Production of erythroid potentiating factor(s) by a human monocytic cell line

U-937 is a human monocytic cell line that has been to elaborate factors that affect normal human hematopoiesis in vitro. Studies on the effects of these factors demonstrated an erythroid potentiating factor (EPF) and a potent inhibitor of granulocyte-macrophage (CFU-GM) colony growth. The EPF was present in both serum-containing and serum-free U- 937 conditioned media, had a dose-dependent effect on erythroid colony formation and was remarkably heart stable. The CFU-GM inhibitory activity was also detected in serum-free conditioned medium, was dose- dependent, heart labile and its effect was reversed by Indomethacin. Indomethacin (Sigma, St. Louis, Mo.) did not alter the erythroid effects of the U-937 conditioned medium. No colony stimulating factor (CSF) or erythropoietin (Ep) could be detected in this medium. The existence of a human cell line capable of production EPF without simultaneous CSF production will permit further studies on the biochemical and biologic nature of these factors.     

Axillary lymph node metastases in breast cancer: preoperative detection with US

The importance of axillary node status in the prognosis of breast cancer led the authors to conduct a prospective study comparing the value of clinical examination with ultrasound (US) performed by a transpectoral approach. All 60 patients examined underwent axillary dissection. Sensitivity was 45.4% for clinical examination versus 72.7% for US. US provides valuable information for breast cancers treated solely by irradiation, after insufficient dissection, and for large tumors not amenable to primary surgery. When the nodal region is treated by surgery and/or radiotherapy, local monitoring with US appears unnecessary owing to the low incidence of nodal recurrence.     

CT densities in delayed iodine hepatic scanning

Sixty patients underwent CT scanning of the liver prior to, immediately after, and four hours after intravenous administration of 60% meglumine diatrizoate. Twenty patients received a 50 ml bolus of contrast material (14.6 g of iodine), 20 received 100 ml (29.2 g of iodine), and 20 received 200 ml (58.4 g of iodine). In each group, delayed CT scanning safely raised the inherent density of the liver significantly (increase of 14.3% using 50 ml; 23.9% using 100 ml; and 40.7% using 200 ml). Thus, delayed scanning with doses presently used in abdominal and neurological CT examinations may be helpful in detecting hepatic lesions.     

In-111-labeled liposomes: dosimetry and tumor depiction

Neutral phospholipid vesicles (liposomes) were loaded with 0.5 mCi (18.5 MBq) indium-111 and administered to 24 patients with various types of cancer. The median diameter of the liposomes was 77 nm, and lipid dose was 0.78-6.25 mg/kg. Scans obtained 24 and 48 hours after injection of In-111 liposomes showed gradual blood clearance with homogeneous uptake in the normal liver and spleen. Dosimetric estimates for these organs were 2.3 +/- 1.1 and 2.3 +/- 1.4 rad (.02 +/- .01 Gy), respectively, with a whole-body estimate of 0.28 rad (.003 Gy). Radiation dose did not correlate with lipid dose. Total renal excretion of In-111 was less than 2% of the injected dose in all but two patients. Transient eosinophilia occurred in two patients. Tumor was seen in the scans of 22 of 24 patients (unbinded readings). In-111-labeled liposomes may enable the demonstration of suspected or unsuspected sites of tumor.     

Acetylcholinesterase activity of lymphocytes: an enzyme characteristic of T-cells

Acetylcholinesterase (AchE) activity of normal human peripheral blood lymphocytes was determined by an adaptation of the colorimetric and radiometric techniques described for other cells. The enzyme activity seemed to be correlated to the number of T-lymphocytes in the blood. To decide whether only the T-cells possess AchE activity the lymphocytes were separated on Leucopac filter and on Percoll density gradient. B-lymphocytes had no detectable enzyme activity, while the T-lymphocyte fraction represented the total activity measured in the unseparated sample. The majority of AchE activity could be demonstrated in T-lymphocytes of lower density (TLD). The role of AchE in the plasma membrane of various blood cells is not known. Nevertheless, the enzyme is a good marker of the integrity and functional state of the membrane. The difference observed in AchE activity of the lymphocyte populations seems to be suitable for using it to characterize T-lymphocytes.