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Biomedical subjects

R Dummer

Publications and source records attributed to R Dummer.

At least 37 records · Page 2Linked to original sources
PubMed2003

A novel attenuated replication-competent adenovirus for melanoma therapy.

To generate a replication-competent adenovirus (Ad) with specificity for melanoma, we constructed a tissue-specific promoter restricting E1A expression to melanoma cells. The combination of four copies of a mouse tyrosinase enhancer element (TE) fused to the human tyrosinase promoter (TP) yielded up to 2000-fold higher luciferase reporter activity in tyrosinase-expressing melanoma cells than in nonmelanoma cells. Insertion of the composite TETP construct upstream of the E1A gene was combined with deleting as far as possible the intertwined endogenous Ad enhancer/promoter (EP). The resulting AdDeltaEP-TETP vector, also deleted for the E3 region, was found to replicate in tyrosinase-positive melanoma cells, such as SK-Mel23 as efficiently as wild-type Ad5, but at a more than 50-fold reduced level in nonmelanoma tumour cells and primary human cells. Injection of AdDeltaEP-TETP into xenotransplanted melanomas, but not into HeLa-derived tumours led to long-lasting tumour regression in nude mice. This AdDeltaEP-TETP virus might be useful for the treatment of accessible lesions in advanced melanoma patients.

Adenoviridae↗
PubMed2003

Imiquimod in basal cell carcinoma: how does it work?

Imiquimod is a topical immune response modifier that binds to Toll-like receptor-7 and -8, inducing interferon-alpha. We treated superficial basal cell carcinomas (BCC) with imiquimod 5% cream daily for 5-8 days. The BCC lesions were biopsied before treatment and following imiquimod treatment, when the lesion showed the signs of erosion. We applied histology, immunohistochemistry and gene array technology (Affymetrix) to gain further insight into the mode of action of imiquimod. Our findings demonstrate that imiquimod-induced BCC regression is associated with a strong activity of the innate immune response, mediated by cells of macrophage-monocyte origin and is associated with the induction of apoptosis.

Adjuvants, Immunologic↗
PubMed2003

Pyogenic lymphoma of the skin: a peculiar variant of primary cutaneous neutrophil-rich CD30+ anaplastic large-cell lymphoma. Clinicopathological study of four cases and review of the literature.

Systemic anaplastic large-cell lymphoma (ALCL) in human immunodeficiency virus (HIV)-infected individuals showing an extensive infiltrate of neutrophils has been reported and referred to as 'neutrophil-rich' CD30+ ALCL. Secondary cutaneous involvement has been found in a subset of these cases. We report the clinicopathological features of four immunocompetent patients with primary cutaneous neutrophil-rich ALCL and present a new histological subtype with a dissolute growth pattern of CD30+ tumour cells. Four HIV-negative patients presented with rapidly growing solitary or multiple tumours located on the face. Ulceration of the lesions with purulent discharge was a typical finding. Various inflammatory dermatoses were considered clinically in all cases. The histological hallmark was a large number of neutrophils in the infiltrate that masked neoplastic CD30+ anaplastic cells. In two cases, a dissolute growth pattern of anaplastic tumour cells was observed. In two cases, a strong correlation between tumour growth and interleukin (IL)-8 cytokine pattern as well as the production of IL-8 by tumour cells was demonstrated. The diagnosis of neutrophil-rich ALCL is challenging clinically and histologically as the tumour cell compartment is masked by an extensive inflammatory infiltrate of neutrophils and other reactive cells such as histiocytes which may be mainly due to release of IL-8 by tumour cells. The term 'pyogenic' designates the typical feature of this distinct neutrophil-rich ALCL, namely abscess formation ('pyo-') by cytokines (IL-8) produced by tumour cells ('-genic'). The clinical behaviour of this type is the same as in primary cutaneous CD30+ ALCL with classical histological presentation.

Abscess↗
PubMed2003

Blastic natural killer-cell lymphoma of the skin associated with myelodysplastic syndrome or myelogenous leukaemia: a coincidence or more?

We report three patients with blastic natural killer (NK)-cell lymphoma of the skin associated with myelodysplastic syndrome (MDS) (two patients) or subacute myelomonocytic leukaemia (one patient). In two patients MDS was diagnosed before skin lesions; the patient with leukaemia initially presented with skin lesions. Our patients had several clinical features in common, namely multiple skin lesions with a bruise-like appearance, involvement of the oral mucosa, and good general status at presentation but very rapid deterioration in the course of the disease. All patients died of disease 4-14 months after the diagnosis. Histopathologically, there were cutaneous infiltrates of slightly pleomorphic medium-sized cells expressing CD4, CD56, terminal deoxynucleotidyl transferase (focally) and being negative for surface CD3, cytotoxic molecules, B-cell-associated markers and myelomonocytic markers. Erythrocyte extravasation was seen in all patients. T-cell receptor genes were in germline configuration. MDS was classified as refractory cytopenia with multilineage dysplasia and ring sideroblasts and refractory anaemia with transition to refractory anaemia with excess of blasts. We reviewed similar cases reported in the literature showing coexistence of blastic NK-cell lymphoma/leukaemia and MDS or myelogenous leukaemia. We conclude that given an overall limited number of reported cases of blastic NK-cell lymphoma/leukaemia, its association with various myelodysplastic/myeloproliferative disorders seen in a subset of patients ( approximately 15-20%) is more than coincidental and may indicate their common origin.

Aged↗
PubMed2003

Therapy of cutaneous lymphoma--current practice and future developments.

Cutaneous lymphomas include various types of clonal lymphoproliferative disorders. The adequate treatment approach depends on the exact diagnosis and should be non-aggressive in most cases. In early stages, local approaches such as UV or radiotherapy are preferred. In advanced stages, systemic drugs such as interferon-alpha or bexarotene can be administered. Experimental approaches for cutaneous lymphomas include vaccination and gene therapy.

Humans↗
PubMed2002

Fibroblasts enhance the invasive capacity of melanoma cells in vitro.

In previous experiments we have shown an enhanced expression of matrix metalloproteinase-1 (MMP-1) in fibroblasts obtained from the border of invasive melanoma in comparison to fibroblasts more distant from the tumour. In the study reported here we sought to determine whether melanoma-derived soluble factors are responsible for the stimulation of MMP-1 expression in fibroblasts. By real-time PCR and enzyme-linked immunosorbent assays, we demonstrated that the stimulation of fibroblasts with melanoma cell conditioned medium led to an increased expression of MMP-1 mRNA as well as MMP-1 protein, whereas melanoma cells themselves did not produce detectable amounts of MMP-1 protein. Basic fibroblast growth factor (bFGF) was detected as an important factor responsible for the enhanced expression of MMP-1 by fibroblasts after stimulation with melanoma cell conditioned medium. In a three-dimensional in vitro invasion assay, we demonstrated that fibroblasts are essential for melanoma cell invasion into a collagen I matrix. These findings support the hypothesis that stromal fibroblasts assist the invasion of melanoma cells through the extracellular matrix by producing elevated amounts of proteolytic enzymes after interaction with soluble factors (e.g. bFGF).

Cells, Cultured↗
PubMed2002

Prognostic factors for survival and factors associated with long-term remission in patients with advanced melanoma receiving cytokine-based treatments: second analysis of a randomised EORTC Melanoma Group trial comparing interferon-alpha2a (IFNalpha) and interleukin 2 (IL-2) with or without cisplatin.

The aim of this study was to define prognostic factors for survival, and especially for long-term survival in a mature data-set of patients with stage IV melanoma treated within a randomised trial of cytokine-based protocols. Long-term follow-up data on patients enrolled into a European Organization for Research and Treatment of Cancer (EORTC) trial comparing interferon-alpha (IFNalpha) plus interleukin-2 (IL-2) with or without cisplatin were collected. Univariate and multivariate Cox regression analyses were performed to define prognostic factors for survival. The characteristics of patients alive at 2 and 5 years after randomisation were compared with the entire cohort using the chi(2) test. The minimum potential follow-up of the 131 evaluable patients was 5 years. 18 patients (14%) were alive 2 years after randomisation, and 11 (8%) 5 years after randomisation. Pretreatment performance status (PS), serum lactate dehydrogenase (LDH) and tumour mass were significant predictors for survival, whereas site of metastases and number of sites were non-significant. PS and LDH were the only independent prognostic factors. All except 1 patient alive at 2 and 5 years had a pretreatment PS of 100%, and only three long-term survivors had elevated pretreatment LDH. There was no association between the site of metastases and long-term survival. Response to treatment was a major predictor for long-term survival, whereas addition of cisplatin did not impact upon overall survival probability or on long-term survival. The probability of long-term survival in stage IV melanoma patients after IL-2-based treatments is governed by pretreatment PS, serum LDH and response to treatment. Site of metastases, the basis for the M-subcategories of the new AJCC staging system, was not informative in this study.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2002

Primary subcutaneous follicular centre cell lymphoma with involvement of the galea: a case report and short review of the literature.

Primary cutaneous follicular centre cell lymphoma (FCCL) is a distinct subtype of cutaneous lymphoma that originates from germinal centre cells. Histologically, the disease is typified by a bottom-heavy infiltrate with a diffuse or follicular growth pattern situated in the mid or deep dermis. In some cases, the neoplastic infiltrate may involve the underlying subcutaneous tissue, but so far primary subcutaneous FCCL has not been reported. We report the first case of primary FCCL located primarily in the deep subcutis with extension into the galea and review the literature on primary subcutaneous B-cell lymphomas.

Female↗
PubMed2002

T-zone lymphoma with cutaneous involvement: a case report and review of the literature.

T-zone lymphoma (TZL) is a rare subtype of nodal peripheral T-cell lymphoma characterized by a clonal expansion of T-zone lymphocytes accompanied by a proliferation of other T-zone constituents. Non-specific cutaneous alterations are seen in about one-third of all cases, but specific cutaneous involvement is extremely rare. We present a case of TZL with secondary skin infiltration, review the literature on cutaneous manifestations of TZL and discuss the differential diagnosis of TZL.

Adult↗
PubMed2002

A retrospective study of 150 patients with lentigo maligna and lentigo maligna melanoma and the efficacy of radiotherapy using Grenz or soft X-rays.

BACKGROUND: Lentigo maligna (LM) and lentigo maligna melanoma (LMM) are the most common melanocytic neoplasms on sun-exposed skin of elderly patients. OBJECTIVES: To perform a retrospective study of 150 patients with LM and LMM treated with radiotherapy using Grenz or soft X-rays. METHODS: The information recorded and analysed included gender, age, diagnosis, size of the lesion, localization, X-ray treatment, recurrence rate, other skin malignancies and non-dermatological neoplasms. RESULTS: The 150 patients comprised 78 women and 72 men (mean age 70 years). Ninety-three patients had LM, 54 had LMM and three had both neoplasms. Ninety per cent of lesions were located on the face. Treatment was with Grenz rays in 96 patients with LM and 11 with LMM (70%) and with soft X-rays in 46 patients with LMM (30%). Three patients were treated using both modalities. One hundred and one patients were followed up for at least 2 years after radiotherapy (mean 8 years). The mean time to recurrence was 45.6 months, and the recurrence rate was 7% (seven of 101). Other skin malignancies were observed in 65 of 150 patients, including basal cell carcinoma in 23 (35%) and actinic keratosis in 20 (31%). Four patients developed internal cancers. CONCLUSIONS: The study showed that radiotherapy of LM and LMM was curative. In particular, radiotherapy proved to be an excellent treatment for elderly patients. Owing to the high incidence of other skin cancers, LM patients need careful follow-up.

Adult↗
PubMed2002

A case of Sézary's syndrome associated with granulomatous lesions, myelodysplastic syndrome and transformation into CD30-positive large-cell pleomorphic lymphoma.

Sézary's syndrome (SS) is a leukaemic variant of mycosis fungoides, a cutaneous T-cell lymphoma showing distinct clinical, histological, immunological, and genotypic features. We report a 10-year follow-up of a patient with SS exhibiting unusual features such as granulomatous skin lesions, transformation to a CD30-positive large-cell pleomorphic T-cell lymphoma, and development of myelodysplastic syndrome and review the cases of SS reported in the literature with these unusual and rare complications.

Fatal Outcome↗
PubMed2002

Histological, immunological and molecular features of a nasal mucosa primary melanoma associated with nasal melanosis.

Nasal mucosa melanoma is a rare entity that may occur together with nasal melanosis. The histological and immunological features and loss of heterozygosity analysis of such lesions have not been reported to date. In the study presented here short-term cell cultures were established from the patient's melanoma and subsequent relapses. Histology, immunohistochemistry, reverse transcription-polymerase chain reaction enzyme-linked immunosorbent assay, human leukocyte antigen analysis, microdissection with subsequent polymerase chain reaction for analysis of loss of heterozygosity were used to characterize the tumour and other cells. Melanoma of the nasal cavity was found, with a surrounding proliferation of atypical melanocytes corresponding to nasal melanosis. Immunoreactivity was found for S-100, gp100, tyrosinase and MelanA protein. Loss of heterozygosity for a p16-flanking marker was found in the tumour and the melanotic cells. Short-term cell cultures expressed tyrosinase and MUC18 at the mRNA level and intercellular adhesion molecule-1 (ICAM-1) and interleukin-12 receptor at the protein level. This is the first time short-term cell cultures have been established and analysed from such a tumour. Melanoma-associated antigens were identified within the tumour. The melanoma and the melanotic cells showed loss of heterozygosity for the p16 gene, which is implicated in melanoma development. This points to a common origin in tumorigenesis. Pathways of tumour escape, such as expression of CD54 and interleukin-10, were observed. The clinical, immunological and molecular features suggest that nasal melanosis should be followed closely.

Adult↗
PubMed2002

Prevention campaign against skin cancer.

BACKGROUND: The melanoma incidence has increased over recent decades. Educational campaigns aim to encourage protection from the sun and early detection of melanoma. METHODS: During a campaign in Switzerland, information on risk factors, sun protection and melanoma prevention was distributed. 10987 people completed a questionnaire regarding risk factors, and 2746 people were examined by a dermatologist. RESULTS: Men had a higher risk as assessed by skin type, ultraviolet exposure, family history, number of moles and sunburns during childhood. Changes in moles were reported significantly more often by people with: (1). a positive family history (p < 0.0001); (2). multiple moles (p < 0.0001), and (3). sunburns during childhood (p < 0.0001). A precancerous or cancerous condition was suspected in 16% of individuals examined. CONCLUSION: Early detection of melanoma can be achieved by this type of campaign. Primary prevention is a long-term approach and educational efforts targeting risk groups must be continued.

Female↗
PubMed2002

Trichogerminoma: a rare cutaneous adnexal tumor with differentiation toward the hair germ epithelium.

In 1992, Sau and colleagues described 14 cases of a rare cutaneous adnexal tumor with differentiation toward the hair germ epithelium. All cases in their study displayed a unique constellation of histological features which allowed the authors to consider the neoplasm to be a distinct entity and to designate it as 'trichogerminoma' (TG). We present a case of an adnexal tumor identical to that described as TG and report the immunophenotypical features of this neoplasm for the first time. A biopsy from a 41-year-old man revealed a well-demarcated epithelial tumor composed of multiple lobules located in the deep dermis without connection to the overlying epidermis and surrounded by a fibrous pseudocapsule. The tumorous lobules were composed of uniform basophilic cells with vesicular nuclei, dispersed chromatin and prominent nucleoli showing no prominent peripheral palisading. Some of the lobules had the appearance of densely packed 'cell balls' with peripheral condensation of the tumor cells. The stroma showed a moderate number of fibroblasts and mast cells. Reticulum staining revealed fine reticulum fibers surrounding the tumor aggregates with accentuation of the 'cell balls'. Immunohistochemically, the tumor cells expressed AE1/AE3, CK5/8, CK5/6, CAM5.2 and stained negatively for CK20, CK7, calretinin, Lu-5 and Thomsen- Friedensreich antigen. There was no increase in the numbers of CK20-positive Merkel cells in the epidermis overlying the tumor; however, a few Merkel cells were scattered in some tumor lobules. In addition, we stained 6 trichoblastomas (TBs) and found a particular pattern of calretinin expression in this tumor which was not observed in our case of TG. We conclude that pathological features allow the delineation of TG as a distinct adnexal neoplasm. Histological differential diagnosis includes basal-cell carcinoma (pilar type), large nodular TB, trichoblastic fibroma, trichoepithelioma, tricholemmoma, pilomatricoma and matrical carcinoma.

Adult↗
PubMed2001

[Manifestations of the "pretherapeutic phase" of malignant melanoma of the skin in Switzerland 1996-1998].

62 patients with a histologically confirmed diagnosis of cutaneous malignant melanoma were interviewed from 1996 to 1998. Lesions were found mostly on patients backs (30.6%) and they were noted most frequently because of a change in colour (darker) (50%) and increase in size (43.5%). The median time between first noticing the melanoma and visiting a physician was one month, but for 28% of the patients it was more than three months. The median time between a medical examination and surgical removal was shorter than one month, but for 22% of the patients it was more than three months. Patients with bleeding lesions sought medical help later (14 months). Misdiagnosis led to a six months delay in treatment and if no action was taken there was a 13 months delay.

Adult↗
PubMed2001

Interleukin-7 and interleukin-15 regulate the expression of the bcl-2 and c-myb genes in cutaneous T-cell lymphoma cells.

Interleukin-7 (IL-7) and IL-15 have been recently identified as growth factors for cutaneous T-cell lymphoma (CTCL) cells, and they protect these cells from cell death. Using the CTCL cell line SeAx as a test system now shows that IL-7 and IL-15 are indeed necessary to maintain high levels of bcl-2. The up-regulation of bcl-2 was paralleled by increased DNA-binding activities of the transcription factors STAT2, STAT5, STAT6, and c-Myb to bcl-2 gene promoter-enhancer elements. Because STAT5 and c-Myb positively regulate bcl-2, IL-7 and IL-15 may mediate some of their effects on cell death survival gene expression through these 2 factors. Constitutive activities of the 3 STAT factors and c-Myb were found in the IL-7- and IL-15-independent CTCL cell lines HUT78 and MyLa 2059. The c-Myb protein was also present in CTCL cells of the skin lesions of all investigated patients. These results indicate that IL-7 and IL-15 may increase bcl-2 expression in CTCL cells by the activation of c-myb and STAT factors.

DNA-Binding Proteins↗
PubMed2001

Dacarbazine and interferon alpha with or without interleukin 2 in metastatic melanoma: a randomized phase III multicentre trial of the Dermatologic Cooperative Oncology Group (DeCOG).

In several phase II-trials encouraging tumour responses rates in advanced metastatic melanoma (stage IV; AJCC-classification) have been reported for the application of biochemotherapy containing interleukin 2. This study was designed to compare the efficacy of therapy with dacarbazine (DTIC) and interferon alpha (IFN-alpha) only to that of therapy with DTIC and IFN-alpha with the addition of interleukin 2 (IL-2) in terms of the overall survival time and rate of objective remissions and to provide an elaborated toxicity profile for both types of therapy. 290 patients were randomized to receive either DTIC (850 mg/m(2)every 28 days) plus IFN-alpha2a/b (3 MIU/m(2), twice on day 1, once daily from days 2 to 5; 5 MIU/m(2)3 times a week from week 2 to 4) with or without IL-2 (4.5 MIU/m(2)for 3 hours i.v. on day 3; 9.0 MIU/m(2) i.v. day 3/4; 4.5 MIU/m(2) s.c. days 4 to 7). The treatment plan required at least 2 treatment cycles (8 weeks of therapy) for every patient. Of 290 randomized patients 281 were eligible for an intention-to-treat analysis. There was no difference in terms of survival time from treatment onset between the two arms (median 11.0 months each). In 273 patients treated according to protocol tumour response was assessable. The response rates did not differ between both arms (P = 0.87) with 18.0% objective responses (9.7% PR; 8.3% CR) for DTIC plus IFN-alpha as compared to 16.1% (8.8% PR; 7.3% CR) for DTIC, IFN-alpha and IL-2. Treatment cessation due to adverse reactions was significantly more common in patients receiving IL-2 (13.9%) than in patients receiving DTIC/IFN-alpha only (5.6%). In conclusion, there was neither a difference in survival time nor in tumour response rates when IL-2, applied according to the combined intravenous and subcutaneous schedule used for this study, was added to DTIC and IFN-alpha. However, toxicity was increased in melanoma patients treated with IL-2. Further phase III trials with continuous infusion and higher dosages must be performed before any final conclusions can be drawn on the potential usefulness of IL-2 in biochemotherapy of advanced melanoma.

Adolescent↗