Search PubMed⌕ Search

Biomedical subjects

P Toti

Publications and source records attributed to P Toti.

At least 55 records · Page 3Linked to original sources
PubMed1996

Celiac disease with cerebral calcium and silica deposits: x-ray spectroscopic findings, an autopsy study.

An increased incidence of seizures and cerebral calcifications, usually bilateral and located in the occipital cortex, has been reported in celiac patients. The histology of cerebral lesions is not well defined, and their pathogenesis is only speculative. We report the autopsy results of a patient with celiac disease, seizures, and cerebral calcifications who died following a cerebral hemorrhage caused by Fisher-Evans syndrome. Calcifications were restricted to the cortical gray matter and composed of aggregates of small calcified spicules. Calcium deposition was present as psammoma-like bodies, along small vessels, and within neurons. X-ray spectroscopy of the calcified areas revealed that calcium (43%) and silica (57%) were present in the lesions. High silica content was also found in the cerebral hemorrhagic fluid. Silica toxicity has to be considered in regard to the pathogenesis of the cerebral lesions and of the seizures.

Autopsy↗
PubMed1996

Localization of merosin in the normal human brain: implications for congenital muscular dystrophy with merosin deficiency.

A particular form of congenital muscular dystrophy with merosin deficiency has recently been described. Magnetic resonance imaging has shown that affected children show brain abnormalities. We investigate the localization of merosin in the normal human brain by immunohistochemistry. Other organs, such as the kidney, lung and liver, were also included in this study. We show that in the normal central nervous system merosin is localized in the basement membrane of blood vessels. No expression of merosin was found at the level of the liver and lungs, whereas the glomerular mesangial matrix of the kidney was intensely positive. These results suggest that merosin deficiency in the basement membrane of blood vessels in the central nervous system could play an important role in the physiopathology of brain abnormalities found in children affected by the congenital muscular dystrophy associated with merosin deficiency. Furthermore, the potential absence of merosin in the glomerular mesangial matrix of the kidney suggests a multi-system involvement.

Adult↗
PubMed1994

Morphological and pathogenetic aspects of proliferative vitreo-retinopathy. A histological and immunohistochemical study.

Proliferative vitreo-retinopathy (PVR) and subretinal membrane proliferation are the most common complication and cause of failure in retinal-detachment (RD) surgery. In this study, material withdrawn from 21 patients was observed. The vitreal taps of 16 bulbs affected by PVR and which had undergone vitrectomy, along with 5 bulbs obtained by enucleation, were stained with Hematoxylin Eosin and studied immunohistochemically. The cells involved in this proliferative tissue include macrophages, cellular elements of pigmented epithelium origin, fibroblasts and myofibroblasts. From the examination of enucleated bulbs, we can easily recognize that the cellular components of the membrane are represented by fibroblasts, capillaries, and occasional macrophages; meanwhile, PE cells remain at the base of the newly formed tissue.

Adult↗
PubMed1993

A new case of severe congenital nemaline myopathy.

The case of a neonate with a rapidly fatal course of nemaline myopathy is reported. Neonatal history and clinical findings suggested a postasphyxia syndrome, but dependence on mechanical ventilation in the absence of severe brain damage or evidence of heart and lung involvement prompted us to perform a muscle biopsy. The typical rod-shaped bodies of nemaline myopathy were observed in skeletal and heart muscle which is unusual in infantile forms. Neonatal bone fractures, which have not been reported previously, were detected. Due to the rapid evolution of the neonatal form, many of these patients may die undiagnosed in the perinatal period, the families remaining unaware of the existence of the genetic disorder. Therefore, if severe hypotonia persists in a neonate, together with dependence on assisted breathing, specific examinations, such as muscle enzyme determination, NCV, EMG and if indicated, muscle biopsy should be performed to rule out neuromuscular disease.

Female↗
PubMed1993

Non-conventional ultrasonography (power spectrum analysis) in the management of retinoblastoma.

The differential diagnosis among the diseases that may simulate retinoblastoma is supported by several techniques; however, none of them can give an undeniable answer. In the authors' opinion the tissue characterization by power spectrum analysis of the radiofrequency ultrasound data may play an important role in the backscattered signal spectrum while being sensitive to the spectral shift trend. In order to evaluate the patterns of regression of quiescence of retinoblastoma foci after conservative treatment the authors try to create a model of tissue characterization that provides information not available in conventional A & B scan ultrasonography about cell type, vascularization and necrosis.

Choroid Neoplasms↗
PubMed1991

The subretinal fluid in retinal detachment. A cytologic study.

Following retinal detachment, subretinal fluid (SRF) fills the neoformed space. Subsequently subretinal and preretinal strands of proliferative tissue begin to form. We have collected the subretinal fluid withdrawn during retinal detachment surgery. We have studied subretinal fluid cytologically to evaluate the number and the type of cells present in the fluid, and by means of transmission electron microscopy. The first cell type to be present in the fluid represented degenerated aspects of pigmented epithelial cells (PECs). Successively, other cell types appeared in the fluid as nerve cells (rods, cones and glial cells), macrophages and well preserved pigmented epithelial cells.

Adolescent↗
PubMed1989

Histopathological evaluation for the prognosis of retinoblastoma.

In the present study histologic, clinical and follow-up data of 37 cases of retinoblastoma were statistically analyzed by means of a multivariate method. The evaluated histological parameters were: growth pattern, degree of differentiation, number of mitoses, presence of necrosis, pseudorosettes, blood vessel basophilia, calcification, extension to anterior chamber, invasion of optic nerve and ocular coats (choroid and sclera). The analysis was based upon the Cox proportional hazards regression model. Invasion of ocular coats proved to be highly correlated to the prognosis (p less than 0.0002). None of the other parameters showed a significant relation to survival.

Child↗
PubMed1989

Influence of CDP-choline administration on the aortic wall lesions in dietically hypercholesterolaemic rabbits: a morphometric evaluation.

In New Zealand rabbits subjected for a 2 month period to a 1% or 2% hypercholesterolic diet, larger intimal involvement and histologically heavier lesions were observed in the animals on a hypercholesterolic diet. The intimal involvement was larger in the aortic arch. In groups of rabbits simultaneously subjected to similar diets and to i.v. CDP-choline injections, the intimal involvement appeared reduced (p less than 0.01) both in the arch and in the descending tract of the thoracic aorta.

Animals↗
PubMed1988

Cerebro-ocular dysplasia and muscular dystrophy: report of two cases.

The authors report two cases with severe cerebro-ocular malformations and muscular dystrophy who died at 14 and 8 months of age. In both, muscular dystrophy was confirmed by EMG and high muscle enzyme values. In one case, autopsy showed severe cerebral malformation consisting of lissencephaly, hydrocephalus, agenesis of corpus callosum, chiasma and olfactory bulb and lobe, absence of pyramides and cerebellar vermis. In sections of cerebral cortex a clear absence of structural cellular organization and spongiosis of the white matter were evident. Similar disorganization was found in the cerebellum where numerous calcifications were present. The muscle showed signs of primitive muscular dystrophy. The clinical autonomy of the cerebro-ocular-dysplasia-muscular-dystrophy syndrome is discussed. The clinical and pathological data are compared with the two other similar syndromes (i.e. Fukuyama's and Warburg's diseases).

Abnormalities, Multiple↗
PubMed1988

Ultrastructural computerized morphometry of platelets in chronic myelogenous leukemia making use of ultra-thin sections and freeze-fracture procedure. A preliminary approach.

Biochemical and morphological data have shown that the circulating platelets are deeply altered in patients with chronic myelogenous leukemia. In this report we describe the results of ultrastructural morphometry performed by means of a computerized device of the platelet shape (ultra-thin sectioned platelets) and of the platelet plasma-membrane (freeze-fractured platelets). Platelets appeared deeply modified: reduced mean platelet area and perimeter, increased surface density of the openings of the surface connected canalicular system, abnormal features of the platelet cytoplasm and some aspects of platelets joined together even if with heterogeneity in these findings did appear from patient to patient.

Adult↗
PubMed1987

The increase of the openings of the surface-connected canalicular system in weakly stimulated platelets is prevented by a carbochromen derivative. A computerized morphometric analysis of freeze-etched human platelet plasma-membrane.

When thrombin is added to platelet rich plasma at very low concentrations (0.02 U/ml), platelets undergo an activation process. Under these conditions platelets discharge beta-thromboglobulin, platelet factor 4 and the "platelet derived growth factor". In this paper we present evidence that when human platelets are weakly stimulated with thrombin, the number of openings of the surface connected canalicular system (SCCS) increases. This was observed ultrastructurally by the freeze-etching technique. 8-chlorocarbochromen, an antiaggregating drug, seems to inhibit this increase.

Adult↗
PubMed1986

Ultrastructural modifications of the platelet plasma membrane in vascular diseases and the effect of a carbochromen derivative as studied by freeze-fracture and computer measurement.

A high surface density of the openings of the surface connected canalicular system (SCCS) has been observed in the freeze-fractured plasma membrane of circulating platelets in rabbits fed an atherogenic diet and in hypercholesterolemic type IIa patients. In vitro tests have revealed a correlation between the increased surface density of the SCCS openings and the initial steps of platelet activation. 8-Chlorocarbochromen, a new drug which enhances the in vivo release of prostacyclin from the arterial wall, has been found to be effective in reducing the high surface density of SCCS openings in platelets of rabbits on an atherogenic diet. The present study shows that circulating platelets from patients with peripheral vascular disease present a high surface density of SCCS openings compared to that observed in control subjects. After a single oral administration of 8-chlorocarbochromen, a reduction of the high number of these openings has been observed. Likewise, beta-thromboglobulin levels were found to be high in the patients and to be significantly reduced after oral administration of the drug. This study shows ultrastructural modifications of platelets in conditions related to atherosclerosis and includes data on the effectiveness of 8-chlorocarbochromen in reducing the platelet activation of these patients.

Administration, Oral↗
PubMed1986

Platelet plasma membrane changes in human type IIa hypercholesterolemia.

We have examined platelets collected from hypercholesterolemic (HC) young patients (n = 12) and from normocholesterolemic young volunteers (n = 9) by means of freeze fracture. The mean value of the surface density per square micrometer of the openings of the surface-connected canalicular system was significantly higher (p less than 0.03) in the HC patients (2.4 +/- 0.6) compared with the controls (1.8 +/- 0.5). It was also positively correlated with the low-density lipoprotein cholesterolemia/total cholesterol ratio (p less than 0.005) and inversely correlated with the high-density lipoprotein cholesterolemia/total cholesterol ratio (p less than 0.01). These data indicate that the circulating platelets of HC type IIa patients appear changed at ultrastructural level and that their modification may be somehow related to the atherogenetic processes.

Adolescent↗
PubMed1985

Platelets in the platelet-vessel wall interaction.

Ultrastructural and biochemical aspects of reversible and non-reversible platelet-vessel wall interaction are presented. Special attention is directed towards the role of release products of platelets, the plasmatic coagulation factors and the prostaglandin system. An up-to-date view of the role of platelet-vessel wall interaction in atherogenesis is discussed.

Animals↗
PubMed1985

Observations on the effects of some antiaggregating drugs on platelet specific protein discharge after a very weak stimulus.

Platelet adhesion, aggregation, secretion, and survival have been shown to be changed in atherosclerosis disease and thromboembolic phenomena thus further increasing interest on antiaggregating drugs. In this paper we present some evidence that 8-chlorocarbochromen and carbochromen are significantly effective in preventing the discharge of platelet specific proteins from platelets subjects to a very weak stimulus while acetylsalicylic acid and aminophylline are ineffective in this regard.

Aminophylline↗
PubMed1984

[Preliminary observations on the structure of the medio-intimal area of the rabbit coronary arteries. (A. Observations on 4-month-old rabbits)].

The presence of the diffuse intimal thickening (DIT) is commonly considered the structural basis for the early atherosclerotic involvement of the coronary arteries. In the ambit of a systematic morphometric comparison of experimental atherosclerotic plaques of aorta and coronaries, we have studied the coronary medio-intimal junctions of 4 months old rabbits. Both at sub-epicardic and intra-myocardic coronary arteries level we have found fiber structures similar to DIT. These findings may help explaining why coronary atherosclerosis in rabbits does not represent, in the usual experimental models, a lesion particularly severe nor of precocious appearance.

Age Factors↗