| 1. |
- Alonso-Castro, Leticia, et al.
(författare)
-
The effect of pulsed dye laser on high-risk basal cell carcinomas with response control by Mohs micrographic surgery
- 2015
-
Ingår i: Lasers in medical science. - : Springer Science and Business Media LLC. - 1435-604X .- 0268-8921. ; 30:7, s. 2009-2014
-
Tidskriftsartikel (refereegranskat)abstract
- Several reports have shown the effectiveness of pulsed dye laser (PDL) for the treatment of basal cell carcinoma (BCC). Most studies have focused on low-risk BCCs, but an important limitation has been the lack of histologic confirmation of the treatment results. The aim of this study was to assess the effectiveness of PDL in high-risk BCCs with complete histologic evaluation with Mohs micrographic surgery (MMS). Seven patients with high-risk BCCs located on the face were included. All tumors were treated with three sessions of PDL (595nm) at 4-week intervals. The tumor and 4mm of peripheral skin were treated with two stacked pulses with a 1-s delay, a fluence of 15J/cm(2), a pulse duration of 2ms, and a spot size of 7mm. MMS was performed at least 1month after the last PDL session including excisional tumor debulking prior to the first stage of MMS for standard histologic evaluation. Apparent complete clinical response was achieved in five of seven patients. MMS was finally performed in six patients, and clear margins were achieved after one stage of MMS. The histologic evaluation of the tumor debulking specimens showed complete clearance in four of six cases. One patient who did not undergo MMS showed a recurrence after 14months. This is the first pilot study that demonstrates that PDL can be effective for the treatment of high-risk BCCs. Until further scientific evidence is available, treatment of high-risk BCCs should include histologic confirmation of clearance.
|
|
| 2. |
- Andersson-Engels, S., et al.
(författare)
-
Aspects of tumour demarcation in rats by means of laser-induced fluorescence and haematoporphyrin derivatives
- 1988
-
Ingår i: Lasers in Medical Science. - 0268-8921. ; 3:239, s. 239-248
-
Tidskriftsartikel (refereegranskat)abstract
- The effects of different parameters of interest for the localization of malignant tumours in situ by means of laser-induced fluorescence and haematoporphyrin derivatives were investigated. Such parameters are drug composition, drug concentration, laser pulse energy and excitation wavelength. In order to assess the relative merits of the two tumour-seeking agents Photofrin (haematoporphyrin derivative) and Photofrin II (dihaematoporphyrin ether) we have performed a comparative study on rat tissues. The results suggest that Photofrin is at least as good as the therapeutically more potent agent Photofrin II. A linear relation between drug dose and recorded porphyrin fluorescence intensity was also found. Using not only the porphyrin fluorescence, but also natural tissue autofluorescence, better tumour demarcation is observed when utilizing an excitation wavelength shorter than the porphyrin excitation peak at 405 nm.
|
|
| 3. |
- Andersson-Engels, Stefan, et al.
(författare)
-
Autofluorescence of various rodent tissues and human skin tumour samples
- 1987
-
Ingår i: Lasers in Medical Science. - 0268-8921. ; 2:1, s. 41-49
-
Tidskriftsartikel (refereegranskat)abstract
- Fluorescence spectra from different organs in rats and mice have been recorded to explore the potential of non-intrusive tissue diagnostics. The fluorescence was induced by a nitrogen laser that emitted at a wavelength of 337 nm. Optical multichannel techniques were used for the detection. Spectra are given from 19 different sites in Wistar/Furth rats, including an inoculated malignant tumour. The spectra seem to be a sum of two wavelength distributions only, each distribution occurring with a different weight in different organs. Spectra obtained from living and dead tissue were compared to verify that the measurements on sacrificed experimental animals were valid. Preliminary results are given for some human tumours, transplanted in nude mice, and for some human skin samples.
|
|
| 4. |
- Andersson-Engels, Stefan, et al.
(författare)
-
Clinical recording of laser-induced fluorescence spectra for evaluation of tumour demarcation feasibility in selected clinical specialities
- 1991
-
Ingår i: Lasers in Medical Science. - 0268-8921. ; 6:4, s. 415-424
-
Tidskriftsartikel (refereegranskat)abstract
- Laser-induced autofluorescence spectra from humans were recorded in vivo at three different clinics in a study aimed at investigating the capability of this method to discriminate between malignant tumours and normal surrounding tissues. For the recordings a mobile trolley with the necessary equipment was constructed for use in an examination room or in an operating theatre environment. Laser light was guided through a 600m optical fibre to the target tissue. The fluorescence from the excited tissue was collected with the same fibre and was fed to an optical multichannel analyser. Two excitation wavelengths were used (337 and 405 nm) in order to optimize the fluorescence signals in two interesting wavelength regions (380–500 and 550–700 nm). Oral and oropharyngeal tumours excited with 405 nm light contained detectable endogenous porphyrins and were in this way discriminated from the normal mucosa. Astrocytoma grade III–IV fluorescence different from that of normal brain tissue, while tumours in the bronchial tree were not detectable using the spectral shape of the pure tissue autofluorescence.
|
|
| 5. |
- Andersson-Engels, Stefan, et al.
(författare)
-
Identification of brain tumours in rats using laser-induced fluorescence and haematoporphyrin derivative
- 1989
-
Ingår i: Lasers in Medical Science. - 0268-8921. ; 4:4, s. 241-249
-
Tidskriftsartikel (refereegranskat)abstract
- Laser-induced fluorescence has been used for the identification of brain tumours in rats, which have been previously given tumour-seeking haematoporphyrin derivative. A pulsed nitrogen laser (λ=337 nm) was used in conjunction with an optical multichannel analyzer. For both inoculated RG-2 and TCVC rat-brain-tumour models, the blue autofluorescence was strongly reduced in the tumour compared with normal brain tissue, and at the same time the characteristic red-drug signal increased. The contrast between tumour and normal tissue was strongly enhanced by forming the ratio between the two signals. Implications for possible improvement of tumour delineation in brain tumour surgery are discussed.
|
|
| 6. |
- Andersson-Engels, Stefan, et al.
(författare)
-
Laser-induced fluorescence used in localizing atherosclerotic lesions
- 1989
-
Ingår i: Lasers in Medical Science. - 0268-8921. ; 4:3, s. 171-181
-
Tidskriftsartikel (refereegranskat)abstract
- We have investigated laser-induced fluorescence frompost mortem human arteries in order to find spectroscopic properties allowing discrimination between normal and atherosclerotic vessel wall. A pulsed nitrogen laser emitting light at a wavelength of 337.1 nm was used as an excitation source. The fluorescence spectrum from 370 to 700 nm was captured and analysed by an optical multichannel analyser. Dimensionless contrast functions were formed by using characteristic spectral features at 390, 415, 480, 580 and 600 nm. All samples were investigated in scans across a region where normal as well as diseased vessel wall appeared. The types of plaque were histopathologically divided into four groups, of which three could be singled out using one or more of our spectroscopic criteria. We also investigated the different layers of the normal and diseased vessel wall in order to determine the various contributions to the fluorescence signal. Furthermore, plasma emission spectra were recorded while ablating the normal as well as the diseased vessel wall with an excimer laser, emitting radiation at 308 nm, thus detecting the change in spectral characteristics during the ablation process down into deeper layers.
|
|
| 7. |
- Andersson-Engels, Stefan, et al.
(författare)
-
Tumour marking properties of different haematoporphyrins and tetrasulfonated phthalocyanine - A comparison
- 1989
-
Ingår i: Lasers in Medical Science. - 0268-8921. ; 4:2, s. 115-123
-
Tidskriftsartikel (refereegranskat)abstract
- Several photosensitizers were screened for their tumour-marking ability using laserinduced fluorescence in Wistar/Furth rats bearing subcutaneous adenocarcinomas inoculated in muscle. Of the studied photosensitizers, dihaematoporphyrin ether appeared to exhibit the best tumour-demarcation properties. Polyhaematoporphyrin ester and tetrasulfonated phthalocyanine were almost as good although the fluorescence yield was much lower. Monomeric haematoporphyrin also showed some tumour-marking qualities. By forming fluorescence intensity ratios, information from both the blue and the red spectral regions were used to provide the highest tumour-to-muscle contrast. Two excitation wavelengths were used, of which 337 nm rather than 405 nm excitation light seemed to yield a better tumour demarcation, due to a greater difference in the superimposing autofluorescence between tumour and surrounding tissue. The study included measurements on many inner organs in an attempt to gain a better understanding of the interaction between the drugs and various kinds of tissue.
|
|
| 8. |
- Ericson, Marica B, 1974, et al.
(författare)
-
A spectroscopic study of the photobleaching of protoporphyrin IX in solution
- 2003
-
Ingår i: Lasers in Medical Science. - 0268-8921. ; 18:1, s. 56-62
-
Tidskriftsartikel (refereegranskat)abstract
- Photodynamic therapy (PDT) has developed into an important new clinical treatment for cancer during the past 30 years. The method is non-invasive and based on the photochemical activity of a photosensitising agent present in cells and tissues. In so-called ALA-PDT, protoporphyrin IX (Pp IX) is induced from aminolaevulinic acid (ALA) applied topically or systemically. It has been shown that Pp IX is photodegraded by a photo-oxidation process and that its photoproducts have a characteristic absorption band around 670 nm, as observed both in solution and in cells incubated with ALA. In this study, the involvement of oxygen in the photobleaching process was verified by studying the effect of oxygen depletion using the freeze-pump-thaw (FPT) method. A solution of Pp IX in dimethylformamide (DMF) was exposed to light in the wavelength region 600-700 nm (peak centred at 620 (+/-25) nm) both in the presence and in the absence of oxygen. The bleaching process was observed by absorbance and fluorescence measurements. Photobleaching was observed in the presence of oxygen, as verified by the build-up of a photoproduct absorbing at 670 nm. When the sample was deoxygenated with the FPT method, the photoproduct absorption peak at 670 nm was missing. These results confirm that the formation of photo-protopor-phyrin is a photo-oxidation process and that no photobleaching takes place in the absence of oxygen. When comparing our results to the studies carried out by N-2 bubbling, the N-2 bubbling seems to be insufficient to remove the oxygen completely from the solution.
|
|
| 9. |
- Fakhar-e-Alam, Muhammad, et al.
(författare)
-
Photodynamic effects of zinc oxide nanowires in skin cancer and fibroblast
- 2014
-
Ingår i: Lasers in Medical Science. - : Springer London. - 0268-8921 .- 1435-604X. ; 29:3, s. 1189-1194
-
Tidskriftsartikel (refereegranskat)abstract
- Cytotoxic effects of zinc oxide (ZnO) nanomaterials, individual and conjugated with a photosensitizer (protoporphyrin IX), were studied in the presence and absence of ultraviolet light exposure (240 nm of light wavelength for a very short time exposure) in cell cultures of human normal and cancerous skin models. Zinc Oxide nanowires (ZnO NWs) were grown on the capillary tip and conjugated with protoporphyrin IX (PpIX). This coated tip was used as tool/pointer for intracellular drug delivery protocol in suggested normal as well as carcinogenic cellular models. After true delivery of optimal drug, the labelled biological model was irradiated with UV-A, which led to a loss of mitochondrial membrane potential, as tested by neutral red assay (NRA).
|
|
| 10. |
- Fakhar-e-Alam, Muhammad, et al.
(författare)
-
Sensitivity of A-549 human lung cancer cells to nanoporous zinc oxide conjugated with Photofrin
- 2012
-
Ingår i: Lasers in Medical Science. - : Springer Verlag (Germany). - 0268-8921 .- 1435-604X. ; 27:3, s. 607-614
-
Tidskriftsartikel (refereegranskat)abstract
- In the present study, we demonstrated the use of nanoporous zinc oxide (ZnO NPs) in photodynamic therapy. The ZnO NPs structure possesses a high surface to volume ratio due to its porosity and ZnO NPs can be used as an efficient photosensitizer carrier system. We were able to grow ZnO NPs on the tip of borosilicate glass capillaries (0.5 mu m diameter) and conjugated this with Photofrin for efficient intracellular drug delivery. The ZnO NPs on the capillary tip could be excited intracellularly with 240 nm UV light, and the resultant 625 nm red light emitted in the presence of Photofrin activated a chemical reaction that produced reactive oxygen species (ROS). The procedure was tested in A-549 cells and led to cell death within a few minutes. The morphological changes in necrosed cells were examined by microscopy. The viability of control and treated A-549 cells with the optimum dose of UV/visible light was assessed using the MTT assay, and ROS were detected using a fluorescence microscopy procedure.
|
|
