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Biomedical subjects

H Franz

Publications and source records attributed to H Franz.

At least 55 records · Page 3Linked to original sources
PubMed1989

Effects of an ultra-long-distance (1000 km) race on lipid metabolism.

The influence was examined of ultra-long-distance running (1000 km race lasting 20 days) on changes in serum lipids. The 110 participants received two types of diet, a conventional Western diet and a wholesome vegetarian diet. Of the 55 finishers the serum concentration of total cholesterol, low density lipoprotein (LDL)-cholesterol, apolipoprotein B and triglycerides decreased significantly during the first 8 days of the run, but rose again towards the end of the race without reaching pre-race levels. The high density lipoprotein (HDL)-cholesterol increased initially but decreased in the final days of the run. The values for apolipoprotein A-I were not correlated with HDL-cholesterol. The free fatty acids and free glycerol showed marked increases (five times the prerace concentration), falling towards the end of the run. Changes in serum lipids showed no correlation with changes in body mass. Similar changes were observed in both dietary groups.

Adult↗
PubMed1989

Selective killing of human monocytes by an immunotoxin containing partially denatured mistletoe lectin I.

The in vitro activity of an immunotoxin (IT) prepared by conjugating the monocyte specific RoMo-1 monoclonal antibody and partially inactivated Mistletoe lectin I (dMLI) containing inactivated B chain has been initially characterized. It is shown that while not affecting other mononuclear cells viability, this IT is capable of selectively destroying human monocytes after 24 h exposure thus resulting in the abrogation of monocyte support for PHA reactivity in mononuclear cell preparations. Therefore it seems to be possible to use this non-sugar binding holotoxin for immunotoxin preparation.

Antibodies, Monoclonal↗
PubMed1989

Visualization of anionic sites using polyethyleneimine-metal complexes.

17 Polyethyleneimine-metal complexes were synthesized and 3 of them were tested cytochemically for visualization of negative tissue charges. The demonstration of the anionic sites was carried out on rat cerebral cortex and on frog cutaneous pectoral muscle. As controls, neuraminidase digestion, methylation, and omission of osmium-postfixation were used. The osmiophilic properties of polyethyleneimine, polyethyleneimine salts, and polyethyleneimine-metal complexes were discussed.

Animals↗
PubMed1989

Effects of long-distance running on iron metabolism and hematological parameters.

In 110 well-trained participants of a 1000-km running competition lasting for 20 days hematological parameters, iron metabolism, and their respective changes during the race were investigated. Thirty-nine men and 11 women were accustomed to wholesome vegetarian food (lacto-ovovegetarian), 52 men and 8 women consumed a conventional western diet. In each group 50% of the runners finished the race. Before the competition started red blood cell count, hematocrit, and hemoglobin were on average below the values observed in the normal population in all groups. Both male and female runners consuming the wholesome diet showed significantly lower ferritin values than those on a western diet. During the first days of the competition hemolysis occurred leading to increased serum concentrations of bilirubin and iron and decreased haptoglobin levels. Hb concentrations showed a constant decrease during the race. Serum ferritin concentration rose about twofold within the first days and then decreased again without reaching pre-race levels. Serum iron concentrations showed a significant decrease between days 3 and 6. Iron loss was caused by hematuria (25% of all urines tested), gastrointestinal blood loss (10% of all stool specimens tested), and by sweating (4.5 micrograms iron/dl sweat). Our results suggest that especially in female long-distance runners it may be difficult to supply sufficient quantities of iron with the diet.

Adult↗
PubMed1989

Detection and quantification of ligand leakage from lectin affinity columns.

The usefulness of lectin affinity chromatography for the preparation of glycoproteins is impaired by ligand release. Ligand leakage from mistletoe lectin (MLI) Sepharose 4B column was detected by 24 h skin reaction in mice and by immunoblotting. Immunoaffinity chromatography was found to be an efficient method for the separation of lectin traces from the glycoprotein fraction. A sugar concentration dependent increase of lectin release from MLI-Sepharose 4B column was detected by a solid phase enzyme immunoassay.

Animals↗
PubMed1988

The site of action of the A-chain of mistletoe lectin I on eukaryotic ribosomes. The RNA N-glycosidase activity of the protein.

The site of action of the A-chain of mistletoe lectin (ML-A) from Viscum album on eukaryotic ribosomes was studied. Treatment of rat liver ribosomes with ML-A, followed by treatment of the isolated rRNA with aniline, caused the release of a fragment with about 450 nucleotides from 28 S rRNA. Further analysis of nucleotide sequences of this fragment revealed that the aniline-sensitive site of phosphodiester bond was between positions A-4324 and G-4325 in 28 S rRNA. These results indicate that ML-A inactivates the ribosomes by cleaving a N-glycosidic bond at A-4324 of 28 S rRNA in the ribosomes as ricin A-chain does.

Animals↗
PubMed1988

Demonstration of negative tissue charges by means of polyethyleneimine-metal complexes.

Three polyethyleneimine-metal complexes were synthesized and cytochemically tested for demonstration of negatively charged sites. For this purpose rat cerebral cortex synaptosomes were used. It was established that both types of polyethyleneimine-copper complexes labeled the synaptosomal membrane and synaptic vesicles with electron-dense granules, whereas the polyethyleneimine-lead complex marked the anionic sites with amorphous electron-dense material.

Animals↗
PubMed1988

A method for demonstration of lectin-binding sites using a blood group substance A/ferritin conjugate.

A new technique for demonstration of lectin-binding sites is proposed. At the 1st step of the method, the lectin binds the respective monosaccharide constituent of the glycoconjugate and at the 2nd step, the blood-group substance A-ferritin conjugate is used as a marker. The following lectins were tested: wheat germ agglutinin, soybean agglutinin, mistletoe lectin I, and concanavalin A. Human red blood cells were used as material. By means of control experiments, the specificity of the proposed technique was proved.

ABO Blood-Group System↗
PubMed1987

Effects of lectin I from mistletoe (ML I) and its isolated A and B chains on human mononuclear cells: mitogenic activity and lymphokine release.

The interaction of lectin I from mistletoe (Viscum album) (ML I) and its isolated A and B chains with mononuclear cells from healthy human donors was investigated with respect to proliferation capacity (mitogenicity) and monokine/lymphokine factor (MSF) production. The factor produced was studied by means of the electrophoretic mobility inhibition assay using guinea pig macrophages as indicator cells. ML I and its B chain exhibited comparable inhibitory effects on the proliferation of mononuclear cells (MNC, lymphocytes) that differed in quantity only. After 72 h the tritiated thymidine incorporation had diminished in comparison to the control over a concentration range from 10(-7) to 10(-11) mol/l (ML I) or from 3 X 10(-7) to 3 X 10(-9) mol/l (B chain), respectively. The ML I was about 30 times more active than the B chain. Moreover, MSF production could be substantiated for the B chain at a concentration of 3 X 10(-8) mol/l. In contrast to the B chain, the A chain stimulated the MNC to blastogenic transformation at concentrations of 3 X 10(-8) and 3 X 10(-9) mol/l. The stimulation index was much lower than after PHA stimulation. The same concentrations induced the production of lymphokine (MSF). The lymphokine activity on the indicator cells could be inhibited by L-fucose. Perhaps both cytotoxicity and lymphocyte stimulation are important for anti-tumor activity after application in vivo.

Humans↗
PubMed1986

A method for the fine-structural demonstration of lectin receptors.

A new two-step method using an Fc-fragment/ferritin conjugate as a marker for the visualization of lectin-binding sites on neuronal and other cell membranes is described. In this study of rat synaptosomes, three lectins were tested: concanavalin A, mistletoe lectin I and wheat germ agglutinin. The specificity of the method was proved by control experiments.

Animals↗
PubMed1986

Identification of actin-, alpha-actinin-, and vinculin-containing plaques at the lateral membrane of epithelial cells.

In this paper, a new type of spot desmosome-like junction (type II plaque) is described that is scattered along the entire lateral plasma membrane of rat and human intestinal epithelium. Ultrastructurally type II plaques differed from the classical type of epithelial spot desmosome ("macula adherens", further denoted as type I desmosome) by weak electron density of the membrane-associated plaque material, association of the plaques with microfilaments rather than intermediate filaments, and poorly visible material across the intercellular space. Thus, type II plaques resemble cross-sections of the zonula adherens. Immunofluorescence-microscopic studies were done using antibodies to a main protein associated with the plaques of type I desmosomes (desmoplakin I) and to the three major proteins located at the plaques of the zonula adherens (actin, alpha-actinin, and vinculin). Two types of plaques were visualized along the lateral surface of intestinal and prostatic epithelium: (a) the type I desmosomes, which were labeled with anti-desmoplakin but did not bind antibodies to actin, alpha-actinin, and vinculin, and (b) a further set of similarly sized plaques, which bound antibodies to actin, alpha-actinin, and vinculin but were not stained with anti-desmoplakin. Three-dimensional computer reconstruction of serial sections double-labeled with anti-desmoplakin and anti-alpha-actinin further confirmed that both types of plaques are spatially completely separated from each other along the lateral plasma membrane. The computer graphs further revealed that the actin-, alpha-actinin-, and vinculin-containing plaques have the tendency to form clusters, a feature also typical of type II plaques. It is suggested that the type II plaques represent spot desmosome-like intercellular junctions, which, like the zonula adherens, appear to be linked to the actin filament system. As the type II plaques cover a considerable part of the lateral cell surface, they might play a particular role in controlling cellular shape and intercellular adhesion.

Actinin↗
PubMed1986

Mistletoe lectins and their A and B chains.

Mistletoe lectins are of high biological activity. The mistletoe lectin I (ML I) is a naturally occurring conjugate of an enzyme (A chain) and a lectin (B chain). Its cytotoxicity is caused by inhibiting the protein synthesis on the ribosomal level. Prominent properties of the A chain are mitogenicity and inhibition of the protein synthesis in cell-free systems. The A chain is also a candidate for the construction of immunotoxins. The B chain as well as the intact lectins activate macrophages and release lymphocytes. They both inhibit the allergen-induced histamine release from leukocytes and the collagen-induced serotonin release from platelets. It cannot be excluded that the combination of selectively cytotoxic and immunopotentiating properties of mistletoe lectins and their chains are decisive for the therapeutic effects of mistletoe preparations.

Animals↗
PubMed1986

[Characterization of lectin receptors on cell surfaces with regard to functional aspects].

The actual definitions of lectins are presented and discussed and lectins are classified as one group of the affinitins. The ability of lectins to bind carbohydrates serves as a widely used principle in the nature for cell recognition and adhesion processes. By means of labelled glycoconjugates the identification, localization and quantitation of receptor bound lectins can be investigated as by lectinological as by a combination of lectinological and immunological reactions. The special properties of toxic lectins are discussed by use of the lectin I from mistletoe as characteristic example. The coupling of A-chains with antibodies (immunotoxins) or other haptomers (affinotoxins) leads to agents render it possible to influence directly cell functions.

Animals↗
PubMed1985

Distribution of negative charges of rat brain synaptosomes established by means of protamine-ferritin conjugate.

The negative electric charges on the synaptosomes from rat cerebral cortex were studied by means of protamine-ferritin conjugate. The synaptic vesicles in some synaptosomes were heavily labelled with the positively charged conjugate. The synaptosomal membranes including presynaptic and postsynaptic membranes were also stained but in a lesser degree. It was established that the major dense line and the intraperiod line of myelin contaminants were labelled, too.

Animals↗
PubMed1985

Mistletoe lectin I binding sites on the synaptosomes of the rat cerebral cortex.

By means of combined lectinological and immunological methods were demonstrated mistletoe lectin I binding sites on rat cerebral cortex synaptosomes. The mistletoe lectin I binds specifically D-galactose. Galactosyl residues were established on the junctional and nonjunctional synaptosomal membrane, on the synaptic vesicles, mitochondria and on myelin contamination. The relative number of mistletoe lectin I receptors per unit area of synaptosomal membrane was calculated.

Animals↗