Planning for PACS at Osaka University Hospital.

We have a plan to adopt PACS as a medical image information system in the new hospital. In order to construct PACS suitable for our hospital, a preliminary survey was carried out to determine how PACS should be introduced and what are the physicians requirements for a new medical image system. The most important requirement of the physicians was a good quality workstation. Our plan of a new medical image information system is as follows. A primary database will be constructed according to each of modalities in the Department of Radiology. In the Department of Medical Information Science, we will make a secondary database according to the patient. Although it may be difficult for us to obtain a sufficient budget digitalizing all medical images by our move to the new hospital, our goal is to establish total PACS throughout the new hospital in 1995.     

Characterization of CA125 glycoprotein using 3 monoclonal antibodies with different specificities

Dementia of frontal type (DFT) is a fairly common degenerative disease distinct from Alzheimer's disease (AD), whose reportedly distinctive instrumental feature is frontal lobe hypoperfusion on SPECT. We evaluated the cortical dopaminergic system in 6 AD, 5 DFT, and 6 control subjects with SPECT and both [99Tc]-HM-PAO, a perfusion tracer, and [123I]-IBZM, a D2 postsynaptic ligand. Both in AD and DFT patients, [99Tc]-HM-PAO SPECT showed a relative frontal hypoperfusion. On the contrary, [123I]-IBZM SPECT showed significantly reduced ligand uptake in superior frontal regions of DFT (0.89 +/- 0.08 relative to control subjects) as compared to AD patients (0.97 +/- 0.02; difference of means: 0.08, 95% Confidence Interval 0.004 to 0.156; p = 0.041). Results suggest more marked involvement of the frontal cortical dopaminergic system in DFT than in AD patients.     

Effects of pH and SO2 on solubility coefficients of inert gases in human whole blood

We systematically investigated the quantitative importance of pH and O2 saturation (SO2) of hemoglobin on the solubility coefficients (alpha) for six inert gases: sulfur hexafluoride, N2, ethane, cyclopropane, halothane, and diethyl ether. Measurements of alpha were made at 37 degrees C with SO2 of 0-1.0 and pH of 7.2-7.7 by use of whole blood obtained from three healthy subjects. No significant dependence of alpha on pH was demonstrated for sulfur hexafluoride, N2, halothane, or diethyl ether, but an appreciable augmentation of alpha with increasing pH was found for ethane and cyclopropane. No alpha value obtained for oxygenated blood differed statistically from that for deoxygenated blood. In addition to the basic findings on the effects of pH on alpha values of ethane and cyclopropane with the multiple inert gas elimination technique (data obtained from 22 patients with either interstitial pneumonia or chronic obstructive pulmonary disease), we also found that dependence of alpha on blood pH exerted no significant influence on the recovery of ventilation-perfusion distribution in the lung. We concluded that: 1) pH plays an appreciable role in determining gas solubilities in blood, 2) SO2 is not a decisive factor for gas solubilities in blood, and 3) the influence of various pH values in pulmonary capillaries on inert gas exchange is negligible.     

A submilliampere-threshold multiquantum-well AlGaAs laser withoutfacet coating using single-step MOCVD

An extremely low threshold current, of 0.88 mA under continuous wave (CW) operation was obtained for a three-quantum-well AlGaAs-GaAs laser without facet coating at room temperature. This laser was fabricated using only single-step metalorganic chemical vapor deposition (MOCVD) on a nonplanar GaAs substrate. The energy conversion efficiency from input electric power to light output power was 42% at 1 mW/facet, which is the highest value for all types of lasers. The laser beam shape was nearly round with an aspect ratio of 0.86     

Synthesis and characterization of some poly-p-sliphenylenes

Summary The syntheses of some representative low molecular weight poly-p-silphenylenes containing SiMe₂ or SiPh₂ groups in the main chain are using either THF or Et₂O as solvent. The insertion of the butylenoxy units in the main chains of the polymers was observed when THF was used as a solvent. The polymers were characterized by a combination of IR,¹H and¹³C — NMR spectra and vapour pressure osmometric analysis. The thermal behaviour of the poly-p-silphenylenes was analysed by thermogravimetry.     

A scanning electron microscopic study of the degenerative cartilage in patellar chondropathy

Patellar chondropathy as cartilage degeneration localized in patellar cartilage in young persons is characterized by cartilaginous changes, such as softening, swelling, and fissuring. With a view to structural characterization of early cartilaginous degeneration before erosion, the morphology of affected cartilage was studied under a scanning electron microscope. The surface network of cartilage constituting fibrils had an edematous change, presenting with fibrillation on the medial facet, whereas many fibrils of the central ridge had a collagen bundle, and fissuring of varying size was observed. It appeared that a mechanical force (shearing) acting on the site of the central ridge was associated with the formation of a collagen bundle and its destruction. On the lateral facet, fibrils were arranged perpendicular to the joint surface; the superficial layer of fibrils was worn by hyper-pressure acting on the lateral facet. On the fractured surface, the coarseness of collagen fibrils showed changes that varied with the site and stage of cartilage degeneration. Frequent changes were signs of fibril loosening (coarsening), such as reduction in fibril density (i.e., edematous change), collagen fibril aggregation, and fissuring, and longitudinal restructuring of fibrils. The patellar cartilage in the patients of this series showed a structure adapted to the mechanical force. The initial structural changes of cartilage consisted of collagen fibril aggregation and reduction in fibril density. These changes give rise to matrix rarefaction, which in turn causes cartilage degeneration to progress. These changes were concurrent in both the superficial and middle layers and were not localized as basal degeneration.     

Age at onset and language disturbances in Alzheimer's disease

This study examined the effect of age at symptom onset of Alzheimer's disease (AD) on the pattern of language disturbance. We assessed 150 consecutive patients with a clinical diagnosis of mild-to-moderate AD using the Western Aphasia Battery and a 100-item picture-naming test. A multivariate linear regression analysis examined the effect of age at onset after controlling for gender, education, severity of dementia and duration of the disease. Patients with early onset performed significantly worse than did patients with late onset on the word comprehension and sequential commands subtests. On the other hand, late-onset patients performed more poorly than early-onset patients on the picture-naming test in a subgroup with mild language deficits. However, the trend disappeared in other subgroups with more degraded language function. We consider that the concomitant effects of normal aging worsened the picture-naming deficits in the late-onset patients, and the rapid decline of naming ability in the early-onset patients masked the aging effect with the progression of language deficits. The deterioration of word comprehension and the rapid decline of naming ability are the characteristics of early-onset patients. The different patterns of language deficits between early- and late-onset patients may correspond to the genetic heterogeneity of AD.     

Model analysis for combustion characteristics of RDF pellet

Fundamental studies of the combustion characteristics and the de-HCl behavior of a single refuse-derived fuel(RDF) pellet were carried out to explain the de-HCl phenomena of RDF during fluidized bed combustion and to provide data for the development of high efficiency power generation technology using RDF previously. For further interpreting the devolatilization and the char combustion processes of RDF quantitatively, an unsteady combustion model for single RDF pellet, involving reaction rates, heat transfer and oxygen diffusion in the RDF pellet, was developed. Comparisons of simulation results with experimental data for mass loss of the RDF samples made from municipal solid waste, wood chips and poly-propylene when they were heated at 10K/min or put into the furnace under 1073K show the verifiability of the model. Using this model, the distributions of the temperature and the reaction ratio along the radius of RDF pellet during the devolatilization process and the char combustion process were presented, and discussion about the inference of heating rate on the combustion characteristics were performed.