Web-based digital radiology teaching file: facilitating case input at time of interpretation.

OBJECTIVE: Our goal was to develop a software system that allows easy and rapid input of digital radiology images and text reports, at the time of interpretation, into an easily searchable electronic teaching file database using the Internet and the World-Wide Web protocols, servers, and browsers. CONCLUSION: Using the Internet, the World-Wide Web, and our software system, we can rapidly input digital radiology images and associated text reports into an easily searchable database accessed by privileged users. This inexpensive and simple method for building a digital teaching file database allows cross-platform access for users who have a Web browser.

Hopelessness predicts future depressive symptoms: a prospective analysis of cognitive vulnerability and cognitive content specificity.

Beck's content specificity hypothesis predicts distinct cognitive content within specific psychological disorders. We evaluated whether the third component of the "cognitive triad", negative view of the future (hopelessness), would be related 4 weeks later to depressive symptoms, but not to anxiety. University student participants (83 females, 71 males) were tested on the Beck Depression Inventory and the Beck Anxiety Inventory at two points in time, separated by 4 weeks. The Hopelessness Scale was administered at time 1 and a Life Events Inventory at time 2. Concurrent cognitive content specificity was replicated. For males only, hopelessness predicted future depression severity scores, but not anxiety. Hopelessness predicted depressive symptoms over and above life event stressors, but not vice versa.

An augmented computer model of motor unit reorganization in neurogenic diseases of skeletal muscle.

A computer model of denervation and complete reinnervation in skeletal muscle was originally developed for the purpose of furthering an understanding of the underlying mechanisms of motor unit reorganization in neurogenic diseases. We now describe its successor, a computer model for investigating different rates of denervation and reinnervation, as well as incomplete reinnervation. The new model introduces the concept of permanent denervation and features enhanced interactive control over the distribution of motor unit centers and additional measures of dispersion and co-dispersion of muscle fibers. The use of this model for investigating pathophysiologically significant issues in denervating diseases is illustrated with five different sets of parameters. These simulate some of the processes that may be operational in chronic spinal muscular atrophy, amyotrophic lateral sclerosis, and progressive postpolio muscular dystrophy. The enhanced model will allow in-depth analysis of the influence of hypothesized pathophysiological processes on clinical, electrophysiological and pathological outcomes in human disease.

A computer model of denervation-reinnervation in skeletal muscle.

A computer model of the process of denervation and complete reinnervation of skeletal muscle has been developed for the purpose of exploring underlying mechanisms and for use in the development of new clinical and research tools for evaluating neuromuscular disease. Progressive motor neuron death and reinnervation in this model reproduces the fiber-type grouping, increased fiber density, and minimal increase of motor unit size seen in human chronic denervating diseases. Studies using the model suggest that (1) preferential involvement of motor units of one type could account for the abnormal fiber-type proportions observed in some diseases, (2) reinnervation by axons innervating adjacent fibers is compatible with single fiber multielectrode study results in that it does not produce a large increase in motor unit area, and (3) such reinnervation is sufficient to account for the increases in motor unit density that have been observed. The model has also been used in the development and testing of the Codispersion Index, a measure of the codistribution of two fiber types, which is useful in detecting fiber-type grouping.

The effects of anabolic agents and breed on the fibers of the longissimus muscle of male cattle.

Sample of longissimus muscle were taken from carcasses of steers, steers implanted with anabolic agents and bulls of Friesian and Charolais X Friesian breeds of cattle. Percent and mean cross-sectional areas (CSA) of three myofiber types (beta R, alpha R and alpha W) were determined. The percentage of beta R myofibers did not vary significantly with treatment. The implanted steers had 26% more alpha R and 8% less alpha W myofibers than the untreated steers, while the bulls had 33% more alpha R and 20% less alpha W myofibers than the implanted steers (P less than .001). In the implanted steers the mean CSA of the beta R myofibers was significantly greater than that of the untreated steers, but did not differ from that of the bull. The mean CSA of the alpha R myofibers increased considerably with treatment, but only that of the bull was significantly greater than that of the untreated steers. The mean CSA of the alpha W myofibers in the implanted steers was identical with that of the untreated steers and significantly smaller than that of the bulls. In comparison to the untreated steers, significant hypertrophy of all three myofiber types occurred in bulls. These findings demonstrate a significant increase in the oxidative capacity of the longissimus when the levels of both endogenous and exogenous anabolic agents are increased. They are also consistent with the greater efficiency of deposition of protein obtained with implanted steers and bulls.(ABSTRACT TRUNCATED AT 250 WORDS)

The co-dispersion index for the measurement of fiber type distribution patterns.

There is a need for a practical and statistically manageable quantitative index of fiber type co-dispersion in skeletal muscle to allow investigation of the distribution of motor units in normal muscle and their rearrangement in pathological states. A new measure for this purpose, the Co-Dispersion Index (CDI), is introduced. This measure is based on contingency table analysis of nearest-neighbor relationships between muscle fibers. The CDI has a continuous range of values from -1 to +1, in which larger negative values indicate a greater tendency toward regular intermixing of fibers of different types, and larger positive values a greater segregation of fiber types. CDI evaluation overcomes the limitations of previously published quantitative methods for co-dispersion measurement and is well correlated with subjective human estimates of fiber type grouping.

Discrimination and consistency of five myosin ATPase stains in human normal and Duchenne dystrophic muscle.

Limitations in the ability of the human visual system to assess accurately the relative staining densities of individual fibers in muscle tissue stained for myosin. ATPase can complicate the objective evaluation of fiber type populations. In this study a novel approach is employed which utilizes human visual capabilities to provide accurate fiber classification. Using this approach, the ability of five ATPase staining techniques to discriminate fiber type categories in single samples of human normal and Duchenne dystrophic skeletal muscle is evaluated, as is the consistency of the fiber type classifications between stains. While no major discrepancies in fiber typing were observed in the sample of normal muscle, significant differences in classification, along with a decrease in the ability to discriminate fiber types were noted in the sample of Duchenne muscular dystrophy. For the most part, these discrepancies were resolved by a re-interpretation of the staining characteristics of fibers in one stain.

Automated morphometric analysis of corneal endothelial cells.

This paper describes a feasibility study for computer image analysis of corneal endothelial specular micrographs. The analysis involved image enhancement, boundary detection of individual cells, and subsequent calculation of cell area, cell area distribution, cell perimeter, cell orientation, and cell diameter. Cell areas produced by automated analysis agreed well with manually measured cell areas from the same photomicrographs. The computer methods required little human guidance or correction, produced accurate results, and could be made to run fairly quickly with modest computing resources.