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Biomedical subjects

E Schulze

Publications and source records attributed to E Schulze.

At least 91 records · Page 5Linked to original sources
PubMed1990

[N-procollagen(III)peptide and lysosomal beta-galactosidase in progressive scleroderma and silicosis].

The concentration of type III collagen aminopropeptide and the activity of lysosomal beta-galactosidase were determined in the serum of patients with progressive sclerosis (PS), silicosis and PS associated with silicosis. In PS-patients, the serum levels of both parameters were significantly increased with a high correlation to the stage of the disease and to each other. In patients with silicosis normal serum concentrations of both parameters were found, whereas in all patients suffering from silicosis and PS significantly elevated serum levels were detectable, independent of the stage of PS. Both parameters can also be used as markers of therapy (e.g. with D-penicillamine) and as early indicators for the development of PS in patients with silicosis.

Adult↗
PubMed1989

[Results of therapy of 100 patients with acute leukemia--a retrospective unicenter 5-year analysis].

The results of therapy in 100 patients who newly fell ill (68 AML, 32 ALL) with acute leukaemia were evaluated (1981 to 1985). The 5-year-survival chance of all patients is 15% for AML, 18% for ALL, first of all it is depending on the degree of remission obtained. The CR rate is nearly 43% (AML) and 66% (ALL), respectively, shows a dependence upon age and is impaired above all by a high early death rate (supportive therapy). With increasing aggressiveness the results of the remission induction therapy improve, as it becomes clear in a comparison with an evaluation of patients 1965-1980 (CR: 15-32%). Also in the postremission therapy the results of intensive forms of therapy are more favourable: 4 years recurrence-free survival after CR in autologous bone marrow transplantation 50%, in allogenic bone marrow transplantation 40%, in cyclic chemotherapy 17%, in oral permanent therapy 0%. Starting from these findings the present conception of the therapy of acute leukaemias is discussed in connection with the literature.

Adolescent↗
PubMed1989

The use of long-term bone marrow cultures (LTBMC) to detect hematotoxic side effects of purging methods.

With a view to the establishment of purging methods it is necessary to investigate complete-remission bone marrow as the real target of purging, rather than bone marrow from healthy donors. The results of LTBMC are superior to those of GM-CFC where the hematopoietic recovery of bone marrow is concerned. One-stage LTBMC after bone marrow manipulations may reflect mixed hematopoietic/stromal effects. The use of two-stage LTBMC allows the evaluation of the stem cell recovery without the possible influence of a damaged microenvironment.

Bone Marrow↗
PubMed1989

Concentrations of volatile fatty acids and acetate production rates in the forestomachs of grazing camels.

1. Concentration profiles of volatile fatty acids (VFA), fluid volumes and turnover rates, and acetate production rates were measured in two different seasons in the forestomachs of four fistulated dromedary camels grazing in the Kenyan thornbush savannah. 2. VFA profiles and average concentrations were similar under both feeding conditions but, due to a smaller fluid turnover, VFA outflow to lower gastric sections in the dry season was reduced by almost 50%. 3. The mean acetate production rate fell from 2234 mmol/hr in the green season to 816 mmol/hr in the dry season, i.e. by approximately 64%.

Acetates↗
PubMed1989

Growth of hemopoietic cells after incubation with VP 16-213.

We examined the effect of various concentrations of VP 16-213 (25-125 microM/l, 2-h incubation on normal and complete remission bone marrow from patients with acute leukaemia and on leukaemic blasts. The maximal tolerated dose of the drug for normal bone marrow GM-CFC was between 75 and 100 microM/l whereas that for complete remission bone marrow was distinctly lower. More early stem cells measured by aid of LTBMC were more resistant in normal, but not in every remission bone marrow. We have to examine if these LTBMC results are influenced by a damaged microenvironment by using 2 stage LTBMC. Spontaneous leukaemic cells showed a different, sometimes lower sensitivity to VP 16-213 doses maximally tolerated by normal hemopoietic cells so that the VP 16-213 incubation must not be effective for every leukaemia.

Bone Marrow↗
PubMed1988

New features of microtubule behaviour observed in vivo.

The microtubule cytoskeleton is thought to be intimately involved in generating and maintaining cell polarity and can generate many different morphological structures from a few structural elements. The mechanism by which these structures are generated has been partially elucidated from studies of microtubule polymerization both in vitro and in vivo. Microtubules in vitro exist in growing (polymerizing) and shrinking (depolymerizing) populations that interconvert infrequently. This behaviour, termed dynamic instability, permits microtubules in the cell rapidly to explore different arrangements and allows selective stabilization of specific morphologies. To investigate the regulation of these processes, we have implemented techniques for direct observation of fluorescently labelled microtubules and developed them to observe the dynamic behaviour of individual microtubules in single living cells. Sammak and Borisy recently used this technique to show that the dynamics of microtubules in fibroblasts is explained by dynamic instability. Although we also conclude here that dynamic instability explains much of microtubule behaviour in vivo, we find significant deviations from the properties of tubulin in vitro. These results suggest that local cytoplasmic factors strongly influence microtubule dynamics; such control has important implications for cellular morphogenesis.

Animals↗
PubMed1988

Metabolism of naturally occurring [13C]glucose given orally to horses.

In 5 horses, 13CO2/12CO2 ratios in expired air were determined using isotope mass spectroscopy to investigate metabolism of naturally occurring [13C]glucose. Oral glucose tolerance tests (OGTT) were performed using maize or beet glucose. Maize has a higher 13C concentration than that of most plants. The 13CO2/12CO2 ratios after OGTT was performed using maize glucose were compared with 13CO2/12CO2 ratios in expired air after OGTT was performed using beet glucose. The ratio also was determined during the period horses were not fed. Using OGTT, all horses were glucose tolerant. The OGTT performed using beet glucose led to minimal changes in 13CO2/12CO2 ratios. The 13CO2/12CO2 ratios decreased significantly (P less than 0.01) when horses were not fed. After oral dosing with maize glucose, 13CO2/12CO2 ratios reached maximal increases 5 hours after dosing and reached baseline values 15 hours after dosing.

Animals↗
PubMed1987

Origin of the enhanced activity of lysosomal beta-galactosidase in serum and skin in progressive systemic sclerosis.

In 14 patients with progressive systemic sclerosis (PSS) the activities of acid lysosomal glycosidases (alpha-, beta-galactosidase, beta-glucosidase, beta-glucuronidase, and beta-N-acetyl-glucosaminidase) were determined fluorometrically in serum, leukocytes, and skin tissue. The beta-galactosidase was the only enzyme which exhibited a significantly elevated activity in PSS serum and skin but not leukocytes, as compared to the control. The activity patterns of the studied glycosidases in serum were similar to those found in skin, but differ from the distribution of glycosidase activities in leukocytes. In cultured dermal fibroblasts derived from PSS patients, an elevated intracellular activity of beta-galactosidase was detected. These results suggest that the increased beta-galactosidase activity in the serum originates from the skin fibroblasts.

Adult↗
PubMed1987

Interaction of adrenal and pancreatic hormones in the control of hepatic enzymes during development.

In the liver of suckling rats, the synthesis of hepatic tyrosine aminotransferase, serine dehydratase, and phosphofructokinase 2 as well as of renal beta-glucosidase is controlled by the circulating concentrations of adrenal and pancreatic hormones. Glucagon is capable of stimulating enzyme synthesis only in the presence of a steroid hormone. Dexamethasone and estradiol have been found to exert a permissive function on the inducibility of the studied enzymes by glucagon. Between the hormones of the adrenal medulla and glucagon antagonistic effects in enzyme induction were observed. Obviously, this antagonism is mediated by the alpha 1-adrenergic signal transferring system. A characteristic age dependence of enzyme induction by dexamethasone has been established. This might be correlated to alterations in the degree of methylation of the respective promoters. The methylation inhibitor 5-azacytidine influences significantly the enzyme induction by glucocorticoid hormones.

Adrenal Cortex Hormones↗
PubMed1987

Dynamic and stable populations of microtubules in cells.

Using a new immunocytochemical technique, we have visualized the spatial arrangement of those microtubules in cells that are stable to biotin-tubulin incorporation after microinjection. Cells fixed at various periods of time after injection were exposed to antibody to biotinylated tubulin and several layers of secondary antibodies; these layers prevented reaction of biotin-containing microtubules with antitubulin antibodies. The microtubules that had not incorporated biotin-tubulin could then be stained with anti-tubulin and a fluorescent secondary antibody. In BSC1 cells, most microtubules in the cell exchange with a half-time of 10 min. A separate population of microtubules can be detected, using the above techniques, that are stable to exchange for 1 h or more; these have a characteristic pericentrosomal spatial arrangement as compared to the majority of dynamic microtubules. Unlike the dynamic microtubules, most of the stable microtubules are nongrowing. The average BSC-1 cell contains approximately 700 microtubules: approximately 500 growing at 4 micron min-1, 100 shrinking at approximately 20 micron min-1, and approximately 100 that are relatively more stable to exchange. The potential significance of these stable microtubules is discussed.

Animals↗
PubMed1987

Posttranslational modification and microtubule stability.

We have probed the relationship between tubulin posttranslational modification and microtubule stability, using a variation of the antibody-blocking technique. In human retinoblastoma cells we find that acetylated and detyrosinated microtubules represent congruent subsets of the cells' total microtubules. We also find that stable microtubules defined as those that had not undergone polymerization within 1 h after injection of biotin-tubulin were all posttranslationally modified; furthermore dynamic microtubules were all unmodified. We therefore conclude that in these cells the stable, acetylated, and detyrosinated microtubules represent the same subset of the cells' total network. Posttranslational modification, however, is not a prerequisite for microtubule stability and vice versa. Potorous tridactylis kidney cells have no detectable acetylated microtubules but do have a sizable subset of stable ones, and chick embryo fibroblast cells are extensively modified but have few stable microtubules. We conclude that different cell types can create specific microtubule subsets by modulating the relative rates of posttranslational modification and microtubule turnover.

Animals↗
PubMed1987

[The value of cell cultures in leukemias, aplastic anemias and bone marrow transplantations].

In a survey different methods of culture are represented for the purpose of identifying and quantifying haemopoietic stem cells (CFU-GEMM, CFU-GM, CFU-E/BFU-E) in human bone-marrow or peripheral blood respectively. On the basis of findings from international medical literature their validity is explained in the diagnostics and prognosis of some haematological diseases, such as acute and chronic myeloic leukemia, aplastic anemia, preleukemia. Special attention is given to their significance within bone-marrow transplantation. Their importance in evaluating transplantations after their preceding in-vitro manipulation as to the separation of rest tumour and T-cells is particularly referred to.

Anemia, Aplastic↗