Human lymphoblastoid cells produce extracellular matrix-degrading enzymes and induce endothelial cell proliferation, migration, morphogenesis, and angiogenesis

Human lymphoproliferative diseases can be hypothesized to invade locally and to metastatize via mechanisms similar to those developed by a variety of solid tumors, i.e., the secretion of extracellular matrix-degrading enzymes and stimulation of angiogenesis. To assess this hypothesis, Namalwa, Raji, and Daudi cell lines (Burkitt’s lymphoma), LIK and SB cell lines (B-cell lymphoblastic leukemia), CEM and Jurkat cell lines (T-cell lymphoblastic leukemia), and U266 cell line (multiple myeloma) were evaluated for their capacity to produce matrix metalloproteinase-2 and -9, and urokinase-type plasminogen activator. These cell lines were also assessed for their ability: (1) to produce the angiogenic basic fibroblast growth factor and vascular endothelial growth factor; (2) to induce an angiogenic phenotype in cultured endothelial cells, represented by cell proliferation, chemotaxis, and morphogensis; (3) to stimulate angiogenesis in different in vivo experimental models. All cell lines expressed the mRNA for one or both metalloproteinases. Namalwa, Raji, LIK, SB, and U266 cells secreted the active form of both metalloproteinases, while Daudi, CEM, and Jurkat cells produced metalloproteinase-2 but not -9. In contrast, urokinase-type plasminogen activator was secreted only by SB cells. While Raji, LIK, SB, CEM, and Jurkat cells secreted both basic fibroblast growth factor and vascular endothelial growth factor, Daudi and U266 cells produced only the former, and Namalwa cells only the latter. Accordingly, the conditioned medium of all cell lines stimulated cell proliferation and/or chemotaxis in cultured endothelial cells, with the exception of that of Namalwa cells which was ineffective. The conditioned medium of CEM and Jurkat cells induced morphogenesis in cultured endothelial cells grown on a reconstituted basement membrane (Matrigel). Lastly, Namalwa, Raji, LIK, SB, U266, CEM, and Jurkat cells induced angiogenesis and mononuclear cell recruitment in the murine Matrigel sponge model and in a chick embryo chorioallantoic membrane assay. The extent of angiogenesis in both models was strictly correlated with the density of the mononuclear cell infiltrate. The results indicate that human lymphoproliferative disease cells possess both local and remote invasive ability via the secretion of matrix-degrading enzymes and the induction of angiogenesis which is fostered by host inflammatory cells and by an intervening ensemble of angiogenic factors.     

Variability in anticardiolipin antibody detection: role of nonspecific IgG binding and different microtiter plates.

There are many studies that are available on the Internet that attempt to standardize the assay for anticardiolipin antibody evaluation because of the variability of results. The aim of this study was to evaluate simultaneously the role of different microplates and the importance of sample nonspecific binding in determining different results in anticardiolipin antibody detection. Sera from 8 patients with raised levels of IgG anticardiolipin antibodies and 10 control sera were assayed by enzyme-linked immunosorbent assay in the presence (specific binding) or in the absence of cardiolipin (sample blank) with four different microplates, that is, NUNC PolySorp, FALCON ProBIND, Greiner 655061 (high binding), and Greiner 655001 (medium binding). Results were expressed as optical densities or net-optical densities (following sample blank subtraction) as well as international IgG anticardiolipin units (GPL) or net-GPL. A wide interplate variability of optical densities was found. When results were expressed as GPL, significant differences were only found between Greiner 655061, FALCON ProBIND, and NUNC PolySorp (P < .05 and P < .001, respectively) whereas differences were not statistically significant if interplate variability was analyzed as net-GPL. Results expressed as categorical variables (ie, positive/negative, according to a GPL cut-off and net-GPL cut-off, obtained with sera from 100 apparently healthy blood donors) showed a good or excellent Cohen's kappa coefficient of concordance among plates when positivity was evaluated on net-GPL. Our data strongly suggest that quantification and subtraction of sample blank may improve both interlaboratory agreement and reliability of anticardiolipin assay and minimize false-positive results.     

'Doctors must not kill'

Four physicians respond to "It's over, Debbie," an anonymous resident physician's account of an incident when he or she injected a terminally ill cancer patient with a lethal dose of morphine (JAMA 1988 Jan 8; 259(2): 272). Gaylin and his colleagues condemn both the physician's violation of legal and ethical norms, and the conduct of JAMA's editor in publishing the article without editorial rebuke or comment. They warn that the issue of active euthanasia "touches medicine at its very moral center," and that, as pressure to legalize euthanasia in response to patient demand increases, the medical profession must repudiate direct and intentional killing of patients and discipline doctors who kill.     

Intersections of Western biomedical ethics and world culture: problematic and possibility

...What emerges from the intersection of systems of medical ethics across cultural lines is a recognition of the need for and the possibility of some form of metacultural ethic that can ameliorate cultural relativism. In medical ethics, all ethical positions are not of equal moral status -- regardless of how tightly bound they may be to a particular culture; for example, consider the nearly universal approbation for cooperative efforts of physicians who oppose the use of nuclear weapons and the condemnation of physicians who torture or experiment with prisoners of war. Even if violations of patient rights are tolerated in certain social and cultural settings, they are not tolerable in any common ethic of medicine. Growing recognition of the moral rights of patients, their special vulnerability as sick persons, and their dependency on the physician's knowledge constitute the empirical foundation of a morally defensible ethic of medicine. Those cultural systems that violate such norms cannot be given equal moral standing with systems that respect these norms, not because the cultural systems that support human and patients' rights are per se superior but because the protection of human rights is grounded in something more fundamental than culture -- the deference owed to all human beings qua human beings. This is a norm by which every culture may be judged....     

Different patterns of 11q allelic losses in digestive endocrine tumors

Most foregut digestive endocrine neoplasms may be associated with the multiple endocrine type 1 (MEN-1) syndrome. In contrast, midgut/hindgut carcinoids never show such association. To investigate the pathogenetic involvement of the MEN-1 gene and of putative additional oncosuppressor gene(s) distal to it, a comparative analysis of loss of heterozygosity (LOH) at chromosome 11q13 to 11qter was performed in 27 foregut (pancreatic endocrine tumors [PETs]), 23 midgut (ileal and appendiceal), and 3 hindgut (rectal) endocrine tumors. LOH at the MEN-1 gene locus at 11q13 was observed in 52% of the 23 sporadic and in all 4 MEN-1-associated PETs and was found to consistently and continuously span to the most distal marker investigated at 11qter. In contrast, only occasional, discontinuous, and mostly interstitial LOH for 11q markers was observed in ileal (midgut) carcinoids, whereas no LOH was found in all appendiceal (midgut) and rectal (hindgut) carcinoids. The consistent extension of LOH from the MEN-1 region to 11qter in sporadic PETs suggests a mechanism of gene inactivation via chromosomal breakage and complete loss of chromosome 11q; furthermore, these results expand beyond the 11q13 region the search for additional oncosuppressor gene(s) potentially involved in the genesis of these neoplasms. The low frequency, limited extension, and discontinuous distribution of 11q deletions in midgut/hindgut carcinoids suggest that MEN-1 gene is not involved in the pathogenesis of these tumors.     

Schistosoma mansoni: impairment of the cell-mediated immune response in mice.

Skin-graft rejection in mice experimentally infected with Schistosoma mansoni is delayed when grafting is performed 60 days after the infection. In mice infected 30 days prior to the grafting, the grafts were rejected at the same time both in infected and in control animals. This observation indicates that impairment of cell-mediated immune response occurs in mice with mature S. mansoni infections.     

Chronic morphine treatment alters endogenous opioid control of hippocampal mossy fiber synaptic transmission

Synaptic adaptations are thought to be an important component of the consequences of drug abuse. One such adaptation is an up-regulation of adenylyl cyclase that has been shown to increase transmitter release at several inhibitory synapses. In this study the effects of chronic morphine treatment were studied on mossy fiber synapses in the guinea pig hippocampus using extracellular field potential recordings. This opioid-sensitive synapse was chosen because of the known role of the adenylyl cyclase cascade in the regulation of glutamate release. Long-term potentiation (LTP) at the mossy fiber synapse was enhanced after chronic morphine treatment. In control animals, opioid antagonists increased LTP but had no effect in morphine-treated guinea pigs. In contrast, the long-lasting depression of transmission induced by a mGluR agonist and CA1 LTP were not altered. Chronic morphine treatment neither caused tolerance to mu- and kappa-receptor-mediated inhibition at the mossy fiber synapse nor modified total hippocampal dynorphin levels. The results suggest that the phasic inhibition of glutamate transmission mediated by endogenous opioids is reduced after chronic exposure to morphine.     

Characterization of a minisatellite repeat locus in the chloroplast genome of Orchis palustris (Orchidaceae)

We describe the occurrence of a tandem repeat in the chloroplast genome of the marsh orchid, Orchis palustris. The repeat unit is an AT-rich, 16-bp sequence located in the chloroplast tRNALEU intron. Southern blot analysis confirmed that the O. palustris tRNALEU intron including the minisatellite locus has not been transferred to the nucleus, but is indeed located on the chloroplast genome. The 16-bp repeat unit was found to be present in all O. palustris accessions studied, as well as in the closely related O. laxiflora. Variation in repeat numbers among individuals was found in O. palustris from central and northern Italy; and this was consistently associated with a 13-bp sequence motif preceding the repeat. This motif was absent from O. palustris from southern Italy, Greece, and from O. laxiflora. In these accessions, no variation in repeat numbers was found. Our results suggest that the O. palustris chloroplast minisatellite locus evolved relatively recently, presumably in central Italy, and may represent a valuable marker for population genetic studies.     

Antibody-coated protein A-bearing Staphylococcus aureus: a versatile and stable immune reagent.

The human beta2-microglobulin antigen-antibody system was used as a model to illustrate the versatility of a microradioimmunoassay technique using protein A-bearing Staphylococcus aureus Cowan I strain (SACI) bacteria as a non-specific immunoadsorbent in place of a second antibody. Experimental conditions are described for a sensitive microassay which makes it possible to process large numbers of samples more rapidly and with minimum handling. Furthermore, SACI coated with specific antibodies by mixing with unfractionated antisera are a versatile reagent not only for radioimmunoassays but also for use as molecular probes to characterize cell surface antigens. Antibody-coated SACI could be lyophilized and proved extremely stable in storage thus providing a unique advantage for use in binding inhibition assays and as versatile reagent for clinical and investigative immunology.     

Structural studies of murine I-E and human DR antigens.

The structures of murine I-E antigens from two strains of mice were compared to each other and to human DR antigens. Murine and human antigens were isolated by using allo- and xenoantiserum, respectively, and purified by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The murine I-E and human DR antigens consist of two polypeptide chains designated α and β. The E_α and DR_α chains display a high degree of amino acid sequence homology as do the E_β and DR_β chains, provided a gap is inserted at position 1 of the DR_β chain. Comparison of N-terminal sequences reveals several differences between the β chains of I-E antigens from the two strains of mice. In contrast no sequence differences between the two α chains are observed. In addition, comparison of tryptic peptides examined by isoelectrofocusing reveals several differences between the two E_β chains, but not between the two E_α chains. Thus, the polymorphism of murine I-E antigens and by analogy human DR antigens, may result from structural differences in the smaller (β) chain.