Search PubMed⌕ Search

Biomedical subjects

E Berardesca

Publications and source records attributed to E Berardesca.

At least 37 records · Page 2Linked to original sources
PubMed1996

Racial differences in skin pathophysiology.

Racial differences in skin function occur and may be responsible for differences in skin reactivity in physiologic and pathologic conditions. This article reviews the main racial anatomic and physiologic differences as well as mechanisms of irritation, sensitization, and drug absorption reported in the recent literature. Racial differences in transcutaneous penetration of chemicals and drug absorption have been described. Decreased transcutaneous penetration has been reported in black persons. In contrast, conflicting findings have been reported concerning some aspects of irritation and sensitization. Decreased erythematous reactions have been found in pigmented skin, whereas white persons have a stronger resistance to water barrier damage. Regional variation in skin function is more evident in fair skin because of the modifying effects of long-term UV exposure.

Asian People↗
PubMed1996

Effects of systemic treatment with statins on skin barrier function and stratum corneum water-holding capacity.

BACKGROUND: Topical application of inhibitors of HMGCoA reductase, the rate-limiting enzyme of cholesterol synthesis, has been shown to induce impairment of barrier function. OBJECTIVE: Assessing whether oral administration of statins used for reducing blood levels of cholesterol induces functional changes in stratum corneum barrier. MATERIALS AND METHODS: 69 subjects of both sexes under-going treatment for hypercholesterolemia (mean age 48 +/- 11 years) entered the study; 43 had been treated with simvastatin and 11 with pravastatin for 6 months; 15 only on dietary regimen served as controls. Efficiency of stratum corneum water barrier was evaluated by transepidermal water loss (TEWL) measurement using an evaporimeter; water-holding capacity of the stratum corneum was assessed by the sorption-desorption test measured by capacitance. Statistical analysis was performed using ANOVA. RESULTS: No differences were found between the groups (simvastatin, pravastatin, diet) concerning both basal TEWL and the dynamic of water binding in the stratum corneum. CONCLUSIONS: Prolonged treatment with cholesterol-lowering drugs based on inhibition of HMGCoA reductase does not alter the permeability barrier of the skin.

Administration, Oral↗
PubMed1995

Effects of water temperature on surfactant-induced skin irritation.

Surfactant-induced irritant reactions may be elicited by several endogenous and exogenous factors. Among these, surfactant concentration, and duration and frequency of exposure play important rôles. The study focuses on the influence of water temperature in determining damage of the skin barrier. 10 subjects of both sexes entered the study. 4 areas (4 x 4 cm2) were randomly selected on the volar forearm and were treated with a daily open application of 5% sodium lauryl sulphate for 4 days. The solutions were at 3 temperatures: 4 degrees, 20 degrees and 40 degrees C. One site served as untreated control. On the 5th day, skin irritation was evaluated using transepidermal water loss (TEWL) measurements, erythema (a* value), skin reflectance (L* value), hydration (capacitance) and desquamation (stripping). The results show a significant effect of the solution's temperature in determining skin irritation (P < 0.001). Skin damage was higher in sites treated with warmer temperatures and a highly significant correlation (P < 0.001) between irritation and temperature was found. In conclusion, the study shows that water temperature during washing has an important effect on the onset of irritant contact dermatitis.

Adult↗
PubMed1994

The modulation of skin irritation.

Irritant contact dermatitis (ICD) is a multifactorial disease, the onset and modulation of which depend on both endogenous and exogenous factors. Among the former, age, race, site, sex and history of dermatitis may all be important. Such variables can now readily be quantified by objective noninvasive techniques, such as measurement of transepidermal water loss (TEWL). Moreover, effects of irritants on the epidermis are related to the particular chemical properties of each molecule, contributing further to clinical heterogeneity. Release of cytokines and mediators may be initiated by a number of cells, including living keratinocytes and those of the stratum corneum, thus modulating inflammation and repair. Furthermore, differences in mechanisms of inflammation between acute and chronic ICD may exist, the former being characterized predominantly by inflammation, the latter by hyperproliferation and transient hyperkeratosis. These findings may explain the complexity and difficulty of investigating ICD. Better understanding and quantification of these mechanisms may lead to identification of high-risk individuals and more effective prevention and treatment.

Acute Disease↗
PubMed1994

Effects of fluid volume changes during hemodialysis on the biophysical parameters of the skin.

Water plays an important role in maintaining skin suppleness and elasticity. We used hemodialysis as a model to investigate the effects on biophysical properties of the skin induced by removal of fluids and water from the body. The following parameters have been investigated before and immediately after a hemodialysis session: body weight, skin elasticity and distensibility, skin hydration, transepidermal water loss (TEWL) and skin thickness. A significant decrease was recorded after treatment in body weight, skin thickness (p < 0.01) and skin elasticity (p < 0.01). Significant linear correlations were found between stratum corneum water content, skin distensibility and TEWL. The data reveal that rapid removal of body fluids influences skin biophysical properties: early changes in skin thickness and ground substance occur in the dermis and affect mechanical properties of the skin. The decrease in water content in the upper layers of the skin occurs at a later stage and influences skin hydration rather than TEWL. This model is a useful tool to investigate water kinetics through the skin.

Biophysical Phenomena↗
PubMed1994

Non-invasive evaluation of topical calcipotriol versus clobetasol in the treatment of psoriasis.

Topical treatment of psoriasis with calcipotriol has been proven effective. The efficacy of calcipotriol has been compared to that of topical corticoids in a number of studies using subjective visual scoring systems such as the PASI index. The purpose of this study was to compare, with objective data, the efficacy of calcipotriol and clobetasol propionate 0.05% in the treatment of plaque type psoriasis. Transepidermal water loss (TEWL) and laser Doppler velocimetry (LDV) were used to monitor restoration of water barrier and normalization of blood flow, respectively, in psoriatic plaques of the limbs of 24 male patients during 3 weeks of treatment. Data were compared to subjective evaluation using the PASI index of the same areas. Significant differences were recorded during treatment in both groups. The results correlated well with the PASI score. Clobetasol was faster in restoring barrier function than calcipotriol. However, no significant differences were detected between the two groups. The use of vitamin analogues may be effective in the topical treatment of psoriasis by normalizing skin biophysical parameters and minimizing the risks of side-effects induced by potent topical corticoids.

Administration, Topical↗
PubMed1994

Noninvasive measurement of the effect of lifetime exposure to the sun on the aged skin.

The cumulative and comparative effects of chronological and actinic changes to the skin were studied in an elderly population. Two adjacent sites with different degrees of exposure to the sun were examined to distinguish the contribution of each factor, by means of noninvasive measurements. The following parameters were measured on the skin of the low neck (an exposed site), as well as on the adjacent clothes-protected skin of 30 elderly women: electrical conductance, color, microrelief, biomechanical properties and the thickness of both the full skin and the subepidermal nonechogenic band (SENEB), using ultrasound measurements. Persistent exposure to the sun accentuated most of the age-induced modifications. The following changes were significantly more marked in exposed skin: SENEB thickening, full-skin thinning, loss of extensibility and elasticity, and color heterogeneity. The cumulative effects of sun exposure and chronological aging lead to atrophy in elderly people. These results suggest that, if there is an autoprotective skin reaction, such as thickening in young adults, it is eliminated in old people.

Aged↗
PubMed1994

PUVA-treated psoriatic skin as a model for cutaneous wrinkling assessed by skin replicas.

Psoriatic patients may offer a useful model for PUVA-induced skin wrinkling. This study deals with the changes induced by PUVA therapy on the cutaneous microrelief of psoriatic patients assessed by surface replicas. A non-exposed body area (buttocks) was considered. The microrelief was evaluated by means of replicas analysed by an automatic image analyser. Three groups of patients were considered: 1) 10 psoriatic patients who had been undergoing PUVA treatment for the first time and who had received a total PUVA dose of 200 +/- 20 J/cm2; 2) 16 psoriatic patients in long-term PUVA treatment (> 1000 J/cm2); 3) 13 psoriatic controls whose buttocks had never been affected by psoriasis nor exposed to sunlight or PUVA. The results showed that the number and the entity of the cutaneous crests and furrows had been increased by PUVA therapy. In particular the skin pattern analysis showed significant statistical differences between the second and the third group, while no changes were evident between the first and third group (ANOVA and Tukey test for multiple comparisons). In conclusion, our findings indicate that long-term PUVA therapy causes marked changes in the cutaneous microrelief, that this phenomenon can be measured non-invasively and that the changes observed are dependent on the PUVA-dose energies received.

Adult↗
PubMed1993

Plastic occlusion stress test as a model to investigate the effects of skin delipidization on the stratum corneum water holding capacity in vivo.

The purpose of the study was to develop an in vivo model to study the effects of lipid removal on skin barrier. 16 subjects (age 41 +/- 8) were delipidized in vivo on the volar forearm using respectively ether/acetone (EA; 1:1) and chloroform/methanol (CM; 2:1). A third site served as control. Water holding capacity (WHC) was measured according to the plastic occlusion stress test (POST) procedure: the water desorption curve after removal of the occlusion was recorded in terms of skin surface water loss (SSWL) using an evaporimeter for 30 min. In the central part of the evaporation curve (bound water) the CM-treated site is significantly different from control and EA-treated sites (p < 0.01). The SSWL decay constants reflecting the desorption rate of water from SC are higher in the CM-treated site (p < 0.01). The data are consistent with the effect of CM delipidization (polar lipids) on bound water. No differences are recorded in the evaporation of free water. We conclude that polar lipids have a key role in modulating barrier function and WHC of the stratum corneum. The POST can represent a useful in vivo model to study the effects of lipid extraction on skin function.

Administration, Cutaneous↗
PubMed1993

Transcutaneous CO2 and O2 diffusion.

Transcutaneous gas measurements offer a useful tool for non-invasive monitoring of skin function, but are affected by several variables that restrict their use in clinical and investigative dermatology. Skin thickness, stratum corneum and barrier function damage, blood vessel reactivity, arterial-gas concentration, skin and environmental temperature are important factors influencing transcutaneous gas flux. Improvement of techniques and standardization of methods with guidelines for operators should improve this interesting research approach.

Blood Gas Monitoring, Transcutaneous↗
PubMed1992

Effect of occlusive dressings on the stratum corneum water holding capacity.

Occlusion of the skin is used in clinical dermatology to promote wound healing and to increase the transcutaneous penetration of topically applied drugs. These effects are related to the degree of occlusion exerted and depend on the physicochemical nature of the dressing. We have evaluated the effects of four different materials on the skin barrier and the stratum corneum water holding capacity (WHC) using the Plastic Occlusion Stress Test (POST). The following materials were compared: hydrocolloid dressing, polyurethane film, polyethylene film, and a plastic chamber. These devices were applied on the volar forearm for 24 hours in 10 healthy volunteers (mean age 32 +/- 4 years). Upon their removal, the stratum corneum WHC, measured as skin surface water loss (SSWL), was recorded continuously for 25 minutes using an Evaporimeter. SSWL decay curves showed significant differences between the occlusive materials (analysis of variance, p less than 0.01). Higher SSWL values were recorded in sites occluded with the plastic chamber, whereas the polyurethane film resulted in poor occlusive capacity. Hydrocolloid dressing and polyethylene gave similar responses with higher WHC values compared to polyurethane (p less than 0.05). The relevance of these findings to clinical dermatology in terms of wound healing and drug absorption is discussed.

Adult↗
PubMed1992

Blood transfusions in the therapy of a case of prolidase deficiency.

A case is reported of a 15-year-old boy with prolidase deficiency and marked urinary excretion of the iminodipeptide gly-pro. Prolidase activity of erythrocytes against substrate glycyl-proline was deficient, but after blood transfusions this was increased to 15.7% of donor activity and declined to 12% and 3.4% of normal activity after 8 and 45 days, respectively. Urinary iminodipeptide levels following transfusion remained unaltered.

Adolescent↗
PubMed1992

Immune defects in families and patients with xeroderma pigmentosum and trichothiodystrophy.

Xeroderma pigmentosum (XP) is a rare autosomal recessive disease characterized by photosensitivity, a high incidence of cancer in sun-exposed portions of the skin and a reduced capacity to repair the u.v.-induced DNA damage. One of the XP mutations (XP-D) has also been identified in patients affected by trichothiodystrophy (TTD), a rare autosomal recessive disease characterized by brittle hair, mental and physical retardation, peculiar face and ichthyosis. However, in these patients there is no evidence of increased skin tumour incidence. Since an impairment of cell-mediated immunity has been proposed as a co-factor in the cancer proneness of XP patients, we investigated the involvement of immune defect(s) in five XP patients, five TTD patients, their parents, and 24 TTD relatives. We evaluated the phenotype of circulating lymphocytes, natural killer (NK) cell lytic activity, target cell binding of NK cells at single cell level and the effect of interferons (IFN) alpha and beta on NK cell activity. The relative proportion of CD3+ and CD4+ circulating lymphocytes was reduced in XP but not in TTD patients. NK cell lytic activity was decreased in XP patients and their mothers, but their fathers showed normal lytic activity. NK activity varied among TTD families: four out of five patients and their relatives presented low NK cell activity, and one family was normal. In TTD family members, NK activity increased after incubation with IFN-alpha or IFN-beta, but never reached normal values. In contrast, in XP patients and their mothers, the defect was almost completely corrected after in vitro incubation with IFN-alpha or IFN-beta. Our study indicates impaired NK lytic activity in the majority of TTD and XP patients and that this defect is present also in members of their families. In addition, XP patients present a low number of circulating T cells. These multiple abnormalities, together with DNA repair defects, could be related to the increased cancer risk in XP patients.

Abnormalities, Multiple↗
PubMed1992

Erythema induced by organic solvents: in vivo evaluation of oxygenized and deoxygenized haemoglobin by reflectance spectroscopy.

OBJECTIVE: (i) using a new non-invasive technique capable of evaluating quantitatively and qualitatively the haemoglobin content of the skin (ii) to evaluate delipidization induced by organic solvents. PATIENTS: 11 Caucasians treated for 1 min in a randomized manner on the volar forearm with a mixture of chloroform/methanol (2:1) (CM) and ether/acetone (1:1) (EA) to delipidize the skin. METHOD: erythema was evaluated by computerized remittance spectroscopy immediately after delipidization and hourly for 2 h. RESULTS: only CM application induced subjectively observed and objectively quantified erythema. Erythema was related to a significant increase in oxygenized haemoglobin content due to dilatation of arterioles in the subpapillary plexus (P less than 0.01). The increased blood flow induced a significant (P less than 0.01) reduction in de-oxygenized haemoglobin in venous vessels immediately after CM application. CONCLUSION: short contact with certain potent solvent mixtures causes erythema, possibly due to massive lipid extraction and damage of the skin barrier. Using computerized remittance spectroscopy the visible erythema was composed of an increase in oxygenized haemoglobin and a relative decrease in deoxygenized haemoglobin.

Dermatitis, Irritant↗