Thalamo-cortical spiking model of incremental learning combining perception,context and NREM-sleep

The brain exhibits capabilities of fast incremental learning from few noisy examples, as well as the ability to associate similar memories in autonomously-created categories and to combine contextual hints with sensory perceptions. Together with sleep, these mechanisms are thought to be key components of many high-level cognitive functions. Yet, little is known about the underlying processes and the specific roles of different brain states. In this work, we exploited the combination of context and perception in a thalamo-cortical model based on a soft winner-take-all circuit of excitatory and inhibitory spiking neurons. After calibrating this model to express awake and deep-sleep states with features comparable with biological measures, we demonstrate the model capability of fast incremental learning from few examples, its resilience when proposed with noisy perceptions and contextual signals, and an improvement in visual classification after sleep due to induced synaptic homeostasis and association of similar memories.     

Effect of flavonoid pigments on the accumulation of fumonisin B1 in the maize kernel

Mycotoxins are secondary metabolites with potential dangers for animal and human health. In particular, maize (Zea mays L.) infection caused by Fusarium and the consequent fumonisin contamination is widespread in several countries such as Italy. We developed six maize populations differing in their constitution of regulatory genes able to accumulate respectively anthocyanins in the aleurone layer (r1 gene), pericarp (b1 and pl1 genes) and phlobaphene in the pericarp (p1 gene). These coloured populations, with the related control colourless populations were analysed for mycotoxin content in the kernels during three field seasons with the aim of understanding if there were any correlations with their ability to accumulate flavonoids in kernel tissues. Our results indicate that accumulation of flavonoid pigments in the seeds, in particular phlobaphenes, is able to reduce the level of fumonisin B1. This finding could be used to minimize kernel mycotoxin contamination in this crop, in particular, the development of sweet, pop and polenta coloured corn varieties will help the farmer to keep the level of fumonisin under the threshold of contamination established for human corn consumption.     

Coronary involvement in Mediterranean spotted fever

Mediterranean spotted fever (MSF) is a tick-borne acute febrile disease caused by Rickettsia conorii and characterized by fever, a maculo-papular rash and a black eschar at the site of the tick bite. We describe the case of a 3-year-old boy with MSF who developed a transient right coronary artery ectasia. The patient was brought to the hospital after four days of fever and mild myalgia of the legs. The suspicion of MSF arose due to the presence of a maculo-papular skin rash and treatment with oral clarithromycin was started. After four days fever persisted and the differential diagnosis of Kawasaki syndrome was considered. Echocardiography showed a dilated right coronary artery with hyperreflective walls. Treatment with intravenous immunoglobulin was initiated while clarithromycin was continued. After one day the fever disappeared. An immunofluorescent antibody test performed after four weeks confirmed a R. conorii infection. A follow-up echocardiography was normal six weeks and six months later. We suggest that ectasia of the coronary arteries may be a manifestation of rickettsial vasculitis. Prospective studies are needed to understand the frequency and the possible consequences of this phenomenon in the course of MSF.     

The Biological Connection Markup Language: a SBGN-compliant format for visualization, filtering and analysis of biological pathways

MOTIVATION: Many models and analysis of signaling pathways have been proposed. However, neither of them takes into account that a biological pathway is not a fixed system, but instead it depends on the organism, tissue and cell type as well as on physiological, pathological and experimental conditions. RESULTS: The Biological Connection Markup Language (BCML) is a format to describe, annotate and visualize pathways. BCML is able to store multiple information, permitting a selective view of the pathway as it exists and/or behave in specific organisms, tissues and cells. Furthermore, BCML can be automatically converted into data formats suitable for analysis and into a fully SBGN-compliant graphical representation, making it an important tool that can be used by both computational biologists and 'wet lab' scientists. Availability and implementation: The XML schema and the BCML software suite are freely available under the LGPL for download at http://bcml.dc-atlas.net. They are implemented in Java and supported on MS Windows, Linux and OS X.     

Insight on cellular and humoral components of innate immunity in Squilla mantis (Crustacea, Stomatopoda)

For deeper insights into the function of crustacean haemocytes in immune responses, we studied the morphology and enzyme content of circulating cells of the mantis shrimp Squilla mantis from the North Adriatic Sea, together with their ability to phagocytose foreign cells. We also assayed the enzyme content and the agglutinating and haemolytic activities of cell-free haemolymph. Three haemocyte types, i.e., hyalinocytes, semigranulocytes and granulocytes, can be distinguished, according to cell and nuclear morphology and the presence of cytoplasmic granules. All of them share the same patterns of enzyme activities and are recognised by the same lectins. Spreading cells (hyalinocytes and semigranulocytes) can ingest foreign cells; granules of semigranular and granular cells have similar cytochemical properties. Injection of Micrococcus luteus into the heart sinus results in an increase in the frequency of hyaline cells and a decrease in the frequency of granulocytes. After 24 h from the injection, a decrease in the number of phagocytosing hyalinocytes, and a general decrease in the frequency of acid phosphatase-positive cells was reported. Our data match previous results and suggest the existence of a single differentiation pathway for Squilla haemocytes with the three haemocyte morphs as different stages of cell differentiation. Results also indicate that Squilla haemolymph performs immunosurveillance, through rapid changes in haemocyte distribution, increase of antimicrobial and antioxidant enzymes and secretion of lectins stimulating agglutination, phagocytosis and encapsulation.     

Ex vivo-expanded bone marrow CD34(+) for acute myocardial infarction treatment: in vitro and in vivo studies

Background aimsBone marrow (BM)-derived cells appear to be a promising therapeutic source for the treatment of acute myocardial infarction (AMI). However, the quantity and quality of the cells to be used, along with the appropriate time of administration, still need to be defined. We thus investigated the use of BM CD34⁺-derived cells as cells suitable for a cell therapy protocol (CTP) in the treatment of experimental AMI.MethodsThe need for a large number of cells was satisfied by the use of a previously established protocol allowing the expansion of human CD34⁺ cells isolated from neonatal and adult hematopoietic tissues. We evaluated gene expression, endothelial differentiation potential and cytokine release by BM-derived cells during in vitro culture. Basal and expanded CD34⁺ cells were used as a delivery product in a murine AMI model consisting of a coronary artery ligation (CAL). Cardiac function recovery was evaluated after injecting basal or expanded cells.ResultsGene expression analysis of in vitro-expanded cells revealed that endothelial markers were up-regulated during culture. Moreover, expanded cells generated a CD14⁺ subpopulation able to differentiate efficiently into VE-cadherin-expressing cells. In vivo, we observed a cardiac function recovery in mice sequentially treated with basal and expanded cells injected 4 h and 7 days after CAL, respectively.ConclusionsOur data suggest that combining basal and expanded BM-derived CD34⁺ cells in a specific temporal pattern of administration might represent a promising strategy for a successful cell-based therapy.