We have studied the intracellular location of glycerol-3-phosphate oxidase and NAD+-linked glycerol-3-phosphate dehydrogenase, two enzymes involved in the very active dihydroxyacetone phosphate : glycerol-3-phosphate cycle in Trypanosoma brucei. Isopycnic centrifugation of a largegranule fraction resulted in a 10-20-fold purification of the oxidase and showed that the enzyme behaved like the mitochondrial ATPase, isocitrate dehydrogenase and the particulate malate dehydrogenase. The activity profiles of these four enzymes in sucrose gradients were identical with maximal activity at a density of 1.17 g/cm3. Electron micrographs of a fraction equilibrating at this density only showed mitochondrial profiles.The particle-bound NAD+-linked glycerol-3-phosphate dehydrogenase activity was found to band at a density of 1.23 g/cm3 in sucrose. A fraction equilibrating at this density was highly enriched in microbodies; it contained few mitochondrial profiles and less than 3 % of the specific oxidase activity of the mitochondrial fraction. Because of the absence of microbody markers in T. brucei we turned to the insect trypanosome Crithidia luciliae, which contains a high activity of the microbody marker catalase. In C. luciliae part of the catalase activity bands at the same density as the particle-bound NAD +-linked glycerol-3-phosphate dehydrogenase (@ = 1.26 g/cm3).From these results we conclude that in T. brucei bloodstream forms glycerol-3-phosphate oxidase is located in the mitochondrion and not in the microbodies, as proposed by a number of other investigators, and that the particle-bound NAD+-linked glycerol-3-phosphate dehydrogenase is located within the microbodies. It is likely that this highly active dehydrogenase plays an essential role in glycolysis.
This is the third in a series of articles exploring international trends in health science librarianship in the first decade of the 21st century. The invited authors were asked to reflect on developments in their country
Background. Translational research is a complex cumulative process that takes time. However, the operating environment for cancer centers engaged in translational research is now financially insecure. Centers are challenged to improve results and reduce time from discovery to practice innovations. Performance assessment can identify improvement areas that will help reduce translational delays. Currently, no standard method exists to identify models for use in performance assessment. This study aimed to critically appraise translational research models for suitability in performance assessment of cancer centers.Methods. We conducted a systematic review to identify models and developed a set of criteria based on scientometrics, complex adaptive systems, research and development processes, and strategic evaluation. Models were assessed for linkage between research and care components, new
In this series, specifications, properties and test results of microcomputer software for information storage and retrieval are listed and compared. This article is devoted to the previously defined category of end‐user software, sometimes also referred to as bibliographic formatting software. Eight different programs have been tested and assessed: Archivist, BIB/Search, Library Master, Notebook II, Papyrus, Pro‐Cite, The Ref‐Filer and Reference Manager. All programs run under MS‐DOS, though there are also Apple Macintosh versions for Pro‐Cite and Reference Manager. For each of the eight programs about 100 facts and test results are tabulated. All the programs are individually discussed as well.
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