The effect of a corticosteroid cream and a barrier-strengthening moisturizer in hand eczema. A double-blind, randomized, prospective, parallel group clinical trial.

BACKGROUND: Hand eczema is a common and persistent disease with a relapsing course. Clinical data suggest that once daily treatment with corticosteroids is just as effective as twice daily treatment. OBJECTIVES: The aim of this study was to compare once and twice daily applications of a strong corticosteroid cream in addition to maintenance therapy with a moisturizer in patients with a recent relapse of hand eczema. METHODS: The study was a parallel, double-blind, randomized, clinical trial on 44 patients. Twice daily application of a strong corticosteroid cream (betamethasone valerate 0.1%) was compared with once daily application, where a urea-containing moisturizer was substituted for the corticosteroid cream in the morning. The investigator scored the presence of eczema and the patients judged the health-related quality of life (HRQoL) using the Dermatology Life Quality Index (DLQI), which measures how much the patient's skin problem has affected his/her life over the past week. The patients also judged the severity of their eczema daily on a visual analogue scale. RESULTS: Both groups improved in terms of eczema and DLQI. However, the clinical scoring demonstrated that once daily application of corticosteroid was superior to twice daily application in diminishing eczema, especially in the group of patients with lower eczema scores at inclusion. CONCLUSIONS: Twice daily use of corticosteroids was not superior to once daily use in treating eczema. On the contrary, the clinical assessment showed a larger benefit from once daily treatment compared with twice daily, especially in the group of patients with a moderate eczema at inclusion.

In vivo growth inhibition of human colon carcinoma cells (HT-29) by all-trans-retinoic acid, difluoromethylornithine, and colon mitosis inhibitor, individually and in combination.

BACKGROUND: An important strategy in experimental chemotherapy of cancer is to combine agents with different mechanisms of action in order to achieve enhanced effect by synergism. We studied the combination of all-trans-retinoic acid (RA), difluoromethylornithine (DFMO) and the tripeptide colon mitosis inhibitor (CMI) on the in vivo growth of human colon carcinoma cells (HT-29) in athymic mice. MATERIALS AND METHODS: DFMO was given as 2% in the drinking water. RA (400 nmol/animal) and CMI (1 pmol/animal) were administered i.p. daily. RESULTS: RA, DFMO or CMI given alone, reduced the tumour growth by 40-60% (P < 0.001). When DFMO was given as a standard therapy, significant synergism was achieved with RA (P = 0.008). In contrast, CMI acted antagonistically with DFMO (P = 0.013). DFMO + RA + CMI was not more effective than DFMO + RA. Without DFMO administration, CMI achieved synergism with RA (P < 0.001). CONCLUSIONS: Synergism was shown between RA and DFMO, and RA and CMI, but not between CMI and DFMO.

Retinoic acid provokes a regeneration-like proliferative response in murine epidermis. A bivariate DNA/bromodeoxyuridine flow cytometric study.

Retinoic acid (RA) is an inducer of epidermal proliferation by a mechanism of action which is not fully known. We examined the proliferative response of hairless mouse epidermis to a single topical application of different doses of RA (0.1-1000 nmol). The mitotic rate was assessed using the stathmokinetic method, and change in epidermal cell numbers were scored per microscopic vision field in tissue sections. Cell cycle parameters were measured by bivariate bromodeoxyuridine/DNA flow cytometry on isolated epidermal basal cells after pulse labelling up to 10 days after RA treatment. The results showed a dose-dependent increase in mitotic activity with a maximum at 3 days after RA application, and a dose-dependent hyperplasia with a maximum at 4 days after RA application. Cell-cycle analysis showed an immediate proliferative response after RA application similar to that following various skin irritants. Although differences in the G2 phase transit were seen, this indicates a similar mechanism of action of RA-induced epidermal proliferation and that associated with epidermal regeneration in general.

Topical application of calcitriol alters expression of filaggrin but not keratin K1 in mouse epidermis.

Calcitriol (1 alpha,25-dihydroxyvitamin D3) and its analogues are antiproliferative agents which promote epidermal differentiation in vitro, possibly reflecting their modes of action in the treatment of psoriasis. We examined the effect of calcitriol on early and late terminal differentiation in mouse epidermis in vivo using an immunofluorescence assay to detect keratin K1 and filaggrin expression. Pulse labelling with the tymidine analogue 5-bromo-2-deoxyuridine (BrdUrd) was performed by intraperitoneal injection of mice immediately or 16 h after a single topical application of 0.72 nmol calcitriol. The BrdUrd labelling index (LI) and keratin K1 or filaggrin expression of postmitotic cell cohorts were scored by paired immunofluorescence staining for up to 72 h after BrdUrd labelling. Calcitriol induced cell proliferation as shown by a 100% increase in the BrdUrd LI 17 h after application. The onset of keratin K1 expression in the postmitotic period was, however, unchanged in both series after calcitriol treatment. Filaggrin expression appeared earlier after calcitriol treatment than in control epidermis, probably reflecting altered cell kinetics with increased epidermal turnover. The results suggest that calcitriol only influences the later stages of the keratinocyte differentiation programme, possibly secondarily to its hyperproliferative effect.

[Naproxen-induced bullous photodermatitis (pseudoporphyria)]. / Naproxenutløst bulløs fotodermatitt (pseudoporfyri).

The author describes two cases of naproxene-induced bullous photodermatitis (pseudoporphyria) with recurrent blisters and fragility of the skin of hands and face. The cutaneous changes were clinically and histologically indistinguishable from those noted in porphyria cutanea tarda, but were without the associated haematological abnormalities. The lesions remitted upon the cessation of naproxene therapy. Pseudoporphyria may be considered as a phototoxic reaction to drugs or unknown chromophores and is also seen in hemodialysis patients and users of UVA-sunbeds. Naproxene-induced pseudoporphyria has not been previously reported in Norway.

[Psycho-cutaneous disorders in practice. Self-inflicted skin diseases of psychological origin]. / Psykokutane lidelser i praksis. Selvpåførte hudsykdommer med psykologisk primaerårsak.

Patients with self-inflicted cutaneous lesions often consult practitioners or dermatologists rather than psychiatrists. The factitious skin lesions are pleomorphic, and may range from wounds, abrasions, blisters or burns, to relatively harmless patient-dependent aggravation of known dermatological diseases. The underlying psychopathology is highly divergent, ranging from socially induced stress behaviour to serious psychiatric disease with a high incidence of suicide. The basic psychological mechanisms of these diseases are poorly understood, and psychocutaneous disorders are difficult to treat effectively. The main challenge is to establish a trustful doctor-patient relationship, in which a joint therapeutic strategy can be established. The author describes six different psychocutaneous disorders in two selected cases, showing both the distinctions between the joint disorders and their common features. The need for constructive collaboration between practitioner or dermatologist and psychiatrist is emphasized.

Calcitriol and its analog KH 1060 induce similar changes in keratinocyte cell cycle progression after topical application to mouse skin. A bromodeoxyuridine pulse-chase flow cytometric study.

Calcitriol and its analogs are used in the treatment of psoriasis and may also induce epidermal proliferation, hyperplasia, and irritation in normal skin by an unknown mechanism. The effects of a single dose of calcitriol and the 20-epi-vitamin D3 analog KH 1060 were therefore examined by performing 5-bromo-2'-deoxyuridine (BrdU) pulse chase labeling experiments in unperturbed hairless mouse epidermis in vivo. One cohort of basal cells was exposed to calcitriol mainly during the S phase, whereas another cohort in G1/G0 phase was stimulated by calcitriol or KH 1060 into S phase 16 h before BrdU labeling. Basal keratinocytes were isolated from epidermis and analyzed by bivariate BrdU/DNA flow cytometry. Calcitriol and KH 1060 induced similar proliferative responses, with a peak of cells in S phase at about 16 h after drug applications. The cohorts in G1/G0 phase at the time of drug application displayed a reduced cell cycle, whereas the cohort of cells in S phase at the time of calcitriol application did not show a similar reduction. The proliferation kinetics observed are thus different from those seen after retinoic acid treatment, since retinoic acid did not reduce the cell cycle time under similar conditions. Reduction of cell cycle time may be a characteristic effect of calcitriol and KH 1060, similar to that seen after other hyperplasiogens. The results also indicate that the drugs exert differential effects on cells depending on the cells' position in the cell cycle during treatment.

Topical application of retinoic acid induces murine epidermal proliferation without reducing the cell cycle time. A bivariate BrdUrd/DNA flow cytometric study.

Topical application of retinoic acid (RA) induces skin irritation, increased epidermal DNA synthesis and hyperplasia by an unknown mechanism, possibly in common with other hyperplasiogens. To further characterize this regeneration-like effect of RA, the cell cycle traverse in hairless mouse epidermis in vivo after application of a single dose of 100 nmol RA was investigated. Two BrdUrd labelled basal cell cohorts, one exposed to RA during the S phase, the other stimulated by RA into S phase 16 h earlier, were followed for 30 h in their progression through the cell cycle. The basal cells were isolated and prepared for bivariate BrdUrd/DNA flow cytometry analysis (FCM). Both cohorts showed induced proliferation of cells stimulated from G0/G1 into S phase as shown by increase in the S phase fraction, but without reduction in cell cycle time as expected for regenerative growth. This implies that RA stimulates proliferation differently than other hyperplasiogens, and hence may induce irritation and growth stimulation through another mechanism.

Expression of keratins K6 and K16 in regenerating mouse epidermis is less restricted by cell replication than the expression of K1 and K10.

Biosynthesis of the hyperproliferation-associated keratins K6 and K16 was studied in mouse epidermis following a single topical application of the tumour promoter 12-O-tetradecanoylphorbol-13-acetate (TPA). An epidermal cell cohort was followed by pulse-labelling with the thymidine analogue 5-bromodeoxyuridine (BrdUrd). Mice were injected intraperitoneally with BrdUrd 1 h before a single topical application of TPA. TPA induced regenerative epidermal hyperplasia with hyperproliferation and shortened suprabasal transit time. The BrdUrd-labelled cell cohort was followed for 96 h after TPA-treatment by two-colour immunofluorescence staining with antibodies to BrdUrd, keratin K6 and K16. In control animals, K6 and K16 were found only in the hair follicles. K6 expression was immediately induced in all epidermal cell layers of TPA-treated epidermis, including actively replicating cells and it was expressed during the whole observation period. K16 was only present in post-mitotic cells and was transiently expressed 8-72 h after TPA treatment. Our results suggest that the expression of K6 and K16 is less restricted by cellular replication than the normally occurring K1 and K10 keratins.

Differential effects of topical retinoic acid application on keratin K1 and filaggrin expression in mouse epidermis.

Retinoic acid (RA) modulates epidermal homeostasis and affects differentiation-associated proteins such as keratin K1 and filaggrin. Because results from in vitro and in vivo studies have been conflicting with respect to RA effects on keratinization, we examined the terminal differentiation of epidermal cell cohorts after RA stimulation in vivo. Pulse-labelling with 5-bromo-2-deoxyuridine (BrdU) was performed by intraperitoneal injection of mice immediately or at 16 h after a single topical application of 100 nmol RA. The cell cohort labelled at the time of RA application consisted of previously unperturbed cells exposed to RA after initiation of S-phase, whereas the cohort labelled 16 h after RA application consisted of cells stimulated into the S-phase by RA. These two cohorts of partially synchronized cells were followed for up to 72 h after BrdU labelling. Such labelling combined with keratin K1 or filaggrin expression was scored by paired immunofluorescence staining of skin sections. The onset of keratin K1 expression was unchanged in both series after RA treatment, while filaggrin appeared earlier than in controls. The differential effect of RA on the maturation markers was related to the proliferative activity, the increased cell turnover, and the shortened epidermal transit time. The onset of keratin expression appeared to be regulated before the postmitotic period, whereas filaggrin expression appeared to be regulated during the late phase of the maturation process, thus being influenced by the actual epidermal kinetics and structural alterations. These results suggested that the effect of RA on epidermal differentiation is secondary to its effect on proliferation, as determined by the altered cellular age distribution following regenerative proliferation.

Topical application of 12-O-tetradecanoylphorbol-13-acetate induces dyssynchronous expression of keratins K1 and K10 in mouse epidermis.

12-O-tetradecanoylphorbol-13-acetate (TPA) is a potent tumor promoter that causes severe alterations in the biosynthesis of epidermal keratins. This study shows that TPA induces a dyssynchronous effect on keratin expression in stratified squamous epithelium. The effect of TPA on the separate expression of the maturation-associated keratins K1 and K10 was studied by immunohistochemistry in an unperturbed replicative keratinocyte population of hairless mice epidermis in relation to changes in the cell cycle time during regeneration. Keratinocytes in DNA synthesis were pulse-labeled by intraperitoneal injection of the thymidine analogue 5-bromodeoxyuridine (BrdUrd) 1 h before a single topical application of TPA. The BrdUrd-labeled cell cohort, representing an originally unperturbed replicative keratinocyte population exposed to TPA mainly in the postreplicative period, was followed for up to 97 h. The results suggested unaltered timing of the onset of K1 and K10 expression compared with normal epidermis (18 and 24 h, respectively, following DNA synthesis). This indicates that the synthesis of both keratins was programmed before the keratinocytes entered their last DNA synthesis. A reduction in K10 expression from about 30 h compared with that of K1 expression was observed. Mathematical modeling suggested a delay in K10 expression related to the second and third rounds of cell divisions after pulse-labeling. How TPA induces such dyssynchrony in K1 and K10 regulation remains unknown.

1,25-Dihydroxyvitamin D3 and the vitamin D analogue KH1060 induce hyperproliferation in normal mouse epidermis. A BrdUrd/DNA flow cytometric study.

1,25-dihydroxyvitamin D3 (calcitriol) affects differentiation and proliferation of epidermal keratinocytes in vitro and in vivo. We have studied the topical effects of calcitriol (0.08-2.0 micrograms/ml) and of a new vitamin D analogue, the epi-20-analogue KH1060 (0.4-2.0 micrograms/ml) on epidermal proliferation in normal hairless mice. Epidermis was examined at intervals from 4 h to 8 days after a single-dose application. The mitotic rate was assessed by the stathmokinetic method and hyperplasia was scored in histological sections. Cell cycle parameters were measured by bivariate bromodeoxyuridine (BrdUrd)/DNA flow cytometry on isolated epidermal basal cells after pulse-labelling with BrdUrd. Both calcitriol and KH1060 induced a dose- and time-dependent increase in the mitotic rate and in hyperplasia, the latter drug being the most effective. Calcitriol and KH1060 induced changes in the cell cycle traverse compatible with the regenerative reaction seen after other hyperplasiogens, but with an additionally increased accumulation of cells in the G2 phase. This is similar to that seen after topical application of retinoic acid to mouse skin. Our results are thus in contrast to the anti-proliferative effects of calcitriol observed in vitro and following treatment of the hyperproliferative disease psoriasis with calcitriol as well as other vitamin D analogues.

Application of cantharidin or 12-O-tetradecanoylphorbol-13-acetate on mouse epidermis induces a cell population shift that causes altered keratin distribution.

The tumour promoter 12-O-tetradecanoyl-phorbol-13-acetate (TPA) causes changes in epidermal protein expression, especially in the major differentiation products keratins K1 and K10. These keratins and filaggrin were studied in a pulse-labelled cell cohort in hairless mouse epidermis stimulated to proliferate by TPA or the hyperplasiogen cantharidin. Cells in DNA synthesis were pulse-labelled by 5-bromo-2-deoxyuridine (BrdU) 16 h after topical application of cantharidin or TPA. The BrdU-labelled cell cohort, the two keratins, and filaggrin were spatially mapped by paired immunofluorescence staining. Both cantharidin- and TPA-treated epidermis displayed altered distributions of K1 and K10 with expression only in the outermost cell layers, but the start of their postreplicative expression paralleled that in normal epidermis (18 h for K1 and 24 h for K10 after the last round of DNA synthesis). Cantharidin- and TPA-induced epidermal hyperplasia showed increased basal cell proliferation, accelerated suprabasal migration, and shortened transit time. Thus, the newly formed hyperplastic epidermis was composed of keratinocytes with a lower mean cellular age than that seen in unperturbed epidermis, which caused altered distribution of K1 and K10. Both hyperplastic and normal epidermis showed filaggrin expression in stratum granulosum; this started earlier in treated (30-36 h) than in untreated (96 h) skin. We concluded that the postmitotic onset of K1 and K10 expression was unaltered in regenerative epidermis, whereas filaggrin expression was considerably accelerated and thus influenced by the cell kinetic changes.