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Biomedical subjects

A Roessner

Publications and source records attributed to A Roessner.

At least 271 records · Page 15Linked to original sources
PubMed1976

Development of tumors in the glandular stomach of rats after oral administration of carcinogens. I. Histological findings.

Experimental carcinomas in the glandular stomach of rats were induced by oral administration of MNNG (M-methyl-N'-nitro-N-nitrosoguanidin) for 35 weeks or ENNG (N-ethyl-N'-nitro-N-nitrosoguanidin) for 20 weeks. Rats were killed at different times after beginning of carcinogen treatment and tissue specimens were prepared for histologic investigation. Particular interest was placed on the development of tumors and on pathological findings possibly contributing to early diagnosis of stomach cancer. During the development of tumors, several dysplastic reactions were observed in the antral mucosa. They could be classified into 4 groups: One was regenerative hyperplasia (1) that meant irregular glandular proliferations without cell atypism at the margin of erosions and ulcers. This lesion was mainly found 1-9 weeks after administration of MNNG. In glandular hyperplasia (2) either crypts or glands were extended and mucosal layers were thickened. No signs of cell atypism were observed. This lesion was mainly found 12-17 weeks after administration of MNNG. Dysplasia (3) was combined with considerable structural modifications and cellular atypism. However, this lesion was limited to the mucosal layer. Neoplastic changes (4) were characterized by marked cellular atypism and extension to tunica submucosa and tunica serosa. Some tumors showed the histological patterns of benign tumors, but most of them were adenocarcinomas. In some cases metastases into pancreas, liver and lymph nodes and in one case into the 12th rib were observed. No particular enzyme patterns were found by histochemistry.

Animals↗
PubMed1976

Development of tumors in the glandular stomach of rats after oral administration of carcinogens. II. Different cell types in antral carcinoma as revealed by electron microscopy.

In the present study electron microscopic investigations of tumors of the glandular stomach of rats induced by oral administration of MNNG or ENNG are dealt with. The aim of the study was to describe the different cell types found in the carcinoma and to elucidate the possible relationship between the undifferentiated carcinoma cells and the more differentiated cell types found in the tumor. The results show that besides undifferentiaded carcinoma cells, several differentiated cell types such as goblet cells, endocrine cells, cells with lamellated inclusions in their cytoplasm, and squamous carcinoma cells can be observed. The most conspicuous findings were carcinomatous gland cells with well differentiated microvilli on their luminal surface and typical tonofilamentous structures in their cytoplasm. These cells exhibited signs of the squamous epithelium and of gland cells. Therefore they may be considered as intermediate variants between adenocarcinoma cells and squamous carcinoma cells. The occurrence of such intermediate steps points to the possibility of differentiation by cell division of adenocarcinoma cells into several metaplastic cell types in the experimental stomach carcinoma induced by MNNG or ENNG.

Adenocarcinoma↗
PubMed1975

[Ultrastructural-morphometric analysis of liver biopsies in patients with intrahepatic cholestasis. I. Correlations between morphometry of bile canaliculi and so-called "marker enzymes of cholestasis" (author's transl)].

Reports on correlations between the activity of so-called "marker enzymes of cholestasis" in serum and the ultrastructural changes of the liver are rare. Therefore studies of ultrastructural changes were carried out in 40 patients with intrahepatic cholestasis. In the patients' serum activity of alkaline phosphatase, bile duct alkaline phosphatase, leucine-aminopeptidase (LAP), and 5'-nucleotidase (5'-Nu) as well as the concentration of bilirubin were determined. The results showed a significant correlation between the morphometry of the bile canaliculi and the serum activity of LAP and 5'-Nu. In patients with elevated LAP, an enlargement of the bile canaliculi could be proved. An increased serum activity of 5'-Nu correlated with a higher incidence of bile canaliculi in the ultrastructural picture. The results suggest an investigation of the ultrastructure of bile canaliculi and the determination of marker enzymes of cholestasis in the serum may both contribute to the assessment of cholestatic liver disease.

Alkaline Phosphatase↗
PubMed1975

[Fine structure of megakaryocytes in aleukemic megakaryocytic meyelosis].

Megakaryocytes from a case of aleukemic megakaryocytic myelosis were examined by electron microscope. They were considerably increased in number and their ultrastructure was different from normal megakaryocytes in certain aspects. Myelinfigures became demonstrable in the cytoplasm in increased number. An effective development of the demarcation membran system could not be observed.

Aged↗
PubMedDate not supplied

[Short rib-polydactyly syndromes].

The authors report on a newborn which died only a few hours after birth. It manifested generalized dropsy and ascites, a central upper lip cleft, narrow thorax, severe dysraphia, short limbs but normal-length trunk, and brachydactyly. Particularly striking radiologic findings were the extremely short, horizontal ribs and a shortening of the long bones, with rounded calcification zones. On the basis of comparison with other cases of short rib-polydactyly syndromes (SRPS) and other chondrodysplasias, this case was classified as Majewski's syndrome, even though there was no polydactyly and the shortness of the tibiae was not as extreme as in typical cases.

Adult↗
PubMedDate not supplied

[Fibrous dysplasia versus osteofibrous dysplasia. Morphological, differential diagnostic and clinical aspects. Experiences from the Westfalen bone tumor registry].

Histologically, this lesion, which was first described by Campanacci, is characterized by an osteofibrous stroma replacing normal bone, showing trabeculae which, unlike in FD, are surrounded by a regular rim of prominent cubic osteoblasts, mature lamellar bone and zonal segmentation with newly formed trabeculae mostly in the cortical region. Radiologic features are eccentric, usually diaphyseally localized osteolytic lesions of the tibia with ground glass appearance. Differential diagnosis includes FD and adamantinoma. Just like OFD, the latter occurs almost exclusively in the tibia, its potential malignancy calling for a more radical therapeutical procedure. Being such a rare lesion, there are no clear guidelines regarding formal pathogenesis and therapy of adamantinoma in combination with osteofibrous stromal reaction. The mean age of the eleven patients with OFD was nine years, which is considerably lower than that of patients with FD (30 years). The lesions were found exclusively in the tibia. Surgical therapy is often followed by a recurrence of the tumor (in two cases in the present material), so it should be avoided, where possible. Thus, surgery should only be performed if complications are imminent, such as marked bone deformation or pseudoarthrosis. Unlike in FD, once bone maturation is completed, surgical treatment of OFD is not normally followed by recurrent disease. Thus, the prognosis of OFD with restricted surgical therapy is more favourable than that of FD, which frequently shows extensive skeletal involvement and recurrent disease even after many years. The more aggressive course of OFD reported by other authors must therefore be explained by too early surgical intervention, i.e. during bone maturation.

Adolescent↗
PubMedDate not supplied

[Giant cell tumor of bone].

This retrospective study analyses 67 patients with 69 giant cell tumors of bone staged according to the Surgical Staging System of benign and malignant lesions of Enneking (1980, 1986). A significant correlation between Stage 2 and Stage 3 benign lesions in respect to local recurrence as well as between the therapeutic procedures and recurrence was found. Intralesional excision with temporary acrylic cement implantation showed to be the preferable initial treatment of these tumors. Special attention to surgical staging, surgical techniques and a supervised rehabilitation program minimize the incidence of recurrence and at the same time giving am maximum of joint function.

Adolescent↗
PubMedDate not supplied

[High-grade direct roentgen magnification--a new possibility in skeletal diagnosis?].

High-grade direct X-ray magnification represents a new technique. Its possibilities are demonstrated taking as example a comparison between histological and directly X-ray magnified images of bone tumour specimens. With its method, which has previously not been introduced, it is possible to obtain images of anatomical structures the display of which was previously the preserve of histological techniques. The still high local radiation exposure currently limits use in the main to basic research.

Bone Diseases↗