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Biomedical subjects

M Landthaler

Publications and source records attributed to M Landthaler.

At least 289 records · Page 16Linked to original sources
PubMed1987

Comparison of the maximum coagulation depth in human skin for different types of medical lasers.

The values for the maximum coagulation depth (MCD) of various types of lasers which are specified in the literature are not comparable, because often different irradiation times were used. MCD depends not only on the wavelength of laser light, but also on the time of action of the laser beam, because of heat transfer. In excised human skin MCD was determined histologically for irradiation with the argon laser, Nd:YAG laser, and CO2 laser. Extending the irradiation time from 0.2 s to 10 s results in a 4-6-fold increase in MCD. Coagulation experiments performed with a soldering iron have shown results similar to those obtained with the CO2 laser. Enlargement of the laser-beam diameter from 1 to 2 mm leads to a 50% increase in MCD. Additional chilling of the skin with water during laser irradiation protects the skin from evaporation, and the values for MCD increase to 3.5 mm for the argon laser and 5.5 mm for Nd:YAG laser. Detailed knowledge of the MCD is necessary to obtain the desired therapeutic effect, and also to avoid unwanted effects.

Connective Tissue↗
PubMed1987

Benign symmetric lipomatosis Launois-Bensaude. Report of ten cases and review of the literature.

Benign symmetric lipomatosis Launois-Bensaude is a disease rarely reported in the American literature and not mentioned in the standard English textbooks of dermatology. It seems, however, to be relatively common in Europe. Between 1981 and 1985 we examined twelve patients, and a number of case reports have been published in French and German literature. We describe ten typical cases and review the literature. The disease is characterized by massive symmetric fat deposits predominantly in the neck and shoulder girdle area. Pathogenetically, the increase in fatty tissue is assumed to result from a localized defect in catecholamine-induced lipolysis. The disease is frequently associated with alcoholism, hepatopathy, glucose intolerance, hyperuricemia, and malignant tumors of the upper airways, requiring thorough clinical evaluation of all patients. Dietary treatment and weight loss are of limited value in the management of benign symmetric lipomatosis. Surgical removal of lipomatous tissue is frequently followed by recurrence and should be restricted to decompression in patients with functional impairment.

Adult↗
PubMed1987

[Adjuvant therapy of melanoma patients with gamma interferon].

In a pilot study, 25 patients with high-risk malignant melanomas (a tumor thickness of more than 3 mm and/or a prognostic index of more than 13) and 15 patients with regional lymph-node metastases from malignant melanoma underwent standard surgical procedures. Afterwards, they were treated with gamma interferon in an adjuvant setting. Gamma interferon (200 micrograms) was given subcutaneously three times a week for 6 months. For three times a week for 6 months. For 25 patients, the follow-up has been 12 months or more; for 15 patients, it has been between 7 and 12 months. Tumor relapse occurred in 9 of 25 patients (36%) with high-risk primary tumors and in 5 of 15 patients (33%) with lymph-node metastases. Since these tumor-progression rates are in the same range as those in comparable patients, who did not undergo adjuvant therapy, one can conclude that the adjuvant gamma interferon regimen used is not effective in patients with high-risk malignant melanomas.

Combined Modality Therapy↗
PubMed1987

[Treatment of naevi flammei with the argon laser].

We report on 901 patients with port wine stains treated by means of an argon laser. The treatment results have been definitively evaluated in 371 patients. They were significantly influenced by the patients' age and by the colour of the lesions. The worst response to the therapy was seen in pink port wine stains in children and juvenile patients (20% good results), in contrast to red and purple lesions in adult patients (80% excellent and good results). The size of the port wine stains did not significantly influence the treatment results, but in extensive lesions homogeneous lightening could not usually be attained and treatment often extended over some years. Port wine stains in the head and neck area responded best to therapy, and lesions on the legs, worst. Altogether, in 60%-70% of adult patients excellent or good results were obtained, the lesions being completely removed or significantly lightened and reduced in size. The side-effects of laser therapy were scar formation (7.3%) and changes in pigmentation (8.6%).

Adolescent↗
PubMed1987

[Radioimmunoscintigraphy with monoclonal antibodies].

Radioimmunoscintigraphy is presented as a new imaging modality in nuclear medicine, using specific antigen-antibody interactions. Monoclonal antibodies to tumor-associated antigens facilitate the characterization of molecular differences between tumors and normal cells. Labelled with gamma-emitting radioisotopes like I-131, I-123, In-111, and Tc99M, these antibodies can be used for in-vivo imaging. Radioimmunoscintigraphy does not compete with morphological modalities like CT and ultrasound, but provides additional information based on its functional principle. Hidden lesions may be detected. Target-to-background ratios, however, are still rather low hampering scintigraphic imaging. The use of Single Photon Emissions Computed Tomography (SPECT) in addition to planar scintigraphy resolves background activities thus providing better visualization and localization of tumors, and increasing sensitivity. The high cost of these time-consuming studies is still a limiting factor to its wider use. Its preliminary indication is founded on the suspicion of tumor progression, based on clinical findings and/or increasing serum tumor markers (CEA, CA 19-9, CA 12-5). This paper provides an overview over possible applications of radioimmunoscintigraphy. Its clinical use is demonstrated by studies of malignant melanoma, colorectal cancer and ovarian cancer.

Antibodies, Monoclonal↗
PubMed1987

[Epidermolysis bullosa hereditaria dystrophica (Hallopeau-Siemens). Case report and therapy trial with (+)-cyanidanol-3 in 3 patients].

The diagnosis of hereditary epidermolysis bullosa dystrophica (Hallopeau-Siemens) in three patients was confirmed by clinical and histological means as well as by electron microscopy. The clinical course was followed for many years. Since (+)-cyanidanol-3 has been shown to reduce the susceptibility of collagen to mammalian collagenase under in vitro conditions, (+)-cyanidanol-3 was used to treat the three patients for a period of 27 weeks. A decrease in the amount of blistering was observed in all three patients.

Adult↗
PubMed1986

[Therapy and prognosis of malignant melanoma of the skin].

Since 1967 a total of 2403 patients with malignant melanoma have been treated according to a standardized regimen. The five-year survival rate for all patients in stage I was 79%. It was clearly dependent on tumour thickness or prognostic index, respectively. If tumour thickness was less than 0.75 mm or the prognostic index under 6, more than 90% survived for five years. With a tumour thickness of more than 3 mm or a prognostic index of greater than 13 the survival rate decreased to about 50%. Irrespective of tumour thickness the first signs of progression were local recurrence (20%), lymph-node metastases (50%), or distal metastases (30%). In case of progression symptoms recurred in about 80% within the first three years after tumour removal, in about 90% within five years. However, some 10% of progression signs occurred after more than five years. Prognosis was not significantly improved in stage I by adjuvant treatment with dacarbazine and BCG. In stage II the five-year survival rate was still about 30%. But in stage III only those patients with exclusively cutaneous distal metastases had a somewhat better prognosis. Only a few patients lived more than three years after the occurrence of organ metastases.

Adult↗
PubMed1986

Effects of argon, dye, and Nd:YAG lasers on epidermis, dermis, and venous vessels.

The aim of the present study, which was performed at the dorsal aspects of the ears of guinea pigs, was to compare effects of different lasers on epidermis, dermis, and small venous vessels. Irradiations were performed with argon, dye, and Nd:YAG lasers. In the first series tissue repair processes were studied after argon laser application. Laser defects were excised after 1, 4, 8, and 14 days and were prepared for routine histological examination. The breadth of epidermal defect and extent of dermal coagulation and occlusion of vessels by thrombus formation were examined histologically. In a second series parameters of irradiation (ie, exposure time, laser power) of the three different lasers were changed systematically. Laser-induced morphological tissue changes could be best observed 24 hours after irradiation. Each of the lasers led to occlusion of vessels by thrombus formation and also coagulated epidermis and dermis. The extent of dermal and epidermal coagulation was less pronounced after dye laser application. Using short exposure times it was possible to reduce the extent of epidermal damage caused by argon and Nd:YAG lasers. Only 50-msec dye laser pulses led to intravascular thrombus formation without epidermal and dermal damage.

Animals↗
PubMed1986

Neodymium-YAG laser therapy for vascular lesions.

Three patients with port-wine stains with a nodular surface, one patient with macrocheilia resulting from a port-wine stain, and one patient with a capillary hemangioma were treated with a Nd-YAG laser (mediLas, MBB-AT, Munich). Irradiance was between 800 and 1,600 watts/cm2, with energy fluence between 400 and 1,600 joules/cm2. Treatments were performed with local anesthesia on an outpatient basis. In all patients, marked improvements could be obtained after only a few treatments. Histologically there was necrosis of epidermis and dermis immediately after laser application, and ectatic vessels contained coagulated erythrocytes. Depth of coagulation was up to 3.5 mm. Quick restoration of epidermis was observed. After some days, macrophages, fibroblasts, and capillary blood vessels grew into the agglutination thrombi and ectatic vessels were replaced by granulation tissue and, later, by fibrous tissue. In comparison with the argon laser, the Nd-YAG laser coagulates at a much deeper level, but processes of tissue repair take longer and fibrosis is more pronounced after Nd-YAG laser application. Clinically, therefore, scar formation is more likely. Chilling the skin surface during irradiation and shorter exposure times may be effective in reducing the risk of scar formation in the future.

Adult↗
PubMed1986

Laser therapy of bowenoid papulosis and Bowen's disease.

Six patients with bowenoid papulosis and two patients with Bowen's disease of the genital area were treated by means of an argon, Nd:YAG, and CO2 laser. In all of the patients, complete resolution of the lesions was achieved. Due to a superficial coagulating effect, application of the argon laser should be restricted to macular and papular pigmented lesions. In contrast, Nd:YAG and CO2 lasers could be used even for treatment of extensive leukoplakia-like and verrucous lesions. Advantages and disadvantages of these two lasers are discussed.

Adult↗
PubMed1986

[Side effects of drugs on the salivary glands and mouth mucosa].

Changes to the salivary glands and the mucous membrane of the mouth can result from a substantial number of drugs. Since such changes are extremely heterogeneous, it is rarely possible to establish the medication responsible for the clinical-morphological findings. Furthermore, in many cases the symptoms resemble those associated with salivary gland or dermatological diseases, so that considerable diagnostic and differential-diagnostic problems can arise. A number of exemplary cases are presented and some differential-diagnostic recommendations are made for the practitioner.

Diagnosis, Differential↗
PubMed1986

[Pigment demarcation lines in pregnancy].

A 37-year-old female patient from Indonesia is reported, who developed pigmentary demarcation lines during the last trimenon of her first pregnancy. The lines resolved spontaneously after delivery.

Adult↗