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Biomedical subjects

W Bäumler

Publications and source records attributed to W Bäumler.

At least 19 recordsLinked to original sources
PubMed2006

[Laser therapy for tattoos].

Tattoos are produced by bringing colorants of various compositions into the skin. The ingredients of these colorants are not declared and are not subjected to pharmacological and toxicological tests. Ultrashort and high intensity laser pulses are used to remove tattoos. The laser beam breaks up the pigments embedded in the skin so that they can be transported away from the site. Clinically, the pigment becomes less intense or completely disappears. The success of the laser treatment essentially depends on the pigments used in the tattoo and on how deeply the pigments are embedded in the skin. The laser treatment is slightly painful and has a low rate of permanent side effects.

Coloring Agents↗
PubMed2006

In vitro and in vivo comparison of two different light sources for topical photodynamic therapy.

BACKGROUND: Photodynamic therapy (PDT) with 5-aminolaevulinic acid (ALA) is an effective and safe treatment option for the treatment of actinic keratosis (AK). Incoherent lamps are often used, matching the absorption maxima of ALA. OBJECTIVES: A comparative trial was performed to evaluate the efficacy of recently developed light-emitting diodes (LEDs). METHODS: Human epidermal keratinocytes were incubated for 24 h with ALA (100, 200, 300, 400 or 500 micromol L(-1)) and irradiated consecutively using either an incoherent halogen lamp (lambda(em) = 580-750 nm; 24 J cm(-2); 40 mW cm(-2)) or an LED system (lambda(em) = 633 +/- 3 nm; 3, 6, 12 or 24 J cm(-2); 40 mW cm(-2)). Topical ALA-PDT was performed on 40 patients with AK (n = 584) in a symmetrical distribution suitable for two-sided comparison. After incubation with ALA (20% in cream base) irradiation was performed with the incoherent lamp (100 J cm(-2); 160 mW cm(-2)) on one side and the LED system (40 J cm(-2); 80 mW cm(-2)) on the opposite side followed by re-evaluation up to 6 months. RESULTS: No significant differences between the LED system (3, 6, 12 or 24 J cm(-2)) and the incoherent light source (24 J cm(-2)) regarding cytotoxicity was found in vitro. The complete remission rate yielded in the in vivo investigation was also not significantly different at 6 weeks (P = 0.95), 3 months (P = 0.75) and 6 months (P = 0.61) following therapy. Six weeks following therapy complete remission rates of 84.3% (LED system) and 82.8% (incoherent lamp) were achieved. There was also no significant difference between both light sources regarding pain during light treatment (P = 0.67), patient satisfaction (P = 1.0) or cosmesis (P = 1.0) following therapy. CONCLUSIONS: These results show the efficacy of an LED system for ALA-PDT both in vitro and in vivo. ALA-PDT with the LED system showed a noninferiority regarding the clinical outcome in the treatment of AK compared with the incoherent lamp.

Adult↗
PubMed2006

Optimal parameters for the treatment of leg veins using Nd:YAG lasers at 1064 nm.

BACKGROUND: The treatment of large vessels such as leg veins is successfully performed in clinical practice using pulsed Nd:YAG lasers. However, it is still unclear how laser parameters such as wavelength, fluence and pulse duration influence vessel destruction in leg veins. OBJECTIVES: To elucidate the governing parameters in selective photothermolysis of large vessels. METHODS: A recently developed mathematical model for photothermolysis has been adapted for the treatment of leg veins. The model was used to analyse the effectiveness of the selective photothermolysis process in laser treatment of leg veins by Nd:YAG at 1064 nm. The efficiency of laser-induced vessel heating was defined as a ratio between the absorbed and delivered energy. RESULTS: The efficiency improved with increasing vessel diameter, in agreement with clinical findings in various studies. The pulse duration made a minor contribution for laser fluences of 100-400 J cm(-2), whereas the efficiency was better for a small spot. The use of moderate fluences of 100-200 J cm(-2) reduced excess dermis heating and pain. CONCLUSIONS: We provide reference parameters for optimal treatment of leg veins using Nd:YAG lasers at 1064 nm. Our model predicts a maximal efficiency of a range of fluences (100-200 J cm(-2)) and pulse durations (10-100 ms).

Computer Simulation↗
PubMed2005

Macular function and morphology after peeling of idiopathic epiretinal membrane with and without the assistance of indocyanine green.

AIM: To investigate macular function and morphology after surgical removal of idiopathic epiretinal membrane (IEM) with and without assistance of indocyanine green (ICG). METHODS: A retrospective study as a consecutive case series, of 39 patients with IEM. 39 patients, 23 female, 16 male, mean age 67 years, underwent standard three port pars plana vitrectomy with removal of epiretinal membrane. Two groups of patients were consecutively operated: in 20 patients ICG 0.1% in glucose 5% was used to stain the epiretinal membrane. 19 patients underwent the identical procedure but without use of ICG. Postoperative follow up was 1-92 months (mean 15.5 months). Functional outcome was assessed with subjective improvement, best corrected visual acuity (BCVA), Amsler grid test, 10 degrees and 30 degrees automated perimetry (Heidelberg visual field analyser) (HFA), and Goldmann kinetic perimetry. Macular morphology was assessed with stereoscopic biomicroscopy and optical coherence tomography (OCT). The main outcome measures were macular function as determined by BCVA, presence of visual field defects, and metamorphopsia as determined by Amsler grid test, macular morphology as determined by slit lamp biomicroscopy, and OCT. RESULTS: BCVA improved in 28 patients, remained unchanged in eight patients, and decreased in three patients. Improvement of BCVA was statistically significant in both groups (p = 0.003). Mean BCVA in patients operated with ICG improved from 0.33 preoperatively to 0.53 postoperatively. Mean BCVA in patients operated without ICG improved from 0.32 preoperatively to 0.54 postoperatively. Reduction of macular oedema as measured by OCT was statistically significant in both groups (p<0.01). There was no statistically significant difference in postoperative BCVA, macular oedema as measured by OCT, postoperative Amsler grid test, and subjective improvement between the two groups. The incidence of residual or recurrent epiretinal membrane was greater in the group operated without ICG (p = 0.014). Visual field defects were detected in one patient operated with ICG and in three patients operated without ICG. CONCLUSIONS: Removal of epiretinal tissue with or without assistance of ICG improved visual function and reduced macular oedema in most patients. Adverse effects clearly attributable to the use of ICG were not observed but further investigation is warranted.

Adult↗
PubMed2004

Structure-activity relationships of three differently substituted 2,7,12,17-tetrakis-(beta-methoxyethyl) porphycene derivatives in vitro.

The subcellular localization, efficacy and photooxidative mechanism of three new photosensitizing porphycenes (HexoTMPn, PeloTMPn, CpoTMPn) for photodynamic therapy with different substituents at position 9 of the tetrapyrrole macrocycle were investigated in vitro using different human skin-derived cell lines (HaCaT, SCL I, SCL II) with the aim of customizing the side-chain chemistry to accelerate cellular uptake and so enhance photodynamic activity. Cells were incubated with a porphycene and costained with organelle-specific markers. Subcellular localization was determined by fluorescence microscopy. Also, cells were incubated with different sensitizer concentrations (0-1000 nmol/l) and irradiated by an incoherent light source (lambda(em) = 600-750 nm, 40 mW/cm(2), 24 J/cm(2)) with/without quenchers or enhancers (NaN(3), histidine, mannitol or D(2)O). Cell viability was assessed. All porphycenes were localized in perinuclear lysosomes and induced a decrease in mitochondrial activity following irradiation. HexoTMPn was the most efficient in all three cell lines (EC(50) in HaCaT cells: HexoTMPn 14 nmol/l, CpoTMPn 62 nmol/l, PeloTMPn 89 nmol/l). Addition of either NaN(3) or histidine reduced the phototoxicity significantly. Due to the short lifetime of singlet oxygen, the sites of sensitizer localization are the initial subcellular targets. The cytotoxicity of each sensitizer varied depending on singlet oxygen quantum yield and cell line. Despite the different chemical structures, the biological effects were not very distinct, since they seemed to be mostly determined by the tetrapyrrole ring and only slightly modified by the substituent at position 9. Also, there was only a narrow margin between biological compatibility and efficacy.

Cell Line↗
PubMed2004

Early detection of skin cancer (EDISCIM) through the use of non-invasive confocal imaging.

In the past 15 years the number of malignant melanomas and non-melanoma skin cancer, (i.e. squamous cell carcinoma, basal cell carcinoma), have increased dramatically throughout the whole world, in particular among people with white skin. For example, in Germany the number of new cases of melanoma is about 10 to 12 per 100,000 people, (for basal cell carcinoma as a non-melanoma skin cancer 140 per 100,000), the absolute number of annual new cases of melanoma is an estimated 9,000 to 10,000, and the increasing rate is 5 to 10%. However, there are more than 40 differential diagnoses for skin cancer which makes it difficult even for expert dermatologists to give correct diagnosis, (estimated 75% correct diagnoses). This figure is even worse for doctors from other specialities. There is only a chance of high cure rates when skin tumours are detected at an early stage. The prognosis of skin cancer is dependent very much on the thickness, (as a sign of invasiveness), of the tumour and the number of mitotic figures in the tumour, (as a sign of proliferation activity). However, the final diagnosis of skin cancer is usually done by biopsy, the sample being investigated by a specialist. This is an invasive method, which is painful for the patient and might require several cuts and samples taken before being absolutely certain. Due to the potential risk of dissemination of tumour cells, taking an incisional biopsy is obsolete in malignant melanoma. Therefore the correct diagnosis of malignant melanoma can be made only after a total removal of the lesion and consecutive histopathological examination. The EDISCIM project intends to develop a system for the early diagnosis of skin cancer which uses confocal imaging for the non-invasive diagnosis of the upper layers of the skin that aids the physician in the analysis of the images and therefore with the diagnosis, allows for potential remote diagnosis by specialist dermatologists via tele-diagnosis if need be. The objectives of the system are Captures microscopic images of the skin by confocal imaging, Processes and records these images in real time, Compares these images against a knowledge base of known skin symptoms, Displays the results in a suitable interface to the physician performing the diagnosis, And supports the online telematic support by specialists.

Animals↗
PubMed2002

Correlations between light penetration into skin and the therapeutic outcome following laser therapy of port-wine stains.

For several years the flashlamp-pumped pulsed dye laser (FPDL) has been the favoured method for the treatment of port-wine stains (PWS). The therapeutic outcome of FPDL laser therapy depends on the anatomical location of the PWS and is mainly attributed to morphological parameters such as size and depth of the PWS blood vessels. The aim of this study was to show a correlation between the therapeutic outcome following FPDL therapy and the optical properties of the skin overlying the PWS vessels. For this purpose the therapeutic outcome following FPDL treatment (585 nm; 0.45 ms) of 884 PWS situated on different body sites was evaluated by judging the grade of fading of PWS colour. On the other hand the light penetration into 123 skin samples (thickness 0.10-1.35 mm) was determined between 450 nm and 1030 nm and compared with the PWS laser therapy outcome for equal locations by statistical analysis. PWS on the neck, trunk, arms or legs yielded a higher mean grade of fading as compared to PWS on the head. Within the face, a wide range of fading was evident. The light penetration into skin increased linearly with increasing wavelength and location-dependent differences were found. The attenuation coefficient was 22.8+/-5.3 mm(-1) at 585 nm. No significant or strong correlation was observed between the therapeutic outcome of PWS laser therapy and the light penetration into skin. However, a correlation was obvious by plotting the respective profile plots. Therefore, among other effects, in particular morphological parameters of PWS vessels, the optical properties of the skin contribute to a small extent to the clinical outcome of PWS laser therapy.

Adolescent↗
PubMed2001

[Treatment of therapy-resistant verruca vulgaris with long-pulsed tunable dye laser].

BACKGROUND: Common warts are induced by human papilloma virus (HPV) types 1-4, 26-29, 38, 41, 49, 57, 63, and 65 and can be found in up to 10% of adults and children. Many treatment modalities have been used to destroy the infected viral cells. These include the use of various methods such as salicylic acids, cryosurgery, curettage, and electrocautery. PATIENTS/METHODS: The purpose of this study was to examine the efficacy of the long-pulsed tunable dye laser (LPTDL) in the treatment of verrucae vulgares. Twenty-four patients with recalcitrant warts were included in the study. Thirty-one warts were treated in these patients. RESULTS: Two patients (6.5%) were completely freed of their warts, and a reduction of > 75% was attained in 12.9%. Nine patients (29%) experienced a reduction of < 50%. CONCLUSIONS: The LPTDL represents another quick treatment modality with low side effects, but only low clearance rates could be found in this study.

Humans↗
PubMed2000

Q-switch laser and tattoo pigments: first results of the chemical and photophysical analysis of 41 compounds.

BACKGROUND AND OBJECTIVE: In the Western world, there are at least 20-30 million people with tattoos. Improved self-image and social stigmatization are the main reasons for removing tattoos from skin. Q-switched lasers are applied to destroy the tattoo compounds in the skin. The treatment of tattoos containing ink often gives excellent results, whereas the results of treatments for coloured tattoos are not predictable and usually are worse. The chemical structure and the absorption spectra of the tattoo pigments are usually unknown. However, the efficacy of the treatment by using light of different Q-switched lasers (wavelengths 510, 532, 694, 755, 1064 nm) is correlated to both the chemical structure of the tattooed compounds yielding specific absorption spectra and the laser wavelength used. STUDY DESIGN/MATERIALS AND METHODS: A structural and spectroscopic analysis of 41 coloured pigments was performed. RESULTS: The 41 substances were identified, and they consist of 16 individual chemicals of different structured well-known industrial organic pigments. The absorption spectra of the 16 pigments were measured quantitatively. CONCLUSION: The results of the present analysis explain to some extent the outcome of clinical studies regarding laser therapy of coloured tattoos. Because the laser energy used produces a high temperature in the azo or polycyclic pigments, it is necessary to investigate whether that change causes possibly toxic or cancerogenic compounds.

Coloring Agents↗
PubMed2000

[Fluorescence-assisted biopsy of basal cell carcinomas].

BACKGROUND AND OBJECTIVE: The diagnosis of precancerous and cancerous skin lessons in pretreated or scarred skin can be difficult. The determination of the right biopsy site in a suspected area depends largely on the physician's experience. PATIENTS/METHODS: The possibility of using a CCD-camera system and measuring tumor fluorescence following topical application of 5-aminolevulinic acid was employed in a single case to facilitate accurate choice of biopsy site. RESULTS: An user-independent evaluation of the induced fluorescence intensity was achieved by means of the described optical system and digital imaging. The contrast of the acquired fluorescence images can be significantly enhanced and allows the determination of a threshold. As result an initial, clinically not visible basal cell carcinoma was detected and excised by a punch biopsy in toto. CONCLUSIONS: Using the described optical system the early recognition of a superficial basal cell carcinoma and the determination of the exact biopsy site was achieved in pretreated skin. The routine employment of the system will be assessed in a prospective study.

Administration, Topical↗
PubMed2000

Indocyanine green (ICG) and laser irradiation induce photooxidation.

The cellular uptake and subcellular localization of indocyanine green (ICG; absorption band 700-850 nm), and cell survival and ultrastructural changes following ICG-mediated phototherapy were investigated in vitro in four different cell lines derived from human skin (SCL1 and SCL2 squamous cell carcinoma, HaCaT keratinocytes and N1 fibroblasts). The cellular uptake of ICG (1-50 microM, incubation times 1, 4, 24 h) was saturable, highly cumulative and could be inhibited by the addition of 250 microM bromosulphophthalein indicating the involvement of the organic anion transporting polypeptide (OATP). For HaCaT cells, the maximum cellular uptake (Vmax) and the Michaelis constant (K(m)) were 9.9 +/- 1.1 mM and 47 +/- 16 microM, respectively, following a 24-h incubation with ICG. Fluorescence microscopy revealed a cytoplasmic distribution of ICG, probably bound to glutathione S-transferase. Following irradiation with a cw-diode laser (805 nm, 80 mW/cm2) at doses of 24 or 48 J/cm2, the phototoxicity was determined using the MTT assay as a measure of cell viability. For all cell lines, ICG concentrations above 25 microM produced a significant phototoxic effect. The EC50, of ICG for HaCaT cells following irradiation at 24 J/cm2 was 20.1 +/- 3.9 microM. Growth curves showed that even HaCaT cells treated at the EC50 were killed within a week following treatment. Electron microscopy 1 h after ICG-mediated phototherapy revealed cytoplasmic vesiculation, dilation of the rough endoplasmic reticulum, the Golgi complex and the perinuclear cisternae and the beginning of chromatin condensation in the nucleus. These ultrastructural findings are not consistent with a photothermal action of ICG-mediated phototherapy. Taken together with those of previous studies by our group these results support photooxidation as a major cell-killing mechanism.

Cell Line↗
PubMed1999

Long-pulse dye laser for photodynamic therapy: investigations in vitro and in vivo.

BACKGROUND AND OBJECTIVE: Continuous wave lasers or incoherent lamps are used effectively for photodynamic therapy (PDT). As the mechanism of action of pulsed lasers in PDT is not known, we investigated the efficacy of PDT with 5-aminolevulinic acid (ALA) using a long-pulse (1.5 ms) tunable flashlamp-pumped pulsed dye laser (LPDL) in vitro and in vivo. STUDY DESIGN/MATERIALS AND METHODS: HaCaT human keratinocytes were incubated with ALA (3 mmol/l) and irradiated (0-50 J/cm(2)) using the LPDL at 585 nm, 595 nm, or 600 nm vs. an incoherent light source (580-740 nm). Topical ALA-PDT was performed on 24 patients with actinic keratoses (AK) on the head (n = 200) after incubation with a 20% ALA emulsion and irradiation by either an incoherent light source (160 mW/cm(2), 60-160 J/cm(2)) or the LPDL (585 nm, 18 J/cm(2)). RESULTS: Maximal cytotoxic effects in vitro were achieved using the LPDL at 585 nm or the incoherent lamp (50 J/cm(2)). Sodium azide, a quencher of singlet oxygen, significantly reduced cell killing, suggesting that the cytotoxic effects are mainly mediated by singlet oxygen. This is supported by an increase of lipid peroxides as determined by malondialdehyde after adding D(2)O. Complete remission was achieved in 79% of 100 AK treated by ALA and the LPDL and in 84% of 100 AK treated by ALA and the incoherent lamp. Pain during light treatment was significantly reduced by using the LPDL. Control lesions (LPDL without ALA) did not clear. CONCLUSION: These results show the in vitro and in vivo efficacy of ALA-PDT using a pulsed light source mediated by singlet oxygen.

Adolescent↗
PubMed1999

Endoscopic fluorescence detection of dysplasia in patients with Barrett's esophagus, ulcerative colitis, or adenomatous polyps after 5-aminolevulinic acid-induced protoporphyrin IX sensitization.

BACKGROUND: Surveillance of patients with Barrett's esophagus or ulcerative colitis for dysplasia is confined to biopsy specimens taken randomly during endoscopy because dysplasia remains undetectable by visual inspection. We attempted to visualize dysplastic tissue during endoscopy after sensitization with 5-aminolevulinic acid (5-ALA) leading to accumulation and formation of protoporphyrin IX and induction of characteristic red fluorescence of the latter substance using blue light illumination. METHODS: Six patients with histologically proven low- or high-grade dysplasia (Barrett's esophagus 2, ulcerative colitis 1, Billroth-II stomach 1, rectal polyps 2) were treated with oral administration of different concentrations of 5-ALA (10 to 20 mg/kg) or by local instillation of 3 gm 5-ALA in the rectum. Endoscopic fluorescence detection was performed 1 to 6 hours after sensitization using a blue light source and compared with conventional white light endoscopy. Biopsies of fluorescent and nonfluorescent areas were compared with histologic findings. RESULTS: Normal duodenal mucosa and squamous epithelium showed more intense 5-ALA-induced background red fluorescence compared with normal mucosa in the stomach or Barrett's mucosa. Histologically, dysplasia was exclusively found in areas with red fluorescence. False-positive fluorescence was associated with microscopic inflammation of the mucosa or feces in the colon. CONCLUSIONS: 5-ALA-induced protoporphyrin IX fluorescence may be useful in the detection of dysplasia in the gastrointestinal tract by enhancement of endoscopic surveillance of patients at a high risk for dysplasia.

Adenomatous Polyps↗
PubMed1999

Photosensitization of human skin cell lines by ATMPn (9-acetoxy-2,7,12,17-tetrakis-(beta-methoxyethyl)-porphycene) in vitro: mechanism of action.

9-Acetoxy-2,7,12,17-tetrakis-(beta-methoxyethyl)-porphycene (ATMPn) is a promising new photosensitizer characterized by high absorption around 640 nm and high singlet oxygen yield. To study the mechanism of action in vitro we have investigated uptake, intracellular localization, cell survival and ultrastructural changes following photodynamic treatment in human cell lines derived from the skin (SCL1 and SCL2, squamous cell carcinoma; HaCaT keratinocytes; N1 fibroblasts). Using flow cytometry we have determined the cellular fluorescence as a marker for the uptake of ATMPn after incubation for 60 min. Co-staining with ATMPn and fluorescent dyes specific for cell organelles reveals an intracellular localization of ATMPn in lysosomes. Following irradiation using an incoherent light source (580-740 nm) and a light fluence of 24 J cm-2, phototoxicity is determined by means of the 3-4.5 dimethylthiazol-2,5 diphenyl tetrazolium bromide (MTT) assay. For all cell lines ATMPn concentrations above 15 nM yield a significant phototoxic effect. The 50% effective concentration, EC50, for SCL1 cells is 11.2 +/- 2.9 nM ATMPn. ATMPn uptake and phototoxicity are more effective for HaCaT and SCL1 as compared to SCL2 and N1 cells. Growth curves confirmed the results of the MTT assay. Because of the high lysosomal accumulation of ATMPn, already low photosensitizer concentrations without dark toxicity yield a high photodynamic effect. Immunofluorescence and electron microscopy reveal damage to tonofilaments, plasma membrane and mitochondria, indicating a mechanism unrelated to apoptosis. A dose yielding complete cell killing, as needed for oncological indications, might lead to necrosis, whereas lower sub-lethal doses result in induction of apoptosis.

Cell Line↗
PubMed1999

Photo-oxidative killing of human colonic cancer cells using indocyanine green and infrared light.

Despite of the approval of Photofrin in various countries, chemically defined sensitizers for photodynamic therapy (PDT) are still needed for the absorption of light in the infrared spectrum, which provides a maximal penetration of light into tissue. Therefore, both the efficacy and the mechanism of action of the clinically approved dye indocyanine green (ICG) and laser irradiation were investigated in vitro. For the investigation of phototoxic effects, HT-29 cells were incubated 24 h prior to irradiation by using different concentrations of ICG (10-500 microM). In each experiment, cells were irradiated using a continuous wave (cw)-diode laser (lambda(ex) = 805 nm, 30 J cm(-2), 40 mW cm(-2)). After laser irradiation, cell viability of dark control and of cells incubated with 500 microM ICG was 1.27+/-0.11 or 0.28+/-0.05 respectively. Using 100 microM ICG and D2O, cell viability was further decreased from 0.46+/-0.03 (H2O) to 0.11+/-0.01 (D2O). Using D2O and 100 microM ICG, the concentration of malondialdehyde, a marker of lipid peroxidation, increased from 0.89+/-0.10 nmol 10(-6) cells to 11.14+/-0.11 nmol 10(-6) cells. Using 100 microM ICG and laser irradiation sodium azide or histidine (50 mM), quenchers of singlet oxygen reduced the cell killing significantly. In contrast, when using mannitol, a quencher of superoxide anion and hydroxyl radical, cell killing was not inhibited. According to the present results, photoactivated ICG seems to kill colonic cancer cells due to the generation of singlet oxygen and the subsequent formation of lipid peroxides. Therefore, ICG might present a promising photosensitizer for PDT; first clinical results confirm these findings.

Cell Death↗
PubMed1998

[Photodynamic diagnosis of gastrointestinal precancerous lesions after sensitization with 5-aminolevulinic acid. A pilot study].

BASIC PROBLEM AND OBJECTIVE: Endoscopic diagnosis of gastrointestinal precancerous and cancerous lesions is difficult, often even impossible. This study was undertaken to find out whether premalignant or suspected malignant tumors can be diagnosed by preceding sensitization with 5-aminolaevulinic acid (ALA), which in tumors is transformed in increased amounts into photosensitizing protoporphyrin IX, the latter being recognized by its characteristic red fluorescence on exposure to blue light. PATIENTS AND METHODS: 20 patients with known mild or moderately severe dysplasias (Barrett's esophagus, n = 8; colorectal adenoma, n = 3; ulcerative colitis n = 2, and gastric polyps or mucosal changes suspicious of malignancy, n = 5. Two patients with squamous-cell carcinoma, who after radio- and chemotherapy were endoscopically free of tumor, were sensitized with different concentrations of ALA (orally: 5-30 mg/kg; or locally: 3 g in 100 ml 0.9% NaCl). Photodynamic diagnosis (PDD) took place 4-8 h after oral and ca. 1-2 h after local sensitization with blue light (D-light, Storz, Tuttlingen, Germany). RESULTS: Definite red fluorescence with demonstration of dysplasia was found in three of four patients with Barrett's esophagus. Biopies from nonfluorescent areas were free of dysplasia. Two gastric adenomas (10 mg/kg ALA with high-grade dysplasia were definitively endoscopically by their red fluorescence. In one patient mild dysplasia was found in a non-fluorescent area after radio- and chemotherapy of an esophageal carcinoma. Dysplasias were also seen in the rectal biopsy after local applications. CONCLUSIONS: PDD makes it possible for the first time to visualize precancerous lesions of the gastrointestinal tract after preceding ALA sensitization. PDD is a highly promising method for monitoring patients with gastrointestinal disease and an increased risk of cancer, and for clarifying the diagnosis of mucosal changes suspicious of malignancy.

Adenoma↗
PubMed1998

Leg telangiectasia treatment with a 1.5 ms pulsed dye laser, ice cube cooling of the skin and 595 vs 600 nm: preliminary results.

BACKGROUND AND OBJECTIVE: Preliminary results indicate that pulsed dye lasers (PDL) with 1.5 ms pulsewidth and 595 nm wavelength are effective in the treatment of leg telangiectasia. The aim of this study was to evaluate if the clinical results could be improved by a) an effective skin cooling with ice cubes and b) the longer wavelength of 600 nm. STUDY DESIGN/MATERIALS AND METHODS: In 87 patients with vessels up to 1 mm in diameter, 257 single test treatments were performed using wavelengths of 595 and 600 nm, fluences of 16, 18, and 20 J/cm2, a 1.5 ms pulse duration, and an elliptical spot of 2 x 7 mm. In 7 patients, the skin surface temperature curve was measured after cooling with ice cubes vs hydrogel dressings, and spot geometry and fluence were investigated with and without the gel dressing. RESULTS: Vessel clearance was evaluated 6-8 weeks after treatment. 20 J/cm2 were most effective (80% clearance >50%), and 18 J/cm2 were more effective than 16 J/cm2 (66.2 vs 52.5% clearance >50%). There was a tendency towards better results with 595 nm, but the differences were not significant. Vessels with a diameter <0.5 mm cleared significantly better than those with 0.5-1 mm (69.1 vs 31.9% clearance >50%). Hypo- and hyperpigmentation were seen in 32% of the patients. Cooling with ice cubes proved to be far more effective than with hydrogel dressings (temperature decrease approx 15 vs 5 degrees C). Additionally, the gel dressing caused an energy loss of approx 35% and an irregular spot geometry as shown on burn paper. CONCLUSIONS: Treatment of leg telangiectasia with the 1.5 ms-PDL is safe and effective, especially in vessels smaller than 0.5 mm in diameter; 595 nm and 18 J/cm2 seem to be somewhat more effective as 600 nm and 16 J/cm2; and 20 J/cm2 are even more effective, but persistent hyperpigmentation cannot yet be excluded due to insufficient follow-up time. Cooling with ice cubes is more effective and less expensive than gel dressings, and the short term clinical results are equivalent, even if the frequency of transient pigmentary changes is increased.

Bandages↗