Trypanosoma cruzi prevalence and epidemiologic trends in lemurs on St. Catherines Island, Georgia

Lemurs on St. Catherines Island, Georgia were tested for Trypanosoma cruzi infection to develop a better understanding of the epizootiology of the parasite in nonhuman primates in the southeastern United States. Fifty-six ring-tailed (Lemur catta), blue-eyed black (Eulemur macaco flavifrons), and black-and-white ruffed (Varecia variegata variegata) lemurs were tested by hemoculture and serology to determine the prevalence of T. cruzi in the population. Of those tested 3 (5%) were identified as culture positive and 25 (44.6%) as seropositive. When hemoculture results were compared with those from a similar study performed in 1997, prevalence remained unchanged. Genetic characterization of the 3 culture isolates indicated they belong to the T. cruzi IIa group, which is identical to strains previously isolated from raccoons on the island. Despite the occurrence of T. cruzi in the population, there was no evidence that the health of the lemurs was compromised as a result of infection. Based upon prevalence and available breeding records we speculate that both vertical and vector-mediated transmission play significant roles in the epidemiology of T. cruzi on the island. This also represents the first report of autochthonous infection in blue-eyed black and black-and-white ruffed lemurs.     

Density and community structure of soil- and bark-dwelling microarthropods along an altitudinal gradient in a tropical montane rainforest

Microarthropod communities in the soil and on the bark of trees were investigated along an elevation gradient (1,850, 2,000, 2,150, 2,300 m) in a tropical montane rain forest in southern Ecuador. We hypothesised that the density of microarthropods declines with depth in soil and increases with increasing altitude mainly due to the availability of resources, i.e. organic matter. In addition, we expected bark and soil communities to differ strongly, since the bark of trees is more exposed to harsher factors. In contrast to our hypothesis, the density of major microarthropod groups (Collembola, Oribatida, Gamasina, Uropodina) was generally low and decreased with altitude. However, as we predicted the density of each of the groups decreased with soil depth. Density of microarthropods on tree bark was lower than in soil. Overall, 43 species of oribatid mites were found, with the most abundant higher taxa being Poronota, pycnonotic Apheredermata, Mixonomata and Eupheredermata. The oribatid mite community on bark did not differ significantly from that in soil. The number of oribatid mite species declined with altitude (24, 23, 17 and 13 species at 1,850, 2,000, 2,150 and 2,300 m, respectively). Rarefaction curves indicate that overall about 50 oribatid mite species are to be expected along the studied altitudinal gradient. Results of this study indicate (1) that microarthropods may be limited by the quality of resources at high altitudes and by the amount of resources at deeper soil layers, and (2) that the bark of trees and the soil are habitats of similar quality for oribatid mites.     

Transcriptomic Identification of ADH1B as a Novel Candidate Gene for Obesity and Insulin Resistance in Human Adipose Tissue in Mexican Americans from the Veterans Administration Genetic Epidemiology Study (VAGES)

Type 2 diabetes (T2D) is a complex metabolic disease that is more prevalent in ethnic groups such as Mexican Americans, and is strongly associated with the risk factors obesity and insulin resistance. The goal of this study was to perform whole genome gene expression profiling in adipose tissue to detect common patterns of gene regulation associated with obesity and insulin resistance. We used phenotypic and genotypic data from 308 Mexican American participants from the Veterans Administration Genetic Epidemiology Study (VAGES). Basal fasting RNA was extracted from adipose tissue biopsies from a subset of 75 unrelated individuals, and gene expression data generated on the Illumina BeadArray platform. The number of gene probes with significant expression above baseline was approximately 31,000. We performed multiple regression analysis of all probes with 15 metabolic traits. Adipose tissue had 3,012 genes significantly associated with the traits of interest (false discovery rate, FDR ≤ 0.05). The significance of gene expression changes was used to select 52 genes with significant (FDR ≤ 10^-4) gene expression changes across multiple traits. Gene sets/Pathways analysis identified one gene, alcohol dehydrogenase 1B (ADH1B) that was significantly enriched (P < 10^-60) as a prime candidate for involvement in multiple relevant metabolic pathways. Illumina BeadChip derived ADH1B expression data was consistent with quantitative real time PCR data. We observed significant inverse correlations with waist circumference (2.8 x 10^-9), BMI (5.4 x 10^-6), and fasting plasma insulin (P < 0.001). These findings are consistent with a central role for ADH1B in obesity and insulin resistance and provide evidence for a novel genetic regulatory mechanism for human metabolic diseases related to these traits.     

Influence of gender and castration on liver and CNS N-demethylation of morphine in rats1

Rats were injected with combinations of morphine-N-¹⁴CH₃ and morphine-6³H and the isotope content of the brain and liver was measured by combustion in a tissue oxidizer. The liver of intact male rats showed a significant increase in the ³H to ¹⁴C isotope ratio relative to the blood reflecting the existence of N-demethylation in this organ. This increase was not observed in the liver of either intact females or castrated males or females. Centrally, the hypothalamus, medial thalamus, and corpus striatum of both intact and castrated male and female rats exhibited increases in ³H to ¹⁴C isotope ratios indicating the presence of N-demethylation in these tissues. These results indicate that testicular hormones serve to increase the hepatic N-demethylation of morphine, but apparently reduce the comparable reaction in the CNS.     

GM1 Ganglioside: In Vivo and In Vitro Trophic Actions on Central Neurotransmitter Systems

Abstract: There is now substantial evidence that GM1 ganglioside is effective in partially correcting the consequences of neuroinjury in a number of in vivo and in vitro model systems. Although the molecular mechanism(s) and the substrates for the neurotrophic activity of the gangliosides are not fully understood, the published experimental work suggests that GM1 has antineurotoxic, neuroprotective, and neurorestorative effects on various central neurotransmitter systems. This review focuses attention on studies reporting that GM1 restores neuronal integrity and function in the brain of lesioned young as well as aged animals. Critical analysis of these studies can provide guidance for future ganglioside research and may point to novel approaches for treating neuroinjury and a variety of degenerative conditions, including aging.     

Complete amino acid sequence of tenebrosin-C, a cardiac stimulatory and haemolytic protein from the sea anemone Actinia tenebrosa

The complete amino acid sequence of the cardiac stimulatory and haemolytic protein tenebrosin-C, from the Australian sea anemone Actinia tenebrosa, has been determined by Edman degradation of the intact molecule and fragments produced by treatment of the polypeptide chain with cyanogen bromide and enzymatic cleavage with endoproteinase Asp-N, thermolysin and trypsin. The molecule is a single-chain polypeptide consisting of 179 amino acid residues with a calculated molecular mass of 19,797 Da. Tenebrosin-C shows a high degree of amino acid sequence similarity (63%) with Stoichactis helianthus cytolysin III [Blumenthal, K. M. and Kem, W. R. (1983) J. Biol. Chem. 258, 5574-5581] and is identical to a partial sequence (90 residues) reported for equinatoxin, a cardiostimulatory and haemolytic protein isolated from the European sea anemone Actinia equina [Ferlan, I. and Jackson, K. (1983) Toxicon Suppl. 3, 141-144]. No amino acid sequence similarity was detected between tenebrosin-C and other protein sequences stored in available databases. The predicted secondary structure of tenebrosin-C suggests that it is a compact, highly structured molecule.     

Soil Carbon and Nitrogen Storage in Upper Montane Riparian Meadows

Though typically limited in aerial extent, soils of high-elevation riparian wetlands have among the highest density of soil carbon (C) and nitrogen (N) of terrestrial ecosystems and therefore contribute disproportionally to ecosystem services such as water retention, forage production, wildlife habitat, and reactive N removal. Because much soil C and N is stored in labile forms in anaerobic conditions, management activities or environmental changes that lead to drying cause mineralization of labile soil organic matter, and loss of C and N. Meadows are focal points of human activities in mountain regions, often with incised stream channels from historically heavy grazing exacerbated by extreme runoff events. To quantify soil C and N stores in montane riparian meadows across hydrologic conditions, 17 meadows between 1950- and 2675-m elevation were selected in the central Sierra Nevada Range, California, that were classified using the proper functioning condition (PFC) system. Results indicate that C and N density in whole-solum soil cores were equivalent at forest edge positions of properly functioning, functioning at-risk, and nonfunctioning condition. Soils under more moist meadow positions in properly functioning meadows have at least twice the C, N, dissolved organic C, and dissolved organic N (DON) than those under nonfunctioning meadows. Densities of total N and DON, but not C, of functioning at-risk meadows are significantly lower (P < 0.05) than those of properly functioning meadows at mid-slope and stream-bank positions, suggesting accelerated loss of N early in degradation processes. Though variable, the soil attributes measured correspond well to the PFC riparian wetland classification system.     

N-linked glycosylation of the liver cancer biomarker GP73

The association between elevated circulating levels of GP73 (and fucosylated GP73 in particular) and hepatocellular carcinoma suggests that a thorough analysis of the extent of GP73 glycosylation is warranted. Detailed analysis of the glycosylation patterns of such low abundance proteins are hampered by technical difficulties. Using conventional lectin affinity chromatography, we have established that three quarters of the GP73 secreted from a cell line derived from HCC is fucosylated. Using mass spectrometry, we have established that at least two of three potential sites of N-linked glycosylation are occupied on most molecules of GP73 secreted from cultured hepatoma cells. Furthermore, the oligosaccharides added to recombinant GP73 resemble those present in the bulk of secreted protein, mostly bi-antennary with core fucose, with a smaller fraction of tri- and tetra-antennary structures. The frequency of fucosylation observed on the recombinant protein agrees well with the pattern of lectin binding of the endogenous secreted protein. Finally, we have developed a method to interrogate the glycans added to either the near full length protein or at a particular sequon, providing proof of concept that a small peptide embedded in a heterologous context can preserve both fucosylation and a high level of branching of oligosaccharides added.     

Com Yield Increases Relative to Nonfumigant Chemical Control of Nematodes

Corn yields were measured after application of nematicides in 16 experiments, mostly in medium-to-heavily textured soil, at 12 locations in Iowa during 1973-1976. The average maximum yield increase in plots treated with nematicides was 21% over yields in untreated plots. Yields were correlated negatively with nematode numbers or nematode biomass in nearly all comparisons. Correlations of nematode numbers in the soil with yield averaged -0.56 for Helicotylenchus pseudorobustus, -0.45 for Hoplolaimus galeatus, -0.51 for Pratylenchus spp., and -0.64 for Xiphinema americanum. Correlation coefficients for numbers of nematodes in the roots and yield averaged -0.63 for Pratylenchus spp. and -0.56 H. galeatus. Correlation coefficients for yield and total number of nematodes averaged -0.65 in roots and -0.55 in soils. Negative correlations also were greater for comparisons of yield with total parasitic-nematode biomass than with numbers of individual nematodes of a species or total numbers of parasitic nematodes.