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Bdelloid rotifer genomes show signatures of asyngamous recombination leading to loss of heterozygosity. This has been hypothesised to occur via chromosome pairing during egg formation through a meiosis-like but non-reductional process. Evidence of genetic exchange in bdelloid populations requires further validation in our view. Around 10% of bdelloid genes have been acquired horizontally from other kingdoms of life; the mechanisms and consequences of high horizontal gene transfer (HGT) prevalence remain to be confirmed by functional and comparative studies. Bdelloids tolerate desiccation and radiation stress, and appear to repair the resulting DNA double-strand breaks by different mechanisms in the soma versus germline; other aspects of stress tolerance remain to be investigated. Links between parthenogenesis, desiccation tolerance and horizontal gene transfer have been hypothesised, but several key steps remain to be tested. Bdelloid rotifers constitute a class of microscopic animals living in freshwater habitats worldwide. Several strange features of bdelloids have drawn attention: their ability to tolerate desiccation and other stresses, a lack of reported males across the clade despite centuries of study, and unusually high numbers of horizontally acquired, non-metazoan genes. Genome sequencing is transforming our understanding of their lifestyle and its consequences, while in turn providing wider insights about recombination and genome organisation in animals. Many questions remain, not least how to reconcile apparent genomic signatures of sex with the continued absence of reported males, why bdelloids have so many horizontally acquired genes, and how their remarkable ability to survive stress interacts with recombination and other genomic processes. [ABSTRACT FROM AUTHOR]

Sighs are a response to hypoxia, altered lung volume, and emotional state. A recent study employing in vivo physiology, optogenetics, chemoablation, and genetic silencing shows the importance of gastrin releasing peptide-expressing neurons in mediating sighs. [ABSTRACT FROM AUTHOR]

Background: Supraphysiologic bone morphogenetic protein (BMP)-2 concentrations are required to induce spinal fusion. In this study, a BMP-2/BMP-6/activin A chimera (BV-265), optimized for BMP receptor binding, delivered in a recombinant human collagen:CDHA [calcium-deficient hydroxyapatite] porous composite matrix (CM) or bovine collagen:CDHA granule porous composite matrix (PCM), engineered for optimal BV-265 retention and guided tissue repair, was compared with BMP-2 delivered in a bovine absorbable collagen sponge (ACS) wrapped around a MASTERGRAFT Matrix (MM) ceramic-collagen rod (ACS:MM) in a nonhuman primate noninstrumented posterolateral fusion (PLF) model.Methods: In vivo retention of 125I-labeled-BV-265/CM or PCM was compared with 125I-labeled-BMP-2/ACS or BMP-2/buffer in a rat muscle pouch model using scintigraphy. Noninstrumented PLF was performed by implanting CM, BV-265/CM, BV-265/PCM, or BMP-2/ACS:MM across L3-L4 and L5-L6 or L3-L4-L5 decorticated transverse processes in 26 monkeys. Computed tomography (CT) images were acquired at 0, 4, 8, 12, and 24 weeks after surgery, where applicable. Manual palpation, μCT (microcomputed tomography) or nCT (nanocomputed tomography), and histological analysis were performed following euthanasia.Results: Retention of 125I-labeled-BV-265/CM was greater than BV-265/PCM, followed by BMP-2/ACS and BMP-2/buffer. The CM, 0.43 mg/cm3 BMP-2/ACS:MM, and 0.05 mg/cm3 BV-265/CM failed to generate PLFs. The 0.15-mg/cm3 BV-265/CM or 0.075-mg/cm3 BV-265/PCM combinations were partially effective. The 0.25-mg/cm3 BV-265/CM and 0.15 and 0.3-mg/cm3 BV-265/PCM combinations generated successful 2-level PLFs at 12 and 24 weeks.Conclusions: BV-265/CM or PCM can induce fusion in a challenging nonhuman primate noninstrumented PLF model at substantially lower concentrations than BMP-2/ACS:MM.Clinical Relevance: BV-265/CM and PCM represent potential alternatives to induce PLF in humans at substantially lower concentrations than BMP-2/ACS:MM. [ABSTRACT FROM AUTHOR]

Transposable elements (TEs) are selfish genomic parasites whose ability to spread autonomously is facilitated by sexual reproduction in their hosts. If hosts become obligately asexual, TE frequencies and dynamics are predicted to change dramatically, but the long-term outcome is unclear. Here, we test current theory using whole-genome sequence data from eight species of bdelloid rotifers, a class of invertebrates in which males are thus far unknown. Contrary to expectations, we find a variety of active TEs in bdelloid genomes, at an overall frequency within the range seen in sexual species. We find no evidence that TEs are spread by cryptic recombination or restrained by unusual DNA repair mechanisms. Instead, we find that that TE content evolves relatively slowly in bdelloids and that gene families involved in RNAi-mediated TE suppression have undergone significant expansion, which might mitigate the deleterious effects of active TEs and compensate for the consequences of long-term asexuality. [ABSTRACT FROM AUTHOR]

To assess management impacts on the functionality of intensively managed agroecosystems, a modeling framework was developed with a bottom-up approach and spatially distributed, process-based models. The framework is equipped with dynamic, data-informed indicators and indices to illuminate the factors influencing sustainability. The proposed dynamic indices consider natural and human aspects of an agroecosystem such as erosion, biogeochemistry, and economics. Most current indicators are static, or slow-changing, soil characterization parameters that reflect better long-term interactions between landscape features, climate, and biology. However, the ever-changing land management and climate necessitates the use of dynamic parameters that reflect agroecosystem responses to different land management on similar timescales (e.g., seasonally). Our framework examines the performance of different ecosystem services including crop productivity, carbon storage, and net income under three different strategies with varying degrees of tillage intensity. The strategy with the highest intensity produced the highest yields, but also had the highest production costs. The second most intense strategy also had high yields, as well as the highest net income. However, these two strategies produced high erosion rates, which depleted the recalcitrant soil carbon, a critical component of system productivity and health. The index that provided the clearest picture of improvement within an agroecosystem was the Carbon Management Index ( CMI), which incorporates carbon lability and the implicit accounting of soil carbon redistribution from erosion. The CMI for the more intense strategies decreased in recent years, showing that they are not sustainable despite their high short-term productivity or profitability. The least intense strategy had the lowest Soil Organic Carbon (SOC) depletion through erosion and the highest CMI with a trend that is still-increasing through the present. Our study shows that to augment SOC storage, it important not only to increase the overall organic matter input, but also increase the amount of recalcitrant carbon in the soil and the longevity of all soil carbon through aggregate formation. [ABSTRACT FROM AUTHOR]

• Assessing combined effects of rainfall events and soil moisture on aggregate dynamics. • Net breakdown of aggregates following initial series of rainfall. • Net formation of aggregates after a subsequent drying-wetting cycle of soil. • Aggregate turnover rate depends on aggregate size and experiment time. Raindrop impact and wetting-drying cycles of soil strongly influence aggregate breakdown and reformation, but these mechanisms have not been examined simultaneously under field conditions. This study examined soil breakdown and aggregation in situ following rain events and inter-event soil moisture variations (referred herein as wetting-drying cycles) using rare earth elements (REEs) as tracers. Four natural aggregate size ranges (8–19 mm, 2–8 mm, 0.075–2 mm, and <0.075 mm) of soil from an agricultural field were tagged with different REEs and returned to the designated plot in the field. Soil samples were collected from the plot following rain events three days and twenty-six days after aggregate application and separated into the original four size ranges to analyze their REE concentrations. Using the change in REE concentrations from the original tagging, it was determined that there were greater proportions of aggregate breakdown (33% ± 11%) than formation (9% ± 4%) during the first three days resulting from relatively high rain power (0.051 ± 0.004 W m−2). In the next twenty-three days, more aggregates were found to reform (16% ± 22%) than break (10 ± 12%) as soil water content decreased from 33% to 23% then increased to 38% following relatively small rain events (rain power was 0.002 ± 0.005 W m−2). The turnover rate was faster for the 2–8 mm (0.014 day−1) and 0.075–2 mm (0.019 day−1) aggregates than for the 8–19 mm and <0.075 mm fractions (0.009 day−1). For a given aggregate size fraction, the turnover rate slowed down over the experiment time. This study demonstrates how REEs can track the aggregate life cycle in situ and advances the fundamental understanding of aggregate dynamics in agroecosystems in the context of raindrop impact and wetting-drying cycles. [ABSTRACT FROM AUTHOR]

Cell behavior in the presence of nanomaterials is typically explored through simple viability assays, but there is mounting evidence that nanomaterials can have more subtle effects on a variety of cellular functions. Previously our lab demonstrated that gold nanorods functionalized with polyelectrolyte multi-layers inhibited rat cardiac fibroblast-mediated remodeling of type I collagen scaffolds by altering fibroblast phenotype and the mechanical properties of the collagen network. In this work, we examine a possible mechanism for these effects: adsorption of cellular proteins by the nanorods. Mass spectrometric and gel electrophoresis of media collected from cultured cells suggests that a number of proteins, some of which mediate cell-cell and cell-matrix interactions, adsorb onto the surface of these nanoparticles in vitro. Polyethylene glycol coating of the nanorods largely mitigates protein adsorption and fibroblast-mediated collagen remodeling. These results suggest that adsorption of proteins by nanorods could have a significant effect on cell functions, including fibroblast-mediated matrix remodeling. [ABSTRACT FROM AUTHOR]

Mast cells are known to respond to a number of stimuli, such as IgE antibody-antigen complexes, pathogens, chemical compounds, and physical stimulation, resulting in the activation of these cells and subsequent release of cytokines, inflammatory mediators and granules which can influence the pathophysiology of neighboring cells. Although different forms of physical stimulation (i.e. shear stress and acupuncture) have been investigated, the effect of cyclic tensile loading on mast cell activation has not. To characterize the response of mast cells to tensile loading, RBL-2H3 cells were embedded in a 3-dimensional fibrin construct and subjected to 24 h of cyclic loading at 0%, 5% or 10% peak tensile strain. Mechanical loading significantly increased RBL-2H3 cell secretion of β-hexosaminidase (2.1- to 2.3-fold, respectively) in a load- and time-dependent manner when compared to the controls. Furthermore, no evidence of load-induced cell death or alterations in cell proliferation was observed. To determine if RGD-dependent integrins mediated the degranulation of mast cells during mechanical loading, cell-matrix interactions were inhibited by treating the cells with echistatin, a disintegrin that binds RGD-dependent integrins. Treatment with echistatin significantly attenuated load-induced degranulation without compromising cell viability. These results suggest a novel mechanism through which mechanical loading induces mast cell activation via RGD binding integrins. [ABSTRACT FROM AUTHOR]

A deeper understanding of the composition and organization of extracellular matrix molecules in native, healthy meniscus tissue is required to fully appreciate the degeneration that occurs in joint disease and the intricate environment in which an engineered meniscal graft would need to function. In this study, regional variations in the tissue-level and pericellular distributions of collagen types I, II and VI and the proteoglycans aggrecan, biglycan and decorin were examined in the juvenile bovine meniscus. The collagen networks were extensively, but not completely, colocalized, with tissue-level organization that varied with radial position across the meniscus. Type VI collagen exhibited close association with large bundles composed of type I and II collagen and, in contrast to type I and II collagen, was further concentrated in the pericellular matrix. Aggrecan was detected throughout the inner region of the meniscus but was restricted to the pericellular matrix and sheaths of collagen bundles in the middle and outer regions. The small proteoglycans biglycan and decorin exhibited regional variations in staining intensity but were consistently localized in the intra- and/or peri-cellular compartments. These results provide insight into the complex hierarchy of extracellular matrix organization in the meniscus and provide a framework for better understanding meniscal degeneration and disease progression and evaluating potential repair and regeneration strategies. [ABSTRACT FROM AUTHOR]

Asexuality has major theoretical advantages over sexual reproduction. Nevertheless, obligately asexual metazoan lineages seldom endure over evolutionary time. The Red Queen hypothesis posits that their limited capacity to generate genetic novelty leads to extermination by rapidly evolving parasites and pathogens. At first glance, rotifers of the class Bdelloidea appear to contradict this view: they have reproduced asexually for over 30 Myr without being overwhelmed by parasites. However, there are special ecological conditions under which Red Queen models can accommodate this unusual outcome. If hosts disperse rapidly within a structured metapopulation during a parasite-free life stage, then in principle they can become spatiotemporally decoupled from coevolving antagonists, and persist without sex. Intriguingly, bdelloid rotifers form dormant propagules when desiccated, which disperse easily by wind. In previous experiments, 7 days of desiccation and wind dispersal removed a fungal parasite from populations of one bdelloid species, allowing them to disperse independently. Here, I extend this finding to two additional bdelloid species and five more fungal parasites, and demonstrate its robustness under various desiccation regimes, and in the presence of multiple parasites. Results support the hypothesis that the unusual physiology of anciently asexual bdelloid rotifers helps them escape fungal parasites in space and time. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 104, 564-574. [ABSTRACT FROM AUTHOR]

The article focuses on the federal jurisdiction over state claims, particularly patent-based malpractice claims. It states that the plaintiff must present the suit within a suit requirement for causation analysis and must arise under federal law, however, the federal courts decisions on whether they will usurp the patent suit relies in the federal question jurisdiction statute. Accordingly, it suggests that federal courts should be skeptic in viewing patent-based malpractice claims.

Abstract: Gold nanorods (AuNRs) have unique optical properties for numerous biomedical applications, but the interactions between AuNRs and proteins, particularly those of the extracellular matrix (ECM), are poorly understood. Here the effects of AuNRs on the self-assembly, mechanics, and remodeling of type I collagen gels were examined in vitro. AuNRs were modified with polyelectrolyte multilayers (PEMs) to minimize cytotoxicity, and AuNRs with different terminal polymer chemistries were examined for their interactions with collagen by turbidity assays, rheological tests, and microscopy. Gel contraction assays were used to examine the effects of the PEM-coated AuNRs on cell-mediated collagen remodeling. Polyanion-terminated AuNRs significantly reduced the lag (nucleation) phase of collagen self-assembly and significantly increased the dynamic shear modulus of the polymerized gels, whereas polycation-terminated AuNRs had no effect on the mechanical properties of the collagen. Both polyanion- and polycation-terminated AuNRs significantly inhibited collagen gel contraction by cardiac fibroblasts, and the nanoparticles were localized in intra-, peri-, and extracellular compartments, suggesting that PEM-coated AuNRs influence cell behavior via multiple mechanisms. These results demonstrate the significance of nanoparticle–ECM interactions in determining the bioactivity of nanoparticles. [Copyright &y& Elsevier]

The Clear Creek, IA Experimental Watershed (CCEW), which drains to the Iowa River, experiences severe surface erosion due to a combination of high slopes, erodible soils, and extensive agriculture. Concurrent with soil loss is the removal of Soil Organic Matter (SOM). High values of SOM have been related to soil quality; therefore, excessive SOM loss corresponds to degrading soil health. Soil quality assessments are important tools for evaluating management practices in agricultural systems; however, it is difficult to measure soil quality directly at the watershed scale because it varies with a number of site-specific soil characteristics. The coupling of soil surveys with GIS and Non-Point Source computer simulation models will effectively forecast the impacts of ever-changing management practices on soil quality at the watershed scale in less time. NPS models can be extended to evaluate the movement of additional particle-bound constituents like SOM, by incorporating erosion rates and enrichment ratios. The ANNualized AGricultural Non-Point Source pollution modeling system (AnnAGNPS) was used to evaluate upland erosion, enrichment ratios, and SOM loss at the watershed scale in the headwaters of the CCEW using current crop rotations. Gross erosion rates averaged 7.73 MT/ha/yr for individual cells within the watershed. In addition, enrichment ratios, which were determined using gross and net erosion values from AnnAGNPS, were coupled with an organic matter coverage map of the watershed to determine an SOM loss of 0.41 MT/ha/yr, which was similar to the loss rates determined by AnnAGNPS (0.29 MT/ ha/yr). To understand the state of soil health in this watershed, the NRCS Soil Conditioning Index (SCI) was determined for the watershed. The average SCI for the watershed was 0.38, which suggests improving soil health conditions. This improvement is most probably due to conservation practices like reduced tillage. [ABSTRACT FROM AUTHOR]

We combined real-time calcium-based neural activity imaging with whole-cell patch-clamp recording techniques to map the spatial organization and analyze electrophysiological properties of respiratory neurons forming the circuit transmitting rhythmic drive from the pre-Bötzinger complex (pre-BötC) through premotoneurons to hypoglossal (XII) motoneurons. Inspiratory pre-BötC neurons, XII premotoneurons (preMNs), and XII motoneurons (MNs) were retrogradely labeled with Ca2+-sensitive dye in neonatal rat in vitro brainstem slices. PreMN cell bodies were arrayed dorsomedially to pre-BötC neurons with little spatial overlap; axonal projections to MNs were ipsilateral. Inspiratory MNs were distributed in dorsal and ventral subnuclei of XII. Voltage-clamp recordings revealed that two currents, persistent sodium current (NaP) and K +-dominated leak current (Leak), primarily contribute to preMN/MN subthreshold current-voltage relationships. NaP or Leak conductance densities in preMNs and MNs were not significantly different. We quantified preMN and MN action potential time course and spike frequency- current (f-I) relationships and found no significant differences in repetitive spiking dynamics, steady-state f-I gains, and afterpolarizing potentials. Rhythmic synaptic drive current densities were similar in preMNs and MNs. Our results indicate that, despite topographic and morphological differences, preMNs and MNs have some common intrinsic membrane, synaptic integration, and spiking properties that we postulate ensure fidelity of inspiratory drive transmission and conversion of synaptic drive into (pre)motor output. There also appears to be a common architectonic organization for some respiratory drive transmission circuits whereby many preMNs are spatially segregated from pre-BötC rhythm-generating neurons, which we hypothesize may facilitate downstream integration of convergent inputs for premotor pattern formation. [ABSTRACT FROM AUTHOR]

In the preparation of bioengineered reparative strategies for damaged or diseased tissues, the processes of biomaterial degradation and neotissue synthesis combine to affect the developing mechanical state of multiphase, composite engineered tissues. Here, cell-polymer constructs for engineered cartilage have been fabricated by seeding chondrocytes within three-dimensional scaffolds of biodegradable polymers. During culture, synthetic scaffolds degraded passively as the cells assembled an extracellular matrix (ECM) composed primarily of glycosaminoglycan and collagen. Biochemical and biomechanical assessment of the composite (cells, ECM, and polymer scaffold) were modeled at a unit-cell level to mathematically solve stress-strain relationships and thus construct elastic properties (n=4 samples per seven time points). This approach employed a composite spheres, micromechanical analysis to determine bulk moduli of: (1) the cellular-ECM inclusion within the supporting scaffold structure; and (2) the cellular inclusion within its ECM. Results indicate a dependence of constituent volume fractions with culture time (p<0.05). Overall mean bulk moduli were variably influenced by culture, as noted for the cell-ECM inclusion (Kc-m=29.7 kPa, p=0.1439), the cellular inclusion (Kc=5.5 kPa, p=0.0067), and its surrounding ECM (Km=373.9 kPa, p=0.0748), as well as the overall engineered construct (K=165.0 kPa, p=0.6899). This analytical technique provides a framework to describe the time-dependent contribution of cells, accumulating ECM, and a degrading scaffold affecting bioengineered construct mechanical properties. [ABSTRACT FROM AUTHOR]

Abstract: Articular cartilage undergoes matrix degradation and loss of mechanical properties when stimulated with proinflammatory cytokines such as interleukin-1 (IL-1). Aggrecanases and matrix metalloproteinases (MMPs) are thought to be principal downstream effectors of cytokine-induced matrix catabolism, and aggrecanase- or MMP-selective inhibitors reduce or block matrix destruction in several model systems. The objective of this study was to use metalloproteinase inhibitors to perturb IL-1-induced matrix catabolism in bovine cartilage explants and examine their effects on changes in tissue compression and shear properties. Explanted tissue was stimulated with IL-1 for up to 24 days in the absence or presence of inhibitors that were aggrecanase-selective, MMP-selective, or non-selective. Analysis of conditioned media and explant digests revealed that aggrecanase-mediated aggrecanolysis was delayed to varying extents with all inhibitor treatments, but that aggrecan release persisted. Collagen degradation was abrogated by MMP- and non-selective inhibitors and reduced by the aggrecanase inhibitor. The inhibitors delayed but did not reduce loss of the equilibrium compression modulus, whereas the losses of dynamic compression and shear moduli were delayed and reduced. The data suggest that non-metalloproteinase mechanisms participate in IL-1-induced matrix degradation and loss of tissue material properties. [Copyright &y& Elsevier]

Identification of protein binding partners is one of the key challenges of proteomics. We recently introduced a screen for detecting protein-protein interactions based on reassembly of dissected fragments of green fluorescent protein fused to interacting peptides. Here, we present a set of comaintained Esoherichia coil plasmids for the facile subcloning of fusions to the green fluorescent protein fragments. Using a library of antiparallel leucine zippers, we have shown that the screen can detect very weak interactions (KD &ap; 1 mM). In vitro kinetics show that the reassembly reaction is essentially irreversible, suggesting that the screen may be useful for detecting transient interactions. Finally, we used the screen to discriminate, cognate from noncognate protein--ligand interactions for tetratricopeptide repeat domains. These experiments demonstrate the general utility of the screen for larger proteins and elucidate mechanistic details to guide the further use of this screen in proteomic analysis. Additionally, this work gives insight into the positional inequivalence of stabilizing interactions in antiparallel coiled coils. [ABSTRACT FROM AUTHOR]

There are several different families of repeat proteins. In each, a distinct structural motif is repeated in tandem to generate an elongated structure. The nonglobular, extended structures that result are particularly well suited to present a large surface area and to function as interaction domains. Many repeat proteins have been demonstrated experimentally to fold and function as independent domains. In tetratricopeptide (TPR) repeats, the repeat unit is a helix-turn-helix motif. The majority of TPR motifs occur as three to over 12 tandem repeats in different proteins. The majority of TPR structures in the Protein Data Bankare of isolated domains. Here we present the high-resolution structure of NlpI, the first structure of a complete TPR-containing protein. We show that in this instance the TPR motifs do not fold and function as an independent domain, but are fully integrated into the three-dimensional structure of a globular protein. The NlpI structure is also the first TPR structure from a prokaryote. It is of particular interest because it is a membrane-associated protein, and mutations in it alter septation and virulence. [ABSTRACT FROM AUTHOR]

Presents a study regarding the novel genetic system in detecting protein-protein interactions. Utilization of the green fluorescent protein (GFP); Purification of the reassembled GFP complex; Visualization of interactions among family proteins in living cells using bimolecular fluorescence complementation.

GABA and adenosine contribute to respiratory inhibition in early postnatal life. In this study the adenosine A2A receptor agonist CGS21680 was used to evaluate adenosine receptor specificity and the interrelation of adenosine and GABA in the inhibition of inspiratory drive. In neonatal piglets (n = 10), CGS21680 was injected into the fourth ventricle resulting in apnea and/or decreased burst area and frequency of phrenic discharge. Phrenic burst area decreased to 58.9 ± 8.6% (S.E.M.) after CGS21680 injection (control = 91.8 ± 1.0%). Expiratory time increased 261.0 ± 59.9% after CGS21680 from control (87.7 ± 2.7%). When bicuculline was injected locally within the rostral ventrolateral medulla (n = 5), or into the fourth ventricle (n = 5), the CGS21680 induced inhibition of phrenic was abolished. To define expression of A2A receptor at the message level (mRNA), we employed in situ hybridization with a digoxigenin-coupled oligonucleotide. Adenosine A2A receptor mRNA was expressed in regions of the medulla oblongata known to contain GABAergic neurons. We conclude that GABAergic inputs affecting respiratory timing and inspiratory drive are modulated by activation of A2A receptors. These findings offer new insight into the mechanism whereby xanthine therapy diminishes apnea of prematurity. [Copyright &y& Elsevier]

Mathematical models to describe extracellular matrix (ECM) deposition and scaffold degradation in cell–polymer constructs for the design of engineered cartilage were developed and validated. The ECM deposition model characterized a product-inhibition mechanism in the concentration of cartilage molecules, collagen and glycosaminoglycans (GAG). The scaffold degradation model used first-order kinetics to describe hydrolysis (not limited by diffusion) of biodegradable polyesters, polyglycolic acid and polylactic acid. Each model was fit to published accumulation and degradation data. As experimental validation, cell–polymer constructs (n=24) and unseeded scaffolds (n=24) were cultured in vitro. Biochemical assays for ECM content and measurements of scaffold mass were performed at 1, 2, 4, 6, 8, or 10 weeks (n=8 per time point). The models demonstrated a strong fit with published data and experimental results (R2=0.75 to 0.99) and predicted the temporal total construct mass with reasonable accuracy (30% RMS error). This approach can elucidate mechanisms governing accumulation/degradation and may be coupled with structure–function relationships to describe time-dependent changes in construct elastic properties. [Copyright &y& Elsevier]

Focuses on a study which examined an approach to implementing the dynamic-clamp protocol, which is commonly used in neurophysiology and cardiac electrophysiology experiments. Theoretical background; Methodology; Findings and discussion.

Investigates the effects of area postrema stimulation on the activity of cardiovascular-related neurons in the rostral ventrolateral medulla in rabbits. Medullary unit responses to area postrema stimulation; Effect of kainic acid on medullary unit responses; Relationship to sympathetic nerve activity, cardiac cycle and baroreceptors.

Niemann–Pick disease type C (NPC) is a fatal neurodegenerative condition caused by genetic mutations of the NPC1 or NPC2 genes that encode the NPC1 and NPC2 proteins, respectively, which are believed to be responsible for cholesterol efflux from late-endosomes/lysosomes. The pathogenic mechanisms that lead to neurodegeneration in NPC are not well understood. There are, however, well-defined spatiotemporal patterns of neurodegeneration that may provide insight into the pathogenic process. For example, the cerebellum is severely affected from early disease stages, compared with cerebral regions, which remain relatively spared until later stages. Using a genome-wide transcriptome analysis, we have recently identified an aberrant pattern of interferon activation in the cerebella of pre-symptomatic Npc1−/− mice. Here, we carried out a comparative transcriptomic analysis of cerebral cortices and cerebella of pre-symptomatic Npc1−/− mice and age-matched controls to identify differences that may help explain the pathological progression within the NPC brain. We report lower cerebral expression of genes within interferon signaling pathways, and significant differences in the regulation of oxidative stress, compared with the cerebellum. Our findings suggest that a delayed onset of interferon signaling, possibly linked to lower oxidative stress, may account for the slower onset of cerebral cortical pathology in the disease. [ABSTRACT FROM AUTHOR]

Asexuality has major theoretical advantages over sexual reproduction. An important evolutionary puzzle, therefore, is why exclusively asexual metazoan lineages rarely endure. The Red Queen hypothesis posits that asexuality is rapidly extinguished by relentlessly coevolving parasites and pathogens. If so, any long-lasting asexual lineage must have unusual alternative mechanisms to deal with these biotic enemies. Bdelloid rotifers are freshwater invertebrates that abandoned sexual reproduction millions of years ago. Here, we show that cultured populations of bdelloids can rid themselves of a deadly fungal parasite through complete desiccation (anhydrobiosis) and disperse by wind to establish new populations in its absence. In Red Queen models, spatiotemporal escape can decouple and protect asexuals from coevolving enemies. Thus, our results may help to explain the persistence of the anciently asexual Bdelloidea. [ABSTRACT FROM AUTHOR]

• Perinatal inflammation is known to adversely effect breathing in preterm babies. • However, lung infection/inflammation impacts both the beginning and "end of life". • Little is known about how inflammation changes respiration, neuronal morphology, or neural function during development. • Animal models of can provide understanding and insight into respiratory development, inflammation, and treatment modalities. • This review summarizes recent work related to inflammation, its impact on development, and treatments for inflammation. Breathing is fundamental to life and any adverse change in respiratory function can endanger the health of an organism or even be fatal. Perinatal inflammation is known to adversely affect breathing in preterm babies, but lung infection/inflammation impacts all stages of life from birth to death. Little is known about the role of inflammation in respiratory control, neuronal morphology, or neural function during development. Animal models of inflammation can provide understanding and insight into respiratory development and how inflammatory processes alter developmental phenotype in addition to providing insight into new treatment modalities. In this review, we focus on recent work concerning the development of neurons, models of perinatal inflammation with an emphasis on two common LPS-based models, inflammation and its impact on development, and current and potential treatments for inflammation within the respiratory control circuitry of the mammalian brainstem. We have also discussed models of inflammation in adults and have specifically focused on hypoglossal motoneurons (XII) and neurons of the nucleus tractus solitarii (nTS) as these nuclei have been studied more extensively than other brainstem nuclei participating in breathing and airway control. Understanding the impact of inflammation on the developmental aspects of respiratory control and breathing pattern is critical to addressing problems of cardiorespiratory dysregulation in disease and this overview points out many gaps in our current knowledge. [ABSTRACT FROM AUTHOR]

We compared the genetic diversity and structure of wild versus captive-propagated at-risk species of freshwater mussels in Canada, Lampsilis fasciola (wavy-rayed lampmussel; WRL) and Ptychobranchus fasciolaris (kidneyshell; KS), using microsatellite-generated genotypes. No significant differences were detected using Kruskal–Wallis tests that compared the genetic diversity metrics of wild and captive-propagated WRL (from 12 mothers) and KS (from seven mothers). After effective population size (Ne) was estimated, considerable overlap was found in the estimated Ne between wild and captive populations of both species. Pairwise FST and Dest values among wild WRL, hatchery-raised WRL juveniles, and across different time periods (2008–2018) were generally low (FST = 0.007–0.043, Dest = 0.005–0.282). Pairwise FST and Dest for KS were not significant and low (0.012, 0.017). When comparing captive-reared offspring with the wild population, STRUCTURE analysis revealed strong support for a single genetic population. With at least seven females contributing to brood stock, genetic diversity was maintained. Further research is needed to assess the male contribution to each glochidial brood as well as the variability of genetic diversity in individual glochidial broods. [ABSTRACT FROM AUTHOR]

During range expansion, invasive species can experience new thermal regimes. Differences between the thermal performance of local and invasive species can alter species interactions, including predator-prey interactions. The Asian tiger mosquito, Aedes albopictus, is a known vector of several viral diseases of public health importance. It has successfully invaded many regions across the globe and currently threatens to invade regions of the UK where conditions would support seasonal activity. We assessed the functional response and predation efficiency (percentage of prey consumed) of the cyclopoid copepods Macrocyclops albidus and Megacyclops viridis from South East England, UK against newly-hatched French Ae. albopictus larvae across a relevant temperature range (15, 20, and 25°C). Predator-absent controls were included in all experiments to account for background prey mortality. We found that both M. albidus and M. viridis display type II functional response curves, and that both would therefore be suitable biocontrol agents in the event of an Ae. albopictus invasion in the UK. No significant effect of temperature on the predation interaction was detected by either type of analysis. However, the predation efficiency analysis did show differences due to predator species. The results suggest that M. viridis would be a superior predator against invasive Ae. albopictus larvae due to the larger size of this copepod species, relative to M. albidus. Our work highlights the importance of size relationships in predicting interactions between invading prey and local predators. [ABSTRACT FROM AUTHOR]

Summary A few metazoan lineages are thought to have persisted for millions of years without sexual reproduction. If so, they would offer important clues to the evolutionary paradox of sex itself [ 1, 2 ]. Most “ancient asexuals” are subject to ongoing doubt because extant populations continue to invest in males [ 3–9 ]. However, males are famously unknown in bdelloid rotifers, a class of microscopic invertebrates comprising hundreds of species [ 10–12 ]. Bdelloid genomes have acquired an unusually high proportion of genes from non-metazoans via horizontal transfer [ 13–17 ]. This well-substantiated finding has invited speculation [ 13 ] that homologous horizontal transfer between bdelloid individuals also may occur, perhaps even “replacing” sex [ 14 ]. In 2016, Current Biology published an article claiming to supply evidence for this idea. Debortoli et al. [ 18 ] sampled rotifers from natural populations and sequenced one mitochondrial and four nuclear loci. Species assignments were incongruent among loci for several samples, which was interpreted as evidence of “interspecific horizontal genetic transfers.” Here, we use sequencing chromatograms supplied by the authors to demonstrate that samples treated as individuals actually contained two or more highly divergent mitochondrial and ribosomal sequences, revealing cross-contamination with DNA from multiple animals of different species. Other chromatograms indicate contamination with DNA from conspecific animals, explaining genetic and genomic evidence for “intraspecific horizontal exchanges” reported in the same study. Given the clear evidence of contamination, the data and findings of Debortoli et al. [ 18 ] provide no reliable support for their conclusions that DNA is transferred horizontally between or within bdelloid species. [ABSTRACT FROM AUTHOR]

• We used reconstructed 3D XII MN morphology in computational models of rat neurons and compared with published experiments. • We simulated postnatal days 3, 10, and 17 hypoglossal motoneurons using a Hodgkin-Huxley formalism. • Postnatal day 3 neurons required I h current and C m to match experimental results when compared to P10 or P17. • Passive properties of simulated neurons showed similar changes to experimentally determined passive properties of XII MNs. We hypothesize that developmental changes in motoneuron volume or surface area in the hypoglossal motor nucleus (XII) can alter the biophysical properties that contribute to motor output. We used the Golgi-Cox technique to stain developing hypoglossal motoneurons (XII MNs) at three postnatal ages (P3, 10, & 17). We removed Sprague-Dawley rat pup brains, processed, sectioned, stained, imaged, and performed 3D reconstructions to quantify the morphometrics of XII MNs. We then used the simulation environment, NEURON, to model the biophysical properties from digitally reconstructed neurons and compared our results to previously published experiments. The total volume of neurons increased from 4766 μ m3 for P3 to 16,904 μ m3 for P17 while the total surface area increased from 4258 μ m2 to 13,510 μ m2 respectively. The P3 simulations required a 10-fold reduction in the hyperpolarization-activated current and doubling of the membrane capacitance to match experimental results. XII MN morphology showed a direct relationship with passive electrophysiological properties and recapitulates the changes seen experimentally. [ABSTRACT FROM AUTHOR]

Intracellular Ca2+ signals are key for the regulation of cellular processes ranging from myocyte contraction, hormonal secretion, neural transmission, cellular metabolism, transcriptional regulation, and cell proliferation. Measurement of cellular Ca2+ is routinely performed using fluorescence microscopy with biological indicators. Analysis of deterministic signals is reasonably straightforward as relevant data can be discriminated based on the timing of cellular responses. However, analysis of stochastic, slower oscillatory events, as well as rapid subcellular Ca2+ responses, takes considerable time and effort which often includes visual analysis by trained investigators, especially when studying signals arising from cells embedded in complex tissues. The purpose of the current study was to determine if full-frame time-series and line-scan image analysis workflow of Fluo-4 generated Ca2+ fluorescence data from vascular myocytes could be automated without introducing errors. This evaluation was addressed by re-analyzing a published "gold standard" full-frame time-series dataset through visual analysis of Ca2+ signals from recordings made in pulmonary arterial myocytes of en face arterial preparations. We applied a combination of data driven and statistical approaches with comparisons to our published data to assess the fidelity of the various approaches. Regions of interest with Ca2+ oscillations were detected automatically post hoc using the LCPro plug-in for ImageJ. Oscillatory signals were separated based on event durations between 4 and 40 s. These data were filtered based on cutoffs obtained from multiple methods and compared to the published manually curated "gold standard" dataset. Subcellular focal and rapid Ca2+ "spark" events from line-scan recordings were examined using SparkLab 5.8, which is a custom automated detection and analysis program. After filtering, the number of true positives, false positives, and false negatives were calculated through comparisons to visually derived "gold standard" datasets. Positive predictive value, sensitivity, and false discovery rates were calculated. There were very few significant differences between the automated and manually curated results with respect to quality of the oscillatory and Ca2+ spark events, and there were no systematic biases in the data curation or filtering techniques. The lack of statistical difference in event quality between manual data curation and statistically derived critical cutoff techniques leads us to believe that automated analysis techniques can be reliably used to analyze spatial and temporal aspects to Ca2+ imaging data, which will improve experiment workflow. [ABSTRACT FROM AUTHOR]

The genetic determinants of many diseases, including monogenic diseases and cancers, have been identified; nevertheless, targeted therapy remains elusive for most. High-throughput screening (HTS) of small molecules, including high-content analysis (HCA), has been an important technology for the discovery of molecular tools and new therapeutics. HTS can be based on modulation of a known disease target (called reverse chemical genetics) or modulation of a disease-associated mechanism or phenotype (forward chemical genetics). Prominent target-based successes include modulators of transthyretin, used to treat transthyretin amyloidoses, and the BCR-ABL kinase inhibitor Gleevec, used to treat chronic myelogenous leukemia. Phenotypic screening successes include modulators of cystic fibrosis transmembrane conductance regulator, splicing correctors for spinal muscular atrophy, and histone deacetylase inhibitors for cancer. Synthetic lethal screening, in which chemotherapeutics are screened for efficacy against specific genetic backgrounds, is a promising approach that merges phenotype and target. In this article, we introduce HTS technology and highlight its contributions to the discovery of drugs and probes for monogenic diseases and cancer. [ABSTRACT FROM AUTHOR]

Bdelloid rotifers are a class of microscopic invertebrates that have existed for millions of years apparently without sex or meiosis. They inhabit a variety of temporary and permanent freshwater habitats globally, and many species are remarkably tolerant of desiccation. Bdelloids offer an opportunity to better understand the evolution of sex and recombination, but previous work has emphasised desiccation as the cause of several unusual genomic features in this group. Here, we present high-quality whole-genome sequences of 3 bdelloid species: Rotaria macrura and R. magnacalcarata, which are both desiccation intolerant, and Adineta ricciae, which is desiccation tolerant. In combination with the published assembly of A. vaga, which is also desiccation tolerant, we apply a comparative genomics approach to evaluate the potential effects of desiccation tolerance and asexuality on genome evolution in bdelloids. We find that ancestral tetraploidy is conserved among all 4 bdelloid species, but homologous divergence in obligately aquatic Rotaria genomes is unexpectedly low. This finding is contrary to current models regarding the role of desiccation in shaping bdelloid genomes. In addition, we find that homologous regions in A. ricciae are largely collinear and do not form palindromic repeats as observed in the published A. vaga assembly. Consequently, several features interpreted as genomic evidence for long-term ameiotic evolution are not general to all bdelloid species, even within the same genus. Finally, we substantiate previous findings of high levels of horizontally transferred nonmetazoan genes in both desiccating and nondesiccating bdelloid species and show that this unusual feature is not shared by other animal phyla, even those with desiccation-tolerant representatives. These comparisons call into question the proposed role of desiccation in mediating horizontal genetic transfer. [ABSTRACT FROM AUTHOR]

The goal of this study was to understand better the co-play of intrinsic soil properties and extrinsic factors of climate and management in the estimation of saturated hydraulic conductivity ( K sat ) in intensively managed landscapes. For this purpose, a physically-based, modeling framework was developed using hydro-pedotransfer functions (PTFs) and watershed models integrated with Geographic Information System (GIS) modules. The integrated models were then used to develop K sat maps for the Clear Creek, Iowa watershed and the state of Iowa. Four types of saturated hydraulic conductivity were considered, namely the baseline ( K b ), the bare ( K br ), the effective with no-rain ( K e-nr ) and the effective ( K e ) in order to evaluate how management and seasonality affect K sat spatiotemporal variability. K b is dictated by soil texture and bulk density, whereas K br , K e-nr , and K e are driven by extrinsic factors, which vary on an event to seasonal time scale, such as vegetation cover, land use, management practices, and precipitation. Two seasons were selected to demonstrate K sat dynamics in the Clear Creek watershed, IA and the state of Iowa; specifically, the months of October and April that corresponded to the before harvesting and before planting conditions, respectively. Statistical analysis of the Clear Creek data showed that intrinsic soil properties incorporated in K b do not reflect the degree of soil surface disturbance due to tillage and raindrop impact. Additionally, vegetation cover affected the infiltration rate. It was found that the use of K b instead of K e in water balance studies can lead to an overestimation of the amount of water infiltrated in agricultural watersheds by a factor of two. Therefore, we suggest herein that K e is both the most dynamic and representative saturated hydraulic conductivity for intensively managed landscapes because it accounts for the contributions of land cover and management, local hydropedology and climate condition, which all affect the soil porosity and structure and hence, K sat . [ABSTRACT FROM AUTHOR]

How sensory information influences the dynamics of rhythm generation varies across systems, and general principles for understanding this aspect of motor control are lacking. Determining the origin of respiratory rhythm generation is challenging because the mechanisms in a central circuit considered in isolation may be different from those in the intact organism. We analyze a closed-loop respiratory control model incorporating a central pattern generator (CPG), the Butera-Rinzel-Smith (BRS) model, together with lung mechanics, oxygen handling, and chemosensory components. We show that 1) embedding the BRS model neuron in a control loop creates a bistable system; 2) although closed-loop and open-loop (isolated) CPG systems both support eupnea-like bursting activity, they do so via distinct mechanisms; 3) chemosensory feedback in the closed loop improves robustness to variable metabolic demand; 4) the BRS model conductances provide an autoresuscitation mechanism for recovery from transient interruption of chemosensory feedback; and 5) the in vitro brain stem CPG slice responds to hypoxia with transient bursting that is qualitatively similar to in silico autoresuscitation. Bistability of bursting and tonic spiking in the closed-loop system corresponds to coexistence of eupnea-like breathing, with normal minute ventilation and blood oxygen level and a tachypnea-like state, with pathologically reduced minute ventilation and critically low blood oxygen. Disruption of the normal breathing rhythm, through either imposition of hypoxia or interruption of chemosensory feedback, can push the system from the eupneic state into the tachypneic state. We use geometric singular perturbation theory to analyze the system dynamics at the boundary separating eupnea-like and tachypnea-like outcomes. NEW & NOTEWORTHY A common challenge facing rhythmic biological processes is the adaptive regulation of central pattern generator (CPG) activity in response to sensory feedback. We apply dynamical systems tools to understand several properties of a closed-loop respiratory control model, including the coexistence of normal and pathological breathing, robustness to changes in metabolic demand, spontaneous autoresuscitation in response to hypoxia, and the distinct mechanisms that underlie rhythmogenesis in the intact control circuit vs. the isolated, open-loop CPG. [ABSTRACT FROM AUTHOR]

Dike structures have been used in many streams to control streambank erosion by redirecting the flow away from the banks towards the centre of the channel. In this study, the 2D finite-element surface water modelling system (FESWMS) was used to enhance the design of dike structures in two meandering stream reaches along the Raccoon River, Iowa, USA. FESWMS was used to find the optimal number and spacing between the dikes and to access their overall performance in controlling river-bank erosion in the study reaches. The study included also field measurements for model calibration and verification. The model results showed that the proposed dike structures, consisting of alternate five bendway weirs and four spurs at each site with a spacing of about 50 m, successfully reduced the flow velocity along the outside bank and increased the conveyance of the flow to the stream centre. The average lengths of the spurs and bendway weirs were about 16 and 32 m, respectively. The estimated velocity and Froude number values along the outside riverbank where the dikes were constructed were less than 1.0 m/s and 0.3, respectively, which are within the recommended values for erodible channel stability design. Site visits one year after the dike construction showed that the dikes were successful in controlling streambank erosion by allowing incoming sediment to deposit between the dikes and along the bank line. Sediment transport measurements at the study sites showed that the maximum deposition was about 0.8 m, which is much higher than a typical averaged deposition value of about 0.3 m/year. Further, recent Google Earth pictures for the sites showed that the bank slope lines almost recovered back in their original profiles and that the dikes became part of the restored banks, a strong indication of the success of the proposed dikes design. [ABSTRACT FROM AUTHOR]

Sexual reproduction is costly, but it is nearly ubiquitous among plants and animals, whereas obligately asexual taxa are rare and almost always short-lived. The Red Queen hypothesis proposes that sex overcomes its costs by enabling organisms to keep pace with coevolving parasites and pathogens. If so, the few cases of stable long-term asexuality ought to be found in groups whose coevolutionary interactions with parasites are unusually weak. In theory, antagonistic coevolution will be attenuated if hosts disperse among patches within a metapopulation separately from parasites and more rapidly. We examined whether these conditions are met in natural communities of bdelloid rotifers, one of the longest-lived asexual lineages. At any life stage, these microscopic invertebrates can tolerate the complete desiccation of their ephemeral freshwater habitats, surviving as dormant propagules that are readily carried by the wind. In our field experiments, desiccation and wind transport enabled bdelloids to disperse independently of multiple fungal parasites, in both time and space. Surveys of bdelloid communities in unmanipulated moss patches confirmed that fungal parasitism was negatively correlated with extended drought and increasing height (exposure to wind). Bdelloid ecology therefore matches a key condition of models in which asexuals persist through spatio-temporal decoupling from coevolving enemies. [ABSTRACT FROM AUTHOR]

Background: There is evidence from various models of hypoxic-ischemic injury (HII) that nitric oxide (NO) is protective. We hypothesized that either inhaled NO (iNO) or nitrite would alleviate brain injury in neonatal HII via modulation of mitochondrial function. Methods: We tested the effects of iNO and nitrite on the Rice-Vannucci model of HII in 7-day-old rats. Brain mitochondria were isolated for flow cytometry, aconitase activity, electron paramagnetic resonance, and Seahorse assays. Results: Pretreatment of pups with iNO decreased survival in the Rice-Vannucci model of HII, while iNO administered post-insult did not. MRI analysis demonstrated that pre-HII iNO at 40 ppm and post-HII iNO at 20 ppm decreased the brain lesion sizes from 6.3±1.3% to 1.0±0.4% and 1.8±0.8%, respectively. Intraperitoneal nitrite at 0.165 μg/g improved neurobehavioral performance but was harmful at higher doses and had no effect on brain infarct size. NO reacted with complex IV at the heme a3 site, decreased the oxidative stress of mitochondria challenged with anoxia and reoxygenation, and suppressed mitochondrial oxygen respiration. Conclusions: This study suggests that iNO administered following neonatal HII may be neuroprotective, possibly via its modulation of mitochondrial function. [ABSTRACT FROM AUTHOR]

In this study, detailed field experiments were conducted at three hillslopes in southeast Iowa with different agricultural management practices, namely Conservation Reserve Program (CRP), no-till, and conventional till, to identify the effects of land use on saturated hydraulic conductivity, K sat , variability. On average, 40 measurements per field were concomitantly performed using an array of semi-automated double ring infiltrometers (DRIs) to ensure adequate spatial representation of K sat per hillslope. The semi-automated DRIs allowed for continuous operation up to 200 h so that a “true” steady state condition could be reached during the monitoring period. These measurements were complemented with pedon measurements for soil texture, bulk density, and other biogeochemical properties at the same locations. A statistical analysis showed that K sat exhibited a log-normal distribution and the harmonic mean of the K sat values proved to be the most representative mean. Two distinct patterns were observed in the developed K sat spatial distribution maps for the three hillslopes. The map for the CRP hillslope showed a “strip pattern” while the cultivated fields depicted a “mosaic pattern”. The strip pattern at the CRP was attributed to past flow-driven preferential erosion along the main drainage-way, which removed the finer soil fractions and exposed a loam substratum with a relatively higher sand content that yielded higher K sat values in the drainage-way. The mosaic patterns in the no-till and tilled fields were attributed to the mixing of soil from cultivation during the crop rotations. A correlation analysis between K sat and different soil properties confirmed the patterns shown in the K sat maps and further revealed the correspondence of K sat with key soil properties. Soil texture dominated the infiltration process in soils with a higher sand content (> 15%), whereas bulk density dominated the infiltration process in soils experiencing the effects of compaction due to agricultural activity. [ABSTRACT FROM AUTHOR]

In the developing heart, cardiomyocytes undergo terminal differentiation during a critical window around birth. Hypoxia is a major stress to preterm infants, yet its effect on the development and maturation of the heart remains unknown. We tested the hypothesis in a rat model that newborn anoxia accelerates cardiomyocyte terminal differentiation and results in reduced cardiomyocyte endowment in the developing heart via an endothelin-1-dependent mechanism. Newborn rats were exposed to anoxia twice daily from postnatal day 1 to 3, and hearts were isolated and studied at postnatal day 4 (P4), 7 (P7), and 14 (P14). Anoxia significantly increased HIF-1α protein expression and pre-proET-1 mRNA abundance in P4 neonatal hearts. Cardiomyocyte proliferation was significantly decreased by anoxia in P4 and P7, resulting in a significant reduction of cardiomyocyte number per heart weight in the P14 neonates. Furthermore, the expression of cyclin D2 was significantly decreased due to anoxia, while p27 expression was increased. Anoxia has no significant effect on cardiomyocyte binucleation or myocyte size. Consistently, prenatal hypoxia significantly decreased cardiomyocyte proliferation but had no effect on binucleation in the fetal heart. Newborn administration of PD156707, an ETA-receptor antagonist, significantly increased cardiomyocyte proliferation at P4 and cell size at P7, resulting in an increase in the heart to body weight ratio in P7 neonates. In addition, PD156707 abrogated the anoxia-mediated effects. The results suggest that hypoxia and anoxia via activation of endothelin-1 at the critical window of heart development inhibits cardiomyocyte proliferation and decreases myocyte endowment in the developing heart, which may negatively impact cardiac function later in life. [ABSTRACT FROM AUTHOR]

L-cysteine ethylester (L-CYSee) is a membrane-permeable analogue of L-cysteine with a variety of pharmacological effects. The purpose of this study was to determine the effects of L-CYSee on morphine-induced changes in ventilation, arterial-blood gas (ABG) chemistry, Alveolar-arterial (A-a) gradient (i.e., a measure of the index of alveolar gas-exchange), antinociception and sedation in male Sprague Dawley rats. An injection of morphine (10 mg/kg, IV) produced adverse effects on breathing, including sustained decreases in minute ventilation. L-CYSee (500 μmol/kg, IV) given 15 min later immediately reversed the actions of morphine. Another injection of L-CYSee (500 μmol/kg, IV) after 15 min elicited more pronounced excitatory ventilatory responses. L-CYSee (250 or 500 μmol/kg, IV) elicited a rapid and prolonged reversal of the actions of morphine (10 mg/kg, IV) on ABG chemistry (pH, pCO 2 , pO 2 , sO 2) and A-a gradient. L-serine ethylester (an oxygen atom replaces the sulfur; 500 μmol/kg, IV), was ineffective in all studies. L-CYSee (500 μmol/kg, IV) did not alter morphine (10 mg/kg, IV)-induced sedation, but slightly reduced the overall duration of morphine (5 or 10 mg/kg, IV)-induced analgesia. In summary, L-CYSee rapidly overcame the effects of morphine on breathing and alveolar gas-exchange, while not affecting morphine sedation or early-stage analgesia. The mechanisms by which L-CYSee modulates morphine depression of breathing are unknown, but appear to require thiol-dependent processes. • L-CYSee is converted to S-nitrosylated L-CYSee (SNO-L-CYSee) in ventilatory control pathways via the actions of constitutive nitric oxide synthase (NOS). • SNO-l-CYSee is the active form inside of cells that modulates signaling events. • The minimal presence of constitutive NOS in analgesic pathways allows for only minimal formation of SNO-L-CYSee and therefore minimal disruption of opioid analgesia. [Display omitted] • L-cysteine ethyl ester (L-CYSee) reverses morphine-induced respiratory depression. • L-CYSee reverses morphine-induced changes in arterial-blood-gas chemistry. • L-CYSee reverses morphine-induced changes in alveolar gas-exchange. • L-CYSee minimally affects morphine-induced analgesia. • The effects of L-CYSee are not mimicked by L-serine ethyl ester. [ABSTRACT FROM AUTHOR]

Persistent mild to moderate hyperoxaluria (PMMH) is a common side effect of bariatric surgery. However, PMMH's role in the progression to calcium oxalate (CaOx) urolithiasis and its potential effects on non-renal tissues are unknown. To address these points, a trigger + maintenance (T + Mt) model of PMMH was developed in rats (Experiment 1). The trigger was an i.p. injection of PBS (T PBS) or 288 μmol sodium oxalate (T 288). Maintenance (Mt) was given via minipumps dispensing PBS or 7.5–30 μmol potassium oxalate/day for 28 days. Urinary oxalate ranged from 7.7 ± 0.8 μmol/day for T PBS + Mt PBS to 18.2 ± 1.5 μmol/day for T 288 + Mt 30 ( p ≤ 0.0005). All rats receiving T 288 developed CaOx nephrocalcinosis, and many developed ‘stones’. This was also true for Mt doses that did not elevate urinary oxalate above that of T PBS + Mt PBS ( p > 0.1) and for rats that did not have a detectable surge in urinary oxalate post T 288. When T PBS was administered, CaOx nephrocalcinosis did not develop regardless of the Mt dose even if urinary oxalate was elevated compared to T PBS + Mt PBS ( p ≤ 0.0005). One of the risks associated with PMMH is oxalate accumulation within tissues. Hence, in a second set of experiments (Experiment 2) different doses of oxalate (Mt 0.05, Mt 15, Mt 30) labeled with 14C-oxalate ( 14C-Ox) were administered by minipump for 13 days. Tissues were harvested and 14C-Ox accumulation assessed by scintillation counting. 14C-Ox accumulated in a dose dependent manner ( p ≤ 0.004) in bone, kidney, muscle, liver, heart, kidney, lungs, spleen, and testis. All these tissues exhibited 14C-Ox concentrations higher ( p ≤ 0.05) than the plasma. Extrapolation of our results to patients suggests that PMMH patients should take extra care to avoid dietary-induced spikes in oxalate excretion to help prevent CaOx nephrocalcinosis or stone development. Monitoring for oxalate accumulation within tissues susceptible to damage by oxalate or CaOx crystals may also be required. [ABSTRACT FROM AUTHOR]

Both detrimental and beneficial effects of post-traumatic neuroinflammation have become a major research focus as they offer the potential for immediate as well as delayed targeted reparative therapies. Understanding the complex interactions of central and peripheral immunocompetent cells as well as their mediators on brain injury and recovery is complicated by the temporal, regional, and developmental differences in their response to injuries. Microglia, the brain-resident macrophages, have become central in these investigations as they serve a major surveillance function, have the ability to react swiftly to injury, recruit various cellular and chemical mediators, and monitor the reparative/degenerative processes. In this review we describe selected aspects of this burgeoning literature, describing the critical role of cytokines and chemokines, microglia, advances in neuroimaging, genetics and fractal morphology analysis, our research efforts in this area, and selected aspects of pediatric post-traumatic neuroinflammation. [ABSTRACT FROM AUTHOR]

Proteoglycan-4 ( Prg4) protects synovial joints from arthropathic changes by mechanisms that are incompletely understood. Parathyroid hormone (PTH), known for its anabolic actions in bone, increases Prg4 expression and has been reported to inhibit articular cartilage degeneration in arthropathic joints. To investigate the effect of Prg4 and PTH on articular cartilage, 16-week-old Prg4 mutant and wild-type mice were treated with intermittent PTH (1-34) or vehicle control daily for six weeks. Analyses included histology of the knee joint, micro-CT of the distal femur, and serum biochemical analysis of type II collagen fragments (CTX-II). Compared to wild-type littermates, Prg4 mutant mice had an acellular layer of material lining the surfaces of the articular cartilage and menisci, increased articular cartilage degradation, increased serum CTX-II concentrations, decreased articular chondrocyte apoptosis, increased synovium SDF-1 expression, and irregularly contoured subchondral bone. PTH-treated Prg4 mutant mice developed a secondary deposit overlaying the acellular layer of material lining the joint surfaces, but PTH-treatment did not alter signs of articular cartilage degeneration in Prg4 mutant mice. The increased joint SDF-1 levels and irregular subchondral bone found in Prg4 mutant mice introduce novel candidate mechanisms by which Prg4 protects articular cartilage. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 183-190, 2013 [ABSTRACT FROM AUTHOR]

Abstract: Approximate and Sample Entropy are two widely used techniques to measure system complexity or regularity based on chosen parameters such as pattern length, , and tolerance, . In this paper, we investigate how different values of the time delay parameter, can be used in conjunction with standard values of and in the computation of Approximate and Sample Entropy. The results show that for time series generated by nonlinear dynamics that have long range correlation, a time delay equal to the first zero crossing or minimum of the autocorrelation function can provide additional information into the characteristics of the time series that may be useful in comparative analysis. With a unity delay, we demonstrate that Approximate and Sample Entropy are possibly measuring only the (linear) autocorrelation properties of the signal, and these are highly invariant under surrogate data generation methods. Hence when this occurs, the complexity measures of the surrogate and original data are not statistically different. [Copyright &y& Elsevier]

Abstract: Diamond-based electrodes promise major advantages over present electrode technologies used in biomedical research. To demonstrate these advantages, boron-doped diamond microelectrodes were developed for in vitro detection of adenosine, an important neuromodulator in the central nervous system. Diamond was selectively deposited as part of a unique fabrication strategy to obtain non-planar, needle-like diamond microelectrodes. Preliminary flow injection analysis showed quantified adenosine down to 10 nM, a lower level than the estimated basal adenosine level in vivo, and lower than what is achieved on other electrode materials. As an example of in vitro application, the diamond probe was used to investigate the role of adenosine in respiratory rhythmogenesis (i.e., the modulation of one''s breathing rate). [Copyright &y& Elsevier]

We have identified thiolesters that reverse the negative effects of opioids on breathing without compromising antinociception. Here we report the effects of d-cystine diethyl ester (d-cystine diEE) or d-cystine dimethyl ester (d-cystine diME) on morphine-induced changes in ventilation, arterial-blood gas chemistry, A-a gradient (index of gas-exchange in the lungs) and antinociception in freely moving rats. Injection of morphine (10 mg/kg, IV) elicited negative effects on breathing (e.g., depression of tidal volume, minute ventilation, peak inspiratory flow, and inspiratory drive). Subsequent injection of d-cystine diEE (500 μmol/kg, IV) elicited an immediate and sustained reversal of these effects of morphine. Injection of morphine (10 mg/kg, IV) also elicited pronounced decreases in arterial blood pH, pO2 and sO2 accompanied by pronounced increases in pCO2 (all indicative of a decrease in ventilatory drive) and A-a gradient (mismatch in ventilation-perfusion in the lungs). These effects of morphine were reversed in an immediate and sustained fashion by d-cystine diME (500 μmol/kg, IV). Finally, the duration of morphine (5 and 10 mg/kg, IV) antinociception was augmented by d-cystine diEE. d-cystine diEE and d-cystine diME may be clinically useful agents that can effectively reverse the negative effects of morphine on breathing and gas-exchange in the lungs while promoting antinociception. Our study suggests that the d-cystine thiolesters are able to differentially modulate the intracellular signaling cascades that mediate morphine-induced ventilatory depression as opposed to those that mediate morphine-induced antinociception and sedation. [ABSTRACT FROM AUTHOR]