Synthesis of granulocyte colony-stimulating factor and its requirement for terminal divisions in chronic myelogenous leukemia.

In this paper we demonstrate that maturing neoplastic cells from patients with chronic myelogenous leukemia (CML) constitutively produce G-CSF and are also receptive for this molecule. G-CSF functions as an autocrine growth factor in stable phase CML, and thus is responsible for divisions of maturing leukemic cells leading to an expansion of the compartment of mature cells. This observation is well in line with in vivo features of CML in stable phase, i.e., the hyperplasia of the mature granulocyte compartment. In acute blastic phase of CML expression of the G-CSF gene seems to be less common and not related to autonomous blast growth.

Interleukin 1 stimulates T lymphocytes to produce granulocyte-monocyte colony-stimulating factor.

T lymphocytes are thought to cooperatively interact with monocytes to produce colony-stimulating factors (CSF). However, little is known about monocyte-mediated signals leading to CSF-secretion by T lymphocytes, although soluble monocyte products have been implicated. We have employed monoclonal antibody anti-T3B covalently coupled to CnBr-activated Sepharose 4B beads, to show that multimeric ligation of T cell antigen receptor leads to T cell receptiveness to interleukin 1 (IL-1), as indicated by T cell production of CSF, which induces growth of myeloid progenitor cells into neutrophil, eosinophil, and monocyte colonies. To investigate the molecular basis of these findings, total RNA was extracted from T3B Sepharose-primed and IL-1-stimulated T lymphocytes and probed for granulocyte-monocyte-CSF (GM-CSF), granulocyte-CSF (G-CSF), and monocyte-CSF (M-CSF) mRNA. GM-CSF, but not G-CSF or M-CSF, messages were detected. Nuclear "run on" assays revealed that IL-1 action is effective primarily at the level of GM-CSF gene transcription. These results suggest a previously unrecognized role of IL-1 in the regulation of GM-CSF secretion by T cells.

Granulocyte-macrophage colony-stimulating factor induces cytokine secretion by human polymorphonuclear leukocytes.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is known as an inducer of proliferation and functional activation of myeloid cells. This study was carried out to characterize the effects of GM-CSF on polymorphonuclear leukocytes (PMN) more extensively. Using Northern blot analysis, we show that PMN are able to accumulate mRNAs for different cytokines, including tumor necrosis factor-alpha (TNF-alpha); G-CSF, and M-CSF, all of which are involved in inflammation and hematopoiesis. Biological assays and immunoassays demonstrate that PMN translate these mRNAs, except TNF-alpha, into secretory proteins. However, the expression of these cytokines is dependent on stimulation by exogenous signals, preferentially provided by the T cell-derived lymphokine GM-CSF. Stimulation of hematopoiesis and amplification of defense mechanisms after T cell activation thus might involve not only monocytes but also PMN, a cell type previously believed to be biosynthetically inactive.

Participation of the cytokines interleukin 6, tumor necrosis factor-alpha, and interleukin 1-beta secreted by acute myelogenous leukemia blasts in autocrine and paracrine leukemia growth control.

Autonomous in vitro growth of myeloid leukemic colony-forming cells may in part result from autocrine production of colony-stimulating factors (CSF). Some acute myeloid leukemia (AML) samples, however, fail to synthesize CSF despite growing autonomously in agar, and are therefore believed to bypass CSF requirements. Cytokines such as IL-6, tumor necrosis factor (TNF)-alpha, and IL-1, products of cells of the myeloid lineage, are known to be involved in growth control of myeloid progenitor cells. Since these molecules may also contribute to autocrine and paracrine growth regulation of myeloid leukemias, we screened a series of AML for cytokine production. In addition, possible roles of IL-6, TNF-alpha, and IL-1 in growth control of AML were investigated in vitro. We show that a substantial proportion of AML cells produce IL-6, TNF-alpha, and IL-1-beta and use these mediators to stimulate their growth by disparate mechanisms: IL-6 acts as a costimulator to enhance CSF-induced clonogenicity of AML blasts. TNF-alpha induces CSF production by endothelial cells and may therefore provide a paracrine loop to support leukemia growth.

Hematopoietic responses in patients with advanced malignancy treated with recombinant human granulocyte-macrophage colony-stimulating factor.

The in vivo effect of yeast-derived recombinant human granulocyte-macrophage colony-stimulating factor (rh GM-CSF) was investigated in 30 patients with advanced malignancy in a phase Ib trial. Patients were treated at four different dose levels (120 to 1,000 micrograms/m2/d) by either daily intravenous (IV) bolus injection or 24-hour continuous infusion. Administration of rh GM-CSF resulted in a broad spectrum of dose- and schedule-dependent hematopoietic effects. Sustained infusion of rh GM-CSF elicited a maximum 17-fold average peak increase of the total WBC count with mainly neutrophils, eosinophils, and monocytes accounting for this rise, and increases in bone marrow cellularity with a shift to immature myeloid elements. Elevation of lymphocytes, platelets, and reticulocytes was not induced. Within five days after discontinuation of treatment the leukocytosis had disappeared. Adverse reactions encountered with rh GM-CSF seen in 65% of the patients studied were never life-threatening and always rapidly reversible. They included mild myalgias, facial flushing, low-grade fever, headache, bone discomfort, nausea, dyspnea, and transient decline of platelet counts. These results suggest that rh GM-CSF can be safely administered at the doses and schedules used and that it can induce in vivo some of the biological effects reported in in vitro studies. Although no objective antitumour responses have been seen, the ability of rh GM-CSF to increase number and function of leukocytes in vivo may prevent neutropenia and infections when GM-CSF is added to cytotoxic cancer therapy.

Erythropoietin for the treatment of anemia of malignancy associated with neoplastic bone marrow infiltration.

This clinical trial was performed to study the effects of intravenously (IV) administered recombinant human (rh) erythropoietin (EPO) at escalating doses (150, 300, and 450 U/kg, administered as an IV bolus injection, twice weekly, for 6, 4, and 4 weeks, respectively) in five patients with low-grade non-Hodgkin's lymphoma (Ig NHL) and bone marrow involvement and one patient with multiple myeloma (MM). All patients were anemic due to underlying disease. None of the patients had a history of bleeding, hemolysis, renal insufficiency, or other disorders causing anemia in addition to bone marrow infiltrating malignancy. Endogenous EPO serum levels were significantly increased in all patients (74 to 202 mU/mL). Five patients (one MM, four small-cell lymphocytic [SCLC] NHL) showed a dramatic increase of hemoglobin (Hb), hematocrit (Hk) and RBC count becoming obvious on the second EPO dose level. Initial ferritin serum values, which were high mostly due to polytransfusion, were significantly reduced in responding patients. Erythropoiesis of one patient with extensive follicular mixed (fm) NHL did not respond to EPO treatment. Platelet (PLT) count increase (greater than 75% above starting levels) during and following EPO therapy was observed in one patient with MM. Adverse events due to EPO therapy have not been recorded. These findings point out a previously unrecognized capacity of EPO given at pharmacologic doses to stimulate erythropoiesis in patients with anemia due to bone marrow infiltration by neoplastic lymphocytes in spite of enhanced endogenous EPO expression.

Phase III randomized trial of amifostine as a radioprotector in head and neck cancer.

PURPOSE: Radiotherapy for head and neck cancer causes acute and chronic xerostomia and acute mucositis. Amifositine and its active metabolite, WR-1065, accumulate with high concentrations in the salivary glands. This randomized trial evaluated whether amifostine could ameliorate these side effects without compromising the effectiveness of radiotherapy in these patients. PATIENTS AND METHODS: Patients with previously untreated head and neck squamous cell carcinoma were eligible. Primary end points included the incidence of grade > or =2 acute xerostomia, grade > or =3 acute mucositis, and grade > or =2 late xerostomia and were based on the worst toxicity reported. Amifostine was administered (200 mg/m(2) intravenous) daily 15 to 30 minutes before irradiation. Radiotherapy was given once daily (1.8 to 2.0 Gy) to doses of 50 to 70 Gy. Whole saliva production was quantitated preradiotherapy and regularly during follow-up. Patients evaluated their symptoms through a questionnaire during and after treatment. Local-regional control was the primary antitumor efficacy end point. RESULTS: Nausea, vomiting, hypotension, and allergic reactions were the most common side effects. Fifty-three percent of the patients receiving amifostine had at least one episode of nausea and/or vomiting, but it only occurred with 233 (5%) of 4,314 doses. Amifostine reduced grade > or =2 acute xerostomia from 78% to 51% (P<.0001) and chronic xerostomia grade > or = 2 from 57% to 34% (P=.002). Median saliva production was greater with amifostine (0.26 g v 0.10 g, P=.04). Amifostine did not reduce mucositis. With and without amifostine, 2-year local-regional control, disease-free survival, and overall survival were 58% versus 63%, 53% versus 57%, and 71% versus 66%, respectively. CONCLUSION: Amifostine reduced acute and chronic xerostomia. Antitumor treatment efficacy was preserved.

Phase II trial of oral altretamine for relapsed ovarian carcinoma: evaluation of defining response by serum CA125.

PURPOSE: A phase II study was performed of oral altretamine in 71 patients with ovarian carcinoma who entered clinical complete remission with CA125 levels less than 35 U/mL after initial or second-line chemotherapy, and relapsed more than 6 months later. Response was compared between standard and CA125-based criteria. PATIENTS AND METHODS: Altretamine 260 mg/m2 was given in divided doses daily for 14 days per month. Response was evaluated according to European Organization for Research and Treatment of Cancer (EORTC) criteria in 45 of 66 eligible patients. Response was assessed according to precise CA125 criteria in 51 patients based on either a confirmed > or = 50% or > or = 75% decrease in CA125 levels. RESULTS: A combination of domperidone, dexamethasona, and chlorpromazine at night controlled toxicity in most patients, which was mainly nausea (National Cancer Institute criteria grade 2 or 3 in 27), vomiting (grade 2 or 3 in 19, grade 4 in one), and tiredness (grade 2 or 3 in 15). Responses (complete plus partial) were seen in 18 (40%; 95% confidence interval [CI], 25.4% to 54.6%) of those evaluated according to EORTC criteria and in 20 (39%; 95% CI, 25.5% to 52.9%) of those evaluated according to CA125 level. The overall response rate was 26 of 57 (45.6%) and was related to treatment-free interval: 6 to 12 months, 35%; 12 to 24 months, 52%; and greater than 24 months, 67%. The medium duration of response was 8 months. CONCLUSION: Oral altretamine is a useful agent in patients-who relapse after previously responsive ovarian cancer. Response evaluation by a strict CA125 definition gave a similar estimate of the efficacy of altretamine as EORTC criteria.

Adjuvant therapy with recombinant interleukin-3 and granulocyte-macrophage colony-stimulating factor.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-3 (IL-3) are important members of the system of hematopoietic growth factors which control blood formation. Recombinant human (rh) GM-CSF stimulates proliferation and differentiation of myeloid cells and enhances effectively the regeneration of granulocytes and monocytes after chemotherapy or bone marrow transplantation. RhIL-3 acts on multipotent progenitor cells and induces an increase of leukocytes, platelets and reticulocytes after in vivo application. Combination of rhIL-3 and rhGM-CSF exerts a highly synergistic action on several hematopoietic cell lineages in monkeys and patients. Sequential application of rhIL-3 (5 days) followed by rhGM-CSF (10 days) has equivalent effects on myelopoiesis and thrombopoiesis compared with the effects of 15 days' monotherapy with rhGM-CSF on myelopoiesis and of a 15 days' treatment with IL-3 on platelet production. This combination seems to be very potent to reduce risk of neutropenia-associated infection and thrombocytopenic bleeding in patients with hematopoietic failure.

N-RAS gene activation in acute myeloid leukemia: association with expression of interleukin-6.

The 21 kDa proteins encoded by RAS genes are thought to be involved in intracellular signal transduction. Expression of RAS genes activated by point mutations after transfection into mammalian cells can modulate the response of these cells to exogenously added growth factors and their expression patterns of growth factors. We analyzed leukemic cells from 50 patients with acute myeloid leukemia (AML) for the presence of activating point mutations of the N-RAS gene using polymerase chain reaction (PCR) and differential oligonucleotide hybridization. This assay allows semiquantitative determination of the relative abundance of cells carrying N-RAS mutations. Clonal activation of N-RAS, noted in the large majority of leukemic cells of the six of these patients, was correlated significantly (p = 0.0003) with the ability of these cells to express interleukin 6 (IL-6), previously shown to be expressed at high levels in approximately 30% of primary AML cells. In 16 patients, the presence of N-RAS mutations was observed only in subpopulations of leukemic cells. The 'subclonal' involvement of some but not all leukemic cells was further demonstrated by PCR analysis of individual clones grown in soft agar culture. We investigated whether additional, complementary changes in oncogene structure occurred in cells exhibiting clonal activation of N-RAS. For instance, concomitant activation of N-RAS and amplification or rearrangement of c-MYC have been observed in various tumor tissues. Southern blot analysis did not, however, reveal gross alternations of MYC gene structure or copy number in these cells.

Remission of juvenile chronic myeloid leukemia following graft failure of an unrelated marrow transplant and autologous recovery of marrow function promoted by GM-CSF and IL-3.

The unusual course of a boy with juvenile chronic myeloid leukaemia is presented. After bone marrow transplantation (BMT) from an unrelated donor followed by graft failure and subsequent stimulation by rhu GM-CFC and II-3, this patient experienced complete recovery of autologous haematopoiesis. At 17 months post-BMT the patient was off any therapy with completely normal blood counts and no signs of disease.

A multicenter trial of interleukin-2 and low-dose cyclophosphamide in highly chemotherapy-resistant malignancies.

The anti-tumor activity of high-dose recombinant interleukin-2 (IL-2) has been demonstrated in several recent preclinical and clinical studies. In an attempt to study possible synergistic effects with low-dose cyclophosphamide (CYC), a phase II clinical trial was initiated in 32 patients, 18 with malignant melanoma (MM) and 14 with renal cell carcinoma (RCC). The recombinant IL-2 (Cetus Corp., Emeryville, Ca, U.S.A.) was given once daily at 3 x 10(6) U/m2, as a 30-min infusion for 14 days in cycle I and for five days twice in cycles II and III, respectively; if tolerated, the dose was escalated to a maximum of 6 x 10(6) U/m2/day; the cycles, separated by 1-week treatment-free intervals, were each preceded by a single i.v. bolus of CYC at 350 mg/m2. The most prominent side-effects encountered in this trial consisted of a capillary leak syndrome, myalgia and fever requiring dose reduction in half of the patients during the first cycle. Given the limit of tolerable toxicities in a standard care unit, the regimen employed achieved minor anti-tumor activity. No objective responses were achieved in patients with RCC and a 15% remission rate (PR + MR) was seen in melanoma patients.

Protection of normal tissue from the cytotoxic effects of chemotherapy and radiation by amifostine: clinical experiences.

The clinical trials described in this review indicate that amifostine protects normal tissues from the toxicities of various antitumour regimens. In a controlled trial, pretreatment with amifostine reduced the frequency of cyclophosphamide-induced neutropenia. Comparisons of the effects of cisplatin with and without pretreatment with amifostine indicated that patients pretreated with amifostine had fewer nephrotoxic and neurotoxic effects and tolerated higher doses of cisplatin before the onset of neurotoxic effects. In a randomised trial, patients who received amifostine prior to treatment with cyclophosphamide and cisplatin discontinued chemotherapy because of haemato, nephro- or ototoxicity less frequently than patients treated with cyclophosphamide and cisplatin alone. Tumour response rates and survival were comparable in both groups indicating that amifostine selectively protects only normal tissues. A regimen of amifostine plus cisplatin and vinblastine followed by amifostine plus radiation in patients with non-small cell lung cancer revealed a 73% response to treatment. Other studies showed that amifostine protected against late radiation toxicity to pelvic organs without interfering with the antitumour effect of radiotherapy, and decreased the haematological and mucosal toxicity of combined treatment with cisplatin and radiation therapy.

A phase I-II study of N-(phosphonacetyl)-L-aspartic acid (PALA) added to 5-fluorouracil and folinic acid in advanced colorectal cancer.

N-(phosphonacetyl)-L-aspartic acid (PALA) inhibits the enzyme L-aspartic acid transcarbamoylase (ATCase) which is important in de novo pyrimidine synthesis. Low dosages of PALA modulate the in vitro activity of 5-fluorouracil (5-FU) and PALA (250 mg/m2) inhibits pyrimidine synthesis in patients. PALA (250 mg/m2 day 1) was combined with an established 5-FU/folinic acid (FA) regimen [FA (200 mg/m2 over 2 h days 2 + 3) and bolus and 22 h infusional 5-FU (300-500 mg/m2 days 2 + 3)] without the need for dose reduction of 5-FU or FA. 35 patients were entered. Treatment was well tolerated; 4/27 patients experienced > or = ECOG grade 3 toxicity at full 5-FU dosage (500 mg/m2 bolus/infusion). However, the response rate in 33 evaluable patients was only 6.1% [95% confidence intervals (C.I.) 0.2-21.8%]. Median response duration was short (4 months, 95% C.I. 3-6 months) and overall median survival was 10 months (95% C.I. 7-16 months). Although PALA (250 mg/m2) can be combined with full dosage 5-FU/FA, the combination has poor activity in colorectal cancer.

Effect of amifostine on patient assessed clinical benefit in irradiated head and neck cancer.

PURPOSE: To determine if head and neck (H/N) cancer patients receiving daily amifostine during radiation therapy (RT) experienced clinical benefit (improvement in their ability to carry out normal functions with reduced discomfort) compared to nonamifostine treated patients. METHODS AND MATERIALS: This was an open-label, multi-institutional randomized trial in 303 H/N cancer patients treated with RT +amifostine. Clinical benefit was measured using an 8-item validated Patient Benefit Questionnaire (PBQ) during and up to 11 months after RT. RESULTS: 301 patients completed one or more PBQ assessments. Amifostine patients had significantly better PBQ scores (p < 0.05) than controls. The improvement in PBQ scores was most significant during chronic xerostomia. CONCLUSIONS: Amifostine use results in improved Patient Benefit Questionnaire (PBQ) scores, which is indicative of improved oral toxicity related outcomes and improved clinical benefit. Less oral toxicity should lead to preservation of late dental and oral health, and improvements in activities such as diet, nutrition, and sleep.

Incidence of lineage promiscuity in acute myeloblastic leukemia: diagnostic implications of immunoglobulin and T-cell receptor gene rearrangement analysis and immunological phenotyping.

Sixty-nine blood or bone marrow samples from both children and adults with acute myeloblastic leukemia (AML) were investigated to elucidate the frequency of immunoglobulin (IG) and T-cell receptor (TCR)-gene rearrangements. Non-germline configuration for the IG heavy chain (h) gene was detected in the specimens of nine patients of various subtypes according to the French-American-British classification (FAB), including FAB M1, M2, M4 and M5. Rearrangement of the IG kappa chain (k) gene was present in one of these cases which simultaneously revealed a rearranged TCR-beta (b) chain gene. In another two AML samples we found TCR-b gene rearrangements, in one case in combination with an IG-h gene rearrangement. IG-h gene rearrangements were detected in 10 cases, in one case in conjunction with an IG-kappa (k) and TCR-b gene rearrangement. A highly significant correlation between the occurrence of DNA rearrangements of the IG-h locus and nuclear staining with the enzyme terminal deoxynucleotidyl transferase (TdT) and surface expression of the CD 19 and CD 34 antigen could be identified: all 10 TdT positive AML samples rearranged IG-h. Similarly, six out of 69 AML samples exhibited surface expression of CD 19, five of these in combination with CD 34 and all of them rearranged the IG-h gene. The one leukemia with TCR-b gene rearrangement only was TdT positive as well, but did not express CD 19 or CD 34. We conclude that IG-h gene is rearranged in a substantial proportion of AML, strongly associated with a specific immunophenotype (TdT+, CD19+, CD34+), whereas TCR-b gene rearrangement appears more rarely. No positive correlation between occurrence of IG-h and TCR-b gene-rearrangements and one AML FAB-subtype was found, although a clustering of M1 and M4 FAB subtypes in the AML group showing reconstructed IG-h gene became evident.

Effect of rhGM-CSF on haematopoietic reconstitution after chemotherapy in small-cell lung cancer.

In three consecutive pilot studies the effect of recombinant human granulocyte/macrophage-colony-stimulating factor (rhGM-CSF) on haematopoetic recovery after chemotherapy in patients with small-cell lung cancer was investigated. In study I, 20 patients received AIO chemotherapy (A, Adriamycin 25 mg/m2 on days 1 + 2; I, ifosfamide 2 g/m2 on days 1-5; O, vincristine 2 mg on day 1) at 4-week intervals either with or without rhGM-CSF (250 micrograms/m2 sc) from day 8 until recovery of leucocytes. Neither the degree nor the duration of myelosuppression was markedly influenced by rhGM-CSF. Suggesting that these disappointing results were caused by the late onset of GM-CSF application, in the following study we shortened chemotherapy to 3 days and started with GM-CSF on day 4. The main objective of this study was to test whether the earlier administration of GM-CSF allowed treatment intervals to be reduced or the dose to be escalated. After 10 patients had received a starting dose of AIO (A, 50 mg/m2 on day 1; I, 2 g/m2 on days 1-3; 0,2 mg on day 1) alternating with cisplatin (90 mg/m2 on day 1) and etoposide (150 mg/m2 on days 1-3), the dose of ifosfamide and etoposide was escalated to 2.5 g/m2 on days 1-3 and 200 mg/m2 on days 1-3 in the next 10 patients. Treatment was given at 2-week intervals when leucocytes were greater than 3500/mm3 and thrombocytes were greater than 100,000 mm3 on day 14. At each dose level patients were randomized to receive either rhGM-CSF 250 micrograms/m2 s.c. on days 4-12 or no GM-CSF. In this study, rhGM-CSF markedly shortened the duration of leukopenia. Reinstitution of chemotherapy on day 15 was possible at dose level 1 in 1/4 patients without and in 3/4 patients with GM-CSF, and at dose level 2 in 0/5 patients without and in 5/5 patients with GM-CSF. However, the degree of myelosuppression was not improved by GM-CSF. In a third study we tried to apply rhGM-CSF simultaneously with chemotherapy. After 3 patients had received GM-CSF starting on day 1 concurrent to AIO chemotherapy, we noticed an increase of myelosuppression with prolonged neutropenia and thrombocytopenia and stopped this investigation. Considering all patients included in these three consecutive pilot studies, there is no difference in response rates and survival between patients with and without rhGM-CSF treatment.(ABSTRACT TRUNCATED AT 400 WORDS)

Chemoprotective and radioprotective effects of amifostine: an update of clinical trials.

Amifostine (Ethyol), the first broad-spectrum cytoprotectant approved in many countries for clinical use, is an analog of cysteamine and was originally developed by the U.S. Walter Reed Army Institute of Research in the 1950s as a radioprotective agent. Studies have shown that amifostine selectively protects normal tissues of various organs from the effects of radiation and multiple cytotoxic chemotherapeutic drugs. Amifostine has demonstrated broad-spectrum cytoprotection against myelotoxicity, nephrotoxicity, xerostomia, and mucositis associated with various chemotherapy and radiation modalities. Amifostine has been evaluated in large comparative clinical trials in patients with advanced ovarian cancer, rectal cancer, and head and neck cancer, and in many phase 2 trials in patients with various neoplastic diseases. These trials have shown that amifostine delivers protection from the cytotoxic effects of cisplatin, cyclophosphamide, and radiation on various organs. Pretreatment with amifostine has also improved salivary gland tolerance of high-dose radioiodine treatment. Recent unique observations include improvement in cytopenia in patients with myelodysplastic syndrome. This review summarizes preclinical and clinical data on amifostine and includes trials that evaluated the drug's chemoprotective and radioprotective effects and other potential uses in clinical oncology.

Development and validation of a chiral high-performance liquid chromatography assay for rogletimide and rogletimide-N-oxide isomers in plasma.

The purpose of the present study was to develop and validate a stereo-specific high-performance liquid chromatography (HPLC) assay for rogletimide (Rog) and rogletimide-N-oxide (Nox) isomers in plasma. The assay was performed with a chiral cellulose-[4-methylbenzoate]ester column (Chiracel OJ). Optimal separation was achieved isocratically with a mobile phase consisting of n-hexane/anhydrous ethanol (65/35, v/v) at a flow rate of 0.9 ml/min, with the column being thermostated at +35 degrees C (UV detection at 257 nm). Under these conditions, retention times were approximately 17, 28, 31 and 76 min for R-Rog, S-Rog, R-Nox and S-Nox, respectively. S-aminoglutethimide (S-Ag) served as the internal standard (retention time 70 min). An extraction procedure from plasma samples was developed on Bond Elut RP8 500-mg cartridges; conditioning was performed with 5 ml methanol and 5 ml water, after which 1 ml plasma that had previously been spiked with 5 microM S-Ag was applied. Washing was done with 6 ml water and elution, with 4 ml methanol. After evaporation to dryness, residues were dissolved in 400 microliters anhydrous ethanol and 12-48 microliters was injected onto the HPLC system. Blank plasma from healthy donors showed the random presence of a small interference eluting at the retention time of R-Rog, precluding the accurate quantification of R-Rog concentrations below 2.5 microM. Reproducibility assays demonstrated the need to use an internal standard. Taking into account the internal standard, at 2.5 microM the intra- and inter-assay coefficients of variation were 10.5% and 21.0% for R-Rog 5.5% and 8.7% for S-Rog, 7.6% and 20.8% for R-Nox and 11.7% and 6.4% for S-Nox, respectively. The detection limit was 2.5 microM for R-Rog, 0.5 microM for S-Rog, 0.25 microM for R-Nox and 0.5 microM for S-Nox. Linearity was satisfactory at concentrations ranging from 2.5 to 10 microM for R-Rog, from 0.5 to 10 microM for S-Rog, from 0.25 to 2.5 microM for R-Nox and from 0.50 to 2.5 microM for S-Nox. This assay was applied to plasma obtained from rog-letimide-treated breast cancer patients receiving conventional oral doses and demonstrated its feasibility with regard to sensitivity. The preliminary pharmacokinetic results reported herein suggest for the first time that both the R-Rog and S-Rog isomers are metabolized into rogletimide-N-oxide.

Cytokines in the pathogenesis and management of non-Hodgkin's lymphomas.

Recombinant DNA technology has made possible the analysis of cytokine gene expression in both in vitro and in vivo studies of human hematopoietic malignancies and has facilitated the production of large amounts of recombinant cytokines. This development has led to advances in our understanding of the role of aberrant cytokine production in these diseases. These results support the concept of autocrine stimulation of leukemic growth, for instance, in multiple myeloma and acute myelogenous leukemia, and may lead to new therapeutic concepts such as the application of antibodies directed against these cytokines. Availability of recombinant cytokines has also allowed clinical testing in settings of disease- or therapy-related neutropenias and anemias, and particularly GM-CSF, G-CSF, and EPO have proven efficient in this respect. Thus, there is the prospect of more dose-intensive chemotherapy protocols as well as combinations of different cytokines that may prove more effective than application of a single compound.