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Biomedical subjects

J P Césarini

Publications and source records attributed to J P Césarini.

At least 19 recordsLinked to original sources

Immediate effects of UV radiation on the skin: modification by an antioxidant complex containing carotenoids.

BACKGROUND/AIMS: The ultraviolet (UV) portion of sunlight is involved in the induction and development of skin cancers against which a limited photoprotection may be provided by reduced time of exposure, clothing, and sunscreen applications. The concept of an effective, safe, systemic photoprotection will circumvent many of the shortcomings. The UV-induced oxidative stress is a cause of DNA damage and a few publications have shown, in humans, minimal benefits, if any, of the oral intake of antioxidant complex, contrasting with the large literature showing beneficial effects in vitro or in animal models. METHODS: We investigated, in 25 healthy individuals, the capacity of an antioxidant complex (AOC) - vitamins (lycopene, beta-carotene, alpha-tocopherol), selenium - to reduce UV-induced damages. The AOC was administered orally, daily during 7 weeks. Before and after irradiations, before and after the intake of the product, six parameters were studied: skin color by chromametry, minimal erythemal dose and, on skin biopsies, sunburn cells (SBCs), p53 detected by immunohistochemistry, pigmentation index, and levels of lipoperoxides (thiobarbituric acid reaction). RESULTS: After the oral intake of AOC, we observed an elevation of the actinic erythema threshold (+20%, P=0.01) and a general reduction of the UV-induced erythemas, a reduction of the UV-induced p53 expression (P<0.05) and of SBCs (P<0.01), and a parallel reduction of the lipoperoxide levels (P<0.01). The pigmentation was increased (P<0.01). CONCLUSION: After the oral intake of an antioxidant complex, many parameters of the epidermal defense against UV-induced damages are significantly improved. The oral intake of AOC could provide a safe, daylong and efficient complement to photo-protective measures provided by topical and physical agents and may contribute to reduce the DNA damages leading to skin aging and skin cancers.

Administration, Oral↗

Sunscreen use and intentional exposure to ultraviolet A and B radiation: a double blind randomized trial using personal dosimeters.

A previous randomized trial found that sunscreen use could extend intentional sun exposure, thereby possibly increasing the risk of cutaneous melanoma. In a similarly designed trial, we examined the effect of the use of sunscreens having different sun protection factor (SPF) on actual exposure to ultraviolet B (UVB) and ultraviolet A (UVA) radiation. In June 1998, 58 European participants 18-24 years old were randomized to receive a SPF 10 or 30 sunscreens and were asked to complete daily records of their sun exposure during their summer holidays of whom 44 utilized a personal UVA and UVB dosimeter in a standard way during their sunbathing sessions. The median daily sunbathing duration was 2.4 hours in the SPF 10 group and 3.0 hours in the SPF 30 group (P = 0.054). The increase in daily sunbathing duration was paralleled by an increase in daily UVB exposure, but not by changes in UVA or UVB accumulated over all sunbathing sessions, or in daily UVA exposure. Of all participants, those who used the SPF 30 sunscreen and had no sunburn spent the highest number of hours in sunbathing activities. Differences between the two SPF groups in total number of sunbathing hours, daily sunbathing duration, and daily UVB exposure were largest among participants without sunburn during holidays. Among those with sunburn, the differences between the two groups tended to reduce. In conclusion, sunscreens used during sunbathing tended to increase the duration of exposures to doses of ultraviolet radiation below the sunburn threshold.

Adolescent↗

Should subjects who used psoralen suntan activators be screened for melanoma? Epidemiology and Prevention Subgroup, EORTC Melanoma Cooperative Group EORTC Prevention Research Division.

BACKGROUND: Psoralens are potent tanning activators that have been introduced in France and in Belgium in some tanning lotions and sunscreens. It was shown that poor tanners who ever used psoralen tanning activators display a four-fold increase in melanoma risk when compared to poor tanners using regular sunscreens. Although psoralens have now banned from suntan lotions, it is likely that the increase in melanoma risk linked to their previous use will persist for several years. METHODS: The melanoma risk attributable to psoralens use was calculated to evaluate the population at risk in France and Belgium. RESULTS: Melanoma incidence for the year 1995 was estimated to be of 10.2 per 100,000 in France and of 10.0 per 100,000 in Belgium, representing 5,900 and 1,000 melanoma cases. From the melanoma incidence among poor tanner who ever used psoralens (52 per 100,000) and estimation of the percentage of psoralen users among poor tanners, it can be derived that, for the year 1995, 267 melanoma cases could be attributed to psoralen tanning activators. CONCLUSIONS: Subjects who used psoralen suntan activators should be informed of their increased melanoma risk and be encouraged to participate in clinical programmes for early detection of melanoma, more especially when they are poor tanners and display a high naevi count. Such an action could save a significant number of lives.

Ficusin↗

Intractable infant diarrhea associated with phenotypic abnormalities and immunodeficiency.

We report on eight children with severe diarrhea beginning in the first 6 months of life (< 1 month in six cases), who had a number of features in common. All were small for gestational age and had an abnormal phenotype, including facial dysmorphism, hypertelorism, and woolly, easily removable hair with trichorhexis nodosa. Two were products of consanguineous marriages. Severe secretory diarrhea persisted despite bowel rest (n = 7). Jejunal biopsy specimens showed total or subtotal villous atrophy with crypt necrosis, and inconstant T-cell activation in some cases (n = 3). Colon biopsy specimens showed moderate nonspecific colitis. All the patients had defective antibody responses despite normal serum immunoglobulin levels, and defective antigen-specific skin tests despite positive proliferative responses in vitro. Three had monoclonal hyper-immunoglobulinemia A. The course was marked by diffuse erythroderma in two cases and mental retardation in three. Treatment included bowel rest, intravenous administration of immune globulins, administration of corticosteroids (n = 6) and cyclosporine (n = 2), and bone marrow transplantation (n = 1). Five patients died between the ages of 2 and 5 years (of sepsis or cirrhosis), two are being fed enterally, and one continues to receive total parenteral nutrition. The cause of the combined low birth weight, dysmorphism, severe diarrhea, trichorrhexis, and immunodeficiency is unclear. These features may constitute a specific syndrome within the group of intractable diarrheas of infancy.

Chronic Disease↗

Protective effect of oral selenium plus copper associated with vitamin complex on sunburn cell formation in human skin.

An organic form of selenium (plus copper) and a vitamin complex (with tocopherol and retinol) were examined for their ability to prevent sunburn cell formation in human skin exposed to ultraviolet radiation from a xenon solar simulator. After three weeks of supplementation with selenium, especially in association with vitamins, there was a relative protection (versus placebo) against ultraviolet-induced cell damage in the suberythemal range but not in the supraerythemal area. Antioxidant properties of the compounds can explain such cellular photoprotective effect. Supplementation was ineffective in preventing light-induced erythema.

Administration, Oral↗

High-protection sunscreen formulation prevents UVB-induced sunburn cell formation.

A human sunburn cell (SBC) count is used to evaluate the reduction in UV-induced skin damage achieved by a highly protective sunscreen formulation containing 3 filters and reflective pigments (sun protection factor 34). Results indicate that, for the same minimal erythema level, SBC counts do not significantly differ between protected and unprotected skin, showing that the very high efficacy demonstrated against actinic erythema also extends to UV-induced skin damage.

Adult↗

Histopathologic and electron microscopic studies of the effects of Solcoderm on normal epidermis and superficial cutaneous tumors.

Histologic and electron microscopic studies of Solcoderm-treated normal skin and human lesions were performed to help elucidate the mode of action of this new agent. Its fixative properties were readily demonstrated and generally proved to be adequate for histological diagnosis from the post-treatment scab. The degree of preservation of fine intracellular structures was particularly remarkable, since similar treatment with equivalent strengths of nitric acid alone destroys these substructures. Dermal lipids and collagen were found to be natural barriers against the penetration of Solcoderm applied to the skin surface. Mild mechanical disruption and the disturbed cellular continuity of pathologic tissue allows the solution to penetrate treated lesions more freely and enhances the likelihood of their complete destruction when an appropriate quantity of solution is properly delivered by an experienced therapist.

Acetates↗

[Establishment of a 2-stage prognostic classification of primary malignant melanoma derived from a multidimensional analysis and from an agreement study].

Slides of 198 patients with primary malignant melanoma have been reevaluated independently by three pathologists; considered parameters were histologic type, Clark's level and tumor thickness. The agreement between pathologists is excellent, especially for histologic type and thickness. The use of the Cox's regression model, dealing with disease free interval as response criterion, shows that the main prognostic factor is tumor thickness, whatever the pathologist. A prognostic staging is thus proposed, based only on the tumor thickness, less than 2 mm, greater than 2 mm. The prognostic value of this staging is confirmed on a new sample of 145 patients. This classification is used as decision tool in a new randomized clinical trial.

Clinical Trials as Topic↗

Characterization of the mononuclear cell infiltrate in human malignant melanoma.

In the skin infiltrate of superficial spreading melanoma, non phagocytosing mononuclear cells (NPMC) represent a major cell component. The number of NPMCs decreases as a function of tumour progression. In addition, when an NPMC is in contact with a malignant melanocyte, the latter cell exhibits ultrastructural degenerative changes. In the blood of healthy donors and of melanoma patients, atypical mononuclear cells (AMC) can be identified. AMCs have been shown to participate in antibody-dependent cellular cytotoxicity (ADCC) reactions against melanoma cells in vitro. In this paper, it is reported that NPMCs and AMCs have in common their size, and some ultrastructural features such as indented nuclei, dispersed organelles, rough endoplasmic reticulum profiles and surface microvilli. The two cell types are negative for non-specific esterase. They also fail to react for peroxidase at either the light or the electron microscopic level. They do not adhere to glass. AMCs do not form spontaneous E rosettes, they have no surface IgG and they have no receptors for complement. However, they do form rosettes with EAIgG. On frozen sections firm binding of EAIgG has been seen on the skin infiltrate in three cases out of 10. It is concluded that NPMCs might react with tumour cells in vivo, in the same manner as do AMCs in vitro.

Cell Membrane↗