Behavior of rat bone marrow stem cells on titanium surfaces modified by laser-beam and deposition of calcium phosphate.

OBJECTIVES: The aim of this study was to evaluate the behavior of rat bone marrow stem cells seeded on a Ti-15Mo alloy surface modified by laser-beam irradiation followed by calcium phosphate deposition. MATERIALS AND METHODS: A total of four groups were evaluated: polished commercially pure titanium (cpTi): Ti-P; laser irradiation + calcium phosphate deposition on cpTi: Ti-LCP; polished Ti-15Mo alloy: Ti15Mo-P; and laser irradiation + calcium phosphate deposition on Ti-15Mo alloy: Ti15Mo-LCP. Before and after laser irradiation and calcium phosphate deposition on the surfaces, physicochemical and morphological analyses were performed: Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDX). The wettability of the samples was evaluated by contact angle measurement. In addition, the behavior of osteoblast-like cells to these surfaces was evaluated for cell morphology, adhesion, proliferation and viability, evaluation of alkaline phosphatase formation and gene expression of osteogenesis markers. RESULTS: Surfaces wet-abrade with grit paper (P) showed oriented groves, while the laser irradiation and calcium phosphate deposition (LCP) produced porosity on both cpTi and Ti15Mo alloy groups with deposits of hydroxyapatite (HA) crystals (SEM). EDX showed no contamination after surface modification in both metal samples. A complete wetting was observed for both LCP groups, whereas P surfaces exhibited high degree of hydrophobicity. There was a statistical difference in the intragroup comparison of proliferation and viability (p < 0.05). The ALP activity showed higher values in the Ti15Mo alloy at 10 days of culture. The gene expression of bone related molecules did not present significant differences at 7 and 14 days among different metals and surface treatments. CONCLUSION: Ti15-Mo seems to be an alternative alloy to cpTi for dental implants. Surface treatment by laser irradiation followed by phosphate deposition seems to positively interact with bone cells. CLINICAL RELEVANCE: Ti-15Mo alloy surface modified by laser-beam irradiation followed by calcium phosphate deposition may improve and accelerate the osseointegration process of dental implants.

Maturação in vitro de oócitos de cutias (Dasyprocta prymnolopha, Wagler 1831) seguida de fertilização in vitro e ativação partenogenética / In vitro maturation of agoutis (Dasyprocta prymnolopha) oocytes followed by in vitro fertilization and parthenogenetic activation

O objetivo foi avaliar protocolos de maturação in vitro (MIV) para oócitos de cutias, seguida de fertilização in vitro (FIV) e ativação partenogenética (AP). Os oócitos imaturos (CCOs) foram obtidos por fatiamento do ovário, após OSH, e submetidos a três grupos: MAT - 16 (16 horas de maturação), MAT - 20 (20 horas de maturação) e MAT - 24 (24 horas de maturação), em incubadora de cultivo a 38,8°C, com atmosfera de 5% de CO2 e 95% de umidade relativa. A maturação foi analisada pela presença do primeiro corpúsculo polar. Em seguida, os CCOs maduros foram submetidos à FIV, com período de coincubação dos CCOs e dos espermatozoides de 15h, a 38,8ºC e 5% de CO2, e AP com ionomicina. Os grupos de MIV foram analisados utilizando-se o teste qui-quadrado e, nos experimentos de FIV e AP, foram analisadas a taxa de clivagem e a proporção de desenvolvimento embrionário. A análise estatística foi realizada utilizando-se o programa SAS. Houve diferença significativa entre os grupos de maturação, tendo os grupos MAT - 20 e MAT - 24 apresentado maior porcentagem de oócitos maturados in vitro. As taxas de clivagem e de desenvolvimento embrionário foram de 8,6% e 2,9%, respectivamente, na FIV, e de 63,6% e 15,1%, na AP. Entretanto, nos dois casos, o embrião não passou do estágio de mórula.(AU)

The objective was to evaluate IVM protocols for agouti oocytes, followed by in vitro fertilization (IVF) and parthenogenetic activation (PA). The immature oocytes (CCOs) were obtained by slicing the ovary after OSH and submitted to three groups: MAT - 16 (16 hours maturation), MAT - 20 (20 hours maturation) and MAT - (24 hours maturation), in a culture incubator at 38.8°C, with an atmosphere of 5% CO2 and 95% relative humidity. The maturation was analyzed by the presence of the first polar corpuscle. Then, mature CCOs were submitted to IVF, with co-incubation period of CCOs and spermatozoa from 15h to 38.8°C and 5% of CO2, and PA with inomycin. The IVM groups were analyzed using the chi-square test and in the FIV and PA experiment the rate of cleavage and the rate of embryonic development were analyzed. Statistical analysis was performed using the SAS program. There was a significant difference between the maturation groups, and the MAT - 20 and MAT - 24 groups showed a higher percentage of matured oocytes in vitro. The rates of cleavage and embryonic development were 8.6% and 2.9%, respectively in FIV and 63.6% and 15.1% in PA. However, in both cases the embryo did not pass beyond the morula stage.(AU)

Effect of (+)-dehydrofukinone on GABAA receptors and stress response in fish model.

(+)-Dehydrofukinone (DHF) is a major component of the essential oil of Nectandra grandiflora (Lauraceae), and exerts a depressant effect on the central nervous system of fish. However, the neuronal mechanism underlying DHF action remains unknown. This study aimed to investigate the action of DHF on GABAA receptors using a silver catfish (Rhamdia quelen) model. Additionally, we investigated the effect of DHF exposure on stress-induced cortisol modulation. Chemical identification was performed using gas chromatography-mass spectrometry and purity was evaluated using gas chromatography with a flame ionization detector. To an aquarium, we applied between 2.5 and 50 mg/L DHF diluted in ethanol, in combination with 42.7 mg/L diazepam. DHF within the range of 10-20 mg/L acted collaboratively in combination with diazepam, but the sedative action of DHF was reversed by 3 mg/L flumazenil. Additionally, fish exposed for 24 h to 2.5-20 mg/L DHF showed no side effects and there was sustained sedation during the first 12 h of drug exposure with 10-20 mg/L DHF. DHF pretreatment did not increase plasma cortisol levels in fish subjected to a stress protocol. Moreover, the stress-induced cortisol peak was absent following pretreatment with 20 mg/L DHF. DHF proved to be a relatively safe sedative or anesthetic, which interacts with GABAergic and cortisol pathways in fish.

Effect of (+)-dehydrofukinone on GABAA receptors and stress response in fish model

(+)-Dehydrofukinone (DHF) is a major component of the essential oil of Nectandra grandiflora (Lauraceae), and exerts a depressant effect on the central nervous system of fish. However, the neuronal mechanism underlying DHF action remains unknown. This study aimed to investigate the action of DHF on GABAA receptors using a silver catfish (Rhamdia quelen) model. Additionally, we investigated the effect of DHF exposure on stress-induced cortisol modulation. Chemical identification was performed using gas chromatography-mass spectrometry and purity was evaluated using gas chromatography with a flame ionization detector. To an aquarium, we applied between 2.5 and 50 mg/L DHF diluted in ethanol, in combination with 42.7 mg/L diazepam. DHF within the range of 10-20 mg/L acted collaboratively in combination with diazepam, but the sedative action of DHF was reversed by 3 mg/L flumazenil. Additionally, fish exposed for 24 h to 2.5-20 mg/L DHF showed no side effects and there was sustained sedation during the first 12 h of drug exposure with 10-20 mg/L DHF. DHF pretreatment did not increase plasma cortisol levels in fish subjected to a stress protocol. Moreover, the stress-induced cortisol peak was absent following pretreatment with 20 mg/L DHF. DHF proved to be a relatively safe sedative or anesthetic, which interacts with GABAergic and cortisol pathways in fish.