A novel, noninvasive transdermal fluid sampling methodology: IGF-I measurement following exercise

This study tested the hypothesis that transdermal fluid (TDF) provides a more sensitive and accurate measure of exercise-induced increases in insulin-like growth factor-I (IGF-I) than serum, and that these increases are detectable proximal, but not distal, to the exercising muscle. A novel, noninvasive methodology was used to collect TDF, followed by sampling of total IGF-I (tIGF-I) and free IGF-I (fIGF-I) in TDF and serum following an acute bout of exercise. Experiment 1: eight men (23 ± 3 yrs, 79 ± 7 kg) underwent two conditions (resting and 60 min of cycling exercise at 60% Vo(2)(peak)) in which serum and forearm TDF were collected for comparison. There were no significant changes in tIGF-I or fIGF-I in TDF obtained from the forearm or from serum following exercise (P > 0.05); however, the proportion of fIGF-I to tIGF-I in TDF was approximately fourfold greater than that of serum (P ≤ 0.05). These data suggest that changes in TDF IGF-I are not evident when TDF is sampled distal from the working tissue. To determine whether exercise-induced increases in local IGF-I could be detected when TDF was sampled directly over the active muscle group, we performed a second experiment. Experiment 2: fourteen subjects (22 ± 4 yr, 68 ± 11 kg) underwent an acute plyometric exercise condition consisting of 10 sets of 10 plyometric jumps with 2-min rest between sets. We observed a significant increase in TDF tIGF-I following exercise (P ≤ 0.05) but no change in serum tIGF-I (P > 0.05). Overall, these data suggest that TDF may provide a noninvasive means of monitoring acute exercise-induced changes in local IGF-I when sampled in proximity to exercising muscles. Moreover, our finding that the proportion of free to tIGF-I was greater in TDF than in serum suggests that changes in local IGF-I may be captured more readily using this system.     

Free radical mediated peroxidative damage in systemic lupus erythematosus

Free radicals and damage caused by these molecular species are implicated in the pathogenesis of a variety of diseases, including autoimmune. Here we have examined oxidative damage, SOD activity and autoantibodies against SOD in systemic lupus erythematosus (SLE), a multifactorial disease with autoantibody production as an universal feature. We found significantly increased amounts of conjugated dienes in the SLE patients compared to normals (mean value of 0.917 vs 0.627, p = 0.0001) and MDA formation (6.96 vs 4.17 nmoles/microl, p = 0.0006) as well as decreased SOD activity. In addition, we found autoantibodies binding SOD by both ELISA and immunoblot. The presence of anti-SOD antibodies was associated with increased free radical damage in SLE patients. Heat inactivated anti-SOD autoantibodies were able to inhibit the activity of the enzyme. We propose that the inhibition of SOD by autoantibodies is, in part, responsible for the increased free radical damage seen in the disease.     

A novel approach for multi-domain and multi-gene family identification provides insights into evolutionary dynamics of disease resistance genes in core eudicot plants

Background

Recent advances in DNA sequencing techniques resulted in more than forty sequenced plant genomes representing a diverse set of taxa of agricultural, energy, medicinal and ecological importance. However, gene family curation is often only inferred from DNA sequence homology and lacks insights into evolutionary processes contributing to gene family dynamics. In a comparative genomics framework, we integrated multiple lines of evidence provided by gene synteny, sequence homology and protein-based Hidden Markov Modelling to extract homologous super-clusters composed of multi-domain resistance (R)-proteins of the NB-LRR type (for NUCLEOTIDE BINDING/LEUCINE-RICH REPEATS), that are involved in plant innate immunity.

Results

To assess the diversity of R-proteins within and between species, we screened twelve eudicot plant genomes including six major crops and found a total of 2,363 NB-LRR genes. Our curated R-proteins set shows a 50% average for tandem duplicates and a 22% fraction of gene copies retained from ancient polyploidy events (ohnologs). We provide evidence for strong positive selection and show significant differences in molecular evolution rates (Ka/Ks-ratio) among tandem- (mean = 1.59), ohnolog (mean = 1.36) and singleton (mean = 1.22) R-gene duplicates. To foster the process of gene-edited plant breeding, we report species-specific presence/absence of all 140 NB-LRR genes present in the model plant Arabidopsis and describe four distinct clusters of NB-LRR “gatekeeper” loci sharing syntenic orthologs across all analyzed genomes.

Conclusion

By curating a near-complete set of multi-domain R-protein clusters in an eudicot-wide scale, our analysis offers significant insight into evolutionary dynamics underlying diversification of the plant innate immune system. Furthermore, our methods provide a blueprint for future efforts to identify and more rapidly clone functional NB-LRR genes from any plant species.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-15-966) contains supplementary material, which is available to authorized users.     

Microbialite response to an anthropogenic salinity gradient in Great Salt Lake,Utah

A railroad causeway across Great Salt Lake, Utah (GSL), has restricted water flow since its construction in 1959, resulting in a more saline North Arm (NA; 24%–31% salinity) and a less saline South Arm (SA; 11%–14% salinity). Here, we characterized microbial carbonates collected from the SA and the NA to evaluate the effect of increased salinity on community composition and abundance and to determine whether the communities present in the NA are still actively precipitating carbonate or if they are remnant features from prior to causeway construction. SSU rRNA gene abundances associated with the NA microbialite were three orders of magnitude lower than those associated with the SA microbialite, indicating that the latter community is more productive. SSU rRNA gene sequencing and functional gene microarray analyses indicated that SA and NA microbialite communities are distinct. In particular, abundant sequences affiliated with photoautotrophic taxa including cyanobacteria and diatoms that may drive carbonate precipitation and thus still actively form microbialites were identified in the SA microbialite; sequences affiliated with photoautotrophic taxa were in low abundance in the NA microbialite. SA and NA microbialites comprise smooth prismatic aragonite crystals. However, the SA microbialite also contained micritic aragonite, which can be formed as a result of biological activity. Collectively, these observations suggest that NA microbialites are likely to be remnant features from prior to causeway construction and indicate a strong decrease in the ability of NA microbialite communities to actively precipitate carbonate minerals. Moreover, the results suggest a role for cyanobacteria and diatoms in carbonate precipitation and microbialite formation in the SA of GSL.     

Autoreactive blood cells and programmed cell death in growth and development of protochordates

The tunicate Botryllus is a marine protochordate whose clonal colonies undergo regulated natural transplantations when they come into contact in nature. The outcome of these transplantations (fusion or rejection) is controlled by genes of a highly polymorphic histocompatibility system that resembles in many respects the mammalian major histocompatibility complex (MHC). While fusion or rejection reactions are often completed within 24 hr after transplantation, resorption of one partner of a pair of fused semiallogeneic colonies may occur days to weeks after initial contact. The latter process is similar to the degeneration of old individuals, or zooids, that precedes maturation of each new generation of asexual buds. Here we describe comparisons of in vitro reactions of a) mixtures of cells from allogeneic animals and b) cells taken from animals at the zooid-resorption ("takeover") stage of colony development. In vitro autoreactivity of cells from resorbing colonies may reflect in vivo responses to senescent cells, which in turn may be related to allorecognition events that govern fusion or rejection between colonies.     

Continued Synthesis of Bacterial DNA After Infection by Bacteriophage T4

Early in infection by bacteriophage T4, before replication has commenced, one can detect the presence of newly synthesized DNA which cosediments with parental phage DNA on sucrose gradients. As shown earlier (R. E. Murray and C. K. Mathews, 1969), some of this represents covalent attachment of new material to parental phage DNA molecules. However, as shown herein, most of it is bacterial DNA, which is synthesized after infection and presumably degraded to T4 DNA-sized pieces. The small amount of phage-specific DNA synthesis which occurs is apparently a repair process, for its extent is greatly increased if the phage are irradiated with ultraviolet light prior to infection. Analysis by means of pulse labeling with [(3)H]thymidine and DNA-DNA hybridization shows that host DNA synthesis continues at a significant rate (40 to 80% of the preinfection rate) as late as 10 min after infection at 37 C. Very early in infection this is primarily replicative synthesis, but later a repair process predominates. Presumably this represents attempted repair of damage being inflicted on host DNA by phage-coded nucleases.     

Pathways of acetone's metabolism in the rat

Distributions of 14C were different from those of 13C in glucoses formed by livers of rats in diabetic ketosis and perfused with [2-14C]acetone and [2-13C]lactate. There was 32-73% of the 14C and 8-12% of the 13C in carbons 3 and 4 of the glucoses with the remaining 14C and 13C distributed about equally in the other carbons. Incorporations of 14C from [2-14C]acetone (14-39%) also exceeded those from [2-14C]pyruvate (8-10%) into carbons 3 and 4 of glucoses formed by hepatocytes from rats fed acetone or fasted. [2-14C]Acetone and [2-14C]pyruvate were infused into rats that were fed, fasted, given acetone in their drinking water, or in diabetic ketosis. Thirty-seven to 52% of the 14C in the glucoses formed was in their carbons 3 and 4 when the acetone was infused and 8 to 14% when the pyruvate was infused. [1,3-14C]Hydroxybutyrate was formed by the rats in diabetic ketosis given [2-14C]acetone. It is concluded that acetone is metabolized in rats to a large extent by a pathway in which lactate or its metabolic equivalent is not an intermediate and that pathway is via acetyl-CoA. via acetyl-CoA.