Relating gene expression data on two-component systems to functional annotations in Escherichia coli

<p>Abstract</p> <p>Background</p> <p>Obtaining physiological insights from microarray experiments requires computational techniques that relate gene expression data to functional information. Traditionally, this has been done in two consecutive steps. The first step identifies important genes through clustering or statistical techniques, while the second step assigns biological functions to the identified groups. Recently, techniques have been developed that identify such relationships in a single step.</p> <p>Results</p> <p>We have developed an algorithm that relates patterns of gene expression in a set of microarray experiments to functional groups in one step. Our only assumption is that patterns co-occur frequently. The effectiveness of the algorithm is demonstrated as part of a study of regulation by two-component systems in <it>Escherichia coli</it>. The significance of the relationships between expression data and functional annotations is evaluated based on density histograms that are constructed using product similarity among expression vectors. We present a biological analysis of three of the resulting functional groups of proteins, develop hypotheses for further biological studies, and test one of these hypotheses experimentally. A comparison with other algorithms and a different data set is presented.</p> <p>Conclusion</p> <p>Our new algorithm is able to find interesting and biologically meaningful relationships, not found by other algorithms, in previously analyzed data sets. Scaling of the algorithm to large data sets can be achieved based on a theoretical model.</p

Synopsis methodica fungorum : sistens enumerationem omnium huc vsque detectarum specierum, cum breuibus descriptionibus nec non synonymis et obseruationibus selectis

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Composite tissue allotransplantation to treat veterans with complex amputation injuries

Amputee rehabilitation may be limited by complexity of injury (e.g. bilateral arm amputation), associated injury (e.g. colostomy) or by the level of amputation (e.g. high above knee). Our objective is to assess the potential for composite tissue allotransplantation (CTA) to overcome these barriers. Medical literature was searched and programs were surveyed regarding the current status of CTA. Results CTA remains an experimental reconstructive option that involves a large collaborative (physiatry, orthopaedic, plastic and transplant surgeons). Limb transplantation has evolved out of limb reimplantation surgery and organ transplantation. Approximately 10 programs world wide, with almost a decade of experience, report 90% success with good function. Most experience in forearm transplantation (50 grafts in 36 patients). Research in London ON, where a civilian CTA program is being developed, has demonstrated the protective effect immunologically of vascularized bone marrow so that the immunosuppressive requirements are equivalent or less than those for organ transplantation. A review of Canadian casualties suggests that relatively few will require forearm transplantation and more would benefit from above-knee leg replacement. Knee transplantation, permitting conversion to a below knee prosthesis, has been as successful as forearm transplantation. Conclusions CTA may offer options for treatment of carefully selected veterans who are motivated to take part in an experimental reconstructive program. Lay Summary: Carefully selected combat casualties with difficult amputations may be good candidates for a limb transplantation program being developed in London ON. Worldwide experience suggests forearm transplantation is very successful with relatively low immunosuppressive drug requirements. Combat casualties will require leg as well as hand transplantation

Dissertationes academicae Vpsaliae habitae svb praesidio Carol. Petr. Thvnberg ...

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