PubMed Health⌕ Search

Biomedical subjects

J Boxer

Publications and source records attributed to J Boxer.

16 recordsLinked to original sources

Synthesis, opioid receptor binding profile, and antinociceptive activity of 1-azaspiro[4.5]decan-10-yl amides.

A series of azaspiro[4.5]decanyl amides were prepared by a novel cyclization route and examined for opiate receptor binding and antinociceptive activity. Selected tertiary amides in this series showed potent selective mu-receptor binding and antinociceptive activity, in contrast to the less conformationally restricted secondary amides, which showed relatively weak activity. Although structurally similar to the kappa-agonist U-50488H (1), these compounds showed virtually no tendency to bind to the kappa-receptor. An X-ray crystal structure of compound (21) confirms that the spirocyclic amine does not cause distortion away from the chair conformation of the cyclohexane ring. Either this receptor has very specific requirements for the orientation of the two nitrogens of these compounds or this ring system fills a portion of space more readily tolerated by the mu- and delta-receptors.

Analgesia↗

Assessment of fetal lung maturity by a microviscosimeter.

A new method of rapid antenatal assessment of fetal lung maturity was evaluated in relation to the newborn outcome and two other accepted test. This method is based on fluorescence depolarization (FD) technique. The special instrumentation required for this method (the Microviscosimeter) was found to be simple and easy to handle even to nonprofessional personnel. Analysis of 47 samples of amniotic fluid received within 48 hours of delivery demonstrated that lung maturity threshold may be related to a numeric value (P value) measured by this technique. With a P value of less than 0.320 respiratory distress syndrome (RDS) is unlikely to develop. With a P value greater than 0.340, chances for RDS, usually severe, are high. With a P value of less than 0.340 but greater than 0.320, RDS may or may not develop. This method did not prove to be more reliable then the determination of L/S ratio by thin layer chromatography, but its advantage is that it supplies the results in less then an hour. The FD technique proved to be more reliable then the commonly used foam stability test.

Amniotic Fluid↗

Urinary calcium excretion in schoolboys. Ethnic group differences.

The urinary calcium/creatinine ratio was estimated in two groups of schoolboys--village Arabs and urban Jewish (Ashkenazic) schoolboys, aged 10 to 11 years. Both the mean calcium/creatinine ratio and the frequency of hypercalciuria were higher among the Arab boys, and may be related to the higher incidence of chilidhood urolithiasis in Arab children in Israel.

Calcium↗

Lecithin/sphingomyelin ratio versus rapid surfactant test in normal and diabetic pregnancies.

Lecithin/sphingomyelin (L/S) ratio was measured and rapid surfactant test (RST) was performed on amniotic fluid samples drawn from 60 normal and 18 diabetic pregnancies, for determination of fetal lung maturity. The results were compared to the neonatal outcome. Comparison of L/S ratio and RST demonstrates a good correlation (95%) between the two tests in normal pregnancies. In diabetic pregnancies, however, correlation is notably lower (54%). Respiratory distress syndrome (RDS) was predicted in both L/S ratio and RST in 35-40% of normal pregnancies, with 60-65% of false negative results. In diabetic pregnancies the L/S ratio was as reliable as in normal pregnancies, but the RST was less reliable, with an RDS prediction rate of 18%. The assumption is made that increased amniotic fluid volume in diabetic pregnancies, results in dilution of the surfactant giving more false negative results in RST than are seen with L/S ratio, as in the latter, by measuring the ratio between the two constituents of amniotic fluid, the dilution factor is abolished. In diabetic pregnancies, a positive RST is reliable, but with negative results, L/S ratio must be determined for correct assessment of fetal lung maturity.

Adult↗