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Biomedical subjects

Thilo Gambichler

Publications and source records attributed to Thilo Gambichler.

At least 19 recordsLinked to original sources
PubMed2007

In vivo optical coherence tomography of basal cell carcinoma.

BACKGROUND: Optical coherence tomography (OCT) is a promising non-invasive imaging technique that has not systematically been studied in skin cancer such as basal cell carcinoma (BCC). OBJECTIVE: We aimed, first, to describe the in vivo histologic features of BCC by using OCT, and second, to find out whether it is possible to differentiate BCC subtypes by means of OCT. METHODS: Prior to the excision, the BCCs (n=43) as well as adjacent non-lesional skin sites were assessed by OCT in vivo. The lesional area of interest was marked prior to OCT and tattooed after excision, respectively, in order to enable topographical concordance between the cross-sectional OCT images and the histologic sections. RESULTS: Compared to non-lesional skin, a loss of normal skin architecture and disarrangement of the epidermis and upper dermis was observed in the OCT images of BCCs. Features that were frequently identified by OCT and correlated with histology included large plug-like signal-intense structures, honeycomb-like signal-free structures, and prominent signal free cavities in the upper dermis. With regard to the aforementioned OCT features, no statistically significant (P<0.05) difference was found between nodular, multifocal superficial, and infiltrative BCCs, respectively. CONCLUSIONS: OCT is capable to visualize altered skin architecture and histopathological correlates of BCC. However, there is not at this time sufficient data supporting the clinical use of OCT for the differentiation of BCC subtypes.

Aged↗
PubMed2006

Differential expression of decorin in localized scleroderma following ultraviolet-A1 irradiation.

Patients with localized scleroderma underwent an 8-week course of ultraviolet A1 phototherapy. At baseline, decorin levels of lesional skin were significantly lower than those of nonlesional skin and healthy control subjects. After ultraviolet A1 phototherapy, decorin levels of lesional skin were significantly higher than baseline. Decorin may be of significance in the pathogenesis of localized scleroderma.

Adult↗
PubMed2006

In vivo data of epidermal thickness evaluated by optical coherence tomography: effects of age, gender, skin type, and anatomic site.

BACKGROUND: The knowledge of epidermal thickness (ET) is of great significance in many areas of medical and biological research. OBJECTIVES: We aimed to assess optical coherence tomography (OCT) in terms of precision, and to investigate the influence of several constitutional factors, such as age, gender, skin type, and anatomic site, on the mean ET using OCT in vivo. METHODS: Eighty-three subjects were studied using OCT in vivo. Intra- and inter-day repeatability measurements were performed. The mean ET was assessed in six different body sites of young (20-40 years old) and old (60-80 years old) Caucasians, respectively. An ethnic group was included into the study. RESULTS: OCT proved to be a precise technique in terms of repeatability and reproducibility as expressed in low coefficients of variation. Comparison of young and old Caucasians demonstrated a significant decrease of ET with age in all anatomic sites investigated. ET assessed in males and females did not significantly differ, except for forehead skin which is significantly thinner in old females than in males. ET observed in Caucasians did not significantly differ from ET measured in ethnic individuals. Anatomic sites insignificantly influenced ET on an inter-individual level. However, differences of ET between body sites on an intra-individual level are significant. CONCLUSIONS: This was the first systematic in vivo study on ET investigating several influencing parameters of the epidermal dimension in a reasonable study sample by means of OCT. The results presented here may serve as ET reference data in a variety of clinical and experimental matters.

Adult↗
PubMed2006

Ultraviolet A1 phototherapy decreases inhibitory SMAD7 gene expression in localized scleroderma.

Localized scleroderma (LS) is a connective skin disease with marked sclerosis of the skin as the most prominent feature. Transforming growth factor beta (TGF-beta) plays a central role in the pathogenesis of sclerotic skin diseases. Recently, special attention was contributed to a family of transcription factor proteins involved in TGF-beta signal transduction from cell surface to the nucleus, the so-called SMADs. Ultraviolet (UV) irradiation has been reported to alter TGF-beta/SMAD pathway in human skin. We sought to investigate the effects of UVA1 on the gene and protein expressions of the TGF-beta/SMAD pathway in LS. UVA1 phototherapy was performed in eight LS patients five times weekly for 8 weeks resulting in a total of 40 treatment sessions (single dose 50 J/cm(2), cumulative dose 2,000 J/cm(2)). TGF-beta1, SMAD3, SMAD4, and SMAD7 mRNA expressions were determined by semiquantitative real-time reverse transcription polymerase chain reaction in lesional and unaffected skin of patients with LS. Additionally, immunohistochemical staining was performed in lesional skin before and after irradiation. Skin status markedly improved in all patients, resulting in a significant reduction of the clinical score from baseline to the end of treatment. Inhibitory SMAD7 mRNA was significantly higher in lesional skin as compared to unaffected skin, and significantly decreased after UVA1 phototherapy. In contrast, SMAD7 mRNA levels remained unchanged in irradiated, healthy skin after UVA1. Both TGF-beta and SMAD3 mRNA levels decreased after UVA1, whereas SMAD4 mRNA increased. However, changes in TGF-beta, SMAD3, and SMAD4 mRNA after UVA1 did not reach statistical significance. Immunohistochemical investigation did not reveal significant changes in the protein expression of SMADs after UVA1. Similar to scleroderma, SMAD7-mediated negative regulation seems to be impaired in LS. UVA1 phototherapy demonstrated the alteration of SMAD7 gene expression in LS, as SMAD7 mRNA levels normalized after UVA1. The pathogenetic relevance of SMAD7 levels with respect to clinical improvement needs further investigation.

Adult↗
PubMed2006

Topical tacrolimus neither prevents nor abolishes ultraviolet-induced erythema.

A dose- and vehicle-controlled study on the pretreatment and posttreatment effect of 0.1% tacrolimus ointment on erythema induced by solar-simulated ultraviolet (UV) radiation was performed. Surprisingly, comparisons of clinical erythema scores and colorimetric data obtained 24 and 72 hours after UV exposure did not reveal significant differences between the control, tacrolimus, and vehicle preirradiation and postirradiation treated sites (P > .05). Our data strongly indicate that topical tacrolimus neither prevents nor abolishes UV-induced erythema in a clinical meaningful degree.

Administration, Topical↗
PubMed2006

A randomized controlled study of low-dose UVA1, medium-dose UVA1, and narrowband UVB phototherapy in the treatment of localized scleroderma.

BACKGROUND: In previous trials, UV therapy has been demonstrated to be effective in the treatment of localized scleroderma (LS). To date, a randomized comparison study to evaluate the efficacy and safety of different, commonly used phototherapeutic modalities in LS is still outstanding. OBJECTIVE: The aim of this study was to compare the safety and efficacy of low-dose (LD) UVA1, medium-dose (MD) UVA1, and narrowband (NB) UVB phototherapy in the treatment of LS. METHODS: Sixty four patients with LS were consecutively included in a prospective, open, randomized controlled 3-arm study. Severity of LS was determined by means of a clinical score, and clinical improvement was also monitored by histopathologic analysis and 20-MHz ultrasound. RESULTS: A total of 27 patients were treated with LD UVA1 (20 J/cm2), 18 patients received MD UVA1 (50 J/cm2), and 19 patients were treated with NB UVB dependent on their skin type. Phototherapy was performed 5 times weekly for 8 weeks. Two of the 64 patients included in this trial discontinued therapy. Skin status significantly improved in all patients who finished the treatment protocol, resulting in a reduction of the clinical score in all groups (LD UVA1, 7.6-5.0 [P < .001, 95% confidence interval 1.6-3.4]; MD UVA1, 11.1-6.6 [P < .001, 95% confidence interval 2.5-6.2]; NB UVB, 7.3-4.9 [P < .001, 95% confidence interval 1.6-3.2]). The reduction of the score was accompanied by an improvement of the visual analog scale for itching and tightness, histologic score, and 20-MHz ultrasound. MD UVA1 was significantly more effective than NB UVB (P < .05). There were no significant differences between LD UVA1 and NB UVB and the former and MD UVA1 (P > .05). LIMITATIONS: We had a relatively small study sample and nonblinded assessment of primary outcome. CONCLUSION: Phototherapy, as previously reported in several noncontrolled trials, is an effective therapeutic option in LS, with a favorable risk/benefit ratio. UVA1 phototherapy should be considered among the first approaches in the management of LS.

Adolescent↗
PubMed2006

1% pimecrolimus, 0.005% calcipotriol, and 0.1% betamethasone in the treatment of intertriginous psoriasis: a double-blind, randomized controlled study.

OBJECTIVE: During the last decades, management of intertriginous psoriasis (IP) has been unsatisfactory because of the adverse effects associated with long-term corticosteroid application and the lack of alternatives. Recently, both pimecrolimus and tacrolimus have been investigated for this indication and shown to be safe and effective. So far, to our knowledge, a comparison of one of these drugs with standard regimens for IP has not been performed. DESIGN: A single-center, 4-week, double-blind, randomized, vehicle-controlled comparison study to assess the safety and efficacy of 1% pimecrolimus, 0.005% calcipotriol, and 0.1% betamethasone valerate in the treatment of IP. SETTING: Dermatologic hospital at Ruhr University of Bochum. PATIENTS: Eighty adults with IP. INTERVENTIONS: Treatment of IP with 1% pimecrolimus, 0.005% calcipotriol, 0.1% betamethasone, or the vehicle once daily for 28 days. MAIN OUTCOME MEASURES: Mean reduction of the Modified Psoriasis Area and Severity Index (M-PASI) score after 28 days of treatment was considered the primary outcome measure, which was analyzed on an intention-to-treat basis. The secondary outcome was a visual analog scale score for itching. RESULTS: After 4 weeks of treatment, the 3 active compounds and the vehicle resulted in a significant decrease in mean M-PASI score (86.4% for 0.1% betamethasone, 62.4% for 0.005% calcipotriol, 39.7% for 1% pimecrolimus, and 21.1% for vehicle). The 0.1% betamethasone was significantly more effective than 1% pimecrolimus during the study period (P<.05). No significant difference was found between 0.005% calcipotriol and 0.1% betamethasone and between 0.005% calcipotriol and 1% pimecrolimus. The visual analog scale score for pruritus decreased by 78% for 0.1% betamethasone, 57% for 0.005% calcipotriol, 35% for 1% pimecrolimus, and 43% for the vehicle, again demonstrating a clear advantage for the corticosteroid (P<.05). CONCLUSIONS: The 1% pimecrolimus was shown to be less potent than 0.1% betamethasone in the treatment of IP. Considering the adverse-effect profile of long-term application of corticosteroids, occasional or intermittent rescue therapy with short-term topical corticosteroids and maintenance with a less potent agent, such as 1% pimecrolimus or 0.005% calcipotriol, might be appropriate for patients with IP in general practice.

Administration, Cutaneous↗
PubMed2006

Clinical and serological characteristics of progressive facial hemiatrophy: a case series of 12 patients.

BACKGROUND: Progressive facial hemiatrophy (PFH) is characterized by a slowly progressive atrophy of soft tissues and in some cases bony structures. Coexisting features of localized scleroderma (LS) are commonly observed, indicating the close nature of both disorders. OBJECTIVE: We sought to investigate clinical, serological, and radiographic findings in PFH from 278 patients with LS and to discuss the relationship to linear scleroderma en coup de sabre (LSCS). METHOD: A total of 12 patients with PFH were retrospectively evaluated on the basis of clinical, serological, and radiographic findings. RESULTS: Five patients (42%) presented with complete PFH, and 7 patients (58%) with partial PFH involving either cheek or forehead. Five of the patients (42%) had a coexisting LSCS lesion, and 3 of them (25%) had concomitant LS of the trunk. Intraoral involvement was present in 6 cases. Neurological involvement was common, in particular, epileptic seizures. Serologic investigations showed neither evidence for infection with Borrelia burgdorferi nor any other indication of underlying systemic immunological disorders. LIMITATIONS: There were a relatively small number of patients in a retrospective study. CONCLUSION: The reported cases suggest a close relationship between PFH and LSCS. PFH might appear as two different subtypes, one involving cutaneous structures and presenting with clinical features similar to LSCS, one being strictly restricted to subcutaneous structures, primarily affecting the cheek area. The manifold clinical features of central nervous system involvement indicate the pathogenetic importance of neurological involvement in the development of PFH. Magnetic resonance imaging should be included in the tools of standard diagnostic procedures in patients with PFH. The etiologic relevance of autoimmunity as well as preceding trauma should be investigated in larger collective studies.

Adolescent↗
PubMed2006

A pilot study to optimize laser-assisted hair removal using real-time high-speed infrared imaging.

OBJECTIVE: The aim of this study was to investigate thermal effects on the skin surface during laser-assisted hair removal using real-time high-speed infrared imaging. BACKGROUND DATA: Although hair laser removal (HLR) can be considered an inherently safe treatment, there may be approaches to optimise the benefit/risk ratio of this common therapeutic and cosmetic procedure. METHODS: In this pilot study on three subjects, a ruby laser equipped with a cryogen spray cooling (CSC) system was used to investigate the effect of different CSC durations and delay times between CSC and the laser impulse. Skin surface temperature (SST) was assessed in real-time using a high-speed infrared camera (ThermaCam Phoenix) and a special image analysis software (analySIS Doku). RESULTS: There was no substantial difference of SST between the use of CSC spurts of 10 and 20 msec (6.1 degrees C versus 5.7 degrees C). The use of single laser and cooling parameters revealed baseline SST of 31.7 degrees C, immediately after CSC (10 ms) SST of 6.5 degrees C, and after laser pulse SST of 47 degrees C. Using fluences of 10-20 J/cm(2), a marked difference in temperature was observed between the skin surface and hair (e.g., 26.7 degrees C versus 57.5 degrees C). SST of 62-64 degrees C was observed using fluences of 18-20 J/cm(2), resulting in adverse effects. A maximum SST of 59 degrees C was observed using a CSC spurt of 40 msec, whereas a maximum SST of 60 degrees C was recorded for 30, 20, and 10 msec. The use of CSC delay time of 600 msec revealed baseline SST of 34.6 degrees C, immediately after CSC (10 msec) SST of 5.2 degrees C, after 600 msec delay SST of 21.5 degrees C, and SST of 60 degrees C following the laser pulse. By contrast, 100 msec delay time revealed baseline SST of 34.8 degrees C, immediately after CSC (10 ms) SST of 7 degrees C, after 100 msec delay SST of 7.5 degrees C, and SST of 55.2 degrees C following the laser pulse. CONCLUSION: Our preliminary data indicate that side effects of HLR can be avoided using CSC duration of 10 msec with a delay of about 200 msec. Short delay times between the CSC and laser pulse seem to result in lower post-irradiation SST and may therefore lead to less adverse effects. With regard to the fluence used in HLR, it is of importance that the maximum SST remains below 60 degrees C. Based on these preliminary results, real-time high-speed infrared imaging seems to be an interesting method to study the thermodynamics on skin surface during laser treatment.

Adult↗
PubMed2006

Erbium:YAG laser-assisted preparation of a combined dermal/full thickness sandwich skin graft.

BACKGROUND: Skin grafting is a common procedure to close defects after tumor resection. However, delicate areas such as the heel or the sole of the foot can be closed with a specially designed graft as described in this article. OBJECTIVE: To describe a surgical technique by means of erbium:YAG laser-assisted preparation of a combined dermal/full-thickness sandwich skin graft that facilitates the closure of defects, especially at mechanically stressed anatomic sites. METHODS: Tumor defects on the sole of the foot of 28 patients were closed with a new dermal/full-thickness sandwich skin graft. To obtain this special graft, half of a full-thickness skin graft twice the size of the wound defect was deepithelialized with an erbium:YAG laser. After complete defatting of the transplant, the deepithelialized part was folded beneath the full-thickness part (upside down) resulting in a sandwich graft, enabling contact of the papillary dermis with the wound surface. Graft results were graded as excellent when more than 75%, good if 50-75%, fair if 25-50%, and poor if less than 25% of the transplant healed. RESULTS: Results were graded as excellent in 32%, good in 54%, fair in 11%, and poor in 3% of the patients. Total graft loss was experienced in 1 of 28 patients. Complications such as bulky margins or infection were encountered in 14% of the patients. CONCLUSION: The laser-assisted preparation of the combined dermal/full-thickness sandwich skin graft is a new technique that facilitates the closure of defects in delicate anatomic locations with high mechanical stress like the plantar sole.

Aged↗
PubMed2006

Review of literature on amicrobial pustulosis of the folds associated with autoimmune disorders.

Amicrobial pustulosis of the folds (APF) is characterized by relapsing, primary aseptic, pustular eruptions mainly affecting the cutaneous folds, scalp, and periorificial regions such as the mouth, external ear canal, and nostrils. APF is a rare condition that has previously been reported in 25 women exhibiting a wide spectrum of autoimmune abnormalities, particularly systemic lupus erythematosus. Histology of the skin lesions usually shows spongiform pustulation in the upper layer of the epidermis and a polymorphonuclear infiltrate in the dermis. APF must be differentiated from other noninfectious pustular diseases such as subcorneal pustulosis (Sneddon-Wilkinson disease) and pustular forms of psoriasis. APF should be included in the spectrum of reactive neutrophilic dermatoses, even though the exact pathomechanisms remain obscure. However, the striking female predominance may be of pathogenetic significance. Based on the small number of previously reported patients, the most effective therapy seems to be medium-dose systemic corticosteroids.

Autoimmune Diseases↗
PubMed2005

Acute skin alterations following ultraviolet radiation investigated by optical coherence tomography and histology.

Optical coherence tomography (OCT) appears to be a promising technique to study skin in vivo. As part of an exploratory study to investigate UV induced effects non-invasively we aimed to evaluate the kinetics of acute UVB- as well as UVA1 induced skin alterations by means of OCT, and to correlate the results obtained with routine histology. Twelve healthy subjects received daily 60 J/cm2 of UVA1 and 1.5 minimal erythema doses of UVB on their upper back over three consecutive days. One day (24 h) after the last UV exposure, OCT measurements and skin biopsies were performed in four subjects (day 1) on the centre of the irradiated sites and an adjacent non-irradiated control site. The same procedure was performed in four subjects 3 days and 6 days after irradiation, respectively. Prior to OCT assessment two waterproof marks were drawn on the centre of UVB and UVA1 exposed sites and the control site. The OCT scanner, SkinDex 300, was used in the RI1D measurement modus in order to investigate morphological features, epidermal thickness, and scattering coefficients. Immediately after OCT assessment, 4 mm punch biopsies were taken from the previously marked sites. OCT as well as histological examinations performed on day 1, 3, and 6, revealed markedly higher values for epidermal thickness on UVB exposed skin sites, and slightly increased epidermal thickening in UVA1 exposed sites. UVB exposed sites showed disruption of the entrance signal in the B-scan of OCT resulting in a thickened layer with a signal-poor centre corresponding to hyperkeratosis and parakeratosis as confirmed by routine histology. Surprisingly, the mean scattering coefficients of the epidermis were slightly lower on UVA1 exposed sites, as compared to non-irradiated skin. By contrast, the scattering coefficient of the upper dermis of UVA1 irradiated skin was hardly altered. Moreover, the scattering coefficient of the upper dermis assessed on UVB exposed skin on day 1 was clearly smaller than the scattering coefficient observed on non-irradiated and UVA1 exposed skin. Conclusively, it was possible to demonstrate by means of OCT differences of epidermal thickness and pathological features of the stratum corneum following UV exposure. UVA1 induced epidermal pigmentation as well as UVB induced dermal inflammation may affect the light attenuation in the tissue indicated by a decrease of the scattering coefficient. OCT seems to be a useful tool to monitor UV induced effects in vivo.

Adult↗