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H Franz

Publications and source records attributed to H Franz.

At least 19 recordsLinked to original sources
PubMed1992

Structural analysis of the carbohydrate chains isolated from mistletoe (Viscum album) lectin I.

Two glycopeptide fractions prepared from mistletoe (Viscum album) lectin I by Pronase digestion were fractioned by affinity chromatography on a concanavalin A-Sepharose column. With 400-MHz 1H NMR spectroscopy, in conjunction with sugar analysis, the following oligosaccharide structures could be determined: two oligomannose-type glycans in the ratio 4:1, one containing six mannose and the other containing five mannose units, both with two 2-acetamido-2-deoxyglucose units. In addition, a mannotriosyl-->N,N'-diacetylchitobiose glycan containing a xylosyl group and an alpha-fucosyl group (1-->3)-linked to the 2-acetamido-2-deoxyglycosyl-1 residue, a common core element of many plant glycoproteins, was also observed.

Carbohydrate Sequence↗
PubMed1992

Carbohydrate specificity of the receptor sites of mistletoe toxic lectin-I.

The carbohydrate specificity of mistletoe toxic lectin-I (ML-I) was studied by haemagglutination-inhibition assay. The results indicated that ML-I has a broad range of affinity for Gal alpha,beta linked sequences. The galabiose (E, Gal alpha 1----4Gal) sequence, a receptor of the uropathogenic E. coli ligand, was one of the best disaccharide inhibitors tested. The lectin also exhibits affinity for Lac(Gal beta 1----4Glc), T(Gal beta 1----3GalNAc), I/II(Gal beta 1----3/4GlcNAc) and B(Gal alpha 1----3Gal) sequences. Gal alpha 1----4Gal and Gal beta 1----4Glc are frequently occurring sequences of many glycosphingolipids located at the mammalian cell membranes, such as intestinal and red blood cell membranes, for ligand binding and toxin attachment. This finding provides important information concerning the possible mechanism of intoxication of cells by the mistletoe preparation.

Binding Sites↗
PubMed1992

A controlled study of maternal serum concentrations of lipoproteins in pregnancy-induced hypertension.

Seventeen women with pregnancy-induced hypertension (PIH) and 17 controls with uncomplicated pregnancy who were matched for maternal and gestational age were investigated for lipid concentrations in whole serum and lipoprotein fractions. The triglyceride level in the low-density lipoprotein fraction was higher in PIH patients than in controls (P < 0.03). The differences between values of other parameters did not attain the level of statistical significance, although the tendency of the results was consistent with findings reported in other studies. The differences observed were small and the data exhibited wide variation. Therefore, it appears unlikely that serum lipid and lipoprotein concentrations could gain major clinical importance as diagnostic parameters in PIH.

Cholesterol↗
PubMed1992

Biochemical, hematological and endocrinological parameters during repeated intense short-term running in comparison to ultra-long-distance running.

In order to see the differences in the acute effects of two kinds of running on biochemical, hematological and hormonal parameters, we investigated in one 24 h race (same exterior conditions) two groups of runners (NR = nonstop runners; RR = relay runners). From each participant blood samples were taken before, 3 times during and after the race. In both groups the lipid parameters cholesterol, triglycerides and LDL-cholesterol declined significantly, triglycerides even to 40% of their initial value, whereas HDL-cholesterol increased significantly. Renal parameters showed similar increases in both groups except for uric acid, which rose by 73% in RR compared with only 23% increase in NR. A difference was also found in the lactate and glucose concentrations, showing a four-fold increase and a 34% increase at 4 h respectively in RR, whereas the NR remained constant. Changes in the hematological parameters were similar in both groups. Cortisol and prolactin showed similar alterations during the race but LH and testosterone declined to approximately half of their initial concentration (p greater than 0.05) in NR after 4 to 8 h, in contrast to RR, where the concentration of LH or testosterone remained constant or changed only moderately but insignificantly during the race. Our investigation indicates that in ultra-long-distance running and intense short-term exercise performed under the same exterior conditions, many parameters show similar changes but great differences can be found as well if certain hormones, glucose metabolism and renal parameters are considered.

Adolescent↗
PubMed1992

Identity of the N-terminal sequences of the three A chains of mistletoe (Viscum album L.) lectins: homology with ricin-like plant toxins and single-chain ribosome-inhibiting proteins.

Mistletoe lectin (ML) I increases the production of cytokines by mononuclear cells and has been proposed as a useful biological response modifier in the treatment of cancer. Two other lectins, ML II and ML III, have been identified in mistletoe. We report that the N-terminal sequences of the three A chains of ML I, ML II and ML III are identical, and have interesting homology with the N-terminal sequences of the A chain of ricin-like toxins and of single-chain ribosome-inhibiting proteins. In addition, the three mistletoe lectins inhibit the growth of the human tumor cell line Molt 4, ML III being the most potent. followed by ML II and ML I. This inhibition is suppressed by addition of rabbit anti-ML I antibodies to the cultured cells. The data obtained suggest that the three lectins have amino acid sequences which show extensive homology and exert very similar biological effects. They may be derived from the same precursor.

Amino Acid Sequence↗
PubMed1992

Comparative lectinhistochemical studies on paraffin- and glycol methacrylate-embedded CNS tissue specimens from AIDS autopsies. Mistletoe lectin I (ML I) as cell-marker.

Brain tissue and spinal cord tissue from 12 patients who had died of AIDS was fixed in neutral formalin; then after the embedment of some of it in paraffin and some of it in glycol methacrylate, it was analyzed lectinhistochemically with mistletoe lectin I (ML I). Mistletoe lectin (ML I) is a reliable marker for microglia cells and macrophages and for special cell forms (polynuclear giant cells, so-called pericytes) belonging to this cell system. In both the embedding procedures used, the representation of the cells is very clear and subtly differentiated so that the preparations are very well suited to the study of AIDS-associated tissue damage in the CNS. Whereas the immunological macrophage markers (CD 68 markers) KPI, PG-M1 produce good results on paraffin-embedded material but are completely useless on material embedded in glycol methacrylate, the cells of the monocyte-macrophage system can be represented very well and reliably after being embedded in glycol methacrylate with mistletoe lectin I (ML I).

AIDS Dementia Complex↗
PubMed1991

Induction of tumor necrosis factor expression by a lectin from Viscum album.

A purified lectin (MLI) from Viscum album was used to test whether peripheral monocytes from human blood can be activated for the production of tumour necrosis factor (TNF). Cytotoxic activity was detected in the supernatant of MLI-stimulated monocyte cultures. This cytotoxic activity was completely inhibited by monoclonal antibodies to TNF alpha. Small amounts of soluble TNF protein were measured in a TNF alpha-specific enzyme-linked immunospecific assay system. Strong expression of TNF alpha mRNA was induced in human monocytes as well as in macrophage cultures from C3H/HeJ mice having a low response to endotoxin after 2 h of stimulation. Both chains of the MLI were found to induce TNF mRNA equally well in human monocytes. In macrophages of endotoxin-low-responder mice the toxic A chain was a better inducer of TNF mRNA than the galactose-specific lectin B chain. Thus, MLI has immunomodulating effects in activating monocytes/macrophages for inflammatory responses.

Animals↗
PubMed1991

Immunotoxin with mistletoe lectin I A-chain and ricin A-chain directed against CD5 antigen of human T-lymphocytes; comparison of efficiency and specificity.

Monoclonal anti-CD5 antibody was coupled to the enzymatically active subunit of plant toxin [either mistletoe lectin I (ML) or ricin]. The obtained conjugates proved to be selectively toxic to CD5-bearing target cells. The immunotoxin prepared from ML A-chain (MLA) was as toxic as native ML and approximately 80-fold more active than the corresponding conjugate with ricin A-chain (RTA). The comparative studies of the structural properties of isolated MLA and RTA were carried out using intrinsic fluorescence spectroscopy. The results showed similar properties for both proteins. No antigenic cross-reactivity against both toxins was detected when using polyclonal antibodies. The results suggest that MLA-antibody conjugates may be potential candidates for therapeutical use.

Antigens, CD↗
PubMed1991

Enhancement of the cytotoxicity of mistletoe lectin-1 (ML-1) by high pH or perturbation in Golgi functions.

We have studied the cytotoxicity of Mistletoe lectin-1 (ML-1), a cytotoxic protein produced by Viscum album, in CHO and V79 cells and in mutant cell lines altered in Golgi functions or in endosomal acidification. In wild-type CHO cells, cytotoxicity of ML-1 was greatly enhanced by ammonium chloride or nigericin. A CHO mutant defective in endosomal acidification (DMPR-2), which is resistant to diphtheria toxin, modeccin and Pseudomonas aeruginosa exotoxin A and hypersensitive to ricin, showed increased sensitivity to ML-1. MonR-31 and MF-1 are monensin- and compactin-resistant mutants derived from CHO and V79 cell lines, respectively, and are presumably altered in Golgi functions. The cytotoxicity of ML-1 was found to be increased in both MonR-31 and MF-1 cells as compared with their parental cells. These results indicate that the effects of chemicals or mutations altering endosomal acidification and Golgi functions on the cytotoxicity of ML-1 are similar to those on ricin cytotoxicity. Our results suggest that the cytotoxicity of ML-1 is enhanced by an increase in endosomal pH, as well as by chemicals or mutations altering the structure/functions of the Golgi regions. Like ricin, the intoxication process of ML-1 may involve the Golgi regions.

Ammonium Chloride↗
PubMed1990

Analysis of cell-surface sugar receptor expression by neoglycoenzyme binding and adhesion to plastic-immobilized neoglycoproteins for related weakly and strongly metastatic cell lines of murine tumor model systems.

Recognition of the carbohydrate part of cellular glycoconjugates by cell-surface sugar receptors may contribute to interactions, essential to the establishment of metastases. Comparison of the properties of strongly metastatic variants to their related, less metastatic counterparts offers a generally accepted approach to the discovery of metastasis-associated characteristics. The chemically induced murine lymphoma line Eb and its spontaneously arising variant ESb with increased potential for lung and liver colonization, the virally induced lymphosarcoma cell line RAW117-P and its in vivo selected variant H10 with increased potential for liver colonization, and the B16-F1 melanoma line and its in vivo selected variant F10 with increased potential for lung colonization, were chosen. A panel of 12 types of chemically glycosylated E. coli beta-galactosidase, exposing the pivotal carbohydrate residues for specific carbohydrate-dependent cell binding, was employed to study the expression of respective cell-surface sugar receptors on these cell lines. Specific binding occurred in a non-uniform manner for the individual probes. Systematic measurements at a non-saturating ligand concentration revealed quantitative differences between the 2 cell lines of each system. However, there were no consistent changes associated with the metastatic phenotype. A similar result was obtained employing Scatchard analyses for quantitative evaluation of binding characteristics in several cases. Surface receptor expression was responsive to chemical induction of differentiation in the lymphosarcoma model. Analyses of sugar-inhibitable cell adhesion to neoglycoprotein-coated plastic wells for the lymphoma and lymphosarcoma cells revealed that the presence of cell-surface sugar receptors, even at similar densities to those defined by neoglycoenzyme binding, will not necessarily translate into an identical adhesive response. Several carbohydrates, especially N-acetyl-D-galactosamine, can differentially affect this interaction at a non-toxic concentration in both model systems.

Acetylgalactosamine↗
PubMed1990

Histochemical response of mice to mistletoe lectin I (ML I).

The acute toxicity of lectin ML I from the toxic drug, mistletoe, was demonstrated in previous experiments. Because the reason for this extremely high toxicity is not yet clear, mice were studied histochemically at different times after treatment with various doses of ML I, ML I A or ML I B chain separately, or recombinations of ML I A and ML I B. Various plasma membrane-associated hydrolases as well as Golgi apparatus-and endoplasmic reticulum-linked hydrolases, peroxisomal and extraperoxisomal oxidases, lysosomal hydrolases, mitochondrial dehydrogenases, the cytoskeletal proteins keratin and vimentin as well as iron, glycogen and lipids were analysed in all organs and tissues of female mice. Irrespective of the dose, a clear-cut response was only observed in the liver. After ML I treatment, glycogen disappeared completely from all hepatocytes, and this effect did not depend on the ML I-concentration and exposure time. The increase in activity of Golgi-associated thiamine pyrophosphatase in hepatocytes and of non-specific alkaline phosphatase in the sinusoidal endothelial cells depended on the applied ML I concentration and the time of treatment. Doses of 600 or 900 ng ML I/kg drastically increased the phosphatase activities. These clear-cut changes of glycogen and enzyme activities were not observed after administration of the ML I B chain alone, and less so when the mice were treated only with the ML I A chain, or were treated with a recombination of ML I A and ML I B even at concentrations higher than that of ML I.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaline Phosphatase↗
PubMed1990

[100 years of lectin research--a balance].

A hundred years of lectin research has led to the development of lectinology as an independent field of study. Although lectinology is in part related to immunology, fundamental differences exist. Lectins are important tools in biochemistry, histochemistry and clinical diagnosis. The essential in vivo function of lectins is to combine glycoconjugates. The function of lectins in microorganisms and in animals is partially known, whereas the function of lectins in plants is mostly unclear. Of special interest, now as before, are the toxic lectins of the ricin type consisting of an A-chain (N-glycosidase) and a B-chain (D-galactose-specific lectin).

Animals↗
PubMed1990

Anionic sites in the myelin sheath as shown by cationized ferritin.

The distribution of anionic sites in the myelin sheath of sciatic nerves of rabbits was studied using cationized ferritin. Ferritin molecules were observed on the cytoplasmic sides of the myelin lamellae stratified in paranodes and Schmidt-Lanterman clefts. In the compact myelin, ferritin molecules have not been found in the tissue sections. They have been observed on membranes of the myelin fraction. The significance of the localization of negatively charged groups on the cytoplasmic side of membranes is discussed.

Animals↗
PubMed1990

Ultra-long-distance running and the liver.

During an ultra-long-distance race (1000 km in 20 days) the influence of running was examined on the enzymes aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (AP), gamma-glutamyl-transferase (GGT), and glutamate dehydrogenase (GLDH) with regard to their release from the liver cells or their induction. Furthermore the liver synthetic capacity was assayed by measuring the enzyme activity of cholinesterase and the concentration of serum albumin during the race. Of the 110 participants, 55 finished the race and only the results of these runners were used in our study. AP increased continuously from day 0 (mean = 102 U/L) to day 19 (mean = 120 U/L). A fivefold increase of AST and a twentyfold increase of CK up to day 3 was followed by a significant decrease towards the end of the race. ALT rose as well up to day 6 from a mean value of 8 U/L to 24 U/L but remained at this level. Surprising was the individual increase of the enzymes GLDH (up to twentyfold) and GGT (up to sixfold) in more than half of the finishers on various days indicating liver cell injuries. The activity of CHE and the concentration of serum albumin decreased during the race, both were significantly correlated.

Adult↗
PubMed1990

[A universal verification and protocol system for teletherapy].

To increase the quality of radiotherapy a verify and record system (VPS) was developed for teletherapy equipments, that takes control of manually adjusted irradiation parameters and of recording all relevant data of radiotherapy. The VPS can be adapted to special wishes of the user and it lends itself to application on different irradiation equipments. In the represented paper especially the extent of efficiency of the system is shown which is characterized by high operating comfort, flexible reacting to exceptional cases and by high date and operating security. The testing phase on an accelerator model has been brought to a close, actually the system is installed to an electron linear accelerator "Neptun 10p" and led to clinical trial.

Humans↗
PubMed1989

The mechanism of action of the cytotoxic lectin from Phoradendron californicum: the RNA N-glycosidase activity of the protein.

A toxic lectin from Phoradendron californicum (PCL) was found to inactivate catalytically 60 S ribosomal subunits of rabbit reticulocytes, resulting in the inhibition of protein synthesis. To study the mechanism of action of PCL, rat liver ribosomes were treated with the toxin and the extracted rRNA was treated with aniline. A fragment containing about 450 nucleotides was released from the 28 S rRNA. Analysis of the nucleotide sequence of the fragment revealed that the aniline-sensitive phosphodiester bond was between A4324 and G4325 of the 28 S rRNA. These results indicate that PCL inactivates the ribosomes by cleaving an N-glycosidic bond at A4324 of 28 S rRNA in the ribosomes as does ricin A-chain.

Animals↗