Cell_motility: a cross-platform, open source application for the study of cell motion paths

BACKGROUND: Migration is an important aspect of cellular behaviour and is therefore widely studied in cell biology. Numerous components are known to participate in this process in a highly dynamic manner. In order to obtain a better insight in cell migration, mutants or drugs are used and their motive phenotype is then linked with the disturbing factors. One of the typical approaches to study motion paths of individual cells relies on fitting mean square displacements to a persistent random walk function. Since the numerous calculations involved often rely on diverse commercial software packages, the analysis can be expensive, labour-intensive and error-prone work. Additionally, due to the nature of algorithms employed the calculations involved are not readily reproducible without access to the exact software package(s) used. RESULTS: We here present the cell_motility software, an open source Java application under the GNU-GPL license that provides a clear and concise analysis workbench for large amounts of cell motion data. Apart from performing the necessary calculations, the software also visualizes the original motion paths as well as the results of the calculations to help the user interpret the data. The application features an intuitive graphical user interface as well as full user and developer documentation and both source and binary files can be freely downloaded from the project website at . CONCLUSION: In providing a free, open source software solution for the automated processing of cell motion data, we aim to achieve two important goals: labs can greatly simplify their data analysis pipeline as switching between different computational software packages becomes obsolete (thus reducing the chances for human error during data manipulation and transfer) and secondly, to provide scientists in the field with a freely available common platform to perform their analyses, enabling more efficient data quality control through peer reviewing

Aggravation of allergic airway inflammation by cigarette smoke in mice is CD44-dependent

Background : Although epidemiological studies reveal that cigarette smoke (CS) facilitates the development and exacerbation of allergic asthma, these studies offer limited information on the mechanisms involved. The transmembrane glycoprotein CD44 is involved in cell adhesion and acts as a receptor for hyaluronic acid and osteopontin. We aimed to investigate the role of CD44 in a murine model of CS-facilitated allergic airway inflammation. Methods : Wild type (WT) and CD44 knock-out (KO) mice were exposed simultaneously to house dust mite (HDM) extract and CS. Inflammatory cells, hyaluronic acid (HA) and osteopontin (OPN) levels were measured in bronchoalveolar lavage fluid (BALF). Proinflammatory mediators, goblet cell metaplasia and peribronchial eosinophilia were assessed in lung tissue. T-helper (Th) 1, Th2 and Th17 cytokine production was evaluated in mediastinal lymph node cultures. Results : In WT mice, combined HDM/CS exposure increased the number of inflammatory cells and the levels of HA and OPN in BALF and Th2 cytokine production in mediastinal lymph nodes compared to control groups exposed to phosphate buffered saline (PBS)/CS, HDM/Air or PBS/Air. Furthermore, HDM/CS exposure significantly increased goblet cell metaplasia, peribronchial eosinophilia and inflammatory mediators in the lung. CD44 KO mice exposed to HDM/CS had significantly fewer inflammatory cells in BALF, an attenuated Th2 cytokine production, as well as decreased goblet cells and peribronchial eosinophils compared to WT mice. In contrast, the levels of inflammatory mediators were similar or higher than in WT mice. Conclusion : We demonstrate for the first time that the aggravation of pulmonary inflammation upon combined exposure to allergen and an environmental pollutant is CD44-dependent. Data from this murine model of concomitant exposure to CS and HDM might be of importance for smoking allergic asthmatics

Studies on intercellular invasion in vitro using rabbit peritoneal neutrophil granulocytes. II. Adhesive interaction between cells.

A possible mechanism for intercellular invasion is that the strength of adhesion between host and invading cells is greater than the average of the strengths of homotypic adhesions. This hypothesis has been examined by a study of the kinetics of aggregation of dispersed populations of an invasive cell type (the rabbit peritoneal neutrophil granulocyte) and a host cell type (the chick embryo heart fibroblast) in shaken suspension culture. Since aggregation in mixed populations of the 2 cell types demonstrated tissue specificity, the hypothesis is not supported by these studies, heterotypic adhesions seem in fact to be weaker than homotypic adhesions

Studies on intercellular invasion in vitro using rabbit peritoneal neutrophil granulocytes. II. Adhesive interaction between cells.

A possible mechanism for intercellular invasion is that the strength of adhesion between host and invading cells is greater than the average of the strengths of homotypic adhesions. This hypothesis has been examined by a study of the kinetics of aggregation of dispersed populations of an invasive cell type (the rabbit peritoneal neutrophil granulocyte) and a host cell type (the chick embryo heart fibroblast) in shaken suspension culture. Since aggregation in mixed populations of the 2 cell types demonstrated tissue specificity, the hypothesis is not supported by these studies, heterotypic adhesions seem in fact to be weaker than homotypic adhesions

The Arum-Paris continuum of mycorrhizal symbioses

The definitive version may be found at www.wiley.com•  A survey of 12 plants colonized by six species of arbuscular mycorrhizal fungi was conducted to explore the diversity of Arum and Paris mycorrhizal structures. •  Surveyed root material was sectioned both longitudinally and transversely, double-stained and mycorrhizal structures were identified. A detailed time course experiment using four plant, and four fungal species, was used to investigate the sequential development of hyphae, arbuscules, hyphal coils, arbusculate coils and vesicles. •  The survey indicated that there was a continuum of mycorrhizal structures ranging from Arum to Paris, depending upon both the host plant and the fungus. The time course showed that total colonization increased, and that the establishment of the various mycorrhizal structures did not appear to change greatly over time. •  It was concluded that identification of fungal structures and their subsequent development into morphological types is not easily defined. Visual inspection of root squashes is not always adequate, especially where transverse sections are needed to determine if longitudinal hyphae are inter or intracellular; this is essential to distinguish intermediate types.S. Dickso