[Evaluation of 99mTc-HIDA complex as a cholescintigraphic agent (author's transl)]

In the reaction labeling N-(2,6-dimethylphenylcarbamoylmethyl) iminodiacetic acid (HIDA) with 99mTc, several complexes with different chemical characteristics were observed to occur with slight changes in the labeling conditions. Among these complexes, a complex detected in the bile of rats was limited to one complex, named as complex II. The preparation method of 99mTc-HIDA complex II and the exchange reaction between this complex and penicillamine indicate that 99mTc is coordinated with HIDA as low-hydrolyzed 99mTc in this complex. This complex is excreted rapidly through the bile and within 1 hr, about 65% of the total activity injected is recovered from bile in rats. The organ distribution of this complex was studied in mice by radioassay and in rabbits by scintillation camera and, in both cases, the radioactivity was accumulated in the gallbladder. These results suggest that the 99mTc chemical state, low-hydrolyzed state, relates to the bile excretion behavior of this complex, a potentially useful cholescintigraphic agent.

Blood chimeric twins: an example of blood cell chimerism

A man and his twin sister were found to have two types of circulating red cells. The man had 89% A1 cells of his own and 11% A1B cells derived from his sister. The woman had 12% A1B cells of her own and 88% A1 cells derived from her brother. The two lines of red cells also had different Duffy and Kidd groups. The lymphocyte karyotype in the brother was 68% XY and 32% XX, and that in the sister was 60% XX and 40% XY. The possible mechanisms for producing different proportions of red cells and lymphocytes are discussed.

Preparation of a chemically characterized 99mTc-penicillamine complex

In the reaction labeling penicillamine with 99mTc, serveral different chemical states of 99mTc were observed to occur with slight changes in the labeling conditions, such as the concentrations of penicillamine, 99mTcO4-, stannous chloride, and hydrogen ion. We have studied the effects of these conditions on the formation of the monomer complex that we call Complex I, in which 99mTc is coordinated with the penicillamine as 99mTcO+2. Our approach is based on the thesis that Complex I formation competes with 99mTcO+2 hydrolysis, which leads to other 99mTc complexes. On this basis, the specific labeling conditions for Complex I formation have been established. Highly reproducible in vivo behavior in mice and rats was obtained with this chemically controlled Complex I.

Frequency-dependency of pulmonary compliance and its relation to airway conductance

Dynamic compliance was determined in patients with 6 chronic obstructive lung diseases, 2 sarcoidosis and in 4 control healthy subjects at several breathing frequencies ranging between 0.2 and 1.3 Hz. The compliance exhibited an apparent fall with the increase in frequency of the patients, while it remained unaltered in the controls. A significant correlation was found between the frequency-dependency of compliance and the airway conductance determined plethysmographically. A similar relationship was also found in previous data appearing in the literature. Mathematical simulation based on the time constant theory revealed that the above correlation might be expected when airway obstruction occurred inhomogeneously in the peripheral region, of the lungs leaving the central airways intact.