ISSN:0302-3427    

DOI:10.1159/000211091

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

A new echographic evaluation method employing a B scanner and a dedicated software (Dermavision 2D, Cortex Technology, Hadsund, Denmark) was used in assessing the potency of three different corticosteroids. Experimental lesions were induced by patch tests with nickel sulfate 5 % in petrolatum in 10 sensitized subjects and treated with two medications of different steroids (clobetasol propionate, fiuocinolone acetonide or clobe-tasone butyrate) performed 16 and 40 h after the application of the nickel patch tests. Clinical and echographic evaluations were carried out at the beginning of the experiment and 64 h after the induction of the reactions. After obtaining echographic images, these were processed by software, enabling the selection of amplitudes of interest, the highlighting of parts of images and their assessment by a value corresponding to the number of pixels (picture elements). For evaluations a low reflecting band was chosen, marking edema and inflammatory infiltration. At positive patch test sites we observed a progressive increase in the number of low reflecting pixels, in accordance with the intensity of the reaction. Therapeutic response was assessed as the difference between values of treated and untreated test sites. The rank order of the efficacy of test substances as determined echographically was identical to the rank order generally accepted for these steroids. This evaluation method of topical corticosteroid activity could be usefully employed besides traditional evaluation methods.

ISSN:0302-3427    

DOI:10.1159/000211092

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Male Sprague-Dawley rats were treated 10 times either with 2 or 10 mg/kg s.c. prednisolone acetate or with 300 or 1,000 mg/kg p.o. D-penicillamine or with 100 or 300 mg/kg p.o. aminoacetonitrile bisulfate. Samples of dorsal skin were tested either longitudinally or perpendicularly to the body axis. Relaxation and hysteresis experiments were performed at different degrees of elongation. Finally, ultimate values were measured. In all groups, ultimate strain was much higher perpendicularly than longitudinally to the body axis. A dose-dependent increase of all parameters indicating strength or elasticity was found after prednisolone acetate treatment, whereas the indicators of viscosity showed a decrease. D-Peni-cillamine treatment decreased all parameters of strength and elasticity and increased viscosity and plasticity. Aminoacetonitrile bisulfate induced biphasic changes: after high-dose treatments strength and elasticity were increased and viscosity decreased. The results are discussed in view of changes of biochemical composition and cross-linking of collagen.

ISSN:0302-3427    

DOI:10.1159/000211093

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The mechanical behavior of rat skin during repeated strain in vivo and the restoration process thereafter were studied following 10 days’ treatment with desmotropic drugs (300 mg/kg p.o. D-penicillamine or 10 mg/kg s.c. prednisolone acetate). Repeated (30 times) elongations of up to 40% were performed under anesthesia both longitudinally and perpendicularly to the body axis. Evaluation of this first run of 30 cycles showed stress values as well as the moduli of elasticity to be decreased after D-penicillamine, whereas they were greatly increased after prednisolone acetate treatment. The decay of stress values during repeated strain revealed similar effects of treatment. In the second part of the experiment, the restoration process was evaluated by a second run of 30 cycles after 1, 6 and 16 h. In the late phases of recovery, an even better restitu-tio ad integrum was found in treated animals. Overall, in contrast to other biomechanical parameters, the restoration process is barely influenced by treatment with desmotropic compounds.

ISSN:0302-3427    

DOI:10.1159/000211094

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The effects of topically applied sodium lauryl sulfate were studied in vivo, in man, through noninvasive methods and compared with those obtained in vitro, using human stratum corneum as a model. The results show that the very marked increase of transepidermal water loss obtained in vivo cannot be related to any removal of epidermal lipids. The most likely explanation of our findings lies in the hyperhydration of stratum corneum consecutive to the inflammation process and a possible disorganization of the lipid bilayers.

ISSN:0302-3427    

DOI:10.1159/000211095

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The effect of various fatty acids or alcohols on the penetration rates and skin concentrations of cyclosporin A (Sandimmune; CyA) was evaluated in an in vitro model using skin of hairless rats. The influence of chain length, number and position of double bonds and branching of the carbon chain of the enhancer were investigated. In addition the penetration dependency of CyA on the concentration of both enhancer and CyA was studied. CyA was quantitated by high-performance liquid chromatography. The penetration rates of CyA through rat skin decreased with increasing number of double bonds of the enhancer and decreasing CyA concentrations in the donor solution, and increased with increasing chain length of the enhancer. Enhancers increase penetration rates by a factor of up to 20–90 in alcoholic vs. maximally 5-fold in oily compositions. Enhancers increase skin concentrations of CyA by a factor of up to 10–25 in alcoholic and about 4–20 in oily compositions.

ISSN:0302-3427    

DOI:10.1159/000211096

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

It has been demonstrated by various workers in the past that glucocorticosteroids block hair growth. Using the mouse model for studying hair growth induction we reexamined the effect of topically applied steroids on hair growth to establish at what stage the steroid block acts. In accord with studies by others, we found that these steroids block hair growth at the point of anagen initiation, but that once the steroid applications are stopped, hair growth starts. Since steroid withdrawal alone did not induce hair growth, it is clear that these steroids do not block, either spontaneous or manipulated, hair growth induction, but they do block, the apparent next step, i.e., hair formation. Moreover, since hair growth could be induced even while the animals were being treated with the steroid, the induction step appears independent of the steroid block-These studies and those of others lead us to conclude that these steroids block the expression of hair-forming genes, but do not interfere with the signal(s) that initiates those genes. This system appears to be ideal for identifying the signals (perhaps, genes) responsible for initiating hair growth.

ISSN:0302-3427    

DOI:10.1159/000211097

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Testing of pharmacological agents that affect growth of epidermal keratinocytes (EK) requires a standardized assay. We have developed an assay measuring net effects of stimulatory (e.g. growth factors), inhibitory (e.g. methotrexate) or toxic (e.g. Triton X-100) compounds. The amount of crystal violet staining viable EK attached to the wells of standard 96-well microplates is measured in situ using an ELISA plate reader. Optical density readings are directly converted into cell counts by computer software. Counts obtained by this method strongly correlate with the results obtained using the [3H]thymidine uptake assay and direct cell counts. The assay standardizes measurements of nonimmortalized EK lines with different innate proliferative properties and allows accurate quantitation of EK numbers in the range of 2,500–500,000 EK/well.

ISSN:0302-3427    

DOI:10.1159/000211098

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The lipoxygenase inhibitor 2-phenylmethyl-1 -naphthol (DuP 654) has been shown to be an active anti-inflammatory drug in a murine skin inflammation model. Since 12-HETE is as-sumed to have a pathophysiological role in inflammatory skin diseases, and epidermal cells possess high affinity binding sites for 12(S)-HETE, we studied the effect of DuP 654 on 12(S)-HETE binding to the human epidermal cell line SCL-II. DuP 654 antagonized 12(S)-HETE binding in a dose-dependent manner with a Ki of 3.41 ± 0.23 nM. The antagonistic effect was reversible. After 1- and 24-hour preincubation, the drug had no more significant inhibitory effect at concentrations between 10-10 and 10-5M on specific 12(S)-HETE binding (Bmax of 215,000 ± 21,000 receptors per cell) or on receptor affinity (Kd of 3.25 ± 0.42 nM). Our results show that DuP 654, in addition to its 5-lipoxygenase inhibitory activity, exhibits 12-HETE receptor antagonist effect, and therefore may be of benefit in skin diseases with elevated 12-HETE leve

ISSN:0302-3427    

DOI:10.1159/000211099

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Spectroscopic techniques are reported on which allow to study in vivo the penetration behaviour of topically applied light-absorbing drugs into human skin. Remittance specroscopy, a purely optical method, provides a good tool in both, skin adaptation by use of a remote viewing head coupled to the spectrometer via optical fibres, and adequate sensitivity for the detection of small amounts of the applied drugs. The measuring depth in the skin is determined by the wavelength-dependent optical penetration depth, which itself depends on light absorption and light scattering. In the UV-spectral region the optical penetration depth is of the order of the thickness of the stratum corneum (UV-A) or of only a superficial part of it (UV-B, UV-C). Fluorescence spectroscopy, another optical method, offers two kinds of drug detection, a direct one in case of self-fluorescent drugs or an indirect one being based on the light absorption of the drug, which may give rise to a screening of the self-fluorescence of the skin itself or of an applied marker. The measuring depth is comparable to that achieved with remittance spectroscopy. A third method is photothermal spectroscopy which is determined by thermal properties of the skin in addition to optical properties. Photothermal spectroscopy is unique in that it allows depth profiles of drug concentration to be measured non-invasively, as the photothermal measuring depth can be changed by varying the modulation frequency of the intensity-modulated incident light. Results of measurements demonstrating the potentials of these spectroscopic methods are presented.

ISSN:0302-3427    

DOI:10.1159/000211100

出版商:S. Karger AG    

年代:1993

数据来源: Karger