Glucagon-like peptide-1 accelerates the onset of insulin action on glucose disappearance in mice

Glucagon-like peptide-1 (GLP-1) plays a significant role in glucose homeostasis through its incretin effect on insulin secretion. However, GLP-1 also exhibits extrapancreatic actions, and in particular its possible influences on insulin sensitivity are controversial. To study the dynamic action of GLP-1 on insulin sensitivity, we applied advanced statistical modeling methods to study glucose disappearance in mice that underwent intravenous glucose tolerance test with administration of GLP-1 at various dose levels. In particular, the minimal model of glucose disappearance was exploited within a population estimation framework for accurate detection of relationships between glucose disappearance parameters and GLP-1. Minimal model parameters were estimated from glucose and insulin data collected in 209 anesthetized normal mice after intravenous injection of glucose (1 g/kg) alone or with GLP-1 (0.03-100 nmol/kg). Insulin secretion markedly increased, as expected, with increasing GLP-1 dose. However, minimal model-derived indexes, i.e., insulin sensitivity and glucose effectiveness, did not significantly change with GLP-1 dose. Instead, fractional turnover rate of insulin action [P2 = 0.0207 +/- 24.3% (min) at zero GLP-1 dose] increased steadily with administered GLP-1 dose, with significant differences at 10.4 nmol/kg (P2 = 0.040 +/- 15.5%, P = 0.0046) and 31.2 nmol/kg (P2 = 0.050 +/- 29.2%, P = 0.01). These results show that GLP-1 influences the dynamics of insulin action by accelerating insulin action following glucose challenge. This is a novel mechanism contributing to the glucose-lowering action of GLP-1.     

Experimental-numerical analysis of minipig's multi-rooted teeth

The paper pertains to the analysis of the biomechanical behaviour of the periodontal ligament (PDL) by using a combined experimental and numerical approach. Experimental analysis provides information about a two-rooted pig premolar tooth in its socket with regard to morphological configuration and deformational response. The numerical analysis developed for the present investigation adopts a specific anisotropic hyperelastic formulation, accounting for tissue structural arrangement. The parameters to be adopted for the PDL constitutive model are evaluated with reference to data deducted from experimental in vitro tests on different specimens taken from literature. According to morphometric data relieved, solid models are provided as basis for the development of numerical models that adopt the constitutive formulation proposed. A reciprocal validation of experimental and numerical data allows for the evaluation of reliability of results obtained. The work is intended as preliminary investigation to study the correlation between mechanical status of PDL and induction to cellular activity in orthodontic treatments.     

Isolation, purification and properties of new restriction endonucleases from Bacillus badius and Bacillus lentus

We tentatively named two enzymes as BbaI and BleI, which were isolated and purified from Gram-positive mesophilic bacteria Bacillus badius 1458 and Bacillus lentus 1689 respectively, by ammonium sulphate precipitation, phosphocellulose and heparin-sepharose column chromatography. SDS-PAGE protein profiles for BbaI and BleI showed denatured molecular weights of 52 and 48 kDa, respectively. BbaI hydrolyzed pUC18 DNA into 1900 and 700 bp, pBR322 DNA into two fragments of 2800 and 1500 bp and Φ×174 DNA into 3800 and 1600 bp. BleI hydrolyzed pUC18 DNA into 1800 and 800 bp, pBR322 DNA into two fragments of 2700 and 1600 bp and Φ×174 DNA into 3700 and 1700 bp. The effects of temperature, ionic strength, pH and Mg²⁺ ion concentrations were studied to demonstrate some biochemical properties of BbaI and BleI. Maximum activities of these enzymes were observed at 37 °C (pH 8.0) with 100 mM NaCl and 10 mM Mg²⁺ concentrations.     

Optimization of two-phase thermophilic anaerobic digestion of biowaste for hydrogen and methane production through reject water recirculation

The optimization of a two-phase thermophilic anaerobic process treating biowaste for hydrogen and methane production was carried out at pilot scale using two stirred reactors (CSTRs) and without any physical/chemical pre-treatment of inoculum. During the experiment the hydrogen production at low hydraulic retention time (3d) was tested, both with and without reject water recirculation and at two organic loading rate (16 and 21 kgTVS/m³d). The better yields were obtained with recirculation where the pH reached an optimal value (5.5) thanks to the buffering capacity of the recycle stream. The specific gas production of the first reactor was 51 l/kgVS_fed and H₂ content in biogas 37%. The mixture of gas obtained from the two reactors met the standards for the biohythane mix only when lower loading rate were applied to the first reactor, with a composition of 6.7% H₂, 40.1% CO₂ and 52.3% CH₄ the overall SGP being 0.78 m³/kgVS_fed.     

SeqMaT: A sequence manipulation tool for phylogenetic analysis

Most bioinformatics tools require specialized input formats for sequence comparison and analysis. This is particularly true for molecular phylogeny programs, which accept only certain formats. In addition, it is often necessary to eliminate highly similar sequences among the input, especially when the dataset is large. Moreover, most programs have restrictions upon the sequence name. Here we introduce SeqMaT, a Sequence Manipulation Tool. It has the following functions: data format conversion,sequence name coding and decoding,redundant and highly similar sequence removal, anddata mining utilities. SeqMaT was developed using Java with two versions, web-based and standalone. A standalone program is convenient to manipulate a large number of sequences, while the web version will guarantee wide availability of the tool for researchers and practitioners throughout the Internet. AVAILABILITY: The database is available for free at http://glee.ist.unomaha.edu/seqmat.     

Autumnal emergence of Anagrus wasps,egg parasitoids of Empoasca vitis,from grapevine leaves and their migration towards brambles

• 1 The Anagrus‘atomus’ parasitoid group (Hymenoptera: Mymaridae), associated with Empoasca vitis (Göthe) (Homoptera: Cicadellidae), overwinters on vegetation surrounding vineyards. The emergence of parasitoid adults from grapevine leaves in autumn was studied in north‐eastern Italy, both in relation to the E. vitis egg‐laying period and to the presence of leafhoppers overwintering as eggs on Rubus bushes.
• 2 Autumnal peaks of Anagrus captured using yellow sticky traps were observed first on grapevines and then on brambles. Parasitoid captures in vineyards were observed for more than 1 month after the last first‐instar nymphs of the grape leafhoppers were noticed. Two species belonging to the A. ‘atomus’ group, Anagrus atomus and Anagrus ustulatus, were captured both on grapevines and brambles.
• 3 Parasitoids of the A.‘atomus’ group can emerge from third‐generation grape leafhopper eggs in accordance with two different development time patterns (i.e. normal or delayed). Individuals with delayed emergence required up to 2.2‐fold more time to develop from an egg to adult than individuals with normal emergence. This meant that some parasitoid adults emerged in autumn from eggs of grape leafhopper laid in August.
• 4 A delayed emergence as a result of a slower development ensures that the A.‘atomus’ parasitoid group is synchronized with the egg‐laying of leafhoppers that overwinter as eggs on Rubus spp.
• 5 Consequently, leafhoppers overwintering as eggs on brambles play a key role in the ecology of the relationship between grape leafhoppers and the A.‘atomus’ parasitoid group.