11 results on '"Fernandes KF"'
Search Results
2. Understanding the effects of Bothrops erythromelas and Bothrops leucurus venoms on human blood coagulation.
- Author
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Venancio de Lima EO, Tasima LJ, Hatakeyama DM, Farias Rodrigues MA, Serino-Silva C, Stuginski DR, Machado da Silveira GP, Prezoto BC, Grego KF, Sant'Anna SS, Tanaka-Azevedo AM, and de Morais-Zani K
- Abstract
Coagulation disorders are a primary symptom of envenomation caused by snakes belonging to the genus Bothrops. In the Northeast region of Brazil, the species Bothrops erythromelas and Bothrops leucurus are the main responsible for snakebite accidents. Due to the specific action of Bothrops venoms on several components of the coagulation cascade, the objective of this work was to characterize the coagulotoxic profile of B. erythromelas and B. leucurus venoms and the neutralizing potential of bothropic antivenom, considering that their venom are not used in the production of antivenom. Regarding the clotting components targeted by the venom of these species, B. leucurus samples had higher thrombin-like activity and ability to activate prothrombin, while the activation of Factor X was comparable between these two species. B.erythromelas and B. leucurus venom displayed α- and β-fibrinogenolytic activities, with the former presenting higher overall fibrinogenolytic activity. In contrast, B. erythromelas venom showed greater procoagulant activity on human plasma, assessed through the coagulation time induced by the venom samples and thromboelastometry. Bothropic antivenom inhibited the procoagulant potential of B. leucurus venom better than B. erythromelas. However, the ability of the antivenom to neutralize this activity is lower compared to that determined for the venom of B. jararaca, which is used for antivenom production. The results shown herein describe the procoagulant activity of B. leucurus and B. erythromelas venoms and highlight the differences regarding their procoagulant capacity on human plasma, contributing to a deeper understanding of the pathophysiology of the envenomation caused by these species., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 Elsevier Ltd. All rights reserved.) more...
- Published
- 2025
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3. Analysis of Naja kaouthia snake venom composition and in-vitro enzymatic activities of 29 specimens in captivity: Highlighting the importance of individual variation in venom pool production.
- Author
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Kopel B, Serino-Silva C, Jantsch RB, Sorila IC, Sant'Anna SS, Grego KF, and Tanaka-Azevedo AM
- Subjects
- Animals, Male, Female, Phospholipases A2, Chromatography, High Pressure Liquid, Electrophoresis, Polyacrylamide Gel, Elapid Venoms chemistry
- Abstract
Naja kaouthia is a medically important snake, widely distributed throughout Southeast Asia, with a diverse venom composition. N. kaouthia venom is subject to significant intraspecific variation, caused by several factors, such as the wide geographic distribution of the species, sexual and ontogenetic factors. However, individual variation is a factor that has only been studied with small sample size groups and/or with pooled samples. With this in mind, this study evaluates the composition and in-vitro enzymatic activities of 29 individual venom samples from specimens born in captivity, with a similar genetic background caused by inbreeding, using SDS-PAGE under reducing conditions, RP-HPLC profiles and enzymatic activities of PLA
2 , LAAO and proteolytic activity over azocasein. Even in this scenario, we were able to observe significant variations in abundance and activity of PLA2 . Individual variations in LAAO activity, as well as a sexual dimorphism in which males present a significantly higher LAAO activity than females were observed. Phosphodiasterase and CRiSP abundance were also found and considered to have multiple effects in the clinical manifestations of envenomation by presenting synergistic effects with other proteins from N. kaouthia venom. The RP-HPLC profiles were better at detecting compositional differences than SDS-PAGE profiles and better correlated with enzymatic activities, being a better technique to screen variation profiles and reinforcing the importance of individual venom analysis prior to pooling., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.) more...- Published
- 2024
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4. An alternative method for comparing hemorrhagic activity of snake venoms following one of the 3R's principles.
- Author
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Tasima LJ, Kavazoi VK, Lima EOV, Grego KF, and Tanaka-Azevedo AM
- Subjects
- Animals, Mice, Animal Testing Alternatives, Elapid Venoms toxicity, Crotalid Venoms toxicity, Snake Bites, Hemorrhage chemically induced, Snake Venoms toxicity
- Abstract
Venom-induced hemorrhage analysis usually is performed by Minimum Hemorrhagic Dose (MHD), however a similar method can be used to compare venoms with fewer laboratory animals. Our work compared the MHD of five different venoms, with the size of hemorrhagic spot, finding good correlations in the results. Considering the 3Rs principle, we propose the use of the hemorrhagic spot method to compare hemorrhagic activity of snake venoms, rather than using the MHD method, since the first one needs 5 times less animals than the other., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.) more...
- Published
- 2024
- Full Text
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5. Seasonality in Crotalus durissus venom.
- Author
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Tasima LJ, Lima EOV, Hatakeyama DM, Vidueiros JP, Stuginski DR, Grego KF, and Tanaka-Azevedo AM
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- Animals, Male, Female, Brazil, Chromatography, High Pressure Liquid, Phospholipases A2, Venomous Snakes, Seasons, Crotalus, Crotalid Venoms toxicity, Crotalid Venoms chemistry
- Abstract
Rattlesnakes belonging to the genus Crotalus are widely distributed throughout the Americas. In Brazil, symptoms commonly associated with envenomation by Crotalus durissus collilineatus include myalgia, rhabdomyolysis, renal failure, neurotoxicity, and progressive paralysis, which are related to the protein composition of this venom. Snake venom composition exhibits compositional variability that may reflect geographic distribution, age, captivity, diet, sex, and even individual genetics. Although seasonality is also considered a possible source of variation, there are few reports of such variability in snake venom. In this work, venoms of the same eight C. durissus collilineatus were extracted every three months for two years, to analyze seasonal changes in composition and activities. To this end, venom composition was analyzed by protein quantification, SDS-PAGE, and HPLC, and the LAAO, PLA
2 and coagulant activities were measured. Venoms of these C. d. collilineatus showed minor seasonal differences in venom activities and no composition differences were found. LAAO and coagulant activities displayed a pattern of seasonal change, while PLA2 activity seemed to have no seasonality tendency. Also, there are sexual differences, in which males seem to be more stable than females in regard to some activities. Individual variability occurs even in seasonal variation of activities, highlighting the importance of controlling circumstances of venom extraction before comparing results between groups of snakes., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Anita Mitico Tanaka Azevedo reports financial support was provided by State of Sao Paulo Research Foundation. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.) more...- Published
- 2024
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6. Analyzing the influence of age and sex in Bothrops pauloensis snake venom.
- Author
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Tasima LJ, Hatakeyama DM, Aguiar WDS, Lima EOV, Miyamoto JG, Tashima AK, Sant'Anna SS, Grego KF, Morais-Zani K, and Tanaka-Azevedo AM
- Subjects
- Animals, Antivenins, Female, Male, Metalloproteases metabolism, Phospholipases A2 metabolism, Proteins, Snake Venoms chemistry, Snakes, Bothrops metabolism, Crotalid Venoms chemistry, Crotalid Venoms toxicity
- Abstract
Considerable heterogeneity and ontogenetic changes in venom composition have already been observed in different species of snakes within the Viperidae family. Since the venom of young and adult can cause distinct pathological effects and because the antivenom may be less effective in neutralizing envenoming by young snakes compared to adults, it is of paramount importance to understand the ontogenetic variation of snake venom. Thus, the present study aimed to analyze and compare the venom of Bothrops pauloensis snakes, searching for possible influences of ontogeny and sex in their biochemical and biological aspects. The venom of younger individuals was more complex in relation to high molecular mass proteins, with a greater abundance of metalloproteinases, while adults showed a greater abundance of medium and low molecular mass proteins, such as phospholipases A
2 (PLA2 ), C-type lectins and serine proteases. The antivenom showed better immunorecognition towards the venom of adult snakes than younger ones, in addition to a deficiency in the recognition of medium molecular mass proteins, suggesting the need for an improvement in the antivenom. Younger snakes showed higher coagulant, caseinolytic, and hemorrhagic activity, while adult snakes showed higher L-amino acid oxidase (LAAO) activity and acted faster in lethality. Differences between males and females were observed mainly in the rate of loss of coagulant activity, change in PLA2 activity and lethality action time. Furthermore, considering only the adult groups, males showed a higher LAAO and thrombin-like activity, while females showed a higher caseinolytic and hyaluronidase activity. With the results obtained in this work, it was possible to conclude that there is an ontogenetic variation in the composition and some activities of the B. pauloensis snake venom, in addition to differences between the venom of males and females, reinforcing that there is an intraspecific variation that may result in different symptoms in their envenoming and, consequently, differences in the response to treatment with the antivenom., (Copyright © 2022. Published by Elsevier Ltd.) more...- Published
- 2022
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7. A comparative study of endogenous phospholipase A 2 inhibitors in the serum of Brazilian pit vipers.
- Author
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Kavazoi VK, Serino-Silva C, Bittencourt Rodrigues CF, Hatakeyama DM, Carvalho de Souza D, Grego KF, de Morais-Zani K, and Tanaka-Azevedo AM
- Subjects
- Animals, Brazil, Phospholipase A2 Inhibitors chemistry, Phospholipases A2, Snakes, Crotalinae
- Abstract
This work compared the presence of phospholipase A
2 inhibitors (PLIs) in the serum of 19 snake species maintained at Instituto Butantan to better understand the mechanisms of venom resistance in snakes and improve the treatment of snakebite. PLI was isolated from blood of 19 snake species by one-step chromatography and identified in all samples, besides its identity was confirmed through the interaction with both phospholipase A2 and anti-γPLI. These findings highlight the diversity of snake serum PLIs and emphasize the importance of structure-function studies., (Copyright © 2022 Elsevier Ltd. All rights reserved.) more...- Published
- 2022
- Full Text
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8. Snake venom color and L-amino acid oxidase: An evidence of long-term captive Crotalus durissus terrificus venom plasticity.
- Author
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Lima EOV, Tasima LJ, Hatakeyama DM, Serino-Silva C, Rodrigues CFB, Galizio NDC, Chiarelli T, Nishiduka ES, Rocha MMTD, Sant'Anna SS, Grego KF, Tashima AK, Tanaka-Azevedo AM, and Morais-Zani K
- Subjects
- Animals, Electrophoresis, Polyacrylamide Gel, Humans, Snake Venoms, Crotalid Venoms, Crotalus, L-Amino Acid Oxidase metabolism
- Abstract
The venom color variation of Crotalus durissus terrificus (Cdt) is attributed to the presence of the toxin L-amino acid oxidase (LAAO). During the venom milking routine of Instituto Butantan, we have noticed that most venoms of captive Cdt specimens show a yellowish color, while most venoms of wild specimens are white. Here we describe a comparative analysis of long-term captive (LTC) and recently wild-caught (RWC) Cdt, focusing on LAAO variation. For the identification of LAAO in individual venoms, four different approaches were employed: evaluation of the enzymatic activity, SDS-PAGE, Western blotting, and ELISA. In addition, mass spectrometry analysis was performed using pooled samples. Although some variation among these methodologies was observed, it was possible to notice that the presence of LAAO was significantly higher in the venom of LTC individuals. LAAO was identified in 60-80% LTC specimens and in only 10-12% of RWC specimens. Furthermore, this enzyme accounts for 5.6% of total venom proteins of LTC Cdt pooled venom, while it corresponds to only 0.7% of RWC Cdt pooled venom. These findings strongly suggest that captive maintenance increases the expression of LAAO in Cdt venom., (Copyright © 2021 Elsevier Ltd. All rights reserved.) more...
- Published
- 2021
- Full Text
- View/download PDF
9. Ontogenetic study of Bothrops jararacussu venom composition reveals distinct profiles.
- Author
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da Silva Aguiar W, da Costa Galizio N, Sant'Anna SS, Silveira GPM, de Souza Rodrigues F, Grego KF, de Morais-Zani K, and Tanaka-Azevedo AM
- Subjects
- Animals, Snakes, Bothrops, Crotalid Venoms chemistry
- Abstract
Concerning snake venoms, numerous authors worked with different species of Bothrops focusing on the ontogeny of these animals. However, according to PubMed database, no results on studies related to Bothrops jararacussu ontogeny were displayed until now. This fact led us to develop a greater interest in the venom ontogenetic variability of this species, which is little explored so far. Among snakes of the genus Bothrops, B. jararacussu was previously described as the one with highest myotoxic activity. Another peculiarity was also observed in its venom: a low rate of immunogenicity. In addition, its activity is not efficiently neutralized by the specific antibothropic serum. Considering these particularities, we performed an ontogenetic study of B. jararacussu using venom samples from newborns of the same litter (<6 months) and adults (>24 months). Our results identified two distinct profiles in the venom of these animals: young individuals with little PLA
2 K-49 and more proteases; and adults with a lot of the same myotoxic PLA2, but less proteases. The HPLC and SDS-PAGE profiles corroborated our findings. Adults showed more hemorrhagic activity in vivo than juveniles, while adult males showed less activity when compared to females. In vivo myotoxicity activity was higher in adults than in juveniles. Immune recognition assays showed different results for the distinct venom., (Copyright © 2020 Elsevier Ltd. All rights reserved.) more...- Published
- 2020
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10. Use of infrared thermography in a case of systemic envenomation by the coral snake Micrurus frontalis (Duméril et al., 1854) in Sao Paulo, Brazil.
- Author
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Medeiros CR, Souza SN, Lara AN, and Grego KF
- Subjects
- Animals, Antivenins therapeutic use, Brazil, Elapid Venoms poisoning, Female, Humans, Infrared Rays, Male, Middle Aged, Paralysis chemically induced, Snake Bites therapy, Coral Snakes, Snake Bites diagnostic imaging, Thermography methods
- Abstract
Infrared thermography is a technique that quantifies the thermal (infrared) radiation emitted by an object and produces a high-resolution, digital thermal image of it. Medically, this technique is used to visualize the body's surface temperature distribution in a non-invasive, safe, and convenient fashion. However, to the best of our knowledge, the use of infrared thermography for assessing the systemic effects of envenomation by coral snakes has not been reported. In this case report, we describe the use of this technique in the management of a case of snakebite in Sao Paulo, Brazil. A 51-year-old woman was bitten on the back of the right hand by Micrurus frontalis, a species of coral snake, 10 min prior to her arrival at the hospital. Infrared imaging performed at admission revealed elevated temperatures at the bite site and in the elbow, as well as the preservation of a normal distal thermal gradient in both hands. A few minutes later, the patient developed muscle weakness in the upper limbs and in the eyelids, and infrared imaging showed an alteration of the thermal gradient in both hands, reflecting the systemic action of the venom. Following these observations, the patient was treated with the specific antivenom and was discharged 48 h post admission. At the two-week follow-up, the thermal image obtained showed no anomalies, indicating the recovery of the patient. Hence, infrared thermography can be very useful in the early identification of systemic neurotoxicity in cases of Micrurus snake bites, facilitating the decision to prescribe the antivenom., (Copyright © 2019 Elsevier Ltd. All rights reserved.) more...
- Published
- 2019
- Full Text
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11. Viperid venom glands with defective venom production. Morphological study.
- Author
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Giannotti KC, Sesso A, Grego KF, Fernandes W, Cardoso RP Jr, Camargo GG, and Carneiro SM
- Subjects
- Animals, Exocrine Glands ultrastructure, Bothrops anatomy & histology, Crotalid Venoms metabolism, Crotalus anatomy & histology, Exocrine Glands pathology
- Abstract
The venom of viperid snakes is collected monthly at Butantan Institute for research purposes and production of antivenoms. Here we describe histological and ultrastructural changes on Crotalus durissus terrificus and Bothrops sp. venom glands with defective venom production. Secretory tubules commonly showed partial or total obliteration of their lumina by masses of necrotic cells and cellular debris. Secretory cells showed varying degrees of degenerative and/or metaplastic alterations seriously affecting the structures responsible for the synthesis and secretion of venom. The intertubular connective tissue presented fibroblast hyperplasia, inflammatory cells infiltration, vacuolated cells and blood vessels alterations. In two venom glands out of nineteen snakes examined, virus-like particles were found. The alterations observed in most of the glands could have been caused by excessive manual pressure, during venom extraction routine, causing disruption of the secretory tubules and leakage of venom to the intertubular connective tissue., (Copyright © 2013 Elsevier Ltd. All rights reserved.) more...
- Published
- 2013
- Full Text
- View/download PDF
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