Clinical Utility of an AI-powered, Handheld Elastic Scattering Spectroscopy Device on the Diagnosis and Management of Skin Cancer by Primary Care Physicians.

BACKGROUND: Patients with lesions suspicious for skin cancer often present to primary care physicians (PCPs), who may have limited training in skin cancer diagnosis. OBJECTIVE: To measure the impact of an adjunctive handheld device for PCPs that employs elastic scattering spectroscopy (ESS) on the diagnosis and management of skin cancer. METHODS: Fifty-seven PCPs evaluated 50 clinical images of skin lesions (25 malignant and 25 benign), first without and then with knowledge of the handheld ESS device output, and in each case indicated if a lesion was likely to be benign or malignant. RESULTS: The diagnostic sensitivity of the PCPs with and without the use of the ESS device was 88% (95% CI, 84%-92%) and 67% (95% CI, 62%-72%), respectively (P < .0001). In contrast, no significant difference was observed in the diagnostic specificity. The management sensitivity of the physicians with and without the use of the ESS device was 94% (95% CI, 91%-96%) and 81% (95% CI, 77%-85%), respectively (P = .0009). Similarly, no significant difference was observed in the management specificity. CONCLUSION: The use of the ESS device may have the potential to help improve skin cancer diagnosis and confidence in management decision-making in a primary care setting.

Isolated Peptide from Spider Venom Modulates Dendritic Cells In Vitro: A Possible Application in Oncoimmunotherapy for Glioblastoma.

Dendritic cells (DCs) vaccine is a potential tool for oncoimmunotherapy. However, it is known that this therapeutic strategy has failed in solid tumors, making the development of immunoadjuvants highly relevant. Recently, we demonstrated that Phoneutria nigriventer spider venom (PnV) components are cytotoxic to glioblastoma (GB) and activate macrophages for an antitumor profile. However, the effects of these molecules on the adaptive immune response have not yet been evaluated. This work aimed to test PnV and its purified fractions in DCs in vitro. For this purpose, bone marrow precursors were collected from male C57BL6 mice, differentiated into DCs and treated with venom or PnV-isolated fractions (F1-molecules < 3 kDa, F2-3 to 10 kDa and F3->10 kDa), with or without costimulation with human GB lysate. The results showed that mainly F1 was able to activate DCs, increasing the activation-dependent surface marker (CD86) and cytokine release (IL-1ß, TNF-α), in addition to inducing a typical morphology of mature DCs. From the F1 purification, a molecule named LW9 was the most effective, and mass spectrometry showed it to be a peptide. The present findings suggest that this molecule could be an immunoadjuvant with possible application in DC vaccines for the treatment of GB.

Nursing students' opinion on the use of Escape ZOOM® as a learning strategy: Observational study.

The teaching-learning process has gone through major changes due to the COVID-19 pandemics and it has been left to professors to adapt the teaching process and find ways to keep students engaged. There has been a need to establish collaborative and active strategies for working in the online environment. The development of a game for both teaching and evaluating de interdisciplinary learning content on an online platform may create a gameful experience and stimulating environment that makes complex learning goals achievable. To analyze how nursing students feel in relation to their participation and learning in an Escape Room activity taking place in an online environment. This is a descriptive and exploratory cross-sectional cohort study. The study was carried out in a higher education institution. The sample consisted of 73 students. After implementation of Escape Zoom® in the first semester of 2021, adapted questionnaires to assess students' satisfaction and perception of learning were applied. In the Educational Practices Questionnaire, all statements obtained greater than 70% agreement, which revealed students' satisfaction, especially with learning with colleagues. As for learning, 93.2% of students' statements expressed that the Escape Zoom® favors teamwork and 91.8% of student's statements agreed that the activity is effective for learning and would recommend it to other colleagues. The Escape Zoom® is an effective teaching strategy, perceived with satisfaction by students as a form of learning with colleagues, in a game-oriented way. It also has the potential to promote the development of soft skills.

Morphological Changes in Major Salivary Glands in Mice Treated With a Choline and Methionine Deficient Diet.

BACKGROUND/AIM: It has been shown that the methionine-choline deficient (MCD) diet induces hepatocarcinogenesis, but not in extrahepatic organs, such as the testis, and pancreas, although may increase chemical-induced carcinogenesis in the colon, mammary gland, esophagus, and pancreas. Accumulating evidence suggests that salivary glands are very susceptible to stress conditions, such as radiation, hyperglycemia, and exposure to xenobiotics in vivo. This study aimed to analyze the histological changes on the major salivary glands (parotid, submandibular, and sublingual) after MCD diet administration. MATERIALS AND METHODS: Male Swiss mice were submitted to ad libitum access to the control (AIN-76) or MCD diet for 28 days. The rebound group received the MCD diet for 24 days and the control diet for 10 days. Using the AxioImager A2 microscope, the hematoxylin-eosin (HE) stained specimens (4 mm) were evaluated for tissue degeneration, nuclear hyperchromatism and atrophy. RESULTS: In the parotid gland from the MCD group, tissue degeneration, pyknosis, apoptosis and atrophy were observed, which remained in the rebound group, associated with hyperchromatism. In the submandibular gland from both MCD and rebound groups, severe tissue disorganization was associated with cell pleomorphism, hyperchromatic cells, apoptosis, increased eosinophilia, and inflammatory infiltrate. Finally, in the sublingual gland, there were no histological alterations in the experimental groups compared to the control. CONCLUSION: MCD can induce pre-neoplastic changes in the mouse parotid and submandibular glands, which are not reversed by a change in the diet.

Isolated Components From Spider Venom Targeting Human Glioblastoma Cells and Its Potential Combined Therapy With Rapamycin.

Glioblastomas (GBs) are responsible for a higher mortality rate among gliomas, corresponding to more than 50% of them and representing a challenge in terms of therapy and prognosis. Peptide-based antineoplastic therapy is a vast and promising field, and these molecules are one of the main classes present in spider venoms. Recently, our research group demonstrated the cytotoxic effects of Phoneutria nigriventer spider venom (PnV) in GBs. The present study aimed to select the purified PnV-components with potential antineoplastic effects, as well as to compare different metabolic conditions. Human GB (NG97) cells were treated with the PnV fractions: F1 (less than 3 kDa), F2 (between 3 and 10 kDa), and F3 (greater than 10 kDa). After treatments, viability (MTT), proliferation (CFSE), death (Annexin V/propidium iodide-PI), and cell cycle (PI) assays were performed. The F1 and F2 fractions in acute periods (1 and 5 h) and low concentrations (0.1 and 1 µg/ml) showed more relevant effects and were repurified in subfractions (SF1-SF11); from these, SF3 and SF4 showed the most significant effects. The previous inhibition of mTOR by rapamycin had a synergistic effect with SFs, reducing cell viability even more significantly than the untreated control. Taken together, the results point to components present in SF3 and SF4 as potential prototypes for the development of new drugs for GB treatment and stimulate studies to use these compounds in combination therapy with a rapamycin-like activity. Future studies will be conducted to characterize, synthesize the molecules, and to evaluate the efficacy and safety in preclinical models.

First case report of Ctenus medius envenomation: Clinical features of a patient bitten three times by the same spider.

A 22 years old undergraduate student was injured three times by a C. medius spider while wearing pants. Right foot and internal lower leg were bitten in three sites, leading to local pain and oedema, besides a total leg paresthesia as immediate symptoms. A series of photographs of the sites were taken since day 0 until resolution in day 10. Two hours after the accident, the victim received intravenous promethazine. Despite cessation of pain and paresthesia after 24 hours, an intense erythema and itching emerged reaching the maximum in day 4, when the victim returned to hospital and received topic dexamethasone and oral dexchlorpheniramine. The regression was complete in day 10. This accident opened room for discussion of empiric drug choice for immediate and subsequent symptoms of unknown envenomations, as good as a reference for further accidents with this common spider. Biological aspects such as venom composition and spider control of delivered venom amount are also discussed.

Validação de um Algoritmo de Inteligência Artificial para a Predição Diagnóstica de Doença Coronariana: Comparação com um Modelo Estatístico Tradicional / Validation of an Artificial Intelligence Algorithm for Diagnostic Prediction of Coronary Disease: Comparison with a Traditional Statistical Model

Resumo Fundamento: A análise prognóstica multivariada tem sido realizada tradicionalmente por modelos de regressão. No entanto, muitos algoritmos surgiram, capazes de traduzir uma infinidade de padrões em probabilidades. A acurácia dos modelos de inteligência artificial em comparação à de modelos estatísticos tradicionais não foi estabelecida na área médica. Objetivo: Testar a inteligência artificial como um algoritmo preciso na predição de doença coronariana no cenário de dor torácica aguda, e avaliar se seu desempenho é superior a do modelo estatístico tradicional. Métodos: Foi analisada uma amostra consecutiva de 962 pacientes admitidos com dor torácica. Dois modelos probabilísticos de doença coronariana foram construídos com os primeiros 2/3 dos pacientes: um algoritmo machine learning e um modelo logístico tradicional. O desempenho dessas duas estratégias preditivas foi avaliado no último terço de pacientes. O modelo final de regressão logística foi construído somente com variáveis significativas a um nível de significância de 5%. Resultados: A amostra de treinamento tinha idade média de 59 ± 15 anos, 58% do sexo masculino, e uma prevalência de doença coronariana de 52%. O modelo logístico foi composto de nove preditores independentes. O algoritmo machine learning foi composto por todos os candidatos a preditores. Na amostra teste, a área sob a curva ROC para predição de doença coronariana foi de 0,81 (IC95% = 0,77 - 0,86) para o algoritmo machine learning, similar à obtida no modelo logístico (0,82; IC95% = 0,77 - 0,87), p = 0,68. Conclusão: O presente estudo sugere que um modelo machine learning acurado não garante superioridade à um modelo estatístico tradicional

Abstract Background: Multivariate prognostic analysis has been traditionally performed by regression models. However, many algorithms capable of translating an infinity of patterns into probabilities have emerged. The comparative accuracy of artificial intelligence and traditional statistical models has not been established in the medical field. Objective: To test the artificial intelligence as an accurate algorithm for predicting coronary disease in the scenario of acute chest pain and evaluate whether its performance is superior to traditional statistical model. Methods: A consecutive sample of 962 patients admitted with chest pain was analyzed. Two probabilistic models of coronary disease were built using the first two-thirds of patients: a machine learning algorithm and a traditional logistic model. The performance of these two predictive strategies were evaluated in the remaining third of patients. The final logistic regression model had significant variables only, at the 5% significance level. Results: The training sample had an average age of 59 ± 15 years, 58% males, and a 52% prevalence of coronary disease. The logistic model was composed of nine independent predictors. The machine learning algorithm was composed of all candidates for predictors. In the test sample, the area under the ROC curve for prediction of coronary disease was 0.81 (95% CI = 0.77 - 0.86) for the machine learning algorithm, similar to that obtained in logistic model (0.82; 95% CI = 0.77 - 0.87), p = 0.68. Conclusion: The present study suggests that an accurate machine learning prediction tool did not prove to be superior to the statistical model of logistic regression.

Components from spider venom activate macrophages against glioblastoma cells: new potential adjuvants for anticancer immunotherapy.

Immunomodulation has been considered an important approach in the treatment of malignant tumours. However, the modulation of innate immune cells remains an underexplored tool. Studies from our group demonstrated that the Phoneutria nigriventer spider venom (PnV) administration increased the infiltration of macrophage in glioblastoma, in addition to decreasing the tumour size in a preclinical model. The hypothesis that PnV would be modulating the innate immune system led us to the main objective of the present study: to elucidate the effects of PnV and its purified fractions on cultured macrophages. Results showed that PnV and the three fractions activated macrophages differentiated from bone marrow precursors. Further purification generated 23 subfractions named low weight (LW-1 to LW-12) and high weight (HW-1 to HW-11). LW-9 presented the best immunomodulatory effect. Treated cells were more phagocytic, migrated more, showed an activated morphological profile and induced an increased cytotoxic effect of macrophages on tumour cells. However, while M1-controls (LPS) increased IL-10, TNF-alpha and IL-6 release, PnV, fractions and subfractions did not alter any cytokine, with the exception of LW-9 that stimulated IL-10 production. These findings suggest that molecules present in LW-9 have the potential to be used as immunoadjuvants in the treatment of cancer.

Validation of an Artificial Intelligence Algorithm for Diagnostic Prediction of Coronary Disease: Comparison with a Traditional Statistical Model. / Validação de um Algoritmo de Inteligência Artificial para a Predição Diagnóstica de Doença Coronariana: Comparação com um Modelo Estatístico Tradicional.

BACKGROUND: Multivariate prognostic analysis has been traditionally performed by regression models. However, many algorithms capable of translating an infinity of patterns into probabilities have emerged. The comparative accuracy of artificial intelligence and traditional statistical models has not been established in the medical field. OBJECTIVE: To test the artificial intelligence as an accurate algorithm for predicting coronary disease in the scenario of acute chest pain and evaluate whether its performance is superior to traditional statistical model. METHODS: A consecutive sample of 962 patients admitted with chest pain was analyzed. Two probabilistic models of coronary disease were built using the first two-thirds of patients: a machine learning algorithm and a traditional logistic model. The performance of these two predictive strategies were evaluated in the remaining third of patients. The final logistic regression model had significant variables only, at the 5% significance level. RESULTS: The training sample had an average age of 59 ± 15 years, 58% males, and a 52% prevalence of coronary disease. The logistic model was composed of nine independent predictors. The machine learning algorithm was composed of all candidates for predictors. In the test sample, the area under the ROC curve for prediction of coronary disease was 0.81 (95% CI = 0.77 - 0.86) for the machine learning algorithm, similar to that obtained in logistic model (0.82; 95% CI = 0.77 - 0.87), p = 0.68. CONCLUSION: The present study suggests that an accurate machine learning prediction tool did not prove to be superior to the statistical model of logistic regression.

FUNDAMENTO: A análise prognóstica multivariada tem sido realizada tradicionalmente por modelos de regressão. No entanto, muitos algoritmos surgiram, capazes de traduzir uma infinidade de padrões em probabilidades. A acurácia dos modelos de inteligência artificial em comparação à de modelos estatísticos tradicionais não foi estabelecida na área médica. OBJETIVO: Testar a inteligência artificial como um algoritmo preciso na predição de doença coronariana no cenário de dor torácica aguda, e avaliar se seu desempenho é superior a do modelo estatístico tradicional. MÉTODOS: Foi analisada uma amostra consecutiva de 962 pacientes admitidos com dor torácica. Dois modelos probabilísticos de doença coronariana foram construídos com os primeiros 2/3 dos pacientes: um algoritmo machine learning e um modelo logístico tradicional. O desempenho dessas duas estratégias preditivas foi avaliado no último terço de pacientes. O modelo final de regressão logística foi construído somente com variáveis significativas a um nível de significância de 5%. RESULTADOS: A amostra de treinamento tinha idade média de 59 ± 15 anos, 58% do sexo masculino, e uma prevalência de doença coronariana de 52%. O modelo logístico foi composto de nove preditores independentes. O algoritmo machine learning foi composto por todos os candidatos a preditores. Na amostra teste, a área sob a curva ROC para predição de doença coronariana foi de 0,81 (IC95% = 0,77 ­ 0,86) para o algoritmo machine learning, similar à obtida no modelo logístico (0,82; IC95% = 0,77 ­ 0,87), p = 0,68. CONCLUSÃO: O presente estudo sugere que um modelo machine learning acurado não garante superioridade à um modelo estatístico tradicional.

Spider venom components decrease glioblastoma cell migration and invasion through RhoA-ROCK and Na+/K+-ATPase ß2: potential molecular entities to treat invasive brain cancer.

BACKGROUND: Glioblastoma (GB) cells have the ability to migrate and infiltrate the normal parenchyma, leading to the formation of recurrent tumors often adjacent to the surgical extraction site. We recently showed that Phoneutria nigriventer spider venom (PnV) has anticancer effects mainly on the migration of human GB cell lines (NG97 and U-251). The present work aimed to investigate the effects of isolated components from the venom on migration, invasiveness, morphology and adhesion of GB cells, also evaluating RhoA-ROCK signaling and Na+/K+-ATPase ß2 (AMOG) involvement. METHODS: Human (NG97) GB cells were treated with twelve subfractions (SFs-obtained by HPLC from PnV). Migration and invasion were evaluated by scratch wound healing and transwell assays, respectively. Cell morphology and actin cytoskeleton were shown by GFAP and phalloidin labeling. The assay with fibronectin coated well plate was made to evaluate cell adhesion. Western blotting demonstrated ROCK and AMOG levels and a ROCK inhibitor was used to verify the involvement of this pathway. Values were analyzed by the GraphPad Prism software package and the level of significance was determinate using one-way analysis of variance (ANOVA) followed by Dunnett's multiple comparisons test. RESULTS: Two (SF1 and SF11) of twelve SFs, decreased migration and invasion compared to untreated control cells. Both SFs also altered actin cytoskeleton, changed cell morphology and reduced adhesion. SF1 and SF11 increased ROCK expression and the inhibition of this protein abolished the effects of both subfractions on migration, morphology and adhesion (but not on invasion). SF11 also increased Na+/K+-ATPase ß2. CONCLUSION: All components of the venom were evaluated and two SFs were able to impair human glioblastoma cells. The RhoA effector, ROCK, was shown to be involved in the mechanisms of both PnV components. It is possible that AMOG mediates the effect of SF11 on the invasion. Further investigations to isolate and biochemically characterize the molecules are underway.

Spider venom administration impairs glioblastoma growth and modulates immune response in a non-clinical model.

Molecules from animal venoms are promising candidates for the development of new drugs. Previous in vitro studies have shown that the venom of the spider Phoneutria nigriventer (PnV) is a potential source of antineoplastic components with activity in glioblastoma (GB) cell lines. In the present work, the effects of PnV on tumor development were established in vivo using a xenogeneic model. Human GB (NG97, the most responsive line in the previous study) cells were inoculated (s.c.) on the back of RAG-/- mice. PnV (100 µg/Kg) was administrated every 48 h (i.p.) for 14 days and several endpoints were evaluated: tumor growth and metabolism (by microPET/CT, using 18F-FDG), tumor weight and volume, histopathology, blood analysis, percentage and profile of macrophages, neutrophils and NK cells isolated from the spleen (by flow cytometry) and the presence of macrophages (Iba-1 positive) within/surrounding the tumor. The effect of venom was also evaluated on macrophages in vitro. Tumors from PnV-treated animals were smaller and did not uptake detectable amounts of 18F-FDG, compared to control (untreated). PnV-tumor was necrotic, lacking the histopathological characteristics typical of GB. Since in classic chemotherapies it is observed a decrease in immune response, methotrexate (MTX) was used only to compare the PnV effects on innate immune cells with a highly immunosuppressive antineoplastic drug. The venom increased monocytes, neutrophils and NK cells, and this effect was the opposite of that observed in the animals treated with MTX. PnV increased the number of macrophages in the tumor, while did not increase in the spleen, suggesting that PnV-activated macrophages were led preferentially to the tumor. Macrophages were activated in vitro by the venom, becoming more phagocytic; these results confirm that this cell is a target of PnV components. Spleen and in vitro PnV-activated macrophages were different of M1, since they did not produce pro- and anti-inflammatory cytokines. Studies in progress are selecting the venom molecules with antitumor and immunomodulatory effects and trying to better understand their mechanisms. The identification, optimization and synthesis of antineoplastic drugs from PnV molecules may lead to a new multitarget chemotherapy. Glioblastoma is associated with high morbidity and mortality; therefore, research to develop new treatments has great social relevance. Natural products and their derivatives represent over one-third of all new molecular entities approved by FDA. However, arthropod venoms are underexploited, although they are a rich source of new molecules. A recent in vitro screening of the Phoneutria nigriventer spider venom (PnV) antitumor effects by our group has shown that the venom significantly affected glioblastoma cell lines. Therefore, it would be relevant to establish the effects of PnV on tumor development in vivo, considering the complex neoplastic microenvironment. The venom was effective at impairing tumor development in murine xenogeneic model, activating the innate immune response and increasing tumor infiltrating macrophages. In addition, PnV activated macrophages in vitro for a different profile of M1. These activated PnV-macrophages have potential to fight the tumor without promoting tumorigenesis. Studies in progress are selecting the venom molecules with antitumor and immunomodulatory effects and trying to better understand their mechanisms. We aim to synthesize and carry out a formulation with these antineoplastic molecules for clinical trials. Spider venom biomolecules induced smaller and necrotic xenogeneic GB; spider venom activated the innate immune system; venom increased blood monocytes and the migration of macrophages to the tumor; activated PnV-macrophages have a profile different of M1 and have a potential to fight the tumor without promote tumorigenesis.

Venom of the Phoneutria nigriventer spider alters the cell cycle, viability, and migration of cancer cells.

The mechanisms of cancer involve changes in multiple biological pathways. Multitarget molecules, which are components of animal venoms, are therefore a potential strategy for treating tumors. The objective of this study was to screen the effects of Phoneutria nigriventer spider venom (PnV) on tumor cell lines. Cultured human glioma (NG97), glioblastoma (U-251) and cervix adenocarcinoma (HeLa) cells, and nontumor mouse fibroblasts (L929) were treated with low (14 µg/ml) and high (280 µg/ml) concentrations of PnV, and analyzed through assays for cell viability (thiazolyl blue tetrazolium blue), proliferation (carboxyfluorescein succinimidyl ester), death (annexin V/propidium iodide [Pi]), the cell cycle (Pi), and migration (wound healing and transwell assay). The venom decreased the viability of U-251 cells, primarily by inducing cell death, and reduced the viability of NG97 cells, primarily by inhibiting the cell cycle. The migration of all the tumor cell lines was delayed when treated with venom. The venom significantly affected all the tumor cell lines studied, with no cytotoxic effect on normal cells (L929), although the nonglial tumor cell (HeLa) was less sensitive to PnV. The results of the current study suggest that PnV may be composed of peptides that are highly specific for the multiple targets involved in the hallmarks of cancer. Experiments are underway to identify these molecules.

Venom of the Phoneutria nigriventer spider alters the cell cycle, viability, and migration of cancer cells

The mechanisms of cancer involve changes in multiple biological pathways. Multitarget molecules, which are components of animal venoms, are therefore a potential strategy for treating tumors. The objective of this study was to screen the effects of Phoneutria nigriventer spider venom (PnV) on tumor cell lines. Cultured human glioma (NG97), glioblastoma (U-251) and cervix adenocarcinoma (HeLa) cells, and nontumor mouse fibroblasts (L929) were treated with low (14?µg/ml) and high (280?µg/ml) concentrations of PnV, and analyzed through assays for cell viability (thiazolyl blue tetrazolium blue), proliferation (carboxyfluorescein succinimidyl ester), death (annexin V/propidium iodide [Pi]), the cell cycle (Pi), and migration (wound healing and transwell assay). The venom decreased the viability of U-251 cells, primarily by inducing cell death, and reduced the viability of NG97 cells, primarily by inhibiting the cell cycle. The migration of all the tumor cell lines was delayed when treated with venom. The venom significantly affected all the tumor cell lines studied, with no cytotoxic effect on normal cells (L929), although the nonglial tumor cell (HeLa) was less sensitive to PnV. The results of the current study suggest that PnV may be composed of peptides that are highly specific for the multiple targets involved in the hallmarks of cancer. Experiments are underway to identify these molecules.

Venom of the Phoneutria nigriventer spider alters the cell cycle, viability, and migration of cancer cells

The mechanisms of cancer involve changes in multiple biological pathways. Multitarget molecules, which are components of animal venoms, are therefore a potential strategy for treating tumors. The objective of this study was to screen the effects of Phoneutria nigriventer spider venom (PnV) on tumor cell lines. Cultured human glioma (NG97), glioblastoma (U-251) and cervix adenocarcinoma (HeLa) cells, and nontumor mouse fibroblasts (L929) were treated with low (14?µg/ml) and high (280?µg/ml) concentrations of PnV, and analyzed through assays for cell viability (thiazolyl blue tetrazolium blue), proliferation (carboxyfluorescein succinimidyl ester), death (annexin V/propidium iodide [Pi]), the cell cycle (Pi), and migration (wound healing and transwell assay). The venom decreased the viability of U-251 cells, primarily by inducing cell death, and reduced the viability of NG97 cells, primarily by inhibiting the cell cycle. The migration of all the tumor cell lines was delayed when treated with venom. The venom significantly affected all the tumor cell lines studied, with no cytotoxic effect on normal cells (L929), although the nonglial tumor cell (HeLa) was less sensitive to PnV. The results of the current study suggest that PnV may be composed of peptides that are highly specific for the multiple targets involved in the hallmarks of cancer. Experiments are underway to identify these molecules.

Presynaptic Activity of an Isolated Fraction from Rhinella schneideri Poison.

Purpose: Rhinella schneideri is a toad found in many regions of the South America. The poison of the glands has cardiotoxic effect in animals and neuromuscular effects in mice and avian preparation. The purpose of this work was to identify the toxin responsible for the neuromuscular effect in avian and mice neuromuscular preparation. Methods: The methanolic extract from R. schneideri poison was fractioned by reversed phase HPLC. The purity and molecular mass were determined by LC/MS mass spectrometry. Chick biventer cervicis and mouse phrenic-nerve diaphragm were used as neuromuscular preparations to identify the toxin. Results: The purification resulted in 32 fractions, which 4 of them were active in neuromuscular preparation. The toxin of fraction 20 were chosen for better reproducibility of the whole extract activity and its molecular mass was 730.6 Da. The toxin produced facilitation of the muscle contraction followed by a complete neuromuscular blockade in chick biventer cervicis preparation in 90 min without interfering with the exogenous response to ACh and KCl. The quantal content was increased from 128 ± 13 (control) to 216 ± 44 (after 5 min and sustained until 60 min) in the presence of the toxin. Conclusion: In conclusion, our results demonstrated that the neuromuscular action of the poison of Rhinella schneideri is a multitoxin effect. More, the present work first isolated a 730.6 Da toxin that better represent the whole poison neuromuscular effect, to which is attributed a presynaptic action in avian and mouse neuromuscular preparation.

Will elevated atmospheric CO2 boost the growth of an invasive submerged macrophyte Cabomba caroliniana under the interference of phytoplankton?

The growth of most submerged macrophytes is likely to be limited by the availability of carbon resource, and this is especially true for the obligatory carbon dioxide (CO2) users. A mesocosm experiment was performed to investigate the physiological, photophysiological, and biochemical responses of Cabomba caroliniana, an invasive macrophyte specie in the Lake Taihu Basin, to elevated atmospheric CO2 (1000 µmol mol-1); we also examined the possible impacts of interferences derived from the phytoplankton proliferation and its concomitant disturbances on the growth of C. caroliniana. The results demonstrated that elevated atmospheric CO2 significantly enhanced the biomass, relative growth rate, and photosynthate accumulation of C. caroliniana. C. caroliniana exposed to elevated atmospheric CO2 exhibited a higher relative maximum electron transport rate and photosynthetic efficiency, compared to those exposed to ambient atmospheric CO2. However, the positive effects of elevated atmospheric CO2 on C. caroliniana were gradually compromised as time went by, and the down-regulations of the relative growth rate (RGR) and photosynthetic activity were coupled with phytoplankton proliferation under elevated atmospheric CO2. This study demonstrated that the growth of C. caroliniana under the phytoplankton interference can be greatly affected, directly and indirectly, by the increasing atmospheric CO2.

Presynaptic activity of an isolated fraction from Rhinella schneideri poison

Purpose: Rhinella schneideri is a toad found in many regions of the South America. The poison of the glands has cardiotoxic effect in animals and neuromuscular effects in mice and avian preparation. The purpose of this work was to identify the toxin responsible for the neuromuscular effect in avian and mice neuromuscular preparation. Methods: The methanolic extract from R. schneideri poison was fractioned by reversed phase HPLC. The purity and molecular mass were determined by LC/MS mass spectrometry. Chick biventer cervicis and mouse phrenic-nerve diaphragm were used as neuromuscular preparations to identify the toxin. Results: The purification resulted in 32 fractions, which 4 of them were active in neuromuscular preparation. The toxin of fraction 20 were chosen for better reproducibility of the whole extract activity and its molecular mass was 730.6 Da. The toxin produced facilitation of the muscle contraction followed by a complete neuromuscular blockade in chick biventer cervicis preparation in 90 min without interfering with the exogenous response to ACh and KCl. The quantal content was increased from 128 ± 13 (control) to 216 ± 44 (after 5 min and sustained until 60 min) in the presence of the toxin. Conclusion: In conclusion, our results demonstrated that the neuromuscular action of the poison of Rhinella schneideri is a multitoxin effect. More, the present work first isolated a 730.6 Da toxin that better represent the whole poison neuromuscular effect, to which is attributed a presynaptic action in avian and mouse neuromuscular preparation.

Presynaptic activity of an isolated fraction from Rhinella schneideri poison

Purpose: Rhinella schneideri is a toad found in many regions of the South America. The poison of the glands has cardiotoxic effect in animals and neuromuscular effects in mice and avian preparation. The purpose of this work was to identify the toxin responsible for the neuromuscular effect in avian and mice neuromuscular preparation. Methods: The methanolic extract from R. schneideri poison was fractioned by reversed phase HPLC. The purity and molecular mass were determined by LC/MS mass spectrometry. Chick biventer cervicis and mouse phrenic-nerve diaphragm were used as neuromuscular preparations to identify the toxin. Results: The purification resulted in 32 fractions, which 4 of them were active in neuromuscular preparation. The toxin of fraction 20 were chosen for better reproducibility of the whole extract activity and its molecular mass was 730.6 Da. The toxin produced facilitation of the muscle contraction followed by a complete neuromuscular blockade in chick biventer cervicis preparation in 90 min without interfering with the exogenous response to ACh and KCl. The quantal content was increased from 128 ± 13 (control) to 216 ± 44 (after 5 min and sustained until 60 min) in the presence of the toxin. Conclusion: In conclusion, our results demonstrated that the neuromuscular action of the poison of Rhinella schneideri is a multitoxin effect. More, the present work first isolated a 730.6 Da toxin that better represent the whole poison neuromuscular effect, to which is attributed a presynaptic action in avian and mouse neuromuscular preparation.

Pharmacological Characterization of the Edema Caused by Vitalius dubius (Theraphosidae, Mygalomorphae) Spider Venom in Rats.

Bites by tarantulas (Theraphosidae, Mygalomorphae) in humans can result in mild clinical manifestations such as local pain, erythema, and edema. Vitalius dubius is a medium-sized, nonaggressive theraphosid found in southeastern Brazil. In this work, we investigated the mediators involved in the plasma extravasation caused by V. dubius venom in rats. The venom caused dose-dependent (0.1-100 µg/site) edema in rat dorsal skin. This edema was significantly inhibited by ((S)1-{2-[3(3-4-dichlorophenyl)-1-(3-iso-propoxyphenylacetyl)piperidine-3-yl]ethyl}-4-phenyl-1-azoniabicyclo[2.2.2]octone, chloride) (SR140333, a neurokinin NK1 receptor antagonist), indomethacin [a nonselective cyclooxygenase (COX) inhibitor], cyproheptadine (a serotonin 5-hydroxytryptamine1/2 and histamine H1 receptor antagonist), and N(ω)-nitro-L-arginine methyl ester (a nitric oxide synthase inhibitor). In contrast, mepyramine (a histamine H1 receptor antagonist), D-Arg-[Hyp(3),Thi(5),D-Tic(7),Oic(8)-]-BK (JE 049, a bradykinin B2 receptor antagonist), and ((S)-N-methyl-N-[4-(4-acetylamino-4-phenylpiperidino)-2-(3,4-di-chlorophenyl)butyl]benzamide) (SR48968, a neurokinin NK2 receptor antagonist) had no effect on the venom-induced increase in vascular permeability. In rat hind paws, the venom-induced edema was attenuated by ketoprofen (a nonselective COX inhibitor) administered 15 minutes postvenom. Preincubation of venom with commercial antiarachnid antivenom attenuated the venom-induced edema. These results suggest that the enhanced vascular permeability evoked by V. dubius venom involves serotonin, COX products, neurokinin NK1 receptors, and nitric oxide formation. The attenuation of hind paw edema by ketoprofen suggests that COX inhibitors could be useful in treating the local inflammatory response to bites by these spiders.

Antimicrobial activity of the toxin VdTX-I from the spider Vitalius dubius (Araneae, Theraphosidae).

BACKGROUND: Currently there is an urgent need to develop new classes of antimicrobial agents with different mechanisms of action from conventionally antibiotics used for the control of pathogenic microorganisms. The acylpolyamine called VdTX-I was isolated from the venom of the tarantula Vitalius dubius, and first described with activity as an antagonist of nicotinic cholinergic receptors. The main objective of this study was to investigate the antimicrobial activity found in the venom of the spider, with emphasis on the toxin VdTX-I. METHODS: Antimicrobial assays were performed in 96 well plates culture against 14 micro-organisms (fungi, yeasts and bacteria), which were tested concentrations from 0.19 to 100 µM of VdTX-I. After qualitative analysis, dose-response curve assays were performed in bacterial kill curve using MTT reagent and hemolytic assay. RESULTS: The antimicrobial activity of the VdTX-I toxin was observed in 12 tested species of Candida, Trichosporiun, Staphylococcus and Micrococcus. The toxicity had a dose-response at 3.12 µM - 100 µM in Candida albicans, Candida guillermondii, Micrococcus luteus and Escherichia coli. VdTX-I took about 5 min to inhibit bacterial growth, which was faster than streptomycin. The toxin showed no hemolytic activity between 0.19 and 100 µM. At 2.5 µg/mL of toxin it was observed no growth inhibition against a mammalian cell lineage. CONCLUSIONS: The VdTX-I toxin has a significant antimicrobial activity, with broad spectrum, and is experimentally inert to mammalian blood cells. GENERAL SIGNIFICANCE: This paper explores the antimicrobial potential of the spider toxin VdTX-I, which can provide a new model to design new antimicrobial drugs.