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Biomedical subjects

G Seifert

Publications and source records attributed to G Seifert.

At least 163 records · Page 9Linked to original sources
PubMed1980

Intraductal proliferation in the pancreas and its relationship to human and experimental carcinogenesis.

In 21 patients who had undergone total pancreatectomy for pancreatic head carcinoma, the uninvolved pancreas was examined with regard to the type, incidence and regional distribution of duct epithelial proliferation. The results were compared with those in 37 operative specimens from patients with chronic pancreatitis, in 46 normal pancreases from autopsies and with findings in experimental pancreatic carcinogenesis. While the incidence of squamous metaplasia and non-papillary epithelial hypertrophy varied little in the different groups, papillary epithelial hyperplasia was found three times more often in cases of carcinoma, with associated mild duct obstruction. Atypical epithelial proliferation was only detected in the vicinity of carcinomas. Unequivocal transition from papillary hyperplasia to atypical proliferation was not observed. In hamsters treated with dihydroxy-di-n-propylnitrosamine (DHPN) for induction of pancreatic duct carcinomas, the early duct lesions closely resembled atypical epithelial proliferation of human pancreas. It is concluded that (1) papillary epithelial hyperplasia is probably only indicative of early duct obstruction and/or a general neoplastic stimulus, (2) intraductal epithelial proliferation with atypia is a true precursor of duct carcinoma, and (3) chronic pancreatitis lacks atypical duct lesions.

Adult↗
PubMed1980

Lymphoid lesions of the oral cavity.

The lymphoid lesions of the oral cavity may be classified into three groups: 1. Benign lesions. 2. Malignant lesions. 3. Other lymphoid-like lesions. 1. Benign lymphoid lesions: In this group the following lesions must be differentiated: reactive lymph node hyperplasia, enlarged follicle of the lingual tonsil, lymphoepithelial cysts, lymphoepithelial lesions, lymphoid polyps, and cystadenolymphomas. The most frequent locations of benign lymphoid lesions are the lingual tonsil, buccal mucosa, tongue, and floor of mouth. 2. Malignant lesions: One subgroup includes the systemic lymphoid diseases, the other subgroup the lymphoid tumors. According to the WHO classification, the following entities belong to systemic lymphoid diseases: acute and chronic lymphoid leukemia, Waldenström's macroglobulinemia, plasma-cell leukemia, heavy-chain disease, Sézary's disease, and chronic lymphoproliferative diseases (unclassified). WHO has classified the lymphoid tumors as follows: lymphosarcoma, mycosis fungoides, plasmacytoma, reticulosarcoma, unclassified malignant lymphomas, Hodgkin's disease. The WHO classification is compared to the Kiel classification. The special cell types and the differences of the two international classifications are interpreted, especially terms such as centroblastic-centrocytic lymphomas, immunoblastic lymphomas, and the different terminology of reticulosarcomas. 3. Other lymphoid-like lesions: The following examples are discussed in relation to the oral cavity: eosinophilic granuloma, sarcoidosis, Melkersson-Rosenthal's syndrome, Wegener's granulomatosis, foreign body granuloma, and other lesions.

Cysts↗
PubMed1980

[Morphological aspects of the carcinoma of the hypopharynx (author's transl)].

On an average 35%, of the carcinomas of the pharynx are localized in the hypopharynx. 44 carcinomas of the hypopharynx were analyzed which were observed 1970-1979 in the Institute of Pathology of the University of Hamburg. The age peak lays in the 7th decade of age. 84% of the patients were male. 68% of the cases were localized in the sinus piriformis, 21% in the posterior wall and 11% in the post-cricoid area. The stage T4 of the TNM classification existed in 87% of the cases, a formation of hematic pulmonary metastases in 40%. The highest frequency of metastases if found in the carcinomas of the sinus piriformis. According to the WHO classification 91% of the carcinomas were squamous cell carcinomas and 9% anaplastic carcinomas. 9% of the squamous cell carcinomas were high differentiated, 52% moderate and 30% poor differentiated. A very distinct stromal reaction was observed in the high differentiated carcinomas. The plasma cells showed a high content of IgA and IgG as revealed by the application of the indirect immunoperoxidase method. The content of Ig-containing plasma cells is distinctly reduced in poor differentiated carcinomas or after radiation therapy. A positive marking of carcinoembryonic antigen could be demonstrated in high and moderate differentiated carcinomas, especially in the keratinized areas. Prestages of the carcinomas are leukoplakias with dysplasia and papillomas, early stages the carcinoma in situ. Risk factors are tobacco abuse, alcoholism and the Plummer-Vinson's syndrome.

Adult↗
PubMed1979

Histomorphometric analysis of bone changes in surgically proven primary hyperparathyroidism and nephrolithiasis--the importance of bone biopsy in diagnosis.

The morphologic changes in trabecular bone were studied in 60 patients with surgically proven hyperparathyroidism and in 69 patients with nephrolithiasis. The hyperparathyroid bone lesions showed substantial variation in their extent. Four, typical stages were defined. The structure of trabecular bone remained intact in most cases. Bone turnover is significantly higher in the patients with primary hyperparathyroidism. Fifty percent of all patients with nephrolithiasis had bone changes similar to those found in the surgically proven hyperparathyroidism group. In 50% of so-called asymptomatic cases of hyperparathyroidism, the iliac crest biopsy is a useful supplement to clinical and hormonal data in deciding whether to operate on the parathyroid glands. In about 45% of cases, however, no definite diagnoses is possible. The determination of serum parathyroid hormone in primary hyperparathyroidism has a greater importance for diagnostic purposes than morphologic investigation of the bone biopsy.

Adolescent↗
PubMed1979

Diagnostic value of pancreatic biopsy.

This review emphasizes that the value of pancreatic biopsy is unquestionable for the preoperative and peroperative diagnosis of pancreatic carcinoma. Improvement of biopsy methods will further increase the importance of the preoperative pancreatic biopsy. However, the considerable technical difficulties and the time expenditure associated with these methods do not allow the use of pancreatic biopsy or one of the other diagnostic procedures as a screening procedure for detecting pancreatic carcinoma before it has led to subjective symptoms such as biliary obstruction. We should concentrate on the development of an immunological test for identifying the asymptomatic patients. Some progress on this area has been initiated by an attempt to characterize a pancreas-specific oncofetal antigen (Hobbs, 1976). The early demonstration of such an antigen in serum and pancreatic fluid would substantially improve the otherwise unfavourable diagnosis of pancreatic carcinoma. Therefore, we hope that the pessimism regarding the diagnosis and prognosis of pancreatic cancer will be replaced by realistic optimism in the future.

Biopsy↗
PubMed1978

[On the occurrence of so-called clear cells in salivary gland tumors. Ultrastructure and differential diagnosis (author's transl)].

Clear cell tumors of the salivary glands are monomorphic clear cell adenomas, clear cell carcinomas, clear cell variants of acinic cell and mucoepidermoid tumours, sebaceous cell tumors, salivary duct carcinomas and pleomorphic adenomas with clear cell sectors. At the light microscopical level the descriptive term of the clear cell comprises cell types of different origin and functional importance which can be differentiated by cytochemistry and electron microscopy. The following cell types were analysed precisely: indifferent duct cells (small formation of organelles, desmosomes), storing striated duct cells (glycogen granules, multiple mitochondrias, basal labyrinth), myoepithelial cells (myofilaments, pinocytosis vesicles, lipofuscin granules, hemidesmosomes), goblet cells (mucous vacuoles, basal endoplasmatic reticulum), sebaceous cells (lipid droplets, microvilli, desmosomes) and clear acinic cells (electron pale secretory granules, small mitochondrias, small golgi apparatus). Clear cell tumor types of the salivary gland region which primarely do not derive from the salivary gland tissue must also be included in the differential diagnoses. These are metastases of hypernephroid renal carcinomas, paragangliomas, glomus tumors of Masson, granular cell tumor and alveolar soft-part sarcomas.

Adenoma↗
PubMed1978

Morphology of osteosarcoma: new qualitative and quantitative investigations.

Results on seven cases of osteosarcoma are reported, based on new morphologic methods and quantitative procedures. Tumor tissue was embedded without prior decalcification in plastic and sectioned. Imprint cytology preparations were produced from fresh tumor tissue, and cell nuclei were measured with an electronic image analysing computer system. The loss of differentiation seen in osteosarcomas differs among osteoblasts, osteocytes, and osteoclasts. The differentiation of osteoclasts, namely their resorptive characteristics, disappears relatively early. Tumor osteocytes show loss of differentiation in their osteocyte processes. The new formation of tumor bone tissue remains in the near normal range of volume density when nuclear polymorphy is limited. The formation of ground substance and mineralization are apparently closely couplet to one another, since in our cases mostly ordered osteoid seams were observed. The capacity for mineralization of bone tissue is lost with marked polymorphy. The significance of these results for diagnostic statements and therapeutic consequences will be further discussed in long term studies.

Adolescent↗