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1.
Sci Total Environ ; 691: 516-527, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31325852

RESUMO

European standards for the protection of forests from ozone (O3) are based on atmospheric exposure (AOT40) that is not always representative of O3 effects since it is not a proxy of gas uptake through stomata (stomatal flux). MOTTLES "MOnitoring ozone injury for seTTing new critical LEvelS" is a LIFE project aimed at establishing a permanent network of forest sites based on active O3 monitoring at remote areas at high and medium risk of O3 injury, in order to define new standards based on stomatal flux, i.e. PODY (Phytotoxic Ozone Dose above a threshold Y of uptake). Based on the first year of data collected at MOTTLES sites, we describe the MOTTLES monitoring station, together with protocols and metric calculation methods. AOT40 and PODY, computed with different methods, are then compared and correlated with forest-health indicators (radial growth, crown defoliation, visible foliar O3 injury). For the year 2017, the average AOT40 calculated according to the European Directive was even 5 times (on average 1.7 times) the European legislative standard for the protection of forests. When the metrics were calculated according to the European protocols (EU Directive 2008/50/EC or Modelling and Mapping Manual LTRAP Convention), the values were well correlated to those obtained on the basis of the real duration of the growing season (i.e. MOTTLES method) and were thus representative of the actual exposure/flux. AOT40 showed opposite direction relative to PODY. Visible foliar O3 injury appeared as the best forest-health indicator for O3 under field conditions and was more frequently detected at forest edge than inside the forest. The present work may help the set-up of further long-term forest monitoring sites dedicated to O3 assessment in forests, especially because flux-based assessments are recommended as part of monitoring air pollution impacts on ecosystems in the revised EU National Emissions Ceilings Directive.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/estatística & dados numéricos , Monitoramento Ambiental/métodos , Ozônio/análise , Conservação dos Recursos Naturais , Ecossistema , Agricultura Florestal , Florestas , Estômatos de Plantas
2.
Aliment Pharmacol Ther ; 48(4): 440-450, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29952013

RESUMO

BACKGROUND: Cryoglobulinaemic vasculitis (CV) is a lymphoproliferative disorder related to hepatitis C virus (HCV) infection; anti-viral therapy is the first therapeutic option. CV can be incapacitating, compromising the patients' quality of life (QoL). In a controlled study, interferon-based therapy was associated with a lower virological response in vasculitic patients than in patients without vasculitis. Limited, uncontrolled data on direct-acting anti-virals are available. AIM: To evaluate safety, clinical efficacy, virological response and the impact of interferon-free treatment on QoL in HCV patients with and without mixed cryoglobulinaemia (MC). METHODS: We prospectively studied HCV patients with cryoglobulinaemia (with vasculitis-CV- and without vasculitis-MC-) and without cryoglobulinaemia (controls), treated with direct-acting anti-virals. Hepato-virological parameters, CV clinical response and impact on QoL were assessed. RESULTS: One hundred and eighty-two HCV patients were recruited (85 with CV, 54 with MC and 43 controls). A sustained virological response at 12 weeks (SVR12) was achieved in 166 (91.2%) patients (77/85 CV, 48/54 MC, 41/43 controls). In CV SVR patients, cryocrit levels progressively decreased and clinical response progressively improved, reaching 96.7%, 24 weeks after treatment. QoL, baseline physical and mental component summaries were lower in the CV group compared to the other groups (P < 0.05). Scores improved in all groups, and significantly in CV patients after SVR. CONCLUSIONS: No significant differences in SVR rates were recorded between cryoglobulinaemic patients and controls and a high clinical and immunological efficacy was confirmed in CV, supporting the role of interferon-free therapy as the first therapeutic option. Interestingly, CV patients had worse baseline QoL than other HCV-positive groups and interferon-free therapy was effective in significantly increasing QoL, suggesting the important role of direct-acting anti-viral-based therapy in improving CV's individual and social burden.


Assuntos
Antivirais/uso terapêutico , Crioglobulinemia/tratamento farmacológico , Crioglobulinemia/virologia , Hepatite C Crônica/complicações , Hepatite C Crônica/tratamento farmacológico , Adulto , Idoso , Feminino , Hepacivirus/fisiologia , Humanos , Imunoterapia , Masculino , Pessoa de Meia-Idade , Qualidade de Vida , Resposta Viral Sustentada , Resultado do Tratamento
3.
Environ Pollut ; 206: 575-81, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26310976

RESUMO

This is the longest continuous experiment where ethylenediurea (EDU) was used to protect plants from ozone (O3). Effects of long-term ambient O3 exposure (23 ppm h AOT40) on biomass of an O3 sensitive poplar clone (Oxford) were examined after six years from in-ground planting. Trees were irrigated with either water or 450 ppm EDU. Above (-51%) and below-ground biomass (-47%) was reduced by O3 although the effect was significant only for stem and coarse roots. Ambient O3 decreased diameter of the lower stem, and increased moisture content along the stem of not-protected plants (+16%). No other change in the physical wood structure was observed. A comparison with a previous assessment in the same experiment suggested that O3 effects on biomass partitioning to above-ground organs depend on the tree ontogenetic stage. The root/shoot ratios did not change, suggesting that previous short-term observations of reduced allocation to tree roots may be overestimated.


Assuntos
Poluentes Atmosféricos/toxicidade , Ozônio/toxicidade , Compostos de Fenilureia/farmacologia , Populus/efeitos dos fármacos , Madeira/efeitos dos fármacos , Poluentes Atmosféricos/análise , Biomassa , Ozônio/análise , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Caules de Planta/efeitos dos fármacos , Caules de Planta/crescimento & desenvolvimento , Populus/crescimento & desenvolvimento , Água/química , Madeira/crescimento & desenvolvimento
4.
Placenta ; 32(1): 99-101, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21093910

RESUMO

Plasma corticotrophin-releasing factor (CRF) and urocortin are elevated in preterm labour and/or fetal growth restriction (FGR). FGR is associated with reduced placental system A amino acid transporter activity and in vitro data suggest altered endocrine status could be responsible. Here we test the hypothesis that CRF and urocortin inhibit placental system A activity. Chronic (48h) exposure of term placental villous explants to these hormones (10(-7)M) significantly reduced system A activity (Na(+)-dependent (14)C-methylaminoisobutyric acid uptake), whereas 1h exposure had no effect. We propose elevated CRF and urocortin contribute to FGR through negative regulation of placental system A activity.


Assuntos
Sistema A de Transporte de Aminoácidos/metabolismo , Vilosidades Coriônicas/efeitos dos fármacos , Hormônio Liberador da Corticotropina/farmacologia , Urocortinas/farmacologia , Biópsia , Células Cultivadas , Gonadotropina Coriônica/farmacologia , Vilosidades Coriônicas/metabolismo , Vilosidades Coriônicas/patologia , Regulação para Baixo , Feminino , Idade Gestacional , Humanos , Ouabaína/farmacologia , Gravidez , Nascimento a Termo/metabolismo , Nascimento a Termo/fisiologia , Fatores de Tempo
5.
Plant Biol (Stuttg) ; 12(2): 341-54, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20398240

RESUMO

A transcriptome analysis of the Populus alba cambial region was performed with the aim of elucidating the gene network underlying the response to water deficit within the cambium and differentiating derivative cambial cells. Water stress was induced in 1-year-old P. alba plants by withholding water for 9 days. At that time, leaf predawn water potential fell to -0.8 MPa, resulting in a significant reduction in stomatal conductance, CO(2) assimilation and a consistent increment of stem shrinkage. These effects were almost fully reversed by re-hydration. The water deficit resulted in changes in gene expression that affected several functional categories, such as protein metabolism, cell wall metabolism, stress response, transporters and transcriptional regulation. The function of up- and down-regulated genes is discussed considering the physiological response of the plants to water deficit.


Assuntos
Desidratação , Perfilação da Expressão Gênica , Populus/genética , Madeira/genética , Análise de Sequência com Séries de Oligonucleotídeos , Folhas de Planta/fisiologia , Transpiração Vegetal/fisiologia , Populus/fisiologia , RNA de Plantas/genética , Água/fisiologia , Madeira/fisiologia
6.
Eur Rev Med Pharmacol Sci ; 12(5): 303-8, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19024214

RESUMO

The aim of this study was to analyze the effects about the use of a new completely flexible ring for mitral valve anuloplasty, the "Rama-Valvuloplasty-ring", in 182 patients operated on in the Pitié-Salpétrière Hospital, Paris, France for mitral valve regurgitation (MVR). From January 1998 to December 2003, 182 patients with mitral regurgitation (MR) underwent mitral reconstructive surgery at our institution with the "Rama-Valvuloplasty-Ring". This group was made up of 117 men (64.3%) and 65 women (35.7%). The age ranged from 19 to 87 years (mean 62.51 +/- 8.2 years). The patients surviving the operation were the subject of a prospective follow-up. In the preoperative stage sinus rhythm was found in 71.97% (131) of patients and atrial fibrillation in the remaining 28.03% (51) of patients. The mean NYHA FC was 2.9 +/- 1.7 and subdivided as follows: 65 patients in FC I-II (35.72%), 104 patients in FC III (57.14%) and 13 patients in FC IV (7.14%). Most of the patients have shown, in the preoperative echocardiogram, grade II M.R. (46.15% N. 84) and grade III M.R. (29.12%, N.53); 24.72% of the patients (N. 45) had grade IV M.R. The mean E.F. was 42.8 +/- 9.7%. Left ventricular end diastolic diameter (LVEDD) was 57.7 +/- 9.7 mm. The causes of mitral valve insufficiency were degenerative disease in 141 patients (77.47%), post-ischemic disease in 21 patients (11.53%), rheumatic valvular disease in 11 patients (6.05%) and infectious endocarditis in 9 patients (4.95%). All the patients were operated using the Rama-Valvuloplasty-Ring. Ring sizes most commonly used were 30 mm and 32 mm, respectively in 92 patients (50.55%) and 41 patients (22.54%), followed by 28 mm (43 patients, 23.62%), 34 mm (5 patients, 2.74%), 36 mm (1 patient, 0.55%). The surgical tecnique was valve quadrangular resection in 103 patients (56.60%), triangular resection in 57 patients (31.32%) and no valve resection in 22 patients (12.08%). Among the above, 89 patients (48.90%) underwent an associated intervention as follows: 44 patients (24.18%) underwent coronary revascularization: 18 patients (9.89%) with single by-pass surgery, 21 patients (11.54%) with double by-pass, 5 patients with triple by-pass (2.75%); 42 patients (23.07) underwent aortic valve replacement (AVR); 3 patients (1.65%) underwent aortic repair. Early postoperative mortality was 2.19% (4 of 182 patients). Early postoperative echocardiographic control showed MR grade 0 in 142 patients (79.78%) and grade I in 36 (20.22%) with mean grade 0.4 +/- 0.12; no patients with grade III or IV. Therefore, there was no mitral annuloplasty failure requiring valve replacement (MVR). During the follow-up there were 12 late deaths (12 of 178 patients, 6.74%). Only one death was valve-related (thrombosis) whereas the other 11 ones were non cardiac-related deaths (subdural frontal haematoma, septic shock). Postoperative transthoracic echocardiogram data were available in 166 patients at 5 years: the presence of postoperative MR was evaluated and severity was graded as mild in 33 patients (19.88%), moderate in 18 patients (10.84%), severe in 3 (1.81%) patients. There was no MR in the other 112 patients (67.47%); LVEDD was 49.4 +/- 6.5 mm; EF was 51.8 +/- 4.3%. The mean NYHA FC was 0.8 +/- 0.4. Only one patient was reoperated on during the follow-up because of mitral annuloplasty failure with MVR. In conclusion, mid-term 5-years follow up is good for patients operated on with the new completely flexible Rama-Valvuloplasty-Ring for mitral annuloplasty. This study has also verified the advantage about the Rama-Valvuloplasty-Ring use in the preservation of native valve apparatus.


Assuntos
Próteses Valvulares Cardíacas , Insuficiência da Valva Mitral/cirurgia , Valva Mitral , Idoso , Feminino , Seguimentos , França , Próteses Valvulares Cardíacas/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Insuficiência da Valva Mitral/diagnóstico por imagem , Ultrassonografia
7.
Eur Rev Med Pharmacol Sci ; 12(4): 271-4, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18727461

RESUMO

The isthmic aortic rupture represents the main cause of death in car crash accidents, because of closed chest trauma. Early medical and surgical care and endovascular prosthesis treatment with semi-invasive method can improve short and mid term survival. Nine patients with traumatic isthmic aortic rupture underwent endoprosthesis aortic implantation. All the patients were male, mean age 42.48 +/- 17.66 years. Operations included 5 acute cases and 4 chronic cases (chance diagnosis). In all cases the diagnosis was performed by tomodensitometric exam. Cloth prostheses were used (self-expansible Goretex- or Dacron-stent). Three years after the endoprosthesis implantation, we obtained the complete thrombosis of the false aortic lumen in all patients, both acute and chronic, as well as the levelling of the false aneurysms without complications of any kind.


Assuntos
Ruptura Aórtica/cirurgia , Implante de Prótese Vascular/métodos , Prótese Vascular , Stents , Doença Aguda , Adulto , Aorta/lesões , Aorta/cirurgia , Implante de Prótese Vascular/efeitos adversos , Doença Crônica , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Trombose/etiologia , Tomografia Computadorizada por Raios X/métodos , Ferimentos não Penetrantes
8.
Eur J Endocrinol ; 157(3): 279-84, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17766709

RESUMO

OBJECTIVE: Placental corticotropin-releasing factor (CRF) affects myometrial contractility and the secretion of several uterotonins such as prostaglandins (PGs); however, the activity of CRF is counteracted by CRF-binding protein (CRF-BP). At term and pre-term labor, CRF levels in maternal plasma are highest whereas those of CRF-BP are falling, and the cause of this fall is unknown. Thus, in this study, we investigated the effect of PG administration for labor induction on maternal plasma CRF and CRF-BP concentrations. DESIGN: Maternal plasma CRF and CRF-BP levels were assayed before and after (2 h later) induction of labor by intracervical administration of prostaglandin E(2) (PGE(2)), and at delivery in a group of healthy post-term pregnancies (n=18). Controls were women at term out of labor (n=22), who subsequently progressed to deliver a healthy singleton baby. METHODS: CRF was measured by two-site immunoradiometric assay, and CRF-BP was assayed by radioimmunoassay. RESULTS: Maternal plasma CRF levels were significantly (P<0.0001) lower and CRF-BP significantly (P<0.0005) higher in post-term than in term pregnancies. With respect to induction of labor, 2 mg PGE(2) were sufficient to increase maternal plasma CRF levels at delivery (P<0.005). While 0.5 mg PGE(2) significantly decreased maternal plasma CRF-BP levels at delivery (P<0.001), 2.0 mg PGE(2) significantly reduced CRF-BP concentrations both after 2 h (P<0.05) and at delivery (P<0.0001). CONCLUSIONS: In the light of the well-known stimulation of prostaglandin release by CRF, these data suggest a positive feedback effect of PGE(2) on maternal CRF release during induced labor.


Assuntos
Proteínas de Transporte/sangue , Hormônio Liberador da Corticotropina/sangue , Dinoprostona/administração & dosagem , Trabalho de Parto Induzido/métodos , Ocitócicos/administração & dosagem , Gravidez Prolongada/sangue , Adulto , Dinoprostona/metabolismo , Retroalimentação Fisiológica/efeitos dos fármacos , Feminino , Humanos , Recém-Nascido , Ocitócicos/metabolismo , Parto/sangue , Parto/efeitos dos fármacos , Gravidez , Contração Uterina/efeitos dos fármacos , Contração Uterina/metabolismo
9.
Placenta ; 28(10): 1020-3, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17561251

RESUMO

INTRODUCTION: Neurokinin B (NKB) is a neuropeptide belonging to the family of tachykinins-related peptides that elicits contractility of human myometrial strips in vitro. The present study evaluates whether placental mRNA and peptide expression of NKB change in women at preterm labor. METHODS: A group of 26 women with singleton pregnancies were enrolled in the study. Placental tissue specimens were collected from pregnant women delivering after elective cesarean section, after labor at term, or after preterm labor. Changes in placental NKB mRNA and protein expression were evaluated by real-time quantitative RT-PCR analysis and by immunofluorescence respectively. RESULTS: Placental mRNA expression of NKB was significantly higher after term and preterm labor (P<0.001) than cesarean section, and highest after preterm labor. Immunofluorescent staining in placentas from preterm or term labor was more intense than after cesarean section (P<0.001). In particular, NKB protein expression was higher in placentas collected after preterm labor than those collected after term labor. DISCUSSION: Neurokinin B mRNA and protein are highly expressed in placenta at term and preterm labor; thus, the involvement of this neuropeptide in the events cascade leading to parturition may be suggested.


Assuntos
Trabalho de Parto/fisiologia , Neurocinina B/genética , Trabalho de Parto Prematuro/fisiopatologia , Placenta/fisiopatologia , Estudos Transversais , Feminino , Humanos , Neurocinina B/biossíntese , Gravidez , RNA Mensageiro/metabolismo
10.
Ital J Anat Embryol ; 110(2 Suppl 1): 183-7, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16101037

RESUMO

In this review we present data concerning the localization of some important growth factors and their receptors in the human placenta. We focus our attention on molecules playing a fundamental role in angiogenesis and morphologic processes as beta-FGF, EGF and TGF-beta. The distribution of these growth factors and their receptors in the placental villi during gestation suggests that these molecules play a pivotal role in growth and differentiation of the villous tree.


Assuntos
Substâncias de Crescimento/metabolismo , Placenta/metabolismo , Placentação/fisiologia , Receptores de Fatores de Crescimento/metabolismo , Vilosidades Coriônicas/irrigação sanguínea , Vilosidades Coriônicas/metabolismo , Vilosidades Coriônicas/ultraestrutura , Feminino , Humanos , Microcirculação/crescimento & desenvolvimento , Microcirculação/ultraestrutura , Neovascularização Fisiológica/fisiologia , Placenta/irrigação sanguínea , Circulação Placentária/fisiologia , Gravidez
11.
Biometals ; 13(3): 217-22, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11127893

RESUMO

The Cu site structure of human serotransferrin and hen ovotransferrin using XANES spectroscopy has been investigated. Although the transferrin family proteins have been extensively studied, the results reported herein are the first concerning the structure of the metal site in C-terminal and N-terminal in the whole protein. Our structural data show that these proteins differ with regard to the independence of the two binding sites and the geometry of copper coordination, ranging from a poorly to a significantly distorted octahedron.


Assuntos
Conalbumina/química , Cobre/química , Transferrina/química , Animais , Sítios de Ligação , Galinhas , Humanos , Fragmentos de Peptídeos/química , Espectrometria por Raios X , Espectrofotometria Ultravioleta
12.
J Physiol ; 529 Pt 1: 83-91, 2000 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-11080253

RESUMO

1. The influx of Zn2+ through the channels of fetal and adult mouse muscle nicotinic acetylcholine receptors (gamma- and epsilon-AChRs) and its effects on receptor function were studied in transiently transfected human BOSC 23 cells, by combining patch-clamp recordings with digital fluorescence microscopy. 2. ACh-induced whole-cell currents were reversibly reduced by external ZnCl2, with half-maximal inhibitory concentrations of 3 and 1 mM for gamma- and epsilon-AChRs, respectively. 3. Both gamma- and epsilon-AChR channels were permeable to Zn2+, as shown by fluorescence measurements using Zn2+-sensitive dyes. The fractional current carried by Zn2+ (Pf,Zn; 0.5 mM Zn2+ in Ca2+- and Mg2+-free medium) through gamma- and epsilon">-AChR channels was 1.7 and 4 %, respectively. 4. Pf,Zn increased with the concentration of ZnCl2, but was little affected by physiological concentrations of Ca2+ and Mg2+ in the external medium. 5. The conductance of ACh-evoked unitary events, measured by cell-attached or outside-out recordings, decreased when the patched membrane was exposed to ZnCl2 (1 or 3 mM). Simultaneous application of ACh and Zn2+ to the extra-patch membrane lengthened channel open duration (tau op) by 50%. No obvious increment of tau op was observed following exposure of inside-out patches to Zn2+. 6. The possible physiological relevance of zinc-induced modulation of AChR channels is discussed.


Assuntos
Canais Iônicos/metabolismo , Músculo Esquelético/metabolismo , Receptores Colinérgicos/metabolismo , Zinco/metabolismo , Animais , Linhagem Celular , Estimulação Elétrica , Eletrofisiologia , Canais Iônicos/ultraestrutura , Camundongos , Microscopia Confocal , Músculo Esquelético/ultraestrutura , Nicotina/farmacologia , Agonistas Nicotínicos/farmacologia , Técnicas de Patch-Clamp , Permeabilidade , Receptores Colinérgicos/ultraestrutura , Espectrometria de Fluorescência
13.
Eur J Neurosci ; 12(7): 2497-504, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10947825

RESUMO

The functional expression of the seven-transmembrane domain G protein-coupled chemokine receptor CXCR-4/fusin in rat nerve cell was demonstrated by staining with a polyclonal anti-CXCR-4 Ab, and by evaluating the calcium responses to the physiological agonist stromal-derived cell factor-1alpha (SDF-1alpha) in both cerebellar granule cells in culture and Purkinje neurons (PNs) in cerebellar slices. Cerebellar glial, granule and Purkinje cells showed a pronounced staining for CXCR-4. Furthermore, cultured granule cells exhibited Ca2+ transients elicited by the application of SDF-1alpha, both in cell bodies and in neuronal processes. Whole-cell patch-clamped PNs in cerebellar slices responded to SDF-1alpha application by a slow inward current followed by an increase of both intracellular Ca2+ level and spontaneous synaptic activity. In particular, the SDF-1alpha-induced slow inward current was considerably reduced by ionotropic glutamate receptor blockers, but developed fully in a medium in which synaptic transmission was inhibited, indicating that this current might be, at least in part, mediated by extrasynaptic glutamate, possibly released from the surrounding glial and/or nerve cells. Taken together, these findings indicate a functional involvement of CXCR-4 in the modulation of synaptic transmission, adding another member to the repertoire of the chemokine receptors exerting a neuromodulatory role in the cerebellum.


Assuntos
Quimiocinas CXC/farmacologia , Células de Purkinje/fisiologia , Transmissão Sináptica/efeitos dos fármacos , 6-Ciano-7-nitroquinoxalina-2,3-diona/farmacologia , Animais , Anticorpos , Cálcio/metabolismo , Células Cultivadas , Quimiocina CXCL12 , Eletrofisiologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Microglia/química , Microglia/citologia , Microglia/fisiologia , Microscopia Confocal , Neuroimunomodulação/fisiologia , Neurônios/química , Neurônios/citologia , Neurônios/fisiologia , Células de Purkinje/química , Células de Purkinje/citologia , Ratos , Ratos Wistar , Receptores CXCR4/análise , Receptores CXCR4/imunologia , Transmissão Sináptica/fisiologia , Tetrodotoxina/farmacologia
14.
Proc Natl Acad Sci U S A ; 97(11): 6197-201, 2000 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-10811878

RESUMO

Cultured cerebellar granule neurons are widely used as a cellular model to study mechanisms of neuronal cell death because they undergo programmed cell death when switched from a culture medium containing 25 mM to one containing 5 mM K(+). We have found that the growth-related gene product beta (GRObeta) partially prevents the K(+)-depletion-induced cell death, and that the neuroprotective action of GRObeta on granule cells is mediated through the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) type of ionotropic glutamate receptors. GRObeta-induced survival was suppressed by 6-cyano-7-nitroquinoxaline-2,3-dione, which is a specific antagonist of AMPA/kainate receptors; it was not affected by the inhibitor of N-methyl-D-aspartate receptors, 2-amino-5-phosphonopentanoic acid, and was comparable to the survival of granule cells induced by AMPA (10 microM) treatment. Moreover, GRObeta-induced neuroprotection was abolished when granule cells were treated with antisense oligonucleotides specific for the AMPA receptor subunits, which significantly reduced receptor expression, as verified by Western blot analysis with subunit-specific antibodies and by granule cell electrophysiological sensitivity to AMPA. Our data demonstrate that GRObeta is neurotrophic for cerebellar granule cells, and that this activity depends on AMPA receptors.


Assuntos
Apoptose/efeitos dos fármacos , Benzodiazepinas , Córtex Cerebelar/efeitos dos fármacos , Quimiocinas CXC , Fatores Quimiotáticos/farmacologia , Substâncias de Crescimento/farmacologia , Peptídeos e Proteínas de Sinalização Intercelular , Proteínas do Tecido Nervoso/fisiologia , Fármacos Neuroprotetores/farmacologia , Receptores de AMPA/fisiologia , 2-Amino-5-fosfonovalerato/farmacologia , 6-Ciano-7-nitroquinoxalina-2,3-diona/farmacologia , Animais , Ansiolíticos/farmacologia , Córtex Cerebelar/citologia , DNA Complementar/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Interleucina-8/farmacologia , Ativação do Canal Iônico , Proteínas do Tecido Nervoso/efeitos dos fármacos , Proteínas do Tecido Nervoso/genética , Oligodesoxirribonucleotídeos Antissenso/farmacologia , Potássio/farmacologia , Potássio/fisiologia , Ratos , Ratos Wistar , Receptores de AMPA/efeitos dos fármacos , Receptores de AMPA/genética , Receptores de N-Metil-D-Aspartato/efeitos dos fármacos
15.
Clin Cancer Res ; 6(4): 1590-7, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10778993

RESUMO

The relationship between modification of energy metabolism and extent of drug resistance was investigated in two sublines (LoVoDX and LoVoDX10) from human LoVo colon carcinoma cells that exhibit different degrees of resistance to doxorubicin. Results indicated that the extent of alteration in energy metabolism strictly correlated with degree of resistance. In LoVoDX cells, only 14CO2 production was enhanced, whereas in the more resistant LoVoDX10 cells, both 14CO2 and aerobic lactate production were stimulated. The basal and glucose-supported efflux rate and the amount of drug extruded by LoVoDX10 cells were significantly higher than in the resistant LoVoDX cells. Because the expression of surface P-170 glycoprotein was similar in both cell lines, this phenomenon was attributed to increased efflux pump activity resulting from greater ATP availability. Inhibition of 14CO2 production, aerobic glycolysis, and clonogenic activity by lonidamine (LND) increased with enhancement of the energy metabolism. Moreover, LND, by affecting energy-yielding processes, reduced intracellular ATP content, lowered the energy supply to the ATP-driven efflux pump, and inhibited, almost completely, doxorubicin extrusion by resistant LoVo cells. These findings strongly suggest that LND, currently used in tumor therapy, reduces drug resistance by restoring the capacity to accumulate and retain drug of cells with the MDR phenotype that overexpress P-170.


Assuntos
Neoplasias do Colo/metabolismo , Metabolismo Energético , Trifosfato de Adenosina/metabolismo , Antineoplásicos/farmacologia , Dióxido de Carbono/metabolismo , Divisão Celular/efeitos dos fármacos , Citrato (si)-Sintase/metabolismo , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/patologia , Relação Dose-Resposta a Droga , Doxorrubicina/farmacologia , Resistencia a Medicamentos Antineoplásicos , Metabolismo Energético/efeitos dos fármacos , Glucose/metabolismo , Hexoquinase/metabolismo , Humanos , Indazóis/farmacologia , Concentração Inibidora 50 , Isocitrato Desidrogenase/metabolismo , Cinética , Ácido Láctico/metabolismo , Células Tumorais Cultivadas/efeitos dos fármacos , Células Tumorais Cultivadas/metabolismo
16.
J Biol Chem ; 274(51): 36537-43, 1999 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-10593952

RESUMO

The growth-related gene product beta (GRObeta) is a small chemoattractant cytokine that belongs to the CXC chemokine family, and GRObeta receptors are expressed in the brain, including the cerebellum. We demonstrate that rat cerebellar granule neurones express the GRObeta receptor CXCR2. We also show that, in addition to the known stimulation of a phosphoinositide-specific phospholipase C, GRObeta activates both neutral (N-) and acidic (A-) sphingomyelinases (SMase) and the stress-activated c-Jun N-terminal kinase 1 (JNK1). Although both exogenous ceramide and bacterial SMase stimulate JNK1, GRObeta-induced JNK1 activation is an event probably independent of ceramide generated by A-SMase, since it is maintained in the presence of compounds that block A-SMase activity. This is the first report on the activation of the SMase pathway by chemokines.


Assuntos
Cerebelo/metabolismo , Quimiocinas CXC , Fatores Quimiotáticos/metabolismo , Substâncias de Crescimento/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Neurônios/metabolismo , Esfingomielinas/metabolismo , Animais , Fatores Quimiotáticos/genética , Ativação Enzimática , Regulação da Expressão Gênica , Substâncias de Crescimento/genética , Hidrólise , Proteínas Quinases JNK Ativadas por Mitógeno , Ratos , Ratos Wistar , Transdução de Sinais
17.
Neuroreport ; 9(16): 3601-6, 1998 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-9858367

RESUMO

We report here that, in cultured cerebellar granule cells, the CXC chemokine GRObeta stimulates the signaling pathway of the extracellular signal-regulated kinases, and enhances both evoked and spontaneous postsynaptic currents in patch clamped Purkinje neurons from rat cerebellar slices. The GRObeta-induced enhancement of the excitatory post-synaptic currents evoked by stimulating the parallel fibres is blocked by the inhibitor of the extracellular signal-regulated kinases pathway PD98059, which also reduces both basal frequency of spontaneous post-synaptic currents and mean amplitude of evoked excitatory post-synaptic currents. Our results suggest that GRObeta modulates neurotransmitter release in the cerebellum through the activation of the extracellular signal-regulated kinases pathway.


Assuntos
Quimiocinas CXC , Fatores Quimiotáticos/metabolismo , Inibidores do Crescimento/metabolismo , Substâncias de Crescimento/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular , Proteínas Quinases Ativadas por Mitógeno , Neurotransmissores/metabolismo , Células de Purkinje/enzimologia , Animais , Proteínas Quinases Dependentes de Cálcio-Calmodulina/antagonistas & inibidores , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Células Cultivadas , Quimiocina CXCL1 , Inibidores Enzimáticos/farmacologia , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Potenciais Pós-Sinápticos Excitadores/fisiologia , Flavonoides/farmacologia , Proteína Quinase 1 Ativada por Mitógeno , Proteína Quinase 3 Ativada por Mitógeno , Técnicas de Cultura de Órgãos , Técnicas de Patch-Clamp , Células de Purkinje/citologia , Ratos , Transdução de Sinais/fisiologia , Transmissão Sináptica/fisiologia , Tetrodotoxina/farmacologia
18.
Thromb Haemost ; 80(1): 58-64, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9684786

RESUMO

Cardiopulmonary bypass (CPB) is associated with impaired platelet function and a systemic inflammatory response. The present study was designed to evaluate whether any correlation between platelet activation and inflammatory response during CPB exists. The results obtained from 8 patients undergoing hypothermic CPB for cardiac surgery showed the occurrence of a moderate degree of platelet activation during CPB, demonstrated by an increase of platelet CD62P expression in correlation with an increase of beta-thromboglobulin levels, with a concomitant decrease of in vitro platelet response. Plasma IL-1beta levels significantly increased during CPB, with a peak between 1 and 4 h after CPB. Similarly, IL-6 levels were elevated 30 min from CPB starting, peaked at 4 h, and remained elevated after 24 h. A direct correlation was found between plasma IL-1beta and IL-6 levels. A significant correlation between plasma IL-1beta and beta-thromboglobulin levels was also found. In turn, plasma beta-thromboglobulin levels correlated with CD62P expression on activated platelets. An inverse correlation was found between in vitro platelet aggregation and plasma IL-1beta or IL-6 levels. From the present results it may be speculated that platelet activation during CPB may contribute, through the release of IL-1beta, to activation of endothelial cells and subsequent release of other cytokines with chemotactic and pro-inflammatory properties, thus playing an important role in the inflammatory response associated with CPB.


Assuntos
Ponte Cardiopulmonar/efeitos adversos , Citocinas/biossíntese , Hipotermia Induzida , Inflamação/etiologia , Ativação Plaquetária , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polímeros , Propriedades de Superfície
19.
J Neuroimmunol ; 92(1-2): 122-32, 1998 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-9916887

RESUMO

We give here evidence that Purkinje neurons (PNs) of mouse cerebellar slices studied with patch clamp technique combined with laser confocal microscopy, respond to human IL-8 and GROalpha by (i) a cytosolic Ca2+ transient compatible with inositol (1,4,5) trisphosphate (InsP3) formation; (ii) an enhancement of the neurotransmitter release; and (iii) an impairment of the long-term depression of synaptic strength (LTD). It was also found the expression of IL-8 receptor type 2 in PN and granule cells by immunofluorescence, immunoblotting and RT-PCR analysis. Considered together these findings suggest that IL-8 and GROalpha may play a neuromodulatory role on mouse cerebellum.


Assuntos
Quimiocinas CXC , Fatores Quimiotáticos/farmacologia , Inibidores do Crescimento/farmacologia , Substâncias de Crescimento/farmacologia , Peptídeos e Proteínas de Sinalização Intercelular , Interleucina-8/farmacologia , Células de Purkinje/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Cálcio/metabolismo , Quimiocina CXCL1 , Citosol/metabolismo , Condutividade Elétrica , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Potenciais Pós-Sinápticos Excitadores/fisiologia , Corantes Fluorescentes , Humanos , Técnicas In Vitro , Inositol 1,4,5-Trifosfato/metabolismo , Potenciação de Longa Duração/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Compostos Orgânicos , Células de Purkinje/metabolismo , Células de Purkinje/fisiologia , Ratos , Ratos Wistar , Receptores de Quimiocinas/metabolismo , Receptores de Interleucina/metabolismo , Receptores de Interleucina-8B
20.
Biometals ; 10(4): 363-7, 1997 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9353887

RESUMO

The Al site structure of serum transferrin and lactoferrin is investigated using X-ray absorption near edge structure (XANES) spectroscopy. Al K-edge spectra in the mono- and dialuminum forms of the proteins have been recorded for the first time. Our results show that the aluminium ion is hexa-coordinated in an octahedral-like symmetry and that the monoaluminum form, where only the C-terminal binding site is saturated, has an increased structural distortion around the metal site.


Assuntos
Alumínio/análise , Lactoferrina/química , Transferrina/química , Alumínio/química , Sítios de Ligação , Espectrometria por Raios X
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