Pilot study: alterations of intestinal microbiota in obese humans are not associated with colonic inflammation or disturbances of barrier function

BACKGROUND

Obesity is associated with low-grade inflammation contributing to insulin-resistance. Gut barrier alterations, described in animal models of obesity, probably favour inflammation. This has not been hitherto described in obese humans.

AIM

To evaluate gut permeability in asymptomatic obese and its association with plasma (C-reactive protein (CRP), arachidonate/eicosapentaenoate ratio) and faecal (calprotectin and leptin) markers of inflammation and microbiota alterations.

METHODS

A total of 13 obese (age: 33.9 ± 11.5 years; BMI: 35.9 ± 5.0 kg/m²) and 11 control subjects (age: 30.3 ± 8.1 years; BMI: 23.5 ± 2.4 kg/m²) were recruited. Gut permeability was assessed by the lactulose-mannitol-sucralose test, plasma fatty acids by gas chromatography, faecal calprotectin and leptin by Elisa and faecal microbiota by G+C profiling.

RESULTS

C-reactive protein was increased in the obese subjects (P = 0.01), but neither the plasma arachidonate/eicosapentaenoate ratio, the faecal levels of calprotectin and leptin, nor the gut permeability were altered. The faecal microbiota was altered in the obese (P = 0.0002), with predominance of bacterial populations having a lower G+C content and decreased concentrations of high G+C populations.

CONCLUSIONS

Asymptomatic obese individuals with systemic low-grade inflammation do not have evidence of colonic inflammation or gut barrier alteration; however, the biodiversity of their intestinal microbiota is affected.

Bacterial community in copper sulfide ores inoculated and leached with solution from a commercial-scale copper leaching plant

Most copper bioleaching plants operate with a high concentration of sulfate salts caused by the continuous addition of sulfuric acid and the recycling of the leaching solution. Since the bacteria involved in bioleaching have been generally isolated at low sulfate concentrations, the bacterial population in ores leached with the high-sulfate solution (1.25 M) employed in a copper production plant was investigated. The complexity of the original population was assessed by the length pattern of the spacer regions between the 16S and 23S rRNA genes, observed after PCR amplification of the DNA extracted from the leached ore. Six main spacers were distinguished by electrophoretic migration, but they could be further resolved into eight spacers by nucleotide sequence homology. The degree of homology was inferred from the electrophoretic migration of the heteroduplexes formed after hybridization. One of the spacers was indistinguishable from that found in Thiobacillus thiooxidans, four could be related to Thiobacillus ferrooxidans, and three could be related to Leptospirillum ferrooxidans. Only five of the spacers in the original sample could be recovered after culturing in media containing different inorganic energy source. Altogether, the results indicate that the bacteria in the leached ore formed a community composed of at least three species: a fairly homogeneous population of T. thiooxidans strains and two heterogeneous populations of T. ferrooxidans and L. ferrooxidans strains.

Biodegradability of kraft mill TCF biobleaching effluents: application of enzymatic laccase-mediator system

The great amount of pollutants released from kraft pulp processes, mainly from cooking and bleaching stages, is one of the most relevant environmental problems in this type of industry. New bleaching sequences are being studied based on the use of oxidative enzymes from fungal cultures. In this study, the bleaching systems consisting of Laccase and different mediators such as 1-hydroxybenzotriazole, violuric acid, syringaldehyde and methyl syringate in the bleaching sequence of Eucalyptus globulus kraft pulp were applied. The main objective of this study is to evaluate the aerobic and anaerobic biodegradability and toxicity to Vibrium fischeri of generated L-stage and total bleaching sequence effluents. The highest levels of aerobic and anaerobic degradation of the generated effluents were achieved for treatments with laccase plus violuric acid, with 80% of aerobic degradation and 68% of anaerobic biodegradation. V. fischeri toxicity was remarkably reduced for all the effluents after aerobic degradation.

Melatonin and elimination of kynurenines in children with Down's syndrome

BACKGROUND

Heightened activity of superoxide dimutase is an effect derived from the gene dose in the trisomy of Down's syndrome (DS), and has been related to the increased production of hydrogen peroxide and with greater lipid peroxidation. Many of the degenerative changes observed in patients with DS have been associated with the pathological effects of free radicals, and for this reason it is of interest to determine the levels present in these patients of powerful antioxidant molecules such as melatonin, and of metabolites with important neuroprotector and neurotoxic consequences such as those derived from the kynurenine pathway.

PATIENTS AND METHODS

A study was made of 15 children with DS, together with a control group of 15 non-DS children, matched for age and sex, examined at the Hospital Costa del Sol, Marbella, Spain. Serum melatonin and serotonin were analyzed by RIA; urinary tryptophan metabolites (kynurenine pathway) were determined during periods of light and darkness (09.00-21.00 h and 21.00-9.00 h) by thin-layer chromatography.

RESULTS

The mean values of serotonin and melatonin were found to be lower in the patients with DS, although the level of nocturnal secretion of melatonin was higher. Urinary excretion of kynurenine was lower in the patients with DS, although greater quantities of kynurenic acid and anthranilic acid were excreted.

CONCLUSIONS

Patients with DS present levels of plasma melatonin and urinary kynurenine that are lower than the corresponding levels in the control population, together with higher values of kynurenic acid and anthranilic acid. These circumstances constitute an added risk to these patients of damage by free radicals.

Cannabinoids and neurodegenerative diseases

Although significant advances have taken place in recent years on our understanding of the molecular mechanisms of different neurodegenerative diseases, its translation into effective therapeutic treatments has not been as successful as could be expected. There is still a dramatic lack of curative treatments for the most frequent disorders and only symptomatic relief for many others. Under this perspective, the search for novel therapeutic approaches is demanding and significant attention and efforts have been directed to studying additional neurotransmission systems including the endocannabinoid system (ECS). The neuroprotective properties of exogenous as well as endogenous cannabinoids have been known for years and the underlying molecular mechanisms have been recently unveiled. As discussed later, antioxidative, antiglutamatergic and antiinflammatory effects are now recognized as derived from cannabinoid action and are known to be of common interest for many neurodegenerative processes. Thus, these characteristics make cannabinoids attractive candidates for the development of novel therapeutic strategies [1]. The present review will focus on the existing data regarding the possible usefulness of cannabinoid agents for the treatment of relevant neurological pathologies for our society such as Alzheimer's disease, multiple sclerosis, Huntington's disease and amyotrophic lateral sclerosis.

The neuroprotective effect of cannabidiol in an in vitro model of newborn hypoxic-ischemic brain damage in mice is mediated by CB(2) and adenosine receptors

To investigate the mechanisms involved in cannabidiol (CBD)-induced neuroprotection in hypoxic-ischemic (HI) immature brain, forebrain slices from newborn mice underwent oxygen and glucose deprivation in the presence of vehicle, or CBD alone or with selective antagonists of cannabinoid CB(1) and CB(2), and adenosine A(1) and A(2) receptors. CBD reduced acute (LDH efflux to the incubation medium) and apoptotic (caspase-9 concentration in tissue) HI brain damage by reducing glutamate and IL-6 concentration, and TNFalpha, COX-2, and iNOS expression. CBD effects were reversed by the CB(2) antagonist AM630 and by the A(2A) antagonist SCH58261. The A(1A) antagonist DPCPX only counteracted the CBD reduction of glutamate release, while the CB(1) antagonist SR141716 did not modify any effect of CBD. In conclusion, CBD induces robust neuroprotection in immature brain, by acting on some of the major mechanisms underlying HI cell death; these effects are mediated by CB(2) and adenosine, mainly A(2A), receptors.

Holographic ghost imaging and the violation of a Bell inequality

We demonstrate the contrast enhancement of images within a ghost-imaging system by use of nonlocal phase filters. We use parametric down-conversion as the two-photon light source and two separated phase modulators, in the signal and idler arms which represent different phase filters and objects, respectively. We obtain edge enhanced images as a direct consequence of the quantum correlations in the orbital angular momentum (OAM) of the down-converted photon pairs. For phase objects, with differently orientated edges, we show a violation of a Bell-type inequality for an OAM subspace, thereby unambiguously revealing the quantum nature of our ghost-imaging arrangement.

Violation of a Bell inequality in two-dimensional orbital angular momentum state-spaces

We observe entanglement between photons in controlled super-position states of orbital angular momentum (OAM). By drawing a direct analogy between OAM and polarization states of light, we demonstrate the entangled nature of high order OAM states generated by spontaneous downconversion through violation of a suitable Clauser Horne Shimony Holt (CHSH)-Bell inequality. We demonstrate this violation in a number of two-dimensional subspaces of the higher dimensional OAM Hilbert space.

Molecular analysis of microbiota along the digestive tract of juvenile Atlantic salmon (Salmo salar L.)

Dominant bacterial microbiota of the gut of juvenile farmed Atlantic salmon was investigated using a combination of molecular approaches. Bacterial community composition from the stomach, the pyloric caeca, and the intestine was assessed by extracting DNA directly from each gut compartment. Temporal temperature gradient gel electrophoresis (TTGE) analysis of 16S ribosomal DNA (rDNA) amplicons showed very similar bacterial compositions throughout the digestive tract. Band sequencing revealed a narrow diversity of species with a dominance of Pseudomonas in the three compartments. However, cloning revealed more diversity among the Pseudomonas sequences. To confirm these results, we analyzed the bacterial community by amplifying the variable 16S-23S rDNA intergenic spacer region (ITS). Similar ITS profiles were observed among gastrointestinal compartments of salmon, confirming the TTGE results. Moreover, the dominant ITS band at 650 bp, identified as Pseudomonas, was observed in the ITS profile from fish collected in two seasons (July 2003 and 2004). In contrast, aerobic culture analysis revealed Shewanella spp. as the most prevalent isolate. This discrepancy was resolved by evaluating 16S rDNA and ITS polymerase chain reaction amplification efficiency from both Shewanella and Pseudomonas isolates. Very similar efficiencies were observed in the two bacteria. Hence, this discrepancy may be explained by preferential cultivation of Shewanella spp. under the experimental conditions. Also, we included analyses of pelleted feed and the water influent to explore environmental influences on the bacterial composition of the gut microbiota. Overall, these results indicate a homogeneous composition of the bacterial community composition along the gastrointestinal tract of reared juvenile salmon. This community is mainly composed of Pseudomonas spp., which could be derived from water influent and may be selectively associated with salmon in this hatchery.

Modeling the adsorption of Cr(III) from aqueous solution onto Agave lechuguilla biomass: study of the advective and dispersive transport

The biosorption of Cr(III) onto packed columns of Agave lechuguilla was analyzed using an advective-dispersive (AD) model and its analytical solution. Characteristic parameters such as axial dispersion coefficients, retardation factors, and distribution coefficients were predicted as functions of inlet ion metal concentration, time, flow rate, bed density, cross-sectional column area, and bed length. The root-mean-square-error (RMSE) values 0.122, 0.232, and 0.285 corresponding to the flow rates of 1, 2, and 3 (10(-3))dm3min(-1), respectively, indicated that the AD model provides an excellent approximation of the simulation of lumped breakthrough curves for the adsorption of Cr(III) by lechuguilla biomass. Therefore, the model can be used for design purposes to predict the effect of varying operational conditions.

First Report of Clover yellow vein virus in Grain Legumes in Spain

From 1999 to 2002, field surveys were conducted in the legume-growing areas of Spain including Ávila, Badajoz, Cádiz, Córdoba, León, Málaga, Murcia, Salamanca, and Zamora provinces. Leaf tissue from 35 asymptomatic and 224 virus symptomatic plants was sampled and analyzed by indirect-ELISA with a specific monoclonal antibody against the potyvirus group (Adgia, Elkhart, IN). All symptomatic plants of bean (Phaseolus vulgaris L.), broad bean (Vicia faba L.), lentils (Lens culinaris L.), and chickpea (Cicer arietinum L.) were positive for potyvirus infection. Identification as Bean yellow mosaic virus (BYMV) was obtained by double-antibody sandwich (DAS)-ELISA with a polyclonal antiserum (Loewe Biochemica Gmbh, Sauerlach, Germany). To analyze the genetic variability of BYMV Spanish isolates, 33 Spanish isolates were selected at random from our BYMV collection, and extracts from these plants were used with primers 1985 (5'-gagagaatgatacacatactgaa-3') and 1984 (5'-caaggtgagtggacaatgatgg-3') to amplify by immunocapture (IC)-reverse transcription (RT)-PCR a 524-nt fragment of the BYMV genome that includes the C-terminal 417 nt of the coat protein and 107 nt from the 3' untranslated region. The IC-RT-PCR products were cloned into pGEM-T easy vector (Promega, Madison, WI) and a minimum of three clones from each PCR amplification were sequenced. BLAST analysis showed that the sequences of 30 samples were 96 to 98% identical to BYMV, but three samples (GenBank Accession Nos. EU860364-66) from bean, broad bean, and lentils had a high (98%) identity with Clover yellow vein virus (ClYVV). Sequence alignments of the ClYVV Spanish isolates and 14 ClYVV isolates from the GenBank (Accession Nos. AB03308, AB004545, AB011819, AF185959, AF203536, D86044, S77521, D95538-94) were obtained using the Clustal X software. Genetic distances were estimated using the Kimura two-parameter method. Within-population and between-population nucleotide diversities were estimated from the genetic distances (2). ClYVV sequences were phylogenetically separated into two clades: one with the three isolates from Japan (Accession Nos. D89542, D89543, and D89544) and the other with the remaining isolates. Molecular clustering coincides with biology and serological variations of strains 1 and 2 (3). Phylogenetic distances were independent of geographic origin, host, or time of sampling. The nucleotide diversity value among populations (0.18) was higher than within the subpopulations (0.017 and 0.029). dNS/dS in the ClYVV population was 0.031 (<1) and we can conclude that negative selection is occurring in the gene in study and that the population of ClYVV present in Spain is homogenous. In Spain, ClYVV was reported infecting borage (Borago officinalis L.) (1). To our knowledge, this is the first report of natural infection of bean, broad bean, and lentils with ClYVV in Spain. ClYVV might cause important economic losses in grain legumes since it causes an important viral disease of legumes worldwide. References: (1) M. Luis-Arteaga et al. Plant Pathol. 45:38, 1996. (2) M. Nei and T. Gojobori. Mol. Biol. Evol. 3:418, 1986. (3) T. Sasaya et al. Virology 87:1014, 1987.