[Effects of tachykinin receptor antagonists on allergic asthma in guinea pigs]

In conscious sensitized guinea pigs, CP-96345 (2.06 mumol.kg-1, i.p.), a specific antagonist for tachykinin NK-1 receptors, SR-48968 (1.66 mumol.kg-1, i.p.), an NK-2 receptor antagonist, and the combination of both agents decreased the wheezing percentage and the mortality from anaphylactic shock induced by 0.25% ovalbumin (OA, for 0.5 or 2 min) aerosol inhalation. In the anesthetized guinea pigs, SR-48968 attenuated OA (5 mg.kg-1, i.v.)-induced bronchoconstriction, while CP-96345 inhibited OA-induced Evans blue extravasation in bronchi and intrapulmonary airways. In the isolated tracheal and bronchial smooth muscle preparations of guinea pigs, SR-48968 concentration-dependently inhibited OA (10 micrograms.ml-1)-induced contraction both in trachea and in bronchi, while CP-96345 only attenuated the contraction of bronchi. Pretreatment with capsaicin, a depleting agent of sensory neuropeptides from sensory nerve C-fibers, attenuated the OA-induced contractions both in trachea and in bronchi. The results indicate that (1) tachykinins in the airways are involved in the pathogenesis of allergic asthma; (2) tachykinin receptor antagonists have inhibitory effects on the allergic asthmatic responses, which is at least partly through the inhibition of antigen-induced contraction of airway smooth muscles (NK-2 receptor effect) and airway microvascular leakage (NK-1 receptor effect).

Interleukin-10 is a growth factor for human myeloma cells by induction of an oncostatin M autocrine loop

We have a previously reported that interleukin-10 (IL-10) is a potent but IL-6-unrelated growth factor for freshly explanted myeloma cells (Lu et al, Blood 85:2521, 1995). We have also shown that exogenous IL-10 supported the growth of XG-1 and XG-2 human myeloma cell lines (HMCL) through an IL-6-independent mechanism. (Lu et al, Blood 85:2521, 1995). Because the IL-10 receptor does not involve the gp 130 IL-6 transducer, we have attempted to elucidate the mechanisms of IL-10 action on myeloma cells. Our results indicate that the myeloma cell growth factor activity of IL-10 was abrogated by an antibody to the gp 130 IL-6 transducer, indicating that it was mediated through one of the gp 130-activating cytokines. We found that myeloma cells from XG-1 and XG-2 HMCL and from 5 of 6 patients' tumoral samples produced oncostatin M (OM) constitutively but failed to produce IL-6, IL-11 and leukemia-inhibitory factor (LIF). The autocrine OM was inactive in the absence of IL-10 due to lack of a functional OM receptor on myeloma cells. IL-10, by inducing the receptor for LIF (LIFR), produced a functional autocrine OM loop in XG-1 and XG-2 cells and in primary myeloma cells from 2 patients. We also found that some myeloma cell lines (XG-4, XG-6, and XG-7) an fresh myeloma cells from 3 of 6 patients produced an autocrine IL-10 and that these cells constitutively expressed LIFR. One HMCL (XG-7) produced IL-10, OM, and IL-6 an expressed LIFR. The XG-7 cells used OM and IL-6 as autocrine growth factors. We have previously shown that IL-10 could induce IL-11 receptor in myeloma cells and confer on them sensitivity to IL-11 (Lu et al, FEBS Lett 377:515, 1995). Taken together, these results show that IL-10 is a key cytokine for inducing the expression of LIFR and IL-11R and possibly another uncharacterized OM coreceptor on myeloma cells and that OM and IL-10 might be produced by myeloma cells. They also emphasize that all myeloma cell growth factors reported to data involve an activation of the gp130 IL-6 transducer.

A ciliary neurotrophic factor-sensitive human myeloma cell line

We obtained a human myeloma cell line (XG4-CNTF) whose growth was completely dependent on addition of ciliary neurotrophic factor (CNTF). Half-maximal proliferation was induced by adding 20 pg/mL CNTF. Response to CNTF correlated with expression of membrane CNTF receptor alpha-chain (CNTFR alpha), as shown by PCR analysis and immunostaining with anti-CNTFR alpha antibodies. CNTF-induced proliferation was completely inhibited by antibodies to gp130 interleukin-6 (IL-6) transducer, unlike antibodies to IL-6 or IL-6 receptor (IL-6R). Growth of XG4-CNTF cells using the gp130 IL-6 transducer was also supported by other cytokines: IL-6, leukemia inhibitory factor (LIF), and oncostatin M (OM). This cell line should be very useful for studying the interactions of IL-6-related cytokines with their receptors.

[Experimental study of Salvia miltiorrhiza on prevention of restenosis after angioplasty]

For evaluating the possibility of Salvia miltiorrhiza (SM) on the prevention of arterial restenosis after angioplasty, we investigated the effect of SM on the intimal thickening of air-injured carotid artery of rats. The results showed that the maximal intimal thickness of the injured arteries was much thinner in the treatment group than that in the control group, indicated that SM could prevent experimental restenosis in rat model. Furthermore, we examined the effect of SM on the proliferation of the isolated rabbit arterial smooth muscle cells (SMC) cultivated in vitro. The results showed that SM inhibited the 3H-TdR take-up and proliferation of SMC in a dose-dependent manner. The study raised the possibility that SM could be used to prevent arterial restenosis after angioplasty.

Interleukin-10 induces interleukin-11 responsiveness in human myeloma cell lines

Interleukin (IL)-6-dependent human myeloma cell lines (HMCL) can be reproducibly obtained from patients with multiple myeloma and terminal disease. The growth of some of these HMCL can also be supported by IL-11. We show that IL-11-responsive, but not -unresponsive, HMCL expressed the gene of human IL-11 receptor (IL-11R) and produced an autocrine IL-10. All HMCL expressed the IL-10 receptor. In addition, IL-10 induced IL-11R gene expression and conferred IL-11 responsiveness on unresponsive HMCL. The ability of HMCL to produce IL-10 was strictly correlated with the capacity of the original patient's myeloma cells to produce IL-10 or not, and with the presence or absence of IL-10 in the patient's plasma.

Effect of captopril on membrane currents of ventricular myocytes

Using whole-cell patch-clamp technique, the present study examined the effects of captopril on membrane currents of ventricular myocytes. The results were as follow: when the concentration of captopril was 6 x 10(-4)mol, the fast inward sodium current and slow inward calcium current were all decreased significantly (P < 0.05). Besides, when the concentration exceeds 10(-3)mol, the delayed rectifier potassium current was increased (P < 0.05) as well. But if the experimental concentration was under 6 x 10(-4)mol, these three kinds of currents was not affected. These findings suggested that captopril has no direct antiarrhythmic effect at the average therapeutic serum level.

Measurement of whole body interleukin-6 (IL-6) production: prediction of the efficacy of anti-IL-6 treatments

A major limitation on the therapeutic use of cytokine antagonists is that the amount of cytokine to be neutralized in vivo is not presently known. We previously reported that anti-interleukin-6 (IL-6) monoclonal antibody (MoAb) administered to a patient with multiple myeloma (MM) induced high amounts of IL-6 to circulate in the form of monomeric immune complexes. Based on this observation, the present study developed a new methodology to estimate daily IL-6 production in 13 patients with MM or renal cancer who received anti-IL-6 MoAb. Treatment was considered effective when the production of C-reactive protein (CRP) was inhibited. The production of this acute-phase protein by hepatocytes is dependent on the activation of IL-6 gp130 transducer. Inhibition of tumor proliferation was also evaluated in patients with MM. In 7 of 13 patients whose CRP production was completely inhibited (> 96%) and who showed some antitumoral effects, whole-body IL-6 production in vivo was less than 18 micrograms/d (median, 5.7 micrograms/d; range, 0.5 to 17.5 micrograms/d). In the other 6 patients, subtotal inhibition of CRP production and a lack of antitumoral response were associated with high IL-6 production (median, 180 micrograms/d; range, 18 to 358 micrograms/d). These in vivo observations were consistent with mathematical modeling that predicted that anti-IL-6 MoAb treatment would be efficient only in low IL-6 producers. These data indicate the difficulty of neutralizing IL-6 with a single anti-IL-6 MoAb in vivo and call for new strategies to avoid accumulation of IL-6 in the form of stable immune complexes.

[Arrhythmogenic right ventricular disease on a young peasant]

This article, together with literatures, discusses one case of arrhythmia right ventricular dysplasia (ARVD) we treated. This disease should be taken into account in some arrhythmias from right ventricle, especially refractory arrhythmias in youths. Some non-invasive techniques such as echocardiography, cardial single photon emission computed tomography (SPECT), and magnetic resonance imaging (MRI) play more and more important role in the diagnosis of ARVD. These techniques can provide specific data for the early diagnosis.

An interleukin 1 receptor antagonist blocks the IL-1-induced IL-6 paracrine production through a prostaglandin E2-related mechanism in multiple myeloma

By analogy with the model of pristane-induced mouse plasmacytomas, we have wondered about the putative role of prostaglandin E2 (PGE2) in the human multiple myeloma (MM) cytokine network, involving interleukin 6 (IL-6) and interleukin 1 (IL-1) as essential myeloma cell growth factors and inducing cofactors respectively. We show that PGE2 is produced in short-term cultures of bone marrow cells of patients with MM, concomitantly with both IL-6 and IL-1. Indomethacin, a potent inhibitor of cyclo-oxygenase and of PGE2 synthesis, significantly inhibits IL-6 production (but not IL-1 production) by 35% to 90% depending on the different MM patients studied and concurrently to that of PGE2. Exogenous PGE2 reverses this inhibition or even stimulates IL-6 production. An IL-1 receptor antagonist (IL-1RA) also significantly inhibits PGE2, IL-6 production and myeloma cell growth. The inhibition of IL-6 production is reversed by adding exogenous PGE2. These results show that induction of IL-6 by IL-1 is related to PGE2 in the bone marrow of patients with MM. Inhibition of PGE2 synthesis (as obtained with indomethacin and the IL-1RA) might be helpful to inhibit myeloma cell proliferation by reducing IL-1-induced endogenous IL-6 production not only in vitro (as demonstrated here) but also in vivo.

Biologic effects of anti-interleukin-6 murine monoclonal antibody in advanced multiple myeloma

In patients with advanced multiple myeloma (MM) there is an excess of production of interleukin-6 (IL-6) in vivo, and elevated serum levels are associated with plasmablastic proliferative activity and short survival. These data prompted us to perform a clinical trial with a murine anti-IL-6 monoclonal antibody (MoAb) to neutralize the excess of this putatively deleterious factor in these patients. Ten MM patients with extramedullary involvement frequently were treated with anti-IL-6 MoAb. The MoAb was administered intravenously to 9 patients; 1 patient with malignant pleural effusion received intrapleural therapy. Of the 3 patients who succumbed to progressive MM after less than 1 week of treatment (including the only 1 treated locally), 2 with evaluable data exhibited marked inhibition of plasmablastic proliferation. Among the 7 patients remaining more homogeneous receiving the anti-IL-6 MoAb for more than 1 week, 3 had objective antiproliferative effect marked by a significant reduction of the myeloma cell labelling index within the bone marrow. One of these 3 patients achieved a 30% regression of tumor mass. However, none of the patients studied achieved remission or improved outcome as judged by standard clinical criteria. Of major interest, objective antiproliferative effects were associated with complete inhibition of C-reactive protein (CRP) synthesis and low daily IL-6 production in vivo. On the other hand, the lack of effect in 4 patients was associated with a higher IL-6 production and inability of the MoAb to neutralize it. Anti-IL-6 was also associated with resolution of low-grade fever in all the patients and with worsening thrombocytopenia and mild neutropenia. The generation of human antibodies to Fc fragment of the murine anti-IL-6 MoAb observed in 1 patient was associated with dramatic progression. These data show that anti-IL-6 MoAb can suppress the proliferation of myeloma cells and underscore the biologic role of IL-6 for myeloma growth in vivo. Furthermore, suppression of CRP and worsening of neutropenia/thrombocytopenia both indicate that IL-6 is critically involved in acute-phase responses and granulopoiesis/thrombopoiesis.

A comparative study of radiofrequency ablation in unipolar and bipolar fashion

In this study we compared the effects of radiofrequency (RF) energy applied to the swine endocardium in a unipolar fashion and in a bipolar one with two different interelectrode distances (5 mm, 10 mm). RF energy (500 kHz) delivered to the swine endocardium was divided into eight categories: 100 J, 101-200 J, 201-300 J, 301-400 J, 401-500 J, 501-600 J, 601-1000 J, and > 1000 J. The results showed that when RF energy was applied in a bipolar fashion, the lesions involved the catheter/tissue interface and partly the interelectrode spacing, while in a unipolar fashion. They were found in the catheter/tissue interface only. At any energy level, there were no statistically significant differences in lesion depths among all the three fashions, and the lesion surface areas produced by the bipolar fashion (with 5 mm or 10 mm interelectrode spacing) were all greater than those by the unipolar fashion (P < 0.05). When the delivered energy was under 500 joules, a greater lesion surface area was found in 5 mm bipolar fashion than in 10mm bipolar fashion (P < 0.05), while energy exceeded 500 joules, the differences in the lesion surface areas were no longer significant between these two bipolar fashions.

Interleukin-10 is a proliferation factor but not a differentiation factor for human myeloma cells

Because interleukin-10 (IL-10) is a potent differentiation factor of human B cells into mature plasma cells, we investigated its effect on human malignant plasma cells. IL-10 did not induce any differentiation and increase in Ig synthesis in four human IL-6-dependent malignant plasma cell lines. However, it stimulated the proliferation of two of four cytokine-dependent cell lines in the absence of IL-6 and IL-10-dependent myeloma cell lines have been obtained. The myeloma cell growth activity of IL-10 was unaffected by anti-IL-6 and anti-IL-6R antibodies. Similarly, IL-10 stimulated (P = .001) the proliferation of freshly-explanted myeloma cells in IL-6-deprived cultures of tumor samples from patients with active multiple myeloma (MM) and produced twice as many myeloma cells in these cultures. Again, this cytokine was unable to induce further differentiation (assessed by rate of Ig production) of fresh myeloma cells. A very sensitive enzyme-linked immunosorbent assay (ELISA; 1 pg/mL) only rarely detected IL-10 in the sera of MM patients (3 of 89). On the contrary, serum IL-10 was detected in 60% of patients with plasma cell leukemia (12 of 20). These data show that IL-10 is an IL-6-unrelated growth factor for malignant plasmablastic cells. This cytokine could be involved in the late phase of MM in vivo.

Purification of deformin, an extracellular protein synthesized by Bartonella bacilliformis which causes deformation of erythrocyte membranes

A factor capable of deforming erythrocyte membranes, found in the culture supernatants of Bartonella bacilliformis, was purified 1840-fold using hydrophobic, ion exchange and gel exclusion chromatography. The final fractions contained a single detectable polypeptide species, referred to as deformin, having a molecular weight of 67000 by SDS-PAGE and a native molecular weight of 130,000 by gel exclusion chromatography or velocity sedimentation in a glycerol gradient. Erythrocytes treated with deformin acquire trenches, indentations, and invaginations which could be reversed by vanadate, dilauroylphosphatidylcholine (DLPC), or by raising the internal Ca2+ concentrations with the inophore A23187. Internal vacuoles also form. Erythrocytes treated with trypsin or neuraminidase are much more sensitive to deformin than untreated erythrocytes; erythrocytes treated with phospholipase D are less sensitive to deformin. This protein may play a role in causing the severe anemia which can result as a consequence of infection by B. bacilliformis.

Effect of radiofrequency catheter ablation on calcium channel of ventricular myocytes

Using whole-cell patch-clamp technique, the effect of radiofrequency catheter ablation (RFCA) on calcium current (Ica) of guinea pig ventricular myocytes was examined. The radiofrequency energy delivered was 20 W x 10 s. RF-CA decreased Ica apparently with the affected area reaching up to 1.2 cm from the ablation focus. In the meanwhile, the pathological lesion size resulted from RFCA was merely 0.41 +/- 0.11 cm. These findings indicate that RFCA, apart from causing tissue necrosis by heat, can affect myocyte membrane currents in a large area. This may explain why RFCA has a very high success rate with a small pathological lesion.

A highly sensitive quantitative bioassay for human interleukin-11

Human interleukin-11 (IL-11) is a cytokine with a broad spectrum of activity, similar to interleukin-6 (IL-6). However, its role in human disease is poorly understood, partly because of a lack of sensitive bioassays. A subclone (B9-11) obtained from the B9 hybridoma (which responds poorly to human IL-11) enabled us to develop a highly sensitive bioassay for human IL-11. B9-11 cells responded only to human IL-11 and IL-6 and not to other human cytokines using the same gp130 transducer chain (ciliary neurotrophic factor, leukemia inhibitory factor and oncostatin M) or to other human interleukins (interleukin-1 to interleukin-13), human hematopoietic cytokines (granulocyte colony stimulating factor, granulocyte-macrophage colony stimulating factor, colony stimulating factor-1) and various other human cytokines (interferon-alpha, tumor necrosis factor-alpha, tumor necrosis factor-beta, fibroblast growth factor and nerve growth factor). In addition, these cytokines did not interfere with the IL-11 response of B9-11 cells. IL-11-induced proliferation of B9-11 cells was unaffected by anti-murine IL-6 receptor mAb but inhibited by anti-gp130 mAb. Half-maximal proliferation of B9-11 cells was obtained with 30 pg/ml of recombinant IL-11, a concentration 300-fold lower than IL-11 concentrations known to be active on human cells. Finally, culturing of B9-11 cells with an anti-IL-6 mAb enabled us to measure the natural IL-11 produced by various cell lines. Thus, B9-11 cells should be useful for studies of IL-11 involvement in various human diseases as well as for a better understanding of the mechanisms of action of this cytokine.

Reproducible obtaining of human myeloma cell lines as a model for tumor stem cell study in human multiple myeloma

We report a novel, reproducible methodology which enabled 10 human myeloma cell lines (HMCL) to be obtained from each of 10 tumor samples harvested from 9 patients with extramedullary proliferation. Fresh samples were cultured with interleukin 6 (IL-6) and granulocyte macrophage-colony stimulating factor (GM-CSF) at a high cell density and resulting HMCL growth became progressively dependent on IL-6 alone, no longer requiring GM-CSF. These HMCL, which had the same immunoglobulin gene rearrangements as the patients' original myeloma cells, were designated XG-1 to XG-9. XG HMCL had a plasma cell morphology, expressed plasma cell antigen (Ag), namely cytoplasmic immunoglobulins, CD38, B-B4 Ag, and CD77, and lacked the usual B-cell Ag. They also expressed activation antigens such as CD28 with coexpression of CD28 and its ligand, B7 Ag, in four HMCL. Six HMCL expressed CD40, 4 CD23, and 5 its ligand, CD21. The XG HMCL bore adhesion molecules VLA-4 and CD44 (all 10 HMCL), VLA-5 (7 HMCL), and CD56 (4 HMCL). Finally, cytogenetic study of 8 HMCL indicated a 14q+ chromosome, and t(11,14) translocation was found in 6 of 8 and 5 of 8 HMCL, respectively. The possibility of obtaining malignant plasma cell lines reproducibly from each patient with extramedullary proliferation offers a unique tool for studying the phenotype and abnormalities of the still unidentified tumor stem cell in this disease.

Epitope analysis of human IL-6 receptor gp80 molecule with monoclonal antibodies

Gp80 human IL-6R was studied using 7 murine mAb (M37, M91, M113, M139, M164, M182 and M195) obtained after fusion of splenocytes of Balb/c mice immunised with a mixture of recombinant IL-6 receptor (rIL-6R) and cells from 2 cell lines expressing IL-6R. These were U266, which is IL-6 independent and XG-1 which is IL-6-dependent. In ELISA the 7 mAb reacted against the rIL-6R and against the natural soluble form found in plasma (nIL-6R), which both lack transmembrane and cytoplasmic domains. However, M195 reacted less with the natural than with the recombinant soluble IL-6R. Using FACS analysis, the 7 mAb were shown to bind to U266 cells but not to the Namalva cell line which is deprived of IL-6R. This showed that they all recognised the membrane form of the IL-6R. Three of the anti-IL-6R mAb reacted with rIL-6R by Western blotting. Four different epitopes of the molecule were identified, either by cross-blocking experiments of mAb binding to IL6R in ELISA or by the biosensor Biacore technology. A group of 4 mAb (M37, M113, M139 and M164) and another mAb (M195) identified 2 different epitopes involved in IL-6 binding. These antibodies were able to inhibit the binding of IL-6 to IL-6R and the proliferation of the IL-6-dependent XG-1 cell line. M91 and M182 recognized 2 other epitopes that were not involved in IL-6 binding. As expected, M91 did not inhibit XG-1 proliferation; in contrast, M182 interfered with the proliferative response of the XG-1 cell line.(ABSTRACT TRUNCATED AT 250 WORDS)

Ciliary neurotropic factor, interleukin 11, leukemia inhibitory factor, and oncostatin M are growth factors for human myeloma cell lines using the interleukin 6 signal transducer gp130

Interleukin 6 (IL-6) is a major growth factor for tumor plasma cells involved in human multiple myeloma (MM). In particular, human myeloma cell lines (HMCL), whose growth is completely dependent on addition of exogenous IL-6, can be obtained reproducibly from every patient with terminal disease. Four cytokines, ciliary neurotropic factor (CNTF), IL-11, leukemia inhibitory factor (LIF), and oncostatin M (OM), use the same transducer chain (signal transducer gp130) as IL-6 and share numerous biological activities with this IL. We found that these four cytokines stimulated proliferation and supported the long-term growth of two out of four IL-6-dependent HMCL obtained in our laboratory. Half-maximal proliferation was obtained with cytokine concentrations ranging from 0.4 to 1.2 ng/ml for IL-11, LIF, and OM. CNTF worked at high concentrations only (90 ng/ml), but addition of soluble CNTF receptor increased sensitivity to CNTF 30-fold. The growth-promoting effect of these four cytokines was abrogated by anti-gp130 antibodies, contrary to results for anti-IL-6 receptor or anti-IL-6 antibodies. No detectable changes in the morphology and phenotype were found when myeloma cells were cultured with one of these four cytokines instead of IL-6. Concordant with their IL-6-dependent growth, the four HMCL expressed membrane IL-6R and gp130 detected by FACS analysis. LIF-binding chain gene (LIFR) was expressed only in the two HMCL responsive to LIF and OM.