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1.
J Wound Care ; 17(5): 210-4, 2008 May.
Article in English | MEDLINE | ID: mdl-18546995

ABSTRACT

OBJECTIVE: To investigate the effect and safety of an ibuprofen-releasing foam (Biatain-Ibu, Coloplast A/S) combined with an ionised silver-releasing wound contact layer (Physiotulle Ag, Coloplast A/S) on painful, infected venous leg ulcers. METHOD: This open non-comparative study involved 24 patients with painful, exuding, locally infected, and stalled venous leg ulcers. Persistent pain and pain at dressing change were monitored using a 11-point numerical box scale (NBS). The composition of the wound bed, the dressing combination's ability to absorb exudate and minimise leakage, ibuprofen content in the exudate, reduction in wound area and adverse effects were also recorded. RESULTS: Persistent wound pain decreased from a mean of 6.3 +/- 2.2 to 3.0 +/- 1.7 after 12 hours and remained low thereafter. Pain at dressing change also decreased and remained low. Forty-eight hours after the first dressing application, the mean concentration of ibuprofen in the wound exudate reached a constant level of 35 +/- 21 microg/ml. After 31 days, the relative wound area had reduced by 42%, with an associated decrease in fibrin and an increase in granulation tissue. The number of patients with wound malodour decreased from 37% to 4%. No serious adverse events were reported. CONCLUSION: The combined use of the ibuprofen-releasing foam dressing and silver-releasing contact layer reduced wound pain and promoted healing without compromising safety.


Subject(s)
Anti-Infective Agents, Local/administration & dosage , Anti-Inflammatory Agents, Non-Steroidal/administration & dosage , Ibuprofen/administration & dosage , Occlusive Dressings , Pain/prevention & control , Silver Compounds/administration & dosage , Varicose Ulcer/therapy , Aged , Anti-Infective Agents, Local/adverse effects , Anti-Inflammatory Agents, Non-Steroidal/adverse effects , Delayed-Action Preparations , Drug Therapy, Combination , Exudates and Transudates/drug effects , Female , Humans , Ibuprofen/adverse effects , Male , Occlusive Dressings/adverse effects , Silver Compounds/adverse effects , Wound Healing/drug effects
2.
J Wound Care ; 15(3): 97-100, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16550661

ABSTRACT

OBJECTIVE: To investigate the clinical performance and safety of a new silver-containing wound-contact layer, Physiotulle -Ag (Coloplast), in the treatment of chronic venous leg ulcers with delayed healing and signs of critical colonisation. METHOD: This was an open prospective non-comparative multicentre clinical study. Patients were treated for four weeks with Physiotulle -Ag, which was covered by Alione Hydrocapillary Dressing (Coloplast). RESULTS: Thirty patients were recruited into the study. One ulcer healed after three weeks of treatment. The mean relative ulcer area reduced by 55% after four weeks. Over the study period the mean amount of healthy granulation tissue increased from 26% to 62%, and the mean amount of fibrin decreased from 63% to 32%. The ratio of malodorous wounds was 50% at inclusion, 20% after one week and 3% after four weeks. The dressing was considered easy or very easy to apply in 100% and easy to remove in 89% of dressing evaluations. The dressing combination showed good exudate-management properties. Incidence and severity of maceration, erythema and eczema decreased during the study and no device-related adverse events were recorded. CONCLUSION: Physiotulle -Ag is safe and easy to use in chronic venous leg ulcers in which healing is delayed and with signs of critical colonisation.


Subject(s)
Bandages , Silver Compounds/therapeutic use , Varicose Ulcer/diagnosis , Varicose Ulcer/therapy , Wound Healing/drug effects , Aged , Aged, 80 and over , Chronic Disease , Denmark , Female , Follow-Up Studies , Humans , Male , Prospective Studies , Risk Assessment , Severity of Illness Index , Single-Blind Method , Treatment Outcome , Wound Healing/physiology
3.
J Eur Acad Dermatol Venereol ; 14(1): 19-21, 2000 Jan.
Article in English | MEDLINE | ID: mdl-10877248

ABSTRACT

In a randomized, controlled, left-right comparison study, 20 patients with chronic plaque psoriasis were treated with UVB. One side of the body received UVB in a conventional regimen with fixed dose increments, the other side was given UVB doses according to measurements of skin pigmentation. Skin pigmentation was quantified by the skin reflectance technique. The relationship between skin pigmentation and sensitivity to UV radiation was used to optimize and individualize the initial UVB exposure dose. Clinical outcome, initial, final and cumulative UVB doses, time to 50% reduction in PASI score, and side-effects were compared. The consequence of the optimization of the UVB doses with a skin reflectance meter was that the initial UVB dose was significantly higher than in the conventional UVB regimen. PASI scoring demonstrated a more rapid improvement during the first 2 weeks of treatment on the half body receiving the optimized treatment compared to the other side (P < 0.05). This new technique offers the same therapeutical advantages and security as a dose regimen guided by minimal erythema dose testing. However, measurement of skin pigmentation by skin reflectance is a quick method which can be operated easily by nurses.


Subject(s)
Psoriasis/radiotherapy , Ultraviolet Therapy , Adult , Aged , Female , Humans , Male , Middle Aged
4.
Acta Derm Venereol ; 78(6): 445-50, 1998 Nov.
Article in English | MEDLINE | ID: mdl-9833046

ABSTRACT

The pulsed dye laser is the treatment of choice for port-wine stains. In this study we evaluate the importance of preoperative skin pigmentation and skin redness for the development of side effects from one treatment with the pulsed dye laser. A risk assessment is performed and skin reflectance measurement objectifies postoperative pigmentary changes. Fourteen human volunteers (skin types I to V) were laser-treated on the inside of the proximal brachium. Photographic documentation was used for blinded, clinical evaluation of side effects 3 and 6 months postoperatively. Skin was artificially reddened using topical application of 10% nicotinic acid cream. The development of pigmentary alterations and texture changes depended on the preoperative pigmentation and redness degrees. The risk of inducing clinically visible pigmentary alterations and texture changes increased with higher preoperative skin pigmentation and redness degrees, and with the application of increasing laser doses. Pigmentary alterations were induced at a lower fluence level than texture changes. The risk of side effects was higher 3 months postoperatively than 6 months postoperatively, substantiating a gradual disappearance of side effects. Skin reflectance measurements documented postoperative hyperpigmentation that faded partially from 3 to 6 months postoperatively. This is the first human experimental model for port-wine stains which provides quantitative data on the relationship between preoperative skin colours and postoperative clinically disturbing side effects.


Subject(s)
Laser Coagulation/adverse effects , Skin Pigmentation/physiology , Skin/pathology , Administration, Cutaneous , Adult , Color , Female , Follow-Up Studies , Humans , Hyperpigmentation/etiology , Male , Middle Aged , Niacin/administration & dosage , Niacin/pharmacology , Photography , Pigmentation Disorders/etiology , Placebos , Port-Wine Stain/pathology , Port-Wine Stain/surgery , Risk Assessment , Risk Factors , Single-Blind Method , Skin/drug effects , Skin Pigmentation/drug effects
5.
Clin Exp Dermatol ; 23(2): 79-83, 1998 Mar.
Article in English | MEDLINE | ID: mdl-9692312

ABSTRACT

In this retrospective study the clinical, laboratory and histological features, treatment methods and disease course in 17 patients with papuloerythroderma (PE) are reviewed. The median age at diagnosis was 72 years and the female/male ratio was 1:4:7. The most common abnormal laboratory findings were eosinophilia and an elevated serum IgE level. Psoralen photochemotherapy (PUVA) and oral prednisolone 10-20 mg daily given in combination or alone were very efficient treatments, while UVB phototherapy in combination with topical steroids was also successful. However, potent topical corticosteroids alone or in combination with oral antihistamines were not effective. The patients were observed for a median of 19 months from diagnosis, three being followed for more than 5 years. Five of the patients relapsed, but only one had multiple relapses, two developed cutaneous T-cell lymphoma (CTCL) and two others had histological features suggestive of that disorder. Six of the patients died, cardiovascular disease being the most common cause. PE is a distinct clinical entity with a polymorphous aetiology which frequently includes an association with CTCL or visceral malignancy. PUVA, oral corticosteroids and UVB in combination with topical corticosteroids appear to be effective therapeutic modalities.


Subject(s)
Dermatitis, Exfoliative/drug therapy , Dermatitis, Exfoliative/pathology , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , PUVA Therapy , Retrospective Studies
6.
Article in English | MEDLINE | ID: mdl-9582079

ABSTRACT

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 occurrence 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.


Subject(s)
Dermatitis, Atopic/radiotherapy , Ultraviolet Therapy , Adult , Female , Humans , Male , Radiotherapy Dosage , Retrospective Studies , Ultraviolet Therapy/methods
7.
Plast Reconstr Surg ; 101(5): 1315-22, 1998 Apr.
Article in English | MEDLINE | ID: mdl-9529218

ABSTRACT

Laser therapy is today considered the treatment of choice for vascular skin lesions, which commonly are located on the face and, therefore, frequently are exposed to sunlight. The purpose of this study was to examine whether preoperative and postoperative ultraviolet irradiation influences the development of laser-induced side effects. We laser-treated hairless mice with a copper vapor laser; three different intensities were used at a constant pulse duration. Simulated solar ultraviolet radiation was administered either before the laser treatment (3 consecutive days, daily doses of 2.48 J/cm2) or after the laser treatment (four times weekly in 4 weeks, daily doses of 1.66 J/cm2). Laser-induced wounds, scars, and hyperpigmentation were evaluated by macroscopic, histologic, and biochemical examinations. Preoperative ultraviolet exposure enlarged the laser-induced wounds and the areas with texture change at some of the laser intensities used. However, the most pronounced effect was seen for postoperative ultraviolet-irradiated mice. These mice developed, at some of the laser intensities, a higher incidence of bulging infiltration as well as higher degrees of fibrosis and hyperpigmentation, thus developing a poor cosmetic appearance. Furthermore, ultraviolet irradiation after laser treatment resulted in slowly healing wounds of reduced size, indicating deep, constricted skin damage. We conclude that ultraviolet exposure before and after copper vapor laser treatment increases the risk of inducing side effects from dermatological laser treatment.


Subject(s)
Cicatrix/etiology , Dermatologic Surgical Procedures , Hyperpigmentation/etiology , Laser Coagulation/adverse effects , Ultraviolet Rays/adverse effects , Animals , Cicatrix/metabolism , Cicatrix/pathology , Contracture/etiology , Copper , Esthetics , Facial Dermatoses/surgery , Female , Fibrosis , Hydroxylysine/analysis , Hydroxyproline/analysis , Hyperpigmentation/metabolism , Hyperpigmentation/pathology , Incidence , Mice , Mice, Hairless , Mice, Inbred C3H , Mice, Inbred Strains , Proline/analysis , Radiation Dosage , Risk Factors , Skin/metabolism , Skin/pathology , Skin/radiation effects , Skin Diseases/etiology , Skin Diseases, Vascular/surgery , Skin Pigmentation/radiation effects , Sunlight/adverse effects , Wound Healing/radiation effects
8.
Lasers Surg Med ; 22(3): 159-64, 1998.
Article in English | MEDLINE | ID: mdl-9510100

ABSTRACT

BACKGROUND AND OBJECTIVE: To clarify whether epidermal thickness is of importance to the purpuric reaction from treatment with the pulsed dye laser (PDL). STUDY DESIGN/MATERIALS AND METHODS: Fifteen fairly pigmented volunteers were laser treated in two test regions of varying epidermal thicknesses: normal buttock skin and ultraviolet B (UVB)-exposed buttock skin. Laser treatments were performed with the flashlamp-pumped PDL (585 nm). Fluences ranged from 3-6.5 J/cm2, spot size was 7 mm, and each volunteer received at least six fluences in each treatment region. Assessment of the response was based on clinical evaluation (threshold dose to purpura 10 minutes and 1 day after treatment) and skin reflectance-evaluated redness (1 and 6 days, 2 and 6 weeks after treatment). RESULTS: The total epidermal thickness differed between the unexposed buttock skin (median, 72.7 microm) and the UVB-exposed buttock skin (87.2 microm) (P < 0.01). There was no correlation between the epidermal thickness and the threshold dose to induce purpura 10 minutes and 1 day after laser exposure. Skin reflectance revealed no correlation between the epidermal thickness and the skin reflectance evaluated redness on 1, 6 days, and 2 weeks postoperatively. A dose-response relation was seen within the two test regions; 6 weeks after laser exposure, there was no remaining laser-induced skin redness. CONCLUSION: The epidermal thickness is unimportant to the purpuric reaction after PDL treatment.


Subject(s)
Epidermis/pathology , Laser Therapy/adverse effects , Purpura/etiology , Adult , Humans , Laser Therapy/methods , Laser-Doppler Flowmetry , Purpura/pathology , Reference Values , Statistics, Nonparametric , Ultraviolet Rays/adverse effects
9.
Photochem Photobiol ; 66(4): 493-6, 1997 Oct.
Article in English | MEDLINE | ID: mdl-9337620

ABSTRACT

Photodynamic therapy (PDT) with topical application of delta-aminolevulinic acid (ALA) followed by irradiation with visible light (ALA-PDT) is a relatively new and promising experimental treatment of superficial premalignant and malignant skin neoplasms. The purpose of this study was to determine whether ALA-PDT can prevent photocarcinogenesis in hairless mice exposed to solar UV. A total of 140 mice was divided into seven groups of 20 mice each. Group 1: solar-UV exposure. Group 2: solar UV and a cream base+visible light once a week. Group 3: solar UV and ALA-PDT once a week. Group 4: solar UV and ALA-PDT once every second week. Group 5: solar UV and ALA-PDT every fourth week. Group 6: ALA-PDT once a week. Group 7: no treatment. The time to first and to second tumor > or = 1 mm was registered. Predefined endpoints, such as one tumor > or = 4 mm or an area of small confluent tumors on the back of the mice were criteria for withdrawal from the experiment. The time to first and to second tumor was significantly longer in the ALA-PDT-treated mice than in mice only exposed to solar UV and solar-UV/cream base-visible light (P < 0.005). However, we observed an increased death and accident rate in the ALA-PDT-treated groups compared to the groups not treated with ALA-PDT (chi-square test, P = 0.0250). Significantly more ALA-PDT-treated mice were withdrawn because of a tumor > or = 4 mm (P = 0.0005). The UV unexposed mice developed no tumors. Repetitive treatments with ALA-PDT delay photoinduced carcinogenesis in mice.


Subject(s)
Aminolevulinic Acid/administration & dosage , Neoplasms, Radiation-Induced/prevention & control , Photochemotherapy , Skin Neoplasms/prevention & control , Administration, Topical , Animals , Female , Mice , Mice, Hairless , Neoplasms, Radiation-Induced/etiology , Skin Neoplasms/etiology , Time Factors , Ultraviolet Rays/adverse effects
12.
Lasers Surg Med ; 20(3): 233-41, 1997.
Article in English | MEDLINE | ID: mdl-9138251

ABSTRACT

BACKGROUND AND OBJECTIVE: The intention of the present study was to clarify whether UV-exposure prior to laser treatment of albino mouse skin may influence laser-induced side effects and if a possible influence may be explained by epidermal thickening. STUDY DESIGN/MATERIALS AND METHODS: Albino, hairless mice were irradiated 0, 8, and 22 consecutive times with simulated solar UV (1.4 J/cm2 per treatment). Subsequently, two areas on the back of the mice (1.26 cm2 each) were treated with a copper vapor laser that was connected to a Hexascan. The beam diameter was 1 mm, pulse duration 200 msec, and intensities 0.6 W, 0.8 W, and 1.0 W. Laser-induced wounds, scars, and histologically evaluated fibrosis were evaluated. RESULTS: We found that mice irradiated with UV before laser treatment developed smaller wounds, smaller texture change areas, and less fibrosis as compared with nonirradiated control groups, and significant, negative correlations were demonstrated between epidermal thicknesses (stratum corneum, the cellular part of epidermis, and the entire epidermis) and laser-induced skin reactions. A dose response was obtained between laser intensities and laser-induced skin reactions, which tended to be more severe in the cranial back location as compared with the caudal back location. Epidermal layers increased significantly after eight consecutive times of UV irradiation and increased to a steady level after 22 times of irradiation. CONCLUSION: We conclude that UV exposure prior to laser treatment of albino mice reduced laser-induced side-effects, which could be explained by increased epidermal thickening. Variations in epidermal thickness might thus contribute to variations in clinical response to dermatological laser treatment with the copper vapor laser.


Subject(s)
Lasers/adverse effects , Skin/radiation effects , Ultraviolet Rays/adverse effects , Animals , Cicatrix/pathology , Dose-Response Relationship, Radiation , Female , Mice , Mice, Hairless , Radiation Injuries, Experimental/pathology , Skin/pathology
13.
Arch Dermatol ; 132(4): 403-7, 1996 Apr.
Article in English | MEDLINE | ID: mdl-8629843

ABSTRACT

BACKGROUND AND DESIGN: A fundamental idea of laser treatment of tattoos is that the wavelength must be well absorbed by the tattoo color. In this study, absorption by different tattoo colors was therefore measured in vivo by skin reflectance to establish optimal laser wavelengths for different tattoo colors. Spectral reflectance by tattooed skin and by normal, uninvolved skin was measured in 10-nm steps in a wavelength range from 300 to 800 nm on eight human volunteers with a total of 13 tattoos, which consisted of 14 different tattoo colors. Wavelength ranges for maximal absorption were established. RESULTS: We found that tattoos absorbed maximally in the following ranges: red tattoos, from 505 to 560 nm (green spectrum); green tattoos, from 630 to 730 nm (red spectrum); and a blue-green tattoo, in two ranges from 400 to 450 nm and from 505 to 560 nm (blue-purple and green spectrums, respectively). Yellow tattoos absorbed maximally from 450 to 510 nm (blue-green spectrum), purple tattoos-absorbed maximally from 550 to 640 nm (green-yellow-orange-red spectrum), blue tattoos absorbed maximally from 620 to 730 nm (red spectrum), and orange tattoos absorbed maximally from 500 to 525 nm (green spectrum). Black and gray absorbed broadly in the visible spectrum, but these colors were most effective from 600 to 800 nm. Optimal and suboptimal laser wavelengths are proposed. CONCLUSIONS: We recommend that wavelength ranges should be established for maximal tattoo absorption before laser treatment of decorative tattoos to select the most optimal laser wavelength present.


Subject(s)
Dermatologic Surgical Procedures , Laser Therapy , Lasers , Tattooing , Adult , Color , Female , Fiber Optic Technology/instrumentation , Humans , Male , Scattering, Radiation
14.
Acta Derm Venereol ; 75(6): 488-9, 1995 Nov.
Article in English | MEDLINE | ID: mdl-8651032

ABSTRACT

A case of solar pruritus is reported. Severe pruritus of the back, shoulders and upper lateral aspects of the arms, without any eruption, developed in a 28-year-old outdoor worker during 4 to 6 weeks of intensive solar exposure. The pruritus was intense and described as a burning sensation deep in the skin. Only a few excoriations and slight xerosis were found. Solar pruritus or brachioradial pruritus is a condition primarily seen in Caucasian people living in the tropics or subtropics. Previously the disease has only been reported once outside these areas.


Subject(s)
Photosensitivity Disorders/etiology , Pruritus/etiology , Sunlight/adverse effects , Adult , Humans , Male
15.
Photochem Photobiol ; 62(4): 773-9, 1995 Oct.
Article in English | MEDLINE | ID: mdl-7480154

ABSTRACT

The carcinogenic and melanogenic effects of a filtered metal halide source (UVASUN) that emits UV radiation in a range from 340 to 400 nm and a bank of Philips TL 09R tubes (TL 09) emitting in a range from 310 to 400 nm were studied in lightly pigmented hairless hr/hr C3H/Tif mice. Both the carcinogenic effect of the two UVA radiation sources alone and in combination with a UV source, consisting of one Philips TL 12 and five Bellarium-S SA-1-12 tubes emitting radiation somewhat similar to the UV part of the solar spectrum (SOLAR UV), were investigated. Finally, the melanogenic effect of exposure to the two UVA sources were studied. The mice were exposed to the UVA sources 30 min/day 5 days/week, in equal erythemogenic doses, calculated by using the Commission Internationale de l'Eclairage human erythema action spectrum. Equal erythemogenic doses of TL 09 and UVASUN induced the same degree of skin pigmentation, but skin tumor development was enhanced in mice exposed to TL 09 compared with UVASUN (P < 0.0005). For all but one tumor, endpoint pretreatment with TL 09 or UVASUN for 91 days did not influence tumor development during subsequent exposure to SOLAR UV radiation 10 min/day, 4 days/week. Exposure to the two UVA radiation sources after 91 days of SOLAR UV exposure significantly enhanced skin tumor development. Overall, the data on the interaction between exposure to the UVA sources and SOLAR UV indicated that the risk of SOLAR UV-induced carcinogenesis was independent of the type of prior-UVA exposure and post-UVA exposure.


Subject(s)
Melanins/biosynthesis , Neoplasms, Radiation-Induced/pathology , Skin Neoplasms/pathology , Skin Pigmentation/radiation effects , Skin/radiation effects , Ultraviolet Rays , Animals , Dose-Response Relationship, Radiation , Erythema/etiology , Erythema/physiopathology , Humans , Mice , Mice, Hairless , Neoplasms, Radiation-Induced/etiology , Skin/metabolism , Skin Neoplasms/etiology , Sunlight
17.
Photodermatol Photoimmunol Photomed ; 11(1): 14-7, 1995 Feb.
Article in English | MEDLINE | ID: mdl-7654561

ABSTRACT

A new in vivo method of visual scoring of pigmentation in hairless hr/hr mice with a C3H/Tif background is described. The mice were placed under a bank of 6 Philips TL08 fluorescent ultraviolet A (UVA) tubes in a dark room, and the pigmentation of the skin was compared with a Kodak Gray Scale with 20 different shades from white to black. The radiation from the tubes changed both the color of the back of the mouse and the gray scale into purple hues. The purple color of the back of each mouse could then be classified as one of 20 shades on the gray scale. An experiment was conducted exposing 3 groups of 20 mice to different doses of UV radiation from Philips TL01 tubes. One group of 20 mice was not irradiated and served as control. The pigmentation of each mouse was scored by one investigator every 2-3 weeks. After a few weeks of exposure a clear distinction between the groups was seen. To evaluate the inter- and intrapersonal variation of the method, 30 mice with various degrees of pigmentation were scored independently and blindly by two investigators. This was done twice during the study with a few days' interval. No interpersonal difference was found, but one investigator scored differently the first and second time by only 0.5 points. The described method provides a reproducible in vivo method, with very good discrimination, for estimation of pigmentation in hairless mice.


Subject(s)
Mice, Hairless , Skin Pigmentation/radiation effects , Ultraviolet Rays , Animals , Female , Mice , Radiation Dosage , Reproducibility of Results
18.
Article in English | MEDLINE | ID: mdl-8738715

ABSTRACT

Khellin is used together with either UVA irradiation or sun exposure in the treatment of vitiligo. The purpose of this study was to investigate the carcinogenic effect of topically applied khellin together with UVA or solar simulated radiation (SSR) in lightly pigmented C3H/Tif mice. For comparison purposes a 0.1% 8-methoxypsoralen (8-MOP) cream was also tested in combination with SSR. Fifty microliters of a 5% khellin cream, a 0.1% 8-MOP cream, or a cream without active substances were spread uniformly on the back of the mice 30 minutes before UVA or SSR irradiation. All mice were irradiated 3 times a week until age or skin tumor development necessitated killing. Treatment with topical khellin and UVA irradiation was carcinogenic to lightly pigmented hairless mice, time to 50% of the mice had developed one tumor (t50) was 507 days. This indicates that the combination of topical khellin and UVA radiation, formerly expected to be rather innocuous, is carcinogenic to mice. Also the combination of khellin and SSR (t50 = 268 days) enhanced skin tumor development significantly compared with control cream and SSR (t50 = 330 days), P < 0.05. In addition, the combination of khellin and SSR was found to have the same carcinogenic effect as treatment with 0.1% 8-MOP and SSR (t50 = 262 days). This study shows that topically applied khellin increases the carcinogenic effect of both UVA and sunlight.


Subject(s)
Cocarcinogenesis , Khellin/toxicity , Neoplasms, Radiation-Induced/etiology , Skin Neoplasms/etiology , Skin Pigmentation/radiation effects , Sunlight/adverse effects , Administration, Topical , Animals , Female , Khellin/administration & dosage , Methoxsalen/toxicity , Mice , Mice, Hairless , Photosensitizing Agents/toxicity , Skin Neoplasms/chemically induced , Skin Pigmentation/drug effects , Ultraviolet Rays/adverse effects
19.
Article in English | MEDLINE | ID: mdl-8738717

ABSTRACT

Tanning and thickening of the epidermis are cardinal defensive responses of human skin to ultraviolet (UV) radiation that lead to increased photoprotection. Earlier studies have shown that skin pigmentation can be used to predict minimal erythema dose and minimal phototoxic dose. In this study it was calculated how much of the increase in photoprotection after 4 weeks of repeated exposure to suberythemogenic doses of either UVA or UVB radiation sources or psoralen plus UVA (PUVA) therapy that was attributable to melanogenesis. The backs of 12 volunteers were exposed to 6 different UVA and UVB radiation sources 9 times during 4 weeks. Skin pigmentation was assessed by skin reflectance measuring. Photoprotection was determined from the minimal erythema dose. Melanogenesis accounted for 63-95% of the increase in photoprotection after 4 weeks of exposure to UVA radiation. Exposure to two UVB sources induced a significant increase in photoprotection but not in pigmentation. Melanogenesis accounted only for 6-11% of the increase in photoprotection after 4 weeks of UVB exposure. The pigmentary and photoprotective responses to PUVA therapy were followed in 14 patients. After 2 weeks of exposure, the increase in photoprotection was significantly higher than predicted from the increase in skin pigmentation. After 4 weeks, melanogenesis accounted for only 36% of the increase in photoprotection. This study shows that melanogenesis accounts for the increased photoprotection after 2 weeks of exposure to UVA radiation, but after 4 weeks other protective mechanisms occur. During suberythemal UVB exposure and during PUVA therapy the importance of skin pigmentation in the overall photoprotection gradually decreases during a 4-week irradiation period.


Subject(s)
PUVA Therapy , Skin Pigmentation/radiation effects , Skin/anatomy & histology , Skin/radiation effects , Ultraviolet Rays , Adult , Aged , Erythema , Humans , Middle Aged , Psoriasis/drug therapy
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