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Biomedical subjects

D Stiller

Publications and source records attributed to D Stiller.

At least 163 records · Page 9Linked to original sources
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↗
PubMed1974

[Morphology and histochemistry of medullary thyroid carcinomas (author's transl)].

The medullary thyroid carcinoma was characterized as clinicopathological entity by Hazard, Hawk and Crile as early as 1959. As reported in literature the incidence of these tumors ranges from 3.5 to 11.9% of the thyroid carcinomas. In the study presented the morphological, histochemical and electron microscopical investigations in 8 cases of medullary thyroid carcinoma are reported. Different methods are used to demonstrate polysaccharides, proteins, especially polypeptide hormones, and amyloid. Furthermore several silver impregnation techniques for differentiation of argentaffin and argyrophilic cells were performed. The age of the 8 patients ranged from 30 to 65 years, 5 patients were females, the sex ratio of females to males runs to 1.7:1. In 4 cases metastases in regional lymph nodes were found. The tumor tissue preponderately showed a solid-travecular pattern. The tumor cells were seen in cord-like and nest-like arrangement. In places also a typical endocrine structure was present revealing an orientation of cells around capillaries here and there. A differentiation of light and dark cells was possible. Electron microscopically these light microscopical observations could be confirmed: dark cells possessed more organeles than light cells. Infiltrations of blood vessels did not occur, but infiltrations of lymph vessels were the rule. The tumors contained variable amounts of amyloid which could be seen by fluorescence and polarization microscopical methods in fine fiber-like structures or in coarse deposits. At the ultrastructural level typical secretory granules varying in electron density and having a diameter of 220-560 nm were visible. Some light tumor cells exhibited 50-120 A thick fibrils which could not be distinguished from extracellular amyloid fibrils. The histochemical findings evidenced moderately abundant proteins in the cytoplasm of tumor cells. Histochemically the amyloid corresponds to the so-called apudamyloid. A great deal of the proteins is orderly arranged in amyloid whereas this is not the case in the tumor cell cytoplasm as proved by the coupled tetrazonium reaction which was evaluated polarization microscopically. In amyloid tryptophan was absent. The medullary thyroid carcinoma has a low-grade malignancy and, in accordance to other authors, it is to be stated that this tumor is histogenetically related to the parafollicular cells (C-cells). Its distinction from other thyroid tumors is warranted basing on morphological and pathophysiological features. Structural patterns common with those of other endocrine tumors are demonstrable. The findings point to a relationship of medullary thyroid carcinoma with the APUD series or Feyrter's Helle-Zellen-System. Considering the possible simultaneous occurrence of pheochromocytomas and adenomas of the parathyroid gland it must be assumed that the medullary thyroid carcinoma is one of the dysplasias of the neural ectoderm.

Adult↗