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Biomedical subjects

Michael Landthaler

Publications and source records attributed to Michael Landthaler.

87 records · Page 5Linked to original sources
PubMed2002

Photodynamic therapy and fluorescence diagnosis of skin cancers.

In several countries throughout the world the photosensitizer porfimer-sodium has been approved for systemic photodynamic therapy (PDT) for different oncological indications. However, owing to the prolonged photosensitization entailed, the use of this porphyrin derivative is restricted. Currently, the most promising sensitizers in dermatology that can be applied topically are 5-aminolevulinic acid (ALA) or ester derivatives that are precursors of heme biosynthesis. ALA has shown good clinical and excellent cosmetic results in superficial skin cancer and precancerous conditions, e.g. superficial basal cell carcinoma (BCC), or actinic keratoses (AK): phase III studies have demonstrated its efficacy especially in Bowen's disease and AK. ALA-PDT for AK was therefore approved by the FDA in late 1999, and the corresponding registration process is currently in train in Europe. Besides its usefulness in oncological therapy, ALA also has a unique feature that can be exploited for diagnostic purposes: after topical or systemic application protoporphyrin IX is induced rather selectively in epithelial tumors, with a high tumor-to-surrounding tissue ratio, which can be visualized after excitation with light. By using a CCD camera system together with digital imaging, the contrast of the acquired fluorescence images can be significantly enhanced and allows the determination of a threshold, which can be utilized either for a directed biopsy or for preoperative planning when Mohs' surgery is scheduled. At present, the routine employment of such systems is being assessed in prospective studies.

Fluorescence↗
PubMed2002

IgE-mediated anaphylactic reaction induced by succinate ester of methylprednisolone.

BACKGROUND: In systemic administration the prevalence of anaphylactic reactions attributable to corticosteroids is approximately 0.3%. Positive prick tests with different corticosteroids have been reported suggesting an immunoglobulin (Ig)E-mediated mechanism. OBJECTIVE: A 42-year-old man with multiple sclerosis developed flush, erythema, and itching a few minutes after the begin of an intravenous infusion of methylprednisolone-21-sodium succinate. DIAGNOSTIC AND RESULTS: Prick tests were found to be positive with methylprednisolone-21-sodium succinate and prednisolone-21-sodium succinate, whereas prick tests with prednisolone without ester and betamethasone-21-dihydrogen phosphate showed negative results. Oral challenge with prednisolone without ester and intravenous challenge with betamethasone-21-dihydrogen phosphate were well tolerated. Specific IgE-antibodies against methylprednisolone-21-sodium succinate were found in the serum of the patient. Because of the positive prick test and specific IgE antibodies against methylprednisolone-21-sodium succinate, the diagnosis of IgE-mediated anaphylactic reaction could be proven. Succinate ester was suspected to be immunogenic, as other corticosteroids without this particular ester or with other substitutions at the C21 remained negative both in the prick and the challenge tests. CONCLUSIONS: This patient showed an adverse reaction caused by methylprednisolone-21-sodium succinate. The uniqueness in this case was the presence of specific IgE antibodies against this esterified corticosteroid in the patient's serum proving that this reaction was based upon a true IgE-mediated mechanism.

Adult↗
PubMed2002

The effect of different spot sizes on the efficacy of hair removal using a long-pulsed diode laser.

BACKGROUND: In the last years several lasers have proven their efficacy for hair removal. However, little is known about the efficacy of varying the spot size with those lasers. OBJECTIVE: To evaluate the long-term efficacy of hair removal using a diode laser with different spot sizes. METHODS: A long-pulsed diode laser (2 x 60 msec) was used. The spot size was 8 mm, 12 mm, or 14 mm. Twenty consenting volunteers were treated three times at regular intervals of 3 weeks. The ratio of the number of hairs in the treated area to an adjacent area left untreated (control) was referred to as regrowth. RESULTS: One month after laser treatment, regrowth was 23% (8 mm), 12% (12 mm), and 13% (14 mm). After 3 months regrowth was 67% (8 mm), 54% (12 mm), and 55% (14 mm). Fifteen months after treatment 4 of 16 volunteers had a regrowth rate of less than 25%. CONCLUSION: The results provide evidence for an effective and long-lasting growth delay of hairs using the long-pulsed diode laser. The use of large spot sizes improved the growth delay of hairs measured 1 month after treatment.

Adult↗
PubMed2002

Benign Degos' disease developing during pregnancy and followed for 10 years.

Degos' disease, or malignant atrophic papulosis, is a rare and often fatal multisystem vasculopathy of unknown etiology. The cutaneous manifestations comprise erythematous papules, which heal to leave scars with a pathognomonic central porcelain-white atrophic area and a peripheral telangiectatic rim. Involvement of the gastrointestinal tract is observed in 50% of cases, with intestinal perforation being the most common cause of death. Other organ systems can also be affected; 20% of cases involve the central nervous system. Systemic manifestations usually develop from weeks to years after onset of skin lesions or, in rare instances, may precede skin lesions. In the patient with Degos' disease reported in this article, the characteristic skin lesions developed during pregnancy, a precipitating event not previously reported. She has survived an unusually long time (10 years) without visceral or neurological involvement, despite florid cutaneous lesions. Moreover, we could detect the presence of antiphospholipid antibodies, the significance of which are currently unclear. These observations therefore confirm that there may be a strictly cutaneous form of Degos' disease with a favourable prognosis.

Antibodies, Antiphospholipid↗
PubMed2002

Eruptive multiple lentigo-maligna-like lesions in a patient undergoing chemotherapy with an oral 5-fluorouracil prodrug for metastasizing colorectal carcinoma: a lesson for the pathogenesis of malignant melanoma?

Induction of multiple eruptive dermal and atypical melanocytic naevi has frequently been reported in children with malignant haematological diseases and chemotherapy-induced immunosuppression. This is the first report of an adult patient to develop multiple eruptive melanocytic skin lesions while undergoing chemotherapy with an oral 5-fluorouracil prodrug for metastasizing cancer. Our observation adds further evidence to the link between systemic (iatrogenic or intrinsic) immunosuppression and the induction of melanocyte proliferation and transformation.

Administration, Oral↗
PubMedDate not supplied

Cowpox and a cat.

Explore the source record for details and available documents.

Adolescent↗
PubMedDate not supplied

Follicular mycosis fungoides: variability of a rare entity.

OBJECTIVE: Three patients with follicular mycosis fungoides (FMF), a rare variant of folliculotropic cutaneous T-cell lymphoma, are discussed. Follicular involvement in cutaneous T-cell lymphoma commonly presents clinically with alopecia, follicular cysts, or comedo-like lesions usually associated with follicular mucinosis and strong epidermotropism. In contrast, FMF, in a strict sense, has been defined as a lymphocytic infiltration of hair follicles in the absence of both epidermal invasion and follicular mucin. DISCUSSION: Case 1 shows a clinically stable form of FMF characterized by circumscribed alopecia and its persistent resistance to topical therapeutic approaches. In contrast, Cases 2 and 3 demonstrate that classic mycosis fungoides lesions and FMF can occur simultaneously and that transitions occur from mycosis fungoides to FMF and vice versa. These observations strengthen the concept that FMF and mycosis fungoides represent just two variants of one entity of cutaneous T-cell lymphoma. In Case 3, rapid progression into tumor-stage mycosis fungoides and the follicular infiltration was controlled with bexarotene. CONCLUSIONS: Because it was previously suggested that FMF may have a worse prognosis compared with classic mycosis fungoides, this impressive response to bexarotene is of great clinical interest and may spark new studies employing this novel retinoid for FMF treatment.

Adult↗
PubMedDate not supplied

Tattoo pigments are cleaved by laser light-the chemical analysis in vitro provide evidence for hazardous compounds.

In the western world, more than 80 million people decorate their skin with tattoos. Tattoo colorants are injected into the skin, like medical drugs. Most tattoo colorants are industrial pigments, and chemical industries have never produced them for human use but only to stain consumer goods. Up to 10% of tattooed people request removal of their tattoos because of an improved self-image or social stigmatization. In contrast to tattooing, physicians usually perform the tattoo removal. For that purpose laser light at very high intensities irradiates the skin to destroy the tattoo pigments. Based on a recent analysis of tattoo pigments, two widely used azo compounds were irradiated in suspension with laser and subsequently analyzed by using quantitative high-performance liquid chromatography and mass spectrometry. The high laser intensities cleaved the azo compounds, leading to an increase of decomposition products such as 2-methyl-5-nitroaniline, 2-5-dichloraniline and 4-nitro-toluene, which are toxic or even carcinogenic compounds. Moreover, the results of the chemical analysis show that the tattoo colorants already contain such compounds before laser irradiation. Because of a high number of patients undergoing laser treatment of tattoos and based on the results of our findings in vitro, it is an important goal to perform a risk assessment in humans regarding laser-induced decomposition products.

Azo Compounds↗
PubMedDate not supplied

Multiple, bilateral and painful ear nodules of the anthelices: a variant of chondrodermatitis nodularis?

A case of a distinctive clinicopathologic condition of the ear cartilage is presented, characterized by multiple, bilateral and painful nodules of the anthelices without epidermal involvement. Histologically, there was a peri-chondrial lymphohistiocytic infiltrate and a small focus of degenerate, basophilic cartilage as well as cystic chondromalacia containing an amorphous mass. This condition is both clinically and histopathologically distinct from other causes of ear nodules, although the lesions seen in our patient exhibit features of chondrodermatitis nodularis helices and therefore could well be a variant of the latter.

Adult↗
PubMedDate not supplied

Dead Sea treatment - principle for outpatient use in atopic dermatitis: safety and efficacy of synchronous balneophototherapy using narrowband UVB and bathing in Dead Sea salt solution.

Safety and efficacy of this new treatment modality for out-patients were evaluated by an uncontrolled multicenter trial under GCP-conditions. Patients had to undergo 3-5 treatment sessions per week up to 35 in total. SCORAD (SC) was assessed at baseline, after 20 and 35 sessions. For patients with early study withdrawal the last-observation-carry-forward-principle was used. 615 intention-to-treat (itt)- (baseline SC: 59.4) and 143 according-to-protocol (atp)-patients (baseline SC: 60.1) could be analysed. 289 patients (47%) (baseline SC: 59.1) underwent less than 35 sessions. Main reasons were: lack of time (16%), non-compliance (12%), good improvement (7%), lack of efficacy (6%), intercurrent disease (4%) and side effects (3%). Mean number of sessions in atp-group was 35, in itt 26, and in patients with early study withdrawal 15.8. SC decreased in atp-group to 37.5 (itt: 44.5/patients with early study withdrawal: 46.1) after 20 sessions and to 27.1 (35.2/42.6) at end of treatment. Relative SC-improvement was statistically significant in atp- (55%), itt-group (41%), and in patients with early study withdrawal (26%). Most frequent side effects were: erythema in 7.3%, burning of skin due to salt solution in 3.6%. Safety and efficacy could be proven in both atp- and itt-group. A marked difference in efficacy between atp and itt underlines the importance of evaluating itt-data providing a more realistic assessment of a treatment modality in practice. This treatment is especially recommended for patients with chronic type of AD, high compliance and time free for therapy.

Adolescent↗
PubMedDate not supplied

Cutaneous ulcerations on hands and heels secondary to long-term hydroxyurea treatment.

Hydroxyurea is a chemotherapeutic agent used to treat myeloproliferative disorders and other non-neoplastic conditions. Cutaneous side-effects have been described in long-term therapy with hydroxyurea and include xerosis, hyperpigmentation, skin atrophy, erythema, alopecia, skin tumours and ulceration of the skin, particularly of the legs. We present a 71-year old patient with chronic myelocytic leukemia (CML) who developed extremely painful ulcers on the hands and heels as well as skin tumours while on long-term therapy with hydroxyurea. The ulcers were resistant to therapy but healed three months after discontinuation of hydroxyurea therapy.

Aged↗
PubMedDate not supplied

Photodynamic therapy in dermatology.

Currently, topical photodynamic therapy (PDT) has received approval for the treatment of dermato-oncologic conditions like actinic keratoses, Bowen's disease, in-situ squamous cell carcinoma and basal cell carcinoma in many countries all over the world. For many non-neoplastic dermatological diseases like localized scleroderma, acne vulgaris and viral warts a therapeutical benefit of PDT is evident, too. Unlike the formerly used, only systemically-applicable haematoporphyrin derivates, the recently developed topical photosensitizers 5-aminolevulinic acid (ALA) or its methyl ester (MAL) induce photosensitizing porphyrins. Moreover, the latter do not induce strong generalized cutaneous photosensitization. Due to the easy accessibility of skin to light activation, incoherent lamps or LED arrays are suitable for PDT. The production of reactive oxygen intermediates like singlet oxygen depends on the applied light dose as well as the concentration and localization of the photosensitizer in the diseased tissue. Either cytotoxic effects resulting in tumor destruction or immunomodulatory effects improving inflammatory skin conditions are induced. Treating superficial non-melanoma skin cancer, PDT has been shown to be highly efficient despite the low level of invasiveness. The excellent cosmetic results after treatment are beneficial, too.

Basal Cell Carcinoma↗
PubMedDate not supplied

Dermatoscopy of "dysplastic nevi": a beacon in diagnostic darkness.

The sequential progression model for melanocytic tumours from common nevus to malignant melanoma was proposed by Clark almost 30 years ago. The "dysplastic nevus" has frequently been considered a logical offspring of this concept and as a direct precursor of melanoma, analogous to the epithelial dysplasia-carcinoma sequence. Despite the use of modern molecular methods, there is no consensus as to if the dysplastic nevus represents a true precursor lesion of melanoma, a separate distinct type of nevus, or a diagnostic dilemma. Currently, the concept of melanocytic dysplasia remains subject to confusing definitions at all levels of the diagnostic process, i.e. clinical appearance, dermatohistopathology, and molecular biology. In this review, we collect evidence that nevi fulfilling Clark and Elder's classic histological criteria mostly represent "endpoints" of nevocytic evolution, whereas a minority of "dysplastic nevi" represent true melanoma precursors. The unsolved dilemma is that neither clinical, histopathological nor molecular criteria exist to make a distinction between dysplastic nevi and early melanomas. Our analysis of the current knowledge on dysplastic nevi shows that dermatoscopy remains the only quantifiable, easily applicable and reproducible diagnostic tool to approach the problem. Due to a "quantum leap" in optical resolution, objective scores can be established, e.g. the total dermatoscopy score (TDS) according to the ABCD rule, and documentation of changes over time are possible by digital image storage devices. Although dermatoscopy does not solve the dilemma of discriminating early, basically feature-less melanomas from dysplastic nevi, and it does not prove that dysplastic nevus is a distinct entity, it helps make melanocytic tumours with unclear malignant potential a manageable disease.

Dermatology↗