Hans Christian Wulf

Photodynamic therapy with 5-aminolaevulinic acid or placebo for recalcitrant foot and hand warts: randomised double-blind trial

BACKGROUNDnPhotodynamic therapy (PDT) with topical 5-aminolaevulinic acid (ALA) followed by irradiation with incoherent light (ALA-PDT) for recalcitrant warts have had beneficial results. Therefore, we undertook a randomised, parallel, double-blind clinical trial of ALA-PDT versus placeboPDT for recalcitrant foot and hand warts.nnnMETHODSnRecalcitrant foot and hand warts were randomly assigned to six repetitive ALA-PDT or placebo-PDT interventions combined with standard treatment encompassing paring followed by a keratolytic (Verucid). Standardised photographs of each wart were taken before, during (week 7) and after treatment (weeks 14 and 18). The area of each wart compared with entry area was the primary outcome variable, measured from photographs by an evaluator unaware of treatment allocation for intervention. Pain intensity immediately and 24 h after each intervention was assessed by a five-point scale.nnnFINDINGSnA total of 232 foot and hand warts in 45 patients were entered into the trial: 117 warts were allocated to ALA-PDT and 115 warts to placebo-PDT. In week 14, the median relative reduction in wart area was 98% in the ALA-PDT group (interquartile range 100%, 55%) versus 52% (100%, 0) in the placebo group (p=0.0006). In week 18, the median relative reduction in wart area was 100% in the ALA-PDT group (100%, 57%) versus 71% (100%, 0) in the placebo-PDT arm (p=0.008). Both the number of vanishing warts and the difference in relative wart area of persisting warts at week 14 and 18 were significant (p<0.05) in favour of ALA-PDT. Significantly more ALA-PDT warts were graded at a higher pain intensity after treatment than placebo-PDT warts.nnnINTERPRETATIONnALA-PDT is superior to placebo-PDT when both wart area and number of vanishing warts are considered.

Urinary excretion of phthalates and paraben after repeated whole-body topical application in humans

Diethyl phthalate (DEP), dibutyl phthalate (DBP) and butyl paraben (BP) are man-made chemicals used in personal care products, such as lotions and creams. Exposure to these chemicals causes a variety of adverse reproductive outcomes in animal studies. Humans can be exposed to these chemicals through dermal absorption, but there are no published data on absorption, metabolism, and excretion after dermal application. This study investigates urinary concentrations of BP and metabolites of DEP and DBP after topical application. In a 2-week single-blinded study, 26 healthy Caucasian male subjects were given a whole body topical application of basic cream 2 mg/cm(2) (control week) and then a cream containing 2% (w/w) of DEP, DBP and BP each (treatment week) daily. Twenty-four-hour urine samples were collected. Urinary total, and unconjugated BP, monoethyl phthalate (MEP) and monobutyl phthalate (MBP) metabolites were analysed by Liquid Chromatography-Tandem Mass Spectroscopy (LC-MS/MS). All 26 subjects showed increased excretion of MEP, MBP and BP following topical application. Total MEP, MBP and BP (mean +/- SEM) excreted in urine in the treatment week were, respectively, 41 +/- 1.9, 11.8 +/- 0.6 and 2.6 +/- 0.1 mg/24 h. On average 5.79, 1.82 and 0.32%, respectively, of the applied DEP, DBP and BP could be recovered in urine as MEP, MBP and BP. The concentration of the compounds peaked in urine 8-12 h after application. The fractions of unconjugated MEP, MBP, and BP were 78, 8.0 and 2.1%, respectively. Absorption of DEP, DBP and BP through skin could potentially contribute to adverse health effects. The three chemicals are systemically absorbed, metabolized and excreted in urine following application on the skin in a cream preparation. More DEP than DBP was absorbed, presumably because of a faster absorption rate for DEP.

Role of mitochondria in ultraviolet-induced oxidative stress

The biological effects of ultraviolet radiation (UV), such as DNA damage, mutagenesis, cellular aging, and carcinogenesis, are in part mediated by reactive oxygen species (ROS). The major intracellular ROS intermediate is hydrogen peroxide, which is synthesized from superoxide anion (•O2−) and further metabolized into the highly reactive hydroxyl radical. In this study, we examined the involvement of mitochondria in the UV‐induced H2O2 accumulation in a keratinocyte cell line HaCaT. Respiratory chain blockers (cyanide‐p‐trifluoromethoxy‐phenylhydrazone and oligomycin) and the complex II inhibitor (theonyltrifluoroacetone) prevented H2O2 accumulation after UV. Antimycin A that inhibits electron flow from mitochondrial complex III to complex IV increased the UV‐induced H2O2 synthesis. The same effect was seen after incubation with rotenone, which blocks electron flow from NADH‐reductase (complex I) to ubiquinone. UV irradiation did not affect mitochondrial transmembrane potential (ΔΨm). These data indicate that UV‐induced ROS are produced at complex III via complex II (succinate‐Q‐reductase). J. Cell. Biochem. 80:216–222, 2000.

Biomonitoring of genotoxic exposure among stainless steel welders

A biosurvey in the Danish metal industry measured the genotoxic exposure from stainless steel welding. The study comprised measurements of chromosomal aberrations (CA), sister-chromatid exchanges (SCE), unscheduled DNA synthesis (UDS) in peripheral lymphocytes and serum immunoglobulin G. Environmental monitoring of welding fumes and selected metal oxides, biomonitoring of chromium and nickel in serum and urine and mutagenic activity in urine, and evaluation of semen quality were also done. Manual metal arc (MMA) welding and tungsten inert gas (TIG) welding were the dominant welding processes. A higher frequency of chromosomal aberrations, classified as translocations, double minutes, exchanges and rings, was observed in stainless steel welders than in non-welders. SCE was lower in welders working with both MMA and TIG welding than in reference persons. N-Acetoxy-N-acetylaminofluorene (NA-AAF)-induced UDS was lower in 23 never-smoking welders than in 19 unexposed never-smokers. Smoking was a confounding factor resulting in significantly higher CA, SCE, NA-AAF binding to DNA and mutagenic activity in urine. Age was also a confounder: CA, SCE, NA-AAF binding to DNA and UDS increased significantly with age. No significant correlation between SCE and CA or between CA and UDS was found. UDS decreased significantly with increasing lymphocyte count and a higher lymphocyte count was seen in MMA welders than in reference persons and in smokers than in non-smokers. Differences in the composition among lymphocytes in exposed persons compared with non-exposed are suggested. MMA welding gave the highest exposure to chromium, an increased number of chromosomal aberrations and a decrease in SCE when compared with TIG welding. Consequently improvements in the occupational practice of stainless steel welding with MMA is recommended.

Interdependence between body surface area and ultraviolet B dose in vitamin D production: a randomized controlled trial

Backgroundu2002 Ultraviolet (UV) B radiation increases serum vitamin D level expressed as 25‐hydroxyvitamin‐D3 [25(OH)D], but the relationship to body surface area and UVB dose needs investigation.

Vitamin D production depends on ultraviolet-B dose but not on dose rate: a randomized controlled trial.

Abstract:u2002 Ultraviolet‐B (UV‐B) radiation increases serum vitamin D level expressed as 25‐hydroxyvitamin D3 (25(OH)D), but the dose–response relationship and the importance of dose rate is unclear. Of 172 fair‐skinned persons screened for 25(OH)D, 55 with insufficient baseline 25(OH)Du2003≤u200350u2003nm (mean 31.2u2003nm) were selected and randomized to one of 11 groups of five participants. Each group was exposed to one of four different UV‐B doses: 0.375, 0.75, 1.5 or 3.0 standard erythema dose (SED) for 1, 5, 10 or 20u2003min. All participants had four UV‐B sessions with 2‐ to 3‐day interval with 24% of their skin exposed. Skin pigmentation and 25(OH)D were measured before and after the irradiations. The increase in 25(OH)D after UV‐B exposure (adjusted for baseline 25(OH)D) was positively correlated with the UV‐B dose (Pu2003=u20030.001; R2u2003=u20030.176) but not to dose rate (1–20u2003min). 25(OH)D increased in response to four UV‐B treatments of 3 SED with 24.8u2003nm on average and 14.2u2003nm after four UV‐B treatments of just 0.375 SED. In conclusion, the increase in 25(OH)D after UV‐B exposure depends on the dose but not on the dose rate (1–20u2003min). Further, a significant increase in 25(OH)D was achieved with a very low UV‐B dose.

Common variants in CYP2R1 and GC genes are both determinants of serum 25-hydroxyvitamin D concentrations after UVB irradiation and after consumption of vitamin D3–fortified bread and milk during winter in Denmark

BACKGROUNDnLittle is known about how the genetic variation in vitamin D modulating genes influences ultraviolet (UV)B-induced 25-hydroxyvitamin D [25(OH)D] concentrations. In the Food with vitamin D (VitmaD) study, we showed that common genetic variants rs10741657 and rs10766197 in 25-hydroxylase (CYP2R1) and rs842999 and rs4588 in vitamin D binding protein (GC) predict 25(OH)D concentrations at late summer and after 6-mo consumption of cholecalciferol (vitamin D₃)-fortified bread and milk.nnnOBJECTIVESnIn the current study, called the Vitamin D in genes (VitDgen) study, we analyzed associations between the increase in 25(OH)D concentrations after a given dose of artificial UVB irradiation and 25 single nucleotide polymorphisms located in or near genes involved in vitamin D synthesis, transport, activation, or degradation as previously described for the VitmaD study. Second, we aimed to determine whether the genetic variations in CYP2R1 and GC have similar effects on 25(OH)D concentrations after artificial UVB irradiation and supplementation by vitamin D₃-fortified bread and milk.nnnDESIGNnThe VitDgen study includes 92 healthy Danes who received 4 whole-body UVB treatments with a total dose of 6 or 7.5 standard erythema doses during a 10-d period in winter. The VitmaD study included 201 healthy Danish families who were given vitamin D₃-fortified bread and milk or placebo for 6 mo during the winter.nnnRESULTSnAfter UVB treatments, rs10741657 in CYP2R1 and rs4588 in GC predicted UVB-induced 25(OH)D concentrations as previously shown in the VitmaD study. Compared with noncarriers, carriers of 4 risk alleles of rs10741657 and rs4588 had lowest concentrations and smallest increases in 25(OH)D concentrations after 4 UVB treatments and largest decreases in 25(OH)D concentrations after 6-mo consumption of vitamin D₃-fortified bread and milk.nnnCONCLUSIONnCommon genetic variants in the CYP2R1 and GC genes modify 25(OH)D concentrations in the same manner after artificial UVB-induced vitamin D and consumption of vitamin D₃-fortified bread and milk.

Topical tacrolimus in combination with simulated solar radiation does not enhance photocarcinogenesis in hairless mice.

Abstract:u2002 Numerous studies have demonstrated the utility of topical tacrolimus ointment in atopic dermatitis. However, there is a concern that local immunosuppression by calcineurin inhibitors may enhance dermal photocarcinogenesis and carcinogenesis. Therefore, we investigated the influence of topical tacrolimus ointment on squamous cell carcinoma formation in hairless female C3.Cg/TifBomTac immunocompetent mice exposed to solar simulated radiation (SSR). In a first experiment, mice (nu2003=u2003200) had tacrolimus applied on their dorsal skin three times weekly followed by SSR (2, 4 or 6 standard erythema doses, SED) 3–4u2003h later. Tacrolimus did not reduce the time to tumor development and in the group receiving 4 SED it even had a protective effect (156u2003days vs 170u2003days, Pu2003=u20030.008). In a second experiment, mice (nu2003=u200350) were irradiated with 6 SED three times weekly for 3u2003months and subsequently treated five times weekly with topical tacrolimus to mimic the use of tacrolimus on sun‐damaged skin. The median time to the first skin tumor was 234u2003days in SSRu2003+u2003tacrolimus group compared with 227u2003days in the only SSR‐irradiated group (Pu2003=u20030.160). In a third experiment, mice (nu2003=u200325) had tacrolimus applied on their dorsal skin every day for 1u2003month, thereafter the group was irradiated with 4 SED three times weekly. The median time to the first skin tumor was 142u2003days in tacrolimusu2003+u2003SSR group compared with 156u2003days in the only SSR‐irradiated group from experiment 1 (Pu2003=u20030.363). We conclude that tacrolimus ointment does not accelerate photocarcinogenesis or induce any dermal carcinogenicity in hairless mice.

Topical pimecrolimus and tacrolimus do not accelerate photocarcinogenesis in hairless mice after UVA or simulated solar radiation.

Abstract:u2002 Pimecrolimus and tacrolimus are topical calcineurin inhibitors developed specifically for the treatment of atopic eczema. Experience with long‐term use of topical calcineurin inhibitors is limited and the risk of rare but serious adverse events remains a concern. We have previously demonstrated the absence of carcinogenic effect of tacrolimus alone and in combination with simulated solar radiation (SSR) on hairless mice. The aim of this study is to determine whether pimecrolimus accelerates photocarcinogenesis in combination with SSR or pimecrolimus and tacrolimus accelerate photocarcinogenesis in combination with UVA. We used 11 groups of 25 hairless female C3.Cg/TifBomTac immunocompetent mice (nu2003=u2003275). Pimecrolimus cream or tacrolimus ointment was applied on their dorsal skin three times weekly followed by SSR (2, 4, or 6 standard erythema doses, SED) or UVA (25u2003J/cm2) 3–4u2003h later. This was done up to 365u2003days in the SSR‐treated groups and up to 500u2003days in the UVA‐treated groups. Pimecrolimus did not accelerate the time for development of the first, second or third tumor in any of the groups. Median time to the first tumor was 240u2003days for the control‐2SED group compared with pimecrolimus‐2SED group (233u2003days), control‐4SED group (156u2003days) compared with pimecrolimus‐4SED group (163u2003days) and control‐6SED group (162u2003days) compared with pimecrolimus‐6SED group (170u2003days). Only one mouse in each of the three UVA groups developed a tumor. We conclude that pimecrolimus in combination with SSR and both pimecrolimus and tacrolimus in combination with UVA do not accelerate photocarcinogenesis in hairless mice.

A UVB phototherapy protocol with very low dose increments as a treatment of atopic dermatitis

From 1991 to 1992, 15 patients with atopic dermatitis were treated with a new UVB treatment regimen guided by skin reflectance measurements. The new treatment was characterized by very low dose increments from start to end of therapy. The median cumulative dose increment during therapy was only 20%. The severity of the disease, the efficacy of the treatment, the occurence of adverse effects and the cumulative UVB dose were obtained from the case records. This data were compared in an open study with the data obtained from 17 patients with atopic dermatitis who were treated from 1988 to 1991 at the department with a standard UVB treatment regimen with stepwise dose increments. There was no difference in the severity of the disease at the beginning of the therapy between the two groups. The skin reflectance‐guided low‐dose UVB therapy was not significantly faster (3.5 weeks) than the regimen with stepwise dose increments (4.5 weeks). The cumulative UV exposure was four times lower with the new treatment regimen (34 standard erythema doses) compared with the old regimen (161 standard erythema doses), P<0.001. The healing score was significantly higher with the new treatment regimen compared with the old, P<0.05. This study indicates that skin reflectance‐guided UVB phototherapy may enable the dermatologist to lower the cumulative UVB exposure significantly without losing effect.