Crossed raised arm position improves the flow of contrast medium in torso contrast-enhanced computed Tomography.

INTRODUCTION: This retrospective cohort study examined the effects of the crossed raised arm (CRA) position in contrast-enhanced computed tomography (CECT) on contrast medium influx and image quality relative to the conventional position. METHODS: Contrast medium influx into the collateral veins on CECT images was evaluated in 92 participants. The CT values of the pulmonary artery, descending aorta, and spleen were obtained in both positions and compared. Anatomical changes in the diameters and area of the subclavian vein and costoclavicular distance were also analyzed. RESULTS: Contras 27 and 6 patients in the conventional and CRA positions, respectively. The influx risk ratio in the CRA position versus that in the conventional position was 0.22 (95% confidence interval, 0.10-0.51). Elevations in the median CT value of the pulmonary artery, descending aorta, and spleen in the CRA position were 7.0% (p < .001), 7.4% (p < .001), and 9.8% (p < .001), respectively. Enlargements in the major and minor diameters of the subclavian vein, subclavian vein area, and costoclavicular distance in the CRA position versus those in the conventional position were 19.3% (p < .001), 28.1% (p < .001), 53.6%, and 30.0% (p < .001), respectively. CONCLUSION: The CRA position effectively prevented contrast medium influx into the collateral veins due to SVS and increased CT values in the target organs in CECT. The diameters and area of the subclavian vein and costoclavicular distance were enlarged at the thoracic outlet, which improved the flow of the contrast medium into the targeted organs. IMPLICATIONS FOR PRACTICE: The CRA position can contribute to obtaining better CECT images during common clinical assessments at no additional cost.

SU-E-I-62: Investigation of Dominant Factors Affecting Fatigue in Image Reading of Radiologists.

PURPOSE: To investigate dominant factors affecting fatigue in image reading of radiologists. METHODS: Two kinds of fatigue were assessed in this study. One was fatigue in the central nervous system evaluated by the critical fusion frequency (CFF). The other was eye fatigue evaluated by a score determined from a questionnaire based on the oculomotor strain subscale from the Simulator Sickness Questionnaire (SSQ). When fatigue increases, the CFF and the SSQ score indicate low and high values, respectively. The fatigue of seventeen radiologists was assessed before and after their daily image reading. The reading times and the numbers of images were different among the assessments, and ranged about 1.5 - 5.0 hours and 1,000 - 12,000 images, respectively. The assessments of fatigue were repeated four times for each radiologist on different days. Finally, the measurements of the two kinds of fatigue were analyzed in terms of years of experience, age, sleeping time the previous night, ambient light conditions, reading time, and the numbers of interpreted images, series, and cases. RESULTS: The CFF and SSQ score after image reading were significantly lower and higher than those measured before image reading, respectively. Younger and less experienced radiologists indicated a higher level of fatigue than older and more experienced radiologists in both the CFF and the SSQ score. When radiologists interpreted clinical images for longer hours, the SSQ score tended to be higher. On the other hand, there was little incremental difference in the CFF among different lengths of reading time. No obvious differences were observed in the other items. CONCLUSIONS: Less experience with reading images, a younger age, and a longer reading time could be dominant factors affecting fatigue in image reading.

The promotion of hydrolysis of acetylsalicylic acid in AOT/near-critical propane microemulsion.

A significant acceleration of the hydrolysis of acetylsalicylic acid was accomplished by the introduction of an AOT/near-critical propane microemulsion at lower W0 values; the rate constant at W0 = 1 was found to be 54 times that in aqueous buffer medium in the presence of imidazole catalyst.

Noncatalytic Organic Synthesis Using Supercritical Water: The Peculiarity Near the Critical Point.

Pinacol and Beckmann rearrangements can be carried out effectively by using supercritical water (scH(2)O) both as an acid catalyst as well as a medium. In the near-critical region not only are the rates significantly accelerated (see picture), but the nature of supercritical water can be adjusted to give weak acidity, which opens a new reaction pathway to a Diels-Alder adduct between dehydrated products.

Supercritical fluids: an interesting medium for chemical and biochemical processes.

Interactions between solute and solvent in supercritical fluids (SCFs) are of fundamental importance because small changes in pressure or temperature near the critical point may alter reactivity in chemical and biochemical processes, and were examined such as those for ester synthesis catalyzed by a lipase in supercritical carbon dioxide and for a FT-IR study on the structures of reverse microemulsions in supercritical ethane. We previously conducted ester synthesis from acyl donors and terpene alcohols catalyzed by Candida cylindracea (CCL) lipase in supercritical carbon dioxide. In the near-critical region, (S)-(-)-terpene esters were stereoselectively synthesized from acyl donors and a primary alcohol such as (+/-)-citronellol. In a very limited pressure range near the critical point, interactions between carbon dioxide and enzyme molecules greatly increased with consequent drastic conformational changes in the enzyme, causing active sites to emerge to catalyze stereoselective synthesis. Therefore, supercritical carbon dioxide medium in the near-critical region should trigger the activation of the enzyme by causing movement of its surface groups and creating active sites. Two molecular aggregates, an enzyme and micelle, in supercritical fluids were studied with respect to their microstructure and activity for chemical reactions. High-pressure FT-IR spectroscopy has thus been used to clarify (i) the rotational isomerism of AOT molecules, (ii) characteristics of water and the water-head group, and (iii) RSO3-Na+ interactions in AOT reverse micellar aggregates in supercritical ethane. At 35.0 MPa, the proportion of trans-like to gauche-like conformers greatly increased as W0 was increased. A system of water/AOT/supercritical ethane was in a one-phase microemulsion state at W0 values less than 15 at 35.0 MPa and 306.1 K. At higher W'0 the system was in a two-phase state. The addition of lithium chloride makes the system become motionless in a one-phase microemulsion state at W0 above 30. This work demonstrates interesting pressure-, temperature, and salt effects on an enzyme-catalyzed esterification and/or maintenance of a one-phase microemulsion in supercritical fluids from practical and theoretical points of view.

The Promotion of Alkaline Fading of Crystal Violet by AOT Micelles Dispersed in Supercritical Ethane Medium

The alkaline fading of crystal violet (CV) is accelerated by using a w/o microemulsion of H2 O/AOT/ethane under supercritical conditions. The rate of fading can be changed by three orders of magnitude with the molar ratio of water to AOT and operating pressure. The highest rate of CV fading observed is larger by a factor of 100 or more compared to those reported so far in the literature. The structure of AOT molecules and the type of interior water molecules seem to account for the rate enhancement with an increase in the water/AOT molar ratio. It is suggested that the intermicellar and AOT-ethane interactions are of significance for the promotion effect of pressure.

The Nature and Structure of Water/AOT/Ethane (W/O) Microemulsion under Supercritical Conditions Studied by High-Pressure FT-IR Spectroscopy

High-pressure FT-IR spectroscopy was used to study a W/O microemulsion system of AOT micelles dispersed in supercritical ethane. The system was found to be in a single-phase state depending on the pressure (P), temperature (T), and water-to-AOT molar ratio (W0). The number of water molecules that the AOT micelles were able to solubilize reached about 15 at 35.0 MPa and 343.1 K. This presents a striking contrast to AOT micelles in ordinary organic liquids, in which the number of solubilized water molecules ranges from 2 to 6. The solubilized water molecules were present in three different types and their relative quantities depended on W0, P, and T. The presence of trans-like and/or gauche-like AOT isomers also depended on the operating variables, which affected the interactions between AOT molecules and the water molecules solubilized in them. The solubilization of water and the rotational isomerism of AOT were significantly influenced in different ways by the addition of salts, including lithium chloride, guanidine hydrochloride, and cesium iodide.

[Two cases of Ewing's sarcoma originating from the adult rib].

Two cases of Ewing's sarcoma originating from the adult rib were reported. Case 1: A 23-year-old male was admitted for further examination of a right anterior chest wall tumor. The tumor was resected and the pathological examination revealed Ewing's sarcoma. Adriamycin, vincristine, cyclophosphamide and actinomycin-D were administered. After 1 year the patient died due to local relapse. Case 2: A 28-year-old male was found to have a left extrapleural tumor on chest roentgenogram. He responded to chemotherapy consisting of CDDP, etoposide, ifosfamide and radiotherapy at a dose of 38.4 Gy before surgery. On the surgical specimen no tumor cells were observed and his postoperative course has been good. According to our experience, exact preoperative diagnosis and adjuvant therapy are necessary to improve the prognosis of Ewing's sarcoma patient.

[Clinical studies on sulbactam/cefoperazone in the field of obstetrics and gynecology].

Sulbactam cefoperazone (SBT/CPZ), a combination drug of SBT and CPZ, was administered to 5 cases with obstetrical and gynecological infections in a daily dose of 2-6 g for 3-5 days. Clinical efficacy was good in 4 cases and poor in 1 case with adnexitis. Bacteriologically, organisms were detected in 2 out of 5 cases, beta-lactamase producing P. aeruginosa was detected in 1 case, but, their bacteriological responses were not clarified. Neither side effect nor abnormal laboratory findings due to this drug were observed. From the results we concluded that SBT/CPZ was an effective and safe antibiotic in the field of obstetrics and gynecology.