Antibacterial and antimycotic effect of a newly discovered secretion from larvae of an endoparasitic insect,Pimpla turionellae L. (Hym.)

Three analogues of the peptidyl pheromone, pheromone of Saccharomyces kluyveri, synthesized based on the amino acid sequence proposed by Sato et al. (Agric Biol Chem 45:1531–1533, 1981) were tested for both shmoo-inducing and agglutinability-inducing actions. Purified natural pheromone of the yeast showed the highest activity among the peptides tested. When methionine in the peptides was oxidized, the activity decreased significatly. Pheromone of S. kluyveri induced sexual agglutinability in a cells of Saccharomyces cerevisiae, and shmoo in a cells of S. cerevisiae and S. kluyveri. a Pheromone of S. kluyveri had no agglutinability-inducing action on cells of S. cerevisiae. a Cells of S. kluyveri inactivated only pheromone of the same species, but a cells of S. cerevisiae inactivated pheromones of both S. cerevisiae and S. kluyveri.     

The HLA-A:HLA-B crossovers and their contribution in analysing possible haplotype-specific recombination rates

Summary The 266 haplotypes associated with 133 reported HLA-A:HLA-B crossovers in Whites were distributed in a manner representative for European populations. From this observation it follows that differential recombination rates (haplotype-controlled crossover reduction or enhancement mechanisms) do not operate in the human histocompatibility complex.Supported by the Deutsche Forschungsgemeinschaft     

Do benzodiazepines bind at adenosine uptake sites in CNS?

Benzodiazepines inhibit adenosine uptake into rat cerebral cortical synaptosomes and their potency as inhibitors of adenosine uptake is closely correlated with therapeutic efficacy. Agents which possess “benzodiazepine like” activities such as CL218,872, zopiclone and fominoben and which displace benzodiazepine binding to brain cell membranes, are also inhibitors of adenosine uptake into brain synaptosomes. The IC₅₀ values of all these compounds as inhibitors of adenosine uptake are in close agreement with the IC₅₀ values obtained for the displacement of benzodiazepine binding to the brain receptors. Adenosine uptake inhibitors (dipyridamole, hexobendine, papaverine, 6-(2-hydroxy-5-nitrobenzyl)thioguanosine) which competitively inhibit adenosine uptake, presumably by blocking adenosine binding to its carrier-protein, are competitive inhibitors of diazepam binding to the brain membrane receptors. The finding of a pronounced correlation between inhibition of benzodiazepine binding and inhibition of adenosine uptake further supports the proposal that benzodiazepines may exert part of their pharmacological action through the inhibition of adenosine uptake.     

Effects of inhibitors of DNA synthesis on spontaneous and ultraviolet light-induced sister-chromatid exchanges in Chinese hamster cells

Effects of inhibitors of DNA synthesis on spontaneous and ultraviolet light (UV)-induced sister-chromatid exchanges (SCE) were examined in a Chinese hamster cell line, V79 B-1. The inhibitors used were hydroxyurea (HU), 1-beta-D-arabinofuranosylcytosine (ara-C), aphidicolin (APC), 2',3'-dideoxythymidine triphosphate (ddTTP), neocarzinostatin (NCS), novobiocin (NB) and cycloheximide (CHX). HU, ara-C, and APC increased spontaneous SCE frequency, and had a synergistic effect on UV-induced SCE frequency. DdTTP, NCS and NB failed to show any statistically significant effect on either spontaneous or UV-induced SCE frequencies, though NCS and NB did slightly increase both spontaneous and UV-induced SCE frequencies. On the contrary, CHX decreased spontaneous SCE frequency, and more drastically, also UV-induced SCE frequency. These results are interpreted with respect to the replicating fork of DNA, a structure postulated to be involved in the formation of spontaneous and UV-induced SCE. A new model for SCE formation is proposed.     

Dose-dependent inhibitory and non-inhibitory action of somatostatin on insulin release in rats

The dose-dependent effect of intravenously infused synthetic somatostatin-14 on basal and postprandial insulin and gastrin release was assessed in anesthetized rats.Infusion of 1 ng · kg^?1 · min^?1 elicited a significant reduction of basal and postprandial insulin levels compared to the saline control group. At 15 ng · kg^?1 · min^?1 basal insulin was not affected but postprandial insulin levels were still significantly reduced. At 30 ng · kg^?1 · min^?1 neither basal nor stimulated insulin levels were affected. At the highest concentration of 120 ng · kg^?1 · min^?1 basal and postprandial insulin levels were suppressed similar to the lowest infusion rate of 1 ng · kg^?1 · min^?1. Basal gastrin levels were significantly reduced only at the highest rate of 120 ng · kg^?1 · min^?1. A significant reduction of postprandial gastrin levels was observed at 15 ng · kg^?1 · min^?1 and all higher infusion rates employed. Measurements of plasma somatostatin-like immunoreactivity (SLI) demonstrated that plasma SLI levels during the lowest infusion rate of 1 ng · kg^?1 · min^?1 were not different from the controls. No significant rise of plasma SLI levels was observed in response to the test meal. The higher infusion rates elicited a dose-dependent increase in plasma SLI levels. These data demonstrate that in rats somatostatin exerts a biological effect on insulin release at very low doses while certain greater infusion rates have no suppressive effect. Gastrin secretion is inhibited in a more linear pattern.     

Les otolithes des Téléostéens du Plio-Pleistocène belge

The study of approximately twenty three thousand otoliths from Plio-Pleistocene sites in the harbour region of Antwerp, as well as a critical revision of already published material allowed us to identify a teleostean fauna with fourty seven species (including two subspecies and seven species in open nomenclature). Two of these, Ophidion springeri and Uranoscopus septentrionalis are new to science. The fauna is typical for coastal waters slightly warmer than those of the actual North Sea and caracterized by the predominance of Gadidae. Biostratigraphically this fauna is well individualized with respect to preceeding ones (only seven species in common with the Miocene fauna) and those following twenty-three species in common with the extant fauna). The following biostratigraphical subdivision has been recognized in the Upper Miocene and the Plio-Pleistocene of the Antwerp region: (1) an association with «genus? Macrouridarum labiatus, Trisopterus sculptus, Gadiculus benedeni and Trisopterus luscus spectabilis, in the Sands of Deurne (Upper Miocene); (2) an association with Gadiculus benedeni and Merlangius pseudaeglephinus, in the Formation of Kattendijk (Pliocene); (3) an association with Gadiculus verticalis and Merlangius pseudaeglefinus in the Formation of Lillo (Plio-Pleistocene); (4) an association with Gadus morhua and Merlangius pseudaeglefinus in the so called «Icenian deposits not present in Belgium but found in the Netherlands.     

Size, subunit composition, and secondary structure of the Friend virus genome.

Electron microscope and gel electrophoresis studies show that the high-molecular-weight (50 to 70S) RNA extract from Friend virus (FV) is a dimer with the same basic structure previously observed for the RNAs from RD-114 virus, baboon virus, and woolly monkey virus. This observation greatly strengthens the inference that the dimer structure is a general characteristic of the RNAs of all mammalian type C viruses. The FV dimer is slightly less stable than the RNA dimer of woolly monkey virus, which is, in turn, much less stable than those of RD-114 and baboon virus. There are three FV monomer components, small (S), medium (M), and large (L), with molecular lengths of 6.7 +/- 0.6, 7.7 +/- 0.6, and 9.5 +/- 0.6 kilobases, respectively. There are approximately equal amounts of the S and M components and much less of the L component. Most of the dimers are homodimers (SS, MM, and LL). The frequency of heterodimers (SM, SL, ML) is much less than expected for a random assortment model.     

Observations nouvelles sur les otolithes des Téléostéens du Calcaire Grossier (Eocène du bassin de Paris)

An important new collection of otoliths from theCalcaire Grossier of the Paris Basin, as well as a critical review of already published material is studied and reveals the presence of 56 species. Five of these are new: Muraenesox spatulus, Genus Synodontidarum intermedius, Genus Ophidiidarum spinosus, Chanda bohlkei and Mene sekharani. The assemblage is indicative of tropical to subtropical marine and neritic environment with solid bottom. Biogeographically, it shows affinities with the recent Indo-pacific fauna. The association of the sites at Fercourt and Château-Rouge is clearly different from the one found at the sites of Condé-en-Brie and Damery, as it is less littoral than the second association mentioned.