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Biomedical subjects

M Landthaler

Publications and source records attributed to M Landthaler.

At least 181 records · Page 10Linked to original sources
PubMed1996

Nonradioactive arbitrarily primed polymerase chain reaction: a novel technique for detecting genetic defects in skin tumors.

Initiation and progression of melanocytic and non-melanocytic skin tumors are accompanied and probably caused by a variety of genetic defects. In contrast to other human tumors, however, limited amounts of available tissue in skin cancer often hamper extensive genetic studies of native material of early lesions. Therefore, we applied a novel DNA fingerprinting technique based on polymerase chain reaction (PCR), the arbitrarily primed PCR (AP-PCR). This technique enabled us to scan large parts of the genome (about 30 kb/PCR reaction) for somatic mutations starting with minute amounts of tissue. In contrast to previous reports on AP-PCR, we were able to visualize PCR products by a rapid nonradioactive silver-staining technique using a simple device for staining of large polyacrylamide gels. In nine benign and malignant melanocytic skin tumors, the method provided a set of reproducible DNA fingerprints. Genetic defects were detected by comparing the fingerprints of tumor cells and constitutive DNA from blood leukocytes. Since nonradioactive AP-PCR fingerprinting also offers the unique capability to isolate and sequence polymorphic DNA fragments from fingerprint gels, we conclude that this technique seems to be important and practically feasible for elucidating the genetic roots of skin tumors.

Base Sequence↗
PubMed1996

Characteristic but unfamiliar--the cowpox infection, transmitted by a domestic cat.

An 11-year-old girl had been suffering from 2 recently developed reddish ulcerated nodules on the right side of her neck and, concomitantly, from a very hard swelling as well as from painless lymphadenopathy. Subsequently, thick black eschars appeared on the surface of the ulcers. Using the negative staining technique, an orthopox virus infection could be identified by electron microscopy. The patient's characteristic history as well as her close contact with a cat frequently hunting nice indicated the diagnosis of a cowpox infection, which was unequivocally confirmed by identification of both the viral culture and specific antibodies in the serum of the patient.

Animals↗
PubMed1996

Photodynamic therapy with topical application of 5-aminolevulinic acid in the treatment of actinic keratoses: an initial clinical study.

BACKGROUND: The incidence of actinic keratoses (AK) is rising and there is still a need for therapeutic alternatives. OBJECTIVE: To demonstrate the efficacy and tolerability of topical photodynamic therapy (PDT) using 5-aminolevulinic acid (ALA) in the treatment of AK. METHODS: Ten patients with 36 lesions (19 at hands and arms, 17 on the head) received ALA-PDT once (occlusive application of a 10% ALA emulsion for 6 h, irradiation with red light, 580-740 nm, 150 J/cm2) and were then monitored for 3 months. Therapeutic efficacy was judged using a score evaluating infiltration and keratosis of AK. RESULTS: After 28 days, significantly lower score sums were observed (head: mean = 15%; hand: mean = 67%) compared to the initial score (100%). Complete remission was achieved in 71% of AK localized on the head. No notable side effects were observed. CONCLUSION: This study demonstrated the potential of good efficacy and tolerability in the treatment of AK using topical ALA-PDT. How efficacy for lesions on the hand can be improved and whether PDT is able to concur with established treatment modalities remains to be shown in further studies.

Administration, Topical↗
PubMed1996

Q-switched ruby laser application is safe and effective for the management of actinic lentigo (topical glycolic acid is not).

A study was designed to evaluate the effectiveness of single q-switched ruby laser exposure to erase actinic lentigo. A peeling fluid containing glycolic acid designed to treat lentigines was evaluated comparatively. Ten female patients presenting with actinic lentigines on the forearms and dorsal aspects of their hands were treated with the q-switched ruby laser on the right side. Single ruby laser irradiation of actinic lentigines on the dorsal aspects of forearms and hands caused transient crusting due to exfoliation of the epidermal surface, which generally lasted for 2 weeks. Four weeks after treatment total fading of the lesions was evident. Topical application of peeling fluid applied on the left forearms caused burning sensations, local irritation and superficial scaling but could not clear the lentigines. A single course of q-switched ruby laser exposure is safe and efficient for the management of actinic lentigines, as it completely clears these obvious signs of aging. Topical treatment of lentigines using a commercial peeling solution leads to moderate or severe irritation and is ineffective.

Administration, Topical↗
PubMed1996

Side-effects and complications of flashlamp-pumped pulsed dye laser therapy of port-wine stains. A prospective study.

The flashlamp-pumped pulsed dye laser (FPDL) was the first laser system specifically developed for the treatment of cutaneous vascular lesions such as port-wine stains (PWS), telangiectases and haemangiomas. Its theoretical advantages have been verified by numerous excellent clinical results. As there are few systematic studies on the adverse effects of this laser system, we investigated 100 consecutive patients who received FPDL therapy of PWS. Pain during and after laser therapy was a common complaint. Post-treatment erythema occurred in 29%, oedema in 73%, formation of bullae in 1%, and serous crusting in 46-83% of patients (based on our observations and the patients histories, respectively), all of which lasted for a maximum of 7 days. Furthermore, complications such as impetigo-like crusting occurred in 25%, bleeding in 12%, a pyogenic granuloma in 1%, hyperpigmentation in 27%, hypopigmentation in 1%, atrophic scarring in 3%, and an hypertrophic scar in 1%. Although most of these changes were only focal, and were predominantly transient, our results indicate that the incidence of side-effects and complications produced by the FPDL (wavelength 585 nm, pulsewidth 450 microseconds) may be higher than previously documented in the literature.

Adolescent↗
PubMed1996

[The ruby laser: can removal of pigmented skin changes with the ruby laser be done by non-physician personnel?].

Chromophores of the skin, especially melanin and exogenous pigments (e.g., tattoos), absorb red ruby laser light (694 nm) comparatively well. Selective photothermolysis of melanin, melanosomes, and tattoo particles theoretically leads to clearing or removing of cutaneous pigmented lesions and tattoos. The excellent cosmetic results after ruby laser treatment are leading to the increasingly widespread use of these costly laser systems. Not only physicians, but also cosmeticians and masseurs work with ruby lasers to remove tattoos and cutaneous pigmented lesions, often without correct dermatological diagnosis. An ever-increasing number of patients present themselves at our department with nevi previously treated with ruby laser. The dimensions and potential sequelae of these treatments are still unknown. Therefore, we present the principles of ruby laser treatment and its indications, side effects, and the main risks.

Humans↗
PubMed1995

Carbon dioxide laser therapy of a widespread epidermal nevus.

BACKGROUND AND OBJECTIVE: The treatment of epidermal nevi is difficult and often unsatisfactory. Many therapeutic approaches have been tried, of which the surgical methods including lasers aim to avoid recurrences and hypertrophic scarring. Here we report the case of a widespread, life-impairing epidermal nevus, summarize the available treatment modalities, and discuss CO2 laser therapy with respect to the clinically soft variants of these developmental defects. STUDY DESIGN/PATIENTS AND METHODS: A patient with a widespread, recurrent, biopsy-proven epidermal nevus was treated with a 10,600-nm CO2 laser. After test treatments in local anaesthesia, four sessions were performed under general anaesthesia each with a follow-up time of 4 years to date. RESULTS: CO2 laser vaporization resulted in complete removal of the treated nevus without any obvious scarring. The patient is free of recurrence 4 years postoperatively. CONCLUSION: CO2 laser treatment of epidermal nevi is a useful modality in selected variants.

Adult↗
PubMed1995

Prognostic significance of DNA cytometry in comparison with histologic measurements in malignant melanomas.

In the present study we evaluated the prognostic impact of both DNA cytometry and quantitative histology in patients with malignant melanoma (MM). In contrast to previous investigations on sections, rapid image analysis (IA) of imprint specimens was performed to measure DNA cytometric features; 34 cases of stage I MM with low (< 1.5 mm, n = 20) and higher tumor thickness (TTH) (> 1.5 mm, n = 14) were analyzed. We found significant correlations between cytometric features and TTH, which is accepted as the most important prognostic criterion in MM. Higher TTH was closely correlated with the rate of markedly aneuploid nuclei, which is indicated by the 5c exceeding rate (5cER; r, 0.89; p < 0.001). The gain of chromatin in thicker tumors was accompanied by higher mean nuclear area (MAREA; r, 0.60; p < 0.001) and mean DNA content (MDNA; r, 0.58; p < 0.001). Additional evidence for prognostic significance of cytometry was obtained by preliminary survival analysis of 16 cases (four patients died within 2 1/2 years and 12 patients survived for at least 4 1/2 years). Applying multivariate stepwise discriminant analysis, a combination of TTH, level of invasion (LEV), 2c deviation index (2cDI), and modified standard deviation of the DNA values (SDNAM) proved to be most effective. One hundred percent of the cases were correctly classified as survivors or nonsurvivors. TTH and the 5cER were found to be the best univariate criteria for prognosis. In the U test according to Mann and Whitney, a significant discrimination of survivors and nonsurvivors was possible using either TTH or the 5cER, respectively (p < 0.02). Thus, we would like to conclude that IA of imprint specimens can be recommended as a rapid and simple additional method for grading.

Algorithms↗
PubMed1995

Laser therapy of skin tumors.

Malignant skin tumors can be treated by CO2 laser excision or vaporization, neodymium: yttrium aluminum garnet (Nd:YAG) laser coagulation, and systemic or topical photodynamic therapy (PDT). Possible indications for CO2 laser vaporization include superficial basal cell carcinomas, actinic keratoses, Bowen's disease, actinic cheilitis, and leukoplakias. The Nd:YAG laser may be used for coagulation of basal cell carcinomas, squamous cell carcinomas, Kaposi's sarcoma, and metastatic skin tumors. Systemic and topical PDT is still an experimental modality and is mostly applied for treatment of basal cell carcinomas. However, laser treatment of skin tumors is not yet considered as standard therapy and should be confined to selected patients. Further clinical studies are necessary to determine the role of laser therapy in this special indication.

Basal Cell Carcinoma↗
PubMed1995

[Nevi flammei in childhood and adolescence. Treatment with the flashlamp-pumped pulsed dye laser].

In 77 patients with port-wine stain under 18 years of age we performed 100 test treatments with the flashlamp-pumped pulsed dye laser (585 nm, 450 microseconds, 5 mm beam diameter). In 54% of cases we could obtain excellent or good lightening with one test treatment. In only 9% of cases did the patients show bad or no response to laser therapy. In the following treatment of larger areas (n = 125), the rate of good or excellent lightening was even higher (60%). Side effects were infrequent and consisted mostly of transient hyperpigmentation. In contrast to argon laser therapy, the flashlamp-pumped pulsed dye laser is safe and effective for treatment of port-wine stains in childhood and adolescence. Our results and the good results reported in the literature confirm the flashlamp-pumped pulsed dye laser as the laser of choice for port-wine stain treatment in young patients.

Adolescent↗
PubMed1995

[Positive tuberculin reaction in sarcoidosis].

Scar sarcoidosis is one of the rare cutaneous manifestations of sarcoidosis. Apart from the clinical picture, suppression of the cell-mediated immunity can often be determined when tuberculin tests and testing for recall antigens are carried out. In the present case of a 68-year-old woman patient scar sarcoidosis and pulmonary sarcoidosis were detected. Remarkably, a strongly positive tuberculin reaction was found, while acute tuberculosis and former BCG vaccination were excluded. Both references in the literature and the case presented demonstrate that a positive tuberculin test, while very unusual in sarcoidosis, does not however, preclude the diagnosis. On the basis of some case reports in the literature, our patient was treated with allopurinol; impressive improvement of both the skin and the pulmonary manifestations was noted. Despite the well-known phenomenon of spontaneous regression in sarcoidosis, we recommend a clinical trial with allopurinol as this substance is well tolerated.

Allopurinol↗
PubMed1995

[Topical photodynamic therapy in treatment of superficial skin tumors].

Photodynamic therapy (PDT) is an experimental treatment modality which is based on photochemical destruction of tumour tissue by means of different sensitizers and irradiation with red light. The greatest disadvantage of systemic administration of photosensitizers (mostly porphyrins) is cutaneous photosensitization of the patient, which lasts for some months. An alternative therapeutic technique for superficial skin tumours is the topical application of sensitizers, especially 5-aminolevulinic acid (ALA). Therapeutic selectivity derives from enhanced ALA penetration across abnormal parakeratotic stratum corneum and from preferential accumulation of bioconverted protoporphyrin IX, which serves as photosensitizer in cells of epithelial origin. Two patients suffering from different epithelial tumours (superficial basal cell carcinoma, Bowen's disease) and treated with topical PDT after ALA application are reported. Both tumours showed complete remission, and up to 12 months after treatment there were no clinical or histological signs of tumour recurrence. Cosmetic results were good.

Aged↗
PubMed1995

[Necrobiotic xanthogranuloma with eye involvement. Overview and case report].

Necrobiotic xanthogranuloma is a rare disease marked by yellowish-brown plaques with destructive growth and a tendency to ulceration, which shows a characteristic histopathological pattern of palisading granuloma with foam cells, Touton's and foreign-body giant cells, bizarre multinuclear giant cells, cholesterol clefts and marked necrobiosis of the connective tissue. Necrobiotic xanthogranuloma is associated with IgG paraproteinaemia, and occasionally with an IgA paraproteinaemia. Ocular symptoms and visceral involvement are common. We report a case of a 53-year-old woman with periorbital necrobiotic xanthogranuloma, ocular involvement and IgG paraproteinaemia, who had undergone argon-laser treatment to no avail following a diagnosis of xanthelasma. Periorbital xanthelasma-like lesions with a tendency to ulceration in combination with unexplained ocular symptoms consisting of keratitis, scleritis, episcleritis or uveitis should suggest the diagnosis of necrobiotic xanthogranuloma, especially if they are associated with paraproteinaemia.

Diagnosis, Differential↗
PubMed1995

[Malignant infiltrating blue nevus of the plaque type. Case report and literature review].

We present, to the best of our knowledge, the first case of a malignant, primary plaque-type blue naevus in a 61-year-old male. Two biopsy specimens had been examined within 13 years, and revealed a common and cellular blue variant as a precursor. Locally invasive growth and regional lymph node swelling were present, but these alone could not confirm malignancy before evaluation of all clinical and histopathological features, as they are known to occur with benign cellular blue naevi. The recent literature and our case indicate that there is a malignant potential in every histological and clinical variant of blue naevus.

Biopsy↗
PubMed1995

Wavelength dependency of photodynamic effects after sensitization with 5-aminolevulinic acid in vitro and in vivo.

A promising new therapeutic modality for skin cancer, administration of the heme precursor 5-aminolevulinic acid followed by light irradiation, is known as photodynamic therapy. Photofrin, the only clinically approved sensitizer, has an absorption maximum at 630 nm, the wavelength used in most experimental and clinical trials with 5-aminolevulinic acid. We investigated photodynamic efficacy of irradiation with coherent light at wavelengths ranging from 622 to 649 nm in vitro and in vivo as well as the content and distribution of intracellular porphyrin after administration of 5-aminolevulinic acid. HaCaT immortalized human keratinocytes were sensitized with 30 micrograms/ml 5-aminolevulinic acid for 24 h in vitro. By cell viability determined with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay, the best cell-killing effects were observed after irradiation at 635 nm. Using an amelanotic melanoma (A-Mel-3) grown subcutaneously in Syrian Golden hamsters, we confirmed these results in vivo: tumor growth was markedly delayed in animals treated with 100 mg/kg 5-aminolevulinic acid intravenously and irradiated with coherent light at 635 nm as compared to animals irradiated at 630 nm. This photodynamic effect is probably mediated by large amounts of the photosensitizing porphyrin, protoporphyrin IX, localized in cell membranes as visualized by confocal laser scan microscopy and as determined by high pressure liquid chromatography in vitro. The results suggest that irradiation at 635 nm with a coherent light source is more effective than irradiation at 630 nm for photodynamic therapy with 5-aminolevulinic acid.

Aminolevulinic Acid↗
PubMed1995

Epidermal damage and limited coagulation depth with the flashlamp-pumped pulsed dye laser: a histochemical study.

To investigate vessel coagulation depth and tissue damage in therapy with the flashlamp-pumped pulsed dye laser (585 nm, 5 mm spot size, 450 microsecond pulse duration, 6-8 J/cm2), we used the nitroblue-tetrazolium chloride stain in 22 post-treatment biopsy specimens from patients with port wine stain. With this method, thermally damaged tissue can be easily differentiated from unchanged tissue to the level of single cells. The results showed that in superficial port wine stain vessels up to 150 microns in diameter, vessel coagulation was complete and selective without further dermal damage. With the increase of vessel diameter, strong superficial hemoglobin absorption led to only partial vessel-wall coagulation and, in some cases, to superficial dermal damage. Likewise, deeper vessels were not coagulated because of shadow effects by superficial vessel layers. Thus, the overall vessel-wall coagulation depth of the flashlamp-pumped dye laser was limited to a maximum of 0.65 mm (mean 0.37 mm). In addition, some degree of epidermal damage was present in most specimens, which significantly increased with epidermal melanin content and resulted in epidermal coagulation and blistering in pigmented skin. Our results explain the occurrence of crusting, hyperpigmentation, and hypopigmentation in therapy with the flashlamp-pumped dye laser and its limited effect on dark or hypertrophic port wine stains in adults featuring large vessel diameters or multiple vessel layers.

Adult↗