Using an integrated point of care system: a nursing perspective.

Nurses at LDS Hospital, Salt Lake City, Utah, have had the ability to document patient data and nursing care on a bedside computer for over nine years. This ability has had numerous ramifications for the medical record, nursing practice, and clinical decision making. This article is an effort to describe how and why certain decisions were made, the implications of these decisions, mistakes that were made and their solutions, and the tremendous impact on clinical decision making and improved patient outcomes that is only beginning to be realized by computerization of the medical record.

Blood flow dynamics in the vertebrobasilar system: correlation of a transparent elastic model and MR angiography.

Purpose: To describe the flow patterns in a model of the vertebrobasilar artery and use these observations to explain the appearance of the flow on the MR images.

Methods: We created an anatomically precise, transparent elastic model of the human vertebrobasilar artery containing a basilar tip aneurysm and perfused the model with non-Newtonian fluid which has similar rheologic properties to blood. Flow patterns in the vessels were directly observed.

Myocardial extraction of 1-[11C] betamethylheptadecanoic acid.

Unlabelled: Betamethylheptadecanoic acid (BMHA) is a branched chain fatty acid analog that is transported into myocardial cells by the same long chain fatty acid carrier protein mechanism as natural fatty acids, but cannot be completely catabolized and accumulates in the tissue. Thus, 11C-labeled BMHA is a useful tracer for the noninvasive evaluation of myocardial fatty acid utilization by positron emission tomography (PET).

Methods: As a prelude to PET studies, the metabolism of BMHA was studied by classical techniques.

Contrast induced myocardial signal reduction: effect of lanthanide chelates on ultra high speed MR images.

The myocardial MR signal reduction associated with an intravenous bolus of Gd-DTPA and Dy-DTPA was studied in a canine model. Imaging was performed with a high speed echo-planar type imaging system (Instascan, Advanced NMR Systems, Inc.).

Monitoring of pO2 by spin-spin relaxation rate 1/T2 of 19F in a rabbit abscess model.

The purpose of this study was to confirm the relationship of T1 and T2 relaxation rate vs. pO2 in vivo of 19F MR signal measured from intracellular perflubron. Our work to date has demonstrated that 1/T2 is more sensitive to pO2 than 1/T1 in the in vitro environment.

Cloning of the cDNA (DSC1) coding for human type 1 desmocollin and its assignment to chromosome 18.

Desmosomes are adhesive epithelial junctions that contain two distinct classes of cadherin-related glycoproteins (desmogleins and desmocollins), both of which occur as several different isoforms whose expression is related to epithelial differentiation. We have now isolated cDNA clones encoding a human desmocollin that is expressed in the more differentiated layers of human epidermis. This isoform has 53% amino acid identity with the previously isolated human (type 3) desmocollin, which is expressed in the basal layers of the epidermis.

Pulsatile flow artifacts in 3D magnetic resonance imaging.

Some of the important features of how pulsatile flow generates artifacts in three-dimensional magnetic resonance imaging are analyzed and demonstrated. Time variations in the magnetic resonance signal during the heart cycle lead to more complex patterns of artifacts in 3D imaging than in 2D imaging. The appearance and location of these artifacts within the image volume are shown to be describable as displacements along a line in a plane parallel to that defined by the phase and volume encode directions.

Pulsatile flow artifacts in two-dimensional time-of-flight MR angiography: initial studies in elastic models of human carotid arteries.

Initial experimental and numerical analysis of artifacts due to pulsatile flow in two-dimensional time-of-flight (2D-TOF) magnetic resonance (MR) angiography are presented. The experimental studies used elastic models of the carotid artery bifurcation cast from fresh cadavers and accurately reproducing the twisting and tapering of the human blood vessels, allowing direct comparison of images with and without flow. Prominent image artifacts, including periodic ghosts and signal loss, were produced by pulsatile flow even though flow-compensated gradient waveforms were used.

Stratification-related expression of isoforms of the desmosomal cadherins in human epidermis.

Desmosomal junctions are abundant in epidermis and contain two classes of transmembrane glycoprotein, the desmocollins and the desmogleins, which are members of the cadherin superfamily of Ca(2+)-dependent cell adhesion molecules. The desmocollin subfamily includes DGIV/V and DGII/III while the desmoglein subfamily includes DGI, HDGC and the autoantigen of the blistering skin disease pemphigus vulgaris (PVA). There are also several non-glycosylated proteins, including the desmoplakins and plakoglobin, present in the desmosomal plaque, which forms a link between the glycoproteins and the cytokeratin intermediate filaments.

The diffusion sensitivity of fast steady-state free precession imaging.

Steady-state free precession (SSFP) imaging with an added field gradient pulse is strongly sensitive to self-diffusion and other motions of water. In an earlier theoretical analysis of diffusion attenuation due to a single gradient pulse Wu and Buxton (J. Magn.

Distortions from curved flow in magnetic resonance imaging.

We present an analysis of how vessel curvature can create distortions in magnetic resonance images of flowing blood. Steady flow in curved vessels produces distortions of the vessel shape and intensity variations in the image due to motion during the interval between phase encoding or slice selection and the echo center. Even with steady flow, vessel curvature produces motion moments higher than velocity (acceleration, etc.

MR diffusion imaging of cerebral infarction in humans.

Purpose: MR diffusion imaging was performed to investigate changes in water diffusion in patients with cerebral infarction.

Methods: Diffusion maps of the apparent diffusion coefficient (ADC) were created to show local water mobility in the brain tissue in 15 patients. These ADC maps were compared with conventional T2-weighted images.

Structure and interactions of desmosomal and other cadherins.

The cadherin superfamily of cell-cell adhesion molecules is now known to include proteins of the desmosome as well as of the adherens type of junction. The desmosomal cadherins consist of two families of proteins, the desmocollins and the desmogleins, both of which are represented by different isoforms which are differentially expressed in epidermis. The desmocollins are quite similar to the classic cadherins in overall structure, but with alternatively spliced variants; the desmogleins have extra cytoplasmic sequences added onto the basic cadherin structure.

Elimination of oblique flow artifacts in magnetic resonance imaging.

We present an analysis of how flow oblique to the frequency-encoding direction generates displacement artifacts in MR imaging and show that for flow which has constant velocity between the start of the phase encoding and the center of the echo it is possible to eliminate these artifacts by gradient moment nulling in the phase-encoding direction. However, unlike the standard moment nulling calculations for flow compensating the frequency-encode and slice-selection gradients, the phase-encoding first moment must be nulled specifically with respect to the echo center. Limitations of this method imposed by finite gradient strengths are analyzed.

The human gene (DSG2) coding for HDGC, a second member of the desmoglein subfamily of the desmosomal cadherins, is, like DSG1 coding for desmoglein DGI, assigned to chromosome 18.

Desmoglein is a transmembrane glycoprotein of the cadherin superfamily present in the desmosomal junction in vertebrate epithelial cells. At least two variants of desmoglein are differentially expressed in human tissues: DGI, a characteristic desmosomal protein; and HDGC, which is, for example, expressed in the simple epithelium of the colon. Using a PCR assay, we were able to assign DSG2, the gene coding for desmoglein HDGC, to chromosome 18, the same chromosomal localization to which we have previously assigned DSG1 coding for desmoglein DGI.

The human gene (DSG3) coding for the pemphigus vulgaris antigen is, like the genes coding for the other two known desmogleins, assigned to chromosome 18.

Pemphigus vulgaris (PV) is a potentially lethal skin disease in which epidermal blisters occur as the result of the loss of cell-cell adhesion caused by the action of autoantibodies against a keratinocyte cell surface glycoprotein, the PV antigen (PVA). This latter protein is a member of the desmoglein subfamily of the cadherin superfamily of cell-cell adhesion molecules, present in the desmosome type of intercellular junction. The other two known desmogleins are DGI, which is a target antigen in another autoantibody-mediated blistering disease of the epidermis, pemphigus foliaceous, and HDGC, which is expressed in the basal layer of the epidermis and in the simple epithelium of, for example, the colon.

Correction of chemical-shift artifacts in 19F imaging of PFOB: a robust signed magnitude method.

This paper describes a method for correcting the chemical-shift artifacts in 19F NMR imaging of perfluoroctylbromide emulsion (PFOB) by utilizing the two spectral peaks of PFOB which have a long T2 value in conjunction with the Dixon method. Corrected images are obtained from the magnitude of the measured images using the sign determined from the phase images. The method was tested in the presence of several phase deformation factors, such as static magnetic field inhomogeneity and inaccurate time shift of the pi refocusing pulse, which affect the phase errors of each pixel in the reconstructed image.

Expression, glycosylation and secretion of yeast acid phosphatase in hamster BHK cells.

The gene PHO5 coding for one of the repressible acid phosphatases of the yeast Saccharomyces cerevisiae has been expressed at high efficiency in the baby hamster kidney (BHK) cell line. The expression vector was constructed from PHO5 driven by the human beta-actin promoter and was transfected into BHK cells by the calcium phosphate method. The recombinant APase (r-APase) which was secreted in active form from the cells was estimated by SDS/polyacrylamide gel electrophoresis to have molecular mass M(r) = 62,000, indicating substitution of the polypeptide moiety by 2-3 asparagine-linked glycans.

The use of Imagent BP in diagnostic imaging research and 19F magnetic resonance for PO2 measurements.

Imagent BP (90% w/v perflubron emulsion) is radiopaque and serves as an X-ray contrast medium. Quantitative X-ray Computed Tomography, provides the means to non-invasively estimate tissue perflubron concentration providing three unique capabilities: 1) The use of the same animal for biodistribution and elimination analysis; 2) The precise geographic distribution of the agent to more accurately quantitate localized accumulations; and 3) The ability to gather physiologic data by monitoring the time dependent distribution of perflubron. It is known that the T1(-1) of 19F of perfluorochemicals is linearly related to the dissolved oxygen which allows the quantitation of PO2 in-vivo.

Quantitation of structural distortion of the cervical neural foramina in gradient-echo MR imaging.

Quantitative errors (due to magnetic susceptibility artifacts) in the measurement of the cervical spinal neural foramina with fast gradient-echo (GRE) magnetic resonance imaging were assessed. Cylindric phantoms of different materials were used to demonstrate the nature of magnetic susceptibility artifacts, emphasizing the dependence of the artifact on tissue geometry. Neural foramina diameters measured on thin, sagittal GRE and spin-echo (SE) images through the neural foramina of a fresh human cervical spine specimen were then compared with direct measurements with calipers.

Transmembrane molecular assemblies regulated by the greater cadherin family.

The cadherin family of cell-cell adhesion molecules is turning out to be much more diverse than previously thought, with members involved in several kinds of intercellular junctions. The adhesive specificity and cytoskeletal interaction of these members varies. Their cytoplasmic terminals are specialized for binding several families of 'mediator' proteins which interconnect to the actin or intermediate filament systems.