Impairment of splenic natural killer cell activity of mice infected with the polycythemic strain of friend leukemia virus

Summary The natural killer (NK) cell activity of DBA/2J mice infected with the polycythemic variant of Friend leukemia virus (FLV-P) declines early after virus challenge, being non-detectable 2 weeks after FLV-P inoculation. Cells capable of suppressing the in vitro cytolytic activity of NK effector lymphocytes were detected in the spleen of infected mice. The mechanism of suppression could be based on cell-mediated impairment of NK effector function, or on antigenic competition from splenocytes expressing NK antigens elicited by FLV-P.     

Selective lipase-catalyzed preparation of diol monobenzoates by transesterification and alcoholysis reactions in organic solvents

Lipases from Mucor miehei (MML) and Candida antarctica (CAL) are able to catalyze the monobenzoylation of the primary hydroxy group of 1,2- 1,4- or 1,5-diols with vinyl benzoate in an organic solvent, the reaction proceeding with high regioselectivity and moderate enantioselectivity. The lipase-catalyzed debenzoylation of 1,2-propanediol dibenzoate by alcoholysis with 1-octanol most satisfactorily occurred with Pseudomonas cepacia lipase absorbed onto celite that allowed also to prepare (R)-1-benzoyloxy-2-methylpropan-3-ol from 2-methyl-1,3-propanediol dibenzoate, a result complementary to MML-catalyzed benzoylation of 2-methyl-1,3-propanediol that affords the (S)-monobenzoate.     

Optimization of whey fermentation in a shaken-flask fermenter

Summary A composite design technique was used to optimize the fermentation of whey by Kluyveromyces fragilis IMAT 1872. The experimental variables (temperature T, salts NP, yeast-extract YE and lactose level L), but not pH, were found to be significant at a level of 5%. The optimal operating conditions were determined (T=36.4°C, pH=5.1, NP=0.47% w/v, YE=0.114% w/v, and L=24.75 g/l). Temperature and lactose level exhibited a great influence on the biomass yield about the stationary point. Canonical analysis showed that these variables are not mutually independent. The optimal conditions will be used as starting point for a factorial design on a jar fermenter.     

Synthesis of one diastereomeric couple of the mucolytic drug domiodol [(4S, 2R,S)-2-iodomethyl-4-hydroxymethyl-1,3-dioxolane] from D-mannitol as chiral starting material

The acid-catalyzed reaction of D-mannitol 4 with bromoacetaldehyde diethyl acetal followed by periodate cleavage of the corresponding diacetal 5 afforded (4S, 2R, S)-2-bromomethyl-4-hydroxymethyl-1,3-dioxolane 3c in good yields, from which the title compound 1 is obtained by displacement of the bromine with lithium iodide. © 1995 Wiley-Liss, Inc.     

Ultrastructural Study of Haemocytes of the Freshwater Snail Planorbarius corneus (L.) (Gastropoda, Pulmonata)

Ultrastructural studies were performed on the blood cells of Planorbarius corneus. Spreading and round cell forms were observed. The spreading form can be distinguished from the round form by its abundant cytoplasm, pseudopods and irregularly shaped nucleus. Electron dense granules in the mitochondrial matrix are found in the round form and are lacking in the spreading form. Moreover, cellular apoptosis is observed in the round form. The ultrastructural findings and the previously described characteristics support the idea that the two cell forms belong to two basic cell types.     

New insights into autophagic cell death in the gypsy moth Lymantria dispar: a proteomic approach

Autophagy is an evolutionary ancient process based on the activity of genes conserved from yeast to metazoan taxa. Whereas its role as a mechanism to provide energy during cell starvation is commonly accepted, debate continues about the occurrence of autophagy as a means specifically activated to achieve cell death. The IPLB-LdFB insect cell line, derived from the larval fat body of the lepidoptera Lymantria dispar, represents a suitable model to address this question, as both autophagic and apoptotic cell death can be induced by various stimuli. Using morphological and functional approaches, we have observed that the culture medium conditioned by IPLB-LdFB cells committed to death by the ATPase inhibitor oligomycin A stimulates autophagic cell death in untreated IPLB-LdFB cells. Moreover, proteomic analysis of the conditioned media suggests that, in IPLB-LdFB cells, oligomycin A promotes a shift towards lipid metabolism, increases oxidative stress and specifically directs the cells towards autophagic activity. Electronic Supplementary Material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. This work was supported by an F.A.R. grant from the University of Modena and Reggio Emilia (D.M. and E.O.) and by an “Experimental approaches to the study of evolution” grant from the Department of Animal Biology of the University of Modena and Reggio Emilia (D.M.).     

Facies and palaeoecology of Upper Jurassic (Middle Oxfordian) coral reefs in England

Summary This study documents the facies and fauna of Late Jurassic (Middle Oxfordian) coral reefs in England. Sedimentological and palaeoecological analysis of these reefs distinguishes three generic reef types: (1) small reef patches and thickets associated with siliciclastic deposits; (2) small reef patches and thickets associated with siliciclastic-free bioclastic grainstones and packstones; and (3) biostromal units associated with deep water facies. The depositional environments of these reef types are discussed. Two coral assemblages are identified: (1) the microsolenid assemblage; and (2) theThamnasteria, Isastraea, Fungiastraea andThecosmilia assemblage (Thamnasteria assemblage). TheThamnasteria assemblage developed in all shallow water environments in the study area, regardless of local environmental conditions. The fauna is very eurytopic,r-selected and can tolerate significant environmental fluctuations on short temporal scales (sub-seasonal). The main control on the development of the microsolenid assemblage was low light intensity, low background sedimentation rates and low hydrodynamic energy levels.