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An enzyme immunoassay for NuMA was evaluated in a retrospective clinical study for its potential utility in the detection of colorectal cancer. The concentrations of NuMA and CEA (Abbott IMx) were measured in sera from 86 patients (presurgical) with colorectal cancer, 72 subjects with benign gastrointestinal diseases, 80 subjects with risk factors for colorectal cancer, and 141 age-matched healthy subjects. Reference values for NuMA and CEA were calculated by two methods: 95% cumulative distribution and ROC analyses versus healthy subjects. By the first method, NuMA and CEA both had approximately 20% sensitivity for colorectal cancer. By the second method (which generated lower reference values), NuMA was more sensitive than CEA for colorectal cancer. This improved sensitivity was most evident in Dukes B subjects. By either analysis method, NuMA was more sensitive than CEA for subjects at risk for developing colorectal cancer, whereas CEA was more specific for benign gastrointestinal diseases.

Flow cytometric or manual microscopic techniques can be employed for the identification and quantitation of T lymphocytes in peripheral blood. Two flow cytometric devices (the Ortho Spectrum III and the Cytofluorograf FC200) were compared with each other and with two manual methods, each of the latter performed by two independent investigators, to evaluate the technical sensitivity and reproducibility of each method. Flow cytometry proved to be the most sensitive and consistent procedure for the enumeration of T cells. Among the manual methods examined, the enhanced immunofluorescence technique was found to be the least subjective and most reproducible.

Immunoglobulin-synthesizing cells from the spleen and bursa were fractionated by the 1 X G sedimentation velocity technique and characterized by their ability to synthesize immunoglobulin and by staining with fluorescent anti-light chain chain. Four subpopulations of immunoglobulin-synthesizing cells were identified. In the bursa, slowly sedimenting (S 2.3 mm/hr) and rapidly sedimenting (S greater than 3.5 mm/hr) subpopulations with surface immunoglobulin were present; in the spleen, a slowly sedimenting (S 2.3 mm/hr) subpopulation with surface immunoglobulin and plasma cells (S greater than 3.5 mm/hr) with large concentrations of intracellular immunoglobulin existed. The subpopulations differed most markedly in their ability to synthesize immunoglobulin (cpm Ig synthesized/10(6) Ig-positive cells); the rates of immunoglobulin synthesis were in the ratio 1:2:1:900. The slowly sedimenting B cells from the spleen and both subpopulations of B cells from the bursa released small amounts of immunoglobulin into the culture media, whereas, the plasma cells released immunoglobulin at a rate as much as 3700 times greater. Bursal B cells could be further distinguished from splenic B cells by a greater amount of DNA synthesis.

Evidence is reviewed that supports the concept of extrinsic stem cell colonization of inductive micro-environments for B-cell formation in the bursa of Fabricius of chickens and foetal liver of mammals. In these organs, the first distinctive marker of B-lineage differentiation (readily detectable immunoglobulin) is synthesized and displayed on cells which have extensive proliferative and differentiative capacity. The degree of commitment of these cells to the synthesis of trace or large quantities of immunoglobulin of the respective major classes when they colonize peripheral lymphoid tissues and the role of antigen in this process are considered.

The T lymphocyte population was studied by immunofluorescent staining with monoclonal antibodies and laser flow cytometry in the blood of 50 patients with end-stage renal disease undergoing long-term maintenance intermittent hemodialysis. The absolute number of T cells was lower in patients receiving dialysis for more than one year (p less than 0.001), as was the absolute count of helper T cells (p less than 0.005). In patients under 30 years of age, the absolute number of helper T cells was markedly reduced, whereas the number of suppressor/cytotoxic T lymphocytes was not changed. In patients between the ages of 30 and 60 years, both helper and suppressor cells were significantly reduced. In patients over 60 years of age, only the number of helper T cells was reduced. The in vitro response of patients' lymphocytes was reduced both in the mixed lymphocyte reaction (p less than 0.01) and after phytohemagglutinin stimulation (p less than 0.001). Natural killer cytotoxicity of patients' peripheral blood mononuclear cells, however, was unaffected.