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Biomedical subjects

U W Schnyder

Publications and source records attributed to U W Schnyder.

At least 19 recordsLinked to original sources
PubMed1992

Anchoring fibrils, collagen VII, and neutral metalloproteases in recessive dystrophic epidermolysis bullosa inversa.

Structure of the anchoring fibrils, expression of collagen VII, and gelatinolytic activity in skin fibroblasts were assessed in six patients with epidermolysis bullosa dystrophica (EBD) inversa and in control groups consisting of probands with other EBD subtypes and healthy individuals. All six patients with EBD inversa, as well as the patients with generalized non-mutilating and localized EBD, showed positive staining with antibodies to collagen VII, the major anchoring fibril protein. Four patients with severe generalized mutilating EBD exhibited negative staining. Ultrastructurally, normal anchoring fibrils were demonstrable in uninvolved skin of patients with localized, inversa, and generalized non-mutilating subtypes. At the same time, a high degree of variability was observed in the amount and quality of anchoring fibrils in the various stages of lesional skin, including co-existence of normal and partially degraded anchoring fibrils. Of all 12 patients only one localized and two inversa cases showed an increased gelatinolytic activity in vitro. However, the high activity was associated with neither the severity of the disease nor the inversa subtype. In addition, intact collagen VII could be extracted from the dermis of one inversa patient. The present data show no correlation between increased in vitro gelatinolytic activity and abnormalities of the anchoring fibrils or collagen VII in skin of patients with recessive EBD, and therefore suggest molecular heterogeneity of the causative pathogenetic mechanisms.

Adolescent↗
PubMed1992

Patch test results of the Dermatology Clinic Zurich in 1989: personal computer-aided statistical evaluation.

The patch test results of 921 consecutively tested patients were registered on an IBM personal computer. A computer program based on the dBase III plus database software, especially designed for this purpose, was used. The statistical evaluation was performed with dBase III plus. 59% of the probands were females and 41% males. The average age was 42.8 years. 26% of the probands were inpatients and 74% outpatients. A majority of the patients presented with eczema of the hands, face or the lower legs. The largest occupational groups were houseworkers and cleaning personnel, office workers and pensioners. To 450 of the 921 patients, at least 4 test series were applied simultaneously. These included European standard, vehicles and emulgators, topical medications, and preservatives and biocides. The other 20 test series available were employed only by 2-81 patients each. The highest sensitization rates were found with: nickel, 18.7%; cobalt, 10.2%; balsam of Peru, 8.8%; framycetin, 8.0%; neomycin, 6.8%; potassium dichromate, 6.1%; p-phenylene diamine, 5.4%; paramix, 4.9%; formaldehyde, 4.8%, and (chlor)methylisothiazolinone, 4.7%. The critical evaluation of the data showed two kinds of problems: first, test-specific aspects led to optimization of the patch test procedures; second, the crucial importance of an adequate statistical analysis for epidemiological investigation was revealed.

Adolescent↗
PubMed1992

Dysplastic nevus syndrome: intrafamilial identification of carriers by cytogenetics.

Seven members of a family with dysplastic nevus syndrome (DNS) were examined clinically; skin biopsies of unaffected skin from 6 were taken. Biopsy-derived cultivated fibroblasts were examined by cytogenetic methods, i.e. by measuring the spontaneous and the UVB- and UVC-driven increase in sister chromatid exchange (SCE). A male patient with malignant melanoma, his son and his nephew, both with multiple dysplastic nevi, showed a distinctive elevation of UV-induced SCE, whereas the other, unaffected members of the family showed normal values. These results give evidence that in siblings with DNS the affected members can be identified not only on clinicopathological grounds but also by UV-induced elevated SCE at the cytogenetic level.

Adult↗
PubMed1992

[Family study of erythrokeratodermia figurata variabilis].

Erythrokeratodermia figurata variabilis (EKV) is a rare disorder of cornification inherited as an autosomal dominant trait. Genetic linkage to the Rh locus on chromosome 1 has been recently documented. In 1957, Sommacal and Schnyder reported on a family with 14 affected members. We have reexamined this pedigree, which counts 77 members with 29 affected persons over five generations (45 females, 31 males). Twenty females and 9 males were affected. In all patients EKV presented in the first year of life, and several mothers noted the erythematous lesions at birth of their children. The hyperkeratotic lesions appeared later. The reddish macules changed within hours to days. The erythematous areas were sharply outlined and sometimes surrounded by an anemic border. Only few members stated that their erythema could persist for more than a week. Clear triggers were emotional stress and changes of temperature. In all but two of the patients erythema was prominent and in the others hyperkeratotic lesions were more severe. Most patients had a burning sensation in their red areas. There was a marked tendency for improvement of EKV after puberty. Five females reported regular superficial skin peeling on hands and feet. The features in these patients had some similarities with erythrokeratolysis hiemalis.

Adolescent↗
PubMed1991

The ultrastructure of congenital naevocytic naevi. III. Morphological variability of melanosomes.

In congenital naevocytic naevi (CNN), the ultrastructure of melanosomes has been demonstrated only in a few case reports. In the present study, five defined skin levels were systematically compared by electron microscopy in five giant and seven medium-sized CNN. The ages of the patients ranged from 5 days to 29 years. Six common acquired naevocytic naevi (ANN) served as controls. Melanosomes were classified morphologically into several groups. Epidermal melanosomes were normal in all cases. In 10 of the 12 patients, the morphology and size of dermal melanosomes corresponded well with those in ANN, although in four young children (up to 4-years-old) a few enlarged or atypical forms were found. On the other hand, two new-born babies showed rather different, grossly enlarged dermal melanosomes of various shapes and some unusual internal features. They were seen focally even in lower dermal layers and in naevus cells in subepidermal sweat ducts. We conclude that dermal naevus cells in CNN of new-borns, at least in some cases, may contain melanosomes with unusual morphological variations. This does not necessarily indicate malignant transformation.

Adolescent↗
PubMed1991

Cylindroma overexpresses collagen VII, the major anchoring fibril protein.

The cell clusters of the human adnexal tumor, cylindroma, are surrounded by an unusual, thick, unorganized basement membrane-like zone in vivo. Ultrastructural analysis of this electron-dense zone revealed recesses that contained numerous anchoring fibrils. Indirect immunofluorescence staining with antibodies to collagen VII, the major structural component of the anchoring fibrils, showed strong fluorescence of this zone. Collagen VII could be isolated from tumor tissue by limited pepsin digestion or by extraction with chaotropic agents. Cylindroma cells were cultured from the tumor and passaged several times. The cells exhibited a strong expression of collagen VII in vitro, when assayed with immunofluorescence staining or immunoblotting of culture extracts. These results suggest that cylindroma can be used as an abundant source to produce collagen VII in vitro to study the biosynthesis and regulation of collagen VII and the formation of the anchoring fibrils, as other culture systems have failed to produce ample amounts of this anchoring fibril protein.

Aged↗
PubMed1991

Becker's nevus and malignant melanoma.

We describe 9 patients who presented Becker's nevus (BN) together with a malignant melanoma (MM). Eight patients were male. In 5 patients the MM was on the same body site as the BN. The melanoma was of the superficial-spreading type in 7 cases and in 1 patient was within the BN. Twice a dysplastic-nevus syndrome was diagnosed and in 2 patients a familial melanoma. To the best of our knowledge this is the first report of the co-occurrence of BN and MM.

Adult↗
PubMed1991

Nodular cutaneous mucinosis--an unusual multiple type of euthyreotic focal mucinosis.

A 32-year-old Turkish man with a progressive appearance of indolent, skin-colored nodules on the trunk and proximal extremities is presented. Clinical and laboratory examinations did not reveal any other relevant abnormalities. Histological specimens showed focal, ill-defined depositions of acid mucopolysaccharides mainly in the reticular dermis. Collagen fibers were split up and separated. Ultrastructurally, activated fibroblasts and an increased synthesis of collagen fibrils and elastic microfibrils as well as numerous macrophages were noticed. Diagnostically, an unusual multiple type of cutaneous focal mucinosis is most likely.

Adult↗
PubMed1991

[Werner syndrome with torpid trophic ulcera cruris].

Werner's syndrome is a rare, autosomal recessive inherited disorder with a distinctive clinical picture. The characteristic physiognomy, shortness of stature with thin extremities, and large trophic ulcers are the key signs for the diagnosis. Premature greying of the hair and baldness, juvenile cataracts, a tendency to diabetes mellitus, hypogonadism, calcifications of the blood vessels, osteoporosis, metastatic calcifications of the soft tissue and an elevated incidence of neoplasms are further important features. We describe two patients with this disorder.

Aged↗
PubMed1991

[Necrobiosis lipoidica and Koebner phenomenon].

Our report describes a 52-year-old female patient with bilateral foci of necrobiosis lipoidica in pretibial scars. The skin changes appeared 6 months after internal fixation of a tibial fracture in each case.

Cicatrix↗
PubMed1990

Type VII collagen is expressed but anchoring fibrils are defective in dystrophic epidermolysis bullosa inversa.

A patient with dystrophic epidermolysis bullosa inversa was studied using electron microscopy and indirect immunofluorescence using antibodies to matrix macromolecules of the dermoepidermal junction zone. There was splitting below the lamina densa with an apparently normal basement membrane, but a lack of intact anchoring fibrils and with a disarranged papillary connective tissue. Indirect immunofluorescence examination with antibodies to type VII collagen, the major structural protein of anchoring fibrils, showed a normal linear staining pattern. Synthesis of type VII collagen which is unable to form stable, resistant anchoring fibrils may be a distinct feature of this subtype of recessive dystrophic epidermolysis bullosa.

Adult↗
PubMed1990

Epidermolysis bullosa dystrophica inversa in a child.

A 4-year-old child with dystrophic epidermolysis bullosa inversa is described. Clinical features were blistering of the skin, erosions, scarring and milia formation. The areas involved included the trunk, with preference for the axillary and inguinal folds, the neck and sacral area, and proximal extremities. Notably, the hands and feet were completely spared, with only mild nail dystrophy. Ultrastructural analysis revealed dermolytic blistering and absent or rudimentary anchoring fibrils. Collagen VII, the main structural protein of these fibrils, was present in the skin, as shown by indirect immunofluorescence. These findings suggest that a mutation that prevents appropriate supramolecular aggregation of collagen VII into anchoring fibrils may underlie this subtype of dystrophic epidermolysis bullosa in some patients.

Autoantibodies↗
PubMed1990

Squamous cell carcinoma and basal cell carcinoma within the clinical picture of a chronic venous insufficiency in the third stage.

Two cases of neoplastic ulcers of the leg will be described which presented themselves within the clinical picture of a chronic venous insufficiency in its third stage. Both cases had a phlebological anamnesis. The transformation of chronic ulcers of the leg into spinal cell carcinomas is well known. With the presence of an ulcus cruris, however, basal cell carcinomas are rarely considered in a differentiated diagnosis. Yet both of these (by and large common) skin tumors can occur in the clinical picture of an ulcus cruris. The role of the dermatologist in the early diagnosis and treatment such neoplastic ulcers is therefore an important one.

Aged↗
PubMed1990

Rosacea-like angiosarcoma of the face.

We present an 84-year-old white male patient who, during a 2-year period, developed successively tumor infiltrations of an angiosarcoma in his face. The tumor started at the right lower eyelid, later appeared on the nose, the front, the cheeks and the earlobes. The first clinical impression was that of a rosacea. The tumors where successfully treated by soft X-rays, the total doses ranging from 4,800 to 5,600 cGy.

Aged↗
PubMed1990

Kaposiform acro-angiodermatitis with arteriovenous malformation (Stewart-Bluefarb syndrome).

A case of acro-angiodermatitis with congenital arteriovenous fistulae (Stewart-Bluefarb syndrome) at the distal right foot in a young man is reported. The lesion evolved slowly from a small dark-red spot existing from birth. Besides mechanical disturbances, the patient's only symptoms were a warmer and somewhat bigger right foot compared to the left nonaffected side. He presented a circumscribed spongy, livid-red coloured angiomatous lesion at the upper part of the distal right foot, also involving the proximal parts of the three middle toes. The diagnosis was based on the clinical aspect and the findings by Doppler ultrasonographic and oscillographic examination. The transcutaneous oxygen pressure showed a marked hypoxia at the edge of the acro-angiodermatitis. Finally, arteriovenous fistulae were demonstrated by arteriography.

Acrodermatitis↗