Dimitrios Georgas

Ruhr-Universität Bochum, Bochum, North Rhine-Westphalia, Germany

Are you Dimitrios Georgas?

Claim your profile

Publications (19)53.57 Total impact

  • Journal of the American Academy of Dermatology 10/2014; 71(4):e129-30. · 4.91 Impact Factor
  • Source
    M Sand, D Georgas, S Hessam, F G Bechara
    British Journal of Cancer 02/2014; · 5.08 Impact Factor
  • Journal der Deutschen Dermatologischen Gesellschaft 02/2014; 12(2). · 1.40 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background:Surgical treatment of multiple and recurring invasive carcinomas on the dorsum of the hand often results in a reconstructive challenge. Reconstruction is limited due to reduced adjacent tissue. Preserving the functionality of the hand is pivotal and needs to be respected while planning reconstruction.Objective:We present a case of extensive, multiple, and recurring invasive squamous cell carcinoma on the dorsum of the hand and describe a prophylactic surgical approach.Methods:We performed a radical excision of the skin on the dorsum of the hand and surgical reconstruction using a bilayer dermal skin substitute and split-thickness skin grafting.Results:After a 1-year follow-up, we observed an excellent cosmetic and functional result with no signs of recurrence.Conclusions:In case of extensive invasive squamous cell carcinoma on the dorsum of the hand, prophylactic resection and surgical reconstruction using a dermal regeneration template should be considered.
    Journal of Cutaneous Maedicine and Surgery 01/2014; 18:56-9. · 0.78 Impact Factor
  • Journal der Deutschen Dermatologischen Gesellschaft 11/2013; · 1.40 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: With great interest, we read the article of Mogensen and co-workers, which was published in this journal.(1) They studied 11 actinic keratoses and 23 basal cell carcinomas (< 2 mm thickness) using conventional optical coherence tomography (OCT, 20 μm lateral resolution) and 20-MHz ultrasound. OCT and 20-MHz ultrasound were compared with routine histology. The authors concluded that systematic comparison between mean OCT and 20-MHz ultrasound lesion thickness demonstrated that OCT is more accurate and less biased than 20-MHz ultrasound, even though both methods tended to overestimate the thickness of the lesion. Recently, high-definition OCT (HD-OCT) scanners have been developed providing significantly higher lateral resolution (1 μm to 3 μm) than conventional OCT with lateral resolution of about 10 μm to 20 μm.(2-4) Hence, HD-OCT is a new non-invasive technique for morphological investigation of tissue with cellular resolution filling the imaging gap between reflectance confocal microscopy and conventional optical coherence tomography. The paper of Mogenson and colleagues (1) prompted us to report our data on HD-OCT measurements for the determination of ET in actinic keratoses and psoriasis. This article is protected by copyright. All rights reserved.
    British Journal of Dermatology 10/2013; · 3.76 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background:Direct closure is the reconstruction of choice for surface soft tissue defects; however, it may not be suitable for larger defects due to extensive tension. A variety of techniques are available for achieving tension free closure, including skin grafts, skin flaps, and internal or external tissue expansion.Materials and Methods:The external skin expander developed by Blomqvist and Steenfos consists of single tissue expander units that contain an atraumatic needle and two friction stoppers connected via a silicone string. Each device of the expander is inserted under local anaesthesia on each side of the defect at a distance of about 2 cm from each other. Postoperative the silicone strings have to be tightened at least once a day. After about 5 to 10 days a sufficient expansion is achieved and the defect can be closed directly after expander removal.Results:The external tissue expander developed by Blomqvist and Steenfos is an efficient, time-effective, easy-to-handle device that can be inserted under local anesthesia, providing a good functional and satisfactory cosmetic outcome. Due to the comparatively low complication rate, even outpatient treatment is possible. The major drawback of this technique is the possibility of developing uncommon secondary scars under the plastic stoppers.
    Journal of Cutaneous Maedicine and Surgery 01/2013; 17(6):423-5. · 0.78 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Perturbations in microRNA (miRNA) expression profiles have been reported for cutaneous malignant melanoma (CMM) predominantly when examined in cell lines. Despite the rapidly growing number of newly discovered human miRNA sequences, the availability of up-to-date miRNA expression profiles for clinical samples of primary cutaneous malignant melanoma (PCMM), cutaneous malignant melanoma metastases (CMMM), and benign melanocytic nevi (BMN) is limited. Specimens excised from the center of tumors (lesional) from patients with PCMM (n=9), CMMM (n=4), or BMN (n=8) were obtained during surgery. An exploratory microarray analysis was performed by miRNA expression profiling based on Agilent platform screening for 1205 human miRNAs. The results from the microarray analysis were validated by TaqMan quantitative real-time polymerase chain reaction. In addition to several miRNAs previously known to be associated with CMM, 19 unidentified miRNA candidates were found to be dysregulated in CMM patient samples. Among the 19 novel miRNA candidates, the genes hsa-miR-22, hsa-miR-130b, hsa-miR-146b-5p, hsa-miR-223, hsa-miR-301a, hsa-miR-484, hsa-miR-663, hsa-miR-720, hsa-miR-1260, hsa-miR-1274a, hsa-miR-1274b, hsa-miR-3663-3p, hsa-miR-4281, and hsa-miR-4286 were upregulated, and the genes hsa-miR-24-1*, hsa-miR-26a, hsa-miR-4291, hsa-miR-4317, and hsa-miR-4324 were downregulated. The results of this study partially confirm previous CMM miRNA profiling studies identifying miRNAs that are dysregulated in CMM. However, we report several novel miRNA candidates in CMM tumors; these miRNA sequences require further validation and functional analysis to evaluate whether they play a role in the pathogenesis of CMM.
    Cell and Tissue Research 10/2012; · 3.68 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: MicroRNAs (miRNAs) are a novel class of short RNAs that are capable epigenetically regulating gene expression in eukaryotes. MicroRNAs have been shown to be dysregulated in a variety of cancers. The data on miRNA expression in cutaneous squamous cell carcinoma (cSCC) are very limited, and microarray-based miRNA expression profiles of cSCC have not yet been determined. OBJECTIVE: To describe differentially expressed miRNAs in cSCC. METHODS: Seven patients with cSCC were enrolled in the present study. Tumor biopsies (n=7) were taken from the center of each tumor. Adjacent healthy skin (n=7) was biopsied as a control (intraindividual control). miRNA expression profiles of all specimens were detected by microarray miRNA expression profiling based on miRBAse 16 scanning for 1205 potential human miRNA target sequences. The microarray results were confirmed by TaqMan quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS: Non-stringent filtering with a non-adjusted p≤0.05 revealed thirteen up-regulated and eighteen down-regulated miRNAs. Non-stringent filtering with a non-adjusted p≤0.01 revealed three up-regulated (hsa-miR-135b, hsa-miR-424 and hsa-miR-766) and six down-regulated (hsa-miR-30a*, hsa-miR-378, hsa-miR-145, hsa-miR-140-3p, hsa-miR-30a and hsa-miR-26a) miRNAs in cSCC. CONCLUSION: This study reveals differentially expressed miRNAs that may play a role in the molecular pathogenesis of cSCC and that are excellent candidates for further validation and functional analysis.
    Journal of dermatological science 09/2012; · 3.71 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background: Previous work has indicated that extracorporeal photochemotherapy (ECP) may be a safe and effective treatment in patients with severe atopic dermatitis. Methods: We performed a prospective study to investigate the effect of a defined 20-week ECP protocol in patients with severe, refractory atopic dermatitis. The patient inclusion criteria included (i) disease duration of at least 1 year, (ii) SCORAD > 45, and (iii) resistance to first-line therapy, including topical steroids, topical calcineurin inhibitors, and one form of phototherapy (UVA, UVB, or PUVA) or one second-line therapy, including systemic steroids or cyclosporine. Ten patients (4 women and 6 men; age range 29 to 61 years) were enrolled and treated with two sessions of standard ECP in 2-week intervals for 12 weeks and 4-week intervals thereafter until week 20. The patients' clinical status and response was determined by SCORAD at baseline and every 2 weeks, and quality of life was assessed every 4 weeks using SKINDEX, SF-36, and FACT scores. Results: There was a statistically significant (p = 0.015) reduction of the mean SCORAD by 10.3 (95% CI, 2.5 to 18.0) from 64.8 at baseline to 54.5 (i.e., 15.9% reduction) at week 20. In a subset of patients (all of female sex), the relative reduction in SCORAD after ECP was more than 25% at week 20. Improvement in quality of life measured by SKINDEX, SF-36, and FACT did not reach statistical significance. Conclusions: We detected a small but significant therapeutic effect of ECP in patients with severe, refractory atopic dermatitis.
    Photochemical and Photobiological Sciences 09/2012; · 2.92 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Antimicrobial peptides and proteins are not only effectors of the immune system but are also attributed important roles in tumour progression or tumour suppression in several malignancies such as oral squamous cell carcinoma (SCC). These reports encouraged us to systematically investigate the expression of different classes of antimicrobial peptides and proteins in tissue samples of cutaneous SCC and its precursor lesions. The protein expression of human beta-defensin (hBD)-1, -2, and -3, ribonuclease (RNase)-7 and the S100 protein psoriasin were analysed in 25 patients with actinic keratosis (AK), 30 with SCC in situ (SCCis), 23 with SCC, nine healthy skin controls and 10 healthy, chronically ultraviolet (UV)-exposed controls, by means of immunohistochemistry. Expression of hBD-1 was significantly reduced in SCC compared with UV-exposed healthy skin, AK and SCCis. RNase-7 expression was reduced gradually parallel to every step of malignant transformation, with the highest expression in healthy skin and the lowest expression in SCC. hBD-2 and psoriasin were significantly overexpressed in SCC and SCCis, compared with healthy controls. hBD-3 showed significantly more frequent expression in AK than in healthy controls, and in patients with SCCis and SCC. It is tempting to speculate that hBD-1 and RNase-7 might act as tumour suppressors while hBD-2 and psoriasin might act in the opposite way as promoters of tumour progression. Further investigations should clarify whether hBD-2 and hBD-3 could be potential targets for the development of pharmacological therapy.
    British Journal of Dermatology 06/2012; 167(3):591-7. · 3.76 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background  Photodynamic therapy (PDT) and laser ablation (LA) are frequently used treatment options for multiple actinic keratoses (AK), yet they have not been compared head to head. Objectives  To compare PDT and carbon dioxide (CO(2) ) LA in the management of multiple AK using objective and subjective outcome measures. Methods  A single-centre, randomized, two-treatment half-side comparative study of PDT vs. CO(2) LA was performed. Patients with at least four bilateral (e.g., scalp, forearms) AK were included. The primary outcome measure was the reduction of AK 3 months (v3) after therapy. Secondary outcome measures included the reduction of AK 4 weeks (v2) after therapy, decrease of epidermal p53 and Ki-67 protein expression, micromorphological changes as assessed by optical coherence tomography (OCT) in vivo, and investigators' and patients' satisfaction scoring. Results  In total, 20 patients (18 men and 2 women) completed the study. Both treatments reduced AK quantity significantly. On v3, relative reduction of AK quantity was significantly higher following PDT (P = 0·0362). Ki-67 and p53 protein expression was reduced significantly from baseline (Ki-67, median 49·5%; p53, median 64·8%) to v2 by both procedures (PDT, median 18·5%, P < 0·0001; LA, median 16·2%, P < 0·0001). AK features as assessed by OCT imaging were also significantly reduced by both procedures. The investigators and patients rated the side-effects and inconveniences of PDT as more severe, but both overall preferred PDT due to the superior clinical outcome. Conclusions  CO(2) LA and PDT are both effective therapy options for multiple AK, yet PDT seems to be superior in terms of AK reduction and participants' and investigators' overall satisfaction.
    British Journal of Dermatology 06/2012; · 3.76 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Although several studies have shown a dysregulation of microRNA (miRNA) expression profiles in cutaneous melanoma, there has been little research on the miRNA machinery itself. In this study, we investigated the mRNA expression profiles of different miRNA machinery components in primary cutaneous malignant melanoma (PCMM), cutaneous malignant melanoma metastases (CMMM) and benign melanocytic nevi (BMN). Patients with PCMM (n = 7), CMMM (n = 6) and BMN (n = 7) were included in the study. Punch biopsies were harvested from the centers of tumors (lesional) and from BMN (control). In contrast to previous reports exploring specific clusters of miRNAs in PCMM, the present study investigates mRNA expression levels of Dicer, Drosha, Exp5, DGCR8 and the RISC components PACT, argonaute-1, argonaute-2, TARBP1, TARBP2, MTDH and SND1, which were detected by TaqMan real-time reverse transcription polymerase chain reaction (RT-PCR). Argonaute-1, TARBP2 and SND1 expression levels were significantly higher in BMN compared to PCMM (p < 0.05). TARBP2 expression levels were significantly higher in CMMM compared to PCMM (p < 0.05). SND1 expression levels were significantly higher in CMMM compared to PCMM and BMN (p < 0.05). Dicer, Drosha, DGCR8, Exp5, argonaute-2, PACT, TARBP1 and MTDH expression levels showed no significant differences within groups (p > 0.05). The results of this study show that the miRNA machinery components argonaute-1, TARBP2 and SND1 are dysregulated in PCMM and CMMM compared to BMN and may play a role in the process of malignant transformation.
    Cell and Tissue Research 06/2012; 350(1):119-26. · 3.68 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background  Perturbations in the expression profiles of microRNAs (miRNAs) have been reported for a variety of different cancers. Differentially expressed miRNAs have not been systematically evaluated in basal cell carcinoma (BCC) of the skin. Objectives  To initiate a microarray-based miRNA profiling study to identify specific miRNA candidates that are differentially expressed in BCC. Methods  Patients with BCC (n = 7) were included in this study. Punch biopsies were harvested from the tumour centre (lesional, n = 7) and from adjacent nonlesional skin (intraindividual control, n = 7). Microarray-based miRNA expression profiles were obtained on an Agilent platform using miRBase 16 screening for 1205 Homo sapiens (hsa)-miRNA candidates. To validate the microarray data, the expression of seven dysregulated miRNAs was measured by TaqMan quantitative real-time reverse transcription polymerase chain reaction. Results  We identified 16 significantly upregulated (hsa-miR-17, hsa-miR-18a, hsa-miR-18b, hsa-miR-19b, hsa-miR-19b-1*, hsa-miR-93, hsa-miR-106b, hsa-miR-125a-5p, hsa-miR-130a, hsa-miR-181c, hsa-miR-181c*, hsa-miR-181d, hsa-miR-182, hsa-miR-455-3p, hsa-miR-455-5p and hsa-miR-542-5p) and 10 significantly downregulated (hsa-miR-29c, hsa-miR-29c*, hsa-miR-139-5p, hsa-miR-140-3p, hsa-miR-145, hsa-miR-378, hsa-miR-572, hsa-miR-638, hsa-miR-2861 and hsa-miR-3196) miRNAs in BCC compared with nonlesional skin. Data mining revealed connections to many tumour-promoting pathways, such as the Hedgehog and the mitogen-activated protein kinase/extracellular signal-regulated kinase signalling cascades. Conclusions  This study identified several miRNA candidates that may play a role in the molecular pathogenesis of BCC.
    British Journal of Dermatology 04/2012; 167(4):847-55. · 3.76 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Generally, axillary hyperhidrosis (AH) is treated with antiperspirant agents, botulinum toxin, or local surgery. The effect of laser treatment on sweat secretion in patients with AH has not been investigated. To evaluate the effect of diode laser epilation on the sweat rate of patients with AH. We performed a randomized half-side controlled trial. Twenty-one patients were treated with 5 cycles of an 800-nm diode laser. Sweat rates were documented using gravimetry and a visual analogue scale. Histologic examination was performed in all patients before and after treatment. A significant reduction in sweat rate was observed on the laser-treated (median 89 mg/min, range 42-208 mg/min vs 48 mg/min, range 17-119 mg/min; p < .001) and the untreated contralateral (median 78 mg/min, range 25-220 mg/min vs median 65 mg/min, range 24-399 mg/min; p = .04) sides, although no significant difference was found between the treated and untreated sides (p = .10). Although we observed a significant decrease in sweat rate on laser-treated sites, laser epilation was not able to reduce the sweat rate significantly more than on the untreated contralateral side. These results probably indicate a placebo effect rather than a direct therapeutic effect of laser epilation.
    Dermatologic Surgery 01/2012; 38(5):736-40. · 1.87 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The microprocessor complex mediates intranuclear biogenesis of precursor microRNAs from the primary microRNA transcript. Extranuclear, mature microRNAs are incorporated into the RNA-induced silencing complex (RISC) before interaction with complementary target mRNA leads to transcriptional repression or cleavage. In this study, we investigated the expression profiles of the microprocessor complex subunit DiGeorge syndrome critical region gene 8 (DGCR8) and the RISC components argonaute-1 (AGO1), argonaute-2 (AGO2), as well as double-stranded RNA-binding proteins PACT, TARBP1, and TARBP2 in epithelial skin cancer and its premalignant stage. Patients with premalignant actinic keratoses (AK, n = 6), basal cell carcinomas (BCC, n = 15), and squamous cell carcinomas (SCC, n = 7) were included in the study. Punch biopsies were harvested from the center of the tumors (lesional), from healthy skin sites (intraindividual controls), and from healthy skin sites in a healthy control group (n = 16; interindividual control). The DGCR8, AGO1, AGO2, PACT, TARBP1, and TARBP2 mRNA expression levels were detected by quantitative real-time reverse transcriptase polymerase chain reaction. The DGCR8, AGO1, AGO2, PACT, and TARBP1 expression levels were significantly higher in the AK, BCC, and SCC groups than the healthy controls (P < 0.05). There was no significant difference in the TARBP2 expression levels between groups (P > 0.05). This study indicates that major components of the miRNA pathway, such as the microprocessor complex and RISC, are dysregulated in epithelial skin cancer. © 2011 Wiley Periodicals, Inc.
    Molecular Carcinogenesis 10/2011; 51(11):916-22. · 4.27 Impact Factor
  • Dermatology 02/2008; 216(2):180-1. · 2.02 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Minimally invasive surgeries are frequently used in patients suffering from focal axillary hyperhidrosis (FAH). Sweat glands are removed surgically and the axillary skin is thinned out, with skin necrosis being a possible complication due to reduced microcirculation. Although of considerable interest, studies evaluating pre- and postoperative skin perfusion are unavailable. To evaluate the blood flow of axillary skin in patients with severe focal axillary hyperhidrosis before and after liposuction curettage (LC). The blood flow in the axillary skin of 11 patients was measured by laser Doppler perfusion imaging before surgery and on days 1, 7 and 28 after LC with a rasping cannula. Skin perfusion was measured in arbitrary units (AU) with measuring points in the axillary center (AC), the operated skin 2 cm from the center (2C) and the surrounding healthy skin (HS). No significant differences of preoperative skin perfusion were found (AC: 0.39 +/- 0.08 AU/2C: 0.38 +/- 0.07 AU/HS: 0.39 +/- 0.07 AU; p > 0.05). On the first and seventh postoperative days, AC (0.2 +/- 0.04 AU/0.27 +/- 0.81 AU) and 2C (0.2 +/- 0.03 AU/0.28 +/- 0.06 AU) area were significantly less perfused, whereas the HS showed higher perfusion values (0.59 +/- 0.1 AU/0.53 +/- 0.09 AU). Twenty-eight days after LC the 2C (0.36 +/- 0.07 AU) and HS (0.4 +/- 0.06 AU) skin revealed no significant differences compared to preoperative skin perfusion (p > 0.05). The AC perfusion was still slightly reduced (0.37 +/- 0.09 AU) without significant difference compared to preoperative findings. LC reduces the axillary skin blood flow with the axillary center being the least perfused area. However, in our collective, no correlation to possible side effects was observed.
    Dermatology 01/2008; 216(2):173-9. · 2.02 Impact Factor
  • Dimitrios Georgas, Falk Bechara