RESUMO
To determine Toll-like receptors (TLR)2 and TLR4 expression levels and associate them with matrix metalloproteinases (MMPs) in asymptomatic apical periodontitis (AAP), symptomatic apical periodontitis (SAP), and healthy controls. Apical tissue/lesion samples were obtained from chronic AAP (n = 35) and SAP (n = 29), and healthy periodontal ligament (HPL, n = 10) with indication of tooth extraction, respectively. mRNA expression levels of TLR2, TLR4, MMP-1, MMP-2, MMP-8, and MMP-13 were determined by real-time reverse-transcription polymerase chain reaction. The data were analyzed with Kruskal-Wallis and Dunn's pot hoc test (p < 0.05). The correlation coefficient was obtained using the Spearman correlation (p < 0.05). TLR2, MMP-1, MMP-2, and MMP-13 mRNA levels were the highest in SAP followed by AAP and controls (p < 0.05). TLR4 and MMP-8 were over expressed in AAP and SAP compared to HPL (p < 0.05). TLR2 positively correlated with TLR4, MMP-1, MMP-8, and MMP-13 in SAP (p < 0.05). TLR2 and TLR4 are overexpressed in apical lesions versus healthy periodontal ligament and correlate with collagenolytic MMPs. Particularly, TLR2 is overexpressed in SAP in association with MMP-1, MMP-8, and MMP-13. Our results suggest that the activation of TLR2 along with MMP overexpression might contribute to SAP clinical presentation and progression. TLRs, MMPs, and their interaction can explain the clinical presentations and evolution of apical periodontitis and might represent key targets for new diagnostic and treatment approaches.
Assuntos
Metaloproteinases da Matriz/metabolismo , Periodontite Periapical/metabolismo , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo , Estudos Transversais , Humanos , Periodontite Periapical/patologia , Ligamento Periodontal/efeitos dos fármacos , Ligamento Periodontal/metabolismo , Receptor 2 Toll-Like/genética , Receptor 4 Toll-Like/genética , Ápice Dentário/metabolismoRESUMO
We demonstrated a method to construct high efficiency saturable absorbers based on the evanescent light field interaction of CVD monolayer graphene deposited on side-polished D-shaped optical fiber. A set of samples was fabricated with two different core-graphene distances (0 and 1 µm), covered with graphene ranging between 10 and 25 mm length. The mode-locking was achieved and the best pulse duration was 256 fs, the shortest pulse reported in the literature with CVD monolayer graphene in EDFL. As result, we find a criterion between the polarization relative extinction ratio in the samples and the pulse duration, which relates the better mode-locking performance with the higher polarization extinction ratio of the samples. This criterion also provides a better understanding of the graphene distributed saturable absorbers and their reproducible performance as optoelectronic devices for optical applications.
RESUMO
The effect of glycine receptor activation on neurite outgrowth and survival was studied in 5 DIV (days in vitro) spinal neurons. These neurons were depolarized by spontaneous synaptic activity and by glycine, but not by glutamate. These responses were accompanied by increases in intracellular calcium concentration measured with Indo-1 and Fluo-3. Glycine (100 microM, 48 h) increased (46 +/- 6%) the number of primary neurites and total neuritic length. This effect was mediated by synaptic activity and calcium influx because TTX (1 microM) and nimodipine (4 microM) blocked the stimulatory effect of glycine. Neuronal survival, on the other hand, was not affected. This study shows for the first time the modulatory effect of glycine receptors on spinal neuron development.
Assuntos
Fatores de Crescimento Neural/metabolismo , Neuritos/metabolismo , Neurônios/metabolismo , Receptores de Glicina/metabolismo , Medula Espinal/metabolismo , Animais , Cálcio/metabolismo , Diferenciação Celular/fisiologia , Células Cultivadas , Feto , Glicina/metabolismo , Glicina/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/citologia , Receptores de Glicina/efeitos dos fármacos , Medula Espinal/citologiaRESUMO
We established two immortalized cell lines from cerebral cortex of normal (CNh) and trisomy 16 (CTb) mouse fetuses, an animal model of human trisomy 21. Those cells loaded with the fluorescent Ca2+ dyes, Indo-1 and Fluo-3, exhibited increments of intracellular Ca2+ ([Ca2+]i) in response to external glutamate, NMDA, AMPA and kainate. CTb cells exhibited higher basal Ca2+ concentrations and had higher amplitude and slower time-dependent kinetics in the decay than CNh cells, suggesting an impaired Ca2+ buffering capacity in the trisomy 16-derived cell line. Nicotine also induced increments of [Ca2+]i. The CTb cell line could represent a model for studying cellular alterations related to Down syndrome.
Assuntos
Sinalização do Cálcio/fisiologia , Córtex Cerebral/fisiologia , Cromossomos Humanos Par 16 , Trissomia , Animais , Cálcio/metabolismo , Linhagem Celular Transformada , Córtex Cerebral/citologia , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/embriologia , Feto/citologia , Ácido Glutâmico/farmacologia , Humanos , Membranas Intracelulares/metabolismo , Ácido Caínico/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Nicotina/farmacologia , Concentração Osmolar , Receptores de Glutamato/metabolismo , Valores de Referência , Trissomia/genética , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiônico/farmacologiaRESUMO
The effects of the increase of intracellular calcium, induced by membrane depolarization with 50 mM KCl, and arachidonic acid (AA) on the expression of 25-kD synaptosomal-associated protein (SNAP-25) were studied in cultured rat hippocampal and cerebellar explants, and PC12 rat pheochromocytoma cells, using immunoblot analysis. Incubation periods of 24 h and 48 h in 50 mM KCl increased SNAP-25 levels in hippocampal explants and PC12 cells, but not on cerebellar explants. Otherwise, a 24 h incubation with 10 microM AA increased SNAP-25 expression only in hippocampal explants, although 100 ng/ml phorbol 12-myristate 13-acetate (PMA) did not have effect. These results indicate that intracellular calcium and AA can modulate the expression of SNAP-25, depending on the origin of the tissue.
Assuntos
Ácido Araquidônico/farmacologia , Cálcio/metabolismo , Cerebelo/citologia , Hipocampo/citologia , Proteínas de Membrana , Proteínas do Tecido Nervoso/genética , Animais , Expressão Gênica/efeitos dos fármacos , Immunoblotting , Proteínas do Tecido Nervoso/análise , Neurônios/química , Neurônios/citologia , Neurônios/metabolismo , Células PC12 , Cloreto de Potássio/farmacologia , Ratos , Ratos Sprague-Dawley , Proteína 25 Associada a SinaptossomaRESUMO
The effect of verapamil and nimodipine on verbal learning was evaluated in a double-blind clinical trial. Thirty-seven healthy volunteers were distributed in three groups to receive a treatment with nimodipine, verapamil or placebo. Neither verapamil nor nimodipine modifies verbal learning as measured by the selective remembering test of Buschke and Fuld.
Assuntos
Bloqueadores dos Canais de Cálcio/farmacologia , Aprendizagem Verbal/efeitos dos fármacos , Adolescente , Adulto , Feminino , Humanos , Masculino , Nimodipina/farmacologia , Verapamil/farmacologiaRESUMO
The photostability and phototoxic potential of two new 4-alkyl-1,4-dihydropyridines (PCA-4230 and PCA-4248) were investigated. When these 4-alkyl-1,4-dihydropyridines were irradiated with a multilamp photoreactor (band centred at 350 nm), both exhibited a slow photodegradation showing first-order kinetics. The photodegradation rate constants were 0.37 h-1 for PCA-4248 and 0.39 h-1 for PCA-4230 in oxygenated conditions. The photodecomposition was slower for both drugs in the absence of oxygen. In order to evaluate the phototoxicity induced by these drugs, red blood cells and Hep-2 (human laringo carcinoma cell line) were irradiated using a minisolarium, which emits UVA radiation (350-390 nm). The results showed that PCA-4248 and PCA-4230 did not exhibit a phototoxic effect in the two models tested.
Assuntos
Di-Hidropiridinas/química , Eritrócitos/efeitos dos fármacos , Fármacos Fotossensibilizantes/química , Carcinoma de Células Escamosas , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Di-Hidropiridinas/efeitos da radiação , Di-Hidropiridinas/toxicidade , Eritrócitos/efeitos da radiação , Fibrinolíticos/química , Humanos , Cinética , Luz , Estrutura Molecular , Fármacos Fotossensibilizantes/toxicidade , Fatores de Tempo , Células Tumorais CultivadasRESUMO
Alterations of the cationic permeability of red blood cell membranes induced by the photosensitiser nalidixic acid were demonstrated by evaluating the potassium loss from intact erythrocytes. The results show that an increase in intracellular potassium efflux, precedes the photohemolysis induced by nalidixic acid. The addition of a nonpermeable osmotic solute, such as sucrose, inhibited photohemolysis but not the potassium loss, indicating a colloid osmotic lysis. Lipid peroxidation induced by nalidixic acid and other photosensitiser quinolones (oxolinic acid and rosoxacin) was time irradiation-dependent. Although rosoxacin was the most photoperoxidative, none of the three quinolones studied produced significant lipid peroxidation. However, of the three quinolones studied, only rosoxacin considerably diminished the percentage of the cholesterol extracted from red blood cell membranes. It is postulated that the increased cation permeability induced by nalidixic and oxolinic acids cannot be attributed to cholesterol oxidation nor to lipid peroxidation; a more probable mechanism is photo-oxidation of amino acid residues of the membrane proteins. However, the lysis induced by rosoxacin is caused by photo-oxidation of cholesterol, not excluding other cellular targets.
Assuntos
4-Quinolonas , Anti-Infecciosos/toxicidade , Eritrócitos/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Ácido Nalidíxico/toxicidade , Ácido Oxolínico/toxicidade , Potássio/metabolismo , Quinolonas/toxicidade , Permeabilidade da Membrana Celular/efeitos dos fármacos , Colesterol/análise , Cromatografia Líquida de Alta Pressão , Eritrócitos/efeitos da radiação , Humanos , Oxirredução , Fotólise/efeitos dos fármacosRESUMO
The photohaemolytic potentials of the quinolones oxolinic acid, pipemidic acid, rosoxacin, norfloxacin, ciprofloxacin and M-193324 (synthesis intermediary) were evaluated and compared with the photohaemolysis induced by nalidixic acid. Quinolones with a piperazine group in position 7 (pipemidic acid, norfloxacin and ciprofloxacin) did not induce photohaemolysis. However, oxolinic acid, rosoxacin and M-193324 produced a concentration- and oxygen-dependent photohaemolysis. Ascorbic acid, histidine and thiourea inhibited the photohaemolysis induced by oxolinic acid, rosoxacin and M-193324, suggesting a photodynamic mechanism similar to that found with nalidixic acid. In addition, deuterium oxide increased the photohaemolysis induced by photohaemolytic quinolones, indicating that this process is mediated by singlet oxygen.
Assuntos
Hemólise/efeitos dos fármacos , Quinolonas/farmacologia , Radiossensibilizantes/farmacologia , Ácido Ascórbico/farmacologia , Hemólise/efeitos da radiação , Histidina/farmacologia , Humanos , Luz , Fotólise , Relação Estrutura-Atividade , Tioureia/farmacologiaRESUMO
The phototoxic effects of nalidixic and oxolinic acids were evaluated in two types of cultured cells: chick embryo fibroblast and Hep-2 (human laryngo carcinoma cell line). In order to evaluate the phototoxicity induced by nalidixic and oxolinic acids, both cell types were irradiated for 5 min in the presence of each drug. The results showed an inverse relationship between cell survival and the concentration of the drug added to the culture medium. The concentrations of nalidixic and oxolinic acids necessary to induce a phototoxic effect were in the range of therapeutic blood levels. Both chick embryo fibroblasts and Hep-2 cells were more sensitive to the phototoxic effect induced by nalidixic acid than oxolinic acid.
Assuntos
Fibroblastos/efeitos dos fármacos , Neoplasias Laríngeas/patologia , Ácido Nalidíxico/toxicidade , Ácido Oxolínico/toxicidade , Animais , Carcinoma/patologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Embrião de Galinha , Fibroblastos/efeitos da radiação , Humanos , Luz , Células Tumorais CultivadasRESUMO
Erythrocyte lysis photosensitized by nalidixic acid was investigated. This photohemolysis was found to be oxygen dependent. The effects of various antioxidants and hydroxyl radical scavengers on photohemolysis induced by nalidixic acid suggested a photo-oxidative step. In addition, using the oxygen quencher histidine and the deuterium oxide effect on the singlet oxygen lifetime we obtained evidence indicative of a photodynamic mechanism mediated by oxygen singlet and hydroxyl radicals. On the other hand, pre-irradiated nalidixic acid was not lytic to erythrocytes, yet photoproducts of nalidixic acid demonstrated a greater photohemolytic potential than nalidixic acid itself.