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Biomedical subjects

D Katenkamp

Publications and source records attributed to D Katenkamp.

At least 199 records · Page 11Linked to original sources
PubMed1977

[Studies of the mucopolysaccharid metabolism in the juvenile angiofibroma (author's transl)].

The mucopolysaccharide content of juvenile angiofibromas is investigated using histochemical and ultrahistochemical methods (histochemical in ten cases, ultrahistochemical in four cases). The investigations result in typical histochemical features and show the localization of acid mucopolysaccharides at electronmicroscopical level. The endothelium of the vessels exhibits a strong PAS-reaction and also shows acid groups at the cell surfaces. The interstitial tissue demonstrates neutral perjodatreactive substances as well as acid mucopolysaccharides. The latter substances mainly reacted in perifibrillar position. Electronmicroscopically the perjodreactive material was localized in the cytoplasma of typical fibroblasts and their modulations resembling histiocytes. The acid groups of carboxylated and sulfated mucopolysaccharides of the intercellular substance could be determined as hyaluronic acides and chondroitinsulfates (Chondroitin-4 and Chondroitin-6 sulfate) using the critical-electrolyte-concentration method after Scott and Dorling. Ultrastructurally these acid groups are localized as cell coat covering the fibroblasts and between the collagen fibrils. This histochemical investigation also supports the thesis of an organoid growth pattern of juvenile angiofibroma.

Adolescent↗
PubMed1977

[Hormone therapy of the juvenile angiofibroma (author's transl)].

Four juvenile angiofibromas were examined with the electron microscope. Preceding the operation a hormonal therapy with stilbestrol disphosphate (Cytonal, Honvan) was carried out in the cases. The therapeutical effect after application of this drug is clearly correlated to especial changes in histology and cytology. The changes comprise reactions of the vascular component and of the stromal fibroblasts. Endothelial cells and pericytes show a markedly diminished cellular activity, a proliferation of vascular wall cells is not to be proved. The stromal fibroblasts may predominantly be classified as fibroblasts with histiocyte-like features, at which the organelle equipment speaks for a high activity of their metabolism. Furthermore an increased number of myofibroblasts and smooth muscle-like elements are encountered in the stroma. The striking diminution of lesion size and the reduction of disposition to bleeding from the beginning of the hormone therapy is suggested as a direct consequence of cellular contraction. Additionally alterations of synthesis of collagen fibers and ground substance by fibroblasts with histiocyte-like features contribute to a further gradual decrease of the growths.

Adolescent↗
PubMed1977

[Electron microscopic examination on cytogenesis of juvenile nasopharyngeal angiofibromas (author's transl)].

After the electron miscroscopic examination of tissue samples of juvenile nasopharyngeal angiofibromas obtained from 9 male patients ranging in their age from 7-24 years the problems of cytogenesis and classification are discussed. Besides it is tried to correlate particular morphological findings to certain clinical phenomenons. The vascular component of juvenile nasopharyngeal angiofibromas shows a clear proliferation of the vascular wall cells. Particularly, proliferating pericytes, cells withous peculiar characteristics ("undifferentiated" cells) and cells in various stages of differentiation are to be emphasized. Obviously, vascular wall cells emigrate into the surrounding tissue and transform themselves into small fibroblasts. The second component of juvenil nasopharyngeal angiofibromas is represented by stromal fibroblasts with several cytological variations. Only activated "classical" fibroblasts and fibroblasts with histocyte-like features reveal the nuclear pattern unique for these growths which is characterized by the combination of protrusions of nuclear membrane with formation of nuclear "blebs" and of dense intranuclear granules. Cells with these nuclear characteristics were considered as preexisting fibroblasts. Thus juvenile nasopharyngeal angiofibromas are formed by the proliferation of two tissue components, namely by the proliferation of vascular wall cells and stromal fibroblasts, and can be conceived as reactive hyperplasias. The swelling body-like and organoid appearance, cytological pecularities, characteristic topographic relations (localization and supplying vessesl) and the sex-dependent occurrence speak for a tumor-like hyperplasia of a rudimentary organ unknown till now.

Adolescent↗
PubMed1976

Cellular differentiations and structural characteristics in nasopharyngeal angiofibromas. An electron-microscopic study.

An electron-microscopic study of 9 nasopharyngeal angiofibromas was performed in order to elucidate the ultrastructural characteristics. Stromal fibroblasts and proliferating cells of the microvasculature were found. The stromal fibroblasts were subdivided into 3 different groups: (1) "classical" fibroblasts, (2) fibroblasts with histiocytelike features, and (3) fibroblasts with myoid features. By proliferation the cells of the capillary vessels change into stromal cells. A particular pattern of nuclei and dense intranuclear granules is only found in stromal fibroblasts. Consequently fibroblasts as well as cells of the microvasculature contribute to the pool of tumor cells.

Adolescent↗
PubMed1976

Ultrastructural cytology of regenerating tendon--an experimental study.

Cellular differentiations in regenerating tendon tissue of rats and guinea pigs were examined by the aid of the electron microscope. Fibroblasts with certain variations were found as basic cell types. Corresponding to the organelle composition classical fibroblasts, fibroblasts with histiocyte-like features and fibroblasts with myoide differentiations (comparable to the so-called myofibroblasts) were identified. Furthermore, proliferating capillaries with remarkable pericytic activities among other things producing fibroblast-like features must be mentioned. This fact led to the conclusion, that a part of fibroblasts in the proliferating connective tissue during tendon repair may derive from pericytes. Our ultrastructural investigations showed proof of the great plasticity of fibroblasts which function as stem cells in connective tissue regeneration.

Achilles Tendon↗
PubMed1976

Ultrastructural features of proliferating fibroblasts in inflammatory granulomas.

Proliferating fibroblasts in subcutaneous connective tissue of rats after injection of peanut oil or implantation of an almost insoluble synthetic material (silicap) were characterized electron microscopically. In tissue samples of both the foreign body granulomas typical fibroblasts with abundant rough endoplasmic reticulum and a peculiar cellular modulation resembling histiocytes concerning their organelle composition were found. The morphological picture of the latter cells does not allow the conclusion that their function must be a merely phagocytic one. True myofibroblasts as detected in other stages of connective tissue proliferation are not present. The capillary vessels show a clear proliferation of their vascular cells and migration of these cells with assumption of fibroblastic features is suggested basing on morphological observations.

Animals↗
PubMed1976

[Dupuytren's palmar fibromatosis--a result of vascular hyperproliferation? Ultrastructural studies (author's transl)].

Dupuytren's contracture is represented by a proliferation of fibroblasts. In the study presented here 5 cases of Dupuytren's contracture were examined with the aim to conclude from cytological details of the cells to the possibilities of morphogenesis. The cytological pictures varied relative to the organelle composition. Three types of fibroblasts could be found constituting the great majority of cells in Dupuytren's disease: 1. classical fibroblasts, 2. fibroblasts with myoide differentiations and 3. fibroblasts with histiocyte-like features. The second principal finding were the capillaries with increased amount of pericytes and pericyte-like cells somewhat distant from the vessels. The latter observation led to the assumption that pericytes in this lesion are able to migrate from the vascular wall into the surrounding tissue.

Capillaries↗
PubMed1975

Cellular features in desmoid fibromatosis and well-differentiated fibrosarcomas: an electron microscopic study.

In the study presented here the ultrastructural cellular features of three desmoids and four well-differentiated fibrosarcomas were compared. Electron microscopically, the tumors were almost identical relative to qualitative traits. The majority of cells corresponded to fibroblast-like cells with certain morphological variations. Especially cells with characteristics of myofibroblasts must be emphasized, whereas cells with an organelle composition of classical fibroblasts were surprisingly seldom. Considering the relations of cells to each other and to vessels the prevailing origin of tumor cells from preexisting fibroblasts is suggested.

Adult↗
PubMed1975

The subcutaneous fascial analogue of myositis proliferans: electron microscopic examination of two cases and comparison with myositis ossificans localisata.

Two cases of the so-called fascial analogue of myositis proliferans were investigated by histological and electron microscopic methods. It was found that the structure of the fascial variant corresponds almost completely to the true myositis proliferans localized within the musculature. The electron microscopic observations show a preponderantly histiocytic differentiation of the cells and strongly activated proliferating capillaries, and exclude a myogenic origin of the characteristic ganglion-like giant cells. Ultrastructurally a traumatic genesis appears possibly, the cells of the lesion could derive from multipotent cells of the microvasculature. The relations to myositis ossificans and fascitis nodularis are discussed.

Adult↗
PubMed1975

Cellular composition of the so-called dermatofibroma (histiocytoma cutis).

9 typical cases of dermatofibroma or histiocytoma cutis resp. were studied by the aid of histochemical, enzyme histochemical and electron microscopical methods to examine the cellular composition of these lesions. The results suggest an anabolic and katabolic function of cells. Electron microscopically a broad spectrum of patterns of mesenchymal cells was found. Besides defined fibroblast-like and histiocyte-like elements a cell type was detected which was characterized by particular traits, as irregular nuclear outline, abundant rough endoplasmic reticulum, free ribosomes, bundles of filaments with single dense zones, micropinocytotic vesicles and a basement membrane-like material on the outer cell surface. This cell type constitutes the majority of cells in dermatofibroma or histiocytoma cutis resp. In some cells an arrangement of filament bundles resembling that in smooth muscle could be seen. By reason of these findings a certain resemblance to the so-called myofibroblasts can be stated. The variegation of the morphological picture suggests a multipotent precursor cell; the possibility of an origin from pericytes is discussed.

Basement Membrane↗
PubMed1975

Morphogenesis of intracytoplasmic dense (inclusion) bodies in a recurring digital fibrous tumor of childhood. Light- and electron-microscopic investigations.

This study presents the results of light-microscopic, histochemical, and electron-microscopic investigations of dense (inclusion) bodies in a recurring digital fibrous tumor of childhood. At ultrastructural level it was possible to observe several stages of development correlated with changes of ergastoplasmic reticulum. The viral nature of these bodies was refuted and the conclusion was drawn that their formation is associated with a disturbed intracellular metabolism. The defective intracellular transport of collagen precursors followed by abnormal deposition of collagenous proteins, which are also to some extent abnormally aggregated, could be of special importance.

Collagen↗
PubMed1975

Jugular body tumors: hyperplasias or true neoplasms? Light and electron microscopical investigations.

Problems of classification of certain growth processes were discussed using jugular body tumors to find out cytological criteria for characterizing growth traits. For this purpose light microscopical (9 cases), electron microscopical (6 cases) and enzyme histochemical investigations (3 cases) were performed. For comparison 4 carotid body tumors were examined. We are inclined to assume a neoplastic nature. An explanation as hyperplastic proliferation is refuted because a remarkable cellular variation in size and form, only sparse nerve fibers and lacking synaptic contacts, because submicroscopical features and because the clinical picture and course of the disease. It is pointed to the origin of the tumor cells from rudimentary endocrine-like cells occurring in the glomus jugulare-tympanicum in analogy to other neoplasias. The clinical symptoms, the course and the pathologic anatomical pattern suggest an interpretation of jugular body tumors as potential malignant growths.

Adult↗
PubMed1975

Structural patterns and histological behaviour of experimental sarcomas. I. General considerations, histology and histochemistry.

Methylcholanthrene-induced rat sarcomas were used as a model for the examination of morphological and cytological differentiations in tumours of the connective tissue. Particular attention was paid to the question how far these sarcomas are comparable to human connective tissue tumours. The histological examination yields a broad spectrum of mesenchymal differentiations ranging from undifferentiated anaplastic sarcomas over less differentiated fibrosarcomas and malignant fibrous histocytomas to well-differentiated fibrosarcomas, myosarcomas and haemangiopericytomas. It is worth mentioning that different histological structures can be encountered with one and the same tumour.

Animals↗
PubMed1975

Structural patterns and histological behaviour of experimental sarcomas. II. Ultrastructural cytology.

In continuation of our investigations on methylcholanthrene-induced rat sarcomas, in analogy to light microscopical results, various cytological differentiations could be demonstrated by the electron microscope. Some tumour cells are comparable to the cellular counterpart in normal connective tissue, whereas most of the tumour cells show various series of cytological traits of different types of normal connective tissue cells simultaneously. The vast majority of tumour cells exhibited characteristics of fibroblasts and histiocytes coincidently. However, classical fibroblasts and histiocytes were seldom present. One part of the tumour cells showed structural features as known from so-called myofibroblasts and smooth muscles cells. Furthermore, vasoformative potencies of sarcomas with imitation of endothelial and pericytic cells must be emphasized. With respect to the histogenesis of these sarcomas possible origin from the microvasculature is discussed.

Animals↗