Biomedical subjects
Publications and source records attributed to Robert O'Connor.
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1,10-Phenanthroline (phen) and metal-phen complexes display fungicidal and fungiststic activity, disrupt mitochondrial function and induce oxidative stress. We have examined the effect of these drugs on the structure of yeast and mammalian cell organelles and the integrity of cellular DNA. Exposure of Candida albicans to [Mn(phen)2(mal)].2H2O or [Ag2(phen)3(mal)].2H2O (mal H2 = malonic acid) resulted in DNA degradation whereas exposure to phen or [Cu(phen)2(mal)].2H2O did not. All drugs induced extensive changes to the internal structure of yeast cells including retraction of the cytoplasm, nuclear fragmentation and disruption of the mitochondrion. In the case of cultured mammalian cells [Cu(phen)2(mal)].2H2O induced apoptosis as evidenced by the ladder pattern of DNA fragments following gel electrophoresis and also the blebbing of the cell membrane. The other drugs produced non-specific DNA degradation in mammalian cells. In conclusion, phen and metal-phen complexes have the potential to induce apoptosis in fungal and mammalian cells. Given their distinct mode of action compared to conventional anti-fungal drugs, phen and metal-phen complexes may represent a novel group of anti-fungal agents for use either in combination with existing drugs or in cases where resistance to conventional drugs has emerged.
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Idiopathic pulmonary fibrosis (IPF) is a progressive fatal fibrotic lung disease. Transforming growth factor (TGF)-beta1 is present in a biologically active conformation in the epithelial cells lining lesions with advanced IPF. To determine the role of aberrant expression of biologically active TGF-beta1 by alveolar epithelial cells (AECs), the AECs of explanted normal rat lungs were transfected with the TGF-beta1 gene using the retrovirus pMX-L-s223,225-TGF-beta1. In situ hybridization using a digoxigenin-labeled cDNA of the puromycin resistance gene contained in the pMX demonstrated that pMX-L-s233,225-TGF-beta1 was selectively transfected into AECs of the explants. Conditioned media overlying explants obtained 7 days after being treated with pMX-L-s223,225-TGF-beta1 contained 14.5 +/- 3.15 pg/ml of active TGF-beta1. With the use of Masson's trichrome staining of explant sections obtained 14 days after transfection, there were lesions similar to those in IPF, characterized by type II AEC hyperplasia, interstitial thickening, extensive increase in interstitial and subepithelial collagen, an increase in the number of fibroblasts, and areas resembling fibroblast buds. Collagens I, III, IV, and V and fibronectin were increased in explants treated with pMX-L-s223,225-TGF-beta1. The findings in the current study suggest that IPF may be a disorder of epithelial cells and not inflammatory cells.
BACKGROUND: Allergic rhinitis afflicts more than 40 million people in the United States and is a leading cause of reduced productivity at work and in school. Patients with allergic rhinitis have a wide range of symptoms that are often treated with oral combination products that contain antihistamines, decongestants, and analgesics. OBJECTIVE: To evaluate the onset of action and the extent of efficacy and safety of a combination (CPA) of clemastine (0.68 mg), pseudoephedrine (60 mg), and acetaminophen (1,000 mg) versus a combination (PA) of pseudoephedrine and acetaminophen versus placebo in the treatment of seasonal allergic rhinitis (SAR). The primary goal was to evaluate the benefit of adding clemastine to the PA combination product to treat the symptoms of SAR. METHOD: A 1-day, multicenter, double-blind, double-dummy, randomized, parallel-group park study was organized, and medication was given at 9:00 AM and 3:00 PM. RESULTS: A total of 298 subjects participated at two outdoor facilities. The primary efficacy outcome was the major symptom complex score averaged over the period of 2 to 5 hours after each dose. Mean absolute and percentage reduction in major symptom complex averaged over the period of 2 to 5 hours in the CPA group was significantly superior to those of either the PA (P < 0.01) or placebo (P < 0.03) groups. Somnolence, fatigue, and nausea were the most common volunteered adverse events; only somnolence was significantly greater after CPA than after either PA or placebo. CONCLUSIONS: Treatment with CPA was safe and highly effective in reducing symptoms associated with SAR. It was more effective than either PA or placebo over most of the postdose observation period.
Practice guidelines and performance measures are critical elements of an effective quality improvement process for emergency medical services for children (EMSC). Practice guidelines address the clinical management of individual patients, and performance measures assess the quality of care delivered to a population. The public and private sectors have invested considerable resources in developing practice guidelines and performance measures to improve the quality of health care services. As organizations continue development efforts, health care professionals who are actively involved in emergency care must collaborate to develop guidelines that address the unique physiologic, psychologic, and cultural needs of children. The Emergency Medical Services for Children Managed Care Task Force recommended the development of a series of white papers to focus on issues related to practice guidelines and performance measures in EMSC. The Maternal and Child Health Bureau, Health Resources and Services Administration, the National Highway Traffic Safety Administration, and the Robert Wood Johnson Foundation jointly sponsored the project. The paper was developed by a panel selected from a pool of experts in managed care, quality improvement, and emergency medical services. After a review of the literature, the panelists met to discuss critical issues related to practice guidelines and performance measures in EMSC. The panelists developed recommendations that can serve as resources for managed care organizations, health care providers, professional associations, and governmental policy makers. The panel recognized the lack of nationally recognized pediatric emergency care guidelines and performance measures and called for immediate action in these areas.
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BACKGROUND: A number of cellular proteins, including P-glycoprotein (P-gp) and Multiple drug Resistance Protein (MRP-1), act as drug efflux pumps and are important in the resistance of many cancers to chemotherapy. We previously reported that a small number of NSAIDs could inhibit the activity of MRP-1. MATERIALS AND METHODS: We chose sulindac as a candidate agent for further investigation as it has the most favourable efficacy and toxicity profile of the agents available for a potential specific MRP-1 inhibitor. NCI H460 cells expressed MRP-1 protein (by Western blot) and also the toxicity of doxorubicin (a substrate of MRP-1) could be potentiated in this line using non-toxic concentrations of the MRP-1 substrate/inhibitor sulindac. These cells were implanted in nude mice and the animals divided into various groups which were administered doxorubicin and/or sulindac. RESULTS: Sulindac was shown to significantly potentiate the tumour growth inhibitor activity of doxorubicin in this MRP-1-overexpressing human tumour xenograft model. CONCLUSION: Sulindac may be clinically useful as an inhibitor of the MRP-1 cancer resistance mechanism.