THE BULLETIN OF TOKYO MEDICAL AND DENTAL UNIVERSITY
Online ISSN : 2435-0761
Print ISSN : 0040-8921
28 巻 , 3 号
選択された号の論文の4件中1~4を表示しています
  • Abdul R. S. BUKHARI
    1981 年 28 巻 3 号 p. 77-86
    発行日: 1981年
    公開日: 2020/11/22
    ジャーナル オープンアクセス
    A theoretical model for computer simulation has been introduced to predict the unipolar epicardial potentials corresponding to the different angles of propagation of the excitation wavefront. The simulated waveforms were compared with those observed in the animal experiments. In these experiments three unipolar epicardial potentials and one intramural potential were recorded using a thumbtack electrode with and without bipolar epicardial pacing. The direction of the propagation of the excitation was determined from the arrival time of the recorded waveforms. There was a close correspondence between the observed and the simulated waveforms. Furthermore, it was attempted to establish a quantitative relationship between the unipolar potential waveshape and the angle of propagation θ of the excitation. The difference between the positive and the negative peak normalized by the peak-to-peak height was used to define the change in the wavshape. A distinct relation was found to exist between the normalized difference R and the angle θ for the simulated potentials. There was a good correlation (r= 0.96 for n=85) between angle θ1 calculated from the arrival times and θ2, determined from R, which suggests that the angle θ can be estimated from the unipolar epicardial potentials alone, without using any intramural electrode.
  • Yoshihisa IMAMURA, Shuji SASSA, Ryohei OKAMOTO
    1981 年 28 巻 3 号 p. 87-90
    発行日: 1981年
    公開日: 2020/11/22
    ジャーナル オープンアクセス
    The interaction of estrogen and androgen was studied at the estrogen receptor level of adult rat uterus by the in vivo experiment. Both the free and total estrogen receptor in the cytosol and nucleus were assayed by the controlled pore glass beads method [2]. Testosterone was given by daily injection for 5 days to the rats treated with estradiol dipropionate (long-acting estradiol) 3 or 5 days before. In the estradiol dipropionate-treated rats the plasma estradiol concentration remained at an extremely high level for 7 days and then decreased to 5-fold of that of proestrus control by the 14th day. There was no significant change in the uterine estrogen receptor of the adult rat with a high estradiol concentration induced by testosterone.
  • USING DUAL ENERGY RADIOGRAPHIC DENSITOMETRY METHOD IN A SINGLE EXPOSURE
    Tsuguhisa KATOH, Kimio SAKAMAKI, Tadashi NAKAMURA
    1981 年 28 巻 3 号 p. 91-98
    発行日: 1981年
    公開日: 2020/11/22
    ジャーナル オープンアクセス
    Quantitative observations of bone mineral distribution in the maxillo-mandibular bone are of great interest in the clinical field. Radiographic densitometry is the most simple method but the film density is influenced by the X-ray exposure and processing conditions and by the soft tissue layer. This fluctuation can be corrected from the image of the wedge of the reference material simultaneously projected with the object on the same film. There is no other method than the dual energy technique to correct the effect of the soft tissue layer to be applicable in the maxilla-mandibular region. Two radiograms of the object obtained by a different beam quality represent the different X-ray contrast. When the penetrated fractions of the incident X-rays through the object at different energies are obtained from the film density and the characteristic curve of the film and substituted for the first order simultaneous equation whose coefficients are the mass attenuation coefficients of the bone mineral and soft tissue to the X-rays of the respective energy, the bone mineral content is obtained as the solution of the equation in the form of the product of the mineral density and the thickness of the bone (mg/cm2). This paper shows the principle of the method and the results of the experiment which agreed closely with the data obtained by the chemical assessment.
  • Katsuiku HIROKAWA, Shigeru HATAKEYAMA, Toshihiko SADO
    1981 年 28 巻 3 号 p. 99-109
    発行日: 1981年
    公開日: 2020/11/22
    ジャーナル オープンアクセス
    The anti-SRBC antibody response of normal young adult mice (about 3 months old) was specifically suppressed, when the spleen cells derived from the syngeneic donor mice that had been previously primed with a high dose of SRBC were adoptively transferred at the time of antigenic challenge. The suppression was antigen-specific and was mediated by a fraction of the immune spleen cells which appeared to belong to either B cells or their progeny antibody-forming cells. The differences were observed in the properties of the suppressor cells in terms of the period after the priming and the radiosensitivity; i.e., immune spleen cells taken from the mice which had been immunized with SRBC 5 days earlier were able to suppress only 19S PFC, whereas those taken from the mice which had been immunized 14 days earlier were able to suppress both the 19S and 7S PFC responses, and the former cells were susceptible to 400 R X-rays, but not the latter. These two types of suppressor cells appeared to play an important role in the regulation of the sequential change of 19S and 7S antibodies during the primary immune response.
feedback
Top