Ventilação mandatória intermitente sincronizada versus ventilação com suporte pressórico e volume garantido em coelhos induzidos à hemorragia aguda / Synchronized intermittent mandatory ventilation versus volume assured pressure support ventilation in rabbits induced to acute hemorrhage

Avaliaram-se os efeitos da ventilação mandatória intermitente sincronizada (SIMV) e da ventilação com pressão de suporte e volume garantido (VAPSV) sobre os parâmetros cardiorrespiratórios em coelhos anestesiados com propofol e submetidos à hipovolemia aguda. Vinte animais da raça Nova Zelândia foram distribuídos aleatoriamente em dois grupos: GM sob SIMV e GV sob VAPSV. Na medicação pré-anestésica, foram administradas quetamina (15mg/kg) e xilazina (1mg/kg) intramuscular. O propofol foi administrado na indução (8mg/kg) e na manutenção anestésica (0,5mg/kg/min). Em seguida, em cada grupo foi iniciada a modalidade ventilatória. Após 30 minutos da indução, os coelhos foram submetidos à hipovolemia, retirando-se 12mL/kg de sangue arterial. A primeira mensuração das características (M0) foi efetuada 40 minutos após a indução anestésica, seguida de mensurações em intervalos de 10 minutos depois da hipovolemia (M1 a M6). A partir de M3, o débito cardíaco foi maior em GM. Em ambos os grupos, as pressões arteriais e pressão venosa central diminuíram a partir de M1, enquanto a pressão arterial de oxigênio no sangue arterial aumentou a partir de M4. O esforço respiratório foi maior no GV em todos os momentos estudados. Conclui-se que a SIMV e a VAPSV foram seguras quanto à oxigenação arterial, garantindo uma adequada troca gasosa. Contudo, a SIMV mostrou-se a mais indicada em coelhos hipovolêmicos por manter melhor a estabilidade hemodinâmica, com a vantagem de proporcionar menor trabalho respiratório.

The effects of synchronized intermittent mandatory ventilation (SIMV) versus volume assured pressure support ventilation (VAPSV) on cardiorespiratory parameters in propofol-anesthetized rabbits induced to acute hypovolemia were evaluated. Twenty New Zealand white rabbits were randomly allotted to: GM under SIMV and GV under VAPSV. In premedication, ketamine (15mg/kg) and xylazine (1mg/kg) were administered intramuscularly. Propofol was used to induce (8mg/kg) and to maintain anesthesia (0.5mg/kg/min). Following, according to each group, the ventilation mode was started. After thirty minutes of anesthesia induction, rabbits were induced to hypovolemia by removing 12ml/kg of arterial blood. The initial measurement of parameters (M0) was recorded thirty minutes after anesthesia induction. Additional recordings were performed at 10-minute intervals after hypovolemia induction (M1 to M6). Cardiac output (CO) was bigger in GM. In both groups, arterial pressures and central venous pressure (CVP) decreased from M1, while arterial partial pressure of oxygen (PaO2) increased from M4. The respiratory effort was greater in GV at all times studied. In conclusion, VAPSV and SIMV were safe for arterial oxygenation and provided adequate gas exchange. However, the SIMV is more appropriate for hypovolemic rabbits, because it maintains hemodynamic stability and promotes lower respiratory work.

Evaluation of glycoproteins purified from adult and larval camel ticks (Hyalomma dromedarii) as a candidate vaccine

In order to identify antigens that can help prevent camel tick infestations, three major glycoproteins (GLPs) about 97, 66 and 40 kDa in size were purified from adult and larval Egyptian ticks, Hyalomma (H.) dromedarii, using a single-step purification method with Con-A sepharose. The purified GLPs were evaluated as vaccines against camel tick infestation in rabbits. The rabbits received three intramuscular inoculations of GLPs (20 microg/animal) on days 0, 14, and 28. In the immunoblot analysis, Sera from the immunized rabbits recognized the native GLPs and other proteins from larval and adult H. dromedarii ticks along with those from other tick species such as Rhipicephalus sanguineus but not Ornithodoros moubata. The effects of immunity induced by these GLPs were determined by exposing rabbits to adult H. dromedarii ticks. These results demonstrated that GLP immunization led to a slightly decreased reproductive index and significantly reduced rates of egg hatchability. These results demonstrated that immunization with the purified GLPs can provide protection against infestation by H. dromedarii and some other tick species. Further studies are needed to confirm the effectiveness of immunization with GLPs against other tick species.

Estimación del costo de producción de dos técnicas de radioinmunoanálisis en fase líquida para medir progesterona en plasma sanguíneo / Estimation of production costs of two radioimmunoanalysis in liquid stage to measure progesterone in blood plasma

Introducción. La mediación de progesterona de origen ovárico, es un prodecidimiento que permite determinar la funcionalidad reproductiva de las hembras de todos los mamíferos domésticos, inclusive en la mujer. En México, la tecnología del radioinmunoanálisis (RIA) es la más utilizada para medir progesterona sanguínea. Sin embargo, no existe alguna industria mexicana que se dedique a producir estuches comerciales. En el presente trabajo se estimó el costo de producción de dos técnicas de RIA en fase líquida para medir progesterona sanguínea. Material y métodos. A partir de los insumos primarios (anticuerpo, calibrador o analito y trazador) se establecieron y validaron dos técncias de RIA para medir progesterona sanguínea. La técnica A utilizó anticuerpos antipropgesterona inducidos en conejo y extraídos del suero sanguíneo. La técnica B utilizó anticuerpos antiprogesterona inducidos en gallina de postura y extraídos de la yema del huevo. Resultados. La sensibilidad de ambas técnicas de RIA permitió detectar valores relativamente bajos de la hormona, lo suficiente para poder detectar actividad luteal. El costo de producción por tubo (de USD 0.14 a 0.20) disminuyó conforme aumentó el rendimiento del anticuerpo. Discusión. En nuestro medio la producción de anticuerpos contra progesterona para establecer un RIA es una alternativa viable y disminuiría el costo de utilización de esta técnica

Obtención de inmunoglobulina G anti-Cryptococcus / Obtention of anti-Crypstococcus neoformans immunoglobulin G

Con el objetivo de obtener una IgG anti-Cryptococcus neoformans, se llevaron a cabo simultáneamente 2 esquemas de inmunización en conejos con una cepa autóctona. Para ambos se emplearon células enteras formalinizadas que se diferenciaban entre sí en cuanto a dosis y vías de inmunización. Los sueros obtenidos fueron titulados y se seleccionó el de mayor título (1:1 024 por el método de aglutinación en lámina) el cual fue purificado mediante precipitación salina y cromatografía de intercambio iónico, con la obtención de una IgG de pureza y actividad biológica altas

Mechanism of enhancement of renal (Na+ + K+) ATPase activity following chronic ethanol exposure

A method was devised to determine the nature of the mechanism of the increase in renal (NA++K+)-ATPase in rats fed dilute ethanol for ten weeks. Antiserum to (NA++K+)-ATPase obtained from rabbits was added to microssomal fractions of Kidney and the activities of (NA++K+)-ATPase and Mg2+ ATPase were determined. The addition of antiserum resulted in a same pattern of dose-related inhibition of (NA++K+)-ATPase activity in control and ethanol-fed rats, whereas mg2+-ATPase was not affected by the antiserum. These results suggest that the mechanism of ethanol-induced enhancement of renal (NA++K+)-ATPase activity could be explained through an increase in the number of catalytic units.

Modifications morphologiques du tissu lymphoide bronchique au decours d'une immunisation intra tracheale chez le lapin

Le travail experimental decrit; a ete realise chez le lapin. Ce travail concerne; apres immunisation intra tracheale primaire et secondaire par les globules rouges heterologues; l'etude comparee des reponses bronchiques; ganglionnaires et mesenteriques. Enfin; une etude des modifications morphologiques du tissu lymphoide bronchique a ete simultanement menee; et a permis de noter l'hyperplasie des cellules calciformes (cellules a mucus); l'hypertrophie des nodules lympho-epitheliaux (NLE); du lympho-epithelium; la dimunition des cellules ciliees; l'augmentation des NLE; des amas lymphoides et enfin une infiltration massive des cellules dans le lympho-epithelium. Cette infiltration pourrait plaider en faveur d'un transfert preferentiel et d'une reconnaissance antigenique au niveau des nodules lympho-epitheliaux bronchiques

Enzyme-linked thyroglobulin immunoassay

A one-step enzyme linked sandwich immunoassay using Silicone rods coated with rabbit anti-human thyroglobulin anti-Tg) immunoglobulin G (Fab') conjugated with beta-D-galactosidase was established for the measurement of thyroglobulin in human sera. The volume of serum needed for the assay was 2 mul The sensitivity of the assay was 1.52 amol/tube, corresponding to O.5 ng/ml. The precision was proven by coefficients of variation: intra-assay, 7.0 to 9.1 per cent: inter-assay, 5.3 to 7.4 per cent. The correlation between this EIA and RIA was O.91, p < O.O1.

Lysine- and threonine-sensitive aspartokinase isoenzymes from spinach leaves share common antigenic determinants.

The lysine- and threonine-sensitive isoenzymes of aspartate kinase were purified to homogeneity from spinach leaves and polyclonal antibodies were raised in rabbits. The antibodies were characterized by various immunological tests like Ouchterlonys-double-diffusion, titrations of the inhibition of enzyme activity and ELISA. The antibodies against the lysine-sensitive isoenzyme could recognise as little as 50 ng of the pure antigen protein and that against the threonine-sensitive form could recognise 200 ng of the protein in the ELISA tests. The immunological tests have also shown that the lysine and threonine sensitive isoenzymes of aspartate kinase share some common antigenic determinants and differ in others.

Characterization of poly- and monoclonal antibodies to physalis mottle (tymo) virus.

Polyclonal antibodies were raised against the Physalis mottle virus (PhMV) and its denatured coat protein (PhMV-P). Analysis of the reactivity of the polyclonal antibodies with tryptic peptides of PhMV-P in dot-blot assays revealed that many of the epitopes were common to intact virus and denatured coat protein. Five monoclonal antibodies to the intact virus were obtained using hybridoma technology. These monoclonal antibodies reacted well with the denatured coat protein. Epitope analysis suggested that probably these monoclonal antibodies recognize overlapping epitopes. This was substantiated by epitope mapping using the CNBr digest of PhMV-P in western blots. All the five monoclonals recognized the N-terminal 15 K fragment. Attempts to further delineate the specific region recognized by the monoclonals by various enzymatic cleavages resulted in the loss of reactivity in all the cases. The results indicate that these monoclonals probably recognize epitopes within the N-terminal 15 K fragment of the coat protein.

Termination of pregnancy in mice following antiserum administration to modified chicken riboflavin carrier protein.

Rabbit antibodies to native riboflavin carrier protein (RCP), are to a large extent directed towards conformational epitopes and antibodies to disulphide bond reduced carboxymethylated RCP (RCM-RCP) are towards sequential epitopes. The major cyanogen bromide (CNBr) fragments and tryptic fragments of RCM-RCP interact with both antiserum to RCM-RCP and RCP. Passive immunization of pregnant mice with antibodies to RCM-RCP results in bioneutralization, leading to termination of pregnancy. Recently, a major tryptic fragment of RCM-RCP (24 +/- 2 kd) which could assume conformation at the antibody combining site of native RCP, obtained following mild trypsinization has been identified [Natraj et al. J. Biosci, 15 (1990) 341]. Rabbit antibodies to RCM-RCP treated with trypsin generated antibodies of low titer which interacted with RCM-RCP as well as RCP. The interaction of this antibody with RCP was of high affinity and could be displaced with RCP. The bioneutralizing ability of the antibody was demonstrated by its ability to cause termination of pregnancy in mice.

A search for immunocontraceptive agent from marine sources--role of antispermatheca globulin of Telescopium telescopium on fertility regulation in male rat.

Polyclonal antisera were developed in rabbits against 'spermatheca', the reproductive gland of T. telescopium, a marine mollusc. The gland contains spermatozoa. Antisera and its IgG fraction (ASTG) indicated common antigenic determinants by immunodiffusion and had titer values 81920 and 1280 against crude antigen extract. Cycling female rats when exposed to passively immunized male rats with different doses of ASTG, had reduction in implantation sites and litter size. Females had pseudopregnancy when exposed to higher doses of immunized males and had normal cycle after 20 days in average. ASTG in male rats caused decrease in weight of the reproductive glands, alteration in sperm concentration, motility and morphology, formation of multinucleated giant cells and vacuoles leading to arrest of spermatogenesis and reduction in seminiferous tubular diameter. The effects were dose dependent with reversible infertility. The results indicate presence of a common antigenic determinants which cross-react with vertebrates and existence of common relation through phylogenetic evolution and their immune responses.

Desarrollo de un ensayo de dot-blot para la detección de adhesinas en Escherichia coli enterotoxigéna / Dot-blot immunoenzymatic reaction to detec adhesins from enteropathogenic Escherichia coli

Un método de detección de adhesinas K99, K88 y F41 de Escherichia coli enterotoxigénica ha sido desarrollado sobre membranas de nitrocelulosa, basado en la reacción inmunoenzimática de dot-blot. Suspensiones estandarizadas de este microorganismo, portando distintos tipos de adhesinas fueron sembrados en el papel y enfrentados a anticuerpos-sonda de especificidad probada y posteriormente a un conjugado peoxidasa-antianticuerpo. La prueba mostró ser de alta sensibilidad y específica del tipo de adhesina, pudiendo emplearse como ensayo diagnóstico en la detección de esos factores de virulencia

Efecto del ácido cafeico y del ácido acetilsalicílico en el embolismo graso producido por médula ósea autóloga en el conejo / Caffeic acid and acetylsalicylic acid effects in fat embolism produced by autologous bone maroww in rabbit

La fisiopatología del síndrome de embolia grasa (SEG) se ha asociado a diferentes mediadores proinflamatorios. En este trabajo se postula la participación del tromboxaqno A2 (TxA2) y de los leucotrienos (Lts). Se desarrolló un modelo experimental de embolismo graso en el mediante la fractura del emur y la administración de médula ósea autóloga. Se midieron la presión arterial media (PAM), la presión venosa central (PVC), la sobrevida y los gases arteriales en cuatro grupos (n=7) que recibieron los siguientes tratamientos; una hora antes del embolismo: grupo 1, sin tratamiento; grupo 2, bicarbonato de sodio al 3 por ciento; grupo 3, ácido acetilsalicílico (AAS) como inhibidor de la síntesis TxA2 (10mg/Kg) y grupo 4, ácido cafeico como inhibridor de la síntesis de Lts (15 mg/Kg). En todos los casos se demostraron los signos histopatológicos, los cambios en las presiones y la gasometria, compatibles con embolismo graso. El AAS y el ácido cafeico brindaron protección parcial (en el cambio en la presión venosa central y en la sobrevida). El AAS disminuyó además, los cambios en la gasometría. Se concluye que el TxA2 y los Lts. entre otros medidores participan en el modelo utilizado, el cual reproduce el embolismo grado humano y podría ser utilizado como prueba de cernimientos de las drogas con potencial terapéutico en el SEG.

Miosite imunológica experimental / Immunological experimental myositis

Dezenove ratos de raça Lewis foram submetidos a injeçöes de extrato muscular heterológo de coelho e o tecido muscular avaliado por métodos de coloraçöes histoquímicas. Ocorreram disfunçöes inespecíficas nas fibras musculares e infiltrado inflamatório semelhante aos observados na dermatopolimiosite humana em oito animais evidenciando o envolvimento imunológico no desencadeamento da doença

Miosite imunológica experimental e terapêutica imunossupressor agents

Os aspectos imunológicos e terapêuticos da dermatopolimiosite (DPM) säo contraditórios. Os autores procuraram desenvolver miosite imunológica experimental com antígenos musculares de coelho e verificar o papel da terapêutica imunossupressora esteroídica (Prednisosna) e näo (Azatioprina). Trinta e quatro ratos subdiovididos em grupos A) Cinco animais (controle - soluçäo salina - SS); B) Dez injetados com 0,5 ml de extrato de músculo heterólogo (EMH) mais 0,5 ml de SS; C) cinco, estimulados com 0,5 ml de EMH + 0,5 ml de adjuvante completo de Freund (ACF); D) cinco animais, experimento semelhante ao grupo C + 1 mg/Kg/dia de Prednisona; E) cinco ratos, experimento homólogo ao C + 1 mg/Kg/dia de Azarioprina; F) cinco, estimulados com 0,5 ml d ACF + 0,5 ml de SS. O experimento durou sete semanas e o tecido musuclar foi analisado por hematoxilina-eosina e histoquímica. Ocorreram lesöes musculares semelhantes às encontradas na DPM humana em sete animais do grupo B. O grupo C revelou alteraçöes metabólicas musculares à histoquímica. Nos grupos tratados com imunossupressores esteroídicos e näo, as lesöes do tecido musuclar foram menos freqüentes e de pequena monta embora pertencessem ao grupo estimulados também com ACF

Influencia de la célula huésped en las reacciones de neutralización cruzada entre virus Junín y Tacaribe / Effect of the host cells in the crossed neutralization reactions between Junín and Tacaribe viruses

La inoculación de virus Tacaribe proveniente de cerebro de ratón lactante induce en el cobayo la aparición de anticurepos neutralizantes heterólogos anti-virus Junín. En este trabajo se trató de establecer si dichos anticuerpos neutralizantes estaban dirigidos contra antígenos celulares arrastados por los viriones al brotar o contra antígenos codificados por el genoma ciral. Con este fin de prepararon stocks de ambos virus en distintos huépedes (cerebro de ratón lactante, células Vero y RK13). Se inocularon cobayos con 1000 DICT50 de cada uno de los stocks de virus Tacaribe y 66 días más tarde se desafiaron con 1000 DL50 de virus Junín provenientes de cerebro de ratón. A los 30, 60 y 80 días p.i. con virus Tacaribe, se sangraron los animales y los inmunosueros obtenidos se ensayaron en reacciones directa y cruzada enfrentando a los virus Tacaribe y Junín crecidos en los distintos huésédes. Los resultados mostraron que en todos los casos los títulos de los sueros fueron mayores cuando se realizó la neutralización usando como antígeno virus que había multiplicado en el mismo huésped que el empleado para inmunizar a los animales. Sin embargo, el hecho que inmunosueros provenientes de animales inoculados con virus Tacaribe pudieran neutralizar al virus Junín cuando ambos virus provinieron de distintos huéspedes descarta la posibilidad que los anticurepos heterólogos encontrados en estos animales en el día 60 p.i. con Tacaribe estén dirigidos solamente contra antígenos celulares. Por el contrario dichos anticuerpos neutralizantes parecen estar dirigidos contra antígenos codificados por el genoma viral, confirmando las estreschas relaciones antigénicas existentes entre ambos virus