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1.
Dalton Trans ; 46(21): 7082-7091, 2017 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-28524209

RESUMO

Pyochelin (PCH) is a siderophore (extracellular chelator) produced by the pathogenic bacterium Pseudomonas aeruginosa (PAO). PCH is implicated in iron (Fe3+) transport to PAO, and is crucial for its metabolism and pathogenicity. Due to the chemical similarity with Fe3+, gallium (Ga3+) interferes with vital iron-dependent processes in bacterial cells, thereby opening new perspectives for the design of specific metal-based antibacterial drugs. However, the structural basis for the Fe3+-mimetic properties of Ga3+ complexed with the PCH siderophore is still lacking. A precise knowledge of the coordination chemistry at the metal site is one of the topmost issues in the production of novel biomimetic metal-based drugs. Elucidation of this issue by means of a deep structural spectroscopic investigation could lead to an improved interference with, or a specific inhibition of, relevant biological pathways. For this reason, we applied Synchrotron Radiation induced X-ray Photoelectron Spectroscopy (SR-XPS) and X-ray Absorption Spectroscopy (XAS) to probe the electronic nature and coordination chemistry of Fe3+ and Ga3+ coordinative sites in PCH metal complexes. Combined XAFS and SR-XPS studies allow us to demonstrate that both Fe and Ga have the same valence state in Fe-PCH and Ga-PCH, and have the same octahedral coordination geometry. Moreover, a similar next neighbour distribution for Fe and Ga, resulting from the EXAFS data analysis, strongly supports similar coordination chemistry at the origin of the biomimetic behaviour of Ga.


Assuntos
Complexos de Coordenação/química , Gálio/química , Fenóis/química , Pseudomonas aeruginosa/metabolismo , Tiazóis/química , Antibacterianos/química , Antibacterianos/farmacologia , Materiais Biomiméticos/química , Materiais Biomiméticos/metabolismo , Complexos de Coordenação/síntese química , Complexos de Coordenação/metabolismo , Ferro/química , Ferro/metabolismo , Conformação Molecular , Espectroscopia Fotoeletrônica , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/genética , Espectroscopia por Absorção de Raios X
2.
Eur J Paediatr Dent ; 17(1): 43-6, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26949238

RESUMO

AIM: To evaluate the consequences of prolonged sucking habits on the development of the orofacial complex in deciduous dentition. MATERIALS AND METHODS: A cross-sectional study was carried out involving 235 preschool children. A questionnaire for children parents and clinical examinations were carried out by calibrated blinded examiners. The chi-square test and the T-Student test were used for statistical analysis. RESULTS: The prevalence of non-nutritive sucking habits (NNSH) in the sample was 74%. Anterior open-bite (AOB) was detected in 18%, and it was significantly related to non-nutritive sucking habits, bottle-feeding (only in the 3-year-old group) and persistent use of pacifier (p<0.05). CONCLUSIONS: NNSH and type of feeding were important contributing factors in the development of anterior open-bite in deciduous dentition.


Assuntos
Sucção de Dedo , Mordida Aberta/epidemiologia , Chupetas/estatística & dados numéricos , Alimentação Artificial/estatística & dados numéricos , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Lactente , Itália/epidemiologia , Masculino , Prevalência , Dente Decíduo
3.
J Laryngol Otol ; 129(7): 638-43, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26091105

RESUMO

OBJECTIVE: This study aimed to examine tinnitus prevalence in patients with different types of headache and the relationship between tinnitus and the pericranial muscle tenderness and cervical muscle tenderness scores. METHODS: A cross-sectional study was conducted of 1251 patients with migraine and/or myogenous pain, arthrogenous temporomandibular joint disorders and tension-type headache. Standardised palpation of the pericranial and cervical muscles was carried out and univariable and multivariable analysis was used to measure the odds ratio of suffering tinnitus by the different diagnoses and muscular tenderness grade. RESULTS: A univariable analysis showed that myogenous pain, pericranial muscle tenderness and cervical muscle tenderness scores, sex, and age were associated with tinnitus. When a multivariable model including only age, sex and a headache diagnosis was used, myogenous pain, migraine and age were found to be associated with tinnitus. When muscle tenderness scores were also included, only the cervical muscle tenderness and pericranial muscle tenderness scores were found to be significantly associated with tinnitus. CONCLUSION: In a population of patients with headache and craniofacial pain, tinnitus was related to increased cervical muscle tenderness and pericranial muscle tenderness scores, rather than to any particular form of headache.


Assuntos
Dor Facial/epidemiologia , Transtornos da Cefaleia/epidemiologia , Transtornos de Enxaqueca/epidemiologia , Mialgia/epidemiologia , Transtornos da Articulação Temporomandibular/epidemiologia , Zumbido/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Comorbidade , Estudos Transversais , Feminino , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Sistema de Registros , Estudos Retrospectivos , Estatística como Assunto , Cefaleia do Tipo Tensional/epidemiologia , Zumbido/etiologia , Adulto Jovem
4.
Eur J Clin Microbiol Infect Dis ; 34(2): 357-65, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25217227

RESUMO

Invasive fungal infections (IFIs) are an increasing problem in intensive care units (ICUs), and conventional diagnostic methods are not always reliable or timely enough to deliver appropriate antimicrobial therapy. The dosage of fungal antigens in serum is a promising diagnostic technique, but several confounding factors, such as treatment with immunoglobulins (Ig), albumin, or antifungals, could interfere with the correct interpretation of the (1,3)-beta-D-glucan (BG) assay. This study assessed the reliability of the BG assay and the influence of timing and dosage of major confounding factors on circulating levels of IFI biomarkers. 267 ICU patients who underwent a BG assay were retrospectively studied. The timing and dosage of albumin, use of azole treatment, and infusions of intravenous IgG, red blood cells, concentrated platelets, and frozen plasma were analyzed to find possible correlations with the BG results. The sensitivity and specificity of the BG assay were calculated. The BG test in serum showed high sensitivity (82.9 %) but low specificity (56.7 %). The optimal cut-off for the test was 95.9 pg/mL. The mean BG level in proven invasive candidiasis was around 400 pg/mL. The only factor that was found to significantly confound (p < 0.05) the diagnostic performance of the BG assay was the administration of more than 30 g of albumin within 2 days prior to BG testing. The BG assay remains a useful diagnostic test in ICU patients and the levels of BG are useful in evaluating the positive predictive value of this biomarker. The only confounding factor in our study was the use of albumin.


Assuntos
Antígenos de Fungos/sangue , Candida/imunologia , Candidíase Invasiva/diagnóstico , beta-Glucanas/sangue , Idoso , Antifúngicos/sangue , Candida/isolamento & purificação , Candidíase Invasiva/microbiologia , Feminino , Humanos , Imunoglobulinas/sangue , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade , Albumina Sérica
5.
Eur J Paediatr Dent ; 14(1): 63-7, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23597224

RESUMO

AIM: This was to evaluate changes in spheno-occipital synchondrosis one year after rapid maxillary expansion (RME), in order to assess the influence that any change might have on sagittal and vertical skeletal cephalometric variables. MATERIALS AND METHODS: Patients were selected consecutively and grouped into: Group 1 comprised 30 Caucasian patients (13 m; 17 f) undergoing RME therapy; after active expansion therapy, the Haas expander was worn as passive retainer for an average of 7 months. Group 2 as control included 14 untreated subjects (6 m, 8 f), matched by age, sex and vertebral skeletal maturity (CVM method, stages 1-3). Six cephalometric variables concerning spheno-occipital synchondrosis were studied: N-S-Ba; SOS-Ba; SOS-S; S-Ba; Ba-N; S-N; nine skeletal variables for sagittal and vertical evaluation were also checked. T-test was used for comparing the 2 groups data. RESULTS: A statistically-significant opening of the spheno-occipital synchondrosis and increase of the posterior cranial base length (Ba-SOS) were found between group 1 and 2. After 1 year, these modifications in spheno-occipital syncondrosis produced no change in the anteroposterior or vertical skeletal parameters examined. CONCLUSION: After RME there were statistically significant effects on spheno-occipital synchondrosis length and cranial base angle; however, these changes in the mid-term did not affect the vertical or sagittal parameters of the skeletal maxillomandibular complex.


Assuntos
Suturas Cranianas/patologia , Mandíbula/patologia , Maxila/patologia , Osso Occipital/patologia , Técnica de Expansão Palatina , Osso Esfenoide/patologia , Estudos de Casos e Controles , Cefalometria/métodos , Criança , Feminino , Seguimentos , Humanos , Masculino , Má Oclusão de Angle Classe I/terapia , Má Oclusão de Angle Classe II/terapia , Osso Nasal/patologia , Desenho de Aparelho Ortodôntico , Contenções Ortodônticas , Técnica de Expansão Palatina/instrumentação , Base do Crânio/patologia , Dimensão Vertical
6.
Chemosphere ; 86(3): 223-7, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22024093

RESUMO

In this study we evaluated the use of Talitrus saltator as biomonitor of polybrominated diphenyl ethers (PBDEs) contamination of the supralittoral zone of Mediterranean sandy shores, an area characterized by a strong input of contaminants but not yet investigated about the presence of these pollutants. We detected the presence of twenty PBDE congeners in amphipods and sand samples collected along the Tyrrhenian coast of central Italy. Eight congeners were detected in all samples. Among them, the BDE-209 was the most abundant in both amphipods and sand samples followed by BDE-99, BDE-153 and BDE-47 in animals, and BDE-99, BDE-47 and BDE-100 in sediment. The ΣPBDEs in amphipods was higher (on the average 2.5-5-fold) than in sand for almost the totality of congeners detected and each sampling site, suggesting the good capacity of sandhoppers to accumulate these pollutants. Moreover statistical analysis revealed significant differences in PBDE concentrations recorded in tissues of T. saltator among sampling sites. Therefore our results suggested the possible utilization of T. saltator as a biomonitor of PBDE contamination of the supralittoral zone of Mediterranean sandy shores.


Assuntos
Anfípodes/metabolismo , Monitoramento Ambiental/métodos , Éteres Difenil Halogenados/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Praias , Ecossistema , Éteres Difenil Halogenados/análise , Poluentes Químicos da Água/análise
7.
Biol Bull ; 219(1): 72-9, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20813991

RESUMO

The semi-terrestrial sandhopper Talitrus saltator uses celestial visual cues to orient along the sea-land axis of the beach. Previous spectral-filtering experiments suggested that it perceives directional information from wavelengths in the ultraviolet (UV)-blue range. Binary choice experiments between dark and UV (380-nm) light carried out on dark-adapted individuals of T. saltator showed photopositive movement to UV. Morphologically, each ommatidium in the eye consists of five retinula cells, four large and one small. In electroretinogram experiments, sensitivity of the dark-adapted eye is dominated by a receptor maximally sensitive at about 390-450 nm and secondarily sensitive at about 500-550 nm. Selective light-adaptation experiments at 580 nm showed the apparent sensitivity decreasing at around the secondary sensitive range, thus disclosing the existence of UV-blue photoreceptor cells. Here the existence of UV-blue detection is confirmed, and evidence is provided that green and UV-blue visual pigments are located in the large and small retinula cells, respectively.


Assuntos
Anfípodes/fisiologia , Comportamento Animal/efeitos da radiação , Olho Composto de Artrópodes , Raios Ultravioleta , Anfípodes/efeitos da radiação , Animais , Olho Composto de Artrópodes/fisiologia , Olho Composto de Artrópodes/ultraestrutura , Eletrorretinografia/efeitos da radiação , Estimulação Luminosa , Percepção Visual
8.
Environ Pollut ; 158(5): 1638-43, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20034716

RESUMO

Trace metals are one of the groups of pollutants that reduce genetic variability in natural populations, causing the phenomenon known as "genetic erosion". In this study we evaluate the relationship between trace metals contamination (Hg, Cd and Cu) and genetic variability, assessed using fluorescent Inter-Simple Sequence Repeats (fISSRs). We used eight populations of a well-established biomonitor of trace metals on sandy beaches: the amphipod Talitrus saltator. The trace metals analysis confirmed the ability of sandhoppers to accumulate Hg, Cd and Cu. Moreover, populations from sites with high Hg availability had the lowest values of genetic diversity. Our results validate the use of fISSR markers in genetic studies in sandhoppers and support the "genetic erosion" hypothesis by showing the negative influence of Hg contamination on sandhopper genetic diversity. Therefore, genetic variability assessed with fISSR markers could be successfully employed as a biomarker of Hg exposure.


Assuntos
Anfípodes/genética , Poluentes Ambientais/metabolismo , Variação Genética , Metais Pesados/metabolismo , Dióxido de Silício/análise , Anfípodes/classificação , Anfípodes/efeitos dos fármacos , Anfípodes/metabolismo , Animais , Poluentes Ambientais/análise , Poluentes Ambientais/toxicidade , Região do Mediterrâneo , Metais Pesados/análise , Metais Pesados/toxicidade , Filogenia
9.
Cephalalgia ; 28(5): 541-52, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18318746

RESUMO

This study was an 8-month controlled trial to evaluate the effectiveness of a workplace educational and physical programme in reducing headache and neck and shoulder pain. Central registry office employees (n = 192; study group) and 192 peripheral registry office and central tax office employees (controls) in the city of Turin, Italy were given diaries for the daily recording of pain episodes. After 2 months, the study group only began the educational and physical programme. The primary end-point was the change in frequency of headache and neck and shoulder pain expressed as the number of days per month with pain, and as the proportion of subjects with a >or= 50% reduction of frequency (responder rate). The number of days of analgesic drug consumption was also recorded. Diaries completed for the whole 8 months were available for 169 subjects in the study group and 175 controls. The baseline frequency of headache (days per month) was 5.87 and 6.30 in the study group and in controls; frequency of neck and shoulder pain was 7.12 and 7.79, respectively. Mean treatment effects [days per month, 95% confidence interval (CI)] on comparing the last 2 months vs. baseline were: headache frequency -2.45 (-3.48, -1.43); frequency of neck pain -2.62 (-4.09, -1.16); responder rates (odds ratio, 95% CI) 5.51 (2.75, 11) for headache, 3.10 (1.65, 5.81) for neck and shoulder pain, and 3.08 (1.06, 8.90) for days with analgesic drug consumption. The study suggests that an educational and physical programme reduces headache and neck and shoulder pain in a working community.


Assuntos
Cefaleia/prevenção & controle , Cervicalgia/prevenção & controle , Doenças Profissionais/prevenção & controle , Educação de Pacientes como Assunto/estatística & dados numéricos , Modalidades de Fisioterapia/estatística & dados numéricos , Dor de Ombro/prevenção & controle , Adulto , Comorbidade , Feminino , Cefaleia/epidemiologia , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Cervicalgia/epidemiologia , Doenças Profissionais/epidemiologia , Terapia Ocupacional/métodos , Prevalência , Dor de Ombro/epidemiologia , Resultado do Tratamento
10.
Artigo em Inglês | MEDLINE | ID: mdl-16133498

RESUMO

Adults of Talorchestia martensii were individually released in a confined environment, with and without the natural magnetic field, under the sun and in a dark room. The sandhoppers scanned the horizontal component of the magnetic field by left and right oscillations of the entire major body axis. The frequency of this behaviour increased in a zeroed magnetic field, as did the frequencies of other behavioural indicators that reflect the difficulty in identifying the ecologically efficient orientation direction (sea-land axis). Therefore, like head scans in birds, body scans seem to be used by equatorial sandhoppers to detect the magnetic symmetry plane.


Assuntos
Anfípodes/fisiologia , Magnetismo , Orientação/fisiologia , Animais , Comportamento Animal/fisiologia , Meio Ambiente , Movimento/fisiologia , Células Receptoras Sensoriais/fisiologia , Sistema Solar
11.
Mar Pollut Bull ; 50(11): 1328-34, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15949821

RESUMO

We assessed the capacity for heavy metals accumulation in Talorchestia ugolinii by standard methods of heavy metals analysis. To compare the bioaccumulation in syntopic sandhopper species, we collected samples of T. ugolinii and Talitrus saltator living on the same and on different beaches in Corsica. There was a marked difference in the zonal distribution of the two species along the sea-land axis of the beach: T. ugolinii was distributed nearer the water line than T. saltator. The bioaccumulation capacity of T. ugolinii only partly matched that of the Mediterranean T. saltator: while Hg, Zn, Cu, and Cd were accumulated by both species, Al and Fe were accumulated by T. saltator but not by T. ugolinii. Pb was accumulated only by T. ugolinii, while Cr did not seem to be accumulated by either species. The bioaccumulation in sympatric T. saltator and T. ugolinii specimens collected on the same beach reflected the general trend of the two species on the Tyrrhenian and Corsican coasts, respectively. Moreover, six of the eight heavy metals considered (Hg, Pb, Zn, Fe, Al, Cu) were present in higher quantities in T. ugolinii than in T. saltator, independently of whether the trace elements were accumulated by the two species. Thus, there are some differences between T. ugolinii and T. saltator, even when the two species live in the same locality. These differences involve their zonation within the damp belt of sand, the bioaccumulation of some heavy metals (Al, Pb, Fe), and the quantity of each heavy metal in the body, independent of the bioaccumulation capacity.


Assuntos
Anfípodes/metabolismo , Monitoramento Ambiental/métodos , Monitoramento Ambiental/estatística & dados numéricos , Metais Pesados/farmacocinética , Animais , França , Geografia , Metais Pesados/análise , Especificidade da Espécie , Espectrofotometria Atômica
12.
Artigo em Inglês | MEDLINE | ID: mdl-15351897

RESUMO

To acquire more information about the identification and use of the sun and other celestial cues in the sea-land orientation of the sandhopper Talitrus saltator, we carried out releases in a confined environment during a partial solar eclipse and at sunset. The sandhoppers were unable to identify the sun (86% covered) during the eclipse nor to use other celestial compass factors of orientation. This was probably due to the low level of light intensity (close to the minimum level for orientation recorded at sunset) and to the variations in intensity and pattern of skylight polarization.


Assuntos
Anfípodes/fisiologia , Orientação/fisiologia , Sistema Solar , Animais , Sinais (Psicologia) , Radiometria , Luz Solar
13.
Mar Pollut Bull ; 48(5-6): 526-32, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14980468

RESUMO

The use of sandhoppers and beachfleas as biomonitors of heavy metals contamination is relatively recent. Using adult individuals of Talitrus saltator from nine localities on the northern Mediterranean Sea, we studied the concentrations of eight trace elements: Al, Cd, Cr, Fe, Hg, Pb, Cu, Zn, both in the substratum and in the individuals. We also carried out a preliminary investigation of the correspondence between the sandhoppers' genetic variability and heavy metal contamination at the sampling sites. T. saltator accumulated Cd, Cu, Zn and Hg (at higher concentrations than in the sand) and also Al and Fe (at lower concentrations than in the sand). It seems that Mediterranean sandhoppers do not accumulate Pb and Cr. An intraspecific comparison between northern European (Baltic) and Mediterranean populations of T. saltator was made. Finally, we observed a tendency to a positive correlation between the sandhoppers' genetic variability and heavy metals contamination.


Assuntos
Anfípodes/química , Monitoramento Ambiental/métodos , Metais Pesados/análise , Anfípodes/genética , Animais , Variação Genética , Genética Populacional , Mar Mediterrâneo , Metais Pesados/farmacocinética , Distribuição Tecidual
14.
Brain Res ; 871(2): 223-33, 2000 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-10899289

RESUMO

The effect of the mGluR(5) antagonist, MPEP (2-Methyl-6-(phenylethynyl)-pyridine), and of the mGluR(1) antagonist, AIDA((RS)-1-Aminoindan-1,5-dicarboxylic acid), were examined on nociceptive neurons in the ventroposterolateral (VPL) nucleus of the thalamus in response to pressure stimuli to the contralateral hindpaw of rats under urethane anesthesia. Intravenous (i.v.) injection of MPEP (0.1, 1, and 10 mg/kg) blocked responses to noxious stimulation in a dose-dependent and reversible manner. AIDA (3 and 15 mg/kg, i.v.), in contrast, had no effect on these cells. MPEP action was selective to noxious stimulation because even when tested at the highest dose (10 mg/kg, i.v.) it did not alter the responses of non-nociceptive neurons to brush stimulation. To investigate the site of action of MPEP, intra-thalamic injections were made during electrophysiological recordings. Using this method, the mGluR(5) antagonist did not affect nociceptive responses, suggesting that thalamic receptors were not involved in this action. On the other hand, the NMDA thalamic receptors seem to be involved because the NMDA receptor antagonist, MK801, successfully blocked responses to noxious pressure stimulation following intra-thalamic injections. In the spinal cord in vitro model, MPEP (30 microM, 60 min) was also able to attenuate ventral root potentials after single shock electrical stimulation of the dorsal root and inhibit wind-up response evoked by repetitive stimulation. Taken together, these findings suggest that blockade of the mGluR(5), but not mGluR(1) decreases nociceptive transmission in the thalamus and that these effects may be mediated by spinal cord receptors.


Assuntos
Antagonistas de Aminoácidos Excitatórios/farmacologia , Nociceptores/efeitos dos fármacos , Receptores de Glutamato Metabotrópico/efeitos dos fármacos , Receptores de Glutamato Metabotrópico/metabolismo , Transmissão Sináptica/efeitos dos fármacos , Animais , Estimulação Elétrica , Técnicas In Vitro , Indanos/farmacologia , Injeções Intravenosas , Masculino , Neurônios/citologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Nociceptores/metabolismo , Dor/tratamento farmacológico , Dor/fisiopatologia , Piridinas/farmacologia , Ratos , Ratos Sprague-Dawley , Receptor de Glutamato Metabotrópico 5 , Receptores de Glutamato Metabotrópico/antagonistas & inibidores , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Receptores de N-Metil-D-Aspartato/efeitos dos fármacos , Receptores de N-Metil-D-Aspartato/metabolismo , Medula Espinal/citologia , Medula Espinal/efeitos dos fármacos , Medula Espinal/metabolismo , Transmissão Sináptica/fisiologia , Núcleos Ventrais do Tálamo/citologia , Núcleos Ventrais do Tálamo/efeitos dos fármacos , Núcleos Ventrais do Tálamo/fisiopatologia
15.
Neuropharmacology ; 38(10): 1569-76, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10530818

RESUMO

The specific metabotropic glutamate receptor (mGluR)5 agonist (RS)-2-chloro-5-hydroxyphenylglycine (CHPG) is able to potentiate NMDA and AMPA responses recorded from ventral roots of the isolated hemisected baby rat spinal cord. Previously we have demonstrated that activation of group I mGluRs (mGluR1 and mGluR5) with the broad spectrum mGluR agonist 1S,3R-1-amino-1,3-cyclopentanedicarboxylate (ACPD) produced potentiation of ionotropic glutamate responses. In contrast to ACPD-induced potentiation, however, no evidence for an involvement of protein kinase C (PKC) is found in the CHPG-induced potentiation of both NMDA and AMPA depolarization because the PKC blockers chelerythrine chloride or calphostin C did not antagonize this effect. Moreover, in the absence of Ca2+ in the perfusing medium or depleting intracellular Ca2+ stores with thapsigargin or dantrolene did not modify the CHPG-induced enhancement of NMDA depolarizations. Phorbol-12,13-diacetate (PDA), on the other hand, was able to attenuate this effect, which was reversed by chelerythrine chloride. These results suggest that both mGluR5 and mGluR1 may act to enhance ionotropic glutamate responses but the two types of mGluRs may have different intracellular mechanisms of action.


Assuntos
Antagonistas de Aminoácidos Excitatórios/farmacologia , Glicina/análogos & derivados , Neurônios Motores/fisiologia , N-Metilaspartato/farmacologia , Fenilacetatos/farmacologia , Receptores de Glutamato Metabotrópico/agonistas , Medula Espinal/fisiologia , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiônico/farmacologia , Alcaloides , Animais , Animais Recém-Nascidos , Benzofenantridinas , Cálcio/metabolismo , Cicloleucina/análogos & derivados , Cicloleucina/farmacologia , Sinergismo Farmacológico , Glicina/farmacologia , Técnicas In Vitro , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Neurônios Motores/efeitos dos fármacos , Fenantridinas/farmacologia , Ratos , Ratos Sprague-Dawley , Receptor de Glutamato Metabotrópico 5
16.
Prog Neurobiol ; 59(1): 55-79, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10416961

RESUMO

Glutamate is the major excitatory neurotransmitter in the brain and plays a unique role in a variety of central nervous system (CNS) functions. The discovery of the metabotropic receptors (mGluRs), a family of G-protein coupled receptors than can be activated by glutamate, has led to an impressive number of studies in recent years aimed at understanding their biochemical, physiological and pharmacological characteristics. The eight mGluRs now known are divided into three groups according to their sequence homology, signal transduction mechanisms, and agonist selectivity. Group I mGluRs include mGluR1 and mGluR5, which are linked to the activation of phospholipase C; Groups II and III include all others and are negatively coupled to adenylyl cyclases. The availability in recent years of agents selective for Group I mGluRs has made possible the study of the physiological roles of these receptors in the CNS. In addition to mediating glutamatergic neurotransmission, Group I mGluRs can modulate other neurotransmitter receptors, including GABA and the ionotropic glutamate receptors. Group I mGluRs are involved in many CNS functions and may participate in a variety of disorders such as pain, epilepsy, ischemia, and chronic neurodegenerative diseases. This class of receptor may provide important pharmacological therapeutic targets and elucidating its functions will be relevant to develop new treatments for neurological and psychiatric disorders in which glutamatergic neurotransmission is abnormally regulated. In this review anatomical, physiological and pharmacological results are presented with a special emphasis on the role of Group I mGluRs in functional and pathological processes.


Assuntos
Encefalopatias/fisiopatologia , Encéfalo/fisiopatologia , Receptores de Glutamato Metabotrópico/fisiologia , Animais , Química Encefálica , Humanos , Potenciação de Longa Duração , Neurônios/patologia , Neurônios/fisiologia , Receptores de Glutamato Metabotrópico/agonistas , Receptores de Glutamato Metabotrópico/análise , Receptores de Glutamato Metabotrópico/antagonistas & inibidores , Transmissão Sináptica
17.
J Pharmacol Exp Ther ; 290(1): 158-69, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10381772

RESUMO

Central sensitization is a condition of enhanced excitability of spinal cord neurons that contributes to the exaggerated pain sensation associated with chronic tissue or nerve injury. N-methyl-D-aspartate (NMDA) receptors are thought to play a key role in central sensitization. We have tested this hypothesis by characterizing in vitro and in vivo a novel antagonist of the NMDA receptor acting on its glycine site, GV196771A. GV196771A exhibited an elevated affinity for the NMDA glycine binding site in rat cerebral cortex membranes (pKi = 7.56). Moreover, GV196771A competitively and potently antagonized the activation of NMDA receptors produced by glycine in the presence of NMDA in primary cultures of cortical, spinal, and hippocampal neurons (pKB = 7.46, 8. 04, and 7.86, respectively). In isolated baby rat spinal cords, 10 microM GV196771A depressed wind-up, an electrical correlate of central sensitization. The antihyperalgesic properties of GV196771A were studied in a model of chronic constriction injury (CCI) of the rat sciatic nerve and in the mice formalin test. In the CCI model GV196771A (3 mg/kg twice a day p.o.), administered before and then for 10 days after nerve ligature, blocked the development of thermal hyperalgesia. Moreover, GV196771A (1-10 mg/kg p.o.) reversed the hyperalgesia when tested after the establishment of the CCI-induced hyperalgesia. In the formalin test GV196771A (0.1-10 mg/kg p.o.) dose-dependently reduced the duration of the licking time of the late phase. These antihyperalgesic properties were not accompanied by development of tolerance. These observations strengthen the view that NMDA receptors play a key role in the events underlying plastic phenomena, including hyperalgesia. Moreover, antagonists of the NMDA glycine site receptor could represent a new analgesic class, effective in conditions not sensitive to classical opioids.


Assuntos
Analgésicos não Entorpecentes/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Hiperalgesia/tratamento farmacológico , Indóis/farmacologia , Pirróis/farmacologia , Receptores da Glicina/antagonistas & inibidores , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Animais , Comportamento Animal/efeitos dos fármacos , Ligação Competitiva , Córtex Cerebral/metabolismo , Tolerância a Medicamentos , Eletrofisiologia , Embrião de Mamíferos , Técnicas In Vitro , Masculino , Camundongos , Medição da Dor/efeitos dos fármacos , Técnicas de Patch-Clamp , Ensaio Radioligante , Ratos , Ratos Sprague-Dawley , Medula Espinal/efeitos dos fármacos
18.
Neuropharmacology ; 36(8): 1047-55, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9294969

RESUMO

Application of the metabotropic glutamate receptor (mGluR) agonist (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid (1S,3R-ACPD) and the Group I selective mGluR agonist (RS)-3,5-dihydroxyphenylglycine (DHPG) potentiated NMDA- and AMPA-induced potential changes recorded from ventral roots of the isolated hemisected baby rat spinal cord. Potentiation produced by 1S,3R-ACPD was completely abolished by the Group I selective mGluR antagonists (S)-4-carboxyphenylglycine (4CPG) or (+)-alpha-methyl-4-carboxyphenylglycine (MCPG). In addition, the protein kinase C (PKC) blockers staurosporine or chelerythrine chloride were able to antagonize the 1S,3R-ACPD-induced potentiation of both NMDA and AMPA response, suggesting that the enhancing effect induced by Group I mGluRs is modulated by a PKC-mediated mechanism. The mGluRs-induced potentiation of NMDA and AMPA responses may be important in modulating various forms of synaptic plasticity and nociceptive processes.


Assuntos
Agonistas de Aminoácidos Excitatórios/farmacologia , Neurônios Motores/efeitos dos fármacos , N-Metilaspartato/farmacologia , Receptores de Glutamato Metabotrópico/agonistas , Medula Espinal/efeitos dos fármacos , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiônico/farmacologia , Animais , Cicloleucina/análogos & derivados , Cicloleucina/farmacologia , Sinergismo Farmacológico , Glicina/análogos & derivados , Glicina/farmacologia , Técnicas In Vitro , Masculino , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Neurônios Motores/fisiologia , Proteína Quinase C/antagonistas & inibidores , Ratos , Ratos Sprague-Dawley , Resorcinóis/farmacologia , Medula Espinal/fisiologia
19.
Comp Biochem Physiol B Biochem Mol Biol ; 116(4): 407-17, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9149394

RESUMO

The effects of embryonic exposure on brain phospholipid levels were studied by injecting various concentrations of ethanol into fertile chicken eggs at 0 days of development. At 18 days of development, the levels of total phospholipids and various phospholipid classes were assayed in brain tissue and correlated to neuron densities within the cerebral hemispheres and the optic lobes. Although ethanol concentrations ranging from 0 to 3700 microns/Kg egg wt. failed to influence either total brain weight or total brain phospholipid levels, ethanol-induced changes in the levels of individual phospholipid classes were observed. When injected with 7 microns of ethanol/Kg egg wt., a 2- to 3-fold increase in brain phosphatidylethanolamine (PE) levels were observed with reduced levels of brain phosphatidylcholine (PC) and brain sphingomyelin (SP). When injected with 74 microns of ethanol/Kg egg wt., ethanol-induced increases in brain phosphatidylserine (PS) and PE were observed with ethanol-induced decreases in brain PC and SP. Cell fractionation studies demonstrated ethanol-induced increases in brain PE and PS and ethanol-induced decreases in brain PC and SP in nuclear, mitochondrial, and microsomal membranes. These ethanol-induced alterations in brain phospholipid profiles correlated with ethanol-induced reductions in neuron densities within the cerebral hemispheres and optic lobes.


Assuntos
Química Encefálica/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/fisiologia , Etanol/farmacologia , Fosfolipídeos/química , Animais , Encéfalo/embriologia , Membrana Celular/química , Membrana Celular/efeitos dos fármacos , Núcleo Celular/química , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/ultraestrutura , Embrião de Galinha , Lipídeos de Membrana/análise , Lipídeos de Membrana/química , Mitocôndrias/química , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/ultraestrutura , Neurônios/efeitos dos fármacos , Lobo Óptico de Animais não Mamíferos/efeitos dos fármacos , Fosfolipídeos/análise
20.
Anim Behav ; 54(6): 1425-1438, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9794770

RESUMO

We investigated the factors involved in the orientation of raiders of the European Amazon ant, Polyergus rufescensand how these factors are used by raiders during the different phases of slave-making expeditions. Ants at the head of the raiding column did not follow previously deposited chemical trails but oriented by celestial cues. Raiders in the middle of the column used celestial factors but were also strongly affected by the recruiting activity of the ants that preceded them. During the return trip, raiders used both chemical and celestial cues. The latter allowed the ants to assume the correct home direction while following the chemical trail. Perception of the ultraviolet band of the light spectrum was of crucial importance for the orientation of the raiders, during both the outbound and inbound journeys. This supports the hypothesis that P. rufescens workers, like other ants, perceive the pattern of polarized skylight in the ultraviolet range.Copyright 1997 The Association for the Study of Animal Behaviour

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