The Cloning and Characterization of a Three-Finger Toxin Homolog (NXH8) from the Coralsnake Micrurus corallinus That Interacts with Skeletal Muscle Nicotinic Acetylcholine Receptors.

Coralsnakes (Micrurus spp.) are the only elapids found throughout the Americas. They are recognized for their highly neurotoxic venom, which is comprised of a wide variety of toxins, including the stable, low-mass toxins known as three-finger toxins (3FTx). Due to difficulties in venom extraction and availability, research on coralsnake venoms is still very limited when compared to that of other Elapidae snakes like cobras, kraits, and mambas. In this study, two previously described 3FTx from the venom of M. corallinus, NXH1 (3SOC1_MICCO), and NXH8 (3NO48_MICCO) were characterized. Using in silico, in vitro, and ex vivo experiments, the biological activities of these toxins were predicted and evaluated. The results showed that only NXH8 was capable of binding to skeletal muscle cells and modulating the activity of nAChRs in nerve-diaphragm preparations. These effects were antagonized by anti-rNXH8 or antielapidic sera. Sequence analysis revealed that the NXH1 toxin possesses eight cysteine residues and four disulfide bonds, while the NXH8 toxin has a primary structure similar to that of non-conventional 3FTx, with an additional disulfide bond on the first loop. These findings add more information related to the structural diversity present within the 3FTx class, while expanding our understanding of the mechanisms of the toxicity of this coralsnake venom and opening new perspectives for developing more effective therapeutic interventions.

Sinais/sintomas de emergência na perspectiva dos pacientes em quimioterapia ambulatorial / Emergency signs / symptoms from the perspective of patients undergoing patient chemotherapy

Objectives: to identify the knowledge of oncological patients undergoing outpatient chemotherapy regarding emergency signs and symptoms.Methods: It is a descriptive, qualitative study. Two instruments were used: a questionnaire to characterize the participants and an open interview. The analysis of the first instrument was based on simple descriptive statistics; the second by thematic analysis. Results: The symptoms described by the participants were: fever, nausea, vomiting, constipation, inability/difficulty with food intake, headache, generalized pain or pain in places that refer to the tumor, dyspnea, vertigo, loss of consciousness, loss of ability to walk, chest pain and sudden changes in systemic pressure level (increase or decrease). As conditions that can interfere with the decision to seek emergency services, the manifestation of abnormal symptoms for the patient, the patient's knowledge about the pathology and treatment, as well as the patient's previous experience with the emergency service was identified.Conclusion: In short, the reasons that lead cancer patients to seek emergency are linked to the "severity" that it attributes to the effects of treatment.

Objetivo: identificar o conhecimento de pacientes oncológicos em tratamento quimioterápico ambulatorial sobre os sinais e sintomas de emergência. Métodos: Estudo descritivo, qualitativo. Utilizaram-se dois instrumentos: um questionário de caracterização dos participantes e uma entrevista aberta. A análise do primeiro instrumento foi por estatística descritiva simples; o segundo por análise temática. Resultados: Os sintomas descritos pelos participantes foram: febre, náuseas, vômitos, constipação, incapacidade/dificuldade de ingestão alimentar, cefaleia, dor generalizada ou dor nos locais que remetem ao tumor, dispneia, vertigem, perda de consciência, perda da capacidade de andar, dor no peito e variações bruscas de nível de pressão sistêmica (aumento ou diminuição).Como condições que podem interferir na decisão da busca pelo serviço de emergência, foi identificada a manifestação de sintomas anormais para o paciente, o conhecimento do paciente sobre a patologia e tratamento, além da experiência prévia do paciente com o serviço de emergência. Conclusão: Em suma, os motivos que levam o paciente oncológico a buscar a emergência estão ligados à "gravidade" que o mesmo atribui aos efeitos do tratamento.