ABSTRACT
The growth hormone 1 (GH1)/insulin-like growth factor I (IGF-I) axis plays an important role in the development of breast cancer. By binding to its receptor, GH1 stimulates the production of IGF-I and its binding protein IGFBP3, resulting in the regulation of cell proliferation, differentiation and apoptosis. The GH1 gene expression is regulated by a highly polymorphic proximal promoter and a distal locus control region (LCR) 14.5 kb upstream of the gene. We investigated the effect of single nucleotide polymorphisms (SNPs) in the LCR and in the promoter region and an intron 4 SNP (IVS4+90 T/A) on breast cancer risk in a large cohort of Polish and German familial breast cancer cases and controls. SNPs in the LCR did not show an influence on breast cancer risk, either alone or in haplotypes. Three SNPs in the promoter region (G-340T, A-68G/C and A-63T/C) showed an increased and four SNPs (A-137G, G-119T, G-93delG and T-4G) a decreased allele frequency in the cases compared with the controls. Two of the SNPs (A-137G and G-93delG) lead to a decreased breast cancer risk among the minor allele carriers in the joint analysis of the two populations (odds ratio (OR) 0.62, 95% confidence interval (95% CI) 0.44-0.89, P = 0.01 and OR 0.65, 95% CI 0.47-0.90, P = 0.01, respectively). Haplotype analysis with these seven promoter SNPs revealed a protective association (OR 0.61, 95% CI 0.37-1.00, P = 0.04) for the haplotype GAGdAAT, containing the G-93delG variant allele, which in the single analysis already showed a protective effect. The effect was marginally stronger in combination with the LCR GC haplotype (OR 0.49, 95% CI 0.23-1.01, P = 0.04).
Subject(s)
Breast Neoplasms/genetics , Human Growth Hormone/genetics , Polymorphism, Single Nucleotide , Adult , Aged , Aged, 80 and over , Female , Haplotypes , Humans , Linkage Disequilibrium , Middle Aged , Polymorphism, Restriction Fragment Length , Promoter Regions, GeneticABSTRACT
The radiation polymerization of acrylamide and N-vinylpyrrolidin-2-one in aqueous solutions has been investigated. The effect of the monomer concentration as well as the dose rate of the ionizing radiation on the process has been determined. The radical mechanism of the polymerization process has been confirmed experimentally. The effect of the individual transient species of the water radiolysis on the initiation of the polymerization process as well as the changes of the molecular weights of the arising polymers have been investigated. The dependence of the galation dose of the system on the monomer concentration has been determined.
Subject(s)
Acrylamides/chemical synthesis , Biocompatible Materials/chemical synthesis , Contact Lenses, Hydrophilic , Prostheses and Implants , Pyrrolidinones/chemical synthesis , Acrylamide , Acrylamides/radiation effects , Biocompatible Materials/radiation effects , Cobalt Radioisotopes , Pyrrolidinones/radiation effects , Radiation Dosage , Solutions , Technology, Radiologic , WaterABSTRACT
The authors present a review of publications connected with the production of the materials for biomedical purposes using of radiation technology. The general characteristic of the radiation methods and examples of applications of the results of investigations are given.
Subject(s)
Biocompatible Materials/chemical synthesis , Cobalt Radioisotopes , Contact Lenses, Hydrophilic , Polymers/chemical synthesis , Prostheses and Implants , Biocompatible Materials/radiation effects , Polymers/radiation effects , Technology Assessment, BiomedicalABSTRACT
The penetrability of the ionizing radiation through the matter makes possible the sterilization of the medical devices in the packed form by radiation method. The effect of the radiation should not bring any destructive changes in the material used for the package. In this paper have been discussed the results of the investigations of the one--and multilayer packaging materials from the point of view their utility for the radiation sterilization purposes. The changes of the useful parameters of the investigated materials have been determined in the dependence on the absorbed dose immediately after irradiation and the period of the durable keeping after the sterilization. The results of the mechanical investigations in the correlation to the results of the microbiological effects of the sterilized materials enabled to draw practical conclusions concerned the usability of the particular packages.
Subject(s)
Equipment Contamination/prevention & control , Sterilization/methods , Cellophane , Cobalt Radioisotopes , Paper , Permeability , Polyvinyl Chloride/radiation effects , Tensile StrengthABSTRACT
Utilization of ionizing radiation for the sterilization purposes enables the sterilization of dressing materials in packed form together with the protecting packages. This procedure secures advantageous conditions for prolongation of storage time of manufactured articles in the sterile state. In this work the results of six years investigations dealing with the sterility of dressings sterilized by 60Co gamma-irradiation and packed in one--and multilayer packaging materials were shown. After sterilization those materials were storaged in various temperature conditions.
Subject(s)
Bandages , Cobalt Radioisotopes , Drug Packaging , Sterilization/methods , Aluminum/radiation effects , Bacteria/radiation effects , Fungi/radiation effects , Gossypium/microbiology , Gossypium/radiation effects , Paper , Polyethylenes/radiation effectsABSTRACT
The results of investigations in the field of application of 60 Co gamma-irradiation for sterilization of cellulose dressing materials have been presented on the ground of our own experiments. The investigations were carried out for the model objects which are contents of all dressing materials, nowadays used in medical practice: cotton gauze, viscose-cotton gauze, cotton wool and cotton-viscose wool. In the present report there have been discussed the results of the test estimation of sterilized materials immediately after irradiation and during long storage as well (3-5 years after irradiation). The estimation was carried out according to the requirements of Pharmacopoeia. Moreover, the choice of parameters of sterilization process from the view-point of microbiological experiments and estimation of initial contamination degree of irradiated materials have been discussed.