C.P.S.—Its Strengths and Weaknesses

The following, a supplement to the annual report of the Board of Trustees of California Physicians'' Service that was published in the March 1961 issue of California Medicine, was delivered at the 1961 Annual Session of the House of Delegates by Dr. John G. Morrison, chairman of the board.     

Raoul Combes (1883–1964) et la S.I.G.M.A.

Sans résumé     

邓叔群(S.C.Teng)先生生平

1902年12月12日出生于福建省福州市。 1915年考入北京清华学堂。 1923年赴美国康奈尔大学留学取得农学士、森林学硕士学位。 1925—1928年攻读康奈尔大学植物病理学博士并被授予全美国最高科学学会 PHI-KAPPA-PHI和SIGMA-XI两枚金钥匙证章并成为其荣誉会员。 1928年回国,任岭南大学、金陵大学和中央大学一级教授。 1932—1941年历任中国科学社生物研究所、中央自然历史博物馆、中华教育文化基金董事会和中央研究院动植物研究所研究员、中央研究院林业实验研究所副所长。 1941—1946年任甘肃省水利林牧公司林业部经理。 1948年当选…     

In Memory of P. I. Marikovsky (1912–2008)

Entomological Review -     

Chromosome studies on capsicum (Solanaceae) I. Karyotype analysis in C. Chacoënse

The somatic chromosomes and karyotypes of two Argentine populations of Capsicum chacoënse A. T. Hunz. have been studied, both of which have 2n=24. The karyotypes are symmetrical, being composed of 11 m paris + one st pair; two pairs of chromosomes are satellied: pairs 1 and 12 in one population and pairs 11 and 12 in the other one. A heteromorphic pair of satellited chromosomes in one individual suggests a spontaneous reciprocal translocation. Results are compared with previous reports for the species and genus. Data show an intraspecific karyotype variation.     

Supramolecular interaction between adenosine 5′-triphosphate (ATP) and polycharged tetraazamacrocycles. Thermodynamic and 31P NMR studies

The interaction of adenosine 5′-triphosphate (ATP) with the tetraammonium macrocyclic receptors 1,1,4,4,7,7,10,10-octamethyl-1,4,7,10-tetraazacyclododecane tetrakis(iodide) (L1·4I) and 1,6,11,16-tetraazacycloeicosane (L2) in its fully protonated form, has been studied by potentiometry and ³¹P NMR in water at I = 0.15 mol dm⁻³ and 25 °C H₄L2⁴⁺ reacts both with ATP⁴⁻ and HATP³⁻ to produce H₄L2·ATP and (H₄L2·HATP)⁺ whose equilibrium constants are 6.46 × 10³ and 1.10 x 10³, respectively. In the case of L1, in which the quaternarization of the nitrogen atoms prevents the formation of hydrogen bonds, no detectable interactions arise with ATP. These results are consistent with the hypothesis that the formation of hydrogen bonds play a role of major importance in the interaction between ATP and tetrammonium receptors.     

Peak drug levels in linear pharmacokinetic systems—I. Effect of rate of injection

This paper presents three theorems on the peak drug levels that result from injection into a linear pharmacokinetic system. As a preliminary, the “rate of injection” is defined in terms of time expansion or time contraction of the injection function (input). The first theorem then states that the peak drug level will not be greater when the rate of injection is slow than when it is fast, if the impulse response is unimodal. The second theorem sets limits for the time of the maximum drug level, in relation to the time of the maximum of the (unimodal) impulse response and the duration of the input. The third theorem defines conditions which assure a definitely lower peak drug level if the rate of injection is slower. A graphical method is suggested for determining the times and magnitudes of the peak drug levels that result from constant infusions of a fixed dose at different rates. An example is provided to show that if the impulse response is multimodal then the peak drug level may sometimes increase with a decrease in the injection rate. Supported in part by U.S. Public Health Service Research Grant GM 21269 from the National Institute of General Medical Sciences, and in part by Biomedical Research Support Grant S07 RR 05392 from the National Institutes of Health. A portion of this work was presented at the Annual Meeting of the Society for Mathematical Biology at the Medical School of the University of Pennsylvania, Philadelphia, August 1976.     

Microbial metabolism of aromatic nitriles. Enzymology of C–N cleavage by Nocardia sp. (Rhodochrous group) N.C.I.B. 11216

1. An organism utilizing benzonitrile as sole carbon and nitrogen source was isolated by the enrichment-culture technique and identified as a Nocardia sp. of the rhodochrous group. 2. Respiration studies indicate that nitrile degradation proceeds through benzoic acid and catechol. 3. Cell-free extracts of benzonitrile-grown cells contain an enzyme that catalyses the conversion of benzonitrile directly into benzoic acid without intermediate formation of benzamide. 4. This nitrilase enzyme was purified by DEAE-cellulose chromatography and gel filtration on Sephadex G-100 in the presence and absence of substrate. The purity of the enzyme was confirmed by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and isoelectric focusing on polyacrylamide gel. 5. The enzyme shows a time-dependent substrate-activation process in which the substrate catalyses the association of inactive subunits of mol.wt. 45000 to form the polymeric 12-unit active enzyme of mol.wt. 560000. The time required for complete association is highly dependent on the concentration of the enzyme, temperature and pH. 6. The associated enzyme has a pH optimum of 8.0 and K(m) with benzonitrile as substrate of 4mm. The activation energy of the reaction as deduced from the Arrhenius plot is 51.8kJ/mol. 7. Enzyme activity is inhibited by thiol-specific reagents and several metal ions. 8. Studies with different substrates indicate that the nitrilase is specific for nitrile groups directly attached to the benzene ring. Various substituents in the ring are compatible with activity, though ortho-substitution, except by fluorine, renders the nitrile invulnerable to attack. 9. The environmental implications of these findings and the possible significance of the enzyme in the regulation of metabolism are discussed.