Abstract Background: Phoneutria nigriventer venom contains Phα1β. This toxin and its recombinant form have a remarkable analgesic potential that is associated with blockage of voltage-gated calcium channels and TRPA1 receptors. Although morphine is a mainstay drug to treat moderate and severe pain related to cancer, it has serious and dose-limiting side effects. Combining recombinant Phα1β and morphine to treat pain is an interesting approach that has been gaining attention. Therefore, a quantitative and reliable method to establish the strength of the antinociceptive interaction between these two substances is necessary. The present study was designed to investigate the nature of the functional antinociceptive (analgesic) interaction between Phα1β recombinant toxin and morphine in a model of cancer pain. Methods: Melanoma was produced by intraplantar inoculation of B16-F10 cells into the right paw of C57BL/6J mice. Von Frey filaments measured the paw-withdrawal threshold after intrathecal administration of morphine, recombinant Phα1β, and their combination. Thermal hyperalgesia was assessed using Hargreaves apparatus. The degree of interaction was evaluated using isobolographic analysis. Spontaneous and forced motor performance was assessed with the open-field and rotarod tests, respectively. Results: Co-administration of recombinant Phα1β and morphine synergistically reverses the melanoma-induced mechanical hyperalgesia. The potency of the mixture, measured as the effective dose to reach 50% of maximum possible effect (MPE) in ameliorating mechanical hyperalgesia, was about twice fold higher than expected if the interaction between morphine and recombinant Phα1β was merely additive. Treatment with the combination at doses necessary to reach 50% of MPE caused no spontaneous nor forced motor alterations. Conclusion: The combinatorial use of recombinant Phα1β and morphine allows significant and effective dose reduction of both agents, which has translational potential for opioid-sparing approaches in pain management related to cancer.

Objetivou-se investigar o efeito neuroprotetor da aplicação intralesional da MVIIA em ratos submetidos ao trauma medular. Foram utilizados ratos Wistar, machos, com peso entre 300g±23.4, distribuídos em cinco grupos: controle negativo (SHAM), placebo (PLA), 5µM MVIIA, 10µM MVIIA e 20µM MVIIA. Após a laminectomia da vértebra torácica 12 (SHAM), os grupos PLA, 5µM MVIIA, 10µM MVIIA e 20µM MVIIA foram submetidos ao trauma medular agudo compressivo por cinco minutos e, cinco minutos após o trauma, receberam o tratamento específico em volume total padrão de 2µL, pela via intralesional, sendo utilizado como placebo o PBS estéril. A atividade locomotora foi avaliada pela escala proposta por Basso Beattie Bresnahan (BBB), com intuito de mostrar a padronização do trauma medular. Com 48 horas do trauma, os animais foram submetidos à eutanásia, coletou-se amostra do líquor no espaço atlantooccipital e um segmento medular, incluindo o epicentro e região caudal à lesão. Foram realizados ensaios de viabilidade mitocondrial, dosagem de glutamato, produção de espécies reativas de oxigênio (ERO) e peroxidação lipídica (PL). O delineamento do estudo foi inteiramente casualizado e os dados submetidos ao ANOVA, com comparação de médias pelo teste de SNK e os dados do teste BBB foram comparados utilizando o teste Kruskal-Wallis (P<0.05). Em relação aos escores do BBB, não houve diferença entre os grupos. A MVIIA não promoveu a diminuição dos níveis do glutamato, ERO, PL e não preservou a mitocôndria na aplicação intralesional, cinco minutos após o trauma medular em ratos.

This study aimed to investigate the neuroprotective effect of ω-conotoxin MVIIA (MVIIA) intralesional application in rats submitted to spinal cord injury. Male Wistar rats, weighing 300g±23.4, were distributed in five groups: negative control (SHAM), placebo (PLA), 5μM MVIIA, 10μM MVIIA and 20μM MVIIA MVIIA. After laminectomy of the 12th thoracic vertebra (SHAM), the PLA, 5μM MVIIA, 10μM MVIIA and 20μM MVIIA groups were subjected to acute compressive spinal cord trauma for five minutes, and then five minutes later, the animals received specific treatment in a standard total volume of 2µL, by intralesional route, using sterile PBS as placebo. Locomotor activity was assayed using Basso Beattie Bresnahan (BBB) scale to show the patterning of SCI. With 48 hours of injury, the animals were euthanized, the liquor sample was collected in atlantooccipital space, and also the spinal segment, including the epicenter and caudal region to injury. Assays were performed for mitochondrial viability, serum glutamate, production of reactive oxygen species (ROS) and lipid peroxidation (LP) were performed. The study design was randomized and the data submitted to ANOVA and comparison of means by SNK test, and data from BBB scale were evaluated using Kruskal-Wallis test (P<0.05). There was no significant difference between groups in BBB scores. The MVIIA did not promote decrease in the levels of glutamate, ROS, LP, and did not preserve the mitochondria in the intralesional application five minutes after spinal cord injury in rats.

Background:Calcium channel blockers such as conotoxins have shown a great potential to reduce brain and spinal cord injury. MVIIC neuroprotective effects analyzed in in vitromodels of brain and spinal cord ischemia suggest a potential role of this toxin in preventing injury after spinal cord trauma. However, previous clinical studies with MVIIC demonstrated that clinical side effects might limit the usefulness of this drug and there is no research on its systemic effects. Therefore, the present study aimed to investigate the potential toxic effects of MVIIC on organs and to evaluate clinical and blood profiles of rats submitted to spinal cord injury and treated with this marine toxin. Rats were treated with placebo or MVIIC (at doses of 15, 30, 60 or 120 pmol) intralesionally following spinal cord injury. Seven days after the toxin administration, kidney, brain, lung, heart, liver, adrenal, muscles, pancreas, spleen, stomach, and intestine were histopathologically investigated. In addition, blood samples collected from the rats were tested for any hematologic or biochemical changes.Results:The clinical, hematologic and biochemical evaluation revealed no significant abnormalities in all groups, even in high doses. There was no significant alteration in organs, except for degenerative changes in kidneys at a dose of 120 pmol.Conclusions:These findings suggest that MVIIC at 15, 30 and 60 pmol are safe for intralesional administration after spinal cord injury and could be further investigated in relation to its neuroprotective effects. However, 120 pmol doses of MVIIC may provoke adverse effects on kidney tissue.

Os transtornos psiquiátricos estão entre as doenças humanas mais comuns. Os mecanismos celulares e moleculares subjacentes à sua complexa fisiopatologia ainda não estão totalmente esclarecidos. Nosso grupo está envolvido na investigação de anormalidades moleculares nas principais vias de sinalização das doenças psiquiátricas nos últimos 10 anos. Evidências recentemente obtidas pelo Instituto Nacional de Ciência e Tecnologia de Medicina Molecular (INCT-MM), utilizando análise comportamental de modelos animais, forneceram informações valiosas sobre as alterações moleculares subjacentes responsáveis por muitos distúrbios neuropsiquiátricos complexos, sugerindo que os "defeitos" nas vias de sinalização intracelular têm um papel importante na regulação do neurodesenvolvimento, bem como na fisiopatologia e eficácia do tratamento. Recursos do INCT nos permitiram iniciar pesquisas na área de imagem molecular. A imagem molecular é uma disciplina de investigação que visualiza, caracteriza e quantifica processos biológicos que ocorrem em níveis celular e molecular em seres humanos, e em outros sistemas vivos, através dos resultados de imagem dentro da realidade do ambiente fisiológico. A fim de reconhecer alvos, a imagem molecular aplica instrumentos específicos (PET, por exemplo) que permitem a visualização e quantificação em espaço e tempo real dos sinais dos agentes de imagem molecular, fornecendo medições de processos a nível molecular e celular. O objetivo da medicina molecular é individualizar o tratamento e melhorar a assistência ao paciente. Desse modo, a imagem molecular consiste em mais uma ferramenta para atingirmos nosso objetivo final.

Psychiatric disorders are among the most common human illnesses; still, the molecular and cellular mechanisms underlying their complex pathophysiology remain to be fully elucidated. Over the past 10 years, our group has been investigating the molecular abnormalities in major signaling pathways involved in psychiatric disorders. Recent evidences obtained by the Instituto Nacional de Ciência e Tecnologia de Medicina Molecular (National Institute of Science and Technology - Molecular Medicine, INCT-MM) and others using behavioral analysis of animal models provided valuable insights into the underlying molecular alterations responsible for many complex neuropsychiatric disorders, suggesting that "defects" in critical intracellular signaling pathways have an important role in regulating neurodevelopment, as well as in pathophysiology and treatment efficacy. Resources from the INCT have allowed us to start doing research in the field of molecular imaging. Molecular imaging is a research discipline that visualizes, characterizes, and quantifies the biologic processes taking place at cellular and molecular levels in humans and other living systems through the results of image within the reality of the physiological environment. In order to recognize targets, molecular imaging applies specific instruments (e.g., PET) that enable visualization and quantification in space and in real-time of signals from molecular imaging agents. The objective of molecular medicine is to individualize treatment and improve patient care. Thus, molecular imaging is an additional tool to achieve our ultimate goal.

O propósito do presente estudo foi avaliar a influência da aplicação tópica de peróxido de carbamida na expressão imunohistoquímica do antígeno nuclear de proliferação celular (PCNA) na mucosa oral da língua de ratos. Doze ratos Wistar machos foram selecionados e submetidos a aplicação tópica de peróxido de carbamida a 10% sobre um lado do dorso da língua. O tratamento foi feito uma vez por semana por três semanas consecutivas. Água destilada foi aplicada no lado controle. Os animais foram sacrificados nos dias 0, 10, e 20 depois da última aplicação. A língua foi fixada em tampão de formalina por 24 horas e embebido em parafina. Cortes de tecido de 3 µm foram submetidos ao sistema de amplificação streptavidina-biotina para identificação do PCNA. A porcentagem de células basais epiteliais positivas em cada lado da mucosa da lingua foi calculada (experimental e controle). O resultado demonstrou que a aplicação tópica de peróxido de carbamida a 10% aumenta a expressão imunohistoquímica do PCNA na camada basal do epitélio da mucosa oral de ratos no dia 0 depois do tratamento. Concluiu-se que a uso em curto período de peróxido de carbamida a 10% induz proliferação celular epitelial transitória da mucosa oral de ratos.

The purpose of the present study was to evaluate the influence of short course topical application of carbamide peroxide on proliferating cell nuclear antigen (PCNA) immunohistochemical expression in the oral tongue mucosa of rats. Twelve male Wistar rats were submitted to topical application of 10% carbamide peroxide on one side of the dorsal tongue once a week for three consecutive weeks. Only distilled water was applied on the control side. The animals were killed on days 0, 10, and 20 after the last application. The tongue was fixed in buffered formalin for 24 h and embedded in paraffin. Tissue blocks (3 µm) were subjected to the biotin-streptavidin amplified system for identification of PCNA. The percentage of epithelial-positive basal cells in each side of the tongue mucosa was calculated. The results demonstrated that topical application of 10% carbamide peroxide increases PCNA immunohistochemical expression on the basal layer of the oral mucosa epithelium of rats on day 0 after treatment. In conclusion, short-course use of carbamide peroxide induces transient epithelial cell proliferation of the oral mucosa of rats.