Anestésicos Intravenosos/administração & dosagem , Tartarugas/fisiologia , Antagonistas Adrenérgicos alfa/administração & dosagem , Anestésicos Dissociativos/administração & dosagem , Animais , Esquema de Medicação , Eletrorretinografia/veterinária , Feminino , Frequência Cardíaca , Hipnóticos e Sedativos/administração & dosagem , Imidazóis/administração & dosagem , Infusões Intravenosas/veterinária , Injeções Intramusculares/veterinária , Ketamina/administração & dosagem , Medetomidina/administração & dosagem
14.
Nutr Res ; 39: 61-68, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28385290

RESUMO

A single high-fat meal (HFM) leads to an increase in triglycerides and oxidative stress. Oxidative stress can be assessed via 8-isoprostane generation, which is associated with the development of asthma and cardiovascular disease. No previous research has investigated whether airway and systemic 8-isoprostane increases postprandially in nonasthmatic participants according to the energy and fat content of a meal. Our purpose was to assess airway and systemic 8-isoprostane after a HFM and a true-to-life moderate-fat meal (MFM). We hypothesized that airway and systemic 8-isoprostane would increase after a HFM and a MFM, with the greatest increase in the HFM condition. Eight nonasthmatic men (25.8±6.9years) completed the HFM and MFM trials in a randomized crossover design. After a 10-hour fast, participants consumed either a HFM (71.13kJ/kg body mass, 60% fat, 23% CHO) or a MFM (35.56kJ/kg body mass, 30% fat, 52% CHO). Exhaled breath condensate to assess airway 8-isoprostane was collected at baseline and at 3 and 6hours postmeal. Venous blood samples were collected at baseline and hourly until 6hours postmeal to assess triglycerides, and every 3hours for systemic 8-isoprostane. Airway 8-isoprostane responses were not significant as a main effect of time (P=.072), between conditions (P=.365), or between time and condition (P=.319) postmeal. Systemic 8-isoprostane increased over time (P<.001), but not between conditions (P=.124) or between time and condition (P=.649) postmeal. Triglyceride incremental area under the curve was different in the HFM compared to the MFM condition (P=.013). After a HFM and a MFM, 8-isoprostane increases systemically; however, airway 8-isoprostane does not change.


Assuntos
Dieta Hiperlipídica , Gorduras na Dieta/farmacologia , Dinoprosta/análogos & derivados , Refeições , Período Pós-Prandial , Triglicerídeos/sangue , Adulto , Área Sob a Curva , Doenças Cardiovasculares/etiologia , Estudos Cross-Over , Gorduras na Dieta/administração & dosagem , Dinoprosta/sangue , Dinoprosta/metabolismo , Humanos , Masculino , Sistema Respiratório/metabolismo , Fatores de Risco , Comportamento Sedentário , Adulto Jovem
15.
Dev Comp Immunol ; 30(5): 473-84, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16139358

RESUMO

A quantitative real-time reverse transcription polymerase chain reaction (RT-PCR) assay was developed to measure transforming growth factor-beta (TGF-beta) in Atlantic menhaden (Brevoortia tyrannus), an estuarine-dependent species plagued by ulcerative skin lesions in the estuaries along the eastern United States. Atlantic menhaden were acclimated in a closed system for two weeks prior to initiation of the study. The synthetic glucocorticoid, triamcinolone acetonide (10mg/kg body weight) was administered by intracoelomic injection and its effect on the splenic mononuclear cell TGF-beta mRNA transcription, liver-somatic index, spleno-somatic index, hematology, and plasma chemistry were compared to untreated fish at 48 and 96h post-treatment. Triamcinolone-treated Atlantic menhaden showed suppression of TGF-beta mRNA production, neutrophilia, monocytosis, lymphopenia, and an increase in blood glucose concentrations. The health indices used in this study may help us interpret some of the changes observed during the development of ulcerative skin lesions in wild-caught menhaden.


Assuntos
Anti-Inflamatórios/farmacologia , Peixes/sangue , Peixes/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Triancinolona Acetonida/farmacologia , Animais , Sequência de Bases , Glicemia/análise , Doenças dos Peixes/sangue , Doenças dos Peixes/imunologia , Doenças dos Peixes/metabolismo , Peixes/imunologia , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Dados de Sequência Molecular , Plasma , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Úlcera Cutânea/imunologia , Úlcera Cutânea/metabolismo , Úlcera Cutânea/veterinária , Baço/efeitos dos fármacos , Baço/metabolismo
17.
J Neurosci ; 21(8): 2600-9, 2001 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-11306613

RESUMO

The major goal of this study was to compare mechanisms of the neuroprotective potential of 17 beta-estradiol in two models for oxidative stress-independent apoptotic neuronal cell death with that in necrotic neuronal cell death in primary neuronal cultures derived from rat hippocampus, septum, or cortex. Neuronal apoptosis was induced either by staurosporine or ethylcholine aziridinium (AF64A), as models for necrotic cell death glutamate exposure or oxygen-glucose deprivation (OGD) were applied. Long-term (20 hr) pretreatment (0.1 microm 17 beta-estradiol) was neuroprotective in apoptotic neuronal cell death induced by AF64A (40 microm) only in hippocampal and septal neuronal cultures and not in cortical cultures. The neuroprotective effect was blocked by the estrogen antagonists ICI 182,780 and tamoxifen and the phosphatidylinositol 3-kinase (PI3-K) inhibitor LY294002. In glutamate and OGD-induced neuronal damage, long-term pretreatment was not effective. In contrast, short-term (1 hr) pretreatment with 17 beta-estradiol in the dose range of 0.5-1.0 microm significantly reduced the release of lactate dehydrogenase and improved morphology of cortical cultures exposed to glutamate or OGD but was not effective in the AF64A model. Staurosporine-induced apoptosis was not prevented by either long- or short-term pretreatment. The strong expression of the estrogen receptor-alpha and the modulation of Bcl proteins by 17 beta-estradiol in hippocampal and septal but not in cortical cultures indicates that the prevention of apoptotic, but not of necrotic, neuronal cell death by 17 beta-estradiol possibly depends on the induction of Bcl proteins and the density of estrogen receptor-alpha.


Assuntos
Apoptose/efeitos dos fármacos , Colina/análogos & derivados , Estradiol/farmacologia , Necrose , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Animais , Aziridinas/farmacologia , Hipóxia Celular/efeitos dos fármacos , Células Cultivadas , Córtex Cerebral/citologia , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Colina/farmacologia , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Antagonistas de Estrogênios/farmacologia , Receptor alfa de Estrogênio , Glucose/deficiência , Glucose/metabolismo , Ácido Glutâmico/toxicidade , Hipocampo/citologia , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , L-Lactato Desidrogenase/metabolismo , Neurônios/citologia , Neurônios/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ratos , Ratos Wistar , Receptores de Estrogênio/metabolismo , Septo do Cérebro/citologia , Septo do Cérebro/efeitos dos fármacos , Septo do Cérebro/metabolismo , Estaurosporina/farmacologia , Fatores de Tempo
18.
J Neurosci ; 21(14): 5045-53, 2001 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-11438580

RESUMO

After mild ischemic insults, many neurons undergo delayed neuronal death. Aberrant activation of the cell cycle machinery is thought to contribute to apoptosis in various conditions including ischemia. We demonstrate that loss of endogenous cyclin-dependent kinase (Cdk) inhibitor p16(INK4a) is an early and reliable indicator of delayed neuronal death in striatal neurons after mild cerebral ischemia in vivo. Loss of p27(Kip1), another Cdk inhibitor, precedes cell death in neocortical neurons subjected to oxygen-glucose deprivation in vitro. The loss of Cdk inhibitors is followed by upregulation of cyclin D1, activation of Cdk2, and subsequent cytoskeletal disintegration. Most neurons undergo cell death before entering S-phase, albeit a small number ( approximately 1%) do progress to the S-phase before their death. Treatment with Cdk inhibitors significantly reduces cell death in vitro. These results show that alteration of cell cycle regulatory mechanisms is a prelude to delayed neuronal death in focal cerebral ischemia and that pharmacological interventions aimed at neuroprotection may be usefully directed at cell cycle regulatory mechanisms.


Assuntos
Isquemia Encefálica/metabolismo , Quinases relacionadas a CDC2 e CDC28 , Proteínas de Ciclo Celular , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Quinases Ciclina-Dependentes/antagonistas & inibidores , Proteínas Associadas aos Microtúbulos/metabolismo , Neurônios/metabolismo , Proteínas Proto-Oncogênicas , Proteínas Supressoras de Tumor , Animais , Isquemia Encefálica/patologia , Bromodesoxiuridina , Ciclo Celular/fisiologia , Morte Celular , Hipóxia Celular , Células Cultivadas , Ciclina D1/metabolismo , Quinase 2 Dependente de Ciclina , Quinase 4 Dependente de Ciclina , Inibidor p16 de Quinase Dependente de Ciclina/deficiência , Inibidor de Quinase Dependente de Ciclina p27 , Quinases Ciclina-Dependentes/metabolismo , Modelos Animais de Doenças , Inibidores Enzimáticos/farmacologia , Glucose/deficiência , Glucose/metabolismo , Marcação In Situ das Extremidades Cortadas , Cinetina , Camundongos , Camundongos Endogâmicos , Proteínas Associadas aos Microtúbulos/deficiência , Neurônios/patologia , Oxigênio/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Purinas/farmacologia , Ratos , Ratos Wistar
19.
Cardiovasc Res ; 35(1): 68-79, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9302349

RESUMO

OBJECTIVE: The aim of this study was to investigate whether cardiodepressant mediators are released after myocardial ischaemia during reperfusion. METHODS: Using a double heart model, the effect of the reoxygenated coronary effluent of an isolated guinea pig heart on a sequentially perfused second heart was studied under control conditions and after 10 min ischaemia of the first heart. Investigation of the modulating role of known autacoids took place by using free radical scavengers, an NO synthase inhibitor and adenosine receptor antagonists. In order to identify the chemical nature of cardiac metabolites, the coronary effluent was also subjected to different chemical treatment modes. RESULTS: No haemodynamic changes were observed during sequential perfusion under control conditions. After 10 min of global ischaemia in heart I, a marked decrease in LVP (-22%), LVdP/dtmax (-43%), LVdP/dtmin (-41%) and coronary perfusion pressure (-25%) was measured in heart II during sequential perfusion. The negative inotropic effect was rapid in onset and reversible within 5 min; free radicals, nitric oxide and adenosine were not involved. Storage of the coronary effluent of the first heart up to 24 h, heating, or protease treatment did not modify its cardiodepressant effects on the second sequentially perfused heart. CONCLUSIONS: These results suggest the release--from an isolated heart after ischaemia during reperfusion--of a cardiodepressant mediator which induces a potent reversible negative inotropic effect on a sequentially perfused heart. The mediator is stable and in all probability not a protein.


Assuntos
Autacoides/metabolismo , Contração Miocárdica/efeitos dos fármacos , Isquemia Miocárdica/metabolismo , Reperfusão Miocárdica , Miocárdio/metabolismo , Adenosina Desaminase/farmacologia , Antagonistas Adrenérgicos beta/farmacologia , Animais , Catalase/farmacologia , Depressão Química , Feminino , Sequestradores de Radicais Livres , Cobaias , Masculino , Metoprolol/farmacologia , Naftalenos/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Nitroarginina/farmacologia , Perfusão , Fosfolipases A/antagonistas & inibidores , Antagonistas de Receptores Purinérgicos P1 , Antagonistas do Receptor Purinérgico P2 , Pironas/farmacologia , Superóxido Dismutase/farmacologia , Teobromina/análogos & derivados , Teobromina/farmacologia , Xantinas/farmacologia
20.
J Cereb Blood Flow Metab ; 21(9): 1090-6, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11524613

RESUMO

Oxidative injury contributes to cellular damage during and after cerebral ischemia. However, the downstream catabolic pathways of damaged cellular components in neurons are largely unknown. In the current study, the authors examined the formation of oxidized proteins and their active degradation by the proteasome. In near-pure rat primary cortical neurons, it was found that protein-bound carbonyls as markers for oxidized proteins are increased after oxygen-glucose deprivation (OGD). During and after OGD, degradation of proteins metabolically radiolabeled before OGD increases two-to threefold compared with the normal protein turnover. Proteolysis after reoxygenation was attenuated by the presence of dimethylthiourea, a radical scavenger, and was blocked by lactacystin, a specific proteasome inhibitor. Lactacystin also increased the amount of protein carbonyls formed. In contrast, the activity of the proteasome complex itself after OGD was not different from sham-washed controls. The authors suggest that oxygen-glucose deprivation increases free radicals, which, in turn, oxidize proteins that are recognized and actively degraded by the proteasome complex. This protease itself is relatively resistant against oxidative injury. The authors conclude that the proteasome may be an active part of the cellular defense system against oxidative stress after cerebral ischemia.


Assuntos
Acetilcisteína/análogos & derivados , Cisteína Endopeptidases/metabolismo , Glucose/farmacologia , Complexos Multienzimáticos/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neurônios/enzimologia , Oxigênio/farmacologia , Acetilcisteína/farmacologia , Animais , Isquemia Encefálica/metabolismo , Morte Celular/efeitos dos fármacos , Morte Celular/fisiologia , Células Cultivadas , Córtex Cerebral/citologia , Inibidores de Cisteína Proteinase/farmacologia , Complexos Multienzimáticos/antagonistas & inibidores , Neurônios/citologia , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Complexo de Endopeptidases do Proteassoma , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo
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