[A new cerebellar neuron: the brush or monopolar cell. Characteristics and possible function]. / Nueva célula 'en cepillo' (brush cell) o célula monopolar del cerebelo. Características y posible función.

The basic neuronal structure and circuitry of the cerebellum has been well known since Cajal's time. In recent years, however, a number of new neuronal connections and new immunohistochemically defined neuronal subtypes and functional cerebellar modules have been described. This new morphofunctional concept of the cerebellum seems to be in agreement with its newly assumed roles in learning and memory. In this new functional structure, a new cell (the brush cell, monopolar cell or monodendritic cell, Altman and Bayer, 1977; Mugnaini, 1994) specific to the cerebellar cortex and cochlear nucleus, could be of great importance. In all species studied, including man, this cell shows very particular morphology, immunohistochemical reactivity (against calretinin, some glutamate receptors and some neurofilament antibodies) and synaptic connections. The main afferents of these neurons are the mossy fibres, which form giant synaptic structures with them. The axons of monopolar cells end either in contact with extracerebellar neurons, or terminate intracortically at other brush cells (in the form of mossy fibres) or other cortical neurons of still-unknown morphology. In every animal species examined, these monopolar cells show different embryological development. No involution of them has been seen either in senility or in neurodegenerative disease.

Nueva célula `en cepillo' (brush cell) o célula monopolar del cerebelo. Características y posible función / A new cerebellar neuron: the brush or monopolar cell. Characteristics and possible function

La estructura del cerebelo y los circuitos que forman sus neuronas se conocen muy bien desde la época de Cajal. En los últimos años se ha descrito un cierto número de nuevas conexiones neuronales y subtipos neuronales, así como compartimentos funcionales mediante técnicas inmunohistoquímicas. Esta nueva concepción morfofuncional del cerebelo se corresponde con las nuevas funciones que se le asignan en aprendizaje y memoria. Dentro de este esquema puede ser clave una nueva célula, mencionada por Altman y Bayer (1977) y descrita por Mugnaini (1994), la célula `en cepillo', monopolar o monodendrítica, específica de la corteza cerebelosa -junto a los núcleos cocleares-, que presenta en todas las especies, incluido el hombre, morfología, reacción inmunohistoquímica (anticalretinina, receptores para glutamato, neurofilamentos, etc.) y conexiones muy características. La formación de una sinapsis gigante con una fibra musgosa es su principal aferencia, y posee o puede poseer terminales extracerebelosos directos, intracorticales -sobre otras células en cepillo en forma de terminal musgosa, o sobre otras neuronas-. En cada especie animal tiene un desarrollo diferente y parece que no involucionan ni en la senilidad ni en las enfermedades neurodegenerativas (AU)

The basic neuronal structure and circuitry of the cerebellum has been well known since Cajal’s time. In recent years, however, a number of new neuronal connections and new immunohistochemically-defined neuronal subtypes and functional cerebellar modules have been described. This new morphofunctional concept of the cerebellum seems to be in agreement with its newly assumed roles in learning and memory. In this new functional structure, a new cell (the brush cell, monopolar cell or monodendritic cell, Altman and Bayer, 1977; Mugnaini, 1994) specific to the cerebellar cortex and cochlear nucleus, could be of great importance. In all species studied, including man, this cell shows very particular morphology, immunohistochemical reactivity (against calretinine, some glutamate receptors and some neurofilament antibodies) and synaptic connections. The main afferents of these neurons are the mossy fibres, which form giant synaptic structures with them. The axons of monopolar cells end either in contact with extracerebellar neurons, or terminate intracortically at other brush cells (in the form of mossy fibres) or other cortical neurons of still-unknown morphology. In every animal species examined, these monopolar cells show different embryological development. No involution of them has been seen either in senility or in neurodegenerative disease (AU)

Características citológicas por PAAF de carcinoma epitelial-mioepitelial de parótida / Cytoligic characteristics by fine-needle aspiration of epithelial-myoepithelial carcinoma of the parotid gland

El carcinoma epitelial-mioepitelial constituye aproximadamente el 1 por ciento de los tumores de glándulas salivales. Este tumor ha ganado reconocimiento tras su inclusión en la clasificación de los tumores de glándulas salivales de la OMS. Describimos el cuadro citológico de la PAAF de uno de estos casos, haciendo especial énfasis en el diagnóstico diferencial. En la revisión bibliográfica sólo hemos encontrado 15 casos descritos. El tratamiento de elección de esta neoplasia es la escisión quirúrgica amplia. La recurrencia local alta tras tratamiento quirúrgico adecuado plantea la posibilidad de un origen multicéntrico, como describimos en este caso (AU)

Cytomorphologic differentiation of common acute lymphoblastic leukemia from other immunologic subtypes. Report of a case of peripheral relapse with cytochemical and immunochemical study.

Of the subtypes of acute lymphoblastic leukemia (ALL), the "common" subtype (c-ALL) bears the best prognosis. Nevertheless, there has been no report of cytologic criteria that can distinguish c-ALL from the B-cell (B-ALL) and T-cell (T-ALL) subtypes. We present a case of c-ALL with relapse, with cytochemical and immunocytochemical as well as cytologic studies. Certain cytologic observations in this case could serve to differentiate c-ALL from B-ALL and T-ALL; the morphologic criteria suggested have been seen by us in other c-ALL cases. We think they will be useful in future fine needle aspiration studies in order to demonstrate extramedullary relapses as well as to differentiate ALL subtypes without the need of more costly immunologic studies.