Reduction of dietary phosphorus absorption by phosphorus binders. A theoretical, in vitro, and in vivo study.

Antacids used to decrease phosphorus absorption in patients with renal failure may be toxic. To find more efficient or less toxic binders, a three-part study was conducted. First, theoretical calculations showed that phosphorus binding occurs in the following order of avidity: Al3+ greater than H+ greater than Ca2+ greater than Mg2+. In the presence of acid (as in the stomach), aluminum can therefore bind phosphorus better than calcium or magnesium. Second, in vitro studies showed that the time required to reach equilibrium varied from 10 min to 3 wk among different compounds, depending upon solubility in acid and neutral solutions. Third, the relative order of effectiveness of binders in vivo was accurately predicted from theoretical and in vitro results; specifically, calcium acetate and aluminum carbonate gel were superior to calcium carbonate or calcium citrate in inhibiting dietary phosphorus absorption in normal subjects. We concluded that: (a) inhibition of phosphorus absorption by binders involves a complex interplay between chemical reactions and ion transport processes in the stomach and small intestine; (b) theoretical and in vitro studies can identify potentially better in vivo phosphorus binders; and (c) calcium acetate, not previously used for medical purposes, is approximately as efficient as aluminum carbonate gel and more efficient as a phosphorus binder than other currently used calcium salts.     

A comparative study of the effects of chronic administration of propoxyphene salts to normal volunteers

Two salts of the oral analgesic agent propoxyphene, the hydrochloride salt and the 2-naphthylene sulfonic acid salt, were evaluated for safety in a 6-month study in normal male inmates of a penal institution. Parameters measured included subjective side effects, hematologic response, blood chemistry, and urine analysis as well as routine physical examination. There were 40 subjects in each drug group initially, and a concomitant control group of 40 subjects received placebo capsules for the duration of the study. There were no changes in any of the parameters measured which could be attributed to the drugs. An epidemic of mild, anicteric hepatitis did produce changes in liver function as measured by serum transaminases and alkaline phosphatase levels; however, these occurred with equal frequency in all 3 groups and were also observed in subjects not participating in the study. The results indicate the value of concomittant placebo controls in a study of this type.     

A Survey of the Sources and Availability of Computer Software Applicable to Psychophysiological Research in the Periodical Literature

PP-T0003-0-I The increased usage of small computers in the research laboratory has made it necessary for the individual investigator to become familiar with computer science. A survey of sources, availability, and types of information distributed about computer software was made to determine their relevance to psychophysiology. Periodicals are divided into five classes and discussed as to the assets and liabilities of some of the present indexing and source references. The desirability of increasing the accessibility of software applications to psychophysiology is noted.