L'Ichthyofaune des marnes messiniennes des environs de senigallia (Marche,Italie): Signification paleoecologique et paleogeographique

The revision of the fish fauna from the Messinian marls of Senigallia (Marche, Italy) leads to the reduction of the faunal list of the fossil Fishes found in this locality to only four species. One new genus is created: Cryptolebias new. gen.. This fish fauna characterizes an environment with a variable salt content: it may have been more or less temporarily connected with the sea, although it was also exposed to noticeable continental influences, as demonstrated by the occurrence of Amphibians and Reptiles (Ophidians).     

Biosynthesis of sesquiterpenes in Hymenaea inferred from their quantitative co-occurrence

Leaf pocket resins of 11 species of the tropical arborescent genus Hymenaea are virtually identical qualitatively, but of widely varying quantitative proportions. Within this large range of variability, several strong positive quantitative correlations between resin constituents were found, especially between caryophyllene and β-humulene and between γ-muurolene and δ-cadinene. These data lead to clarification of sesquiterpene biosynthetic routes in Hymenaea. In addition, quantitative relationships found among caryophyllene, α- and β-selinene, γ-muurolene and δ-cadinene are explained only with difficulty by long accepted biosynthetic pathways, and the intermediacy of germacrenes is suggested.     

Evidence for a multiple innervation of purkinje cells by climbing fibers in the immature rat cerebellum

Climbing fiber (CF)–-Purkinje cell (PC) relationships were studied electrophysiologically on the cerebellum of 8 to 15 day old rats. Some animals were rendered agranular by x-irradiation from birth; some others were treated with 3-acetyl pyridine 3 days before study to selectively destroy the CF. Unitary extracellular recordings in 8–9 day old normal rats revealed that more than 50μ of the PC units each exhibited either two types of all-or-none climbing fiber responses (CFR) or stepwise graded CFRs. The other PC units only presented one type of all-or-none CFR. These activities were entirely mediated via CF since they persisted at the same age in x-irradiated rats, but were absent in animals treated with 3-acetyl pyridine. Interaction experiments were performed between juxtafastigial and Inferior Olive stimulations on 49 PC units in 8–9 day old normal rats. Collisions between impulses set up in CFs were disclosed in 21 out of the 24 PCs which exhibited only one type of CFR. In the three others and in each of the 25 PCs that displayed two types of all-or-none CFRs, or CFRs graded by steps, no collision was detected. Moreover intracellular recordings of epsp's mediated via CFs in PCs of 8–9 day old normal rats revealed that they frequently fluctuated in stepwise fashion. These results demonstrate that in the immature rat more than 50μ of PCs are each innervated by at least two distinct CFs; later on, the disappearance of the supernumerary synapses between CF and PC leads, as early as day 15, to the one-to-one relationship between CF and PC.     

La criocerine: Nouvel alcaloide isole des tiges de Crioceras dipladeniiflorus

Seven indolic alkaloids have been isolated from the stem bark of Crioceras dipladeniiflorus. One of them is new and has been called criocerine. Its structure, 7, has been established by use of physical data and chemical correlation with [Δ¹⁴]-vincamine.     

Mercurial perturbation of brush border membrane permeability in rabbit ileum

The sulfhydryl reagents Hg++ and p-chloromercuribenzene sulfonate (PCMBS) at millimolar concentrations reduced the mucosal entry of sugars and amino acids to 80-90% of control levels within several minutes. Based on 50% levels of inhibition, Hg++ proved to be 20 and 10 times as potent as PCMBS in blocking sugar and amino acid transport, respectively; both systems were equally sensitive to Hg++. Concomitant measurements of 203Hg-PCMBS demonstrated a progressive tissue uptake, which, unlike inhibition, did not saturate with increasing times of exposure, thus suggesting appreciable epithelial entry with prolonged exposures (less than 30 min at 1 mM). At similar dose levels, no significant change in mucosal Na+ entry was detected. Inhibition was not reversed by 30-min washes in cholinesalt solutions; however, 10-min exposures to dithiothreitol [10 mM] reversed Hg++ and PCMBS inhibition by 40 and 100%, respectively. Alanine and galactose influx kinetics measured at concentrations of 0-100 mM exhibited a linear or diffusional entry component in addition to the usual saturable component for both control and Hg++-treated ileum. The presence of a diffusional term in the flux equation resulted in two sets of parameters giving nearly equal fits to these measurements. It was shown that this ambiguity could be resolved by determining the change in diffusional entry with Hg++ treatment. A 20-min exposure to 0.5 mM Hg++ caused an increase from 0.050 and 0.045 to 0.064 and 0.070 cm/hr in the coefficient of diffusional entry for alanine and galactose, respectively. On the basis of this increase, it is argued that Hg++ causes a decrease in Jmax and little change in Km for both transport mechanisms. This analysis has a general bearing on kinetic measurements of transport in which passive fluxes are comparable to those mediated by specific pathways. The alanine results are consistent with bimolecular reactions between mercurial and two membrane inhibitory sites, each producing approximately 40% reduction in membrane translocation rate. The estimated reaction rate constants were 5.0 and 0.4 mM min.     

BIOCHEMICAL, HEMATOLOGIC AND COAGULATION VALUES IN THE HEREFORD CALF

Biochemical, hematologic and coagulation values have been determined in normal Hereford calves of both sexes, two to six months of age. These data generally agree with those of others and indicate a similarity in calves irrespective of their age, sex or breed. Prothrombin times are markedly longer in the calf than in man. This has resulted in alterations of anticoagulation regimens after implantation of mechanical circulatory support systems.