The extraction behavior of Zn, Ni and Fe in the alkaline solution has been studied with diethyldithiocarbamate. Zn (II), Ni (II) and Fe (II) can be extracted into CCl4, whereas Fe (III) remains in the aqueous layer. The behavior of Zn (II), Ni (II) and Fe (II) is explained on the basis of the extraction equilibrium taking into account the hydrolysis reactions of these ions. The apparent formation constant of ZnCO3is calculated to be 5×106. Accordingly, the presence of carbonate has no effect on the extraction of Zn (II) under a given condition.
A measurement of the15N abundance ratio in trace amounts of amino acids by GC-MS is possible. However, in the N-trifluoroacetyl ester derivatives of amides, the15N abundance ratio of amido base nitrogen in the asparagine and glutamine is impossible to measure. The present report describes an analytical method for determination of the15N abundance ratio of amido base nitrogens of amides. Normal and15N amido base nitrogen-labeled asparagine and glutamine are converted to the trimethylsilyl derivative of methylthiazolinone (TMS-MT) . The 2TMS, and 3TMS MT derivatives of asparagine and glutamine formed are analyzed by a magnetic field scanning method using GC-MS. The mass fragment ions of asparagine of m/e 388 and 242 were monitored. For glutamine, the mass fragment ions of ml e 402 and 131 were monitored. By this method the15N abundance ratio of amido base nitrogen in the amides is measurable with a coefficient of variation of less than 0.6%.
The correlative study of myocardial perfusion assessed by201Tlmyocardial ECT with the pathological finding of the heart was performed in 10 autopsied cases with mean age of 77 years old (range: 60-90 y) . In 6 cases with myocardial infarction (MI) 7 perfusion defects were observed, that was, 3 in anteroseptal wall, 1 in anterolateral wall and 3 in posterior wall on the images of SPECT. Seven MIs were also found in postmortem examination. Six MIs were observed at autopsy corresponding to perfusion defect on SPECT images. In one myocardial perfusion defect at inf eroposterior portion on SPECT, α non-transmural MI was found at anteroseptum. In one case with valvular disease a false positive result was obtained at posterior wall where neither myocardial necrosis nor fibrosis was observed at autopsy. This case had aortic stenosis due to bicuspid aortic valve by autopsy. The ventricle was devided into 16 segments in each of 4 short axial images to evaluate extent of MI. SPECT for extent of MI showed sensitivity of 81.9%, specificity of 96.0% and diagnostic accuracy of 92.5%. False negative segment was apt to be observed at the surrounding of non-transmural MI or basal half of left ventricle (L V) with transmural MI, while false positive segment was at posterior portion of basal half of LV. It was concluded that myocardial ECT was useful for evaluation of the site and extent of MI.
Behavior of40Kand137Cs on the radial direction of the annual ring of sugi (Cryptomeria japonica D. DON) was investigated by means of γ-ray spectrometry. It was confirmed that40Kand137Csmove from one annual ring to another. The concentration of the activity of these nuclides are almost constant in the heartwood, but changes markedly near the sap and heartwood boundary. Distribution profiles of these radioactive nuclides along the radial direction of the annual ring are similar to those of their stable isotopes and of another alkali metal elements such asNaandRb.The results suggest that alkali metal elements have intimate relation with the heartwood formation of sugi.
A new method was developed to display left ventricular wall motion using two dimensional polar representation of cardiac SPECT image. After intravenous administration of 740 MBq (20 mCi) 99mTe (in vivo labeling of red blood cell), ECG-gated SPECT image of cardiac pool was recorded (32 directions, 180 degrees) . The short axis images of left ventricle were constructed at end-diastole (ED) and end-systole (ES) . Then the functional images of (ED-ES) /ED were calculated at each compatible slices and displayed in color according the degree of wall motion. In 8 cases with cardiac diseases this method was applied and clinically useful functional images could be obtained. The area of akinesia or hypokinesia are successfully demonstrated clearly separated from the area of normokinesia. We conclude that this method is useful to show left ventricular wall motion and to evaluate the segment and grade of abnormal wall motion of left ventricle.
In a field of bio-medical science, low energy β-emitting nuclides, such as3Hand14C, are used frequently. However, contamination with those nuclides on laboratory workers is not detectable by the ordinary hand-foot-cloth monitor, if it occurs. Therefore, a new contamination check method, hand washing combined with lyophilization, was studied and feasibility of the method has been confirmed. The lyophilizaion step of the method takes about ten hours so it is not practical to use the method as a daily contamination check. However, it can be done at regular intervals and it will give valuable information for the maintenance of the radioisotope laboratory.