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Biomedical subjects

H Baum

Publications and source records attributed to H Baum.

At least 73 records · Page 4Linked to original sources
PubMed1989

[Contaminating substances in 22 over-the-counter fish oil and cod liver oil preparations: cholesterol, heavy metals and vitamin A].

Fish oil capsules are increasingly used by self-medicating patients. We studied 22 commercial fish oil and menhaden oil preparations in respect to accompanying substances that could be harmful. The substances measured were: cholesterol as determined by gas liquid chromatography, heavy metals measured by atomic absorption, and vitamin A as determined by high-performance liquid chromatography (HPLC). The contents of cholesterol and heavy metals were in ranges which can be regarded as negligible; the content of vitamin A in menhaden oils, however, was found in amounts which warrant that pregnant women do not exceed the dosage as recommended by the manufacturers.

Animals↗
PubMed1988

Inactivation of alpha-1-proteinase inhibitor in serum by stimulated human polymorphonuclear leucocytes. Evidence for a myeloperoxidase-dependent mechanism.

Triggered polymorphonuclear leucocytes (PMNL) can decrease the elastase inhibitory capacity of serum by inactivating the main inhibitor of elastase alpha-1-proteinase inhibitor (alpha-1-PI). Maximal inactivation occurs with stimuli that release myeloperoxidase from PMNL along with hydrogen peroxide. Specific protection of alpha-1-PI function is obtained with antioxidants that interfere with this system. PMNL that are activated with phorbol myristate acetate release hydrogen peroxide but not myeloperoxidase, and only inactivate alpha-1-PI in the presence of exogenously-added PMNL-derived supernatants which contain this enzyme. Cell-free inactivation requires both active enzyme and hydrogen peroxide, and is greatest at pH 6.2, the pH optimum for myeloperoxidase-catalysed inactivation of alpha-1-PI. This data supports the notion that leucocyte myeloperoxidase may act to suppress the antiprotease screen afforded by alpha-1-PI by generating hypochlorous acid in the presence of chloride and respiratory burst-derived hydrogen peroxide, and in the microenvironment of lowered pH associated with degranulation. Pulmonary emphysema seems to be associated with an imbalance between elastase and its inhibitors at the lung surface. PMNL are likely to play an important role in the pathogenesis of emphysema since they contain both elastase, which can solubilize connective tissue elastin, and the constituents of an oxidative system which can inactivate the most important antielastase, alpha-1-PI.

Antioxidants↗
PubMed1988

Expression of the primary biliary cirrhosis antigens in yeast: aspects of mitochondrial control.

The mitochondria of 21 yeast strains were tested for the expression of primary biliary cirrhosis (PBC) specific antigens. The amounts of the antigens in the mitochondrial preparations varied with the strains. Genetic analysis of the strain differences in antigen expression indicated nuclear control which was complex. Those strains expressing the least amounts of antigens exhibited coagulating mitochondria in organellar preparations. Additional evidence relating expression of antigens to the physiological/structural state of mitochondria was that cells grown in the presence of the mitochondrial uncoupling agent, 2,4-dinitrophenol (DNP), failed to produce any antigens, and that glucose repression of mitochondria suppressed antigen expression. Blockage of mitochondrial protein synthesis either through petite mutation or by culture in the presence of erythromycin decreased the content of antigens in the mitochondria but did not completely block antigen production. The presence of the PBC antigen in the mitochondria of these cells with nonfunctional mitochondrial synthesizing machinery further indicates that these antigens are cytoplasmically synthesized. Analysis of the pre- and postmitochondrial fractions of all homogenates confirmed that the antigens are not only cytoplasmically synthesized but also have an extramitochondrial location in cells, probably in the plasma membrane.

Antigens, Fungal↗
PubMed1988

Heterogeneity of antimitochondrial antibodies with the M2-M4 pattern by immunofluorescence as assessed by Western immunoblotting and enzyme linked immunosorbent assay.

Seventy seven sera with antimitochondrial antibody exhibiting the M2-M4 pattern in immunofluorescence (56 from primary biliary cirrhosis (PBC), 21 from non-primary biliary cirrhosis patients) were studied by the combined use of Western immunoblotting with beef heart mitochondria and an enzyme linked immunosorbent assay (ELISA) with beef heart submitochondrial particles. Forty seven sera (10 without autoantibodies and 37 with different auto-antibodies) were included as controls. By immunoblotting, seven mitochondrial peptides reacting with antimitochondrial antibody positive sera were detected. These were of molecular weight 74 kD, 58 kD, 55 kD, 52 kD, 51 kD, 46 kD, and 43 kD. All primary biliary cirrhosis sera and 71% of antimitochondrial antibody-positive non-primary biliary cirrhosis sera reacted with one or more of these peptides, while none of the 47 antimitochondrial antibody negative sera reacted in immunoblotting. The 74 kD band was the most frequently detected (84% of primary biliary cirrhosis and 57% of non-primary biliary cirrhosis cases). All the primary biliary cirrhosis sera which failed to react with this peptide, showed a positive reaction with that of molecular weight 52 kD. 67/77 (87%) immunofluorescence antimitochondrial antibody positive sera reacted in the ELISA test (93% of primary biliary cirrhosis and 71% of non-primary biliary cirrhosis cases). All the 47 immunofluorescence antimitochondrial antibody negative sera were confirmed negative by ELISA. The ELISA values correlated with the immunofluorescence titres (p less than 0.05). By comparison of the results obtained by these two techniques, it emerged that the ELISA test (using our preparation of submitochondrial particles) was not able to detect the antibody directed against the mitochondrial peptide of 52 kD, which thus seems to be different from the other specificities.

Animals↗
PubMed1988

Differential growth inhibition of human diploid fibroblasts by 2-deoxyglucose and antimycin A with ageing in vitro.

The relative growth inhibitory effects of 2-deoxyglucose and antimycin A were monitored at five stages during the life-span in vitro of human diploid fibroblasts. A marked age-dependent response was observed with 2-deoxyglucose but not with antimycin A. The results confirm an increase in the rate of glycolysis with ageing, which appears to be independent of cellular mitochondrial respiratory chain capacity. This may be associated with reduced utilization of the hexose monophosphate shunt and a consequent decline in the availability of ribose moieties for nucleic acid biosynthesis.

Antimycin A↗
PubMed1988

[Nuclear magnetic resonance studies of the orbit].

Magnetic resonance tomography enables sensitive and specific three dimensional imaging processes in the bulbus, the soft parts of the orbita and the optic foramen as well as their relation to intracerebral structures. Besides a very exact imaging of the morphology it is also possible to characterise the tissue, this being a decisive factor in arriving at a correct diagnosis.

Diagnosis, Differential↗
PubMed1987

Biologically-significant scavenging of the myeloperoxidase-derived oxidant hypochlorous acid by some anti-inflammatory drugs.

Neutrophils contain the enzyme myeloperoxidase, which oxidizes Cl- ions into the powerful oxidant hypochlorous acid (HOCl). HOCl inactivates alpha 1-antiprotease, permitting uncontrolled protease activities. Most anti-inflammatory drugs tested are capable of reacting with HOCl, but the reactions seem insufficiently rapid under physiological conditions to protect alpha 1-antiprotease against inactivation by HOCl. However, rapid scavenging of HOCl might contribute to the anti-inflammatory effects of penicillamine, gold sodium thiomalate, phenylbutazone and primaquine.

Animals↗
PubMed1987

The specificity of thiourea, dimethylthiourea and dimethyl sulphoxide as scavengers of hydroxyl radicals. Their protection of alpha 1-antiproteinase against inactivation by hypochlorous acid.

Thiourea and dimethylthiourea are powerful scavengers of hydroxyl radicals (.OH), and dimethylthiourea has been used to test the involvement of .OH in several animal models of human disease. It is shown that both thiourea and dimethylthiourea are scavengers of HOCl, a powerful oxidant produced by neutrophil myeloperoxidase. Hence the ability of dimethylthiourea to protect against neutrophil-mediated tissue damage cannot be used as evidence for a role of .OH in causing such damage. Dimethyl sulphoxide also reacts with HOCl, but at a rate that is probably too low to be biologically significant at dimethyl sulphoxide concentrations up to 10 mM. Neither mannitol nor desferrioxamine, at the concentrations normally used in radical-generating systems, appears to react with HOCl.

Deferoxamine↗
PubMed1987

The antioxidant action of human extracellular fluids. Effect of human serum and its protein components on the inactivation of alpha 1-antiproteinase by hypochlorous acid and by hydrogen peroxide.

The elastase-inhibitory capacity of purified human alpha 1-antiproteinase is inactivated by low concentrations of the myeloperoxidase-derived oxidant hypochlorous acid, but much higher concentrations are required to inhibit the elastase-inhibitory capacity of serum samples. The protective effect of serum appears to be largely due to albumin. High concentrations of H2O2 also inactivate the elastase-inhibitory capacity of alpha 1-antiproteinase, by a mechanism not involving formation of hydroxyl radicals. Serum offers protection against H2O2 inactivation of alpha 1-antiproteinase. The relevance of these results to the tissue damage produced by activated phagocytes is discussed.

Blood↗
PubMed1987

Reaction pattern of mitochondrial antibodies of primary biliary cirrhosis (PBC) is species specific but not organ specific.

The cross reactivity of a well-characterized PBC serum was studied with mitochondria from a number of sources. These studies were to establish the nonorgan, species specificity of the reaction of PBC sera. As well as confirming some previously reported data, we have strong evidence suggesting that, in spite of species differences in Mr of the major antigenic bands, all mitochondria contain a set of common cross-reactive epitopes. The multiplicity of antigenic bands seen for mitochondria from some sources are shown to arise, in part, as proteolytically derived artefacts of bands of higher Mr, retaining some antigenic reactivity.

Animals↗
PubMed1987

The occurrence and localization in trypanosomes and other endo-parasites of an antigen cross-reacting with mitochondrial antibodies of primary biliary cirrhosis.

1. A mitochondrion-associated antigen to primary biliary cirrhosis (PBC) in man has been shown by solid-phase radioimmunoassay and immunoautoradiography to occur in several parasitic protozoa (Trypanosoma, Plasmodium and Eimeria spp.) and in the helminths Ascaridia galli and Nippostrongylus brasiliensis. 2. Stercorarian trypanosomes and T. brucei procyclics, with more highly-developed mitochondria, appear to contain more PBC antigen than the salivarian trypomastigote, in accordance with the known mitochondrial association of the antigen. 3. Trypanosoma lewisi and A. galli gave consistently high reactivity for PBC antigen, the antigen of the former being localized predominantly to the microsomal fraction.

Animals↗
PubMed1987

[Possibilities of magnetic resonance tomography in cardiac diagnosis].

32 patients with different cardiac lesions underwent examinations by magnetic resonance imaging (MRI). In order to reduce moving artefacts measurements were carried out with ECG-triggering. It was possible to make visible precise anatomical details of the heart in cases of congenital diseases, aneurysms, myocardial infarction etc. Important advantages are contrasted with obvious disadvantages.

Heart Defects, Congenital↗