Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
1.
Dentomaxillofac Radiol ; 53(6): 417-422, 2024 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-38810138

RESUMEN

OBJECTIVES: To assess the influence of two conventional and one adapted cheek and lip retractors and three emissivity setting values on intraoral infrared thermography (IT) temperature values. METHODS: The sample was composed by 50 volunteers. Three cheek and lip retractors were tested: Group 1-flex retractor (FR); Group 2-FR adapted with Styrofoam; Group 3-U-type retractor (UR) for cheek and lip. All thermograms were acquired using FLIR T650 infrared camera. A set of three thermograms in frontal norm were acquired for each lip and cheek retractor at 0.91, 0.96, and 0.98ε, with an interval of 15 min between each set of images to avoid thermal interference. All images were assessed by two observers. The ROIs' mean temperature of the four upper incisors was recorded. Two-way ANOVA and Sidak post-test were used for data assessment with a significance level of 5%. RESULTS: Group 3 showed higher mean temperature than Groups 1 and 2 at all emissivity settings for all assessed teeth (P < .05). 0.91ε showed higher temperature than 0.96ε and 0.98ε for all assessed variables (P < .01). Contralateral teeth assessed using Group 3 at 0.91ε showed statistical differences between each other (P < .05). No statistical difference was observed between contralateral teeth assessed using Groups 1 and 2 at 0.96ε and 0.98ε (P > .05). CONCLUSIONS: The choice of cheek and lip retractor and emissivity setting can interfere on intraoral IT temperature values. U-type cheek and lip retractor and 0.91ε setting should not be used for IT image acquisition when assessing dental tissues.


Asunto(s)
Mejilla , Rayos Infrarrojos , Labio , Termografía , Humanos , Termografía/métodos , Termografía/instrumentación , Labio/diagnóstico por imagen , Mejilla/diagnóstico por imagen , Masculino , Femenino , Adulto , Diseño de Equipo , Adulto Joven
2.
Chem Biol Interact ; 394: 110986, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38583853

RESUMEN

Snake venom metalloproteases (SVMPs) are hydrolytic enzymes dependent on metal binding, primarily zinc (Zn2+), at their catalytic site. They are classified into three classes (P-I to P-III). BjussuMP-II, a P-I SVMP isolated from Bothrops jararacussu snake venom, has a molecular mass of 24 kDa. It exhibits inhibitory activity on platelet aggregation and hydrolyzes fibrinogen. TNF-α upregulates the expression of adhesion molecules on endothelial cell surfaces, promoting leukocyte adhesion and migration during inflammation. Literature indicates that SVMPs may cleave the TNF-α precursor, possibly due to significant homology between metalloproteases from mammalian extracellular matrix and SVMPs. This study aimed to investigate BjussuMP-II's effects on human umbilical vein endothelial cells (HUVEC), focusing on viability, detachment, adhesion, release, and cleavage of TNF-α, IL-1ß, IL-6, IL-8, and IL-10. HUVEC were incubated with BjussuMP-II (1.5-50 µg/mL) for 3-24 h. Viability was determined using LDH release, MTT metabolization, and 7AAD for membrane integrity. Adhesion and detachment were assessed by incubating cells with BjussuMP-II and staining with Giemsa. Cytokines were quantified in HUVEC supernatants using EIA. TNF-α cleavage was evaluated using supernatants from PMA-stimulated cells or recombinant TNF-α. Results demonstrated BjussuMP-II's proteolytic activity on casein. It was not toxic to HUVEC at any concentration or duration studied but interfered with adhesion and promoted detachment. PMA induced TNF-α release by HUVEC, but this effect was not observed with BjussuMP-II, which cleaved TNF-α. Additionally, BjussuMP-II cleaved IL-1ß, IL-6, and IL-10. These findings suggest that the zinc metalloprotease BjussuMP-II could be a valuable biotechnological tool for treating inflammatory disorders involving cytokine deregulation.


Asunto(s)
Adhesión Celular , Citocinas , Células Endoteliales de la Vena Umbilical Humana , Metaloproteasas , Humanos , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Citocinas/metabolismo , Metaloproteasas/metabolismo , Adhesión Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Bothrops/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Animales , Venenos de Crotálidos/metabolismo , Venenos de Crotálidos/toxicidad , Proteolisis/efectos de los fármacos
3.
Curr Med Chem ; 2024 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-38676530

RESUMEN

The pursuit of novel treatment alternatives to address the accumulated resistance to antimicrobials over the years has prompted the scientific community to explore biodiversity, particularly animal venom, as a potential source of new antimicrobial drugs. Snake venoms, with their complex mixtures of components, are particularly promising targets for investigation in this regard. The search for novel molecules exhibiting antimicrobial activity against multidrug-resistant strains is of paramount importance for public health and numerous research groups worldwide. High expectations within the healthcare field are supported by the scientific literature, which highlights the potential development of innovative drugs through in vivo and in vitro application, depending on dose titration. Snake venoms and their molecules and peptides offer exponential possibilities for biotechnological applications as antimicrobial agents. However, many uncertainties and unexplored avenues remain, presenting opportunities for discoveries and research.

4.
J Photochem Photobiol B ; 255: 112919, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38677261

RESUMEN

Endolysosomes perform a wide range of cellular functions, including nutrient sensing, macromolecule digestion and recycling, as well as plasma membrane repair. Because of their high activity in cancerous cells, endolysosomes are attractive targets for the development of novel cancer treatments. Light-activated compounds termed photosensitizers (PS) can catalyze the oxidation of specific biomolecules and intracellular organelles. To selectively damage endosomes and lysosomes, HT-29 colorectal cancer cells were incubated with nanomolar concentrations of meso-tetraphenylporphine disulfonate (TPPS2a), an amphiphilic PS taken up via endocytosis and activated by green light (522 nm, 2.1 J.cm-1). Several cellular responses were characterized by a combination of immunofluorescence and immunoblotting assays. We showed that TPPS2a photosensitization blocked autophagic flux without extensive endolysosomal membrane rupture. Nevertheless, there was a severe functional failure of endolysosomes due to a decrease in CTSD (cathepsin D, 55%) and CTSB (cathepsin B, 52%) maturation. PSAP (prosaposin) processing (into saposins) was also considerably impaired, a fact that could be detrimental to glycosphingolipid homeostasis. Therefore, photosensitization of HT-29 cells previously incubated with a low concentration of TPPS2a promotes endolysosomal dysfunction, an effect that can be used to improve cancer therapies.


Asunto(s)
Autofagia , Lisosomas , Fármacos Fotosensibilizantes , Humanos , Células HT29 , Lisosomas/metabolismo , Lisosomas/efectos de los fármacos , Autofagia/efectos de los fármacos , Autofagia/efectos de la radiación , Fármacos Fotosensibilizantes/farmacología , Fármacos Fotosensibilizantes/química , Endosomas/metabolismo , Endosomas/efectos de los fármacos , Catepsinas/metabolismo , Catepsinas/antagonistas & inhibidores , Luz , Porfirinas/farmacología , Porfirinas/química , Catepsina D/metabolismo , Catepsina B/metabolismo
5.
Int J Biol Macromol ; 238: 124357, 2023 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-37028634

RESUMEN

Animal venoms and their chemical compounds have aroused both empirical and scientific attention for ages. However, there has been a significant increase in scientific investigations in recent decades, allowing the production of various formulations that are helping in the development of many important tools for biotechnological, diagnostic, or therapeutic use, both in human and animal health, as well as in plants. Venoms are composed of biomolecules and inorganic compounds that may have physiological and pharmacological activities that are not related to their principal actions (prey immobilization, digestion, and defense). Snake venom toxins, mainly enzymatic and non-enzymatic proteins, and peptides have been identified as potential prototypes for new drugs and/or models for the development of pharmacologically active structural domains for the treatment of cancer, cardiovascular diseases, neurodegenerative and autoimmune diseases, pain, and infectious-parasitic diseases. This minireview aims to provide an overview of the biotechnological potential of animal venoms, with a focus on snakes, and to introduce the reader to the fascinating world of Applied Toxinology, where animal biodiversity can be used to develop therapeutic and diagnostic applications for humans.


Asunto(s)
Neoplasias , Venenos de Serpiente , Animales , Humanos , Venenos de Serpiente/química , Serpientes/metabolismo , Proteínas/química , Péptidos/farmacología , Neoplasias/tratamiento farmacológico
6.
PLoS One ; 17(7): e0271758, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35905118

RESUMEN

INTRODUCTION: A wide variety of viruses can cause rash diseases (RDs) or acute febrile illness (AFIs) in children, adolescents and adults; however, approximately 19% of RD cases and 40% of AFI cases remain without a defined etiology. Parvovirus B19 (B19V) and herpesvirus infection can also cause RD and/or AFI, and in some risk groups, these infections can become persistent (or latent) and may require hospital treatment. Since these infections do not have mandatory reporting, they can be hidden by other diseases, such as those caused by arboviruses (e.g., dengue virus). In this context, the aim of this study was to pursue the differential laboratory diagnoses of B19V and herpesvirus infections in patients with RD and AFI, without a defined etiology, seen in hospitals and/or reference centers for infectious diseases in Rio de Janeiro. METHODS: A total of 114 participants were enrolled in the study, including 54 children and 60 adults. B19V infection was assessed by real-time PCR (qPCR) and ELISA (anti-B19V IgM and IgG). EBV was assessed through qPCR, and betaherpesviruses (HCMV, HHV-6 and HHV-7) were assessed through multiplex qPCR. Sociodemographic and clinical data were obtained from the medical record data of these participants. RESULTS: The median age of children with RD was 2 years (interquartile range (IQR): 5), and 55.6% were male. Among adults with AFI, the median age was 38 years (IQR: 21), and 56.7% were female. Regarding RD patients, viral prevalence (and load) were 5.5%(104IU/mL), 3.4%(104IU/mL), 5.5%(104IU/mL) and 11.1%(105IU/mL) for B19V, EBV, HCMV and HHV-6 infection, respectively, and in AFI patients they were 6.6%(105IU/mL), 1.6%(103IU/mL), 3.3%(104IU/mL) for B19V, HCMV and HHV-6, respectively. HHV-7 was not detected in RD or AFI patients. CONCLUSION: These results suggest the importance of including B19V and herpesviruses in the differential laboratory diagnoses for patients with RD and AFI, not only for epidemiological purposes but also for the proper management of the patient.


Asunto(s)
Arbovirus , Exantema , Herpesvirus Humano 6 , Infecciones por Parvoviridae , Parvovirus B19 Humano , Adolescente , Adulto , Anticuerpos Antivirales , Brasil/epidemiología , Niño , Preescolar , ADN Viral , Diagnóstico Diferencial , Exantema/diagnóstico , Exantema/epidemiología , Femenino , Fiebre/diagnóstico , Humanos , Inmunoglobulina M , Masculino , Parvovirus B19 Humano/genética
7.
Saúde debate ; 46(spe2): 277-292, 2022. graf
Artículo en Portugués | LILACS-Express | LILACS | ID: biblio-1390408

RESUMEN

RESUMO As fronteiras do capital neoextrativista avançam sobre territórios de populações tradicionais, provocando conflitos socioambientais, agravando a crise civilizatória, ameaçando a sustentação da vida no planeta. A pedagogia do território, a práxis acadêmica no Núcleo Tramas, traz pistas para que os sujeitos da universidade incidam na assimetria de forças presente nos territórios em conflito ambiental. Duas experiências iluminam as reflexões deste ensaio. Na luta pela construção do seu território camponês, as vivências das comunidades de Apodi/RN anunciam a agroecologia como forma de resistir ao Projeto da Morte. Por sua vez, o Núcleo de Reflexões, Estudos e Experiências em Agroecologia e Justiça Ambiental revelam o protagonismo das mulheres na construção da agroecologia e na defesa de seus territórios. Sob a perspectiva decolonial, discutem-se as bases teórico-epistemológicas, que incitam metodologias insurgentes e fomentam o diálogo de saberes, ressignificando os sujeitos cognoscentes. A mediação entre as vozes dos povos do semiárido e o campo científico da saúde coletiva provoca a reflexão: quais são os recados desses povos para a academia? Enquanto ainda se buscam possibilidades, os camponeses já têm, há muito, anunciado a agroecologia como alternativa para produzir, existir harmonicamente na natureza, promover saúde e resistir aos efeitos da colonialidade.


ABSTRACT Neoextractive capitalism advances over territories of traditional populations. The consequence is the increase in environmental conflicts and the deepening of the civilization crisis threatening life on the planet. Pedagogia do território (territory pedagogy), as an academic practice in the Núcleo Tramas, presents possibilities for the university to contribute to the reduction of the existing inequality in the context of environmental conflicts. Two reports help to reflect on this essay. In the struggle for the construction of peasant territory, the communities in the city of Apodi present agroecology as a way to resist the Projeto da Morte (Death Project). In turn, the Center for Reflections, Studies, and Experiences in Agroecology and Environmental Justice reveals the action of women in the construction of agroecology and in the defense of their territories. Based on decolonial theories, we discuss our theoretical and epistemological bases, which encourage insurgent methodologies and foster the dialogue of different knowledges. The mediation between the voices of semi-arid territories and the scientific field of collective health leads us to think: what are the messages from these peoples to the academy? While we are looking for possibilities, peasants are announcing agroecology as an alternative to produce, live harmoniously with nature, promote health, and resist the effects of coloniality.

8.
Amino Acids ; 53(10): 1635-1648, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34482475

RESUMEN

The worrisome emergence of pathogens resistant to conventional drugs has stimulated the search for new classes of antimicrobial and antiparasitic agents from natural sources. Antimicrobial peptides (AMPs), acting through mechanisms that do not rely on the interaction with a specific receptor, provide new possibilities for the development of drugs against resistant organisms. This study sought to purify and proteomically characterize the antimicrobial and antiparasitic peptidomes of B. atrox and B. jararacussu snake venoms against Gram-positive (Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus-MRSA), Gram-negative (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae) bacteria, and the protozoan parasites Leishmania amazonensis and Plasmodium falciparum (clone W2, resistant to chloroquine). To this end, B. atrox and B. jararacussu venom peptides were purified by combination of 3 kDa cut-off Amicon® ultracentrifugal filters and reverse-phase high-performance liquid chromatography, and then identified by electrospray-ionization Ion-Trap/Time-of-Flight mass spectrometry. Fourteen distinct peptides, with masses ranging from 443.17 to 1383.73 Da and primary structure between 3 and 13 amino acid residues, were sequenced. Among them, 13 contained unique sequences, including 4 novel bradykinin-potentiating-like peptides (BPPs), and a snake venom metalloproteinase tripeptide inhibitor (SVMPi). Although commonly found in Viperidae venoms, except for Bax-12, the BPPs and SVMPi here reported had not been described in B. atrox and B. jararacussu venoms. Among the novel peptides, some exhibited bactericidal activity towards P. aeruginosa and S. aureus, had low hemolytic effect, and were devoid of antiparasitic activity. The identified novel antimicrobial peptides may be relevant in the development of new drugs for the management of multidrug-resistant Gram-negative and Gram-positive bacteria.


Asunto(s)
Antiinfecciosos/química , Antiinfecciosos/farmacología , Venenos de Crotálidos/química , Péptidos/farmacología , Animales , Antibacterianos/química , Antibacterianos/farmacología , Antimaláricos/química , Antimaláricos/farmacología , Bothrops , Venenos de Crotálidos/aislamiento & purificación , Hemolíticos/química , Hemolíticos/farmacología , Humanos , Leishmania/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Péptidos/química , Péptidos/aislamiento & purificación , Plasmodium falciparum/efectos de los fármacos , Pseudomonas aeruginosa/efectos de los fármacos , Espectrometría de Masa por Ionización de Electrospray , Staphylococcus aureus/efectos de los fármacos
9.
Amino Acids, v. 53, p. 1635–1648, out. 2021
Artículo en Inglés | Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP | ID: bud-3939

RESUMEN

The worrisome emergence of pathogens resistant to conventional drugs has stimulated the search for new classes of antimicrobial and antiparasitic agents from natural sources. Antimicrobial peptides (AMPs), acting through mechanisms that do not rely on the interaction with a specific receptor, provide new possibilities for the development of drugs against resistant organisms. This study sought to purify and proteomically characterize the antimicrobial and antiparasitic peptidomes of B. atrox and B. jararacussu snake venoms against Gram-positive (Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus—MRSA), Gram-negative (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae) bacteria, and the protozoan parasites Leishmania amazonensis and Plasmodium falciparum (clone W2, resistant to chloroquine). To this end, B. atrox and B. jararacussu venom peptides were purified by combination of 3 kDa cut-off Amicon® ultracentrifugal filters and reverse-phase high-performance liquid chromatography, and then identified by electrospray-ionization Ion-Trap/Time-of-Flight mass spectrometry. Fourteen distinct peptides, with masses ranging from 443.17 to 1383.73 Da and primary structure between 3 and 13 amino acid residues, were sequenced. Among them, 13 contained unique sequences, including 4 novel bradykinin-potentiating-like peptides (BPPs), and a snake venom metalloproteinase tripeptide inhibitor (SVMPi). Although commonly found in Viperidae venoms, except for Bax-12, the BPPs and SVMPi here reported had not been described in B. atrox and B. jararacussu venoms. Among the novel peptides, some exhibited bactericidal activity towards P. aeruginosa and S. aureus, had low hemolytic effect, and were devoid of antiparasitic activity. The identified novel antimicrobial peptides may be relevant in the development of new drugs for the management of multidrug-resistant Gram-negative and Gram-positive bacteria.

10.
Am J Med Genet C Semin Med Genet ; 184(4): 955-964, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33258288

RESUMEN

Rare diseases comprise a diverse group of conditions, most of which involve genetic causes. We describe the variable spectrum of findings and clinical impacts of exome sequencing (ES) in a cohort of 500 patients with rare diseases. In total, 164 primary findings were reported in 158 patients, representing an overall diagnostic yield of 31.6%. Most of the findings (61.6%) corresponded to autosomal dominant conditions, followed by autosomal recessive (25.6%) and X-linked (12.8%) conditions. These patients harbored 195 variants, among which 43.6% are novel in the literature. The rate of molecular diagnosis was considerably higher for prenatal samples (67%; 4/6), younger children (44%; 24/55), consanguinity (50%; 3/6), gastrointestinal/liver disease (44%; 16/36) and syndromic/malformative conditions (41%; 72/175). For 15.6% of the cohort patients, we observed a direct potential for the redirection of care with targeted therapy, tumor screening, medication adjustment and monitoring for disease-specific complications. Secondary findings were reported in 37 patients (7.4%). Based on cost-effectiveness studies in the literature, we speculate that the reports of secondary findings may influence an increase of 123.2 years in the life expectancy for our cohort, or 0.246 years/cohort patient. ES is a powerful method to identify the molecular bases of monogenic disorders and redirect clinical care.


Asunto(s)
Exoma , Enfermedades Raras , Niño , Estudios de Cohortes , Consanguinidad , Exoma/genética , Femenino , Humanos , Embarazo , Enfermedades Raras/diagnóstico , Enfermedades Raras/genética , Secuenciación del Exoma
11.
Sci Rep ; 10(1): 22312, 2020 12 18.
Artículo en Inglés | MEDLINE | ID: mdl-33339861

RESUMEN

Plants may contain beneficial or potentially dangerous substances to humans. This study aimed to prepare and evaluate a new drug delivery system based on a glass-ionomer-Brazilian pepper extract composite, to check for its activity against pathogenic microorganisms of the oral cavity, along with its in vitro biocompatibility. The ethanolic Brazilian pepper extract (BPE), the glass-ionomer cement (GIC) and the composite GIC-BPE were characterized by scanning electron microscopy, attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), and thermal analysis. The BPE compounds were identified by UPLC-QTOF-MS/MS. The release profile of flavonoids and the mechanical properties of the GIC-BPE composite were assessed. The flavonoids were released through a linear mechanism governing the diffusion for the first 48 h, as evidenced by the Mt/M∞ relatively to [Formula: see text], at a diffusion coefficient of 1.406 × 10-6 cm2 s-1. The ATR-FTIR analysis indicated that a chemical bond between the GIC and BPE components may have occurred, but the compressive strength of GIC-BPE does not differ significantly from that of this glass-ionomer. The GIC-BPE sample revealed an ample bacterial activity at non-cytotoxic concentrations for the human fibroblast MRC-5 cells. These results suggest that the prepared composite may represent an alternative agent for endodontic treatment.


Asunto(s)
Anacardiaceae/química , Cementos de Ionómero Vítreo/síntesis química , Boca/efectos de los fármacos , Extractos Vegetales/química , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Brasil , Fuerza Compresiva , Frutas/química , Cementos de Ionómero Vítreo/química , Cementos de Ionómero Vítreo/farmacología , Humanos , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Boca/química , Boca/microbiología , Extractos Vegetales/farmacología , Espectroscopía Infrarroja por Transformada de Fourier
12.
Eur J Case Rep Intern Med ; 7(9): 001712, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32908829

RESUMEN

Inflammatory myofibroblastic tumour (IMT) is a rare mesenchymal tumour. It is usually benign but may behave as a malignant tumour with multiple recurrences and metastases. We present the case of a young woman with weight loss associated with diffuse abdominal pain, who was shown to have a large pancreatic mass. Investigation revealed fusocellular mesenchymal neoplasia, compatible with the diagnosis of IMT. As the mass was unresectable, glucocorticoid therapy was initiated with an excellent response and regression of the tumour. LEARNING POINTS: Inflammatory myofibroblastic tumour (IMT) is a rare entity.Since IMT can occur in different locations, its clinical presentation is varied, with non-specific symptoms.Prognosis is usually benign, but relapse and metastasis have been reported.

13.
J Belg Soc Radiol ; 104(1): 55, 2020 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-32984762

RESUMEN

Teaching Point: Aggressive angiomyxoma is a rare and benign soft tissue lesion, characterized by a "whorled" or "layering" appearance on T2-weighted and post-gadolinium magnetic resonance.

14.
Toxicon X ; 7: 100053, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32793880

RESUMEN

Snakes of the genus Lachesis, commonly known as bushmasters, are the largest venomous snakes in the Americas. Because these snakes have their habitats in areas of remote forests they are difficult to find, and consequently there are few studies of Lachesis taxa in their natural ecosystems. Bushmasters are distributed in tropical forest areas of South and Central America. In Brazil they can be found in the Amazon Rainforest and the Atlantic Forest. Despite the low incidence of cases, laquetic envenoming causes severe permanent sequelae due to the high amount of inoculated venom. These accidents are characterized by local pain, hemorrhage and myonecrosis that can be confused with bothropic envenomings. However, victims of Lachesis bites develop symptoms characteristic of Lachesis envenoming, known as vagal syndrome. An important message of this bibliographic synthesis exercise is that, despite having the proteomic profiles of all the taxa of the genus available, very few structure-function correlation studies have been carried out. Therefore the motivation for this review was to fill a gap in the literature on the genus Lachesis, about which there is no recent review. Here we discuss data scattered in a number of original articles published in specialized journals, spanning the evolutionary history and extant phylogeographic distribution of the bushmasters, their venom composition and diet, as well as the pathophysiology of their bites to humans and the biological activities and possible biotechnological applicability of their venom toxins.

15.
Artículo en Inglés | MEDLINE | ID: mdl-32362928

RESUMEN

BACKGROUND: The Brazil's lancehead, Bothrops brazili, is a poorly studied pit viper distributed in lowlands of the equatorial rainforests of southern Colombia, northeastern Peru, eastern Ecuador, southern and southeastern Venezuela, Guyana, Suriname, French Guiana, Brazil, and northern Bolivia. Few studies have been reported on toxins isolated from venom of Ecuadorian and Brazilian B. brazili. The aim of the present study was to elucidate the qualitative and quantitative protein composition of B. brazili venom from Pará (Brazil), and to carry out a comparative antivenomics assessment of the immunoreactivity of the Brazilian antibothropic pentavalent antivenom [soro antibotrópico (SAB) in Portuguese] against the venoms of B. brazili and reference species, B. jararaca. METHODS: We have applied a quantitative snake venomics approach, including reverse-phase and two-dimensional electrophoretic decomplexation of the venom toxin arsenal, LC-ESI-MS mass profiling and peptide-centric MS/MS proteomic analysis, to unveil the overall protein composition of B. brazili venom from Pará (Brazil). Using third-generation antivenomics, the specific and paraspecific immunoreactivity of the Brazilian SAB against homologous (B. jararaca) and heterologous (B. brazili) venoms was investigated. RESULTS: The venom proteome of the Brazil's lancehead (Pará) is predominantly composed of two major and three minor acidic (19%) and two major and five minor basic (14%) phospholipase A2 molecules; 7-11 snake venom metalloproteinases of classes PI (21%) and PIII (6%); 10-12 serine proteinases (14%), and 1-2 L-amino acid oxidases (6%). Other toxins, including two cysteine-rich secretory proteins, one C-type lectin-like molecule, one nerve growth factor, one 5'-nucleotidase, one phosphodiesterase, one phospholipase B, and one glutaminyl cyclase molecule, represent together less than 2.7% of the venom proteome. Third generation antivenomics profile of the Brazilian pentabothropic antivenom showed paraspecific immunoreactivity against all the toxin classes of B. brazili venom, with maximal binding capacity of 132.2 mg venom/g antivenom. This figure indicates that 19% of antivenom's F(ab')2 antibodies bind B. brazili venom toxins. CONCLUSION: The proteomics outcome contribute to a deeper insight into the spectrum of toxins present in the venom of the Brazil's lancehead, and rationalize the pathophysiology underlying this snake bite envenomings. The comparative qualitative and quantitative immunorecognition profile of the Brazilian pentabothropic antivenom toward the venom toxins of B. brazili and B. jararaca (the reference venom for assessing the bothropic antivenom's potency in Brazil), provides clues about the proper use of the Brazilian antibothropic polyvalent antivenom in the treatment of bites by the Brazil's lancehead.

16.
J. venom. anim. toxins incl. trop. dis ; 26: e20190103, 2020. tab, graf
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1101265

RESUMEN

The Brazil's lancehead, Bothrops brazili, is a poorly studied pit viper distributed in lowlands of the equatorial rainforests of southern Colombia, northeastern Peru, eastern Ecuador, southern and southeastern Venezuela, Guyana, Suriname, French Guiana, Brazil, and northern Bolivia. Few studies have been reported on toxins isolated from venom of Ecuadorian and Brazilian B. brazili. The aim of the present study was to elucidate the qualitative and quantitative protein composition of B. brazili venom from Pará (Brazil), and to carry out a comparative antivenomics assessment of the immunoreactivity of the Brazilian antibothropic pentavalent antivenom [soro antibotrópico (SAB) in Portuguese] against the venoms of B. brazili and reference species, B. jararaca. Methods: We have applied a quantitative snake venomics approach, including reverse-phase and two-dimensional electrophoretic decomplexation of the venom toxin arsenal, LC-ESI-MS mass profiling and peptide-centric MS/MS proteomic analysis, to unveil the overall protein composition of B. brazili venom from Pará (Brazil). Using third-generation antivenomics, the specific and paraspecific immunoreactivity of the Brazilian SAB against homologous (B. jararaca) and heterologous (B. brazili) venoms was investigated. Results: The venom proteome of the Brazil's lancehead (Pará) is predominantly composed of two major and three minor acidic (19%) and two major and five minor basic (14%) phospholipase A2 molecules; 7-11 snake venom metalloproteinases of classes PI (21%) and PIII (6%); 10-12 serine proteinases (14%), and 1-2 L-amino acid oxidases (6%). Other toxins, including two cysteine-rich secretory proteins, one C-type lectin-like molecule, one nerve growth factor, one 5'-nucleotidase, one phosphodiesterase, one phospholipase B, and one glutaminyl cyclase molecule, represent together less than 2.7% of the venom proteome. Third generation antivenomics profile of the Brazilian pentabothropic antivenom showed paraspecific immunoreactivity against all the toxin classes of B. brazili venom, with maximal binding capacity of 132.2 mg venom/g antivenom. This figure indicates that 19% of antivenom's F(ab')2 antibodies bind B. brazili venom toxins. Conclusion: The proteomics outcome contribute to a deeper insight into the spectrum of toxins present in the venom of the Brazil's lancehead, and rationalize the pathophysiology underlying this snake bite envenomings. The comparative qualitative and quantitative immunorecognition profile of the Brazilian pentabothropic antivenom toward the venom toxins of B. brazili and B. jararaca (the reference venom for assessing the bothropic antivenom's potency in Brazil), provides clues about the proper use of the Brazilian antibothropic polyvalent antivenom in the treatment of bites by the Brazil's lancehead.(AU)


Asunto(s)
Animales , Oxidorreductasas , Mordeduras de Serpientes , Venenos de Serpiente , Mordeduras y Picaduras , Antivenenos , Bothrops , Proteoma
17.
Acta Med Port ; 2019 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-31738704
18.
Artículo en Inglés | MEDLINE | ID: mdl-30181737

RESUMEN

BACKGROUND: Cnidarians produce toxins, which are composed of different polypeptides that induce pharmacological effects of biotechnological interest, such as antitumor, antiophidic and anti-clotting activities. This study aimed to evaluate toxicological activities and potential as antitumor and antiophidic agents contained in total extracts from five cnidarians: Millepora alcicornis, Stichodactyla helianthus, Plexaura homomalla, Bartholomea annulata and Condylactis gigantea (total and body wall). METHODS: The cnidarian extracts were evaluated by electrophoresis and for their phospholipase, proteolytic, hemorrhagic, coagulant, fibrinogenolytic, neuromuscular blocking, muscle-damaging, edema-inducing and cytotoxic activities. RESULTS: All cnidarian extracts showed indirect hemolytic activity, but only S. helianthus induced direct hemolysis and neurotoxic effect. However, the hydrolysis of NBD-PC, a PLA2 substrate, was presented only by the C. gigantea (body wall) and S. helianthus. The extracts from P. homomalla and S. helianthus induced edema, while only C. gigantea and S. helianthus showed intensified myotoxic activity. The proteolytic activity upon casein and fibrinogen was presented mainly by B. annulata extract and all were unable to induce hemorrhage or fibrinogen coagulation. Cnidarian extracts were able to neutralize clotting induced by Bothrops jararacussu snake venom, except M. alcicornis. All cnidarian extracts were able to inhibit hemorrhagic activity induced by Bothrops moojeni venom. Only the C. gigantea (body wall) inhibited thrombin-induced coagulation. All cnidarian extracts showed antitumor effect against Jurkat cells, of which C. gigantea (body wall) and S. helianthus were the most active; however, only C. gigantea (body wall) and M. alcicornis were active against B16F10 cells. CONCLUSION: The cnidarian extracts analyzed showed relevant in vitro inhibitory potential over the activities induced by Bothrops venoms; these results may contribute to elucidate the possible mechanisms of interaction between cnidarian extracts and snake venoms.

19.
Food Chem Toxicol ; 116(Pt B): 360-368, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29704577

RESUMEN

Remains unknown if dietary lipids and anabolic steroids (AS) can interact to modify energy metabolism, hepatic structure and function. We investigated the impact of AS on gene expression, lipid profile, redox status and the development of nonalcoholic fatty liver disease (NAFLD) in mice treated with a diet rich in trans fatty acids. Seventy-two C57BL/6 mice were equally randomized into six groups and treated with a standard diet (SD) or high-fat diet (HFD) alone or combined with testosterone cypionate (10 or 20 mg/kg) for 12 weeks. When combined with a HFD, AS reduced plasma HDL cholesterol levels. It also upregulated SREBP-1, PPARα, SCD-1 and ACOX1 gene expression; plasma and hepatic triglyceride levels; oxidative stress; circulating hepatic transaminase levels and NAFLD severity. Our finding indicated that the activity of antioxidant enzymes such as catalase, glutathione-s-transferase and superoxide dismutase was attenuated by HFD, an effect whose implications for AS-induced hepatotoxicity requires further investigation. Increased lipid, protein and DNA oxidative damage as well as worsening NAFLD in response to the interaction of HFD and AS were also potentially associated with the ability of AS to amplify the activation of regulatory lipid metabolism genes that are also involved in the control of cellular redox balance.


Asunto(s)
Interacciones Alimento-Droga , Hígado/efectos de los fármacos , Enfermedad del Hígado Graso no Alcohólico/inducido químicamente , Enfermedad del Hígado Graso no Alcohólico/fisiopatología , Congéneres de la Testosterona/toxicidad , Ácidos Grasos trans/toxicidad , Triglicéridos/metabolismo , Acil-CoA Oxidasa/genética , Alanina Transaminasa/sangre , Animales , Antioxidantes/metabolismo , Aspartato Aminotransferasas/sangre , Composición Corporal , Catalasa/sangre , Dieta Alta en Grasa , Regulación de la Expresión Génica , Glutatión Transferasa/sangre , Hígado/metabolismo , Ratones Endogámicos C57BL , Enfermedad del Hígado Graso no Alcohólico/genética , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Estrés Oxidativo/efectos de los fármacos , PPAR alfa/genética , Estearoil-CoA Desaturasa/genética , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/genética , Superóxido Dismutasa/sangre , Triglicéridos/sangre , Regulación hacia Arriba
20.
Artículo en Inglés | MEDLINE | ID: mdl-29467796

RESUMEN

BACKGROUND: Wasp venoms constitute a molecular reservoir of new pharmacological substances such as peptides and proteins, biological property holders, many of which are yet to be identified. Exploring these sources may lead to the discovery of molecules hitherto unknown. This study describes, for the first time in hymenopteran venoms, the identification of an enzymatically inactive phospholipase A2 (PLA2) from the venom of the social wasp Polybia occidentalis. METHODS: P. occidentalis venom was fractioned by molecular exclusion and reverse phase chromatography. For the biochemical characterization of the protein, 1D and 2D SDS-PAGE were performed, along with phospholipase activity assays on synthetic substrates, MALDI-TOF mass spectrometry and sequencing by Edman degradation. RESULTS: The protein, called PocTX, was isolated using two chromatographic steps. Based on the phospholipase activity assay, electrophoresis and mass spectrometry, the protein presented a high degree of purity, with a mass of 13,896.47 Da and a basic pI. After sequencing by the Edman degradation method, it was found that the protein showed a high identity with snake venom PLA2 homologues. CONCLUSION: This is the first report of an enzymatically inactive PLA2 isolated from wasp venom, similar to snake PLA2 homologues.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA