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Biomedical subjects

J Serup

Publications and source records attributed to J Serup.

At least 37 records · Page 2Linked to original sources
PubMed1997

Characterization of irritant patch test reactions to topical D vitamins and all-trans retinoic acid in comparison with sodium lauryl sulphate. Evaluation by clinical scoring and multiparametric non-invasive measuring techniques.

The study was a single-centre, double-blind randomized, placebo-controlled within-subject comparison of 42 healthy volunteers. Occlusive patch test for 48 h was performed with solutions of 1 alpha,25(OH)2D3 (calcitriol), two vitamin D analogues (calcipotriol and KH 1060 (lexacalcitol)), all-trans retinoic acid and sodium lauryl sulphate (SLS) as reference irritant. Solution vehicles and an empty chamber was also included. Test evaluation was performed at day 2, day 3 and again on day 7. Test evaluation was based both on clinical scoring and on various non-invasive measuring methods. 1 alpha,25(OH)2D3, calcipotriol and KH 1060 all showed mild irritation in the concentrations tested. The number and severity of test reactions was found to be dose dependent based both on clinical scoring and on non-invasive measurements. Irritation of the vitamin D analogues mainly affected the vasculature with vasodilation and increased cutaneous blood flow. All-trans retinoic acid showed irritant reactions with some similarity to the tested vitamin D analogues; however, the reactions were more prolonged. Transepidermal water loss (TEWL) was affected neither after application of vitamin D analogues nor after application of all-trans retinoic acid and it was thus concluded that these substances are non-corrosive. SLS showed the known irritant mechanism with corrosion and increase in TEWL as the primary event.

Adult↗
PubMed1997

Guidelines on sodium lauryl sulfate (SLS) exposure tests. A report from the Standardization Group of the European Society of Contact Dermatitis.

This report reviews the clinical and histopathological reactions caused by sodium lauryl sulfate (SLS), and the non-invasive methods that can characterize these reactions. Furthermore, SLS exposure techniques and factors that may influence the outcome of these exposures are discussed. Finally, guidelines are introduced for each exposure technique in order to have a uniform approach to SLS testing in man. Since different study aims warrant different testing conditions, we have proposed 2 categories, namely susceptibility testing and provocative testing, tailored to the aim with which the study is performed.

Dermatitis, Contact↗
PubMed1997

Topical D-vitamins: multiparametric comparison of the irritant potential of calcipotriol, tacalcitol and calcitriol in a hairless guinea pig model.

The irritant potential of calcipotriol, 1 alpha,24-dihydroxyvitamin D3 (tacalcitol) and 1 alpha,25-dihydroxy-vitamin D3 (calcitriol) was compared in a hairless guinea pig model, Randomized, occlusive patch testing for 2 days was used. Each group of 8 animals was tested simultaneously with the 3 substances and a placebo vehicle. 3 dose levels i.e. 500 micrograms/ml, 50 micrograms/ml and 5 micrograms/ml were used. Test sites were evaluated at day 2 (2 h after removal of the patches) and again at day 3. Evaluation was blinded and based on a multiple parameter assessment of skin irritancy, comparing clinical scoring, skin perfusion using high resolution laser Doppler image scanning, skin colour (a*, Minolta ChromaMeter) and skin thickening (20 MHz ultrasound) indicating oedema. Skin biopsies were taken for histological preparation and assessment of epidermal hyperplasia. No difference was observed between the irritant potential for calcipotriol, tacalcitol and calcitriol based on clinical scoring as well as objective non-invasive measuring techniques. All 3 substances showed a dose-dependent and equal increase in clinical irritation score, cutaneous blood flow, skin colour and epidermal hyperplasia. The cutaneous inflammatory reaction was dominated by vasodilation and increased cutaneous perfusion. Oedema formation was only seen at the highest dosages tested. Skin barrier damage was not induced as TEWL remained unaffected. The hairless guinea pig appears a valid model to test irritancy of topical D-vitamins since the same profile of irritancy was previously established in humans for 2 of the compounds tested, calcitriol and calcipotriol.

Administration, Topical↗
PubMed1996

Guidelines for measurement of skin colour and erythema. A report from the Standardization Group of the European Society of Contact Dermatitis.

This report reviews individual-related variables (age, sex, race, anatomical site, skin surface properties), intra- and interindividual variation (temporal, physical and mental activity, orthostatic effect, menstrual cycle/menopause), environment-related variables (light conditions, temperature) and various instrument-related variables that influence skin colour. CIE colorimetry (Minolta Chroma Meter) and spectrophotometric measurement (Derma Spectrometer) are considered. The guidelines give recommendations for measuring conditions and procedures.

Adult↗
PubMed1996

Patch test study with calcipotriol ointment in different patient groups, including psoriatic patients with and without adverse dermatitis.

One hundred and sixty-eight individuals (psoriatic patients treated with calcipotriol with dermatitis due to calcipotriol, psoriatic patients treated with calcipotriol with no dermatitis, psoriatic patients never treated with calcipotriol, patients with eczema and healthy volunteers) were patch-tested (Finn chambers, back, 48 h) with dilutions of calcipotriol ointment (50, 10, 2, 0.4 micrograms/g) and an ointment vehicle. Test evaluation was based on clinical scoring and various non-invasive measuring methods. Doubtful (?+) and weak (1+) reactions were common, irrespective of patient group and history. Moderate (2+) reactions were uncommon and with no increased frequency among psoriatic patients with adverse dermatitis during calcipotriol treatment. The blood flow of test sites measured by laser Doppler flowmetry was, however, increased in psoriatics, who developed dermatitis during calcipotriol treatment as an isolated finding. Furthermore a 1-week repeated open application test (ROAT) was performed on all subjects. None of the persons having a strong reaction in the patch test showed any dermatitis in the ROAT test, indicating that they were not sensitized. Calcipotriol was found to be a mild irritant of the non-corrosive type, i.e. with no influence on the skin barrier. Reactions were dominated by redness (increased laser Doppler flow and chroma a*) and only oedema formation in advanced reactions. The calcipotriol dose-irritation curve was found to be scattered. Calcipotriol induced no increase of transepidermal water loss (TEWL) versus the ointment vehicle, but the ointment vehicle itself increased TEWL. The special ointment vehicle needed for calcipotriol for stability reasons may itself be irritant and cause some impairment of the skin water barrier, with increase in TEWL values. Future patch test studies for calcipotriol allergy should not be done with this vehicle. The non-irritant threshold concentration of calcipotriol in an appropriate test vehicle is still unknown.

Adult↗
PubMed1995

Stimulation of epidermal proliferation in mice with 1 alpha, 25-dihydroxyvitamin D3 and receptor-active 20-EPI analogues of 1 alpha, 25-dihydroxyvitamin D3.

The effects of 1 alpha, 25-dihydroxyvitamin D3 (1 alpha, 25-(OH)2D3) and receptor-active 20-epi vitamin D analogues (MC 1288, 20-epi-1 alpha, 25-(OH)2D3; MC 1301, 20-epi-24a-homo-26,27-dimethyl-1 alpha, 25-(OH)2D3, and KH 1060: 20-epi-22-oxa-24a-homo-26,27-dimethyl-1 alpha, 25-(OH)2D3) on epidermal proliferation in mice were studied in vivo. Single topical applications of all compounds induced epidermal proliferation in a dose-dependent manner. The relative potencies in vivo (KH 1060 > MC1301 > MC1288 > 1 alpha, 25-(OH)2D3) correlated well with the known activities of these compounds to inhibit U 937 cell proliferation in vitro. Vitamin D3 and 1 beta, 25-(OH)2D3, two compounds that do not bind the vitamin D receptor, did not affect epidermal proliferation. Our study shows that vitamin D3 compounds that bind to the vitamin D receptor stimulate epidermal proliferation in mice.

Administration, Cutaneous↗
PubMed1995

The effects of KH 1060, a potent 20-epi analogue of the vitamin D3 hormone, on hairless mouse skin in vivo.

Dermal effects of KH 1060, a novel, highly potent 20-epi analogue of 1 alpha,25-dihyroxyvitamin D3, were investigated in a hairless mouse model. During daily topical applications of a 0.4 microM solution of KH 1060 for 4 weeks, epidermal hyperplasia and an increase of dermal thickness and mass were observed. KH 1060 upregulated glycosaminoglycan and collagen synthesis in the skin, and increased glycosaminoglycan deposition in the subepidermal region. Reverse transcription-polymerase chain reaction amplification of the transforming growth factor (TGF) beta 1-specific mRNA revealed that KH 1060 stimulated expression of this growth factor in the epidermis, but not in the dermis. Changes observed after application of 1 alpha,25-dihydroxyvitamin D3 were much less pronounced but qualitatively similar to the effects of KH 1060, whereas structurally related but receptor inactive compounds, vitamin D3 and 1 beta,25-dihydroxyvitamin D3, did not produce any effects. Furthermore, we were unable to demonstrate the involvement of the non-genomic, receptor-independent vitamin D signalling in the skin, using a specific stimulator (Ro 24-2090) and a blocker (1 beta,25-dihydroxyvitamin D3) of this pathway. Our findings provide the first evidence that a strong vitamin D3 analogue triggers synthesis of skin connective tissue, possibly via vitamin D receptor activation and the paracrine action of epidermis-derived TGF-beta 1.

Animals↗
PubMed1995

Ultrastructure of murine epidermis treated with the vitamin D3 analogue KH-1060.

A new highly potent analogue (KH-1060) of vitamin D3 has been recently shown to stimulate the growth and differentiation of keratinocytes. This study was intended to determine the effects of this new analogue on epidermis at the ultrastructural level. KH-1060 was applied topically on the backs of hairless mice for 4 weeks; the skin was then studied by routine electron microscopy. The effects were compared with those of betamethasone-17-valerate and with concomitant treatment of KH-1060 following betamethasone. KH-1060 stimulated normal function of keratinocytes and formed a thick epidermis. The ultrastructure of the thick epidermis represents an enhanced normal process of keratinization and proliferation. Moreover, KH-1060 diminished the atrophogenic effects of betamethasone.

Administration, Cutaneous↗
PubMed1994

Ultrasound structure and digital image analysis of the subepidermal low echogenic band in aged human skin: diurnal changes and interindividual variability.

Subepidermal low-echogenic band is a consistent echostructural finding in aged and photodamaged skin. The thickness of subepidermal low-echogenic band is considered to closely reflect the degree of cutaneous aging and its use for the monitoring of the severity of photoaging and the efficacy of drugs is rapidly expanding. We investigated subepidermal low-echogenic band structure in 23 old healthy volunteers (ages 75-100) with a high-frequency ultrasound scanner (B-mode, 20 MHz). Images were collected from the volar fore-arm twice daily: in the morning before getting up and 12 h later. To assess the severity of subepidermal low-echogenic band, echogenicity of the subepidermal region was determined by the image analysis and compared with visual scoring and subepidermal low-echogenic band thickness. All three methods gave consistent results, image analysis being the most sensitive, reliable, and bias-free. Significant interindividual variability of subepidermal low-echogenic band echostructure was revealed. Moreover, circadian variability of subepidermal low-echogenic band echogenicity was observed. These major interindividual and diurnal variations of subepidermal low-echogenic band suggest that this band does not only represent an irreversible structural change but also a redistribution of fluid in the aged dermis. Diurnal variations in the subepidermal low-echogenic band would limit the use of this parameter in studies of skin aging, photoaging, and efficiency of medication.

Aged↗
PubMed1994

Age-related diurnal changes of dermal oedema: evaluation by high-frequency ultrasound.

Using high-frequency ultrasound, we measured the influence of gravitational stress on skin echogenicity in 22 young (age range 17-27; median 19) and 22 elderly (age range 75-100; median 87) healthy adults. B-mode ultrasound images were obtained from the medial malleolus, lateral calf, anterior thigh, volar forearm and the medial aspect of the arm three times daily: in the morning, immediately before rising, and 2 and 12 h later. The echogenicity was measured by counting the number of low echogenic pixels in the image. Pronounced changes of low echogenic pixel numbers were seen in the areas exposed to high gravitational stress, i.e. the ankle and calf. In the young age-group echogenicity of the skin increased steadily during the day, whereas in the elderly population echogenicity decreased 2 h after getting up in the morning, and subsequently returned to the baseline level. In a control group of 10 people (aged 17-83; median 18), who remained in the supine position throughout the day, the echogenicity of the skin remained unchanged. As the echogenicity of the dermis is inversely related to the amount of fluid it contains, our results indicate that young skin responds to gravitational stress by fluid depletion. In the skin of the elderly, the mechanism of fluid removal appears to be defective. The impaired protection against the development of intradermal oedema in the elderly may predispose to the development of lipodermatosclerosis and leg ulceration.

Adolescent↗
PubMed1994

Inhibition of glucocorticoid-induced epidermal and dermal atrophy with KH 1060--a potent 20-epi analogue of 1,25-dihydroxyvitamin D3.

1. The possibility of preventing and treating glucocorticoid-induced skin atrophy with KH 1060 (the potent 20-epi-22-oxa-24a-homo-26,27-dimethyl analogue of 1,25-dihydroxyvitamin D3) was examined in a hairless mouse model. 2. KH 1060 (0.625-6.25 pmol cm-2 of skin) applied topically for 7 days together with 2.5 nmol cm-2 betamethasone-17-valerate prevented, in a concentration-dependent manner, the development of epidermal, dermal and total skin thinning caused by the glucocorticoid. The effect of KH 1060 on the epidermis occurred at a lower dose than on the dermis, and at doses above 1.25 pmol cm-2 KH 1060 caused epidermal hyperplasia. 3. KH 1060 (2.5 pmol cm-2) prevented the development of betamethasone-associated skin atrophy in mice during a long-term (4 weeks) treatment, and reversed established cutaneous glucocorticoid atrophy. 4. Radiolabelling experiments with [35S]-sulphate and [3H]-proline in vivo revealed that KH 1060 stimulated the synthesis of sulphated glycosaminoglycans and hydroxyproline in skin treated with betamethasone. 5. These findings strongly suggest that KH 1060 prevents and reverses glucocorticoid-induced skin atrophy by stimulating epidermal proliferation and enhancing synthesis of extracellular matrix in the dermis.

Animals↗
PubMed1994

Guidelines for measurement of cutaneous blood flow by laser Doppler flowmetry. A report from the Standardization Group of the European Society of Contact Dermatitis.

The report reviews individual-related variables (age, sex, race, anatomical site), intra- and inter-individual variation (temporal, physical and mental activity, food and drugs), and environment-related variables (air convection, temperature). Technical variation, instrument validation including a standard reactive hyperemia experiment, and a standard operating procedure are discussed and included in the guidelines.

Adolescent↗
PubMed1994

Measurement of color parameters of psoriatic plaques by narrow-band reflectance spectrophotometry and tristimulus colorimetry.

Color parameters were measured on 50 psoriatic plaques in 10 patients, after scoring the amount of scales on them by inspection, with a narrow-band reflectance spectrophotometer (erythema/melanin index expression) and tristimulus colorimeter (CIE L*a*b* expression). Both erythema index a* (redness) were highest in the group of erythematous plaque with little scale (twice as high as in controls) and decreased significantly as the plaques were covered with thicker scale, while L* (brightness) changed in just the opposite fashion of a*. These portable 'color indicators' can be utilized to express the appearance of psoriatic plaques quantitatively, especially the extent of erythema and the amount of the scale on it.

Adult↗