Measurement of functioning hepatocyte mass via [99mTc]galactosyl-neoglycoalbumin

Technetium-99m-galactosyl-neoglycoalbumin (TcNGA) is a synthetic radiolabeled ligand specific for hepatic binding protein (HBP), a receptor that resides exclusively on hepatocytes.In vivo measurement of receptor concentration was obtained via kinetic analysis of liver and blood time-activity data obtained during the hepatic clearance of intravenously administered TcNGA. The purpose of this study was to assess receptor concentration as a measure of the functioning hepatocyte mass. Therefore, TcNGA and dualinjection indocyanine green maximal removal rate (ICG R_max) studies were performed on nine patients with hepatic cirrhosis associated or not with hepatocellular carcinoma. Receptor concentration was compared with ICG R_max, which is a validated method for the estimation of the functioning hepatocyte mass. The correlation coefficient was 0.76 (P=0.017). It is concluded that HBP concentration ([HPB]_o) as measured by functional imaging is a measure of functioning hepatocyte mass. This implies that measurement of an individual's receptor concentration by using nuclear medicine techniques provides an objective index of hepatic functional mass and supports attempts to rigorously evaluate [HBP]_o for its clinical efficacy.     

非溶蚀型药物体系的释放动力学新模型──Fick第一扩散定律的修正及其应用

基于以下两点事实:Fick第一扩散定律中的扩散系数并非严格的常数,它随浓度变化;Fick第一扩散定律只适用于浓度梯度恒定的稳定扩散,而许多实验表明浓度梯度也是一个时间函数,本文对Fick第一扩散定律作出两点修正将原定律中浓度梯度和扩散系数分别修正为时间函数和浓度函数,从而导出关于非溶蚀型药物体系的释放动力学模型。该模型较其他常用释放模型有更好的拟合效果,其参数也有较为明确的物理意义。     

Immune parameters in athletes before and after strenuous exercise

Secretory IgA levels were studied in nationally ranked Nordic skiers before and after the national cross-country races held in February 1981. Comparing the skiers with age-matched controls, there was a significantly lower level of salivary IgA before the race. Concentrations of IgA decreased further following the competition (50 km for males; 20 km for females) to very low levels. There also were a significant increase in the percentage of B lymphocytes and a decrease in the null population (non-T, non-B) in the athletes after the race compared with the controls. The mechanism responsible for these changes is unknown, but the low salivary IgA levels may result from depletion of nasal fluid and/or malfunction of the mucosal plasma cells due to a decreased temperature in the mucous membranes. We speculated that a temporary antibody deficiency on the mucosal surface might lead to a susceptibility to acquiring viral and bacterial infections, especially during the interval immediately following strenuous exercise.     

Interstitial hyperthermia in combination with brachytherapy

Flexible coaxial cables were modified to serve as microwave antennas operating at a frequency of 915 MHz. These antennas were inserted into nylon afterloading tubes that had been implanted in tumors using conventional interstitial implantation techniques for iridium-192 seed brachytherapy. The tumor volume was heated to 42-45 degrees C within 15 minutes and heating was continued for a total of 1 hour per treatment. Immediately following a conventional brachytherapy dose and removal of the iridium seeds the tumors were heated again in a second treatment. This interstitial technique for delivering local hyperthermia should be compatible with most brachytherapy methods. The technique has proved so far to be practical and without complications. Temperature distributions obtained in tissue phantoms and a patient are described.     

Value of plasma calcium, phosphate, and alkaline phosphatase measurements in the diagnosis of histological osteomalacia

Plasma calcium and phosphate concentrations and alkaline phosphatase activities were examined retrospectively in 50 patients with histologically proven osteomalacia and 50 age- and sex-matched control subjects with normal bone histology. An abnormal plasma alkaline phosphatase activity was more useful than an abnormal plasma calcium or phosphate concentration in distinguishing between normal and osteomalacic subjects, producing a false-negative rate of 14% and a false-positive rate of 8%. False-negative and false-positive rates of 10% and 8% respectively were obtained when the presence of an abnormality in any one of the three biochemical measurements was used as a predictor of histological osteomalacia. When discriminant analysis was applied to plasma calcium, phosphate and alkaline phosphatase together a false-negative rate of 12% and a false-positive rate of 0% was obtained.