Virtual temporal bone: creation and application of a new computer-based teaching tool.

The human temporal bone is a 3-dimensionally complex anatomic region with many unique qualities that make anatomic teaching and learning difficult. Current teaching tools have proved only partially adequate for the needs of the aspiring otologic surgeon in learning this anatomy. We used a variety of computerized image processing and reconstruction techniques to reconstruct an anatomically accurate 3-dimensional computer model of the human temporal bone from serial histologic sections. The model is viewed with a specialized visualization system that allows it to be manipulated easily in a stereoscopic virtual environment. The model may then be interactively studied from any viewpoint, greatly simplifying the task of conceptualizing and learning this anatomy. The system also provides for simultaneous computer networking that can bring distant participants into a single shared virtual teaching environment. Future directions of the project are discussed.

The Virtual Pelvic Floor, a tele-immersive educational environment.

This paper describes the development of the Virtual Pelvic Floor, a new method of teaching the complex anatomy of the pelvic region utilizing virtual reality and advanced networking technology. Virtual reality technology allows improved visualization of three-dimensional structures over conventional media because it supports stereo vision, viewer-centered perspective, large angles of view, and interactivity. Two or more ImmersaDesk systems, drafting table format virtual reality displays, are networked together providing an environment where teacher and students share a high quality three-dimensional anatomical model, and are able to converse, see each other, and to point in three dimensions to indicate areas of interest. This project was realized by the teamwork of surgeons, medical artists and sculptors, computer scientists, and computer visualization experts. It demonstrates the future of virtual reality for surgical education and applications for the Next Generation Internet.

Limitations of distributed segmentation for three-dimensional radiological modeling.

While the use of three-dimensional models has been shown to be useful clinically, the specialized computational equipment and expertise necessary for their construction and use keeps these tools out of reach of most physicians. This paper explores the construction of a Web-based Java application that allows medical radiological models to be built on a remote server and navigated locally on the physician's desktop PC. This paper will also address issues that arose from a public, unrestricted testing of usability over the Internet, such as model size management, easy navigation, processor loading and security. Based on observations and data collected, we suggest what steps are necessary to make a telemedicine application useable in a true clinical setting.

Clinical care and the factory floor.

The purpose of this article is to provide the author's perspective on whether it is likely or feasible that those working in the health care domain will adapt and use lessons learned by those in the industrial domain. This article provides some historical perspective on the changes brought about in the industrial domain through the introduction of new technologies, including information technologies. The author discusses how industrialization catalyzed changes in health care delivery that paralleled but lagged behind those of the broader U.S. economy. The article concludes that there is ample reason for those interested in improving the quality and effectiveness of health informatics to systematically evaluate information technology strategies used in the industrial domain. Finally, it outlines some challenges for health informaticians and a number of factors that should be considered in adapting lessons from industry to the health care domain.

Preparing chief information officers for the clinical information systems environment.

Over the past decade, the chief information officer (CIO) in the health care enterprise has gained recognition as a member of the senior management team based on an understanding of business processes and business language. The clinical information system (CIS) in the health care environment poses a new frontier for CIOs, who are generally unfamiliar with both clinical languages and clinical processes. The authors discuss the role formal informatics training can have in preparing learners for future careers as CIOs in CIS environments. The health information management (HIM) specialization within the MBA program at the University of Illinois at Chicago is one example of an educational program designed to train future CIOs who can manage the business, technical, and clinical aspects of the health care environment.

The virtual temporal bone.

The human temporal bone is a 3-dimensionally complex portion of the skull that contains delicate and vital anatomic structures imbedded within dense bone. Current teaching tools have proven to be only marginally adequate for the needs of the aspiring otologic surgeon in learning this anatomy. A variety of image processing and reconstruction techniques were used to reconstruct an anatomically accurate 3-dimensional model of the human temporal bone from serial histologic sections. Using CAVE technology, the model can be manipulated in a stereoscopic virtual environment so that it can be studied from any viewpoint, greatly simplifying the task of learning this anatomy. Applications in surgical planning and Internet based teaching are discussed.

Web-based segmentation and display of three-dimensional radiologic image data.

In many clinical circumstances, viewing sequential radiological image data as three-dimensional models is proving beneficial. However, designing customized computer-generated radiological models is beyond the scope of most physicians, due to specialized hardware and software requirements. We have created a simple method for Internet users to remotely construct and locally display three-dimensional radiological models using only a standard web browser. Rapid model construction is achieved by distributing the hardware intensive steps to a remote server. Once created, the model is automatically displayed on the requesting browser and is accessible to multiple geographically distributed users. Implementation of our server software on large scale systems could be of great service to the worldwide medical community.

[Osteopoikilosis--case report]. / Plamistosc kosci--opis przypadku.

A case of osteopoikilosis in 15 years old female with painful hip is presented. Genetic background of this condition has been confirmed by finding mother, two brothers and sister of the patient who affected with osteopoikilosis.

The Internet: will this highway serve the digital library?

The future of the biomedical enterprise and the biomedical libraries that serve it is tied closely to digital information. The changing nature of this type of information will create new pressures on libraries, particularly in health care organizations. Libraries must learn to deal with these pressures. Currently, libraries depend on the Internet primarily for connections to resources and other libraries; thus enhancements to the Internet will impact the libraries of the present and future significantly. This paper provides an overview of the technical capabilities that will be available in the near to midterm, what libraries will be able to do with those capabilities, and how libraries can position themselves to take advantage of the impending changes.

Networking: an overview for leaders of academic medical centers.

Organizations face a unique challenge over the next decade. When technology was expensive, it was arguably necessary to use an undifferentiated, or monolithic, model for computer-based solutions to problems. This has fundamentally changed. Technology is now so inexpensive that solutions are not limited by costs, but rather by how well the implementors understand the many different problem domains. Thus, academic medical centers are faced with successive waves in information technology use. First, there will be a wave of innovation, driven by the need for specialization in problem solving. This will be followed by consolidation of the best of the approaches into the core systems of the institution. The average level of heterogeneity (cost) will be higher, but the overall quality of the solutions (benefit) will also be higher. If one can develop a strategy for managing and creatively limiting the heterogeneity, the cost-benefit ratio will be much more favorable. While there may be other strategies that will do this, we support the use of a strategy centered on enterprise networking. This strategy emphasizes not simply technology but also the cultural and organizational changes that empower innovation--within a framework that makes it possible to simply implement interoperability and data sharing within nearly all solutions. The organizations that survive the coming period of change and external pressure will be those that do the best job of managing their resources. Information will continue to be one of the most important resources.(ABSTRACT TRUNCATED AT 250 WORDS)

A path to integration in an academic health science center.

This article describes a networking and integration strategy in use at the University of Michigan Medical Center. This strategy builds upon the existing technology base and is designed to provide a roadmap that will direct short-term development along a productive, long-term path. It offers a way to permit the short-term development of incremental solutions to current problems while at the same time maximizing the likelihood that these incremental efforts can be recycled into a more comprehensive approach.

Qualitative differences in estrogenic/antiestrogenic effects of clomiphene and zuclomiphene.

Depending upon the rat assay end point, the estrogenic or antiestrogenic activity of clomiphene (CC) or its isomer, zuclomiphene (Zu), varies considerably. For uterine/body weight ratio, Zu = estradiol greater than CC; for the estrogenic effect on uterine epithelium, Zu greater than estradiol = CC; higher CC doses were antiestrogenic. For endometrial stroma, Zu = estradiol much greater than CC. In the effect of estrogen receptor, low-dose CC = estradiol; high-dose CC was antiestrogenic. For Zu, both doses were about equal and highly antiestrogenic. Essentially the same was seen with progesterone receptor. For plasma LH suppression, Zu much greater than CC much greater than estradiol; but for plasma FSH, estradiol much greater than CC = Zu. The intrinsic estrogenicity of these compounds was made more apparent by the castrate status of the rats. This spectrum of activities may make it possible to select estrogenic or antiestrogenic activities for clinical purposes, depending upon the end-organ effect desired.

A new model for enhanced information services in an academic medical center.

The information base used in the biomedical enterprise, already large, continues to expand at a striking rate. Networking and desktop computing technology is playing a more important role in the operations of academic medical centers. Integration efforts aimed at enhancing information access by using distributed computing are very substantial technical challenges. However, if these integration efforts focus only on the technical aspects, they are doomed to failure. New organizational approaches are also needed. This paper describes an new model for enhanced information services. This model calls for the central information supplier to provide a set of core services. Users, who may be individuals or units and generally have more insight into the nature of their problems, will be encouraged to add value to these core services in the form of specialization or customization to meet their unique and critical needs. This model provides a way to adapt and transform current organizational elements to effectively use the large information technology investments and to meet the increasing challenges of biomedical information use.

Hormone receptors and disease-free survival in breast cancer: impact of increasing threshold levels.

Laboratory data from Milan and Houston were evaluated to determine the extent to which the distribution of estrogen receptor (ER) and progesterone receptor (PgR) has changed with time. Results from over 11,500 ER and over 8,200 PgR determinations (6,194 ER and 3,127 PgR from Milan) were analyzed. All assays in Milan were performed by a dextran-coated charcoal method and in Houston by a sucrose density-gradient method. The data demonstrate a time-dependent, upward drift in the amount of ER and PgR detected, with the effect most pronounced at the lower end of the distribution curves. We attribute this change to optimization of all facets of the receptor assay procedures (tissue harvesting and storage) as well as to a change in breast cancer biology. These results suggest that studies correlating certain biological parameters with receptor status (whether using qualitative or quantitative scales) need to be re-examined. For example, a population of 349 node-negative patients who did not receive any adjuvant treatment was studied in Milan to determine any association between disease-free survival (DFS) and receptor status. If the "historical" threshold values (10 fmol/mg protein) were used to determine receptor status, no significant difference in DFS at 5 years was detected. Even the combination of ER and PgR did not improve the predictive power of receptor status. In the premenopausal subgroup, ER status did predict the 5-year DFS. However, if the threshold value for PgR was adjusted to 25 fmol/mg protein, patients with ER-positive, PgR-positive tumors had significantly better 5-year DFS than patients with ER-negative, PgR-negative tumors. In addition, PgR status alone was associated with significantly improved 3-year DFS if the subgroups of PgR less than 5 fmol/mg protein and PgR greater than 100 fmol/mg protein were compared. We conclude from these data that: 1) historical threshold values for receptor positivity should be re-examined in all laboratories; 2) studies involving receptor results determined over an extended period of time should attempt to "normalize" these results; and 3) the quantitative assessment of receptor status should be used whenever possible.

Dihydrotestosterone heptanoate: synthesis, pharmacokinetics, and effects on hypothalamic-pituitary-testicular function.

Dihydrotestosterone heptanoate (DHT-hp), a seven-carbon fatty acid ester of DHT, was synthesized, and its pharmacokinetics and effects on hypothalamic-pituitary-testicular function were determined in men and pubertal boys. Plasma DHT levels markedly increased 24 h after im injection of DHT-hp, reached their peak during the first week, and fell to baseline levels after 4-6 weeks. An estimated 43-55% of DHT-hp was converted to DHT 4-6 weeks after injection. Plasma testosterone, estradiol, LH, and FSH levels decreased by 4 days after DHT-hp injection, were lowest during the second week, and returned to baseline values after 4-6 weeks. The LH and FSH responses to GnRH were diminished by chronic administration of DHT-hp to pubertal boys at 3-week intervals for 15 weeks. The affinity of DHT-hp was 100 times less than the affinity of DHT for the human androgen receptor, and no affinity for the estrogen receptor in breast tissue could be demonstrated. Since DHT is a nonaromatizable androgen, and neither DHT nor DHT-hp binds readily to the estrogen receptor, suppression of LH and FSH secretion by this drug probably occurs via an androgen-dependent mechanism. Receptor binding and pharmacokinetic data indicate that unesterified DHT is the active principle. DHT-hp is a useful derivative of DHT, since prompt, predictable, and sustained rises in DHT occur after its administration.

Carcinoembryonic antigen and steroid receptors in the cytosol of carcinoma of the breast. Relationship to pathologic and clinical features.

Cytosols of 159 primary breast carcinomas were assayed for estrogen and progesterone receptors and 60 of these for carcinoembryonic antigen (CEA). The relationships of pathologic and clinical features previously shown to be of prognostic significance and the biochemical parameter measured were examined. It was found that degree of histologic differentiation was significantly related to receptor status. There were significant inverse relationships between estrogen receptor and lymphocytic infiltrate as well as tumor necrosis. Relationships between estrogen, but not progesterone, receptor and patient age, menstrual status, and race existed. Cytosol CEA, on the other hand, related only to pathologic stage and not to histologic differentiation and other pathologic variables. Therefore, steroid receptors and CEA appear to provide information about different biologic characteristics of a carcinoma. Furthermore, the information provided by CEA appears to be independent of many known pathologic, clinical, and biochemical prognostic indicators.

Mechanism of androgen-receptor augmentation. Analysis of receptor synthesis and degradation by the density-shift technique.

The ductus deferens smooth muscle tumor cell line (DDT1MF-2) contains receptors for, and is stimulated by, androgens. Cells cultured in the absence of androgens maintain a basal level of androgen receptors. Following incubation with various concentrations of the synthetic androgen methyltrienolone (R1881) for 1-6 h, the concentration of these receptors increased from 6.0 to 12.2 fmol/micrograms of DNA, while the equilibrium dissociation constant (Kd) of 0.5 nM for this steroid remained unchanged. The steroid-induced increase in androgen receptor levels was specific for androgens and dependent upon protein synthesis. The mechanism of receptor augmentation was examined by utilization of isotopically dense amino acids to determine rates of receptor appearance and degradation in the presence or absence of [3H]R1881. In the absence of androgens, the half-life of the androgen receptor was 3.1 h, with a rate constant (kD) of 0.22/h. In the presence of 1 nM [3H]R1881, however, the half-life was 6.6 h, with kD = 0.11/h. The rate constant for receptor synthesis (ks) in the absence or presence of [3H]R1881 was calculated to be 1.35 and 2.23 fmol/micrograms of DNA/h, respectively. Thus, androgen-induced androgen-receptor augmentation is explained by an increase both in receptor half-life and in rates of receptor synthesis.

Steroid hormone binding macromolecules in meningiomas. Failure to meet criteria of specific receptors.

Cytoplasmic estrogen and progesterone binding proteins were assayed in 26 meningiomas using an assay developed for the measurement of estrogen and progesterone receptors in human target tissue. The steroid specificity of the binding proteins was studied in both individual and pooled meningioma tissue by competitive binding assays. Eight meningiomas contained significant amounts of estrogen-binding protein and 18 contained significant amounts of progesterone-binding protein. There was no correlation between the amount of hormone-binding protein and patient age, sex, menstrual status or presentation, or tumor occurrence, location, or pathologic features. The competition studies demonstrated a lack of steroid specificity for these hormone-binding proteins. Therefore, the authors conclude that, contrary to recent reports, the hormone-binding proteins found in meningiomas are unlikely to be specific steroid receptors.