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Biomedical subjects

C Alessandrini

Publications and source records attributed to C Alessandrini.

At least 37 records · Page 2Linked to original sources
PubMed1991

Peptidergic innervation of mesenteric lymphatics in guinea pigs: an immunocytochemical and pharmacological study.

By immunocytochemistry, substance P immunoreactive (SP-IR) and vasoactive intestinal peptide immunoreactive (VIP-IR) nerve fibers were examined in guinea pig mesenteric lymph collectors. The immunoreactive nerve fibers, located in the adventitia of lymphatics, were few and were irregularly distributed along the vessel wall. These fibers appeared to be more numerous and more evenly distributed along the corresponding artery and vein walls within the same area. SP immunoreactivity in the vascular nerves was depleted in guinea pigs injected with capsaicin but was unaffected by the injection of 6-hydroxydopamine. By contrast, VIP-IR nerve fibers were unaffected by both treatments. It is concluded that SP-IR nerve fibers in the lymphatics are likely to be of sensory origin and that VIP containing nerves in the lymph collectors are distinct from SP-containing and noradrenergic nerves. It is also suggested that lymph collectors possess a complex although limited innervation pattern not only of autonomic nerve fibers containing classic neurotransmitters but also of peptidergic nerve fibers of a different origin with a vasomotor and/or sensory action.

Animals↗
PubMed1989

[Bullous congenital ichthyosiform erythroderma in a mother and son].

The occurrence of two cases of bullous congenital ichthyosiform erythroderma (BCIE) in a mother and son is reported. Clinical diagnosis was confirmed by histological and ultrastructural findings, which demonstrated marked changes in the cyto-skeleton of the keratinocytes of the Malpighian layer and areas of cytolysis and hypoplasia of the tonofilament-hemidesmosome complexes in the cells of the granulosa layer. These results and the possible aetiopathogenic mechanisms are discussed in the light of the most recent data in the literature. Treatment with oral etretinate proved to be helpful, but not long lasting.

Adult↗
PubMed1988

Type 3 (chronic) GM1 gangliosidosis presenting as infanto-choreo-athetotic dementia, without epilepsy, in three sisters.

Three sisters (ages 27, 24, and 17 years) presented with slowly progressing dystonic dementia and spastic tetraparesis with infantile onset. CSF, bone marrow, and conjunctival cells showed storage vacuoles. Biochemical analysis revealed increased urinary oligosaccharide excretion and decreased activity of acid beta-D-galactosidase and beta-D-fucosidase in serum, leukocytes, and cultured fibroblasts. The parents' enzyme values were in the heterozygous range. This is the only case in the literature of severe dementia associated with the clinical symptoms of type 3 GM1 gangliosidosis. The clinical heterogeneity of GM1 gangliosidosis and the significance of the combination of beta-D-galactosidase and beta-D-fucosidase defects in this syndrome are discussed.

Adolescent↗
PubMed1988

The "switch-off" mechanism of spontaneous resolution of acute gout attack.

Urate crystal size change and the modification of coated proteins by oxygen radicals released by stimulated polymorphonuclear cells (PMN) could represent a likely "switch-off" mechanism of the spontaneous resolution of acute gout attack. The absorption spectra and the uric acid, allantoin and urea concentrations were determined before and after in vitro exposition of monosodium urate (MSU) crystals to superoxide anion (O2) photochemically generated. The results showed a complete dissolution of MSU crystals after incubation under O2-, with decrease of uric acid and increase of allantoin and urea concentrations. Our results were confirmed by polarizing, electron microscopy and calorimetric techniques. The results obtained seem to confirm that the spontaneous resolution of acute gout attack could be attributed to the dissolving effect on urate crystals and the modification of coated proteins by O2- released by phagocytizing PMN.

Acute-Phase Reaction↗
PubMed1987

Free sialic acid storage disease. A new Italian case.

Increased amounts of free sialic acid were found in cultured fibroblasts and urine of a 4-year-7-month-old Italian boy with mental retardation, hypotonia, failure to thrive, coarse facial features, convergent strabismus, pale skin and fair hair. Ultramicroscopic examination of conjunctival and skin tissues showed a number of membrane-bound vacuoles containing low-density granular material in the cytoplasm of the fibroblasts. The clinical, biochemical and ultrastructural findings are similar to those described in Salla disease. Neuraminidase activity is normal. The molecular basis of the sialic acid storage disease is not known. Evidence for defective transport of sialic acid across the lysosomal membrane has been demonstrated in the patient's fibroblasts. It is possible that this might represent the metabolic abnormality.

Carbohydrate Metabolism, Inborn Errors↗
PubMed1986

Ultrastructural observations in lichen nitidus.

Lichen nitidus (LN) and lichen planus (LP) are considered by some investigators to be two variants of the same disease, and by others to be two distinct dermatoses. In order to obtain further information about the relationship between LN and LP we examined the ultrastructure of lesions from two LN patients. In the central part of the lesion, the basement membrane was absent, or was interrupted by migrating phagocytes or lymphocytes. The basal cells and the lower cells of the stratum spinosum exhibited karyolysis and appeared to be compressed and often necrotic. In the upper dermis irregular cell debris full of clumps of tonofilaments and colloid-body-like structures was observed. A dense dermal infiltrate of macrophages, lymphocytes, fibrocytes, and Sezary-like cells was present. Signs of cooperation between lymphocytes and macrophages were also evident. The periphery of the lesion showed no pathological features except for enlargement of the intercellular spaces and the presence of mononuclear cells scattered through the epidermis. Several normal Langerhans cells were noticed. These ultrastructural findings were quite similar to those reported for LP.

Adult↗
PubMed1986

Enzyme activities and ultrastructure of intestinal epithelium in the mouse treated with chloramphenicol.

Several enzyme activities in the enteric mucous membrane (maltase, lactase, leucineaminopeptidase) were assayed and intestinal epithelium ultrastructure was evaluated in mice treated with chloramphenicol, per os, in different doses (50 mg/Kg and 100 mg/Kg), for 10 days. Of the enzyme activities assayed, only leucineaminopeptidase was found to be significantly lower in treated animals than in controls. Enterocyte ultrastructure and mitochondrial morphometrical parameters were not found to be significantly modified in treated animals.

Administration, Oral↗
PubMed1986

Delayed development of intimal lesions in cerebral arteries of spontaneously hypertensive rats subjected to a short-term atherogenic diet (TEM observations).

In adult spontaneously hypertensive rats, subjected to an atherogenic diet (2% cholic acid in a 5% hypercholesterolic diet) for 19 weeks both aortic and carotid artery lesions were already detectable on TEM examination while the cerebral arteries did not show any lesions. Similar findings have been previously obtained in rabbits and in monkeys on atherogenic diets.

Animals↗
PubMed1985

Giant axonal neuropathy. Endocrinological and histological studies.

A case of giant axonal neuropathy (GAN) in a boy of 4 years and 6 months, is reported. Nerve conduction velocity (NCV), EEG and CT scan indicated both peripheral and central nervous system involvement. Intestinal absorption tests did not reveal vitamin B12 malabsorption; the endocrine situation was found to be substantially normal. The clinical picture was not modified by 18 months cyanocobalamine administration followed by 2 months therapy with prednisone. Electron microscopic (EM) examination revealed longitudinal and opposing grooves (pili canaliculi) in the hair and bundles of neuro-filaments in the myelinated and unmyelinated nerve fibre axons in sural nerve. EM of conjunctiva and skin revealed masses of intermediate-sized filaments within mast cells, fibroblasts, melanocytes, endothelial and Schwann cells. These findings confirm the hypothesis that GAN is a generalised abnormality of cytoplasmic microfilament formation, probably linked to an unknown disorder of protein metabolism.

Axons↗
PubMed1985

[Enzyme activity and ultrastructure of the intestinal epithelium in mice treated with rifampicin].

Some enzymatic activities and the ultrastructure of the intestinal epithelium of mouse were valued after a treatment with rifampicin, per os, in different doses (25 mg/Kg and 50 mg/Kg), for 90 days. Neither alteration of maltase, lactase, leucine aminopeptidase (LAP), nor modification of the morphology of jejunal mucous membrane enterocytes and of their mitochondria were noticed in treated animals, as to controls.

Animals↗
PubMed1984

Localization of dopamine receptors in the rabbit renal artery: a histoautoradiographic study.

The localization of dopamine receptors within rabbit renal artery was studied using 3H-spiroperidol as a label for dopamine receptors and a histoautoradiographic technique. Preliminary radioreceptor binding studies showed that 3H-spiroperidol was bound to sections of renal artery in a manner consistent with the existence of dopamine receptors. In fact the binding was found to be saturable, stereospecific and of high affinity, with a Bmax approximately of 158.3 fmol/mg protein and a Kd of 13.5 nmol/l. The microscopic examination of sections processed for the histoautoradiographic demonstration of 3'-spiroperidol binding sites showed that the distribution of dopamine receptors in the renal artery was widespread. The highest concentration of dopamine receptors was found primarily in the smooth muscle cells of the media and then, in the following order, in endothelial cells of the intima and in fibrous and connective cells of the adventitia. The direct demonstration of dopamine receptors in the media of rabbit renal artery strongly supports the hypothesis that these receptors may be involved in the relaxation of the artery caused by infusion or application of dopamine.

Animals↗