ABSTRACT
One of the most important principles of scientific endeavour is that the results be reproducible from lab to lab. Although research groups rarely redo the published experiments of their colleagues, research plans almost always rely on the work of someone else. The assumption is that if the same experiment were repeated in another lab, results would be so similar that the same interpretation would be favoured. This notion allows one researcher to compare his/her own results to earlier work from other labs. An essential prerequisite for this is that the experiments are done in identical conditions and therefore the methodology must be clearly stated. While this may be scientific common sense, adherence is difficult because "standard" methods vary from one laboratory to another in subtle ways that are often not reported. More importantly, for many years the field ofyeast meiotic recombination considered typical differences to be innocuous. This chapter will highlight the documented environmental and genetic variables that are known to influence meiotic recombination in Saccharomyces cerevisiae. Other potential methodological sources of variation in meiotic experiments are also discussed. A careful assessment of the effects of these variables, has led to insights into our understanding of the control of recombination and meiosis.
Subject(s)
Environment , Epistasis, Genetic/physiology , Meiosis/genetics , Saccharomyces cerevisiae/genetics , Cell Culture Techniques , Food , Genetic Variation/physiology , Organisms, Genetically Modified , Spores, Fungal/physiologyABSTRACT
BACKGROUND: Thrombolytic therapy with urokinase 5000 units has been the standard therapy for the restoration of thrombosed central catheters. However, with the decreased availability of urokinase, alternatives needed to be sought. The aim of the study was to determine the efficacy, bioactivity, dwell time and cost of cryopreserved recombinant tissue plasminogen activator (rTPA) in the restoration of occluded central venous access devices. MATERIALS AND METHODS: For children < 10 kg, a dose of 0.5 mg, and for children >10 kg, a dose of 1mg was used. The dwell time was 1-2 hours. RESULTS: Of the 40 courses of rTPA, 39 fully restored central venous line patency (97%). Successful courses were instilled for an average of 1 hour. CONCLUSION: Cryopreserved rTPA appears to be safe and effective in the dose used to restore the patency of occluded central venous access devices in pediatric oncology patients.
