ABSTRACT
The risk of an individual woman to develop breast cancer over a 5-year period can be estimated using the Gail Model. The risk factors included in this model effectively classify patients into two different subgroups. One subgroup comprises patients at increased risk because of increased exposure to estrogen. These women are more likely to benefit from endocrine chemopreventive therapies, namely selective estrogen receptor modulators (SERMs) and aromatase inhibitors (AIs). The second subgroup comprises women who have inherited genetic mutations that predispose them to breast cancer. Chemoprevention in these patients is more likely to be achieved by novel agents, such as lapatinib, gefitinib, fenretinide, rexinoids and poly(ADP-ribose) polymerase (PARP)-inhibitors.
Subject(s)
Antineoplastic Agents/therapeutic use , Breast Neoplasms/prevention & control , Chemoprevention/methods , Aromatase Inhibitors/therapeutic use , Breast Neoplasms/etiology , Breast Neoplasms/genetics , Estrogens/metabolism , Female , Genetic Predisposition to Disease , Humans , Risk Factors , Selective Estrogen Receptor Modulators/therapeutic useABSTRACT
Chemical monitoring for butyltins in bulk seawater, surface microlayer and superficial sediments determined that the two main local sources of marine contamination by tributyltin (TBT) compounds in Malta are ship-repairing dockyards and marinas. In bulk seawater, TBT values ranged from below the detection limit of 5 ng Sn l(-1) to 300 ng Sn l(-1); in sediments derived from the most polluted areas, TBT concentrations as high as 1500 ng Sn g(-1) were measured. At TBT levels found in local harbours, several sublethal biological responses are possible and were observed, including a significant reduction in MFO enzyme system activities of fish; digestive cell atrophy in the oyster Ostrea edulis; and induction of imposex in the snail Hexaplex trunculus. The latter two responses are evident at TBT concentrations below the environmental quality standard (20 ng TBT l(-1)). The ecological implications of these results are discussed and it is concluded that exposure of marine organisms to TBT in local harbours may be expected to lead to a reduction in the long-term survival of a number of such organisms. For these reasons, both the use of TBT-based antifouling paints for pleasure boats as well as drydock practices need to be controlled by appropriate regulations and their enforcement.
Subject(s)
Trialkyltin Compounds/adverse effects , Water Pollutants, Chemical/adverse effects , Animals , Environmental Monitoring , Eukaryota , Fishes/physiology , Gonads/abnormalities , Ostreidae/anatomy & histology , Ostreidae/drug effects , Paint , Ships , Snails/anatomy & histology , Snails/drug effects , Trialkyltin Compounds/analysis , Water Pollutants, Chemical/analysisABSTRACT
The aim of this study was to investigate the effects of ultrasound irradiation on a biodegradable drug delivery system. Microporous, disk-shaped specimens of a 50-50% copolymer of polylactic and polyglycolic acids were gel cast from an acetone solution. A protein was incorporated in these specimens, which were then immersed in phosphate buffered saline and subjected to ultrasound irradiation every second day. The investigation was performed in two phases: in the first, a study was performed for 58 days to determine if ultrasonic irradiation affected the kinetics of protein release from the specimens. In the second phase, effects of frequency and duration of the ultrasound signal on the degradation of the implant were studied for 40 days. The results indicate that ultrasound irradiation resulted in almost a threefold increase in protein elution from the specimens. Both the ultrasound frequency and signal duration affected the molecular weight loss and mass loss, and changed the overall degradation kinetics of the polymer.