Leptin concentrations in the abdominal subcutaneous adipose tissue of patients with anorexia nervosa assessed by in vivo microdialysis

OBJECTIVE: The adipocyte-derived hormone leptin is involved in energy metabolism and body weight regulation. Plasma leptin concentrations are significantly reduced in patients with anorexia nervosa (AN) and with severe malnutrition. Whether reduced plasma leptin is reflected by its decreased production by the adipose tissue is unknown. METHODS: In the present study we measured leptin concentrations locally in the abdominal subcutaneous adipose tissue of 9 female AN patients and 11 healthy controls by in vivo microdialysis. RESULTS: Adipose tissue free leptin levels were not different in patients with AN compared to controls (2.59+/-1.99 vs 2.36+/-0.25 ng/ml, P>0.05). Plasma leptin soluble receptor (sOb-R) levels were significantly higher in patients with AN than in healthy subjects (58.05+/-38.69 vs 12.79+/-5.08 U/ml, P<0.01). The area of adipocyte in AN was considerably smaller than in the controls (183+/-104.01 microm2 compared to 2145.8+/-1003.41). CONCLUSIONS: We conclude that decreased plasma leptin levels in patients with AN are not directly related to dialysate leptin levels in the abdominal subcutaneous adipose tissue.     

Evolution of microalgal biotechnology: a survey of the European Patent Office database

Microalgal biotechnology is an innovative sector in the field of biotechnology and has evolved exponentially in the last 100 years. With the aim of finding out the current situation of the sector and its development, patents on microalgal biotechnology were surveyed in Espacenet, the European Patent Office database. The objective of this study was to identify the main trends in microalgae-related patents in the most commercial genera: Chlorella, Spirulina, Dunaliella, Haematococcus and model organism Chlamydomonas.     

The effects of individual tree species on species diversity in a tropical dry forest change throughout ontogeny

Understanding how diversity is maintained in species‐rich communities, such as tropical forests, remains a challenge in ecology. Recent work suggests that the controversy between competing theories could be better resolved by considering the spatial scale at which different processes rule community assembly. Here we use individual species–area relationships (ISAR) to evaluate the spatial organization of tree diversity around individuals of different species in a completely‐mapped tropical dry forest in south Ecuador. We test two hypotheses. First, stressful environmental conditions promote facilitative interactions that will generate spatial signals of accumulation of diversity around individual trees – contrary to what has been reported in humid tropical forests. Second, spatial signals will shift through ontogeny. As, as larger, older trees generate new microsite conditions that affect the recruitment of younger, smaller trees. We compute ISAR functions for adult trees, for young trees and a new crossed‐ISAR function measuring the accumulation of diversity of young trees around the old trees. We compare observed ISARs to the expectations of inhomogeneous Poisson (i.e. null) models controlling for the effects of environmental variation and habitat association on tree distribution. Although the prevalent response among adult trees was not different from null expectations, which means that the organization of diversity in this size class could be explained by environmental heterogeneity alone, most species accumulated more diversity than expected over short spatial scales in the small stem size class. Only two species accumulated significant diversity in the crossed‐ISARs. Our study indicates the role of facilitation in the organization of plant diversity in this dry forest, but that facilitation is limited to some key species acting on early life stages and accumulating diversity around them. Our results demonstrate the benefit of considering different life‐stages and crossed analyses to disentangle the processes affecting community assembly in tropical dry forests.     

White‐tailed deer as the last megafauna dispersing seeds in Neotropical dry forests: the role of fruit and seed traits

Endozoochory is a prominent form of seed dispersal in tropical dry forests. Most extant megafauna that perform such seed dispersal are ungulates, which can also be seed predators. White‐tailed deer (Odocoileus virginianus) is one of the last extant megafauna of Neotropical dry forests, but whether it serves as a legitimate seed disperser is poorly understood. We studied seed dispersal patterns and germination after white‐tailed deer gut passage in a tropical dry forest in southwest Ecuador. Over 23 mo, we recorded ca 2000 seeds of 11 species in 385 fecal samples. Most seeds belonged to four species of Fabaceae: Chloroleucon mangense, Senna mollissima, Piptadenia flava, and Caesalpinia glabrata. Seeds from eight of the 11 species dispersed by white‐tailed deer germinated under controlled conditions. Ingestion did not affect germination of C. mangense and S. mollissima, whereas C. glabrata showed reduced germination. Nevertheless, the removal of fruit pulp resulting from ingestion by white‐tailed deer could have a deinhibition effect on germination due to seed release. Thus, white‐tailed deer play an important role as legitimate seed dispersers of woody species formerly considered autochorous. Our results suggest that more research is needed to fully understand the ecological and evolutionary effects of the remaining extant megafauna on plant regeneration dynamics in the dry Neotropics.     

Life cycle assessment of European anchovy (<Emphasis Type="Italic">Engraulis encrasicolus</Emphasis>) landed by purse seine vessels in northern Spain

Purpose

The main purpose of this article is to assess the environmental impacts associated with the fishing operations related to European anchovy fishing in Cantabria (northern Spain) under a life cycle approach.

Methods

The life cycle assessment (LCA) methodology was applied for this case study including construction, maintenance, use, and end of life of the vessels. The functional unit used was 1 kg of landed round anchovy at port. Inventory data were collected for the main inputs and outputs of 32 vessels, representing a majority of vessels in the fleet.

Results and discussion

Results indicated, in a similar line to what is reported in the literature, that the production, transportation, and use of diesel were the main environmental hot spots in conventional impact categories. Moreover, in this case, the production and transportation of seine nets was also relevant. Impacts linked to greenhouse gas (GHG) emissions suggest that emissions were in the upper range for fishing species captured with seine nets and the value of global warming potential (GWP) was 1.44 kg CO₂ eq per functional unit. The ecotoxicity impacts were mainly due to the emissions of antifouling substances to the ocean. Regarding fishery-specific categories, many were discarded given the lack of detailed stock assessments for this fishery. Hence, only the biotic resource use category was computed, demonstrating that the ecosystems’ effort to sustain the fishery is relatively low.

Conclusions

The use of the LCA methodology allowed identifying the main environmental hot spots of the purse seining fleet targeting European anchovy in Cantabria. Individualized results per port or per vessel suggested that there are significant differences in GHG emissions between groups. In addition, fuel use is high when compared to similar fisheries. Therefore, research needs to be undertaken to identify why fuel use is so high, particularly if it is related to biomass and fisheries management or if skipper decisions could play a role.

     

Caspase-Cleaved Tau Impairs Mitochondrial Dynamics in Alzheimer’s Disease

Alzheimer’s disease (AD) is characterized by the presence of aggregates of tau protein. Tau truncated by caspase-3 (D421) or tau hyperphosphorylated at Ser396/S404 might play a role in the pathogenesis of AD. Mitochondria are dynamic organelles that modify their size and function through mitochondrial dynamics. Recent studies have shown that alterations of mitochondrial dynamics affect synaptic communication. Therefore, we studied the effects of pathological forms of tau on the regulation of mitochondrial dynamics. We used primary cortical neurons from tau(?/?) knockout mice and immortalized cortical neurons (CN1.4) that were transfected with plasmids containing green fluorescent protein (GFP) or GFP with different tau forms: full-length (GFP-T4), truncated (GFP-T4C3), pseudophosphorylated (GFP-T42EC), or both truncated and pseudophosphorylated modifications of tau (GFP-T4C3-2EC). Cells expressing truncated tau showed fragmented mitochondria compared to cells that expressed full-length tau. These findings were corroborated using primary neurons from tau(?/?) knockout mice that expressed the truncated and both truncated and pseudophosphorylated forms of tau. Interestingly, mitochondrial fragmentation was accompanied by a significant reduction in levels of optic atrophy protein 1 (Opa1) in cells expressing the truncated form of tau. In addition, treatment with low concentrations of amyloid-beta (Aβ) significantly reduced mitochondrial membrane potential, cell viability, and mitochondrial length in cortical cells and primary neurons from tau(?/?) mice that express truncated tau. These results indicate that the presence of tau pathology impairs mitochondrial dynamics by reducing Opa1 levels, an event that could lead to mitochondrial impairment observed in AD.     

Molecular and genetic characterization of the <Emphasis Type="Italic">Ry</Emphasis><Subscript><Emphasis Type="Italic">adg</Emphasis></Subscript> locus on chromosome XI from Andigena potatoes conferring extreme resistance to potato virus Y

Key message

We have elucidated the Andigena origin of the potato Ry_adg gene on chromosome XI of CIP breeding lines and developed two marker assays to facilitate its introgression in potato by marker-assisted selection.

Abstract

Potato virus Y (PVY) is causing yield and quality losses forcing farmers to renew periodically their seeds from clean stocks. Two loci for extreme resistance to PVY, one on chromosome XI and the other on XII, have been identified and used in breeding. The latter corresponds to a well-known source of resistance (Solanum stoloniferum), whereas the one on chromosome XI was reported from S. stoloniferum and S. tuberosum group Andigena as well. To elucidate its taxonomic origin in our breeding lines, we analyzed the nucleotide sequences of tightly linked markers (M45, M6) and screened 251 landraces of S. tuberosum group Andigena for the presence of this gene. Our results indicate that the PVY resistance allele on chromosome XI in our breeding lines originated from S. tuberosum group Andigena. We have developed two marker assays to accelerate the introgression of Ry_adg gene into breeding lines by marker-assisted selection (MAS). First, we have multiplexed RYSC3, M6 and M45 DNA markers flanking the Ry_adg gene and validated it on potato varieties with known presence/absence of the Ry_adg gene and a progeny of 6,521 individuals. Secondly, we developed an allele-dosage assay particularly useful to identify multiplex Ry_adg progenitors. The assay based on high-resolution melting analysis at the M6 marker confirmed Ry_adg plex level as nulliplex, simplex and duplex progenitors and few triplex progenies. These marker assays have been validated and can be used to facilitate MAS in potato breeding.