Galactolipid composition of the star-shaped dinoflagellate Asterodinium gracile (Kareniaceae): presence of hexadecatetraenoic acid (16:4(n-3))-containing monogalactosyldiacylglycerol as the predominant galactolipid and chemotaxonomic closeness to Karenia mikimotoi as the only other known Kareniacean producer of this fatty acid

Asterodinium gracile is a morphologically distinct, star-shaped member of the Kareniaceae with, like canonical Kareniaceae, a tertiary plastid of haptophyte origin. However, A. gracile's complement of carotenoid photosynthetic pigments has been shown to be chemotaxonomically atypical in that it possesses much less fucoxanthin when compared to that of other, canonical Kareniaceae in the genera Karenia, Karlodinium, and Takayama, also with a tertiary plastid of haptophyte origin. To date, Karenia mikimotoi, Karenia papilionacea, and Karenia selliformis are the only canonical Kareniaceae that have been shown to have a chemotaxonomically atypical carotenoid pigment composition in that they possess a gyroxanthin diester-like carotenoid not observed in other species of Karenia, Karlodinium, or Takayama (recognizing that Karenia, in general, produces fucoxanthin derivatives not observed in Karlodinium or Takayama). As a photosynthetic organism, K. mikimotoi has been shown to resemble Karenia brevis such that both species possess the chloroplast-associated galactolipids mono- and digalactosyldiacylglycerol (MGDG and DGDG, respectively) enriched with octadecapentaenoic acid (18:5(n-3)) in the sn-1 position, and hexadecenoic acid (16:0) and tetradecanoic acid (14:0) at the sn-2 position. However, K. mikimotoi is chemotaxonomically atypical beyond its carotenoid composition in that it possesses MGDG and DGDG with hexadecatetraenoic acid (16:4(n-3)), which has not been observed in any other members of the Kareniaceae, in the sn-2 position as major galactolipids. The goal of this study was to characterize the galactolipids of A. gracile with the hypothesis that they would also be atypical when compared to other canonical Kareniaceae because of A. gracile's atypical carotenoid pigment composition. To this end, we report that like K. brevis and K. mikimotoi, A. gracile produces MGDG and DGDG enriched in 18:5(n-3) at the sn-1 position and C₁₄ fatty acids, such as 14:0, at the sn-2 position, and like K. mikimotoi, it produces 18:5(n-3)/16:4(n-3) MGDG, yet here as its most abundant galactolipid.     

Fatal pneumonia with terminal emaciation in nude mice caused by pneumonia virus of mice

Athymic nude mice used as sentinel animals in a mouse holding room died of pneumonia 17 to 32 weeks after being placed in the room. Lesions in the pulmonary parenchyma consisted of monocytic exudate, epithelial cell necrosis, hemorrhage, fibrin deposition and interstitial fibrosis. Septal edema, septal cell necrosis and septal capillary stasis were common, but there was limited sloughing of bronchial lining epithelium. Indirect fluorescence microscopy (IFA) of lung sections using pneumonia virus of mice (PVM) antibody was positive. The pneumonia and IFA results were reproduced in euthymic mice inoculated experimentally with lung suspension from naturally infected mice or with tissue culture fluid from cultures infected with American Type Culture Collection PVM. The lungs of a naturally infected nude mouse were studied by transmission electron microscopy. Virus growth was found on Type II alveolar epithelium and on poorly differentiated replacement alveolar epithelium. Virus particles appeared as long exophytic filaments containing one to six linearly arranged nucleocapsids. Inclusion bodies and intracellular virus structures were not observed.     

Renicola metacercariae (Digenea: Renicolidae) in clupeoid fish: new host records

Two distinct types of Renicola metacercariae were found in herring, Clupea harengus L., from Scottish waters, and one in anchovies, Engraulis encrasicholus (L.), from the central North Sea. Both constitute new host records. These parasites may prove to be of value as biological tags for herring and other clupeoid fish.     

Differentiation of the SH-SY5Y Human Neuroblastoma Cell Line

Having appropriate in vivo and in vitro systems that provide translational models for human disease is an integral aspect of research in neurobiology and the neurosciences. Traditional in vitro experimental models used in neurobiology include primary neuronal cultures from rats and mice, neuroblastoma cell lines including rat B35 and mouse Neuro-2A cells, rat PC12 cells, and short-term slice cultures. While many researchers rely on these models, they lack a human component and observed experimental effects could be exclusive to the respective species and may not occur identically in humans. Additionally, although these cells are neurons, they may have unstable karyotypes, making their use problematic for studies of gene expression and reproducible studies of cell signaling. It is therefore important to develop more consistent models of human neurological disease. The following procedure describes an easy-to-follow, reproducible method to obtain homogenous and viable human neuronal cultures, by differentiating the chromosomally stable human neuroblastoma cell line, SH-SY5Y. This method integrates several previously described methods^1-4 and is based on sequential removal of serum from media. The timeline includes gradual serum-starvation, with introduction of extracellular matrix proteins and neurotrophic factors. This allows neurons to differentiate, while epithelial cells are selected against, resulting in a homogeneous neuronal culture. Representative results demonstrate the successful differentiation of SH-SY5Y neuroblastoma cells from an initial epithelial-like cell phenotype into a more expansive and branched neuronal phenotype. This protocol offers a reliable way to generate homogeneous populations of neuronal cultures that can be used for subsequent biochemical and molecular analyses, which provides researchers with a more accurate translational model of human infection and disease.     

Flow microfluorometric analysis of living spermatozoa stained with Hoechst 33342

Bovine spermatozoa were stained with Hoechst 33342. The fluorescence distribution of stained spermatozoa was complex. Non-motile spermatozoa displayed a higher fluorescence than did motile spermatozoa. The fluorescence profile of the motile spermatozoa was bimodal. Sort and reanalysis, and orientation experiments suggested that there are two distinct populations of motile spermatozoa.     

Simple and stereoselective syntheses of nucleoside analogues with a benzo[c]furan glycone moiety.

A series of d4T analogues have been synthesised in which the 2',3'-didehydro-2',3'-dideoxyribose moiety is replaced by a benzo[c]furan core. A simple strategy has been developed to access a range of compounds for biological screening. In addition, a stereoselective approach has been achieved with view to permit more detailed studies.     

The effects of supercritical carbon dioxide extraction and cold-pressed hexane extraction on the chemical composition and feeding value of rapeseed meal for broiler chickens

ABSTRACT

The chemical characteristics of rapeseed meal (RSM) produced from two cultivars of UK-grown rapeseed, by both supercritical carbon dioxide extraction (ScCO₂) and cold-pressed hexane extraction (CpHe) were examined. Their nutritional value, with and without protease, was then assessed in a broiler digestibility trial. Basal feed was substituted with one of four RSM batches (200 g/kg) following adjustments for dry matter (DM) and ether extract (EE) content. Half of each diet was supplemented with a mono-component protease derived from Bacillus subtilis (Axtra®PRO, Danisco Animal Nutrition, Malborough, UK) giving a total of eight test diets. Two control diets, with and without protease were also fed. At 13 d age male Ross 308 broilers were randomly allocated to seven replicate pens (five birds per pen) and assigned to one of 10 diets. Total excreta were collected from 17 to 21 d age and feed intake was recorded. Pre-caecal protein digestibility (pcPd) was determined using TiO₂ as an indigestible marker. Colourimetrically CpHe RSM was substantially darker than ScCO₂ counterparts. The influence of oil recovery method (ORM) was also evident in DM, EE, ash free neutral detergent fibre (aNDFom), neutral detergent insoluble crude protein (NDICP) and glucosinolate content (GLS). The content of DM, EE and GLS was higher in ScCO₂ RSM whereas aNDFom and NDICP levels were greater in CpHe RSM. Protein solubility in KOH was greater in ScCO₂ RSM whilst levels of NDICP were lower. Collectively these results suggest that less heat damage was incurred to the RSM during ScCO₂ extraction. There was no significant main effect of cultivar nor were any significant interactions observed between treatment factors. Rapeseed meal ScCO₂ produced greater metabolisable energy, pcPd, nitrogen retention and energy metabolisability (p < 0.05). Protease supplementation increased pcPd (p < 0.05) irrespective of ORM and cultivar. The key implications of these findings are that by adopting oil recovery methods that minimise the exposure of RSM to thermal treatments and by adding a compatible protease there is scope to increase the nutritional value of RSM for broilers and increase its utilisation in modern poultry production.