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Biomedical subjects

M Landthaler

Publications and source records attributed to M Landthaler.

At least 163 records · Page 9Linked to original sources
PubMed1997

[Steroid-induced scabies norvegica].

Two patients aged 50 and 84 years presented with generalized itching eczema that has been treated with external and internal steroids for months. Despite therapy, the condition worsened continuously. Examination of skin scrapings revealed numerous mites, so Norwegian scabies was diagnosed. General examinations excluded underlying diseases. Treatment with steroids over months most likely led via immunosuppression to the exacerbation of the disease.

Adrenal Cortex Hormones↗
PubMed1997

[Q-switched ruby laser in dermatologic therapy. Use and indications].

The Q-switched ruby laser (QSRL) with its wavelength of 694 nm and a pulse duration of around 40 nsec is an effective modality for the removal of tattoos and cutaneous pigmented lesions. Based on the principle of selective photothermolysis, selective damage to cutaneous pigment or pigmented cells is possible, allowing the scar-free elimination of endogenous or exogenous pigment in the skin. Main indications for the treatment with the QSRL are tattoos (amateur, professional, accidental, or cosmetic) and lentigines but the QSRL can also be used for lightening or even removing other pigmented lesions such as nevus spilus or café au lait macules. Furthermore, pigmented lesions of mucous membranes can be removed easily. Since treatment results in postinflammatory hyperpigmentation, myoplasma, and Becker' nevus have proven to be inconsistent, the QSRL cannot be routinely recommended for these lesions. Melanocytic lesions are generally not treated, with the exception of nevus of Ota and nevus of ito where there exacts a lack of therapeutic alternatives. Non-pigmented cells, which exist in nearly all melanocytic lesions, do not absorb the light of the QSRL and, therefore, do not react to this particular treatment. No information is available on the risk of partially damaged cells to become malignant after QSRL treatment. The QSRL is an excellent therapy for the removal of endogenous and exogenous pigment because of both the excellent treatment results and the lack of side effects, which are limited to transient hypo- and hyperpigmentation. The QSRL has occurred a wide range of applications within the field of dermatology.

Humans↗
PubMed1997

[Classification of vascular abnormalities and neoplasms].

Vascular malformations and neoplasms are very common skin disorders, found in up to 5% of newborns. However, a clear distinction has to be made between proliferating vascular lesions and permanent malformations. An exact classification is also extremely useful, since many new specific diagnostic and therapeutic measures have been developed in recent years. True proliferating tumors are, for example, childhood hemangiomas, glomus tumors, granuloma pyogenicum, tufted angiomas, senile angiomas, and malignant vascular lesions. Vascular malformations can affect capillaries, veins or arteries, as well as lymphatic vessels. Arteriovenous shunts and combined malformations may also exist (Hamburg classification). Nevi flammei, nevi anaemici, hematolymphangiomas, angiokeratotic nevi, circumscribed venous-arterious malformations, and the blue-rubber-blebnevus-syndrome may either be infiltrating or circumscribed and are characterised by a persistence of the primitive vessel network. In contrast, other malformations involve various vascular trunks, showing vessel dilation or obstruction, often combined with changes in bone or soft tissue. Significant large vessel malformations are the Bockenheimer syndrome, the Klippel-Trenaunay syndrome and the Parkes-Weber syndrome. Combinations involving both large trunks and extravascular space such as the Klippel-Trenaunay syndrome also occur.

Adolescent↗
PubMed1997

Topical application of a first porphycene dye for photodynamic therapy--penetration studies in human perilesional skin and basal cell carcinoma.

Photodynamic therapy (PDT) in dermatology has been proven to be a successful noninvasive therapeutic modality for treating skin cancer. To facilitate its clinical introduction, the development of topical photosensitizers is necessary to avoid generalized, cutaneous photosensitivity. Therefore the penetration of synthetic chemically pure 9-acetoxy-2,7,12,17-tetrakis-(beta-methoxyethyl)-porphycene (ATMPn) into human skin was studied. Single specimens of freshly excised perilesional skin (n = 70) and basal cell carcinomas (n = 28) were evaluated after topical application of ethanolic ATMPn solutions (0.1% and 0.05%) for various times (2, 6, 16, 20 h). The penetration depth of ATMPn, recognized as red fluorescence in cryostat sections, was determined qualitatively by fluorescence imaging using a system of scoring related to the morphological structure of human skin (0 no fluorescence, 5 fluorescence deeper than basement membrane). Perilesional skin incubated for 2 or 6 h revealed fluorescence restricted to the upper parts of the epidermis, while after 16 or 20 h of incubation fluorescence was detected down to the basement membrane resulting in a significantly higher score (mean sum of scores : 2 h 2.6 +/- 0.4; 6 h 3.2 +/- 0.1; 16 h 3.8 +/- 0.1; 20 h 3.6 +/- 0.1). Quantitative evaluation by digital image analysis confirmed the qualitative results. Fluorescence was limited to the epidermis and the fluorescence intensity of the epidermis was higher after 16 h (4.9% of the fluorescence standard) than after 6 h (4.1%) incubation. Basal cell carcinomas showed fluorescence in the deep dermis as early as after 6 h incubation, but restricted to tumour cell nests. These results suggest that penetration of ATMPn into tumour tissue after topical application might be sufficient for topical PDT and that poor penetration into surrounding tissue might prevent scar formation following irradiation for PDT. The penetration characteristics of ATMPn now have to be proven in an in vivo setting.

Administration, Topical↗
PubMed1997

Indocyanine green: intracellular uptake and phototherapeutic effects in vitro.

Indocyanine green (ICG; absorption peak in human plasma 805 nm) was investigated for ICG-mediated phototherapy in vitro. The cellular uptake of ICG (1 microM-50 microM) into HaCaT keratinocytes after an incubation period of 24 h increased up to an intracellular ICG concentration of 12.1 +/- 1.3 nmol per 10(6) cells. To examine dose dependent phototoxic effects in vitro, keratinocytes were incubated with 0 microM-50 microM ICG for 24 h and irradiated by a diode laser (805 nm) with different energy densities (0, 12, 24, 48 J cm-2). All applied ICG concentrations except for 5 microM yielded a cell killing effect in combination with irradiation depending significantly on ICG concentration and light dose. Cell viability for dark control and cells incubated with 50 microM ICG and irradiated with 48 J cm-2 was 0.82 +/- 0.15 and 0.07 +/- 0.02, respectively. Sodium azide (100 mM), a quencher of reactive oxygen species, inhibited significantly the cell killing using 50 microM ICG and 24 J cm-2. Taken together, photoactivation of ICG by irradiation with a diode laser was shown to induce effectively cell killing of HaCaT keratinocytes. Moreover, this effect was inhibited by sodium azide, thus irradiation of ICG might induce a photodynamic reaction.

Antineoplastic Agents↗
PubMed1997

p53-protein and Ki-67-antigen expression are both reliable biomarkers of prognosis in thick stage I nodular melanomas of the skin.

The maximum tumour thickness is the most important prognostic factor in malignant melanomas of the skin. However, the clinical outcome of thick nodular melanomas remains unpredictable. Therefore, we investigated possible prognostic markers in this subset of melanomas. From a melanoma data base, 12 patients with thick (> 3 mm) stage I nodular melanomas of the skin were identified, who were still without signs of progression after five years of follow-up. These tumours were compared to randomly selected series of 12 cases, who did not survive the first five years after removal of the tumours. We performed immunostaining for the p53-protein and the proliferation associated Ki-67-antigen. For quantification of immunostaining the tumours were entirely scanned. In addition, all tumours were investigated for any differences with conventionally applied prognostic features: the tumour thickness: the level of invasion; the prognostic index (tumour thickness multiplied by mitotic count); and the mean volume-weighted mean nuclear volume. We demonstrated significant differences between survivors and non-survivors exclusively in respect of the staining indices for p53 and Ki-67 (P < 0.03 and 0.02, respectively). With both antibodies the tumours of survivors showed lower counts as compared to non-survivors survivors. However, within both groups we found no significant correlations between the p53- and Ki-67-staining results. We conclude that immunostaining for p53-protein and Ki-67-antigen is helpful to identify individuals with thick nodular melanomas who are at risk of metastatic disease.

Adult↗
PubMed1997

Quality-switched ruby laser treatment of solar lentigines and Becker's nevus: a histopathological and immunohistochemical study.

OBJECTIVE: A histopathological and immunohistochemical study was initiated to assess changes in benign human pigmented skin lesions after quality switched ruby laser (QSRL) irradiation. METHOD: A total of 196 solar lentigines on 8 patients' forearms were irradiated in vivo, 13 biopsies were taken. Hematoxylin-eosin staining and immunohistochemical techniques using anti-S-100 and Fontana-Masson stainings, as well as cryosections stained with nitroblue tetrazolium chloride (NBTC), were employed for the evaluation of the specimens. RESULTS: Immediately after QSRL impact selective photothermal damage (vacuolization) of all pigmented epidermal and basal melanocytes, keratinocytes, superficial dermal melanocytes and melanophages could be observed in solar lentigines. Cryosections stained with NBTC featured minimal thermal damage of the surrounding tissue. One Becker's nevus was also exposed to the QSRL, biopsies were taken before and immediately after QSRL exposure. In this lesion, superficially located pigments were selectively damaged, but a fair amount of pigmented cells in adnexal structures persisted throughout this single course of QSRL treatment. Recurrence of lentigines was not observed. In Becker's nevus, following initial fading of the lesion, clinically reactive hyperpigmentation occurred 4 weeks later. CONCLUSION: We found that pigmented lesions featuring a moderate amount of pigment exclusively in and around the basal cell layer, like solar (actinic) lentigo, can be successfully removed by a single QSRL exposure selectively damaging epidermal and basal pigmented structures. Further investigations concerning QSRL treatment of dermally pigmented skin lesions have to be initiated.

Adult↗
PubMed1997

Ex vivo quality-switched ruby laser irradiation of cutaneous melanocytic lesions: persistence of S-100-, HMB-45- and Masson-positive cells.

AIM: To assess changes in human pigmented melanocytic skin lesions after quality-switched ruby laser (QSRL) irradiation. METHODS: Investigations were performed ex vivo on 21 melanocytic pigmented lesions (10 nevus cell nevi, 2 pigmented dermal nevi, 4 congenital nevi, 3 lentigo maligna lesions, 2 superficial spreading melanomas) immediately after surgical excision. A total of 42 biopsy specimens was obtained for comparative investigations before and after QSRL impact. Electron microscopy was performed in 3 lesions. RESULTS: Hematoxylin-eosin stainings showed selective vacuolization of pigmented structures (melanin granules, melanophages, pigmented melanocytes, pigmented keratinocytes) immediately after QSRL irradiation due to selective photothermolysis. Cryosections stained with nitroblue tetrazolium chloride featured minimal thermal damage of the surrounding tissue proving the high selectivity of QSRL light. Immunohistochemical techniques employing anti-S-100, HMB-45 antimelanoma antibody and Fontana-Masson staining revealed selective photothermal damage (vacuolization) of basal melanin granules, pigmented basal melanocytes and epidermal keratinocytes, as well as pigmented superficial dermal melanocytes. Deeper melanocytes and nests of nonpigmented melanocytes persisted unaltered and retained their S-100 and HMB-45 positivity. Masson's staining revealed persisting dermal melanophages. Electron microscopy showed specific damage of both keratinocytes and melanocytes with numerous melanosomes and confirmed the light-microscopic findings. Deeper dermal melanocytes containing only few melanin granules remained unaltered. CONCLUSION: In pigmented lesions extending into the dermis, deeper pigmented melanocytic cells (nevus cells) persist throughout a single course of QSRL exposure. Nonpigmented melanocytic cells remain totally unaffected by QSRL irradiation. Therefore QSRL therapy of melanocytic nevi and congenital nevi should only be performed in controlled studies. Long-term results have to be evaluated before recommendations can be given.

Adolescent↗
PubMed1997

Wells' syndrome associated with idiopathic hypereosinophilic syndrome.

Wells' syndrome, or eosinophilic cellulitis, is characterized by recurrent cutaneous swellings which resemble acute bacterial cellulitis, and by distinctive histopathological changes. Skin lesions show dermal eosinophilic infiltration and the characteristic 'flame figures', which are composed of eosinophil major protein deposited on collagen bundles. The idiopathic hypereosinophilic syndrome is a multisystem disease with a high mortality rate. It is characterized by peripheral blood eosinophilia and eosinophilic infiltration of many organs, including the skin. The most common skin lesions are pruritic maculopapules and nodules over the trunk and limbs, with urticaria and angio-oedema. In contrast to Wells' syndrome, the pathology of these skin lesions is non-specific with variable eosinophil infiltration. We report overlapping clinical and histopathological findings characteristic of both syndromes in one patient. Our data favour the hypothesis that both syndromes represent an abnormal eosinophilic, response to a variety of underlying diseases or causative agents and thus are different expressions of one disease entity linked to the immunobiology of eosinophils.

Adult↗
PubMed1996

[Hydroa vacciniforme].

HISTORY AND CLINICAL FINDINGS: For three years, each time the day after intensive exposure to the sun a 5-year-old girl developed moderately painful erythema and blisters on uncovered parts of her body which subsequently healed with scarring. There was no increased photosensitivity among members of her family. There were numerous blisters and bullae, some of them confluent, filled with serous fluid on her back, on her arms an in the face. There were varioliform scars on the extensor surfaces of her arms. INVESTIGATION: There were no porphyrins in red cells, serum or urine. The characteristic skin changes were reproduced on exposure to UV-A. These findings established the diagnosis of hydroa vacciniforme. TREATMENT AND COURSE: Prolonged sun exposure was to be avoided and protective ointment was prescribed together with administration of beta-carotene, 25 mg twice daily. CONCLUSION: In children light-induced skin changes which heal with scarring may be due to hydroa vacciniforme.

Child, Preschool↗
PubMed1996

[Treatment of pediatric hemangiomas with the flashlamp-pumped pulsed dye laser].

We treated 166 infants and children with 177 hemangiomas with the flashlamp-pumped pulsed dye laser (FPDL, 585 nm, 450 microseconds, 5 mm phi). The hemangiomas were classified as initial, superficial, cutaneous-nodular, and compound (cutaneous-subcutaneous) lesions according to the clinical involvement. After one treatment (n = 124), good results ( > 75% clearance) were obtained in 56% of initial and in 36% of the nodular lesions. With repeated treatment sessions (n = 82), good results were achieved in 63% of the initial, in 67% of the superficial and in 70% of the nodular angiomas. Complete resolution requiring one or more treatment sessions was reached in 44% of the initial, in 42% of the superficial and in 16% of the nodular lesions. In compound lesions, only the cutaneous part responds to treatment owing to the limited penetration depth of the laser light. In our opinion, early FPDL therapy of most initial and/or rapidly growing hemangiomas should be recommended especially since this therapy is fast, has few side effects and can even be used in newborns.

Child↗
PubMed1996

[Sugar beet pollen allergy as a rare occupational disease].

Although there are a few isolated reports in the literature suggesting that sugar beet pollen is highly antigenic, hypersensitivity to components of sugar beet is not a common disease. We report a 29-year-old man with a history of atopic dermatitis who developed both contact dermatitis and allergic rhinitis from sugar beet pollen through his job in a seed nursery.

Adult↗
PubMed1996

[Dermatoses in leg amputees].

Dermatologic disorders of the stump in patients with a leg amputation may have characteristic pathophysiologic and clinical features. A knowledge of these factors may lead to earlier diagnosis and avoid immobilization. There ist no German language review of this aspect of dermatology. After providing an overview of the problem, including a discussion of prostheses, we review the following problems: mechanically induced blisters, follicular keratoses, epidermoid cysts, stump edema syndrome, acroangiodermatitis (pseudo-kaposi sarcoma) and verrucous hyperplasia.

Amputation Stumps↗
PubMed1996

9-Acetoxy-2,7,12,17-tetrakis-(beta-methoxyethyl)-porphycene (ATMPn), a novel photosensitizer for photodynamic therapy: uptake kinetics and intracellular localization.

The optimal photosensitizer for topical or systemic photodynamic therapy (PDT) has not yet been found. A promising new second-generation sensitizer is 9-acetoxy-2,7,12,17-tetrakis-(beta-methoxyethyl)-porphycene (ATMPn) whose time- and temperature-dependent uptake and intracellular localization were investigated in two human-skin-derived cell lines (HaCaT keratinocytes and dermal fibroblasts). Flow cytometry analysis (0-800 s) revealed an immediate increase in fluorescence in the cells after start of incubation with 100 ng ml-1 ATMPn (in cell culture medium). At longer incubation periods (0-24 h) a constant increase in fluorescence up to 12 h, with a steady state up to 24 h, was observed. Keratinocyte showed a faster rate of ATMPn uptake than fibroblasts within the first 12 h. Temperature-dependent ATMPn uptake was measured at 4 and 37 degrees C. An increase in fluorescence was observed even at 4 degrees C, suggesting that cellular uptake of ATMPn is partially based on passive diffusion. Confocal laser scan miscroscopy showed spotty, granular fluorescence inside the cytoplasm after incubation with ATMPn, similar to the pattern of rhodamine 123 which stains mitochondria. These results demonstrated an unusually fast intracellular, probably intramitochondrial, uptake of ATMPn in vitro. Therefore the use of ATMPn in photodynamic therapy might allow a reduction of the time span between administration of drug and irradiation.

Cell Line↗
PubMed1996

Improvement of monitoring of melanocytic skin lesions with the use of a computerized acquisition and surveillance unit with a skin surface microscopic television camera.

BACKGROUND: Photographic documentation of melanocytic skin lesions is important. Storage and retrieval of slides, however, take much time and space. OBJECTIVE: Our purpose was to develop and clinically test a computerized acquisition and surveillance (CAS) unit with a television camera for monitoring including measurements of lesional areas. METHODS: A CAS unit connected with a skin surface microscopic television camera was used for monitoring of melanocytic nevi (MN). The lesional area and the skin surface microscopic appearance (SMA) were analyzed after 10 to 21 months in 54 of 1355 MN. RESULTS: In 19 MN (35.2%), changes were found. In eight cases, changes in size of more or less than 15% were detected; in five cases only the SMA changed. In six cases both characteristics changed. CONCLUSION: In approximately 25% of MN, changes were only detectable in the SMA but not with area measurements. This favors the use of systems such as CAS because only they allow a time-saving comparison of actual and previous images.

Basal Cell Carcinoma↗
PubMed1996

Topical photodynamic therapy in dermatology.

Although photodynamic therapy (PDT) was first used in the treatment of skin diseases, phase-III-clinical trials were primarily conducted for the treatment of bladder cancer, endobronchial and oesophageal carcinoma. In dermatology PDT has most extensively been used for the treatment of malignant cutaneous lesions. Up to now those patients have been treated systemically with first-generation photosensitizers. However, prolonged skin photosensitivity is a major disadvantage of this form of therapy. Topical PDT utilizing a variety of sensitizers bypass this unwanted effect. Of strong interest is 5-aminolevulinic acid (ALA), first introduced in the topical PDT of skin disorders in 1990 by Kennedy and co-workers. ALA serves as a pro-drug, i.e. the active photosensitizing compound is protoporphyrin IX which is synthesized in vivo after exogenous application of ALA. In several oncologic and non-oncologic skin conditions including non-melanoma skin cancer, premalignant conditions like actinic keratoses and in psoriasis, topical ALA-PDT showed it's effectiveness. Besides ALA, new sensitizers like benzoporphyrines and porphycenes may play a role in topical PDT. However, at the moment, there is still a need for comparative studies and standardized therapeutic protocols to define the place of topical PDT in Dermatology.

Administration, Topical↗
PubMed1996

Multivariate DNA cytometry discriminates between Spitz nevi and malignant melanomas because large polymorphic nuclei in Spitz nevi are not aneuploid.

To elucidate the reasons for the malignant histologic appearance of melanocytic nuclei within benign Spitz nevi (SN), we evaluated nuclear DNA distribution and nuclear size using a computerized image analysis system. In each case of 28 SN and 34 malignant melanomas (MM), about 100 randomly sampled nuclei were analyzed, prepared as monolayers from paraffin-embedded tissues. Large nuclei in MM (nuclear area > mean nuclear area of normal melanocytes + 4 delta) were significantly more likely to be aneuploid (DNA content > or = 5c) than large nuclei in SN chi2 test, p < 0.0001). Only two of 990 large SN nuclei exhibited DNA values higher than 5c, whereas 236 of 2,024 large MM nuclei were aneuploid or polyploid. Accordingly, in multivariate analysis, five features of DNA distribution proved to be most important for objective discrimination between MM and SN: 2c deviation index, 5c exceeding rate, standard deviation of the nuclear DNA content, and both the 85th and the 95th percentiles of DNA distributions. On the basis of these features, we could define a linear discriminant function that allowed a correct diagnosis in 94% of the cases. Our data demonstrate that diagnostically misleading large nuclei in SN are euploid, in contrast to MM. It is thus possible to discriminate SN and MM with high accuracy using DNA cytometry. Because paraffin-embedded tissue can be used, this technique could be a valuable complement to routine histology in equivocal cases.

Algorithms↗