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Dive into the research topics where Konstantin Krasagakis is active.

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Featured researches published by Konstantin Krasagakis.


British Journal of Cancer | 1998

Elevated plasma levels of transforming growth factor (TGF)-beta1 and TGF-beta2 in patients with disseminated malignant melanoma.

Konstantin Krasagakis; D Thölke; B Farthmann; J Eberle; U Mansmann; Ce Orfanos

Overexpression of transforming growth factor-beta isoforms (TGF-beta1, -beta2, -beta3) has been previously reported in human melanoma cell lines and tumours. The aim of the present study was to evaluate the plasma levels of TGF-beta isoforms in melanoma patients. Significantly elevated levels of TGF-beta1 (4.2 x the controls, P = 0.0094) and of TGF-beta2 (1.5 x the controls, P = 0.012) but not of TGF-beta3 were measured in patients with disseminated but not locoregional melanoma. These results indicate systemic circulation of potentially immunosuppressive peptides of the TGF-beta family in end-stage melanoma patients.


International Journal of Cancer | 1997

Translation initiation factor eIF-4A1 mRNA is consistently overexpressed in human melanoma cells in vitro

Jürgen Eberle; Konstantin Krasagakis; Constantin E. Orfanos

The oncogenic potential of translation initiation factors (eIF‐4E and eIF‐2α) has been described in previous studies leading to the definition of translational oncogenes. Two previously isolated cDNA clones, expressed differently in human melanoma cells and normal human melanocytes, were identified in this study as coding for the translation initiation factor eIF‐4AI. Northern‐blot analysis revealed consistent overexpression of eIF‐4AI mRNA in a panel of 14 melanoma cell lines (on an average 5.6 times higher than in cultures of normal human melanocytes). In contrast, the mRNAs of the other group‐4 translation initiation factors (eIF‐4A2, eIF‐4B, eIF‐4E and eIF‐4γ) were less and not consistently elevated. Cultures of congenital melanocytic nevi exhibited intermediate expression of eIF‐4AI. Thus, eIF‐4AI overexpression seems to be an important feature of melanoma cells and might contribute to their malignant transformation. Int. J. Cancer 71:396‐401, 1997.


Recent results in cancer research | 1995

Growth control of melanoma cells and melanocytes by cytokines.

Konstantin Krasagakis; Claus Garbe; Ch.C. Zouboulis; Constantin E. Orfanos

Aberrant proliferation of tumor cells characterizes cancer growth. Investigations of cellular growth control mechanisms have contributed to our understanding of carcinogenesis and to the identification of compounds with specific antitumor activity. Many cytokines have been found to act on melanoma tumors, either produced by the tumor cells themselves or by infiltrating host cells. Purified cytokines allowed direct comparison of the growth response between normal human melanocytes and malignant melanoma cells. The present paper summarizes results of a series of our own experiments not yet published and data from a review of the recent literature. Proliferation of normal human melanocytes is enhanced by several cytokines, including basic fibroblast growth factor (bFGF), melanoma growth stimulatory activity (MGSA), hepatocyte growth factor (HGF), and mast cell growth factor (MGF). Melanoma cells are additionally stimulated by epidermal growth factor (EGF)/transforming growth factor alpha (TGF-alpha) and nerve growth factor (NGF). Tumor necrosis factor alpha (TNF-alpha), transforming growth factor beta 1 (TGF-beta 1), and interleukin (IL)-6 are all potent inhibitors of melanocyte growth, but they are less effective on melanoma cells or even stimulate their growth. Interferon (IFN)-alpha and IFN-gamma inhibited proliferation of melanoma cells but not of melanocytes, whereas IFN-beta showed antiproliferative effects in both cell types. These findings suggest an alteration in growth control mechanisms during melanocyte transformation and possibly play a role in melanoma pathogenesis.


Dermatology | 1998

Management of Severe Scleroderma with Long-Term Extracorporeal Photopheresis

Konstantin Krasagakis; Edgar Dippel; Jutta Ramaker; M. Owsianowski; Constantin E. Orfanos

Background: The management of systemic sclerosis remains unsatisfactory. Thus far, the action of extracorporeal photopheresis (ECP) in severe systemic scleroderma has been evaluated in short-term studies, and only limited experience has been obtained with long-term application. Objective: The aim of the present study was to evaluate prospectively the long-term effect of ECP in a group of 16 patients suffering from severe scleroderma, showing visceral involvement and progressive clinical course. Methods: Fourteen patients with systemic scleroderma involving several organs, 1 with CREST syndrome and another with scleroderma-myositis overlap syndrome were treated with ECP over a period of 6–45 months. In 3 cases, γ-IFN was additionally administered. Skin and visceral involvement were assessed by evaluating a series of clinical criteria and results from laboratory, imaging and functional tests. Results: Overall, clear improvement was encountered in 6 patients, mixed response in 2, stable disease in 3 and continuing progressive course in 5 patients. Four out of 6 patients with improvement were treated with ECP early after onset of scleroderma (≤2 years), whereas all patients with a progressive course under ECP had had scleroderma for longer than 2 years. Immunosuppressive drugs previously administered could be reduced or fully withdrawn under ECP treatment in 5 patients, but additional oral medication was introduced in 4 patients due to disease progression. Addition of γ-IFN to ECP did not reveal further benefit. No side-effects were recorded under ECP treatment. Conclusions: Based on this observation, we believe that long-term ECP represents an effective treatment modality in severe scleroderma particularly when started early, with stabilization of the disease course and partial remission of the cutaneous findings, whereas visceral involvement, if present, may rarely improve.


Dermatology | 1998

Cutaneous Mastocytosis in Adults

Beate Tebbe; P.G. Stavropoulos; Konstantin Krasagakis; Constantin E. Orfanos

Background and Objective: Systemic mastocytosis is a rather rare disorder involving the skin and several other organs. The aim of this study was to analyse the extent of extracutaneous manifestations in 14 adult patients who presented with prominent cutaneous involvement within the last 5 years. Results: The cutaneous lesions were clinically diagnosed as telangiectasia macularis eruptiva perstans in 2 patients, urticaria pigmentosa of varying extent in 11 and diffuse erythrodermic mastocytosis in 1 patient. All patients had extracutaneous manifestations with involvement of one additional organ system in 6/14 cases, two in 5/14 and three in 3/14. Ten out of 14 patients suffered from generalized pruritus, and 11/14 reported mild wheal formation, while 3/14 with multi-organ involvement mentioned recurrent flushing episodes. The gastro-intestinal tract was involved in 8/14 cases with an increase in gastric and colon mucosal mast cells in 5/8 cases and gastroduodenitis in 2. Bone marrow involvement was seen in 7/13 patients, hepatosplenomegaly in 2, anaemia in 2 and thrombocytopenia in 3. The disease had a duration of 0.5–32 years, clinical symptoms remaining basically unchanged. Malignant transformation was not seen; only 1 patient developed myelodysplastic syndrome within 2 years after the first cutaneous lesions. Conclusions: Our study shows that extracutaneous involvement should be carefully considered in adult patients with cutaneous mastocytosis. Systemic multi-organ mast cell disease in adults is a long-lasting disorder with recurrent episodes of varying clinical symptomatology. However, the disease shows rather slow progression, and malignant transformation is rare. Satisfactory management is achieved by symptomatic oral drug intake.


Journal of The American Academy of Dermatology | 1997

Merkel cell carcinoma: Report of ten cases with emphasis on clinical course, treatment, and in vitro drug sensitivity

Konstantin Krasagakis; Brigitte Almond-Roesler; Christos C. Zouboulis; Beate Tebbe; Elke Wartenberg; Klaus-Dietrich Wolff; Constantin E. Orfanos

BACKGROUND Merkel cell carcinoma (MCC) is an uncommon primary neuroendocrine skin tumor most often seen in the elderly. The clinical course varies. Treatment is controversial and few data on drug sensitivity are available. OBJECTIVE We evaluated the clinical course and treatment of 10 MCC patients and determined MCC chemosensitivity. METHODS Clinical records as well as laboratory and histopathologic data from 10 patients with MCC treated in our department were examined. Chemosensitivity to various chemotherapeutic agents and interferons of MCC cells from four patients was determined in a soft agar clonogenic assay. RESULTS MCC behaved as an aggressive tumor with early and frequent local relapses (4 of 10 patients at a 2.2-month average), regional (4 of 10 patients at 2.5 months), and distant metastases (5 of 10 patients 9.6 months after excision of the primary tumor). In all but one patient, regional metastases preceded distant ones. Metastatic spread was associated with an average survival of 21 months from the initial diagnosis. Long-term survival (53+ and 65+ months) was observed in two women. Wide excision of the primary tumor, alone or combined with adjuvant chemotherapy and radiotherapy, was the most effective treatment. In advanced disease, chemotherapy and radiotherapy were not able to induce long-term remission. In vitro assays for MCC drug sensitivity revealed cisplatin, doxorubicin, and vindesine to be the most active. CONCLUSION MCC has a poor prognosis in advanced stages; therefore the primary tumor should be aggressively treated. The in vitro clonogenic assay may help to identify the chemosensitivity profile of MCC and to optimize chemotherapy protocols.


Dermatology | 2000

Differentiation between Merkel Cell Carcinoma and Malignant Melanoma: An Immunohistochemical Study

G.J. Kontochristopoulos; P.G. Stavropoulos; Konstantin Krasagakis; S. Goerdt; Ch.C. Zouboulis

Background: Although Merkel cell carcinoma (MCC) exhibits specific clinical and histologic features, differentiation from other cutaneous neoplasms, such as lymphoma, metastatic oat cell carcinoma and malignant melanoma (MM), may sometimes be difficult. Objective: The aim of our study was to immunohistochemically differentiate MCC from MM. Methods: Paraffin sections from 6 cases of primary MCC and 6 cases of primary MM were investigated. For immunostaining, the APAAP method was used. Results: Neuron-specific enolase was positive in all cases of MCC, as well as in 2 cases of MM. Marked positivity for cytokeratins 18, 20 and chromogranin A was observed in the MCC group, whereas a complete absence of expression of these three markers was noted in the MM group. Immunostaining with HMB45 and NKI/C3 was positive in all cases of MM and negative in all cases of MCC. S-100 protein was positive in all but 1 case of MM. In contrast, only 1 case of MCC reacted with S-100 protein. Conclusion: Our results underline the role of immunohistochemistry in the diagnosis and differential diagnosis of MCC. In particular, the combination of neuron-specific enolase, cytokeratins 18, 20 and chromogranin A positivity for MCC and HMB45, NKI/C3 and S-100 protein positivity for MM is of great value in the distinction between these two cutaneous neoplasms.


Melanoma Research | 1991

A fluorometric rapid microassay to identify anti-proliferative compounds for human melanoma cells in vitro.

Ch. C. Zouboulis; Claus Garbe; Konstantin Krasagakis; S. Krüger; Constantin E. Orfanos

A simple, rapid and reproducible assay for the determination of melanoma cell proliferation in vitro is described, based on the hydrolysis of a fluorogenic substrate by cell esterases in the cytoplasm of living cells. Human melanoma cells were cultured at several densities in 96-well culture plates for 24 h and were then incubated with 4-methylumbelliferyl heptanoate. The generated fluorescence showed a strong correlation with the cell numbers, similar to those assessed by determining the [3H]thymidine incorporation into cellular DNA and by quantifying the fluorescence obtained after DNA labelling with Hoechst 33258. The latter, however, was less sensitive and exhibited higher standard deviations. In addition, the method reliably detected the anti-proliferative effects of the anti-cancer compounds cisplatin and vindesine. It is, therefore, suggested that the fluorometric assay with 4− methylumbelliferyl heptanoate as substrate could prove useful for the screening of potential anti-cancer agents with anti-proliferative activity.


British Journal of Dermatology | 2010

The role of endothelial cell apoptosis in the effect of etanercept in psoriasis

G. Avramidis; Sabine Krüger-Krasagakis; Konstantin Krasagakis; I. Fragiadaki; G. Kokolakis; Androniki D. Tosca

Background  Psoriasis is a chronic inflammatory skin disease associated with abnormal vascular expansion in the papillary dermis. Tumour necrosis factor (TNF)‐α is a proinflammatory cytokine that can induce antiapoptotic proteins and endothelial cell activation factors in psoriasis.


BMC Family Practice | 2006

Primary care and pattern of skin diseases in a mediterranean island

Emmanouil K. Symvoulakis; Konstantin Krasagakis; Ioannis D Komninos; Ioannis Kastrinakis; Ioannis Lyronis; Anastasios Philalithis; Androniki D. Tosca

BackgroundIn Greece where primary health care services are not fully developed, patients with simple or minor conditions have to attend to hospitals to be treated. We analysed the data of patients with cutaneous disorders attending the tertiary referral hospital on the Island of Crete, with the aim to identify the most common conditions that patients complain of, in order to define the areas where the education of General Practitioners in Dermatology must focus.MethodsAll patients attending the Dermatology ambulatory office in the Emergency Department of the University General Hospital of Heraklion from January 2003 to December 2003 were included in this retrospective analysis. The medical records of the patients (history, physical examination and laboratory investigations) were analysed to ascertain the diagnosis and the management of cases. All patients were evaluated by qualified dermatologists.ResultsA total of 3715 patients attended the Dermatology Clinic. Most patients were young adults in the age group 21–40 years (38.4%), and the male to female ratio was 1 to 1.2. Allergic skin diseases, mostly dermatitis and urticaria (35.7%) were the most common for attendance, followed by infectious diseases (26.1%) and insect bites (10.2%). Inflammatory and autoimmune disorders accounted for 7.9% of the cases. Pruritus of unknown origin was diagnosed in 6.3% of patients. Skin tumors were detected in 2.7%. The management of the vast majority of cases (85.0%) consisted of advice with or without a prescription, while only 4.8% of patients required admission.ConclusionAllergic and infectious skin diseases were the most common cutaneous diseases in patients attending this tertiary University hospital, while the management of most patients did not require specialised care. On the basis of the present data, the training of primary health care providers in Dermatology should emphasize these common conditions, with the aim of improving primary care and alleviating the burden on hospital care.

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Claus Garbe

University of Tübingen

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Jürgen Eberle

Free University of Berlin

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Beate Tebbe

Free University of Berlin

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Sabine Krüger

Free University of Berlin

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