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Biomedical subjects

U N Riede

Publications and source records attributed to U N Riede.

At least 37 records · Page 2Linked to original sources
PubMed1993

Function and "homing" of the lung macrophages. I. Evidence of functional heterogeneity of mobile cells of the murine lung parenchyma in the bronchoalveolar lavage (BAL).

The object of the present investigation was to extend fundamental understanding of the composition, function and origin of bronchoalveolar lavage (BAL) cells, and to reduce the considerable gaps in our existing knowledge. BAL cells from the B10.D2 mouse were identified by morphological, enzyme cytochemical and immunocytochemical methods and a further functional characterisation of macrophages was undertaken in vitro using latex phagocytosis. The possible bone marrow origin of BAL cells was investigated with a radiation chimera. The bone marrow from H2k-positive F1 mice (B10.BR x B10.D2) was transplanted into the irradiated H2k-negative parent animals. At various time intervals after transplantation, BAL cells were tested immunocytochemically for the presence of H2k-positive cells. The principal finding was that BAL cells are functionally heterogeneous. It was possible by morphological, enzyme cytochemical and immunocytochemical techniques to subdivide the total BAL cell count into 89% macrophages, 8.5% lymphocytes and 2.5% granulocytes. Only 14.3% of the macrophages expressed the corresponding epitope, and this small population could be further subdivided immunocytochemically into mature and immature (7:1) macrophages. The ability to phagocytose, which is typical of active macrophages, could be induced in vitro in only one-third of all BAL macrophages. Three-quarters of the macrophages carried the H2d antigen and 9.5% of the BAL cells were natural killer cells showing a macrophage phenotype. Subdivision of the lymphocytes showed a significant majority of T-cells (75%) to B-cells (20%), and 5% Asialo GM1-positive cells. The CD4/CD8 ratio amounted to 1.3:1 and 38% of the lymphocytes expressed on the surface the H2d antigen.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Collagen stabilization induced by natural humic substances.

Humic substances are polyphenolic compounds. They have antiviral as well as desmutagenic effects and react with biopolymers such as collagen; thereby they have no toxic side effects by oral administration. In vitro incubation with humic substances raises the breaking point of the tail tendon of the rat by about 75%. The chemical resistance of the collagen fibres in tail tendon collagen is also increased by in vitro incubation with humic substances, at least insofar as the ultrastructurally and biophysically measurable destruction of the collagen fibres by 4 M guanidinium chloride is inhibited. As humic substances increase the mechanical and chemical resistance of collagen fibres and promote their "maturity", it seems likely that this effect of humic substances depends upon their interaction with the hydrogen bonding and covalent bonding of the collagen fibres. Such a conclusion is confirmed by the results of X-ray diffraction analysis.

Animals↗
PubMed1991

Humate-induced activation of human granulocytes.

Naturally occurring humic substances are particular chemical compounds which are found in humus. They bind to carbohydrates, amino acids and steroids by means of hydrogen bonds, covalent bonds and epsilon donor-acceptor complexes. Three specimens of low-molecular humic substances were tested (two naturally occurring humates and one synthetically prepared humate). They were all capable of stimulating certain functions of human neutrophils (PMN), such as the respiratory burst which results in the production of toxic oxygen compounds. This PMN stimulation can be demonstrated with the help of chemiluminescence, as well as by cytochemistry and with the electron microscope. The main product of the humate-induced PMN response is H2O2. There was no activation of neutrophilic chemokinesis or chemotaxis. It is suggested that the low-molecular humic substances originating from decaying organic material contain chemical structures which can act as signals to change dormant PMN into activated cells.

Acridines↗
PubMed1990

Interaction of granulocytes and endothelial cells upon stimulation with tumor necrosis factor-alpha: an ultrastructural study.

By the production of microbicidal agents, such as reactive oxygen species, activated PMN are capable of inducing tissue damage in the host. TNF-alpha was recently shown to be a potent activator of PMN oxidative metabolism. To further evaluate the interaction between activated PMN with physiological target cells, the effect of human PMN on cultured bovine aortic and human umbilical vein endothelial cells (EC) upon stimulation with human TNF-alpha was investigated by ultrastructural techniques: Scanning and transmission electron microscopy (SEM and TEM resp.) and ultrastructural detection of H2O2 production. When isolated PMN were added to EC in the presence of recombinant human TNF-alpha (10(3) U/ml) the EC-monolayer was disrupted within 4 h and EC changed their shape by exhibiting a spindle-like structure. PMN were seen in the intercellular spaces. Release of H2O2 was observed at the surface of the PMN plasma membrane, the luminal part of the small intracytoplasmic vacuoles in the PMN as well as in the contact zone between PMN and EC, but not within the EC. Scavengers of reactive oxygen species, such as superoxide dismutase and catalase or D-mannitol failed to block the effect of TNF-alpha-stimulated PMN on EC. In contrast, addition of NaN3 (0.1 mM), an inhibitor of myeloperoxidase activity, almost completely inhibited the disruption of EC-monolayers. Subsequent addition of NaN3-insensitive horseradish peroxidase reconstituted the effect. The results obtained suggest that TNF-alpha-stimulated PMN effectively cause the disruption of EC monolayers by an adherence-dependent mechanism which is mediated by the release of myeloperoxidase. The results may be of major importance for the pathogenesis of inflammatory vascular reactions.

Animals↗
PubMed1990

The effect of prostaglandins on experimental storage disease in rats.

The aim of this study was to investigate the effect of prostaglandins (PGs) on the release of lysosomes into the extracellular space in experimentally-induced storage disease in rats. The generalized phospholipidosis was induced by oral administration of chlorphentermine to Wistar rats. PG-E2 or PG-F2 alpha (50 micrograms/100 g) was injected intravenously into rats with phospholipidosis. Control rats were injected with the same amount of saline. Twenty-four hours later, extracellular and intracellular lysosomes were analysed morphometrically in electromicrographs of the liver, kidney, myocardium, skeletal muscle, aorta and cervix uteri, having been stained with acid-phosphatase. The morphometric parameters used were the numerical density of lysosomes per unit volume and the volume density of lysosomes per unit volume. The results show that, in comparison with the controls, a volumetric increase of extracellular lysosomes and a volumetric decrease of intracellular lysosomes were achieved by PG-E2 or PG-F2 alpha administration in several organs, but not in the myocardium or skeletal muscles. The effect of PG-F2 alpha was greater than that of PG-E2 in the liver and kidney, while the effect of PG-E2 was greater than that of PG-F2 alpha in the aorta and cervix uteri. These results indicate that PGs influence the discharge of storage lysosomes in bipolar epithelial cells in the liver and kidney, and also influence the release of non-storing lysosomes in apolar mesenchymal cells in the aorta and cervix uteri.

Animals↗
PubMed1989

Activation of human polymorphonuclear neutrophilic granulocytes by immuno-modulating cytokines: an ultrastructural study.

Activated granulocytes play an important role in the propagation of inflammatory reactions and are capable of mediating tissue damage by the release of reactive oxygen species and lysosomal contents. Cytokines produced by immunocompetent and other cells were recently suggested to influence granulocyte functions. Therefore, in the present study, we investigated the effect of relevant immuno-modulating cytokines on isolated human granulocytes by ultrastructural criteria: scanning and transmission electron microscopy, ultrastructural detection of H2O2. The following recombinant human cytokines were tested: tumor necrosis factor (TNF), lymphotoxin (LT), GM-CSF, M-CSF, G-CSF, interleukin 1 (IL 1) alpha and beta, IL 2, IL 3, IL 4, IL 6, interferon (IFN)-alpha and gamma. Only TNF, LT, GM-CSF and IL 3 (at high concentrations) induced significant morphological changes (increased adherence to plastic layers, typical polarization, development of intracellular vesicles) and production of H2O2. None of the other cytokines tested induced any detectable effect on isolated granulocytes even at unphysiological concentrations. The results clearly demonstrate that only certain cytokines are capable of influencing granulocytes. Release of these mediators represents a specific signal for granulocyte activation in inflammatory disease states.

Biological Factors↗
PubMed1986

Automated translation of German to English medical text.

The feasibility of automated translation of scientific and medical documents remains controversial. This report describes a minicomputer-based German-to-English translation system (TRANSOFT) that employs word order rearrangement followed by word-for-word translation and disambiguation based on context. This translation system was applied to a computer-readable version of Adler's Knochenkrankheiten (Bone Diseases), which contains 118,604 words, with 10,216 distinct words in 7,211 sentences averaging 16.4 words each. The translation required 2,791 word rearrangement formulas, 78 percent of which were first used in the first half of the document. There were 2,392 occurrences of 12 potentially ambiguous terms, of which only 18 (0.8 percent) were not resolvable from the immediate context. As foreign language medical documents become increasingly available in computer-readable form through computerized typesetting, electronic publishing, and improved optical character recognition equipment, automated translation systems may provide a rapid and inexpensive means of obtaining draft translations.

Computers↗
PubMed1986

Multilingual translation techniques in the analysis of narrative medical text.

The feasibility of computer translation of scientific and medical documents is controversial. This report describes a minicomputer-based translation system (TRANSOFT) that employs word order rearrangement followed by word-for-word translation and resolution of ambiguities based on context. This translation system was applied to an entire medical textbook written in German and to short medical texts written in French, Italian, Spanish and Turkish. Results suggest the versatility of TRANSOFT for narrowly defined translation problems. As foreign language medical documents and medical records become increasingly available in computer readable form through word processing, computerized typesetting and hospital information systems, computer translation methods may provide a rapid and inexpensive means of obtaining draft translations.

Computers↗
PubMed1986

[Sclerosing peritonitis following continuous ambulatory peritoneal dialysis].

Sclerosing peritonitis is a severe complication after CAPD treatment. The visceral peritoneum is thickened and interenteric adhesive parts are found. Myofibroblasts are proliferated and the collageneous tissue is hyperplastic. The mean clinical symptom is the mechanical obstruction of the small bowel. We observed this illness in three out of sixty patients under CAPD. These patients had higher incidence of bacterial peritonitis. In the ascites high concentrations of PG E2 and Thromboxan B2 were observed. After treatment of the infection the concentrations fell down to normal values. Electronoptical observations from peritoneal biopsies showed a proliferation of myofibroblasts and extracellular lysosomes. It is known from these lysosomes that they are able to set free proteasis. These lead to degredation of fibrin and fibrinogen. These splits are mitogen to myofibroblasts. release from HIT cells could also be evoked by the sulphonylureas glibenclamide and tolbutamide and by an increase in concentration of extracellular K+ to 40 mmol/l. The content of cyclic AMP in HIT cells was increased modestly by glucose but not by an increase in extracellular K+. Forskolin elicited a 4-fold increase in cyclic AMP content. We conclude that HIT cells retain the essential features of the insulin secretory response of normal B cells and represent an important tool for further biochemical characterisation of the secretory system.

Adult↗
PubMed1984

Bioptic diagnosis of Wegener's granulomatosis in the absence of vasculitis and granulomas.

We report a case of Wegener's granulomatosis (WG) which differed significantly from the WHO-definition. The patient presented himself with fever and skin lesions which exacerbated after penicillin therapy. The nasal biopsy did not reveal the expected classical vasculitis and granulomas, which were present at autopsy only in the liver and spleen. We emphasize that vasculitis and granulomas may be absent in the biopsy specimen. We stress the institution of chemotherapy with cyclophosphamide, once the clinicopathological impression of WG is probable.

Aged↗
PubMed1984

Cytophotometric measurements of the DNA in Hodgkin lymphomas and non-Hodgkin lymphomas.

In smear preparation of lymph nodes excised from 36 patients with a malignant lymphoma the DNA content was estimated in different tumor cells following Feulgen staining by means of quantitative cytophotometric measurements. The tumors investigated included 11 Hodgkin lymphomas and various types of Non-Hodgkin lymphomas (altogether 25). Whereas the small lymphoid cells found in Hodgkin lymphomas show a diploid DNA content with a wide scattering, in the large mononuclear reticular cells (Hodgkin cells) as well as in Sternberg's giant cells only aneuploid DNA values are seen lying in the hyperdiploid, hypertetraploid and hyperoctoploid regions. DNA stemlines are found in the aneuploid regions, but in some cases they are missing. This indicates that we are dealing with malignant tumor cells. In Non-Hodgkin lymphomas with a low grade of malignancy (centrocytic-centroblastic lymphoma, centrocytic lymphoma, CLL) an aneuploid DNA content is found particularly in the large cells (centroblasts, lymphoblasts) with or without a DNA stemline. These cells must be considered as primary malignant tumor cells. In the immunoblastic lymphoma of high malignancy only aneuploid tumor cells are present showing a particularly intense DNA content in the large immunoblasts, whereas a DNA stemline is usually missing. The range of aneuploid values, the number of polyploid tumor cells and the presence or absence of a DNA stemline are important criterions in determining the degree of malignancy. By means of cytophotometric measurements of the DNA content in the tumor cells of malignant lymphomas it is possible to assertain the degree of malignancy and to establish an objective prognosis.

DNA, Neoplasm↗
PubMed1984

Diagnostic morphometry of the adult respiratory distress syndrome (shock lung).

In the pathogenesis of "shock lung", the morphometric analysis allows us to determine the "point of no return" when the exudative alveolitis turns into the life-threatening sclerosing form. In addition, we found that this "point of no return" is reached much earlier in septic than in traumatic shock. Our studies confirm that the term "shock lung" should not be simply substituted for "respiratory lung". Based on our morphometric methods, we conclude that shock-induced pulmonary fibrosis differs with regard to its functional pathogenesis from the non-shock-induced type of fibrosis.

Epithelium↗
PubMed1983

The effect of prostaglandins on the lysosomal function in the cervix uteri.

Local or systemic prostaglandin (PG) administration leads to the known softening and dilatation of the cervix uteri. Lysosomal enzymes are involved in connective tissue degradation. The question arises whether the effect of PG on the cervix uteri is mediated by lysosomes. Five pregnant women (volunteers after informed consent) in the first trimester received 500 micrograms of PGE2-derivative (Nalador) i.m. at 12 and 8 h before termination by curettage. Five pregnant women without PG-treatment served as controls. Small biopsies were obtained from the endocervical canal and were immediately immersed in cold 2.5% glutaraldehyde and after further preparations examined under a Zeiss electron microscope 9S-2. A second portion of tissue was sliced and prepared for histochemical analysis of the acid phosphatase on lysosomes. Examination of the ultrastructure of the cervix uteri showed vesicles in the extracellular matrix. These were surrounded by a single membrane and contained either fine granular material of myelin-like whorls of membranes. These vesicles lay between collagen fibers, showed the reaction product of acid phosphatase and were often surrounded by an electron-lucent halo. We conclude that these matrix vesicles were "matrix lysosomes" extruded from the cervical myo-fibrocytes into the extracellular space as a result of the PG-E2-administration. Here they are not under cellular control and can initiate the proteolytic degradation of connective tissue. This might be the crucial step in cervical dilatation which, on ultrastructural examination, can be seen as decreasing electron density of the extracellular ground substance near the matrix lysosomes. The relationship between PGE2 and collagenase production is generally accepted. If one believes that lysosomal cathepsin D and cathepsin B act synergistically with collagenase, it can be assumed that PGE2 is involved in a lysosomal degradation of the connective tissue. The morphological sign of this occurrence is the release of matrix lysosomes by PGE2 as described in the present study. Extracellular lysosomes and their physiological significance in cervical function are discussed in detail.

Acid Phosphatase↗
PubMed1983

[Computed tomography in complex fractures of the ankle joint].

Diagnostic value of conventional roentgen technique and computed tomography is proofed by examination of 50 patients with sprain fractures of the ankle joint. The dimension of destruction of the distal tibial joint surface is better documented by CT than by other radiological techniques. Additional informations like multifragmentation of the distal tibia or evaluation of reposition impedigment are found more frequently by CT. Therefore indication and planning of the traumatherapy can be assessed better by the traumatologist.

Ankle↗