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Biomedical subjects

G Wennersten

Publications and source records attributed to G Wennersten.

At least 19 recordsLinked to original sources
PubMed1990

Malignant melanoma: aetiological importance of individual pigmentation and sun exposure.

A case-control study of cutaneous malignant melanoma (CMM) was based on 523 incident cases and 505 age- and sex-matched controls selected from the general population. The purpose was to investigate the relative risk of developing CMM associated with different sun habits and indicators of pigmentation, such as skin type, eye colour and hair colour. Compared to people with black hair, blonde subjects had a relative risk of 74.4 (95% confidence interval, 45.8-120.8). Associations with skin type and eye colour were considerably weaker. Relative risks of about 1.5-2.5 were found for certain sun habits. The results suggest that in a population of Caucasian origin with a predominantly fair complexion, pigmentary status characterized by hair colour is a far more important aetiological factor than sun habits.

Eye Color↗
PubMed1988

The Scandinavian multicenter photopatch study 1980-1985: final report.

At 16 different dermatology clinics in Scandinavia from 1980-1985, photopatch testing was performed on 1993 patients with suspected photodermatosis. The collective results are presented in this article. The most common cause of sun-related dermatosis was polymorphic light eruption (PLE) (38%), while secondary aggravation of pre-existing skin diseases was established in 16% of the patient group. Photocontact dermatitis (11%) and contact dermatitis (10%) were responsible for 274 and 369 positive test reactions (respectively) on photopatch testing using the SPDRG standard series. Musk ambrette and para-aminobenzoic acid were the leading photosensitizers, while perfume mixture, balsam of Peru and lichen mixture were the most frequent causes of contact sensitivity. The principal photoallergens and contact allergens in the PLE, persistent light reaction and actinic reticuloid groups are discussed, together with the problems, risks and possible mechanisms of induction of photosensitization in these patients. The incidence, causes and diagnostic and therapeutic implications of secondary sunscreen sensitivity in these groups are also addressed.

Clinical Trials as Topic↗
PubMed1988

Concentration of trimethylpsoralen in blood and skin after oral administration.

Trimethylpsoralen (TMP) concentrations were determined in blood and skin of 21 patients given oral TMP therapy and were compared to data obtained from 5 patients treated with TMP baths. The quantitative determination was performed by gas chromatography with selected ion monitoring. Concentrations of up to 5.6 ng/ml were detected in whole blood from orally TMP treated patients, with about the same concentrations in patients given TMP baths. Whole skin biopsies from patients ingesting TMP showed concentrations in 14 patients that ranged from 30 to 1250 ng/g skin, median value 85 ng/g. Large interindividual variations were observed. Stripped skin from 5 patients after TMP baths showed a somewhat higher median value of 160 ng/g and their entire skin had fairly high concentrations, with a median value of 390 ng/g, probably mostly bound to stratum corneum. Different concentrations in different parts of the skin may explain the difference in phototoxic capacity when the drug is given locally.

Administration, Oral↗
PubMed1987

PUVA therapy for photosensitive psoriasis.

The purpose of this study was to assess the prophylactic effect of oral photochemotherapy with psoralens and UVA (PUVA) on patients with light-sensitive psoriasis. Of fifteen patients with photosensitive psoriasis, ten with a history of polymorphous light eruption (PMLE) slowly developing into psoriasis were treated with trimethylpsoralen (TMP) and UVA. Five patients with no preceding PMLE reaction were similarly treated; two with 8-methoxypsoralen (8-MOP), two with TMP and one in whom 8-MOP was later changed to TMP. Good to excellent results were obtained in 9/10 of the first category and in 3/5 of the second, giving an overall efficacy of 80%. Preexisting psoriatic lesions did not, however, heal during TMP therapy but did so when treated with 8-MOP. The results confirm, for light-sensitive psoriatics, the efficacy of PUVA in photosensitive disorders.

Female↗
PubMed1987

Photosensitive psoriasis--an immunohistochemical study after light provocation with UVA and UVB.

To gain further insight into the pathogenesis of photosensitive psoriasis, i.e. worsening of psoriasis lesions after sun exposure, 21 patients with this condition were studied following provocation with high doses of UVA and UVB. Thirteen of the patients had a history of polymorphous light eruption (PMLE). Here, a PMLE reaction could be induced by UV provocation. In 7 cases this developed further into psoriasis. In 8 of the 21 patients, psoriatic lesions developed subsequent to provocation with no preceding PMLE reaction. The test areas were periodically biopsied, and processed with a two-stage immunoperoxidase technique using monoclonal antibodies to immunophenotype the cell infiltrate. The dermal infiltrate consisted mainly of Leu-4+ cells (PAN-T). Leu-3+ cells (T-helper/inducer phenotype) dominated, with a smaller proportion of Leu-2+ cells (T-cytotoxic/suppressor phenotype), except in a few cases where these were prominent. This pattern was seen in all the groups investigated, including a control group of non-psoriatic PMLE patients. Exocytosis, with mainly Leu-2+ cells in the epidermis, was seen in most patients after psoriasis had developed. OKT-6+ (Langerhans) cells in the dermis were sparse, except in a few patients in all groups where a considerable number were observed. Leu-M1+ cells in the dermis (monocytes, granulocytes) were also sparse, but increased in most patients after psoriasis had developed. No B1+ cells (B lymphocytes) were seen, and very few Leu-7+ cells (NK). The only significant differences in the reaction pattern between the different clinical groups were the increased number of Leu-M1+ cells and the exocytosis of Leu-2+ cells after psoriasis had developed.

Adult↗
PubMed1986

Current aspects of polymorphous light eruptions in Sweden.

The prevalence of polymorphous light eruptions (PMLE) in a Swedish pharmaceutical company employing 412 individuals was estimated by the use of a detailed questionnaire, and 397 (96.4%) answered the survey. Their ages ranged from 18 to 65 yr (mean 40.2), and 66% were females. Eighty-three individuals (21%), mainly women (89%), had symptoms consistent with the diagnosis PMLE. Duration of their disease ranged from 1 to 53 yr, mean 14 yr. A positive family history of PMLE was surprisingly common (46%). Their threshold for sun tolerance was fairly high. They required rather high doses of sunlight to trigger their eruptions, 42% from 30 min to 2 h, and 45% greater than 2 h of solar irradiation. Only 3% had consulted a physician for their PMLE. A hardening phenomenon occurred in 84%. The PMLE group included habitual sunbathers (70%). A fair complexion was common in the PMLE group, 40% having skin types I and II, but as many as 59% had skin type III. Individuals with no light sensitivity had skin type I and II in 22%, and had skin type III in 69% of cases. In conclusion, PMLE is a common disorder and milder forms seem to be more prevalent than earlier described in northern countries such as Sweden.

Adolescent↗
PubMed1986

Photosensitive psoriasis--clinical findings and phototest results.

A total of 35 patients, 21 women and 14 men, with light-sensitive psoriasis deteriorating in summertime on solar exposure were clinically examined in detail and subjected to standardized phototest procedures. This included provocations with UVB and high dosage UVA exposures by the use of an UVASUN 3000 lamp, and also photopatch testing. All patients had long-standing psoriasis and had observed a photosensitivity from 2 to 40 years (men 11.4 yr). The photosensitivity had remained unchanged since its appearance in 21, had worsened in 13 and improved in only 1. A hardening phenomenon was noticed by 11 patients. Exacerbation of psoriasis from sun exposure was observed mostly on the back of the hands and forearms, followed in frequency by the legs, face, chest and back. No cases of other light-sensitive disorders, e.g. vitiligo, porphyrias or connective tissue diseases such as lupus erythematosus were detected. 5 patients used drugs capable of inducing photoallergy but no such reactions could be substantiated. Photopatch testing revealed no photoallergic contact reactions. Skin type distribution was normal, with no overrepresentation of skin type I-II which was registered in 26% (9/35) and skin type III-IV in 74% (26/35). 18/35 patients had a history of PMLE with a secondary evolution of psoriasis lesions. The PMLE reaction was most easily provoked by high-dosage UVA exposures (12/18). 17/35 had no history of a preceding PMLE reaction and, after provocations, new psoriasis lesions appeared successively, most easily provoked by UVB (9/17). The distribution of skin types was about the same in the two groups.

Female↗
PubMed1985

A qualitative and quantitative transmission electronmicroscopic study of the immediate pigment darkening reaction.

Five healthy Caucasians, 3 having skin type II and 2 having skin type III, were UVA irradiated up to 14.5 J/cm2. Punch biopsies were taken before and immediately after irradiation and processed for transmission electron microscopy. Qualitative observations of the keratinocytes were obtained from the 5 subjects, while morphometry was performed on 1 subject with immediate pigment darkening reaction (IPD) (skin type III) and 1 without IPD (skin type II). The number of preformed melanosomes was 10-fold higher in the melanocytes and keratinocytes of the subject showing IPD as compared with the one who did not. No statistically significant difference, however, was observed in either skin type regarding the number of mature (stage IV) melanosomes of basal keratinocytes or melanocytes, size of melanosomes or redistribution of melanosomes in keratinocytes after UVA irradiation. No changes of the ultrastructure in the keratinocytes could be observed. It is concluded that the IPD consists of a photochemical reaction in preformed melanosomes and that the absence of IPD in skin type II could be due to the presence of too few preformed melanosomes.

Dose-Response Relationship, Radiation↗
PubMed1984

The Scandinavian multicenter photopatch study. Preliminary results.

The Scandinavian photopatch test procedure has been applied to 745 patients with suspected photodermatoses during the years 1980-1981. Our experience has been encouraging with the recording of several relevant reactions. A total of 132 positive photocontact reactions and 120 ordinary contact reactions were seen. Photocontact reactions to musk ambrette (19 cases) and PABA (19 cases) were surprisingly frequent. The next most common photocontact reactions were to promethazine (24), chlorpromazine (22 cases) and fentichlor (12). Ordinary contact reactions were observed to balsam of Peru (30), PABA (23), lichen mix (21), wood mix (14) and to perfume mix (10).

4-Aminobenzoic Acid↗
PubMed1984

Outdoor and office photochemotherapy of vitiligo: a comparison.

The efficacy of oral trimethylpsoralen photochemotherapy with either natural solar exposures or artificial irradiations was investigated in a group of 63 vitiligo patients. Treatment with outdoor exposures during 2-3 summer seasons was found to be an inadequate therapeutic procedure under Swedish summer conditions. Office treatment with UVA cabins twice weekly led to a better therapeutic response but the number of treatments required for satisfactory repigmentation was high.

Adolescent↗