摘要:

Transforming growth factor α (TGFα) is a keratinocyte-growth-stimulating factor which may have a role in epidermal hyperproliferation, psoriasis, and wound healing. Since increased epidermal proliferation occurs in response to UV radiation, we have measured the amount of TGFα in exudates from normal and UVB-irradiated human skin. Cutaneous exudates were obtained using the skin chamber abrasion technique from one side of the back of volunteers (n = 10) with normal skin (collected following skin contact times of 2 and 30 min). Exudates were similarly obtained from the contralateral side of the back at sites irradiated 2 h previously with 3 × the minimum erythemal dose UVB. Levels of TGFα were measured by radioimmunoassay. Normal human skin released TGFα immediately after abrasion: unirradiated, 63 ± 18 ng/ml; irradiated, 89 ± 15 ng/ml. Levels of TGFα increased within 30 min to 110 ± 14 ng/ml in unirradiated skin and to 190 ± 17 ng/ml in irradiated skin. Irradiated sites at 30-min time points were significantly higher (p < 0.05) than all other samples. The presence of releasable TGFα in normal skin suggests a role for TGFα in wound repair mechanisms.

ISSN:0302-3427    

DOI:10.1159/000210925

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

The rhino mouse has been used as an experimental model to screen topically active comedolytic agents. Adult rhino mice were treated on the back once daily for 5 consecutive days per week during 3 weeks. Skin histological preparations were analyzed by image analysis techniques to quantify the number of epidermal comedones, comedo profile and epidermal thickness. Using both a negative (treated with acetone) and a positive (treated with Aberel® gel 0.025%) control group of animals in all experiments conducted over a period of about 3 years, we defined the upper and lower limit of acceptability of the results. Topical treatment with an acetone solution of all-trans retinoic acid (0.01, 0.03, 0.1 %) and 13-cis-retinoic acid (0.1 %) induced comedolysis and a marked increase in epidermal thickness. Commercial preparations of all-trans retinoic acid (Aberel® lotion, gel and cream, Retin A® cream, Retacnyl cream) presented a similar comedolytic activity. However, the epidermal thickening was higher with Retin A and weaker with Retacnyl. CD271, a new modulator of cell differentiation, applied either in acetone solution (0.01, 0.1 %) or in lotion, gel or cream formulations (0.1 %) also demonstrated a marked activity (i.e. comedolysis and epidermal thickening). These data confirm that the rhino mouse model can be used to assay drugs applied either in solvent or in topical formulations. Activity in this model compares favorably with published clinical observations in the treatment of acne.

ISSN:0302-3427    

DOI:10.1159/000210926

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

Human sebocytes obtained as explants after in vitro culture of isolated sebaceous glands were recently shown to maintain in part a sebocytic differentiation. The aim of this study was to further identify markers of sebocytic differentiation in vitro. Therefore, the morphology of cultured human sebocytes, and their differentiation with lipid storing and expression of cellular proteins were investigated by microscopy, electron microscopy, study of cell kinetics, cytochemistry and immunocytochemistry, and were compared to cultured human keratinocytes obtained from the same skin specimens. At first, sebocytes in all stages of sebocytic differentiation were detected in vitro. Abundant cytoplasmic lipids and the absence of desmosomes were identified as their ultrastructural characteristics. Secondly, an increasing number of sebocytes storing lipids was detected during cell proliferation. Sebocytes contained up to 4 times more lipids than keratinocytes in vitro. Squalene and increased quantities of wax/sterol esters could be extracted from secondary sebocyte cultures. Thirdly, the monoclonal antibodies 6B10 (keratin 4), RPN1162 (keratin 7), and OM-1 labeled only sebocytes in vitro. Furthermore, sebocytes presented a marked expression of keratin 19 in comparison to keratinocytes, as detected with CK 4.62, and a lack of RPN1161 (keratins 1 and 2) expression, which was typically found to be expressed in cultured keratinocytes. The culture of human sebocytes possessing several characteristics of sebocytic differentiation in vivo offers unique possibilities in investigating direct effects on sebaceous cell growth, differentiation and their regulation.

ISSN:0302-3427    

DOI:10.1159/000210927

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

Modifications of transepidermal water loss (TEWL) of rat and human skin induced by oral administration of ciclosporin (CS) were investigated. The integrity of the cutaneous barrier was evaluated using TEWL measurement which is a relatively simple and noninvasive means of assessing the functional state of the cutaneous barrier. After 12 weeks, the TEWL of treated rats decreased significantly and this difference was still present after the 16 weeks of treatment. In humans, there was a statistically significant decrease of TEWL on both forearm and thigh in CS-treated patients compared to non-CS-treated patients and controls (p < 0.05). These results suggest that CS causes skin modifications, particularly concerning its barrier status. The nature of these skin modifications still remains to be determined.

ISSN:0302-3427    

DOI:10.1159/000210928

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

This report presents original methods to assess the bioavailability of an antifungal drug from a varnish preparation in finger nails. For the studies with human volunteers a ciclopirox 8 % nail lacquer was used to determine its efficacy in the treatment of onychomycoses. In vivo studies were performed on the fingernails of healthy volunteers by determining the total amount of ciclopirox penetrated per milligram of nail and the partition of the drug in the plate of the nails (technically divided into four layers). Ciclopirox concentrations were evaluated by measuring the inhibition of Candida pseudotropicalis growth in vitro. The ciclopirox concentration after 30 days treatment was determined as 3.35 ± 0.82 μg/mg nail material. This is a sufficient amount to kill the fungal pathogens. In addition, in vitro penetration experiments were carried out with excised pig skin. Lacquer formulations from 0.5 to 8 % were used to inhibit the growth of Trichophyton mentagrophytes. Formulations from 2 to 8% led to a strong to total inhibition of the dermatophyte after 30 min treatment time.

ISSN:0302-3427    

DOI:10.1159/000210929

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

Studies were conducted to assess the penetration of 1 % ciclopiroxolamine cream, establishing the concentrations of the antimycotic compound in different layers of the stratum corneum with two skin models. Results of in vitro studies using skin from domestic pigs indicate that ciclopiroxolamine has the ability to penetrate fast into the epidermis, by inhibiting and killing inoculated Trichophyton mentagrophytes. In vivo investigation of the stratum corneum has been performed in healthy human volunteers by 20 strippings collected in four layers. Fungicidal concentrations of ciclopiroxolamine were determined after extraction from the strippings. These studies demonstrate that the concentrations reached levels which are sufficient to inhibit and kill pathogenic fungi.

ISSN:0302-3427    

DOI:10.1159/000210930

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

Citropten (5,7-dimethoxycoumarin) and bergapten (5-methoxypsoralen) are present in bergamot oil which is used as a cosmetic tanning product. The aim of this study was to quantify, using HPLC, the amount of citropten and bergapten in the skin after the application of suntan products (emulsion and oil formulations). A suction blister technique, performed on the volar aspect of the forearm, permitted the collection of these two molecules. The blister fluid concentrations were 37 and 51 ng/ml (emulsion) and 26 and 23 ng/ml (oil), respectively, for citropten and bergapten. Our results show that the suction blister technique could be used for comparing transepidermal penetration of several compounds in vivo in man.

ISSN:0302-3427    

DOI:10.1159/000210931

出版商:S. Karger AG    

年代:1991

数据来源: Karger

ISSN:0302-3427    

DOI:10.1159/000210932

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

Double-blind, placebo-controlled studies were performed to assess the effect of 0.1 % dimetindene gel on the itch threshold to intracutaneous histamine and on the weal and flare reaction after intracutaneous injection of histamine in normal volunteer subjects. Treatment of the forearm skin in 20 volunteers resulted in an increase in itch threshold with dimetindene gel compared to placebo. Treatment of the forearm skin with dimetindene gel in 32 volunteers had no significant effect on weal thickness in subjects treated for 10, 30 or 60 min, but there was a significant reduction in weal thickness in those subjects treated for 120 min. Topical dimetindene may be of value in treating conditions mediated through histamine release.

ISSN:0302-3427    

DOI:10.1159/000210933

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

A computer-driven device is described which moves the probes of a laser Doppler flowmeter linearly back and forth over the skin and stops precisely at preselected points to measure capillary perfusion. It offers extended possibilities to record the spatiotemporal flux changes in response to a local stimulus (e.g. injection of a vasoactive substance).

ISSN:0302-3427    

DOI:10.1159/000210934

出版商:S. Karger AG    

年代:1991

数据来源: Karger