Biomedical subjects
Publications and source records attributed to B Fernandez.
Perineuronal glial nets in the rat spinal cord were studied. According to the density of the nets and the thickness of the processes which form them, different types of nets were demonstrated. In addition to nets originating from microglial cells, nets formed by smooth protoplasmic astrocytes are also described.
The ciliated neurons of the paraventricular nuclei in old hamsters have been studied by electron microscope. These neurons exhibit cilia of 9 + 0 pattern. The single cilia, emerging from typical basal bodies, project into the intercellular space in parallel to the plasmalemma. The basal bodies are connected to ciliary rootlets and close to the Golgi complex. Double or single centrioles in different locations, frequently related to rootlets, can be observed. From a morphological point of view we suggest that these cilia, in the aging process, may represent a sensory structure which could perceive stimuli from the intercellular space.
A case of bilateral hyperplasia of the coronoid process occurred. The diagnosis was made easily, and the treatment was successful. Speculation is made regarding the cause of the condition.
Intranuclear inclusions have been observed in a wide variety of locations throughout the nervous system. In the present work we have studied the inclusions that appear within the nucleus of non-secretory neurons from both paraventricular and supraoptic nuclei of the hypothalamus of the ageing hamster. We described four morphological types, namely, micro-filamentous, crystalloid, circular and capsuled inclusions. Their relationships with both the nuclear membrane and the nucleolus are discussed in the light of their ultrastructural features.
The distribution of astrocytic lamellae in hamster hypothalamus was studied by electron microscopy. The astrocytic lamellae (AL) are laminar expansions of the larger astrocyte processes devoided of cell organelles. In this paper, we describe the stratified structures of astrocytic lamellae which are found according to the following patterns: surrounding neuronal somata or delimiting one soma from the other, somata from blood vessels or from neuropile. In addition, layers of astrocytic lamellae are found surrounding nervous processes, blood vessels and forming a part of the subpial layer, as well as delineating the synaptic endings. Therefore, the astrocytic lamellae form a network through the hypothalamic components. The functional significance of these structures is discussed in relation to the physiologic studies on astrocytic membranes, as a basis for the understanding of their role in neuron metabolism.
Structures identified as lamellar bodies and subsurface cisterns have been observed in the paraventricular nuclei of the hamster hypothalamus. These neuronal structures can be found in the cytoplasm as single organelles or forming lamellar body-subsurface cistern complexes, which are connected with the nuclear envelope. The morphological features of the complexes are described and their possible functional significance with regard to the ageing process are discussed.
The hypothalamic subpial limitans has been studied by light and electron microscopy. It consists of a palisade of astrocytic cell bodies or their processes. Beneath the optic chiasma (white matter) the glial layer consists of flattened astrocytic cell bodies arranged in parallel to the myelinated fibres or located between the fibres, but sending their processes towards the basement membrane. Beneath the ventral hypothalamus nuclei, the astrocytic cell bodies can appear in two places: a) in contact with the basement membrane with their processes arranged in parallel to it, or b) located a certain distance from the basement membrane, sending long processes that, near the limitant zone, enlarge to form end-feet (supraoptic nuclei) or sending processes located in parallel to the basement membrane (mamillary nuclei). The astrocytic processes forming the glia limitans show gap junctions, and desmosomes. The different arrangement of the astrocytic processes and the different types of junctions suggest that the marginal glia might represent a regulatory mechanism for the diffusion between the different compartments of the brain.
Astrocytic mitochondria in the hypothalamic region of the adult hamster brain have been studied by electron microscopy. Mitochondria showing triangular prismatic cristae, as seen in transverse section, and other unusual forms of mitochondrial cristae, are described and illustrated. Such mitochondria occur primarily in the suprachiasmatic and paraventricular nuclei, especially in perivascular astrocytic processes. The possibility that these atypical mitochondria might develop a specific function is discussed.
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A preterm infant developed fulminant necrotising enterocolitis, subsequently resulting in death. Necropsy examination showed diffuse aspergillosis. Reports are reviewed, and possible mechanisms resulting in Aspergillus infection in this infant are discussed.
The fine structure of the filiform papillae on the hamster tongue is described level by level from the basal layer to the surface. We did not observe two distinct types of cells with different morphology or components which could be held responsible for the production of two different types of keratin as have been described in other animals, but rather a uniformity of cell structures in each layer and only the so-called "smooth" type of keratin. However, keratin granules were more abundant in the anterior part of the papilla.
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Some in vitro functions of purified T and B cells from PPD- and Candida albicans-negative sarcoidosis patients were analyzed. It appears that in those patients there is: 1) A decrease in the absolute number of T lymphocytes and an increase in the number of B cells; 2) a rather normal response of T lymphocytes to PHA and Con A; 3) a rather normal capacity of T and B cells to produce MIF in vitro; and 4) an ability of T cells from sarcoid patients (but not B cells) to produce LMF. These results suggest that the frequent deficit in cell-mediated immunity observed in sarcoidosis seems to correlate with a quantitative deficit in T cells. The cause of this T-cell deficit is unknown.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.