Decoupling of biotic and abiotic patterns in a coastal area affected by chronic metal micronutrients disturbances.

Coastal systems are highly productive areas for primary productivity and ecosystem services and host a large number of human activities. Since industrialization, metal micronutrients in these regions have increased. Phytoplankton use metals as micronutrients in metabolic processes, but in excess, had deleterious effects. In coastal systems, picoeukaryotes represent a diverse and abundant group with widespread distribution and fundamental roles in biogeochemical cycling. We combined different approaches to explore picoeukaryotes seasonal variability in a chronically metal polluted coastal area at the south-eastern Pacific Ocean. Through remote and field measurements to monitor environmental conditions and 18S rRNA gene sequencing for taxonomic profiling, we determined metal chronic effect on picoeukaryote community's structure. Our results revealed a stable richness and a variable distribution of the relative abundance, despite the physicochemical seasonal variations. These results suggest that chronic metal contamination influences temporal heterogeneity of picoeukaryote communities, with a decoupling between abiotic and biotic patterns.

Detection of sentinel bacteria in mangrove sediments contaminated with heavy metals.

Mangroves in the Northwest Coast of South America are contaminated with heavy metals due to wastewater discharges from industries, affecting the biota from this environment. However, bacteria proliferate in these harsh environmental conditions becoming possible sentinel of these contaminations. In this study, bacterial community composition was analyzed by throughput sequencing of the 16S rRNA gene from polluted and pristine mangrove sediments affected by marked differences in heavy metal concentrations. Core bacteria were dominated by Proteobacteria, Firmicutes, and Bacteroidetes phyla, with strong differences between sites at class and genus levels, correlated with metal levels. Increment of abundance on specific OTUs were associated with either elevated or decreased concentrations of metals and with the sulfur cycle. The abundance of Sulfurovum lithotrophicum, Leptolinea tardivitalis, Desulfococcus multivorans and Aminobacterium colombiense increases when metals rise. On contrary, Bacillus stamsii, Nioella nitrareducens and Clostridiisalibacter paucivorans abundance increases when metal levels are reduced. We propose these OTUs as bacterial sentinels, whose abundance can help monitor the restoration programs of contaminated mangrove sediments in the future.

Cognitive function in patients on androgen suppression: A prospective, multicentric study. / Función cognitiva en pacientes tratados con supresión androgénica: estudio prospectivo y multicéntrico.

OBJECTIVE: To assess the effect of androgen deprivation therapy (ADT) on cognitive performance (CP) in patients with prostate cancer (PCa) after 6 months of treatment with luteinizing hormone-releasing hormone (LHRH) analogues. MATERIAL AND METHODS: Prospective, observational, multicentre, open-label study of patients diagnosed with nonmetastatic or asymptomatic metastatic PCa scheduled to receive LHRH analogues for≥6 months. We assessed four CP domains at baseline and after 6 months of ADT: 1) Working memory: Wechsler Adult Intelligence Scale III (WAIS III) Digit Span Subtest (WAIS III-Digit); 2) Visual memory: ad hoc visual memory test; 3) Visuospatial ability: Judgement of Line Orientation (JLO) and Mental Rotation of Three-Dimensional Objects (3D-Rotation); and 4) Nonverbal analytical reasoning: WAIS III Matrix Reasoning Test (WAIS III-MRT). Changes outside the baseline 95% confidence intervals were considered significant. RESULTS: A total of 308 patients completed the study. Of these, 245 (79.6%) experienced no statistically significant changes on any test and 63 patients (20.4%) experienced significant changes in ≥1 test. Of these, most presented a change in only one test, distributed evenly between improvements (58 patients; 18.8%) and worsening (56 patients; 18.2%). For individual tests, most patients (87.8% to 91.8%) had no change from baseline; however, the significant changes (improvement vs. deterioration, respectively) were as follows: WAIS III-Digit (6.3% vs. 5.9%); visual memory (5.3% vs. 5.7%); JLO (5.3% vs. 4.5%); 3D-Rotation (4.1% vs. 4.1%); and WAIS III-MRT (4.8% vs. 5.8%). CONCLUSIONS: CP in patients with PCa does not appear to be adversely affected by 6 months of LHRH analogue administration.

Heavy metal concentration in mangrove surface sediments from the north-west coast of South America.

Mangrove ecosystems are coastal estuarine systems confined to the tropical and subtropical regions. The Estero Salado mangrove located in Guayaquil, Ecuador, has suffered constant disturbances during the past 20 years, due to industrial wastewater release. However, there are no published data for heavy metals present in its sediments and the relationship with anthropogenic disturbance. In the present study, metal concentrations were evaluated in surface sediment samples of the mangrove, showing that B, Cd, Cu, Pb, Se, V, and Zn levels exceeded those declared in international environmental quality standards. Moreover, several metals (Pb, Sn, Cd, Ag, Mo, Zn and Ni) could be linked to the industrial wastewater present in the studied area. In addition, heavy metal levels detected in this mangrove are higher than previous reports on mangrove sediments worldwide, indicating that this mangrove ecosystem is one of the most disrupted on earth.

Higher baseline irisin concentrations are associated with greater reductions in glycemia and insulinemia after weight loss in obese subjects.

Irisin is assumed to be a relevant link between muscle and weight maintenance as well as to mediate exercise benefits on health. The aim of this study was to assess the possible associations between irisin levels and glucose homeostasis in obese subjects with metabolic syndrome (MetS) following an energy-restricted treatment. Ninety-six adults with excessive body weight and MetS features underwent a hypocaloric dietary pattern for 8 weeks, within the RESMENA randomized controlled trial (www.clinicaltrials.gov; NCT01087086). After the intervention, dietary restriction significantly reduced body weight and evidenced a dietary-induced decrease in circulating levels of irisin in parallel with improvements on glucose homeostasis markers. Interestingly, participants with higher irisin values at baseline (above the median) showed a greater reduction on glucose (P=0.022) and insulin (P=0.021) concentrations as well as on the homeostasis model assessment index (P=0.008) and triglycerides (P=0.006) after the dietary intervention, compared with those presenting low-irisin baseline values (below the median). Interestingly, a positive correlation between irisin and carbohydrate intake was found at the end of the experimental period. In conclusion, irisin appears to be involved in glucose metabolism regulation after a dietary-induced weight loss.

The reduction of the metabolyc syndrome in Navarra-Spain (RESMENA-S) study: a multidisciplinary strategy based on chrononutrition and nutritional education, together with dietetic and psychological control.

INTRODUCTION: The high prevalence of metabolic syndrome (MS) in Spain requires additional efforts for prevention and treatment. OBJECTIVE: The study RESMENA-S aims to improve clinical criteria and biomarkers associated with MS though an integral therapy approach. METHODS: The study is a randomized prospective parallel design in which is expected to participate a total of 100 individuals. The RESMENA-S group (n = 50) is a personalized weight loss (30% energy restriction) diet, with a macronutrient distribution (carbohydrate / fat / protein) of 40/30/30, high meal frequency (7 / day), low glycemic index/load and high antioxidant capacity as well as a high adherence to the Mediterranean diet. The control group (n = 50) is assigned to a diet with the same energy restriction and based on the American Heart Association pattern. Both experimental groups are under dietary and psychological control during 8 weeks. Likewise, for an additional period of 16 weeks of self-control, is expected that volunteers will follow the same pattern but with no dietary advice. RESULTS: Anthropometrical data and body composition determinations as well as blood and urine samples are being collected at the beginning and end of each phase. This project is registered at www.clinicaltrials.gov with the number NCT01087086 and count with the Research Ethics Committee of the University of Navarra approval (065/2009). CONCLUSIONS: Intervention trials to promote the adoption of dietary patterns and healthy lifestyle are of great importance to identify the outcomes and nutritional mechanisms that might explain the link between obesity, metabolic syndrome and associated complications.

Novel polymerase chain reaction primers for the specific detection of bacterial copper P-type ATPases gene sequences in environmental isolates and metagenomic DNA.

AIMS: In the last decades, the worldwide increase in copper wastes release by industrial activities like mining has driven environmental metal contents to toxic levels. For this reason, the study of the biological copper-resistance mechanisms in natural environments is important. Therefore, an appropriate molecular tool for the detection and tracking of copper-resistance genes was developed. METHODS AND RESULTS: In this work, we designed a PCR primer pair to specifically detect copper P-type ATPases gene sequences. These PCR primers were tested in bacterial isolates and metagenomic DNA from intertidal marine environments impacted by copper pollution. As well, T-RFLP fingerprinting of these gene sequences was used to compare the genetic composition of such genes in microbial communities, in normal and copper-polluted coastal environments. New copper P-type ATPases gene sequences were found, and a high degree of change in the genetic composition because of copper exposure was also determined. CONCLUSIONS: This PCR based method is useful to track bacterial copper-resistance gene sequences in the environment. SIGNIFICANCE AND IMPACT OF THE STUDY: This study is the first to report the design and use of a PCR primer pair as a molecular marker to track bacterial copper-resistance determinants, providing an excellent tool for long-term analysis of environmental communities exposed to metal pollution.

Soil bacteria are differentially affected by the resin of the medicinal plant Pseudognaphalium vira vira and its main component kaurenoic acid.

The diterpenoid kaurenoic acid is the main component of the resin from the medicinal plant Pseudognaphalium vira vira. As some diterpenoids have antimicrobial properties, the effect of this resin and the kaurenoic acid on soil bacteria was studied. The resin of P. vira vira and purified kaurenoic acid were two to four times more effective as antibacterial agents with Gram-positive than with Gram-negative soil isolates. The chemical stability of kaurenoic acid and the antibacterial activity of both the resin and the diterpenoid were studied in microcosms containing plant-associated soil. After 15 days of incubation, the diterpenoid was stable, as determined by 1H nuclear magnetic resonance and thin-layer chromatography, and soil extracts still exhibited antibacterial activity. However, after 30 days of incubation, loss of antibacterial activity of soil extracts correlated with removal or chemical modification of kaurenoic acid. The effect of the resin or this diterpenoid on the soil bacteria community was analyzed by the terminal restriction fragment length polymorphisms technique. After 15 days of incubation, the resin and the pure compound caused significant changes in the soil bacterial community. The relative abundance of specific bacterial groups was differentially affected by the resin components, being the effects with the resin stronger than with the kaurenoic acid. After 30 days of incubation, these changes mostly reverted. These results indicate that a plant resin containing diterpenoid compounds plays a significant role controlling specific groups of microorganisms in the soil associated with the plant.

Factors influencing the composition of bacterial communities found at abandoned copper-tailings dumps.

AIMS: To study the effect that copper residues exert on bacterial communities and the ability of bacteria to colonize different microhabitats in abandoned tailing dumps. METHODS AND RESULTS: We used the terminal-restriction fragment length polymorphism technique, a culture-independent molecular approach based on PCR amplification of ribosomal genes, to compare the structure of the bacterial communities from samples taken at two nearby located abandoned tailing dumps found in the Mediterranean-climate area of central Chile. Our results show that elevated available copper content in tailings has a strong effect on the bacterial community composition, but that other factors like pH and organic matter content also play an important role in the structure of these communities. We also found that the number of abundant bacteria in these samples was significantly lower than in soils not exposed to metal pollution. CONCLUSIONS: In addition to bioavailable copper, bacterial communities found in copper-tailings dumps are also affected by several other environmental factors. SIGNIFICANCE AND IMPACT OF THE STUDY: This first report on environmental factors influencing microbial communities in copper-tailings dumps will help to devise appropriate restoration procedures in this type of polluted habitat.

Genetic organization of the catabolic plasmid pJP4 from Ralstonia eutropha JMP134 (pJP4) reveals mechanisms of adaptation to chloroaromatic pollutants and evolution of specialized chloroaromatic degradation pathways.

Ralstonia eutropha JMP134 (pJP4) is a useful model for the study of bacterial degradation of substituted aromatic pollutants. Several key degrading capabilities, encoded by tfd genes, are located in the 88 kb, self-transmissible, IncP-1 beta plasmid pJP4. The complete sequence of the 87,688 nucleotides of pJP4, encoding 83 open reading frames (ORFs), is reported. Most of the coding sequence corresponds to a well-conserved IncP-1 beta backbone and the previously reported tfd genes. In addition, we found hypothetical proteins putatively involved in the transport of aromatic compounds and short-chain fatty acid oxidation. ORFs related to mobile elements, including the Tn501-encoded mercury resistance determinants, an IS1071-based composite transposon and a cryptic class II transposon, are also present in pJP4. These mobile elements are inefficient in transposition and are located in two regions of pJP4 that are rich in remnants of lateral gene transfer events. pJP4 plasmid was able to capture chromosomal genes and form hybrid plasmids with the IncP-1 alpha plasmid RP4. These observations are integrated into a model for the evolution of pJP4, which reveals mechanisms of bacterial adaptation to degrade pollutants.