PubMed Health⌕ Search

Biomedical subjects

M Pocchiari

Publications and source records attributed to M Pocchiari.

85 records · Page 5Linked to original sources
PubMed1985

Characterization of antisera against scrapie-associated fibrils (SAF) from affected hamster and cross-reactivity with SAF from scrapie-affected mice and from patients with Creutzfeldt-Jakob disease.

Antisera raised in rabbits and also for the first time in mice against scrapie-associated fibril (SAF) protein from hamster brain have been quantified by a modified ELISA technique (NC-ELISA) and used for a detailed analysis of SAF proteins obtained from hamster, mouse, and from patients who died of Creutzfeldt-Jakob disease. The antisera predominantly detected five bands in a Western blot analysis with apparent molecular weights of about 26000 (26K), 24K, 20K, 18K and 16K. By gel electrophoresis these antigens seem to be identical in mouse, hamster and man. The amount of material in the various bands, however, varies according to host or agent. In control materials from healthy brain SAF protein was found to be absent even when this material was used in a 50-fold excess compared to diseased brain.

Animals↗
PubMed1985

Serotoninergic system in scrapie-infected hamsters.

Hamsters inoculated with scrapie virus show a dramatic hypersensitivity to serotoninergic drugs, developing a behavioral syndrome not unlike that obtained with pharmacologically induced lesions of the raphe nuclei. In an attempt to explain the state of hypersensitivity and to determine whether or not serotoninergic neurons were targets of the scrapie virus, pre- and postsynaptic serotoninergic sites were studied in the cerebral cortices of scrapie-infected and sham-inoculated hamsters. [3H]Imipramine binding and the uptake of endogenous 5-hydroxytryptamine (5-HT, serotonin) in synaptosomes prepared from scrapie-inoculated animals were not different from those of controls. This suggests integrity of the serotoninergic neurons in scrapie-infected hamsters. In contrast, affinity for the 5-HT1 receptor (which modulates inhibitory response) was diminished whereas that for the 5-HT2 receptor (which modulates excitatory response) was increased. This "imbalance" between the two receptors which is amplified in in vivo responses may account for the 5-HT hypersensitivity. The alteration in the affinity of the two postsynaptic 5-HT receptors supports the observation that scrapie virus alters cell plasma membranes.

Animals↗
PubMed1984

Choline acetyltransferase activity and [3H]quinuclidinylbenzilate binding in brains of scrapie-infected hamsters.

Choline acetyltransferase (ChAT) activity and [3H]quinuclidinylbenzilate binding were studied in the brain of scrapie-infected hamsters and sham inoculated controls. Although scrapie-infected hamsters showed no reduction of ChAT activity compared to the controls, they showed a decrease in the affinity and maximum number of post-synaptic muscarinic receptors. Scrapie virus thus alters the cholinergic system at the post-synaptic rather than at the pre-synaptic level.

Animals↗
PubMed1983

Ultrastructural studies on synaptic formations in dissociated fetal mouse brain cultures.

Sequential electron microscopic studies of cultures of neurons derived from dissociated fetal mouse brain on the eleventh day of gestation revealed the formation of well-developed synapses during the second and third weeks of growth in vitro. Synaptic junctions were associated with synaptic vesicles nd dense synaptic membranes. Dense-core vesicles were also observed frequently in presynaptic terminals.

Animals↗
PubMed1983

Creutzfeld-Jakob disease in the province of Siena: two cases transmitted to monkeys.

Two cases of histopathologically documented Creutzfeldt-Jakob disease were observed in the same area of the province of Siena in 1974-1975. The transmission of the disease was obtained through brain homogenates and lymphnodes in one of the two cases. This confirms that the agent is present in other tissues besides the brain and underlines further the analogies between Creutzfeld-Jakob disease and scrapie.

Aged↗
PubMed1982

Peripheral neuropathy in the course of progressive systemic sclerosis: light and ultrastructural study.

We present the case of a woman with progressive systemic sclerosis (PSS) in whom the usual symptoms were preceded by a rapidly progressive peripheral neuropathy. Few cases of peripheral nerve involvement have been described. For the first time we report an ultrastructural study of an affected peripheral nerve and muscle. In the sural nerve we found an almost complete loss of myelinated fibers. Schwann cells showed an abnormal hyperplasia of their basal membranes and structural signs of denervation. Spindle-shaped banded structures were seen in the cytoplasm of Schwann cells and in the endoneurium. On the basis of these ultrastructural data some hypotheses on the pathogenetic mechanism of this neuropathy are discussed.

Female↗
PubMed1982

Light microscopy and ultrastructural studies of Sturge-Weber disease.

Different degrees of cerebral calcifications together with encephalofacial angiomatosis and seizure disorders characterize the Sturge-Weber syndrome. According to the observations reported in the literature, calcium deposits may be found in the wall of cerebral vessels, in the perivascular tissue and rarely within the neurons. Corresponding to the variety of localizations, the interpretation of the phenomenon remains obscure. Most theories postulate the role of a vascular factory and of a mesenchymal factor. Ultramicroscopic studies of the specimens obtained in 2 children with the Sturge-Weber Syndrome provided the following findings. A mucopolysaccharidic substance constitutes the substratum for the deposition of calcium. Small amounts of this substance and calcium deposits may be detected within the connective tissue of cerebral vessels precociously; later on, while increasing in size and calcium concentration, they obviously migrate to outside the vessels. Successively, the calcium deposits seem to localize around the blood vessels, In our opinion, these observations stress the role of a primitive vascular factor; consequently, anoxia, necrosis of cerebral tissues, and variation in the calcium ion concentration would act only as secondary factors.

Angiomatosis↗
PubMed1981

Arachnoid cysts in children: ultrastructural findings.

Light and electron microscopic features of four arachnoid cysts in children are presented. The wall of the cyst appeared composed of a dense collagen tissue in which dark and clear cells were intermingled without any specific arrangement. Abutting onto this membrane, at the luminal surface, these cells were arranged in layers. Tight junctions between arachnoid cells were absent. It is suggested that the arachnoid cysts derive from a developmental aberration of the meninges.

Arachnoid↗
PubMedDate not supplied

The nucleus basalis of Meynert in parkinsonism-dementia of Guam: a morphometric study.

The nucleus basalis of Meynert (nbM) was studied morphometrically in three Guamanians with parkinsonism-dementia (PD) and in two Guamanian and two non-Guamanian controls. Paraffin-embedded blocks of the nbM were serially sectioned (20 microns thick) at increments of 200 microns so that a total of 24 sections (eight each from the anterior, intermediate and posterior sectors of the nbM) were studied. The mean cell density was determined for each sector and the diameter of 50 neurons, randomly chosen in the region of apparent maximal density, was calculated. A decrease of the mean cell density, due to the loss of neurons with diameters larger than 20 microns, was found in the PD cases compared to the controls. Two PD patients exhibited striking neuronal loss (65-95%) with predominant involvement of the intermediate and posterior sectors, while the third case showed only minimal neuronal loss in these sectors (15-40%). In both Guamanian and non-Guamanian controls large neurons (diameters greater than or equal to 20 microns) exceeded small neurons while the reverse was true in all sectors of the nbM for the PD cases. These data, while confirming a previous study reporting neuronal loss in the nbM of PD patients, underline the importance of detailed morphometric analysis of the different sectors of the nbM to recognize those patients in whom lesions are not uniformly distributed.

Aged↗