Resident mesenchymal cells and fibrosis

Fibrosis is a major clinical problem associated with as many as 45% of all natural deaths in developed nations.It can affect all organs and accumulating evidence indicates that fibrogenesis is not merely a bystander product of injury, but is a central pathological problem directly contributing to loss of organ function. In the majority of clinical cases, fibrogenesis is strongly associated with the recruitment of leukocytes, even in the absence of infection. Although chronic infections are a significant cause of fibrogenesis, in most cases fibrotic disease occurs in the context of sterile injury, such as microvascular disease, toxic epithelial injury or diabetes mellitus. Fibrogenesis is a direct consequence of the activation of extensive, and previously poorly appreciated, populations of mesenchymal cells in our organs which are either wrapped around capillaries and known as ‘pericytes’, or embedded in interstitial spaces between cell structures and known as resident ‘fibroblasts’. Recent fate-mapping and complementary studies in several organs indicate that these cells are the precursors of the scar-forming myofibroblasts that appear in our organs in response to injury. Here we will review the literature supporting a central role for these cells in fibrogenesis, and highlight some of the critical cell to cell interactions that are necessary for the initiation and continuation of the fibrogenic process. This article is part of a Special Issue entitled: Fibrosis: Translation of basic research to human disease.     

Reviewers’ Ratings and Bibliometric Indicators: Hand in Hand When Assessing Over Research Proposals?

Background

The peer review system has been traditionally challenged due to its many limitations especially for allocating funding. Bibliometric indicators may well present themselves as a complement.

Objective

We analyze the relationship between peers’ ratings and bibliometric indicators for Spanish researchers in the 2007 National R&D Plan for 23 research fields.

Methods and Materials

We analyze peers’ ratings for 2333 applications. We also gathered principal investigators’ research output and impact and studied the differences between accepted and rejected applications. We used the Web of Science database and focused on the 2002-2006 period. First, we analyzed the distribution of granted and rejected proposals considering a given set of bibliometric indicators to test if there are significant differences. Then, we applied a multiple logistic regression analysis to determine if bibliometric indicators can explain by themselves the concession of grant proposals.

Results

63.4% of the applications were funded. Bibliometric indicators for accepted proposals showed a better previous performance than for those rejected; however the correlation between peer review and bibliometric indicators is very heterogeneous among most areas. The logistic regression analysis showed that the main bibliometric indicators that explain the granting of research proposals in most cases are the output (number of published articles) and the number of papers published in journals that belong to the first quartile ranking of the Journal Citations Report.

Discussion

Bibliometric indicators predict the concession of grant proposals at least as well as peer ratings. Social Sciences and Education are the only areas where no relation was found, although this may be due to the limitations of the Web of Science’s coverage. These findings encourage the use of bibliometric indicators as a complement to peer review in most of the analyzed areas.     

Continuous succinic acid production from xylose by <Emphasis Type="Italic">Actinobacillus succinogenes</Emphasis>

Continuous, anaerobic fermentations of D-xylose were performed by Actinobacillus succinogenes 130Z in a custom, biofilm reactor at dilution rates of 0.05, 0.10 and 0.30 h^?1. Succinic acid yields on xylose (0.55–0.68 g g^?1), titres (10.9–29.4 g L^?1) and productivities (1.5–3.4 g L^?1 h^?1) were lower than those of a previous study on glucose, but product ratios (succinic acid/acetic acid = 3.0–5.0 g g^?1) and carbohydrate consumption rates were similar. Also, mass balance closures on xylose were up to 18.2 % lower than those on glucose. A modified HPLC method revealed pyruvic acid excretion at appreciable concentrations (1.2–1.9 g L^?1) which improved the mass balance closure by up to 16.8 %. Furthermore, redox balances based on the accounted xylose consumed and the excreted metabolites, indicated an overproduction of reducing power. The oxidative pentose phosphate pathway was shown to be a plausible source of the additional reducing power.     

Risk of Advanced Neoplasia in First-Degree Relatives with Colorectal Cancer: A Large Multicenter Cross-Sectional Study

BackgroundFirst-degree relatives (FDR) of patients with colorectal cancer have a higher risk of developing colorectal cancer than the general population. For this reason, screening guidelines recommend colonoscopy every 5 or 10 y, starting at the age of 40, depending on whether colorectal cancer in the index-case is diagnosed at <60 or ≥60 y, respectively. However, studies on the risk of neoplastic lesions are inconclusive. The aim of this study was to determine the risk of advanced neoplasia (three or more non-advanced adenomas, advanced adenoma, or invasive cancer) in FDR of patients with colorectal cancer compared to average-risk individuals (i.e., asymptomatic adults 50 to 69 y of age with no family history of colorectal cancer).ConclusionsIndividuals having two FDR with colorectal cancer showed an increased risk of advanced neoplasia compared to those with average-risk for colorectal cancer. Men had over 2-fold higher risk of advanced neoplasia than women, independent of family history. These data suggest that screening colonoscopy guidelines should be revised in the familial-risk population.     

Human metapneumovirus Induces Reorganization of the Actin Cytoskeleton for Direct Cell-to-Cell Spread

Paramyxovirus spread generally involves assembly of individual viral particles which then infect target cells. We show that infection of human bronchial airway cells with human metapneumovirus (HMPV), a recently identified paramyxovirus which causes significant respiratory disease, results in formation of intercellular extensions and extensive networks of branched cell-associated filaments. Formation of these structures is dependent on actin, but not microtubule, polymerization. Interestingly, using a co-culture assay we show that conditions which block regular infection by HMPV particles, including addition of neutralizing antibodies or removal of cell surface heparan sulfate, did not prevent viral spread from infected to new target cells. In contrast, inhibition of actin polymerization or alterations to Rho GTPase signaling pathways significantly decreased cell-to-cell spread. Furthermore, viral proteins and viral RNA were detected in intercellular extensions, suggesting direct transfer of viral genetic material to new target cells. While roles for paramyxovirus matrix and fusion proteins in membrane deformation have been previously demonstrated, we show that the HMPV phosphoprotein extensively co-localized with actin and induced formation of cellular extensions when transiently expressed, supporting a new model in which a paramyxovirus phosphoprotein is a key player in assembly and spread. Our results reveal a novel mechanism for HMPV direct cell-to-cell spread and provide insights into dissemination of respiratory viruses.     

Species-Specific Responses of Carnivores to Human-Induced Landscape Changes in Central Argentina

The role that mammalian carnivores play in ecosystems can be deeply altered by human-driven habitat disturbance. While most carnivore species are negatively affected, the impact of habitat changes is expected to depend on their ecological flexibility. We aimed to identify key factors affecting the habitat use by four sympatric carnivore species in landscapes of central Argentina. Camera trapping surveys were carried out at 49 sites from 2011 to 2013. Each site was characterized by 12 habitat attributes, including human disturbance and fragmentation. Four landscape gradients were created from Principal Component Analysis and their influence on species-specific habitat use was studied using Generalized Linear Models. We recorded 74 events of Conepatus chinga, 546 of Pseudalopex gymnocercus, 193 of Leopardus geoffroyi and 45 of Puma concolor. We found that the gradient describing sites away from urban settlements and with low levels of disturbance had the strongest influence. L. geoffroyi was the only species responding significantly to the four gradients and showing a positive response to modified habitats, which could be favored by the low level of persecution by humans. P. concolor made stronger use of most preserved sites with low proportion of cropland, even though the species also used sites with an intermediate level of fragmentation. A more flexible use of space was found for C. chinga and P. gymnocercus. Our results demonstrate that the impact of human activities spans across this guild of carnivores and that species-specific responses appear to be mediated by ecological and behavioral attributes.     

Phenological growth stages of nashi tree (Pyrus pyrifolia): codification and description according to the BBCH scale

The phenological growth stages of nashi tree were firstly described here using the BBCH scale. Based on this general scale, nashi phenology showed 8 of the 10 principal stages (0–9): bud, leaf and shoot development, inflorescence emergence, flowering, fruit development, fruit maturity and senescence. A schematic representation of the chronological progression of principal growth stages of nashi is also shown. The codification of the different growth stages is important for correct timing of general orchard management, particularly for disease and pest management. Besides, it will help farmers to efficiently schedule and manage nashi cultivation, as well as to improve knowledge dissemination among scientists around the World.     

Age-related changes in photosensitive melanopsin-expressing retinal ganglion cells correlate with circadian rhythm impairments in sighted and blind rats

The melanopsin system consists of intrinsically photosensitive retinal ganglion cells containing the photopigment melanopsin (mRGCs). These mRGCs mediate several non-image-forming visual functions, including light entrainment of circadian rhythms. Here we evaluate age-related alterations of the melanopsin system and circadian rhythms in P23H line 1 (P23H-1) rats, a rodent model of retinitis pigmentosa (RP). In homozygous P23H-1 rats and wild-type control rats from the same genetic background (Sprague–Dawley), body temperature and locomotor activity were continuously monitored at 10-min intervals for 7 days, once every 4–5 weeks, between 2 and 24 months of age, using a telemetry transmitter. The distribution and number of mRGCs were assessed in control rats at 12, 18, and 24 months of age and in P23H-1 rats aged 12, 18, 24, and 30 months by immunostaining whole-mount retinas with antibodies against melanopsin. The mean density of mRGCs in control rats showed no significant variations when evaluated at 12 and 18 months of age, and fell by approximately 56% between 18 and 24 months of age. Meanwhile, a significant decrease in the mean number of mRGCs was found in 18-month-old P23H-1 rats as compared to 18-month-old control rats (81% decrease). Parametric and non-parametric analyses of the records showed a gradual age-dependent weakening of body temperature and locomotor activity circadian rhythms robustness in both control and P23H-1 rats from 2 to 24 months of age. However, body temperature and locomotor activity circadian patterns were less robust throughout the experiment in P23H-1 as compared to control rats, with lower amplitude, weaker coupling strength to environmental zeitgebers and higher fragmentation of the rhythms. The present study shows that the degeneration of photoreceptors and inner retinal neurons, characteristic of RP, has age-related degenerative effects on the melanopsin system and is associated with weaker circadian patterns.     

Origin of Fish Biomass in a Diverse Subtropical River: An Allochthonic-Supported Biomass Increase Following Flood Pulses

Ecosystems - The origin of resources supporting metazoan biomass in rivers has long been a subject of debate. The river wave concept (RWC) postulates that the energetic basis of food webs varies...     

A risk‐based inventory of invasive plant species of Queensland,Australia: Regional,ecological and floristic insights

Invasive alien plant species threaten agriculture and biodiversity globally and require ongoing management to minimise impacts. However, the large number of invasive species means that a risk‐based approach to prioritisation is needed, taking into account the spatial scale of management decisions and myriad of available information. Here, we developed a risk‐based inventory of invasive plants in Queensland, Australia, using both current species distribution/abundance and the severity of their impacts. Our assessment followed a comprehensive data collection process including a scoping of local government pest management plans, herbarium records, the published literature and structured elicitation of expert knowledge during a series of regional stakeholder workshops. From ~300 plant species that were identified as established and/or emerging invaders in the State, only one‐third were considered by practitioners to pose significant risks across regions to be considered management priorities. We aggregated regional species lists into a statewide priority list and analysed the data set (107 species) for historical, geographical, floristic and ecological patterns. Regions on the mainland eastern seaboard of the State share similar invasive plant communities, suggesting that these regions may form a single management unit, unlike the western/inland and the extreme far north (Torres Strait Islands) regions, which share fewer invasive plant species. Positive correlations were detected between invasiveness and time since introduction for some but not all plant life forms. Stakeholders identified research and management priorities for the invasive plant list, including biological control options, public awareness/education, effective herbicide use, ecology/taxonomy and risk analysis. In the course of the exercise, a statewide invasive plant priority list of high‐, medium‐ and low‐impact scores for policy, research and management was compiled. Finally, our approach to invasive plant species prioritisation highlighted that planning and policy documents are not necessarily reflected at the grass‐root level in terms of species identity and management priorities.