L-N6-(1-iminoethyl)-lysine (L-NIL) but not S-methylisothiourea sulphate (SMT) displays selectivity towards NOS-2

Our aim was to verify potency and selectiveness of two most widely used drugs regarded as NOS-2 inhibitors: L-N6-(1-iminoethyl)-lysine (L-NIL) and S-methylisothiourea sulphate (SMT). Thioglycolate-elicited rat peritoneal macrophages and coronary endothelium of isolated guinea pig heart were used as assay systems for NOS-2 and NOS-3, respectively. A non-selective NOS inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME) was used as a reference compound. We found that L-NIL but not SMT was a selective NOS-2 inhibitor. Interestingly, L-NAME displayed selectivity towards NOS-3.

Comparison of immune reconstitution after unrelated and related T-cell-depleted bone marrow transplantation: effect of patient age and donor leukocyte infusions

Unrelated bone marrow transplantation (BMT) is often complicated by fatal opportunistic infections. To evaluate features unique to immune reconstitution after unrelated BMT, the lymphoid phenotype, in vitro function, and life-threatening opportunistic infections after unrelated and related T-cell-depleted (TCD) BMT were analyzed longitudinally and compared. The effects of posttransplant donor leukocyte infusions to treat or prevent cytomegalovirus (CMV) or Epstein-Barr virus (EBV) infections on immune reconstitution were also analyzed. This study demonstrates that adult recipients of TCD unrelated BMTs experience prolonged and profound deficiencies of CD3(+), CD4(+), and CD8(+) T-cell populations when compared with pediatric recipients of unrelated BMT and adults after related BMT (P <.01), that these adults have a significantly increased risk of life-threatening opportunistic infections, and that the rate of recovery of CD4 T cells correlates with the risk of developing these infections. Recovery of normal numbers of CD3(+), CD8(+), and CD4(+) T-cell populations is similar in children after related or unrelated BMT. This study also demonstrates that adoptive immunotherapy with small numbers of unirradiated donor leukocytes can be associated with rapid restoration of CD3(+), CD4(+), and CD8(+) T-cell numbers, antigen-specific T-cell responses, and resolution of CMV- and EBV-associated disease after unrelated TCD BMT.

Molecular mapping with functional antibodies localizes critical sites on the human IL receptor common gamma (gamma c) chain

The IL receptor common gamma (gamma c) chain is required for the formation of high affinity cytokine receptor complexes for IL-2, IL-4, IL-7, IL-9, and IL-15, and for signals regulating cell survival, growth, and differentiation. Our current understanding of how gamma c chain associates with multiple ligands and receptor subunits is drawn largely from its structural homology to the human growth hormone (hGH) receptor and known structure of the hGH/hGH receptor complex. These receptors share distinct features in their extracellular portions and are believed to function by a mechanism of ligand-induced association of receptor subunits. Here, we report the first directed mutational analysis of the human gamma c chain by alanine scanning conducted across seven regions likely to contain residues required for intermolecular contact. Functionally distinct, neutralizing anti-gamma c mAbs were employed to define critical residues. One particular mAb, CP.B8, unique in its ability to inhibit IL-2-, IL-4-, IL-7-, and IL-15-induced proliferation and high affinity cytokine binding of normal T cells as an intact mAb and as a Fab fragment, localized critical residues to four noncontinuous stretches, namely residues in loops AB and EF of domain 1, in the interdomain segment, and in loop FG of domain 2. Notably, these residues form a contiguous patch on the gamma c chain surface in a three-dimensional structural model. These results provide functional evidence for the location of contact points on gamma c chain required for its association with multiple ligands.

Cyclophosphamide-induced changes of serum angiotensin converting enzyme activity and pulmonary microvessels ultrastructure

The effect of cyclophosphamide (CP) on the ultrastructure of the lung tissue and the activity of angiotensin converting enzyme (ACE) in serum was evaluated in rats. The animals were given cyclophosphamide (CP) in a single intraperitoneal dose of 150 mg/kg b.w. ACE activity was evaluated in the blood serum collected from the left ventricle of the heart using the spectrophometric method. In all time subgroups, the CP-receiving animals showed a decrease in ACE activity. Ultrastructural examinations of CP-treated animals revealed increased adhesion of neutrophiles and monocytes to the damage endothelium of the alveolar septa vessels and focally accumulation of the platelets.

Cyanonitrosylmetallates as potential NO-donors

The [M(CN)xNOy]n- complexes (where M = Cr(I), Mn(I), Mn(II), Fe(I), Fe(II), Fe(III)) were studied as potential NO-donors using both pharmacological and theoretical semi-empirical methods. Only iron complexes appeared to be pharmacologically active. The quantum chemical calculations indicated that these complexes have the highest predisposition to undergo a nucleophilic attack followed by the NO+ release. The results allowed us to interpret the metabolism of the [M(CN)xNOy]n- complexes in terms of the NO(+)-donation.

Comparative activity of melarsoprol and arsenic trioxide in chronic B-cell leukemia lines

Inorganic arsenic trioxide (As2O3) was recently shown to induce apoptosis in NB4 promyelocytic leukemic cells. We have investigated the effects of the organic arsenical, melarsoprol (a drug used for treatment of trypanosomiasis), upon induction of apoptosis in cell lines representative of chronic B-cell lymphoproliferative disorders. An Epstein-Barr virus (EBV)-transformed B-prolymphocytic cell line (JVM-2), an EBV-transformed B-cell chronic lymphocytic leukemia (B-CLL) cell line (I83CLL), and one non-EBV-transformed B-CLL cell line (WSU-CLL) were used as targets. Dose-response experiments with melarsoprol (10(-7) to 10(-9) mol/L) were performed over 96 hours. Unexpectedly, we found that melarsoprol caused a dose- and time-dependent inhibition of survival and growth in all three cell lines. In contrast, As2O3 at similar concentrations had no effect on either viability or growth. After 24 hours, all three cell lines treated with melarsoprol (10(-7) mol/L) exhibited morphologic characteristics of apoptosis. We also observed prominent concentration-dependent downregulation of bcl-2 mRNA after 24 hours of exposure to melarsoprol in WSU-CLL, I83CLL, and JVM-2 cells. Decrease of bcl-2 protein expression was also observed in all three cell lines, whereas As2O3 had no effect on this parameter. We conclude that melarsoprol may inhibit the growth of lymphoid leukemic cell by promoting programmed cell death. Results of these studies suggest that melarsoprol shows promising therapeutic activity in these diseases, and a study to evaluate clinical effects of this drug has been initiated.

Effects of pentoxifylline on some peripheral blood parameters and haemostasis in acute pulmonary tissue injury after cyclophosphamide

Cyclophosphamide (CP) is one of the widely used cytostatic drugs, with a strong toxic influence on pulmonary tissue. Experimental works have shown that a single high dose of CP causes injury to all elements of the interalveolar septum, especially to the alveolar endothelial and epithelial cells. The aim of this work was to evaluate the influence of pentoxifylline (PTXF) (30 mg/kg b.w.) on the ultrastructure of lungs capillaries and blood cell count as well as plasma fibrinogen levels in Wistar rats after intraperitoneal injection of 150 mg/b.w. CP. We established that in the doses applied PTXF had no statistically significant influence on the number of leukocytes and erythrocytes determined in the left ventricular blood of rats receiving CP, while the number of white cells from animals given PTXF only was higher than in controls. There was a smaller decrease in the number of platelets (p < 0.05) and smaller reduction in fibrinogen level (p < 0.01) in the serum of PTXF-CP animals than in the CP group. The results obtained suggest a protective effect of PTXF on CP induced changes, which have been evidenced in some of the parameters examined. Ultrastructural examinations found the lungs to be the organ of extramedullary thrombocytopoiesis in CP-treated animals and revealed that platelet accumulation in the system of lung capillaries was a potential cause of the decrease observed in the number of blood platelets following CP administration.

Pilot study of 5-azacytidine (5-AZA) and carboplatin (CBDCA) in patients with relapsed/refractory leukemia

5-azacytidine (5-AZA) and carboplatin (CBDCA) are two agents which have demonstrated antileukemic activity in a number of phase I-II trials. Their mechanisms of action and pharmacology related to cell resistance suggested suitability for combination therapy. The aim of this pilot was to evaluate the effects of this combination in the treatment of patients with relapsed/refractory acute leukemia. A total of 21 patients was enrolled. 5-azacytidine, at doses ranging from 50-150 mg/m2/day, was administered as a 2-hr infusion for 5 consecutive days. On day 3, patients began a 5-day course of CBDCA given as a 24-hr continuous intravenous infusion of 250 mg/m2/day. There were no complete remissions with this regimen. Although there were three partial responses, these were generally of short duration. Nonhematologic toxicities were mild. No correlation was seen between response and serum platinum levels. These results demonstrate that the 5-AZA/CBDCA combination is ineffective therapy for heavily pretreated patients with acute leukemia.

Ischaemic cardiac hyperaemia: role of nitric oxide and other mediators

In the perfused guinea-pig heart reactive hyperaemia (RH) after occlusion of coronary flow (1-60 s) was inhibited by 100-60% with NG-nitro-L-arginine (100 microM) and to a lesser extent (by 35%) after 8-phenyltheophylline (10 microM), but not by indomethacin (5 microM). Inhibition of adenosine deaminase by erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA) (5 microM) not only increased the concentration of adenosine in the coronary perfusate, but also prolonged the duration of RH. RH induced cardiac generation of prostacyclin, nitric oxide and adenosine as indicated by the appearance of 6-keto-PGF1 alpha, cyclic GMP, adenosine, inosine, hypoxanthine, xanthine and urate in the perfusate. Only NO and adenosine, but not prostacyclin, were responsible for RH. RH after short-term (1-10 s) coronary occlusion was mediated by NO, whereas adenosine and NO maintained RH that followed after longer (20 s-10 min) periods of cardiac ischaemia. Prostacyclin never participated in the mediation of RH.

Treatment of chronic neutropenia associated with large granular lymphocytosis with cyclosporine A and filgrastim

A patient with neutropenia and life-threatening infections secondary to T-gamma lymphoproliferative disease, who did not respond to treatment with recombinant human G-CSF (filgrastim), was treated with filgrastin plus cyclosporine A (CyA). The patient achieved a good response in the absolute neutrophil count and subsequently required a dose reduction in the filgrastim. The patient was eventually discontinued from the CyA but continues on filgrastim alone. While on therapy, the large granular lymphocytes disappeared from the circulation and the beta-TCR rearrangement, which was present prior to beginning therapy, became undetectable. The patient had no significant toxicity to the CyA or the filgrastim and he has not experienced any serious infections or required hospitalization. Filgrastim has proven to be relatively nontoxic and of some benefit to patients with this disease and should probably be utilized first when treatment is necessary. However, if improvement is not observed, these findings suggest that a trial of the combination of CyA plus filgrastim may be beneficial.

A pilot study of the biologic and therapeutic effects of granulocyte colony-stimulating factor (filgrastim) in patients with acute myelogenous leukemia

In a carefully monitored pilot study, the in vivo biologic effects of filgrastim were investigated in eight patients with relapsed/refractory acute myelogenous leukemia. Within each patient, filgrastim was administered as a single agent prior to any chemotherapy in escalating doses of 0.12-6.0 micrograms/kg/day as a continuous intravenous infusion. The dose was increased every 14 days until an ANC of > or = 2500/mm3 had been achieved or there was evidence of proliferation of the leukemia. In patients who demonstrated growth of the leukemic clone, cytosine arabinoside was initiated at 200 mg/m2/day for 5 days. Through-out the course of therapy, the effects of filgrastim on maturation and proliferation were assessed by in vitro studies of bone marrow aspirates. Three patients demonstrated a sustained increase in ANC; one achieved a partial remission and remained on therapy for 31 weeks. Two of the three responding patients had hypocellular marrows at the time of initiating filgrastim and demonstrated a low but normal pattern of growth in CFU-GM assay early in the treatment course. This suggested that these two characteristics may define an environment in which filgrastim can induce a growth advantage for the normal residual hematopoietic elements. In this study of selected patients, filgrastim appeared safe.

Vascular cell adhesion molecule-Ig fusion protein selectively targets activated alpha 4-integrin receptors in vivo. Inhibition of autoimmune diabetes in an adoptive transfer model in nonobese diabetic mice

The alpha 4 beta 1-integrin (CD49d, CD29) constitutively expressed on leukocytes regulates cell migration to inflammatory sites, cell activation, and development through its interactions with two alternate ligands, vascular cell adhesion molecule-1 (VCAM-1; CD106) expressed on cytokine-activated endothelium, dendritic and stromal cells, and the extracellular matrix protein fibronectin. Another alpha 4-integrin receptor, alpha 4 beta 7, expressed on leukocytes also binds VCAM-1 and fibronectin (FN), and controls homing to mucosal tissues through its interactions with mucosal vascular addressin MAdCAM-1. In vitro studies have shown that alpha 4-dependent cell adhesion is regulated by the activation state of the cell and by divalent cations. However, the existence and role of cells with different alpha 4 activation states in vivo have not been defined. Herein we show that a soluble ligand with the two N-terminal domains of human VCAM-1 fused to a human IgG1 constant region, VCAM-Ig, binds selectively to activated alpha 4-receptors on murine cells, such as those induced by Mn2+ in vitro. To determine whether the cells identified by VCAM-Ig were required under physiologic conditions, we assessed its anti-inflammatory effect. We show that VCAM-Ig is not bound to the majority of murine alpha 4+ cells after in vivo administration, yet it significantly delays the onset of adoptively transferred autoimmune diabetes. Thus, soluble VCAM-Ig can modify alpha 4-dependent disease progression, apparently by its selective action on cells with activated alpha 4-integrin receptors, thereby providing evidence for distinct alpha 4 activation states in vivo.

Vascular cell adhesion molecule-Ig fusion protein selectively targets activated alpha 4-integrin receptors in vivo. Inhibition of autoimmune diabetes in an adoptive transfer model in nonobese diabetic mice

The alpha 4 beta 1-integrin (CD49d, CD29) constitutively expressed on leukocytes regulates cell migration to inflammatory sites, cell activation, and development through its interactions with two alternate ligands, vascular cell adhesion molecule-1 (VCAM-1; CD106) expressed on cytokine-activated endothelium, dendritic and stromal cells, and the extracellular matrix protein fibronectin. Another alpha 4-integrin receptor, alpha 4 beta 7, expressed on leukocytes also binds VCAM-1 and fibronectin (FN), and controls homing to mucosal tissues through its interactions with mucosal vascular addressin MAdCAM-1. In vitro studies have shown that alpha 4-dependent cell adhesion is regulated by the activation state of the cell and by divalent cations. However, the existence and role of cells with different alpha 4 activation states in vivo have not been defined. Herein we show that a soluble ligand with the two N-terminal domains of human VCAM-1 fused to a human IgG1 constant region, VCAM-Ig, binds selectively to activated alpha 4-receptors on murine cells, such as those induced by Mn2+ in vitro. To determine whether the cells identified by VCAM-Ig were required under physiologic conditions, we assessed its anti-inflammatory effect. We show that VCAM-Ig is not bound to the majority of murine alpha 4+ cells after in vivo administration, yet it significantly delays the onset of adoptively transferred autoimmune diabetes. Thus, soluble VCAM-Ig can modify alpha 4-dependent disease progression, apparently by its selective action on cells with activated alpha 4-integrin receptors, thereby providing evidence for distinct alpha 4 activation states in vivo.

9-cis retinoic acid induces complete remission but does not reverse clinically acquired retinoid resistance in acute promyelocytic leukemia

9-cis retinoic acid (RA) is a high-affinity ligand for both retinoic acid receptors (RARs) and retinoid "X" receptors (RXRs). Although all-trans RA does not bind to RXRs, RAR/RXR heterodimers or RXR/RXR homodimers bind to specific DNA response elements and modulate proliferation and differentiation of normal and malignant cells. Because the development of clinical resistance to all-trans RA has been associated with a progressive decrease in plasma drug concentrations, we evaluated the ability of 9-cis RA to induce in vitro cytodifferentiation in subclones of a retinoid-sensitive and resistant APL cell line (NB4) and in short-term cultures of fresh leukemic cells aspirated from patients. We also evaluated the clinical activity and pharmacokinetics of 9-cis RA (LGD 1057) in patients with APL who were previously treated with all-trans RA. In vitro tests of both retinoid-sensitive NB4 cells, as well as samples of fresh cells from 11 patients with APL, showed relatively equivalent degrees of sensitivity to both 9-cis RA and all-trans RA at concentrations ranging from 10(-6) to 10(-8) mol/L; however, no substantial cytodifferentiation was observed using either drug alone or in combination (10(-6) mol/L of each) in retinoid-resistant NB4 cells. Seven patients with APL who had previously relapsed from a remission induced by all-trans RA were treated with 9-cis RA at daily oral doses ranging from 30 to 230 mg/m2. Pharmacokinetic studies showed that the mean terminal plasma half-life of 9-cis RA (1.3 hours) changed very little after several weeks of dosing, although the mean change per dose level in area under the plasma concentration x time curves and peak plasma concentrations showed a decrease by 49% and 45%, respectively. Peak plasma concentrations equaled or exceeded concentrations that were effective against retinoid-sensitive cells in vitro. Despite these favorable pharmacokinetic results, only one of the seven patients achieved complete remission, corroborating in vitro studies of blasts from three of the nonresponders that showed a relatively equivalent degree of resistance to both retinoids. Our results suggest that while 9-cis RA may not induce its own catabolism to the same degree as all-trans RA, this feature does not appear to overcome clinically acquired resistance to all-trans RA in APL. Nonetheless, the drug can induce complete remissions in patients with APL and may be useful for extended therapy in other diseases. Future studies should address the use of lower doses in patients who have not previously received retinoid therapy.(ABSTRACT TRUNCATED AT 400 WORDS)

Vascular cell adhesion molecule (VCAM)-Ig fusion protein defines distinct affinity states of the very late antigen-4 (VLA-4) receptor

The Very Late Antigen-4 receptor (VLA-4) (alpha 4 beta 1) is constitutively expressed on leukocytes and plays a role in cell trafficking, activation and development through its interaction with two alternative ligands, Vascular Cell Adhesion Molecule (VCAM-1) and fibronectin (FN). VLA-4-dependent cell adhesion is augmented by various stimuli, such as divalent cations, certain beta 1-specific monoclonal antibodies (mAbs) and cell activation. However, the steps of the adhesive process which they affect are currently undefined. In order to investigate whether or not these stimuli affect the primary step, VLA-4/ligand binding, we employed a recombinant VCAM-IgG fusion protein (VCAM-Ig) as a soluble ligand for VLA-4. Using this soluble ligand, we have directly demonstrated that the VLA-4 receptor can exist in at least three different affinity states on the cell surface. Two distinct high affinity states are induced on normal peripheral blood T cells, one by the anti-beta 1 mAb TS2/16, and one of 15-20 fold higher affinity by the divalent cation Mn2+. Interestingly, activation through the T cell receptor (TcR), through CD31 or by the Macrophage Inflammatory Protein-1 beta chemokine (MIP-1 beta) do not detectably increase VLA-4 affinity although they do augment VLA-4 dependent cell adhesion in vitro. Thus, VCAM-Ig binding defines high affinity VLA-4 receptors, revealing unique effects of the TS2/16 mAb and Mn2+ cations in vitro, and distinguishes VLA-4/VCAM interactions from subsequent steps in cell adhesion.

Protection against adoptive transfer of autoimmune diabetes mediated through very late antigen-4 integrin

The very late antigen-4 (VLA-4) integrin expressed on the surface of lymphocytes and macrophages can regulate their migration to inflammatory sites as well as control cellular activation. The role of VLA-4 in the establishment of autoimmune diabetes is not easily predicted given the multiplicity of adhesion pathways and their differential use by various cell types. The contribution of VLA-4 to insulin-dependent diabetes mellitus was investigated by administration of VLA-4-specific monoclonal antibodies (MoAb) in an adoptive transfer model of disease in NOD mice. This study shows that VLA-4-specific MoAbs profoundly inhibit the development of diabetes with protection sustained by repeated MoAb exposure. Insulitis was completely inhibited during treatment and progressed to a severe degree once MoAb treatment was suspended, yet approximately 40% of treated recipients failed to become diabetic during 1-2 months post-treatment. Although we cannot rule out depletion of a relatively minor subpopulation of cells by prolonged anti-VLA-4 MoAb exposure, this inhibition of diabetes onset by treatment with MoAbs to VLA-4 supports a dependence on VLA-4 for cellular functions leading to diabetes and demonstrates that a significant disease modifying effect can be mediated by targeting the VLA-4 integrin.

Resolution enhanced NMR spectroscopy in biological systems via magnetic susceptibility matched sample immersion chambers

A technique is described which reduced the magnetic susceptibility induced line broadening in NMR spectra obtained from three biological systems at 4.7 Tesla. Proton spectra from a sealed suspension of HL60 leukemic myeloblasts yielded minimum linewidths of 1.3 Hz at 200 MHz (0.0065 ppm) after 10 min of automated shimming. 31P spectra from an in vivo murine MCa mammary carcinoma yielded a well-resolved phosphorylcholine resonance without proton decoupling and with the resistive shim coil currents set to zero. 31P spectra from a perfused suspension of RIF-1 fibrosarcoma cells exhibited a gamma-nucleoside triphosphate resonance which was resolved into purine and pyrimidine components.

A randomized controlled phase III trial of recombinant human granulocyte colony-stimulating factor (filgrastim) for treatment of severe chronic neutropenia

Patients with idiopathic, cyclic, and congenital neutropenia have recurrent severe bacterial infections. One hundred twenty-three patients with recurrent infections and severe chronic neutropenia (absolute neutrophil count < 0.5 x 10(9)/L) due to these diseases were enrolled in this multicenter phase III trial. They were randomized to either immediately beginning recombinant human granulocyte colony-stimulating factor (filgrastim) (3.45 to 11.50 micrograms/kg/d, subcutaneously) or entering a 4-month observation period followed by filgrastim administration. Blood neutrophil counts, bone marrow (BM) cell histology, and incidence and duration of infection-related events were monitored. Of the 123 patients enrolled, 120 received filgrastim. On therapy, 108 patients had a median absolute neutrophil count of > or = 1.5 x 10(9)/L. Examination of BM aspirates showed increased proportions of maturing neutrophils. Infection-related events were significantly decreased (P < .05) with approximately 50% reduction in the incidence and duration of infection-related events and almost 70% reduction in duration of antibiotic use. Asymptomatic splenic enlargement occurred frequently; adverse events frequently reported were bone pain, headache, and rash, which were generally mild and easily manageable. These data indicate that treatment of patients with severe chronic neutropenia with filgrastim results in a stimulation of BM production and maturation of neutrophils, an increase in circulating neutrophils, and a reduction in infection-related events.

Interleukin-1 modulation of cytokine receptors on human neutrophils: in vitro and in vivo studies

Interleukin-1 (IL-1) modulation of cytokine receptors (human IL-1 receptor [hIL-1R], human granulocyte colony-stimulating factor [hG-CSFR], human granulocyte-macrophage CSF receptor [hGM-CSFR], and human tumor necrosis factor receptor [hTNFR]) on human neutrophils was studied both in vitro and in vivo. In vitro, incubation of neutrophils with IL-1 at 37 degrees C for 0.5 or 8 hours caused a reduction of IL-1 binding in a dose-dependent manner, but did not demonstrably affect binding of the other cytokines tested. In vivo, neutrophils from patients with gastrointestinal malignancies who were participating in a clinical trial of recombinant human IL-1 beta (rhIL-1 beta) demonstrated modulation of cytokine receptors in an IL-1 beta dose- and time-dependent manner. At the two highest dose levels of IL-1 beta (0.068 and 0.1 microgram/kg), reduction (> 40%) of G-CSF binding and elevation (twofold to sixfold) of IL-1 binding to neutrophils was observed after 1 hour and 4 to 8 hours, respectively. In addition, IL-1 beta rapidly elevated G-CSF and glucocorticoid levels in plasma. Patients at the lowest dose level (0.002 microgram/kg) had a less dramatic change in these parameters. Further in vitro studies showed that synthetic glucocorticoids and G-CSF synergistically up-modulated IL-1 binding to neutrophils in a dose- and time-dependent manner. Scatchard analysis of binding data showed that this in vitro synergistic modulation was due to an increase in receptor numbers, rather than an increase in binding affinity. In addition, both human umbilical cord blood and bone marrow neutrophils responded to G-CSF and dexamethasone (Dex) with a superadditive increase in IL-1 binding. Therefore, one of mechanisms for IL-1 up-modulation of IL-1R on human neutrophils in vivo was due to the fact that IL-1 rapidly elevates serum levels of G-CSF and glucocorticoids.

Interleukin-1: biological effects in human hematopoiesis

Interleukin-1 (IL-1) produces many direct and indirect effects in hematopoiesis. Il-1 stimulates hematopoietic progenitors, and enhances production of other cytokines. Experimental data suggest a role in ameliorating the myelosuppression that occurs following cytotoxic chemotherapy. Recombinant human interleukin-1 has now entered clinical trial. We conducted a phase I trial of IL-1 beta alone, and following a myelosuppressive dose of 5-fluorouracil in patients with cancer. A prominent neutrophilia was noted within several hours, with a later, more sustained thrombocytosis. Hypotension was dose-limiting. We observed fewer days of neutropenia following 5-FU plus IL-1 compared to IL-1 alone, but the difference did not reach statistical significance. Early results from other investigators suggest a possible protective effect from chemotherapy-induced myelosuppression. Preclinical data suggest that combinations of IL-1 and lineage specific growth factors may produce synergistic hematologic effects.

Structure/function studies on vascular cell adhesion molecule-1

Vascular cell adhesion molecule-1 (VCAM1) is a member of the immunoglobulin (Ig) superfamily which interacts with the integrin very late antigen-4 (VLA4). The VCAM1/VLA4 interaction mediates both adhesion and signal transduction and is thought to play an important role in inflammatory and immune responses in vivo. The major form of human VCAM1 contains seven extracellular Ig-like domains, with domain 1 designated as the most N-terminal. We have examined the relationship between human VCAM1 structure and function using a combination of domain truncation mutants and proteolytic fragmentation of recombinant soluble VCAM1. We have characterized two regions of VCAM1, localized to domains 4 and 5, which are highly sensitive to proteolytic cleavage, localized the epitope of the blocking monoclonal antibody 4B9 to domain 1, and found that domains 1-3 are sufficient for both its adhesive function and its ability to initiate T cell activation.

Continuous treatment with all-trans retinoic acid causes a progressive reduction in plasma drug concentrations: implications for relapse and retinoid "resistance" in patients with acute promyelocytic leukemia

Although all-trans retinoic acid (RA) induces complete remission in a high proportion of patients with acute promyelocytic leukemia (APL), all groups have described clinical relapses despite continued RA treatment. This finding suggests that resistance to the cytodifferentiating effects of the retinoid had been acquired. To investigate potential mechanisms of clinical resistance to RA, we serially evaluated the clinical pharmacology of the drug in APL patients treated with this agent. Leukemic cells from patients relapsing from RA treatment were cultured in the presence of RA and examined for evidence of morphologic maturation. We also studied messenger RNA expression of the newly described gene product of the (15;17) translocation in APL, PML/RA receptor-alpha (PML/RAR-alpha). Serial pharmacokinetic studies showed that continuous daily RA treatment was associated with a marked decrease in plasma drug concentrations at the time of relapse compared with the initial day of therapy. Doubling the RA dose in six patients failed to reinduce response at the time of relapse and also failed to significantly augment plasma RA concentrations. However, leukemic cells obtained at the time of relapse from four patients retained in vitro sensitivity to the differentiating activity of RA (10(-6) mol/L). No change was observed in the pattern of PML/RAR-alpha expression assessed by Northern blot analysis at the time of relapse compared with pretreatment in two patients who were tested. These results indicate that clinical relapse and "resistance" to continuous treatment with all-trans RA in APL is associated with progressive reduction of plasma concentrations, potentially to levels below those that sustain differentiation of leukemic cells in vivo. Long-term success of this treatment will require the development of strategies that circumvent this pharmacologic phenomenon.

Signaling by vascular cell adhesion molecule-1 (VCAM-1) through VLA-4 promotes CD3-dependent T cell proliferation

Vascular cell adhesion molecule, VCAM-1, is an adhesion molecule expressed on activated endothelium thought to play a role in leukocyte migration to sites of inflammation. VCAM-1 adheres to leukocytes through the VLA-4 integrin. Recombinant soluble VCAM-1 (rsVCAM) and anti-CD3 mAb OKT3 were utilized to address the role of the VCAM-1/VLA-4 pathway in antigen-dependent T cell activation. Monocyte-depleted T cells proliferated upon exposure to co-immobilized OKT3 and rsVCAM but to neither alone. In contrast, an anti-VLA-4 mAb HP1/2 failed to co-activate with OKT3, despite the fact that both rsVCAM and HP1/2 support T cell adhesion comparably. These data indicate that adhesive function is not sufficient for co-stimulatory activity. They also reveal that VCAM-1 may play a role in regulating T cell immune responses as well as migration in vivo.

A phase I trial of recombinant human interleukin-1 beta alone and in combination with myelosuppressive doses of 5-fluorouracil in patients with gastrointestinal cancer

We studied escalating doses of recombinant human interleukin-1 beta (IL-1 beta) alone and after a myelosuppressive dose of 5-fluorouracil (5-FU) in patients with gastrointestinal cancer. Transient neutropenia, monocytopenia, and lymphocytopenia were observed followed by a 1.3- to 6.0-fold (mean, 3.46-fold) dose-dependent neutrophil leukocytosis (P less than .00001) on the days of IL-1 beta administration. Increases in platelet counts were observed at a median of 14 days (range, 6 to 23) after IL-1 beta administration. Transient hypoglycemia, rebound hyperglycemia, elevations in serum cortisol, and C-reactive protein were observed. Side effects included fever, rigors, and headache in the majority of patients. Hypotension was observed in three of five patients at the highest dose level (0.1 micrograms/kg) and was dose-limiting. Fewer days of neutropenia were noted after 5-FU plus IL-1 beta than after 5-FU alone; however, this difference did not reach statistical significance. These data show that IL-1 beta has stimulatory effects in human hematopoiesis.

Clinical pharmacology of deoxyspergualin in patients with advanced cancer

Pharmacokinetic studies were carried out in 25 patients with advanced cancer receiving deoxyspergualin (DSG), a candidate anticancer agent, in a dose-finding Phase I study. The dosage range explored was 80 to 2160 mg/m2/day for 5 days by continuous i.v. infusion. The drug levels in plasma and urine were measured by high-performance liquid chromatography with postcolumn derivatization and fluorescence detection. One drug metabolite was demonstrated in plasma and urine of treated patients. This metabolite was extracted from urine and purified to homogeneity; thereafter, it was examined by high-performance liquid chromatography, nuclear magnetic resonance, and fragmentation mass spectrometry and was demonstrated to be identical to chemically synthesized desaminopropyl-DSG. The mean steady state plasma concentrations of DSG ranged from 0.28 to 11.1 microM at, respectively, the 80- and 2160-mg/m2 dosage levels. The plasma concentration at steady state and the area under the plasma concentration versus time curve of DSG were proportional to dose (r = 0.97). Following discontinuance of the infusion, DSG was cleared from the plasma in a biexponential fashion. The mean total body clearance was 364 +/- 78 ml/min/m2. Desaminopropyl-DSG was formed extensively at all dosage levels; mean steady state plasma levels of this metabolite reached a plateau 2.65 microM at a dose of 720 mg/m2/day and did not rise with further dose increments. The urinary content of DSG was examined in 20 patients over the dosage range from 160 to 960 mg/m2/day; in this group less than 10% of the administered dose was excreted as DSG. In four patients at the 720- and 960-mg/m2/day dosage levels, the total DSG plus metabolite excretion ranged from 7 to 18% of the administered dose, with comparable quantities occurring as the parent drug and desaminopropyl-DSG.

Differentiation therapy of acute promyelocytic leukemia with tretinoin (all-trans-retinoic acid)

BACKGROUND AND METHODS

Patients with acute promyelocytic leukemia have a characteristic (15;17) translocation, with a breakpoint on chromosome 17 in the region of the retinoic acid receptor-alpha (RAR-alpha). Since this receptor has been shown to be involved with growth and differentiation of myeloid cells in vitro, and since recent clinical studies have reported that tretinoin (all-trans-retinoic acid) induces complete remission in patients with acute promyelocytic leukemia we studied the effects of tretinoin on cellular maturation and molecular abnormalities in patients undergoing the induction of remission with this agent.

RESULTS

Eleven patients with acute promyelocytic leukemia were treated with tretinoin administered orally at a dose of 45 mg per square meter of body-surface area per day. Nine of the 11 patients entered complete remission. In two patients, complete remission was preceded by striking leukocytosis that then resolved despite continued drug treatment. Serial studies of cellular morphologic features, cell-surface immunophenotypic analysis, and fluorescence in situ hybridization with a chromosome 17 probe revealed that clinical response was associated with maturation of the leukemic clone. All patients who responded to treatment who were tested by Northern blot analysis had expression of aberrant RAR-alpha. As patients entered complete remission, the expression of the abnormal RAR-alpha message decreased markedly; however, it was still detectable in several patients after complete morphologic and cytogenetic remission had been achieved.

CONCLUSIONS

Tretinoin is a safe and highly effective agent for inducing complete remission in patients with acute promyelocytic leukemia. Clinical response to this agent is associated with leukemic-cell differentiation and is linked to the expression of an aberrant RAR-alpha nuclear receptor. Molecular detection of the aberrant receptor may serve as a useful marker for residual leukemia in patients with this disease.

In vivo measurements of bone marrow cellularity using volume-localized proton NMR spectroscopy

Volume-localized proton NMR spectroscopy was used to estimate bone marrow cellularity in the posterior iliac crests of patients undergoing treatment with hematopoietic growth factors for a variety of hematologic and neoplastic disorders. Twelve patients were accrued, six of whom were studied more than once, yielding a total of 25 measurements. These data were compared to cellularity assessments derived from conventional bone marrow core biopsies obtained within a 24-h period before or after the NMR exam. The results obtained by the two methods are well correlated (R = 0.94, P less than 0.001), suggesting that this noninvasive technique may preclude the need for biopsies in some cases.

CD4-Pseudomonas exotoxin hybrid proteins: modulation of potency and therapeutic window through structural design and characterization of cell internalization

Replacing the Pseudomonas exotoxin A (PE) cell binding domain with the human immunodeficiency virus (HIV) gp120 binding domain from CD4 yields a hybrid toxin (CD4-PE) with potential therapeutic use in treating acquired immunodeficiency syndrome (AIDS). To find the most therapeutically potent combination of CD4 and PE four different hybrid toxins composed of one [CD4(122)] or two [CD4(181)] Ig-like CD4 domains and sequences of PE where the binding domain was partially [PE(392)] or completely [PE(364)] removed were constructed and expressed in Escherichia coli. The number of CD4 domains determined the binding affinity to gp120 and in cell viability assays the window between specific and nonspecific cytotoxicity. The length of PE determined the potency of the drug. The optimal hybrid toxin was composed of two Ig-like domains of CD4 and PE(392). Investigation of the internalization mechanism of CD4-PE revealed that the hybrid toxin binds to target cells and is endocytosed within one hour. However, more than 6 hours are required for maximum translation inhibition. In contrast to PE which is inhibited by ammonium chloride treatment, cell toxicity of CD4-PE is not affected by ammonium chloride. Further investigations showed that the acid-induced hydrophobicity change which is required for membrane translocation is also observed with CD4-PE but at significantly higher pH than with PE.

CD4-Pseudomonas exotoxin conjugates delay but do not fully inhibit human immunodeficiency virus replication in lymphocytes in vitro

The CD4 molecule is a high affinity receptor for the human immunodeficiency virus (HIV) envelope glycoprotein (gp160 or gp120). This glycoprotein is expressed on the surface membrane of cells infected with HIV. It has, therefore, been suggested that a soluble form of CD4 might be used as a targeting agent to deliver toxins selectively to cells infected with HIV. We demonstrate that CD4-Pseudomonas exotoxin A (PE) conjugates inhibit the proliferation of gp160-transfected Chinese hamster ovary cells and block HIV replication in virus-infected H9 cells. However, this inhibition of HIV replication appears to be incomplete since virus replication occurs following removal of the toxin conjugates from these cultures. Moreover, CD4-PE conjugates delay but do not inhibit HIV replication in human peripheral blood lymphocytes. These studies suggest that such conjugates should be assessed only as potential adjunctive therapies in the acquired immunodeficiency syndrome.

[Studies on the combined effects of shift work and noise on permanent hearing loss]

Combined exposure to shiftwork and noise was investigated with respect to its aural damaging effect. The investigations were carried out on 347 male and female noise-exposed textile workers working in single-shift and three-shift systems. The average hearing loss for the PTS at 3 kHz, 4 kHz, the total hearing loss at 0.5, 1, 2, 4, 6, 8 kHz and percentage of hearing loss according to Fowler/Sabine served as indicators. To fulfil this task an epidemiological cross-sectional study was performed. The results of the present study show lower average hearing loss values in the case of three-shift workers as compared with single-shift workers.

Experimental neonatal syphilis in a susceptible (C4D) and a resistant (Albany) strain of guinea pig

Despite similar levels of natural antibodies and treponemicidal activity, 83% of fourth complement component-deficient (C4D) mother guinea pigs developed ulcerative lesions to a challenge of 5 x 10(7) Treponema pallidum, whereas 75% of offspring 1 to 5 days old were temporarily (2-3 months) resistant to development of dermal lesions. In contrast, only 17% of Albany-strain mothers developed small papular lesions, while 68% of 1- to 5-day-old newborns developed large papular or ulcerative lesions within 9-15 days postinfection. These findings, together with the late development of both dermal lesions and antibodies in C4D neonates, preclude the concept of an antibody-associated natural resistance. T. pallidum infection in either C4D or Albany neonates was not associated with depletion of any particular cell population in lymphoid tissue. However, marked age- and strain-dependent histologic differences were noted. Histologic examination of lymph nodes and spleens from 17-day-old and 3- to 4-month-old animals showed that maturation of lymphoid tissues in C4D animals lagged behind the Albany strain at either age. Moreover, 75% of C4D newborns contained significantly higher levels of immunomodulatory alpha 1 fetoprotein than Albany neonates. The possibility that differences in susceptibility to T. pallidum infection between C4D and Albany guinea pigs as neonates and again as adults is the result of genetically associated changes in immunologic recognition is discussed.

Granulocyte colony-stimulating factor: preclinical and clinical studies

The production of neutrophil granulocytes is a complex and dynamic process during which a small number of self-renewing stem cells give rise to lineage-specific progenitors. One hematopoietic glycoprotein that appears to specifically control the survival, cycle activation, proliferation and terminal maturation of this myeloid lineage is granulocyte colony-stimulating factor (G-CSF). Some topics discussed are its molecular characterization, biochemical purification, sources, and effects of administration.

Electromyographic activity and noradrenaline content of the rabbit oviduct under different hormonal states

Spontaneous electromyographic (EMG) activity of the oviduct recorded in vivo in untreated, estrogen-treated, and progesterone-treated castrated rabbits was found to exhibit two main patterns: short spike bursts lasting 1-10 s and long trains of action potentials lasting several minutes, which constituted the major component of EMG activity. After estrogen treatment, both wet weight and noradrenaline (NA) content of the castrated rabbit oviduct were enhanced mainly at the ampullary-isthmic junction; long trains of discharges were significantly shorter (2.0-2.7 min vs 3.6-4.6 min) and appeared at more frequent intervals (9.8-12.2 min vs 14.2-22.6 min). After progesterone treatment, spontaneous EMG activity was not significantly different from that in untreated castrated rabbits (as was the NA content) except at the ampullary-isthmic junction. NA injection elicited a stimulatory response of the oviduct lasting 1-7 min in the three hormonal states. Phentolamine strongly depressed spontaneous EMG activity but the inhibition was more transient in castrated rabbits than in estrogen-treated and progesterone-treated animals. Propranolol had no effect on spontaneous EMG activity. These data and the high NA concentrations found in all parts of the isthmus support the hypothesis that adrenergic innervation plays a role in the organization of oviductal motility in the rabbit.

Immunogenicity of three recombinant Treponema pallidum antigens examined in guinea pigs

The immunogenicity of recombinant treponemal antigens TmpA, TmpB and TmpC incorporated in RIBI adjuvant and injected into inbred strain 2 guinea pigs has been examined. The immune status of these animals has been challenged by infection with Treponema pallidum, Nichols. The immune response evaluated by the fluorescent-antibody test, microhemagglutination test and ELISA demonstrated high titers of antibodies to the T. pallidum antigens. The immunoblot analysis proved that the antibodies were directed to the 43-(Tmp A) 34- (Tmp B) and 35-kdalton (Tmp C) polypeptides. Antibodies cross-reacting with Treponema phagedenis biotype Reiter were, however, also detected. In spite of high titers of antibodies the animals were not protected against challenging infection with 10(8) organisms of T. pallidum.

Phase I study of granulocyte colony-stimulating factor in patients with transitional cell carcinoma of the urothelium

Recombinant human granulocyte colony-stimulating factor (rhG-CSF) was administered at a dose of 1-60 micrograms/kg of body weight to 22 patients with transitional cell carcinoma before chemotherapy as part of a Phase I/II study. In all patients, a specific dose-dependent increase in the absolute neutrophil count (ANC) of 1.8-12 fold was seen. In addition, this augmentation in the ANC was accompanied by an increase in leukocyte alkaline phosphatase, a marker of secondary granule formation. In six of eight patients analyzed, an increase in bone marrow myeloid to erythroid cell ratio was seen. Day 14 peripheral blood cell derived colony forming unit granulocyte macrophage were also increased by day 6 of rhG-CSF treatment. Circulating levels of eosinophils and basophils were unchanged; however, a 10-fold increase in monocytes was observed in patients treated at the highest doses. There was also a small increase in CD3+ lymphocytes that was not dose dependent. Hemoglobin, hematocrit, and platelet count remained near baseline throughout the period of rhG-CSF administration. These findings demonstrate that rhG-CSF is a potent stimulus for normal neutrophil proliferation and maturation.

Clinical features of abdominal tuberculosis

The clinical features of 81 cases of abdominal tuberculosis (TB) are presented. The peritoneum was involved in 41 patients, the ileocecal area in 17, the anorectal area in 16, and mesenteric glands in 8. There was one case each involving the liver and sigmoid colon. Most patients were young women. The tuberculin reaction was significant in 83% of patients tested, and 54% had evidence of TB elsewhere. Tuberculous peritonitis was more common in native North American Indians and presented as an acute abdomen, abdominal tumor, or cirrhosis. Asians developed the majority of ileocecal and mesenteric lymph node disease and were frequently diagnosed as having Crohn's disease, appendicitis, or cancer. Anorectal cases presented with fistulae or abscesses and usually had concomitant pulmonary TB. The disease was fatal in five patients (6%), four of whom were diagnosed only after death. One noncompliant patient had a relapse. All other patients were cured after receiving treatment.

Effect of granulocyte colony-stimulating factor on neutropenia and associated morbidity due to chemotherapy for transitional-cell carcinoma of the urothelium

We evaluated the ability of human recombinant granulocyte colony-stimulating factor (rhG-CSF) to prevent chemotherapy-induced neutropenia or to accelerate recovery from this complication and thus allow patients to receive full doses of antineoplastic agents on time, according to protocol design. Twenty-seven patients with transitional-cell carcinoma of the urothelium who were undergoing treatment with methotrexate, doxorubicin, vinblastine, and cisplatin were given rhG-CSF (up to 60 micrograms per kilogram of body weight per day) before their first cycle of combination chemotherapy, during the first cycle, or at both points. Treatment with rhG-CSF before chemotherapy resulted in a dose-dependent increase in the absolute neutrophil count. Treatment with rhG-CSF after chemotherapy significantly reduced the number of days (91 percent) per patient on which the absolute neutrophil count was 1000 per microliter or less (P = 0.0039), reduced the number of days (1 vs. 35) on which antibiotics were used to treat fever and neutropenia, and significantly increased the percentage (100 vs. 29 percent) of patients qualified to receive planned chemotherapy on day 14 of the treatment cycle (P = 0.0015). In addition, the incidence of mucositis was significantly decreased (11 vs. 44 percent, P = 0.041), as was its severity. These findings demonstrate that rhG-CSF is a potent stimulus of normal neutrophil proliferation and maturation. In addition, its administration can reduce both the hematopoietic and oral toxicity of chemotherapy.

Effect of irradiation and depletion of C3-complement component on the course of Treponema pallidum infection in a resistant guinea pig strain

The role of complement and ionizing radiation in the natural resistance to Treponema pallidum infection of Albany guinea pigs was explored. Depletion of C3 by cobra venom factor for a period of 14 days affected neither the host's susceptibility to infection nor the humoral response. Total body irradiation with 420 or 800 R was fatal within 20-30 days and there was no multiplication of treponemes in the infected host. Animals showing lethal signs were euthanized and tissues removed for examination. Exposure to a nonlethal dose of 300 R increased the susceptibility to infection (46% symptomatic lesions) and facilitated multiplication of treponemes at the site of inoculation and in the lymphoid organs, but the humoral response was not different from that of non-irradiated controls. The results seem to suggest a defect in antigen recognition by the immunocompetent cells in the resistant Albany guinea pigs.

Factors affecting the clinical course of Treponema pallidum infection in guinea pigs

The clinical course of infection with Treponema pallidum (Nichols) in inbred strain 2 guinea pigs was shown to be affected by age, sex and site of inoculation.

Active abdominal tuberculosis in Canada in 1970-81

We reviewed all 341 cases of abdominal tuberculosis reported in Canada between 1970 and 1981. Over the study period abdominal tuberculosis accounted for a stable proportion (0.8%) of all reported cases of tuberculosis in Canada. Its incidence declined steadily. It was more common in women, in native Indians and in people born in Asia. Detailed records of the 55 cases reported to Statistics Canada from British Columbia and of an additional 31 cases not reported to Statistics Canada (usually because they involved concomitant disease elsewhere, notably the lungs) were studied. Five of the 55 cases reported to Statistics Canada had been reported incorrectly. Of the 81 cases in British Columbia 51% involved peritonitis, 21% ileocecal disease, 20% anorectal disease, 10% mesenteric lymphadenitis, 1% disease of the sigmoid colon and 1% disease of the liver. The rate of bacteriologic confirmation was low (51%).

Adoptive transfer of immunity to Treponema pallidum Nichols infection in inbred strain 2 and C4D guinea pigs

T lymphocytes purified from lymph nodes and spleens of chancre-immune, inbred strain 2 guinea pigs, when infused into syngeneic guinea pigs, conferred protection against challenge with Treponema pallidum subsp. pallidum Nichols. No protection was conferred by similar injections of cell suspensions from normal guinea pigs or guinea pigs immunized with T. phagedenis biotype Reiter or T. pallidum-free testis supernatants from infected rabbits. Similar results were obtained with homozygous C4D guinea pigs. After several months of infection, 2 of 11 strain 2 and 1 of 8 strain C4D recipients of T. pallidum-immune cells developed an erythematous reaction of short duration at the injection site; 2 of these recipients were positive for T. pallidum. Throughout the experimental period the humoral response to treponemal antigens was substantially lower in the adoptively immune guinea pigs than in various unprotected control groups. Passive immunity to infection with T. pallidum, however, seems to be dose related, since asymptomatic infection persisted for as long as 3 months after challenge in strain 2 guinea pigs transfused with 10(8) T. pallidum-immune lymphocytes, but not in C4D recipients of twice as many immune cells.