Helminth infection in mice improves insulin sensitivity via modulation of gut microbiota and fatty acid metabolism.

Intestinal helminths are prevalent in individuals who live in rural areas of developing countries, where obesity, type 2 diabetes, and metabolic syndrome are rare. In the present study, we analyzed the modulation of the gut microbiota in mice infected with the helminth Strongyloides venezuelensis, and fed either a standard rodent chow diet or high-fat diet (HFD). To investigate the effects of the microbiota modulation on the metabolism, we analyzed the expression of tight-junction proteins present in the gut epithelium, inflammatory markers in the serum and tissue and quantified glucose tolerance and insulin sensitivity and resistance. Additionally, the levels of lipids related to inflammation were evaluated in the feces and serum. Our results show that infection with Strongyloides venezuelensis results in a modification of the gut microbiota, most notably by increasing Lactobacillus spp. These modifications in the microbiota alter the host metabolism by increasing the levels of anti-inflammatory cytokines, switching macrophages from a M1 to M2 pattern in the adipose tissue, increasing the expression of tight junction proteins in the intestinal cells (thereby reducing the permeability) and decreasing LPS in the serum. Taken together, these changes correlate with improved insulin signaling and sensitivity, which could also be achieved with HFD mice treated with probiotics. Additionally, helminth infected mice produce higher levels of oleic acid, which participates in anti-inflammatory pathways. These results suggest that modulation of the microbiota by helminth infection or probiotic treatment causes a reduction in subclinical inflammation, which has a positive effect on the glucose metabolism of the host.

Mineral Type and Solution Chemistry Affect the Structure and Composition of Actively Growing Bacterial Communities as Revealed by Bromodeoxyuridine Immunocapture and 16S rRNA Pyrosequencing.

Understanding how minerals affect bacterial communities and their in situ activities in relation to environmental conditions are central issues in soil microbial ecology, as minerals represent essential reservoirs of inorganic nutrients for the biosphere. To determine the impact of mineral type and solution chemistry on soil bacterial communities, we compared the diversity, composition, and functional abilities of a soil bacterial community incubated in presence/absence of different mineral types (apatite, biotite, obsidian). Microcosms were prepared containing different liquid culture media devoid of particular essential nutrients, the nutrients provided only in the introduced minerals and therefore only available to the microbial community through mineral dissolution by biotic and/or abiotic processes. By combining functional screening of bacterial isolates and community analysis by bromodeoxyuridine DNA immunocapture and 16S rRNA gene pyrosequencing, we demonstrated that bacterial communities were mainly impacted by the solution chemistry at the taxonomic level and by the mineral type at the functional level. Metabolically active bacterial communities varied with solution chemistry and mineral type. Burkholderia were significantly enriched in the obsidian treatment compared to the biotite treatment and were the most effective isolates at solubilizing phosphorous or mobilizing iron, in all the treatments. A detailed analysis revealed that the 16S rRNA gene sequences of the OTUs or isolated strains assigned as Burkholderia in our study showed high homology with effective mineral-weathering bacteria previously recovered from the same experimental site.

Glutamate-dependent translational regulation in cultured Bergmann glia cells: involvement of p70S6K.

Glutamate, the main excitatory amino acid transmitter in the vertebrate brain is involved in the dynamic changes in protein repertoire that underlie synaptic plasticity. Activity-dependent differential expression patterns occur not only in neurons but also in glial cells. In fact, a membrane to nuclei signaling has been described after ionotropic glutamate receptor stimulation in cultured chick cerebellar Bergmann glia cells. In order to characterize other levels of protein expression regulation, we explored the effect of glutamate treatment in [35S]-methionine incorporation into newly synthesized polypeptides. A time-dependent modification in protein synthesis was found. An important component of translational control is the ribosomal S6 protein kinase. Threonine phosphorylation renders the kinase active increasing translation initiation. Glutamate exposure results in ribosomal S6 protein kinase Thr389 phosphorylation in a dose and time-dependent manner that matches perfectly with the overall protein synthesis profile detected upon the excitatory amino acid. Pharmacological characterization of the receptors involved suggests the participation of both ionotropic as well as metabotropic glutamate receptors. The non-receptor tyrosine kinase Src, phosphatidylinositol 3-kinase, protein kinase B and the mammalian target of rapamycin are mediators of the glutamate effect. These results not only demonstrate that glutamate receptors activation is critically involved in translational control in glial cells adjacent to synaptic processes like cerebellar Bergmann glia cells, but also further strengthen the notion of an active participation of glial cells in synaptic transmission.

Population structure and dispersal in the Canary Island caddisfly Mesophylax aspersus (Trichoptera, Limnephilidae).

Population genetic structure of the circum-Mediterranean caddisfly Mesophylax aspersus (Trichoptera, Limnephilidae) on the Canary Islands was investigated by studying allozyme variation at nine putative loci in five populations. Genetic variability, population structure and gene flow were compared with data in the literature for continental taxa to assess the effect of isolation of island populations on the genetic structure. Larvae were collected from streams on the islands of Tenerife (one population), La Gomera (two populations in the same catchment) and La Palma (two populations in different catchments). Genetic variability within populations was high relative to that recorded previously for continental Trichoptera, e.g. mean heterozygosity was 0.119--0.336 (0.035--0.15 in continental taxa). Highly significant population structuring was observed (mean F(ST)=0.250), and there was significant within-population structuring (mean F(IS)=0.098). Populations from the same catchment or island were no more similar than populations from different islands, which suggests that occasional long-distance dispersal, both between and within islands, is the predominant influence on the population structure. This dispersal ability has contributed to the colonization of most permanent streams on the Canary Islands by M. aspersus.

Evaluation of an approach to choosing a left double-lumen tube size based on chest computed tomographic scan measurement of left mainstem bronchial diameter.

OBJECTIVE: Evaluation of an approach to choosing left double-lumen tube size based on chest computed tomographic (CT) scan measurement of left bronchial diameter. DESIGN: Prospective. SETTING: The operating rooms of a university hospital. PARTICIPANTS: Patients scheduled for elective thoracic surgery. INTERVENTIONS: Patients had their left bronchial diameter measured on the preoperative chest CT scan. Left double-lumen tube size for the individual patient was chosen from a protocol based on left bronchial diameter. MEASUREMENTS AND MAIN RESULTS: The double-lumen tube size was considered appropriate for the patient if some air leak was detected when the bronchial cuff was deflated and if airtight seal of the left bronchus was obtained with a bronchial cuff volume of 2 mL or less. In 17 of 20 patients, the double-lumen tube size fulfilled both criteria. In 3 women with left bronchi measuring 10 mm or less, the bronchus was sealed without any air in the bronchial cuff of size 35 Fr left double-lumen tubes. In 1 patient, who was excluded from the study, the double-lumen tube size was chosen based on measurement of the left bronchial diameter on chest radiograph because of motion artifact on the chest CT scan. CONCLUSIONS: Chest CT scan measurement of left bronchial diameter can successfully guide the choice of left double-lumen tube size for an individual patient. In individuals with a small left bronchus measuring less than 10.0 mm in diameter, currently available adult double-lumen tube sizes will tightly wedge in their bronchus.

Clinical experience with the isotopic cardiac pacemaker.

Clinical experience with isotopic pacemakers in 59 patients is compared with that in 77 control patients having conventional chemical battery-powered pulse generators. The review covers a 51/2-year period. Statistical analysis of the two series is impossible because of the numerous variables such as age, type of disease, number of controls, types of test and control pulse generators, dates of insertion, and protocol regulations. However, there were pulse generator failures in the control group, but not in the test group. Though not proven in this study, the isotopic cardiac pacer is likely to last longer than conventional chemical battery-powered units, and could provide lifetime pacing for many patients. The risk of carcinogenesis is minimal and seems negligible in older patients. The isotopic cardiac pacer, in spite of restrictions of the Nuclear Regulatory Commission, should be considered for any patient with a life expectancy of 10 or more years. Paradoxically, it might be indicated in older rather than younger patients.

Permanent pervenous atrial sensing and pacing with a new J-shaped lead.

We have developed a new J-shaped lead for atrial pacing. The lead has silicone rubber tines which become entangled in the trabeculae and thereby anchor the lead firmly in the left atrial appendage. Later, scar tissue forms around the tines, rather than around the electrode, so that there is no problem with either lead displacement or loss of sensing.

Preliminary clinical experience with a new radioisotope-powered cardiac pacemaker.

A small light-weight nuclear-powered pacer has been developed. The pulse generator weight 61 Gm. and occupies a volume of 33 sq. cm. It is a standard R-wave inhibited (VVI) demand pulse generator. The unit has met all United States and foreign atomic energy commission safety specifications including mechanical shock, industrial fire, accidental crush, cremation, impact, and corrosion. Its calculated life is in excess of 20 years. The unit has been shown to be insensitive to electromagnetic interference (EMI) over a wide range of commonly encountered sources of interference. An extensive dog testing program has been carried out and is continuing. The United States Atomic Energy Commission (AEC) has issued a license to conduct clinical trials. These began in October, 1974, and a total of 30 units of 30 units have been implanted so far. An equal number of chemical battery-powered pulse generators has been implanted in a control series of 30 patients. Preliminary results have been gratifying.