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Biomedical subjects

I Ferrer

Publications and source records attributed to I Ferrer.

At least 397 records · Page 22Linked to original sources
PubMed1979

A Golgi and electron microscopic study of a dysplastic gangliocytoma of the cerebellum.

The fine structure of a dysplastic gangliocytoma of the cerebellum is studied by means of the Golgi method and electron microscopic examination. Thick proximally unbranched dendrites with terminal arborizations and varicose inflorescences in the form of a basket are stained with the Golgi method. Axons are always descendant to the inner myelinated layer of the redistributed cerebellar cortex, while ascendant collaterals are observed at the level of the outer myelinated layer. Clear and dense-core vesicles and synapses are common in the cellular profiles under electron microscopic examination. From these data and because of the lack of putative connections through the white matter, an organized, self-regulated, catecholamine-mediated complex may be postulated.

Axons↗
PubMed1979

[Gm1 gangliosidosis types 1 and 2 (author's transl)].

Two cases of gangliosidosis due to aggregates of Gm1 are described. The first patient was a female infant with noticeable retardation in psychomotor development, coarse facies, hepatomegaly, and X-rays showing skeletal anomalies in the large bones, vertebral column, cranium and ribs. She died at the age of 10 months of a septic condition. The second patient was a male infant; deterioration in psychomotor development was first noticed 8 months after birth and this progressed slowly to arrive at a vegetative state with convulsions and myoclonus. The child died at the age of 4 years. There were no signs of enlargement of visceral organs but a cherry red stain was observed in the ophthalmologic examination. In the first case, necropsy revealed the presence of a deposit substance in the histiocytes of the hepatic sinusoids, spleen, pancreas, thymus, septi and pulmonary alveoli, intestinal lamina propria, epithelial cells of the renal glomeruli, and in the neurons and glial cells of the brain. The same deposits were observed only in the neurons and glial cells in the second case. Ultrastructural examination showed the presence of typical cytoplasmic membranous bodies in the central nervous system of both patients. The beta-galactosidase activity in the urine of both patients during life was zero. There was a higher than normal total amount of gangliosides in brain tissue samples from both (1906.7 and 2459.9 NANA/g respectively) as compared with normal values (724.0). This increase was proportional to the rise in Gm1 ganglioside (76.8 and 89.6 percent molar respectively) as compared to control (27.0). These clinical, morphologic, and biochemical data characterize both types 1 and 2 of gangliosidosis due to Gm1 aggregates.

Cerebral Cortex↗
PubMed1979

Cerebral mixed tumour: osteo-condrosarcoma--glioblastoma multiforme.

A 49-year-old woman had a left frontal expanding mass with calcified areas. A craniotomy and resection of the mass were performed. Histological sections showed a mixed tumour: osteochondrosarcoma-glioblastoma multiforme. The absence of previous irradiation and its location, deep in the frontal lobe and apparently unattached to the meninges, add to the rarity of this association. A brief discussion concerning the presence of osseous or cartilaginous areas in brain tumours and the problem of cerebral mixed tumours follows the description of the case.

Brain Neoplasms↗
PubMed1978

Multicystic encephalomalacia of infancy: clinico-pathological report of 7 cases.

Clinical follow up and complete neuropathological examination was made on seven cases of multicystic encephalomalacia of infancy. Etiological factors were carefully studied in all the cases. They consisted of prenatal injuries presenting as a cord prolapse, in 3 cases; prolonged labour with marked cyanosis; abdominal trauma during gestation, and various maternal infections at different stages of pregnancy. Pathological interest is centred on the variable involvement of different areas of the brain, generally sparing the cerebellum and brain stem, and being minimal or absent in the occipito-temporal areas. This distribution may be explained by a different effect of the "causal agency" on these different areas, or by a different capacity of these regions to react against injury. Among the etiological factors reviewed in the literature, the anoxic theory appears the most probable, as there was a close parallelism between lesions and vascular areas, mainly the carotid and vertebro-basilar systems.

Asphyxia Neonatorum↗
PubMed1977

[Lissencephaly: agyria. A study using the Golgi technic].

A case of lissencephaly (agyria) is reported in which the Golgi stain was used to study the fronto-parietal cortex. The external cellular layer, the so-called true cortex, was shown to be made up of neurons from the 5th and 6th layers of the normal cortex. The neurons in the much less cellular layer were shown to be large pyramidal cells with well-developed dendritic branching and spines. The deeper cellular layer was a neuronal pool without well-defined layering. All the neural forms from the normal cortex were represented. In this layer the inner neurons showed a less advanced stage of development than did those in the outer groups. In the external cellular layer there was a disorganization of neuronal disposition as well. Otherwise typical large and medium-sized pyramidal cells from the outer third showed apical dendrites directed towards deeper structures, and the basal dendrites ran through the marginal layer. Neurons with doulbe dendritic branching and fusiform neurons were present in an abnormal rotated position. In both cases, the axons always showed a descending direction. These findings add to existing knowledge concerning the anatomy of the lissencephalic cortex, although the exact interpretation of the abnormalities found in the external cellular layer remains speculative.

Cerebral Cortex↗
PubMedDate not supplied

Towards a method for automated classification of 1H MRS spectra from brain tumours.

Recent studies have shown that MRS can substantially improve the non-invasive categorization of human brain tumours. However, in order for MRS to be used routinely by clinicians, it will be necessary to develop reliable automated classification methods that can be fully validated. This paper is in two parts: the first part reviews the progress that has been made towards this goal, together with the problems that are involved in the design of automated methods to process and classify the spectra. The second part describes the development of a simple prototype system for classifying 1H single voxel spectra, obtained at an echo time (TE) of 135 ms, of the four most common types of brain tumour (meningioma (MM), astrocytic (AST), oligodendroglioma (OD) and metastasis (ME)) and cysts. This system was developed in two stages: firstly, an initial database of spectra was used to develop a prototype classifier, based on a linear discriminant analysis (LDA) of selected data points. Secondly, this classifier was tested on an independent test set of 15 newly acquired spectra, and the system was refined on the basis of these results. The system correctly classified all the non-astrocytic tumours. However, the results for the the astrocytic group were poorer (between 55 and 100%, depending on the binary comparison). Approximately 50% of high grade astrocytoma (glioblastoma) spectra in our data base showed very little lipid signal, which may account for the poorer results for this class. Consequently, for the refined system, the astrocytomas were subdivided into two subgroups for comparison against other tumour classes: those with high lipid content and those without.

Brain Neoplasms↗
PubMedDate not supplied

Lignin biodegradation by the ascomycete Chrysonilia sitophila.

The lignin biodegradation process has an important role in the carbon cycle of the biosphere. The study of this natural process has developed mainly with the use of basidiomycetes in laboratory investigations. This has been a logical approach since most of the microorganisms involved in lignocellulosic degradation belong to this class of fungi. However, other microorganisms such as ascomycetes and also some bacteria, are involved in the lignin decaying process. This work focuses on lignin biodegradation by a microorganism belonging to the ascomycete class, Chrysonilia sitophila. Lignin peroxidase production and characterization, mechanisms of lignin degradation (lignin model compounds and lignin in wood matrix) and biosynthesis of veratryl alcohol are outstanding. Applications of C. sitophila for effluent treatment, wood biodegradation and single-cell protein production are also discussed.

Ascomycota↗
PubMedDate not supplied

Cell death and decreased synaptic protein expression in the ventral horn of Holstein-Friesian calves with spinal muscular atrophy.

A neuropathological study of Holstein-Friesian calves with spinal muscular atrophy (SMA) demonstrated decreased numbers of motor neurons in the brachial and lumbo-sacral regions of the spinal cord, together with swelling and accumulation of phosphorylated neurofilaments, and neuronophagia in most of the remaining motor neurons. The pyramidal tracts, motor cortex and thalamus were not affected. Synaptophysin immunohistochemistry revealed a marked reduction of punctate terminals but only around swollen neurones, suggesting loss of terminal afferents on motor neurons at advanced stages of the degenerative process. An immunohistochemical study of proteins linked with cell death and cell survival demonstrated reduced expression of Fas, Fas-L, Bcl-2 and Bax in swollen motor neurons. Punctate cytochrome C immunoreactivity, consistent with mitochondrial localization, was detected in the soma of normal motor neurons, but not in swollen motor neurons. Finally, no labelling of motor neurons with antibodies to cleaved (active) caspase-3 (17kD) was detected, suggesting a lack of involvement of the apoptotic pathways in motor neuron death. Taken together, the present findings point to necrosis as a major cause of motor neuron death in the advanced stages of SMA in Holstein-Friesian calves.

Animals↗
PubMedDate not supplied

Creutzfeldt-Jacob disease: a golgi study.

A cerebral biopsy of a patient with Creutzfeldt-Jacob (C-J) disease was examined with the Golgi method. Distortion of soma and neuronal processes associated with vacuolization of the neuropil was observed. The main findings were decreased numbers of basal dendrites and of branches of the apical dendrite of the pyramidal cells, marked loss of synaptic spines, and varicosities in the proximal segment of some apical and basal dendrites. These changes, though non-specific, may be interpreted as the result of deafferentation, although primary reactions related to C-J disease cannot be ruled out. These changes underline the intense disruption of intracortical connections which takes place in this condition in addition to the neuronal loss.

Biopsy↗
PubMedDate not supplied

A Golgi study of cerebellar atrophy in human chronic alcoholism.

When processed by the rapid Golgi method, a significant reduction (P less than 0.002) of the dendritic arborization of Purkinje cells located at the tips of the folia of the rostral vermis was demonstrated in four human cases of cerebellar atrophy, related to chronic alcohol consumption. Except for isolated damaged Purkinje cells located on the depth of the sulci of the rostral vermis in all but one case, no significant differences were observed between alcoholic cases and controls of comparable ages among Purkinje cells located in the remainder of the vermis or the cerebellar hemispheres. These results suggest that structural changes, which precede neuronal death and cell loss, are present in Purkinje cells of the rostral vermis in human cerebellar alcoholic degeneration.

Adult↗
PubMedDate not supplied

Effects of prenatal exposure to ethanol on the maturation of the pyramidal neurons in the cerebral cortex of the guinea-pig: a quantitative Golgi study.

The effects of chronic ethanol consumption during gestation on the development of layer V pyramidal cells was studied quantitatively in the somatosensory cerebral cortex of the newborn guinea-pig. The spread of the basilar dendritic arborizations and counts of dendritic spines on the apical dendrite of neurons that had been processed with the rapid Golgi method were compared with those found in age-matched controls receiving an isocaloric diet without alcohol. There were significant differences in the number of primary basilar dendrites (P less than 0.05) and dendritic ramifications at a distance of 25 micron from the soma (P less than 0.01) between the alcohol-exposed and control animals. There also were significant differences in the number of dendritic spines on the apical dendrite (P less than 0.001). This experimental model further illustrates developmental anomalies in the cerebral cortex following prenatal ethanol exposure.

Animals↗
PubMedDate not supplied

Effects of prenatal ethanol exposure on physical growth, sensory reflex maturation and brain development in the rat.

In the offspring of ethanol-treated rats during gestation (25% ethanol in drinking water) decreased litter size, increased postnatal mortality rate, reduced body weight and body size, delayed ear opening, eyelid opening and teeth eruption, retarded air righting reflex acquisition, impaired brain growth, reduced cortical thickness and delayed maturation of layer Vth's pyramidal neurons: reduced basilar dendritic arborization and decreased number of spines in the apical dendrite, were observed when compared with age-matched controls fed with a standard diet. Minimal effects were found in the offspring of fibre-treated rats during gestation (standard diet mixed with cellulose) in which the body weight was similar to that of controls, although both the calorific intake from food and the mother's weight gain during pregnancy were similar to those of the ethanol-treated group. All these abnormal parameters became normal at the end of the first month of postnatal life, indicating recovery of these developmental defects produced by prenatal ethanol consumption.

Animals↗
PubMedDate not supplied

Focal dendritic swellings in Purkinje cells in mucopolysaccharidoses types I, II and III. A Golgi and ultrastructural study.

Focal dendritic swellings in secondary dendrites of Purkinje cells were observed in post-mortem samples of the cerebellum processed by the Golgi method from three patients affected by mucopolysaccharidoses (MPS) types I-H, II and III. These focal dendritic swellings exhibited smooth surfaces but secondary formation of spine-like appendages was absent; in contrast, terminal, spiny branchlets were preserved. Complementary electron-microscopical examination of these samples revealed that membranous cytoplasmic bodies and zebra-like inclusions accounted for the material stored in these focal swellings in MPS I-H and MPS II; in addition, granulomembranous cytosomes with fine, densely-packed membranous profiles were encountered in MPS III. Focal dendritic swellings in Purkinje cells may result in abnormal electrical activity, thus producing informational imbalance on the Purkinje cell dendritic arborization in human mucopolysaccharidoses.

Adolescent↗