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Synovial fluids from 26 knees of patients with juvenile rheumatoid arthritis were analyzed for partial pressure of oxygen (pO2) and carbon dioxide (pCO2), pH, and for lactate. As in adult rheumatoid arthritis, a low Po2 level was associated with a high concentration of lactate (r = −0.81), and inverse relationships were demonstrated between levels of lactate and pH (r = −0.87), and pCO2 and pH (r = −0.86). These physiologic abnormalities were unrelated to the clinical severity of local joint disease or to the spread of joint involvement.

The capacity to extract slow-reacting substance of anaphylaxis (SRS-A) from human lung tissue or cells after immunologic activation, together with the measurement of SRS-A in both the extract and the surrounding fluid, permits study of total SRS-A generation. That the material extracted is SRS-A was established by both differential bioassay and purification. SRS-A accumulation was entirely intracellular after limited IgE-dependent direct or reversed anaphylactic activation. Intracellular accumulation also generally preceded release, with generation of SRS-A continuing well beyond a plateau in the cellular SRS-A level and the release of preformed mediators. The quantity of SRS-A generated after immunologic activation was modulated by the introduction of exogenous cyclic nucleotides, revealing a site of cyclic nucleotide action distinct from that on mediator release. The capacity to determine not only the release of preformed mediators but also the generation of a newly formed mediator, the sum of SRS-A in cells and supernate, adds an additional dimension to the analysis of the cellular events of immediate hypersensitivity.

A biologically active neutral peptide mediator is cleaved from a plasma protein substrate by an α-1-antitrypsin-inhibitable serine protease apparently residing on the membrane of the human neutrophil. The peptide mediator has an approximate mol wt of 1,000, and is distinguished from the kinin peptides by a neutral isoelectric point, susceptibility to inactivation by trypsin as well as chymotrypsin and activity on the isolated, atropinized, and antihistamine-treated guinea pig ileum with relatively little action on the estrous rat uterus. The neutrophil protease is fully inhibitable by DFP, trypsin inhibitors from lima or soy bean, and α-1-antitrypsin and is associated with the high mol wt fragments of the neutrophil and not the nuclear, lysosomal, or cytoplasmic subcellular fraction. The substrate has an approximate mol wt of 90,000 and is chromatographically separable from kininogen. The exquisite sensitivity of the neutrophil protease to α-1-antitrypsin was established both by inhibition with highly purified α-1-antitrypsin and by the inability of the protease to generate detectable neutral peptide in a homozygous (ZZ) α-1-antitrypsin-deficient patient without heat inactivation of the residual inhibitor. On the other hand, plasma from a (null) α-1-antitrypsin-deficient patient supported neutral peptide generation and revealed an additional factor which inactivated neutral peptide.

The eosinophil chemotactic factor of anaphylaxis (ECF-A), previously recognized as being released from sensitized human or guinea pig lung tissue by antigen challenge, has been demonstrated to exist preformed in these tissues and in isolated rat mast cells. The presence of performed ECF-A in the mast cell of the rat was established by the full recovery of ECF-A with mast cells purified from a mixed peritoneal cell population and cellular subfractionation which revealed the preformed ECF-A to be largely associated with the mast cell granules. The sum of the ECF-A released by antigen and that remaining in the sensitized challenged human or guinea pig lung tissue or isolated rat mast cells equalled that extractable from the equivalent unchallenged lung tissue or rat mast cells, indicating that the ECF-A available exists entirely in a preformed state.

The neutrophil-immobilizing factor (NIF) derived from human leukocytes inhibited the random migration and chemotactic response of purified human neutrophils and eosinophils but not of monocytes. Concentrations of NIF sufficient to suppress mobility did not diminish phagocytic capacity or adherence to plastic Petri dishes of human neutrophils; the increased activity of the hexose monophosphate shunt associated with either phagocytosis or direct interaction with chemotactically active concentrations of kallikrein or C5a was also not suppressed. It is postulated that the in vivo role of NIF may relate to its ability to concentrate neutrophils in inflammatory foci without depressing their phagocytic potential or metabolic activation.

The conversion of plasminogen proactivator to plasminogen activator by Hageman factor fragments results in the generation of chemotactic activity for human neutrophils. This chemotactic activity can be distinguished from that generated by Hageman factor activation of prekallikrein and is demonstrable in plasma that is genetically deficient in prekallikrein (Fletcher factor deficiency). Both the plasminogen-activating activity and chemotactic activity produced by the interaction of Hageman factor fragments and plasminogen proactivator to yield plasminogen activator were inhibited by diisopropyl fluorophosphate (DFP) indicating an essential role for the enzymatic site in both these activities. The finding that the plasminogen proactivator tolerated a dose of DFP, which completely inactivated the plasminogen activator, reveals that the active site is protected in the precursor protein.

Purified monomer (4S) and dimer (7S) bovine serum albumin (BSA) were isolated from solutions of crystalline BSA by gel filtration. Mercaptoethanol reduction of BSA in buffered saline resulted in the appearance of only three sulfhydryl groups per molecule (3-SH BSA). Complete reduction in 8 M urea produced 34 free sulfhydryl groups per molecule (34-SH BSA). These BSA preparations were studied by optical rotatory dispersion, ultracentrifugation, quantitative precipitation and hemagglutination with homologous and heterologous antisera, and immunologic cutaneous reactions. Significant distortion of the native BSA conformation by complete reduction and carboxymethylation (34-SH BSA) resulted in loss of precipitation with anti-native BSA. Partial unfolding of the native conformation of BSA resulted in greater precipitation with anti-native BSA and greater reactivity with anti-3-SH BSA hemagglutinins. This increase in antigenic reactivity was directly proportional to the loss of native α-helix content and accordingly was greater for 3-SH BSA than dimer native BSA. The augmented antigenic binding is felt to be due to an exposure of hidden antigenic determinants or the creation of new determinants associated with these conformational alterations. Completely reduced carboxymethylated 34-SH BSA is a potent immunogen inducing high titers of non-IgG antibodies with passive hemagglutination and cutaneous anaphylactic activities, but no precipitating ability. Monomer 34-SH BSA does not precipitate or fix complement with any anti-BSA antisera, and therefore may be a univalent antigen. The strong Arthus reaction produced by the 34-SH BSA immunologic system despite a lack of precipitation and complement fixation in vitro suggests the possibility of antigenic aggregation in vivo.

Random migration of human platelets has been recognized as a parameter of platelet function which can be assessed in a reproducible manner by modification of the Boyden micropore filter technique for evaluating this function in other cells (Boyden, S. 1962. J. Exp. Med. 115: 453-466). Because platelets are extremely susceptible to aggregation, the conditions for collecting and isolating platelets and the migration buffer (Ca(++) and Mg(++)-free phosphate buffered saline, pH 6.8, with glucose and gelatin) were selected to minimize such a possibility. The random movement of platelets into the micropore filter was maximal at 30-37 degrees C and was contingent upon the metabolic integrity of the cell; thus, it can be attributed to active spontaneous migration. While the initiating and enhancing effects of epinephrine on the platelet aggregation-release reaction are mediated by an alpha-adrenergic receptor, the inhibition of random migration involved a beta-receptor. Equimolar propranolol but not phentolamine prevented epinephrine inhibition of random migration, and isoproterenol had activity comparable to epinephrine while phenylephrine was inactive. The capacity of the cholinomimetic agent, carbachol, to increase platelet migration is reminiscent of the recent findings in several cell systems in which beta-adrenergic and cholinergic stimuli have opposite effects. The prostaglandins E1 and E2 augmented spontaneous migration in contrast to their well established inhibitory action on platelet aggregation at the concentrations employed. The suppression by indomethacin of prostaglandin enhancement and of spontaneous migration implies a requirement for the prostaglandin biosynthetic pathway during the migration process. Thus, the spontaneous migration of human platelets, an additional parameter of platelet function for in vitro investigations, disclosed not only a beta-adrenergic receptor for epinephrine, but also a capacity for cholinergic augmentation and an apparent requirement for prostaglandin biosynthesis.

The quality of outpatient diagnostic medicine at the Peter Bent Brigham Hospital was assessed in a two-phase study. In phase 1 the records of 249 randomly selected outpatients were graded ...

Two of the principal mechanisms by which immunologic reactions generate chemical mediators of the inflammatory response differ both in their mode of interaction with target cell membranes and in their ultimate effect on these membranes. In the cytolytic reaction [Fig. 1(A)] antibodies of certain immunoglobulin classes (IgM or IgG) bind to the target cell via combining sites specific for antigens which are either intrinsic to the cell membrane or have become passively bound to it. A resultant configurational change in the Fc portion of the antibody (Ashman and Metzger, 1971) is associated with the initiation of a sequence of reactions among certain serum proteins, the components of complement,* contained in the surrounding milieu. The physicochemical characteristics and mechanism of interaction of the nine components have recently been reviewed (Muller-Eberhard, 1968; Ruddy, et al., 1972). Chemical mediators of inflammation are generated during the complement reaction sequence per se, by the limited proteolysis of the components. These mediators represent both major (e.g., C3b, an enhancer of opsonization) and minor (e.g., C3a, an anaphylatoxin) fragments of component cleavage as well as complexes (e.g., C567, a chemotactic principle) formed by the interaction of products from different components. If completion of the reaction sequence occurs on a cell membrane, cytolytic destruction of the cell results which in some instances, may eventuate in mediator release.

Cyclophosphamide is a potent anti-inflammatory and immunosuppressive cytostatic and cytotoxic drug used for such diverse medical problems as neoplasia, tissue transplantation, and inflamma...

Thirteen women with lupus nephritis were hospitalized for a 10-week double-blind therapeutic trial comparing oral cyclophosphamide with placebo. Concurrent corticosteroid therapy, up to 30...

Lactate acid dehydrogenase was irradiated in the presence of its substrates and the coenzymes. The coenzymes afforded protection against the inactivation by irradiation over the entire pH range studied. Both pyruvate and lactate afforded specific protection to the enzyme at the pH optima for their binding. Studies of the four isozymes present in the LDH preparation indicated that the irradiation caused no major structural changes. However, there was an indication of slight configurational changes. These data support the concept of specific substrate protection. Furthermore, the data support the hypothesis that the substrate can bind to LDH independently of the coenzyme and that this binding is strongly pH-dependent.