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F Hofstädter

Publications and source records attributed to F Hofstädter.

At least 91 records · Page 5Linked to original sources
PubMed1989

[Liver calcifications in metastasizing vipoma].

A 53-year-old woman had suffered from watery diarrhoea and substitution-requiring hypokalaemia for 18 months. Ultrasonography and abdominal x-ray revealed multiple calcifications in the liver. Retrograde cholangiopancreaticography, performed because an endocrine-secreting pancreatic tumour was suspected, demonstrated occlusion of the major pancreatic duct and calcification in the body of the pancreas. Gastrointestinal hormone levels were elevated (vasoactive intestinal polypeptide 950 pg/ml, pancreatic polypeptide 1000 pmol/l and neurotensin 86 pmol/l) in the blood, and immunohistochemical results on cells of an adenocarcinoma obtained by needle biopsy confirmed a metastasizing VIPoma. Administration of the somatostatin analogue SMS 201-995 achieved marked improvement.

Adenoma, Islet Cell↗
PubMed1989

Morphological changes of urothelial and intestinal mucosa after ureterosigmoidostomy during experimental urogenic carcinogenesis.

To analyze the effect of chemical carcinogens on urothelial and intestinal mucosa on 214 female Wistar rats an ureterosigmoidostomy was performed. After 10-14 days 123 surviving rats were randomly divided into 4 groups: Group I-III received 0.05 per cent N-Butyl-N-(4-hydroxybutyl)-nitrosamine (BBN) in drinking water over a period of 15 weeks. Group IV received normal drinking water over the same period. The defunctionalized bladders were instilled each second day: Group I: physiologic saline solution, Group II: urine of normal rats, Group III and IV: urine of BBN-treated rats. 30 rats without diversion but BBN treatment served as a control. The evaluation of the histological data gave the following results: In the control group urothelial tumors were found in the bladder exclusively. Dependent on the grade of obstruction in the BBN-treated groups, with diversion urothelial tumors in the renal pelvis and ureter could be documented, whereas in the bladder no tumor growth could be shown. In the intestinal mucosa of BBN-treated animals a high incidence of adenocarcinoma was found. The chemical tumor induction by BBN is related to the urine and takes place by direct contact to the mucosa when the metabolites excreted by the kidneys are activated in the urine. BBN or other urogenic carcinogens seem to have no urothelial specificity. The incidence of bowel carcinoma after diversion must lead to intensive long-term follow up.

Adenocarcinoma↗
PubMed1989

Distribution of lymphocytes in intermingled skin grafts.

Chinese intermingled skin grafts of allogenic material interspersed with small autogenic islets heal permanently with no signs of a rejection reaction. A study of the T-helper and T-suppressor cells in the region of the autogenic islets and the remaining allodermis revealed a distinctly greater frequency of these cells in the islets, with marked massing of the cells between the autoepithelium and the autodermis. Histologically it could be shown, that the Langerhans' cells grow over the allodermis together with the epithelium, although compared with the autogenic islets their number in the newly formed epidermis remained reduced.

Humans↗
PubMed1989

What's new in the application of Southern blot analysis of malignant lymphomas?

With the introduction of gene probes for the immunoglobulin and T cell receptor gene segments and the use of the Southern Blot Analysis a new method for the diagnostic characterization of malignant lymphomas was established. Although the method is not absolutely specific for the determination of lineage and clonality of a given lymphoid neoplasm, it provides a lot of additional information for the pathologist. It is the first method that gives proof to the clonality of T cell lymphomas; reactive lymph node processes can be distinguished from true neoplasms; within lymph nodes of mixed lymphoid populations the clonally proliferated can be detected and the lineage can be determined. Therefore the Southern Blot Analysis is a method that should be applied for the diagnosis of malignant lymphomas together with histology and immunohistochemistry. Using the combination of all these methods an extensive characterization of lymphoid neoplasms can be made.

Animals↗
PubMed1989

Reduced deposition of aluminium in trabecular bone of uraemic rats treated with dihydroxylated vitamin D metabolites.

The rate of aluminium accumulation in bone may be related to the presence of vitamin D metabolites. The present study investigated the effect of 1,25(OH)2D3 (24 pmol/d s.c.) and 24R,25(OH)2D3 (480 pmol/day), combined or alone, on the deposition of aluminium (119 mumol/kg per day) in bone of uraemic rats during concomitant parenteral administration of aluminium for 9 weeks. Bone histomorphometry of trabecular bone revealed a severe low-turnover osteodystrophy in aluminium-treated uraemic rats, as evidenced by a decrease in osteoblastic osteoid surfaces and mineral apposition rates. 1,25(OH)2D3 as well as 24R,25(OH)2D3 decreased stainable bone aluminium and the aluminium content of trabecular bone and, in parallel, the number of osteoblasts and osteoclasts increased. Additional treatment with one or both vitamin D metabolites 14 days prior to the aluminium load further improved these results. Despite these effects, dynamic histomorphometric parameters remained suppressed and osteoidosis persisted. Serum PTH concentrations were significantly elevated in aluminium-loaded uraemic rats treated with 24R,25(OH)2D3 alone compared to controls. In conclusion, administration of 1,25(OH)2D3 or 24R,25(OH)2D3 reduces the accumulation of aluminium in trabecular bone in uraemic rats and prevents some of its excess toxicity. The mechanism of action may be different for either vitamin D metabolite; however, combined treatment does not result in further reduction of the accumulation rate of aluminium in bone in this model.

24,25-Dihydroxyvitamin D 3↗
PubMed1989

Frequency of medullary thyroid carcinoma in an endemic goiter area.

A series of 41 poorly differentiated follicular carcinomas of the thyroid gland without histopathological features of medullary or papillary carcinoma and 9 cases of undifferentiated thyroid carcinoma of the small cell type (diagnosed between 1967 and 1983) were investigated immunohistochemically. Two poorly differentiated follicular carcinomas showed a considerable number of calcitonin-positive cells in addition to the weakly thyroglobulin-positive tumor cells. One of these cases revealed several areas with calcitonin-positive tumor cells with additional squamous metaplasia with keratinization. No medullary carcinomas could be demonstrated among the 9 cases previously diagnosed as undifferentiated thyroid carcinomas of the small cell type. From the epidemiological point of view the application of immunohistochemistry does not significantly increase the proportion of medullary carcinomas detected in our endemic goiter area. The incidence of medullary carcinoma remains surprisingly low when compared with nonendemic areas.

Adenocarcinoma↗
PubMed1988

Interactions between bladder tumor cells as tumor spheroids from the cell line J82 and human endothelial cells in vitro.

Multicellular tumor spheroids (MCTS) are a reliable model of nonvascularized tumor cell aggregates showing a well defined three-dimensional growth pattern and are comparable with small metastatic cancer cell complexes in blood circulation. In the present study we have established a co-culture system of multicellular bladder tumor spheroids with human endothelial cells on extracellular matrix (ECM) in order to investigate morphological and proliferative changes of endothelial and tumor cells within a defined time of cell-cell interaction. The MCTS--endothelial cell--extracellular matrix complex was observed within coculture periods from 1/2 to seven days. Morphological changes (light microscopy, scanning and electron microscopy) indicated that MCTS are not influenced by cocultured endothelial cells. The tumor cells invaded into the ECM after degradation of endothelial cells in the center of the contact zone. Endothelial cells, however, showed degenerative changes as well as a complex reaction in their proliferation activities. We could recognize an initial increase of proliferation of endothelial cells next to the MCTS. Later on, endothelial cells next to invading tumor cells showed changes in morphological polarity. The model system used has the advantage of using human tumor tissue. It distinguishes between basic cellular mechanisms like adherence, migration, DNA synthesis and proliferation in the study of the contact of tumor cells and vascular endothelial cells as an important event in hematogenous tumor spread.

Cell Communication↗
PubMed1987

Stage T1, grade 3 transitional cell carcinoma of the bladder: an unfavorable tumor?

Transurethral resection only was performed in 172 patients with initial stage Ta, T1 transitional cell carcinoma of the bladder. Additional treatment during the course of disease was given to 9 patients with carcinoma in situ and to 8 patients with tumor progression. The mean followup was 106 months. The 10-year survival rates were 95 per cent for patients with stage Ta, grade 1 disease, 89 per cent for stage Ta, grade 2, 84 per cent for stage Ta, grade 3, 78 per cent for stage T1, grade 2 and 50 per cent for stage T1, grade 3. The percentage of first tumor recurrence at the same site increased with tumor grade (stage T1, grade 3 was 74 per cent). The recurrence rate in stage T1, grade 3 tumors (4.08) differed significantly from the other groups of superficial tumors. The tumor progression rate for stage T1, grade 3 tumors (32.5 per cent) was significantly higher as well. The characteristics of stage T1, grade 3 tumors with and without progression were different in regard to multiplicity, recurrence rate, mean interval to recurrence and type of tumor invasion. Of the 13 patients who died of progressive neoplastic disease 11 presented initially with stage T1, grade 3 tumors. When these results are considered it is obvious that a patient with a stage T1, grade 3 tumor deserves additional therapy, such as chemotherapy, immunotherapy or phototherapy.

Aged↗
PubMed1987

Carcinoma in situ of the bladder extending into the seminal vesicles.

Involvement of the urethra or distal ureter in 30 to 50 per cent of the patients with carcinoma in situ of the bladder is well known. Carcinoma in situ of the bladder extending to the seminal vesicles rarely has been mentioned. We discuss 2 patients with extension of carcinoma in situ into the seminal vesicles and replacement of the normally present cylindroid mucosal lining. Carcinoma in situ of the ureter, bladder and prostatic ducts also was present in both patients.

Aged↗
PubMed1987

Multicellular bladder tumor spheroids in coculture with human endothelial cell monolayers.

Multicellular tumor spheroids (MCTS) are avascular spherical tumors grown systematically out of single cells in vitro. The coculture of MCTS of the human bladder carcinoma cell line J 82 with confluent human endothelial cell layers serves as a model to study cell-cell interactions as an important feature in hematogenous tumor spread. Basic information is obtained by phase contrast microscopy and histochemistry. More detailed information is given by the application of scanning and transmission electron microscopy. Immunohistochemistry helps to differentiate endothelial cells from tumor cells (factor VIII-related antigen). The application of this coculture model and of the various methods of evaluation enables us to study cell-to-cell contact phenomena systematically.

Carcinoma, Transitional Cell↗
PubMed1987

[Tumor markers in the histopathology of urologic tumors].

A critical account of the development of immunohistochemical techniques and their adoption in histopathological diagnosis is given. The main topics presented are prostatic carcinoma (organ-specific markers), testicular tumors (histogenesis), urothelial carcinoma (differentiation antigens and early neoplastic lesions), and renal carcinoma (intermediate filaments). There is particular emphasis on the relations with histopathological problems and on new developments which it is thought will surpass histopathology in diagnostic capacity.

Adenocarcinoma↗
PubMed1986

Urothelial dysplasia and carcinoma in situ of the bladder.

Urothelial cells were pepsin-extracted from paraffin-embedded specimens taken from human nontumorous bladder mucosa, dysplasia, and carcinoma in situ. After Feulgen staining for DNA, nuclei were measured with an integrating microdensitometer. The measurements show that normal urothelium consists mostly of diploid nuclei. Dysplasia means that there is a predominance of tetraploid DNA values, whereas carcinoma in situ is characterized by a high percentage of aneuploid cells. In both dysplasia and carcinoma in situ there is a considerable percentage of diploid nuclei. Thus, DNA cytophotometry can be used for standardization of preneoplastic and early stages of tumor development in bladder cancer.

Carcinoma in Situ↗