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Biomedical subjects

G Wennersten

Publications and source records attributed to G Wennersten.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1983

Studies of DNA and chromosome damage in skin fibroblasts and blood lymphocytes from psoriasis patients treated with 8-methoxypsoralen and UVA irradiation.

Exposure of human lymphocytes and skin fibroblasts in vitro to a single, clinically used dose of PUVA, i.e., 0.1 micrograms/ml of 8-methoxypsoralen (8-MOP) plus 0.9-4 J/cm2 of longwave ultraviolet radiation (UVA), lead to the formation of DNA damage as determined by alkaline elution, and to chromosome aberrations and sister chromatid exchanges (SCE). When lymphocyte-enriched plasma was obtained from psoriasis patients 2 h after oral intake of 8-MOP and then UVA irradiated (1.8-3.6 J/cm2) in vitro, an increased frequency of chromosome aberrations and SCE was observed. Normal levels of chromosome aberrations and SCE were found in lymphocytes of psoriasis patients after 3-30 weeks of PUVA treatment in vivo. A small but statistically significant increase in the SCE frequency was observed in the lymphocytes of psoriasis patients treated for 1-6 years with PUVA (mean 18.0 SCE/cell) as compared with before PUVA (mean 15.8, p less than 0.05). Skin fibroblasts of psoriasis patients analyzed 5 years after the start of PUVA treatment showed a normal number of SCE but a high fraction of filter-retained DNA in the alkaline elution assay, suggesting the presence of cross-linked DNA.

Chromosome Aberrations↗
PubMed1983

Long-term photochemotherapy for psoriasis: a histopathological and clinical follow-up study with special emphasis on tumour incidence and behavior of pigmented lesions.

A thorough clinical and microscopical investigation was conducted in patients with severe longstanding psoriasis maintained on long-term photochemotherapy with PUVA. 250 patients were reinvestigated after PUVA therapy for up to 7 years, 49% for 5 to 7 years. No serious side effects were observed. Occasional peculiar hyperkeratoses of a bowenoid type were seen in 3 patients (1.2%) and solitary lesions at actinic keratoses in 5 patients (2%). No occurrence of squamous cell carcinoma nor basal cell carcinoma was detected. Lentiginosis of varying degree was fairly common and seen in 33% and a very profuse disseminated lentiginosis in 4%. Six patients (2.4%) developed isolated, clinically dark and irregular lentiginous spots which on biopsy showed microscopically an aberrant morphology and were therefore classified as atypical lentigines. All of them had earlier been subjected to extensive courses of UVB treatment and 3 of them had history of earlier arsenic therapy. No malignant transformation was seen but those were for reasons of safety referred to the risk group category and may prove to be at particular risk on future PUVA therapy.

Adult↗
PubMed1983

The immediate action of long-wave ultraviolet radiation (UVA) on suprabasal melanocytes in human skin: a transmission electron microscopical study.

The immediate effects of long-wave ultraviolet irradiation (UVA) in non-erythemal doses on suprabasal melanocytes in normal skin of healthy caucasians with skin types II and III was investigated with the transmission electron microscopy (TEM) in order to detect possible morphological changes. In skin type III the melanocytes remained essentially unaltered, but in skin type II, multiple pinocytotic vesicles, large vacuoles, swelling, and partial to total dissolution of the inner membranes of the mitochondria and numerous small vesicles associated with an enlarged Golgi apparatus were observed after 3.6 to 14.5 J/cm2 of UVA irradiation. No IPD reaction was observed in any of the subjects with skin type II irradiated with UVA up to 20 J/cm2.

Adult↗
PubMed1983

Complications in the intralesional injection of triamcinolone acetonide by jet injector (Dermojet).

Two patients with lichenified eczematous lesions on the dorsal aspect of the hands were treated intralesionally with triamcinolone acetonide injected with an air-powered high-pressure device, Dermojet. The therapy was complicated by tendon rupture in one patient and by the development of a subcutaneous nodule, which was suspected to be a foreign body granulomatous reaction, in the other patient.

Aged↗
PubMed1982

The Scandinavian standard photopatch test procedure.

Recognizing the growing need for international standardization of photopatch testing techniques, a standard procedure has been used by Scandinavian dermatological clinics since January 1980. The set-up includes a standardized patient examination scheme, including phototest evaluation of the patient's UVA- and UVB-sensitivity, a standard photopatch tray containing 19 substances, and uniform techniques and criteria for the application and evaluation of the tests. Although modifications may be necessary in the future, preliminary experience with the Scandinavian photopatch set-up has been encouraging, and several positive reactions to most of the substances used have been recorded in the first 350 patients tested.

Humans↗
PubMed1982

Ophthalmological study of patients undergoing long-term PUVA therapy.

In the present study 46 patients with severe psoriasis maintained on long-term PUVA therapy have been followed up to 6 1/2 years after the initiation of treatment. Repeated ophthalmological examinations were performed in order to detect any early sign of lens changes. No ocular side effects attributed to the photochemotherapy were revealed during this period. Continued use of appropriate eye shielding is recommended and also routines to remind patients to actually wear their protective glasses.

Adult↗
PubMed1982

Chloroquine in treatment of porphyria cutanea tarda. Long-term efficacy of combined phlebotomy and high-dose chloroquine therapy.

The combined treatment with phlebotomy and high-dose chloroquine for PCT is described and 21 patients treated were followed up for periods of up to 6 years. Clinical and laboratory remissions were experienced by all patients. The urinary excretion of porphyrin and serum hepatic enzyme levels rose rapidly during therapy and then fell, mostly to levels well below that before treatment. The periods required for normalization of laboratory tests, median value, were 1.5 months for liver enzymes and 7 months for uroporphyrins. Clinical symptoms soon disappeared, blistering within 3 weeks and skin fragility within 12. Mild nausea or subfebrility was noted in some cases, but no other serious acute or chronic adverse reactions were observed. Clinical or biochemical relapse appeared in 9/21 (43%) patients who were then retreated. Relapsing cases showed a symptomfree period of 1-2.5 years after each treatment. Liver biopsy was performed in 4 relapsing cases prior to the repeated treatment and showed only mild siderosis and a mild fatty infiltration consistent with pathological liver findings in PCT but no evidence of chloroquine-induced permanent liver damage. The longest symptomfree period observed up to date was assessed for 7 patients who were followed up for more than 2 years after 1 single treatment. Four (57%) of them were symptomfree 5-6 years and no clinical or biochemical signs of relapse were observed. Our data confirm the efficacy of the high-dose therapeutic procedure, and the combined regimen with 1-2 phlebotomies prior to the chloroquine administration seems to be a safe procedure without any serious side effects. Our findings are discussed in relation to other current therapeutic modalities.

Adult↗
PubMed1981

Further evidence for increased light sensitivity in patients with malignant melanoma.

Minimal erythema dose (MED), immediate pigment darkening (IPD) and skin typing were performed on 130 patients with malignant melanoma and on seventy-three controls. The tumours were histologically classified according to Clark as superficial spreading melanoma, nodular melanoma, and lentigo maligna melanoma. The tumours of twelve patients were not possible to classify. Patients belonging to skin type IV and patients with lentigo maligna melanoma had a significantly higher mean age. The IPD reaction was significantly higher in skin type II than in skin types III and IV both in patients and in controls. IPD and MED showed no significant correlation to age and sex. MED was significantly lower among patients with malignant melanoma than controls. These data indicate that light sensitivity is of aetiological importance in malignant melanoma.

Age Factors↗
PubMed1980

Carotenoid treatment for light sensitivity: a reappraisal and six years' experience.

Long-term treatment with oral carotenoids in 57 patients suffering from a variety of photodermatoses and disorders associated with cutaneous light sensitivity was evaluated. All patients were treated for two or more 6-month periods in separate years. Best therapeutic results were seen in PMLE patients, a good to excellent therapeutic response was noted for 65% of all patients, increasing to 81% of those assigned to skin types III and IV, and decreasing to 47% of those with skin types I and II. The therapeutic effect observed in disorders characterized by other mechanisms than provocation by solar radiation per se was less conspicuous, viz. for light-sensitive psoriasis and lupus erythematosus. Even here, therapeutic failure seems to be more common in individuals with skin types I and II than for skin types III and IV. Photodermatoses such as persistent light reaction, actinic reticuloid and solar urticaria did not respond to any significant degree to carotenoid treatment. Our findings would appear to justify further treatment with oral carotenoids in selected cases of PMLE, and a higher dosage level may be tried for non-responding individuals with light-sensitive psoriasis and DLE or SLE. Serious side effects have not been observed in spite of long-term therapy lasting several years.

Administration, Oral↗
PubMed1980

Clinical aspects of the immediate pigment darkening (IPD) reaction in normal individuals.

In order to investigate the clinical characteristics of the immediate pigment darkening (IPD) reaction for normal healthy Caucasian individuals and its conceivable relation to age, sex, skin type and to the minimal erythema dose (MED), a standardized light testing procedure was used and 72 subjects were studied. Skin type III was the most common, being found in 78% of the individuals; skin types II and IV were less common, found in only 12.5% and 9.5% respectively. Skin type I was not observed at all. Individuals with skin type II were found to have a significantly lower mean MED than those with skin types III and IV, and the IPD threshold dose was 9.0 J/cm2 or more, which was significantly more than for skin types III and IV. The IPD reaction was absent in several individuals with skin type II under the experimental conditions used. Some differences were observed concerning the mean MED and IPD threshold doses between skin types III and IV but they were not statistically significant. Age or sex did not appear to be significantly related to the MED and IPD threshold doses observed, and, furthermore, no significant correlation, either positive or negative, was found between the MED and the IPD threshold doses when investigated for individuals with skin type III.

Adult↗
PubMed1979

Effect of food on kinetics of 8-methoxsalen.

Kinetics of 8-methoxsalen were studied in 5 healthy subjects under fasting and nonfasting conditions. The plasma concentration-time data could be fitted to a zero order absorption one-compartment model. The area under the curve (AUC) values were higher (p less than 0.05) under nonfasting compared to fasting conditions, indicating higher relative bioavailability of the drug in the presence of food. No significant differences were observed in the lag-time for the start of the absorption, the apparent zero-order absorption rate constant, or the elimination rate constant. It is suggested that the drug should be taken in a standardized way in relation to food during the ultraviolet (UV) light treatment.

Biological Availability↗