RESUMO
The use of ultraviolet B light (UVB) has been proven to be highly effective for treatment of various inflammatory skin diseases, but UVB phototherapy is limited by its carcinogenic side effects. It is necessary to uncover effectors that augment UVB so that similar or improved efficacy can be obtained with lower UVB doses. We found that low frequency, low intensity electromagnetic fields (EMFs) can act as such an effector and synergistically inhibit T lymphocyte proliferation. We first characterized the effects of UVB on Jurkat cells, a model for cutaneous T lymphocytes, and determined UVB's dose dependent inhibition of cell proliferation and induction of apoptosis. Cells exposed to a sublethal UVB dose retained their sensitivity to UVB, but repetitive irradiation seemed to cause accumulation of delayed DNA damage. We then exposed cells to combinations of UVB plus EMFs and found that 100 Hz, 1 mT EMFs decrease DNA synthesis of UVB-activated Jurkat cells by 34 +/- 13% compared to UVB alone. The decrease is, however, most effective when relatively high UVB doses are employed. Since EMFs alone had only a very weak inhibitory effect (10 +/- 2%), the data suggest that EMFs augment the cell killing effects of UVB in a synergistic way. These findings could provide the basis for development of new and improved clinical phototherapy protocols.
Assuntos
Divisão Celular/efeitos da radiação , DNA/biossíntese , DNA/efeitos da radiação , Campos Eletromagnéticos , Terapia Ultravioleta , Apoptose/efeitos da radiação , Fragmentação do DNA/efeitos da radiação , Humanos , Células Jurkat , Fototerapia/métodos , Linfócitos T/citologia , Linfócitos T/metabolismo , Linfócitos T/efeitos da radiação , Timidina/metabolismoRESUMO
Review of the literature on CQI/TQM in both health care and non-health care settings reveals some evidence of a positive impact for selected dimensions of CQI/TQM. There is little research, however, that examines CQI/TQM as a holistic integrated approach to quality improvement, nor are there many studies that go beyond single or small sample case studies. Using a conceptual framework involving cultural, technical, strategic, and structural dimensions, a number of barriers to CQI implementation are identified along with suggestions for high-priority areas of research.