The image qualities of radiograms produced by a film changer (AOT, made by Elema-Schonander) under various conditions, especially concerned with cerebral angiography in our institution, were evaluated by graphical representations of the contrast response in comparison with the image of ordinary cassette radiography. The results of evaluation were demonstrated in Fig.5-8. Several practical aspects of their evaluation in serial cerebral angiography in routine work were briefly discussed.
A comparison was made of four X-ray analyzers including a new type and conventional direct measuring methods. Values for voltage by X-ray analyzers agreed with those by conventional direct measuring methods for the 2 peak, 12 peak, and constant potential generators. Exposure periods determined by X-ray analyzers also agreed with those by conventional direct measuring methods over 10 msec. The stability and reproducibility results by X-ray analyzers are excellent. They are thus applicable to the quality control of X-ray generators. There are two types of the X-ray analyzers; one is for the storage of data, and the other is not. They differ in size. A more appropriate type should be used according to certain purposes and conditions. In the case of inverter type X-ray generators with the same percent ripple and frequency as constant potential generators, the data for tube voltage by X-ray analyzers agreed with those by conventional direct measuring methods. In the case of generators with larger ripple and higher frequency, the data differed from those by conventional direct measuring methods. The error is attributed to the sampling time of X-ray analyzers.
The luminescent electrooxidation of methanol in tris(2,2' - bipyridine) ruthenium (Ⅱ) [Ru(bpy)32+ ] alkaline solution on a glassy carbon electrode has been studied. At the potential of +1. 28V (vs. Ag/AgCl), methanol was oxidized to methoxyl radical, and the excited formaldehyde was generated by a disprotionation reaction of the methoxyl radical to yield light emission with the wavelength of 545 nm. Brighter light emission could be found if small amount of Ru(bpy)32+ was added. The luminescent wavelength was 608 nm because Ru(bpy)32+ was oxidized to Ru(bpy)33+ and reacted with methoxyl radical to produce the excited state of Ru(bpy)32+* .
NAGAMOTO, N., SAITO Y., IMAI, T., SUDA, H., TAKAHASHI, S., USUDA, K., KANMA, K., SAGAWA, M., OHTA, S., SATO, M., NAKADA, T., SATO, H. and HASHIMOTO, K. Histogenesis and Characterization of Minimal Bronchogenic Carcinoma Observed in Heavy Smokers. Tohoku J. exp. Med., 1987, 153 (3), 265-284 - The present article describes the results of observations of 11 lesions in 8 cases of roentgenographically occult in situ or microinvasive squamous cell carcinoma with a size of 4×4mm or less which were detected by detailed histologic investigations of 59 cases of occult bronchogenic carcinoma. The 59 cases were discovered mainly by mass screening for the detection of early lung cancers using chest x-ray combining sputum cytology for heavy smokers. The resected specimens were processed with the method of serial block sectioning. All the serial blocks of these minimal carcinomas were observed in detail to confirm the presence or absence of carcinoma and of morphological changes of the bronchial epithelium contiguous to carcinoma. Adjacent to carcinoma, there were normal bronchial epithelium in three lesions, squamous metaplasia with marked atypia in four, basal cell hyperplasia in two, and markedly atypical basal cells without hyperplasia in two. An inference on histogenesis of bronchogenic squamous cell carcinoma was drawn from the detailed observations as follows: (1) A carcinoma develops in the area of squamous metaplasia with marked atypic; (2) A carcinoma arises from markedly atypical basal cells with or without prior hyperplasia. Even in such small-sized carcinomas, there is a difference in type of invasion within the bronchial wall. One is the creeping type which shows a marked horizontal growth and the other is the penetrating type which shows a marked downward growth.
