Terpenoid and morphological variability of Pinus quadrifolia and the natural hybridization with Pinus monophylla in the San Jacinto Mountains in California

Monoterpenoids from wood of Pinus quadrifolia and Pinus monophylla from south of the San Jacinto Mountains in southern California were analysed by gas-liquid chromatography (GLC). The number of needles per fascicle, the number of resin canals, and the number of abaxial and adaxial stomatal rows in the needles were determined. Percentages of mycrene, α-pinene, and to a minor extent of camphene, β-pinene, limonene, and β-phellandrene, the above mentioned morphological characteristics and previously obtained data were all used for identification and characterisation of species intermediacy in the San Jacinto area. It was concluded that many P. quadrifolia trees in the mixed Buck Ridge stand and some trees in two pure stands of the same area were hybrids and that sympatric and to a lesser extent allopatric introgression of P. monophylla into P. quadrifolia takes place in the San Jacinto region. Introgression of P. quadrifolia into P. monophylla could not be demonstrated.     

Circadian and Ultradian Rhythms in Blood Glucose and Plasma Insulin of Healthy Adults

The circadian and ultradian variations of blood glucose and plasma insulin have been characterized individually and as a group phenomenon in five healthy young adults studied while adhering as closely as possible to their usual routine of sleep, activity, meal content and timing. Three complementary methods were used to analyze the data: displaying raw data as a function of time; cosinor method according to Nelson and Halberg; and time series analyses as proposed by De Prins and Malbecq. The subjects were studied in the laboratory and their life routine were controlled, but very close to that of their habitual routine. They had mainly ultradian rhythms of blood glucose (mainly about 6 hr) and circadian rhythms of immunoreactive insulin (I.R.I.). Blood glucose ultradian rhythms seem to be mainly but not exclusively mealtime dependent, while I.R.I, circadian rhythms appear to be primarily endogenous in origin. Therefore, the role played by insulin in the control of blood glucose levels seems to be programmed on a circadian basis rather than by a time independent feedback phenomenon as postulated by the conventional homeostatic hypothesis. The advantage of this chronophysiologic approach is to consider circadian rhythms of both I.R.I. and insulin effectiveness as an adaptive phenomenon able to maintain blood sugar changes in the ultradian domain of rhythms.     

Microbial survey of a full-scale, biologically active filter for treatment of drinking water

The microbial community of a full-scale, biologically active drinking water filter was surveyed using molecular techniques. Nitrosomonas, Nitrospira, Sphingomonadales, and Rhizobiales dominated the clone libraries. The results elucidate the microbial ecology of biological filters and demonstrate that biological treatment of drinking water should be considered a viable alternative to physicochemical methods.     

In vitro existence of a trypsin dependent C-peptidase in human plasma. Discussion of its possible role in vivo

The C-peptide immunoreactivity (CPR) is markedly increased after a short incubation of human plasma with trypsin. Three experiments (study of the action of trypsin-treated plasma on labelled CPR, precipitation of plasma proteins with polyethylene glycol, CPR measurement with three different radioimmunoassays kits) were made in order to account for this phenomenon. The concordant results obtained and the inhibitory action of aprotinin observed in these experiments led us to conclude to the existence in plasma of a trypsin dependent C-peptidase with a specificity for the COOH terminus of the complete CPR (Arg - Arg - C-peptide - Lys - Arg). The role of this protease is probably minor in the C-peptide degradation process but could have an effect on the insulin catabolism through the existence of the alpha 2 - macroglobulin - trypsin complexes and insulin protease. This suggests a possible influence of the exocrine pancreas on the endocrine pancreas.     

Secretion into the circulating medium of lipids synthetized by isolated Wistar rat liver perfused with high concentrations of oleic acid and glycerol

In previously 18-h fasting Wistar rats, the liver is isolated and perfused with [9, 10(-3)H2] oleic acid (346 mumol and [1-14C] glycerol (115 mumol). Then, in a circulating medium, the secretion of triacylglycerols -- synthetized de novo and by esterification of exogenous oleic acid -- and VLDL is inhibited. On the other hand, the secretion of phospholipids is getting away that regulatory process.