Biomedical subjects

M Bodo

Publications and source records attributed to M Bodo.

At least 73 records · Page 4Linked to original sources

PubMed1991

Fulvic acid disturbs processing of procollagen II in articular cartilage of embryonic chicken and may also cause Kashin-Beck disease.

Kashin-Beck disease is an endemic osteoarthropathy in China which may lead to skeletal deformation and dwarfism. We have analysed articular cartilage from two patients and found an accumulation of the precursor molecule, pro-pN-collagen II (pN, peptide attached at the amino-terminus) which was not present in extracts of control fetal cartilage. In addition, collagen II isolated from the same tissue by limited pepsin digestion had a decreased electrophoretic mobility, increased proline hydroxylation and decreased thermal stability. Previously, a genetic defect in pro-pN-collagen-I processing has been described in calf and sheep (dermatosparaxis) and man (Ehlers-Danlos, type VII) which caused an extreme fragility of the skin [Lenaers, A., Ansay, M., Nusgens, B.V. & Lapière, C.M. (1971) Eur. J. Biochem. 23, 533-541; Helle, O. & Nes, N.J. (1972) Acta Vet. Scand. 13, 443-445; Lichtenstein, J.R., Martin, G.R., Kohn, L.D., Byers, P.H. & McKusick, V.A. (1973) Science 182, 298-300]. Accordingly, one may assume that the impaired conversion of pro-pN-collagen II to collagen II and the structural alteration of collagen II, presumably caused by fulvic acid and other environmental factors, play an important role in the pathogenesis of Kashin-Beck disease.

Adult↗

PubMed1991

beta-Hexosaminidase expression in chick embryo fibroblasts in vitro.

1. Two forms of beta-hexosaminidase, similar to hexosaminidase A and hexosaminidase C, were separated by DEAE-cellulose chromatography in chick embryo skin fibroblasts in vitro. 2. beta-Hexosaminidase specific activity increases during development in cultured chick embryo skin fibroblasts in vitro. 3. Concanavalin-A treatment determines the increase of the neutral form, hexosaminidase C, during development. 4. Concanavalin-A reduces the specific activity of beta-hexosaminidase during development.

Animals↗

PubMed1991

Characterization of the cytoskeleton in human normal and otosclerotic osteoblast-like cells.

The localization and distribution of some cytoskeletal protein components were studied by immunostaining methods in normal and ostosclerotic osteoblast-like cells. The protein components investigated were microtubules (beta-tubulin), intermediate filaments (vimentin), microfilaments (actin and myosin) and structural proteins (alpha-actinin and fibronectin). Although the mechanism is not yet clear, the alterations observed in the pathological cells could well play a role in the expression of otosclerosis.

Actinin↗

PubMed1991

Effects of steroids on human normal and otosclerotic osteoblastic cells: influence on thymidine and leucine uptake and incorporation.

Steroid hormones are able to influence the metabolism of bone tissue in vivo, but reports regarding their direct action on bone cells fail to agree. In this study, in vitro administration of 17 beta-estradiol, testosterone and corticosterone to normal and otosclerotic osteoblastic cells induced a drop in DNA synthesis in both populations, an increase in the neosynthesis of endocellular proteins in normal cells and a rise, mainly in proteins secreted into the medium, in otosclerotic cells. The fact that 3H-thymidine and 3H-leucine uptake were lower in otosclerotic than in normal cells suggests that the membrane permeability differs in the two populations and that steroids exert an influence on both isotope uptake and directly modulate DNA and protein synthesis.

Corticosterone↗

PubMed1990

A critical crosslink region in human-bone-derived collagen type I. Specific cleavage site at residue Leu95.

Collagen was extracted from human adult bone by limited pepsin digestion and collagen types were purified by consecutive salt precipitation first under neutral and then under acid conditions. In SDS/PAGE, all collagen type I preparations showed a protein band [alpha 1s(I)] migrating between alpha 1(I) and alpha 2(I) as well as a band [alpha 2s(I)] migrating in front of alpha 2(I). The collagenous nature of the pepsin-stable alpha 1s(I) protein was clearly demonstrated by digestion with human-leucocyte-derived collagenase, immunoblotting with antibodies against collagen type I and amino acid analysis. Partial amino acid sequencing of alpha 1(I) and alpha 1s(I) identified alpha 1s(I) as a shortened alpha 1(I) chain due to a specific cleavage site between residues Leu95 and Asp96 which is in close vicinity to the hydroxylysine-derived crosslink at position 87. In circular dichroism, the proportion of thermally labile collagen molecules was proportional to the amount of shortened alpha 1(I) and alpha 2(I) chains, respectively. The melting temperature was found to be 36 +/- 0.5 degrees C as judged from circular dichroism and susceptibility to proteolysis. Our data provide clear evidence that a shortened alpha 1-derived collagen chain can be extracted from human adult bone whereas it is hardly found in human skin. The unique cleavage site might provide important information about the collagen I molecule embedded in the calcified matrix of human bone.

Adult↗

PubMed1990

Cytoskeletal and DNA synthesis modification by concanavalin A in embryonic fibroblasts maintained in serum-free and serum-added medium.

The administration of lectin concanavalin A (Con A) to in vitro cultures of chick embryo fibroblasts caused dose-dependent changes in cell shape, cytoskeleton network and DNA synthesis. After 6 hrs. even a low doses of Con A produced evident effects in serum-free cultures, whereas higher doses were required to cause alterations in cells cultured in serum-added medium. As the sugar competitor mannoside abolishes the effects, it would seem that the lectin acts by binding to transmembrane receptors and that the fibronectin present in the serum engages the receptors so that they are not available to Con A.

Animals↗

PubMed1990

Restoration of a normal phenotype, microtubular pattern and DNA synthesis in embryonic fibroblasts concanavalin A pretreated.

The present research investigated the time required for reconstructing normal microtubular pattern and the phenotype of cells after short-term (30 min.) and long-term (24 hrs.) pretreatment with the lectin concanavalin A (Con A). Short-term pretreatment led to the formation of incomplete tubules within 2 and 24 hrs. in cells cultured in 199 medium alone. The addition of serum to the medium reversed the globular phenotype and allowed the formation of normal microtubules, even after prolonged pretreatment with Con A. Whereas long-term Con A treatment provoked a reduction in DNA synthesis in 199 alone, in serum-added 199 the percentage of 3H-thymidine incorporation of treated cells tended to reach that of controls over time.

Animals↗

PubMed1990

Effects of lectins on cytoskeleton and morphology or cultured chick embryo fibroblasts.

The microfilaments and microtubules of cultured chick embryo skin fibroblasts were studied in the presence of exogenous lectins by an indirect immunofluorescence technique. Lectin treatment induced modifications in the arrangement of myosin, actin and tubulin, determined depolymerization of the proteins and caused changes in cell shape and size. The results suggest that the interaction between lectins and their specific membrane receptors triggers a series of changes in the cytoskeletal pattern via transmembrana as yet unknown mechanisms and that these are responsible for the alterations in cell shape and size.

Actin Cytoskeleton↗

PubMed1989

beta-N-acetylhexosaminidase isoenzymes during chick embryo development.

1. Two forms (I and II) with acidic pH optima and a neutral form of beta-hexosaminidase has been separated by DEAE-cellulose chromatography and characterized in skin and lung of 7, 9, 11, 14 day chick embryos and 1 day old chicken. 2. Forms I and II are similar to hexosaminidase A and B for their behaviour on DEAE-cellulose chromatography, Concanavalin A-Sepharose column and thermal stability. 3. Neutral form has a neutral pH optimum and higher molecular weight and a more acidic I. P. than forms I and II, a low beta-N-acetylgalactosaminidase activity and it is not bound by a Concanavalin A-Sepharose column and in that resemble hexosaminidase C and/or other neutral hexosaminidases. 4. We have found differences in the percentage of neutral form and in the specific activities of the extracts in the skin in different stages of development. 5. No significant differences were observed in the lung.

Animals↗

PubMed1989

Ability of retinoic and ascorbic acid to interfere with the binding of benzo(a)pyrene to DNA in explants from donors with bronchial cancer.

The capability of ascorbic acid (AA) and transretinoic acid (RA) to interfere with 3H-benzo(a)pyrene [B(a)P] binding to DNA has been evaluated in cultured bronchial mucosa explants from patients with bronchial cancer. The results show that the DNA-bound 3H-B(a)P is smaller in treated cultures than in controls. To explain this finding, it is proposed that AA, acting as antioxidant, inhibits the oxidative degradation of B(a)P, and that RA, a lipophilic compound interacting with the lipid components of mixed function oxidases, could modify the activities of these enzymes. Both vitamins decrease the concentration of ultimate carcinogen metabolites, which can interact with DNA. Furthermore, the treatment with RA does not increase DNA synthesis, while AA inhibits 3H-thymidine incorporation.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1989

The role of antioxidant enzymes in benzo(a)pyrene-induced carcinogenesis.

Chick embryo hepatocytes were cultured in the presence of benzo(a)pyrene in order to study the effects of this carcinogen on catalase, glutathione peroxidase and superoxide dismutase activity. The results demonstrate that benzo(a)pyrene is incapable of modifying the activity of these enzymes, even though it is taken up by cultured cells to form benzo(a)pyrene-DNA adducts. The effect of culturing, however, caused a marked reduction in the activity of these enzymes. The significance of these activity variations in benzo(a)pyrene in vitro carcinogenesis is discussed.

Animals↗

PubMed1989

Beta-N-acetyl-D-glucosaminidase activity in embryonic chick skin and lung tissue and cultured fibroblasts.

During development the content of mesenchymal glycosaminoglycans (GAG) undergoes prominent changes, currently considered to act as regulatory signals in the epithelial-mesenchymal interactions. The factors involved in controlling GAG composition are as yet completely unknown. Lysosomal enzymes play a key role in GAG turnover. A possible mechanism for regulating GAG content could therefore be linked to developmental modulation of lysosomal glycosidases activity. We have examined the activity of the beta-N-acetyl-D-glucosaminidase (EC 3.2.1.30; a lysosomal hydrolase cleaving glycosidic linkage of the non-reducing terminal beta-N-acetyl-D-glucosamine residues) in chick embryo skin and lung (rudiments whose GAG composition has previously been studied) at various embryonic stages. Determinations were carried out on whole organs as well as on primary cultures of fibroblasts obtained from the two rudiments. beta-N-acetyl-D-glucosaminidase activity varied greatly during development, and it was significantly different in embryonic skin and lung tissues at various incubation days. In cultured fibroblasts, the enzymatic activity varied at different incubation days correlating with the in vivo data. Developmental changes of beta-N-acetyl-D-glucosaminidase paralleled mesenchymal GAG pattern both in vivo and in vitro. Our results, therefore, support the possibility that lysosomal enzymes could be involved in the regulation of mesenchymal GAG content during development.

Acetylglucosaminidase↗

PubMed1988

Age related and lectin influenced changes of exoglycosidases activity in cultured chick embryonic skin fibroblasts.

beta-N-acetyl-D-glucosaminidase, beta-N-acetyl-galactosaminidase and a beta-D-galactosidase activity was determined in untreated and lectins (ConA, PNA, SBA and WGA) treated chick embryonic skin fibroblasts at two incubation stages. Activity of all three glycosidases increased between 7 and 14 incubation days. ConA and WGA affected the levels of enzymatic activity; while SBA and PNA were uneffective. We discuss these findings in relation to a possible role of glycosidases in controlling mesenchymal GAG turnover.

Acetylglucosaminidase↗

PubMed1987

Different behaviour of normal and neoplastic cells cultured in vitro in the presence of catalase and superoxide dismutase.

Chicken embryo fibroblasts and hepatocytes were studied in the presence of catalase and superoxide dismutase in order to establish whether these enzymes had the capacity to favour cell multiplication as previously shown for in vitro tumour ascites cells (ATP C+). The results indicate that, unlike ATP C+ cells, both fibroblasts and hepatocytes are inhibited in their multiplication by superoxide dismutase. Similar effects are exerted on hepatocytes by catalase, whereas the multiplication of fibroblasts is favoured by high doses of this enzyme. Enzyme determinations revealed high levels of catalase and superoxide dismutase in hepatocytes, whereas both enzymes were poor in fibroblasts and ATP C+.

Animals↗

PubMed1986

Antagonism between catalase and ascorbic acid in control of normal and neoplastic cell multiplication.

The authors studied the effects of a treatment with ascorbic acid on in vitro multiplication of ascites tumour cells (ATP C+), of fibroblast-like cells and of hepatocytes from chick embryos, by measuring [3H]thymidine incorporation into DNA. The results obtained show that the ATP C+ cells are the most sensitive to the toxic effects of the experimental treatment, while the hepatocytes are the most resistant cell population. A treatment with catalase was able to greatly reduce the damage caused by ascorbic acid on the ATP C+ cells. It is hypothesized that ascorbic acid inhibits cell multiplication by the H2O2 formed by its oxidation and that the cells having the highest level of catalase are more resistant to its toxic effects.

Animals↗

PubMed1986

Inhibition of the binding of 7,12-dimethylbenz[a]anthracene to DNA by ascorbic acid, reduced glutathione and cysteine in chick embryo cells cultured in vitro.

A study on the capacity of ascorbic acid, reduced glutathione and cysteine to interfere with 3H-7,12-dimethylbenz[a]anthracene (3H-DMBA) binding to DNA in cultured fibroblast-like cells from 11-day-old chick embryos showed that, although the total amount of 3H-DMBA in the treated cells was greater than in the untreated cells, the DNA-bound 3H-DMBA was less. Comparisons between the various experimental groups demonstrated that the greater 3H-DMBA in the ascorbic acid-, reduced glutathione-, and cysteine-treated groups could not be attributed to an initially higher number of cells, nor to a treatment-induced increase in DNA synthesis. It is proposed that the three substances examined inhibit the oxidative degradation of 3H-DMBA, thereby favoring its accumulation within the cell and reducing the formation of DNA-binding metabolites.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed1985

Influence of sexual hormones on solid tumor growth and ATP C+ cell replication.

Solid tumors obtained by implanting ATP C+ cells subcutaneously into the back of BALB/cf/Had/Se substrain mice developed more rapidly in males than females. Experiments conducted on gonadectomized animals demonstrated that female gonads inhibit the development of this tumor. Studies on ATP C+ cells cultured in vitro with various doses of male and female hormones showed that mainly progesterone, but to a lesser extent also estradiol, significantly inhibit cell proliferation with respect to testosterone. The treatment of normal and gonadectomized animals with testosterone and progesterone confirms the results obtained in vitro. Analyses carried out on ATP C+ cells do not reveal presence of estradiol and progesterone receptors.

Animals↗

PubMed1984

[Organotypic culture of normal and neoplastic laryngeal mucosa].

Mucous membrane's phragments from human normal and neoplastic larynx have been maintained in a organ culture system. A set of cultures has been prepared for optical microscope studies and a parallel set for incorporation studies using 3H Thymidine and 3H Leucine. The results show that there is a good incorporation of 3H Thymidine and a greater incorporation of 3H Leucine at the 7th day due to a differentiation in vitro with a new synthesis of cheratin. These data agree with the morphologic evidence of considerable horny structures in the pathological mucous membrane after 11 days at culture.

Humans↗