MARIS: Method for Analyzing RNA following Intracellular Sorting

Transcriptional profiling is a key technique in the study of cell biology that is limited by the availability of reagents to uniquely identify specific cell types and isolate high quality RNA from them. We report a Method for Analyzing RNA following Intracellular Sorting (MARIS) that generates high quality RNA for transcriptome profiling following cellular fixation, intracellular immunofluorescent staining and FACS. MARIS can therefore be used to isolate high quality RNA from many otherwise inaccessible cell types simply based on immunofluorescent tagging of unique intracellular proteins. As proof of principle, we isolate RNA from sorted human embryonic stem cell-derived insulin-expressing cells as well as adult human β cells. MARIS is a basic molecular biology technique that could be used across several biological disciplines.Howard Hughes Medical InstituteHarvard Stem Cell InstituteNational Institutes of Health (U.S.) (grant 2U01DK07247307)National Institutes of Health (U.S.) (grant RL1DK081184)National Institutes of Health (U.S.) (grant 1U01HL10040804

Inhibition of natural killer cell-mediated cytotoxicity by lipids extracted from Mycobacterium bovis BCG.

Several studies have demonstrated an augmentation of natural killer (NK) cell-mediated cytotoxicity by various adjuvants including BCG. Inhibitory effects of BCG have also been reported, particularly for relatively high doses. Because the cell wall of Mycobacterium bovis BCG contains a high proportion of lipids, the possibility was considered that these lipids may modulate NK activity. A total lipid fraction was extracted from Mycobacterium bovis BCG and used for the lipid modulation of NK effector and target cells. Treatment of effector or target cells resulted in decreased membrane fluidity and decreased NK cell-mediated cytotoxicity in both cases. Pretreatment of target cells did not affect the binding between target and effector cells, as shown in the single cell assay, whereas pretreatment of effectors resulted in inhibition of conjugation. It was further demonstrated that treatment of target cells which were first programmed for lysis protected these cells from subsequent lysis during the killer cell independent lysis stage. The results of this study suggest that adverse effects of BCG treatment on immune functions may be mediated by BCG derived lipids

Effect of mycobacterial lipids on membrane fluidity and natural killer cell-mediated cytotoxicity

A total lipid fraction was extracted from BCG and used for the lipid modulation of effector and target cells in relation to the effect of mycobacterial lipid on human natural-killer(NK)-cell-mediated cytotoxicity. Treatment of the cells with the lipid fraction resulted in decreased membrane fluidity and inhibition of NK-cell-mediated cytotoxicity irrespective of whether the targets or the effectors were treated. These results were obtained in the chromium release assay and the single cell assay. Pretreatment of target cells did not affect binding between target and effector cells, whereas pretreatment of effectors resulted in inhibition of conjugation. These results are discussed with respect to known effects of lipid modulation of target and effector cells on NK-cell-mediated cytotoxicity and of mycobacterial lipids on immune response

Towards Urban Traffic Regulation using a Multi-Agent System

9th International Conference on Practical Applications of Agents and Multi-Agent Systems, PAAMS11, SALAMANQUE, ESPAGNE, 28-/03/2011 - 30/03/2011This paper proposes a bimodal urban traffic control strategy based on a multi-agent model. We call bimodal traffic a traffic which takes into account private vehicles and public transport vehicles such as buses. The objective of this strategy is to improve global traffic and reduce the time spent by buses in traffic jams so that buses cope with their schedule. Reducing bus delays is done by study-ing time length of traffic lights, giving priority to buses, more precisely to buses running late. Regulation is obtained thanks to communication, collaboration and negotiation between the agents of the system. The implementation has been done using the JADE platform. We have tested our strategy on a small network of six junctions. The first results of the simulation are given. They show that our MAS control strategy improves both bus traffic and private vehicle traffic, decreases bus delays and improve its regularity compared to a classical strategy called fixed-time control

Incorporating a Local Binary Fitting Model into a Maximum Regional Difference Model for Extracting Microscopic Information under Complex Conditions

This paper presents a novel region-based method for extracting useful information from microscopic images under complex conditions. It is especially used for blood cell segmentation and statistical analysis. The active model detects several inner and outer contours of an object from its background. The method incorporates a local binary fitting model into a maximum regional difference model. It utilizes both local and global intensity information as the driving forces of the contour model on the principle of the largest regional difference. The local and global fitting forces ensure that local dissimilarities can be captured and globally different areas can be segmented, respectively. By combining the advantages of local and global information, the motion of the contour is driven by the mixed fitting force, which is composed of the local and global fitting term in the energy function. Experiments are carried out in the laboratory, and results show that the novel model can yield good performances for microscopic image analysis