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Biomedical subjects

P Toti

Publications and source records attributed to P Toti.

71 records · Page 4Linked to original sources
PubMed1982

[On the growth of cultured bovine aortic endothelial cells. Preliminary observations on ultrastructural morphology by freeze-etching and quantitation of growth rate by phase contrast microscopy: effect of glycosaminoglycans].

Bovine aortic endothelial cells (BAEC), detached from thoracic aorta by collagenase treatment, have been studied after adding a mixture of glycosaminoglycans (GAGs) (the composition of which has been studied by Casu et al. -6), at different concentrations. GAGs at the concentration of 90 mg/100 ml of medium (Dulbecco's modification of Eagle's MEM with 10% foetal calf serum) produced an increase in the growth speed. We have quantitized these data both by counting the number of cells 24 h after trypsinization in phase-contrast-microscopy, and by measuring the time necessary to reach a certain number of influences. Ultrastructural observation at transmission electron microscope after freeze-etching preparation, didn't show any relevant modification either in the organization of cell membrane or in the cytoplasmatic structures. In some observations a conspicuous increase of "vesicular openings" ("pits") on the plasmatic membrane was evident. Statistical evaluation of this phenomenon is under consideration.

Animals↗
PubMed1982

[Effects of high density lipoproteins (HDL) and low density lipoproteins (LDL) on cultured bovine aorta endothelial cells. Preliminary observations on ultrastructural morphology of the plasma membrane by freeze-fracturing].

Bovine aortic endothelial cells (BAEC), detached with collagenase, have been studied morphologically after administration, in vitro, of human lipoprotein fractions (200 micrograms/ml of LDL, 200 micrograms/ml of HDL), 24 h before the confluence. One day after the treated cells and the control one were detached with trypsine and prepared for freeze-etching examination. The plasma-membrane has revealed, in the lipoprotein treated cells (HDL or LDL) an increased average value of the number of "pits" present upon a surface unit (P less than 0,05). Moreover, in the HDL-treated cells, the "pits", sometimes, have appeared with a different morphological evidence, similar to the aspects of exocytosis as seen e.g. in platelets or in Langerhans isle cells.

Animals↗
PubMed1981

[Scanning electron microscopic studies of the umbilical arteries and veins of newborn infants of smoking mothers].

We have examined the umbilical cord of ten newborn children of nonsmoking (five) and of smoking (five) mothers (10-20 cigarettes/day). The patients chosen for the study resulted "normal" before and during pregnancy. Immediately after delivery the umbilical cords were tied (to avoid collapse) and cut about 10 cm from the placenta. Umbilical cords were submitted to pressure-perfusion-fixation according to Kjelsen and Thomsen (7). Three randomly chosen specimens for SEM were cut and postfixation was performed in 1% buffered osmium tetroxide (pH 7.4) and after dehydration, were submitted to critical point drying (CO2), coated with gold palladium (sputtering technique), and observed by means of a Super ISI Mini SEM at 7,5 Kv. Luminal surfaces of umbilical arteries and veins from non-smoking mothers revealed a regular endothelial layer all over the surface. Large disendothelialised areas were instead found not only in arteries (1) but also in veins from newborn children of smoking mothers.

Humans↗
PubMed1981

Effects of prostacyclin on ultrastructural features of human platelets in vitro.

Examining platelets plasma-membrane by freeze-etching (FE)-technique irregularly place among the "particles", some larger formations, called by us "protuberances" can be seen. These protuberances may represent the stomata of the open canalicular system (OCS) and the morphological aspect of an exocytotic process. Addition of prostacyclin to platelet rich plasma (PRP) leads to a decrease of the average value of protuberances which is statistically significant in comparison to control platelets.

Blood Platelets↗
PubMed1979

Circulating endothelial-like cells in arterial peripheral blood of hypercholesterolemic rabbits.

In blood smears obtained from the central ear artery of rabbits after 7 days of cholesterol-rich diet, a high number of well staining cells, morphologically very similar to endothelial cells may be found. After 15 days, macrophage-like cells are found in the smears together with degenerated (endothelial or macrophagic) cells. The presence of circulating endothelial cells is in agreement with the findings of de-endothelialized areas of aortic intima observed at scanning and transmission electron microscopy in short term hypercholesterolemic rabbits.

Animals↗
PubMed1977

Aortic surface coat scanning electron-microscopic modifications after short-term hypercholesterolic diet, visualized in rabbits by con A-haemocyanin reaction.

Modifications of the aortic endothelial surface coat have been visualized at SEM with the use of the Con A-haemocyanin method. After fifteen days of an atherogenic diet, a strong increase of the reactive coat was evident in areas near the orifice of the collateral branches. In other areas, the reaction appeared to be intensely diminished.

Animals↗
PubMedDate not supplied

Phthisis bulbi and buphthalmos as presenting signs of retinoblastoma: a report of two cases and literature review.

PURPOSE: To report two cases of bilateral retinoblastoma (RB) with unusual presentations. METHODS: The medical records of 321 patients from the Retinoblastoma Referral Center in Siena were reviewed. A total of 111 patients had bilateral RB, 2 of them presenting with phthisis bulbi and buphthalmos. Both patients underwent bilateral enucleation. Clinical features, imaging studies, and histopathology were reviewed. RESULTS: These 2 cases represent 0.62% (2/321) in our series. Histopathology did not reveal viable tumor cells in the phthisical eyes; in both buphthalmic eyes the tumor was active, infiltrating the choroid and optic nerve. CONCLUSIONS: Phthisis bulbi and buphthalmos are unusual presenting signs of RB. This very rare combination of these two signs in different eyes of the same patient is probably due to a delay in diagnosis.

Child, Preschool↗
PubMedDate not supplied

Keratoconus associated with corneal macular dystrophy: in vivo confocal microscopic evaluation.

PURPOSE: The authors present a case, studied through in vivo confocal microscopy, of concomitant keratoconus and macular corneal dystrophy (MCD). METHODS: A 29-year-old man underwent a penetrating keratoplasty in the right eye in May 2005. Confocal microscopy was performed to examine the cornea of the right eye. RESULTS: A diagnosis of concomitant keratoconus and MCD was suspected, due to the simultaneous findings of corneal ectasia and stromal opacities. CONCLUSIONS: In this case, using in vivo confocal microscopy, morphologic changes were detected in many corneal layers and compared with the histopathologic findings. The morphologic alterations were found mainly in the area of the cornea apex.

Adult↗
PubMedDate not supplied

Some pathogenetic aspects of atherosclerotic lesions. Platelets and atherogenesis. Differences in atherogenesis in different body districts. Regression of arterial lesions in animal models.

The first part of the paper is devoted to the role of platelets in atherogenesis because the new ultrastructural techniques have revealed the morphological basis of platelet "activation". In the second part, the delayed involvement of intracranial vs extracranial cerebral arteries, afferent to the brain is examined on the basis of recent work both in man and in experimental animal models. Regression of arterial lesions is considered in the third part chiefly on the basis of contributions in experimental animals, while more data on regression in humans are expected in the near future.

Animals↗