A cross-platform model for secure Electronic Health Record communication

During the past decade, there have been many regional, national and European projects focused on the development of platforms for secure access and sharing of distributed patient information. A platform is needed because present local or enterprise-wide information systems are typically not intended for cross-organisational secure access of patient data. Most of the present secure platforms are local or regional. Commonly used platform types in the health care environment vary from secure point-to-point communication systems to internet-based portals. This paper defines an enhanced cross-security platform which makes it possible for different kinds of local, regional, and national health information systems to communicate in a secure way. The proposed evolutionary way interconnects regional or national security domains with the help of a cross-platform zone. A more revolutionary model based on peer-to-peer Grid like networks and dynamic security credentials is also discussed. The proposed evolutionary model uses cross-domain security and interoperability services to ensure secure communication and interoperability between different security domains. The platform supports both communication defined beforehand and adhoc dynamic access to distributed electronic health records (EHRs). The internet is proposed as the "glue" between different regional or national security domains.     

A new rabbit model for study of lung preservation

In 1983,Cooper successfully performed the first case of right lung transplantation for a patient with end stage pulmonary fibrosis and long survival was achieved,which confirmed that lung transplantation is feasible clinically.The efficient lung transplantation has become the only hope for patients with end stage lung disease since.It′s crucial for the success of lung transplantation that the harvest and protection of the donor′s lung prior to transplantation.The preservation of donor′s lung is key for the function after lung transplantation.Apart from hypothermic approach,the perfusion procedure and the perfusion solution itself are also very important.The aim of this study was to establish an animal model,which could identify the effectiveness of preservation solution that could minimize the disturbance of the non-experimental factors so as to find the better preservation solution for lung protection.     

A model for normothermic preservation of the rat liver

Current techniques for the preservation of donor livers typically rely on cold temperatures (approximately 0-4 degrees C) to slow down metabolic processes. Recently, normothermic extracorporeal liver perfusion (NELP) has regained interest as a potentially promising approach for long-term liver preservation. Unlike cold-storage techniques, NELP attempts to maintain the liver in a near physiological environment, thus enabling normal metabolic and tissue repair processes to take place, which may help in the recovery of ischemically damaged and fatty donor livers, both of which represent significant untapped sources of donor livers. However, NELP is technically more complex than cold-storage techniques, and the lack of standardized small animal models limits its development. Here we describe a rat NELP system that is simple and cost-effective to run. We show that rat livers that underwent NELP for 6 h could be routinely transplanted into syngeneic recipient rats with excellent 1-month survival. During perfusion, the release of cytosolic enzymes, bile and urea production, and oxygen uptake rate could be readily monitored, thus providing a comprehensive picture of hepatic function before transplantation. This system will help in the optimization of NELP in several ways, such as for the improvement of perfusion conditions and the development of quantitative metabolic criteria for hepatic viability.     

Collaborative deliberation: A model for patient care

Objective

Existing theoretical work in decision making and behavior change has focused on how individuals arrive at decisions or form intentions. Less attention has been given to theorizing the requirements that might be necessary for individuals to work collaboratively to address difficult decisions, consider new alternatives, or change behaviors. The goal of this work was to develop, as a forerunner to a middle range theory, a conceptual model that considers the process of supporting patients to consider alternative health care options, in collaboration with clinicians, and others.

Methods

Theory building among researchers with experience and expertise in clinician–patient communication, using an iterative cycle of discussions.

Results

We developed a model composed of five inter-related propositions that serve as a foundation for clinical communication processes that honor the ethical principles of respecting individual agency, autonomy, and an empathic approach to practice. We named the model ‘collaborative deliberation.’ The propositions describe: (1) constructive interpersonal engagement, (2) recognition of alternative actions, (3) comparative learning, (4) preference construction and elicitation, and (5) preference integration.

Conclusions

We believe the model underpins multiple suggested approaches to clinical practice that take the form of patient centered care, motivational interviewing, goal setting, action planning, and shared decision making.     

A three-compartment model for the transport and distribution of Hippuran.

It is generally believed that after an intravenous injection of Hippuran its concentration in the plasma can be described as the sum of two exponentials. However, by collecting samples during the first minute after injection of the tracer, a third exponential term was found with a half-life of less than one minute. To explain its presence it was assumed that the plasma shares its Hippuran with two peripheral compartments, the rate of transfer from one compartment to another being proportional to the amount in the first of them. The proportionality factors have been determined for 20 adults and averaged. Substituting these averages in the differential equations for the distribution process, the only variable remaining is the renal excretion rate a (the fraction of plasma cleared per minute by the kidneys). If this procedure, which appears to be justified by the experimental results, is correct the shape of the plasma curve will be determined exclusively by a. It is shown that the (small) third compartment has a minor influence on the shape of the renogram curves.     

A multiray model for calculating electron pencil beam distribution

Based on the Fermi-Eyges theory, a set of recursion relations was derived for calculating electron distributions in the layered geometry. The electron distribution at a specific depth was obtained by convolving the upstream electron distribution with a kernel determined by the scattering parameters of the layer. Modifications were made to overcome some inherent limitations of the Fermi-Eyges theory. For each point in the medium, the most probable, or mean, path traversed by the electrons in reaching the point was derived. The skewness of the mean paths and the related energy degradation were included in a multiray model for pencil beam calculations. The resultant electron planar fluence distributions are no longer Gaussian as predicted by the original theory. The effects of edges or localized inhomogeneities are also included. Comparisons between our calculations and Monte Carlo simulations show good agreement.     

A two-fluid model for hematocrit distribution in microvascular networks

A new theoretical network model for evaluating discharge hematocrits, explicitly based on plasma skimming at branches, is introduced. The particular network geometry chosen simulates bat wing microvasculature. Blood in vessels is approximated to be a two fluid with red cell suspension as the core and a plasma layer surrounding it. The plasma layer width depends on hematocrit, which leads to nonlinear hydrodynamic equations solved by iteration. Discharge hematocrit distributions are calculated by a computer for five generations of vessels. Dispersion of hematocrit values was found to be correlated to plasma skimming at branches. Contrary to previous suggestions, plasma skimming did not result in lowered mean hematocrit towards the capillaries. Network structure was found to be an important factor affecting the hematocrits. Mean discharge hematocrit remained steady against changes in vessel dimensions, capillary resistances, red cell concentration in plasma layer, and shape of the separation surface defining the streamlines entering the side branch. This high stable mean hematocrit is based on symmetry of the model network. Enhanced asymmetry tended to lower the hematocrit.     

Filter paper for preservation, storage, and distribution of insect and pathogen DNA samples

Proper DNA storage is critical for studies involving genetic analysis of insects and for molecular diagnostics of pathogens carried by them. Molecular surveillance of pathogens carried by insects can involve screening of thousands of insect DNA samples. Problems with storage and degradation of these samples can arise. In this study, a simple filter paper-based method for storage and preservation of insect DNA was evaluated using polymerase chain reaction (PCR). DNA was isolated from individual house fly, Musca domestica L., adults by using a cell lysis technique. From 50 house flies known to carry Campylobacter spp., a portion of the DNA sample was stored frozen and another portion was pipetted onto filter paper. At monthly intervals for 7 mo, PCR was conducted using 1 microl of the frozen DNA sample and a 2.0-mm disk from the filter paper samples as the PCR template. Two markers were used, a 450-bp region of the insect mitochondrial DNA (mtDNA) ND5 gene and a 857-bp region of the Campylobacter spp. mtDNA 16S rDNA gene. PCR amplification was successful for all of the samples regardless of the storage method. The filter paper method is a simple and economical way to store, preserve, and distribute DNA samples for PCR analysis.     

A systematic approach for analysis and design of secure health information systems

A toolset using object-oriented techniques including the nowadays popular unified modelling language (UML) approach has been developed to facilitate the different users' views for security analysis and design of health care information systems. Paradigm and concepts used are based on the component architecture of information systems and on a general layered security model. The toolset was developed in 1996/1997 within the ISHTAR project funded by the European Commission as well as through international standardisation activities. Analysing and systematising real health care scenarios, only six and nine use case types could be found in the health and the security-related view, respectively. By combining these use case types, the analysis and design of any thinkable system architecture can be simplified significantly. Based on generic schemes, the environment needed for both communication and application security can be established by appropriate sets of security services and mechanisms. Because of the importance and the basic character of electronic health care record (EHCR) systems, the understanding of the approach is facilitated by (incomplete) examples for this application.     

A mathematical model for correcting patient setup errors using a tilt and roll device

An algorithm is presented for determining how to adjust the actuators of a tilt and roll table. The algorithm is based on a geometrical model of the table, which was designed with six degrees of freedom. This design and algorithm allows complete translational and rotational corrections to be applied to the target volume position on a daily basis.     

A field test of the TIME patient simulation model

The Technological Innovations in Medical Education (TIME) Project has created an interactive videodisc patient-simulation model that provides faculty with a new method for patient-centered teaching in the medical school classroom. The TIME model is designed to be controlled by a professor in the classroom setting, and incorporates voice recognition technology and video dramatization to create a believable patient encounter. Under the auspices of the Lister Hill National Center for Biomedical Communications, National Library of Medicine, where the Project originated in 1983, three medical schools participated in a field test of this "high-tech" model. Six faculty members made ten classroom presentations of two TIME simulations to 306 second-year medical students. The principal finding was that, in a group setting, a large majority of the students at all three schools became individually committed to the care and management of the simulated patient. They acted as if the patient's problems were real and left the session feeling as though they had interacted with an actual person. Therefore, in terms of simulating a real patient, the TIME patient-simulation model was validated, providing the basis for the development of new patient-centered methods to teach and test medical students in the classroom setting. The Project has been at the Georgetown University School of Medicine, where the model is being introduced into the existing curriculum, since 1988. It is currently being used as a part of the final examination for second-year students and in discussion-group settings for fourth-year students in the internal medicine clerkship. A field test is also under way using the TIME model to assess the clinical performance of third-year students.     

A chemically polymerized electrically conducting composite of polypyrrole nanoparticles and polyurethane for tissue engineering

A variety of cell types respond to electrical stimuli; accordingly, many conducting polymers (CPs) have been used as tissue engineering (TE) scaffolds, and one such CP is polypyrrole (PPy). PPy is a well-studied biomaterial with potential TE applications because of its electrical conductivity and many other beneficial properties. Combining its characteristics with an elastomeric material, such as polyurethane (PU), may yield a hybrid scaffold with electrical activity and significant mechanical resilience. Pyrrole was in situ polymerized within a PU emulsion mixture in weight ratios of 1:100, 1:20, 1:10, and 1:5, respectively. Morphology, electrical conductivity, mechanical properties, and cytocompatibility with C2C12 myoblast cells were characterized. The polymerization resulted in a composite with a principle base of PU interspersed with an electrically percolating network of PPy nanoparticles. As the mass ratio of PPy to PU increased so did electrical conductivity of the composites. In addition, as the mass ratio of PPy to PU increased, stiffness of the composite increased while maximum elongation length decreased. Ultimate tensile strength was reduced by ~47% across all samples with the addition of PPy to the PU base. Cytocompatibility assay data indicated no significant cytotoxic effect from the composites. Static cellular seeding of C2C12 cells and subsequent differentiation showed myotube formation on the composite materials.     

A functional model of early thyroxine distribution in man

A model is proposed to describe the early thyroxine distribution in man. The four main compartments, plasma, liver, interstitial fluids and other tissues, are characterized by their transfer rate constants and by their distribution spaces. The model implementation on a digital computer only requires easily obtainable data; clinical investigations are simplified by the simulation technique.     

A method for determining the number of documents needed for a gold standard corpus

The unstructured narratives in medicine have been increasingly targeted for content extraction using the techniques of natural language processing (NLP). In most cases, these efforts are facilitated by creating a manually annotated set of narratives containing the ground truth; commonly referred to as a gold standard corpus. This corpus is used for modeling, fine-tuning, and testing NLP software as well as providing the basis for training in machine learning. Determining the number of annotated documents (size) for this corpus is important, but rarely described; rather, the factors of cost and time appear to dominate decision-making about corpus size. In this report, a method is outlined to determine gold standard size based on the capture probabilities for the unique words within a target corpus. To demonstrate this method, a corpus of dictation letters from the Michigan Pain Consultant (MPC) clinics for pain management are described and analyzed. A well-formed working corpus of 10,000 dictations was first constructed to provide a representative subset of the total, with no more than one dictation letter per patient. Each dictation was divided into words and common words were removed. The Poisson function was used to determine probabilities of word capture within samples taken from the working corpus, and then integrated over word length to give a single capture probability as a function of sample size. For these MPC dictations, a sample size of 500 documents is predicted to give a capture probability of approximately 0.95. Continuing the demonstration of sample selection, a provisional gold standard corpus of 500 documents was selected and examined for its similarity to the MPC structured coding and demographic data available for each patient. It is shown that a representative sample, of justifiable size, can be selected for use as a gold standard.     

A review of normative documents on preimplantation genetic testing: Recommendations for PGT-P

PurposeRecently, preimplantation genetic testing (PGT) for polygenic conditions (PGT-P) has been introduced commercially. In view of the lack of specific guidance on this development, we analyzed normative documents on PGT for monogenic conditions (PGT-M) to understand what we can learn from these documents for recommendations for PGT-P.MethodsWe conducted a systematic review of normative guidelines and recommendations on PGT-M. The aim was to understand what the current consensus and disagreements are on ethical acceptability of PGT-M and how this compares with PGT-P.ResultsWe analyzed 38 documents by advisory committees at the national, European, and global level. In total, 2 themes were identified, which included the following: (1) what PGT is considered appropriate for and (2) who can make decisions regarding the use of PGT. Many aspects of PGT-M documents apply to PGT-P as well. Additional factors such as the fact that PGT-P screens for risk indications of multiple polygenic conditions increase ethical difficulties regarding severity, risk, autonomy, and informed decision-making.ConclusionOn the basis of PGT-M normative documents, we conclude that ethical acceptability for PGT-P is limited. Our findings present various factors that have to be considered for the development of guidelines and the appropriateness of PGT.     

A method for preservation of lymphocyte rosettes in agarose.

A simple, reproducible method for preservation of lymphocyte rosettes in agarose-gel as supporting medium had been developed. The method allows many test samples to be stored and examined under similar conditions, and rosette-forming cells to be identified by the morphologic features.