Role of delayed enhancement MRI in patients with acute coronary syndrome and unobstructed coronary arteries: reply

We thank Coceani and L'Abbate for their comments on our paper.We concur that ‘pathophysiology cannot be inferred fromcoronary lumenography alone’, and this was one of thekey motivations in conducting the present study.     

Tamponade caused by cardiac lipomatous hypertrophy.

Cardiac lipomatous hypertrophy is an unusual disorder that typically affects the interatrial septum. We report a case in which large subpericardial deposits of fat were initially mistaken for a pericardial effusion and the subsequent clinical picture resembled tamponade. The patient improved following a pericardiectomy.     

Lymphoma models for B cell activation and tolerance. IV. Growth inhibition by anti-Ig of CH31 and CH33 B lymphoma cells

CH31 and CH33 are B cell lymphomas whose growth in vitro is inhibited by anti-Ig reagents, including both polyclonal and monoclonal anti-mu antibodies, and an anti-idiotype antiserum. Antibodies against class I or class II major histocompatibility complex antigens do not affect the growth of these cells. Inhibition is dependent on surface Ig cross-linking and does not require ligand binding to Fc receptors. Interestingly, the inhibition of growth by anti-mu is reversed in CH31 (but not CH33) by E. coli lipopolysaccharide. These lymphomas should provide excellent models to study the mechanisms of growth inhibition mediated by surface Ig cross-linking and the pathways of its reversal.     

Designing immunotoxins for cancer therapy

Immunotoxins are the rapeutic agents with a high degree of specificity and unique mechanism of action. An immunotoxin is achimeric protein consisting of a targeting moiety linked to a toxin. The targeting moiety selectively binds to a tumor cell and targets it for death via the attached toxin. Generally, immunotoxins are specifically potent against cancer cells in vitro and in animal models of human malignancies. However, immunotoxins can be limited clinically by immunogenicity, toxicity, and instability. In this review, weofferwaysto overcome these limitations to create “ideal immunotoxins” for cancer therapy. These include producing single chain targeting/toxin fusion proteins of fully human origin that are extracellularly stable but once internalized, can be cleaved by intracellular proteases to free the toxin and facilitate its translocation to the cytosol.     

Biased immunoglobulin variable region gene expression by Ly-1 B cells due to clonal selection

Most, if not all, autoantibodies specific for bromelain-treated mouse erythrocytes recognize the common membrane phospholipid, phosphatidyl choline (PtC). Anti-PtC antibodies are produced by 5%-15% of CD5+ Ly-1 B cells of normal unimmunized mice, but not by detectable numbers of conventional CD5- B cells. At 1 week of age PtC-specific B cells are undetectable but then increase dramatically over the next 3 to 4 weeks to reach adult numbers. We report here that PtC-specific Ly-1 B cells in B10.H-2aH-4bp/Wts mice predominantly express either of two heavy and kappa chain variable (V) region gene combinations. In addition, the sequence and length of DH genes are conserved among cells expressing the same V gene combination, and the V kappa-J kappa junctions of one group involve unusual splice sites. Preferential V gene rearrangement models are insufficient to explain the DH and V kappa-J kappa junctional sequences or the delayed appearance of this specificity, and so they cannot solely account for the high frequency of PtC-specific cells. These characteristics are more consistent with antigen selection. We therefore attribute the frequent use of the two V region gene combinations to selection for cells that express them and conclude that the expressed V gene repertoire of Ly-1 B cells in adult mice is influenced by antigen selection. Apparently, there is no selection for mutant anti-PtC antibodies of higher affinity during the formation of the Ly-1 B repertoire because the V region genes expressed by PtC-specific cells are unmutated. Our findings are consistent with an important, germ line-encoded function for the immunoglobulin products of these gene combinations.     

Evaluation of two commercial procedures for rapid identification of Neisseria gonorrhoeae using a reference panel of antigenically diverse gonococci.

Two commercial tests for the rapid identification of Neisseria gonorrhoeae were evaluated. Two hundred seventy-nine organisms were tested, including 202 strains of N. gonorrhoeae. The Syva MicroTrak test results were less subjective but required a fluorescence microscope. The Phadebact Monoclonal GC OMNI Test required modification of the manufacturer's interpretive instructions in order to avoid cross-reactions, but it was a practical test. Specificities of both tests were 100%. Sensitivities of the Phadebact Monoclonal GC OMNI and Syva MicroTrak tests were 100% and approximately 100%, respectively.