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1.
Harold C. Lyon Jr. James C. Healy James R. Bell Joseph F. O'Donnell Edward K. Shultz Robert S. Wigton Frank Hirai J. Robert Beck 《Journal of medical systems》1991,15(2):117-132
Richard E. Clark in his widely published comprehensive studies and meta-analyses of the literature on computer assisted instruction (CAI) has decried the lack of carefully controlled research, challenging almost every study which shows the computer-based intervention to result in significant post-test proficiency gains over a non-computer-based intervention. We report on a randomized study in a medical school setting where the usual confounders found by Clark to plague most research, were carefully controlled. PlanAlyzer is a microcomputer-based, self-paced, case-based, event-driven system for medical education which was developed and used in carefully controlled trials in a second year medical school curriculum to test the hypothesis that students with access to the interactive programs could integrate their didactic knowledge more effectively and/or efficiently than with access only to traditional textual “nonintelligent” materials. PlanAlyzer presents cases, elicits and critiques a student's approach to the diagnosis of two common medical disorders: anemias and chest pain. PlanAlyzer uses text, hypertext, images and critiquing theory. Students were randomized, one half becoming the experimental group who received the interactive PlanAlyzer cases in anemia, the other half becoming the controls who received the exact same content material in a text format. Later in each year there was a crossover, the controls becoming the experimentals for a similar intervention with the cardiology PlanAlyzer cases. Preliminary results at the end of the first two full trials shows that the programs have achieved most of the proposed instructional objectives, plus some significant efficiency and economy gains. 96 faculty hours of classroom time were saved by using PlanAlyzer in their place, while maintaining high student achievement. In terms of student proficiency and efficiency, the 328 students in the trials over two years were able to accomplish the project's instructional objectives, and the experimentals accomplished this in 43% less time than the controls, achieving the same level of mastery. However, in spite of these significant efficiency findings, there have been no significant proficiency differences (as measured by current factual and higher order multiple choice post-tests) between the experimental and control groups. Very careful controls were used to avoid what Clark has found to be the most common confounders of CAI research. Accordingly, this research proved Clark's rival hypothesis, that the computer, in itself, does not appear to contribute to proficiency gains, at least as measured by our limited post-testing. Clark's position is that the computer is primarily a vehicle—as is either a pill or a hypodermic needle for delivering a drug. The hypodermic needle can deliver the drug more efficiently than can the pill, (as can the computer deliver the subject matter content more efficiently, as our research indicates), but the same content is delivered. At the same time, we proved our own hypothesis, as far as efficiency gains resulting from the computer are concerned. However, going beyond Clark's research, we may be teaching processes both more effectively and efficiently with the computer (experience in problem-solving or clinical reasoning and pattern recognition) which our current post-tests do not adequately measure. Our on-going research suggests additional inquiry in several areas: better evaluation instruments to measure the clinical reasoning skills PlanAlyzer was designed to teach; the addition of more advanced cases to determine if this might transform efficiency gains of the computer group into proficiency gains; the addition of enhanced graphic decision support tools and other pedagogical enhancements including cognitive feedback to strengthen PlanAlyzer's power to teach complex concepts of medical decision-making. 相似文献
2.
Although fully explored in larger animals, the role of injection site and sample microsphere content on variability of coronary blood flow (CBF) measurement using the microsphere technique remains controversial in rats despite the fact that this species is extensively used in cardiovascular research. We therefore investigated these variables in two studies. In a first study, we established that the precision of the method, assessed by the variability of four simultaneous CBF determinations, was a function of the sample microsphere number. Coefficient of variation (CV) averaged 4-10% when the tissue and reference samples received greater than 1000 and greater than 100 spheres, respectively, and did not improve appreciably with larger numbers of microspheres. In a second study, flow CV was measured following left atrial (LA) or left ventricular (LV) microsphere injections performed nearly simultaneously in the same conscious animal or in two similar groups of animals. CBF variability was lower by 22-62% after LA than after LV injections. Estimates obtained from separate analysis of the main variability components indicated that, with one exception, the variability associated with LV injections was at least 1.4 to 2.8 times higher than that due to LA injections. These findings establish the minimum number of microspheres needed to obtain precise blood flow determinations in the rat model and confirm previous reports, in anaesthetised rats, that LA microsphere injections generally yield more precise coronary blood flow determinations than LV injections. 相似文献
3.
Tsungai Chipato MRCOG David L. Healy PhD FRACOG Beverley Vollenhoven MRACOG Helen M. Buckler MRCP 《The Australian & New Zealand journal of obstetrics & gynaecology》1991,31(4):383-384
We present these 3 cases to alert others to the possibility of severe pain with rapid shrinkage of fibroids occurring during LHRH analogue treatment. We suggest management of such events should not be surgical except for vaginal excision of prolapsed fibroid polyps. 相似文献
4.
An improved method was devised to measure lysozyme secreted from human neutrophils [polymorphonuclear leukocyte (PMN)] using a microtiter plate reader capable of analyzing enzyme kinetics. The assay is an adaptation of the classical photometric method which detects changes in the turbidity of a bacterial suspension, Micrococcus lysodeikticus, caused by the enzymatic activity of lysozyme. A standard curve using chicken egg white lysozyme was generated, and activity was detectable between the range of 1 and 100 ng/ml. Leukotriene B4 (LTB4)-induced lysozyme release from human PMN was comparable in both the standard assay and the microtiter plate adaptation with EC50 values of 6.5 and 7.2 nM, respectively. Other select stimuli and their receptor antagonists were also used to evaluate the method. Dose-response curves for chemotactic hexapeptide (CHP), recombinant human C5a (rhC5a), and platelet-activating factor (PAF) resulted in EC50 values of 0.14, 0.80, and 542.00 nM, respectively. Inhibition of lysozyme release was studied using receptor antagonists N-t-Boc-L-methionyl-L-leucyl-L-phenylalanine (N-t-Boc), LY223982, and protamine, which are putative inhibitors of formyl peptides (i.e., CHP), LTB4, and C5a, respectively. N-t-Boc inhibited CHP-induced (0.2 nM) enzyme release with an IC50 of 2 microM; LY223982 blocked LTB4-induced (20 nM) release resulting in an IC50 of 52 nM; and protamine inhibited rhC5a-induced (1.5 nM) release with an IC50 of 2 microM. Further studies revealed that CHP, LTB4, and rhC5a were selectively inhibited by their respective antagonists, albeit LY223982 and protamine were also weak inhibitors of CHP and LTB4, respectively.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
5.
L A Jeans T Gilchrist D Healy 《Journal of plastic, reconstructive & aesthetic surgery》2007,60(12):1302-1308
In this study, a new technique for the repair of divided peripheral nerves using a flexible controlled-release glass wrap is described and its successful use is reported. Corglaes is a biodegradable and biocompatible glass which, when used as a solid glass tube form as a nerve conduit, allows nerve regeneration. It is now produced as a flexible, porous wrap (CRG-wrap). In this study, the CRG-wrap was used to repair divided median nerves in the upper forelimb of sheep. The wrap was secured in place around the divided nerve ends using fibrin glue or 6/0 polyglactin sutures. Microsurgical epineurial suturing was used to repair the same injury in another group. Twelve sheep were used in each group. A control group of sheep, on which no operations had been carried out, was also examined. The outcome of each repair was assessed at 7 months by measuring transcutaneous stimulated jitter (TSJ), maximum conduction velocity (CVmax), wet muscle mass and morphometric measurements. Testing was carried out on the limb that had been operated upon and the normal contralateral forelimb. The ratio of the measurements taken in the operated and the normal limb (the right and left forelimbs in the control group) was used when carrying out statistical analyses on the results. The mean and variance of the ratios of each of the measured variables in the three repair groups were similar suggesting that nerve regeneration had occurred to a similar degree in all the repair groups (analyses were carried out using one-way ANOVA and Scheffé's test, with statistical significance assumed at p<0.05). The repair of peripheral nerves using the CRG-wrap is easy to learn, quicker and cheaper than microsurgical epineurial suturing, and can be carried out by any surgeon with basic surgical skills. It was concluded that CRG-wrap is a useful alternative to microsurgical epineurial suturing for the repair of peripheral nerves. 相似文献
6.
In vitro characterization of peptide-modified p(AAm-co-EG/AAc) IPN-coated titanium implants. 总被引:1,自引:0,他引:1
Thomas A Barber Lara J Gamble David G Castner Kevin E Healy 《Journal of orthopaedic research》2006,24(7):1366-1376
Interpenetrating polymer networks (IPNs) of poly(acrylamide-co-ethylene glycol/acrylic acid) [p(AAm-co-EG/AAc)] functionalized with an -Arg-Gly-Asp- containing peptide derived from rat bone sialoprotein [bsp-RGD(15)] were grafted to titanium implants in an effort to modulate osteoblast behavior in vitro. Surface characterization data were consistent with the presence of an IPN, and ligand density measurements established that the range of peptide density on the modified implants spanned three orders of magnitude (0.01-20 pmol/cm2). In vitro biological characterization of the modified implants employing the primary rat calvarial osteoblast (RCO) model resulted in the identification of a critical ligand density (0.01相似文献
7.
Intravenous anaesthesia for cystoscopy: a comparison of propofol or methohexitone with alfentanil 总被引:2,自引:0,他引:2
Sixty out-patients undergoing cystoscopy were allocated randomly into two groups. No premedication was given. Induction of anaesthesia was preceded by intravenous alfentanil 7 micrograms kg-1 given over 20 s, followed by methohexitone 1.5-2 mg kg-1 or propofol 2 mg kg-1, given over 20 s. Anaesthesia was maintained by increments of alfentanil, methohexitone or propofol, given as required. 相似文献
8.
J. Healy 《Australasian journal on ageing》1989,8(2):5-8
‘Ageing’ is a popular multidisciplinary semester-length option, taken by undergraduate students in the School of Social Sciences. The discipline contributions come mainly from Geography, Psychology and Social Administration. The emphasis is upon a social sciences education about ageing rather than the provision of vocational training. The topic particularly attracts women and older students who generally achieve good results. 相似文献
9.
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