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Biomedical subjects

W O Smith

Publications and source records attributed to W O Smith.

At least 19 recordsLinked to original sources
PubMed1996

Screening for prostate cancer: a comparison of urologists and primary care physicians.

Prostate cancer screening has assumed increased importance with increasing mortality from this cancer. Newer diagnostic tests such as measurement of prostate-specific antigen (PSA) have improved detection of early prostate cancer. To determine practice patterns of prostate cancer screening, surveys were sent to 487 urologists (231 responses) and 542 family physicians (205 responses) in the Southeast inquiring about actual screening practices. In screening asymptomatic patients, the digital rectal examination was used by 99% of the urologists and 98% of the family physicians, with the mean age of screening initiation being 45 +/- 7 years for the urologists and 43 +/- 7 years for the family physicians. Serum PSA was used for screening asymptomatic patients by 98% of the urologists and 87% of the family physicians, with 49 +/- 4 years being the mean age of screening initiation for both specialties. Although differences in screening emerged, both physician groups approximated the recommended screening guidelines.

Adult↗
PubMed1984

Determination of the structure of a synthetic impurity in guaifenesin: modification of a high-performance liquid chromatographic method for phenylephrine hydrochloride, phenylpropanolamine hydrochloride, guaifenesin, and sodium benzoate in dosage forms.

An impurity present in all commercial guaifenesin-containing dosage forms examined was isolated and identified as 2-(2-methoxyphenoxy) 1,3-propanediol (VI). The eluant of a previously developed stability-indicating liquid chromatographic method for phenylephrine hydrochloride (I), phenylpropanolamine hydrochloride (II), and guaifenesin (III) was modified to yield a better separation between phenylpropanolamine and the impurity. The method was expanded to include sodium benzoate (IV), a preservative found in some liquid formulations.

Benzoates↗
PubMed1981

Alkyl and omega-amino alkyl agaroses as probes of light-induced changes in phytochrome from pea seedlings (Pisum sativum cv. Alaska).

Partially purified phytochrome from peas (Pisum sativum cv. Alaska) was absorbed to alkyl and omega-amino alkyl agaroses varying in the number of carbons in their alkyl chains from 2 to 10. The absorption and the elution of the absorbed phytochrome from them with KCl, KI, ethylene glycol and surfactants were investigated either in the dark or under red light in order to detect any chemical differences between the red-light-absorbing form of phytochrome (Pr) and the far-red-light-absorbing form of phytochrome (Pfr). With increasing alkyl chain length, more phytochrome was absorbed to the substituted agaroses. Phytochrome was absorbed to a greater extent by alkyl agaroses than by the less hydrophobic omega-amino alkyl agaroses. Absorbed Pfr was eluted by all the eluants tested to a lesser extent than the absorbed Pr. In those cases in which phytochrome could be eluted by KCl, a higher concentration was required to elute Pfr than Pr. As the chain length of the alkyl groups was increased, the difference in elution of Pr and Pfr by KCl increased. Phytochrome was salted out at a lesser concentration of ammonium sulfate after brief red-light irradiation than in the dark. Absorption of phytochrome to DEAE-agarose was also investigated as an example of ionic phytochrome-ligand interactions. The difference between the affinity of Pr and Pfr for DEAE-agarose was less than it was for omega-amino alkyl or alkyl agarose. It is concluded that Pfr is more hydrophobic than Pr.

Fabaceae↗
PubMed1980

Self-induced water intoxication in schizophrenic patients.

The authors report on 21 cases of self-induced water intoxication and cite 25 others in the literature. Three of their patients demonstrated at least temporary inappropriate antidiuretic hormone secretion, 3 were receiving a diuretic, and the other 15 appeared to have "pure" water intoxication. Fifteen patients were receiving a psychotropic medication. Self-induced water intoxication appears to be more common in schizophrenic patients than is generally realized and should be suspected in any schizophrenic patient who develops convulsions or coma. Hyperdopaminergic CNS activity may be involved, and the authors suggest a possible mechanism similar to that for tardive dyskinesia.

Adult↗