Biomedical subjects

M Bodo

Publications and source records attributed to M Bodo.

At least 55 records · Page 3Linked to original sources

PubMed1995

Involvement of the cytoskeleton in regulation of collagen synthesis and secretion.

11-day chick embryo skin fibroblasts administered in vitro with colchicine or cytochalasin B, have been investigated for collagen synthesis and secretion. The cytoskeleton, examined by confocal laser scanning immunofluorescence microscope, exibited in colchicine treated cells a clear loss of microtubules, in cytochalasin B treated cells a diffuse staining and patches of intracellular fluorescence caused by actin disassembly. Cytochalasin B treatment decreased endocellular type I collagen synthesis and the total uptake of 3H-proline, while enhanced collagen secretion. Colchicine did not interfere with the collagen secretion and the label uptake, whereas it increased endocellular collagen synthesis. In addition, both drugs induced an increase of the alpha2:alpha1 ratio of collagen chains. The results obtained suggest that the cytoskeleton controls not only the morphological organization of cell components, but also the organization of biochemical processes.

Actin Cytoskeleton↗

PubMed1995

A complex cerebrovascular screening system (CERBERUS).

Stroke is unique among neurological diseases since it has a high incidence rate, severe burden of illness, high economic cost, and it may be preventable [1]. Described here is a system for screening the cerebral and vascular status of individuals to detect the initial stages of vascular disorders. The computer based polygraphic system (CERBERUS) questions subjects about risk factors, stresses, neurologic symptoms and monitors impedance pulse waves of the head and extremities, EEG, and ECG. The system has been tested in 691 cases. Doppler control studies were carried out on approximately 300 of these cases. Additional somatic measures and psychological tests related to stroke risk factors were carried out for wide biological basis of possible correlation of CERBERUS data base. The high incidence of cerebrovascular disturbance was established by CERBERUS data, further confirmed by additional data gathered, and moreover was compared by traditional medical records. The polygraphic system is more sensitive at detecting physiological asymmetries of blood flow than even a Doppler measurements. This suggests that it may be a significantly improved means for the differential diagnosis of neurological disease and the screening of subjects for arteriosclerosis, transient ischemic attack and stroke prevention to be offered at the lowest level of medical service.

Adolescent↗

PubMed1995

Internalization of Candida albicans and cytoskeletal organization in macrophages and fibroblasts treated with concanavalin A.

This paper investigates the ability of macrophages and of non-typically phagocitic cells such as fibroblasts to internalize 51Cr-labelled C. albicans in presence or in absence of lectin concanavalin A (Con A). The results obtained demonstrate that fibroblasts are also able to internalize C. albicans and that this property is potentiated by the presence of Con A. Lectin modifies only the phenotype of the fibroblast, which, poorly attached to the substrate, is globular in shape. Despite reduced cellular spreading, phagocytosis is stimulated by the lectin. In both cell populations, changes in the organization of some cytoskeletal proteins such as tubulin, actin and alpha-actinin are evident during the C. albicans infection; such rearrangements are more evident and longlasting in the fibroblasts treated with Con A.

Actinin↗

PubMed1995

Phenotype of in vitro human otosclerotic cells and its modulation by TGF beta.

A study was carried out to obtain a more detailed picture of the phenotypes of human otosclerotic and normal bone cells and to analyse the response of both populations to treatment with TGF beta 1. Total collagen synthesis was found to be decreased, but fibronectin secretion increased in otosclerotic with respect to normal cells. Although overall glycosaminoglycan (GAG) synthesis was lower in otosclerotic cells, the sulphated GAG to hyaluronic acid (HA) ratio was higher, in particular there was greater expression of chondroitin (CS) and dermatan sulphates (DS). TGF beta 1 induced a more marked increase in collagen and fibronectin release and greater production of sulphated GAGs as DS and heparan sulphate (HS) in the otosclerotic cells. The fact that the phenotype of the otosclerotic cells differed from that of the normal cells and could be modified by TGF beta 1 treatment, suggests that TGF beta 1 is implicated in the pathogenesis of otosclerosis.

Bone and Bones↗

PubMed1994

Analysis of the age-related composition of human skin collagen and collagens synthesized by fibroblast culture.

Age-related differences in the composition and the post-translational modifications of human skin collagens were examined in the present study. The data were compared with results of collagen synthesis from in vivo-aged fibroblasts in culture. Skin extracts and newly synthesized collagen from fibroblast cultures derived from both old and young donor groups showed the same ratio of collagen III to collagen I. Furthermore, no difference was noted in the degree of prolyl and lysyl hydroxylation of collagen I and collagen III Young and old fibroblasts synthesized a similar quantity of collagen in vitro. The data suggest that fibroblasts maintain a uniform level of collagen production, composition and modification independent of the age of the donor.

Adult↗

PubMed1994

Cell uptake and DNA adduct formation of the 2-amino-3 methyl-imidazo (4,5-f) quinoline in human enterocytes and chick embryo liver cells.

The compound 2-amino-3-methyl-imidazo(4,5-f)quinoline (IQ) is a powerful mutagenic compound that can induce tumours in different rat and murine target organs (liver, forestomach and small and large bowel). The ability of mutagenic IQ to form adducts to human embryonic enterocyte DNA (intestine 407 cell lines ATCC) has been studied, considering the DNA extracted from the cells and DNA of the in vitro-cultured cells. The activation with the rat hepatic microsomial fraction S9 plays an important role not only in DNA binding, but also in the uptake of IQ by the enterocytes. In the presence of S9 mix, the DNA adduct formation increases with the incubation time; in the absence of metabolic activation, the binding does not occur. Parallel experiments were carried out for comparison on chick embryo hepatocytes; for these cells, the metabolic activation with S9 mix is not as critical as for enterocytes in IQ uptake and DNA binding.

Animals↗

PubMed1994

Chondroitin sulphates and embryonic chick skin fibroblast proliferation.

We have investigated the action of sulphated glycosaminoglycans (GAGs) upon primary 11-day chick embryo skin fibroblasts cultured for various periods of time in the presence or absence of fetal calf serum (FCS). Chondroitin 4- and 6-sulphate (CS) added to serum supplemented medium provoked a decrease in DNA synthesis both in sparse and crowded cultures only at high concentrations (250 micrograms/ml). Synthesis of endocellular and secreted proteins was not affected. In contrast, CS administered to fibroblasts for 24 h in serum-free medium stimulated DNA synthesis. We postulate that the CS stimulating effect seen in serum-free cultures might be antagonized by peptide regulators of cell growth normally present in serum.

Animals↗

PubMed1994

Interleukin-1 and interleukin-6 differentially regulate the accumulation of newly synthesized extracellular matrix components and the cytokine release by developing chick embryo skin fibroblasts.

In the present study, we demonstrate that both interleukin-1 (IL-1) and interleukin-6 (IL-6) induced a significant decrease in glycosaminoglycan (GAG) synthesis and, more strikingly, secretion by 7 and 13 day-old chick embryo skin fibroblasts. We demonstrated that interleukin treatment also inhibited the synthesis of collagenase-digestible proteins (type I collagen). In addition, tissue culture supernatants (conditioned media, CM) were tested for reactivity for IL specific ELISAs and for their ability to stimulate proliferative responses in mouse thymocytes and hybridoma cells. Our findings demonstrate that chick embryo skin fibroblasts spontaneously produce IL-1 and, in even greater amounts, IL-6. Highest levels of interleukin secretion were found in the CM of 13 day-old fibroblasts and the IL-1 beta isoform was predominant over IL-1 alpha. Pretreatment of the fibroblasts with either IL-1 or IL-6 increased the secretion of both cytokines. Increased IL-1 levels were correlated with enhanced IL-1 bioactivity in the CM of IL-6 treated fibroblasts. By contrast, the raised concentrations of IL-1 in the CM of IL-1 treated cells and IL-6 in the CM of IL-1 or IL-6 treated fibroblasts failed to translate into augmented bioactivity. These observations, taken together, indicated that IL-1 and IL-6 are able to regulate the synthesis and secretion of ECM macromolecules of developing connective tissues and the cytokine release by chick embryo skin fibroblasts.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

Fulvic acid supplementation and selenium deficiency disturb the structural integrity of mouse skeletal tissue. An animal model to study the molecular defects of Kashin-Beck disease.

High concentrations of fulvic acid and selenium deficiency are the main causative factors of Kashin-Beck disease, an endemic, chronic and degenerative osteoarticular disorder found in China. In the search for an animal model of this disease, mice were exposed to these pathogenetic conditions for two generations and the collagen types from skin, bone and cartilage were analysed. The growth of the treated mice was slightly retarded, and the rate of reproduction was lower in animals maintained on a fulvic acid-supplemented and/or selenium-deficient diet. Irregular bone formation was seen by radiography and morphometry. Biochemical analysis indicated that lysine residues in collagen I from bone and in collagen II from cartilage were overmodified. The values of Hyl/(Hyl+Lys) in bone collagen alpha 1(I) chains from treated mice were about 0.434-0.484, i.e. substantially higher than that of the control (0.277). The values of this parameter for collagen II were 0.482 for control and 0.546-0.566 for treated mice. The melting temperature of collagen I from bones of treated mice was 1 degrees C lower than that of control collagen, indicating decreased thermal stability. The breakage point of the tibiae of treated mice occurred at a lower preload force than for controls, suggesting that the overmodified and thermally less stable collagen molecules are causally related to a lower mechanical strength of bones.

Animals↗

PubMed1993

Coordinate effects of Concanavalin A on cytoskeletal organization, cell shape, glycosaminoglycan accumulation and exoglycosidase activity in chick embryonic cultured fibroblasts.

The effects of Concanavalin A on cell morphology, cytoskeleton arrangement and some metabolic activities of 11-day chick embryo fibroblasts were examined. In fibroblasts, Con A caused a dose-dependent round morphology and a change in tubulin, actin and alpha-actinin arrangement, whereas it did not modify 3H-thymidine incorporation. In addition, lectin stimulated more hyaluronic acid than sulphated glycosaminoglycan synthesis, affected glycosaminoglycan sulphation, and also reduced beta-N-acetyl-D-glucosaminidase, beta-N-acetyl-D-galactosaminidase and beta-glucuronidase activities.

Animals↗

PubMed1993

Application of multivariate, fuzzy set and neural network analysis in quantitative cytological examinations.

Multivariate statistical methods have been used in several studies to increase the diagnostic reliability of TV image analyser systems. In recent years some algorithms for decision support (fuzzy logic) and for pattern recognition (neural nets), both non-linear, were developed. This paper reports on preliminary results obtained with these methods in quantitative cytology and compares them to the traditional classifiers. A total of 21 normal, 15 dysplastic and 23 malignant, gastric imprint smears were Feulgen stained and analysed on a Leitz Miamed DNA cytophotometer system. Mean DNA content, the 2c deviation index (2cDI), 5c exceeding rate (5cER), G1, S, G2 phase fraction ratios, cell nucleus area and form factor were determined. Diagnostic accuracy of the discriminant analysis was 96% for the malignant cases, 87% for dysplasias and 81% for normal cases. Cluster analysis gave no significant result. Our diagnostic system utilizing fuzzy logic has made the diagnostic borders adjustable and reliable. The back-propagation neural net correctly classified the normal and malignant cases (100%) and all but one of the dysplasias (98%). The non-linear mathematical methods improved the reliability of the diagnostic system. These new algorithms gave results comparable to traditional classifiers. The application of these methods to clinical samples is encouraging.

Algorithms↗

PubMed1993

Hyaluronic acid modulates growth, morphology and cytoskeleton in embryonic chick skin fibroblasts.

The action that hyaluronic acid (HA) exerts on cell proliferation was investigated in embryonic chick skin fibroblasts at different ages (7-14 days) and in different cell-cycle stages evaluated by flow cytometry (cells maintained with and without serum). Proliferation was estimated by 3H-thymidine incorporation and cell counting. The results demonstrated hyaluronic acid inhibits cell multiplication in all different environmental conditions examined. The inhibitory effect of HA is more evident in 14-day than 7-day old fibroblasts. The ability of HA to modulate 3H-thymidine incorporation did not involve a change in the time required for cells entering the S phase of the replicating cycle, but is due to a smaller number of cells entering in this phase. As the relationships between components of the extracellular matrix (ECM) and the cytoskeleton are known, parallel studies were carried out on some cytoskeleton proteins. Furthermore, by modifying the capacity of cells to adhere to the substrate, HA induced alterations in cell shape and in cytoskeleton components involved in these processes. We may hypothesize that HA, binding specific membrane receptors, affects cell adhesion and morphology inducing less receptivity of fibroblasts to mitogenic stimuli by transmembrane interactions with cytoskeleton.

Actinin↗

PubMed1992

Lysyl hydroxylation in collagens from hyperplastic callus and embryonic bones.

Tissue from two patients with osteogenesis imperfecta suffering from a hyperplastic callus was studied. Although collagen type I from the compact bone and the skin and fibroblast cultures of these patients showed normal lysyl hydroxylation, collagen types I, II, III and V from the callus tissue were markedly overhydroxylated. Furthermore, the overhydroxylation of lysine residues covered almost equally the entire alpha 1 (I) collagen chain, as demonstrated by the analysis of individual CNBr-derived peptides. In addition, collagen type I was isolated from femoral compact bone of 33 individuals who died between the 16th week of gestational age and 22 years. Lysyl hydroxylation rapidly decreased in both collagen alpha 1 (I) and alpha 2 (I) chains during fetal development, and only little in the postnatal period. The transient increase in lysyl hydroxylation and the involvement of various collagen types in callus tissue argue for a regulatory mechanism that may operate in bone repair and during fetal development.

Adolescent↗

PubMed1992

Comparative study on the thermostability of collagen I of skin and bone: influence of posttranslational hydroxylation of prolyl and lysyl residues.

Pepsin-solubilized collagen I from skin and bone was analyzed with regard to its thermal stability as a triple helical molecule in solution and after in vitro fibril formation. Collagen I from human control bone was compared with samples showing deficiencies or surplus in the degree of hydroxylation of lysine. The helix to coil transitions were studied by circular-dichroism measurements and limited trypsin digestion. Melting of fibrils from standardized in vitro self-assembly was investigated turbidimetrically. Human control bone collagen I has a maximum transition rate (Tm) at 43.3 degrees C in 0.05% acetic acid. This is 1.9 degrees C above control skin (Tm = 41.4 degrees C), most likely, due to a higher degree of prolyl hydroxylation--0.48 in bone vs. 0.41 in skin collagen I. Lysyl overhydroxylation of human and mouse bone collagen I appears to reduce the Tm slightly (approximately 1 degree C). Underhydroxylated bone collagen has a Tm which is 2 degrees C below control. Melting temperatures of in vitro formed fibrils are an indication for higher thermostability in parallel with an increase of lysyl hydroxylation. Accordingly, the melting temperature of such fibrils from human control skin, 49.3 degrees C, exceeds control bone by 1.4 degrees C. The degree of lysyl hydroxylation in these samples is 0.14 and 0.10, respectively. Further underhydroxylation (0.06) reduced it down to 45.4 degrees C, while extensive overhydroxylation did not continue to increase the thermal stability of fibrils.

Adult↗

PubMed1992

Hyperplastic callus formation in osteogenesis imperfecta.

Osteogenesis imperfecta, an inherited disorder of connective tissues, affects roughly (OI) 4000 people in Germany (11). The main clinical symptoms are fragile bones, progressing skeletal deformities, generalized osteoporosis and short stature. Incidentally, the clinical manifestations can range from perinatal lethal forms to phenotypical normal adults. In many instances the underlying causes of the disease are mutations in gene coding for collagen I, the predominant protein in most connective tissues. Fracture healing is usually not impaired, although in a unique group of OI-patients, a tumor-like hyperplastic callus occurs with excessive deposition of extracellular matrix constituents. Biochemical analysis of the callus is reminiscent of bone from early stages of human development and normal fracture healing (e.g. collagen type composition, degree of posttranslational modification). This underlines that, besides collagen mutations, the regulation of collagen synthesis and their posttranslational processing might be disturbed in patients with hyperplastic callus formation.

Bony Callus↗

PubMed1992

Compositional analysis of the collagenous bone matrix. A study on adult normal and osteopenic bone tissue.

The collagenous constituents of mature bone of 30 individuals 22-93 years of age were studied by post-mortem morphological and biochemical analysis. Morphometric evaluation of the second lumbar vertebral body revealed striking interindividual differences in bone mass, mean trabecular density and mean trabecular thickness. Collagen extracted from vertebral trabecular bone by limited pepsin digestion consisted mainly of collagen I (92%) and collagen V (8%). Immunohistochemistry revealed a distinct distribution of these two collagen types within the bone matrix. The degree of lysyl hydroxylation of the alpha 2(I) collagen chain correlated inversely with the trabecular bone volume (TBV) and with the mean trabecular plate density. This correlation was statistically significant for the entire study group as well as for the female and male subgroups. Within the female subgroup, the lysyl hydroxylation/TBV ratio was higher in postmenopausal than in premenopausal women and was highest in women with established osteoporosis. No significant correlation was found between the level of lysyl hydroxylation and the age of the patients. The alpha 1(I) collagen chain showed a nearly constant degree of lysyl hydroxylation in all 30 samples. The results provide convincing evidence that morphometric changes associated with osteopenia in adult bone are accompanied by an altered level of lysyl hydroxylation of the alpha 2(I)-chain of collagen I. The biochemical alterations observed may be responsible for the deposition of a deficient bone matrix in osteopenic conditions.

Adult↗

PubMed1992

Modulation of phenotype and cytoskeleton architecture by interleukin-1 alpha in human osteoblast-like cells in vitro.

Interleukin-1 alpha, a growth factor produced by macrophages as well as many other types of cells, is able to modulate biosynthetic activities in bone cells. In this work, the authors show that the administration of interleukin-1 alpha to osteoblast-like cells in vitro induces a marked change in cell morphology, which becomes dendritic, with a smaller cellular body and numerous prolongations. The morphological changes are also accompanied by an altered expression in the pattern of cytoskeleton proteins.

Cells, Cultured↗

PubMed1992

[The synthesis of collagenous and noncollagenous proteins by cells from the periodontium].

Synthesis of collagenous and noncollagenous proteins by cells originating from the alveolar bone (AB-cells) and from the periodontal ligament (PDL-cells) of 8 minipigs was analyzed in primary cell cultures. Incorporation of 3H-proline into proteins recovered from cell extracts showed, that 13.7% of protein synthesized by AB-cells and 8.0% of protein synthesized by PDL-cells were collagens. In both cell lines relative amounts of collagens synthesized decreased significantly on subculturing (AB-cells: 9.3%, PDL-cells: 6.0%). Preincubation of 2nd subculture AB-cells with beta-glycerophosphate had no significant effect on collagen synthesis. Considering the fact that relative amounts of collagen recovered from cell extracts represent only 10-20% of collagen recovered from whole culture (i.e. cells and culture medium), we suggest that collagen synthesis is an important component of in vitro-protein synthesis of cells originating from the alveolar bone and the periodontal ligament.

Alveolar Process↗