Search PubMed⌕ Search

Biomedical subjects

L Rossi

Publications and source records attributed to L Rossi.

At least 451 records · Page 25Linked to original sources
PubMed1982

Carbamoylation of Cu,Zn-superoxide dismutase by cyanate. Role of lysines in the enzyme action.

Reaction with cyanate leads to a reversible change of the EPR spectrum of Cu,Zn-superoxide dismutase and to time-dependent carbamoylation of the lysine residues of the enzyme, producing a stable covalent derivative with more negative charge. The carbamoylated enzyme is less active than the native enzyme in spite of unaltered EPR spectra. The extent of this inactivation is much less when the enzyme activity is measured at low ionic strength. These results show that integrity of the active site is not the sole factor playing a role in the enzyme mechanism and that the ionic strength effect is related to electrostatic interactions between O-2 and surface charges of the protein.

Animals↗
PubMed1982

[Lipid variations in coronary disease].

Levels of total cholesterol (TC), triglyceride (Tg), high-density-lipoprotein-cholesterol (HDL-C), apolipoproteins A and B (ApoA and ApoB), were assayed in the serum of 63 patients suffering from coronary atherosclerosis, who survived myocardial infarction (M.I.) compared to healthy subjects. TC was assayed by an enzymatic-colorimetric technique: after precipitation with PEG 6000 the same method was used to determine HDL-C. Tg were assessed using total enzymatic method and ApoA and ApoB by RID. On the basis of TC, Tg, HDL-C, ApoA and ApoB values we have identified 6 main patterns, presenting a very characteristic lipaemic model. No significant difference was found between survivors and controls as regards TC and Tg; on the contrary, there was a statistical difference between the two groups for HDL-C, ApoA and ApoB.

Cholesterol↗
PubMed1982

[The presence of 3,4-benzopyrene in plants I. Methods].

Purification methods of vegetable extracts have been experienced during our researches on the possible presence of the aromatic polycyclic hydrocarbons (particularly 3,4 benzopyrene) in vegetables. The validity of different methods has been determined by IR spectrophotometric analysis using special apparatus (IR-DATA-STATION). Vegetables extracts have been purified efficaciously by column chromatography, saponification and special methods (Grimmer's method). The described method eliminates, nearly entirely, the polluting substances that could alternate the chemical analysis of the vegetable extracts.

Benzo(a)pyrene↗
PubMed1982

Lack of carcinogenicity of DDT in hamsters.

Syrian golden hamsters were fed for their lifespan a diet containing 0, 125, 250 and 500 parts per million (ppm) of ddt. The incidence of tumour bearing animals was 13% among control females and ranged between 11-20% in treated females. In control males 8% had tumours. The incidence of tumour bearing animals among treated males ranged between 17-28%. The incidence of adrenal cortex tumours showed a dose-related increase among the DDT-treated males. A liver-cell tumour and 2 liver hemangioendotheliomas were observed in 3 males treated with 250 ppm DDT. No liver-cell tumours were observed in the controls. No significant difference in tumour incidence was observed in treated versus control Syrian golden hamsters.

Adrenal Gland Neoplasms↗
PubMed1982

Effects of long-term intake of DDT on rats.

DDT is a pesticide used in malaria-control programmes throughout the world. Its potential carcinogenicity was studied in MRC Porton rats (Wistar-derived) which received dietary concentrations of 0, 125, 250 and 500 parts per million DDT (technical-grade) for life. The treatment had no adverse effects on body growth or survival rate. Various types of tumours were observed in animals in all groups: exposure to DDT resulted in statistically significant increased incidence of liver-cell tumours only in female treated rats; one such tumour was observed in control rats. No metastases of these tumours were found.

Animals↗
PubMed1982

BAEP and autopsy findings in Wallenberg syndrome.

BAEPs were recorded in a 70-year-old man who had developed symptoms indicative of Wallenberg syndrome. He died, of extracerebral causes, shortly after hospitalization and an autopsy study was done on the brainstem lesions. Right ear stimulation disclosed BAEP abnormalities, but gave no indication of the level of the ischemic disorder. Histopathological examination showed a typical right dorsolateral medullary infarct. A detailed study of the acoustic pathways demonstrated their anatomical integrity. These findings confirm the uncertainty that still exists as to the exact location and type of generators of BAEP components. They suggest, moreover, that BAEPs can give objective evidence of functional impairment of brainstem acoustic structures even in the absence of persistent anatomical damage.

Aged↗
PubMed1982

Draft EEC method for the determination of the global migration of plastics constituents into fatty-food simulants: applicability to lacquers, plastics and laminates.

An experimental study was carried out to establish whether the draft EEC method for the determination of the global migration of constituents from plastics packaging materials into fatty food simulants could be applied to all plastics, including lacquers and laminates. Some difficulties were encountered in the use of the EEC method for melamine, for hotmelt-coated packaging materials and for laminates containing one or more layers of materials sensitive to moisture, such as paper, cardboard or regenerated cellulose film.

Dietary Fats↗
PubMed1982

Repeatability and reproducibility of determinations of vinyl chloride in foodstuffs.

In the spring of 1978 and the autumn of 1979, two collaborative investigations were carried out with the aim of determining the variability of measurements of the vinyl chloride (VC) content of foodstuffs. The first investigation was a preliminary test on VC standards in N,N-dimethylacetamide. The results of this test were considered to be satisfactory. In a second test, lemonade and oil samples spiked with VC were investigated. The methods used were based on the headspace gas-chromatographic technique. The amount of VC added was 3 micrograms/kg for the lemonade sample and 20 micrograms/kg for the oil sample. The external standard method yielded a reproducibility of 53 and 39% and a repeatability of 18 and 17% for the lemonade and oil, respectively. The corresponding findings with the addition method were a reproducibility of 119 and 40% and repeatability of 33 and 9%.

Chemistry Techniques, Analytical↗
PubMed1982

Pathologic changes in the cardiac conduction and nervous system in sudden coronary death.

The arrhythmogenic substrates for sudden coronary death were studied in 13 autopsied hearts and in 2 left stellate ganglia (surgically excised). Diffuse or segmentary obstruction of nutritional arteries accounted for acute ischemic injury of the conduction system, which was the underlying cause of high-risk bradycardic arrhythmias in one-third of the cases. However, in one-quarter of the cases the survival of anoxia-resistant subendocardial specialized fibers was probably responsible for reentrant lethal tachycardic arrhythmias. In other cases, early infarct damage could have fatal arrhythmias of either type. Intrinsic and/or extrinsic neuropathologic changes, unbalancing the autonomic action on the heart, were often seen to participate in the arrhythmogenic features of sudden coronary death.

Acute Disease↗