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Biomedical subjects

A Cristaudo

Publications and source records attributed to A Cristaudo.

At least 55 records · Page 3Linked to original sources
PubMed1990

Nickel-keratinocyte interaction: a possible role in sensitization.

Normal human keratinocytes and the keratinocyte-derived cell lines NCTC 2544 and A 431, were exposed for different periods (1-5 days) to various concentrations (0.023-46.6 micrograms/ml) of nickel (Ni2+). A dose- and time-dependent inhibition of cell growth and viability was observed. Cultures exposed to 2.3 micrograms Ni2+/ml showed approximately 50% cell survival at 5 days. An increase in release of interleukin 1 by keratinocytes was detected following culture for 24 h with a Ni2+ concentration of 2.3-11.5 micrograms/ml. Short periods of incubation (30 min) with these concentrations induced an activation of lipoxygenase in leucocytes from healthy subjects, without modifying cell viability. The results suggest that the percutaneous penetration of small amounts of Ni2+ can result in damage to keratinocytes and can initiate sensitization.

Cell Division↗
PubMed1990

Serum concentrations in nickel-sensitive patients after prolonged oral administration.

11 nickel-sensitive subjects were given a gradually increasing daily oral intake of NiSO4 in water. The treatment lasted from between 49 and 152 days and the total intake ranged from 56.43 to 271.70 mg of Ni++. Ni serum concentrations were repeatedly assayed. While the values varied irregularly in the first assessments, they then tended to diminish and to be lower than those found at basal level. The ratio of Ni serum concentration to oral intake demonstrated that, as the doses administered increased, the absorption of nickel decreased. We hypothesize that this trend might be due to an intestinal adaptivity that reduces nickel absorption.

Administration, Oral↗
PubMed1990

Study on cross-reactivity to the para group.

In 80 patients, positive to at least one hapten of the para group (para-phenylenediamine, diaminodiphenylmethane, benzocaine, PPD mix), patch tests were carried out with freshly prepared solutions of para-phenylenediamine (PPD) and of 3 selected aromatic compounds related structurally to PPD (para-aminophenol, ortho-aminophenol, hydroquinone). The number of positive reactions correlated with the rate of decomposition of the substances as evaluated by high-pressure liquid chromatography. PPD, which was almost decomposed after 24 h, gave the highest number of positive reactions, followed by ortho-aminophenol and by para-aminophenol, while hydroquinone, which was oxidized to the extent of 35%, did not give any reactions. To evaluate if a different rate of oxidation can modify the patch test response, in the same patients and in 10 normal volunteers, tests were carried out with PPD solutions containing the oxidizing agent silver oxide (0.1%). By this procedure a significant increase in the number of positive responses was observed. The results suggest that the rate of decomposition and therefore the amount of quinone(s) generated, might be the key to eliciting patch test responses to oxidizable aromatic haptens.

Aminophenols↗
PubMed1989

Nickel dermatitis from cheap earrings.

In 1988, 64% of our patients patch test positive to at least 1 allergen of the ICDRG standard series were nickel sensitive. In 70% of 300 patients evaluated, dermatitis started on the earlobes and was related to the regular wearing of cheap earrings. At the same time, 62% of 735 young schoolgirls were found to have dermatitis of their earlobes and all regularly wore cheap earrings. 9 clasps and clips commonly used in earrings released high quantities of nickel ions (between 49 and 103 micrograms/12 h), having been stored in synthetic sweat. A round piece cut from a clasp was taped to the skin of 30 nickel-sensitive patients, previously tested with 20 microliters of NiSO4 5%, 2.5%, 1% aq. solutions, giving a response similar to that caused by the 5% solution. High daily absorption of Ni ions through the skin follows its repetitive exposure to cheap earrings, causing, firstly, a direct inflammatory reaction, then followed, in our opinion, by sensitization.

Adolescent↗
PubMed1988

Nickel sensitivity: effects of prolonged oral intake of the element.

25 nickel-sensitive females were given 10 mg NiSO4 in water in a single dose. 18 experienced generalized or localized flare-ups. 15 days later, 17 of the 25 patients were given gradually increasing daily doses of NiSO4 in water for 3 months. 14 ended the trial without flare-up, 3 had to stop because of intense worsening of cutaneous manifestations. A relationship does exist between the daily oral intake of nickel and its clinical manifestations, but it is not uniform and depends on the changing quantities and, above all, on the manner of intake. It would seem that a 10 mg NiSO4 oral challenge represents a sudden and large intake of the element to which the majority of sensitized subjects are not able to adapt. On the other hand, a gradual intake permits a majority of subjects to adapt to the element. We hypothesize that this behaviour is more likely due to intestinal adaptivity than to immunological tolerance.

Administration, Oral↗
PubMed1987

Contact dermatitis to fragrances.

2 groups of patients (1200 and 1500 respectively) were patch tested with different concentrations of perfume mix and fragrance raw materials. The study was to evaluate the incidence of contact dermatitis to fragrances in Roma, Italy, and the influence of limited variations in fragrance and perfume mix concentrations on patch test responses. The results showed that a decrease in the perfume mix concentration from 16% to 8% correlated with a decrease in the % of positive patients (from 5.2% to 3.6%). Variations in the concentration of fragrance raw materials did not influence the % of positive reactions in the 2 groups. The perfume mixture at 16% or 8% gave some positive results, without a corresponding reaction to any of the constituents, that were not related to an excited skin syndrome.

Adult↗
PubMedDate not supplied

SV40 can be reproducibly detected in paraffin-embedded mesothelioma samples.

We studied tissue sections from 18 paraffin embedded mesothelioma specimens diagnosed by the Pathology Department of S. Chiara Hospital of Pisa. Using PCR analysis and Southern blot hybridization we examined the specimens for the DNA regulatory region of the virus. 10/18 (55.5%) of the samples tested contained SV40 DNA regulatory sequences, and of these positive samples, 80% were found to contain Tag sequences by PCR and Southern Blot hybridization. These results confirm that SV40 can be amplified and detected in paraffin embedded mesothelioma samples.

Adult↗
PubMedDate not supplied

[The occupational risk in IRCCS of Neurosciences].

The results of meta-analysis carried out on all documents for the valuation of the risk, recorded by IRCCS of Neuroscience, has led to identify a risk matrix for the medical personnel of the Scientific Institute of Neuroscience. Such analysis allowed to tackle the day to day risk faced by hospital staff. As a general rule the IRCCS of Neurosciences distinguishes themselves as structures of mainly neurologic typology and as structures of more typical psychiatric interest. In the first case the analogy with the traditional Hospital structures are more noticeable, in the second case instead the kind of patients and the particular relations between the health worker and the patient himself may represent an important differentiation factor. This is, above all, evident on the biological risk; for it's determinism has an important rule the interpersonal relationship between the health worker and the patient. Concerning other risk factors such as the chemical and the allergic one, it is noticeable a closed analogy with the actual Hospital reality. On work organization level, manual handling of patients is often necessary and also the relatives risks. In this kind of structures the stress factor is of the greatest importance, it should therefore have a strong consideration on the valuation of risk by the IRCCS.

Academies and Institutes↗