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M Dietel

Publications and source records attributed to M Dietel.

At least 181 records · Page 10Linked to original sources
PubMed1987

[Development of adaptation of the cardiovascular system in rehabilitation phase III in patients with acute myocardial infarct].

In 30 men with proven myocardial infarction we performed a complex examination of cardiopulmonary capacity at the beginning (about 8 weeks after myocardial infarction) and at the end of rehabilitation phase III (5-6 months after infarction). Of these patients the results from microcatheterization at rest and during exercise are present. In addition we determined the relative quotient of effort (kpm/kg), maximum oxygen uptake (VO2 max) and maximum oxygen pulse (max O2 pulse). For the majority of the patients the parameters given suggested a significant improvement in the physical capacity after termination of rehabilitation. The improvements also concerned the functional capacity of the heart muscle, its increase in contractility during exercise. Conclusions are drawn about the selection of the patients for physical performance.

Adult↗
PubMed1987

Establishment of primary cell cultures: experiences with 155 cell strains.

Cell culture systems allow the examination of cell populations in a functional state. To simulate in vivo conditions as closely as possible freshly established cell strains are superior to permanent cell lines. Different aspects for the establishment of primary cell cultures obtained from various tissues are compared: Disintegration, culture media supplemented with basal additions, special supplements (growth factors, hormones), and attachment factors. The proliferation rates of the attained cell strains were evaluated by determination of cell doubling times. Procedures for how to obtain a relatively high plating efficiency (approx. 70% in our series of 219 attempts) of primary growth in vitro are described: (1) Mechanical disintegration is superior to enzymatic digestion. If mechanical treatment alone did not produce a sufficient number of viable cells, additional digestion with collagenase/dispase revealed a higher number of proliferating primary cultures than with trypsin. (2) Proliferation of cell cultures from normal and tumorous tissues of epithelial origin was superior in Leibovitz L 15 medium (58 of 87 (67%) cases). Cultures from mesenchymal tissues and tumors were found to have shortest cell doubling times in MEM and RPMI 1640 (16 of 23 (70%) cases). The media were supplemented with the basal additions indicated. (3) In approx. 30% of the cases special supplements like growth factors or hormones increased cell replication, although they were almost always not essential for cell growth. (4) Attachment factors only rarely contributed to the initiation of primary monolayer cultures. The application of various culture conditions does not lead to a protocol optimal for all tissues, for all probes of the same type of tumor, or for all tumor specimens of unique differentiation.

Cell Adhesion↗
PubMed1987

S-100 protein and neuron-specific enolase in parathyroid glands and C-cells of the thyroid.

Normal parathyroid glands and parafollicular cells (C-cells) of man, rat and rabbit, and also human parathyroid adenomas and medullary carcinomas were investigated for the presence of S-100 protein and neuron-specific enolase (NSE). For determination of the proteins immunoperoxidase methods were applied, i.e., the PAP method and the avidin-biotin system. The antisera, of polyclonal origin, were specifically directed against cow S-100 protein and rat or bovine NSE. The respective antisera are known to crossreact with S-100 protein from man, rat, and rabbit, as well as with NSE from man and rat. Surprisingly, the test for S-100 protein was found to be strongly positive in the parathyroid glands of rat and rabbit and was focally positive in normal and adenomatous human parathyroid glands, but completely negative in C-cells and medullary carcinoma cells. NSE was present in C-cells of rat and man, and in medullary carcinoma cells, but was absent in normal and adenomatous parathyroid cells. The results support data that indicate that both parathyroid cells and C-cells are derived from elements of the neural crest, but undergo different maturation processes during embryological development.

Animals↗
PubMed1987

Studies on localization of calcitonin gene-related peptide (CGRP) in the thyroid-parathyroid complex.

Calcitonin gene-related peptide (CGRP) was localized by an immunocytochemical technique in the thyroid-parathyroid complexes of rat, guinea pig, rabbit, and in normal human thyroids and parathyroids. Human medullary carcinomas and parathyroid adenomas were also studied. In man and all animal species examined CGRP was present in the parafollicular cell, however, in guinea pigs only in small amounts. Except in rabbits, presence of CGRP was demonstrated in nerves of the thyroid and parathyroid capsule as well as in the nerve fibers of the capsular blood vessels. In the thyroid of guinea pigs CGRP was also noted in nerve fibers and in blood vessel walls between follicles. CGRP was also present in the parathyroid glands of rat and man, in nerve fibers localized between parathyroid cells. In rabbit the parafollicular cells between parathyroid cells also expressed CGRP immunoreactivity. No CGRP was noted in the parathyroids of the guinea pig. The proximity of parathyroid cells and CGRP containing tissue structures suggests a role for CGRP in the modulation of parathyroid hormone secretion. The importance of these regulatory mechanisms appear to be different in individual species.

Animals↗
PubMed1987

Effect of 1,25-dihydroxyvitamin D3 on human cancer cells in vitro.

1,25-Dihydroxyvitamin D3 (1,25(OH)2D3) dependent growth and differentiation of 6 tumor cell lines has been determined by the use of the monolayer proliferation assay. Cell lines of 4 gastro-intestinal carcinomas, 1 malignant schwannoma, and 1 malignant histiocytoma have been established and characterized. Cells were incubated for 4, 7, and 11 days in the presence of 0.8 or 8 nM 1,25(OH)2D3 and for control without addition of the hormone. Proliferation rates of 1,25(OH)2D3 treated cells were compared with cell growth in the untreated controls. Five out of 6 cell lines showed a 1,25(OH)2D3 dependent growth pattern. With 8 nM 1,25(OH)2D3 they were all inhibited. With 0.8 nM, 3 of them were inhibited at any time of the test period, whereas 1 was stimulated at day 4 and inhibited at days 7 and 11. One cell line was stimulated at days 4, 7, and 11 when incubated with 0.8 nM 1,25(OH)2D3. No striking morphological changes could be observed in the presence of 1,25(OH)2D3. We conclude that 1,25(OH)2D3 dependent cells in vitro are not necessarily growth-inhibited by this compound. Thus, 1,25(OH)2D3 is not an exclusively proliferation inhibiting agent.

Antigens, Neoplasm↗
PubMed1987

What's new in receptor mediated growth promotion of normal and malignant cells?

Growth control of normal cells is regulated by highly complex interactions of environmental signals and cell inherent conditions. Disorder of this system may result in the multi-step event of malignant transformation. This review discusses some aspects of the interaction of growth controlling agents, cell receptors, signal transmission, and cellular response. It focuses on the role of cell receptors that recognize and transduce information of cancer initiating and promoting agents to the cell: e.g. viruses, cancerogens, peptide and steroid hormones, growth factors, local growth promoting agents, and other environmental factors. All these growth modulators may be involved in triggering cell division. The mutual interactions of promotor induced signals, genes, and oncogenes are also discussed.

Animals↗
PubMed1987

Abnormal calcium distribution in human parathyroid adenomas as possible cause of primary hyperparathyroidism.

Current knowledge suggests that normal parathyroid glands and parathyroid adenomas have different sensitivities to environmental calcium. In search for morphological equivalents, 5 normal human and 10 porcine parathyroid glands, as well as 10 human parathyroid adenomas were investigated with regard to intracellular and extracellular calcium distribution. The glands were incubated for 2, 4, 6 and 20 h in tissue cultures using HAM's F10 medium with various calcium concentrations. For visualization of the calcium distribution in the tissue the method of pyroantimonate precipitation was applied. Specificity of the reaction was controlled by X-ray microanalysis. Shifts of the calcium pyroantimonate precipitates were quantitated by morphometry using an area-counting system. The results demonstrate that in normal parathyroid glands calcium precipitates are distributed randomly. Incubation of normal glands in medium with low calcium concentration (0.6 mM) provoked reduced amounts of intracellular and extracellular calcium complexes. When the incubations were performed in medium with high calcium content (2.6 mM), calcium accumulated inside parathyroid and stroma cells. In contrast to normal parathyroid glands, parathyroid adenomas fixed immediately after surgery showed an atypical calcium distribution with low amounts of intracellular and high amounts of extracellular calcium grains. The data suggest that in normal parathyroid glands the intracellular calcium concentration follows the extracellular environmental calcium concentration. Thus, calcium modulates parathyroid hormone (PTH) secretion via intracellular regulatory mechanisms. In parathyroid adenomas the calcium transport via the tumor cell membrane appears to be disturbed resulting in lowered intracellular calcium levels. This is remarkable since the environmental calcium concentration is elevated due to the hypercalcemia of primary hyperparathyroidism.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMed1987

Immunoreactivity of PTH-binding in intact bovine kidney tissue and cultured cortical kidney cells indicative for specific receptors.

Localization of PTH-binding sites has been examined in intact kidney sections and cultured cells derived from bovine kidney cortex. Tissue sections were incubated with 10(-7) M bovine PTH (1-84) for 2 h, cells for 15 min, at 37 degrees C. Visualization of PTH-binding was achieved by immunocytochemistry using a carboxy-terminal specific anti-PTH antiserum (S 478). For control, cell culture incubations were performed applying competitively 10(-7) bovine PTH (1-84) and a 10-fold excess of synthetic 1-34 PTH fragment, not antigenic for S 478. This resulted in a lack of staining. PTH-binding was found in all cells of the proximal and the distal tubule, and with less intensity in the thick ascending limb of Henle's loop. In collecting ducts a PTH specific staining was also present, which was confined to single cells localized between others without PTH binding sites. No staining was seen in glomerula, the thin limb of Henle's loop, in blood vessels, and in connective tissue. The data suggest that large parts of the nephron contain PTH-binding sites, although in different amounts. This is in agreement with the numerous actions of PTH in the kidney. In the collecting segment a distinct cell-to-cell difference was disclosed indicative for different functional states or cellular heterogeneity.

Animals↗
PubMed1987

Co-localization of parathyroid hormone and secretory protein-I in bovine parathyroid glands: a double immunocytochemical study at the electron microscopical level.

Secretory protein-I (SP-I), also known as chromogranin A, is an acidic glycoprotein of unknown function that is found in large amount in the secretory granules of all endocrine and neuroendocrine cells, but not in exocrine or epithelial cells. It is cosecreted with parathyroid hormone (PTH) and by immunocytochemical staining has been reported to exist in the same subcellular structures of the gland. In the present study we have used the colloidal gold-double immunocytochemical technique at the ultrastructural level to precisely define the locales of SP-I and PTH in the bovine parathyroid cell. SP-I and PTH were co-localized to the same secretory granules. The patterns for both gold labels were diffuse ones throughout the granule and suggested that there was a general association of SP-I and PTH. There was little or no localization of the SP-I at the secretory granule membrane. The results support the concept that SP-I is responsible for stabilization of PTH within the secretory granules.

Animals↗
PubMed1986

Antigen detection by the monoclonal antibodies CA 19-9 and CA 125 in normal and tumor tissue and patients' sera.

The tumor markers CA 19-9 and CA 125 defined by the monoclonal antibodies 19-9 and OC 125 were investigated with respect to organ specificity and tumor sensitivity. Normal and tumor tissue specimens, and blood samples from 34 patients with pancreatic carcinomas, 40 with ovarian carcinomas and 39 with miscellaneous tumors were examined. CA 19-9 and CA 125 were determined by immunohistochemistry (IH) applied to sections of the tumors and adjacent normal tissues. In parallel, the antigens were measured in the patients' sera by radioimmunoassay (RIA). By means of IH CA 19-9 and CA 125 were detected in normal surface cells from many different organs. Both antigens were also found in tissue sections of various types of tumors and in the sera of the corresponding patients. Thus, organ specificity could not be demonstrated. Sensitivity of CA 19-9 was found to be high for pancreatic carcinomas, i.e., 88% of the tumors expressed the antigen shown by IH and 85% of the sera revealed concentrations above the cut-off value (greater than 37 units/ml). Evidence for CA 125 was high in ovarian carcinomas with a tissue positivity in 83% and elevated (greater than 35 units/ml) serum levels in 70% of patients. Comparing IH and RIA case by case a discrepancy was found in 14% of cases with positive IH and low serum values a vice versa. Reasons for this finding are small tumor mass not producing elevated serum levels, retention of the antigen inside the tumor cells because of defective release mechanisms demonstrable only by IH, or heterogeneity of tumors with only focal antigen expression not present in the tissue sections investigated and thus disclosable only by RIA. The relevance of immunohistochemical detection of the antigens for therapeutic planning is discussed.

Antibodies, Monoclonal↗
PubMed1986

Pancreatic endocrine carcinoma with ectopic PTH-production and paraneoplastic hypercalcaemia.

In a case of pancreatic endocrine carcinoma hypercalcaemia without bone metastases and normal parathyroid glands prompted our suspicion that there was paraneoplastic production of an osteoclast activating substance by the tumour tissue. This view was further confirmed by bone histology. Immunohistology post mortem revealed the production of PTH in the primary tumour and a liver metastasis. The usefulness of immunohistology in detecting paraneoplastic secretion of hormonal substances is discussed.

Cytoplasmic Granules↗
PubMed1986

Nuclear DNA content of borderline tumors of the ovary: correlation with histology and significance for prognosis.

Scanning-DNA cytophotometry was applied to Feulgen stained sections of 22 borderline tumors of the ovary (BOT). The DNA content was related to conventional histology. In 11 cases clinical follow up for more than 5 years was available. The DNA measurements disclosed two subgroups in the group of BOT. One showed a nuclear DNA content not exceeding tetraploidy (4c) indicating proliferative activity without malignant change and a second one exhibited DNA values higher than 4c indicating malignant transformation. Correlation of histological evaluation with the DNA content revealed a good agreement in 15 cases. However, a discrepancy was found in 7 cases: either the histological evaluation aroused suspicion for malignant potential but the histogram showed DNA values not higher than 4c (n = 4), or histology showed well differentiated lesions with an atypical histogram (n = 3). Clinical monitoring revealed no recurrence or tumor spread in all but one case of the group of lesions with DNA values up to 4c, whereas in the group with atypical DNA histograms (DNA values greater than 4c) relapse appeared in 6 out of 7 cases. The results suggest that DNA analysis has prognostic significance for BOT.

Cell Nucleus↗
PubMed1986

Visualization of binding sites for bovine parathyroid hormone (PTH 1-84) on cultured kidney cells with a biotinyl-b-PTH (1-84) antagonist.

Parathyroid hormone (PTH) receptors have been found in a subpopulation of kidney cells. In this report, we investigated the feasibility of techniques that apply a partial antagonist of PTH conjugated to biotin to localize receptors cytochemically on bovine kidney cortical cells in monolayer culture at the light microscopic level. Biotinylated bovine PTH (1-84) (biotinyl-PTH) was bound to the cultured cells for 1-30 min at 37 degrees C in the amounts of 10(-5) -10(-10) M. In a different set of experiments, the cells were also exposed to a solution containing 10(-6) M biotinylated PTH and an excess of unlabeled PTH, insulin, adrenocorticotropin, or calcitonin for 10 and 30 min at 37 degrees C to test the specificity of the binding. The cells were then fixed in 2.5% glutaraldehyde and stained with the avidin-biotin peroxidase complex (ABC) technique. Diffuse labeling was evident on 30% of the cells in 10 min with concentrations of biotinyl-PTH as low as 10(-8) M. The stain was diffuse, but more intense after 1-10 min in higher concentrations (10(-6) M). If a 15-1500-fold excess of unlabeled PTH was added to the biotinyl-PTH, no staining was observed. The other peptides (insulin, ACTH or calcitonin) had no effect on binding. Longer times in biotinyl-PTH (10(-6) M for 10-30 min) resulted in intense patches of label on the cells resembling caps (in addition to the pale diffuse label). The percentage of labeled cells in the monolayer (30%) did not change with time. These studies show that a partial antagonist of PTH can be used as a cytochemical probe for specific PTH receptors in a subpopulation of cultured cortical kidney cells.

Animals↗
PubMed1986

[Cell receptors].

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Adenylyl Cyclases↗