Radiolabeling human peripheral blood stem cells for positron emission tomography (PET) imaging in young rhesus monkeys.

These studies focused on a new radiolabeling technique with copper ((64)Cu) and zirconium ((89)Zr) for positron emission tomography (PET) imaging using a CD45 antibody. Synthesis of (64)Cu-CD45 and (89)Zr-CD45 immunoconjugates was performed and the evaluation of the potential toxicity of radiolabeling human peripheral blood stem cells (hPBSC) was assessed in vitro (viability, population doubling times, colony forming units). hPBSC viability was maintained as the dose of (64)Cu-TETA-CD45 increased from 0 (92%) to 160 µCi/mL (76%, p>0.05). Radiolabeling efficiency was not significantly increased with concentrations of (64)Cu-TETA-CD45 >20 µCi/mL (p>0.50). Toxicity affecting both growth and colony formation was observed with hPBSC radiolabeled with ≥40 µCi/mL (p<0.05). For (89)Zr, there were no significant differences in viability (p>0.05), and a trend towards increased radiolabeling efficiency was noted as the dose of (89)Zr-Df-CD45 increased, with a greater level of radiolabeling with 160 µCi/mL compared to 0-40 µCi/mL (p<0.05). A greater than 2,000 fold-increase in the level of (89)Zr-Df-CD45 labeling efficiency was observed when compared to (64)Cu-TETA-CD45. Similar to (64)Cu-TETA-CD45, toxicity was noted when hPBSC were radiolabeled with ≥40 µCi/mL (p<0.05) (growth, colony formation). Taken together, 20 µCi/mL resulted in the highest level of radiolabeling efficiency without altering cell function. Young rhesus monkeys that had been transplanted prenatally with 25×10(6) hPBSC expressing firefly luciferase were assessed with bioluminescence imaging (BLI), then 0.3 mCi of (89)Zr-Df-CD45, which showed the best radiolabeling efficiency, was injected intravenously for PET imaging. Results suggest that (89)Zr-Df-CD45 was able to identify engrafted hPBSC in the same locations identified by BLI, although the background was high

A longitudinal investigation of the impact of disordered eating on young women's quality of life

"This article may not exactly replicate the authoritative document published in the APA journal. It is not the copy of record." Author manuscript made available here in accordance with Publisher copyright policy.OBJECTIVE: The extent to which subclinical levels of disordered eating affect quality of life (QOL) was assessed. METHOD: Four waves of self-report data from Survey 2 (S2) to 5 (S5) of a national longitudinal survey of young Australian women (N = 9,688) were used to assess the impact of any level of disordered eating at S2 on QOL over the following 9 years, and to evaluate any moderating effects of social support and of depression. RESULTS: At baseline, 23% of the women exhibited some level of disordered eating, and they scored significantly lower on both the physical and the mental component scores of the SF-36 at every survey; differences in mental health were still clinically meaningful at S5. Social support and depressive symptoms each acted as a moderator of the mental component scores. Women with both disordered eating and low social support, or disordered eating and depression, had the worst initial scores; although they improved the most over time, they still had the lowest scores at S5. Higher social support at baseline resulted in women with disordered eating being largely indistinguishable from women without disordered eating who had low social support. Lower levels of depression resulted in women with disordered eating having a significantly better QOL than women with high levels of depression, regardless of eating status. CONCLUSIONS: This is the first study to examine the long-term impact of subclinical levels of disordered eating on QOL, and it suggests that even apparently minor levels of symptomatology are associated with significant and far-reaching deficits in well-being

Use of Sildenafil to Facilitate Weaning From Inhaled Nitric Oxide in Children With Pulmonary Hypertension Following Surgery for Congenital Heart Disease

Pulmonary hypertension frequently complicates the postoperative management of patients after congenital cardiac surgery. Inhaled nitric oxide is an effective treatment option, but rebound pulmonary hypertension can occur upon its withdrawal. Sildenafil may facilitate its withdrawal by restoring cyclic guanosine monophosphate availability via phosphodiesterase-5 inhibition. The purpose of this study was to evaluate the use of sildenafil in facilitating weaning from inhaled nitric oxide after congenital cardiac surgery in patients who had previously failed weaning, and to compare the effects of sildenafil on pulmonary and systemic hemodynamics. Children who received sildenafil after cardiovascular surgery during a 23-month period at Riley Hospital for Children were identified. Medical records were retrospectively reviewed to determine sildenafil and nitric oxide dosing, pulmonary and systemic blood pressures, and adverse effects. Oral sildenafil was administered to 7 children who had failed attempts at inhaled nitric oxide weaning. Inhaled nitric oxide was weaned from 29.8 ± 5.9 ppm prior to sildenafil initiation to 12.2 ± 3.4 ppm (mean ± SE; P = .024) in the 24 hours after sildenafil. Mean pulmonary artery and systemic arterial pressure were unchanged from baseline when measured 1 hour after sildenafil dosing (mean pulmonary artery pressure, 29 ± 1 to 27 ± 0.7 mm Hg, P = .066; mean systemic arterial pressure, 56 ± 1.2 to 54 ± 1.2 mm Hg, P = .202). Sildenafil may facilitate withdrawal of inhaled nitric oxide and prevent rebound pulmonary hypertension in patients previously failing inhaled nitric oxide weaning attempts

The danger within: the role of genetic, behavioural and ecological factors in population persistence of colour polymorphic species

Polymorphic species have been the focus of important work in evolutionary biology. It has been suggested that colour polymorphic species have specific evolutionary and population dynamics that enable them to persist through environmental changes better than less variable species. We suggest that recent empirical and theoretical work indicates that polymorphic species may be more vulnerable to extinction than previously thought. This vulnerability arises because these species often have a number of correlated sexual, behavioural, life history and ecological traits, which can have a simple genetic underpinning. When exacerbated by environmental change, these alternate strategies can lead to conflict between morphs at the genomic and population levels, which can directly or indirectly affect population and evolutionary dynamics. In this perspective, we identify a number of ways in which the nature of the correlated traits, their underpinning genetic architecture, and the inevitable interactions between colour morphs can result in a reduction in population fitness. The principles illustrated here apply to all kinds of discrete polymorphism (e.g. behavioural syndromes), but we focus primarily on colour polymorphism because they are well studied. We urge further empirical investigation of the genetic architecture and interactions in polymorphic species to elucidate the impact on population fitness

Membrane protein nanoparticles: the shape of things to come

The use of styrene-maleic acid (SMA) for the purification of a wide range of membrane proteins (MPs) from both prokaryotic and eukaryotic sources has begun to make an impact in the field of MP biology. This method is growing in popularity as a means to purify and thoroughly investigate the structure and function of MPs and biological membranes. The amphiphilic SMA copolymer can effectively extract MPs directly from a native lipid bilayer to form discs approximately 10 nm in diameter. The resulting lipid particles, or styrene-maleic acid lipid particles (SMALPs), contain SMA, protein and membrane lipid. MPs purified in SMALPs are able to retain their native structure and, in many cases, functional activity, and growing evidence suggests that MPs purified using SMA have enhanced thermal stability compared with detergent-purified proteins. The SMALP method is versatile and is compatible with a wide range of cell types across taxonomic domains. It can readily be adapted to replace detergent in many protein purification methods, often with only minor changes made to the existing protocol. Moreover, biophysical analysis and structural determination may now be a possibility for many large, unstable MPs. Here, we review recent advances in the area of SMALP purification and how it is affecting the field of MP biology, critically assess recent progress made with this method, address some of the associated technical challenges which may remain unresolved and discuss opportunities for exploiting SMALPs to expand our understanding of structural and functional properties of MPs

RNA polymerase V-dependent small RNAs in Arabidopsis originate from small, intergenic loci including most SINE repeats.

In plants, heterochromatin is maintained by a small RNA-based gene silencing mechanism known as RNA-directed DNA methylation (RdDM). RdDM requires the non-redundant functions of two plant-specific DNA-dependent RNA polymerases (RNAP), RNAP IV and RNAP V. RNAP IV plays a major role in siRNA biogenesis, while RNAP V may recruit DNA methylation machinery to target endogenous loci for silencing. Although small RNA-generating regions that are dependent on both RNAP IV and RNAP V have been identified previously, the genomic loci targeted by RNAP V for siRNA accumulation and silencing have not been described extensively. To characterize the RNAP V-dependent, heterochromatic siRNA-generating regions in the Arabidopsis genome, we deeply sequenced the small RNA populations of wild-type and RNAP V null mutant (nrpe1) plants. Our results showed that RNAP V-dependent siRNA-generating loci are associated predominately with short repetitive sequences in intergenic regions. Suppression of small RNA production from short repetitive sequences was also prominent in RdDM mutants including dms4, drd1, dms3 and rdm1, reflecting the known association of these RdDM effectors with RNAP V. The genomic regions targeted by RNAP V were small, with an estimated average length of 238 bp. Our results suggest that RNAP V affects siRNA production from genomic loci with features dissimilar to known RNAP IV-dependent loci. RNAP V, along with RNAP IV and DRM1/2, may target and silence a set of small, intergenic transposable elements located in dispersed genomic regions for silencing. Silencing at these loci may be actively reinforced by RdDM