Developmental changes in the neurotransmitter properties of dissociated sympathetic neurons: a cytochemical study of the effects of medium

Sympathetic principal neurons were dissociated from the superior cervical ganglia of newborn rats and grown in several culture conditions shown previously to affect the transmitter status of the neurons. In three of these conditions the neurons are known to develop adrenergic functions over a 3- to 4-week period; in a fourth condition, they develop predominantly cholinergic functions. In this ultrastructural study, the transmitter status of the neurons during development in the several different media was examined after permanganate fixation which causes a granular precipitate in synaptic vesicles containing norepinephrine (small granular vesicles or SGV). It was found that as early as 4 days after plating, synapses and varicosities were present. In all four conditions, all of the terminals contained numerous SGV, indicating that the neurons both synthesize and store norepinephrine. Under “adrenergic” growth conditions, the terminals remained adrenergic in appearance during further development. Under “cholinergic” conditions, terminals of cholinergic appearance were present as early as 7 days and their incidence increased with time. Although the cholinergic terminals contained little or no endogenous norepinephrine, many were initially able to take up and store exogenous catecholamine. These results indicate that the dissociated sympathetic neurons of newborn rats which survive in culture acquired adrenergic transmitter functions early. Under “cholinergic” culture conditions, the neurons lose the ability to synthesize detectable quantities of norepinephrine; the ability to take up and store detectable quantities of exogenous catecholamines disappears more slowly.     

Solubilization of gellan gels by chelation of cations

Summary Chelation solubilization of gellan under mild conditions has been accomplished for the first time by exposure to either 10 mM sodium citrate buffer (pH 6.0) or to 1 mM sodium hexametaphosphate (pH 6.6). The citrate system was preferred for most applications since its is a ubiquitous cellular component, its solutions are autoclavable, and because viable plant tissues, fungi, and bacteria could be recovered from culture. Such recovery is not possible from more commonly used media such as agar.     

Unique Microstructural Changes in the Brain Associated with Urological Chronic Pelvic Pain Syndrome (UCPPS) Revealed by Diffusion Tensor MRI,Super-Resolution Track Density Imaging,and Statistical Parameter Mapping: A MAPP Network Neuroimaging Study

Studies have suggested chronic pain syndromes are associated with neural reorganization in specific regions associated with perception, processing, and integration of pain. Urological chronic pelvic pain syndrome (UCPPS) represents a collection of pain syndromes characterized by pelvic pain, namely Chronic Prostatitis/Chronic Pelvic Pain Syndrome (CP/CPPS) and Interstitial Cystitis/Painful Bladder Syndrome (IC/PBS), that are both poorly understood in their pathophysiology, and treated ineffectively. We hypothesized patients with UCPPS may have microstructural differences in the brain compared with healthy control subjects (HCs), as well as patients with irritable bowel syndrome (IBS), a common gastrointestinal pain disorder. In the current study we performed population-based voxel-wise DTI and super-resolution track density imaging (TDI) in a large, two-center sample of phenotyped patients from the multicenter cohort with UCPPS (N = 45), IBS (N = 39), and HCs (N = 56) as part of the MAPP Research Network. Compared with HCs, UCPPS patients had lower fractional anisotropy (FA), lower generalized anisotropy (GA), lower track density, and higher mean diffusivity (MD) in brain regions commonly associated with perception and integration of pain information. Results also showed significant differences in specific anatomical regions in UCPPS patients when compared with IBS patients, consistent with microstructural alterations specific to UCPPS. While IBS patients showed clear sex related differences in FA, MD, GA, and track density consistent with previous reports, few such differences were observed in UCPPS patients. Heat maps illustrating the correlation between specific regions of interest and various pain and urinary symptom scores showed clustering of significant associations along the cortico-basal ganglia-thalamic-cortical loop associated with pain integration, modulation, and perception. Together, results suggest patients with UCPPS have extensive microstructural differences within the brain, many specific to syndrome UCPPS versus IBS, that appear to be localized to regions associated with perception and integration of sensory information and pain modulation, and seem to be a consequence of longstanding pain.     

Plastome phylogenomics of Cephalotaxus (Cephalotaxaceae) and allied genera

Background and Aims Cephalotaxus is a paleo-endemic genus in East Asia that consists of about 7–9 conifer species. Despite its great economic and ecological importance, the relationships between Cephalotaxus and related genera, as well as the interspecific relationships within Cephalotaxus, have long been controversial, resulting in contrasting taxonomic proposals in delimitation of Cephalotaxaceae and Taxaceae. Based on plastome data, this study aims to reconstruct a robust phylogeny to infer the systematic placement and the evolutionary history of Cephalotaxus.MethodsA total of 11 plastomes, representing all species currently recognized in Cephalotaxus and two Torreya species, were sequenced and assembled. Combining these with previously published plastomes, we reconstructed a phylogeny of Cephalotaxaceae and Taxaceae with nearly full taxonomic sampling. Under a phylogenetic framework and molecular dating, the diversification history of Cephalotaxus and allied genera was explored.Key ResultsPhylogenetic analyses of 81 plastid protein-coding genes recovered robust relationships between Cephalotaxus and related genera, as well as providing a well-supported resolution of interspecific relationships within Cephalotaxus, Taxus, Torreya and Amentotaxus. Divergence time estimation indicated that most extant species of these genera are relatively young, although fossil and other molecular evidence consistently show that these genera are ancient plant lineages.ConclusionsOur results justify the taxonomic proposal that recognizes Cephalotaxaceae as a monotypic family, and contribute to a clear-cut delineation between Cephalotaxaceae and Taxaceae. Given that extant species of Cephalotaxus are derived from recent divergence events associated with the establishment of monsoonal climates in East Asia and Pleistocene climatic fluctuations, they are not evolutionary relics.     

Ten Year Trends in Community HIV Viral Load in Barbados: Implications for Treatment as Prevention

Background

Treatment as prevention is a paradigm in HIV medicine which describes the public health benefit of antiretroviral therapy (ART). It is based on research showing substantial reductions in the risk of HIV transmission in persons with optimally suppressed HIV-1 Viral Loads (VL). The present study describes ten year VL trends at the national HIV treatment unit and estimates VL suppression at a population level in Barbados, a Caribbean island with a population of 277,000, an estimated adult HIV prevalence of 1.2%, and served by a single treatment unit.

Methods

The national HIV treatment centre of the Barbados Ministry of Health has a client VL database extending back to inception of the clinic in 2002 (n = 1,462 clients, n = 17,067 VL measurements). Optimal VL suppression was defined at a threshold value of ≤200 viral copies/mL.

Results

Analysis of VL trends showed a statistically significant improvement in VL suppression between 2002 to 2011, from 33.6% of clients achieving the 200 copies/mL threshold in 2002 to 70.3% in 2011 (P<0.001). Taking into account the proportion of clients alive and in care and on ART, the known diagnosed HIV population in Barbados, and estimates of unknown HIV infections, this translates into an estimated 26.2% VL suppression at a population level at the end of 2010.

Conclusions

We have demonstrated a significant trend towards optimal VL suppression in clients utilizing the services of the national HIV treatment program in Barbados over a 10-year period. Estimates of VL suppression at a population level are similar to reports in developed countries that applied similar methodologies and this could suggest a public health benefit of ART in minimizing the risk of sexual transmission of HIV. Continued efforts are warranted to extend HIV testing to hidden populations in Barbados and linking infected persons to care earlier in their disease.     

Blood Viscosity and the Expression of Inflammatory and Adhesion Markers in Homozygous Sickle Cell Disease Subjects with Chronic Leg Ulcers

Objective

To determine differences in TNF-α, IL-1β, IL-10, sICAM-1 concentrations, leg hypoxia and whole blood viscosity (WBV) at shear rates of 46 sec^-1 and 230 sec^-1 in persons with homozygous S sickle cell disease (SCD) with and without chronic leg ulceration and in AA genotype controls.

Design

& Methods: fifty-five age-matched participants were recruited into the study: 31 SS subjects without leg ulcers (SS_n), 24 SS subjects with leg ulcers (SS_u) and 18 AA controls. Haematological indices were measured using an AC.Tron Coulter Counter. Quantification of inflammatory, anti-inflammatory and adhesion molecules was performed by ELISA. Measurement of whole blood viscosity was done using a Wells Brookfield cone-plate viscometer. Quantification of microvascular tissue oxygenation was done by Visible Lightguide spectrophotometry.

Results

TNF-α and whole blood viscosity at 46 sec^-1 and 230 sec^-1 (1.75, 2.02 vs. 0.83, 1.26, p<0.05) were significantly greater in sickle cell disease subjects than in controls. There were no differences in plasma concentration of sICAM-1, IL-1β and IL-10 between SCD subjects and controls. IL-1β (median, IQR: 0.96, 1.7 vs. 0, 0.87; p<0.01) and sICAM-1 (226.5, 156.48 vs. 107.63, 121.5, p<0.005) were significantly greater in SS_u group compared with SS_n. However there were no differences in TNF-α (2, 3.98 vs. 0, 2.66) and IL-10 (13.34, 5.95 vs. 11.92, 2.99) concentrations between SS_u and SS_n. WBV in the SS_u group at 46 sec^-1 and at 230 Sec 1 were 1.9 (95%CI; 1.2, 3.1) and 2.3 (1.2, 4.4) times greater than in the SS_n group. There were no differences in the degree of tissue hypoxia as determined by lightguide spectrophotometry.

Conclusion

Inflammatory, adhesion markers and WBV may be associated with leg ulceration in sickle cell disease by way of inflammation-mediated vasoocclusion/vasoconstriction. Impaired skin oxygenation does not appear to be associated with chronic ulcers in these subjects with sickle cell disease.     

Long-Term Functional Dynamics of an Aphidophagous Coccinellid Community Remain Unchanged despite Repeated Invasions

Aphidophagous coccinellids (ladybeetles) are important providers of herbivore suppression ecosystem services. In the last 30 years, the invasion of exotic coccinellid species, coupled with observed declines in native species, has led to considerable interest in the community dynamics and ecosystem function of this guild. Here we examined a 24-year dataset of coccinellid communities in nine habitats in southwestern Michigan for changes in community function in response to invasion. Specifically we analyzed their temporal population dynamics and species diversity, and we modeled the community’s potential to suppress pests. Abundance of coccinellids varied widely between 1989 and 2012 and became increasingly exotic-dominated. More than 71% of 57,813 adult coccinellids captured over the 24-year study were exotic species. Shannon diversity increased slightly over time, but herbivore suppression potential of the community remained roughly constant over the course of the study. However, both Shannon diversity and herbivore suppression potential due to native species declined over time in all habitats. The relationship between Shannon diversity and herbivore suppression potential varied with habitat type: a positive relationship in forest and perennial habitats, but was uncorrelated in annual habitats. This trend may have been because annual habitats were dominated by a few, highly voracious exotic species. Our results indicated that although the composition of the coccinellid community in southwestern Michigan has changed dramatically in the past several decades, its function has remained relatively unchanged in both agricultural and natural habitats. While this is encouraging from the perspective of pest management, it should be noted that losses of one of the dominant exotic coccinellids could result in a rapid decline in pest suppression services if the remaining community is unable to respond.     

Dynamic life cycle assessment: framework and application to an institutional building

Purpose

This paper uses a dynamic life cycle assessment (DLCA) approach and illustrates the potential importance of the method using a simplified case study of an institutional building. Previous life cycle assessment (LCA) studies have consistently found that energy consumption in the use phase of a building is dominant in most environmental impact categories. Due to the long life span of buildings and potential for changes in usage patterns over time, a shift toward DLCA has been suggested.

Methods

We define DLCA as an approach to LCA which explicitly incorporates dynamic process modeling in the context of temporal and spatial variations in the surrounding industrial and environmental systems. A simplified mathematical model is used to incorporate dynamic information from the case study building, temporally explicit sources of life cycle inventory data and temporally explicit life cycle impact assessment characterization factors, where available. The DLCA model was evaluated for the historical and projected future environmental impacts of an existing institutional building, with additional scenario development for sensitivity and uncertainty analysis of future impacts.

Results and discussion

Results showed that overall life cycle impacts varied greatly in some categories when compared to static LCA results, generated from the temporal perspective of either the building's initial construction or its recent renovation. From the initial construction perspective, impacts in categories related to criteria air pollutants were reduced by more than 50 % when compared to a static LCA, even though nonrenewable energy use increased by 15 %. Pollution controls were a major reason for these reductions. In the future scenario analysis, the baseline DLCA scenario showed a decrease in all impact categories compared with the static LCA. The outer bounds of the sensitivity analysis varied from slightly higher to strongly lower than the static results, indicating the general robustness of the decline across the scenarios.

Conclusions

These findings support the use of dynamic modeling in life cycle assessment to increase the relevance of results. In some cases, decision making related to building design and operations may be affected by considering the interaction of temporally explicit information in multiple steps of the LCA. The DLCA results suggest that in some cases, changes during a building's lifetime can influence the LCA results to a greater degree than the material and construction phases. Adapting LCA to a more dynamic approach may increase the usefulness of the method in assessing the performance of buildings and other complex systems in the built environment.     

Nocturne for an unknown pollinator: first description of a night‐flowering orchid (Bulbophyllum nocturnum)

Bulbophyllum nocturnum , a species of section Epicrianthes from New Britain, is described and illustrated. It is the first known example of an orchid species in which the flowers open after dark and close in the morning. The poorly understood pollination biology of section Epicrianthes, a clade with highly unusual flowers, is discussed. Attention is drawn to the close resemblance between the petal appendages of some species and the fruiting bodies of certain Myxogastria. © 2011 The Linnean Society of London, Botanical Journal of the Linnean Society, 2011, 167 , 344–350.     

Using ITS2 secondary structure to create species-specific oligonucleotide probes for fungi

Oligonucleotide microarray based on ITS2 rDNA sequences would be extremely useful in identifying fungi within soil samples. However ITS2 contains phylogenetic information and duplication of sequences among taxa make false positive detections likely unless a way could be found to identify taxon-specific portions of the ITS2 sequence a priori. Examination of component ITS2 sequences suggested one method of identifying species-specific probes. Analysis of 168 fungal ITS2 sequences showed that all 168 ITS2 rRNA sequences could be folded to produce similar secondary structures of 3-4 loops. Unique probes occurred most often in the second loop. While the loop 2 sequence was unique in all taxa, there were partial congeneric and intergeneric duplicates. Evidence for a decrease in duplicates with increasing phylogenetic distance was mixed. From the evidence, 2 or 3 disjunct oligonucleotide probes from the loop 2 sequence might be sufficient to identify most fungal species. This combination appears minimally susceptible to false positives and conceivably could be extended to design probes to identify any eukaryotic species.