Automatic forensic analysis of automotive paints using optical microscopy.

The timely identification of vehicles involved in an accident, such as a hit-and-run situation, bears great importance in forensics. To this end, procedures have been defined for analyzing car paint samples that combine techniques such as visual analysis and Fourier transform infrared spectroscopy. This work proposes a new methodology in order to automate the visual analysis using image retrieval. Specifically, color and texture information is extracted from a microscopic image of a recovered paint sample, and this information is then compared with the same features for a database of paint types, resulting in a shortlist of candidate paints. In order to demonstrate the operation of the methodology, a test database has been set up and two retrieval experiments have been performed. The first experiment quantifies the performance of the procedure for retrieving exact matches, while the second experiment emulates the real-life situation of paint samples that experience changes in color and texture over time.

Comparative analysis of two methods for wound bed area measurement.

Wound bed area measurements are considered to be an essential part of the wound assessment process. Wound care professionals should be aware of the reliability and validity of the techniques they use. The purpose of this study was to assess whether wound care professionals are able to make as accurate and reproducible a measurement of the wound bed area using two methods for area measurement. Five wound care professionals independently assessed 2285 digital wound images for the wound bed area. Each image was measured in random order, three times, and in four angles by providing the rotated versions of each image (0°, 90°, 180° and 270°). Two techniques were compared: free hand drawing and closed polygon (CP) graph algorithm. Comparison of the two techniques showed differences that are, in our opinion, not acceptable in clinical practice when these techniques are used interchangeably and/or the measurements are carried out by different observers. Variations observed between wounds and observers seem related to the difference in perception of the wound bed margin. Our results indicate that repetition of CP graph area measurement results in the lowest difference in repetitive measurements. Study limitations are related to an incomplete consensus on definitions of wound, wound bed, wound edge and wound border. The development of an ontology related to wound images could aid to reduce these ambiguities.

Baerveldt glaucoma implants in the management of refractory glaucoma after vitreous surgery.

PURPOSE: To examine the effectiveness and safety of Baerveldt glaucoma implants in eyes with refractory glaucoma following vitrectomy. METHODS: We performed a retrospective study of a non-comparative case series of 30 eyes of 30 patients who had undergone the implantation of a Baerveldt glaucoma device. All eyes (30/30) had a minimum follow-up of 6 months, and 16/30 (53%) had a follow-up of 24 months. Surgical success was defined as intraocular pressure (IOP) < 22 mmHg on the last two follow-up visits with or without glaucoma medication and a decrease in IOP of at least 20% compared to preoperative values with or without glaucoma medication. RESULTS: The mean IOP before implantation of a Baerveldt glaucoma device was 30 mmHg [+/- 11.4 mmHg standard deviation (SD)] with maximally tolerated medical therapy. Six months after implantation of the Baerveldt glaucoma device, the mean IOP was 17.3 mmHg (+/- 6.7 mmHg SD) and the mean number of glaucoma medications had gone down from 3.0 (+/- 0.4 SD) to 0.3 (+/- 0.3 SD). Successful outcomes were found in 24 eyes (80%). Small complications occurred in six eyes (20%): transient postoperative hypotony (17%) and tube retraction (3%). Larger complications occurred in another six eyes (20%): corneal decompensation requiring keratoplasty (7%), suprachoroidal haemorrhage (3%) and persistently high IOP (10%). CONCLUSION: Baerveldt glaucoma devices are a valid treatment option in eyes with refractory glaucoma after vitreous surgery, although failure occurred in 20% of our patients. Transient complications occurred in 20% and severe complications in another 20%.

Subjective and objective evaluation of noncultured epidermal cellular grafting for repigmenting vitiligo.

BACKGROUND: Noncultured epidermal cell transplantation in vitiligo permits the coverage of relatively large areas without culturing cells. OBJECTIVE: To investigate the effectiveness of noncultured epidermal cell transplantation in treating stabilized vitiligo using objective and subjective evaluation methods. METHODS: Noncultured autologous melanocytes and keratinocytes were grafted in a hyaluronic-acid-enriched suspension on superficially laser-abraded vitiligo lesions in 40 patients with refractory stable vitiligo (30 with generalized and 10 with localized vitiligo). The repigmentation was evaluated 3-12 months after grafting using a digital image analysis system. Furthermore the treatment was evaluated from the patients' point of view with the DLQI (Dermatology Life Quality Index) and a 'global assessment'. RESULTS: The mean percentage of repigmentation, evaluated at the last follow-up visit, was 72% (median 84%), and a repigmentation of >or=70% was observed in 62% of patients. The best results were achieved in the neck and the presternal region. A subjective evaluation was performed in half of the subjects. The mean DLQI score at inclusion (6.95, SD = 6.68, n = 20) was significantly decreased after treatment (p = 0.013, mean 3.85, SD = 4.13, n = 20). The patients were satisfied with the achieved result, found it worthwhile to undergo the treatment and would choose it again. CONCLUSION: According to both subjective and objective evaluation methods, noncultured epidermal cell transplantation is promising in patients with stable vitiligo.

Café-au-lait spots in neurofibromatosis type 1 and in healthy control individuals: hyperpigmentation of a different kind?

Solitary café-au-lait spots are quite common in the general population but multiple café-au-lait macules (CALM) are often indicative of an underlying genetic disorder. The frequency of having more than five CALM is rare in normal individuals and is therefore considered as a cut-off for the diagnosis of neurofibromatosis type 1 (NF1). The etiopathogenesis of these macules is still very obscure. In this study we compared epidermal melanocyte and dermal mast cell numbers between four groups: control normal and control CALM skin, and NF1 normal and NF1 CALM skin and elaborated a possible role for stem cell factor (SCF) in CALM formation. The groups were analyzed by immunohistochemistry for numerical analysis of the melanocyte and mast cell population and by ELISA, western blot analysis and real-time quantitative PCR for further determination of the role of SCF. We found a significant increase in melanocyte density in NF1 CALM skin compared with the isolated CALM in control individuals. However, both groups displayed a similar increase in mast cell density. In addition, we found increased levels of soluble SCF in NF1 CALM and in NF1 normal fibroblast supernatant. We conclude that SCF is an important cytokine in NF1 skin, but that additional (growth) factors and/or genetic mechanisms are needed to induce NF1-specific CALM hyperpigmentation.

Consistent cutaneous imaging with commercial digital cameras.

OBJECTIVE: To demonstrate how to improve the reproducibility and accuracy of digital images of the skin taken with commercially available digital cameras by transforming them to a standard color space, sRGB. METHODS: Our computer algorithm transforms digital images to the standard sRGB color space. It is based on a card with a number of color squares with known colorimetric properties that is included in the image, thereby removing any ambiguity about the color information in the image. Reproducibility and accuracy of the method were assessed by comparing images of color squares with known colorimetric properties taken with different digital cameras at different exposures and zoom settings. RESULTS: Although calibrated images exhibit markedly improved precision and accuracy compared with noncalibrated images, all variability of the imaging process cannot be eliminated. CONCLUSION: With a little care and effort, a calibrated color chart, and computer software, it is possible to greatly improve the quality of clinical imaging in dermatology and possibly other fields of medicine.

P-cadherin promotes cell-cell adhesion and counteracts invasion in human melanoma.

Malignant transformation of melanocytes frequently coincides with alterations in epithelial cadherin (E-cadherin) expression, switching on of neural cadherin (N-cadherin), and, when progressed to a metastatic stage, loss of membranous placental cadherin (P-cadherin). In vitro studies of melanoma cell lines have shown invasion suppressor and promoter roles for E-cadherin and N-cadherin, respectively. In the present study, we investigated the effect of P-cadherin on aggregation and invasion using melanoma cells retrovirally transduced with human P-cadherin. De novo expression of P-cadherin in P-cadherin-negative cell lines (BLM and HMB2) promoted cell-cell contacts and Ca2+-dependent cell-cell aggregation in two- and three-dimensional cultures, whereas it counteracted invasion. These effects were not observed following P-cadherin transduction of endogenously P-cadherin-positive MeWo cells. In addition, P-cadherin-transduced BLM cells coaggregated with keratinocytes and showed markedly reduced invasion in a reconstructed skin model. The proadhesive and anti-invasive effects of P-cadherin were abolished on targeted mutation of its intracellular juxtamembrane domain or its extracellular domain. For the latter mutation, we mimicked a known missense mutation in P-cadherin (R503H), which is associated with congenital hypotrichosis with juvenile macular dystrophy.

A new digital image analysis system useful for surface assessment of vitiligo lesions in transplantation studies.

So far there is no uniformity in the evaluation methods used in the assessment of treatment outcome in vitiligo studies. The ability to objectively measure surfaces of vitiligo lesions is important for both clinical practice and research. Our objective was to assess the reproducibility, accuracy, user-friendliness and time effectiveness of a new digital image analysis system for surface measurement of vitiligo lesions. Three different observers performed both a visual estimation and a digital image analysis on 30 images of 10 vitiligo lesions. Inter- and intra-observer variation were evaluated and results were compared with the 2D gold standard measurements and a 3D measurement. A high inter- and intra-observer variability was observed for the visual estimation of surfaces. With the digital image analysis system a significant improvement of the reproducibility was achieved (p = 0.01). Moreover, results were accurate and the measurement procedure was user-friendly. Importantly, a systematic underestimation was demonstrated when comparing the 2D with the 3D measurements. We introduced an objective measurement method that might be useful in the future for consistently measuring surfaces of selected vitiligo lesions both before and after different therapeutic modalities.

Management of vitiligo patients and attitude of dermatologists towards vitiligo.

As vitiligo does not cause any physical impairment, it is often considered unimportant by physicians. Vitiligo patients repeatedly experience disinterest from the medical world regarding their skin problem. A questionnaire survey was used to assess the management of vitiligo patients and the attitude of dermatologists towards vitiligo in Belgium. Vitiligo patients (n = 244) visiting an academic affiliated dermatology department were included and 454 out of 558 Belgian dermatologists returned a mailed questionnaire. Vitiligo patients do not often visit a doctor concerning their disease and do not often treat their disease. Disease severity as reported by the patient is correlated with the number of doctor visits (p = 0.001) but not to treatment of the disease. Information about the treatment and physician's encouragement to treat seem important in motivating patients to treat their vitiligo, but 50% of the patients were not adequately informed about their disease and its treatment during their first doctor visit. Today, nearly all the dermatologists report widely informing their patients, but only 36% of them encourage their patients to treat their disease, being pessimistic concerning expected treatment results. Interestingly, two thirds of the patients who ever treated their disease find it worthwhile.