Structural analysis and immunohistochemical localization of two acidic glycosphingolipids from the porcine, parasitic nematode, Ascaris suum

The acidic glycolipid fraction (AF) of the porcine, parasitic nematode, Ascaris suum , consisted of two subfractions. The major component AF II reacted with orcinol-sulfuric acid and molybdate, while the minor component AF I gave a positive reaction with azure-A, a cationic dye specific for sulfatides. Sugar constituent analysis, methanolysis, methylation analysis, matrix-assisted laser desorption/ionization time- of-flight mass spectrometry, liquid secondary-ion mass spectrometry, and gas-liquid chromatography/mass spectrometry specified AF II to be an unusual phosphoinositolglycosphingolipid (Galalpha1-Ins-P-1ceramide) and the minor component AF I to be a 3-sulfogalactosylcerebroside (HSO3- 3Galss1-1ceramide). The ceramide moiety of both components consisted of lignoceric (C24:0) and cerebronic (C24h:0) acids and mainly C17 iso- branched sphingosine. Immunohistochemical localization studies of the glycolipid-bound antigenic determinants with a polyclonal antiserum against AF II and an anti-sulfatide monoclonal antibody against AF I revealed the presence of the AF II-epitope in the intestine, whereas the AF I-epitope was found in the hypodermis, contractile zone of somatic muscle cells and the external musculature of the uterus. To our knowledge, this is the first report of the presence of a sulfatide in an invertebrate.      

ACUTE EFFECTS OF MOVEMENT VELOCITY ON BLOOD LACTATE AND GROWTH HORMONE RESPONSES AFTER ECCENTRIC BENCH PRESS EXERCISE IN RESISTANCE-TRAINED MEN

This study aimed to compare the effects of different velocities of eccentric muscle actions on acute blood lactate and serum growth hormone (GH) concentrations following free weight bench press exercises performed by resistance-trained men. Sixteen healthy men were divided into two groups: slow eccentric velocity (SEV; n = 8) and fast eccentric velocity (FEV; n = 8). Both groups performed four sets of eight eccentric repetitions at an intensity of 70% of their one repetition maximum eccentric (1RMecc) test, with 2-minute rest intervals between sets. The eccentric velocity was controlled to 3 seconds per range of motion for SEV and 0.5 seconds for the FEV group. There was a significant difference (P < 0.001) in the kinetics of blood lactate removal (at 3, 6, 9, 15, and 20 min) and higher mean values for peak blood lactate (P = 0.001) for the SEV group (9.1 ± 0.5 mM) compared to the FEV group (6.1 ± 0.4 mM). Additionally, serum GH concentrations were significantly higher (P < 0.001) at 15 minutes after bench press exercise in the SEV group (1.7 ± 0.6 ng · mL⁻¹) relative to the FEV group (0.1 ± 0.0 ng · mL⁻¹). In conclusion, the velocity of eccentric muscle action influences acute responses following bench press exercises performed by resistance-trained men using a slow velocity resulting in a greater metabolic stress and hormone response.     

Resource partitioning between Pacific walruses and bearded seals in the Alaska Arctic and sub-Arctic

Climate-mediated changes in the phenology of Arctic sea ice and primary production may alter benthic food webs that sustain populations of Pacific walruses (Odobenus rosmarus divergens) and bearded seals (Erignathus barbatus). Interspecific resource competition could place an additional strain on ice-associated marine mammals already facing loss of sea ice habitat. Using fatty acid (FA) profiles, FA trophic markers, and FA stable carbon isotope analyses, we found that walruses and bearded seals partitioned food resources in 2009–2011. Interspecific differences in FA profiles were largely driven by variation in non-methylene FAs, which are markers of benthic invertebrate prey taxa, indicating varying consumption of specific benthic prey. We used Bayesian multi-source FA stable isotope mixing models to estimate the proportional contributions of particulate organic matter (POM) from sympagic (ice algal), pelagic, and benthic sources to these apex predators. Proportional contributions of FAs to walruses and bearded seals from benthic POM sources were high [44 (17–67)% and 62 (38–83)%, respectively] relative to other sources of POM. Walruses also obtained considerable contributions of FAs from pelagic POM sources [51 (32–73)%]. Comparison of δ¹³C values of algal FAs from walruses and bearded seals to those from benthic prey from different feeding groups from the Chukchi and Bering seas revealed that different trophic pathways sustained walruses and bearded seals. Our findings suggest that (1) resource partitioning may mitigate interspecific competition, and (2) climate change impacts on Arctic food webs may elicit species-specific responses in these high trophic level consumers.     

Adaptations to a diet of nectar and pollen in the marsupial Tarsipes rostratus (Marsupialia: Tarsipedidae)

The mouse-sized marsupial Tarsipes rostratus , endemic to south-western Australia, feeds almost exclusively on nectar and pollen. Its tongue has long filiform papillae at the tip and shorter compound papillae over much of the upper surface. These collect nectar and pollen when the long tongue, stiffened by a keratinized keel, is protruded into flowers or over pollen presenters. Pollen is scraped from the papillae by a series of combs on the roof of the mouth. A large diverticulum, off the main chamber of the stomach, may store nectar in times of surplus. Pollen is not digested in the stomach but during passage down the simple intestine, which does not have a caecum. In captive animals, pollen passed through the gut in about six hours and the percentage of grains voided which had lost their contents was related to time spent in the gut. The digestion process remains unresolved but probably takes place through the apertures in the shells of pollen grains. Tarsipes ingests large numbers of pollen grains whose contents probably provide necessary nutrients absent from nectar.     

Molecular cloning and characterization of an alpha1,3 fucosyltransferase, CEFT-1, from Caenorhabditis elegans

We report on the identification, molecular cloning, and characterization of an alpha1,3 fucosyltransferase (alpha1,3FT) expressed by the nematode, Caenorhabditis elegans . Although C. elegans glycoconjugates do not express the Lewis x antigen Galbeta1-- >4[Fucalpha1-->3]GlcNAcbeta-->R, detergent extracts of adult C.elegans contain an alpha1,3FT that can fucosylate both nonsialylated and sialylated acceptor glycans to generate the Lexand sialyl Lexantigens, as well as the lacdiNAc-containing acceptor GalNAcbeta1-->4GlcNAcbeta1-- >R to generate GalNAcbeta1-->4 [Fucalpha1-->3]GlcNAcbeta1-->R. A search of the C.elegans genome database revealed the existence of a gene with 20-23% overall identity to all five cloned human alpha1,3FTs. The putative cDNA for the C.elegans alpha1,3FT (CEFT-1) was amplified by PCR from a cDNA lambdaZAP library, cloned, and sequenced. COS7 cells transiently transfected with cDNA encoding CEFT-1 express the Lex, but not sLexantigen. The CEFT-1 in the transfected cell extracts can synthesize Lex, but not sialyl Lex, using exogenous acceptors. A second fucosyltransferase activity was detected in extracts of C. elegans that transfers Fuc in alpha1,2 linkage to Gal specifically on type-1 chains. The discovery of alpha-fucosyltransferases in C. elegans opens the possibility of using this well-characterized nematode as a model system for studying the role of fucosylated glycans in the development and survival of C.elegans and possibly other helminths.      

The influence of egg-size, mass and composition upon hatching success in the short-tailed shearwater Puffinus tenuirostris (Aves: Procellariiformes)

Short-tailed shearwaters in Bass Strait, Australia, exhibited extreme synchronicity in laying during 1991. Egg dimensions and masses varied by approximately 40% between females and were related to the date of laying but not the fate of the egg at hatching. The composition of eggs was similar to other petrels, and typical of semiprecocial species. Larger egg-size was attributable to relatively more albumen, but less yolk. Thus, hatching succcss may be proximately constrained by behavioural attributes of the patents.     

Seasonal changes in a population of the nectar-feeding marsupial Tarsipes spencerae (Marsupialia: Tarsipedidae)

During 1978 and 1979 over 900 individuals of the mouse-sized marsupial nectarivore Tarsipes spencerae were pitfall trapped in Banksia thickets on the south coast of Western Australia. In both years numbers were highest in spring, when nectar was most abundant and lowest during summer months when it was scarce. The larger number of males caught probably reflects their greater activity rather than their greater abundance.     

Recommendations for Reporting and Flagging of Reference Limits on Pathology Reports

Surveys by the RCPA PITUS Project have shown significant variations in report rendering between Australasian Pathology Providers. The same project collected anecdotal evidence that this variation has led to the misunderstanding and misreading of results - a clinical safety issue. Recommendations are given for the rendering of reference limits on pathology reports, determination and rendering of result flags, and the documentation of sub-population partitions for reference intervals. These recommendations apply equally for paper or electronic reporting, but should not limit the use of novel techniques within electronic reports to convey additional meaning. PITUS Working Group 4 will publish draft recommendations for peer review and comment in relation to the above in the second half of 2014.