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Dive into the research topics where Michael Kendler is active.

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Featured researches published by Michael Kendler.


Journal of Biomedical Optics | 2009

Immunohistochemical investigation of wound healing in response to fractional photothermolysis

Doris Helbig; Marc Oliver Bodendorf; Sonja Grunewald; Michael Kendler; Jan C. Simon; Uwe Paasch

Despite growing clinical evidence of ablative fractional photothermolysis (AFP), little is known about the spatiotemporal molecular changes within the targeted compartments. Six subjects received three different single AFP treatments using a scanned 250 mum CO(2)-laser beam. Spatiotemporal changes of skin regeneration were estimated by immunohistochemical investigation (HSP70, HSP72, HSP47, TGFbeta, procollagen III, CD3, CD20, and CD68) in skin samples 1 h, 3 days, and 14 days postintervention. The remodeling was uniformly started by regrowth of the epidermal compartment followed by partial to complete replacement of the microscopic ablation zones (MAZ) by newly synthesized condensed procollagen III. From day 3 to 14, the number of macrophages as well as giant cells surrounding the MAZ increased. TGFbeta expression was highest 1 h to 3 days following AFP. HSP70 and HSP72 expressions were highest 3-14 days postintervention in the spinocellular layer leading to an upregulation of HSP47. AFP performed by a scanned CO(2)-laser results in an early epidermal remodeling, which is followed by a dermal remodeling leading to a replacement of the MAZ with newly synthesized (pro)-collagen. During this, an inflammatory infiltrate with CD3(+) and CD20(+) cells surrounds the MAZ. The count of macrophages and giant cells involved in the replacement of the necrotic zones seems to be crucial for wound healing.


International Journal of Hyperthermia | 2011

In vivo wound healing and dermal matrix remodelling in response to fractional CO2 laser intervention: Clinicopathological correlation in non-facial skin

Sonja Grunewald; Marc Oliver Bodendorf; Monica Illes; Michael Kendler; Jan C. Simon; Uwe Paasch

Purpose: Ablative fractional photothermolysis is a new concept for treatment of aged skin. Despite the low frequency of side effects there are now several reports about scarring, especially in non-facial regions like the neck. Our study aimed to investigate the in vivo wound healing process and remodelling in an area prone to scarring using a fractional ablative CO2 laser with three different energy protocols. Materials and methods: Six patients with photo-damaged skin received a single fractional ablative treatment using a 250-µm scanning CO2 laser. Three areas on the neck were treated with 50, 100 and 300 mJ/microbeam at densities of 200, 150 and 100/cm2, respectively. Biopsies were taken from untreated skin (control) and 10 minutes, 3 days, 14 days, 21 days and 28 days post-intervention. Results: Fractional ablation with higher energies resulted in increased total thermal damage. Overall, 50 mJ was effective up to the superficial dermis, 100 mJ up to the mid-dermis, and 300 mJ resulted in deep dermal ablation. The intensity of lymphocytic inflammation and dermal remodelling correlated with the total amount of thermal damage. At 300 mJ, granuloma was present and persisted for at least 4 weeks as opposed to clinical healing, which was completed < 2 weeks. Conclusions: With the above-mentioned low and medium parameter settings, ablative fractional photothermolysis is safe and effective in non-facial skin. However, dermal remodelling continues for up to 4 weeks, which should be the minimum space between treatment sessions. Higher energies may induce granuloma formation, possibly a sign of an overstrained remodelling capacity.


International Journal of Hyperthermia | 2013

Antifungal efficacy of lasers against dermatophytes and yeasts in vitro.

Uwe Paasch; Andrea Mock; Sonja Grunewald; Marc Oliver Bodendorf; Michael Kendler; Anna-Theresa Seitz; Jan C. Simon; P. Nenoff

Abstract Purpose: Approximately 2–13% of the world population suffers from onychomycosis. Recently, lasers have been introduced for treatment. However, no effect was found with in vitro laser irradiation of pathogens on agar plates. This study aimed to investigate the efficacy of laser irradiation against fungi using an alternative in vitro approach. Materials and methods: Lasers of 808, 980 and 1064 nm were used to heat cell culture media and a nail clipping. Trichophyton rubrum. T. interdigitale. Microsporum gypseum. Candida albicans. C. parapsilosis, and C. guilliermondii species were subcultured and subjected to laser treatments (808/980 nm: 9–27 J/cm2, 6 ms, 12 × 12 or 12 × 50 mm and 1064 nm: 50–240 J/cm2, 90 ms, 5–10 mm). After irradiation, the fungal elements were transferred onto agar plates using conventional and Drigalski spatulas and were incubated for 6 days. Results: The highest increase in temperature was found using a 980-nm laser with a pulse duration of 6 ms and a fluence of 27 J/cm2. The histology work-up revealed a dissection of the nail plate from the nail bed tissue after laser irradiation. Growth inhibition was only found for C. guilliermondii and T. interdigitale. All other pathogens presented only reduced growth, and C. albicans growth was unaffected. Conclusions: This study demonstrates a clear thermal effect for linear scanning 980-nm and long-pulsed 1064-nm laser systems on either nail clippings or cell culture media. Complete pathogen growth impairment was achieved if temperatures were measured above 50 °C. The results for the 1064-nm system were almost comparable to 980 nm results.


Journal of Vascular Surgery | 2010

Elevated sex steroid hormones in great saphenous veins in men

Michael Kendler; Evgenia Makrantonaki; Jürgen Kratzsch; Ulf Anderegg; Tino Wetzig; Christos C. Zouboulis; Jan C. Simon

INTRODUCTION High serum levels of estradiol are associated with clinical evidence of varicose veins in women; however, the relationship between serum sex steroid hormones and varicose veins in men is unclear. To address this issue, serum levels of testosterone, estradiol, and androstenedione were determined in the great saphenous (GSV) and cubital veins of men with varicose veins. Messenger RNA (mRNA) expression of sex steroid hormones, metabolizing enzymes, and their receptors was investigated in tissue samples of leg veins. METHODS This prospective study included 40 men, comprising 20 with varicose veins and reflux of the GSV (VM) and 20 with healthy veins (HM). All limbs were assessed by duplex ultrasound scanning of selected superficial and deep leg veins. Blood samples were taken from the cubital vein and from the GSV. Quantitative reverse-transcription polymerase chain reaction (qRT-PCR) analysis for sex steroid hormones, their metabolizing enzymes, and receptors in saphenous veins was performed in tissue samples of varicose (n = 6) and healthy veins (n = 6). RESULTS The VM group had significantly higher (P < .001) mean levels for serum testosterone (44.9 nmol/L; range, 8.8-225.1) and estradiol (242.2 pmol/L; range, 79-941) in varicose saphenous veins compared with cubital veins (testosterone, 15.5 nmol/L; range, 8.4-23.3; estradiol, 93.2 pmol/L; range, 31-147). Moreover, significantly (P < .001) higher mean serum estradiol levels (133.2 pmol/L; range, 63-239) were detected in the saphenous veins of the HM group compared with cubital veins (88.15 pmol/L; range, 37-153). Both groups had similar blood counts and serum androstenedione levels in the upper and lower extremity. Interestingly, qRT-PCR revealed that the mRNA expression of 5alpha-reductase type 1, 5alpha-reductase type 2, 17, 20 lyase, 17beta-hydroxysteroid dehydrogenase (17beta-HSD), aromatase and 3beta-HSD type 2, androgen and estrogen receptor 1 was down-regulated (P < .05) in all samples of varicose veins vs veins obtained from healthy men. CONCLUSION Elevated serum estradiol and testosterone levels were detected in men with varicose veins and reflux in the GSV compared with the patients own arm veins. Enzymes and hormonal receptors involved in steroid metabolism were down-regulated in patients with GSV reflux and varicose veins, suggestive of a negative feedback regulation. These data support the notion of a possible causal relationship between sex steroids and varicose veins in men.


Journal Der Deutschen Dermatologischen Gesellschaft | 2010

Local anesthesia in dermatology

Tino Wetzig; Marco Averbeck; Jan C. Simon; Michael Kendler

Local and regional anesthetic procedures are an integral part of daily dermatological practice. Safe and effective analgesia in skin and soft tissues is crucial for otherwise painful diagnostic or therapeutic interventions. Tumescent local anesthesia allows for pain‐free interventions that previously had to be done by using general anesthesia. Older patients with multiple co‐morbidities are especially suited for local anesthetic procedures, because they may significantly reduce surgical risks. For dermatologists, the knowledge of mode of action and toxicity of local anesthetics, as well as the emergency management of their potential complications, is essential.


Journal Der Deutschen Dermatologischen Gesellschaft | 2009

Treatment of basal cell carcinoma

Tino Wetzig; Jan Maschke; Michael Kendler; Jan C. Simon

Basal cell carcinoma is the most common tumor in Central Europe, the U.S. and Australia. The increasing incidence of basal cell carcinoma presents the health care system, especially dermatology, with great challenges. In recent years new options for treating basal cell carcinoma have become available, enriching our therapeutic options. We review the current status of each of these treatment approaches.


Journal Der Deutschen Dermatologischen Gesellschaft | 2007

Foam sclerotherapy — A possible option in therapy of varicose veins

Michael Kendler; Tino Wetzig; Jan C. Simon

The therapy of varicose veins is multimodal and depends on the individual clinical findings. In addition to compression therapy, invasive approaches for elimination of reflux for the treatment of varicose veins are available, such as surgical and interventional methods and sclerotherapy. The administration of a scle‐rosing agent into a varicose vein results in an occlusion of the treated vein. Recently the use of foam sclerotherapy had a renaissance. Several studies have documented the efficacy of foam sclerotherapy in selected patients. The possibility of treating patients in an outpatient setting, with low costs and rapidly, makes foam sclerotherapy very attractive compared to invasive and minimally invasive methods. However long‐term follow‐ups in properly controlled randomized trials are needed before foam sclerotherapy can be recommended as a routine procedure. This paper introduces the method and the treatment possibilities with foam sclerotherapy in chronic venous insufficiency.


British Journal of Dermatology | 2010

No clinical benefit of preoperative fluorescence diagnosis of basal cell carcinoma localized in the H-zone of the face.

Tino Wetzig; Michael Kendler; Jan Maschke; Uwe Paasch; Jan-Christoph Simon

Background  Basal cell carcinoma (BCC) is the most common malignant skin carcinoma. Fluorescence diagnosis (FD) has been suggested as a promising method for noninvasive detection of subclinical tumour cell dissemination in BCC.


Journal Der Deutschen Dermatologischen Gesellschaft | 2013

Histology of saphenous veins after treatment with the ClariVein® device – an ex-vivo experiment

Michael Kendler; Marco Averbeck; Jan C. Simon; Mirjana Ziemer

Endovenous treatment modalities are used increasingly to treat varicose veins. The ClariVein® catheter is a new endoluminal mechanico‐chemical obliteration technique which can be used without tumescent anesthesia. It is still unclear what changes the mechanical tip of the catheter has on the walls of the vein.


Dermatologic Surgery | 2013

Electrochemotherapy Under Tumescent Local Anesthesia for the Treatment of Cutaneous Metastases

Michael Kendler; Martin Micheluzzi; Tino Wetzig; Jan C. Simon

BACKGROUND The surgical management of cutaneous metastasis (CM) is challenging, particularly in elderly patients, in whom general anesthesia can be difficult because of comorbidity. OBJECTIVES To test the effectiveness of tumescent local anesthesia (TLA) to achieve adequate anesthesia during the treatment of extensive CM with electrochemotherapy (ECT), previously only performed under general anesthesia. METHODS We conducted five ECT treatments of CM with intralesional bleomycin under TLA. We examined pain scores before, during, and after treatment; analgesic use; and side effects. The intention of the treatment was palliative in all cases. RESULTS We treated four patients (ages 75–88) with CM with a mean area of 126 cm2 (range 12–198 cm2) with 356 mL of TLA per treatment (range 180–450 mL). The ECT treatment under TLA demonstrated that anesthesia was adequate, with moderate pain during and slight pain after the procedure as measured on a visual analog scale (VAS). CONCLUSIONS In this proof‐of‐principle study, we demonstrated that ECT can be performed under TLA; TLA might be a useful new anesthesia option for patients treated with ECT.

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