Effect of cadmium on glycosaminoglycans in the bone of rats.
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Administration, Oral↗
Biomedical subjects
A Galicka
Publications and source records attributed to A Galicka.
Association of collagen type I alpha1 gene polymorphism with bone density in survivors of childhood cancer--preliminary report.
A candidate gene, involved in the regulation of bone mass is the COLIA1 gene encoding type I collagen, the major protein of bone matrix. The disease per se, the age of its onset and treatment options might exert an impact on bone mineralization in survivors of childhood malignancy. We examined possible allelic influences of COLIA1 gene polymorphism on BMI, BMD spine and total body in 41 survivors (15 girls) of childhood cancer (the mean age 8.9 years). Genotype distribution was 33 (80.5%) SS and 8 (19.5%) Ss. There were no differences in SDS BMD and SDS BMI between patients with SS and Ss genotype. A tendency towards lower SDS values of BMD spine and BMI was observed (not significant). In conclusion, our preliminary observations suggest that COLIA1 genotype may affect bone accrual in a population treated for childhood cancer. Further investigations in a greater population are needed.
Adolescent↗
Defects of type I procollagen metabolism correlated with decrease of prolidase activity in a case of lethal osteogenesis imperfecta.
We have studied the structure and metabolism of type I procollagen in a case of perinatal lethal osteogenesis imperfecta (OI) type II. Cultured skin fibroblasts from the proband synthesized both normal and abnormal forms of type I procollagen. Some abnormal, overmodified molecules were secreted by OI cells, although less efficiently than normal molecules from control cells. The OI fibroblasts accumulated large amounts of abnormal proalpha1(I) and proalpha2(I) chains intracellularly. The extracellular collagenolytic activity was decreased compared to control cells. Furthermore, OI cells produced less type I procollagen and demonstrated lower capacity to synthesize DNA than control cells. We have found that in contrast to prolinase activity, the activity of prolidase (an enzyme essential for collagen synthesis and cell growth) is also significantly reduced in OI cells. No differences were found in the amount of the enzyme protein recovered from both the OI and control cells. However, we found that expressions of beta1 integrin and insulin-like growth factor-I receptor (receptors known to play an important role in up regulation of prolidase activity) were decreased in OI cells compared to control cells. The decrease in prolidase activity may provide an important mechanism of altered cell growth and collagen metabolism involved in producing the perinatal lethal form of the OI phenotype.
Adult↗
[Prenatal and neonatal diagnosis of osteogenesis imperfecta in obstetrical practice].
Osteogenesis imperfecta (OI types I, II, III, IV) is a heterogeneous group of genetically disorders of connective tissue. Quantitative or qualitative abnormalities of type I collagen form pathogenetical basis of the disease. They are caused by mutations in genes encoding collagen proteins or enzymes involved in collagen biosynthesis. The clinical features of each type usually correspond to the type of mutation. Typical manifestations are fragile bones with multiple bone fractures and bone deformities. Currently applied diagnosis in utero of OI II and sometimes OI III may be performed. Diagnosis of other OI phenotypes cannot be made until after birth. We present three cases of OI II (four children) diagnosed, in utero, by ultrasound examination. The analysis in work include: 1. the prenatal sonographic features of OI type II 2. the biochemical properties of collagen in the above cases 3. genetic counselling of the families affected by OI.
Fatal Outcome↗
Identification of a pepsin-sensitive type III-like collagen in breast cancer MCF-7 cells.
Electrophoretic analysis of [3H]proline-labeled culture medium proteins of MCF-7 cells revealed the presence of disulfide-bonded, bacterial collagenase-sensitive component which comigrated with pro(alpha)1 chains of type III and type I collagens. However, it was pepsin- and trypsin-sensitive. Within 1 min of pepsin-digestion, a component with a size of alpha1 chain of type I or III collagen was produced which degraded after 5 min of digestion. Similarly, the pepsin-sensitive band was completely degraded by trypsin at 30 degrees C within 5 min. We examined CNBr peptides of the collagenous band and demonstrated that it was alpha1 chain of type III collagen. When MCF-7 cells were cultured in the presence of 2 nM estradiol, a marked increase in the level of collagen secreted into medium was found. The identified proteinase-sensitive type III-like collagen as major protein of extracellular matrix, would be expected to be more susceptible to degradation which might contribute to tumor progression.
Breast Neoplasms↗
Cytoplasmic inhibitor of eEF-2 ADP-ribosylation catalyzed by diphtheria toxin or endogenous transferase in rat liver cells.
eEF-2 (100 kDa) isolated from rat liver cells undergo ADP-ribosylation in the presence of diphtheria toxin or endogenous ADP-ribosyltransferase, which was co-purified with the factor. We separated the fraction free of elongation factor and endogenous transferase, which strongly inhibited the ADP-ribosylation of eEF-2. This fraction did not affect the activity of the elongation factor. The lack of endogenous transferase activity (which is potentially lethal for the cell) in the postribosomal supernatant could be the result of its inhibition. eEF-2 (65 kDa) which is probably responsible for the process of translocation (Gajko, A. et al. (1999) Biochem. Biophys. Res. Commun. 255, 535-538) was protected from ADP-ribosylation and its irreversible inactivation in the presence of the rat liver extract fraction.
Adenosine Diphosphate Ribose↗
Inhibitory effects of pentamidine analogues on protein biosynthesis in vitro.
Pentamidine despite its rather high toxicity, is currently in clinical use. For development of new drugs of this type it is important to know the mechanism of their action. Two new amidines (I and II) and 4',6-diamidino-2-phenylindole (DAPI) were found in preliminary experiments to inhibit protein synthesis in vitro in the cell-free rat liver system. The three compounds differed in the precise mode of action. The inhibitory effect of I on the activity of the eukaryotic elongation factor eEF-2 and ribosomes seems to suggest that the binding site of eEF-2 on the ribosome was blocked by this compound. eEF-2 has been identified as the primary target of II and eEF-1 as the primary target of DAPI in the system studied.
Animals↗