Biomedical subjects

R U Peter

Publications and source records attributed to R U Peter.

At least 127 records · Page 7Linked to original sources

PubMed1995

Multiple superficial basal cell carcinomas (basalomatosis) following cobalt irradiation.

Basalomatosis is an uncommon skin condition characterized by the occurrence of multiple basal cell carcinomas. Many cases reported in the literature have been attributed to arsenic treatment in psoriasis patients. We report a patient with basalomatosis caused by cobalt-60 (60Co) irradiation. A 55-year-old farmer developed 43 basal cell carcinomas 20 years after treatment of an immunoblastoma with 60Co irradiation. All the tumours were located within the radiation fields. Other possible causes of basalomatosis, such as arsenic intoxication and basal cell naevus syndrome, were excluded. The patient's multiple superficial basal cell carcinomas probably represent a late adverse effect of the 60Co irradiation.

Basal Cell Carcinoma↗

PubMed1995

Successful treatment and prophylaxis of scalp seborrhoeic dermatitis and dandruff with 2% ketoconazole shampoo: results of a multicentre, double-blind, placebo-controlled trial.

Pityrosporum ovale appears to play an important role in the pathogenesis of seborrhoeic dermatitis. Ketoconazole is an antimycotic agent with a high in vitro and in vivo efficacy against P. ovale. We performed a multicentre study to investigate the efficacy of ketoconazole 2% shampoo in the treatment and prophylaxis of seborrhoeic dermatitis and dandruff. Five hundred and seventy-five patients presenting with moderate to severe seborrhoeic dermatitis and dandruff of the scalp were treated with 2% ketoconazole shampoo twice weekly for 2-4 weeks, producing an excellent response in 88%. Of those patients who responded, 312 were included in a prophylactic phase, lasting 6 months. These patients were treated with the active preparation (shampoo containing 2% ketoconazole) once-weekly, once every other week, alternating with placebo (shampoo without ketoconazole), or with placebo only once-weekly. Forty-eight (47%) patients in the placebo group experienced a relapse of seborrhoeic dermatitis, compared with 23 (19%) patients in the active treatment group, and 31 (31%) patients in the active/placebo group. The medication was well tolerated in all three groups. We conclude that ketoconazole 2% shampoo is highly effective, not only in clearing scalp seborrhoeic dermatitis and dandruff, but also in preventing relapse of the disease when used prophylactically once weekly.

Adult↗

PubMed1994

Dicentric and translocation analysis for retrospective dose estimation in humans exposed to ionising radiation during the Chernobyl nuclear power plant accident.

Chromosome analyses were carried out in peripheral blood lymphocytes obtained between September 1991 and March 1992 from 15 persons exposed to ionising radiation during the Chernobyl nuclear power plant accident. At present, all are being treated for symptoms of the delayed stage of the cutaneous radiation syndrome. Biological dose-equivalent estimates were determined, either by measuring the frequency of dicentric and ring chromosomes in first division unstable cells from conventional preparations (Qdr method), or by measuring the frequency of stable translocations using two-colour fluorescence in situ hybridisation (FISH) with composite whole chromosome-specific DNA libraries for human chromosomes 1, 4 and 12 (chromosome painting) and a degenerate alpha-satellite pancentromeric DNA probe. With both methods fairly comparable individual estimates between 1.1 and 5.8 Gy were obtained for 12 of 15 individuals. Three individuals exhibited no elevated aberration frequencies. Perspectives and limitations of chromosome painting for dose reconstruction of past radiation exposures are discussed.

Cells, Cultured↗

PubMed1994

Chronic cutaneous damage after accidental exposure to ionizing radiation: the Chernobyl experience.

BACKGROUND: The hazards of acute radiation exposure are well known. Bone marrow failure from total body gamma or neutron irradiation is the most clinically relevant aspect of acute radiation disease. With nonhomogeneous exposure, as is characteristic in accidents, other organ systems, such as the skin, may be more important in determining clinical prognosis. This became obvious in the two worst radiation accidents since 1945, the Chernobyl accident in April 1986 and the Goiania accident in September 1987. OBJECTIVE: Our purpose was to describe the characteristic chronic sequelae of accidental cutaneous radiation in a group of patients who survived the Chernobyl nuclear power plant accident. METHODS: Fifteen patients with the delayed type of the cutaneous radiation syndrome were examined between September 1991 and January 1992. All patients had a history of acute radiation disease. The exposure pattern was characterized by partial body exposure with high doses of beta and gamma irradiation from radioactive water, steam, or dust. RESULTS: Radiation-induced lesions were confined primarily to the legs and distal arms, but sometimes involved up to 50% of the total body surface. In addition to telangiectases, radiation keratoses, and radiation ulcers, hemangiomas, hematolymphangiomas, splinter hemorrhages in the distal nail bed, lentiginous hyperpigmentation, and severe subcutaneous fibrosis were noted. No malignant transformation could be detected. Associated diseases included cataracts, chronic hepatitis, and recalcitrant bacterial and herpesvirus infections. CONCLUSION: After accidental partial body exposure to high doses of beta and gamma irradiation, the predominant involvement of the skin, described as the cutaneous radiation syndrome, can become the characteristic feature. This causes longlasting, serious diagnostic and therapeutic problems.

Accidents↗

PubMed1994

Ionizing radiation induces human intercellular adhesion molecule-1 in vitro.

Intercellular adhesion molecule-1 (ICAM-1) plays a central role in various inflammatory reactions and its expression is readily induced by inflammatory stimuli such as cytokines or ultraviolet irradiation. We have investigated the effect of ionizing radiation (IR) on human ICAM-1 expression in human cell lines and skin cultures. ICAM-1 mRNA levels in HL60, HaCaT, and HeLa cells were elevated at 3-6 h after irradiation and increased with doses from 10-40 Gy. The rapid induction of ICAM-1 occurred at the level of transcription, was independent of de novo protein synthesis, and did not involve autocrine stimuli including tumor necrosis factor-alpha and interleukin-1. IR also induced ICAM-1 cell surface expression within 24 h. Immunohistologic analysis of cultured human split skin revealed ICAM-1 upregulation on epidermal keratinocytes and dermal microvascular endothelial cells 24 h after exposure to 6 Gy. In conclusion, we propose ICAM-1 as an important radiation-induced enhancer of immunologic cell adhesion, which contributes to inflammatory reactions after local and total body irradiation.

Antibodies↗

PubMed1993

Increased expression of epidermal IL-8 receptor in psoriasis. Down-regulation by FK-506 in vitro.

IL-8 is a chemotactic cytokine with proinflammatory and growth-promoting activities. Recently it has been shown to influence several functions of keratinocytes, including HLA-DR expression, chemotaxis, and proliferation by binding to a specific receptor. Because psoriasis vulgaris is characterized by epidermal hyperproliferation and infiltration of inflammatory cells, we investigated the expression of IL-8 and its receptor in normal and psoriatic epidermis using semiquantitative reverse-transcriptase-polymerase chain reaction. In addition the mRNA levels of the proto-oncogenes c-ras, c-raf, c-myc, and HER-2 were also investigated as potential growth-promoting stimuli in psoriatic epidermis. IL-8 mRNA was only detected in lesional psoriatic epidermis, and IL-8R-specific mRNA was found to be 10 times increased in lesional psoriatic epidermis. There was no significant difference in the protooncogene mRNA levels. In order to test the relevance of the massively increased IL-8R levels in psoriatic epidermis, we investigated the effect of the antipsoriatic drug FK-506 on specific IL-8 and IL-8R mRNA expression. FK-506 dose dependently inhibited IL-8R expression and function. Our data suggest that in psoriatic skin, elevated IL-8 levels and markedly increased IL-8R expression may act in concert to induce the cardinal signs of psoriasis--epidermal hyperproliferation and leukocyte infiltration. IL-8R may prove a molecular target for antipsoriatic drugs such as FK-506.

Adult↗

PubMed1993

Analytic morphology in clinical and experimental dermatology.

During the past several years, quantitative morphology has gained increasing attention in diagnostic pathology and in certain research applications. In the field of dermatopathology, quantitative morphology has been applied to numerous problems, ranging from the interactive measurement of nuclear contours to fully automated, high-resolution image analysis of ultrastructural micrographs. Dermatologic applications are reviewed, and potential developments in the future are briefly outlined.

Animals↗

PubMed1993

Therapeutic efficacy of oral low-dose cyclosporin A in severe psoriatic arthritis.

Six male patients with severe psoriatic arthritis (PA) unresponsive to various topical and systemic therapies have been treated with oral cyclosporin A (CyA; Sandimmun) solution at daily doses ranging usually from 1.5 to 5.0 mg/kg. In 1 case the dose had to be increased to 7 mg/kg/day. At initiation of CyA therapy skin involvement was between 40 and 90% of total body surface. Initiation of CyA therapy resulted in marked improvement of skin lesions within 2-7 weeks accompanied by impressive relief from arthralgias and improvement of joint function. The requirement for nonsteroidal anti-inflammatory drugs was markedly reduced in all cases. All patients in whom CyA therapy was continued remained clinically stable for several months (follow-up period 2-7 months). Although mild to moderate relapses occurred, rebound phenomena were not observed after discontinuation of treatment. Side effects which comprised serum creatinine increases in 3 out of 6 cases were reversed by adjustment of CyA dosage.

Administration, Oral↗

PubMed1993

Increased expression of the epidermal growth factor receptor in human epidermal keratinocytes after exposure to ionizing radiation.

The effect of exposure of human epidermal keratinocytes to ionizing radiation, both in vivo and in vitro, on the expression of the epidermal growth factor receptor (EGF-R) was studied on the protein, mRNA, and functional levels. Quantitative fluorometry of short-term organ cultures incubated with a monoclonal antibody against human EGF-R revealed a dose-dependent increase of EGF-R expression 24 h after irradiation with 4 and 6 Gy, with an additional increase after 48 h. In biopsy specimens from patients undergoing radiation therapy a markedly increased expression could be determined by quantitative fluorometry during radiation therapy which wa still considerably above the baseline level 4 weeks after termination of treatment. Radioligand binding assays demonstrated a 50% increase in 125I-EGF binding to primary keratinocytes and A431 cells, at doses of 1 Gy, with a further increase after 72 and 96 h. Northern blots were performed with total RNA from two human epidermal cell lines (SCLII and A431). In A431 cells, increased EGF-R transcript levels could be detected 48 h after irradiation. In cells of the SCLII cell line, EGF-R expression was not affected by irradiation. These results were confirmed by semiquantitative polymerase chain reaction of primary cultured keratinocytes, demonstrating an increase of transcripts of EGF-R 24 h after irradiation with single doses of 6 Gy. Thus exposure to ionizing radiation leads to an increased expression of functionally intact EGF-R in human keratinocytes, at the protein and mRNA levels, both in vitro and in vivo; we hypothesize that this effect is part of a stress program of epidermal cells in response to ionizing radiation, ensuring rapid repopulation of irradiated areas.

Base Sequence↗

PubMed1993

[Psoriasis arthropathica].

BACKGROUND: Five to seven percent of patients with psoriasis suffer additionally from accompanying arthritis. AIM OF THE STUDY: In this article, we review the current knowledge on clinical, diagnostic and therapeutic aspects of the disease. PATIENTS AND RESULTS: Data are presented on the treatment of six patients with the immunosuppressant ciclosporin. Therapeutic results with this drug are superior to agents traditionally used for management of psoriatic arthritis. CONCLUSION: The therapeutic options have been enlarged by the introduction of new immunosuppressive drugs, particularly ciclosporin.

Adolescent↗

PubMed1993

[Incontinentia pigmenti in a male patient].

Incontinentia pigmenti (Bloch-Sulzberger syndrome) is a rare genetic disorder usually affecting females. Familial cases show an X-linked dominant inheritance with male lethality. The typical skin manifestations occur in several stages and can be associated with various extracutaneous anomalies. We report on a 10-month-old male patient with incontinentia pigmenti (IP) and a normal male karyotype. Besides the typical cutaneous lesions no other signs have been found so far. IP in male patients can be explained by the presence of Klinefelter syndrome, by the half-chromatid mutation model, or by an early somatic mutation. On the basis of this case report we discuss the clinical findings in and the genetics of IP.

Biopsy↗

PubMed1992

Interleukin-8 receptor-mediated chemotaxis of normal human epidermal cells.

Normal human keratinocytes show chemotactic behavior towards interleukin-8 (IL-8). Under physiological conditions this cytokine seems to be present in an equilibrium between monomeric and dimeric forms, as indicated by Western blotting data. Radioligand binding studies suggest that keratinocyte chemotaxis is mediated by receptors specific for IL-8 dimers. IL-8 receptor-specific mRNA can be detected in a keratinocyte cell line by polymerase chain reaction.

3T3 Cells↗

PubMed1992

Prevalence of dysplastic nevi in healthy young men.

Young white men (1176 men, mean age 20 years, age range from 18 to 26 years) were examined for dysplastic nevi. In 78 patients (6.63%), 107 clinically dysplastic nevi were observed, demonstrating all three NIH criteria (diameter greater than 5mm, irregularities of border, irregularities of color) suggestive for clinically dysplastic nevi. Of these, 71 nevi in 52 patients were excised and examined histologically, 46 nevi in 26 patients were not excised due to lack of patients' consent. Fifty-two of 78 (66.6%) patients with clinically dysplastic nevi agreed to excision. In these, seven nevi (13.5% of patients or 9.86% of all nevi excised) were confirmed by histology. According to these data, three additional patients with dysplastic nevi would have been expected among the 26 patients who refused surgery. Referring to the entire study group, the prevalence of dysplastic nevi in young white men is expected to be 0.85%.

Adolescent↗

PubMed1992

Interleukin-8 receptors in normal and psoriatic polymorphonuclear leukocytes.

Polymorphonuclear leukocyte (PMNL) infiltration is an important characteristic in psoriatic lesions. The proinflammatory 8-kD peptide interleukin-8 (IL-8) is present in psoriatic scales and possesses a high chemotactic activity on human neutrophils, which may relate to its role in psoriasis. Its chemotactic activity is mediated via specific receptors on PMNL. The goal of our work was to ascertain whether PMNL infiltration in psoriasis can be accounted for by functional abnormalities of the circulating PMNL due to alterations in the IL-8 receptor density or affinity (or both). Results of radioligand binding studies performed in 10 psoriatic patients, 10 patients with atopic eczema and 11 normal controls showed no difference in receptor affinity (Kd) between the groups. However, a slight but significant elevation in IL-8 receptor density was seen on PMNL from psoriatic individuals (31,230 +/- 3,237 binding sites per cell) compared to those from normal volunteers (24,152 +/- 2,643) and atopic eczema patients (24,092 +/- 2,743). Increased number of IL-8 receptors may, besides elevated cutaneous IL-8 concentrations, contribute to the intraepidermal accumulation of PMNL in psoriasis.

Adult↗

PubMed1992

[Extracutaneous malignant melanomas: clinical aspects and biology].

Approximately 5% of all malignant melanomas originate from primarily non-cutaneous sites. They are preferentially distributed along the choroid, the meninges, the subserous space of the oesophagus and the intestinal tract, at transitional areas of mucous membranes, and along organ capsules, the periadventitial tissues of major blood vessels, and, occasionally, muscle fasciae. Little is known about their biological behaviour; the prognosis, however, generally has to be considered less favourable than that of primary cutaneous malignant melanomas, probably at least in part because they are often not discovered until they are in advanced stages. There are no specific clinical signs suggestive for non-cutaneous malignant melanomas; symptoms vary with the site of manifestation of the tumours. Interpretation of these clinical data based on results from comparative anatomical studies leads to the conclusion that extracutaneous malignant melanomas in humans are residuals of phylogenetically old, extensive and well-developed non-cutaneous pigment cell patterns demonstrable in a variety of lower vertebrates, which result from interactions between organogenesis and pigment cell development during ontogeny. This demonstrates that consideration of fundamental principles of developmental biology can give diagnostic clues to the localizations at which primary non-cutaneous malignant melanomas may be suspected and can thus facilitate decisions about what diagnostic procedures are necessary.

Animals↗

PubMed1992

[Cyclosporin A in the therapy of inflammatory dermatoses].

The experience reported in the literature with cyclosporin A (CyA) in the treatment of various inflammatory and autoimmune dermatological diseases is reviewed and compared with the authors' own experience of treating 36 patients presenting with psoriatic arthritis [8], generalized pustular psoriasis [2], palmoplantar pustular psoriasis [12], Behçet's disease [2], disseminated circumscribed scleroderma [2], acrodermatitis continua suppurativa [2], pemphigus vulgaris [1], lupus erythematosus [3], pyoderma gangrenosum [1], severe atopic eczema [2], and actinic reticuloid [1]. On the basis of the authors' own experience and the reported results, treatment with CyA appears to be primarily indicated in pyoderma gangrenosum, circumscribed scleroderma, psoriatic arthritis and acrodermatitis continua suppurativa. In diseases such as actinic reticuloid, Behçet's disease, localized and generalized pustular psoriasis, treatment with CyA leads to good results with an acceptable risk-benefit ratio. In our view, it is doubtful whether treatment with CyA alone is indicated in alopecia areata, lichen ruber, dermatomyositis, atopic eczema, systemic scleroderma, bullous diseases, and lupus erythematosus, and in the last two it should be given only in combination with systemic steroids. Literature reports provide no support for the use of CyA in ichthyosis vulgaris, pityriasis rubra pilaris, and cutaneous T-cell lymphomas. The risk-benefit ratio of CyA treatment should be carefully considered, especially in diseases that are not life-threatening.

Behcet Syndrome↗

PubMed1992

[Two superficially spreading malignant melanomas on nevus spilus].

A case of a 49-year-old patient with two superficial spreading melanomas arising from a naevus spilus is presented. Although opinions differ on the potential for malignant transformation in naevi spili, they should be carefully watched, and if changes are found these lesions should be subjected to histopathologic examination.

Cell Transformation, Neoplastic↗

PubMed1991

Annular erythema associated with Sjögren's syndrome: a variant of systemic lupus erythematosus.

We present a Burmese patient with widespread annular erythema associated with Sjögren's syndrome. Unlike previously described cases, the disease occurred in the setting of systemic lupus erythematosus. Photoprovocation testing revealed light sensitivity in the UVA range with elicitation of subacute cutaneous lupus erythematosus-like lesions. The presence of an erythema annulare centrifugum-like eruption should initiate the search for Sjögren's syndrome and systemic lupus erythematosus.

Adult↗