The extent of lead fragmentation observed in deer culled by sharpshooting

Sharpshooting is a proven management technique to lower white-tailed deer (Odocoileus virginianus) densities in areas where hunting is precluded. A donation program that allows for the consumptive use of these culled deer is often necessary to gain public approval for such a program. We culled 40 deer in Indiana using sharpshooting methods (head and neck shot placement) and radiographed the carcasses to determine if lead fragmentation spread throughout the skeletal muscle system. In 30 deer where shot placement was between the cranium and fourth cervical vertebrae, we observed no lead fragments in any thoracic or crural muscle tissue. Of 10 deer where shot placement was between the fifth and seventh cervical vertebrae, 8 deer experienced lead fragments in the extensor spinae muscle. Deer culled with highly frangible bullets via sharpshooting in the cranium or upper cervical spine have minimal risk of experiencing lead fragmentation in the thoracic or crural muscle systems. Deer shot in the lower neck may experience lead fragmentation in the anterior extensor spinae muscle, and up to 40 cm of that muscle should be removed before consumption. © 2011 The Wildlife Society.     

24, 25-dihydroxycholecalciferol but not 25-hydroxycholecalciferol suppresses apolipoprotein A-I gene expression

AimsLigands for the vitamin D receptor (VDR) regulate apolipoprotein A-I (apo A-I) gene expression in a tissue-specific manner. The vitamin D metabolite 24, 25-dihydroxycholecalciferol (24, 25-(OH)₂D₃) has been shown to possess unique biological effects. To determine if 24, 25-(OH)₂D₃ modulates apo A-I gene expression, HepG2 hepatocytes and Caco-2 intestinal cells were treated with 24, 25-(OH)₂D₃ or its precursor 25-OHD₃.Main methodsApo A-I protein levels and mRNA levels were measured by Western and Northern blotting, respectively. Changes in apo A-I promoter activity were measured using the chlorampenicol acetytransferase assay.Key findingsTreatment with 24, 25-(OH)₂D₃, but not 25-OHD₃, inhibited apo A-I secretion in HepG2 and Caco-2 cells and apo A-I mRNA levels and apo A-I promoter activity in HepG2 cells. To determine if 24, 25-(OH)₂D₃ represses apo A-I gene expression through site A, the nuclear receptor binding element that is essential for VDRs effects on apo A-I gene expression, HepG2 cells were transfected with plasmids containing or lacking site A. While the site A-containing plasmid was suppressed by 24, 25-(OH)₂D₃, the plasmid lacking site A was not. Likewise, treatment with 24, 25-(OH)₂D₃ suppressed reporter gene expression in cells transfected with a plasmid containing site A in front of a heterologous promoter. Finally, antisense-mediated VDR depletion failed to reverse the silencing effects of 24, 25-(OH)₂D₃ on apo A-I expression.SignificanceThese results suggest that the vitamin D metabolite 24, 25-(OH)₂D₃ is an endogenous regulator of apo A-I synthesis through a VDR-independent signaling mechanism.     

Identification of a sporozoite-specific antigen from Toxoplasma gondii

Reduction of risk for human and food animal infection with Toxoplasma gondii is hampered by the lack of epidemiological data documenting the predominant routes of infection (oocyst vs. tissue cyst consumption) in horizontally transmitted toxoplasmosis. Existing serological assays can determine previous exposure to the parasite, but not the route of infection. We have used difference gel electrophoresis, in combination with tandem mass spectroscopy and Western blot, to identify a sporozoite-specific protein (T. gondii embryogenesis-related protein [TgERP]), which elicited antibody and differentiated oocyst- versus tissue cyst-induced infection in pigs and mice. The recombinant protein was selected from a cDNA library constructed from T. gondii sporozoites; this protein was used in Western blots and probed with sera from T. gondii -infected humans. Serum antibody to TgERP was detected in humans within 6-8 mo of initial oocyst-acquired infection. Of 163 individuals in the acute stage of infection (anti- T. gondii IgM detected in sera, or < 30 in the IgG avidity test), 103 (63.2%) had detectable antibodies that reacted with TgERP. Of 176 individuals with unknown infection route and in the chronic stage of infection (no anti- T. gondii IgM detected in sera, or > 30 in the IgG avidity test), antibody to TgERP was detected in 31 (17.6%). None of the 132 uninfected individuals tested had detectable antibody to TgERP. These data suggest that TgERP may be useful in detecting exposure to sporozoites in early T. gondii infection and implicates oocysts as the agent of infection.     

Secretion of adipokines by human adipose tissue in vivo: partitioning between capillary and lymphatic transport

Peptides secreted by adipose tissue (adipokines) may enter blood via capillaries or lymph. The relative importance of these pathways for a given adipokine might influence its biological effects. Because this has not been studied in any species, we measured the concentrations of seven adipokines and eight nonsecreted proteins in afferent peripheral lymph and venous plasma from 12 healthy men. Data for nonsecreted proteins were used to derive indices of microvascular permeability, which in conjunction with the molecular radii of the adipokines were used to estimate the amounts leaving the tissue via capillaries. Transport rates via lymph were estimated from the lymph adipokine concentrations and lymph flow rates and total transport (secretion) as the sum of this and capillary transport. Concentrations of nonsecreted proteins were always lower in lymph than in plasma. With the exception of adiponectin, adipokine concentrations were always higher in lymph (P < 0.01). Leptin and MCP-1 were secreted at the highest rates (means: 43 μg/h or 2.7 nmol/h and 32 μg/h or 2.4 nmol/h, respectively). IL-6 and MCP-1 secretion rates varied greatly between subjects. The proportion of an adipokine transported via lymph was directly related to its molecular radius (r(s) = +0.94, P = 0.025, n = 6), increasing from 14 to 100% as the radius increased from 1.18 (IL-8) to 3.24 nm (TNFα). We conclude that the lymph/capillary partitioning of adipokines is a function of molecular size, which may affect both their regional and systemic effects in vivo. This finding may have implications for the physiology of peptides secreted by other tissues.     

Population genetics in nonmodel organisms: II. natural selection in marginal habitats revealed by deep sequencing on dual platforms

Population genetics of species living in marginal habitats could be particularly informative about the genetics of adaptation, but such analyses have not been readily feasible until recently. Sonneratia alba, a mangrove species widely distributed in the Indo-West Pacific, provides a very suitable system for the study of local adaptation. In this study, we analyzed DNA variation by pooling 71 genes from 85-100 individuals for DNA sequencing. For each of the two nearby S. alba populations, we obtained ~2,500 × coverage on the Illumina GA platform and for the Sanya population, an additional 5,400 × coverage on the AB SOLiD platform. For the Sanya sample, although each sequencing method called many putative single nucleotide polymorphisms, the two sets of calls did not overlap, suggesting platform-dependent errors. Conventional sequencing corroborated that each population is monomorphic. The two populations differ by 54 bp of 79,000 sites, but 90% of the variants are found in 10% of the genes. Strong local adaptation and high migration may help to explain the extensive monomorphism shared by the two populations in the presence of a small number of highly differentiated loci.     

Crystal structure of human thymidine phosphorylase in complex with a small molecule inhibitor

Human thymidine phosphorylase (HTP), also known as platelet-derived endothelial cell growth factor (PD-ECGF), is overexpressed in certain solid tumors where it is linked to poor prognosis. HTP expression is utilized for certain chemotherapeutic strategies and is also thought to play a role in tumor angiogenesis. We determined the structure of HTP bound to the small molecule inhibitor 5-chloro-6-[1-(2-iminopyrrolidinyl) methyl] uracil hydrochloride (TPI). The inhibitor appears to mimic the substrate transition state, which may help explain the potency of this inhibitor and the catalytic mechanism of pyrimidine nucleotide phosphorylases (PYNPs). Further, we have confirmed the validity of the HTP structure as a template for structure-based drug design by predicting binding affinities for TPI and other known HTP inhibitors using in silico docking techniques. This work provides the first structural insight into the binding mode of any inhibitor to this important drug target and forms the basis for designing novel inhibitors for use in anticancer therapy.     

Australian Dust Storm Associated with Extensive Aspergillus sydowii Fungal “Bloom” in Coastal Waters

A massive central Australian dust storm in September 2009 was associated with abundant fungal spores (150,000/m³) and hyphae in coastal waters between Brisbane (27°S) and Sydney (34°S). These spores were successfully germinated from formalin-preserved samples, and using molecular sequencing of three different genes (the large subunit rRNA gene [LSU], internal transcribed spacer [ITS[, and beta-tubulin gene), they were conclusively identified as Aspergillus sydowii, an organism circumstantially associated with gorgonian coral fan disease in the Caribbean. Surprisingly, no human health or marine ecosystem impacts were associated with this Australian dust storm event. Australian fungal cultures were nontoxic to fish gills and caused a minor reduction in the motility of Alexandrium or Chattonella algal cultures but had their greatest impacts on Symbiodinium dinoflagellate coral symbiont motility, with hyphae being more detrimental than spores. While we have not yet seen any soft coral disease outbreaks on the Australian Great Barrier Reef similar to those observed in the Caribbean and while this particular fungal population was non- or weakly pathogenic, our observations raise the possibility of future marine ecosystem pathogen impacts from similar dust storms harboring more pathogenic strains.