ABSTRACT
Hybridomas were established between murine spleen B cells and the thymoma cell line BW5147, to purify the migration stimulation factor (MStF), a molecule likely involved in immunosuppression. The parental B cells were from Lo/PHA mice previously shown to produce high levels of MStF after immunization by appropriate (tolerogenic) doses of ovalbumin. Among the positive clones, B9 was selected, since it produced high levels of MStF constitutively, and no immunoglobulin. This clone was shown to contain the genome of the B-cell fusion partner, since one of its L chain genes had undergone a VK-JK rearrangement. Isolation of MStF by size-exclusion chromatography showed 2 major peaks of activity, one of which eluted in a 20-kDa, almost protein-free fraction. This elution is unlikely to correspond to the true molecular mass, since MStF was found not to be a protein. Indeed, MStF was TCA-soluble, thermoresistant, highly hydrophobic and protease-resistant, but activity was abolished by neuraminidase digestion. The possibility of its being a small molecule transported by a protein carrier was also ruled out. These results suggest that MStF is a complex molecule containing both sialic residues and a lipid moiety. Experiments are planned to further investigate the chemical structure of this unusual B-cell factor.
Subject(s)
B-Lymphocytes/metabolism , Cytokines/biosynthesis , Animals , Blotting, Southern , Cell Movement/physiology , Chromatography, Gel , Clone Cells , Cold Temperature/adverse effects , Cyclohexanes/pharmacology , Cytokines/drug effects , Cytokines/isolation & purification , Fibronectins , Hybridomas , Mice , Neuraminidase/pharmacology , Pepsin A/pharmacology , Trichloroacetic Acid/pharmacology , Trypsin/pharmacologyABSTRACT
Because hospitals are under increasing pressure to contain costs and yet continue to provide high quality patient care, trustees must be able to make cost-effective technology acquisition decisions. The author discusses the major factors that affect technology purchasing decisions, from information gathering to internal considerations such as financial constraints and the hospital's long-range goals. He also examines the expected effect of prospective pricing on technology management and decisionmaking.
Subject(s)
Medical Laboratory Science/economics , Purchasing, Hospital/economics , Capital Expenditures , Decision Making , Governing Board , Humans , United StatesABSTRACT
The probability of gonorrhea in men attending the DeKalb County, Georgia, clinic for sexually transmitted diseases with the chief complaint of urethral discharge and/or dysuria and whose urethral smears contain intracellular gram-negative diplococci is 94.8%. Absence of intracellular gram-negative diplococci from smears of the same men in associated with a 92.6% probability that they have nongonococcal urethritis rather than gonorrhea. There is a 97.3% probability of gonorrhea in our female patients at high risk of being infected and whose cervical smears contain intracellular gram-negative diplococci. Absence of intracellular gram-negative diplococci is associated with a probability of only 51.2% that these women do not have gonorrhea. The probability of gonorrhea in our male patients, whose smears contain intracellular gram-negative diplococci, drops from 94.8% to 34.9% when specimens are obtained from sexually active men without urethritis and to 53.9% when an inexperienced technician interprets smears from patients with urethritis. Vancomycin . HCl, which is included in Neisseria gonorrhoeae--selective media for suppression of microbial contaminants, also inhibited 2.4% of our gonococcal isolates and resulted in a falsely negative test. Awareness of these and other limitations of tests for gonorrhea, and of the magnitude and means of control of these limitations is essential to determining the presence or absence of gonococcal disease.
