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Biomedical subjects

D Lewis

Publications and source records attributed to D Lewis.

At least 415 records · Page 23Linked to original sources
PubMedDate not supplied

Development of California Public Health Goals (PHGs) for chemicals in drinking water.

As part of a program for evaluation of environmental contaminants in drinking water, risk assessments are being conducted to develop Public Health Goals (PHGs) for chemicals in drinking water, based solely on public health considerations. California's Safe Drinking Water Act of 1996 mandated the development of PHGs for over 80 chemicals by 31 December 1999. The law allowed these levels to be set higher or lower than federal maximum contaminant levels (MCLs), including a level of zero if data are insufficient to determine a specific level. The estimated safe levels and toxicological rationale for the first 26 of these chemicals are described here. The chemicals include alachlor, antimony, benzo[a]pyrene, chlordane, copper, cyanide, dalapon, 1,2-dichlorobenzene, 1,4-dichlorobenzene, 2,4-D, diethylhexylphthalate, dinoseb, endothall, ethylbenzene, fluoride, glyphosate, lead, nitrate, nitrite, oxamyl, pentachlorophenol, picloram, trichlorofluoromethane, trichlorotrifluoroethane, uranium and xylene(s). These risk assessments are to be considered by the State of California in revising and developing state MCLs for chemicals in drinking water (which must not exceed federal MCLs). The estimates are also notable for incorporation or consideration of newer guidelines and principles for risk assessment extrapolations.

Algorithms↗
PubMedDate not supplied

Pulmonary rehabilitation, psychosocial adjustment, and use of healthcare services.

Chronic obstructive pulmonary disease (COPD) is the second most significant illness in those who are in their middle-to-late adult years. Pulmonary rehabilitation is one means of working with individuals with COPD to improve their quality of life. Nurses are often the facilitators and coordinators of pulmonary rehabilitation. Evaluation of the effects of pulmonary rehabilitation is an essential aspect of providing quality care. The purpose of this study was to evaluate the relationship of pulmonary rehabilitation to individuals' use of healthcare services and to their psychosocial adjustment to COPD. A convenience sample was obtained from an outpatient pulmonary rehabilitation program associated with a rural regional medical center in the southwestern United States. The sample consisted of 13 individuals who had no formal pulmonary rehabilitation and 17 individuals who had completed a formal pulmonary rehabilitation program. Psychosocial adjustment was measured by the Psychosocial Adjustment to Medical Illness Scale-Self Reporting (PAIS-SR). No significant statistical difference was found between the two groups in their PAIS-SR scores or use of healthcare services, as measured by the number of days spent in the hospital during the previous year.

Adaptation, Psychological↗
PubMedDate not supplied

A simple universal mechanism of use and conservation of energy: its application to movements of ions and other materials across cell, mitochondrial and other membranes and to oxidative phosphorylation.

A single simple mechanism by which all cells might both use energy to drive active transport to all solutes and also conserve energy in the form of adenosinetriphosphate (ATP) is descirbed. The basic assumption is that injection of energy results in a conformational change of the membrane which both generates transient highly-ordered water structures on its inside surface and changes membrane permeability. Ordered water is propagated through the cell by means of cooperative interactions with proteins, so that during the ordered period intracellular water is incompatible with small cations which require strong primary hydration, but has enhanced affinity for water-structure-breaking solutes. In animal cells cytoplasmic water is ordered by the activity of the plasma-membrane-bound transport ATPases. In mitochondria and bacteria the state of ordered water is identified with the energised state, which can be generated either by passage of electrons down the electron chain, or by ATPase activity. The mechanism is shown to be consistent with the observed transport activities of mitochondria and bacteria, and also provides a simple direct explanation of oxidative phosphorylation.

Adenosine Triphosphate↗