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Biomedical subjects

S Krengel

Publications and source records attributed to S Krengel.

At least 19 recordsLinked to original sources

Melanoma risk in congenital melanocytic naevi: a systematic review.

BACKGROUND: The risk of malignant melanoma in congenital melanocytic naevi (CMN) is a matter of controversial and ongoing debate. OBJECTIVES: The purpose of this systematic review is to provide a careful and detailed summary of the published data, including several recently published studies. METHODS: Articles on CMN (n=1424) were retrieved from Medline, 1966-October 2005. Case reports and studies lacking relevant clinical information were excluded. Only systematic collections of cases were taken into consideration. Series with fewer than 20 patients or studies with a mean follow-up of <3 years were regarded as epidemiologically less significant. RESULTS: Fourteen articles were finally chosen for further analysis. The studies varied significantly with respect to study design (source of cases; retrospective vs. prospective analysis), age of patients, follow-up time, and naevus characteristics. The frequency of melanomas ranged between 0.05% and 10.7% and was significantly higher in smaller studies (P<0.0001). In a total of 6571 patients with CMN who were followed for a mean of 3.4-23.7 years, 46 patients (0.7%) developed 49 melanomas. The mean age at diagnosis of melanoma was 15.5 years (median 7). By comparison with age-adjusted data from the Surveillance, Epidemiology and End Results database, we calculated that patients with CMN carry an approximately 465-fold increased relative risk of developing melanoma during childhood and adolescence. Primary melanomas arose inside the naevi in 33 of 49 cases (67%). In seven cases (14%), metastatic melanoma with unknown primary was encountered; in four cases (8%) the melanoma developed at an extracutaneous site. The risk of developing melanoma and the rate of fatal courses were by far highest in CMN>or=40 cm in diameter. CONCLUSIONS: The overall risk of melanoma of 0.7% in all 14 studies was lower than expected. The higher incidence of melanomas in smaller studies indicates selection bias. The melanoma risk strongly depends on the size of CMN and is highest in those naevi traditionally designated as garment naevi. The median age of 7 years at diagnosis of melanoma points to a risk maximum in childhood and adolescence. Future studies on CMN should report: (i) diameter, percentage of body surface, and localization of the CMN; (ii) percentage of naevus area removed by excision or subject to dermabrasion or other superficial treatments; (iii) mean and median age at entry into the study; (iv) mean and median follow-up time; (v) details on each melanoma case; (vi) standardized morbidity ratio of melanoma; and (vii) percentage of neurocutaneous melanosis.

Adolescent↗

Sepsis with bullous necrotizing skin lesions due to vibrio vulnificus acquired through recreational activities in the Baltic Sea.

This report describes the case of a 59-year-old woman with a history of non-Hodgkin's lymphoma who developed bacteremia with Vibrio vulnificus. The patient had been swimming in the unusually warm Baltic Sea in the summer of 2002. She presented with symptoms of septicemia and severe bullous necrotizing skin lesions of the extremities. Blood culture revealed Vibrio vulnificus as the pathogenic organism. Under treatment with cefotaxime and gentamicin, she recovered slowly without further complications. Vibrio vulnificus is a marine bacterium that is present in aquatic ecosystems worldwide, especially when water temperatures exceed 20 degrees C. Infections with Vibrio vulnificus are uncommon in Europe, and most cases are reported from subtropical or tropical regions.

Anti-Bacterial Agents↗

Growth and characterization of a cell line from a human primary neuroendocrine carcinoma of the skin (Merkel cell carcinoma) in culture and as xenograft.

The primary neuroendocrine carcinoma of the skin or Merkel cell carcinoma (MCC) is a skin tumor with aggressive biological behaviour. Experimental models for investigating the biological properties of the tumor are prerequisite for developing new therapeutic approaches. In this study, we report the establishment and characterisation of a cell line derived from the lymph-node metastasis of a patient with highly aggressive MCC. Merkel carcinoma cells (MCC-1) grew as floating aggregates in suspension cultures for more than two years and over 70 subcultures. The proliferation rate in suspension cultures was rather moderate with a population doubling time of 69 h. The immunocytochemical pattern of the cultured MCC-1 was similar to that of the original tumor with expression of cytokeratin 18, neuron-specific enolase, neurofilaments, and synaptophysin. In addition, reverse transcriptase polymerase chain reaction (RT-PCR) revealed presence of chromogranin A mRNA in the MCC-1 cell line. Furthermore, electron microscopy yielded the rare finding of neuroendocrine granules in the cytoplasm of the cultured cells. The cell line MCC-1 was able to form colonies in soft agar. Nude mice developed solid tumors with similar histology to the original tumor after subcutaneous and intravenous injections of cultured MCC-1, and malignant ascites was seen after intraperitoneal injection. Also, two MCC-1 sublines were established by reculturing cells from the xenografts grown in vivo and immunocytochemistry confirmed their neuroendocrine origin. The MCC-1 line may thus serve as a model for studying the biology and the metastatic potential of Merkel cell carcinoma.

Aged↗

[Radiation-induced acne].

Radiation-induced acne is a rare, clinically and pathogenetically ill-defined acneiform dermatosis with special features that may occur in irradiated skin areas especially after high doses of deeply penetrating radiation. We report on a patient with an oropharyngeal carcinoma who developed severe radiation-induced acne including comedones and cysts as well as few inflammatory papules and pustules in a skin area irradiated with up to 63 gray of a 6 MeV photon beam. Acnegenic drugs may precipitate the disease; our patient was on longterm therapy with carbamazepine whose acnegenic potency is less well documented than that of testosterone or glucocorticoids. Treatment of radiation-induced acne is comedolytic; topical retinoids are especially valuable.

Acne Vulgaris↗

[Livedo racemosa: an unusual late manifestation of borreliosis?].

Classic variants of cutaneous borreliosis are erythema chronicum migrans (ECM), lymphadenosis benigna cutis (LBC) and acrodermatitis chronica atrophicans (ACA). Other dermatoses have been reported in the literature as possibly linked to borreliosis. A 59-year old female patient was seen in the late phases of cutaneous borreliosis with histologically confirmed ACA. In addition, prominent livedo racemosa was seen on the legs, also showing tissue changes similar to those of ACA. Borrelia burgdorferi infection was serologically confirmed by the presence of anti-IgM and anti-IgG antibodies. The clinical spectrum of late cutaneous borreliosis should be enlarged to include livedo racemosa.

Acrodermatitis↗

[Acquired reactive perforating dermatosis. Successful treatment with allopurinol in 2 cases].

Perforating disorders represent a heterogenous group of dermatoses characterized by transepithelial elimination of dermal structures. Primary perforating disorders should be distinguished from secondary perforating disorders in which perforation with transepithelial elimination is a rare component of a variety of dermatoses. The primary perforating disorders are hyperkeratosis follicularis et parafollicularis in cutem penetrans (Kyrle's disease), elastosis perforans serpiginosa and perforating folliculitis. Acquired reactive perforating dermatosis (also known as acquired reactive perforating collagenosis) together with the hereditary variant of the reactive perforating collagenosis represent further examples of the primary perforating disorders. We report on 84 year old and 96 year old female patients with an acquired perforating dermatosis. Both of the patients additionally showed diabetes and hyperuricemia. Oral administration of allopurinol (100 mg daily) led to a healing of the disseminated skin lesions in 1-2 weeks. After a follow-up period of 6 months, both patients were in complete remission. On one hand, these results prove again the existence and the severity of this disease, and on the other hand suggest an immunomodulating or differentiation-promoting action in addition to the uricostatic effect of allopurinol.

Aged↗

[Kaposiform HHV-8 negative acroangiodermatitis in chronic venous insufficiency].

A 76-year-old female patient developed severe manifestations of a kaposi-like acroangiodermatitis (so-called Mali's disease) due to chronic venous insufficiency of the lower extremities. The patient presented with large areas of confluent, violaceous or brown-black papules on both lower legs. Histologically, proliferation of thick-walled capillaries was seen in the upper dermis consisting of fully differentiated endothelial cells, as shown by immunohistochemistry. In contrast to true Kaposi's sarcoma, human-herpes-virus-8 DNA could not be detected by polymerase-chain-reaction in this condition. We review the diagnostic criteria used to distinguish between acroangiodermatitis, also called pseudo-Kaposi's sarcoma, and the true Kaposi's sarcoma.

Acrodermatitis↗

[Hepatitis C virus-associated dermatoses: a review].

Acute infection with hepatitis C virus (HCV) is often clinically inapparent, but may affect several organ systems in its chronic course. In dermatology, common diseases such as lichen planus, cryoglobulinemic vasculitis and porphyria cutanea tarda have been described in association with HCV infection. A number of other dermatologic disorders, e.g., psoriasis, chronic urticaria, chronic pruritus, pseudo-kaposi sarcoma, necrolytic migratory erythema and Behçet disease, have been associated in case reports with HCV-induced liver disease. In this study we summarize the recent literature reports, present three patients observed by our group and update the topic.

Diagnosis, Differential↗

Unilateral angiolymphoid hyperplasia with eosinophilia involving the left arm and hand.

A case report of recurrent angiolymphoid hyperplasia with eosinophilia (ALHE) in an otherwise healthy 20-year-old female with manifestation of the disease limited to the left arm and hand is presented together with brief evaluation of the literature as well as the features distinguishing ALHE and Kimura's disease. Immunohistochemical investigations support the hypothesis that ALHE represents a reactive inflammatory lesion rather than a benign vascular neoplasm. A viral cause of ALHE (e.g., HHV8 or Epstein-Barr virus (EBV)) could not be demonstrated. The recurrent nature of the disease is shown by this case, which also demonstrates the need for frequent medical and surgical management.

Adult↗

Progressive HHV-8-positive classic Kaposi's sarcoma: rapid response to interferon alpha-2a but persistence of HHV-8 DNA sequences in lesional skin.

The pathogenesis of Kaposi's sarcoma (KS) is often attributed to an infectious agent. In particular, the human herpesvirus 8 (HHV-8) was currently shown to be closely related to all known KS types, including HIV-associated KS, European classic KS, African endemic KS and iatrogenic KS. We report here on an HIV-negative, German patient of neither Jewish nor Mediterranean descent with disseminated classic KS showing unusual rapid progression into the tumour stage. After systemic administration of interferon alpha-2a over 4 weeks all tumour lesions cleared completely. Interestingly, HHV-8 DNA sequences detected by nested polymerase chain reaction in KS lesions before the onset of treatment were still present in lesional skin after complete remission of the tumour. No recurrence was seen after a follow-up period of 6 months.

Aged↗

[Superior vena cava syndrome. Description of 3 cases and review of the literature].

Superior vena cava syndrome (VCSS) develops because of a progressive reduction of venous return from the head, neck and the upper extremities. The presenting sign of this relatively rare condition is often a rapidly developing, often massive facial edema. As a consequence, such the patients are often seen initially by a dermatologist. Other clinical characteristics may include cyanotic facial erythema, dilatation of the neck veins, and a prominent venous pattern n the anterior chest. Today, primary lung cancers and other mediastinal tumours represent the most common cause of VCSS, which may take a slowly progressive or a more fulminant course. In these cases, the disease develops rapidly and becomes life-threatening, requiring intensive medial diagnosis and care. We describe three patients with superior vena cava syndrome due to a) bronchogenic carcinoma, b) bihilar sarcoidosis and c) metastasizing malignant melanoma. Since recognition of VCSS broadens the diagnostic spectrum of the dermatologist, an overview on its diagnostic and therapeutic implications is given based on our cases and the literature.

Aged↗

Expression pattern of type II collagen mRNA during early vertebral development in the human embryo.

The role of extracellular matrix molecules in ontogenetic differentiation processes is a matter of increasing interest. In cartilage development, type II collagen is suspected of promoting chondrogenic differentiation, since its expression has been demonstrated in a range of precartilaginous tissues of vertebrate species. Up to now, no studies supplying a coherent description of type II collagen expression in the skeletogenesis of human embryos including early embryonic stages have been published. In this work, we examine the temporal and spatial distribution of type II collagen mRNA during vertebral column development in human embryos from 4 to 12 weeks of gestation using non-radioactive in situ hybridization. The onset of gene expression was demonstrable in the 5th week in precartilaginous mesenchymal cells and in notochordal cells. Additionally, we found a weaker hybridization signal in the mesenchymal precursors of the intervertebral discs. In the anlagen of the axial skeleton, type II collagen expression decreased during osteogenic reconstruction in the 11th/12th week, whereas expression continued in the notochordal remnants of the future nuclei pulposi. The results suggest a relatively late occurrence of type II collagen in human vertebral development compared with other vertebrate species. The distribution of gene expression is concordant with a possible role of this molecule in promoting differentiation of mesenchymal cells into chondrocytes. The mechanism of this influence remains to be established.

Cartilage↗