The Structural Characterization and Antipathogenic Activities of Quinoin,a Type 1 Ribosome-Inactivating Protein from Quinoa Seeds

Quinoin is a type 1 ribosome-inactivating protein (RIP) we previously isolated from the seeds of pseudocereal quinoa (Chenopodium quinoa) and is known as a functional food for its beneficial effects on human health. As the presence of RIPs in edible plants could be potentially risky, here we further characterised biochemically the protein (complete amino acid sequence, homologies/differences with other RIPs and three-dimensional homology modeling) and explored its possible defensive role against pathogens. Quinoin consists of 254 amino acid residues, without cysteinyl residues. As demonstrated by similarities and homology modeling, quinoin preserves the amino acid residues of the active site (Tyr75, Tyr122, Glu177, Arg180, Phe181 and Trp206; quinoin numbering) and the RIP-fold characteristic of RIPs. The polypeptide chain of quinoin contains two N-glycosylation sites at Asn115 and Asp231, the second of which appears to be linked to sugars. Moreover, by comparative MALDI-TOF tryptic peptide mapping, two differently glycosylated forms of quinoin, named pre-quinoin-1 and pre-quinoin-2 (~0.11 mg/100 g and ~0.85 mg/100 g of seeds, respectively) were characterised. Finally, quinoin possesses: (i) strong antiviral activity, both in vitro and in vivo towards Tobacco Necrosis Virus (TNV); (ii) a growth inhibition effect on the bacterial pathogens of plants; and (iii) a slight antifungal effect against two Cryphonectria parasitica strains.     

Reduced mammary tumor progression in a transgenic mouse model fed an isoflavone-poor soy protein concentrate

Dietary exposure to soy has been associated with reduced breast cancer incidence. Soy isoflavones and protein components, such as protease inhibitors and the lunasin peptide, have been indicated as potential agents reducing carcinogenesis. In this study, the effect of soy-based diets was evaluated in a transgenic mouse model of breast carcinoma, overexpressing the neu oncogene. Neu female mice were fed for 20 wk a soy- and isoflavone-free diet (IFD), 4RF21 laboratory mouse diet, soy-based, thus isoflavone-rich (STD), or AIN-76-based semisynthetic diets with a soy protein isolate (SPI) or an isoflavone-poor soy protein concentrate (IPSP) as protein source. Mice were then sacrificed and tumors removed. Mammary tumor weights were not different in SPI versus IFD and STD fed mice. In contrast, mice fed IPSP showed reduced tumor progression versus IFD and STD groups (p < 0.05). Moreover, IPSP fed mice showed lower bromo-2'-deoxyuridine (BrdU) incorporation into breast tumor cells compared to STD and SPI fed animals (p < 0.02). Lung metastases were detected in 80% of IFD fed mice, in 70% of mice fed STD and SPI, and only in 50% of the IPSP fed animals. These results indicate that a diet containing an isoflavone-poor soy protein concentrate may inhibit breast tumor progression and metastasis development.     

A novel method to determine valnemulin in feedingstuffs for several animal species by liquid chromatography-electrospray tandem mass spectrometry

A new method specific for the determination and unambiguous confirmation of the antibiotic valnemulin in feed for all animal species is described. Simple clean-up based on solvent extraction and liquid partition is carried out prior to determination by liquid chromatography coupled to electrospray tandem mass spectrometry on a hybrid QTRAP 4000 system, in multiple reaction monitoring mode. Valnemulin is licensed in the European Union as a veterinary drug for use in feed for pigs and rabbits, but unavoidable carryover in feed for non-target species should be monitored. The method is rapid and reliable, and was validated in-house at 10, 100 and 750 ng g^–1, evaluating the analytical performances according to Commission Regulation (EC) No. 882/2004. Good mean recoveries from 79.7% to 92.6%, and within-laboratory reproducibility RSDs, ranging from 6.2% to 12.1%, were measured; the limit of quantification at 10.0 ng g^–1 also allows for sensitive evaluation of undesirable carryover in feed for non-target species. The results of monitoring 24 compound feeds for several animal species are also reported.     

A multimodal imaging approach to the evaluation of post-traumatic epilepsy

Object

Electroencephalography-functional magnetic resonance imaging (EEG-fMRI) coregistration and high-density EEG (hdEEG) can be combined to map noninvasively abnormal brain activation elicited by epileptic processes. By combining noninvasive imaging techniques in a multimodal approach, we sought to investigate pathophysiological mechanisms underlying epileptic activity in seven patients with severe traumatic brain injury.

Materials and methods

Standard EEG and fMRI data were acquired during a single scanning session. The EEG-fMRI data were analyzed using the general linear model and independent component analysis. Source localization of interictal epileptiform discharges (IEDs) was performed using 256-channel hdEEG. Blood oxygenation level dependent (BOLD) localizations were then compared to EEG source reconstruction.

Results

On hdEEG, focal source localization was detected in all seven patients; in six out of seven it was concordant with the expected epileptic activity as defined by EEG data and clinical evaluation; and in four out of seven in whom IEDs were recorded, BOLD signal changes were observed. These activities were partially concordant with the source localization.

Conclusion

Multimodal integration of EEG-fMRI and hdEEG combining two different methods to localize the same epileptic foci appears to be a promising tool to noninvasively map abnormal brain activation in patients with post-traumatic brain injury.     

Social learning in the golden hamster (Mesocricetus auratus).

Investigates whether golden hamster (Mesocricetus auratus) pups can acquire a new behavior by interacting with an experienced adult conspecific. The behavior consisted of using teeth and forepaws to retrieve a piece of food dangling from a small chain. Instrumental learning techniques were used to train the demonstrators. Four groups of pups were exposed to different kinds of social experience. In the 1st group, the pups interacted with their skilled mother, in the 2nd group, they did the same with their inexperienced mother, in the 3rd group, they interacted with inexperienced littermates; and in the 4th group, the pups were tested individually. At the end of an acquisition period, the pups were tested individually to assess their performance. Results demonstrate that interacting with a skilled mother has a remarkable effect on the acquisition of a new feeding behavior by hamster pups. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mechanical modelling of capacitive RF MEMS shunt switches

The mechanical response of a RF MEMS shunt connected switch in coplanar waveguide configuration has been studied by using both an uni-dimensional approach based on analytical equations and a Finite Element Method (FEM) with commercial software simulations. The analytical model, developed by means of a MATHCAD program, has been used to predict the dynamics of the device, mainly taking into account its re-configuration time and the energy balance involved in the actuation and in the de-actuation mechanisms. After that, 2D and 3D simulations have been performed to get the really deformed shape of the bridge, depending on the central and lateral actuation of the suspended beam. After that, 2D and 3D simulations have been performed by a central and lateral actuation of the suspended beam to get the really deformed shape of the bridge. Theoretical and experimental results about the threshold voltage and the response time of the device confirm the validity of the proposed modeling.     

Narrow-band filtering by means of triangular meta-material resonators based on RF MEMS cantilevers in CPW configuration

Microsystem Technologies - Triangular resonators, designed by using Radio Frequency Micro Electro Mechanical Systems (RF MEMS) cantilevers in coplanar waveguide (CPW) configuration, have been...