An incubation system for the NMR study of kidney tubules

Isolated kidney cortical tubules require a very rapid oxygen supply and mechanical agitation to be optimally functional. A sample chamber in which a tubule suspension is oxygenated by recirculating oxygen gas inside a coil of dialysis fibers to avoid cell loss through bubbling and in which the tubules are agitated by a gas-driven turbine has been designed. In such a system, dog cortical tubules (35-45 mg/ml) were found to be metabolically stable for more than 3 h as indicated by linear lactate consumption and glucose production. Small pH variations resulting from carbon dioxide and bicarbonate productions were measured. Good-quality 23Na NMR spectra of dog kidney cortical tubules were recorded with such a system, allowing a 1-min time resolution.     

Antibody-dependent lymphocyte killer function in human immunodeficiency diseases.

Antibody-dependent cell immunity to the lymphocyte system (ABCIL) has been shown to be a function of a non-thymus-processed cell in the experimental animal. To evaluate its role in the human and to assess its clinical usefulness, we assessed ABCIL in twenty-five patients with various immunodeficiency (ID) syndromes. Our technique measures the lysis of 51Cr-labelled normal human lymphocytes coated with HL-A-specific antibody. Cytotoxicity is expressed as a percentage of 51Cr released after subtracting the spontaneous target cell release. Mean values in normals are 20+/-2 (s.e.). The ten patients with AB deficiency had a mean ABCIL of 7-9+/-2 (Pless than0-01). All eight patients with cellular ID had normal ABCIL (18+/-2), while the ten patients with combined ID had variable results. Effector cell function in the ABCIL test correlated (r=0-74; Pless than0-05) with the percentage of B cells in the peripheral blood. No correlation was found between ABCIL function and serum immunoglobulin levels or rosette-forming cells in the peripheral blood. There is a function for B lymphocytes other than as a precursor of antibody-synthesizing cells.