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Biomedical subjects

M Andreassi

Publications and source records attributed to M Andreassi.

14 recordsLinked to original sources

Selectivity of protein carbonylation in the apoptotic response to oxidative stress associated with photodynamic therapy: a cell biochemical and proteomic investigation.

We previously reported that photodynamic therapy (PDT) using Purpurin-18 (Pu-18) induces apoptosis in HL60 cells. Using flow cytometry, two-dimensional electrophoresis coupled with immunodetection of carbonylated proteins and mass spectrometry, we now show that PDT-induced apoptosis is associated with increased reactive oxygen species generation, glutathione depletion, changes in mitochondrial transmembrane potential, simultaneous downregulation of mitofilin and carbonylation of specific proteins: glucose-regulated protein-78, heat-shock protein 60, heat-shock protein cognate 71, phosphate disulphide isomerase, calreticulin, beta-actin, tubulin-alpha-1-chain and enolase-alpha. Interestingly, all carbonylated proteins except calreticulin and enolase-alpha showed a pI shift in the proteome maps. Our results suggest that PDT with Pu-18 perturbs the normal redox balance and shifts HL60 cells into a state of oxidative stress, which systematically induces the carbonylation of specific chaperones. As these proteins normally produce a prosurvival signal during oxidative stress, we hypothesize that their carbonylation represents a signalling mechanism for apoptosis induced by PDT.

Actins↗

Antioxidant activity of topically applied lycopene.

BACKGROUND: Ultraviolet (UV) rays cause depletion of the antioxidant substances contained in the epidermis. This is the rationale for the use of topical antioxidant substances. METHODS: We studied the protective activity against UV radiation of a product based on lycopene and a product containing a mixture of vitamins E and C. Photostimulation was applied with a solar simulator and the cutaneous response was evaluated instrumentally. RESULTS: The lycopene-based product had a much greater protective ability than the product containing the mixture of vitamins. CONCLUSIONS: Lycopene has suitable characteristics to be used successfully in the prevention of cutaneous damage by free radicals. Its antioxidant ability is probably due to its high reductive power.

Administration, Topical↗

Antioxidants in dermocosmetology: from the laboratory to clinical application.

Oxygen situated in cutaneous cells can be activated by light. This makes the integumentary apparatus particularly vulnerable to oxidative damage and is responsible for the immediate cutaneous damage that is the basis of late phenomena, such as photo-induced ageing and tumours. Thus, the cosmetic industry has undertaken research and development into antioxidant-based products able to protect the skin from the effect of pro-oxidizing noxae. This review re-examines both antioxidants suitable for dermatological application and skin care products with antioxidant capacity, as well as the laboratory methods used to evaluate the effects and in vivo efficacy of antioxidants.

Journal Article↗

New microencapsulated sunscreens: technology and comparative evaluation.

The aim of this work is to obtain new technologically improved microencapsulated sunscreens characterised by UV-radiation stability, good substantivity, low toxicity, a better tolerability and easiness to formulation. For this purpose we prepared two different systems using semisynthetic Hyaluronic Acid (HA) benzyl ester and a synthetic polymer (patent pending). We obtained these systems using two different methodologies: emulsification/solvent evaporation and emulsification/solvent extraction. The comparison between the two formulated systems was carried out in terms of their chemical-physical and biological properties.

Capsules↗

Lymphocyte subset changes in blood and gastrointestinal mucosa after oral nickel challenge in nickel-sensitized women.

This study investigates lymphocyte subsets in both the gastrointestinal mucosa and blood, in patients with nickel allergic contact dermatitis, after 10 mg oral nickel challenge (double-blind, placebo-controlled). 6 such patients with cutaneous symptoms induced only by skin contact with nickel (group A), 6 with a flare-up of cutaneous symptoms after food nickel ingestion (group B) and 6 healthy controls (group C) were enrolled. Blood lymphocyte subsets (CD4, CD45RO, CD8) were analyzed before and after 4 and 24 h from the challenge (test 1, 2, and 3), and intestinal biopsies were performed 2 days later. Challenges were positive in group B and negative in group A and controls. Serum and urine nickel levels significantly increased after nickel ingestion, with no differences between the 3 groups. At test 3, a significant decrease of the all CDs studied was found in group B. Biopsies of this group showed higher levels of CD45RO+ cells in the lamina propria and in the epithelium and lower levels of epithelial CD8+ lymphocytes. This study confirms that ingested nickel may induce flare-up of cutaneous reactions in some nickel-allergic patients, independently of the degree of sensitization and the intake of metal. In these patients, oral nickel stimulates the immune system, inducing maturation of T lymphocytes from virgin into memory cells; these latter cells seem to accumulate in the intestinal mucosa. The immunoreaction also involves CD8+ cells, whose role is not yet clear.

Administration, Oral↗

Systemic effects of ingested nickel on the immune system of nickel sensitised women.

This study evaluates the immune response to ingestion of 10 mg of nickel (Ni) (as Ni sulphate) in 19 young non-atopic Ni-sensitised or 9 non-allergic women (group A). After Ni ingestion at 8 a.m, non-allergic and 12 Ni-sensitised women (group B) were non-symptomatic, while 7 Ni-sensitised women (group C) showed a flare up of urticaria and/or eczema. Serum and urine Ni were greatly lower before Ni administration than after 4 and 24 hours, without difference among the 3 groups. Before treatment, group B and C showed higher values of blood CD19+ and CD5--CD19+ cells than group A, while group C showed higher serum interleukin (IL) 2 and lower serum IL-5. Four hours after Ni ingestion, group C showed significant increase in serum IL-5. Twenty-four hours after treatment, group A showed a significant reduction in blood CD4+-CD45RO- "virgin" cells and an increase of CD8+ lymphocytes, while group C showed a marked decrease in total blood lymphocytes and CD3+, CD4+-CD45RO-, CD4+-CD45RO+, CD8+, CD19+ and CD5--CD19+ cell subsets. These data may be explained with migration of lymphocytes in tissues with a Th0-like immune response, as shown by the elevated serum IL-2 and the increase of serum IL-5 during the test.

Adolescent↗

Expression of lymphocyte subpopulations, cytokine serum levels and blood and urine trace elements in nickel sensitised women.

In this study, 20 non-allergic and 20 non-atopic women sensitised only to nickel (Ni) showed similar levels of urine and serum Ni and serum chromium (Cr). On the contrary, serum copper, a marker of inflammation, was significantly higher in the Ni-sensitised group. Sensitised women also had higher values of blood B CD19+, CD5--CD19+ and B and natural killer CD3--CD25+ lymphocytes, but not alterations of some other lymphocyte subsets and serum cytokines. Urine Ni was correlated with "memory" CD4+-CD45RO+ lymphocytes in the non-allergic women and with T CD4+-CD45RO+ and CD3+-CD25+ cells in the atopic women; these subjects also showed a statistically significant correlation of serum Ni with B CD5+-CD19+ lymphocytes and serum IL-13. Moreover, serum Cr of both groups of women was positively or negatively correlated with activated HLA-DR+ cells and/or serum IL-5 and interferon gamma. These results (confirming in part those of a previous study on non-allergic men) suggest that both Ni and Cr are involved in mechanisms regulating the immune response and that allergy to these metals could be considered an alteration of their physiological role.

Adolescent↗

Serum and urine nickel in nickel-sensitized women: effects of oral challenge with the metal.

15 women with a positive patch test only to nickel (Ni) and without atopy and 10 control women were selected for the study. Blood and urine specimens were collected with a standard procedure either before (at 8 a.m.) or 4 and 24 h after the ingestion of 10 mg of Ni (as Ni sulfate). 7 of the Ni-sensitized patients showed a flare-up of eczema and/or urticaria during the test, while the other women were non-symptomatic. Serum and urine Ni of controls and Ni-sensitized women did not significantly differ. Serum and urine Ni levels determined before the oral Ni challenge were in the range of reference values recently reported by other authors (0.2-2.0 micrograms/l of serum or urine). Ni was greatly augmented in urine and serum 4 h after the challenge (25th-75th percentiles: 43-264 micrograms/l urine Ni and 15-52 micrograms/l serum Ni). 24 h after Ni ingestion, urine Ni was 41-153 micrograms/l and serum Ni 4-17 micrograms/l. Our study confirms a previous investigation showing similar levels of serum and urine Ni following ingestion of the metal in control and Ni-sensitized women without atopy.

Administration, Oral↗

Intravenous immunoglobulins suppress the recurrences of genital herpes simplex virus: a clinical and immunological study.

Effective treatment is not currently available for suppressing the recurrence of genital herpes simplex virus (HSV) infections. Since intravenous immunoglobulins (IVIG) proved useful against HSV in experimental models, we treated patients with very high frequency of HSV genital recurrences (more than 15 episodes per year) with IVIG (400 mg/Kg every fourth week). The control group was treated with intermittent oral acyclovir (800 mg twice a day for one week every month). Both groups were treated for six months and, then, patients were followed-up to further six months. Both IVIG and acyclovir were effective in reducing the frequency of HSV genital recurrences as compared to base-line. However, patients treated with IVIG had a more striking reduction in the frequency of recurrences as well as both a shorter mean duration and a minor severity of the lesions as compared to acyclovir-treated patients. Furthermore, we found a trend indicating IVIG as more effective in reducing the viral load. Since in IVIG-recipients we found a strong increase of peripheral blood lymphocytes with natural killer (NK) surface phenotype, we suggest that the clinical effectiveness of IVIG treatment is probably mediated via the expansion of NK cell populations. Our study indicates that the treatment with IVIG is an effective and safe tool for suppressing the recurrences of genital HSV infections.

Acyclovir↗

Cyclical immunotherapy in patients with psoriasis.

Psoriasis, a chronic and unpredictable dermatosis, is a constant therapeutical challenge to dermatologists. However, new knowledge in immunodermatology has stimulated interest in and encourage the use of new molecules, especially cyclosporin A (CyA). Thanks to certain characteristics, this molecule is capable of modulating and blocking the intense network of cytochine that seems to cause this dermatosis. The first clinical experiments have demonstrated that low dosages (3-5/kg die) can achieve rapid and effective remissions. The Italian experience gathered from numerous centres has been assessed to better understand and manage the use of CyA, especially as regards to tolerance and reliability. There is proven remission in 77% of the cases of plaque psoriasis. The duration of remission, as well as the paucity of side effects, has brought to the concept of cyclical therapy with CyA. The advantages of this mode of therapy are: the possibility of determining the most effective dosage; quantification of the dermatosis-free period; opportunity to personalize treatment and decide its duration; early intervention, should the dermatosis recur; exclusion of side effects and better control over those remaining.

Cyclosporine↗

Factors related to physical therapy students' decisions to work with elderly patients.

The purpose of this study was to determine the factors related to physical therapy students' decisions to work with elderly patients subsequent to graduation. Questionnaires, distributed to students in graduating classes of seven entry-level master's degree programs and seven baccalaureate degree programs, were returned by 326 participants. The questionnaires included 20 questions within four categories--biographical (3), experiential (7), perceived socioeconomic (3), and attitudinal (7) factors--plus 1 question to determine whether students intended to work with elderly patients. Chi-square tests (p less than .05) determined significant relationships between the participants' intentions to work with elderly people and their answers to 10 of the questions (1 biographical, 3 experiential, and 6 attitudinal). The answers to 1 of these experiential questions and 4 of these attitudinal questions were significant at the .001 level. No perceived socioeconomic questions were significant. Our results may help in planning strategies to encourage physical therapy students to work with elderly people.

Aged↗

Efficacy of gamma-linolenic acid in the treatment of patients with atopic dermatitis.

Of 60 patients with atopic dermatitis (30 males and 30 females, 15-30 years old) 30 were treated with gamma-linolenic acid of (C18:3 n-6) at a dosage of 274 mg twice a day; the other 30 patients were given placebo. The patients were treated for 12 weeks, during which their symptoms were assessed on a linear scale both by a dermatologist and by themselves every 4 weeks. The patients who received gamma-linolenic acid, showed gradual improvements in pruritus, erythema, vesiculation and oozing, which were statistically significant compared with the control group (P < 0.001). Only one patient had presented with scaling at the beginning of the study and this symptom appeared to be less influenced by the effects of gamma-linolenic acid. The assessments of symptoms made by the dermatologist were generally consistent with those made by the patients themselves. gamma-linolenic acid was found to be effective and without side-effects for the treatment of atopic dermatitis.

Adolescent↗

[Immuno-histopathologic changes in the gastrointestinal mucosa in patients with nickel contact allergy].

The study concerns the histological and immunohistochemical findings of the gastrointestinal mucosa of 20 patients (group A) suffering from contact allergic dermatitis (CAD) to Ni, with symptom recrudescence due to food ingested Ni. Results were compared with those observed in 20 patients suffering from CAD to Ni (group B), without sensitivity to food ingested Ni, and in 20 normal subjects (controls). The sensitivity to food ingested Ni, as suggested by history, was demonstrated by placebo-controlled oral-Ni challenge. The biopsies for histological and immunohistochemical study were performed during endoscopy and obtained from the antrum and from the duodenal mucosa. In the biopsies obtained from 16 of group A patients there was evidence of inflammatory infiltrate of lymphocytes and plasma cells with oedema and vasodilation in the lamina propria. Slight flattening of the villi and enlongation of the crypts were concomitant. These findings were light in the 4 patients of group A and in 11 of group B and instead were absent in the remaining group B patients and in the controls. Immunohistochemically, lymphocytes in the lamina propria were prevalently CD20 + (B cells) and CD4 + (Th cells), some were CD45RO + (memory) and finally few CD8 + (Tc/s cells). CD45RO + cells was found in cluster in patients of group A and in 4 of group B, whereas in the others were isolated. Since some studies have shown that immunological pattern of skin reaction to Ni is characterized by increased CD45RO + cells, it may be hypothesized that in patients suffering from CAD to Ni, the sensitivity to food-ingested Ni may be induced by a type IV immunological reaction in the gut.

Adolescent↗

[Allergic contact dermatitis to nickel: modification of receptor expression on peripheral lymphocytes of women after oral provocation tests (preliminary data)].

Blood lymphocyte subset evaluation was performed before after oral challenge with 10 mg of Ni, in 9 healthy women and in 15 allergic to Ni. Following challenge, 7 allergic showed a flare up of eczema and/or urticaria. In the controls, CD4+ lymphocytes were modified 24 hours after Ni challenge: CD4+/CD44RO- "virgin" cells were reduced while CD4+/CD45RO+ "memory" cells increased. The allergic women, not sensitive to oral Ni, showed an increase of B lymphocytes after the test. On the contrary, the oral Ni reacting patients presented a reduction of monocytes 4 hours after Ni ingestion and marked reduction (ranging from 20 to 50%) of T and B lymphocytes after 24 hours. These significant T and B lymphocytes changes suggest a migration of the cells in peripheral tissues, likely skin and GUT mucosa.

Administration, Oral↗