Cytokine-primed bone marrow stem cells vs. peripheral blood stem cells for autologous transplantation: a randomized comparison of GM-CSF vs. G-CSF

Autologous transplantation for non-Hodgkins lymphoma and Hodgkin's disease is widely used as standard therapy for those with high-risk or relapsed tumor. Peripheral blood stem cell (PBSC) collections have nearly completely replaced bone marrow stem cell (BMSC) harvests because of the perceived advantages of more rapid engraftment, less tumor contamination in the inoculum, and better survival after therapy. The advantage of PBSC, however, may derive from the hematopoietic stimulating cytokines used for PBSC mobilization. Therefore, we tested a randomized comparison of GM-CSF vs. G-CSF used to prime either BMSC or PBSC before collection for use in autologous transplantation. Sixty-two patients receiving transplants (31 PBSC; 31 BMSC) for non-Hodgkin's lymphoma (n = 51) or Hodgkin's disease (n = 11) were treated. All patients received 6 days of randomly assigned cytokine. Those with cellular marrow in morphologic remission underwent BMSC harvest, while those with hypocellular marrow or microscopic marrow tumor involvement had PBSC collected. Neutrophil recovery was similarly rapid in all groups (median 14 days; range 10-23 days), though two patients had delayed neutrophil recovery using GM-CSF primed PBSC (p = 0.01). Red cell and platelet recovery were significantly quicker after BMSC mobilized with GM-CSF or PBSC mobilized with G-CSF. This speedier hematologic recovery resulted in earlier hospital discharge as well. However, in multivariate analysis, neither the stem cell source nor randomly assigned G-CSF vs. GM-CSF was independently associated with earlier multilineage hematologic recovery or shorter hospital stay. Relapse-free survival was not independently affected by either the assigned stem cell source or the randomly assigned priming cytokine, though malignant relapse was more frequent in those assigned to PBSC (RR of relapse 3.15, p = 0.03). These data document that BMSC, when collected following cytokine priming, can yield a similarly rapid hematologic recovery and short hospital stay compared with cytokine-primed PBSC. Using primed BMSC, no difference in malignant relapse or relapse-free survival was observed. These findings suggest that despite widespread use of PBSC for transplantation, BMSC, when collected following hematopoietically stimulating cytokines, may remain a satisfactory source of stem cells for autologous transplantation. G-CSF and GM-CSF are both effective in priming autologous PBSC or BMSC for collection.

Unexpected augmentation of mycophenolic acid pharmacokinetics in renal transplant patients receiving tacrolimus and mycophenolate mofetil in combination therapy, and analogous in vitro findings

Mycophenolate mofetil (MMF) a potent immunosuppressive agent, has recently been approved for clinical use (CellCept) in renal transplant patients in combination with cyclosporine (CsA). With the expanded use of tacrolimus (Prograf) as well in renal transplant patients, there is a lack of pharmacokinetic studies clarifying drug interactions between the three agents. A pharmacokinetic study was performed on 18 stable renal transplant patients receiving MMF and tacrolimus together, and four control groups, one receiving tacrolimus alone, two receiving CsA, in combination with MMF (1.0 or 1.5 g bid), and one receiving CsA microemulsion (Neoral). Area-under-the-curve values were calculated for each drug to assess if there was a reciprocal effect on the respective bioavailability of each. In vitro, the immunosuppressive effect of trough level plasma from each patient group was studied using mixed lymphocyte culture (MLC), as well as MLC reactions spiked with various combinations of each drug. There was a minimal effect of MMF on tacrolimus pharmacokinetics. However, patients receiving tacrolimus and MMF displayed significantly higher levels (Cmin and area under the curve) of mycophenolic acid (MPA) than those receiving CsA (Sandimmune or Neoral) and the same dose of MMF (50.2 +/- 16.5 vs 32.1 +/- 16.7 micrograms h/ml AUC, p < 0.02). Equivalent MPA levels could be attained in patients receiving CsA if the MMF dose was increased by 50% (1.5 g bid). There were also significantly lower levels of the glucuronide metabolite of MPA (MPAG) (755 +/- 280 vs 1230 +/- 250 micrograms h/ml AUC, p = 0.02), suggesting a specific inhibition (either direct or indirect) of the conversion of MPA to MPAG in tacrolimus patients, as opposed to those receiving CsA. For each drug combination, there was a positive correlation between the plasma immunosuppressive effect seen in MLC assays and the MMF dose. In addition, trough plasma from patients receiving tacrolimus and MMF was significantly more MLC inhibitory than from those receiving CsA or CsA microemulsion and equivalent-dose MMF. Culture media containing MPA and tacrolimus equal to clinical therapeutic trough concentrations (10 ng/ml) were significantly more MLC inhibitory than CsA at equivalent clinical therapeutic trough concentrations (200 ng/ml) with equivalent MPA levels. These studies in renal transplant patients suggest that tacrolimus in combination with MMF may result in a greater degree of immunosuppression than may be anticipated.

Brief expression of a GFP cre fusion gene in embryonic stem cells allows rapid retrieval of site-specific genomic deletions

The Cre DNA recombinase of bacteriophage P1 has become a useful tool for precise genomic manipulation in embryonic stem (ES) cells that have been gene modified by homologous recombination. We have re-engineered the cre gene to allow ready identification of living Cre+cells by constructing a functional fusion between Cre and an enhanced green fluorescent protein from Aequorea victoria (GFPS65T). The GFP cre fusion gene product rapidly targeted the nucleus in the absence of any exogenous nuclear localization signal. Moreover, GFPCre catalyzed efficient DNA recombination in both a mouse 3T3 derivative cell line and in murine ES cells. Fluorescence- activated cell sorting (FACS) of transiently GFP cre -transfected ES cells not only allowed rapid and efficient isolation of Cre+cells after DNA transfection but also demonstrated that a burst of Cre expression is sufficient to commit cells to Cre-mediated 'pop-out' of loxP -tagged DNA from the genome. Thus, GFP cre allows rapid identification of living cells in which loxP - flanked DNA sequences are destined to be removed from the genome by Cre-mediated recombination without reliance on recombinational activation or inactivation of a marker gene at the target locus. In addition, the GFP cre fusion gene will prove useful in tracing tissue-specific Cre expression in transgenic animals, thereby facilitating the generation and analysis of conditional gene knockout mice.

A comparison of the postures assumed when using laptop computers and desktop computers

This study evaluated the postural implications of using a laptop computer. Laptop computer screens and keyboards are joined, and are therefore unable to be adjusted separately in terms of screen height and distance, and keyboard height and distance. The posture required for their use is likely to be constrained, as little adjustment can be made for the anthropometric differences of users. In addition to the postural constraints, the study looked at discomfort levels and performance when using laptops as compared with desktops. Statistical analysis showed significantly greater neck flexion and head tilt with laptop use. The other body angles measured (trunk, shoulder, elbow, wrist, and scapula and neck protraction/retraction) showed no statistical differences. The average discomfort experienced after using the laptop for 20 min, although appearing greater than the discomfort experienced after using the desktop, was not significantly greater. When using the laptop, subjects tended to perform better than when using the desktop, though not significantly so. Possible reasons for the results are discussed and implications of the findings outlined.

Lead, follow, or get out of the way

The more we know about the individuals who work for us, the better understanding we will have of them and the better job we will do in motivating them. Regardless of whether you work in credit, production, accounting, sales, engineering, personnel, or purchasing, you will have one problem in common with all managers. The problem is people. They take up by far the greatest portion of our operating budget. People are difficult. They have their strengths and weaknesses, their ups and downs, their joys and sorrows; and you don't have to be managing people for long before you find out that people don't like change.

The assessment of acute confusion as part of nursing care

Older adults who become acutely confused when hospitalized present challenges to nurses because of their increased care needs and risk for injury. This study evaluated the feasibility of introducing the NEECHAM Confusion Scale as part of usual nursing care as a first step in improving nurses' ability to assess, prevent, and manage acute confusion in hospitalized older adults. By addressing several of the factors that influence adoption and continuation of a new practice, this study found that staff nurses could successfully use the NEECHAM Confusion Scale.

Donor peripheral blood stem cell infusions in recipients of living-related liver allografts

BACKGROUND

In this pilot study, donor peripheral blood stem cell (DPBSC) infusions were performed in three recipients of living-related liver transplants (LRLT).

METHODS

DPBSCs were obtained by leukapheresis after mobilization with granulocyte-colony-stimulating factor (Filgrastim). Donor leukapheresis was performed on the 5th postoperative day, and half of the DPBSCs were infused into the recipient on the day of collection. The second half of the pheresed product was cryopreserved for delayed administration.

RESULTS

Results from preliminary studies of chimerism in LRLT recipients, at 20 weeks posttransplant, suggested that the levels of donor cells detected in LRLT recipients treated with DPBSC infusions may be higher than those observed for recipients of cadaver donor liver allografts and vertebral body marrow infusions.

CONCLUSIONS

The results of this pilot study indicate that administration of mobilized DPBSC to recipients of LRLT is a feasible procedure for both donor and recipient.

Detection of Mycobacterium bovis in formalin-fixed, paraffin-embedded tissues of cattle and elk by PCR amplification of an IS6110 sequence specific for Mycobacterium tuberculosis complex organisms

A presumptive diagnosis of tuberculosis can be made if a tissue has characteristic histopathologic changes and acid-fast organisms. However, definitive diagnosis requires culture and species identification of the causative mycobacterium, a process that takes several weeks to complete. The purpose of work reported here was to determine if formalin-fixed, paraffin-embedded tissues could be tested by polymerase chain reaction (PCR) to provide a more rapid diagnosis of tuberculosis. Nondecalcified tissues from cases of tuberculosis in cattle and elk (Cervus elaphus) were examined. The primers used for PCR amplified a 123-bp fragment of IS6110, an insertion sequence that is specific for organisms in the Mycobacterium tuberculosis complex (M. tuberculosis, M. bovis, M. microti, M. africanum). The PCR test detected this sequence in tissues from 92 of 99 (93%) tuberculosis cases, including 3 of 4 elk. In 80 tissues, the positive results were obtained using material prepared by immersion of paraffin sections in water containing a detergent, followed by alternating boil/freeze cycles. The remaining positive results were obtained with DNA isolated from the crude tissue extracts by proteinase K digestion and phenol/chloroform purification. Accuracy of the IS6110 PCR test was demonstrated by negative test results on 31 tissues that had either nonmycobacterial granulomas or granulomatous lesions caused by other mycobacteria (M. paratuberculosis or M. avium). The findings of this study show that a PCR test usually can provide a rapid diagnosis of tuberculosis when it is applied to paraffin sections that have characteristic lesions and acid-fast organisms.

Structural basis for differential induction of spermidine/spermine N1-acetyltransferase activity by novel spermine analogs

The spermine analog N1,N11-diethylnorspermine (DE-333, also known as DENSPM or BENSPM) is regarded as the most potent known inducer of the polyamine catabolic enzyme, spermidine/spermine N1-acetyltransferase (SSAT), increasing activity by more than 200- to 1000-fold in certain cell types. The relative ability of a series of eight systematically modified DE-333 analogs to affect SSAT expression was examined in Malme-3M human melanoma cells, one of several cell lines known to be especially responsive to induction of this enzyme. In particular, we examined the relative contribution of induction of enzyme mRNA and prolongation of enzyme half-life to analog-mediated increases in enzyme activity. Induction of enzyme mRNA was most influenced by intra-amine carbon distances; relative effectiveness was found to be proportional to the number of three-carbon units. Stabilization of enzyme was most determined by the terminal N-alkyl substituent size; among methyl, ethyl and propyl groups, methyl was least effective. Thus, DE-333, which most potently induces SSAT mRNA and effectively stabilizes SSAT enzyme activity, produces the greatest increase in enzyme activity. Although other contributing mechanisms may be involved, the relative abilities of the various analogs to induce enzyme activity is at least partially attributable to their combined effects on enzyme mRNA and protein half-life. These data reveal the highly sensitive structure-activity relationships that underlie and control spermine analog induction of SSAT activity. Pending further definition of the relationship between SSAT induction and antitumor growth and toxicity in vivo, these relationships may be used to optimize therapeutic efficacy.

Politics and care: a study of Czech Americans within Leininger's theory of culture care diversity and universality

The domain of inquiry for this study was the influence of the American political environmental context on professional and generic care patterns, expressions, and meanings of Czech American immigrants. The purpose of the research was to document, describe, interpret, and analyze the diversities and universalities of professional and generic care for this cultural group, to provide culturally congruent care to Czech Americans, and to explicate the role of politics as an influence on care patterns, health, and well being. The researcher's former transcultural ethnonursing study in Prague, Czechoslovakia in 1991 served as a stimulus for this in-depth study on politics and care. Twelve key and twenty general informants were interviewed. Five major themes were identified. The researcher discovered that the capitalist economic market structure of the United States influenced informant lifeways in all dimensions of Leininger's Theory of Culture Care Diversity and Universality, as depicted in the Sunrise Model. Specific care patterns discovered included care as choice, care as responsibility, and care as helping each other. Findings related to professional and generic care supported researcher predictions that generic culture care patterns would be important to immigrants. Provisions for culturally congruent nursing care were articulated based on research findings.

Heavy fragment production cross sections from 1.05 GeV/nucleon 56Fe in C, Al, Cu, Pb, and CH2 targets

We have obtained charge-changing cross sections and partial cross sections for fragmentation of 1.05 GeV/nucleon Fe projectiles incident on H, C, Al, Cu, and Pb nuclei. The energy region covered by this experiment is critical for an understanding of galactic cosmic ray propagation and space radiation biophysics. Surviving primary beam particles and fragments with charges from 12 to 25 produced within a forward cone of half-angle 61 mrad were detected using a silicon detector telescope to identify their charge and the cross sections were calculated after correction of the measured yields for finite target thickness effects. The cross sections are compared to model calculations and to previous measurements. Cross sections for the production of fragments with even-numbered nuclear charges are seen to be enhanced in almost all cases.

Toward antibody-directed enzyme prodrug therapy with the T268G mutant of human carboxypeptidase A1 and novel in vivo stable prodrugs of methotrexate

Antibody-directed enzyme prodrug therapy (ADEPT) has the potential of greatly enhancing antitumor selectivity of cancer therapy by synthesizing chemotherapeutic agents selectively at tumor sites. This therapy is based upon targeting a prodrug-activating enzyme to a tumor by attaching the enzyme to a tumor-selective antibody and dosing the enzyme-antibody conjugate systemically. After the enzyme-antibody conjugate is localized to the tumor, the prodrug is then also dosed systemically, and the previously targeted enzyme converts it to the active drug selectively at the tumor. Unfortunately, most enzymes capable of this specific, tumor site generation of drugs are foreign to the human body and as such are expected to raise an immune response when injected, which will limit their repeated administration. We reasoned that with the power of crystallography, molecular modeling and site-directed mutagenesis, this problem could be addressed through the development of a human enzyme that is capable of catalyzing a reaction that is otherwise not carried out in the human body. This would then allow use of prodrugs that are otherwise stable in vivo but that are substrates for a tumor-targeted mutant human enzyme. We report here the first test of this concept using the human enzyme carboxypeptidase A1 (hCPA1) and prodrugs of methotrexate (MTX). Based upon a computer model of the human enzyme built from the well known crystal structure of bovine carboxypeptidase A, we have designed and synthesized novel bulky phenylalanine- and tyrosine-based prodrugs of MTX that are metabolically stable in vivo and are not substrates for wild type human carboxypeptidases A. Two of these analogs are MTX-alpha-3-cyclobutylphenylalanine and MTX-alpha-3-cyclopentyltyrosine. Also based upon the computer model, we have designed and produced a mutant of human carboxypeptidase A1, changed at position 268 from the wild type threonine to a glycine (hCPA1-T268G). This novel enzyme is capable of using the in vivo stable prodrugs, which are not substrates for the wild type hCPA1, as efficiently as the wild type hCPA1 uses its best substrates (i.e. MTX-alpha-phenylalanine). Thus, the kcat/Km value for the wild type hCPA1 with MTX-alpha-phenylalanine is 0.44 microM-1 s-1, and kcat/Km values for hCPA1-T268G with MTX-alpha-3-cyclobutylphenylalanine and MTX-alpha-3-cyclopentyltyrosine are 1.8 and 0.16 microM-1 s-1, respectively. The cytotoxic efficiency of hCPA1-268G was tested in an in vitro ADEPT model. For this experiment, hCPA1-T268G was chemically conjugated to ING-1, an antibody that binds to the tumor antigen Ep-Cam, or to Campath-1H, an antibody that binds to the T and B cell antigen CDw52. These conjugates were then incubated with HT-29 human colon adenocarcinoma cells (which express Ep-Cam but not the Campath 1H antigen) followed by incubation of the cells with the in vivo stable prodrugs. The results showed that the targeted ING-1:hCPA1-T268G conjugate produced excellent activation of the MTX prodrugs to kill HT-29 cells as efficiently as MTX itself. By contrast, the enzyme-Campath 1H conjugate was without effect. These data strongly support the feasibility of ADEPT using a mutated human enzyme with a single amino acid change.

Long-term survivors of pediatric heart transplantation: a multicenter report of sixty-eight children who have survived longer than five years

OBJECTIVE

Short-term survival after pediatric heart transplantation is now excellent, but ultimately the efficacy of this procedure will depend on duration and quality of survival. We sought to evaluate the clinical course of long-term survivors of heart transplantation in childhood.

METHODS

Patients who had undergone heart transplantation at the university hospitals of Stanford, Columbia, and Pittsburgh between 1975 and 1989 and survived longer than 5 years from transplantation were identified and their clinical courses retrospectively reviewed.

RESULTS

Sixty eight children have survived more than 5 years from transplantation, and 60 (88%) are currently alive with a median follow-up of 6.8 years (5 to 17.9 years). Thirteen have survived more than 10 years from transplantation. Renal dysfunction caused by immunosuppressive agents was common, and two patients required late renal transplantation. Lymphoproliferative disease or other neoplasm occurred in 12 patients, but none resulted in death. Coronary artery disease was diagnosed in 13 patients (19%), leading to retransplantation in eight. Death after 5 years was related to acute or chronic rejection in 5 of 8 cases. Two of the deaths were directly related to noncompliance with immunosuppressive medication. All survivors are in New York Heart Association class 1.

CONCLUSIONS

Long-term survival with good quality of life can be achieved after heart transplantation in childhood, though complications of immunosuppression remain common. Posttransplantation coronary artery disease is emerging as the main factor limiting long term graft and patient survival.

Dipeptidyl peptidase IV (CD26) activity in human alloreactive T cell subsets varies with the stage of differentiation and activation status

Dipeptidyl peptidase IV (DPP IV), also known as CD26, is a transmembrane serine aminopeptidase which has an ontogenically related expression on T cells and participates on several immunological functions. CD26 appears to play an important role in alloimmunity during host T cell activation subsequent to alloantigen encounter and is a way by which effector T cells traverse graft endothelial barriers. In order to help to elucidate the role of the CD26 molecule in alloimmune responses, DPP IV activity and CD26 antigenic expression were assessed during the initial phases of completely MHC-disparate human mixed lymphocyte reactions (MLRs) and in several long-term alloreactive T cell clones. Our methods involved the use of a rhodamine-110-conjugated dipeptide substrate specific for DPP IV in two-colour cytofluorographic analysis that allowed stimultaneous lineage marker evaluation. Polyclonal populations of alloreactive CD4 and CD8 T cells contained DPP IV activity at 1 and 10 min of incubation that was variably elevated from resting T cells with the enzyme activity confined to CD26+ cells. T cell clones derived from MLRs were established with IL-2 supplementation and alloantigen restimulation and had reduced CD62L expression with functional specificity to the stimulating MHC. While CD26 expression remained stable, DPP IV activity was variable in the alloreactive T cell clones, with enzyme function in the latter appearing to coincide with the timing of alloantigen restimulation. These studies demonstrate that DPP IV activity varies among phenotypically distinct alloreactive T cell subsets and appears to be altered with the activation status of the effector cells. These findings raise the potential of a role for CD26/DPP IV in the generation of specific alloimmunity. With this methodology, it may be possible to reveal whether specific alterations in the activity of this molecule in T cell populations promote graft acceptance and to determine the molecular requirements for these changes.

Post-transplant lymphoproliferative disease in kidney transplant patients in the new immunosuppressive era

Although the kidney transplant program at this center has been active for the past 18 yr, five out of the seven cases of post-transplant lymphoma in kidney transplant patients were observed over the past 2 yr. During this period, we have shifted from cyclosporine to tacrolimus (FK506 or prograf) for maintenance immunosuppression and for rescue therapy. We have also introduced mycophenolate (RS-61443) and have continued an antibody induction regimen in the immediate postoperative period. FK506 is 50-100 times more potent than cyclosporine. We have reported a decreased incidence of rejection, improved graft survival, and a general optimalization of patient survival with these newer regimens. Nonetheless, five cases of post-transplant lymphoma out of 233 kidney transplants (2.1%) performed during this time period (December 1993 to December 1995) occurred between 3 months to 1 yr after the transplant. Four of the five patients are still alive between 12 and 24 months after the diagnosis of lymphoma was made. All were without evidence of ongoing disease. Three of the five have grafts with excellent function for longer than 18 months after transplantation, while one is marginal and one patient expired on dialysis. The third and fourth patients had severe rejection before the diagnosis of PTLD was made. While the occurrence of five cases of post-transplant lymphoma over a 2 yr period is alarming, this is still within the 2-4% incidence of post-transplant lymphoma that has been reported in the literature in kidney transplant patients. Our results probably reflect the increasing potency of our immunosuppressive protocols but do not show any increase in the aggressiveness of this entity of post-transplant lymphoma during the continued follow up.

Separation of extracts from biological tissues into polycyclic aromatic hydrocarbon, polychlorinated biphenyl and polychlorinated dibenzo-p-dioxin/polychlorinated dibenzofuran fractions prior to analysis

A low-pressure liquid chromatography method is presented for separating polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDDs/PCDFs) from biological tissue extracts. After removing lipid from extracts, the PAHs are separated from PCBs and PCDDs/PCDFs on a deactivated 13-24 microns silica gel column. The PCBs are subsequently separated from PCDDs/PCDFs by collecting the first fraction from an automated three column cleanup procedure for PCDDs/PCDFs. The complete method has been used to obtain high recoveries of the three compound classes for analysis by GC-electron capture detection (PCBs) or GC-MS (PAHs and PCDDs/PCDFs).