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1.
Acta Anaesthesiol Scand ; 62(3): 312-318, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29178126

RESUMO

BACKGROUND: This prospective, randomised, controlled study was performed to evaluate the usefulness of the McGrath VL compared with Macintosh laryngoscopy in children with expected normal airway during endotracheal intubation, by comparing the time to intubation and difficulty of intubation. METHODS: Eighty-four patients aged 1-10 years who underwent endotracheal intubation for elective surgery were randomly assigned to the McGrath group (n = 42) or the Macintosh group (n = 42). Anaesthesia was induced with 2.5-3.0 mg/kg of propofol and sevoflurane 5-8 vol%. Orotracheal intubation was performed 2 min after injection of rocuronium 0.6 mg/kg with McGrath VL or Macintosh laryngoscope; the primary outcome was the time to intubation. The Cormack and Lehane glottic grade, intubation difficulty score (IDS), and success rate on intubation were assessed. Haemodynamic changes were also recorded. RESULTS: As the primary outcome, median time to intubation [interquartile range] did not differ between the McGrath group and the Macintosh group (25.0 [22.8-28.3] s vs. 26.0 [24.0-29.0] s, P = 0.301). The incidence of grade I glottic view was significantly higher in the McGrath group than in the Macintosh group (95% vs. 74%, P = 0.013). Median IDS was lower in the McGrath group than in the Macintosh group (0 [0-0] vs. 0 [0-1], P = 0.018). There were no significant differences in success rate on intubation or haemodynamics between the two groups. CONCLUSIONS: McGrath VL provides better laryngeal views and lower IDS but similar intubation times and success rates compared with the Macintosh laryngoscope in children with normal airway.


Assuntos
Intubação Intratraqueal/métodos , Laringoscopia , Gravação em Vídeo , Criança , Pré-Escolar , Humanos , Lactente , Estudos Prospectivos , Fatores de Tempo
2.
Acta Anaesthesiol Scand ; 58(7): 815-9, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24961283

RESUMO

BACKGROUND: Dexmedetomidine can be used as a co-induction agent to facilitate laryngeal mask airway (LMA) insertion with minimal effect on respiratory function. The purpose of the study was to determine the median effective dose (ED50) of dexmedetomidine to facilitate LMA insertion during anaesthesia induction with propofol 2.0 mg/kg without neuromuscular blockade. METHODS: Twenty-two patients, whose American Society of Anesthesiologists physical status was I or II with ages between 18 and 60 years undergoing minor orthopaedic or gynaecological surgery, were enrolled. After an injection of pre-determined bolus dose of dexmedetomidine over 2 min, anaesthesia was induced with propofol 2.0 mg/kg. The modified Dixon's up-and-down method was used to determine the bolus dose of dexmedetomidine, starting from 0.5 µg/kg (step size; 0.1 µg/kg). LMA insertion was conducted 90 s after the propofol injection, and the response of patients was categorized as either 'success' or 'failure.' RESULTS: Insertion of the LMA was unsuccessful in 12 of 22 patients. The ED50 (95% confidence interval) of dexmedetomidine for successful LMA insertion with propofol 2.0 mg/kg was 0.55 (0.44-0.66) µg/kg. Bradycardia occurred in four patients, and seven patients had an apneic episode. CONCLUSION: The single dose of dexmedetomidine for successful LMA insertion to be feasible in 50% of patients was 0.55 µg/kg during anaesthesia induction with propofol 2 mg/kg.


Assuntos
Agonistas de Receptores Adrenérgicos alfa 2/administração & dosagem , Analgésicos não Narcóticos/administração & dosagem , Anestésicos Intravenosos/administração & dosagem , Dexmedetomidina/administração & dosagem , Hipnóticos e Sedativos/administração & dosagem , Intubação Intratraqueal/métodos , Máscaras Laríngeas , Medicação Pré-Anestésica , Propofol/administração & dosagem , Adolescente , Adulto , Apneia/induzido quimicamente , Bradicardia/induzido quimicamente , Tosse/induzido quimicamente , Relação Dose-Resposta a Droga , Feminino , Engasgo/prevenção & controle , Procedimentos Cirúrgicos em Ginecologia , Hemodinâmica/efeitos dos fármacos , Humanos , Intubação Intratraqueal/efeitos adversos , Laringismo/prevenção & controle , Masculino , Pessoa de Meia-Idade , Procedimentos Ortopédicos , Adulto Jovem
3.
Anaesthesia ; 68(9): 938-43, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23841822

RESUMO

We investigated the effects of 10 cmH2O positive end-expiratory pressure on cerebral haemodynamics and cerebral oxygenation in patients undergoing laparoscopic lower abdominal surgery in the 30° Trendelenburg position during desflurane anaesthesia. Twenty-six patients were enrolled in this study. After anaesthesia induction, pneumoperitoneum was applied in Trendelenburg position. Twenty minutes later, positive end-expiratory pressure was applied. There was no change in regional cerebral oxygen saturation (p = 0.376). Cerebral perfusion pressure decreased significantly over time (p < 0.001) and positive end-expiratory pressure caused a further decrease in cerebral perfusion pressure (p = 0.036). The application of 10 cmH2O positive end-expiratory pressure during pneumoperitoneum in the Trendelenburg position preserved regional cerebral oxygen saturation, but cerebral perfusion pressure decreased significantly due to its secondary haemodynamic effects.


Assuntos
Circulação Cerebrovascular/fisiologia , Decúbito Inclinado com Rebaixamento da Cabeça/fisiologia , Hemodinâmica/fisiologia , Pneumoperitônio Artificial/métodos , Respiração com Pressão Positiva/métodos , Abdome/cirurgia , Adulto , Idoso , Anestésicos Inalatórios , Desflurano , Feminino , Humanos , Isoflurano/análogos & derivados , Laparoscopia/métodos , Masculino , Pessoa de Meia-Idade
4.
Int J Obstet Anesth ; 21(2): 185-8, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22341893

RESUMO

Spontaneous spinal-epidural hematoma is uncommon and rare during pregnancy. We were presented with a 31-year-old patient who developed back pain with lower extremity paralysis at 36 weeks of gestation. A magnetic resonance imaging scan demonstrated an acute spinal-epidural hematoma and therefore, an emergency cesarean delivery was performed followed by hemilaminectomy with hematoma removal. Anesthesia was initiated with a volatile-based technique which, following delivery of the baby, was changed to target-controlled infusions of propofol and remifentanil. Postoperatively, dopamine was infused to maintain the blood pressure within the high-normal range to optimize spinal cord perfusion. Successful anesthetic and postoperative management is described together with a review of the literature.


Assuntos
Anestesia/métodos , Anestésicos Inalatórios , Anestésicos Intravenosos , Hematoma Epidural Espinal/cirurgia , Complicações na Gravidez/cirurgia , Adulto , Androstanóis , Dor nas Costas/etiologia , Cesárea , Dopamina , Tratamento de Emergência/métodos , Feminino , Seguimentos , Hematoma Epidural Espinal/complicações , Hematoma Epidural Espinal/patologia , Humanos , Laminectomia/métodos , Imageamento por Ressonância Magnética/métodos , Éteres Metílicos , Fármacos Neuromusculares não Despolarizantes , Paraplegia/etiologia , Piperidinas , Gravidez , Complicações na Gravidez/patologia , Propofol , Remifentanil , Rocurônio , Sevoflurano , Resultado do Tratamento
5.
J Int Med Res ; 39(5): 1816-23, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22117982

RESUMO

The concentration of remifentanil required for acceptable nasotracheal intubation in adults after target-controlled infusion (TCI) of propofol without neuromuscular blockade was compared with that required for orotracheal intubation. Twenty-five patients undergoing oral and maxillofacial surgery received nasotracheal intubation and 25 undergoing ear, nose and throat surgery received orotracheal intubation. Anaesthesia was induced with propofol TCI at a target effect-site concentration of 5.0 µg/ml. The 50% and 95% effective concentrations (EC(50) and EC(95), respectively) for remifentanil, calculated using isotonic regression, were 5.40 and 6.85 ng/ml, respectively, in the orotracheal group and 5.75 and 7.43 ng/ml in the nasotracheal group. The EC(50) (± SD) values for remifentanil, calculated using a modified Dixon's up-and-down method, were 6.08 ± 0.75 and 5.58 ± 0.75 ng/ml for nasotracheal and orotracheal intubation, respectively. Effect-site remifentanil concentrations did not differ significantly between the two groups of patients. Coadministration of propofol and remifentanil can provide acceptable conditions for nasotracheal intubation without neuromuscular blockade.


Assuntos
Anestésicos Combinados , Anestésicos Intravenosos , Intubação Intratraqueal , Piperidinas/uso terapêutico , Propofol/uso terapêutico , Adulto , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Boca , Nariz , Procedimentos Cirúrgicos Bucais , Remifentanil , Adulto Jovem
6.
Oncogene ; 30(21): 2433-42, 2011 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-21278789

RESUMO

Gliomas are associated with high mortality because of their exceedingly invasive character. As these tumors acquire their invasiveness from low-grade tumors, it is very important to understand the detailed molecular mechanisms of invasion onset. Recent evidences suggest the significant role of microRNAs in tumor invasion. Thus, we hypothesized that deregulation of microRNAs may be important for the malignant progression of gliomas. We found that the aberrant expression of miR-21 is responsible for glioma invasion by disrupting the negative feedback circuit of Ras/MAPK signaling, which is mediated by Spry2. Upregulation of miR-21 was triggered by tumor microenvironmental factors such as hyaluronan and growth factors in glioma cells lacking functional phosphatase and tensin homolog (PTEN), but not harboring wild-type PTEN. Consistently with these in vitro results, Spry2 protein levels were significantly decreased in 79.7% of invasive WHO grade II-IV human glioma tissues, but not in non-invasive grade I and normal tissues. The Spry2 protein levels were not correlated with their mRNA levels, but inversely correlated with miR-21 levels. Taken together, these results suggest that the post-transcriptional regulation of Spry2 by miR-21 has an essential role on the malignant progression of human gliomas. Thus, Spry2 may be a novel therapeutic target for treating gliomas.


Assuntos
Regulação para Baixo , Glioma/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , MicroRNAs/genética , Western Blotting , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioma/metabolismo , Glioma/patologia , Células HEK293 , Humanos , Ácido Hialurônico/farmacologia , Imuno-Histoquímica , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas de Membrana , MicroRNAs/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Invasividade Neoplásica , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Interferência de RNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/efeitos dos fármacos , Proteínas ras/metabolismo
7.
Br J Anaesth ; 105(4): 442-7, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20650921

RESUMO

BACKGROUND: Carbon dioxide insufflation during laparoscopic surgery results in an acid-base imbalance. The purpose of this study was to investigate the effect of pneumoperitoneum on the acid-base status using Stewart's approach. METHODS: Thirty patients undergoing abdominal surgery were allocated to the laparotomy group (n=15) or the laparoscopy group (n=15). The acid-base parameters were measured 10 min after the induction (T1), 40 min after opening the peritoneum or pneumoperitoneum according to the group (T2), at the end of the surgery (T3), and 1 h after the surgery (T4). RESULTS: There were no significant differences in the standard base excess (SBE), strong ion gap, or anion gap between the two groups. In both groups, the SBE decreased at T2, T3, and T4 compared with baseline value. At T3 and T4 in the laparotomy group, the apparent strong ion difference (SIDa) and pH were decreased whereas the lactate and chloride were increased compared with their baseline values. At T2 in the laparoscopy group, the pH was decreased whereas Pa(CO(2)) was increased compared with their baseline values. CONCLUSIONS: The decrease in the pH during the pneumoperitoneum was affected by the increase in Pa(CO(2)), which promptly returned to a normal value after the desufflation. On the other hand, the decrease in the pH after laparotomy was affected by the metabolic factors, which persisted an hour after the surgery.


Assuntos
Desequilíbrio Ácido-Base/etiologia , Complicações Intraoperatórias , Laparoscopia/efeitos adversos , Pneumoperitônio Artificial/efeitos adversos , Abdome/cirurgia , Adulto , Dióxido de Carbono/sangue , Feminino , Hemodinâmica , Humanos , Concentração de Íons de Hidrogênio , Masculino , Pessoa de Meia-Idade , Pressão Parcial , Estudos Prospectivos
8.
Acta Anaesthesiol Scand ; 53(5): 678-81, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19419364

RESUMO

BACKGROUND: Emergence agitation is a common problem in paediatric anaesthesia, especially after volatile induction and maintenance anaesthesia (VIMA) with sevoflurane. The purpose of this study was to investigate the effect of alfentanil to prevent emergence agitation without delayed recovery after VIMA with sevoflurane in children undergoing an adenotonsillectomy. METHODS: One hundred and five children, aged 3-10 years, were randomly allocated to receive normal saline (control group), alfentanil 10 microg/kg (A10) or 20 microg/kg (A20) 1 min after loss of the eyelash reflex. Anaesthesia was induced and maintained with sevoflurane. Time to tracheal extubation, recovery time, Paediatric Anaesthesia Emergence Delirium (PAED) scale and emergence behaviour were assessed. RESULTS: The incidence of severe agitation was significantly lower in the A10 and A20 groups compared with those in the control group (11/32 and 12/34 vs. 24/34, respectively) (P=0.007, 0.006, respectively). PAED scales were significantly different between the three groups (P=0.008), and lower in the A10 and A20 groups than that in the control group (P=0.044, 0.013, respectively). However, the incidence of severe agitation and PAED scale was not different between the A10 and the A20 groups. Time to tracheal extubation and recovery time were similar in all three groups. CONCLUSION: The administration of alfentanil 10 microg/kg after induction of anaesthesia for children undergoing an adenotonsillectomy under VIMA reduced the incidence of emergence agitation without delaying the recovery time or causing significant hypotension.


Assuntos
Adenoidectomia , Alfentanil/uso terapêutico , Anestesia por Inalação , Anestésicos Inalatórios/efeitos adversos , Anestésicos Intravenosos/uso terapêutico , Éteres Metílicos/efeitos adversos , Complicações Pós-Operatórias/tratamento farmacológico , Agitação Psicomotora/tratamento farmacológico , Agitação Psicomotora/etiologia , Tonsilectomia , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Complicações Pós-Operatórias/psicologia , Estudos Prospectivos , Agitação Psicomotora/psicologia , Sevoflurano
9.
Anaesthesia ; 63(9): 954-8, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18557970

RESUMO

The purpose of this study was to determine the optimal bolus dose of remifentanil required for the successful insertion of the laryngeal mask airway during propofol induction in children without a neuromuscular blocking agent. Twenty-six paediatric patients, aged 3-10 years, requiring anaesthesia for short ambulatory surgery were recruited. A predetermined bolus dose of remifentanil was injected over 30 s, followed by propofol 2.5 mg.kg(-1) over 10 s. The bolus dose of remifentanil was determined by a modified Dixon's up-and-down method, starting from 0.5 microg.kg(-1) (0.1 microg.kg(-1) as a step size). Laryngeal mask insertion was attempted 90 s after the end of remifentanil injection and the response of patients was classified as either 'movement' or 'no movement'. The bolus dose of remifentanil at which there was a 50% probability of successful laryngeal mask insertion (ED(50)) during induction with 2.5 mg.kg(-1) propofol was 0.56 (0.07) microg.kg(-1) in children without a neuromuscular blocking agent. From probit analysis, the ED(50) and ED(95) of remifentanil were 0.52 microg.kg(-1) (95% confidence limits, 0.42-0.62 microg.kg(-1)) and 0.71 microg.kg(-1) (95% confidence limits, 0.61-1.40 microg.kg(-1)), respectively.


Assuntos
Anestésicos Combinados/administração & dosagem , Anestésicos Intravenosos/administração & dosagem , Máscaras Laríngeas , Piperidinas/administração & dosagem , Propofol/administração & dosagem , Procedimentos Cirúrgicos Ambulatórios , Pressão Sanguínea/efeitos dos fármacos , Criança , Pré-Escolar , Relação Dose-Resposta a Droga , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Masculino , Remifentanil
10.
Acta Anaesthesiol Scand ; 52(1): 106-10, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17976223

RESUMO

BACKGROUND: The purpose of this study was to determine the optimal bolus dose of alfentanil required to provide successful intubating conditions following inhalation induction of anaesthesia using 5% sevoflurane and 60% nitrous oxide without neuromuscular blockade in adult day-case anaesthesia. METHODS: Twenty-four adults, aged 18-60 years, undergoing general anaesthesia for short ambulatory surgery were enroled into the study. After vital capacity induction, with sevoflurane 5% and 60% nitrous oxide in oxygen, pre-determined dose of alfentanil was injected over 30 s. The dose of alfentanil was determined by modified Dixon's up-and-down method (2 microg/kg as a step size). Ninety seconds after the end of bolus administration of alfentanil, the trachea was intubated. Systolic blood pressure, heart rate and SpO2 were recorded at anaesthetic induction, before, 1 min and 3 min after intubation. RESULTS: The bolus dose of alfentanil for successful tracheal intubation was 10.7+/-2.1 microg/kg in 50% of patients during inhalation induction. From probit analysis, 50% effective dose (ED(50)) and ED(95) values (95% confidence limits) of alfentanil were 10.7 microg/kg (8.0-12.9 microg/kg) and 14.9 microg/kg (12.9-31.1 microg/kg), respectively. CONCLUSIONS: Using the modified Dixon's up-and-down method, the bolus dose of alfentanil for successful tracheal intubation was 10.7+/-2.1 microg/kg in 50% of adult patients during inhalation induction using 5% sevoflurane and 60% nitrous oxide in oxygen without neuromuscular blocking agent in day-case anaesthesia.


Assuntos
Alfentanil/administração & dosagem , Procedimentos Cirúrgicos Ambulatórios , Anestesia por Inalação , Anestésicos Inalatórios/efeitos adversos , Intubação Intratraqueal , Éteres Metílicos/efeitos adversos , Entorpecentes/administração & dosagem , Bloqueio Neuromuscular , Adolescente , Adulto , Alfentanil/farmacologia , Anestésicos Inalatórios/administração & dosagem , Anestésicos Inalatórios/farmacologia , Relação Dose-Resposta a Droga , Interações Medicamentosas , Eletroencefalografia/efeitos dos fármacos , Feminino , Hemodinâmica/efeitos dos fármacos , Humanos , Injeções Intravenosas , Masculino , Éteres Metílicos/administração & dosagem , Éteres Metílicos/farmacologia , Pessoa de Meia-Idade , Entorpecentes/farmacologia , Óxido Nitroso/administração & dosagem , Sevoflurano
11.
Inflamm Res ; 54(12): 508-13, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16389572

RESUMO

OBJECTIVES: Heme oxygenase-1 (HO-1) is an enzyme that degrades heme into biliverdin, free iron, and carbon monoxide (CO). This enzyme is known to have cytoprotective and anti-inflammatory effects. In this study, we investigated whether roflumilast, a newly developed specific phosphodiesterase 4 (PDE4) inhibitor, mediates some of its anti-inflammatory effects by blocking nitric oxide (NO) and tumor necrosis factor alpha (TNF-alpha) via the induction of HO-1 expression in macrophages. METHODS: The expression of iNOS and HO-1 was analyzed by western blot analysis. The production of NO and TNF-alpha was assayed by Greiss and ELISA, respectively. RESULTS: Roflumilast markedly suppressed LPS-induced NO and TNF-alpha production and these phenomena were correlated with the induction of HO-1 protein levels. Moreover, the inhibitory effects of roflumilast on NO production were abrogated by a HO-1 inhibitor and a CO scavenger. Tricarbonyldichlrororuthenium(II) dimer, a CO releasing molecule significantly suppressed NO production. CONCLUSIONS: These results suggested that roflumilast exerts its anti-inflammatory effects in macrophages through a novel mechanism that involves the action of HO-1 and its product, CO.


Assuntos
Aminopiridinas/farmacologia , Benzamidas/farmacologia , Lipopolissacarídeos/farmacologia , Macrófagos/metabolismo , Óxido Nítrico/metabolismo , 3',5'-AMP Cíclico Fosfodiesterases/antagonistas & inibidores , Animais , Western Blotting , Monóxido de Carbono/metabolismo , Linhagem Celular , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4 , Ciclopropanos/farmacologia , Ensaio de Imunoadsorção Enzimática , Heme Oxigenase (Desciclizante)/metabolismo , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/enzimologia , Camundongos , Compostos Organometálicos/farmacologia , Fator de Necrose Tumoral alfa/metabolismo
12.
Water Sci Technol ; 43(7): 207-14, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11385849

RESUMO

The objective of this paper is to apply a closed-loop identification to actual dissolved oxygen control system in the coke wastewater treatment plant. It approximates the dissolved oxygen dynamics to a high order model using the integral transform method and reduces it to the first-order plus time delay (FOPTD) or second-order plus time delay (SOPTD) for the PID controller tuning. To experiment the process identification on the real plant, a simple set-point change of the speed of surface aerator under the closed-loop control without any mode change was used as an activation signal of the identification. The full-scale experimental results show a good identification performance and a good tracking ability for set-point change. As a result of improved control performance, the fluctuation of dissolved oxygen concentration variation has been decreased and the electric power saving has been accomplished.


Assuntos
Carvão Mineral , Simulação por Computador , Resíduos Industriais , Oxigênio/análise , Eliminação de Resíduos Líquidos/métodos , Biomassa , Desenho de Equipamento , Modelos Teóricos , Software , Eliminação de Resíduos Líquidos/instrumentação
13.
Leuk Res ; 25(4): 339-46, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11248331

RESUMO

Water-soluble chitosan oligomer (WSCO) has been reported to have anticancer activity, immuno-enhancing effect and antimicrobial activity. However, other biological activities are unknown. Herein, we have shown that WSCO is able to inhibit proliferation of human leukemia HL-60 cells and induce these cells to differentiate. Treatment with WSCO for 4 days resulted in a concentration-dependent reduction in HL-60 cell growth as measured by cell counting and MTT assay. This effect was accompanied by a marked increase in the proportion of G(0)/G(1) cells as measured by flow cytometry. WSCO also induced differentiation of the cells as measured by phorbol ester-dependent reduction of NBT, morphological changes as examined by Wright-Giemsa staining and expression of CD11b but not of CD14 as analysed by flow cytometry, indicating differentiation of HL-60 cells toward granulocyte-like cells. A combination of low dose of WSCO with all-trans retinoic acid, a differentiating agent toward granulocyte-like cells, exhibited a synergistic effect on the differentiation. In addition, treatment of HL-60 cells with WSCO for 6 or 8 days resulted in the induction of apoptosis as assayed qualitatively by agarose gel electrophoresis and quantitatively by Annexin V technique using flow cytometry. Collectively, there is a potential for WSCO in the treatment of myeloid leukemia.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Quitina/farmacologia , Granulócitos/citologia , Leucemia Promielocítica Aguda/tratamento farmacológico , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Quitina/análogos & derivados , Quitosana , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Células HL-60/efeitos dos fármacos , Células HL-60/patologia , Humanos , Leucemia Promielocítica Aguda/patologia , Tretinoína/farmacologia
14.
Oncogene ; 19(39): 4549-52, 2000 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-11002428

RESUMO

The angiopoietin-Tie2 system in endothelial cells is an important regulator of vasculogenesis and vascular integrity. High levels of angiopoietin-2 (Ang2) mRNA are observed in vascular activation during tumorigenesis. Although Ang2 is known to be a naturally occurring antagonist of angiopoietin-1 (Ang1) in vivo, the exact function of Ang2 itself is not known. Here, we found that a high concentration of Ang2 (800 ng/ml) acts as an apoptosis survival factor for endothelial cells during serum deprivation apoptosis. The survival effect of high concentration Ang2 was blocked by pre-treatment with soluble Tie2 receptor and the PI 3'-kinase-specific inhibitors, wortmannin and LY294002. Accordingly, 800 ng/ml of Ang2 induced phosphorylation of Tie2, the p85 subunit of phosphatidylinositol 3'-kinase (PI 3'-kinase), and serine-threonine kinase Akt at Ser473 in the human umbilical vein endothelial cells; lower concentrations of Ang2 (50 - 400 ng/ml) did not produce notable effects. These findings indicate that at high concentrations, Ang2, like Ang1, can be an apoptosis survival factor for endothelial cells through the activation of the Tie2 receptor, PI 3'-kinase and Akt, and thus may be a positive regulator of tumor angiogenesis. Oncogene (2000) 19, 4549 - 4552.


Assuntos
Endotélio Vascular/citologia , Endotélio Vascular/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Serina-Treonina Quinases , Proteínas/farmacologia , Proteínas Proto-Oncogênicas/metabolismo , Androstadienos/farmacologia , Angiopoietina-2 , Apoptose/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Cromonas/farmacologia , Meios de Cultura Livres de Soro/farmacologia , Relação Dose-Resposta a Droga , Endotélio Vascular/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Humanos , Morfolinas/farmacologia , Proteínas de Neoplasias/metabolismo , Proteínas de Neoplasias/farmacologia , Fosfatidilinositol 3-Quinases/efeitos dos fármacos , Inibidores de Fosfoinositídeo-3 Quinase , Fosforilação , Proteínas Proto-Oncogênicas/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt , Receptor TIE-2 , Transdução de Sinais , Veias Umbilicais/citologia , Wortmanina
15.
Circulation ; 101(19): 2317-24, 2000 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-10811601

RESUMO

BACKGROUND AND PURPOSE: Angiopoietin-1 (Ang1) is a vasculogenic factor that signals through the endothelial cell-specific Tie2 receptor tyrosine kinase. We recently reported that Ang1 prevented apoptosis induced by serum deprivation in endothelial cells. In this study, we examined whether Ang1 prevents apoptosis in endothelial cells treated with irradiation or clinical concentrations of mannitol. METHODS AND RESULTS: ++Ang1 prevented irradiation- and mannitol-induced apoptosis in human umbilical vein endothelial cells in a dose-dependent manner. Pretreatment with soluble Tie2 receptor, but not Tie1 receptor, blocked the antiapoptotic effect of Ang1. Two phosphatidylinositol 3'-kinase (PI3-kinase)-specific inhibitors, wortmannin and LY294002, blocked the Ang1-induced antiapoptotic effect. The antiapoptotic potency of Ang1 was similar to or greater than that of vascular endothelial growth factor, basic fibroblast growth factor, and endothelin-1. Ang1 also prevented apoptosis in cultured endothelial cells from porcine pulmonary and coronary arteries and in endothelial cells of explanted rat aorta. CONCLUSIONS: Ang1 promotes the survival of endothelial cells in irradiation- and mannitol-induced apoptosis through Tie2 receptor binding and PI3-kinase activation. Pretreatment with Ang1 could be beneficial in maintaining normal endothelial cell integrity during intracoronary irradiation or systemic mannitol therapy.


Assuntos
Apoptose/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/efeitos da radiação , Manitol/farmacologia , Glicoproteínas de Membrana/farmacologia , Proteínas Proto-Oncogênicas , Angiopoietina-1 , Animais , Células Cultivadas , Vasos Coronários/citologia , Vasos Coronários/efeitos dos fármacos , Citocinas/farmacologia , Relação Dose-Resposta a Droga , Endotélio Vascular/citologia , Substâncias de Crescimento/farmacologia , Humanos , Masculino , Músculo Liso Vascular/citologia , Músculo Liso Vascular/efeitos dos fármacos , Proteínas de Neoplasias/fisiologia , Fosfatidilinositol 3-Quinases/fisiologia , Artéria Pulmonar/citologia , Artéria Pulmonar/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Receptor TIE-2 , Suínos , Veias Umbilicais/citologia , Veias Umbilicais/efeitos dos fármacos , Veias Umbilicais/efeitos da radiação
16.
Circ Res ; 86(1): 24-9, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10625301

RESUMO

Angiopoietin-1 (Ang1) is a strong apoptosis survival factor for endothelial cells. In this study, the receptor/second messenger signal transduction pathway for the antiapoptotic effect of Ang1 on human umbilical vein endothelial cells was examined. Pretreatment with soluble Tie2 receptor, but not Tie1 receptor, blocked the Ang1-induced antiapoptotic effect. Ang1 induced phosphorylation of Tie2 and the p85 subunit of phosphatidylinositol 3'-kinase (PI 3'-kinase) and increased PI 3'-kinase activity in a dose-dependent manner. The PI 3'-kinase-specific inhibitors wortmannin and LY294002 blocked the Ang1-induced antiapoptotic effect. Ang1 induced phosphorylation of the serine-threonine kinase Akt at Ser473 in a PI 3'-kinase-dependent manner. Expression of a dominant-negative form of Akt reversed the Ang1-induced antiapoptotic effect. Ang1 mRNA and protein were present in vascular smooth muscle cells but not in endothelial cells. Cultured vascular smooth muscle cells, but not human umbilical vein endothelial cells, secreted Ang1. These findings indicate that the Tie2 receptor, PI 3'-kinase, and Akt are crucial elements in the signal transduction pathway leading to endothelial cell survival induced by the paracrine activity of Ang1.


Assuntos
Endotélio Vascular/fisiologia , Glicoproteínas de Membrana/fisiologia , Fosfatidilinositol 3-Quinases/fisiologia , Proteínas Serina-Treonina Quinases , Transdução de Sinais/fisiologia , Angiopoietina-1 , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Células Cultivadas , Endotélio Vascular/citologia , Endotélio Vascular/metabolismo , Humanos , Glicoproteínas de Membrana/metabolismo , Glicoproteínas de Membrana/farmacologia , Proteínas de Neoplasias/metabolismo , Comunicação Parácrina/fisiologia , Fragmentos de Peptídeos/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas/fisiologia , Proteínas Proto-Oncogênicas c-akt , Receptor TIE-2 , Proteínas Recombinantes/farmacologia
17.
Cell Immunol ; 194(1): 36-46, 1999 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-10357879

RESUMO

To define the signaling pathways during NO-induced apoptotic events and their possible modulation by two protein kinase systems, we explored the involvement of three structurally related mitogen-activated protein kinase subfamilies. Exposure of HL-60 cells to sodium nitroprusside (SNP) strongly activated p38 kinase, but did not activate c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK). In addition, SNP-induced apoptosis was markedly blocked by the selective p38 kinase inhibitor (SB203580) but not by MEK1 kinase inhibitor (PD098059), indicating that p38 kinase serves as a mediator of NO-induced apoptosis. In contrast, treatment of cells with phorbol 12-myristate 13-acetate (PMA) strongly activated not only JNK but also ERK, while not affecting p38 kinase. However, although SNP by itself weakly activated CPP32-like protease, SNP in combination with PMA markedly increased the extent of CPP32-like protease activation. Interestingly, N6,O2-dibutylyl cAMP (DB-cAMP) significantly blocked SNP- or SNP plus PMA-induced activation of CPP32-like protease and the resulting induction of apoptosis. DB-cAMP also blocked PMA-induced JNK activation. Collectively, these findings demonstrate the presence of specific up- or down-modulatory mechanisms of cell death pathway by NO in which (1) p38 kinase serves as a mediator of NO-induced apoptosis, (2) PKC acts at the point and/or upstream of JNK and provides signals to potentiate NO-induced CPP32-like protease activation, and (3) PKA lies upstream of either JNK or CPP32-like protease to protect NO- or NO plus PMA-induced apoptotic cell death in HL-60 cells.


Assuntos
Apoptose , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Caspases/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Proteínas Quinases Ativadas por Mitógeno , Óxido Nítrico/metabolismo , Proteína Quinase C/metabolismo , Transdução de Sinais , Bucladesina/farmacologia , Caspase 3 , Ativação Enzimática , Células HL-60 , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno , Proteína Quinase 3 Ativada por Mitógeno , Mitógenos/farmacologia , Nitroprussiato/farmacologia , Acetato de Tetradecanoilforbol/metabolismo , Acetato de Tetradecanoilforbol/farmacologia , Proteínas Quinases p38 Ativadas por Mitógeno
18.
FEBS Lett ; 448(2-3): 249-53, 1999 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-10218485

RESUMO

We examined the effect of angiopoietin-1 (Ang1) on apoptosis in human umbilical vein endothelial cells (HUVECs). Ang1 (5-1000 ng/ml) dose-dependently inhibited apoptosis under a serum-deprived state. A significant apoptotic inhibition occurred with as low as 50 ng/ml. Two hundred ng/ml of Ang1 inhibited to approximately 50% of the control apoptotic rates for 96 h. Furthermore, an augmented antiapoptotic effect of Ang1 by the addition of 20 ng/ml vascular endothelial growth factor was observed. This Ang1-induced strong antiapoptotic effect in endothelial cells is a novel and intriguing finding and could be an additional description of Ang1-induced direct biological function.


Assuntos
Apoptose , Fatores de Crescimento Endotelial/metabolismo , Endotélio Vascular/metabolismo , Linfocinas/metabolismo , Glicoproteínas de Membrana/metabolismo , Angiopoietina-1 , Células Cultivadas , Relação Dose-Resposta a Droga , Endotélio Vascular/citologia , Humanos , Proteínas Recombinantes , Fatores de Tempo , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular
19.
J Immunol ; 162(6): 3395-401, 1999 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-10092794

RESUMO

Nitric oxide (NO) induces apoptotic cell death in murine RAW 264.7 macrophages. To elucidate the inhibitory effects of protein kinase C (PKC) on NO-induced apoptosis, we generated clones of RAW 264.7 cells that overexpress one of the PKC isoforms and explored the possible interactions between PKC and three structurally related mitogen-activated protein (MAP) kinases in NO actions. Treatment of RAW 264.7 cells with sodium nitroprusside (SNP), a NO-generating agent, activated both c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK) and p38 kinase, but did not activate extracellular signal-regulated kinase (ERK)-1 and ERK-2. In addition, SNP-induced apoptosis was slightly blocked by the selective p38 kinase inhibitor (SB203580) but not by the MAP/ERK1 kinase inhibitor (PD098059). PKC transfectants (PKC-beta II, -delta, and -eta) showed substantial protection from cell death induced by the exposure to NO donors such as SNP and S-nitrosoglutathione (GSNO). In contrast, in RAW 264.7 parent or in empty vector-transformed cells, these NO donors induced internucleosomal DNA cleavage. Moreover, overexpression of PKC isoforms significantly suppressed SNP-induced JNK/SAPK and p38 kinase activation, but did not affect ERK-1 and -2. We also explored the involvement of CPP32-like protease in the NO-induced apoptosis. Inhibition of CPP32-like protease prevented apoptosis in RAW 264.7 parent cells. In addition, SNP dramatically activated CPP32 in the parent or in empty vector-transformed cells, while slightly activated CPP32 in PKC transfectants. Therefore, we conclude that PKC protects NO-induced apoptotic cell death, presumably nullifying the NO-mediated activation of JNK/SAPK, p38 kinase, and CPP32-like protease in RAW 264.7 macrophages.


Assuntos
Apoptose/imunologia , Proteínas Quinases Dependentes de Cálcio-Calmodulina/fisiologia , Caspases/fisiologia , Macrófagos/enzimologia , Proteínas Quinases Ativadas por Mitógeno , Óxido Nítrico/farmacologia , Proteína Quinase C/biossíntese , Transdução de Sinais/imunologia , Animais , Apoptose/efeitos dos fármacos , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Caspase 3 , Inibidores de Caspase , Caspases/metabolismo , Linhagem Celular , Ativação Enzimática/imunologia , Isoenzimas/biossíntese , Isoenzimas/fisiologia , Proteínas Quinases JNK Ativadas por Mitógeno , Macrófagos/efeitos dos fármacos , Camundongos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno , Proteína Quinase C/fisiologia , Proteínas Quinases p38 Ativadas por Mitógeno
20.
Cancer ; 85(3): 546-53, 1999 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-10091728

RESUMO

BACKGROUND: Cyclins are overexpressed in various malignancies, including carcinoma of the colorectum, esophagus, lung, larynx, and breast. However, to the authors' knowledge, the protein levels and activities of cyclin-dependent kinases (CDKs), which are the functional cyclin partners in the cell cycle, have not been investigated previously. METHODS: Eight samples of cancer tissue and adjacent normal tissue were taken from 23 patients with Stage B2-C1 (AJCC/UICC Stage II-III) colorectal carcinoma during curative resection. The protein levels of cyclin and CDKs were determined by Western blot analysis. The activities of CDKs were determined by the phosphorylation amount using specific substrates after immunoprecipitations. RESULTS: The protein expression of cyclin (D1, D3, E, and A) and CDKs (CDK4, CDK2, and cdc2) was higher in primary colorectal carcinoma tissue than in adjacent normal tissue. Whereas only 3 of 8 patients had increased CDK4 activity in cancer tissue, 8 of 8 and 7 of 8 patients had increased CDK2 and cdc2 activities, respectively, in cancer tissue compared with adjacent normal tissue. However, there were no positive correlations among the pathologic staging or differentiation status and the increased ratio of cyclin protein, CDK protein, or CDK activity. CONCLUSIONS: These results indicate that significant activation of S and M phases of the cell cycle occurs in primary colorectal carcinoma.


Assuntos
Quinases relacionadas a CDC2 e CDC28 , Neoplasias Colorretais/metabolismo , Quinases Ciclina-Dependentes/metabolismo , Proteínas de Neoplasias/metabolismo , Idoso , Western Blotting , Proteína Quinase CDC2/metabolismo , Divisão Celular , Neoplasias Colorretais/patologia , Quinase 2 Dependente de Ciclina , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Proteínas Serina-Treonina Quinases/metabolismo
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