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1.
Pediatr Transplant ; : e13683, 2020 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-32166860

RESUMO

Abdominal wall closure after pediatric liver transplantation (pLT) in infants may be hampered by graft-to-recipient size discrepancy. Herein, we describe the use of a porcine dermal collagen acellular graft (PDCG) as a biological mesh (BM) for abdominal wall closure in pLT recipients. Patients <2 years of age, who underwent pLT from 2011 to 2014, were analyzed, divided into definite abdominal wall closure with and without implantation of a BM. Primary end-point was the occurrence of postoperative abdominal wall infection. Secondary end-points included 1- and 5-year patient and graft survival and the development of abdominal wall hernia. In five out of 21 pLT recipients (23.8%), direct abdominal wall closure was achieved, whereas 16 recipients (76.2%) received a BM. BM removal was necessary in one patient (6.3%) due to abdominal wall infection, whereas no abdominal wall infection occurred in the no-BM group. No significant differences between the two groups were observed for 1- and 5-year patient and graft survival. Two late abdominal wall hernias were observed in the BM group vs none in the no-BM group. Definite abdominal wall closure with a BM after pLT is feasible and safe when direct closure cannot be achieved with comparable postoperative patient and graft survival rates.

2.
Blood Purif ; 49(1-2): 55-62, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31527371

RESUMO

BACKGROUND AND AIMS: Acute and acute on chronic liver failure are life-threatening conditions, and bridging to transplantation is complicated by a paucity of suitable organs for children. While different modalities of extracorporeal liver support exist, their use in children is complicated by a large extracorporeal volume, and data on their use in children is limited. The aim of this analysis was to investigate the efficacy and safety of single-pass albumin dialysis (SPAD) in children with liver failure. METHODS: Retrospective medical chart review of pediatric patients with liver failure treated with SPAD. The decrease in hepatic encephalopathy (HE) and the serum levels of bilirubin and ammonia were measured to determine efficacy. Adverse events were documented to assess safety. RESULTS: Nineteen pediatric patients with a median age of 25.5 months and a median body weight of 11.9 kg were treated with SPAD between January 2011 and March 2018. Total bilirubin (p < 0.001) and ammonia (p = 0.02) significantly decreased after treatment with SPAD. As clinical outcome parameter, HE significantly improved (p = 0.001). Twelve patients were bridged successfully to liver transplantation. In all patients, 71 SPAD sessions were run. Clotting in the dialysis circuit was observed in 49% of all sessions. Heparin and citrate were used for anticoagulation and were significantly superior to dialysis without any anticoagulation (p= 0.03). Transfusion of packed blood cells (57%) and catecholamine therapy (49%) were frequently necessary. CONCLUSIONS: Treatment with SPAD was effective in detoxification, as measured by significant improvement of HE and clearance from surrogate laboratory parameters.

3.
Medicine (Baltimore) ; 98(38): e17185, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31567961

RESUMO

Infections caused by Panton-Valentine leukocidin-positive Staphylococcus aureus (PVL-SA) mostly present as recurrent skin abscesses and furunculosis. However, life-threatening infections (eg, necrotizing pneumonia, necrotizing fasciitis, and osteomyelitis) caused by PVL-SA have also been reported.We assessed the clinical phenotype, frequency, clinical implications (surgery, length of treatment in hospitals/intensive care units, and antibiotic treatments), and potential preventability of severe PVL-SA infections in children.Total, 75 children treated for PVL-SA infections in our in- and outpatient units from 2012 to 2017 were included in this retrospective study.Ten out of 75 children contracted severe infections (PVL-methicillin resistant S aureus n = 4) including necrotizing pneumonia (n = 4), necrotizing fasciitis (n = 2), pyomyositis (n = 2; including 1 patient who also had pneumonia), mastoiditis with cerebellitis (n = 1), preorbital cellulitis (n = 1), and recurrent deep furunculosis in an immunosuppressed patient (n = 1). Specific complications of PVL-SA infections were venous thrombosis (n = 2), sepsis (n = 5), respiratory failure (n = 5), and acute respiratory distress syndrome (n = 3). The median duration of hospital stay was 14 days (range 5-52 days). In 6 out of 10 patients a history suggestive for PVL-SA colonization in the patient or close family members before hospital admission was identified.PVL-SA causes severe to life-threatening infections requiring lengthy treatments in hospital in a substantial percentage of symptomatic PVL-SA colonized children. More than 50% of severe infections might be prevented by prompt testing for PVL-SA in individuals with a history of abscesses or furunculosis, followed by decolonization measures.


Assuntos
Toxinas Bacterianas/metabolismo , Exotoxinas/metabolismo , Leucocidinas/metabolismo , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/metabolismo , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Tempo de Internação , Masculino , Pneumonia Necrosante/microbiologia , Estudos Retrospectivos , Infecções dos Tecidos Moles/microbiologia , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/patologia , Infecções Estafilocócicas/terapia
4.
Minerva Pediatr ; 2019 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-31621272

RESUMO

BACKGROUND: Different studies in adults reported significant outcome improvement for patients treated with high adherence to guidelines. The present study was initiated to evaluate the impact of adherence to antibiotic prescription guidelines on health outcomes of children on paediatric intensive care unit (PICU) suffering from pneumonia. METHODS: This retrospective cohort study was conducted on a paediatric intensive care unit at Charité hospital Berlin. All patients with a length of stay (LOS) >24 hours, age <18 years, antimicrobial therapies and a radiologically confirmed diagnosis of pneumonia according to the "Centers for Disease Control and Prevention" definitions were included during the study period of 2009 and 2010. Adherence to national guidelines was evaluated daily and two groups were defined: Low adherence group (LAG) with a presence of <70% of days with compliant therapy and high adherence group (HAG) with an adherence of ≥70%. RESULTS: High adherence was observed in 65 patients compared with 61 in low-adherence group. Number of patients needing invasive ventilation did not vary between HAG and LAG (n=37 vs. n=41; p=0.235). There was a statistically significant shorter duration of ventilation in HAG patients (p=0.031). Time to clinical recovery from pneumonia tended to be shorter in HAG patients (7.5d vs. 10.9d; p=0.07). There was a significant reduction in LOS in HAG patients (9.3d vs. 13.7d; p=0.016). However, mortality appeared comparable between groups. CONCLUSIONS: Similar to previous evidence in adult patients children with pneumonia seem to benefit from guideline-based antibiotic therapy. Further studies are needed to explore strategies to improve guideline adherence.

5.
Pediatr Infect Dis J ; 38(11): e295-e300, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31626041

RESUMO

BACKGROUND: Intravenous artesunate (ivA) is the standard treatment for severe malaria. Data systematically evaluating the use of ivA in pediatric patients outside malaria-endemic regions are limited. The aim of this case series was to summarize efficacy and safety of ivA for imported severe malaria in children in Germany. METHODS: Our retrospective case series included pediatric patients with imported severe malaria treated with at least 1 dose of ivA (Artesun, Guilin Pharmaceutical; Shanghai, China) at 4 German tertiary care centers. Severe malaria was defined according to World Health Organization criteria. RESULTS: Between 2010 and 2018, 14 children with a median [interquartile range (IQR)] age of 6 (1;9.5) years were included. All children were of African descent. All but 2 patients had Plasmodium falciparum malaria; 1 child had P. vivax malaria and 1 child had P. falciparum and P. vivax co-infection. Median (IQR) parasitemia at admission in patients with P. falciparum was 9.5% (3;16.5). Patients were treated with 1-10 [median (IQR) 3 (3;4)] doses ivA. All but one patient received a full course of oral antimalarial treatment. Parasite clearance was achieved within 2-4 days, with the exception of 1 patient with prolonged clearance of peripheral parasitemia. Three patients experienced posttreatment hemolysis but none needed blood transfusion. Otherwise ivA was safe and well tolerated. CONCLUSIONS: ivA was highly efficacious in this pediatric cohort. We observed episodes of mild to moderate posttreatment hemolysis in approximately one-third of patients. The legal status and usage of potentially lifesaving ivA should be evaluated in Europe.

6.
Klin Padiatr ; 230(2): 88-96, 2018 03.
Artigo em Alemão | MEDLINE | ID: mdl-29342477

RESUMO

BACKGROUND: According to the current update of the German guideline on brain death (BD), participation of paediatricians is now mandatory for the examination of BD in patients younger than 14 years. The present analysis focuses on the previous practice and highlights the challenges that arise from the current update. METHODS: Retrospective evaluation of the patient registry of the German organ procurement organisation (north-eastern bureau) between January, 2001 and December, 2010 with specified paediatric age groups according to the 4th update of the German guideline on BD from the 1st of July 2015. RESULTS: 133 patients (0-17 years) received at least one BD examination. Secondary brain damage was most frequent within the first 6 months of life whereas traumatic and other causes of primary brain damage were predominantly observed thereafter. The number of patients who received BD examination by paediatricians or were treated on neonatal/paediatric intensive care units declined with increasing age. In more than two-third of all paediatric patients, no paediatrician was involved in BD diagnostics. DISCUSSION: After enforcement of the 4th update of the German guideline on BD, the participation of qualified paediatric physicians must be increased significantly compared to previous practice. Advancements in the specialist training of paediatric physicians, adjustments in patient-centered paediatric care and interdisciplinary diagnostic teams may be solutions to meet this demand.


Assuntos
Morte Encefálica/patologia , Recém-Nascido , Unidades de Terapia Intensiva Pediátrica/estatística & dados numéricos , Obtenção de Tecidos e Órgãos/estatística & dados numéricos , Adolescente , Morte Encefálica/classificação , Morte Encefálica/diagnóstico , Criança , Pré-Escolar , Alemanha , Humanos , Lactente , Estudos Retrospectivos
7.
Minerva Pediatr ; 70(4): 331-339, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27830927

RESUMO

BACKGROUND: Medication errors are of concern especially in pediatric patients. This study investigates impact of dosing errors of antibiotics on outcome in critically ill pediatric patients. METHODS: Retrospective study including all consecutive patients admitted to one university pediatric intensive care unit (PICU) in 2010 with length of PICU stay >24 hrs, age <18 years and antibiotic therapy. Antibiotic dosages were evaluated for compliance with recommended dosing individually adapted for bodyweight, age and organ function. Primary endpoint was organ dysfunction defined as occurrence of liver injury (LI) or acute kidney injury (AKI) after initiation of antibiotic therapy. AKI was defined as reduced estimated glomerular filtration below 50 mL/min or renal replacement therapy. LI was defined as more than two-fold elevation of liver enzymes. Additionally, duration of PICU stay, ventilation and all-cause PICU mortality were investigated. RESULTS: Altogether 305 patients were evaluated with 2577 patient PICU days and 4021 antibiotic dosages. Overall 38.6% of dosages were incorrect according to recommendations and were applied in 130 patients (low-adherence-group). 175 children received antibiotic dosing according to recommendations (high-adherence-group). Patients in the low-adherence-group showed a 7-fold increase in adjusted risk to develop new-onset organ dysfunction (95% CI: 2.1-26.4), needed longer median PICU treatment (7 versus 3 days, P<0.001) and prolonged duration of mechanical ventilation (8 versus 2 days, P<0.001). In subgroup analyses, organ dysfunction and PICU mortality were associated with non-adherence to recommendations. CONCLUSIONS: Adherence to a bodyweight- and age-adapted dosage-protocol is associated with less organ dysfunction and a more favorable clinical outcome in pediatric patients.


Assuntos
Antibacterianos/administração & dosagem , Unidades de Terapia Intensiva Pediátrica , Adesão à Medicação , Erros de Medicação , Lesão Renal Aguda/induzido quimicamente , Lesão Renal Aguda/epidemiologia , Adolescente , Antibacterianos/efeitos adversos , Doença Hepática Induzida por Substâncias e Drogas/epidemiologia , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Criança , Pré-Escolar , Estado Terminal , Relação Dose-Resposta a Droga , Feminino , Taxa de Filtração Glomerular , Humanos , Lactente , Tempo de Internação , Masculino , Terapia de Substituição Renal/métodos , Respiração Artificial/métodos , Estudos Retrospectivos
8.
Cardiol Young ; 28(3): 432-437, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29198223

RESUMO

BACKGROUND: Cyclooxygenase inhibitors are widely applied to facilitate ductal closure in preterm infants. The mechanisms that lead to patent ductus arteriosus closure are incompletely understood. Vascular endothelial growth factor plays pivotal roles during ductal closure and remodelling. Aim The aim of this study was to investigate the effects of ibuprofen and indomethacin on the expression of vascular endothelial growth factor and its receptors in a primary rat ductus arteriosus endothelial cell culture. METHODS: Protein expression of vascular endothelial growth factor and vascular endothelial growth factor receptor 1 and 2 was confirmed in rat ductus arteriosus and aorta by immunofluorescence staining. Fetal rat endothelial cells were isolated from ductus arteriosus and aorta using immunomagnetic cell sorting and treated with ibuprofen or indomethacin. mRNA expression levels were assessed by quantitative polymerase chain reaction analysis. RESULTS: In ductal endothelial cells, ibuprofen significantly induced vascular endothelial growth factor and its receptor 2, but not receptor 1, whereas indomethacin did not alter the expression levels of the vascular endothelial growth factor system. In contrast, ibuprofen significantly induced vascular endothelial growth factor and its receptors 1 and 2 in aortic endothelial cells, whereas indomethacin only induced vascular endothelial growth factor receptor 2. CONCLUSION: Our results indicate differential effects of ibuprofen and indomethacin on the expression levels of the vascular endothelial growth factor system in ductus arteriosus endothelial cells. In addition, vessel-specific differences between ductal and aortic endothelial cells were found. Further in vivo studies are needed to elucidate the biological significance of these findings.


Assuntos
Inibidores de Ciclo-Oxigenase/farmacologia , Canal Arterial/citologia , Células Endoteliais/metabolismo , Ibuprofeno/farmacologia , Indometacina/farmacologia , Fatores de Crescimento do Endotélio Vascular/metabolismo , Animais , Aorta/citologia , Aorta/efeitos dos fármacos , Técnicas de Cultura de Células , Canal Arterial/efeitos dos fármacos , Células Endoteliais/efeitos dos fármacos , Feminino , Feto , Imunofluorescência , RNA Mensageiro/análise , Ratos , Ratos Wistar
11.
Ger Med Sci ; 10: Doc07, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22557940

RESUMO

PURPOSE: To date there are only a few studies published, dealing with delirium in critically ill patients. The problem with these studies is that prevalence rates of delirium could only be estimated because of the lack of validated delirium assessment tools for the paediatric intensive care unit (PICU). The paediatric Confusion Assessment Method for the Intensive Care Unit (pCAM-ICU) was specifically developed and validated for the detection of delirium in PICU patients. The purpose of this study was the translation of the English pCAM-ICU into German according to international validated guidelines. METHODS: The translation process was performed according to the principles of good practice for the translation and cultural adaptation process for patient reported outcomes measures: From three independently created German forward-translation versions one preliminary German version was developed, which was then retranslated to English by a certified, state-approved translator. The back-translated version was submitted to the original author for evaluation. The German translation was evaluated by clinicians and specialists anonymously (German grades) in regards to language and content of the translation. RESULTS: The results of the cognitive debriefing revealed good to very good results. After that the translation process was successfully completed and the final version of the German pCAM-ICU was adopted by the expert committee. CONCLUSION: The German version of the pCAM-ICU is a result of a translation process in accordance with internationally acknowledged guidelines. Particularly, with respect to the excellent results of the cognitive debriefing, we could finalise the translation and cultural adaptation process for the German pCAM-ICU.


Assuntos
Confusão/diagnóstico , Delírio/diagnóstico , Inquéritos e Questionários/normas , Tradução , Compreensão , Alemanha , Humanos , Unidades de Terapia Intensiva Pediátrica , Linguagem
12.
Pediatr Res ; 70(3): 236-41, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21629157

RESUMO

The ductus arteriosus (DA), a fetal arterial shunt vessel between the proximal descending aorta and the pulmonary artery, closes shortly after birth. Initial functional closure as a result of the DA's smooth muscle contraction is followed by definite anatomical closure. The latter involves several complex mechanisms like endothelial cushion formation and smooth muscle cell migration resulting in fibrosis and sealing of the vessel. These complex steps indicate highly specialized functions of the DA vascular smooth muscle cells (VSMCs), endothelial cells, and fibroblasts. Herein, we describe a new reproducible method for isolating VSMCs, endothelial cells, and fibroblasts of high viability from fetal rat DA using immunomagnetic cell sorting. Purity of the different cell cultures was assessed by immunohistochemistry and flow cytometry and ranged between 85 and 94%. The capability of the VSMCs to react to hypoxic stimuli was assessed by intracellular calcium and ATP measurements and by VEGF mRNA expression analysis. VSMCs respond to hypoxia with decreases in intracellular calcium concentrations and ATP levels, whereas VEGF mRNA expression increased 3.2-fold. The purified vessel-specific different cell types are suitable for subsequent gene expression profiling and functional studies and provide important tools for improving our understanding of the complex processes involved in the closure of the DA.


Assuntos
Canal Arterial/citologia , Células Endoteliais/citologia , Endotélio Vascular/citologia , Feto/citologia , Fibroblastos/citologia , Músculo Liso Vascular/citologia , Miócitos de Músculo Liso/citologia , Animais , Técnicas de Cultura de Células , Células Cultivadas , Feminino , Humanos , Separação Imunomagnética/métodos , Gravidez , Ratos , Ratos Wistar
13.
Pediatr Crit Care Med ; 12(3): 257-64, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-20921923

RESUMO

OBJECTIVE: To investigate the applicability, efficacy, and safety of single-pass albumin dialysis in children. DESIGN: Retrospective data review of uncontrolled clinical data. SETTING: University-based pediatric intensive care unit collaborating with a local center for liver transplantation. PATIENTS: Nine children, aged 2 to 15 yrs, who were treated with single-pass albumin dialysis for acute liver failure of various origins under a compassionate-use protocol between 2000 and 2006. All patients met high-urgency liver transplantation criteria. INTERVENTIONS: Single-pass albumin dialysis was performed as rescue therapy for children with acute liver failure. MEASUREMENTS AND MAIN RESULTS: The decrease in hepatic encephalopathy (grades 1-4) and the serum levels of bilirubin, bile acids, and ammonium were measured to assess the efficacy of detoxification. As a measure of liver synthesis function, thromboplastin time and fibrinogen were analyzed. The safety of the procedure was assessed by documenting adverse effects on mean arterial blood pressure, platelet count, and clinical course. Seven out of nine patients were bridged successfully to either native organ recovery (n = 1) or liver transplantation (n = 6), one of them twice. Six out of nine patients undergoing single-pass albumin dialysis (ten treatments) survived. In six patients, hepatic encephalopathy could be reduced at least by one degree. Ammonium, bilirubin, and bile acid levels decreased in all patients. One patient had an allergic reaction to albumin. CONCLUSIONS: In childhood acute liver failure, treatment with single-pass albumin dialysis was generally well tolerated and seems to be effective in detoxification and in improving blood pressure, thus stabilizing the critical condition of children before liver transplantation and facilitating bridging to liver transplantation. It may be beneficial in avoiding severe neurologic sequelae after acute liver failure and thereby improve survival. Single-pass albumin dialysis is an inexpensive albumin-based detoxification system that is easy to set up and requires little training. Whether and to what extent single-pass albumin dialysis can support children with acute liver failure until native liver recovery remains unclear.


Assuntos
Albuminas/uso terapêutico , Hemodiafiltração/métodos , Falência Hepática Aguda/terapia , Diálise Renal/métodos , Adolescente , Bilirrubina/sangue , Criança , Pré-Escolar , Feminino , Encefalopatia Hepática/terapia , Humanos , Transplante de Fígado , Masculino , Estudos Retrospectivos , Resultado do Tratamento
14.
Artigo em Alemão | MEDLINE | ID: mdl-19526449

RESUMO

Injuries are responsible for considerable morbidity and much long-term or permanent disability. They are also the leading cause of death for children aged 0 to 5. In high income countries around the world 20000 children die each year from injuries. A recent UNICEF report has compiled data for 2001 on the leading cause of death for Europe. The burden of disease measure has identified injury as causative in 40% of years lost from premature death in children. Drowning and near drowning is the number two killer for children aged 0 to 5. In 30% of all cases cardio-pulmonary resuscitation and intensive care are needed. 11.5% of all drowning accidents are fatal, 9.5% of nearly drowned children show extensive neurologic deficits. Though the absolute number of deaths from injury in children has decreased during the last 20 years (in 1980: 18.8 dead children per 100000; in 2004: 3.0 dead children in 100000), still approximately 400 children die from injuries in Germany every year. The public health approach to injury involves not only deaths but also the burden of disease and loss of health from disability. Severe traumatologic pediatric emergencies are thermal injury, drowning and blunt abdominal trauma.


Assuntos
Traumatismos Abdominais/terapia , Serviços Médicos de Emergência/métodos , Afogamento Iminente/terapia , Pediatria/métodos , Traumatologia/métodos , Ferimentos não Penetrantes/terapia , Traumatismos Abdominais/diagnóstico , Criança , Alemanha , Humanos , Afogamento Iminente/diagnóstico , Ferimentos não Penetrantes/diagnóstico
15.
Cancer Biol Ther ; 7(10): 1685-93, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18836303

RESUMO

Fluoxetine (FLX) is a widely prescribed antidepressant. Concerns were raised about the potential impact of FLX on cancer growth, because FLX was shown to promote development of breast cancer in rodents. Here we studied the effect of FLX on tumor growth in lung (A549), colon (HT29), neuroblastoma (SKNAS), medulloblastoma/rhabdomyosarcoma (TE671), astrocytoma (MOGGCCM) and breast (T47D) cancer cells and explored potential mechanisms of its action. In our study, FLX reduced growth of cancer cells in vitro in a concentration dependent manner. The antiproliferative effect of FLX was already evident after 24 hours exposure and more pronounced at 96 hours. We demonstrate that FLX inhibits phosphorylation of ERK1/2 kinases in a time and concentration-dependent manner, followed by reduced phosphorylation of transcription factor c-Myc in A549 and HT29 cells. After treatment with FLX, A549 and HT29 cells demonstrated concentration-dependent decrease in the expression of c-fos, c-jun, cyclin A, cyclin D1, and increased expression of p21(waf1) and p53 genes, which resulted in slowing of the cell cycle progression. We suggest that these changes could be responsible for observed inhibition of cancer cell proliferation during FLX treatment in vitro.


Assuntos
Antidepressivos/farmacologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Fluoxetina/farmacologia , Ciclo Celular/efeitos dos fármacos , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Citometria de Fluxo/métodos , Humanos , Fosforilação , Receptores de Serotonina/efeitos dos fármacos , Serotonina/metabolismo
16.
Neonatology ; 94(2): 132-7, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18332642

RESUMO

BACKGROUND: Exposure to hyperoxia and nitric oxide (NO) occur frequently during the treatment of neonatal hypoxic pulmonary failure. OBJECTIVE: The aim of the study was to quantify the endogenous synthesis of NO in neonatal polymorphonuclear neutrophils following exposure to hyperoxia and NO in vitro. METHODS: Neonatal cord blood was exposed to room air, 25, 30 and 100% oxygen and 10 or 20 ppm NO added to the different oxygen concentrations for up to 30 min. 4,5-Diaminofluorescein diacetate (DAF-2 DA) is an intracellular dye used to measure real-time changes in NO levels in vivo. The molecular structure of DAF-2 DA changes upon contact with NO to its oxidized and fluorescent form diaminofluorescein-triazol (DAF-2T) and after being hydrolyzed by intracellular esterases cannot leave the cell. DAF-2 DA signals following equilibration with room air were used as controls. RESULTS: Exposure to 100% oxygen increased NO production significantly when compared to 20 ppm NO plus 100% oxygen (p = 0.031) and to 20 ppm NO alone (p = 0.006). 10 ppm NO produced a similar effect. Significant increases in NO production were also noticed following exposure to 25% oxygen. This increase was already present after 10 min of oxygen exposure. CONCLUSION: These findings support the propagated avoidance of hyperoxia not only in preterm infants, but also in term neonates.


Assuntos
Hiperóxia/metabolismo , Neutrófilos/efeitos dos fármacos , Óxido Nítrico/biossíntese , Óxido Nítrico/farmacologia , Oxigênio/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Sangue Fetal/citologia , Citometria de Fluxo , Humanos , Hiperóxia/fisiopatologia , Recém-Nascido , Neutrófilos/metabolismo
17.
Cancer Biol Ther ; 6(12): 1908-15, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18059166

RESUMO

Antagonists at alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA)-type glutamate receptors limit growth of human cancers in vitro. However, the mechanism of anticancer action of AMPA antagonists is not known. Here we report that the AMPA antagonists GYKI 52466 and CFM-2 inhibit the extracellular signal regulated kinase (ERK1/2) pathway, an intracellular signaling cascade which is activated by growth factors and controls proliferation of lung adenocarcinoma cells. AMPA antagonists reduced phosphorylation of cAMP-responsive element binding protein (CREB), suppressed expression of cyclin D1, upregulated the cell cycle regulators and tumor suppressor proteins p21 and p53 and decreased number of lung adenocarcinoma cells in G2 and S phases of the cell cycle. These findings reveal potential mechanism of antiproliferative action of AMPA antagonists and indicate that this class of compounds may be useful in the therapy of human cancers.


Assuntos
Adenocarcinoma/patologia , Benzodiazepinas/farmacologia , Benzodiazepinonas/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Neoplasias Pulmonares/patologia , Proteína Quinase 1 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 3 Ativada por Mitógeno/antagonistas & inibidores , Receptores de AMPA/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiônico/antagonistas & inibidores , Adenocarcinoma/enzimologia , Antineoplásicos/farmacologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral/efeitos dos fármacos , Linhagem Celular Tumoral/metabolismo , Ensaios de Seleção de Medicamentos Antitumorais , Ativação Enzimática/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias Pulmonares/enzimologia , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/genética , Fosforilação/efeitos dos fármacos , Processamento de Proteína Pós-Traducional/efeitos dos fármacos
18.
Proc Natl Acad Sci U S A ; 102(43): 15605-10, 2005 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-16230611

RESUMO

Glutamate antagonists limit the growth of human cancers in vitro. The mechanism of anticancer action of NMDA antagonists is not known, however. In this article, we report that the NMDA antagonist dizocilpine inhibits the extracellular signal-regulated kinase 1/2 pathway, an intracellular signaling cascade that is activated by growth factors and controls the proliferation of cancer cells. Dizocilpine reduces the phosphorylation of cAMP-responsive element binding protein, suppresses the expression of cyclin D1, up-regulates the cell cycle regulators and tumor suppressor proteins p21 and p53, and increases the number of lung adenocarcinoma cells in the G(2) and S phases of the cell cycle. Silencing of the tumor suppressor protein p21 abolishes antiproliferative action of dizocilpine. Consistent with inhibition of the extracellular signal-regulated kinase 1/2-signaling cascade, dizocilpine reverses the stimulation of proliferation induced by epidermal, insulin, and basic fibroblast growth factors in lung adenocarcinoma cells. Furthermore, dizocilpine prolongs the survival of mice with metastatic lung adenocarcinoma and slows the growth of neuroblastoma and rhabdomyosarcoma in mice. These findings reveal the mechanism of antiproliferative action of dizocilpine and indicate that it may be useful in the therapy of human cancers.


Assuntos
Antineoplásicos/farmacologia , Maleato de Dizocilpina/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/fisiologia , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Fosforilação
19.
Pediatr Res ; 57(6): 771-6, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15774829

RESUMO

Glutaryl-CoA dehydrogenase deficiency is an inherited metabolic disease characterized by elevated concentrations of glutaric acid (GA) and its metabolites glutaconic acid (GC) and 3-hydroxy-glutaric acid (3-OH-GA). Its hallmarks are striatal and cortical degeneration, which have been linked to excitotoxic neuronal cell death. However, magnetic resonance imaging studies have also revealed widespread white matter disease. Correspondingly, we decided to investigate the effects of GA, GC, and 3-OH-GA on the rat immature oligodendroglia cell line, OLN-93. For comparison, we also exposed the neuroblastoma line SH-SY5Y and the microglia line BV-2 to GA, GC, and 3-OH-GA. Cell viability was measured by metabolism of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium. Flow cytometry was used to assess apoptosis via annexin-V, anti-active caspase-3 antibody, and propidium iodide staining. GA, GC, and 3-OH-GA reduced OLN-93 oligodendroglia cell viability in a dose-dependent manner. Toxicity of GA, GC, and 3-OH-GA was abrogated by preincubation with the pan-caspase inhibitor z-VAD-fmk. Apoptosis but not necrosis was detected at various stages (early: annexin-V; effector: caspase-3) after 24-48 h of incubation with GA, GC, or 3-OH-GA in OLN-93 but not in neuroblastoma or microglia cells. OLN-93 lacked expression of N-methyl-d-aspartate receptors, making classical glutamatergic excitotoxicity an unlikely explanation for the selective toxicity of GA, GC, and 3-OH-GA for OLN-93 cells. GA, GC, and 3-OH-GA directly initiate the apoptotic cascade in oligodendroglia cells. This mechanism may contribute to the white matter damage observed in glutaryl-CoA dehydrogenase deficiency.


Assuntos
Glutaratos/toxicidade , Oligodendroglia/efeitos dos fármacos , Oligodendroglia/patologia , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/deficiência , Clorometilcetonas de Aminoácidos/farmacologia , Animais , Apoptose/efeitos dos fármacos , Sequência de Bases , Encefalopatias Metabólicas Congênitas/genética , Encefalopatias Metabólicas Congênitas/metabolismo , Encefalopatias Metabólicas Congênitas/patologia , Inibidores de Caspase , Diferenciação Celular , Linhagem Celular , Glutaratos/metabolismo , Glutaril-CoA Desidrogenase , Humanos , Degeneração Neural/induzido quimicamente , Degeneração Neural/metabolismo , Oligodendroglia/metabolismo , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Receptores de Glutamato/genética , Receptores de Glutamato/metabolismo
20.
J Physiol ; 545(1): 93-105, 2002 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-12433952

RESUMO

Voltage-activated proton currents are reported for the first time in human peripheral blood T and B lymphocytes and in the human leukaemic T cell line Jurkat E6-1. The properties of H(+) currents studied using tight-seal voltage-clamp recording techniques were similar in all cells. Changing the pH gradient by one unit caused a 47 mV shift in the reversal potential, demonstrating high selectivity of the channels for protons. H(+) current activation upon membrane depolarisation had a sigmoidal time course that could be fitted by a single exponential function after a brief delay. Increasing pH(o) shifted the activation threshold to more negative potentials, and increased both the H(+) current amplitude and the rate of activation. In lymphocytes studied at pH(i) 6.0, the activation threshold was more negative and the H(+) current density was three times larger than at pH(i) 7.0. Increasing the intracellular Ca(2+) concentration to 1 microM did not change H(+) current amplitude or kinetics detectably. Extracellularly applied Zn(2+) and Cd(2+) inhibited proton currents, slowing activation and shifting the voltage-activation curve to more positive potentials. The H(+) current amplitude was 100 times larger in CD19+ B lymphocytes and in Jurkat E6-1 cells than in CD3+ T lymphocytes. Following stimulation with the phorbol ester PMA, the H(+) current density in peripheral blood T lymphocytes and Jurkat T cells increased. In contrast, the H(+) current density of phorbol ester (PMA)-stimulated B lymphocytes was reduced and activation became slower. The pattern of expression of H(+) channels in lymphocytes appears well suited to their proposed role of charge compensation during the respiratory burst.


Assuntos
Canais Iônicos/fisiologia , Linfócitos/metabolismo , Prótons , Linfócitos B/efeitos dos fármacos , Linfócitos B/metabolismo , Cálcio/fisiologia , Condutividade Elétrica , Eletrofisiologia , Humanos , Concentração de Íons de Hidrogênio , Células Jurkat , Permeabilidade , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo , Acetato de Tetradecanoilforbol/farmacologia , Fatores de Tempo
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