Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 39
Filtrar
2.
Clin Cosmet Investig Dent ; 14: 103-112, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35509813

RESUMEN

Background: The use of discolored teeth is required to test whitening products, and it is difficult to obtain them, given their scarcity. Objective: To present a technique for in vitro darkening of extracted teeth simulating pulpal necrosis discoloration. Materials and Methods: Hemolysates I and II from human blood were subjected or not to laser irradiation (442 nm) for 1 h. The concentration of oxyhemoglobin (O2Hb) was analyzed by ultraviolet/visible spectroscopy, and the conversion of O2Hb to methemoglobin (MetHb) by transmission spectroscopy was assessed immediately and after 3 and 40 days. For darkening evaluation, bovine incisors were divided into two groups (n = 25), and their pulp chambers were filled with hemolysate solution II (HSII) and hemolysate II solution + laser (HSII+L). After storage in artificial saliva for 40 days at 37°C, color changes were measured by a colorimeter and ΔE was compared with the NBS parameters. Data were analyzed using a mixed linear model (α=5%). Results: HSII+L presented the lowest O2Hb and higher MetHb. The conversion of O2Hb to MetHb in HSII+L was 42% higher than in HSII. Both groups were effective in darkening the teeth, according to the NBS. Darkening stabilized from day 35. HSII promoted a marked color difference. Conclusion: The proposed technique was effective in darkening the extracted teeth simulating necrosis discoloration for in vitro models.

3.
ACS Appl Bio Mater ; 5(3): 1013-1024, 2022 03 21.
Artículo en Inglés | MEDLINE | ID: mdl-35171572

RESUMEN

Clinically, bone tissue replacements and/or bone repair are challenging. Strategies based on well-defined combinations of osteoconductive materials and osteogenic cells are promising to improve bone regeneration but still require improvement. Herein, we combined polycaprolactone (PCL) fibers, carbon nanotubes (CNT), and hydroxyapatite (nHap) nanoparticles to develop the next generation of bone regeneration material. Fibers formed by rotary jet spinning (RJS) instead of traditional electrospinning (ES) with embedded bone marrow mesenchymal stem cells (BMMSCs) showed the best outcomes to repair rat calvarial defects after 6 weeks. To understand this, it was observed that different morphologies were formed depending on the manufacturing method used. RJS fibers presented a particular topography with rough fibers, which allowed for better cellular growth and cell spreading in vitro around and into a three-dimensional (3D) mesh, while fibers made by ES were more smooth and cellular growth was only measured on the 3D mesh surface. The fibers with incorporated nHap/CNT nanoparticles enhanced in vitro cell performance as indicated by more cellular proliferation, alkaline phosphatase activity, proliferation, and deposition of calcium. Greater bone neoformation occurred by combining three characteristics: the presence of nHap and CNT nanoparticles, the topography of the RJS fibers, and the addition of BMMSCs. RJS fibers with nanoparticles and seeded with BMMSCs showed 10 136 mm3 of bone neoformation, meaning a 10-fold increase compared to using RJS only and BMMSCs (0.853 mm3) and a 5-fold increase from using ES only (2054 mm3) after 6 weeks of implantation. Conversely, none of these approaches used individually showed any significant difference for in vivo bone neoformation, suggesting that their combination is essential for optimizing bone formation. In summary, our work generated a potential material composed of well-defined combinations of suitable scaffolds seeded with BMMSCs for enhancing numerous orthopedic tissue engineering applications.


Asunto(s)
Células Madre Mesenquimatosas , Nanotubos de Carbono , Animales , Huesos , Durapatita/farmacología , Poliésteres , Ratas , Andamios del Tejido
4.
Commun Biol ; 4(1): 233, 2021 02 19.
Artículo en Inglés | MEDLINE | ID: mdl-33608611

RESUMEN

The engineering of multifunctional surgical bactericidal nanofibers with inherent suitable mechanical and biological properties, through facile and cheap fabrication technology, is a great challenge. Moreover, hernia, which is when organ is pushed through an opening in the muscle or adjacent tissue due to damage of tissue structure or function, is a dire clinical challenge that currently needs surgery for recovery. Nevertheless, post-surgical hernia complications, like infection, fibrosis, tissue adhesions, scaffold rejection, inflammation, and recurrence still remain important clinical problems. Herein, through an integrated electrospinning, plasma treatment and direct surface modification strategy, multifunctional bactericidal nanofibers were engineered showing optimal properties for hernia repair. The nanofibers displayed good bactericidal activity, low inflammatory response, good biodegradation, as well as optimal collagen-, stress fiber- and blood vessel formation and associated tissue ingrowth in vivo. The disclosed engineering strategy serves as a prominent platform for the design of other multifunctional materials for various biomedical challenges.


Asunto(s)
Antibacterianos/farmacología , Materiales Biocompatibles , Gelatina/farmacología , Hernia Abdominal/cirugía , Herniorrafia/instrumentación , Metacrilatos/farmacología , Nanofibras , Poliésteres/farmacología , Infección de la Herida Quirúrgica/prevención & control , Andamios del Tejido , Animales , Antibacterianos/química , Modelos Animales de Enfermedad , Gelatina/química , Hernia Abdominal/patología , Metacrilatos/química , Ratones , Células 3T3 NIH , Nanomedicina , Poliésteres/química , Ratas , Infección de la Herida Quirúrgica/microbiología , Cicatrización de Heridas/efectos de los fármacos
5.
Int J Biol Macromol ; 149: 1241-1251, 2020 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-32035152

RESUMEN

The main systemic alterations present in bothropic envenomation are hemostasis disorders, for which the conventional treatment is based on animal-produced antiophidic sera. We have developed a neutralizing antibody against Bothrops pauloensis (B. pauloensis) venom, which is member of the genus most predominant in snakebite accidents in Brazil. Subsequently, we expressed this antibody in plants to evaluate its enzymatic and biological activities. The ability of single-chain variable fragment (scFv) molecules to inhibit fibrinogenolytic, azocaseinolytic, coagulant and hemorrhagic actions of snake venom metalloproteinases (SVMPs) contained in B. pauloensis venom was verified through proteolytic assays. The antibody neutralized the toxic effects of envenomation, particularly those related to systemic processes, by interacting with one of the predominant classes of metalloproteinases. This novel molecule is a potential tool with great antivenom potential and provides a biotechnological antidote to snake venom due to its broad neutralizing activity.


Asunto(s)
Bothrops/metabolismo , Pruebas de Neutralización , Nicotiana/metabolismo , Proteínas Recombinantes/farmacología , Anticuerpos de Cadena Única/farmacología , Venenos de Serpiente/toxicidad , Animales , Brasil/epidemiología , Caseínas/metabolismo , Pollos , Células Clonales , Reacciones Cruzadas/inmunología , Fibrinógeno/metabolismo , Geografía , Hemorragia/patología , Ratones , Mapas de Interacción de Proteínas , Proteolisis , Anticuerpos de Cadena Única/aislamiento & purificación , Mordeduras de Serpientes/epidemiología
7.
Prog Biomater ; 8(1): 1-9, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30599070

RESUMEN

Hydroxyapatite was obtained by bone calcinations. To study the calcination process, bovine and porcine bones were first autoclaved to remove fat and other non-bone tissues. They were then heated in an alumina pan in an oxidizing atmosphere of air, where simultaneous thermal analysis curves were recorded. To prepare the hydroxyapatites, bone samples were calcined at 850 °C and 1000 °C using a muffle furnace for 1 h. The obtained materials were powdered using mortar and pestle, and sifted in a sieve (60 mesh) without any additional purification or chemical treatment. The materials obtained were characterized by energy-dispersive X-ray spectroscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy. The antimicrobial properties of these materials were determined through direct contact tests against Staphylococcus aureus. The natural hydroxyapatites obtained by bone calcination inhibited S. aureus growth, with the material obtained by calcination of bovine bones at 1000 °C, showing the best antimicrobial activity. These results indicated that bone wastes can be used to obtain hydroxyapatites with antimicrobial activity.

8.
Acta Biomater ; 83: 425-434, 2019 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-30342285

RESUMEN

The combination of kappa-carrageenan (κ-CG) and hydroxyapatite (HA) to generate a bone substitute material has been underexplored to date. Carrageenans (CGs) have remarkable characteristics such as biocompatibility, hydrophilicity, and structural similarities with natural glycosaminoglycans (GAGs), and they have demonstrated the ability to stimulate cellular adhesion and proliferation. Hydroxyapatite nanoparticles have been one of the most investigated materials for bone regeneration due to their excellent biocompatibility, bioactivity and osteoconductivity. In particular, this study presents an approach for the preparation of new bioactive composites of κ-CG/nHA for numerous bone regeneration applications. We performed a set of in vitro experiments to evaluate the influence of the bone substitutes on human osteoblasts. Cell culture studies indicated that all samples tested were cytocompatible. Relative to control substrates, cellular attachment and proliferation were better on all the scaffold surfaces that were tested. The S2 and S3 samples, those permeated by 1.5 and 2.5 wt% of CG, respectively, exhibited an enhancement in cell spreading capacity compared to the S1 test materials which were comprised of 1 wt% of CG. Excellent osteoblast viability and adhesion were observed for each of the tested materials. Additionally, the bone substitutes developed for this study presented a distinct osteoconductive environment. Data supporting this claim were derived from alkaline phosphatase (ALP) and calcium deposition analyses, which indicated that, compared to the control species, ALP expression and calcium deposition were both improved on test κ-CG/nHA surfaces. In summary, the injectable bone substitute developed here demonstrated great potential for numerous bone regeneration applications, and thus, should be studied further. STATEMENT OF SIGNIFICANCE: The novelty of this work lies in the determination of the in vitro cytocompatibility behavior of carrageenan and hydroxyapatite composite materials used as injectable bone substitutes. This injectable biomaterial can fill in geometric complex defects, and it displays bioactivity as well as high bone regeneration capacity. In this study, we evaluated the behaviors of osteoblast cells in contact with the scaffolds, including cellular adhesion and proliferation, cellular metabolism, and mineralization on the fabricated injectable bone substitutes. The results show than the carrageenan and hydroxyapatite substitutes provided a biomaterial with a great capacity for promoting cellular growth, adhesion, and proliferation, as well as contributing an osteoinductive environment for osteoblast differentiation and osteogenesis.


Asunto(s)
Sustitutos de Huesos , Carragenina , Durapatita , Ensayo de Materiales , Nanotubos/química , Osteoblastos/metabolismo , Sustitutos de Huesos/química , Sustitutos de Huesos/farmacología , Carragenina/química , Carragenina/farmacología , Adhesión Celular/efectos de los fármacos , Línea Celular , Proliferación Celular/efectos de los fármacos , Durapatita/química , Durapatita/farmacología , Humanos , Osteoblastos/citología
9.
Echocardiography ; 35(9): 1342-1350, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29920772

RESUMEN

BACKGROUND: The identification of predictors of mitral valve (MV) repair results is important for quality improvement in cardiac surgery. The aim of this study was to evaluate the relationship between MV morphological quantification by three-dimensional (3D) transesophageal echocardiography and mitral repair results. METHODS: Fifty-four patients with MV prolapse who were submitted to surgical repair were divided into 2 groups according to their postoperative mitral regurgitation (MR) degree (group 1, grade 0-I MR; group 2, ≥grade II MR). Morphological parameters related to the mitral ring, dimension of leaflets and prolapse, coaptation line, distance from papillary muscles to the leaflet border and valve angles were analyzed by 3D MV quantification. Cardiac remodeling and MR quantitative parameters were also evaluated. RESULTS: There was no correlation between 3D MV quantification and surgical results; a multivariate analysis did not show an association between morphological parameters and surgical outcome. The distance from the posteromedial papillary muscle to the leaflet border was higher (P = .038) in patients with ≥grade II postoperative MR. The left atrial diameter, left ventricular end-systolic diameter, left ventricular end-diastolic and end-systolic volumes were larger in patients with a significant residual MR (P < .05). CONCLUSION: Three-dimensional MV quantification did not predict the postoperative MR grade; however, the distance from the posteromedial papillary muscles to the leaflet border may be related to suboptimal repair results. Furthermore, excessive cardiac remodeling was related to postoperative MR ≥ grade II, what could suggest a potential benefit of early surgical treatment.


Asunto(s)
Ecocardiografía Tridimensional/métodos , Ecocardiografía Transesofágica/métodos , Prolapso de la Válvula Mitral/cirugía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Válvula Mitral/diagnóstico por imagen , Válvula Mitral/cirugía , Resultado del Tratamiento
10.
Biologicals ; 50: 109-116, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28822684

RESUMEN

Polyclonal antibodies raised in Balb-c mice against BnSP-7, a Lys-49 phospholipase A2, were used to measure cross reactivity against other snake venoms. Using ELISA, these antibodies were able to recognize PLA2s isoforms present in venoms of botropic snakes at 1:6400, 1:3200 and 1:100 ratios (w/w). These antibodies highly recognized proteins of low molecular weight (∼14,000) from crude snake venom Bp and Bm by Western Blotting. PLA2 these venoms, by alignment of primary structures demonstrated high identity with BnSP-7 PLA2, especially in the C-terminal region. However, the crude snake venom Bd and Bj, showed low recognition. The PLA2 activity of Bothrops pauloensis, Bothrops moojeni venoms or BpPLA2-TXI was inhibited significantly when anti-BnSP-7 antibodies were incubated at 1:10 and 1:20 ratios (venoms or toxin:anti-BnSP-7, w/w), respectively. The myotoxic effect induced by the same venoms was also reduced significantly at 1:1, 1:10 and 1:20 ratios, by decreased creatine kinase levels. The anti-PLA2 polyclonal antibodies effectively recognized PLA2s from Bothrops pauloensis and Bothrops moojeni venoms, and neutralized specific catalytic and myotoxic activity.


Asunto(s)
Anticuerpos Monoclonales/inmunología , Bothrops/inmunología , Reacciones Cruzadas/inmunología , Venenos de Crotálidos/inmunología , Fosfolipasas A2/inmunología , Venenos de Serpiente/inmunología , Secuencia de Aminoácidos , Animales , Western Blotting , Bothrops/clasificación , Bothrops/metabolismo , Venenos de Crotálidos/metabolismo , Ensayo de Inmunoadsorción Enzimática , Masculino , Ratones Endogámicos BALB C , Pruebas de Neutralización , Fosfolipasas A2/genética , Fosfolipasas A2/metabolismo , Homología de Secuencia de Aminoácido , Venenos de Serpiente/metabolismo , Especificidad de la Especie
11.
Phys Rev E ; 96(1-1): 012309, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29347163

RESUMEN

In this paper, we propose a methodology that bears close resemblance to the Fourier analysis of the first harmonic to study networks subjected to pendular behavior. In this context, pendular behavior is characterized by the phenomenon of people's dislocation from their homes to work in the morning and people's dislocation in the opposite direction in the afternoon. Pendular behavior is a relevant phenomenon that takes place in public transport networks because it may reduce the overall efficiency of the system as a result of the asymmetric utilization of the system in different directions. We apply this methodology to the bus transport system of Brasília, which is a city that has commercial and residential activities in distinct boroughs. We show that this methodology can be used to characterize the pendular behavior of this system, identifying the most critical nodes and times of the day when this system is in more severe demanded.

12.
Cancer Gene Ther ; 23(8): 254-7, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27364573

RESUMEN

Prostate cancer usually develops to a hormone-refractory state that is irresponsive to conventional therapeutic approaches. Therefore, new methods for treating aggressive prostate cancer are under development. Because of the importance of androgen receptors (ARs) in the development of the hormone-refractory state and AR mechanism of action, this study was designed. A single-stranded DNA as an aptamer was designed that could mimic the hormone response element (HRE). The LNCaP cells as an AR-rich model were divided into three sets of triplicate groups: the test group was transfected with Aptamer Mimicking HRE (AMH), Mock received only transfection reagents (mock) and a negative control. All three sets received 0, 10 and 100 nM of dehydroepiandrosterone (DHEA) separately. Data analysis showed hormone dependency of LNCaP cells in the negative control group upon treatment with 10 and 100 nM DHEA (compared with cells left untreated (P=0.001)). Transfection of AMH resulted in significant reduction of proliferation in the test group when compared with the negative control group with 10 (P=0.001) or 100 nM DHEA (P=0.02). AMH can form a hairpin structure at 37 °C and mimic the genomic HRE. Hence, it is capable of effectively competing with genomic HRE and interrupting the androgen signaling pathway in a prostate cancer cell line (LNCaP).


Asunto(s)
Andrógenos/metabolismo , Aptámeros de Nucleótidos/genética , Receptores Androgénicos/genética , Elementos de Respuesta , Secuencia de Bases , Sitios de Unión , Línea Celular Tumoral , Proliferación Celular/genética , Supervivencia Celular/genética , Expresión Génica , Humanos , Masculino , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/metabolismo , ARN Mensajero/química , ARN Mensajero/genética , Transfección
13.
Hum Vaccin Immunother ; 12(2): 491-502, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26360663

RESUMEN

A single vaccination of Yellow Fever vaccines is believed to confer life-long protection. In this study, results of vaccinees who received a single dose of 17DD-YF immunization followed over 10 y challenge this premise. YF-neutralizing antibodies, subsets of memory T and B cells as well as cytokine-producing lymphocytes were evaluated in groups of adults before (NVday0) and after (PVday30-45, PVyear1-4, PVyear5-9, PVyear10-11, PVyear12-13) 17DD-YF primary vaccination. YF-neutralizing antibodies decrease significantly from PVyear1-4 to PVyear12-13 as compared to PVday30-45, and the seropositivity rates (PRNT≥2.9Log10mIU/mL) become critical (lower than 90%) beyond PVyear5-9. YF-specific memory phenotypes (effector T-cells and classical B-cells) significantly increase at PVday30-45 as compared to naïve baseline. Moreover, these phenotypes tend to decrease at PVyear10-11 as compared to PVday30-45. Decreasing levels of TNF-α(+) and IFN-γ(+) produced by CD4(+) and CD8(+) T-cells along with increasing levels of IL-10(+)CD4(+)T-cells were characteristic of anti-YF response over time. Systems biology profiling represented by hierarchic networks revealed that while the naïve baseline is characterized by independent micro-nets, primary vaccinees displayed an imbricate network with essential role of central and effector CD8(+) memory T-cell responses. Any putative limitations of this cross-sectional study will certainly be answered by the ongoing longitudinal population-based investigation. Overall, our data support the current Brazilian national immunization policy guidelines that recommend one booster dose 10 y after primary 17DD-YF vaccination.


Asunto(s)
Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , Linfocitos B/inmunología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Vacuna contra la Fiebre Amarilla/inmunología , Fiebre Amarilla/prevención & control , Virus de la Fiebre Amarilla/inmunología , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Brasil , Humanos , Memoria Inmunológica/inmunología , Interferón gamma/sangre , Factor de Necrosis Tumoral alfa/sangre , Vacunación , Fiebre Amarilla/virología
14.
Res Pharm Sci ; 10(3): 233-40, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26600850

RESUMEN

Angiogenesis, formation of new blood vessels, play an important role in some diseases such as cancer and its metastasis. Using angiogenesis inhibitors, therefore, is one of the ways for cancer treatment and prevention of metastasis. Medicinal plants have been shown to play a major role in the treatment of a variety of cancers. In this direction, cytotoxic and angiogenic effects of oleo gum resin extracts of Rhus coriaria, Pistacia vera and Pistacia khinjuk from Anacardiaceae family were studied. For IC50 values, cytotoxic effects of the plant extracts were evaluated at different concentrations (1, 10, 20, 40, 80,100 µg/ml) against human umbilical vein endothelial normal cell (HUVEC) and Y79 cell lines using 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. In vitro tube formation on matrigel base was used to evaluate angiogenic effects in the presence of increasing concentrations (50, 100, 250 µg/ml) of the extracts. Vascular endothelium growth factor was used as angiogenesis stimulator. Gas chromatography results showed that α-pinene and ß-pinene were the major essential oils constituents of all plant extracts. According to the MTT assay results, the R. coriaria resin extract was more cytotoxic than those of P. vera and P. khinjuk extracts (IC50, 9.1 ± 1.6 vs 9.8 ± 2.1 and 12.0 ± 1.9, respectively; P<0.05). Cytotoxic effects of all extracts against Y79 cell line was significantly higher than those of HUVEC used as a normal cell line (P<0.05). Tube formation assay also showed that extract of R. coriaria resin inhibited angiogenesis more significantly than other tested extracts (P<0.05). It could be concluded that R. coriaria resin extract possess cytotoxic effect and antiangiogenesis against cancer cells and as an anticancer natural product has a good potential for future studies.

15.
Res Pharm Sci ; 10(2): 169-76, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26487894

RESUMEN

Descurainia sophia is a plant widely distributed and used as folk medicine throughout the world. Different extracts of aerial parts and seeds of this plant have been shown to inhibit the growth of different cancer cell lines in vitro. In this study, cytotoxic activity of D. sophia seed volatile oil was evaluated. D. sophia seed powder was mixed with distilled water and left at 25 °C for 17 h (E1), 23 h (E2) and 28 h (E3) to autolyse. Then, the volatile fractions of E1, E2, and E3 were collected after steam distillation for 3 h. Cytotoxic effects of the volatile oils alone or in combination with doxorubicin (mixture of E1 or E2 at 50 µg/ml or E1 at 100 µg/ml with doxorubicin at 0.1, 1, 10 µM) against MCF-7 cell line were determined using MTT assay. Cytotoxic effect of E1 volatile oil was also determined on HeLa cell line. The results indicated that 1-buten-4-isothiocyanate was the major isothiocyanate found in the volatile oils. The results of cytotoxic evaluations showed that volatile constituents were more toxic on MCF-7 cells with IC50< 100 µg/ml than HeLa cells with IC50> 100 µg/ml. No significant differences were observed between cytotoxic activities of E1, E2 and E3 on MCF-7 cell line. Concomitant use of E1 and E2 (50 µg/ml) with doxurubicin (1 µM) significantly reduced the viability of MCF-7 cells compared to the negative control, doxorubicin alone, or each volatile fraction. The same result was obtained on HeLa cells, when E1 (100 µg/ml) was concurrently used with doxorubicin (1 µM).

16.
J Econ Entomol ; 108(5): 2305-15, 2015 10.
Artículo en Inglés | MEDLINE | ID: mdl-26453719

RESUMEN

Spodoptera frugiperda, the fall armyworm, is a major economic pest throughout the Western Hemisphere of corn (maize), cotton, sorghum, and a variety of agricultural grasses and vegetable crops. Studies in the United States, the Caribbean, and Brazil demonstrated the existence of two subpopulations (previously designated "host strains") that differ in their choice of plant host. Specifically, the corn strain is preferentially found in corn and sorghum, while the rice strain is dominant in rice, turf grass, and alfalfa. However, inconsistent results were reported in surveys of fall armyworm in Argentina, with some indicating that the host plant preferences of the two strains might be compromised or even nonexistent. If correct, this would complicate efforts to control this pest by considerably expanding the range of habitats that would have to be considered as potential sources for fall armyworm infestations in specific crops. A reexamination of Argentine fall armyworm, this time with field collections rather than the laboratory colonies used in previous studies, confirmed the existence of the two strains and their host preferences. Specifically, the corn strain was consistently the majority population infesting corn and was usually so in sorghum, while the rice strain was predominant in pasture/turf grasses and alfalfa. The one outlier was a collection from rice, which had a corn strain majority. Overall, the data were generally consistent with strain behaviors observed in other areas of the Western Hemisphere.


Asunto(s)
Productos Agrícolas , Herbivoria , Spodoptera/fisiología , Animales , Argentina , Complejo IV de Transporte de Electrones/genética , Complejo IV de Transporte de Electrones/metabolismo , Conducta Alimentaria , Proteínas de Insectos/genética , Proteínas de Insectos/metabolismo , Larva/enzimología , Larva/crecimiento & desarrollo , Larva/fisiología , Especificidad de la Especie , Spodoptera/enzimología , Spodoptera/genética , Spodoptera/crecimiento & desarrollo , Triosa-Fosfato Isomerasa/genética , Triosa-Fosfato Isomerasa/metabolismo
17.
Biomed Res Int ; 2014: 196754, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24738050

RESUMEN

L-amino acid oxidases are enzymes found in several organisms, including venoms of snakes, where they contribute to the toxicity of ophidian envenomation. Their toxicity is primarily due to enzymatic activity, but other mechanisms have been proposed recently which require further investigation. L-amino acid oxidases exert biological and pharmacological effects, including actions on platelet aggregation and the induction of apoptosis, hemorrhage, and cytotoxicity. These proteins present a high biotechnological potential for the development of antimicrobial, antitumor, and antiprotozoan agents. This review provides an overview of the biochemical properties and pharmacological effects of snake venom L-amino acid oxidases, their structure/activity relationship, and supposed mechanisms of action described so far.


Asunto(s)
Factores Biológicos/química , Factores Biológicos/farmacología , L-Aminoácido Oxidasa/química , L-Aminoácido Oxidasa/farmacología , Venenos de Serpiente/química , Venenos de Serpiente/farmacología , Humanos , Relación Estructura-Actividad
18.
PLoS One ; 9(2): e86828, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24551041

RESUMEN

BACKGROUND: Venom-induced acute kidney injury (AKI) is a frequent complication of Bothrops snakebite with relevant morbidity and mortality. The aim of this study was to assess the effects of Schizolobium parahyba (SP) extract, a natural medicine with presumed anti-Bothrops venom effects, in an experimental model of Bothrops jararaca venom (BV)-induced AKI. METHODOLOGY: Groups of 8 to 10 rats received infusions of 0.9% saline (control, C), SP 2 mg/kg, BV 0.25 mg/kg and BV immediately followed by SP (treatment, T) in the doses already described. After the respective infusions, animals were assessed for their glomerular filtration rate (GFR, inulin clearance), renal blood flow (RBF, Doppler), blood pressure (BP, intra-arterial transducer), renal vascular resistance (RVR), urinary osmolality (UO, freezing point), urinary neutrophil gelatinase-associated lipocalin (NGAL, enzyme-linked immunosorbent assay [ELISA]), lactate dehydrogenase (LDH, kinetic method), hematocrit (Hct, microhematocrit), fibrinogen (Fi, Klauss modified) and blinded renal histology (acute tubular necrosis score). PRINCIPAL FINDINGS: BV caused significant decreases in GFR, RBF, UO, HcT and Fi; significant increases in RVR, NGAL and LDH; and acute tubular necrosis. SP did not prevent these changes; instead, it caused a significant decrease in GFR when used alone. CONCLUSION: SP administered simultaneously with BV, in an approximate 10∶1 concentration, did not prevent BV-induced AKI, hemolysis and fibrinogen consumption. SP used alone caused a decrease in GFR.


Asunto(s)
Lesión Renal Aguda/tratamiento farmacológico , Bothrops/metabolismo , Fabaceae/química , Extractos Vegetales/uso terapéutico , Lesión Renal Aguda/inducido químicamente , Lesión Renal Aguda/fisiopatología , Lesión Renal Aguda/orina , Proteínas de Fase Aguda/orina , Animales , Biomarcadores/orina , Moléculas de Adhesión Celular/orina , Venenos de Crotálidos , Hematócrito , Hemodinámica/efectos de los fármacos , Pruebas de Función Renal , Necrosis Tubular Aguda/complicaciones , Necrosis Tubular Aguda/patología , Necrosis Tubular Aguda/fisiopatología , Necrosis Tubular Aguda/orina , Lipocalina 2 , Lipocalinas/orina , Masculino , Fitoterapia , Extractos Vegetales/farmacología , Proteínas Proto-Oncogénicas/orina , Ratas , Ratas Wistar
19.
Res Pharm Sci ; 8(4): 298-303, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24082899

RESUMEN

Celecoxib is a non-steroidal anti-inflammatory drug (NSAID) developed as a selective inhibitor of cyclooxygenase-2 (COX-2) for the treatment of rheumatoid arthritis disease. Recently some other mechanisms have been identified for anti cancer activity of these agents including induction of apoptosis, inhibition of tumor vascularization, stimulation of antitumor immune responses and inhibition of cellular protein synthesis. The cytotoxic effects of four synthesisized analogues of celecoxib (coded as D, E, F and G) were evaluated against Hela, MDA-MB-231, A-2780-s and HT-29 cancer cells, using MTT assay; Also their induction of apoptosis using DNA fragmentation analysis were studied. MTT assay showed that cell survival percent of COX-2 positive cell lines (HT-29, MDA-MB-231 and Hela; p≤0.05) were decreased significantly after exposure to the tested COX-2 inhibitors while little effect was observed on the COX-2 negative cell line (A-2780-s). Results also showed that A-2780-s and Hela were the most resistant and the most sensitive cell lines to these compounds, respectively. Moreover, in DNA fragmentation assay, induction of apoptosis was confirmed by electrophoretic pattern of separated DNA fragments in Hela cell line. Compounds E and G in comparison with D and F exerted more cytotoxic effect on COX-2 positive cell lines (Hela, HT-29 and MDA-MB-231). This could be due to the hydrophobic substituent (Cl, CH3) located at the para position of phenyl ring leading to more lipophilicity and cell uptake. In addition, these COX-2 inhibitors induced apoptosis on Hela cell-line, which could be considered as one of the cytotoxic mechanisms of these compounds as potential anti cancer agents.

20.
PLoS One ; 8(4): e60311, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23579784

RESUMEN

Bovine anaplasmosis is a hemoparasitic disease that causes considerable economic loss to the dairy and beef industries. Cattle immunized with the Anaplasma marginale MSP1 outer membrane protein complex presents a protective humoral immune response; however, its efficacy is variable. Immunodominant epitopes seem to be a key-limiting factor for the adaptive immunity. We have successfully demonstrated that critical motifs of the MSP1a functional epitope are essential for antibody recognition of infected animal sera, but its protective immunity is yet to be tested. We have evaluated two synthetic vaccine formulations against A. marginale, using epitope-based approach in mice. Mice infection with bovine anaplasmosis was demonstrated by qPCR analysis of erythrocytes after 15-day exposure. A proof-of-concept was obtained in this murine model, in which peptides conjugated to bovine serum albumin were used for immunization in three 15-day intervals by intraperitoneal injections before challenging with live bacteria. Blood samples were analyzed for the presence of specific IgG2a and IgG1 antibodies, as well as for the rickettsemia analysis. A panel containing the cytokines' transcriptional profile for innate and adaptive immune responses was carried out through qPCR. Immunized BALB/c mice challenged with A. marginale presented stable body weight, reduced number of infected erythrocytes, and no mortality; and among control groups mortality rates ranged from 15% to 29%. Additionally, vaccines have significantly induced higher IgG2a than IgG1 response, followed by increased expression of pro-inflammatory cytokines. This is a successful demonstration of epitope-based vaccines, and protection against anaplasmosis may be associated with elicitation of effector functions of humoral and cellular immune responses in murine model.


Asunto(s)
Anaplasma marginale/inmunología , Anaplasmosis/inmunología , Proteínas de la Membrana Bacteriana Externa/inmunología , Vacunas Bacterianas/inmunología , Epítopos/inmunología , Inmunidad Celular , Inmunidad Humoral , Secuencias de Aminoácidos/inmunología , Anaplasmosis/prevención & control , Animales , Anticuerpos Antibacterianos/sangre , Anticuerpos Antibacterianos/inmunología , Proteínas de la Membrana Bacteriana Externa/química , Bovinos , Citocinas/genética , Citocinas/inmunología , Modelos Animales de Enfermedad , Epítopos/genética , Eritrocitos/inmunología , Eritrocitos/virología , Femenino , Inmunización , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Mediadores de Inflamación/inmunología , Ratones , Péptidos/síntesis química , Péptidos/inmunología , Bazo/citología , Bazo/inmunología , Transcripción Genética
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA