Antileishmanial activity, cytotoxicity and cellular response of amphotericin B in combination with crotamine derived from Crotalus durissus terrificus venom using in vitro and in silico approaches.

OBJECTIVE: To investigate the in vitro activity, synergism, cytotoxicity and cellular immunological response, as well as the molecular affinity between amphotericin B (AmB) and crotamine (CTA), derived from Crotalus durissus terrificus venom against Leishmania amazonensis. METHODS: This study performed the inhibition of promastigotes and amastigotes' growth under different concentrations of the drug and pharmacological combinations (AmB + CTA) based on the Berimbaum method (synergism study). The lactate dehydrogenase (LDH) quantification method was used to determine the cytotoxicity of the drug and combinations employing four cell lines (J774, HepG2, VERO, and C2C12). Following, the levels of Tumour Necrose Factor-alpha (TNF-α) and Interleukin-12 (IL-12) cytokines, using enzyme-linked immunosorbent assay (ELISA) and nitrites, as an indirect measure of Nitric Oxide (NO), using the Griess reaction were assessed in the supernatants of infected macrophages. In silico approach (molecular docking and dynamics) and binding affinity (surface plasmon resonance) between the drug and toxin were also investigated. RESULTS: CTA enhanced AmB effect against promastigote and amastigote forms of L. amazonensis, decreased the drug toxicity in different cell lines and induced the production of important Th1-like cytokines and NO by infected macrophages. The pharmacological combination also displayed consistent molecular interactions with low energy of coupling and a concentration-dependent profile. CONCLUSION: Our data suggest that this pharmacological approach is a promising alternative treatment against L. amazonensis infection due to the improved activity (synergistic effect) achieved against the parasites' forms and to the decreased cytotoxic effect.

Metformin improves depressive-like behavior in experimental Parkinson's disease by inducing autophagy in the substantia nigra and hippocampus.

Parkinson's disease (PD) remains a disease of little known etiology. In addition to the motor symptoms, depression is present in about 40% of patients, contributing to the loss of quality of life. Recently, the involvement of the autophagy mechanism in the pathogenesis of depression has been studied, in addition to its involvement in PD as well. In this study, we tested the effects of metformin, an antidiabetic drug also with antidepressant effects, on depressive-like behavior in a rotenone-induced PD model and on the autophagy process. Mice 8-week-old male C57BL/6 were induced with rotenone for 20 consecutive days (2.5 mg/kg/day) and treated with metformin (200 mg/kg/day) from the 5th day of induction. All the animals were submitted to rotarod, sucrose preference and tail suspension tests. After euthanasia, the substantia nigra and hippocampus were removed for analysis by western blotting or fixed and analyzed by immunofluorescence. The results show that there was an impairment of autophagy in animals induced by rotenone both in nigral and extranigral regions as well as a depressive-like behavior. Metformin was able to inhibit depressive-like behavior and increase signaling pathway proteins, transcription factors and autophagosome-forming proteins, thus inducing autophagy in both the hippocampus and the substantia nigra. In conclusion, we show that metformin has an antidepressant effect in a rotenone-induced PD model, which may result, at least in part, from the induction of the autophagy process.

Multiple Extracranial Metastases from a Rhabdoid Meningioma: A Case Report / Metástases Extracraniais Multiplas de um Meningioma Rabdóide: Relato de Caso

Meningiomas are among the most common intracranial primary tumors, and generally have a benign behavior. The incidence of extracranial metastasis of this pathology is low. There are different variants of them, with a wide variety of aggressiveness and potential tometastatic spread. Among themalignant meningiomas (1­3% of total), the rhabdoid variant is known for its aggressive biological and clinical behavior. It is also known that some histological subtypes are inherently prone to recur or spread, as the latter. In the latest World Health Organization classification, extracranial metastases are not currently considered a pathological criterion for malignancy, and, when present, they are most commonly found in the lung, liver, lymph nodes, and bone. Treatment is usually surgical resection of the metastases, but there is still no consensus about it. Owing to its poor prognosis, the rhabdoid subtype is commonly treated aggressively. Patients are submitted to local radiotherapy to prevent recurrence. Extracranial metastases of meningiomas are rare, but should always be remembered, especially in cases of local recurrence and malignant histology, as the rhabdoid variant. We report one case of extracranial metastases in a patient diagnosed with rhabdoid subtype of meningioma, and discuss the literature on this pathology.

Meningiomas estão entre os tumores intracranianos primários mais comuns, e geralmente possuem comportamento benigno. A incidência de metástases extracranianas desta patologia é baixa. Existem diversas variantes, com uma ampla variedade de agressividade e potencial para disseminação metastática. Entre os meningiomas malignos (1­3% do total), a variante rabdoide é conhecida por seu comportamento agressivo clínico e biológico. Também é sabido que alguns subtipos histológicos são propensos à recidiva e disseminação, como o supracitado. Na última classificação da Organização Mundial de Saúde, metástases extracranianas não são consideradas como critério patológico para malignidade, e, quando presentes, são geralmente encontradas nos pulmões, fígado, linfonodos e ossos. O tratamento é geralmente a ressecção cirúrgica das metástases, embora não há consenso. Devido ao seu prognóstico pobre, o subtipo rabdoide é comumente tratado de forma agressiva. Os pacientes são submetidos à radioterapia local para prevenção de recidivas. As metástases extracranianas de meningiomas são raras, mas sempre devem ser consideradas, especialmente em casos com recidiva local e histologia maligna, como a variante rabdoide. Relatamos um caso de metástases extracranianas em um paciente com o subtipo rabdoide de meningioma, e discutimos a literatura a seu respeito.

ESI-MS/MS identification of a bradykinin-potentiating peptide from Amazon Bothrops atrox snake venom using a hybrid Qq-oaTOF mass spectrometer.

A bradykinin-potentiating peptide (BPP) from Amazon Bothrops atrox venom with m/z 1384.7386 was identified and characterized by collision induced dissociation (CID) using an ESI-MS/MS spectra obtained in positive ion mode on a hybrid Qq-oaTOF mass spectrometer, Xevo G2 QTof MS (Waters, Manchester, UK). De novo peptide sequence analysis of the CID fragmentation spectra showed the amino acid sequence ZKWPRPGPEIPP, with a pyroglutamic acid and theoretical monoisotopic m/z 1384.7378, which is similar to experimental data, showing a mass accuracy of 0.6 ppm. The peptide is homologous to other BPP from Bothrops moojeni and was named as BPP-BAX12.

Cavopulmonary anastomosis improves left ventricular assist device support in acute biventricular failure.

OBJECTIVE: Right ventricular failure during left ventricular assist device (LVAD) support can result in severe hemodynamic compromise with high mortality. This study investigated the acute effects of cavopulmonary anastomosis on right ventricular loading and LVAD performance in a model of severe biventricular failure. METHODS: LVAD support was performed by means of centrifugal pump implantation in 14 anesthetized dogs (20-30 kg) with severe biventricular failure obtained by ventricular fibrillation induction. Animals were randomized to be submitted to classical cavopulmonary anastomosis (Glenn shunt) or to control group and were maintained under LVAD support for 2h. Left and right atrial, right ventricular and systemic pressures were monitored, while total pulmonary flow was simultaneously recorded by transonic flowmeters located on the superior vena cava and pulmonary trunk. Blood gas and venous lactate determinations were also obtained. RESULTS: Ventricular fibrillation maintenance resulted in acute LVAD performance impairment after 90 min in the control group, while animals with Glenn circuit maintained normal LVAD pump flow (55+/-13 ml kg(-1)min(-1) vs 21+/-4 ml kg(-1)min(-1), p<0.001) and better peripheral perfusion (blood lactate of 29+/-10 pg/ml vs 46+/-9 pg/ml, p<0.001). Left and right atrial pressures did not change significantly, while right ventricular pressure was lower in animals with Glenn circuit (13+/-3 mm Hg vs 22+/-8 mm Hg, p=0.005). Right ventricular unloading with Glenn shunt also resulted in superior total pulmonary flow (59+/-13 ml kg(-1)min(-1) vs 17+/-3 ml kg(-1)min(-1), p<0.001). CONCLUSION: The concomitant use of cavopulmonary anastomosis during LVAD support in a model of severe biventricular failure limited right ventricular overloading and resulted in better hemodynamic performance.