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Biomedical subjects

R U Peter

Publications and source records attributed to R U Peter.

At least 37 records · Page 2Linked to original sources
PubMed2001

[Allergic contact dermatitis in beauty parlor clients].

Occupational contact dermatitis in hair dressers and beauticians has increased in importance in the past years. Type IV-allergies against glyceryl monothioglycate components of permanent waves are most common. Other occupational allergens include bleach components such as ammonium persulfate and hair dye ingredients such as p-phenylenediamine (PPD) and p-toluylene-diamine (PTD) base. Allergies to hair dyes in customers of hair dressers have rarely been observed. Two female patients developed allergic contact dermatitis of the scalp and face after repeated use of Polycolor intensivtönung schwarz and of Movida color. We also review the current literature on type IV-allergies to components of hair dressing products components.

Adult↗
PubMed2001

[Circumscribed myxedema of the upper and lower extremities--a rate cutaneous manifestation of Basedow disease. Case report and review of the literature].

A 63 year old man presented with circumscribed myxedema surprisingly involving both the arms and legs. He had a history of thyroiditis with hyperthyroidism and an infiltrative ophthalmopathy leading to the diagnosis of Graves disease. At the time of presentation the patient had already been treated with radioactive iodine and undergone endonasal orbital decompression. We review the pathogenesis and treatment of Graves disease and discuss the first therapeutic attempt with PUVA-bath therapy.

Biopsy↗
PubMed2001

Competitive polymerase chain reaction used to diagnose cutaneous leishmaniasis in German soldiers infected during military exercises in French Guiana.

A competitive polymerase chain reaction (PCR) followed by enzyme-linked-immunoassay-based verification of PCR products has been developed, which facilitated the diagnosis of leishmaniasis in two German soldiers who underwent survival training in the jungle of French Guiana and returned with therapy-resistant pyoderma-like lesions. After treatment with liposomal amphotericin B, the skin manifestations disappeared, and leishmania DNA could no longer be detected by PCR. In the context of growing military involvement in areas where leishmaniasis is prevalent, this assay may help detect or, due to its internal controls, exclude cases of infection with this parasite.

Adult↗
PubMed2001

Coexpression patterns of EGFR, HER2, HER3 and HER4 in non-melanoma skin cancer.

The receptor tyrosine kinases (RTKs) epidermal growth factor receptor (EGFR), HER2, HER3 and HER4 are involved in the pathogenesis of multiple human malignant neoplasias. However, their role in the carcinogenesis of basal cell carcinomas (BCC) and squamous cell carcinomas (SCC) remains to be elucidated. In order to further define the role of these RTKs, 56 human skin tissue samples of normal skin, BCC and SCC were studied by conventional and differential and quantitative reverse transcriptase-polymerase chain reaction (rtPCR). EGFR and HER3 were predominantly expressed in the BCCs and SCCs, while HER2 was ubiquitously expressed. HER4 was not expressed in any sample. Since in vitro studies have provided compelling evidence that heterodimer formation of these receptors are associated with different signal transduction processes, coexpression patterns might be decisive for the induction and maintenance of a malignant phenotype. These results confirm this concept: isolated HER2 expression and EGFR/HER2 were predominantly found in normal skin, while HER2/HER3 and the triple expression of EGFR/HER2/HER3 were seen more frequently in the BCCs and SCCs compared with normal skin (50% and 40% compared with 26%, respectively). The activation of HER3, in addition to EGFR and HER2, might therefore be associated with the malignant phenotype. However, due to the small numbers in this study, further confirmation of the patterns is needed.

Biopsy↗
PubMed2001

Increased blood levels of human S100 in melanoma chick embryo xenografts' circulation.

The chorioallantoic membrane (CAM) of the fertilized egg allows grafting of human melanomas for short-term investigations and offers the opportunity to investigate the behavior of metastasizing cells and the release of S100beta into peripheral blood. Tissue from one primary melanoma as well as cutaneous and subcutaneous metastases of 10 melanoma patients with elevated levels of S100 in the peripheral blood before surgery were transplanted onto the CAM of chick embryos at day 5/6 of development. Grafts were nourished by the host blood supply 2 days after transplantation. Histologically, 3 days after grafting, metastasizing melanoma cells could be found near the vessels of the host membrane, penetrating the endothelial layer and entering the blood system. Growth conditions remained stable for 6 days after transplantation. Blood samples were taken from a larger CAM vessel before collecting the xenografts 5 days after grafting. Measurement of human S100 in peripheral blood was performed in a blinded manner. No negative control showed elevated levels of human S100 protein. Samples deriving from melanoma xenografts contained highly elevated levels of S100 protein in 80% of cases. The data strongly support the concept of graft-host interaction concerning adherence of tumors and extravasation of human melanoma cells.

Animals↗
PubMed2001

UVB-induced decrease of p16/CDKN2A expression in skin cancer patients.

The lack of p16 expression has been shown in cultured melanoma cells, however contradictory evidence for p16 expression in melanoma tissues exist. Ultraviolet (UV) C and UVB have been shown to affect p16 expression, which impairs cell cycle regulation in vitro and in vivo. In this study, p16/CDKN2A gene expression was determined by reverse transcription polymerase chain reaction in seven skin cancer patients, in one dysplastic nevus patient and in seven healthy individuals, prior to UVB exposure and at various times after application of one minimal erythema dose (MED). Five of the seven skin cancer patients showed a down-regulation of p16/CDKN2A expression after UVB exposure, while controls remained unaltered. The UVB-induced decline of p16/CDKN2A in skin cancer patients might offer new insights into photocarcinogenesis. The putative sequence of events could start with a down-regulation of p16/CDKN2A expression, which would lead to impaired cell cycle regulation. Altered expression patterns of p16/CDKN2A following UVB exposure could be of value for identifying people with an increased risk of UV-induced skin cancer.

Adolescent↗
PubMed2001

Does the minimal phototoxic dose after 8-methoxypsoralen baths correlate with the individual's skin phototype?

BACKGROUND/AIMS: Up to now no data have been available concerning whether there is a significant correlation between skin phototypes and the minimum phototoxic dose (MPD) after bath water delivery of 8-MOP. METHODS: The skin phototype of each of 46 patients was determined based on the individual past history of solar-induced burning and tanning. In addition, the MPD of each patient was assesed after photosensitization with a warm water bath (37 degrees C, 98.6 degrees F) containing 1.0 mg/l 8-methoxypsoralen (8-MOP). Statistical analysis was performed using a Mann-Whitney U-test and Spearman rank order correlation. RESULTS: The median MPD in patients with skin phototype II was 2.0 J/cm2 (range < or =0.5 to > or =3.5) versus 1.5 J/cm2 (range 1.0 to > or =3.5) in patients with skin phototype III. There was a considerable overlap between both groups. No significant difference was detected comparing both groups (P=0.7326) and Spearman rank order correlation revealed no correlation between skin phototype and MPD. CONCLUSION: Erythemal sensitivity in PUVA bath therapy, measured as MPD, is not correlated with sun-reactive skin phototype in skin types II and III. Thus skin phototype is not a suitable indicator for the initial UVA dose in PUVA bath photochemotherapy.

Data Interpretation, Statistical↗
PubMed2001

Hidden scabies: diagnosis by polymerase chain reaction.

Diagnosis of scabies infection can be difficult as in many cases only few mites are present on an infected person, and in some cases the skin manifestations can be subtle or atypical. We describe the use of polymerase chain reaction (PCR) to amplify Sarcoptes scabiei DNA in a patient presenting with clinically atypical eczema. Cutaneous scales were PCR positive for S. scabiei DNA before, and negative 2 weeks after, therapy. This method facilitates fast and very sensitive diagnosis of clinically atypical or inapparent scabies infection and therapy control in severely affected patients and may help to identify previously unrecognized scabies cases.

Animals↗
PubMed2001

Outdoor activities in childhood: a protective factor for cutaneous melanoma? Results of a case-control study in 271 matched pairs.

BACKGROUND: A matched case-control study was performed in Munich, Germany, in 1996-97 to evaluate the risk of cutaneous melanoma due to ultraviolet (UV) exposure behaviour in Southern Bavaria, Germany. OBJECTIVES: Patients with cutaneous melanoma and controls were investigated by two physicians using a standardized questionnaire to identify risk factors for the development of melanoma, such as professional and leisure sun exposure behaviour. In each person, a total body examination was performed to detect benign skin alterations, phenotypic characteristics and precursor lesions for skin cancer. PATIENTS/METHODS: A total of 271 melanoma patients and 271 controls were individually matched for residence, age and gender. A multiple conditional logistic regression analysis was performed. RESULTS: Of 56 factors, those risk factors with a strong effect on the development of melanoma were: the existence of melanoma in first degree relatives, solar lentigo, actinic keratosis, actinic cheilitis, skin phototype, immediate skin reaction to UV light at the start of the outdoor season, sunburn in childhood and sun exposure during holidays in sunny areas 20 years before melanoma was diagnosed; outdoor activities in childhood were found to be protective. CONCLUSIONS: Sunburn in childhood and increased sun exposure during annual holidays in sunny areas should be avoided. In contrast, outdoor activities in childhood, including soccer and gardening, should be encouraged because they are associated with a lower risk of melanoma formation.

Adolescent↗
PubMed2001

The PUVA-turban as a new option of applying a dilute psoralen solution selectively to the scalp of patients with alopecia areata.

BACKGROUND: Alopecia areata is a burden for many patients and often resistant, even to extensive therapy. Orally administered PUVA therapy has been shown among numerous systemic and topical treatment modalities to be a therapeutic alternative. However, the clinical use of oral PUVA is often limited by systemic side effects. Bath-PUVA therapy offers an alternative solution because of the negligible systemic absorption of psoralen with this technique. Through use of a "PUVA-turban" it is now possible to administer a dilute bathwater solution containing 8-methoxypsoralen (8-MOP) to the scalp. OBJECTIVE: The purpose of this study was to determine whether PUVA turban therapy is effective in treating alopecia areata in different clinical stages. METHODS: We treated 9 patients with severe, rapidly progressing, treatment-resistant alopecia areata with PUVA-turban treatment as a modification of bath-PUVA therapy. At each treatment session a cotton towel was soaked with a 0.0001% 8-MOP solution (1 mg/L) at 37 degrees C, wrung gently to remove excess water, and wrapped around the patient's head in a turban fashion for 20 minutes. This was directly followed by UVA radiation. Treatment sessions were initially performed 3 to 4 times per week. RESULTS: The cumulative UVA doses given over treatment periods of up to 24 weeks were 60.9 to 178.2 J/cm(2), with single doses ranging from 0.3 to 8.0 J/cm(2). After up to 10 weeks of treatment, hair regrowth could be noticed in 6 of 9 patients. Two patients did not respond to the treatment, and one patient showed only vellus hair regrowth. CONCLUSION: PUVA-turban therapy can be considered a useful method of administering a dilute psoralen solution selectively to the scalp of patients. It has been shown to be a well-tolerated and, in some patients, efficient therapeutic alternative in the treatment of alopecia areata.

Administration, Topical↗
PubMed2001

The outcome of local radiation injuries: 14 years of follow-up after the Chernobyl accident.

The Chernobyl nuclear power plant accident on April 26, 1986 was the largest in the history of the peaceful use of nuclear energy. Of the 237 individuals initially suspected to have been significantly exposed to radiation during or in the immediate aftermath of the accident, the diagnosis of acute radiation sickness (ARS) could be confirmed in 134 cases on the basis of clinical symptoms. Of these, 54 patients suffered from cutaneous radiation syndrome (CRS) to varying degrees. Among the 28 patients who died from the immediate consequences of accidental radiation exposure, acute hemopoietic syndrome due to bone marrow failure was the primary cause of death only in a minority. In 16 of these 28 deaths, the primary cause was attributed to CRS. This report describes the characteristic cutaneous sequelae as well as associated clinical symptoms and diseases of 15 survivors of the Chernobyl accident with severe localized exposure who were systematically followed up by our groups between 1991 and 2000. All patients presented with CRS of varying severity, showing xerosis, cutaneous telangiectasias and subungual splinter hemorrhages, hemangiomas and lymphangiomas, epidermal atrophy, disseminated keratoses, extensive dermal and subcutaneous fibrosis with partial ulcerations, and pigmentary changes including radiation lentigo. Surprisingly, no cutaneous malignancies have been detected so far in those areas that received large radiation exposures and that developed keratoses; however, two patients first presented in 1999 with basal cell carcinomas on the nape of the neck and the right lower eyelid, areas that received lower exposures. During the follow-up period, two patients were lost due to death from myelodysplastic syndrome in 1995 and acute myelogenous leukemia in 1998, respectively. Other radiation-induced diseases such as dry eye syndrome (3/15), radiation cataract (5/15), xerostomia (4/15) and increased FSH levels (7/15) indicating impaired fertility were also documented. This study, which analyzes 14 years in the clinical course of a cohort of patients with a unique exposure pattern, corroborates the requirement for long-term, if not life-long, follow-up not only in atomic bomb survivors, but also after predominantly local radiation exposure.

Cohort Studies↗
PubMed2001

Allergic contact dermatitis from natural latex.

BACKGROUND: Reports on natural latex allergy have increased steadily during the last 10 years. Latex allergy generally refers to a type 1 reaction to natural rubber latex (NRL) proteins with clinical manifestations ranging from contact urticaria to asthma and anaphylaxis. Previous United States studies on NRL allergy largely have been reported by allergists with little detailed information on hand eczema, contact allergy, or on outcome. The present study was performed from March 1998 to November 1999 with the aim of finding out the prevalence of type IV hypersensitivity to latex in patients with suspected rubber allergy. MATERIALS AND METHODS: A total of 167 patients with hand eczema and contact with rubber products underwent patch testing with the standard screening and rubber components (test series Deutsche Kontaktallergiegruppe), and NRL pure provided by Regent (liquid high ammonia 0.7% NRL, accelerator, and preservative-free latex) between March 1998 and November 1999. The charts of all NRL positive patients are reported with the results of history, prick, patch tests, total IgE, specific IgE to latex (FEIA) test and follow-up data (after 6 months). RESULTS: Four patients (3 men) showed positive patch test results to NRL. One of these patients also reacted to the rubber chemical tetraethylthiuram monosulfide, and another one of these patients revealed a type 1 reaction to NRL, diagnosed by positive reaction to prick test. The other 3 patients with patch test reactions to NRL had negative reactions to prick tests to NRL extracts after 20 minutes. All 4 patients had a positive delayed prick test reaction to NRL. Latex FEIA test result was negative in all 4 patients. The contact eczema healed after elimination of the latex gloves and medical latex devices in all patients. Furthermore, 10 of the 167 patch testing patients (6%) were positive for tetramethylthiuram monosulfide 1%. CONCLUSION: In the present study with 167 patients, the prevalence of type IV hypersensitivity to latex was 2.4%. We recommend that the patch test with NRL as well as with rubber additives should be performed in patients of suspected contact dermatitis caused by rubber products.

Adult↗
PubMed2000

c-MYC and nodular malignant melanoma. A case report.

BACKGROUND: The incidence of skin cancer has been rising since the 1950s. About 75% of skin cancer-associated deaths are caused by malignant melanoma. Nodular malignant melanoma accounts for 20% of melanocytic malignant tumors and is associated with a relatively poor prognosis. Extensive research has been undertaken, but a molecular marker that can predict a more aggressive course of melanoma still has not been found. METHODS: The authors applied cytogenetic and molecular genetic techniques to a case of nodular malignant melanoma. They used comparative genomic hybridization (CGH) to identify chromosomal regions affected by genomic changes and interphase fluorescence in situ hybridization (FISH) on touch preparations of the tissue to elucidate the CGH findings further. To investigate the functionality of the affected c-MYC gene, the authors detected its transcript via reverse transcription and polymerase chain reaction. RESULTS: CGH revealed a copy number gain in the 6p and 8q24-8qter region. FISH with c-MYC and centromere eight specific probes revealed that the tumor, in contrast to unaffected skin, was characterized by a gain in copy numbers of the c-MYC gene. The c-MYC gene transcript was detected at higher levels in the tumor than in the tissue taken from the safety margin. CONCLUSIONS: The WAF1 gene located on chromosome 6p, which in this case had a copy number gain, might be involved in melanoma pathogenesis. The authors suggest that the c-MYC gene plays an important role in melanoma development and progression. The c-MYC gene seems to be affected by gaining functional copies, leading to a change in the normally regulated gene-dose effect.

Chromosomes, Human, Pair 6↗