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PubMed2000

Speleotherapy for asthma.

BACKGROUND: Speleotherapy, the use of subterranean environments, is a therapeutic measure in the treatment of chronic obstructive airways diseases. It is virtually unknown in the UK or the US, but has considerable widespread use in some Central and Eastern European countries. OBJECTIVES: To review evidence for the efficacy of speleotherapy in the treatment of asthma. SEARCH STRATEGY: We searched electronic databases (Medline, Embase, Cochrane Airways group database), contacted speleotherapy centres and experts in the field, hand searched proceedings, and checked bibliographies of articles obtained to identify possible relevant publications. SELECTION CRITERIA: We included controlled clinical trials (i.e., both randomized and those not reporting the method of allocation) that compared clinical effects of speleotherapy with another intervention or no intervention in patients with chronic asthma. DATA COLLECTION AND ANALYSIS: Information concerning patients, interventions, results, and methodology were extracted in standardized manner by two independent reviewers and summarized descriptively. MAIN RESULTS: Three trials including a total of 124 asthmatic children met the inclusion criteria, but only one trial had reasonable methodological quality. Two trials reported that speleotherapy had a beneficial short-term effect on lung function. Other outcomes could not be assessed in a reliable manner. REVIEWER'S CONCLUSIONS: The available evidence does not permit a reliable conclusion as to whether speleo-therapeutic interventions are effective for the treatment of chronic asthma. Randomized controlled trials with long-term follow-up are necessary.

Air Ionization↗
PubMed2005

Virtual surgical telesimulations in otolaryngology.

Distance learning can be enhanced with the use of virtual reality; this paper describes the design and initial validation of a Web Environment for Surgery Skills Training on Otolaryngology (WESST-OT). WESST-OT was created aimed to help trainees to gain the skills required in order to perform the Functional Endoscopic Sinus Surgery procedure (FESS), since training centers and specialist in this knowledge are scarce in Colombia; also, it is part of a web based educational cycle which simulates the stages of a real procedure. WESST-OT is one from the WESST family of telesimulators which started to be developed from an architecture proposed at the Medicine Meets Virtual Reality conference 2002; also, it is a step towards the use of virtual reality technologies in Latin America.

Colombia↗
PubMed2006

Challenges to the development of complex virtual reality surgical simulations.

Virtual reality simulation in surgical training has become more widely used and intensely investigated in an effort to develop safer, more efficient, measurable training processes. The development of virtual reality simulation of surgical procedures has begun, but well-described technical obstacles must be overcome to permit varied training in a clinically realistic computer-generated environment. These challenges include development of realistic surgical interfaces and physical objects within the computer-generated environment, modeling of realistic interactions between objects, rendering of the surgical field, and development of signal processing for complex events associated with surgery. Of these, the realistic modeling of tissue objects that are fully responsive to surgical manipulations is the most challenging. Threats to early success include relatively limited resources for development and procurement, as well as smaller potential for return on investment than in other simulation industries that face similar problems. Despite these difficulties, steady progress continues to be made in these areas. If executed properly, virtual reality offers inherent advantages over other training systems in creating a realistic surgical environment and facilitating measurement of surgeon performance. Once developed, complex new virtual reality training devices must be validated for their usefulness in formative training and assessment of skill to be established.

Computer Simulation↗
PubMed2006

Wikis, blogs and podcasts: a new generation of Web-based tools for virtual collaborative clinical practice and education.

BACKGROUND: We have witnessed a rapid increase in the use of Web-based 'collaborationware' in recent years. These Web 2.0 applications, particularly wikis, blogs and podcasts, have been increasingly adopted by many online health-related professional and educational services. Because of their ease of use and rapidity of deployment, they offer the opportunity for powerful information sharing and ease of collaboration. Wikis are Web sites that can be edited by anyone who has access to them. The word 'blog' is a contraction of 'Web Log' - an online Web journal that can offer a resource rich multimedia environment. Podcasts are repositories of audio and video materials that can be "pushed" to subscribers, even without user intervention. These audio and video files can be downloaded to portable media players that can be taken anywhere, providing the potential for "anytime, anywhere" learning experiences (mobile learning). DISCUSSION: Wikis, blogs and podcasts are all relatively easy to use, which partly accounts for their proliferation. The fact that there are many free and Open Source versions of these tools may also be responsible for their explosive growth. Thus it would be relatively easy to implement any or all within a Health Professions' Educational Environment. Paradoxically, some of their disadvantages also relate to their openness and ease of use. With virtually anybody able to alter, edit or otherwise contribute to the collaborative Web pages, it can be problematic to gauge the reliability and accuracy of such resources. While arguably, the very process of collaboration leads to a Darwinian type 'survival of the fittest' content within a Web page, the veracity of these resources can be assured through careful monitoring, moderation, and operation of the collaborationware in a closed and secure digital environment. Empirical research is still needed to build our pedagogic evidence base about the different aspects of these tools in the context of medical/health education. SUMMARY AND CONCLUSION: If effectively deployed, wikis, blogs and podcasts could offer a way to enhance students', clinicians' and patients' learning experiences, and deepen levels of learners' engagement and collaboration within digital learning environments. Therefore, research should be conducted to determine the best ways to integrate these tools into existing e-Learning programmes for students, health professionals and patients, taking into account the different, but also overlapping, needs of these three audience classes and the opportunities of virtual collaboration between them. Of particular importance is research into novel integrative applications, to serve as the "glue" to bind the different forms of Web-based collaborationware synergistically in order to provide a coherent wholesome learning experience.

Audiovisual Aids↗
PubMed2002

Determination of spatial position of multiple targets by ultrasonic binaural method.

The binaural technique used in ultrasonic sonars has a higher performance speed in comparison with a mechanically scanned ultrasonic beam, however, in presence of multiple targets meets a very serious ambiguity problem. In this case the number of targets detected exceeds the actual number of targets, e.g., there are additional non-existing targets found. Objective of this research was development of a simulation tool enabling to model multi-channel sonar in the environment with multiple targets of arbitrary geometry and development of robust signal processing procedures, suitable for detection of multiple targets from the data collected using the binaural method. The developed software enables to simulate operation of multi-channel sonar in an environment with multiple reflectors and predict a time history of the reflected signals. The novel algorithm for separation of real targets from the virtual ones in presence of multiple targets has been developed. Performance of the proposed algorithm was investigated both in the simulated and a real environment. The results obtained indicate a significant improvement of the sonar performance.

Journal Article↗
PubMed2006

[Dynamic VRML for training in medicine].

Experimenting in medicine can be accomplished by virtual reality system. VRML is a tool to build virtual object and scenes which can realize static and animated applications in medicine. However, to creat a real environment, the demanded level of interactivity and dynamics is difficult to achieve. In this paper we describe some approaches and techniques which can realize dynamic 3D. Our demonstration is based on the implementation of a virtual baby model, whose character can be accomplished by external JAVA applications.

Computer Simulation↗
PubMed2004

Creating a virtual sanctuary for scholars.

When people work together digitally, material can be added to a safe shared environment at anytime and can be accessed anywhere. The solutions generate new questions and new problems that then become interconnected. Cultivating this new and rapidly evolving technology of peer-to-peer platforms (1) may prove to be an extremely cost effective way to solve complex institutional or individual dilemmas. The solutions reflect the richness of two or more protected and engaged scholars or institutions working together with a refined degree of connection. After all, as Philip Condit, the CEO of the Boeing Company is often quoted as saying ... "none of us is as smart as all of us." The path to global connection hinges on relationships that are made and sustained one at a time. Progress together along the path similarly is made one step at a time. Sustained progress requires compelling reasons to do this in ways that are consonant with what it means to be human.

Academic Medical Centers↗
PubMed1999

Microphthalmic mice display a B cell deficiency similar to that seen for mast and NK cells.

The microphthalmic mouse (mi) possesses a 3-bp deletion of the Mi gene that alters the DNA binding site of the transcription factor gene product. This animal has diminished numbers of NK and mast cells (MC) and is osteopetrotic due to a lack of the normal complement of functional osteoclasts. The reduction of MC has been proposed to be due to the lack of adequate c-Kit expression that is required for MC differentiation. However, data from other labs has questioned this interpretation. In this report, we present data suggesting bone marrow-derived deficiencies of the mi mouse are not due to a lack of c-Kit expression and function, but instead due to an inhospitable environment within the bone marrow itself. Specifically, we have found that such animals also lack virtually all B cell precursors within the marrow and rely upon other lymphatic sites, such as the spleen, for B cell development and maturation. Although the animal has depressed numbers of NK cells, B cells, and MC, it still possesses a normal thymus and peripheral T cells. Therefore, the block in cellular differentiation must be within the marrow environment, which is essential for maturing B cells, NK cells, and MC but not T cells.

Animals↗
PubMed1994

Human interface technology. An essential tool for the modern surgeon.

Human interface technology is a new science which must be understood by all surgeons in order to cope with the ever-increasing complexity of surgical practice. This science is the understanding of how humans comprehend, interact, and use the world around them. The increasing use of robotics, computers, and virtual reality depend upon this technology to create a "user-friendly" environment to be able to assimilate the massive amount of data and images and to "naturally" interact with machines and computers. Through careful implementation, more complex systems will become easier to use and enhance the surgeon--the technology must adapt to the surgeon, not the reverse.

General Surgery↗
PubMed1996

Virtual resource development in the glycosciences.

The development of Internet-based virtual resources is a relatively new area of scientific and technical activity that is currently undergoing rapid expansion. Major factors fuelling recent growth include the emergence of multimedia capabilities through the rapid evolution of the World Wide Web, the reduction in cost of high quality personal computers and graphics workstations and the provision of mass-marketed provider services. Prior to 1995 the presence of Internet resources in the glycosciences was virtually non-existent. Existing scientific knowledge was primarily made available on the Net through the provision of databases from gopher and ftp sites. A particular example in the glycosciences is the Carbbank database of biological carbohydrate sequences. We will describe here our efforts in 1994-95 in establishing The Glycoscience Network (TGN, http:@ bellatrix.pcl.ox.ac.uk/TGN/). These activities included the establishment of a newsgroup, mailing lists, Web resources and the running of the First Electronic Glycoscience Conference (EGC-1, http:@bellatrix.pcl.ox.ac.uk/egc/). EGC-1 included many novel initiatives in the glycosciences including electronic posters and papers, a Virtual Conference Centre, a Web-based hyperglossary, Virtual Trade and Employment Centres, refereed electronic publishing, and the creation of a Virtual Reality Gallery. We would like to look towards the near future and discuss several initiatives in virtual resource creation that we believe will have significant scientific impact on the glycosciences including the development of bioinformatics-based servers, sophisticated interactive databases, and videoconferencing. Furthermore, we cherish the belief that these resources will foster international scientific collaboration and progress of an extent never previously possible. Finally, we indulge in speculation and make some suggestions on the form and long-term impact of Glycoscience Virtual Resources. We predict that their development may completely reconstruct the scientific environment that we work in as scientists and we reflect on the probable benefits and pitfalls to be encountered.

Carbohydrates↗
PubMed1987

Brain neurons develop in a serum and glial free environment: effects of transferrin, insulin, insulin-like growth factor-I and thyroid hormone on neuronal survival, growth and differentiation.

We have developed a pure cortical neuronal culture free of glial cells, grown in a serum-free environment. The cultured cells immunostained positively with neurofilament antibody while they displayed virtually no glial cell characteristics, such as glial fibrillary acidic protein, glycerol phosphate dehydrogenase or glutamine synthetase. Insulin and transferrin were necessary and sufficient for neuronal survival, neurite extension and glutamic acid decarboxylase (GAD) expression. Insulin-like growth factor-I was able to replace insulin and was active close to its physiological concentration, suggesting it might be the in vivo factor influencing neuronal growth in the brain. The dynamics of the developmental process were striking. The neurons moved on the poly-D-lysine covered plastic dish, and rearrangements in contacts between cells were observed. At first the neurons underwent a general cellular growth manifested by a large increase in the culture total protein content and by the initiation of neurites. A more specific differentiation, as indicated by the sharp increase in GAD levels which was concurrent with an increase in interneuronal contacts, lagged behind the initial growth. Thyroid hormone (TH) affected the differentiation process, causing a future increase in GAD levels during the same time of increase in neurite growth, in interneuronal contacts, in thyroid hormone receptors and thyroid gland maturation. Removal of each of the hormones after a few days of cell growth revealed that transferrin was still required for neuronal survival while insulin became essential for general cellular growth but not specific neuronal differentiation, since it caused an increase in both the total protein and GAD levels but not in GAD specific activity. TH, on the other hand, affected the differentiation process as evident by its ability to increase GAD specific activity. This action of TH, however, required the presence of insulin, without which no increase in GAD level by TH was observed. This neuronal culture, glial and serum-free, provides a new system for investigating neuronal development and function in the complex mammalian central nervous system.

Animals↗
PubMed2006

The use of virtual patients to teach medical students history taking and communication skills.

BACKGROUND: At most institutions, medical students learn communication skills through the use of standardized patients (SPs), but SPs are time and resource expensive. Virtual patients (VPs) may offer several advantages over SPs, but little data exist regarding the use of VPs in teaching communication skills. Therefore, we report our initial efforts to create an interactive virtual clinical scenario of a patient with acute abdominal pain to teach medical students history-taking and communication skills. METHODS: In the virtual scenario, a life-sized VP is projected on the wall of an examination room. Before the virtual encounter, the student reviews patient information on a handheld tablet personal computer, and they are directed to take a history and develop a differential diagnosis. The virtual system includes 2 networked personal computers (PCs), 1 data projector, 2 USB2 Web cameras to track the user's head and hand movement, a tablet PC, and a microphone. The VP is programmed with specific answers and gestures in response to questions asked by students. The VP responses to student questions were developed by reviewing videotapes of students' performances with real SPs. After obtaining informed consent, 20 students underwent voice recognition training followed by a videotaped VP encounter. Immediately after the virtual scenario, students completed a technology and SP questionnaire (Maastricht Simulated Patient Assessment). RESULTS: All participants had prior experience with real SPs. Initially, the VP correctly recognized approximately 60% of the student's questions, and improving the script depth and variability of the VP responses enhanced most incorrect voice recognition. Student comments were favorable particularly related to feedback provided by the virtual instructor. The overall student rating of the virtual experience was 6.47 +/- 1.63 (1 = lowest, 10 = highest) for version 1.0 and 7.22 +/- 1.76 for version 2.0 (4 months later) reflecting enhanced voice recognition and other technological improvements. These overall ratings compare favorably to a 7.47 +/- 1.16 student rating for real SPs. CONCLUSIONS: Despite current technological limitations, virtual clinical scenarios could provide students a controllable, secure, and safe learning environment with the opportunity for extensive repetitive practice with feedback without consequence to a real or SP.

Clinical Competence↗
PubMed1992

Definition and display of steric, hydrophobic, and hydrogen-bonding properties of ligand binding sites in proteins using Lee and Richards accessible surface: validation of a high-resolution graphical tool for drug design.

The accessible surface, described by Lee and Richards (the L&R surface: J. Mol. Biol. 1971, 55, 379), has remarkably useful properties for displaying ligand-protein interactions. The surface is placed one van der Waals radius plus one probe radius away from the protein atoms. The ligands are displayed in skeletal form. With a suitable probe radius, those parts of the ligand in good van der Waals contact with the protein binding site are found superimposed on the L&R surface. Display of the surface using parallel contours therefore provides a very powerful guide for interactive drug design because only ligand atoms lying on or close to the surface are in low-energy contact. The ability of the surface to accurately display steric complementarity between ligands and proteins was optimized using data from small molecule crystal structures. The possibility of displaying the chemical specificity of the binding site was also investigated. The surface can be colored to give precise information about chemical specificity. Electrostatic potential, electrostatic gradient, and distance to hydrogen-bonding groups were tested as methods of displaying chemical specificity. The ability of these methods to describe the complementarity actually observed in the interior of proteins was compared. High-resolution crystal data for ribonuclease and trypsin was used. The environment surrounding extended peptide chains in the protein was treated as a virtual binding site. The peptide chain served as a virtual ligand. This large sample of experimental data was used to measure the correlation between type of ligand atom and the calculated property of the nearest binding site surface. The best correlation was obtained using hydrogen-bonding properties of the binding site. Using this parameter the surface could be divided into three separate zones representing the hydrophobic, hydrogen-bond-acceptor, and hydrogen-bond-donor properties of the binding site. The percentage of hydrophobic ligand atoms found to lie closest to the hydrophobic protein surface was 91%. The equivalent scores for ligand hydrogen-acceptor atoms and hydrogen-donor atoms found at the corresponding complementarity zone were 94% and 91%. The surface zones can be readily displayed using three colors. To test the method on real ligand/binding site interactions, nine thermolysin-inhibitor complexes of known structure were evaluated using the parameters and criteria derived from the protein-packing study and a correlation between complementary contacts and logarithm of potency was obtained which had an r2 of 0.99.(ABSTRACT TRUNCATED AT 400 WORDS)

Binding Sites↗
PubMed2002

Virtual reality training improves operating room performance: results of a randomized, double-blinded study.

OBJECTIVE: To demonstrate that virtual reality (VR) training transfers technical skills to the operating room (OR) environment. SUMMARY BACKGROUND DATA: The use of VR surgical simulation to train skills and reduce error risk in the OR has never been demonstrated in a prospective, randomized, blinded study. METHODS: Sixteen surgical residents (PGY 1-4) had baseline psychomotor abilities assessed, then were randomized to either VR training (MIST VR simulator diathermy task) until expert criterion levels established by experienced laparoscopists were achieved (n = 8), or control non-VR-trained (n = 8). All subjects performed laparoscopic cholecystectomy with an attending surgeon blinded to training status. Videotapes of gallbladder dissection were reviewed independently by two investigators blinded to subject identity and training, and scored for eight predefined errors for each procedure minute (interrater reliability of error assessment r > 0.80). RESULTS: No differences in baseline assessments were found between groups. Gallbladder dissection was 29% faster for VR-trained residents. Non-VR-trained residents were nine times more likely to transiently fail to make progress (P <.007, Mann-Whitney test) and five times more likely to injure the gallbladder or burn nontarget tissue (chi-square = 4.27, P <.04). Mean errors were six times less likely to occur in the VR-trained group (1.19 vs. 7.38 errors per case; P <.008, Mann-Whitney test). CONCLUSIONS: The use of VR surgical simulation to reach specific target criteria significantly improved the OR performance of residents during laparoscopic cholecystectomy. This validation of transfer of training skills from VR to OR sets the stage for more sophisticated uses of VR in assessment, training, error reduction, and certification of surgeons.

Cholecystectomy, Laparoscopic↗
PubMed1979

Radiographic comparison of human lung shape during normal gravity and weightlessness.

Human lung shape was measured during zero gravity (0 G) to decide whether the normal vertical regional differences in ventilation are due directly to distortion of the elastic lung by its own weight, or instead, due indirectly to the effect of gravity on the shape of the rib cage and diaphragm. This was important because we previously established that weightlessness virtually abolishes the normal topographical inequality of ventilation (J. Appl. Physiol.: Respirat. Environ. Exercise Physiol. 45: 987-998, 1978). Chest radiographs were made after 10 s of a weightless flight trajectory aboard a NASA-Ames Research Center Learjet in both posterior-anterior and left lateral projections on five seated volunteers at residual volume, functional residual capacity, and total lung capacity. Lung shape was assessed by measuring lung heights and widths in upper, middle, and lower lung regions. We found no significant differences between any of the normal gravity (1 G) and o G measurements, although there was a slight tendency for the lung to become shorter and wider at o G (mean changes generally less than 3% or about 0.5 cm). By contrast, Grassino et al. (J. Appl. Physiol. 39: 997-1003, 1975) found no change in the vertical distribution of ventilation after voluntarily changing lung dimensions by more than 1 cm by moving the abdomen in or out. We conclude that gravity produces the topographical distribution of ventilation in the upright human lung by distorting the elastic lung tissue within the chest rather than by altering the shape of the rib cage and diaphragm.

Humans↗
PubMed1997

Biospecific polymers: recognition of phosphorylated polystyrene derivatives by anti-DNA antibodies.

The recognition of DNA-like phosphorylated polymers by anti-DNA antibodies from the plasma of systemic lupus erythematosus patients was evidenced a few years ago by our research group. However, the radioimmunological Farr assay used for the assessment of anti-DNA antibodies adsorption was not sensitive enough to give accurate results, particularly in the case of weak levels of antibodies. An alternative method based on the use of radiolabelled species was set up in order to check the validity of previous results. Polystyrene resins with different levels in phosphate groups substitution were assessed with regard to their interactions with anti-DNA antibodies. Results show that the anti-DNA antibodies affinity is dependent on the composition of the polymers and reaches a maximum for a composition of 17.5-22.5 mol of phosphorus per 100 mol of monomeric units. This composition corresponds to the DNA-like polymer previously described. A computer-assisted method was used in order to have an insight into the structure of the active sites responsible for the DNA-like behaviour of this polymer. Numerical simulations of the phosphorylation reaction were performed using a Monte Carlo method, taking the structure predictions and the environment of the phosphorylated units into account. A number of thus generated virtual polymers correlated with the experimental results of the adsorption of anti-DNA antibodies. The chemical structure of the active site was determined by computations introducing selected hypotheses on the structure of the phosphorylated units. Moreover, since the number of active sites is directly related to the number of adsorbed anti-DNA antibodies in the experimental results, the most probable structure of the active sites is proposed and compared to a fragment of DNA. Conclusions are that the distances between the phosphate groups in the active sites of the DNA-like polymer and in the DNA fragment are similar. Optimal conditions for the purification of SLE sera by highly specific liquid chromatography using phosphorylated polystyrene resins of precise compositions as stationary phases can thus be envisaged, as well as a new method for the detection of anti-DNA antibodies.

Adsorption↗
PubMed2002

Virtual reality-augmented rehabilitation for patients following stroke.

BACKGROUND AND PURPOSE: Recent evidence indicates that intensive massed practice may be necessary to modify neural organization and effect recovery of motor skills in patients following stroke. Virtual reality (VR) technology has the capability of creating an interactive, motivating environment in which practice intensity and feedback can be manipulated to create individualized treatments to retrain movement. CASE DESCRIPTION: Three patients (ML, LE, and DK), who were in the chronic phase following stroke, participated in a 2-week training program (3 1/2 hours a day) including dexterity tasks on real objects and VR exercises. The VR simulations were targeted for range of motion, movement speed, fractionation, and force production. OUTCOMES: ML's function was the most impaired at the beginning of the intervention, but showed improvement in the thumb and fingers in range of motion and speed of movement. LE improved in fractionation and range of motion of his thumb and fingers. DK made the greatest gains, showing improvement in range of motion and strength of the thumb, velocity of the thumb and fingers, and fractionation. Two of the 3 patients improved on the Jebsen Test of Hand Function. DISCUSSION: The outcomes suggest that VR may be useful to augment rehabilitation of the upper limb in patients in the chronic phase following stroke.

Aged↗
PubMed2005

Reconstruction of human optic nerve heads for finite element modeling.

PURPOSE: Glaucoma is a common ocular disease whose pathogenesis is hypothesized to involve biomechanical damage to optic nerve tissues. Here we describe a method for the construction of patient-specific models that can be used to evaluate the biomechanical environment within the optic nerve head. We validate the method using a virtual eye, and demonstrate its use in computing optic nerve head biomechanics. METHODS: Human eyes were imaged and the optic nerve head region was processed to allow serial plastic histologic sections to be cut. These sections were photographed, unwarped and aligned so as to reconstruct three-dimensional patient-specific models incorporating sclera, pre- and post-laminar nerve, lamina cribrosa, and pia mater. Deformations, stresses and strains were computed in the resulting model using finite element techniques. RESULTS: The approach successfully reconstructed patient-specific optic nerve head models. Reconstruction of a virtual eye showed excellent agreement between the true and reconstructed geometries, and between the deformations and strains computed on the true and reconstructed geometries. A sample reconstruction showed reasonable agreement between computed and measured retinal surface deformations. CONCLUSION: The technique presented here is viable and can be used to accurately compute human optic nerve head biomechanics.

Biomechanical Phenomena↗