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Biomedical subjects

R W Wilson

Publications and source records attributed to R W Wilson.

At least 109 records · Page 6Linked to original sources
PubMed1981

Children's health in families with cigarette smokers.

Recent studies have indicated higher rates of certain respiratory conditions among children who live in households with adults who smoke cigarettes. This paper analyzes data from the 1970 National Health Interview Survey. Children in families with no smokers had an average of 1.1 fewer restricted-activity days and 0.8 fewer bed-disability days per year than did children in families with two smokers. Children in families with one smoker were in between. Acute respiratory illness accounted for the difference in disability days among children in families with different smoking characteristics. Family smoking was also measured by the combined number of cigarettes smoked by adults; children in families which smoked 45 or more cigarettes a day had 1.9 more restricted activity days and 0.9 more bed-disability days due to acute respiratory conditions than did children in families who did not smoke cigarettes. The age of the child, the number of adults in the family, the education of the family head, and the family income were all controlled and did not eliminate the relationship between children's health and family smoking.

Adolescent↗
PubMed1981

Endorphins.

Explore the source record for details and available documents.

Animals↗
PubMed1981

Preliminary analysis of O.E.C.D. disability on the pretest of the post census disability survey.

The paper reviews the U.S. experience with items from the OECD long-term disability questions. The OECD questions have not yet been used in their entirety in this country, but several surveys, including the National Health Interview Survey, 1977, the Survey of Income and Program Participation, 1978, and the Social Security Disability Study, 1978, have used selected items or ones similar to the OECD items. A number of methodological issues addressed in the Bureau of the Census pretest of the Postcensus Disability Survey, planned for 1980, will be discussed in this paper, and estimates of the percentage of persons with OECD type disability by age, based on several U.S. surveys, will be also presented.

Activities of Daily Living↗
PubMed1980

Polyelectrolyte effects in DNA condensation by polyamines.

The conditions required for the counterion induced collapse of T7 bacteriophage DNA are briefly reviewed. Using Manning's counterion condensation theory we calculate a striking unity among collapse conditions: collapse occurs when from 89% to 90% of the DNA phosphate charges are neutralized by condensed counterions. The forces involved in collapsed DNA are investigated with emphasis on electrostatic repulsion. It is concluded that polyelectrolyte repulsion is the dominant force opposing collapse. Comparison of the results or polyelectrolyte repulsion calculation made using numerical methods and the Poisson-Boltzmann equation, with values of the attractive energies due to London dispersion interactions, leads to the conclusion that dispersion forces are probably large enough to cause collapse when the repulsions have been reduced by the presence of multivalent counterions.

Calorimetry↗
PubMed1980

Comparison of polyelectrolyte theories of the binding of cations to DNA.

Predictions of the binding of counterions to DNA made using the counterion condensation theory developed by Manning are compared with those made using the Poisson-Boltzmann equation, solved numerically by the Runge-Kutta procedure. Ions are defined as territorially or atmospherically bound if they fall within a given distance, defined by counterion condensation theory, from the DNA surface. Two types of experimental situations are considered. The first is the delocalized binding of a single type of counterion to DNA. In this case the Poisson-Boltzmann treatment predicts somewhat lower extents of binding TO DNA, modeled as a 10-A radius cylinder, than does Manning theory. The two theories converge as the radius decreases. The second type of experiment is the competition of ions of different valence for binding to DNA. The theories are compared with literature values of binding constants of divalent ions in the presence of monovalent ions, and of spermidine 3+ in the presence of Na+ or Mg2+. Both predict with fair accuracy the salt dependence of the equilibrium constants.

Cations↗
PubMed1980

Is any pregnancy low risk?

The standards of reproductive potential have not yet been defined. Should we accept a perinatal mortality of 5 to 10 per 1000 in the low-risk population if we have methods available to lower the rate to 1 to 2 per 1000?

Female↗
PubMed1979

Counterion-induced condesation of deoxyribonucleic acid. a light-scattering study.

The addition of the trivalent or tetravalent cations spermidine or spermine to a solution of T7 DNA in aqueous solution causes an alteration of the DNA from its extended coil form to a condensed form. If performed at low DNA concentration and at low ionic strengths, this transformation results in a monomolecular collapse to form a particle with a hydrodynamic radius of about 500 A. We have monitored this change using quasielastic and total intensity light scattering. In a solution of 50% methanol in water, the divalent cations Mg2+ and putrescine also can cause the condensation of DNA. Using Manning's (1978) counterion condensation theory, we calculate a striking unity among these disparate ions: the collapse occurs in each case when from 89 to 90% of the DNA phosphate charges are neutralized by condensed counterions.

Chemical Phenomena↗