Biocompatible, high precision, wideband, improved Howland current source with lead-lag compensation

The Howland current pump is a popular bioelectrical circuit, useful for delivering precise electrical currents. In applications requiring high precision delivery of alternating current to biological loads, the output impedance of the Howland is a critical figure of merit that limits the precision of the delivered current when the load changes. We explain the minimum operational amplifier requirements to meet a target precision over a wide bandwidth. We also discuss effective compensation strategies for achieving stability without sacrificing high frequency output impedance. A current source suitable for Electrical Impedance Tomography (EIT) was simulated using a SPICE model, and built to verify stable operation. This current source design had stable output impedance of 3.3 MΩ up to 200 kHz, which provides 80 dB precision for our EIT application. We conclude by noting the difficulty in measuring the output impedance, and advise verifying the plausibility of measurements against theoretical limitations.

Cefoperazone/sulbactam versus cefoperazone plus mezlocillin: empiric therapy for febrile, neutropenic bone marrow transplant patients

We conducted a prospective, randomized trial in 132 patients undergoing bone marrow transplantation comparing cefoperazone in combination with sulbactam (S), N = 66, vs. cefoperazone plus mezlocillin (CM), N = 66, as empiric antibiotic therapy for fever and neutropenia. Overall duration of neutropenia was 3-55 (median, 13) days. Forty-one patients had positive initial cultures (S = 22 and CM = 19). Twelve of these 41 patients responded to initial study antibacterial agent treatment (S = 6 and CM = 6). Twenty-nine of 41 patients were withdrawn from study because of clinical deterioration, continued fever, or persistently positive cultures (S = 16 and CM = 13). Of the 90 patients who had culture-negative fever (S = 44 and CM = 46), 44 subjects responded with or without the addition of amphotericin B (S = 21 and CM = 23). Thirty-seven of 90 patients were withdrawn from study due to continued fever or clinical deterioration (S = 17 and CM = 20). Nine patients were withdrawn as a result of rash or diarrhea (S = 6 and CM = 3). We conclude that in patients undergoing bone marrow transplantation, there was no difference in efficacy between cefoperazone/sulbactam and the combination of cefoperazone plus mezlocillin in the empiric treatment of the febrile neutropenic patient. Since the majority of initial infections were due to gram positive bacteria, consideration should be given to broadening initial empiric antibacterial agent therapy with drugs that possess potent activity against these organisms.

Pre-mobilization therapy blood CD34+ cell count predicts the likelihood of successful hematopoietic stem cell mobilization

We examined pre-mobilization blood CD34+ cell count to predict ability to mobilize adequate peripheral blood progenitor cells (PBPC) in 106 cancer patients and 36 allogeneic donors. Mean pre-mobilization therapy blood CD34+ cell count was 3.1 cells x 10(6)/l (s.d. = 3.9, r = 0.3-37) and mean CD34+ cells collected were 5.3 x 10(6) cells/kg/leukapheresis procedure (s.d. = 7.0, r = 0.03-53). Yields correlated with pre-mobilization CD34+ cells x 10(6)/l (r = 0.37, P-value < 0.0001); correlation was stronger in allogeneic donors (r = 0.56, P-value = 0.0004) and males (r = 0.46, P-value < 0.0001). Based on classification and regression tree multivariate analysis, the predictive value of pre-mobilization blood CD34+ cell count was confounded by other variables, including age, gender, mobilization regimen and malignancy type. We generated an algorithm to predict a minimum PBPC yield of 1 x 10(6) CD34+ cells/kg/leukapheresis procedure after mobilization. A threshold pre-mobilization blood CD34+ cell count of 2.65 cells x 10(6)/l was the most important decision point in predicting successful mobilization. Only 2% of subjects with pre-mobilization blood CD34+ cell counts > 2.65 cells x 10(6)/l did not achieve the minimum per apheresis, whereas 24% with pre-mobilization values below threshold had inadequate mobilization. Prospectively identifying individuals at risk for mobilization failure would allow for improved treatment planning, resource utilization and time saving.

Increasing underrepresentation of elderly patients with advanced colorectal or non-small-cell lung cancer in chemotherapy trials

BACKGROUND

Elderly patients are underrepresented in chemotherapy trials for advanced colorectal cancer (CRC) and non-small-cell lung cancer (NSCLC). However, the change in underrepresentation over time has not been documented.

AIMS

This study aimed to quantify (i) the change in the median age of patients enrolled in clinical trials for metastatic CRC and NSCLC between 1982-1991 and 1992-2001 compared with the general colorectal and lung cancer population, and (ii) the proportion of trials with an upper age limit for eligibility.

METHODS

A retrospective review of data from the Victorian Cancer Registry and all large published randomized chemotherapy trials for advanced CRC and NSCLC between 1982 and 2001 was conducted.

RESULTS

The median age of patients with CRC enrolled in clinical trials remained constant between the two decades (62.0 and 62.2 years), whereas the median age of the CRC population increased from 68.4 to 70.2 years, increasing the median age difference from 6.4 to 8.0 years. The median age of patients with lung cancer in clinical trials increased from 59.8 to 61.8 years, whereas the median age of the lung cancer population increased from 67.4 to 70.4 years, widening the age difference from 7.6 to 8.6 years. More trials set an upper age limit for eligibility in the first decade than in the second decade for both CRC (51 vs 29%, P = 0.04) and NSCLC (68 vs 41%, P = 0.03).

CONCLUSION

International clinical trials for CRC and NSCLC are becoming increasingly unsuitable for application to Australian patients because of the increasing age discrepancy, despite fewer trials restricting eligibility by age.

Five years managing metastatic non-small cell lung cancer: experience at a teaching hospital

BACKGROUND

The management of patients with metastatic non-small cell lung cancer (NSCLC) is complex. Some studies have demonstrated that the care of patients with NSCLC may be suboptimal.

AIM

To review the management of patients with metastatic NSCLC treated at a single teaching hospital over a 5-year period.

METHOD

All patients with metastatic NSCLC treated at a single teaching hospital over a 5-year period (1998-2002) were identified. Data were collected by a retrospective record review.

RESULTS

Of 343 patients with metastatic NSCLC, 157 patients were deemed eligible for this review. Thirty-one patients (19%) were admitted to the Medical Oncology Unit at initial presentation. Twenty-four patients (15%) were not referred to either the Medical Oncology Unit or the Palliative Care Unit. Forty-four patients (28%) received chemotherapy, six of whom (14%) were enrolled onto a clinical trial. Six separate chemotherapy regimens were used. The median survival was 5 months and the 1-year survival rate was 19.8%.

CONCLUSIONS

The present audit demonstrates some shortfalls in the optimal clinical care of patients with metastatic NSCLC at a large teaching hospital. The main selection criteria of consideration for chemotherapy are age, performance status and presence of symptoms. A subset of patients was not referred to either the Medical Oncology Unit or the Palliative Care Unit and consistency in the choice of chemotherapy was lacking. Survival data and the rate of patients entered onto clinical trials are acceptable; however, further improvements can be made by the institution of multidisciplinary clinics and the education of referring clinicians.

Fludarabine and mitoxantrone: effective and well-tolerated salvage therapy in relapsed indolent lymphoproliferative disorders

BACKGROUND

Prior studies of the combination of fludarabine, mitoxantrone and dexamethasone have yielded high response rates but are associated with a significant risk of opportunistic infections, predominantly Pneumocystis Carinii pneumonia (PCP) requiring routine prophylaxis.

PATIENTS AND METHODS

We evaluated the combination of fludarabine (25 mg/m2/day x 3) and mitoxantrone (10 mg/m2 x 1) without corticosteroids or PCP prophylaxis in 29 patients with relapsed or refractory indolent lymphoproliferative disorders; median age 56 years, 62% refractory to preceding chemotherapy.

RESULTS

A median of four cycles was administered without cumulative myelosuppression. Neutropenia <0.5 x 10(9/)l was seen in 16% of cycles. Infections complicated 10.4% of cycles. with impaired performance status (> or = ECOG 2) and increased age ( > 56 years) significant risk factors (P < or = 0.01). No cases of PCP were encountered. The response rate was 90%, median remission duration 11.9 months and the median survival 57 months. Peripheral blood progenitor cell mobilization was attempted in 11 patients and yielded > or = 2 x 10(6) CD34+ cells/kg in only 5 cases (45%).

CONCLUSIONS

High response rates can be attained with fludarabine and mitoxantrone in combination without corticosteroids, and routine PCP prophylaxis can safely be omitted. Peripheral blood progenitor collections are problematic in these heavily pretreated patients.

Enhancement of platelet recovery after myelosuppressive chemotherapy by recombinant human megakaryocyte growth and development factor in patients with advanced cancer

PURPOSE

To explore the influence of dose and schedule on the ability of pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) to abrogate thrombocytopenia after multiple cycles of chemotherapy and to mobilize peripheral-blood progenitor cells (PBPC).

PATIENTS AND METHODS

In this open-label study, 68 patients with advanced cancer were randomized to receive PEG-rHuMGDF subcutaneously at different doses and durations before administration of carboplatin 600 mg/m(2), cyclophosphamide 1,200 mg/m(2), and filgrastim 5 microgram/kg/d. PEG-rHuMGDF was not given after the first cycle of chemotherapy but was given after the second and subsequent cycles. Chemotherapy was given every 28 days for up to six cycles.

RESULTS

In patients who received the same dose of chemotherapy for at least two cycles, the platelet nadir was significantly higher (47.5 x 10(9)/L v 35.5 x 10(9)/L; P =.003) and duration of grade 3 or 4 thrombocytopenia significantly shorter (0 v 3 days; P =.004) when PEG-rHuMGDF was administered after chemotherapy. There was no evidence of an effect of PEG-rHuMGDF when it was given before chemotherapy. Platelet recovery after the first cycle of chemotherapy was no different for different PEG-rHuMGDF regimens, and there was no difference between patients treated with PEG-rHuMGDF and historical controls treated with identical chemotherapy. There was a modest dose-related increase in progenitor cell levels after administration of PEG-rHuMGDF alone. Peak levels of PBPC occurred later in cycle 2 than in cycle 1 but were not different in magnitude.

CONCLUSION

PEG-rHuMGDF abrogated severe thrombocytopenia after dose-intensive chemotherapy. However, it had only a modest effect on progenitor cell levels and did not enhance progenitor cell mobilization after chemotherapy and filgrastim.

Human rotation-mediated fetal mixed brain cell aggregate culture: characterization and N-methyl-D-aspartate toxicity

One difficulty in generating in vitro models of neuropathogenesis lies in maintaining stable proportions of primary neurons within a mixed brain cell population. Rotation-mediated fetal brain aggregate culture has been modified to permit growth of human primary fetal brain cells containing 50 to 60% neurons. After 12 weeks cholinesterase, neuron specific enolase and microtubule-associated protein-2 were demonstrable by biochemical assay and immunocytochemical labelling of cryostat sections of human fetal brain aggregates. Upon exposure to the glutamate agonist; N-methyl-D-aspartate for 7 days at 35 days in vitro neuron specific enolase and cholinesterase decreased to 60 to 70% of untreated levels. Glial fibrillary acidic protein did not change significantly but swollen astrocytes were seen in labelled sections of treated aggregates. This method is useful to study human neurotoxicity and degeneration in mixed glial culture without astrocyte overgrowth.

Randomized cross-over trial of progenitor-cell mobilization: high-dose cyclophosphamide plus granulocyte colony-stimulating factor (G-CSF) versus granulocyte-macrophage colony-stimulating factor plus G-CSF

PURPOSE

Patient response to hematopoietic progenitor-cell mobilizing regimens seems to vary considerably, making comparison between regimens difficult. To eliminate this inter-patient variability, we designed a cross-over trial and prospectively compared the number of progenitors mobilized into blood after granulocyte-macrophage colony-stimulating factor (GM-CSF) days 1 to 12 plus granulocyte colony-stimulating factor (G-CSF) days 7 to 12 (regimen G) with the number of progenitors after cyclophosphamide plus G-CSF days 3 to 14 (regimen C) in the same patient.

PATIENTS AND METHODS

Twenty-nine patients were randomized to receive either regimen G or C first (G1 and C1, respectively) and underwent two leukaphereses. After a washout period, patients were then crossed over to the alternate regimen (C2 and G2, respectively) and underwent two additional leukaphereses. The hematopoietic progenitor-cell content of each collection was determined. In addition, toxicity and charges were tracked.

RESULTS

Regimen C (n = 50) resulted in mobilization of more CD34(+) cells (2.7-fold/kg/apheresis), erythroid burst-forming units (1.8-fold/kg/apheresis), and colony-forming units-granulocyte-macrophage (2.2-fold/kg/apheresis) compared with regimen G given to the same patients (n = 46; paired t test, P<.01 for all comparisons). Compared with regimen G, regimen C resulted in better mobilization, whether it was given first (P =.025) or second (P =.02). The ability to achieve a target collection of > or =2x10(6) CD34(+) cells/kg using two leukaphereses was 50% after G1 and 90% after C1. Three of the seven patients in whom mobilization was poor after G1 had > or =2x10(6) CD34(+) cells/kg with two leukaphereses after C2. In contrast, when regimen G was given second (G2), seven out of 10 patients failed to achieve the target CD34(+) cell dose despite adequate collections after C1. Thirty percent of the patients (nine of 29) given regimen C were admitted to the hospital because of neutropenic fever for a median duration of 4 days (range, 2 to 10 days). The higher cost of regimen C was balanced by higher CD34(+) cell yield, resulting in equivalent charges based on cost per CD34(+) cell collected.

CONCLUSION

We report the first clinical trial that used a cross-over design showing that high-dose cyclophosphamide plus G-CSF results in mobilization of more progenitors then GM-CSF plus G-CSF when tested in the same patient regardless of sequence of administration, although the regimen is associated with greater morbidity. Patients who fail to achieve adequate mobilization after regimen G can be treated with regimen C as an effective salvage regimen, whereas patients who fail regimen C are unlikely to benefit from subsequent treatment with regimen G. The cross-over design allowed detection of significant differences between regimens in a small cohort of patients and should be considered in design of future comparisons of mobilization regimens.

Multi-purpose silastic dual-lumen central venous catheters for both collection and transplantation of hematopoietic progenitor cells

Autologous peripheral blood progenitor cell (PBPC) transplantation frequently requires sequential placement and use of two separate central venous catheters: (1) a short-term, large-bore, stiff device inserted for leukapheresis, and after removal of that device, (2) a long-term, multi-lumen, flexible, Silastic catheter for administration of high-dose chemotherapy, re-infusion of hematopoietic cells, and intensive supportive care. We reviewed our recent experience with two dual-lumen, large-bore, Silastic multi-purpose ('hybrid') catheters, each of which can be used as a single device for both leukapheresis and long-term supportive care throughout the transplant process. Quinton-Raaf PermCath and Bard-Hickman hemodialysis/apheresis dual-lumen catheters were used as the sole venous access device in 112 consecutive patients who underwent autologous PBPC collection and transplantation. The catheter exit site was monitored three times a week, and lumen patency was assessed using clinical and radiologic techniques. Catheters were removed prematurely for persistent thrombus, positive blood cultures despite appropriate antibiotics, or mechanical dysfunction. There were no intra-operative or immediate post-operative complications relating to insertion. Thirty-two patients experienced catheter occlusion necessitating urokinase instillation. Persistent occlusive problems were noted in 16 patients, and in 10 patients the catheter had to be removed. Two exit site infections and 17 bacteremias occurred. Catheters had to be removed for persistent infection in two subjects and for mechanical problems in five others. Cost analysis comparing the hybrid catheters alone vs conventional devices revealed a charge of $4230 in patients with hybrid catheters vs. $7530 in those requiring a temporary non-Silastic dialysis catheter in addition to a flexible, long-term Silastic catheter. Hybrid, Silastic, dual-lumen, large-bore central venous catheters are safe, cost-effective and convenient multi-purpose venous access devices that may be used in the setting of autologous PBPC collection and transplantation. The rate of thrombotic, infectious and mechanical complications appears comparable to other central venous access devices.

A phase I and pharmacokinetic study of subcutaneously-administered recombinant human interleukin-4 (rhuIL-4) in patients with advanced cancer

PURPOSE

To investigate the pharmacokinetics and tolerability of recombinant human interleukin-4 (rhuIL-4), administered by daily subcutaneous injection, in patients with advanced cancer.

PATIENTS AND METHODS

Fourteen patients with advanced cancer treated with rhuIL-4 at escalating dose levels of 0.25, 1.0 and 5.0 microg/kg/day, on days 1, 8-17, and 28-57. The primary endpoints of the study were toxicity of rhuIL-4 and the determination of the pharmacokinetics of rhuIL-4 when given by subcutaneous injection. Secondary endpoints included effects on blood counts, hematopoietic cell precursors, and various immunologic parameters.

RESULTS

rhuIL-4 was well tolerated at all three dose levels. Detectable serum levels of IL-4 were found in patients at the 1.0 and 5.0 microg/kg/day dose levels. Peak serum IL-4 levels were achieved about 2 h after injection and IL-4 was still detectable 8 h after injection. No grade 4 toxicities were observed and grade 3 toxicities were confined to fever, headache and raised hepatic alkaline phosphatase. No consistent hematological or immunologic effects were observed. Although therapeutic efficacy was not an endpoint, one complete response (Hodgkin's disease) was observed. One patient with chronic lymphocytic leukemia progressed on therapy.

CONCLUSION

rhuIL-4 up to 5.0 microg/kg/day is well tolerated when given by subcutaneous injection. Biologically relevant serum IL-4 levels can be achieved and sustained for at least 8 h after a single injection.

KRN8602 (MX2-hydrochloride): an active new agent for the treatment of recurrent high-grade glioma

PURPOSE

To assess the efficacy and toxicity of KRN8602 when administered as an intravenous bolus to patients with recurrent high-grade malignant glioma.

PATIENTS AND METHODS

Patients with recurrent or persistent anaplastic astrocytoma or glioblastoma multiforme who had not received recent chemotherapy or radiotherapy and were of good performance status (Eastern Cooperative Oncology Group score < or = 2) were treated with an intravenous bolus of 40 mg/m(2) KRN8602 every 28 days. Tumor responses were assessed radiologically and clinically after every second cycle of therapy. Treatment was continued until documented progression or a total of six cycles.

RESULTS

A median of three cycles (range, one to six cycles) of KRN8602 was administered to 55 patients, 49 of whom received at least two cycles and were, therefore, assessable for response. The overall response rate (disease stabilization or better) was 43% (95% confidence interval, 29% to 58%). There were three complete responses, one partial response, seven minor responses, and 10 patients with stable disease. The median time to progression was 2 months (range, 1.5 to 37 months) and overall survival was 11 months (range, 1.5 to 40 months). Neutropenia was the most common toxicity, although it was generally of brief duration, and there were only seven episodes of febrile neutropenia in 176 cycles delivered. Nonhematologic toxicity was mostly gastrointestinal (nausea and vomiting, diarrhea) and events were grade 2 or lower except for a single episode of grade 3 vomiting.

CONCLUSION

KRN8602 is an active new agent with minimal toxicity in the treatment of relapsed or refractory high-grade glioma. Further studies with KRN8602 in combination with other cytotoxics and in adjuvant treatment of gliomas are warranted.

Phase I and subsequent phase II study of filgrastim (r-met-HuG-CSF) and dose intensified cyclophosphamide plus epirubicin in patients with non-Hodgkin's lymphoma and advanced solid tumors

BACKGROUND

To define a maximum tolerated dose (MTD) for the combination of epirubicin and cyclophosphamide with filgrastim (r-met-HuG-CSF) in patients with advanced solid tumors and non-Hodgkin's lymphoma (NHL).

PATIENTS AND METHODS

Thirty-five patients with advanced solid tumors were enrolled in stages I and II. Twenty-one patients were treated in stage I in sequential cohorts of at least three patients at increasing dosage levels of cyclophosphamide and epirubicin, for up to six cycles every 21 days. At the completion of stage I, a MTD for epirubicin was established. Fourteen patients were treated in stage II, in cohorts of three or more. The epirubicin dose remained constant at the MTD dosage from stage I. Cyclophosphamide was further dose-escalated to establish its MTD. Twenty-one patients with previously untreated non-Hodgkin's lymphoma were treated in stage III with the MTD established in the prior stages.

RESULTS

The MTD in stage I was epirubicin 150 mg/m2 and cyclophosphamide 1500 mg/m2 with cumulative neutropenia as the dose-limiting toxicity (DLT). Cumulative thrombocytopenia prevented further dose-escalation of cyclophosphamide in stage II. The stage III regimen consisted of six, 21-day cycles of epirubicin 150 mg/m2, cyclophosphamide 1500 mg/m2, vincristine 2 mg, and prednisolone 100 mg for five days with filgrastim support. Nineteen of twenty-one patients (90%) completed six cycles of treatment, eight (38%) without dose reduction. Common toxicity criteria (CTC) grade 4 neutropenia (neutrophil nadir < 0.5 x 10(9)/l) was documented in 85 of 118 cycles (72%). Neutropenic fever was documented in 17 of 21 patients (81%) on at least one occasion. Severe thrombocytopenia (< 25 x 10(9)/l) was seen in fourteen of 118 cycles (12%) and increased with cycle number. There was no significant non-hematological toxicity.

CONCLUSION

Significant dose-escalation of epirubicin and cyclophosphamide was possible with filgrastim support. The MTD achieved was approximately double that of standard-dose therapy. This study forms the basis of an ongoing randomized study evaluating dose-intensification in intermediate grade NHL.

The neurotoxic effects of methylenedioxymethamphetamine (MDMA) and its metabolites on rat brain spheroids in culture

Rat whole-brain spheroids were used to assess the intrinsic neurotoxicity of methylenedioxy-methamphetamine (MDMA, Ecstasy) and two of its metabolites, dihydroxymethamphetamine (DHMA) and 6-hydroxy-MDMA (6-OH MDMA). Exposure of brain spheroids to MDMA or the metabolite 6-OH MDMA (up to 500 micromol/L) for 5 days in culture did not alter intracellular levels of glutathione (GSH), glial fibrillary acidic protein (GFAP) or serotonin (5-HT). In contrast, exposure to the metabolite DHMA, which can deplete intracellular thiols, significantly increased GSH levels (up to 170% of control) following exposure to 50 and 100 micromol/L DHMA. There was also a significant reduction in the levels of glial fibrillary acidic protein (GFAP) and GSH by DHMA at the highest concentration tested (500 micromol/L) but there was no effect on 5HT. This may constitute a sublethal neurotoxic compensatory response to DHMA in an attempt to replenish depleted intraneural GSH levels following metabolite exposure. Rat whole-brain spheroids may thus be a useful in vitro model to delineate mechanisms and effects of this class of neurotoxin.

Reconstruction of a neocondyle using transport distraction osteogenesis

The process of slow bone expansion by distraction osteogenesis in conjunction with functional remodeling can also be used for the reconstruction of a neomandible and neocondyle. This is the technique of transport distraction osteogenesis. A transport disc is surgically created adjacent to the area of a discontinuity defect, and the transport disc is advanced by the process of distraction osteogenesis, using the Ilizarov principles. The mandible therefore acts as the bony template for reconstruction such that the neomandible created from the distraction process has the same size and shape as the native mandible covered by gingiva. This allows for enhanced prosthetic reconstruction. A reverse-L osteotomy of the ramus can also be performed to create a transport disc to reconstruct a neocondyle. Because the leading edge of the transport disc becomes enveloped by a fibrocartilagenous cap, the ramal transport disc can be moved superiorly to create a new articulation. Patients are encouraged to open and close their mouths during the distraction process, such that the transport disc remodels to form a neocondyle. This technique was successfully used to treat patients with degenerative joint disease, condylar resorption, and bony ankylosis.

Cardiac effects of high-dose epirubicin and cyclophosphamide in women with poor prognosis breast cancer

PURPOSE

To prospectively evaluate the long term cardiac effects of high-dose epirubicin and cyclophosphamide given to women with early stage, poor prognosis breast cancer.

PATIENTS AND METHODS

Women with stage 2 breast cancer and 10+ nodes or 4+ nodes and estrogen receptor negative tumor, or stage 3 breast cancer received three cycles of epirubicin 200 mg/m2 and cyclophosphamide 4 gm/m2 with peripheral blood progenitor cell and filgrastim support. Treatment was given every 28 days (n = 79) or 21 days (n = 20). Fifty patients received radiotherapy to the chest wall or breast, 25 of to the left side. Patients were assessed clinically regularly during chemotherapy and at least three times yearly after completion of treatment. Cardiac left ventricular ejection fraction (LVEF) was assessed by radionuclide scan before therapy, after each cycle of chemotherapy, three months and six months after completion of chemotherapy, and yearly thereafter until relapse.

RESULTS

Ninety-nine women were treated, and 92 completed all three cycles of chemotherapy. The median age was 43 years (range 24 to 60 years). All patients were included in this analysis. The median relapse-free survival was 39 months (11 to 68 months). There was a significant fall in LVEF during chemotherapy. In general, there was no further deterioration in cardiac function from the third month after cessation of treatment, however there was substantial variation between individuals. 35 patients had at least one LVEF measure less than normal (< 50%), but the LVEF returned to normal in 20 of these with further follow-up. Cardiac dysfunction was not increased in women who received radiotherapy and was not different between cohorts given chemotherapy every three or every four weeks. One patient died of acute myocardial necrosis following the third cycle of chemotherapy. Two patients developed clinical evidence of cardiac failure, and another had radiological signs but was asymptomatic. One woman died of progressive cardiac failure, one recovered clinically but also developed recurrent breast cancer, while the third recovered after commencement of medical therapy.

CONCLUSIONS

During follow-up after high-dose epirubicin and cyclophosphamide as delivered in this study, the LVEF fell to below normal in approximately one third of patients. However, in over half of these patients the LVEF subsequently recovered to the normal range, and the incidence of clinically evident chronic cardiac failure was low. Further follow-up is required to assess the long-term safety. A randomized comparison with standard-dose anthracycline-based chemotherapy is needed to determine whether this regimen is associated with an increased risk of clinical cardiac toxicity.

Multicycle high-dose chemotherapy and filgrastim-mobilized peripheral-blood progenitor cells in women with high-risk stage II or III breast cancer: five-year follow-up

PURPOSE

To determine the safety and efficacy of multiple cycles of dose-intensive, nonablative chemotherapy in women with poor-prognosis breast cancer.

PATIENTS AND METHODS

Women with stage II breast cancer and 10 or more involved nodes or four or more involved nodes and estrogen receptor-negative tumors and women with stage III disease received three cycles of epirubicin 200 mg/m2 and cyclophosphamide 4 g/m2, with progenitor cell and filgrastim support every 28 days (n = 79) or 21 days (n = 20). Patients were reviewed at least twice yearly thereafter. Twenty-six patients had bone marrow and apheresis collections assessed for the presence of micrometastatic tumor cells.

RESULTS

Ninety-nine women (median age, 43 years; range, 24 to 60 years) were treated. Ninety-two completed all three cycles of chemotherapy. The major toxicity was severe, reversible myelosuppression that was more prolonged with successive cycles, and this did not differ between patients given treatment every 28 days and those treated every 21 days. Febrile neutropenia occurred in 176 (61%) of 287 cycles. Severe mucositis (grade 3 or 4) occurred in 23% of cycles but tended to be short-lived and was reversible. The cardiac ejection fraction fell by a median of 4% during treatment, and three patients developed evidence of cardiac failure after chemotherapy. Two patients (2%) died of acute toxicity. Three of 26 patients had evidence of circulating micrometastatic tumor cells. The actuarial distant disease-free and overall survival rates at 60-month follow-up were 64% (95% confidence interval [CI], 53% to 75%) and 67% (95% CI, 56% to 78%), respectively.

CONCLUSION

Multiple cycles of dose-intensive, nonablative chemotherapy is a feasible and safe approach. Disease control and survival are similar to those in other studies of myeloablative chemotherapy in poor-prognosis breast cancer. The regimen is being evaluated in a randomized trial of the International Breast Cancer Study Group.

Phase I and pharmacokinetic study of KRN8602 alone and with filgrastim in patients with advanced cancer

PURPOSE

To determine the recommended dose, toxicity profile, and pharmacokinetics of KRN8602 (MX2-hydrochloride), a novel morpholino anthracycline with potent cytotoxicity against anthracycline-sensitive and resistant experimental tumors in vitro and in vivo.

PATIENTS AND METHODS

KRN8602 was administered alone in increasing doses to patients with advanced cancer or high-grade gliomas until dose-limiting toxicity (DLT) was observed in three or more of five patients treated in a dose level. Because neutropenia was dose limiting, further escalation was investigated with filgrastim support.

RESULTS

Fifty-six assessable patients completed at least one cycle of chemotherapy. The recommended dose of KRN8602 alone was 40 mg/m2. Dose escalation was limited by neutropenia. The recommended dose of KRN8602 with filgrastim was 70 mg/m2, and limiting toxicities were neutropenia, diarrhea, and vomiting. The most commonly experienced nonhematologic toxicity was nausea and vomiting. Alopecia and mucositis were infrequent and mild. Pharmacokinetic parameters showed substantial variation, although the area under the plasma concentration-time curve (AUC) and maximum concentration both increased with dose. There was no relationship between pharmacokinetic parameters and toxicity.

CONCLUSION

KRN8602 at doses of 40 mg/m2 when administered alone and 70 mg/m2 when administered with filgrastim appeared to be manageable. The major DLTs were neutropenia and, at higher doses, diarrhea and vomiting. The efficacy of this drug is currently being tested in phase II studies.

Dose escalation study of carboplatin and cyclophosphamide with filgrastim support: a phase I study

This clinical trial was designed to explore dose escalation of carboplatin and cyclophosphamide when supported with filgrastim. Twenty-seven patients who had advanced solid tumors received up to six cycles of treatment; a total of 92 cycles of chemotherapy were delivered. Two control groups received standard-dose carboplatin (300 mg/m2) and cyclophosphamide (600 mg/m2), with and without filgrastim. Subsequently, the doses of both carboplatin and cyclophosphamide were increased simultaneously by 50% of the standard dose in sequential cohorts. Doses of up to 2.5 times the standard dose were explored. A final dose of carboplatin, 600 mg/m2, and cyclophosphamide, 1,500 mg/m2, was tested in 4 patients. The duration of neutropenia was brief, even at the highest dose levels. The mean duration of grade 3 or 4 neutropenia was 5.8 days at standard dose without filgrastim and 5.4 days at 2.5 times standard dose with filgrastim. More severe neutropenia was more prolonged at higher doses but remained brief in duration. The mean duration of neutropenia of less than 100 x 10(6)/l was 0.4 days at standard dose without filgrastim and 1.3 days at 2.5 times standard dose. There was no evidence of cumulative neutropenia over repeated cycles of treatment. In contrast, thrombocytopenia was both dose limiting and cumulative. The mean duration of grade 3 or 4 thrombocytopenia was 1.6 days at standard dose and 9.6 days at 2.5 times standard dose. An average of 2.3 platelet transfusions per cycle of treatment was required at the highest dose. Thrombocytopenia was worse with repetitive cycles of therapy. The mean duration of grade 3 or 4 thrombocytopenia was 2.2 days after the first cycle of chemotherapy and 7.8 days after cycle four. The maximum tolerated dose, as defined prospectively, was not reached but further dose escalation was not thought to be warranted because of the severity of thrombocytopenia. When supported with filgrastim, carboplatin and cyclophosphamide can be administered safely with substantially increased dose and acceptable toxicity.

NMDA-induced increases in rat brain glutamine synthetase but not glial fibrillary acidic protein are mediated by free radicals

Both excitotoxicity and oxidative stress are implicated in the pathophysiology of central nervous system (CNS) ischaemia-reperfusion injury whereby astrocytes offer neural protection through the production of endogenous antioxidants and removal of glutamate from the extracellular milieu. This study investigated whether exogenous alpha-tocopherol, an antioxidant, could prevent N-methyl-D-aspartate (NMDA)-produced increases of the glial specific proteins, glutamine synthetase (GS) and glial fibrillary acidic protein (GFAP) in rat brain spheroids in vitro. NMDA (320 microM; 3 days in vitro (DIV)) was unable to induce lipid peroxidation in rat brain spheroids implying that excitotoxicity in this system did not involve substantial free radical formation. However at non-cytotoxic concentrations, increases in astroglial GS were prevented by alpha-tocopherol treatment, suggesting a role for ROS in the excitotoxic process. In contrast, NMDA-induced increases in GFAP remained unchanged by alpha-tocopherol indicating that oxidative stress may not be involved in reactive gliosis at non-cytotoxic NMDA concentrations.

Rapid hematopoietic recovery after multicycle high-dose chemotherapy: enhancement of filgrastim-induced progenitor-cell mobilization by recombinant human stem-cell factor

PURPOSE

To assess the mobilization potential and safety of recombinant human stem-cell factor (SCF) when coadministered with filgrastim to untreated women with poor-prognosis breast cancer.

PATIENTS AND METHODS

Eligible women had breast cancer with 10 or more positive axillary nodes, or estrogen receptor-negative tumor with 4 positive nodes, or stage III disease. Patients were randomized to receive SCF plus filgrastim or filgrastim alone. Filgrastim 12 microg/kg daily was administered for 6 days by continuous subcutaneous infusion. SCF was administered by daily subcutaneous injection at 5, 10, or 15 microg/kg concurrent with filgrastim for 7 days, or 10 microg/kg daily starting 3 days before filgrastim for a total of 10 days (SCF pretreatment). Apheresis was performed on days 5, 6, and 7 of filgrastim administration. Patients then had three cycles of epirubicin 200 mg/m2 and cyclophosphamide 4 g/m2 every 28 days, each supported by one third of the apheresis product.

RESULTS

Sixty-two women were treated. Greater yields occurred in patients who received SCF 10 microg/kg daily plus filgastim than those who received filgrastim alone (P=.013 for CD34+ cells; P=.07 for granulocyte-macrophage colony-forming cells [GM-CFCs]). The difference was more marked with SCF-pretreatment than concurrent SCF. Fewer aphereses were required to reach the predetermined target of peripheral-blood progenitor/stem cells (PBPCs) in women who received SCF. SCF was generally well tolerated. Hematologic recovery was rapid after each of the three cycles of chemotherapy. There was no difference in recovery between the different treatment groups.

CONCLUSION

Mobilization of PBPCs by filgrastim is significantly enhanced by coadministration of SCF, and commencing SCF before filgrastim can optimize this effect. SCF has the potential to reduce the number of aphereses required to collect a target number of PBPCs.

Progress in management of acute myeloid leukaemia (AML) in Australia since 1980: a single institution retrospective study

BACKGROUND

Much research has been conducted into the pathobiology, diagnosis, and management of acute myeloid leukaemia (AML) since 1980, with major contributions from Australian studies in this period.

AIMS

To determine whether advances in basic and clinical research into AML have translated into improved survival for patients in the community.

METHODS

A retrospective survey of records of all patients with AML presenting to the Royal Melbourne Hospital (RMH) over a 16 year period, analysed according to induction therapy and established prognostic factors. Between 1980 and December 1996 223 (98%) of 227 patients were evaluable.

RESULTS

The probability of survival at five years for patients treated since 1990 has improved significantly compared to the cohort treated between 1980-89 (34 +/- 5% vs 4 +/- 2%; mean +/- standard error). This benefit is most evident in patients less than 60 years of age (50 +/- 7% vs 11 +/- 4%). Successive induction protocols in the context of clinical trials conducted since 1985 contributed to improved outcomes. The selective application of bone marrow transplantation, and use of retinoic acid as induction therapy for acute promyelocytic leukaemia has also improved survival. Despite increases in dose-intensity, early death rates for patients undergoing induction therapy fell during the study period.

CONCLUSIONS

Participation in clinical and basic research with the development of more intense and specific treatments for patients with AML has contributed to better outcomes, underpinned by improvements in supportive care.

Autologous CD34+ cell transplantation for patients with advanced lymphoma: effects of overnight storage on peripheral blood progenitor cell enrichment and engraftment

In order to demonstrate the feasibility of mobilization, enrichment and engraftment of autologous peripheral blood CD34+ cells in patients with relapsed lymphoma, 59 peripheral blood progenitor cell (PBPC) collections from 21 patients were enriched for CD34+ cells using CEPRATE SC (CellPro, Bothell, WA, USA) immunoaffinity column. Following high-dose chemotherapy, a mean of 17 x 10(8) (range, 3-34) nucleated cells/kg containing 8.7 x 10(6) (0.3-26) CD34+ cells/kg were re-infused. Blood cell recovery in these patients was compared to engraftment capacity of unenriched PBPCs in a cohort of lymphoma patients treated with an identical high-dose chemotherapy regimen. Neutrophil and platelet engraftment was rapid in both groups including five patients who received < or = 1 x 10(6) CD34+ cells/kg. After infusion of CD34+ enriched cells, neutrophils exceeded 0.5 x 10(9)/l in 11 (8-14) days and platelets exceeded 20 x 10(9)/l (untransfused) in 15 (9-39) days. In order to optimize the immunoaffinity column utilization we stored the first PBPC collections overnight at 4 degrees C and combined them with the next day's collection prior to the CD34+ enrichment procedure in 11 patients. This maneuver resulted in a significant decrease in the CD34+ cell recovery (resulting in reinfusion of a mean of 42% less CD34+ cells). Although overnight storage did not affect neutrophil engraftment, platelet engraftment was prolonged in this group of patients even when > 2.0 x 10(6) CD34+ cells/kg were re-infused. The overnight storage procedure should be further evaluated for its effects on the CD34+ immunoaffinity enrichment procedure, megakaryocyte progenitors and platelet engraftment. We conclude that CD34+ cells enriched from peripheral blood result in rapid engraftment after high-dose chemotherapy in patients with advanced lymphoma that is comparable to that of patients receiving unenriched PBPCs.

Lack of utility of the lysis-centrifugation blood culture method for detection of fungemia in immunocompromised cancer patients

We retrospectively compared the utility of a fungal isolation device (Isolator) versus conventional techniques for recovering fungal organisms from blood cultures obtained from neutropenic cancer patients. Positive cultures were deemed true pathogens, possible pathogens, or contaminants according to laboratory and clinical criteria. Fifty-three patients had 66 positive blood cultures for fungi, nine on multiple occasions. In 20 episodes true pathogens were recovered, 6 from broth medium alone, 4 from the Isolator system alone, and 10 from both systems. False-negative cultures were noted in 4 of 20 (20%) cases in which broth medium was used and in 6 of 20 (30%) cases in which the Isolator system was used. Possible pathogens were detected in 4 of 66 blood culture-positive cases. Forty-two positive cultures were considered contaminants, 1 collected from standard medium and 41 of 42 (98%) which grew only in Isolators. Eleven of 18 patients with true fungal infections expired as a result of infection, while 4 of 33 patients with a contaminant expired, none from a fungal cause. We do not advocate the routine use of Isolator tubes in the evaluation of the febrile, neutropenic patient due to the high rates of false positives and of contamination.

Enhanced levels and enhanced clonogenic capacity of blood progenitor cells following administration of stem cell factor plus granulocyte colony-stimulating factor to humans

Administration of hematopoietic growth factors is being used increasingly to obtain populations of blood progenitor/stem cells (PBPC) for clinical transplantation. Here we examined the effect of combining stem cell factor (SCF ) and granulocyte colony-stimulating factor (G-CSF ) versus G-CSF alone in a randomized clinical study involving 62 women with early-stage breast cancer. In the first patient cohorts, escalating doses of SCF were administered for 7 days with concurrent G-CSF administration. At baseline, levels of progenitor cells in the bone marrow or blood were comparable in the different patient groups. As with administration of G-CSF alone, the combination of SCF plus G-CSF did not alter the wide variation in levels of PBPC observed between individuals and did not alter the selective nature of PBPC release, with preferential release of day-14 granulocyte-macrophage colony-stimulating factor (GM-CFC) versus day-7 GM-CFC. However, SCF acted to sustain the levels of PBPC after cessation of growth factor treatment; levels of PBPC were elevated 100-fold at later timepoints compared with G-CSF alone. In addition, the maximum levels of PBPC observed were increased approximately fivefold at day 5 of growth-factor administration. The increased levels of PBPC resulted in significantly increased levels of PBPC obtained by leukapheresis. In a subsequent patient cohort, 3-days pretreatment with SCF was introduced and followed by 7 days concurrent SCF plus G-CSF. The 3-days pretreatment with SCF resulted in an earlier wave of PBPC release in response to commencement of G-CSF. In addition, maximum PBPC levels in blood and PBPC yield in leukapheresis products were further increased. Unexpectedly however, SCF pretreatment resulted in progenitor cells with enhanced self-generation potential. Recloning assays documented the ability of approximately 30% of primary granulocyte-macrophage (GM) colonies from control cell populations to generate secondary GM colonies (n = 1,106 primary colonies examined). In contrast approximately 90% of GM colonies from PBPC after SCF pretreatment generated secondary clones and 65% generated secondary colonies. The action of SCF was not explicable in terms of altered SCF, GM-CSF, or G-CSF responsiveness, but SCF pretreatment was associated with maximum serum SCF levels at the time G-CSF was commenced. These results show that PBPC populations mobilized by different growth factor regimens can differ in their functional properties and caution against solely considering number of harvested progenitor cells without regard to their function.

Randomized, blinded, placebo-controlled phase I trial of pegylated recombinant human megakaryocyte growth and development factor with filgrastim after dose-intensive chemotherapy in patients with advanced cancer

Thrombocytopenia caused by chemotherapy is an important cause of morbidity and mortality in the treatment of malignant disease. Recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) is a potent stimulator of megakaryocytopoiesis and prevents chemotherapy-induced thrombocytopenia in preclinical studies. We administered PEG-rHuMGDF with filgrastim after dose-intensive chemotherapy to 41 patients with advanced cancers to determine its safety and effects on hematologic recovery. Carboplatin 600 mg/m2 and cyclophosphamide 1,200 mg/m2 were administered to patients with advanced cancer. Patients were randomly assigned to receive blinded study drug, either PEG-rHuMGDF or placebo (3-to-1 ratio), commencing the day after chemotherapy. PEG-rHuMGDF was given at doses of 0.03, 0.1, 0.3, 1.0, 3.0, and 5.0 microg per kilogram body weight by daily subcutaneous injection for between 7 and 20 days. All patients received concurrent filgrastim 5 microg per kilogram body weight per day until neutrophil recovery. Fifteen patients had received PEG-rHuMGDF alone in a previous phase I study. Platelet function and peripheral blood progenitor cells (PBPC) were assessed. PEG-rHuMGDF enhanced platelet recovery in a dose-related manner when compared with placebo. The platelet nadir occurred earlier in patients given PEG-rHuMGDF (P = .002) but there was no difference in the depth of the nadir. Recovery to baseline platelet count was achieved significantly earlier following PEG-rHuMGDF administration compared with placebo (median, 17 days for PEG-rHuMGDF 0.3 to 5.0 microg/kg versus 22 days for placebo, P = .014). In addition, platelet recovery was faster in patients who had previously received PEG-rHuMGDF, suggesting that pretreatment might be beneficial. Platelet function did not change during or after administration of PEG-rHuMGDF. Levels of PBPC on day 15 after chemotherapy were significantly greater in patients administered PEG-rHuMGDF 0.3 to 5.0 microg/kg and filgrastim compared with those given placebo plus filgrastim. PEG-rHuMGDF was well tolerated at all doses. Two patients given PEG-rHuMGDF had a thrombotic episode. PEG-rHuMGDF accelerates platelet recovery after moderately dose-intensive carboplatin and cyclophosphamide, and is likely to be clinically useful in treatment of chemotherapy-induced thrombocytopenia. Because it enhances mobilization of PBPC by filgrastim, PEG-rHuMGDF might also allow more efficient collection of stem cells for autologous or allogeneic transplantation.

Long-term survival advantage of MACOP-B over CHOP in intermediate-grade non-Hodgkin's lymphoma. The Australian and New Zealand Lymphoma Group

BACKGROUND

The initial publication of the results of the Australian and New Zealand Lymphoma Group (ANZLG) randomized controlled trial comparing MACOP-B and CHOP in patients with intermediate-grade non-Hodgkin's lymphoma (NHL) showed equivalent complete response rates, time to treatment failure, and survival. Here we report the long-term follow-up of the 236 patients entered on that study to determine if there were any long-term advantages or disadvantages associated with MACOP-B.

PATIENTS AND METHODS

Two hundred thirty-six eligible patients were randomized between October 1986 and June 1991. The median duration of follow-up has been extended from 3.2 years in our previous publication to 6.5 years.

RESULTS

As previously reported, the complete response (CR) rate for MACOP-B and CHOP chemotherapy was 51% and 59%, respectively. The estimated failure-free survival rate for MACOP-B and CHOP patients was 42% and 30%, respectively, at 5 years (P = 0.045) and 37% and 25%, respectively, at 8 year (P = 0.057). The estimated overall survival rate at 5 years was 54% for MACOP-B and 41% for CHOP patients (P = 0.035) and at 8 years was 45% and 36%, respectively (P = 0.16).

CONCLUSION

With this extended follow-up, we have shown a long-term survival advantage for MACOP-B chemotherapy over standard CHOP in patients with intermediate-grade non-Hodgkin's lymphoma.

Thrombopoietic effects of pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) in patients with advanced cancer

BACKGROUND

Pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) is a potent stimulator of megakaryocyte colony formation and platelet production. It is likely to be useful in the management of severe thrombocytopenia. To determine its clinical activity and safety, we gave it to patients with advanced cancer before chemotherapy.

METHODS

Patients were randomly assigned to receive either PEG-rHuMGDF or placebo in a three to one ratio. PEG-rHuMGDF was given at a dose of 0.03, 0.1, 0.3, or 1.0 microgram/kg body weight. The study drug or placebo were administered daily by subcutaneous injection for up to 10 days or until a target platelet count was reached.

FINDINGS

17 patients, median age 59 years, received either PEG-rHuMGDF (13 patients) or placebo (four patients). PEG-rHuMGDF produced a dose-dependent increase in platelet counts. Patients given placebo. 0.03, and 0.1 microgram/kg of PEG-rHuMGDF had median increases in platelet counts of 16%, 12%, and 39%. Those receiving 0.3 and 1.0 microgram/kg of PEG-rHuMGDF had an increase in blood platelets of between 51% and 584%. Platelets rose from day 6 of PEG-rHuMGDF administration and continued to rise after stopping the drug. The platelet count peaked between days 12 and 18 and remained above 450 x 10(9)/L for up to 21 days. There were no alterations in white-blood-cell count or haematocrit, and low toxicity. Platelets taken from patients during PEG-rHuMGDF administration and at the time of peak platelet count were morphologically and functionally normal.

INTERPRETATION

The potency with which PEG-rHuMGDF stimulates platelet production and its low toxicity indicate that this is likely to be a useful agent for the management of thrombocytopenia.

Administration of pegylated recombinant human megakaryocyte growth and development factor to humans stimulates the production of functional platelets that show no evidence of in vivo activation

This report describes the effect of pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) on platelet production and platelet function in humans. Subjects with advanced solid tumors received PEG-rHuMGDF daily for up to 10 days. There was no increase in circulating platelet count at doses of 0.03 or 0.1 microgram/kg/d by day 12 of study. At doses of 0.3 and 1.0 microgram/kg/d there was a threefold median increase (maximum 10-fold) in platelet count by day 16. The platelets produced in vivo in response to PEG-rHuMGDF showed unchanged aggregation and adenosine triphosphate (ATP)-release responses in in vitro assays. Tests included aggregation and release of ATP in response to adenosine diphosphate (ADP) (10, 5, 2.5, and 1.25 mumol/L), collagen (2 micrograms/mL), thrombin-receptor agonist peptide (TRAP, 10 mumol/L) and ristocetin (1.5 mg/mL). Administration of aspirin to an individual with platelet count of 1,771 x 10(3)/L resulted in the typical aspirin-induced ablation of the normal aggregation and ATP-release response to stimulation with arachidonic acid (0.5 mg/mL), collagen, and ADP (2.5 and 1.25 mumol/L). There was no change in the expression of the platelet-surface activation marker CD62P (P-selectin) nor induction of the fibrinogen binding site on glycoprotein IIb/IIIa as reported by the monoclonal antibody, D3GP3. An elevation of reticulated platelets was evident after 3 days of treatment with PEG-rHuMGDF and preceded the increase in circulating platelet count by 5 to 8 days; this reflected the production of new platelets in response to PEG-rHuMGDF. At later time points, the mean platelet volume (MPV) decreased in a manner inversely proportional to the platelet count. Levels of plasma glycocalicin, a measure of platelet turnover, rose 3 days after the initial increase in the peripheral platelet count. The level of plasma glycocalicin was proportional to the total platelet mass, suggesting that platelets generated in response to PEG-rHuMGDF were not more actively destroyed. Thus, the administration of PEG-rHuMGDF, to humans, increased the circulating platelet count and resulted in fully functional platelets, which showed no detectable increase in reactivity nor alteration in activation status.

Molecular cloning of a novel human gene (D11S4896E) at chromosomal region 11p15.5

A novel gene (GOK) has been cloned from human chromosome region 11p15.5 that is believed to contain a gene or genes associated with a number of pediatric malignancies, including Wilms tumor. A 4-kb cDNA has been cloned and it encodes a predicted protein of approximately 84 kDa that could be translated in vitro. Computer analysis predicted that the protein had a signal peptide and may contain a transmembrane helix. Restriction mapping by pulsed-field electrophoresis indicates that GOK is located 1.7 kb telomeric of RRM1, and both genes are transcribed in the same direction. GOK displays high evolutionary conservation: cloning and partial sequencing of a mouse genomic clone revealed 90% identity with the human gene at both the nucleotide and the predicted amino acid levels.

Gliotoxicity in brain reaggregate cultures caused by oxidants and excitatory amino acids can be prevented by alpha-tocopherol and MK-801

Glutamine synthetase (GS) is a key enzyme involved in glutamate compartmentalisation which may be pivotal in the course of both central free-radical mediated and excitotoxic events. The ability of the oxidants FeCl2 and H2O2 and the excitatory amino acid, N-methyl-D-aspartate (NMDA) to induce changes in astrocytic GS and glial fibrillary acidic protein (GFAP), were assessed in whole rat brain reaggregate cultures. Both FeCl2 and H2O2 reduced GS activity whereas NMDA produced a large increase in enzyme activity. GFAP was not altered significantly by either oxidant although NMDA increased the level of this protein. These effects on such astroglial markers could be reversed in vitro following exposure to a-tocopherol (FeCl2 and H2O2) and MK-801. This study therefore demonstrates that inactivation of GS can be caused by free radical insult whereas stimulation of brain GS and reactive gliosis is produced by excitatory amino acids acting at neuronal NMDA receptors. The study of these gliotoxic events in 3-dimensional reaggregate cultures suggests that this model may be used to detect neuroprotective effects of novel pharmacological agents.

Laparoscopic liver biopsy to evaluate hepatic dysfunction in patients with hematologic malignancies: a useful tool to effect changes in management

Hepatic dysfunction is common in patients who receive intensive chemotherapy and it is important to determine the etiology in order to institute appropriate therapy. The role of laparoscopic liver biopsy in patients with neutropenia, thrombocytopenia, or both was evaluated as a mean of making treatment decisions and as a determinant of clinical outcome. Laparoscopic liver biopsy was performed in 29 subjects who were receiving intensive cytotoxic therapy with or without bone marrow transplantation. One to three direct-vision laparoscopic liver biopsies were performed in each patient using a Tru-cut needle during general anesthesia. Platelet concentrate transfusions were usually given before, during, and immediately after biopsy. Bleeding was controlled with spatula electrocautery. Thirty-two biopsies were obtained in 29 patients. At the time of liver biopsy, white blood cell and platelet counts ranged from 0 to 14,300/microliters (median: 2500/microliters), and 1000 to 47,000/microliters (median: 20,000/microliters), respectively. Bleeding at the liver biopsy site was readily controlled during the procedure without clinical evidence of significant bleeding; no procedure-related complications were noted and no patients required re-exploration. All biopsies were informative and the lesions observed in 32 biopsies revealed graft-versus-host disease (n = 5), hepatic candidiasis (n =1), hepatic veno-occlusive disease (n = 3), cholestasis (n = 19), hemosiderosis (n = 26), toxic injury (n = 8), hepatic steatosis (n = 4), granuloma (n = 1), viral infection (n =1), and malignancy (n = 1). Laparoscopic liver biopsy has been proven to be an effective means of assessing the cause of liver dysfunction in patients who were thrombocytopenic and immunosuppressed. The diagnosis obtained at laparoscopic liver biopsy altered therapy in nine of 29 (31%) patients.

Human gene for the large subunit of ribonucleotide reductase (RRM1): functional analysis of the promoter

Ribonucleotide reductase comprises two nonidentical protein subunits R1 and R2, both of which are required for enzyme activity and show cell cycle-dependent regulation. The TATA-less promoter of the human RRM1 gene (encodes R1 protein) was examined with reference to regulatory domains upstream of the transcription start site. A region from nt -195 to +3 was found to give maximal expression of a reporter gene when transfected into the human cell line K562. Overall, this 198-bp region shows 58% identity with the equivalent region of the murine promoter; however, it contains two 22-bp domains that were 81 and 91% identical between species. Electrophoretic mobility shift assays were performed using a fragment of the domain closest to the transcription start site. These experiments revealed that several factors were able to bind this region in a sequence-specific manner. One of these factors was shown to be Sp1 by specific competition and supershift using antibody to Sp1. The data presented suggest that Sp1 is involved in the transcription of RRM1.

Sequential changes in serum iron and ferritin in patients undergoing high-dose chemotherapy and radiation with autologous bone marrow transplantation: possible implications for treatment related toxicity

In an effort to define the pattern of iron flux during high-dose chemotherapy or chemo/radiotherapy, we prospectively measured serum iron, iron binding capacity, and ferritin in patients undergoing autologous bone marrow transplantation for various malignancies. Sequential measurement of serum iron from days -7 to +12 was carried out in 88 evaluable patients, and simultaneous measurement of iron, ferritin, and total iron binding capacity was carried out in 32 patients. We found that there was a predictable rise in serum iron on day -2 or -3, and that this was accompanied by an increase in the saturation of transferrin. In addition, there was a similar increase in serum ferritin levels, which peaked by day +2. We suggest that the timing of this change in serum iron and saturation of transferrin may be important in mediating endothelial cell damage and, hence, organ toxicity in the setting of AuBMT. Based on these findings, we suggest that large clinical studies could be a source of patient samples to measure surrogate endpoints such as lipid peroxidation products (malondialdehyde or isoprostanes), or protein oxidation products following high-dose chemo/radiotherapy to determine the role of iron in cellular injury. It is possible that pharmacological manipulations to reduce free radical production or to chelate iron during the days prior to bone marrow reinfusion might help to reduce tissue injury in the setting of bone marrow transplantation.

Acute cholecystitis after autologous bone marrow transplantation for acute myeloid leukemia

BACKGROUND

We investigated the incidence of acute cholecystitis in patients with acute myeloid leukemia (AML) undergoing autologous bone marrow transplantation in complete remission.

PATIENTS AND METHODS

Thirty-five consecutive acute myeloid leukemia patients were given oral busulfan 4 mg/kg/day for 4 days and IV cyclophosphamide 50 mg/kg/day for 4 days followed by reinfusion of autologous bone marrow purged with 4-hydroperoxycyclophosphamide.

RESULTS

Five of 35 patients developed clinical evidence of acute cholecystitis, manifested by fever, nausea, vomiting, right-upper-quadrant pain, and abdominal guarding, within 18 days after autologous bone marrow infusion. Ultrasonography and CT scans of the abdomen supported the diagnosis of cholecystitis. Three patients underwent cholecystectomy, while two patients were treated medically; all recovered uneventfully. A review of 338 consecutive bone marrow transplant patients who underwent marrow transplantation for a variety of diseases and were treated with other high-dose cytotoxic regimens during the same time period revealed significantly fewer cases of cholecystitis, i.e. two, (p < 0.0001).

CONCLUSIONS

Five of 35 AML patients undergoing autologous bone marrow transplant using busulfan, cyclophosphamide, and purged bone marrow developed evidence of acute cholecystitis. These findings suggest that the busulfan/cyclophosphamide preparative regimen may be associated with acute cholecystitis. The true incidence of this injury and its pathogenesis remain to be elucidated.

Hepatic dysfunction in patients with carcinoma who are severely thrombocytopenic and immunosuppressed

BACKGROUND

The use of intensive cytotoxic drug therapy for malignant disorders often results in hepatic dysfunction. It is important to determine the cause of hepatic injury to institute appropriate therapy; however, neutropenia and thrombocytopenia may prevent performance of hepatic biopsy to establish a cause.

STUDY DESIGN

We prospectively evaluated the cause of hepatic dysfunction using laparoscopic biopsy of the liver in 20 consecutive patients who were receiving intensive cytotoxic therapy, with or without bone marrow transplantation, or who were being treated for severe aplastic anemia. One to three direct-vision laparoscopic biopsies were performed in each patient during general anesthesia and bleeding was controlled with spatula electrocautery. Platelet concentrate transfusions were given before, during, and immediately after the biopsy.

RESULTS

Platelet and leukocyte counts at the time of hepatic biopsy ranged from 1,000 to 83,000 per microL (median of 23,500 per microL) and zero to 14,300 per microL (median of 2,200 per microL), respectively. Nineteen of 20 patients had platelet counts of less than 68,000 per microL. Bleeding at biopsy site was controlled during the procedure without evidence of bleeding or complications after biopsy. Biopsy specimens revealed graft-versus-host disease (n = 2), hepatic veno-occlusive disease (n = 1), steatosis (n = 5), cholestasis (n = 19), hemosiderosis (n = 19), and granuloma (n = 1).

CONCLUSIONS

In several patients, the knowledge derived from hepatic biopsy results altered the therapeutic strategy. The use of laparoscopic hepatic biopsy to assess the cause of hepatic dysfunction should be encouraged because it is a safe procedure, even in patients who are severely thrombocytopenic and immunocompromised.

Filgrastim in patients with chemotherapy-induced febrile neutropenia. A double-blind, placebo-controlled trial

OBJECTIVE

To determine if filgrastim (recombinant human methionyl granulocyte colony-stimulating factor) used in addition to standard inpatient antibiotic therapy accelerated recovery from infection associated with chemotherapy-induced neutropenia.

DESIGN

Randomized, double-blind, placebo-controlled trial.

SETTING

Hematology and oncology wards of four teaching hospitals.

PATIENTS

218 patients with cancer who had fever (temperature > 38.2 degrees C) and neutropenia (neutrophil count < 1.0 x 10(9)/L) after chemotherapy.

INTERVENTION

Patients were randomly assigned to receive filgrastim (12 micrograms/kg of body weight per day) (n = 109) or placebo (n = 107) beginning within 12 hours of empiric therapy with tobramycin and piperacillin. Patients received treatment and remained in the study until the neutrophil count was greater than 0.5 x 10(9)/L and until 4 days without fever (temperature < 37.5 degrees C) had elapsed.

MEASUREMENTS

Days of neutropenia and fever and days in the study (hospitalization); time to resolution of fever and febrile neutropenia; and frequency of the use of alternative antibiotics.

RESULTS

Compared with placebo, filgrastim reduced the median number of days of neutropenia (3.0 compared with 4.0 days of a neutrophil count of < 0.5 x 10(9)/L; P = 0.005) and the time to resolution of febrile neutropenia (5.0 compared with 6.0 days; P = 0.01) but not days of fever (3.0 days for both groups). The frequency of the use of alternative antibiotics was similar in the two groups (46% compared with 41%; P = 0.48). The median number of days patients were hospitalized while on study was the same (8.0 days; P = 0.09); however, filgrastim decreased the risk for prolonged hospitalization (> 11 days, 4th quartile) by half (relative risk, 2.1 [95% CI, 1.1 to 4.1]; P = 0.02). In exploratory subset analyses, filgrastim appeared to provide the greatest benefit in patients with documented infection and in patients presenting with neutrophil counts of less than 0.1 x 10(9)/L.

CONCLUSIONS

Filgrastim treatment used with antibiotics at the onset of febrile neutropenia in patients with cancer who have received chemotherapy accelerated neutrophil recovery and shortened the duration of febrile neutropenia.

Randomized comparison of MACOP-B with CHOP in patients with intermediate-grade non-Hodgkin's lymphoma. The Australian and New Zealand Lymphoma Group

PURPOSE

To compare complete response rates, time to failure, survival, and toxicity for patients with intermediate-grade non-Hodgkin's lymphoma (NHL) treated with cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) versus those treated with a regimen consisting of methotrexate, doxorubicin, cyclophosphamide, vincristine, prednisolone, and bleomycin (MACOP-B), in a multicenter, randomized controlled trial performed by 22 centers of the Australian and New Zealand Lymphoma Group (ANZLG).

PATIENTS AND METHODS

Between October 1986 and June 1991, 304 patients were randomized, of whom 236 were eligible for analysis. Eligibility criteria included diffuse small cleaved-cell, diffuse mixed small- and large-cell, follicular large-cell, diffuse large-cell, and large-cell immunoblastic, stages I bulky or II to IV.

RESULTS

There was no significant difference in complete response rates (51% for MACOP-B v 59% for CHOP), failure-free survival, or overall survival in the two treatment arms. The rate of death of MACOP-B patients relative to CHOP patients was estimated to be 0.91 (P = .64) when stratified by prognostic group. There were no significant differences between the two regimens in any of the prognostic subgroups. Toxicity was significantly more severe with MACOP-B, particularly cutaneous toxicity, stomatitis, and gastrointestinal ulceration. The average relative dose-intensity (RDI) of MACOP-B was 0.91 and of CHOP was 0.90, indicating good dose delivery in this multicenter group setting.

CONCLUSION

CHOP chemotherapy produced results equivalent to those of MACOP-B in patients with intermediate-grade NHL and with significantly fewer toxic complications. Despite relatively poor results in some patient subgroups, CHOP remains the standard chemotherapy for this disease, against which all new regimens should be compared.

Marrow cellularity as a predictor of adequate cell yield for transplantation

Clear correlations have not been established between bone marrow cellularity before or at marrow harvest and marrow cell yield for transplantation. The authors therefore retrospectively reviewed 204 marrow donations to ascertain whether biopsy cellularity was predictive of nucleated cell yield at harvest, as measured by final cell counts (FCC)/kg body weight. Preharvest and intraoperative biopsy cellularity were highly correlated with each other; moderate correlation was found between intraoperative biopsy cellularity and FCC. Mean cellularity was slightly but significantly higher in samples yielding an FCC greater than 2 x 10(8) nucleated cells/kg (P < 0.01). Biopsy cellularity less than 20%, seen in 4% of specimens, did not consistently correlate with low FCC, defined as less than 2 x 10(8) nucleated cells/kg. More than 2 x 10(8) cells/kg were consistently obtained only when biopsy cellularity was 65% or more. Marrow biopsies performed before harvest can be used to predict intraoperative cell counts at the time of marrow donation, although a cell yield of more than 2 x 10(8) nucleated cells/kg can be assured only with high marrow cellularity.

Colony-stimulating factors. Present status and future potential

Granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) have been used successfully to enhance neutrophil recovery in patients with various malignancies undergoing standard or high dose chemotherapy, with or without autologous or allogeneic bone marrow transplantation support, and offer potential advantages in these settings in terms of reducing the total costs of healthcare and/or improving therapeutic outcomes. Clinical trials are now aimed at identifying which patients and which nonhaematological malignancies will respond best to colony-stimulating factor (CSF) support, and which of the 2 factors is the most appropriate in each setting. Two areas of considerable interest at present are the potential for chemotherapy dose optimisation and intensification with CSF therapy, and the use of CSFs to permit the harvest and reinfusion of peripheral blood progenitor cells as an alternative to autologous or allogeneic bone marrow transplantation. In the case of dose-intensified chemotherapy, costs of treatment increase but the gain may be an increase in survival rates or disease-free intervals. The potential of G-CSF and GM-CSF therapy in other conditions, notably haematological malignancies such as myelodysplasia and myeloid leukaemias, and AIDS, means that these agents are likely to make a significant impact on the treatment of a wide range of debilitating conditions in the future.

Human R1 subunit of ribonucleotide reductase (RRM1): 5' flanking region of the gene

Ribonucleotide reductase is essential, in dividing cells, for the production of deoxyribonucleotides prior to DNA synthesis in S phase. Neither of its two subunits (R1 and R2) are detectable in quiescent cells. In cycling cells, RRM1 mRNA and R1 protein are present throughout the cell cycle. A fragment of the human cDNA was used to isolate a genomic clone that encompasses the 5' flanking region of human RRM1. Primer extension and PCR experiments were used to define six potential cap sites. The immediate upstream region does not have a TATA box and is not GC-rich. A 1.9-kb fragment (-1670 to +208) was able to direct transcription of a reporter gene in a transient expression system. Understanding the mechanisms regulating expression of this gene will provide insight into the processes involved in cell cycling and may be of particular importance in understanding the deregulated growth of transformed cells.