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Biomedical subjects

P Perfetti

Publications and source records attributed to P Perfetti.

At least 19 recordsLinked to original sources
PubMed1999

Cell ashing for trace element analysis: A new approach based on ultraviolet/ozone.

We studied a new approach to cell ashing based on illuminating the specimens with a low-pressure mercury discharge lamp. We analyzed with synchrotron spectromicroscopy its effects on different physiological elements in neurobiological specimens. Our results demonstrate that carbon is removed, whereas phosphorus, calcium, potassium, and sulfur are retained and their relative concentrations are enhanced. Applied to trace elements, this technique will enhance their practical detectability.

Animals↗
PubMed1998

High sensitivity quantitative analysis of cobalt uptake in rat cerebellar granule cells with and without excitatory amino acids.

We quantified the effect of the excitatory amino acids kainate and glutamate on the uptake of cobalt in primary rat cerebellar granule neurons, by using inductively coupled plasma-atomic emission spectroscopy (ICP-AES). We quantitatively demonstrated that Co2+ uptake, although enhanced by glutamate and kainate also takes place in the absence of excitatory amino acids. We also found that cobalt uptake is not significantly altered by the presence of glutamate receptor competitive or noncompetitive antagonists, indicating that cobalt uptake in granule neurons does not require glutamate receptor stimulation. Our results suggest, therefore, that Co2+ may enter the cell by passive diffusion through the plasma membrane.

Animals↗
PubMed1997

The effect of ashing on cells: spectromicroscopy of physiological elements.

We analyzed the effects of cold oxygen plasma ashing of neurobiological specimens on different elements with synchrotron spectromicroscopy. Our results demonstrate that while carbon is almost completely removed, phosphorus, calcium, potassium, sulfur, and, to some extent, nitrogen are retained and their relative concentration is enhanced.

Animals↗
PubMed1995

Neurone decapping characterization by atomic force microscopy: a topological systematic analysis.

We tested a new approach to cell decapping on rat cerebellar neurones, and observed its effects on cell topography by atomic force microscopy (AFM). The results clearly demonstrate the effectiveness of our decapping approach, and also the ability of AFM to reveal fine details of the decapped cells. Specifically, varying the conditions and duration of the decapping process modifies the extent of the decapping. Such a method can be used to investigate the cytoplasm with surface sensitive techniques.

Animals↗
PubMed1995

Atomic Force microscopy of neuron networks.

We imaged uncoated neuron networks by an atomic force microscope in the repulsive regime of contact mode. Images of granule cells and their axons have been clearly revealed with details smaller than 20 nm. The good stability of the sample and the mechanical reproducibility of the microscope allowed the imaging of a neuron culture area of several square microns. By combining tens of images, we were able to reconstruct a highly defined neuronal network. Furthermore, the images were very reproducible over repeated scanning acquisition, demonstrating the mechanical and thermal stability of the instrument-sample system.

Animal Population Groups↗
PubMed1994

Aluminium in rat cerebellar primary cultures: glial cells and GABAergic neurones.

Experimental evidence of the preferential uptake of aluminium by GABAergic neurones and glial cells was provided by synchrotron spectromicroscopy studies. We observed rat cerebellar cultures enriched for GABAergic neurones or glial cells exposed to aluminium ions, detecting the presence and identifying the chemical status of aluminium on cell structures.

Absorptiometry, Photon↗
PubMed1993

Aluminium in rat cerebellar neural cultures.

A systematic microchemical analysis of unstained and uncoated neurone cultures was performed with synchrotron radiation photoemission spectromicroscopy after exposure to an aluminium solution. Clear evidence was found for localized aluminium uptake in a few cells. Their possible identification based on morphology is discussed.

Aluminum↗
PubMed1993

First results of a mammographic screening program in two municipalities of Massa-Carrara Province (Italy).

AIMS AND BACKGROUND: A mammographic screening for breast cancer was started in 1989 in two municipalities of Massa-Carrara province. This paper describes the results of the first two years and evaluates the quality of the program via early indicators. METHODS: We calculated the attendance rate at first screening, the proportion of women recalled for further examinations (recall rate), the ratio between benign lesions and carcinomas detected by screening, the staging of the screen detected cancers and the ratio between detection rate and expected incidence (P/I ratio). RESULTS: Out of 14826 invited women 10407 (70.2%) attended the first screening; 266 (2.6%) of them were referred for further investigations but only 63 (0.6%) required surgical biopsy. A histological confirmed malignancy was found in 39 women corresponding to a detection rate of 3.7/1000. According to pTNM classification 89.1% of all cancers were either Tis or in stage T1; and in two third of the cases there was no nodes involvement. CONCLUSION: The results achieved so far, evaluated via early indicators, show a good start of the program.

Adult↗
PubMed1992

Metal uptake in neurone cultures: a systematic study.

We present the first comparative study of the uptake of metal ions by neurons, performed for Zn, Cr, Co, Mo, Al, Ni, Mn and Cd. The study reveals substantial differences in the uptake of different metals, under similar exposure procedures. In particular, we found very large uptakes for aluminium and molybdenum. We also found significant effects of excitatory substances, in particular kainate, as stimulants of uptake of some of the metals.

Animals↗