The leachate generated from landfill and aqueous solutions of a humic acid (HA) and fluvic acid (FA), which were separated from the leachate, were irradiated with60Coγ-rays under bubbling air. The effects of irradiation on the pH, TOG, molecular weight distribution, and IR absorption spectrum were investigated by gelpermeation chromatography and IR spectrophotometry. With increasing dose, the total organic carbon content in these solutions decreased smoothly, while the pH of the solution decreased steadily at first to about 3 from the neutral, then became almost invariant. This result suggests the formation of some organic acids by irradiation. In the HA solution which contains mainly high molecular-weight substances, the amount of the high molecular-weight compounds decreased with dose and that of the lower molecular-weight ones, on the contrary, increased and then decreased steadily by subsequent irradiation. In FA solution containing mainly low molecular-weight substances, on the other hand, the molecular-weight distribution shifted to the lower molecular-weight side. These results show that HA and FA were degradated to lower molecular weight compounds. The both acids do not give any new IR absorption band by irradiation, but unidentified com-pounds having oxygen-containing functional groups, such asC-OandCOO-and/orC=O, seem to be produced at first then decrease with dose. Acetic and formic acids were confirmed to produce as organic acids by high-speed liquid chromatography.
Myocardial scintigrams with99mTc-pyrophosphate (PYP) were performed in 30 patients with acute myocardial infarct (AMI) and positive scintigrams were obtained in the 24 patients. In 12 patients the size of the AMI estimated from the scintigram with99mTc-PYP was compared with the pulmonary capillary wedge pressure (PCWP) . In the 7 patients with PCWP below 10 mmHg the mean area of the AMIs was 22±5.5 cm2and that of in the 5 patients with PCWP beyond 10 mmHg was 41±12.4 cm2. This difference was statistically significant (p<0.05) . In comparison with chest X-ray findings, the average size of the AMIs among 6 patients with alveolar and/or interstitial edema was 43±11.9 cm2and that of among 8 patients without pulmonary edema was 25±9 cm2. The left ventricular ejection fraction (LVEF) was obtained by first pass method. In 12 patients LVEF and PCWP was compared. The 7 patients with PCWP below 10 mmHg did show significantly larger LVEF (49±8.2%) than that of 5 patients with PCWP beyond 10 mmHg (33±6.1%) (p<0.01) . The mean LVEF in the 7 patients with pulmonary edema was 35±10.2% and that of in the 8 patients without pulmonary was 48±5.3%. Myocardial scintigram and radionuelide angioeardiography with99mTc-PYP were useful for evaluation of the left ventricular function as well as detection of the AMI.
Fifteen patients with a suspected pancreatic disease were examined by both pancreatic scintigraphy using75Se-selenomethionine and endoscopic retrograde pancreatic parenchymography (ERPP) . These two diagnostic procedures have different mechanism of parenchymal imaging. In scintigraphy, uptake of75Se-selenomethionine depends on metabolic activity of the pancreatic parenchyma while in ERPP visualization of pancreatic tissue depends on patency of the pan-creatic duct, permeability of the periductal tissue and cell function of the pancreatic parenchyma. In comparative study, excellent concordance of findings occurred in 11 of 15 cases. An interesting difference of finding occurred in a case of chronic pancreatitis who had marked involvement of pancreatic duct. In this case, scintigraphy visualized entire pancreas though uptake of the radioisotope was diffusely diminished, while ERPP failed to visualize the body and tail. Another interesting finding was difference of image of pancreatic body. In scinti-graphy, a relatively cold area is often seen in body of the pancreas in normal subjects and explained as a result of anatomical thinning of the organ by impression of vertebra and major blood vessels. In our series, 5 cases showed such a finding in scintigraphy, while in ERPP 4 of these 5 cases showed no evidence of localized thinning of the organ. A combination of these two imaging procedures of pancreatic parenchyma with different mechanism provides more detailed anatomical and pathophysiological condition of the pancreatic diseases.
In order to study the merit or demerit of the dehydration or hydration as the preparation of renographic examination, the following 25 cases—11 cases of uterine cancer, 2 cases of breast cancer, a case of esophageal cancer, pharyngeal cancer, maxillary cancer, salivary gland tumor, leiomyosarcoma of uterus and others are examined by renography using131I-hippurate. Renogram is performed in case of patient's dehydration and followed in case of patient's hydration with 600 ml of water intake. Renographic findings such as Tmax, T1/2, HB/HAand step-like pattern are studied as a parameter. Following 600 ml water intake, Tmax is significantly shortened and the step-like pattern is disappeared. This study is strongly suggested that patient's hydration is significantly necessary in the performance of renogram as the preparatory procedure.