Avaliação morfológica do concentrado autólogo de plaquetas em cães sob refrigeração e criopreservação em DMSO 6% / [Morphological evaluation of the autologous platelet concentrate in dogs under refrigeration and criopreservation in 6% DMSO]

The morphological characteristics of the autologous platelet concentrate (APC) of 31 dogs were evaluated after cooling and freezing in 6% DMSO. Blood from the jugular vein of each patient was collected and centrifuged at 191g for six minutes to obtain APC. In the fresh sample, the platelet count, MPV, PDW and cell morphology were evaluated. Four samples of each animal were sent for storage, one refrigerated at 4°C for seven days, another for 30 days and two more stored in a freezer at -80°C in the same time interval, using 6% DMSO as cryoprotectant. The conserved samples were submitted to the same laboratory analysis as the fresh sample. There was a difference between fresh and preserved samples for platelet count, cell concentration, MPV and PDW (P<0.05), except in the 30-day refrigerated group, which showed severe morphological changes. In the frozen group for seven days, no difference was observed in the percentage of activation (P>0.05). The results obtained lead to the conclusion that cryopreservation with 6% DMSO at -80°C for seven days is a favorable option for the maintenance of platelet concentrations and the morphological characteristics of APC in dogs.(AU)

Dimensões da patela relacionadas à massa corporal do cão para emprego na confecção de prótese: estudo em cadáver / Patellar dimensions related to canine body mass for use in the manufacture of prosthesis: cadaver study

O objetivo deste trabalho foi mensurar as dimensões da patela de cadáveres caninos e avaliar sua relação com a massa corporal. Para a realização das medidas patelares, foram utilizados 70 cadáveres de cães adultos, com massa corpórea de 1 a 50kg, sem evidência clínica de afecção na articulação femorotibiopatelar. Com auxílio de um paquímetro, foram mensurados os comprimentos externo e interno, a largura externa no terço médio, a largura e a espessura internas nos terços proximal, médio e distal das patelas. Também foram mensuradas a largura nos terços proximal, médio e distal, a profundidade nos terços proximal, médio e distal do sulco troclear; essas medidas foram exclusivamente internas. Observou-se, de forma geral, forte correlação entre as medidas patelares e a massa corporal de cadáveres de cães. Nas condições deste estudo, pode-se concluir que o tamanho da patela varia segundo a massa corporal do cão e que essas medidas devem ser consideradas ao se planejar uma substituição protética.(AU)

The aim of this study was to measure the canine cadaver patellar dimensions and evaluate its relationship with body mass. 70 cadavers of adult dogs were used, with a body mass between 1 and 50kg, without clinical evidence of affection in the stifle joint. The external and internal lengths, external width in the middle third, width and thickness of the proximal, middle and distal thirds were measured using a pachymeter. The width was also measured in the proximal third, middle third and distal third, depth in the proximal third, middle third and distal third of the trochlear groove; these measurements were exclusively internal. A strong correlation was observed between the patellar dimension and body mass of canine cadavers. Under this study conditions, it is possible to conclude that the patellar size varies according to the canine body mass and these measures should be considered when planning a prosthetic replacement.(AU)

Effect of divalent metal ions on the activity and stability of Beta-galactosidase isolated from Kluyveromyces lactis

Este estudo demonstra como a Beta-galactosidase pode ser desativada e reativada usando EDTA e íons metálicos divalentes. A enzima foi desativada após 20 minutos na presença de EDTA. Desativação máxima para a menor concentração de EDTA (10-3 mol.L-1) ocorreu na presença do tampão Tris-HCl. A enzima recuperou 50% de sua atividade inicial após 10 minutos na presença de Mg2+ em concentrações superiores a 0,1mmol.L-1.Concentrações de 10-4 e 10-3 mol.L-1 de Mn2+ e Co2+ foram suficientes para reativar a enzima em 300% comparado ao controle de íons Mn2+ e aproximadamente 100% para íons Co2+. A enzima perdeu gradualmente a sua atividade quando a concentração foi de 10-2 mol.L-1. Ni2+ e Zn2+ foram incapazes de restabelecer a atividade catalítica. Km app e Vmax app foram 1,95 ± 0,05 mmol.L-1 e 5,40 ± 0,86 x 10-2 mmol.min-1.mg-1. A temperatura e pH ótimos foram 34ºC e 7,5. A meia vida da holoenzima foi de 17,5 min a 30ºC e para a apoenzima foi de 11,0 min a 30ºC. Quanto à variação de pH, a apoenzima provou ser mais sensível que a holoenzima.

In this study, it was demonstrated that Beta-galactosidase can be deactivated and reactivated with EDTA and divalent metal ions. The enzyme was deactivated after 20 minutes in EDTA solution. Maximal deactivation at the lowest EDTA concentration (10-3 mol.L-1) occurred in the presence of Tris-HCl buffer (pH 7.0). The enzyme recovered 50% of its initial activity after 10 minutes at Mg2+concentrations higher than 0.1 mmol.L-1. Experimental concentrations of 0.1 mmol.L-1 Mn2+ and 1.0 mmol.L-1 Co2+ were sufficient to reactivate the enzyme to around 300% of the control activity for the Mn2+ ion and nearly 100% for the Co2+ ion. The enzyme gradually lost its activity when the Co2+ concentration was 10-2 mol.L-1. Ni2+ and Zn2+ were unable to restore the catalytic activity. Km app and Vmax app were 1.95 ± 0.05 mmol.L-1 and 5.40 ± 0.86x10-2 mmol.min-1.mg-1, with o-NPG as substrate. Optimal temperature and pH were 34oC and 7.5. The half-life (t1/2) at 30ºC was 17.5 min for the holoenzyme and 11.0 min for the apoenzyme. With respect to pH variation, the apoenzyme proved to be more sensitive than the holoenzyme.

Utilización de un modelo animal para entrenamiento, en oxigenación por membrana extracorporea (ECMO) / The use of an animal model for extracorporeal membrane oxygenation (ECMO) training

ECMO es un procedimiento de rescate de recién nacidos (RN) con fallo respiratorio hipoxémico severo que no responde al tratamiento convencional. Previo a la instrumentación de esta técnica en pacientes, se realizó el entrenamiento experimental en animales. Existe escasa bibliografía sobre la utilización de porcinos como modelo animal en ECMO. Se reportan, en cambio, la implementación de otros animales, tales como el cordero. Objetivo: determinar la utilidad y el comportamiento modelo animal eligido, su respuesta al procedimiento de ECMO, describir la técnica utilizada y sus resultados. Método: se utilizaron dos porcinos de la raza Landrace, de 30 y 45 días de vida. Se canularon la vena yugular interna y la arteria carótida interna derechas; se realizó el ensamblado y purgado del circuito. El bypass se inició con un flujo de bomba de 20 mL/K/min, aumentandose hasta 100-120 mL/K/min; logrado un flujo de 80 mL/K/min se disminuyeron los parámetros de Asistencia Respiratoria Mecánica (ARM) a nivel de reposo. Durante el curso de ECMO se practicaron diferentes acciones relacionadas con el manejo del sistema de perfusión y evaluación del comportamiento clínico del modelo. Finalmente se suspendió electivamente el procedimiento; luego el animal fue dacanulado y recuperado. Resultados: tiempo promedio de ECMO: 24.5 horas. Signos vitales del animal estables. No hubo complicaciones relacionadas con el circito, ni presencia de sangrado sistémico. Se lograron tasas deseadas de hemofiltración. Ambos animales sobrevivieron. Como complicación se registró hematuria en un caso. Conclusión: El modelo animal elegido, para el entrenamiento en el manejo de ECMO, fue satisfactorio.

Abdomen agudo obstrutivo por ascaris / Obtructive acute abdomen due to ascaris

Se revisan 15 casos con diagnóstico preoperatorio de Abdomen Agudo Obtructivo por Ascaris, durante el lapso de Enero 1988-Diciembre 1991,evaluándose el manejo quirúrgico de acuerdos a los hallazgos intraoperatorios, la evolición post-operatoria de acuerdo a la técnica empleada y el tratamiento médico coadyuvante. Los autores sugieren la anastomosis primaria en los casos que ameriten resección intestinal

Immunoenzymatic quantitation of antibodies to Bothrops asper myotoxins after polyvalent antivenom administration in mice

Two quantitative enzyme-ummunoassays (EIA) for Bothrops asper myotoxin and anti-myotoxin antibodies, respectively, were utilized to study their in vivo distribution in mice (Swiss, 18 to 20 g). After polyvalent antivenom (0.4 ml) administration by the iv route, there was an immediated peak in plasma anti-myotoxin antibodies which declined rapidly during the first hour, and then decreased more gradually. Anti-myotoxin antibodies were detected in muscular tissue (gastrocnemius) following iv injection of antivenom. After im injection of antivenom (0.4 ml), a slow and steady increase in plasma anmti-myotoxin levels was observed, with a peak at 24 h. Mice that received antivenom (0.4 ml) by the iv or im route 15 min after im injection of B. asper venom (100 ug) had lower levels of plasma anti-myotoxin antibodies than controls injected with antivenom only, suggesting that at least a fraction of the antibodies combines with myotoxins in vivo. Myotoxin was not detected in plasma at any time after venom injection by the im (100 ug) or ip (40 ug) route. Following iv injection of 50 ug of purified myotoxin II, all plasma samples were also negative, at a detection limit of 10 ng/ml. It was demonstrated that myotoxin II binds to mouse erythrocytes in vitro, a fact that could partially explain its rapid in vivo disappearance from plasma. The present results on the distribution of anti-myotoxin antibodies in vivo are in agreement with previous experimental studies reporting the poor neutralization of myotoxicity induced by B. asper venom when antivenom is injected im, in comparison to iv injection

South American snake venom proteins antigenically related to bothrops asper myotoxins

1. the presence of proteins antigenically related to Bothrops asper myotoxins in various snake venoms, mainly from South America, was investigated by using poluclonal and monoclonal antibodies. 2. Myotoxin-like components were detected in the bothrops venoms from South america, and in the venoms of Crotalus atrox (North america), Trimerusurus flavoviridis (Japan), and Micrurus alleni (Costa Rica). 3. Cross-reactive components detected in several Bothrops venoms show a common subunit of 15-16 LDa by sodium dodcyl sulphate-polyacrylamide gel electrophoresis, although significant charge variations are evident by immunoelectrophoresis. 4. It is concluded that proteins antigenically related to B. asper nyotoxins are relatively common in the genus Bothrops and, in the light of findings discussed, are likely to posses myotoxic activity