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Biomedical subjects

I Rosdahl

Publications and source records attributed to I Rosdahl.

At least 37 records · Page 2Linked to original sources
PubMed1997

Vitamin A metabolism and mRNA expression of retinoid-binding protein and receptor genes in human epidermal melanocytes and melanoma cells.

Retinoids inhibit proliferation of melanocytes and melanoma cells and affect disorders of hypo- and hyperpigmentation. Such effects might involve retinoid-binding proteins, retinoid metabolites and nuclear retinoid receptors for transcriptional activation. We detected messenger RNA transcripts for the cellular retinol- and retinoic acid-binding proteins (CRBP, CRABP I and II) in cultured epidermal melanocytes. In the melanoma cell lines the major transcript was CRABP II. Nuclear retinoic acid (RA) receptor transcripts and the 9-cis-retinoic acid receptor transcript were detected in all cells. The endogenous concentrations of retinol (ROH) and its metabolite 3,4-didehydroretinol (ddROH) in melanocytes were five times those in melanoma cells. When cells were incubated with [3H]ROH the main metabolites in the melanocytes were [3H]ddROH (4%) and [3H]RA (0.4%). Formation of [3H]RA was only detected in one melanoma cell line. Both melanocytes and melanoma cells produced an unidentified metabolite when incubated with [3H]ROH and [3H]RA. Dissimilarities in the metabolism and endogenous concentration of retinoids between benign and malignant melanocytes might play a key role in differentiation and growth regulation.

Cells, Cultured↗
PubMed1997

Assessment of sun-related behaviour in individuals with dysplastic naevus syndrome: a comparison between diary recordings and questionnaire responses.

In Sweden, individuals with dysplastic naevus syndrome (DNS-D2), a high risk group for malignant melanoma, are regularly screened and informed about self-examination and sun protection. During the summer of 1994, 54 out of 65 consecutive patients completed 1 month of daily self-recordings of sun-related behaviour. The diary report was compared with questionnaire responses obtained 6 months later concerning sun-related behaviour, both habitual and during the month of self-recording. The correspondence between the sun-related behaviour recorded in the diary and given in response to the questionnaire was fairly high, but 48% underestimated and 29% overestimated their actual number of sunbathing occasions in the questionnaire. Few patients indicated habitual high frequencies of sunbathing, although some of them recorded six or more occasions during 1 month in the diary. Those who recorded multiple sunburns reported the highest number of sunburns in the questionnaire. Patients who scored high on sunbed use also recorded high numbers of sunbathing occasions. Diaries should be used when detailed information about the magnitude of sun-related behaviour is essential, whereas questionnaires should be sufficient in studies aiming to differentiate between high and low frequencies of such behaviour.

Adolescent↗
PubMed1996

Boy with a ring 7 chromosome: a case report with special reference to dermatological findings.

A ring chromosome 7 was found in an 8-year-old boy investigated on account of short stature and facial dysmorphism. He had a fair skin, almost white hair, cafe-au lait spots and many black atypical pigmented naevi. Electron microscopy of his skin revealed structural changes in melanocytes and keratinocytes, suggesting disturbed cell growth and differentiation.

Cafe-au-Lait Spots↗
PubMed1996

Sun-related behaviour in individuals with dysplastic naevus syndrome.

In Sweden, individuals with dysplastic naevus syndrome are regularly screened and informed about self-examination and sun-protection at special clinics. This study describes sun-related behaviour in this group. A total of 54/65 consecutive patients with dysplastic naevus syndrome (28 women and 26 men) completed diary recordings of sun-related behaviour during 1 month in 1994. A majority (81%) reported sunbathing with the intention to get a tan, mean number of occasions 9.2, range 1-24 occasions, during the month of recordings. Out of these, 61% reported sunburns, some of them repeatedly up to 7 times. Sunbathing occurred mainly in bathing suits during midday in sunny weather, with a mean duration of 2.5 h per occasion. Such a hazardous behaviour in the sun in a melanoma high risk group is alarming. New models for intervention to support a more sun protective life style in this group of patient have to be elaborated.

Adolescent↗
PubMed1992

Regional distribution of melanocytic naevi in relation to sun exposure, and site-specific counts predicting total number of naevi.

The role of exposure to ultraviolet light in the formation of melanocytic naevi was analysed by investigating the regional naevus distribution in 310 subjects (30-50 years) from a Swedish census file. The lateral aspect of the arms and the back had the largest concentration of naevi. The mean naevus count per unit surface area was higher in intermittently exposed than in rarely exposed skin (p less than 0.001), while the lowest mean count was found in chronically exposed skin. These results support the idea that intermittent exposure to ultraviolet light has a "naevogenic" effect while chronic exposure might be protective. Dysplastic naevi had a distribution pattern quite different from common naevi. Considering the distribution pattern solely, dysplastic naevi seem to develop independently of exposure to ultraviolet light. The numbers of naevi in different skin areas were tested for their power in predicting the total body naevus count. The strongest correlations were found between total counts and counts on the anterior surface of the thighs and the lateral aspect of the arms. Counts from any of these areas will provide a practical and satisfactory estimate of the total number of naevi.

Adult↗
PubMed1991

Prevalence of common and dysplastic naevi in a Swedish population.

The naevus profile was examined in a Swedish population that was randomly selected from a census file. The participation rate was considered high at 82%. The number of common naevi (CN) and the prevalence of dysplastic naevi (DN) were investigated in 379 subjects (aged 30-50 years). The mean total body count of CN greater than or equal to 2 mm was 67 (range 1-300). As many as 22% of the population had 100 naevi or more and only 18% had less than 25. The counts were not influenced by age or sex. DN were diagnosed clinically in 18% (CI 14-22%) of the subjects and histologically in 8% (CI 5-11%). Subjects with dysplastic naevi had a significantly larger number of common naevi and a more sun-sensitive skin type than subjects without DN, P less than 0.001.

Adult↗
PubMed1991

Melanocytic naevi in sun-exposed and protected skin in melanoma patients and controls.

The possible link between exposure to ultraviolet light and naevus development was studied in 121 melanoma patients and 310 controls by comparing the number of naevi in a sun-exposed area on the back with that in a sun-protected area on the buttocks. Both patients and controls had a four-fold increase in the number of naevi in the exposed compared with the protected area, p less than 0.001. The difference in naevus count between the exposed and the protected area was larger in patients than in controls, p less than 0.001. Subjects with dysplastic naevi, melanoma patients as well as controls, had a larger difference in the number of naevi between the two areas than subjects without dysplastic naevi, p less than 0.001. These results support the idea that sunlight plays an important role in naevus development and may explain why a high naevus count is a risk marker for malignant melanoma.

Adult↗
PubMed1991

Common and dysplastic naevi as risk factors for cutaneous malignant melanoma in a Swedish population.

Common naevi, dysplastic naevi (DN) and other phenotypic features were evaluated as melanoma risk factors in a Swedish case-control study. One-hundred and twenty-one prevalent melanoma cases and 378 randomly selected controls participated. The mean total body naevus count was 115 in the cases and 67 in the controls. Fifty-six per cent of the cases and 18% of the controls had clinical DN. The corresponding figures for histologically diagnosed DN were 40% and 8% respectively. Clinical DN was as good as histologically diagnosed DN in identifying individuals at risk for melanoma. Subjects with sun-sensitive skin, greater than or equal to 150 naevi and presence of DN have 50 times higher melanoma risk than those without these characteristics.

Adult↗
PubMed1989

UVB irradiation induces melanocyte increase in both exposed and shielded human skin.

This study demonstrates for the first time in humans that UV light induces an increase of the melanocyte population in exposed skin as well as in shielded areas. Because an increased mitotic activity could promote tumor development, UV exposure might play a role in melanoma development not only in exposed but also in covered skin. In addition, it was found that subjects who initially had a small melanocyte population showed a larger increase in both exposed and covered skin compared to those with a high initial density. Individuals with a low density might therefore constitute a risk group for the development of malignant melanoma. These findings support the view that infrequent periods of intensive UV irradiation might be more harmful than regular exposure.

Adult↗
PubMed1989

Epidermal Langerhans' cells in chronic eczematous dermatitis of the palms treated with PUVA and UVB.

Epidermal Langerhans' cells (LC) were studied in patients with chronic eczematous dermatitis of the palms. The monoclonal antibodies anti-Leu 6 and anti-HLA-DR were used, and the cells visualized with an immunoperoxidase technique. Increased numbers of LC were found in allergic contact dermatitis as well as in irritant contact dermatitis and hyperkeratotic dermatitis of the palms. The increased number of epidermal LC in lesional skin may facilitate presentation of exogenous or endogenous antigens to activated T-cells. One hand was treated with PUVA or UVB and the other hand served as a non-exposed control. PUVA treatment cleared the dermatitis and the LC number decreased markedly. With UVB treatment clinical improvement was achieved, and a less pronounced decrease in epidermal LC was noticed. There seems to be a crude relationship between the extent of clinical improvement and the reduction in epidermal LC numbers. The change in LC might be a primary event or secondary to a reduction of the inflammatory process.

Adult↗
PubMed1988

Urinary excretion of 5-S-cysteinyldopa in relation to skin type, UVB-induced erythema, and melanocyte proliferation in human skin.

5-S-Cysteinyldopa (5-S-CD) is found in all pigment-producing cells and is the major precursor of phaeomelanin. However, the melanocyte specificity of the compound has been questioned. In order to elucidate the origin of 5-S-CD, we have now systematically studied the relationship between the 5-S-CD excretion in urine and the size of the melanocyte organ, UV-induced melanocyte proliferation, skin type, and the erythemal reaction. The skin type had no influence on the basal excretion of 5-S-CD. There was no significant correlation between the basal 5-S-CD excretion and the size of the melanocyte organ; that is, the number of skin melanocytes and nevi. During the irradiation, subjects with skin type II developed a more pronounced erythema (p less than 0.01) and had a significantly higher 5-S-CD excretion than those with skin type III-IV (p less than 0.01). No correlation was found between 5-S-CD excretion and UV-induced melanocyte proliferation. The lack of correlation between the basal 5-S-CD excretion and skin type or number of melanocytes suggests that the basal 5-S-CD in urine is mainly of extra-melanocytic origin. Our findings favor the view that the increase in 5-S-CD excretion during UV irradiation is due to UV damage.

Adult↗
PubMed1988

Curettage of molluscum contagiosum in children: analgesia by topical application of a lidocaine/prilocaine cream (EMLA).

The analgesic effect of a lidocaine/prilocaine cream (EMLA) for the curettage of molluscum contagiosum was evaluated in 55 children aged 3-14 years. Five to 25 molluscs per child were covered with a maximum of 10 g EMLA cream one hour before the operation. The pain was rated as either none or slight by 93% of the children while the physician's assessment was 96%. On a 100 mm Visual Analogue Scale (VAS) where 0 represented no pain and 100 severe pain, the median rating by the children was 3 mm. Mild vasoreactions such as pallor, redness or oedema were observed locally at the treated skin areas. The results show that EMLA cream provided effective local anaesthesia for the curettage of molluscs.

Administration, Cutaneous↗
PubMed1988

Epidermal Langerhans' cells in patients with pustulosis palmoplantaris treated with etretinate or etretinate + methoxsalen photochemotherapy.

Epidermal Langerhans' cells (LC) were studied in patients with pustulosis palmoplantaris (PPP) by utilizing the monoclonal antibodies anti-Leu6 and anti-HLA-DR in combination with an immunoperoxidase technique. In non-pustular areas of the skin lesions in PPP, an increased number of epidermal LC was found compared with control subjects. No change in LC counts was observed following etretinate monotherapy for 2 weeks. Etretinate was then combined with PUVA treatment of one palm/sole with the contralateral side as a non-UVA exposed control. After 6-12 weeks of etretinate + PUVA treatment the PPP had resolved and the number of epidermal dendritic HLA-DR+ and Leu6+ cells had normalized. On the contralateral side, etretinate treatment induced a marked clinical improvement and a reduction of HLA-DR+ cells. The observation of an increased LC population in active PPP and a reduction during clinical improvement indicates a close relationship between LC and the activity of PPP.

Adult↗
PubMed1988

UVB-induced melanocyte proliferation and 5-S-cysteinyldopa excretion in dysplastic nevus syndrome.

This is the first in vivo study of the effects of UV on the epidermal melanocytes in dysplastic nevus syndrome (DNS). Eleven DNS patients and 22 healthy subjects were given total body UVB irradiation 8 times during 17 days and the melanocyte population was estimated in biopsies from shielded and irradiated skin. There was a doubling of the melanocyte counts in irradiated skin and a less pronounced but significant increase in the shielded skin area. The urinary excretion of 5-S-cysteinyldopa (5-S-CD) was measured before, during and after the irradiation period. The 5-S-CD excretion reached a maximum after 2 weeks of irradiation and returned towards the basal value after the irradiation period. We were not able to document any abnormal melanocytic UV response in DNS patients before, during or after the irradiation.

Adult↗
PubMed1987

HLA-DR3 antigens in erosive oral lichen planus, cutaneous lichen planus, and lichenoid reactions.

HLA antigens were examined in patients with erosive oral lichen planus (OLPe), cutaneous lichen planus (CLP), or lichenoid reactions (LR) adjacent to amalgam fillings. The control group had amalgam restorations in contact with the oral mucosa but without any reactions. A strong association was found between HLA-DR3 and OLPe, with an RR value of 21.0 (p less than 0.05). The corresponding values for CLP and LR were 2.3 and 1.5, respectively (NS). The haplotype A1-B8-DR3 was more frequently found in OLPe (p less than 0.05) and CLP (p less than 0.05) than in LR and controls (NS). The data indicate that OLPe, CLP, and LR, which present with virtually the same histopathologic features, are different in their association with HLA-DR3. Moreover, the increased frequency of HLA-DR3 in OLPe suggests an autoimmune component in the pathogenesis of this disorder.

Adult↗
PubMed1985

Hyperkeratosis lenticularis perstans: report on three cases.

Three women with hyperkeratosis lenticularis perstans (HLP) are described. The lesions developed after the age of 45 and there was no family history of this disease. The possible role of UV-light in the pathogenesis of this disease is discussed.

Aged↗
PubMed1983

An estimate of the melanocyte mass in humans.

The size of the melanocyte system in humans was estimated as though all active melanocytes in the body were assembled in a single compact organ. Our estimates indicate that the epidermal melanocytes constitute the dominant part of the "melanocyte organ." In an adult human not recently exposed to sunlight, the functionally active epidermal melanocytes form a tissue 1.0-1.5 cm3. Other melanocytes, such as those in the mucous membranes, the follicles, and the eyes, constitute only a small proportion of the total melanocyte cell mass.

Body Composition↗