Calbindin D28k Expression and the Absence of Apoptosis in the Cerebellum of Solatium bonariense L-lntoxicated Bovines

Solanum bonariense intoxication is characterized by cerebellar neuronal vacuolation, degeneration, and necrosis. Cerebellar Purkinje cells seem especially susceptible, but more research is needed to determine the pathogenesis of neuronal necrosis and the mechanism of Purkinje cell susceptibility. Calbindin D28k (CbD28k) is highly expressed in Purkinje cells and has been used as a marker for normal and degenerative Purkinje cells. The goal of this study was to describe S bonariense-induced disease by ascertaining Purkinje cell-specific degenerative changes using CbD28k expression and to correlate this with apoptosis in Purkinje cells, as determined using TUNEL (transferase-mediated dUTP-biotin nick end-labeling) and ultrastructural changes. In all cases, an increase in both dose and duration of S bonariense intoxication resulted in a decrease in the number of Purkinje cells. CbD28k immunohistochemistry was an excellent marker for Purkinje cells because immunoreactivity did not change in normal or degenerative tissues. This finding suggests that excessive calcium excitatory stimulation does not induce rapid neuronal degeneration and death. As found in previous studies, TUNEL tests and electron microscopy suggest that Purkinje cell degeneration and death are not occurring via an apoptotic process. These findings suggest that S bonariense poisoning induces progressive Purkinje cell death that is not mediated by excitotoxicity or apoptotic activation.Facultad de Ciencias Veterinaria

Calbindin D28k Expression and the Absence of Apoptosis in the Cerebellum of Solatium bonariense L-lntoxicated Bovines

Solanum bonariense intoxication is characterized by cerebellar neuronal vacuolation, degeneration, and necrosis. Cerebellar Purkinje cells seem especially susceptible, but more research is needed to determine the pathogenesis of neuronal necrosis and the mechanism of Purkinje cell susceptibility. Calbindin D28k (CbD28k) is highly expressed in Purkinje cells and has been used as a marker for normal and degenerative Purkinje cells. The goal of this study was to describe S bonariense-induced disease by ascertaining Purkinje cell-specific degenerative changes using CbD28k expression and to correlate this with apoptosis in Purkinje cells, as determined using TUNEL (transferase-mediated dUTP-biotin nick end-labeling) and ultrastructural changes. In all cases, an increase in both dose and duration of S bonariense intoxication resulted in a decrease in the number of Purkinje cells. CbD28k immunohistochemistry was an excellent marker for Purkinje cells because immunoreactivity did not change in normal or degenerative tissues. This finding suggests that excessive calcium excitatory stimulation does not induce rapid neuronal degeneration and death. As found in previous studies, TUNEL tests and electron microscopy suggest that Purkinje cell degeneration and death are not occurring via an apoptotic process. These findings suggest that S bonariense poisoning induces progressive Purkinje cell death that is not mediated by excitotoxicity or apoptotic activation.Facultad de Ciencias Veterinaria

Calbindin d 28k expression in the cerebellum of normal and solanum bonariense L. Intoxicated bovines

La ingestión natural o experimental de Solanum bonariense L. ocasiona una degeneración cortical cerebelosa en bovinos. Esta lesión se debe a la degeneración específica de las células de Purkinje, postulándose que la misma se debe a alteraciones metabólicas específicas, demostradas previamente por estudios ultraestructurales e inmunohistoquímicos. La Calbindina-28kD (Cb28k) ha sido considerada como un marcador específico de células de Purkinje. La alteración de esta inmunoreacción se vincula al desarrollo de diferentes enfermedades neurodegenerativas en humanos. El objetivo del presente trabajo fue analizar la expresión de Cb28k en cerebelos de bovinos normales y en los intoxicados con Solanum bonariense L.Facultad de Ciencias Veterinaria

Calbindin D28k Expression and the Absence of Apoptosis in the Cerebellum of Solatium bonariense L-lntoxicated Bovines

Solanum bonariense intoxication is characterized by cerebellar neuronal vacuolation, degeneration, and necrosis. Cerebellar Purkinje cells seem especially susceptible, but more research is needed to determine the pathogenesis of neuronal necrosis and the mechanism of Purkinje cell susceptibility. Calbindin D28k (CbD28k) is highly expressed in Purkinje cells and has been used as a marker for normal and degenerative Purkinje cells. The goal of this study was to describe S bonariense-induced disease by ascertaining Purkinje cell-specific degenerative changes using CbD28k expression and to correlate this with apoptosis in Purkinje cells, as determined using TUNEL (transferase-mediated dUTP-biotin nick end-labeling) and ultrastructural changes. In all cases, an increase in both dose and duration of S bonariense intoxication resulted in a decrease in the number of Purkinje cells. CbD28k immunohistochemistry was an excellent marker for Purkinje cells because immunoreactivity did not change in normal or degenerative tissues. This finding suggests that excessive calcium excitatory stimulation does not induce rapid neuronal degeneration and death. As found in previous studies, TUNEL tests and electron microscopy suggest that Purkinje cell degeneration and death are not occurring via an apoptotic process. These findings suggest that S bonariense poisoning induces progressive Purkinje cell death that is not mediated by excitotoxicity or apoptotic activation.Facultad de Ciencias Veterinaria

Modelos experimentales para el estudio de la patogenia de la muerte embrionaria en tricomonosis bovina y herpesvirosis equina

Desde hace mucho tiempo, por razones prácticas, científicas y éticas, se han desarrollado modelos experimentales con animales de laboratorio para su aplicación en investigaciones biomédicas. Los modelos animales se definen como “organismos vivientes con una inherente adquisición natural a procesos patológicos inducidos o espontáneos que, de una u otra manera, semejan el mismo fenómeno ocurrido en el hospedador natural” (Márquez, 1997). Los animales de laboratorio son modelos muy convenientes y herramientas útiles para utilizar en el estudio de muchas enfermedades infecciosas. En el caso de medicina veterinaria, en especial cuando se trata de enfermedades de grandes animales, el uso del hospedador natural para estudiar aspectos patogénicos e inmunológicos de una infección, muchas veces se torna dificultoso, tanto por las inconveniencias que genera el manejo de estos animales como por el costo que implica. Debido al interés y la complejidad en el estudio de las enfermedades infecciosas, hay una búsqueda en la profundización de los conocimientos del proceso intrínseco de la inmunopatogenia que requiere de la creación de modelos animales alternativos a los hospedadores naturales. El objetivo es generar diseños experimentales confiables y reproducibles, desarrollables en medios controlados en espacios reducidos y con menor costo. Entre las múltiples ventajas que derivan de la utilización de modelos experimentales en el estudio de diferentes enfermedades, se mencionan las siguientes como las más importantes: • Conocer la historia natural de la enfermedad, cuya etiología, patogenia, sintomatología y evolución pueden mantenerse en condiciones experimentales, sin la influencia de factores extraños que la modifiquen. • Reproducir la enfermedad en forma experimental, casi a voluntad, lo que permite disponer de la casuística necesaria. • Realizar estudios fisiopatológicos, desarrollando nuevas técnicas diagnósticas para tal enfermedad. • Estudiar las enfermedades en animales endocriados lo que permite un amplio campo de investigación en inmunología, patología y genética, entre otras áreas (Cuba Caparó, 1982). En la selección de la especie utilizada como modelo animal es importante tener en cuenta algunas características generales: a) que permita la transferencia de la información, b) bajo costo y disponibilidad permanentes, c) generalización de los resultados, d) facilidad y adaptabilidad a la manipulación experimental, e) que se pueda contar con un número de animales necesarios para realizar el experimento, f) tiempo de vida, edad en que se alcanza la adultez y generación del número de progenies necesarias en poco tiempo, g) consecuencias ecológicas e implicancias éticas de su uso (Klein, 2000).Incluye las palabras de presentación del proyecto a cargo del Dr. Carlos O. Scoppa.Academia Nacional de Agronomía y Veterinari

La tomografía axial computarizada como herramienta para el diagnóstico y la planificación quirúrgica de la compresión medular

La hernia discal es la causa más frecuente de lesión de la médula espinal en caninos. El 85% de los casos se produce en la región toracolumbar. El Dachshund es una de las razas más susceptibles, debido a factores hereditarios. Desde el punto de vista anatómico, la lesión se localiza, principalmente, entre los espacios intervertebrales T11-T12 hasta L1-L2 y se asocia con la degeneración del núcleo pulposo del disco intervertebral, lo cual produce una extrusión o una protrusión. Las alteraciones neurológicas más frecuentes, como consecuencia de la compresión medular, se engloban dentro del síndrome de la neurona motora superior (SNMS). Se describe el caso de una hembra canina Dachshund de 5 años de edad, entera, con cifosis, dolor en la región toracolumbar y paraparesia, con una evolución de 15 días. Para corroborar el diagnóstico neurológico se utilizó la tomografía axial computarizada (TAC). Las imágenes obtenidas permitieron determinar el alcance y el carácter de las lesiones, consistentes en alteraciones en la apariencia del núcleo pulposo y una compresión medular significativa. La cirugía descompresiva fue el método propuesto para aliviar el déficit neurológico. Durante la cirugía, las imágenes obtenidas mediante la TAC fueron utilizadas para determinar la cantidad de vértebras a ser incluidas en la laminectomia con el fin de facilitar la extracción del material extruido y para ubicar, con mayor precisión, los reparos anatómicos. Durante el control posoperatorio realizado a los 30 días, la paciente mostró una recuperación incipiente de la función motora y coordinación de los movimientos voluntarios. Se concluye que ni la pérdida de la función motora, ni la severidad de los signos clínicos permitieron predecir el resultado del caso e indicar la reversibilidad de las lesiones. El uso de la TAC fue una herramienta de relevancia para el diagnóstico y la resolución del caso.Fil: Delgado Stagnares, J. J.. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Portiansky, Enrique Leo. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sánchez, H. L.. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentin

Estudio inmunohistoquímico de la población de neuronas gnrh en el diencéfalo del coipo (Myocastor coypus)

The goal of this study was to investigate the distribution and morphology of neurones that synthesise and store gonadotrophin releasing factor (GnRH) in the diencephalon of the coypu (Myocastor coypus), a South American rodent of the hystricomorpha suborder. For this purpose the encephalon of three mature male coypus were fixed by intra-arterial perfusion, using a paraformaldehyde and picric acid solution. The hypothalamic blocks were cut with freezing microtome to obtain 40µm thick coronal sections. The slides were exposed to an ultrasound antigen retrieval process in order to unmask hidden antigens. These sections were then processed using an immunohistochemical technique to show the GnRH neurones, using a monoclonal antibody (LRH 13). One group of serial sections was stained with cresyl violet (Nissl techniques) while the other sections were stained using Küver Barrera´s method (luxol fast blue and cresyl violet), to show the nuclei and nervous tracts of the hypothalamus under microscopic observation. Morphometric and quantitative analysis of neuronal bodies were performed using an image analyser. GnRH immunoreactive neurones were bipolar and long. The total number of neuronal bodies for this species was estimated at 1072 ± 27. All the cells were located in the rostral hypothalamus, mainly in the preoptic area. A few neurones were also observed in the bed nucleus of the stria terminalis and hypothalamic preoptic medial nucleus. The immunoreactive fibres were observed in the external layer of the median eminence. According to the data obtained we inferred that the distribution of the GnRH neurones of the coypu mainly coincides with that of other rodents such as the rat.Fil: Silva, L.. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Sánchez, H.. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Acosta, W.. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Portiansky, Enrique Leo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Zuccolilli, Gustavo Oscar. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentin

Increased Number of Neurons in the Cervical Spinal Cord of Aged Female Rats

In the brain, specific signaling pathways localized in highly organized regions called niches allow the persistence of a pool of stem and progenitor cells that generate new neurons in adulthood. Much less is known about the spinal cord where a sustained adult neurogenesis is not observed. Moreover, there is scarce information concerning cell proliferation in the adult mammalian spinal cord and virtually none in aging animals or humans. We performed a comparative morphometric and immunofluorescence study of the entire cervical region (C1-C8) in young (5 mo.) and aged (30 mo.) female rats. Serum prolactin (PRL), a neurogenic hormone, was also measured. Gross anatomy showed a significant age-related increase in size of all of the cervical segments. Morphometric analysis of cresyl violet stained segments also showed a significant increase in the area occupied by the gray matter of some cervical segments of aged rats. The most interesting finding was that both the total area occupied by neurons and the number of neurons increased significantly with age, the latter increase ranging from 16 % (C6) to 34 % (C2). Taking the total number of cervical neurons the age-related increase ranged from 19 % (C6) to 51 % (C3), C3 being the segment that grew most in length in the aged animals. Some bromodeoxyuridine positive-neuron specific enolase negative (BrdU +-NSE 2) cells were observed and, occasionally, double positive (BrdU +-NSE +) cells were detected in some cervical segments of both young and aged rats groups. As expected, serum PRL increased markedly with age. We propose that in the cervical spinal cord of female rats, both maturation of pre-existing neuroblasts and/or possibl

Distribution of tyrosine Hydroxylase-Immunoreactive neurones in the diencephalon and mesencephalon of the coypu (Myocastor coypus)

The aim of the present study was to examine the catecholaminergic neurones located within the midbrain of the coypu, a South American hystricomorph rodent. The neuronal distribution of the catecholaminergic systems and morphological parameters of the immunostained cell bodies and fibres were investigated, using an immunohistochemical method. The brains of five coypu were fixed, immersed in gelatine-glycerol and cut in 40-μm slices using a freezing microtome. Samples were processed with ultrasound-based antigen retrieval and stained with labelled antityrosine hydroxylase monoclonal antibody. An image analyser was used to measure the neuronal bodies. The catecholaminergic neurones of the tuberoinfundibular system were mainly observed in the arcuate and periventricular nuclei with their axons projecting towards to the median eminence; they represented 28% of the global population of tyrosine hydroxylase-immunoreactive cells observed. Significant morphological differences were observed in comparison with the other two studied systems. Fifty per cent of total catecholaminergic neurones were detected in the nigrostriatal system distributed in the reticular and compact substance nigra. Most neuronal bodies had a fusiform aspect. The immunoreactive neurones of the mesolimbic system represented 22% of the total population. They were distributed around the interpeduncular nucleus. Two types of morphologically different catecholaminergic systems of the brain were established: hypothalamic neurones located in the periventricular and arcuate nuclei and mesencephalic neurones located in the substance nigra and interpeduncular nuclei. These systems showed morphological and probably physiological-pharmacological differences.Fil: Sánchez, H. L.. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Silva, Liliana Beatriz. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Acosta, Walter Gustavo. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Portiansky, Enrique Leo. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Zuccolilli, Gustavo Oscar. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentin

Congenital Cerebellar Cortical Degeneration in Holstein Cattle in Southern Brazil

A congenital progressive cerebellar disorder is described in Holstein calves. The clinical signs were progressive and were characterized by ataxia, hypermetria, a wide stance and fine head tremors. When the affected cattle were forced to run, the signs were exacerbated, leading to epileptiform attacks. Histological lesions consisted of a very selective cerebellar cortical degeneration, almost exclusively affecting the Purkinje cells. The disease affected 6 out of 200 Holstein calves from the same bull. However, results of mating tests of the bull with his daughters and granddaughters suggested that it was not hereditary (p = 0.0062) although an environmental–genetic interaction could not be ruled out.Facultad de Ciencias Veterinaria