Phase I/II study of combined granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor administration for the mobilization of hematopoietic progenitor cells

PURPOSE

To study the toxicity and efficacy of combined granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) administration for mobilization of hematopoietic progenitor cells (HPCs).

MATERIALS AND METHODS

Cohorts of a minimum of five patients each were treated subcutaneously as follows: G-CSF 5 micrograms/kg on days 1 to 12 and GM-CSF at .5, 1, or 5 micrograms/kg on days 7 to 12 (cohorts 1, 2, and 3); GM-CSF 5 micrograms/kg on days 1 to 12 and G-CSF 5 micrograms/kg on days 7 to 12 (cohort 4); and G-CSF and GM-CSF 5 micrograms/kg each on days 1 to 12 (cohort 5). Ten-liter aphereses were performed on days 1 (baseline, pre-CSF), 5, 7, 11, and 13. Colony assays for granulocyte-macrophage colony-forming units (CFU-GM) and erythroid burst-forming units (BFU-E) were performed on each harvest.

RESULTS

The principal toxicities were myalgias, bone pain, fever, nausea, and mild thrombocytopenia, but none was dose-limiting. Four days of treatment with either G-CSF or GM-CSF resulted in dramatic and sustained increases in the numbers of CFU-GM per kilogram collected per harvest that represented 35.6 +/- 8.9- and 33.7 +/- 13.0-fold increases over baseline, respectively. This increment was attributable both to increased numbers of mononuclear cells collected per 10-L apheresis and to increased concentrations of progenitors within each collection. The administration of G-CSF to patients already receiving GM-CSF (cohort 4) caused the HPC content to surge to nearly 80-fold the baseline (P = .024); the reverse sequence, ie, the addition of GM-CSF to G-CSF, was less effective. The CFU-GM content of the baseline aphereses correlated with the maximal mobilization achieved (r = .74, P = .001).

CONCLUSION

Combined G-CSF and GM-CSF administration effectively and predictably mobilizes HPCs and facilitates apheresis.

Epigenetic control of an endogenous gene family is revealed by a novel blue fluorescent mutant of Arabidopsis

The Wassilewskija strain of Arabidopsis has four genes encoding the tryptophan enzyme phosphoribosylanthranilate isomerase (PAI) located at three unlinked sites. These four PAI genes are methylated over their regions of DNA homology. When PAI copy number is reduced by deletion of two tandemly arrayed genes (MePAI1-PAI4), a mutant with fluorescent, tryptophan-deficient phenotypes results, because the two remaining methylated PAI genes (MePAI2 and MePAI3) supply insufficient PAI activity. These two methylated genes can be inherited through meiosis, even when they are segregated away from each other in crosses to a strain with unmethylated PAI genes. However, the mutant phenotypes conferred by the methylated PAI genes are unstable, and mutant plants yield occasional revertant somatic sectors and progeny. Revertant lines display coordinately reduced methylation of both PAI2 and PAI3, implying that this hypomethylation acts in a concerted manner across the genome rather than at individual sites.

A phase I trial of interleukin 3 (IL-3) pre-bone marrow harvest with granulocyte-macrophage colony-stimulating factor (GM-CSF) post-stem cell infusion in patients with solid tumors receiving high-dose combination chemotherapy

In humans, interleukin 3 (IL-3) administration increases the cellularity and cycling of bone marrow progenitor cell populations. Initially, in primates and then in humans, IL-3 in sequence with GM-CSF has been shown to stimulate multilineage hematopoiesis. Based upon these effects, we designed a phase I trial of daily IL-3 administered subcutaneously for 10 days at dose levels of 2.5, 5.0, 10.0, 12.5, and 15.0 micrograms/kg followed within 72 h by bone marrow harvest, high-dose chemotherapy, and following chemotherapy, a fixed dose (5.0 micrograms/kg/day) of GM-CSF and bone marrow rescue. The study was designed to assess the toxicity and biological effects of IL-3 administered alone prior to bone marrow harvest and to determine the safety and clinical effects of IL-3 stimulated bone marrow with GM-CSF following high-dose combination chemotherapy. A total of 19 patients with chemotherapy-sensitive non-hematologic malignancies (13 breast, five ovarian, and one testicular cancer) were enrolled. IL-3 up to 15.0 micrograms/kg/day could be administered without dose-limiting toxicities. Flu-like symptoms and headaches were common and poorly tolerated at the highest IL-3 dose. Significant increases in neutrophil counts (P = 0.018) were observed following IL-3. Overall, IL-3 administration was associated with a modest, but significant increase in CFU-GM within the bone marrow (P = 0.034). IL-3 administration had no consistent effect on CD34+ cell number within bone marrow. For the entire group, engraftment of neutrophils to greater than 0.5 x 10(9)/l occurred at a median of 21 days (range of 13-63 days) and platelet independence occurred at a median of 17 days (range 11-120 days). When IL-3 dose levels were analyzed separately, engraftment of neutrophils and platelets, blood product (platelets and packed RBCs) utilization, and discharge date were not superior in those treated with the higher dose (15.0 micrograms/kg) of IL-3. While higher doses of IL-3 were associated with more toxicity, they did not appear to enhance the stem cell pool or speed engraftment later. The effects of pre-bone marrow harvest IL-3 are modest and likely not as impressive as other approaches aimed at enhancing hematologic recovery following high-dose chemotherapy.

Treatment of central venous catheter occlusions with ethanol and hydrochloric acid

BACKGROUND

Occluded central venous lines (CVLs) is a major problem in pediatric patients.

METHODS

To relieve obstructed catheters, infusions of ethanol (up to 3 mL of a 70% solution) for presumed lipid occlusions and hydrochloric acid (HCl, 0.1 N, up to 3 mL) for presumed mineral and drug precipitates were given in an attempt to relieve obstructed catheters.

RESULTS

Patency was restored in 34 of 39 occluded catheters over an 18-month period.

CONCLUSIONS

Clearing occluded CVLs with ethanol and HCl is not only beneficial to the patient but also offers considerable cost savings compared to CVL replacement.

Human dermal endothelial cells express membrane-associated mast cell growth factor

Mast cell growth factor (MGF), a molecule that serves as a ligand for the receptor tyrosine kinase c-kit, is important in mast cell differentiation, migration, and activation. Previous studies of paraffin-embedded human skin using antibody to murine MGF and reverse transcription-polymerase chain reaction have demonstrated MGF protein and mRNA expression in keratinocytes and isolated dermal cells. We utilized a monoclonal antibody to human MGF to further define patterns of immunoreactivity in frozen specimens of neonatal and adult skin from normal individuals and from patients with urticaria pigmentosa. In addition to keratinocytes and isolated dermal cells in normal and urticaria pigmentosa skin, MGF was detected in cells lining superficial and mid-dermal vessels. Co-expression of MGF and the vascular antigen CD31, and immunoelectron microscopy, identified MGF-positive cells as endothelial cells. Patterns of endothelial MGF expression were not influenced by mast cell degranulation and endothelial E-selectin induction in vitro. By ultrastructure, unfixed specimens demonstrated MGF expression both within the endothelial cytoplasm and in association with lumenal, but not ablumenal, surfaces. Specimens fixed with Nakane's solution had diminished endothelial cytoplasmic MGF reactivity, but lumenal expression was maintained, suggesting persistence of a membrane-associated reactivity. MGF mRNA was also detected in cultured dermal microvascular endothelial cells using reverse transcription-polymerase chain reaction. These data establish human dermal endothelial cells as sites of MGF production and expression in human skin. Mast cell precursors must home to skin via vascular channels and differentiate in the immediate perivascular space. Thus, endothelial MGF may be an important determinant of adhesion and differentiation of mast cell progenitors expressing receptors for MGF.

AFC1, a LAMMER kinase from Arabidopsis thaliana, activates STE12-dependent processes in yeast

In the yeast Saccharomyces cerevisiae a kinase cascade activates the transcription factor STE12 leading to mating in haploid cells and pseudohyphal growth in diploid cells. To investigate related signal transduction pathways in higher plants, we have isolated a putative protein kinase gene from Arabidopsis thaliana that restores STE12-dependent functions to yeast with mutations in this signal transduction pathway. This Arabidopsis gene, AFC1, induces three STE12-dependent processes even in signal transduction-defective yeast strains: mating-specific gene expression in haploid yeast, mating of haploid yeast to yield diploids, and pseudohyphal growth in diploid yeast. AFC1 has no effect on transcription of the STE12 gene and, instead, is likely to activate the STE12 protein. However, AFC1 has only limited homology to FUS3 and KSS1, the endogenous yeast kinase regulators of STE12. AFC1 is a member of a recently described CDC2-related kinase subfamily, the LAMMER kinases. A close AFC1 homolog, AFC2, lacks STE12 activation phenotypes, indicating the specificity of AFC1. The phenotypes of AFC1 in yeast provide us with tools to elucidate the role of this kinase in Arabidopsis.

Characterization of metal-binding bioflocculants produced by the cyanobacterial component of mixed microbial mats

Mixed-species microbial mats that were dominated by the cyanobacterium Oscillatoria sp. and contained heterotrophic and purple autotrophic bacteria were constructed for specific bioremediation applications. When the mats were challenged with metals, production and secretion of metal-binding extracellular polysaccharide bioflocculants were observed. The concentration of these negatively charged polysaccharides was correlated with the removal of manganese from the water column beneath a surface microbial mat. Bioflocculants from an Oscillatoria sp. that was isolated from the mat were collected and concentrated for characterization. A chromatographic analysis revealed a heterogeneous population of polysaccharides with respect to charge density and molecular size. The subpopulation of polysaccharides which exhibited the highest level of flocculating activity was polyanionic and had a molecular weight of more than 200,000. A glycosyl analysis of the bioflocculants revealed the presence of galacturonic acid (2.2%) and glucuronic acid (1.86%). The presence of these components, which were negatively charged at the pH levels generated by the mats during photosynthesis (pH > 7.5), may account for the metal-binding properties of the mats.

Response of cellular antioxidants to ozone in wheat flag leaves at different stages of plant development

The effect of ozone (O3) on growth, yield and foliar antioxidants of spring wheat (Triticum aestivum L. cv. Turbo) was investigated in 1990 and 1991 in Braunschweig, Germany. Plants were grown full-season in pots in open-top chambers ventilated with charcoal-filtered (CF) air to which one or two levels of O3 were added. Mean 8 h day(-1) (10.00-18.00 h) O3 concentrations in the CF and CF + O3 treatments were 5.9, 61.2 and 92.5 nl litre(-1) in 1990, and 4.7 and 86.4 nl litre(-1) in 1991. Plants that received the high O3 level showed symptoms of premature senescence of the oldest leaves and yield reductions in both growing seasons. The contents of ascorbate and glutathione and the enzyme activities of ascorbate peroxidase and glutathione reductase were measured in symptomless flag leaves in weekly intervals before and after the beginning of anthesis. Leaf age had a significant effect on all antioxidants investigated. The O3 exposures of about 90 nl litre(-1) increased the activity of ascorbate peroxidase and the concentration of glutathione, but there were no pollutant effects on ascorbate content and glutathione reductase activity. Measurements of the antioxidant levels throughout one day showed no clear indications of diurnal changes in the antioxidative capacity in wheat flag leaves. The results are discussed in relation to the role of antioxidants in O3 detoxification.

Tn10 insertion specificity is strongly dependent upon sequences immediately adjacent to the target-site consensus sequence

Transposon Tn10 inserts preferentially into particular "hotspots" that have been shown by sequence analysis to contain the symmetrical consensus sequence 5'-GCTNAGC-3'. This consensus is necessary but not sufficient to determine insertion specificity. We have mutagenized a known hotspot to identify other determinants for insertion into this site. This genetic dissection of the sequence context of a protein binding site shows that a second major determinant for Tn10 insertion specificity is contributed by the 6-9 base pairs that flank each end of the consensus sequence. Variations in these context base pairs can confer variations of at least 1000-fold in insertion frequency. There is no discernible consensus sequence for the context determinant, suggesting that sequence-specific protein-DNA contacts are not playing a major role. Taken together with previous work, the observations presented suggest a model for the interaction of transposase with the insertion site: symmetrically disposed subunits bind with specific contacts to the major groove of consensus-sequence base pairs, while flanking sequences influence the interaction through effects on DNA helix structure. We also show that the determinants important for insertion into a site are not important for transposition out of that site.

IS10 transposase mutations that specifically alter target site recognition

IS10 inserts preferentially into particular hotspots. We describe here mutations of IS10 transposase, called 'ATS' that confer Altered Target Specificity. These mutations yield a general relaxation in target specificity but do not affect other aspects of transposition. Thus, the preference for specific nucleotide sequences at the target site can be cleanly separated from other steps of the transposition reaction. Eleven ATS mutations identified in a genetic screen occur at only two codons in transposase, one in each of two regions of the protein previously implicated in target site interactions (Patch I and Patch II). Genetic analysis suggests that mutations at the two ATS codons affect the same specific function of transposase, thus raising the possibility that Patch I and Patch II interact. For wild-type IS10, insertion specificity is determined in part by a specific 6 bp consensus sequence and in part by the immediately adjacent sequence context of the target DNA. The ATS mutations do not qualitatively alter the hierarchy with which base pairs are recognized in the consensus sequence; instead, sites selected by ATS transposase exhibit a reduction in the degree to which certain base pairs are preferred over others. Models for the basis of this phenotype are discussed.

Response of nitrogen metabolism in beans (Phaseolus vulgaris L.) after exposure to ozone and nitrogen dioxide, alone and in sequence

Bush bean (Phaseolus vulgaris L.) plants were exposed to low levels of ozone (O₃ ) and/or nitrogen dioxide (NO₂ ) in open-top chambers during the growing seasons of 1988 and 1989. Treatments consisted of charcoal-filtered (CF) air, and CF air enriched with either O₃ (50-60 nll ^-1 ), NO₂ (30-40 nll^-1 ) or both gases. A daily sequential exposure, O₂ followed by NO₂ , was used in each year in the combined treatment: O₂ was added for 8 h d^-1 from 08.00 h until 16.00 h, and NO₂ for 16 h d^-1 from 16.00 h until 08.00 h. Growth variables and key enzymes of N assimilation in leaves were investigated during vegetative growth and at anthesis. Pollutant effects varied between years. No significant effects were found in 1988. In 1989 NO₂ , alone or in sequential exposure with O₃₊ , increased leaf dry weight and total biomass until anthesis. Moreover, there was a parallel increase in the extractable activity of both nitrate and nitrite reductase in the NO₂ treatments during vegetative growth, while glutamine synthetase and glutamate dehydrogenase were only increased by sequential exposure to O₃ + NO₂ . In contrast, during anthesis the activities of nitrite reductase and glutamine synthetase were lowest in leaves sequentially exposed to O₃ + NO₂ . Ozone alone had very little effect on N metabolism but suppressed growth during anthesis. At pod maturity, the lowest leaf dry weight and leaf area occurred in plants exposed to the sequential combination of O₃ + NO₂ , but yield (pod weight) was not significantly affected by any of the pollutant treatments. It is concluded that chronic exposure especially to the sequence O₃ -NO₂ reduced the capacity of the plants for N assimilation. The observed shift in nitrogen metabolism during the plants' development may have contributed to the adverse effects of the sequential treatment O₃ + NO₂ on growth variables at the end of the exposure period.

Genetic evidence against intramolecular rejoining of the donor DNA molecule following IS10 transposition

Tn10 and IS10 transpose by a nonreplicative mechanism in which the transposon is excised from the donor molecule and integrated into a target DNA site, leaving behind a break at the original donor site. The fate of this broken donor DNA molecule is not known. We describe here two experiments that address this issue. One experiment demonstrates that a polar IS10 element gives rise to polarity-relief revertants at less than 1% the frequency of transposition of the same element in the same culture. In a second experiment, transpositions of an IS10 element from one site in the bacterial genome to another are selected and the resulting isolates examined for alterations at the donor site; none of 1088 such isolates exhibited a detectable change at the donor locus. These results are compatible with two possible fates of the transposon donor molecule: degradation ("donor suicide"), or restoration of the original information at the donor site by a recombinational repair mechanism analogous to double-strand break repair. These results argue against the possibility that the donor molecule gap is simply resealed by intramolecular rejoining.

A comparison of passive and active shunting for bypass of the retrohepatic IVC

In order to provide improved shunting of caval blood around the liver for major juxtahepatic venous injuries, a modification of the venovenous bypass (active shunt) used in liver transplantation was developed. Using a porcine model, hemodynamic comparisons of active shunting with an interposed Bio-Medicus pump (group I: n = 6) and passive shunting (group II: n = 4) around the liver for 60 minutes were made. One end of the shunt was placed in the infrahepatic cava and the other end was inserted into the right atrium. Systolic blood pressure (sBP) and cardiac output (CO) were well maintained in group I. However, with passive shunting (group II), sBP fell from 134 +/- 28 to 83 +/- 28 mm Hg (p less than 0.05) and CO fell from 4.1 +/- 0.07 to 1.3 +/- 0.5 L/min (p less than 0.001) after 1 hour. The well-maintained sBP and CO in group I were associated with much better shunt flow rates than in group II (31 +/- 7 vs. 11 +/- 3 mL/kg/min) (p less than 0.001). The cause of the fall in sBP and CO with the passive shunt (group II) in spite of a well-maintained PAWP is unclear at this time. Thus, it appears that active shunting of blood around the liver using a venovenous bypass with a pump is much superior hemodynamically to passive shunting, which relies only on hydrostatic pressure.

Natural killer lines and clones with apparent antigen specificity

Fresh CD3-, CD16+ lymphocytes that adhered to selected allogeneic lymphoblastoid cell lines (LCL) were cultured with LCL in the presence of IL-2-containing medium. The resulting lines as well as clones derived from these lines expressed CD16 and/or CD56, but lacked detectable CD3 or TCR-alpha/beta or TCR-gamma/delta complexes on the cell surface. Northern blot analysis failed to detect CD3 epsilon or TCR-beta transcripts, but revealed the presence of a TCR-gamma chain transcript in one of these lines. In addition to displaying potent cytolytic activity against K562 erythroleukemia cells (a classical NK target), the vast majority of these lines and clones lysed their specific stimulator LCL to a significantly greater extent than irrelevant LCL. This selective killing was inhibited by the addition of cold stimulator LCL or K562 cells, or anti-LFA 1 mAbs, but not by irrelevant LCL or mAbs to CD3, class I or class II MHC antigens. These results indicate that some CD3- lymphocytes, phenotypically indistinguishable from NK cells, can recognize and lyse allogeneic targets in a specific manner.