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Biomedical subjects

S Añor

Publications and source records attributed to S Añor.

13 recordsLinked to original sources

Histological and immunohistochemical study of 30 cases of canine meningioma.

This report describes the incidence, location and histopathological and immunohistochemical features of 30 canine meningiomas, of which 22 were intracranial, three were retrobulbar and five were located in the spinal canal. Nine types of meningioma were diagnosed: transitional (9), meningothelial (5), psammomatous (3), anaplastic (3), fibroblastic (2), angioblastic (2), papillary (2), microcystic (1) and meningiomas arising from the optic nerve (3). One of the optic nerve tumours had a granular cell component. All tumours were examined immunohistochemically with antibodies against vimentin, S100, neuron-specific enolase (NSE), cytokeratin (CK) and glial fibrillary acidic protein (GFAP). Vimentin was demonstrated in all tumours, and concentric whorls of cells showed more intense labelling than did bundles of fibroblastic cells. S100 labelling was detected in all tumours except a single angioblastic meningioma. The intensity of labelling for S100 was lower than that for vimentin, and bundles of fibroblastic cells showed particularly strong positivity. NSE labelling was highly variable, but most tumours displayed moderate positivity. CK expression was observed in five of the 30 meningiomas, and was stronger in areas of microcystic differentiation. Most of the tumours were GFAP-negative, but two fibroblastic meningiomas were strongly positive.

Age Factors↗

A novel spongiform degeneration of the grey matter in the brain of a kitten.

A young female domestic short-hair cat presented with neurological signs consistent with a multifocal encephalic lesion (depressed mental status, head tilt to the right, cervical ventroflexion, head tremors, tetraparesis, conscious propioceptive deficits in all four limbs and visual deficits). No gross lesions were seen at necropsy. On light microscopical examination lesions were found only in the brain and cervical spinal cord. A generalized vacuolation of the grey matter of the brain was observed. Special staining techniques, immunohistochemistry, lectin affinity histochemistry and ultrastructural studies were performed to characterize the lesion; preservation of the white matter and a reactive astrogliosis were demonstrated. Feline retroviruses and PrPsc were not detected. Ultrastructurally, a dilatation of intracytoplasmic membrane-bounded organelles with membrane disruption and dendritic and somatic swelling was found in astrocytes and neurons. The age of the animal and histological changes suggested a novel, possibly congenital, spongiform degeneration of the brain and cervical spinal cord.

Animals↗

Spinal muscular atrophy in Holstein-Friesian calves.

The clinical and neuropathological findings of spinal muscular atrophy (SMA) in Holstein-Friesian calves are described in four females and one male from a dairy farm composed of 150 cows and 2 breeding bulls. Locomotion difficulties started at the age of 15 days, and progressed to paraparesis and tetraparesis in 2 weeks. Signs consistent with denervation were revealed with electromyography. The neuropathological examination showed degeneration and loss of motor neurons in the spinal cord, together with astrocytosis. Among the remaining motor neurons were ghost cells and neurons filled with accumulations of straight filaments measuring 10-12 nm in diameter, which were strongly immunoreactive with antibodies produced against phosphorylated neurofilaments. Degenerating cells in SMA did not stain with the method of in situ labelling of nuclear DNA fragmentation and did not show c-Jun immunoreactivity. This feature contrasts with the in situ labelling of DNA breaks of apoptotic cells and with the strong c-Jun immunoreactivity restricted to dying cells during the whole process of naturally occurring cell death in the developing central nervous system. These features suggest that cell death in SMA differs from programmed cell death during normal development, and that pathological cell death in SMA should not be considered as a mere persistence or reactivation of normally occurring developmental cell death.

Animals↗

Neospora caninum infection in a Napolitan mastiff dog from Spain.

Fetal neosporosis-associated myeloencephalitis was diagnosed in a 4-month-old Napolitan mastiff dog from Spain. Neospora caninum tachyzoites and tissue cysts were observed in lesions in the central nervous system and the diagnosis was confirmed by immunohistochemical staining with anti-N. caninum monoclonal and polyclonal antibodies.

Animals↗

Malignant epithelioid schwannoma affecting the trigeminal nerve of a dog.

A malignant epithelioid schwannoma was diagnosed affecting the trigeminal nerve of an 11-year-old dog. Neurologic abnormalities included an altered mental status, ataxia, left head tilt, postural reaction deficits of all four limbs, a pronounced left masticatory muscle atrophy, and absent left facial sensation. Histologically, a densely arranged epithelioid population with a very high mitotic index was surrounded by a spindle-shaped cell proliferation characteristic of schwannomas. Both cell populations stained positively for vimentin, but only spindle cells were occassionally positive for S-100 protein. The histologic and immunohistochemical features of this tumor were consistent with those found in human epithelioid schwannomas.

Animals↗

Malformations of the vertebral bodies and the ribs associated to spinal dysraphism without spina bifida in a Pekingese dog.

A Pekingese dog with hemivertebrae, rib malformations and spinal cord dysraphism without spina bifida was presented. Two types of hemivertebrae were seen: bilateral and unilateral. Thoracic hemivertebrae were associated with fused ribs and rudimentary ribs. Spinal dysraphism consisted of polycavitary syringomyelia in the dorsal and lateral funiculi, hydromyelia and anomalies of the dorsal median septum and median fissure, associated to lumbar and sacral hemivertebrae. Cauda equina agenesia was also present. To conclude, the dog showed two malformations from different embryonic origins. Vertebral and rib malformations are of mesodermic origin and spinal dysraphism is of ectodermic origin. A possible common mechanism responsible for both anomalies is discussed.

Animals↗

Electrically induced blink reflex and facial motor nerve stimulation in beagles.

Electrophysiologic assessment of the blink reflex test and the muscle-evoked potentials evoked by stimulation of the facial nerve were performed in 15 healthy adult Beagles before and after supraorbital (trigeminal) and facial anesthetic nerve blocks performed by lidocaine injections. Unilateral electrical stimulation of the supraorbital nerve elicited 2 ipsilateral (R1 and R2) and a contralateral (Rc) reflex muscle potential in orbicularis oculi muscles. Electrical stimulation of the facial nerve elicited 2 muscle potentials (a direct response [D] and a reflex faciofacial response [RF]) in the ipsilateral orbicularis oculi muscle. Anesthetic block of the left supraorbital nerve resulted in bilateral lack of responses upon left supraorbital nerve stimulation, but normal responses in right and left orbicularis oculi muscles upon right supraorbital stimulation. Right facial anesthetic block produced lack of responses in the right orbicularis oculi muscle regardless the side of supraorbital nerve stimulation. Results of this study demonstrate that the blink reflex can be electrically elicited and assessed in dogs. Reference values for the blink reflex responses and for the muscle potentials evoked by direct facial nerve stimulation in dogs are provided. The potential usefulness of the electrically elicited blink reflex test in the diagnosis of peripheral facial and trigeminal dysfunction in dogs was demonstrated.

Animals↗

Electrically induced blink reflex in horses.

The electrically induced blink reflex was studied electromyographically in 21 healthy adult, detomidine-sedated horses. Using surface electrodes, the supraorbital nerve was electrically stimulated at the supraorbital foramen. The responses were recorded from the ipsilateral and contralateral orbicularis oculi muscles with concentric needle electrodes inserted in the lateral aspect of the ventral eyelids. Ipsilateral and contralateral recordings were made on successive stimulations of the same side of the face, maintaining a constant stimulus intensity. The electromyographically recorded responses consisted of an early R1 response in the orbicularis oculi muscle ipsilateral to the side of stimulation, a bilateral late response (ipsilateral R2 and contralateral Rc) and a third, R3 response, in the ipsilateral orbicularis oculi muscle. All the responses were polyphasic muscle potentials of variable duration and peak to peak amplitudes. The reflex latency of the R1 response was, as in man, fairly stable. The R2 response showed greater variability both within and between individual horses. The Rc response was recorded in only 13 of the 21 horses and showed a slightly longer latency than the corresponding R2. The R3 response, which is significantly related to pain sensation in man, appeared in 19 horses and showed the greatest variability in latency.

Animals↗