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1.
Acta sci. vet. (Impr.) ; 49: Pub.1805-2021. tab, graf
Artigo em Inglês | VETINDEX | ID: biblio-1458444

Resumo

Background: Automated hematology analyzers have been developed to optimize the time between analyses and havepromising precision and accuracy. Complete blood count (CBC) is often requested as part of veterinary clinical examination. Automated analyzers are often used to determine CBCs, since processing as well as container-related errors mayoccur owing to variable sizes, aggregates, white or red blood cell fragments, and effects of EDTA on cell morphology.Platelet aggregates frequently occur in felines, with studies reporting a prevalence of approximately 71%. The aim of thepresent study was to evaluate the influence of exercise aggregates on the global white blood cell count of domestic catsusing automated hematological counters with the impedance method.Materials, Methods & Results: Blood samples of 140 cats, irrespective of age, sex, and breed, were collected into EDTAcontaining tubes. The samples were obtained via routine clinical examinations at the Veterinary Hospital of the FederalRural University of Rio de Janeiro (UFRRJ) and processed at the Veterinary Parasitology Experimental ChemotherapyLaboratory (LQEPV), belonging to the same institution. All the samples were processed on the Sysmex pocH-100iVDiff automated hematology apparatus according to the manufacturer’s recommendations. Leukocyte counts were alsomanually determined using a duplicate Neubauer chamber. Standard dilutions were prepared immediately after theautomated analysis. To identify the occurrence of platelet aggregates, a blood smear was made and visualized undera brightfield microscope at a magnification of 10× and scored 0 to 3 (G1, G2, G3, and G4) based on the aggregationintensity. In case of changes, the groups were subdivided according to the intensity of occurrence. Of the 140 samples...


Assuntos
Animais , Gatos , Contagem de Leucócitos/métodos , Contagem de Leucócitos/veterinária , Gatos , Agregação Plaquetária , Impedância Elétrica , Plaquetas
2.
Acta sci. vet. (Online) ; 49: Pub. 1805, Apr. 28, 2021. tab, graf
Artigo em Inglês | VETINDEX | ID: vti-762307

Resumo

Background: Automated hematology analyzers have been developed to optimize the time between analyses and havepromising precision and accuracy. Complete blood count (CBC) is often requested as part of veterinary clinical examination. Automated analyzers are often used to determine CBCs, since processing as well as container-related errors mayoccur owing to variable sizes, aggregates, white or red blood cell fragments, and effects of EDTA on cell morphology.Platelet aggregates frequently occur in felines, with studies reporting a prevalence of approximately 71%. The aim of thepresent study was to evaluate the influence of exercise aggregates on the global white blood cell count of domestic catsusing automated hematological counters with the impedance method.Materials, Methods & Results: Blood samples of 140 cats, irrespective of age, sex, and breed, were collected into EDTAcontaining tubes. The samples were obtained via routine clinical examinations at the Veterinary Hospital of the FederalRural University of Rio de Janeiro (UFRRJ) and processed at the Veterinary Parasitology Experimental ChemotherapyLaboratory (LQEPV), belonging to the same institution. All the samples were processed on the Sysmex pocH-100iVDiff automated hematology apparatus according to the manufacturers recommendations. Leukocyte counts were alsomanually determined using a duplicate Neubauer chamber. Standard dilutions were prepared immediately after theautomated analysis. To identify the occurrence of platelet aggregates, a blood smear was made and visualized undera brightfield microscope at a magnification of 10× and scored 0 to 3 (G1, G2, G3, and G4) based on the aggregationintensity. In case of changes, the groups were subdivided according to the intensity of occurrence. Of the 140 samples...(AU)


Assuntos
Animais , Gatos , Gatos , Contagem de Leucócitos/veterinária , Contagem de Leucócitos/métodos , Plaquetas , Agregação Plaquetária , Impedância Elétrica
3.
J. venom. anim. toxins incl. trop. dis ; 24: 33, 2018. tab, graf, ilus
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-976022

Resumo

Snake venom phospholipases A2 (PLA2s) have been reported to induce myotoxic, neurotoxic, hemolytic, edematogenic, cytotoxic and proinflammatory effects. This work aimed at the isolation and functional characterization of a PLA2 isolated from Bothrops jararaca venom, named BJ-PLA2-I. Methods and Results: For its purification, three consecutive chromatographic steps were used (Sephacryl S-200, Source 15Q and Mono Q 5/50 GL). BJ-PLA2-I showed acidic characteristics, with pI~4.4 and molecular mass of 14. 2 kDa. Sequencing resulted in 60 amino acid residues that showed high similarity to other Bothrops PLA2s, including 100% identity with BJ-PLA2, an Asp49 PLA2 previously isolated from B. jararaca venom. Being an Asp49 PLA2, BJ-PLA2-I showed high catalytic activity, and also inhibitory effects on the ADP-induced platelet aggregation. Its inflammatory characterization showed that BJ-PLA2-I was able to promote leukocyte migration in mice at different concentrations (5, 10 and 20 µg/mL) and also at different response periods (2, 4 and 24 h), mainly by stimulating neutrophil infiltration. Furthermore, increased levels of total proteins, IL-6, IL-1 ß and PGE2 were observed in the inflammatory exudate induced by BJ-PLA2-I, while nitric oxide, TNF-α, IL-10 and LTB4 levels were not significantly altered. This toxin was also evaluated for its cytotoxic potential on normal (PBMC) and tumor cell lines (HL-60 and HepG2). Overall, BJ-PLA2-I (2.5-160 µg/mL) promoted low cytotoxicity, with cell viabilities mostly varying between 70 and 80% and significant values obtained for HL-60 and PBMC only at the highest concentrations of the toxin evaluated. Conclusions: BJ-PLA2-I was characterized as an acidic Asp49 PLA2 that induces acute local inflammation and low cytotoxicity. These results should contribute to elucidate the action mechanisms of snake venom PLA2s.(AU)


Assuntos
Animais , Bothrops , Venenos de Crotalídeos/síntese química , Citotoxinas , Citotoxicidade Imunológica , Fosfolipases A2/síntese química
4.
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-976024

Resumo

In recent decades, snake venom disintegrins have received special attention due to their potential use in anticancer therapy. Disintegrins are small and cysteine-rich proteins present in snake venoms and can interact with specific integrins to inhibit their activities in cell-cell and cell-ECM interactions. These molecules, known to inhibit platelet aggregation, are also capable of interacting with certain cancer-related integrins, and may interfere in important processes involved in carcinogenesis. Therefore, disintegrin from Crotalus durissus collilineatus venom was isolated, structurally characterized and evaluated for its toxicity and ability to interfere with cell proliferation and migration in MDA-MB-231, a human breast cancer cell line. Methods: Based on previous studies, disintegrin was isolated by FPLC, through two chromatographic steps, both on reversed phase C-18 columns. The isolated disintegrin was structurally characterized by Tris-TricineSDS-PAGE, mass spectrometry and N-terminal sequencing. For the functional assays, MTT and wound-healing assays were performed in order to investigate cytotoxicity and effect on cell migration in vitro, respectively. Results: Disintegrin presented a molecular mass of 7287.4 Da and its amino acid sequence shared similarity with the disintegrin domain of P-II metalloproteases. Using functional assays, the disintegrin showed low cytotoxicity (15% and 17%, at 3 and 6 µg/mL, respectively) after 24 h of incubation and in the wound-healing assay, the disintegrin (3 µg/mL) was able to significantly inhibit cell migration (24%, p < 0.05), compared to negative control. Conclusion: Thus, our results demonstrate that non-RGD disintegrin from C. d. collilineatus induces low cytotoxicity and inhibits migration of human breast cancer cells. Therefore, it may be a very useful molecular tool for understanding ECM-cell interaction cancer-related mechanisms involved in an important integrin family that highlights molecular aspects of tumorigenesis. Also, non-RGD disintegrin has potential to serve as an agent in anticancer therapy or adjuvant component combined with other anticancer drugs.(AU)


Assuntos
Venenos de Serpentes , Crotalus , Desintegrinas , Neoplasias da Mama
5.
J. Venom. Anim. Toxins incl. Trop. Dis. ; 24: 33, Dec. 17, 2018. ilus, graf
Artigo em Inglês | VETINDEX | ID: vti-877

Resumo

Background: Snake venom phospholipases A2 (PLA2s) have been reported to induce myotoxic, neurotoxic, hemolytic, edematogenic, cytotoxic and proinflammatory effects. This work aimed at the isolation and functional characterization of a PLA2 isolated from Bothrops jararaca venom, named BJ-PLA2-I. Methods and Results: For its purification, three consecutive chromatographic steps were used (Sephacryl S-200, Source 15Q and Mono Q 5/50 GL). BJ-PLA2-I showed acidic characteristics, with pI~4.4 and molecular mass of 14. 2 kDa. Sequencing resulted in 60 amino acid residues that showed high similarity to other Bothrops PLA2s, including 100% identity with BJ-PLA2, an Asp49 PLA2 previously isolated from B. jararaca venom. Being an Asp49 PLA2, BJ-PLA2-I showed high catalytic activity, and also inhibitory effects on the ADP-induced platelet aggregation. Its inflammatory characterization showed that BJ-PLA2-I was able to promote leukocyte migration in mice at different concentrations (5, 10 and 20 g/mL) and also at different response periods (2, 4 and 24 h), mainly by stimulating neutrophil infiltration. Furthermore, increased levels of total proteins, IL-6, IL-1 and PGE2 were observed in the inflammatory exudate induced by BJ-PLA2-I, while nitric oxide, TNF-, IL-10 and LTB4 levels were not significantly altered. This toxin was also evaluated for its cytotoxic potential on normal (PBMC) and tumor cell lines (HL-60 and HepG2). Overall, BJ-PLA2-I (2.5-160 g/mL) promoted low cytotoxicity, with cell viabilities mostly varying between 70 and 80% and significant values obtained for HL-60 and PBMC only at the highest concentrations of the toxin evaluated. Conclusions: BJ-PLA2-I was characterized as an acidic Asp49 PLA2 that induces acute local inflammation and low cytotoxicity. These results should contribute to elucidate the action mechanisms of snake venom PLA2s.(AU)


Assuntos
Animais , Bothrops , Venenos de Víboras/análise , Venenos de Víboras/toxicidade , Fosfolipases A2/toxicidade , Citotoxinas
6.
J. Venom. Anim. Toxins incl. Trop. Dis. ; 24: 28, Nov. 29, 2018. tab, graf
Artigo em Inglês | VETINDEX | ID: vti-18439

Resumo

Background:In recent decades, snake venom disintegrins have received special attention due to their potential use in anticancer therapy. Disintegrins are small and cysteine-rich proteins present in snake venoms and can interact with specific integrins to inhibit their activities in cell-cell and cell-ECM interactions. These molecules, known to inhibit platelet aggregation, are also capable of interacting with certain cancer-related integrins, and may interfere in important processes involved in carcinogenesis. Therefore, disintegrin from Crotalus durissus collilineatus venom was isolated, structurally characterized and evaluated for its toxicity and ability to interfere with cell proliferation and migration in MDA-MB-231, a human breast cancer cell line.Methods:Based on previous studies, disintegrin was isolated by FPLC, through two chromatographic steps, both on reversed phase C-18 columns. The isolated disintegrin was structurally characterized by Tris-Tricine-SDS-PAGE, mass spectrometry and N-terminal sequencing. For the functional assays, MTT and wound-healing assays were performed in order to investigate cytotoxicity and effect on cell migration in vitro, respectively.Results:Disintegrin presented a molecular mass of 7287.4 Da and its amino acid sequence shared similarity with the disintegrin domain of P-II metalloproteases. Using functional assays, the disintegrin showed low cytotoxicity (15% and 17%, at 3 and 6 μg/mL, respectively) after 24 h of incubation and in the wound-healing assay, the disintegrin (3 μg/mL) was able to significantly inhibit cell migration (24%, p < 0.05), compared to negative control.Conclusion:Thus, our results demonstrate that non-RGD disintegrin from C. d. collilineatus induces low cytotoxicity and inhibits migration of human breast cancer cells. Therefore, it may be a very useful molecular tool for understanding ECM-cell interaction cancer-related mechanisms involved in...(AU)


Assuntos
Humanos , Animais , Venenos de Crotalídeos/análise , Desintegrinas/análise , Movimento Celular , Adesão Celular , Neoplasias da Mama/tratamento farmacológico , Crotalus
7.
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1484726

Resumo

Abstract Background: Snake venoms are a complex mixture of proteins, organic and inorganic compounds. Some of these proteins, enzymatic or non-enzymatic ones, are able to interact with platelet receptors, causing hemostatic disorders. The possible therapeutic potential of toxins with antiplatelet properties may arouse interest in the pharmacological areas. The present study aimed to purify and characterize an antiplatelet DC protein from Bothrops alternatus snake venom. Methods: The protein, called BaltDC (DC protein from B. alternatus snake venom), was purified by a combination of ion-exchange chromatography on DEAE-Sephacel column and gel filtration on Sephadex G-75. The molecular mass was estimated by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE). The amino acid sequence of the N-terminal region was carried out by Edman degradation method. Platelet aggregation assays were performed in human platelet-rich plasma (PRP). Infrared (IR) spectroscopy was used in order to elucidate the interactions between BaltDC and platelet membrane. Results: BaltDC ran as a single protein band on SDS-PAGE and showed apparent molecular mass of 32 kDa under reducing or non-reducing conditions. The N-terminal region of the purified protein revealed the amino acid sequence IISPPVCGNELLEVGEECDCGTPENCQNECCDA, which showed identity with other snake venom metalloproteinases (SVMPs). BaltDC was devoid of proteolytic, hemorrhagic, defibrinating or coagulant activities, but it showed a specific inhibitory effect on platelet aggregation induced by ristocetin and epinephrine in PRP. IR analysis spectra strongly suggests that PO 3 2 groups, present in BaltDC, form hydrogen bonds with the PO 2 groups present in the non-lipid portion of the membrane platelets. Conclusions: BaltDC may be of medical interest since it was able to inhibit platelet aggregation.

8.
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-954849

Resumo

Background: Snake venoms are a complex mixture of proteins, organic and inorganic compounds. Some of these proteins, enzymatic or non-enzymatic ones, are able to interact with platelet receptors, causing hemostatic disorders. The possible therapeutic potential of toxins with antiplatelet properties may arouse interest in the pharmacological areas. The present study aimed to purify and characterize an antiplatelet DC protein from Bothrops alternatus snake venom. Methods: The protein, called BaltDC (DC protein from B. alternatus snake venom), was purified by a combination of ion-exchange chromatography on DEAE-Sephacel column and gel filtration on Sephadex G-75. The molecular mass was estimated by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE). The amino acid sequence of the N-terminal region was carried out by Edman degradation method. Platelet aggregation assays were performed in human platelet-rich plasma (PRP). Infrared (IR) spectroscopy was used in order to elucidate the interactions between BaltDC and platelet membrane. Results: BaltDC ran as a single protein band on SDS-PAGE and showed apparent molecular mass of 32 kDa under reducing or non-reducing conditions. The N-terminal region of the purified protein revealed the amino acid sequence IISPPVCGNELLEVGEECDCGTPENCQNECCDA, which showed identity with other snake venom metalloproteinases (SVMPs). BaltDC was devoid of proteolytic, hemorrhagic, defibrinating or coagulant activities, but it showed a specific inhibitory effect on platelet aggregation induced by ristocetin and epinephrine in PRP. IR analysis spectra strongly suggests that PO 3 2 − groups, present in BaltDC, form hydrogen bonds with the PO 2 − groups present in the non-lipid portion of the membrane platelets. Conclusions: BaltDC may be of medical interest since it was able to inhibit platelet aggregation.(AU)


Assuntos
Animais , Venenos de Serpentes , Análise Espectral , Agregação Plaquetária , Bothrops , Transtornos Hemostáticos , Metaloproteases , Dodecilsulfato de Sódio , Eletroforese em Gel de Poliacrilamida
9.
Artigo em Inglês | VETINDEX | ID: vti-31762

Resumo

Background: Snake venoms are a complex mixture of proteins, organic and inorganic compounds. Some of these proteins, enzymatic or non-enzymatic ones, are able to interact with platelet receptors, causing hemostatic disorders. The possible therapeutic potential of toxins with antiplatelet properties may arouse interest in the pharmacological areas. The present study aimed to purify and characterize an antiplatelet DC protein from Bothrops alternatus snake venom. Methods: The protein, called BaltDC (DC protein from B. alternatus snake venom), was purified by a combination of ion-exchange chromatography on DEAE-Sephacel column and gel filtration on Sephadex G-75. The molecular mass was estimated by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE). The amino acid sequence of the N-terminal region was carried out by Edman degradation method. Platelet aggregation assays were performed in human platelet-rich plasma (PRP). Infrared (IR) spectroscopy was used in order to elucidate the interactions between BaltDC and platelet membrane. Results: BaltDC ran as a single protein band on SDS-PAGE and showed apparent molecular mass of 32 kDa under reducing or non-reducing conditions. The N-terminal region of the purified protein revealed the amino acid sequence IISPPVCGNELLEVGEECDCGTPENCQNECCDA, which showed identity with other snake venom metalloproteinases (SVMPs). BaltDC was devoid of proteolytic, hemorrhagic, defibrinating or coagulant activities, but it showed a specific inhibitory effect on platelet aggregation induced by ristocetin and epinephrine in PRP. IR analysis spectra strongly suggests that PO 3 2 − groups, present in BaltDC, form hydrogen bonds with the PO 2 − groups present in the non-lipid portion of the membrane platelets. Conclusions: BaltDC may be of medical interest since it was able to inhibit platelet aggregation.(AU)


Assuntos
Animais , Venenos de Serpentes , Análise Espectral , Agregação Plaquetária , Bothrops , Transtornos Hemostáticos , Metaloproteases , Dodecilsulfato de Sódio , Eletroforese em Gel de Poliacrilamida
10.
Arq. bras. med. vet. zootec. (Online) ; 68(1): 73-81, jan.-fev. 2016. tab, graf
Artigo em Português | VETINDEX | ID: vti-334154

Resumo

Avaliou-se o congelamento do plasma rico em plaquetas (PRP) de equinos, a -196ºC em nitrogênio líquido, utilizando-se como crioprotetor o DMSO em duas concentrações (3% e 6%), e, como ponto final, a avaliação da morfologia e da agregometria plaquetária. Foram utilizadas 12 amostras de PRP em duas repetições. Previamente ao congelamento, as amostras foram submetidas a um resfriamento lento (-0,07ºC/minuto) até a temperatura final de 4-5ºC. A criopreservação do PRP equino, incluindo um resfriamento lento a 4-5ºC, previamente ao congelamento a -197ºC em nitrogênio líquido, foi similar para as concentrações do crioprotetor DMSO a 3% ou 6%, quando avaliado o percentual de ativação e de agregação plaquetária.(AU)


Equine platelet-rich plasma (PRP) frozen at -196°C in liquid nitrogen using DMSO as a cryoprotectant in two different concentrations (3% and 6%) was evaluated, using platelet morphology and aggregometry as the final parameters. Twelve PRP samples were used in two repetitions. The samples were submitted to slow cooling prior to frozen (-0.07°C/minute) until they reached the temperature of 4-5°C. Platelet cryopreserved in 3% or 6% DMSO, presented similar efficacy when the percentage of activation and platelet aggregation was evaluated.(AU)


Assuntos
Animais , Criopreservação/veterinária , Cavalos/sangue , Crioprotetores , Dimetil Sulfóxido , Plasma Rico em Plaquetas , Contagem de Plaquetas , Contagem de Plaquetas/veterinária , Agregação Plaquetária
11.
Acta sci. vet. (Impr.) ; 44(supl): 01-05, 2016. ilus
Artigo em Inglês | VETINDEX | ID: biblio-1457507

Resumo

Background: The aortic thromboembolism in cats is usually associated with cardiomyopathy, when a thrombus or a clot is formed in the heart, transported through the bloodstream and fixed at somewhere. According to Virchows triad, changes in the endocardial surface or in the blood flow/composition can result in thrombus formation. The most common clinical signs are: hind limb paralysis, lack of femoral pulse, cold and cyanotic extremities. The treatment should be performed as soon as possible and it is based on antiplatelet agents, anticoagulants, thrombolytics agents or surgical procedures. It is reported the case of a cat presenting aortic thromboembolism. Case: Macroscopically it was observed that the hind limb extremities were with a dark red color and with a bad odor on cut. There were in the subcutaneous tissue of the hind limbs a severe and diffuse accumulation of a reddish material, translucent, shiny, gelatinous (intense diffuse edema) and the skeletal muscles of the hind limbs had extensive pale and friable areas. Inside the medial saphenous vein lumen there was a greyish-white and soft material which adhered to the vessel wall. The lungs were not fully collapsed, it had a smooth and shiny surface and an extensive dark red area in the right middle lobe (moderate extensive bleeding). The spleen was with slightly bulging edges and on cut flowed moderate amount of blood [...]


Assuntos
Animais , Gatos , Anticoagulantes/uso terapêutico , Aorta/patologia , Fibrinolíticos/uso terapêutico , Inibidores da Agregação Plaquetária/uso terapêutico , Tromboembolia Venosa/veterinária , Cardiomiopatias/veterinária
12.
Acta sci. vet. (Online) ; 44(supl): 01-05, 2016. ilus
Artigo em Inglês | VETINDEX | ID: vti-15136

Resumo

Background: The aortic thromboembolism in cats is usually associated with cardiomyopathy, when a thrombus or a clot is formed in the heart, transported through the bloodstream and fixed at somewhere. According to Virchows triad, changes in the endocardial surface or in the blood flow/composition can result in thrombus formation. The most common clinical signs are: hind limb paralysis, lack of femoral pulse, cold and cyanotic extremities. The treatment should be performed as soon as possible and it is based on antiplatelet agents, anticoagulants, thrombolytics agents or surgical procedures. It is reported the case of a cat presenting aortic thromboembolism. Case: Macroscopically it was observed that the hind limb extremities were with a dark red color and with a bad odor on cut. There were in the subcutaneous tissue of the hind limbs a severe and diffuse accumulation of a reddish material, translucent, shiny, gelatinous (intense diffuse edema) and the skeletal muscles of the hind limbs had extensive pale and friable areas. Inside the medial saphenous vein lumen there was a greyish-white and soft material which adhered to the vessel wall. The lungs were not fully collapsed, it had a smooth and shiny surface and an extensive dark red area in the right middle lobe (moderate extensive bleeding). The spleen was with slightly bulging edges and on cut flowed moderate amount of blood [...](AU)


Assuntos
Animais , Gatos , Tromboembolia Venosa/veterinária , Aorta/patologia , Inibidores da Agregação Plaquetária/uso terapêutico , Anticoagulantes/uso terapêutico , Fibrinolíticos/uso terapêutico , Cardiomiopatias/veterinária
13.
Semina ciênc. agrar ; 37(4): 1981-1990, 2016.
Artigo em Inglês | LILACS-Express | VETINDEX | ID: biblio-1500463

Resumo

Fifteen male New Zealand rabbits were used in this study, with the aim of storing their platelet-rich plasma (PRP) for 30 days at 4-6 C to investigate its conservation and viability during this period. Thirty samples of PRP were prepared and sorted into three equal groups (G1, G2, and G3), and every three days a sample was taken out for evaluationof the number of platelets, mean platelet volume (MPV), pH of the plasma, aggregation post addition of calcium thromboplastin, and for the presence of bacterial and fungal contamination. Results suggested that, for the number of platelets, there was no linear relationship over time. However, when comparing the number of platelets pre-storage to that post-storage, a statistical difference was observed. The hemogram MPV variables, pre and post-storage, also did not relate with time however, there was a statistical difference between the MPV of hemogram and MPV pre-storage, and between MPV pre-storage and MPV post-storage. From the pH evaluation, no influence of time on the variables was found, but statistical differences were found in the samples after storage between 30 and 6 days, 30 and 24 days, and 30 and 27 days. Platelet aggregation occurred within twenty seconds in all samples, independent of storage time. There was no growth of bacteria or yeast in any sample; however, mold growth occurred in the samples stored for 21 days from


Quinze coelhos machos da raça Nova Zelândia foram utilizados neste experimento, com a finalidade de armazenar o plasma rico em plaquetas (PRP) durante 30 dias a 4-6C para investigar a sua conservação e viabilidade durante este período. Trinta amostras de PRP foram preparadas e divididos em três grupos iguais (G1, G2 e G3), e de três em três dias foi retirada uma amostra para avaliação do número de plaquetas, volume plaquetário médio (VPM), pH do plasma, agregação após adição de tromboplastina cálcica, e para a presença de contaminação bacteriana e fúngica. Os resultados sugerem que, para o número de plaquetas, não houve uma relação linear com o tempo. No entanto, quando se compara o número de plaquetas pré-armazenamento com o pós-armazenamento, foi observada diferença estatística. As variáveis VPM no hemograma, pré e pós-armazenamento, também não se relacionou com o tempo, porém, houve diferença estatística entre o VPM do hemograma e pré-armazenamento, e entre VPM pré-armazenamento e pós-armazenamento. A partir da avaliação do pH, não houve influência do tempo sobre as variáveis, porém foram encontradas diferenças estatísticas nas amostras após o armazenamento entre 30 e 6, 30 e 24, e 30 e 27 dias. A agregação de plaquetas ocorreu no prazo de vinte segundos, em todas as amostras, independente do tempo de armazenamento. Não houve crescimento de bactérias ou fungos em qualquer a

14.
Tese em Português | VETTESES | ID: vtt-221027

Resumo

Diversas condições patogênicas podem levar a um estado de hipercoagulabilidade, quando pode haver a formação de trombos e/ou coagulação intravascular disseminada. O método mais indicado para detecção tanto da hipocoagulabilidade quanto hipercoagulabilidade é a tromboelastometria. O hiperadrenocorticismo pode levar a um estado de hipercoagulabilidade por aumentar a atividade de fatores de coagulação, como o fibrinogênio, além de diminuir a ação de anticoagulantes endógenos, como a antitrombina. O objetivo deste trabalho foi verificar se o bissulfato de clopidogrel, agente antiplaquetário, seria capaz de diminuir o estado de hipercoagulabilidade em animais diagnosticados com hiperadrenocorticismo; secundariamente, observamos também os principais fatores relacionados à hipercoagulabilidade em casos de HAC hipófise-dependente. Para tanto, foi realizado um estudo clínico prospectivo e randomizado em que os cães tiveram seu perfil hematológico, bioquímico e hemostático caracterizado no momento do diagnóstico, e após instituição dos protocolos terapêuticos (trilostano com ou sem clopidogrel) e normalização dos níveis de cortisol. Os resultados observados demonstraram que o tratamento com clopidogrel (2 mg/kg/SID) não demonstrou eficácia em reduzir o estado de hipercoagulabilidade, e os animais, mesmo após melhora dos sinais clínicos, permaneceram em risco trombótico, pelo menos pela avaliação tromboelastométrica.


Several pathogenic conditions can lead to a state of hypercoagulability, in which can occur thrombi formation and/or disseminated intravascular coagulation. The more appropriate method for detection of either hypocoagulability or hypercoagulability is thromboelastometry. It is an in vitro test that integrates cell components and soluble of hemostatic process, in order to result in a general assessment of hemostasis. The hyperadrenocorticism can lead to a hypercoagulability state due to increased activity of coagulation factors and fibrinogen concentration, in addition to decreased antithrombin activity, specially by glomerulonephritis and proteinuria. The aim of this study is to evaluate the clopidogrel bisulfate capability of attenuating the hypercoagulability state in dogs diagnosed with hyperadrenocorticism. For this purpose, a prospective and randomized clinical trial, in which patients will be characterized regarding their hemostatic profile on the admission date, and after therapy institution and subsequent normalization of cortisol levels. The results showed that treatment with clopidogrel (2 mg/kg/SID) did not demonstrate efficacy in reducing the state of hypercoagulability, and the animals, even after improvement of clinical signs, remained at thrombotic risk, at least by thromboelastometric evaluation.

15.
J. Venom. Anim. Toxins incl. Trop. Dis. ; 21: 1-11, Oct. 20, 2015. ilus, tab
Artigo em Inglês | VETINDEX | ID: vti-28561

Resumo

Snake venom galactoside-binding lectins (SVgalLs) comprise a class of toxins capable of recognizing and interacting with terminal galactoside residues of glycans. In the past 35 years, since the first report on the purification of thrombolectin from Bothrops atrox snake venom, several SVgalLs from Viperidae and Elapidae snake families have been described, as has progressive improvement in the investigation of structural/functional aspects of these lectins. Moreover, the advances of techniques applied in protein-carbohydrate recognition have provided important approaches in order to screen for possible biological targets. The present review describes the efforts over the past 35 years to elucidate SVgalLs, highlighting their structure and carbohydrate recognition function involved in envenomation pathophysiology and potential biomedical applications.(AU)


Assuntos
Animais , Lectinas , Galactosídeos , Animais Peçonhentos , Bothrops , Venenos de Crotalídeos/uso terapêutico
16.
J. venom. anim. toxins incl. trop. dis ; 21: 1-11, 31/03/2015. ilus, tab
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1484614

Resumo

Snake venom galactoside-binding lectins (SVgalLs) comprise a class of toxins capable of recognizing and interacting with terminal galactoside residues of glycans. In the past 35 years, since the first report on the purification of thrombolectin from Bothrops atrox snake venom, several SVgalLs from Viperidae and Elapidae snake families have been described, as has progressive improvement in the investigation of structural/functional aspects of these lectins. Moreover, the advances of techniques applied in protein-carbohydrate recognition have provided important approaches in order to screen for possible biological targets. The present review describes the efforts over the past 35 years to elucidate SVgalLs, highlighting their structure and carbohydrate recognition function involved in envenomation pathophysiology and potential biomedical applications.


Assuntos
Animais , Animais Peçonhentos , Bothrops , Galactosídeos , Lectinas , Venenos de Crotalídeos/uso terapêutico
17.
J. venom. anim. toxins incl. trop. dis ; 21: 35, 31/03/2015. tab, graf, ilus
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-954748

Resumo

Snake venom galactoside-binding lectins (SVgalLs) comprise a class of toxins capable of recognizing and interacting with terminal galactoside residues of glycans. In the past 35 years, since the first report on the purification of thrombolectin from Bothrops atrox snake venom, several SVgalLs from Viperidae and Elapidae snake families have been described, as has progressive improvement in the investigation of structural/functional aspects of these lectins. Moreover, the advances of techniques applied in protein-carbohydrate recognition have provided important approaches in order to screen for possible biological targets. The present review describes the efforts over the past 35 years to elucidate SVgalLs, highlighting their structure and carbohydrate recognition function involved in envenomation pathophysiology and potential biomedical applications.(AU)


Assuntos
Animais , Venenos de Serpentes , Produtos Biológicos , Viperidae , Bothrops , Relatório de Pesquisa , Lectinas , Galactosídeos
18.
Tese em Português | VETTESES | ID: vtt-220639

Resumo

As doenças cardiovasculares (DCV) estão entre as principais causas de mortalidade mundial. Dentre seus fatores de risco estão a hipertensão arterial sistêmica (HAS), as dislipidemias, o tabagismo e o diabetes melittus. Em relação ao estudo destas enfermidades, ressalta-se a necessidade de desenvolvimento de modelos experimentais que avaliem estes fatores de risco simultaneamente, simulando pacientes e investigando os efeitos terapêuticos das plantas medicinais. Tal necessidade justifica-se na crescente investigação de produtos naturais como terapia alternativa e/ou adjuvante aos tratamentos médicos convencionais, buscando alternativas terapêuticas mais eficazes e com menos efeitos adversos. Neste sentido, a Baccharis trimera (Less.) DC., popularmente conhecida como carqueja, destaca-se. Evidências científicas sobre seus efeitos em modelos animais de doença hepática e cardiovascular apontam efeitos promissores. Entretanto, poucos são os trabalhos que descrevem os efeitos farmacológicos da B. trimera em modelos animais que associem múltiplos fatores de risco. Assim, o primeiro passo deste estudo foi avaliar os efeitos medicinais desta planta frente dois fatores de risco associados: diabetes e idade. Para tanto, ratos Wistar (n = 40) com idade avançada (300 dias) receberam administração intraperitoneal de estreptozotocina (60 mg/kg), modelo clássico de diabetes mellitus. Porém o estudo mostrou-se inviável nesta idade, pois os animais apresentaram efeitos de toxicidade sistêmica, como lesão hepática e renal, após indução do modelo. Então, foi proposto um segundo modelo de estudo de DCV associando 3 fatores de risco (HAS, dislipidemia e tabagismo) com a avaliação da atividade hepato e cardioprotetora da B. trimera. Para tal, Wistar fêmeas (n = 48) foram submetidos ao modelo de hipertensão Goldblatt 2K1C, receberam dieta enriquecida com 0,5% de colesterol e foram expostos a 9 cigarros comerciais/dia, por 8 semanas. Nas 4 últimas semanas, os animais foram tratados com a fração solúvel em etanol de B. trimera (30, 100 e 300 mg/kg) ou sinvastatina (2,5 mg/kg) mais enalapril (15 mg/kg), por via oral através de gavagem. Foram investigados os níveis plasmáticos de alanina e aspartato aminotransferase, ureia, creatinina, perfil lipídico plasmático, hepático e fecal, pressão arterial sistólica, diastólica e média, reatividade vascular, alterações celulares e estado redox cardíaco, hepático e renal. O tratamento com o extrato de B. trimera reverteu todas as alterações apresentadas, com efeito igual ou superior ao tratamento padrão, demonstrando ser uma espécie promissora para o tratamento de pacientes com distúrbios cardiovasculares e hepáticos, especialmente aqueles associados a múltiplos fatores de risco. Por fim, buscou-se revisar na literatura científica atual os principais mecanismos celulares e moleculares das plantas anti-trombogênicas e seus principais componentes. As plantas medicinais são uma fonte importante de agentes anti-trombogênicos e têm sido considerados alternativas notáveis, com maior eficácia e, geralmente, menos efeitos adversos, tornando-se uma alternativa promissora para o manejo de distúrbios da coagulação. Os mecanismos celulares e moleculares que podem ser responsáveis por essa atividade anti-trombogênica das plantas incluem efeitos na agregação plaquetária, efeitos nos fatores de coagulação e efeitos na trombólise. No entanto, os mecanismos de ação responsáveis pela atividade antitrombótica desses agentes permanecem incertos. Mais estudos são necessários para esclarecer as vias centrais da resposta pleiotrópica destes agentes.


Cardiovascular diseases (CVD) are among the main causes of mortality worldwide. Among its risk factors are systemic arterial hypertension (SAH), dyslipidemia, smoking and diabetes mellitus. Regarding the study of these diseases, the need to develop experimental models that simultaneously evaluate these risk factors, simulating patients and investigating the therapeutic effects of medicinal plants, is emphasized. Such a need is justified in the growing investigation of natural products as an alternative and/or adjuvant therapy to conventional medical treatments, seeking more effective therapeutic alternatives with less adverse effects. In this sense, Baccharis trimera (Less.) DC., popularly known as carqueja, stands out. Scientific evidence on its effects on animal models of liver and cardiovascular disease points to promising effects. However, few studies describe the pharmacological effects of B. trimera in animal models that associate multiple risk factors. Thus, the first step of this study was to evaluate the medicinal effects of this plant against two associated risk factors: diabetes and aging. Therefore, Wistar rats (n = 40) with advanced age (300 days) received intraperitoneal administration of streptozotocin (60 mg/kg), a classic model of diabetes mellitus. However, the study proved to be unfeasible at this age, as the animals showed effects of systemic toxicity, such as liver and kidney damage, after the model was induced. Then, a second CVD study model was proposed, associating 3 risk factors (SAH, dyslipidemia and smoking) with the assessment of hepatic and cardioprotective activity of B. trimera. For this, females Wistar (n = 48) were submitted to the Goldblatt 2K1C hypertension model, received a diet enriched with 0.5% cholesterol and were exposed to 9 commercial cigarettes/day, for 8 weeks. In the last 4 weeks, the animals were treated with the ethanol-soluble fraction of B. trimera (30, 100 and 300 mg/kg) or simvastatin (2.5 mg/kg) plus enalapril (15 mg/kg), by oral route, through gavage. Plasma levels of alanine and aspartate aminotransferase, urea, creatinine, plasma lipid profile, hepatic and fecal, systolic, diastolic, and mean arterial pressure, vascular reactivity, cellular changes, and cardiac, hepatic, and renal redox status were investigated. The treatment with the extract of B. trimera reversed all the alterations presented, with an effect equal to or greater than the standard treatment, proving to be a promising species for the treatment of patients with cardiovascular and liver disorders, especially those associated with multiple risk factors. Finally, we sought to review in the current scientific literature the main cellular and molecular mechanisms of anti-thrombogenic plants and their main components. Medicinal plants are an important source of anti-thrombogenic agents and have been considered remarkable alternatives, with greater efficacy and, generally, less adverse effects, becoming a promising alternative for the management of coagulation disorders. The cellular and molecular mechanisms that may be responsible for this anti-thrombogenic activity of plants include effects on platelet aggregation, effects on coagulation factors and effects on thrombolysis. However, the mechanisms of action responsible for the antithrombotic activity of these agents remain uncertain. Further studies are needed to clarify the central pathways of the pleiotropic response of these agents.

19.
Bol. ind. anim. (Impr.) ; 71: 61-61, 2014.
Artigo em Inglês | LILACS-Express | VETINDEX | ID: biblio-1466617

Resumo

Onfaloflebitis is common in lambs born in poor hygienic conditions and occurs where inadequate treatment of umbilical healing is placed. Males are more affected lambs probably because of contact with urine that slows healing umbilical and removes some medications or topical antibiotics applied facilitating the bacteria entrance, mainly Fusobacterium necrophorum affecting joints, lungs, kidneys, liver, leading to animal death. Platelets are blood cells that interact with several receptors and modulate platelet function. It promotes hemostasis through four mechanisms: adhesion, release of platelet secretion, aggregation and pro-coagulation action. Complex network of growth factors are involved in tissue homeostasis such as transforming growth factor (TGF)-b, platelet-derived growth factor (PDGF), insulin-like growth factor (IGF), fibroblast growth factor (FGF)-b and hepatocyte growth factor (HGF). These factors and other bioactive molecules are contained in platelet alpha granules, and the use of intra-articular injections of platelet concentrate has been proposed as a minimally invasive solution to promote cartilage, osteo and muscular healing. Its use in regenerative medicine represents a simple, low-cost, and minimally invasive approach that might fasten healing processes. Regenerative treatment with autologous products, including the PRP (Platelet Rich Plasma) have been widel


O artigo não apresenta resumo em português.

20.
Tese em Português | VETTESES | ID: vtt-213376

Resumo

: A leptospirose é uma zoonose mundialmente disseminada e endêmica nas regiões tropicais e subtropicais do mundo. É causada por espiroquetas patogênicas do gênero Leptospira, que colonizam os túbulos renais proximais de animais domésticos ou silvestres e são eliminadas no ambiente externo pela urina. A transmissão ocorre por meio de contato direto com tecidos, fluidos corporais e urina de animais infectados, ou pela exposição à água ou solo contaminado. Esta doença apresenta grande impacto na saúde pública, além de ser responsável por prejuízos na economia pecuária, pois interfere na produção de leite e causa distúrbios reprodutivos nos animais de criação, como abortamentos e infertilidades. As plaquetas são pequenos fragmentos citoplasmáticos, abundantes no sangue e originados dos megacariócitos da medula óssea. Classicamente, são conhecidas por atuarem no processo de hemostasia, garantindo a manutenção do fluxo sanguíneo e da integridade vascular. No entanto, vários estudos têm demonstrado que as plaquetas, também, participam de processos inflamatórios, do reparo de tecidos, da angiogênese e de mecanismos de defesa do organismo a infecções. Na forma grave da leptospirose, a trombocitopenia tem sido relatada. Provavelmente, os baixos níveis de plaquetas no sangue ocorrem devido à lesão vascular e ao aumento no consumo de plaquetas nas hemorragias observadas durante a infecção por leptospiras. A trombocitopenia também pode ser causada pela ação direta das leptospiras sobre as plaquetas. Neste trabalho, foi investigado a existência de uma possível interação das leptospiras com as plaquetas. Os resultados obtidos, mostraram que os protocolos utilizados para a obtenção das amostras de sangue total, plasma rico em plaquetas e plaquetas lavadas são adequados para a avaliação da possível capacidade das leptospiras em ativar plaquetas. Entretanto, nenhuma das estirpes de leptospiras testadas foram capazes de ativar diretamente as plaquetas em um tempo máximo de 45 minutos, mesmo com diferentes proporções de bactéria:plaqueta. As leptospiras também foram avaliadas quanto a sua capacidade de alterar a agregação plaquetária provocada por agonistas conhecidos (colágeno, TRAP ou ADP). Apesar da agregação plaquetária na presença das leptospiras serem semelhantes ou maiores que o controle positivo, esses valores não foram estatisticamente significantes. Um lisado total da estirpe patogênica de leptospira, L1-130, foi avaliado quanto a capacidade de se ligar a lisados de diferentes frações plaquetárias, previamente ativadas ou não por ADP, através de ensaios de ELISA. O lisado da fração de plaquetas lavadas foi o único que apresentou valores significativos de interação com o lisado de L1-130. Por último, as plaquetas foram avaliadas quanto a sua capacidade de inibir o crescimento bacteriano, com o indicador de crescimento Resazurina. Estes ensaios não foram capazes de identificar uma ação microbicida por parte das plaquetas sobre a estirpe de leptospira utilizada. Os resultados obtidos, neste trabalho, mostraram que as leptospiras não foram capazes de ativar diretamente a agregação plaquetária, porém, a hipótese de interação entre as plaquetas e as leptospiras não deve ser totalmente descartada, uma vez que a fração de plaquetas lavadas foi capaz de aderir ao lisado da estirpe L1-130, por isso novos estudos devem ser realizados.


Leptospirosis is a widespread and endemic zoonosis in the tropical and subtropical regions of the world. It is caused by pathogenic spirochetes of the Leptospira genus, which colonize the proximal renal tubules of domestic or wild animals and are excreted in the environment by the urine. Transmission occurs through the direct contact with tissues, body fluids, and urine of infected animals, or through exposure to contaminated water or soil. This disease has great impact on public health, besides being responsible for losses in the livestock economy, because it interferes in the milk production and causes reproductive disorders in the livestock, such as abortion and infertility. Platelets are small cytoplasmic fragments, abundant in the blood and originated from the megakaryocytes of the bone marrow. Classically, they are known to act in the process of hemostasis, ensuring the maintenance of the blood flow and the vascular integrity. However, several studies have shown that platelets also participate in inflammatory processes, tissue repair, angiogenesis and mechanisms of defense of the body to infections. In the severe form of leptospirosis, thrombocytopenia has been reported. It is probable that the low platelet levels in the blood occur due to vascular injury and due to an increase in the consumption of blood, both observed during leptospiral infection. Thrombocytopenia can also be caused by the direct action of leptospires on platelets. In this work, the existence of a possible interaction between leptospires and human platelets was investigated. The results showed that the protocols used to obtain the samples of whole blood, platelet rich plasma and washed platelets are adequate for the evaluation of the possible ability of leptospires to activate platelets. However, none of the leptospira strains tested were able to directly activate the platelets in a maximum time of 45 minutes, even with different proportions of bacterium:platelet. Leptospires were also evaluated for their ability to alter platelet aggregation caused by known agonists (collagen, TRAP or ADP). Although platelet aggregation in the presence of leptospires was similar to or greater than the positive control, these values were not statistically significant. The total lysate of the pathogenic strain of leptospira, L1-130, was evaluated for the ability to bind to lysates of different platelet fractions, previously activated or not by ADP, by ELISA. The lysate of the washed platelets fraction was the only one that presented significant values of interaction with the L1-130 lysate. Finally, platelets were evaluated for their ability to inhibit bacterial growth, with the Resazurin growth indicator. These assays were not able to identify a microbicidal action by the platelets on the used leptospira strain. The results obtained in this work show that leptospires were not able to directly activate platelet aggregation, however, the hypothesis of interaction between platelets and leptospires should not be totally discarded, since some the washed platelet lysate was able to bind to the strain L1-130 lysate, so further studies should be carried out on this subject.

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