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Biomedical subjects

A Roessner

Publications and source records attributed to A Roessner.

At least 253 records · Page 14Linked to original sources
PubMed1982

Intermediate-sized filaments in cells of normal human colon mucosa, adenomas and carcinomas.

The distribution of intermediate - sized filaments in human colon mucosa as well as in adenomas and carcinomas of the colon was studied by means of both immunohistology and electron microscopy. The epithelial cells of the colonic mucosa are definitely labelled with antibodies against prekeratin (cytokeratin). Interwoven filaments of the prekeratin type are present in the basal compartments of the epithelial cells; they surround the nuclei and mucus droplets and form an apical skeletal disc. Pericryptal connective tissue is prekeratin negative and vimentin positive. Benign hyperplastic polyps have a high content of prekeratin. The potential precursors of colonic carcinoma, i.e., the tubular and villous adenomas, also show an increase in intermediate-sized filaments of the prekeratin type. Correspondingly, electron microscopy reveals elongated bundles of intermediate-sized filaments arising from the desmosomes of the lateral and basal cell membranes. The prekeratin content is particularly high in adenocarcinomas and highest in mucinous carcinomas. As expected, the stroma of all neoplasms studied is prekeratin-negative, but distinctly vimentin-positive. In one moderately differentiated adenocarcinoma there was evidence of "vimentin-positive" tumor cells. These changes may be caused by binding of cytokeratins with an unknown substance in vimentin antisera, as observed similarly by Moll et al. (1982) in a transitional cloacogenic carcinoma.

Adenocarcinoma↗
PubMed1981

Benign fibrous histiocytoma of bone. Light- and electron-microscopic observations.

Case report of a patient with an unusual, rapidly growing bone tumor in the third and fourth cervical vertebrae. Histological and electron-microscopic investigations reveal a tumor composed of histiocytic cells, xanthomatous cells, giant cells of Touton type, and fibroblastic cells. No cellular features of malignancy are observed. From its cytologic appearance the tumor has to be classified as a benign fibrous histiocytoma. Regarding its ultrastructural features, the tumor may not be distinguished from non-ossifying fibroma of bone, but its clinical pattern shows obvious differences of localization and growth potential. the term "benign fibrous histiocytoma of bone" is proposed for these tumors which must be differentiated from non-ossifying fibroma.

Adult↗
PubMed1981

Tumor cell types in osteosarcoma as revealed by electron microscopy. Implications for histogenesis and subclassification.

Ultrastructural studies in 26 osteosarcomas of high grade malignancy which were in diverse locations and of varied histological types revealed seven different tumor cell types. They were characterized by their features as follows: 1) anaplastic cells of malignant blast structure: 2) osteoblastic cells -- some of them with dot-like intranuclear bodies; 3) osteocyte-like cells surrounded by mineralized matrix; 4) fibroblast-like cells; 5) cells of myofibroblastic differentiation; 6) chondroblast-like cells in chondroblastic areas, and even 7) angioblastic cells that may be differentiated from the angioblastic and endothelial structures of capillaries. Histogenetically, osteosarcoma may be derived from stromal mesenchymal cells with a potential for differentiation into these seven tumor cell types, any tumor including, however, the osteoblastic and the osteocyte-like cells with tumor osteoid. This matrix serves as the specific criterion for identifying a tumor as "osteosarcoma", but almost every osteosarcoma of high grade malignancy will show these seven tumor cell types. The predominance of one or the other cell in the population may provide the basic information for achieving a cytologic subclassification of osteosarcoma in order to obtain relevant morphologic criteria in terms of prognosis.

Adolescent↗
PubMed1981

[Radiological behaviour patterns of bone tumours (author's transl)].

The radiograph is usually the first step in diagnosis of tumorous bone lesions. Although definitive diagnosis depends on biopsy in many instances the radiograph allows the most essential decision on malignancy or benignity. This radiological grading of neoplastic bone disease is based on various criteria in particular the pattern of bone destruction and behaviour of the cortex. 3 main types of bone destruction predicting tumour behaviour can be differentiated: 1. the geographic well-defined destruction which is characteristic of static or slowly growing lesions; 2. moth-eaten pattern with scattered and confluent holes reflecting a highly aggressive lesion; 3. most aggressive permeative pattern characterized by multiple tiny holes. The cortex also reflects the response of normal bone against destruction. Depending on the activity of the process, the cortex will either remain intact, or will be expanded, or is even penetrated. The characteristic features of the different destruction patterns are illustrated by radiographs and corresponding pathologico-anatomical slices.

Bone Cysts↗
PubMed1979

Ultrastructure of telangiectatic osteosarcoma.

Recent investigations have shown that telangiectatic osteosarcoma has a poorer prognosis than other osteosarcomas. To elucidate the histogenesis of TOS two cases were investigated on the electron microscopic level. The results show that besides anaplastic, osteoblast-like, and fibroblast-like tumor cells angiosarcomatous components can be observed in this malignant bone tumor, which are characterized by endothelial cells with pinocytotic vesicles, tight intercellular junctions, fine fibrils, and so-called Weibel-Palade bodies in their cytoplasm. From these results, it is concluded that telangiectatic osteosarcoma is derived from multipotent mesenchymal cells with potential differentiation into various directions, such as osteoblast-like cells, and fibroblast-like cells.

Adolescent↗
PubMed1979

Malignant fibrous histiocytoma of bone and osteosarcoma. A comparative light and electron microscopic study.

Malignant fibrous histiocytomas are well-described tumors of the soft tissues. Recent investigations have shown that malignant histiocytoma may also occur as a primary bone tumor. However, difficulties may arise to distinguish malignant histiocytoma of bone from other malignant bone tumors, such as osteosarcoma. In the present study, the ultrastructure of five cases of malignant fibrous histiocytoma of bone is compared with that of osteosarcoma. The results show that malignant fibrous histiocytoma is composed mainly of histiocytic cells and fibroblastic cells. In addition, xanthomatous cells, undifferentiated cells, and giant cells may be observed. By contrast, the predominant cell type in osteosarcoma is the neoplastic osteoblast, characterized by abundant rough endoplasmic reticulum. Signs of matrix calcification in the intercellular matrix between the collagen fibrils are regularly observed in osteosarcoma, but not in malignant histiocytoma. From these results it is concluded that the ultrastructure of malignant fibrous histiocytoma arising in bone is morphologically identical with the soft tissue counterpart of this tumor. The components of the tumor are derived from neoplastic histiocytes. This cytogenesis differs from that of osteosarcoma, which is derived from neoplastic osteoblasts. Therefore, from the ultrastructural point of view, malignant fibrous histiocytoma of bone should be accepted as a distinct histologic entity among bone tumors.

Adolescent↗
PubMed1979

[Correlation of morphometric parameters with enzyme-activities in cases of liver diseases with fibrosis (author's transl)].

50 liver specimens with fibrotic liver disease were taken from current autopsy material and, after preparation, subjected to automatized image analysis by QUANTIMET 720 for quantitation of the connective tissues and their cellularity. In cell-free supernatants of liver tissue homogenates we determined the activities of N-acetyl-beta-glucosaminidase (beta-NAG, E.C. 3.2.1.30), a lysosomal glycosidase that is involved in proteoglycane metabolism of connective tissue. Beta-NAG-isoenzymes were demonstrated by electrofocusing in thin layers of polyamide gel. The results showed statistically significant correlations between beta-NAG activity and morphometrically assessed quantities of connective tissue, and of mesenchymal cells found in the latter or in the whole specimen, respectively. Demonstration of tissue or serum levels of beta-NAG or its isoenzymes provides a readily practicable method for assessing mesenchymal activities of the liver.

Acetylglucosaminidase↗
PubMed1978

Structural alterations of the lung in anthracosilicosis--automatic quantitation with an image-analysing computer.

A morphometric method of assessing anthracosilicotic alterations in lung structure was studied in 4 patients. The introduced model and a special technique for preparation permit the evaluation of anthracosilicotic dust deposits, secondary emphysema, and intact residual parenchyma by means of an image-analysing computer. This method appears particularly suitable for investigating and correlating morphology to clinical data, because the parameter 'intact residual parenchyma' can be reproduced in a short time with sufficient accuracy by random samples.

Aged↗
PubMed1978

Ultrastructural morphometric investigations on normal human liver biopsies.

Normal liver biopsies of 14 volunteers were investigated ultrastructural morphometrically. Besides the determination of morphometric baseline data for comparative purposes particular emphasis was placed on the question, if morphometric evaluations of human livers yield reliable results in spite of the higher range of distribution than in experimental liver material. The results showed that the surface of the smooth endoplasmic reticulum of human liver is significantly greater than the surface of rough endoplasmic reticulum. Otherwise the morphometric data of the human liver tissue did not differ essentially to the values of the laboratory rat. The variance analytical consideration of the mean evaluated from the data of the 14 liver biopsies indicated that the standard error of nearly all proved parameters was less than 10% of the mean. The results suggest that ultrastructural morphometric evaluation of human liver biopsy samples yield reliable results provided the samples investigated are sufficiently extensive.

Animals↗
PubMed1976

[Combined ultrastructural morphometric and biochemical investigations on the rat liver after ligation of the bile duct (author's transl)].

In the present study an ultrastructural morphometric analysis of the rat liver 1, 3 and 7 days after bile duct ligation was performed. Corresponding biochemical investigations included the determination of the cytochrom P 450 contents in the microsomal fraction. In the serum of the rats the activities of GOT and GPT were determined. The quantitative results have shown that the decreased P 450 contents of the microsomal fraction coincided with a considerable increasement of the surface of the smooth endoplasmic reticulum. The smooth endoplasmic reticulum was significantly increased from 1.83 m2/cm3 hepatocytes to 3.49 m2/cm3 hepatocytes after 3 days and remained on this level after 7 days. These results may be considered as quantitative evidence for the term hyperplastic, hypoactive endoplasmic reticulum. - As a second important result our quantitative investigations have shown that the increasement of GLDH activity in the serum especially 1 day after ligation of the bile duct coincided with a signficantly increased mitochondrial volume at this time.

Alanine Transaminase↗
PubMed1976

[Mitochondrial morphology and metabolism in extrahepatic obstruction (author's transl)].

Corresponding to the increased activity of mitochondrial Glutamate-Dehydrogenase (GLDH) in serum in extrahepatic cholestasis a swelling of hepatic mitochondria could be shown on ultrastructural morphometric analysis. The morphometric alterations parallel the serochemical findings. A significant correlation could be calculated between the swelling of mitochondria and the activity of GLDH in serum.

Animals↗
PubMed1976

Effects of clofibrate (alpha-p-chlorophenoxyisobutyryl-ethyl-ester) on male rat liver.

In male rats, fed 0.5% clofibrate in their diet for 8 days and 21 days, the ultrastructural morphometric alterations of the hepatocytes were evaluated and compared with the biochemical data. The morphologic alterations of the microbodies were particularly related to the changes of the catalase activity of the liver homogenates. The results showd a marked hypertrophy of the liver and an increase in the volume of the individual hepatocyte. The numerical density and, even more pronounced, the volume density of the microbodies increased excessively during the treatment. The numerical density of the mitochondria decreased markedly after 21 days of administration. The surface of the rough endoplasmic reticulum showed a significant decrease, whereas the surface of the smooth endoplasmic reticulum showed a hypertrophy. The catalase activity of the liver homogenates increased 2-fold after 8 days and remained at this new steady-state after 21 days of treatment. The results suggest that the enzyme content of the microbodies changed after treatment with clofibrate, and support the suggestion that clofibrate may induce the synthesis of a yet unidentified peroxisomal protein.

Animals↗