Training professionals for real-world application of required knowledge and skills and assessing their competence are major challenges. Simulations are being used in education and training to enhance understanding, improve performance, and assess competence. Validated virtual reality (VR) simulations provide a means of making experiential learning reproducible and reusable. Advanced communication networks, such as Internet2 Access Grid, allow dissemination of these simulations and collaborative learning independent of distance. The prior experiences of our three universities led to an interdisciplinary collaboration to further develop and evaluate an integrated, fully immersive, interactive VR based system. This environment employs simulations that are visually three-dimensional and are driven dynamically by a rules-based artificial intelligence engine within Flatland, a virtual environments development software tool, and associated commodity hardware. Studies include usability and validation, deployment for distributed testing over Internet2, and evaluation of impact on training and performance using concept mapping and knowledge structure methods. Subject matter experts found face and content validity in our closed head injury simulation. Seven pairs of medical students participated collaboratively in problem solving and managing of the simulated patient in VR. Students stated that opportunities to make mistakes and repeat actions in VR were extremely helpful in learning specific principles and they felt more engaged than in standard text-based scenarios. 48 students participated in knowledge structure experiments pre and post simulation experiences. Knowledge structure relatedness ratings were significantly improved in those students with lower pre-VR relatedness ratings indicating a potential value of VR simulation in learning. This research cuts across the integration of computing, networking, human-computer interfaces, learning, and knowledge acquisition. VR creates a safe environment to make mistakes and could allow rapid deployment for just-in-time training or performance assessment.

Medical knowledge and skills essential for tomorrow's healthcare professionals continue to change faster than ever before creating new demands in medical education. Project TOUCH (Telehealth Outreach for Unified Community Health) has been developing methods to enhance learning by coupling innovations in medical education with advanced technology in high performance computing and next generation Internet2 embedded in virtual reality environments (VRE), artificial intelligence and experiential active learning. Simulations have been used in education and training to allow learners to make mistakes safely in lieu of real-life situations, learn from those mistakes and ultimately improve performance by subsequent avoidance of those mistakes. Distributed virtual interactive environments are used over distance to enable learning and participation in dynamic, problem-based, clinical, artificial intelligence rules-based, virtual simulations. The virtual reality patient is programmed to dynamically change over time and respond to the manipulations by the learner. Participants are fully immersed within the VRE platform using a head-mounted display and tracker system. Navigation, locomotion and handling of objects are accomplished using a joy-wand. Distribution is managed via the Internet2 Access Grid using point-to-point or multi-casting connectivity through which the participants can interact. Medical students in Hawaii and New Mexico (NM) participated collaboratively in problem solving and managing of a simulated patient with a closed head injury in VRE; dividing tasks, handing off objects, and functioning as a team. Students stated that opportunities to make mistakes and repeat actions in the VRE were extremely helpful in learning specific principles. VRE created higher performance expectations and some anxiety among VRE users. VRE orientation was adequate but students needed time to adapt and practice in order to improve efficiency. This was also demonstrated successfully between Western Australia and UNM. We successfully demonstrated the ability to fully immerse participants in a distributed virtual environment independent of distance for collaborative team interaction in medical simulation designed for education and training. The ability to make mistakes in a safe environment is well received by students and has a positive impact on their understanding, as well as memory of the principles involved in correcting those mistakes. Bringing people together as virtual teams for interactive experiential learning and collaborative training, independent of distance, provides a platform for distributed "just-in-time" training, performance assessment and credentialing. Further validation is necessary to determine the potential value of the distributed VRE in knowledge transfer, improved future performance and should entail training participants to competence in using these tools.

We have developed a new preparation for in vivo visualization of the glomerular microcirculation, the vas afferens and the vas efferens. This preparation utilizes postischemic hydronephrosis (PIH) to destroy the renal tubular system while preserving a portion of the cortex. In this preparation, glomeruli and associated vasculature remained intact. Observations can be made with either incident light or transillumination. The inner diameter of the vas afferens, measured within 50 microns of the glomerular vascular pole, was 7.9 +/- 0.5 microns (N = 12; SEM) while that of the vas efferens was 7.7 +/- 0.5 microns (N = 12). Both vessels were narrower adjacent to the glomerulus; minimal diameters in this region were 4.5 +/- 0.5 microns (N = 10) and 4.3 +/- 0.5 microns (N = 11), respectively. A specialized round cell, which may act as a sphincter, was seen in the vas efferens. In a second series of experiments, blood velocity was measured in the vas afferens and efferens about 100 microns from the vascular pole. Mean control velocities at these sites were 5.9 +/- 0.9 (N = 14) and 4.6 +/- 1.3 (N = 9) mm X sec-1, respectively; diameters at these same sites were 10.3 +/- 0.6 microns and 11.2 +/- 0.7. During angiotensin II infusion (first series, 0.2 to 0.4 micrograms X min-1 X kg-1, i.v.) the vas efferens in the vicinity of the glomerulus constricted by 22% whereas the corresponding vas afferens showed no consistent response. During angiotensin II infusion, the filtration fraction (GFR/RPF) may, therefore, be elevated by an increased resistance in the vas efferens, particularly at the outflow point of the glomerulus. In the second series of experiments higher dosages of angiotensin II caused vasoconstriction of both vessels, especially at sites more distant from the glomerulus. Furthermore, the new approach is suitable for observing the flow direction within single capillaries of one third to one half of the glomerulus. Therefore, for the first time it is possible to determine the real flow direction in a three-dimensional way.

The purpose of this study was to determine the acute effects of albumin infusion on blood volume and renal function in preterm infants with RDS and low total serum protein values. Ten infants (gestational age 28 to 36 weeks, body weight 0.88 to 2.46 kg) were given albumin 1 gm/kg (as 25% iv solution) over a ten-minute period. Within ten minutes after infusion was completed, total serum protein concentration, colloid osmotic pressure, and blood volume rose significantly while hematocrit fell from their preinfusion levels (P < 0.0005). Mean arterial blood pressure showed a smaller and less clear-cut increase (P < 0.05). Creatinine clearance rose significantly with infusion; even though preinfusion clearances correlated poorly with gestational age (r = 0.43), postinfusion clearances correlated well (r = 0.92). No significant rises in urinary flow rate Uosm/Posm, or free-water clearance were observed. These results indicate that albumin infusion acutely increases both blood volume and glomerular filtration in premature infants with RDS.

This study was done to determine effect of salt-poor albumin on blood volume (BV) and renal function in ten premature infants (GA 28-36 weeks, body weight 1.43 ± 0.15 SE kg) with total serum protein (TSP) < 4.5 g/dl. They were given 1 g/kg albumin as 25% salt-poor solution iv in 5-10 min. Urine was obtained in a bag applied to the infant; the bladder was creded after each voiding and when collection periods ended. Initial BV was measured using Evan's blue; changes over a 40-min period were estimated from changes in hematocrit (Hct). Mean arterial blood pressure (MABP) was continuously monitored through an umbilical arterial catheter. Serum and urine osmolarities and creatinines, TSP, colloid osmotic pressure (COP), BV, and MABP were measured and creatinine clearance (CCr) calculated before and after albumin infusion. An increase in BV from 88 ± 5 to 100 ± 8 ml/kg (P<.0005) was first observed 10 min after infusion and then remained unchanged during the study; this was paralleled by increases in TSP from 4.4 ± 0.1 to 4.8 ± 0.1 g/dl (P<.0005) and COP from 20 ± 1 to 25 ± 1 cm H2O (P<.0005). However, MABP was not significantly changed. There was an increase in CCr from .42 ± .09 to .89 ± .17 ml/min (P< .0005), but CH2O and Uosm/Posm did not significantly change. Apparently, observed changes in MABP, BV, and Hct had a greater influence in increasing GFR than increases in COP had in decreasing it. In conclusion, albumin infusion may help improve GFR in hypoproteinemic premature infants.