Implementing preanalytical automation. The right volume, the right workflow.
Explore the source record for details and available documents.
Autoanalysis↗
Biomedical subjects
R Dadoun
Publications and source records attributed to R Dadoun.
The effect of p-chlorophenylalanine on cerebral metabolism and biogenic amine content of traumatized brain.
It was shown previously that focal cortical freezing lesions in rats cause widespread decrease in local cerebral glucose utilization (LCGU) in cortical areas of the lesioned hemisphere. This was interpreted as reflecting a depression of cortical activity. It was then demonstrated that cortical serotonin (5-HT) metabolism was increased throughout the lesioned hemisphere of a focally injured brain. To find out if the changes in the serotonergic system are of functional importance and mediate the observed changes in LCGU, the effects of the inhibition of 5-HT synthesis with p-chlorophenylalanine (PCPA) on cerebral metabolism and biogenic amine content in injured brain were studied. PCPA in doses up to 300 mg/kg had little, if any, effect on LCGU in intact brain and in doses up to 100 mg/kg did not modify the depressed LCGU in injured brain. In doses of 200 and 300 mg/kg, PCPA selectively increased cortical glucose utilization in the lesioned hemisphere where it was depressed following injury. PCPA decreased 5-HT levels in the cortical and raphe areas of both intact and injured brain in a dose-dependent manner. However, at doses of PCPA ineffective on LCGU (50 and 100 mg/kg), traumatization still resulted in increased 5-HT metabolism. Doses of PCPA that ameliorated the depression of LCGU in injured brain completely prevented increases in both 5-HT and its metabolite 5-hydroxyindoleacetic acid seen following traumatization in untreated animals. These results provide evidence that decreased LCGU in lesioned brain is due to an activation of the serotonergic system by traumatization. The data are in agreement with the postulated inhibitory role of serotonin in the cortex and its involvement in functional alterations associated with injury. They suggest that blockage of this neurotransmitter system may have a potential in the development of novel therapeutic approaches to brain injury.
Animals↗
Effects of injury on the indoleamines in cerebral cortex.
It was shown previously that focal cortical freezing lesions in rats cause widespread depression of local cerebral glucose utilization (LCGU) in cortical areas of the lesioned hemisphere. This was interpreted as reflecting functional depression. The underlying mechanisms were postulated to involve alterations of biogenic amine systems. Accordingly, levels of serotonin (5-HT), its metabolite 5-hydroxyindoleacetic acid (5-HIAA), and its precursor tryptophan were determined by an HPLC method with electrochemical detection in frontoparietal cortical areas of both hemispheres at 4 h and 1, 3, 6, 8, and 10 days after a unilateral cortical freezing lesion. The 5-HT content was significantly lower than normal in the lesioned hemisphere only at 24 h, whereas the 5-HIAA level peaked at 24 h but was significantly elevated above normal values between 4 h and 6 days after lesioning. No changes were noted in 5-HT and 5-HIAA contents in the hemisphere contralateral to the lesion. These results indicate that cortical 5-HT metabolism is increased throughout the lesioned hemisphere of a focally injured brain. The increase in tryptophan content of the lesioned brain appeared to have a time course more closely related to previously demonstrated changes in cortical LCGU than to the increase in 5-HIAA content.
Animals↗
Laboratory service sharing for cost containment.
A pilot project implemented by two Montreal hospitals measured the impact on costs of sharing laboratory services for a limited number of biochemical tests while maintaining quality of care. The incremental costs of shared services were compared to the costs of the hospitals performing tests independently and to those of referring tests to another hospital laboratory. The costs of the tests were based on the average price asked by three major Montreal facilities.
Cost Savings↗
Impact on human resources: Core Laboratory versus laboratory information system versus modular robotics.
Technological advances in laboratory systems have had a great impact on human resources. Surviving the changes requires an in-depth understanding of the technology to implement the appropriate operational model. St. Mary's is a 414-bed, acute care hospital. For 18 months, the laboratories went through the process of moving from a noncomputerized traditional model laboratory (i.e., by discipline) to a fully computerized Core Lab. The Core Lab concept fully integrates biochemistry, hematology, blood bank, and microbiology into two sections (not physically separated): tests processed by automation and tests processed manually. This approach led to a 15% reduction in staff while the volume doubled. The transitions occurred sequentially: from traditional laboratory to Core Lab (noncomputerized), from manual Core Lab to fully computerized Core Lab, and ultimately from a simulation of manual preanalytical phase to automated preanalytical phase (modular robotics). The findings show that Core Lab and computerization have almost the same impact on human resources, 35% and 30% respectively, and modular robotics the least impact with 17%.
Clinical Laboratory Information Systems↗