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Biomedical subjects

W Gebhart

Publications and source records attributed to W Gebhart.

At least 91 records · Page 5Linked to original sources
PubMed1978

[Cytoid bodies in the human skin].

Cytoid bodies represent roundish or polygonal, approximately cell-sized structures in histological sections. Such bodies have been reported to be of pathologic significance in several cutaneous disorders. Histological, immunological and electron microscopic investigations were performed in order to (1) characterize the different types of cytoid bodies in human skin, (2) elucidate their origin and nature and (3) determine their significance in cutaneous histopathology. A distinct identification of elastic globes, Russell bodies, Civatte bodies, amyloid bodies and cytoid fibrin bodies could be made. In addition, other substances such as nuclear or cytoplasmic debris, cytolytic fragments or basement membrane proliferations were found in form of cytoid aggregates in several dermatoses. However, none of the different groups of cytoid bodies was evaluated to be of pathognomonic significance for a specific disease. All of them are rather symptomatic for a number of anatomical or pathological principles and events in the dermo-epidermal junction area. Thus, the presence of cytoid bodies is not a major diagnostic aid in histopathology but may give valuable hints for a better interpretation of the morphogenesis of etiologically unrelated skin disorders.

Amyloid↗
PubMed1978

Demonstration of specific storage material within cutaneous nerves in metachromatic leukodystrophy.

Biopsies of clinically unaltered skin from a 5-year-old girl with metachromatic leukodystrophy were studied by light, fluorescence and analytical electron microscopy. Investigation of hematoxylin-eosin-stained sections revealed no pathologic changes, but a brown metachromatic material was found within cutaneous nerves after acetic acid cresyl violet staining of frozen sections. In semithin Epon sections small dermal nerve fascicles contained endoneural deposits, which proved to correspond with the typical prismatic, dense or Tuffstein bodies described in other organs of patients suffering from MLD. The inclusions were located mainly within Schwann cells and exhibited a bright orange fluorescence after trypaflavine-phosphotungstic acid-treatment as well as a high electron density in serial ultrathin sections. Energy dispersive X-ray microanalysis revealed a high sulfur content in the membrane bound granules. These findings demonstrate the presence of the specific storage material also within cutaneous nerves in MLD and thus suggest skin biopsies as an addiitonal and simple diagnostic acid in this disease.

Child, Preschool↗
PubMed1977

Different types of benign nerve sheath tumors. Light microscopy, electron microscopy and autoradiography.

In a light-, electronmicroscopic and autoradiographic study different types of nerve sheath tumors were classified. Their cellular population was quantitatively evaluated in the electron microscope. In the neurinoma the predominant cell was found to be the Schwann cell, but in the different types of neurofibromata a variable content of connective tissue cells was noted. T-HE DIFFUSE NEUROFIBROMATA SHOWED A QUANTITATIVE CELLULAR COMPOSITION SIMILAR TO NORMAL PERIPHERAL NERVES. In the plexiform neurofibroma a large number of fibroblasts were present and in the argyrophilic neurofibroma high content of perineurial cells was found. In autoradiographic sections the tumors showed in general a low proliferation rate (L.i. 1-3.6%). In the argyrophilic neurofibrom a higher labelling index (9.5%) was found.

Adolescent↗
PubMed1977

[Stress ulcer-an experimental study (author's transl)].

This experimental study demonstrates by means of electromagnetic flow measurements that hypovolaemic shock results in a significant decrease in gastric flow. 14 mongrel dogs were subjected to haemorrhagic shock for 3 or 4 hours. Significant histological changes are seen in the gastric mucosa as a result of the haemodynamic changes, especially when the duration of shock was 4 hours. All stages of stress ulcer from the superficial erosion to deep ulcers were documented. The possibility that the mast cell plays a pathogenetic role as mediator in the origination of a stress ulcer is considered.

Animals↗
PubMed1977

[Comparative investigations of depigmented and melanomatous lesions in gray horses of the lipizzaner breed (author's transl)].

The morphological substrates of pigmented and depigmented skin as well as the structural characteristics of spontaneously developing melanomas were revealed by clinical, light- and electron microscopic methods in gray horses (Lipizzaner breed) from the Vienna Spanish Riding School. On clinical investigations in a group of 31 older horses (more than 10 years old) 20 exhibited melanomas, whereas 23 younger animals (less than 10 years of age) had no evidence for visuable melanotic tumors. Concomitantly with the progressive graying of the hair a depigmentation of the skin was frequently observed. Light and electron microscopic studies of skin biopsies revealed that in pigmented areas melanin is produced by DOPA-positive melanocytes and stored in form of large single melanosomes within keratinocytes. In depigmented areas melanocytes and melanosomes are completely lacking, but a high number of indeterminated cells is present in the basal layer. Melanotic tumors from the root of the tail, the lips, the perianal region, the sholder and intestinal lymph nodes exhibited either encapsulated nodules or diffusely infiltrating melanomatous structures similar to blue nevi in the dermis. Junctional activity could never be observed. A differentiation between melanin-producing tumor cells and melanophages was difficult in light microscopy but possible according to ultrastructural characteristics.

Aging↗
PubMed1977

Nervous lesions in a case of local gigantism.

A case of local gigantism of the thumb was studied by light and electron microscopy. In the lesion, proliferation of fibroadipose tissue and typical alterations of the nerves were found. The alterations in the nerve were isolated hypertrophy of the perineural cells. The relation of the changes to other peripheral nerve tumours especially in neurofibromatosis, is discussed.

Adult↗
PubMed1977

The epidermal cell proliferation in lichen planus.

The proliferative activity of epidermal structures was determined in 6 patients suffering from lichen planus (i.p.). By using the in vitro 3H-thymidine labelling technique, semithin Epon sections of lesional and perilesional uninvolved skin were compared autoradiographically with normal controls. The following results were obtained. The labelling index of epidermal cells was significantly increased within the i.p. papules. The mean values ranged from 41% in acanthotic i.p. to 23% in atrophic i.p. whereas in adjacent unaffected skin (15% and 11% respectively) as well as in normal controls (6%) a lower 3H-index was observed. As regards damage to basal cells within i.p. lesions, a factor--the relation between the number of basal cells in involved and uninvolved skin in reference to the epidermal length--was calculated in order to correct the autoradiographic results in involved skin. The differences between i.p. papules, adjacent skin and controls remained statistically significant even after correction. The intradermal eccrine ducts revealed a significantly increased labelling index in i.p. lesions as compared with perilesional and normal skin. In this respect no difference could be observed between the acanthotic and the atrophic variant of i.p. These findings indicate that replacement of damaged basal cells in i.p. is achieved by an increase in actively dividing keratinocytes in both epidermis and skin appendages within the lesion.

Cell Count↗
PubMed1976

[Septic complications of gonorrhea].

Septic gonococcal complications consist in intermittent fever, arthralgia and skin lesions. In recent years predominantly females suffering from this disease were observed. This diagnosis is made by the demonstration of gonococcal infection combined with the above mentioned clinical symptoms. A further confirmation is possible by blood culture and the demonstration of gonococci in skin lesions or joint fluid.

Arthritis, Infectious↗
PubMed1976

[Cytoid bodies in basal cell epithelioma].

100 basal cell epitheliomas were surveyed for the presence of cytoid bodies by histological and histochemical techniques. By this means a differentiation of the following structures was possible: 1. Elastic globes were present in 32 specimens. Their localisation corresponded in part to the typical subepidermal situation, but invasive tumor growth resulted in their translocation into the deeper corium. 2. Civatte bodies were found in the dermoepidermal junction area in 16 cases. Similar structures were present within the tumor cell islands of 37 patients. 3. Russel bodies could be observed within the inflammatory peritumoral infiltrate containing numerous plasma cells in 30 specimens. 4. Clumpy or ovoid deposits of amyloid were present within the stroma of 41 epitheliomas, whereas no amyloid was found in the tumor cell islands.

Amyloid↗
PubMed1976

Some electron microscopic and autoradiographic results concerning cutaneous neurofibromas in von Recklinghausen's disease.

The cutaneous tumors of 5 patients with clinical symptoms of Recklinghausens neurofibromatosis were investigated by light and electron microscopy. Special reference was given to the study of initial changes of the disease and the structure of the nerve fascicles which end in the tumor. In 2 patients the proliferating cells were determined by using an autoradiographic technique. It was discovered that all cellular elements of a peripheral nerve are involved by the tumor formation. The results were discussed and compared with the alterations during nerve regeneration after traumatic injury.

Cell Division↗
PubMed1976

Epidermal changes in lichen planus.

Ultrastructural investigations in 15 patients with lichen planus (LP) revealed a multitude of epidermal changes. The most consistent findings were (1) multiplication, irregular folding or dislocation of the basal lamina, (2) fragmentation with degenerative changes of basal keratinocytes, (3) formation of numerous fibrillar Civatte bodies and, (4) presence of dyskeratotic elements. In addition, mitotic figures of keratinocytes and Langerhans cells were observed. These findings support the view that the primary event in LP represents an injury involving epidermal basal cells. Furthermore, the replacement of destroyed tissue seems to originate not only from the margin of the lesions or the skin appendages but also from unaffected cells within the LP papule.

Cell Division↗