Myra Joyce - Academia.edu (original) (raw)
Papers by Myra Joyce
Int J Radiat Oncol Biol Phys, 1993
To develop and clinically test a remote sensing system capable of real time monitoring of patient... more To develop and clinically test a remote sensing system capable of real time monitoring of patient position, reporting variations in patient setup from day to day, as well as motion during an individual treatment.
Faseb J, Mar 10, 1991
Ozone induces an inflammatory response in humans. The purpose of this study was to assess the rol... more Ozone induces an inflammatory response in humans. The purpose of this study was to assess the role of epithelial cells in this response. The authors exposed the bronchial epithelial cell line BEAS cultured on collagen-impregnated filters to air or varying concentrations of Oâ. Fluid obtained from either apical or basolateral compartments was analyzed for various inflammatory mediators and other products
The Journal of Neuroscience the Official Journal of the Society For Neuroscience, Jun 15, 1998
Interactions between dopamine and glutamate play prominent roles in memory, addiction, and schizo... more Interactions between dopamine and glutamate play prominent roles in memory, addiction, and schizophrenia. Several lines of evidence have suggested that the ventral midbrain dopamine neurons that give rise to the major CNS dopaminergic projections may also be glutamatergic. To examine this possibility, we double immunostained ventral midbrain sections from rat and monkey for the dopamine-synthetic enzyme tyrosine hydroxylase and for glutamate; we found that most dopamine neurons immunostained for glutamate, both in rat and monkey. We then used postnatal cell culture to examine individual dopamine neurons. Again, most dopamine neurons immunostained for glutamate; they were also immunoreactive for phosphateactivated glutaminase, the major source of neurotransmitter glutamate. Inhibition of glutaminase reduced glutamate staining. In single-cell microculture, dopamine neurons gave rise to varicosities immunoreactive for both tyrosine hydroxylase and glutamate and others immunoreactive mainly for glutamate, which were found near the cell body. At the ultrastructural level, dopamine neurons formed occasional dopaminergic varicosities with symmetric synaptic specializations, but they more commonly formed nondopaminergic varicosities with asymmetric synaptic specializations. Stimulation of individual dopamine neurons evoked a fast glutamatergic autaptic EPSC that showed presynaptic inhibition caused by concomitant dopamine release. Thus, dopamine neurons may exert rapid synaptic actions via their glutamatergic synapses and slower modulatory actions via their dopaminergic synapses. Together with evidence for glutamate cotransmission in serotonergic raphe neurons and noradrenergic locus coeruleus neurons, the present results suggest that glutamatergic cotransmission may be the rule for central monoaminergic neurons.
The TRMI gene of Saccharomyces cerevisiae codes for a tRNA modification enzyme, N2,N2-dimethylgua... more The TRMI gene of Saccharomyces cerevisiae codes for a tRNA modification enzyme, N2,N2-dimethylguanosine-specific tRNA methyltransferase (m2Gtase), shared by mitochondria and nuclei. Immunofluorescent staining at the nuclear periphery demonstrates that m22Gtase localizes at or near the nuclear membrane. In determining sequences necessary for targeting the enzyme to nuclei and mitochondria, we found that information required to deliver the enzyme to the nucleus is not sufficient for its correct subnuclear localization. We also determined that mislocalizing the enzyme from the nucleus to the cytoplasm does not destroy its biological function. This change in location was caused by altering a sequence similar to other known nuclear targeting signals (KKSKKKRC), suggesting that shared enzymes are likely to use the same import pathway as proteins that localize only to the nucleus. As with other well-characterized mitochondrial proteins, the mitochondrial import of the shared methyltransferase depends on amino-terminal amino acids, and removal of the first 48 amino acids prevents its import into mitochondria. While this truncated protein is still imported into nuclei, the immunofluorescent staining is uniform throughout rather than at the nuclear periphery, a staining pattern identical to that described for a fusion protein consisting of the first 213 amino acids of m2Gtase in frame with 13-galactosidase. As both of these proteins together contain the entire m2Gtase coding region, the information necessary for association with the nuclear periphery must be more complex than the short linear sequence necessary for nuclear localization.
Molecular and Cellular Probes, Dec 31, 1990
In this report a rapid, simple and economical means of preparing a cDNA probe of specified length... more In this report a rapid, simple and economical means of preparing a cDNA probe of specified length, sequence and specific activity is described . The process involves the use of a polymerase chain reaction to incorporate radiolabelled nucleotides into a single stranded or double stranded cDNA sequence . A pair of oligonucleotide primers are synthesized, flanking the sense and antisense strands of a selected sequence . The primers are then used with a cloned DNA fragment or a cellular source of RNA or DNA as a template to amplify the specific gene sequence . The sequence to be used as a probe is selected from the known sequence using free energy calculations of the secondary structure . The calculation of free energy predicts regions of stable secondary structure which may hinder transcription and thus are to be avoided . By selecting the distance between primers the probe length can be controlled to allow adequate probe permeability into tissue samples . The specific region of the gene sequence can be chosen to differentiate between closely related sequences by avoiding areas of homology. Altering the concentration of a radiolabelled nucleotide allows direct control of probe specific activity . The use of asymmetric PCR allows the preferential generation of an antisense single stranded cDNA sequence for a higher sensitivity in the detection of low abundance mRNA .
European Journal of Ultrasound, 1997
We have investigated velocity measurements applying phase spectral analysis and a cross correlati... more We have investigated velocity measurements applying phase spectral analysis and a cross correlation technique to calculate the phase and mean pulse velocity in a series of fixed human os calces. The group velocity was also calculated using the slope of the phase velocity as a function of frequency and found to be in the range 1500 1520 m.s ~.
Bone Marrow Transplant, 1997
The Journal of neuroscience : the official journal of the Society for Neuroscience, Jan 15, 1998
Interactions between dopamine and glutamate play prominent roles in memory, addiction, and schizo... more Interactions between dopamine and glutamate play prominent roles in memory, addiction, and schizophrenia. Several lines of evidence have suggested that the ventral midbrain dopamine neurons that give rise to the major CNS dopaminergic projections may also be glutamatergic. To examine this possibility, we double immunostained ventral midbrain sections from rat and monkey for the dopamine-synthetic enzyme tyrosine hydroxylase and for glutamate; we found that most dopamine neurons immunostained for glutamate, both in rat and monkey. We then used postnatal cell culture to examine individual dopamine neurons. Again, most dopamine neurons immunostained for glutamate; they were also immunoreactive for phosphate-activated glutaminase, the major source of neurotransmitter glutamate. Inhibition of glutaminase reduced glutamate staining. In single-cell microculture, dopamine neurons gave rise to varicosities immunoreactive for both tyrosine hydroxylase and glutamate and others immunoreactive m...
AMIA ... Annual Symposium proceedings / AMIA Symposium. AMIA Symposium, Jan 6, 2008
As a strategy to increase the use of the National Cancer Institute's Cancer Information Servi... more As a strategy to increase the use of the National Cancer Institute's Cancer Information Service (CIS) resources by nurses and patients, we integrated tobacco-related CIS resources into an existing mobile decision support system. We then evaluated nurses' use and perceptions of usefulness of context-specific access to CIS resources and of patient referrals to CIS resources-information prescriptions.
BMC neuroscience, Jan 30, 2006
The striatal complex is the major target of dopamine action in the CNS. There, medium-spiny GABAe... more The striatal complex is the major target of dopamine action in the CNS. There, medium-spiny GABAergic neurons, which constitute about 95% of the neurons in the area, form a mutually inhibitory synaptic network that is modulated by dopamine. When put in culture, the neurons reestablish this network. In particular, they make autaptic connections that provide access to single, identified medium-spiny to medium-spiny neuron synaptic connections. We examined medium-spiny neuron autaptic connections in postnatal cultures from the nucleus accumbens, the ventral part of the striatal complex. These connections were subject to presynaptic dopamine modulation. D1-like receptors mediated either inhibition or facilitation, while D2-like receptors predominantly mediated inhibition. Many connections showed both D1 and D2 modulation, consistent with a significant functional colocalization of D1 and D2-like receptors at presynaptic sites. These same connections were subject to GABAA, GABAB, norepine...
Journal of Pediatric Hematology/Oncology, 2000
AMIA ... Annual Symposium proceedings / AMIA Symposium. AMIA Symposium, Jan 6, 2008
Based on criteria for assessing the quality of health information extracted from a review of the ... more Based on criteria for assessing the quality of health information extracted from a review of the literature, we expanded the DISCERN instrument by adding 14 questions. New questions addressed language of the web-based health information resource, level of readability of the resource, and usability of the web page or portal for the resource.
Osteoporosis International, 1999
Some studies have reported low bone mineral density (BMD) in patients with Addison's disease, whe... more Some studies have reported low bone mineral density (BMD) in patients with Addison's disease, whereas others have found BMD to be normal. It is possible that over-replacement of corticosteroids and adrenal androgen deficiency may contribute to a reduction in BMD in these patients. The aims of this study were to examine BMD using dual-energy X-ray absorptiometry in patients with treated Addison's disease at multiple skeletal sites and to investigate the relationships between these measurements and corticosteroid dose. Nineteen men, 3 premenopausal and 7 postmenopausal women with Addison's disease were studied and data from these patients were analyzed separately and as a group. The mean SEM age and duration of Addison's disease of the men were 44 + 3.8 years and 15 + 2.2 years, in the premenopausal women 40 + 2 years and 5 + 2.4 years, and in the postmenopausal women 68 + 4 years and 20 + 5 years, respectively. Eight men were unexpectedly hypogonadal (serum testosterone <13 nmol/l). BMD was expressed as a percent of values in normal controls (n = 418) adjusted for age, sex, ethnic origin, menopausal status and body weight. In the whole group (n = 29), mean BMD of the patients with Addison's disease was not different from normal at any site [mean (+ SEM) lumbar spine 99.5% + 2.9%; femoral neck 99.3% + 2.5%; Ward's triangle 96.2% + 3.5%; trochanter 99.2% + 2.9%; radius 99.8% + 2.1%; total body 98.5% + 1.4%]. However, there was a wide range of bone densities, with some patients having a low BMD at multiple sites. Bone density was negatively correlated with current and cumulative corticosteroid dose per kilogram body weight and duration of Addison's disease. In conclusion, BMD in patients with Addison's disease is little different from normal, but may be lower in patients with disease of long duration and a high cumulative corticosteroid dose. Unexpected hypogonadism in men with Addison's disease is common.
Medical Physics, 2010
ABSTRACT Purpose: Increasing the source to image‐receptor distance (SID) for radiological exposur... more ABSTRACT Purpose: Increasing the source to image‐receptor distance (SID) for radiological exposures is an effective yet under‐utilized optimization technique. Although several studies have demonstrated that dose reductions are achievable using this technique, there is little agreement in the literature as to the precise mechanism behind this reduction. The objective of the current work was to investigate the mechanisms through which SID reduces dose by use of a physical attenuator methodology and to examine the combined effect of this with collimation. Method and Materials: A total of 810 dosimetry measurements were acquired using thermoluminescent dosimeters. Exposures of a homogeneous attenuator composed of poly methyl meth‐acrylate were taken with a GE tube at 90kVp using SIDs of 100cm; 130cm and 150cm respectively. As field size is a known contributor to patient dose three different collimation strategies were also considered: collimating to the outer surface; collimating to the mid‐point and collimating to the image‐receptor. Results: A significant difference was determined for each of the SIDs tested (p<0.001) with a trend of decreasing dose with increasing SID. Reductions in the ratio of the dose recorded at the image‐receptor to that at a position 30cm from the image‐receptor were found to be between 3.9% and 37.9% for 150cm and between 7.5% and 30.6% for 130cm respectively when compared to 100cm. Conclusion: Results from this study demonstrate that increasing the SID above 100cm reduces the dose to a 30cm object as the ratio of the dose at the entrance surface to that at the exit point is reduced with increasing SID. This reduction in dose with increasing SID is exclusive of patient size or collimation method. Further work will investigate if anthropomorphic phantom and patient based studies produce equivalent results. Radiographers should be strongly encouraged to increase the SID above 100cm in the clinical setting.
Annals of Emergency Medicine, 2007
Annals of Emergency Medicine, 2009
The authors' goal was to determine the rate at which emergency physicians document confirmation o... more The authors' goal was to determine the rate at which emergency physicians document confirmation of endotracheal tube (ET) placement. The study was conducted in a 60 000-visit emergency department (ED) of an urban tertiary referral hospital. The authors' airway registry database was used to identify patients requiring airway management; 433 patients met study criteria, 281 (65%) were intubated in the ED, and 152 (35%) were intubated prior to arrival. ET confirmation was documented for 270 (96%) patients intubated in the ED and 52 (34%) patients intubated before arrival (P < .0001). The rate was higher for patients intubated by emergency medical services (40/64 [63%]) than for interhospital transfers (12/88 [14%]) (P < .0001). Documentation of ET placement has implications for patient care and safety. This study indicates that educational interventions are warranted to improve physicians' awareness of the importance of documenting correct tube placement.
This study used heuristic evaluation to identify usability issues of a Web-based prototype for a ... more This study used heuristic evaluation to identify usability issues of a Web-based prototype for a personal digital assistant-based decision support system (PDA-DSS) for the management of obesity. Three usability experts evaluated the prototype using heuristics, scenarios, and ...
Studies in health technology and informatics, 2006
The number of health sciences educational programs that are integrating personal digital assistan... more The number of health sciences educational programs that are integrating personal digital assistants (PDAs) into their curricula is on the rise. In this paper, we report an evaluation of the usefulness of a PDA-based advanced practice nursing (APN) student clinical log through faculty stakeholder exemplars in three areas: pediatric asthma care; procedures of Acute Care Nurse Practitioner (NP) students; and diagnostic and screening procedures of Women's Health NP students. We generated descriptive data through routine queries and through custom SQL queries at the request of a specific faculty member who wished to examine a particular aspect of an educational program. In addition, we discussed the potential implications of the data with the respective faculty members. The exemplars provide evidence that faculty stakeholders found the APN student clinical log to be useful for a variety of purposes including monitoring of student performance, benchmarking, and quality of care assessm...
Int J Radiat Oncol Biol Phys, 1993
To develop and clinically test a remote sensing system capable of real time monitoring of patient... more To develop and clinically test a remote sensing system capable of real time monitoring of patient position, reporting variations in patient setup from day to day, as well as motion during an individual treatment.
Faseb J, Mar 10, 1991
Ozone induces an inflammatory response in humans. The purpose of this study was to assess the rol... more Ozone induces an inflammatory response in humans. The purpose of this study was to assess the role of epithelial cells in this response. The authors exposed the bronchial epithelial cell line BEAS cultured on collagen-impregnated filters to air or varying concentrations of Oâ. Fluid obtained from either apical or basolateral compartments was analyzed for various inflammatory mediators and other products
The Journal of Neuroscience the Official Journal of the Society For Neuroscience, Jun 15, 1998
Interactions between dopamine and glutamate play prominent roles in memory, addiction, and schizo... more Interactions between dopamine and glutamate play prominent roles in memory, addiction, and schizophrenia. Several lines of evidence have suggested that the ventral midbrain dopamine neurons that give rise to the major CNS dopaminergic projections may also be glutamatergic. To examine this possibility, we double immunostained ventral midbrain sections from rat and monkey for the dopamine-synthetic enzyme tyrosine hydroxylase and for glutamate; we found that most dopamine neurons immunostained for glutamate, both in rat and monkey. We then used postnatal cell culture to examine individual dopamine neurons. Again, most dopamine neurons immunostained for glutamate; they were also immunoreactive for phosphateactivated glutaminase, the major source of neurotransmitter glutamate. Inhibition of glutaminase reduced glutamate staining. In single-cell microculture, dopamine neurons gave rise to varicosities immunoreactive for both tyrosine hydroxylase and glutamate and others immunoreactive mainly for glutamate, which were found near the cell body. At the ultrastructural level, dopamine neurons formed occasional dopaminergic varicosities with symmetric synaptic specializations, but they more commonly formed nondopaminergic varicosities with asymmetric synaptic specializations. Stimulation of individual dopamine neurons evoked a fast glutamatergic autaptic EPSC that showed presynaptic inhibition caused by concomitant dopamine release. Thus, dopamine neurons may exert rapid synaptic actions via their glutamatergic synapses and slower modulatory actions via their dopaminergic synapses. Together with evidence for glutamate cotransmission in serotonergic raphe neurons and noradrenergic locus coeruleus neurons, the present results suggest that glutamatergic cotransmission may be the rule for central monoaminergic neurons.
The TRMI gene of Saccharomyces cerevisiae codes for a tRNA modification enzyme, N2,N2-dimethylgua... more The TRMI gene of Saccharomyces cerevisiae codes for a tRNA modification enzyme, N2,N2-dimethylguanosine-specific tRNA methyltransferase (m2Gtase), shared by mitochondria and nuclei. Immunofluorescent staining at the nuclear periphery demonstrates that m22Gtase localizes at or near the nuclear membrane. In determining sequences necessary for targeting the enzyme to nuclei and mitochondria, we found that information required to deliver the enzyme to the nucleus is not sufficient for its correct subnuclear localization. We also determined that mislocalizing the enzyme from the nucleus to the cytoplasm does not destroy its biological function. This change in location was caused by altering a sequence similar to other known nuclear targeting signals (KKSKKKRC), suggesting that shared enzymes are likely to use the same import pathway as proteins that localize only to the nucleus. As with other well-characterized mitochondrial proteins, the mitochondrial import of the shared methyltransferase depends on amino-terminal amino acids, and removal of the first 48 amino acids prevents its import into mitochondria. While this truncated protein is still imported into nuclei, the immunofluorescent staining is uniform throughout rather than at the nuclear periphery, a staining pattern identical to that described for a fusion protein consisting of the first 213 amino acids of m2Gtase in frame with 13-galactosidase. As both of these proteins together contain the entire m2Gtase coding region, the information necessary for association with the nuclear periphery must be more complex than the short linear sequence necessary for nuclear localization.
Molecular and Cellular Probes, Dec 31, 1990
In this report a rapid, simple and economical means of preparing a cDNA probe of specified length... more In this report a rapid, simple and economical means of preparing a cDNA probe of specified length, sequence and specific activity is described . The process involves the use of a polymerase chain reaction to incorporate radiolabelled nucleotides into a single stranded or double stranded cDNA sequence . A pair of oligonucleotide primers are synthesized, flanking the sense and antisense strands of a selected sequence . The primers are then used with a cloned DNA fragment or a cellular source of RNA or DNA as a template to amplify the specific gene sequence . The sequence to be used as a probe is selected from the known sequence using free energy calculations of the secondary structure . The calculation of free energy predicts regions of stable secondary structure which may hinder transcription and thus are to be avoided . By selecting the distance between primers the probe length can be controlled to allow adequate probe permeability into tissue samples . The specific region of the gene sequence can be chosen to differentiate between closely related sequences by avoiding areas of homology. Altering the concentration of a radiolabelled nucleotide allows direct control of probe specific activity . The use of asymmetric PCR allows the preferential generation of an antisense single stranded cDNA sequence for a higher sensitivity in the detection of low abundance mRNA .
European Journal of Ultrasound, 1997
We have investigated velocity measurements applying phase spectral analysis and a cross correlati... more We have investigated velocity measurements applying phase spectral analysis and a cross correlation technique to calculate the phase and mean pulse velocity in a series of fixed human os calces. The group velocity was also calculated using the slope of the phase velocity as a function of frequency and found to be in the range 1500 1520 m.s ~.
Bone Marrow Transplant, 1997
The Journal of neuroscience : the official journal of the Society for Neuroscience, Jan 15, 1998
Interactions between dopamine and glutamate play prominent roles in memory, addiction, and schizo... more Interactions between dopamine and glutamate play prominent roles in memory, addiction, and schizophrenia. Several lines of evidence have suggested that the ventral midbrain dopamine neurons that give rise to the major CNS dopaminergic projections may also be glutamatergic. To examine this possibility, we double immunostained ventral midbrain sections from rat and monkey for the dopamine-synthetic enzyme tyrosine hydroxylase and for glutamate; we found that most dopamine neurons immunostained for glutamate, both in rat and monkey. We then used postnatal cell culture to examine individual dopamine neurons. Again, most dopamine neurons immunostained for glutamate; they were also immunoreactive for phosphate-activated glutaminase, the major source of neurotransmitter glutamate. Inhibition of glutaminase reduced glutamate staining. In single-cell microculture, dopamine neurons gave rise to varicosities immunoreactive for both tyrosine hydroxylase and glutamate and others immunoreactive m...
AMIA ... Annual Symposium proceedings / AMIA Symposium. AMIA Symposium, Jan 6, 2008
As a strategy to increase the use of the National Cancer Institute's Cancer Information Servi... more As a strategy to increase the use of the National Cancer Institute's Cancer Information Service (CIS) resources by nurses and patients, we integrated tobacco-related CIS resources into an existing mobile decision support system. We then evaluated nurses' use and perceptions of usefulness of context-specific access to CIS resources and of patient referrals to CIS resources-information prescriptions.
BMC neuroscience, Jan 30, 2006
The striatal complex is the major target of dopamine action in the CNS. There, medium-spiny GABAe... more The striatal complex is the major target of dopamine action in the CNS. There, medium-spiny GABAergic neurons, which constitute about 95% of the neurons in the area, form a mutually inhibitory synaptic network that is modulated by dopamine. When put in culture, the neurons reestablish this network. In particular, they make autaptic connections that provide access to single, identified medium-spiny to medium-spiny neuron synaptic connections. We examined medium-spiny neuron autaptic connections in postnatal cultures from the nucleus accumbens, the ventral part of the striatal complex. These connections were subject to presynaptic dopamine modulation. D1-like receptors mediated either inhibition or facilitation, while D2-like receptors predominantly mediated inhibition. Many connections showed both D1 and D2 modulation, consistent with a significant functional colocalization of D1 and D2-like receptors at presynaptic sites. These same connections were subject to GABAA, GABAB, norepine...
Journal of Pediatric Hematology/Oncology, 2000
AMIA ... Annual Symposium proceedings / AMIA Symposium. AMIA Symposium, Jan 6, 2008
Based on criteria for assessing the quality of health information extracted from a review of the ... more Based on criteria for assessing the quality of health information extracted from a review of the literature, we expanded the DISCERN instrument by adding 14 questions. New questions addressed language of the web-based health information resource, level of readability of the resource, and usability of the web page or portal for the resource.
Osteoporosis International, 1999
Some studies have reported low bone mineral density (BMD) in patients with Addison's disease, whe... more Some studies have reported low bone mineral density (BMD) in patients with Addison's disease, whereas others have found BMD to be normal. It is possible that over-replacement of corticosteroids and adrenal androgen deficiency may contribute to a reduction in BMD in these patients. The aims of this study were to examine BMD using dual-energy X-ray absorptiometry in patients with treated Addison's disease at multiple skeletal sites and to investigate the relationships between these measurements and corticosteroid dose. Nineteen men, 3 premenopausal and 7 postmenopausal women with Addison's disease were studied and data from these patients were analyzed separately and as a group. The mean SEM age and duration of Addison's disease of the men were 44 + 3.8 years and 15 + 2.2 years, in the premenopausal women 40 + 2 years and 5 + 2.4 years, and in the postmenopausal women 68 + 4 years and 20 + 5 years, respectively. Eight men were unexpectedly hypogonadal (serum testosterone <13 nmol/l). BMD was expressed as a percent of values in normal controls (n = 418) adjusted for age, sex, ethnic origin, menopausal status and body weight. In the whole group (n = 29), mean BMD of the patients with Addison's disease was not different from normal at any site [mean (+ SEM) lumbar spine 99.5% + 2.9%; femoral neck 99.3% + 2.5%; Ward's triangle 96.2% + 3.5%; trochanter 99.2% + 2.9%; radius 99.8% + 2.1%; total body 98.5% + 1.4%]. However, there was a wide range of bone densities, with some patients having a low BMD at multiple sites. Bone density was negatively correlated with current and cumulative corticosteroid dose per kilogram body weight and duration of Addison's disease. In conclusion, BMD in patients with Addison's disease is little different from normal, but may be lower in patients with disease of long duration and a high cumulative corticosteroid dose. Unexpected hypogonadism in men with Addison's disease is common.
Medical Physics, 2010
ABSTRACT Purpose: Increasing the source to image‐receptor distance (SID) for radiological exposur... more ABSTRACT Purpose: Increasing the source to image‐receptor distance (SID) for radiological exposures is an effective yet under‐utilized optimization technique. Although several studies have demonstrated that dose reductions are achievable using this technique, there is little agreement in the literature as to the precise mechanism behind this reduction. The objective of the current work was to investigate the mechanisms through which SID reduces dose by use of a physical attenuator methodology and to examine the combined effect of this with collimation. Method and Materials: A total of 810 dosimetry measurements were acquired using thermoluminescent dosimeters. Exposures of a homogeneous attenuator composed of poly methyl meth‐acrylate were taken with a GE tube at 90kVp using SIDs of 100cm; 130cm and 150cm respectively. As field size is a known contributor to patient dose three different collimation strategies were also considered: collimating to the outer surface; collimating to the mid‐point and collimating to the image‐receptor. Results: A significant difference was determined for each of the SIDs tested (p<0.001) with a trend of decreasing dose with increasing SID. Reductions in the ratio of the dose recorded at the image‐receptor to that at a position 30cm from the image‐receptor were found to be between 3.9% and 37.9% for 150cm and between 7.5% and 30.6% for 130cm respectively when compared to 100cm. Conclusion: Results from this study demonstrate that increasing the SID above 100cm reduces the dose to a 30cm object as the ratio of the dose at the entrance surface to that at the exit point is reduced with increasing SID. This reduction in dose with increasing SID is exclusive of patient size or collimation method. Further work will investigate if anthropomorphic phantom and patient based studies produce equivalent results. Radiographers should be strongly encouraged to increase the SID above 100cm in the clinical setting.
Annals of Emergency Medicine, 2007
Annals of Emergency Medicine, 2009
The authors' goal was to determine the rate at which emergency physicians document confirmation o... more The authors' goal was to determine the rate at which emergency physicians document confirmation of endotracheal tube (ET) placement. The study was conducted in a 60 000-visit emergency department (ED) of an urban tertiary referral hospital. The authors' airway registry database was used to identify patients requiring airway management; 433 patients met study criteria, 281 (65%) were intubated in the ED, and 152 (35%) were intubated prior to arrival. ET confirmation was documented for 270 (96%) patients intubated in the ED and 52 (34%) patients intubated before arrival (P < .0001). The rate was higher for patients intubated by emergency medical services (40/64 [63%]) than for interhospital transfers (12/88 [14%]) (P < .0001). Documentation of ET placement has implications for patient care and safety. This study indicates that educational interventions are warranted to improve physicians' awareness of the importance of documenting correct tube placement.
This study used heuristic evaluation to identify usability issues of a Web-based prototype for a ... more This study used heuristic evaluation to identify usability issues of a Web-based prototype for a personal digital assistant-based decision support system (PDA-DSS) for the management of obesity. Three usability experts evaluated the prototype using heuristics, scenarios, and ...
Studies in health technology and informatics, 2006
The number of health sciences educational programs that are integrating personal digital assistan... more The number of health sciences educational programs that are integrating personal digital assistants (PDAs) into their curricula is on the rise. In this paper, we report an evaluation of the usefulness of a PDA-based advanced practice nursing (APN) student clinical log through faculty stakeholder exemplars in three areas: pediatric asthma care; procedures of Acute Care Nurse Practitioner (NP) students; and diagnostic and screening procedures of Women's Health NP students. We generated descriptive data through routine queries and through custom SQL queries at the request of a specific faculty member who wished to examine a particular aspect of an educational program. In addition, we discussed the potential implications of the data with the respective faculty members. The exemplars provide evidence that faculty stakeholders found the APN student clinical log to be useful for a variety of purposes including monitoring of student performance, benchmarking, and quality of care assessm...