Induction of specific-locus and dominant lethal mutations in male mice by 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) and 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU)

1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) and 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU) induced dominant lethal and specific-locus mutations in male mice. For both compounds the germ cell stage sensitive to the induction of dominant lethal mutations was dose dependent. A dose of 5 mg BCNU per kg b.wt. induced dominant lethal mutations primarily in spermatocytes, whereas higher doses of BCNU induced dominant lethals in spermatids and spermatocytes. Following doses of 5 and 10 mg CCNU per kg b.wt. dominant lethals were induced in spermatids and spermatocytes similar to the results for higher doses of BCNU. Higher dose exposure to BCNU and CCNU was associated with dominant lethals expressed as pre-implantation loss (reduction in total number of implants). In addition, higher doses of CCNU showed a cytotoxic effect in differentiating spermatogonia. Both compounds induced specific-locus mutations in post-spermatogonial germ cell stages of mice. However, CCNU increased also the specific-locus mutation frequency in spermatogonia in two out of three experiments. We conclude in analogy with criteria developed by IARC, that BCNU and CCNU are potential human mutagens.     

Possibility of the use of perfluorochemicals (fluorocarbons) as adjuvants in chemotherapy of cancer

In Fischer 344 rats weighing about 100 gr., 7 X 10(5) 9L tumor cells were implanted into right cerebral hemisphere. BCNU. Fluosol-43 (perfluorochemicals blood substitute), or combined therapy BCNU and Fluosol-43 were initiated on Day 7 postimplantation and its therapeutic effect was studied. Mean survival time of control animals was 15.23 +/- 2.84 (SD) days, the group of Fluosol-43 treated in oxygen chamber (95% Oxygen & 5% Carbon Dioxide) was 15.30 +/- 2.11 (SD) days. BCNU treatment alone prolonged the mean survival time to 20.90 +/- 3.80 (SD) days, BCNU plus Fluosol-43 in normal aeration was 21.20 +/- 2.63 (SD) days. On the other hand, BCNU plus Fluosol-43 in oxygen chamber showed a significant increase of mean survival time of 32.27 +/- 4.80 (SD) days (p less than 0.005). From these results, it was concluded that Fluosol-43 (perfluorochemicals) with oxygen might have a synergistic effect for BCNU chemotherapy.     

Regulation of ribosomal RNA synthesis and processing during inhibition of protein synthesis by 1,3-bis(2-chloroethyl)-1-nitrosourea

The antineoplastic agent BCNU (1,3-bis(2-chloroethyl)-1nitrosourea) at a concentration of 25 mug/ml inhibits initiation of protein synthesis in HeLa cells. At this low concentration of the drug, the rate of synthesis of 45S ribosomal precursor RNA (pre-rRNA) is selectively inhibited without a marked inhibition of nucleoplasmic RNA. The inhibitory effects of the drug are readily reversible upon removal of BCNU from the growth medium. Pulse-chase analysis of the labeled nucleolar RNA in sucrose-gradients and acrylamide gels indicated that the 45S pre-rRNA synthesized before the addition of BCNU matures normally in the presence of the inhibitor. However, the processing of precursor RNA molecules synthesized following the addition of the drug is inhibited when incubation is continued on in the presence of 25 mug/ml BCNU. Since the formation of mature ribosomes is blocked by BCNU, the data would suggest that the effectiveness of the drug as a potent cell growth inhibitor may result from its inhibition of ribosome formation induced by inhibition of protein synthesis.     

Retroviral transfer of a bacterial alkyltransferase gene (ada) into human bone marrow cells protects against O6-benzylguanine plus 1, 3-bis(2-chloroethyl)-1-nitrosourea cytotoxicity

The antitumor activity of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) is limited by the O6-alkylguanine-DNA alkyltransferase (ATase) in tumor cells and by delayed myelosuppression. Inactivation of neoplastic ATase by O6-benzylguanine (BG) improves the therapeutic index for BCNU. We have demonstrated previously that BG + BCNU-induced myelosuppression in mice is reduced by expression of the BG-resistant ATase ada in murine bone marrow. We have now generated an amphotropic retrovirus containing the ada gene and tested the effectiveness of ada expression in preventing BG + BCNU cytotoxicity in human hematopoietic progenitor cells. A retroviral producer clone with a biological titer of 6.5 x 10(4) colony-forming units/ml and 4.4 pmol ATase/mg protein was used for transduction of bone marrow. Cocultivation of these ada producer cells with progenitor cells from six normal individuals resulted in 1.9-3. 9-fold protection against BG + BCNU-induced cytotoxicity in committed progenitor cell assays. Furthermore, this cytoprotective effect was associated with a high transduction efficiency (40%) and a 2-fold increase of ATase activity in the surviving committed progenitor cell colonies. These data provide a basis for testing the clinical effectiveness of retroviral ada gene transfer into hematopoietic cells to increase the therapeutic index of BG + BCNU.     

Differential effects of N-methyl-D-aspartate receptor blockade on nociceptive somatic and visceral reflexes

OBJECTIVE: A Phase I study was conducted to determine the safety, toxicity, and maximum tolerated dose of preirradiation chemotherapy using carmustine (BCNU) and cisplatin in the treatment of high-grade gliomas. METHODS: Patients with newly diagnosed high-grade gliomas received BCNU and cisplatin after surgery, both before and during definitive radiation therapy. Preirradiation chemotherapy consisted of an administration of 40 mg/m2 BCNU on Days 1 through 3 and 30 mg/m2 cisplatin on Days 1 through 3 and 29 through 31 and repeated at 8 weeks to coincide with the start of radiation therapy. Postradiation chemotherapy consisted of an administration of 200 mg/m2 BCNU once every 8 weeks for four cycles. Radiation therapy consisted of 160-cGy fractions administered twice daily for 15 days, yielding a total dose of 4800 cGy. Dose escalation of BCNU was planned. If hematological toxicity was mild, the dose of cisplatin was to be held constant and BCNU dose escalated to 50 mg/m2 on Days 1 through 3. RESULTS: Eighteen patients were studied. The hematological toxicity was dose-limiting. Grade 3 or 4 leukopenia occurred in each of 10 patients (56%), and Grade 3 or 4 thrombocytopenia occurred in each of 9 patients (50%). Other toxicities included anorexia (94%), nausea (83%), emesis (33%), alopecia (94%), mild ototoxicity (50%), and, in one patient, death as a result of BCNU pulmonary toxicity. The median survival time was 14 months. Objective responses occurred in 45% of the patients evaluable for response. The maximum tolerated dose of this combination was 50 mg/m2 BCNU on Days 1 through 3 and 30 mg/m2 cisplatin on Days 1 through 3 and 29 through 31 before radiation and repeated in 8 weeks to coincide with the start of radiation. CONCLUSION: This schedule of the preirradiation administration of BCNU and cisplatin with accelerated hyper-fractionated radiation therapy for the treatment of high-grade gliomas provides a less toxic alternative to that of previous studies of preirradiation chemotherapy with these agents and merits further investigation.     

Salmonella typhimurium encodes an SdiA homolog, a putative quorum sensor of the LuxR family, that regulates genes on the virulence plasmid

OBJECTIVE: Despite improved systemic control of metastatic breast cancer, the incidence of brain metastases from breast carcinoma continues to rise, in part because most systemically administered agents have poor central nervous system penetration. Therefore, as a method of optimizing drug delivery into the central nervous system, we studied the safety and efficacy of chemotherapy delivered locally via biodegradable polymers in a mouse model of breast carcinoma metastases to the brain. METHODS: The chemotherapeutic agents carmustine (BCNU), carboplatin, and camptothecin were incorporated into controlled release polymers and tested individually against intracranial challenges of EMT-6 breast tumor in BALB/c female mice. For each drug, four groups were tested: Group 1, empty polymer (no drug); Group 2, external beam radiotherapy (XRT) alone; Group 3, local chemotherapy from biodegradable polymer alone; and Group 4, local chemotherapy and XRT together. Polymers were implanted 5 days after intracranial tumor inoculation; XRT was administered on Days 7 through 9 (300 cGy/d). RESULTS: BCNU polymer alone (n = 10; median survival time, >200 d; P < 0.0001) and BCNU and XRT together (n = 10; median survival time, 41 d; P = 0.02) significantly improved survival in mice with intracranial EMT-6 breast cancer in comparison with control animals (n = 20; median survival time, 17 d). Carboplatin and camptothecin, either with or without XRT, and XRT alone did not have any significant effect on survival. CONCLUSION: Local delivery of BCNU with biodegradable polymers can significantly prolong survival in a murine model of intracranial metastatic breast cancer. Surgical resection and placement of BCNU polymers into the resection cavity may decrease the incidence of local recurrence of breast cancer metastases with minimal morbidity.     

Experimental chemotherapy with N'N'-bis(2-chloroethyl)-N-nitrosourea (BCNU) in autochthonous neurogenic tumors of the rat transplacentally induced by ethylnitrosourea

Autochthonous neurogenic tumors of the rat induced by transplacental application of ethylnitrosourea were used for the first time to study their suitability as tumor models for experimental chemotherapy. Of 189 transplacentally treated rats, 87% developed neurogenic tumors. After the initial clinical diagnosis of a neurogenic tumor, additional malignant tumors often occurred. The mean number of neurogenic tumors from 62 untreated control rats increased from 1.0 per rat at the time of randomization to 1.2 as revealed by autopsy and 1.5 tumors by histological examinations. Out of all neurogenic tumors, tumors of the brain were observed in 31%, tumors of cranial nerves in 36% (90% tumors of trigeminal nerve), tumors of spinal cord in 21%, and tumors of peripheral nerves in 10%. The median survival time until natural death of 62 control rats was 228 days. Rats with tumors of peripheral nerves lived shortest, followed by rats with tumors of cranial nerves, tumors of the spinal cord, and brain tumors. Brain tumors were mainly astrocytomas and oligodendrogliomas. The survival time of untreated rats from randomization to natural death was longest for those with brain tumors, followed by tumors of peripheral nerves, cranial nerves, and tumors of the spinal cord. There was great variation in survival time from a few days to more than 6 months. To study the responsiveness to chemotherapy, 62 rats received BCNU as a single intravenous dose of 9 and later 10 mg/kg. Sixty-two untreated control rats had a median survival time of 36 days (95% confidence interval 26-52 days), the treated rats 43.5 days (26-62 days). The difference was not statistically significant. BCNU produced a remission or a no change of neurologic symptoms in 60% (37 out of 62) in comparison to 39% (24 out of 62) in the control group (p less than 0.05). The advantages and disadvantages of the present models are discussed. Due to methodical problems and the marginal response to BCNU, autochthonous neurogenic tumors of the rat are not suitable as models for chemotherapeutic studies.     

Molecular basis for thymidine modulation of the efficacy and toxicity of alkylating agents

The antitumor activity of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) in mice previously was shown to be markedly enhanced by co-administration of thymidine. We have examined the cellular mechanisms underlying the augmentation effect of thymidine. It was found that thymidine did not increase the cytotoxicity of BCNU for B16/F10 melanoma or L1210 leukemia cells in vitro. Instead, thymidine appeared to augment the activity of tumor-specific cytotoxic T-cells in tumor-bearing mice, which specifically rejected a secondary challenge with the B16/F10 tumor. Thus, development of an antitumor immune response is facilitated by thymidine in BCNU-induced immunosuppressed mice. These preclinical studies suggested that combination therapy with alkylating agents and thymidine may be a more efficacious and less toxic anticancer therapy. The potential efficacy of the sequential administration of dacarbazine (DTIC), BCNU, and thymidine in patients with advanced malignant melanoma was investigated. As predicted from animal studies, sequential administration of DTIC, BCNU, and thymidine is a relatively nontoxic therapy for metastatic melanoma. This treatment induced durable responses in up to 35% of patients, and hence is superior to many commonly used toxic combination chemotherapies. The mechanism of action, although not well characterized, is thought to be mediated through protection of the cellular immune process, as well as organ function, from alkylating agent toxicity through modulation of DNA repair enzymes such as O(6)-alkylguanine-DNA alkyltransferase in normal tissue. Thus, thymidine is a biomodulator, which not only protects patients from hematologic, pulmonary, and hepatic toxicities associated with DTIC and BCNU chemotherapy, but also potentiates therapeutic efficacy.     

Excretion of a radiolabelled anticancer biodegradable polymeric implant from the rabbit brain

The elimination of a clinically used anticancer biodegradable polymer implant (Gliadel) in the rabbit brain was studied. The implant is composed of N,N-bis(2-chloroethyl)-N-nitrosourea (BCNU) (1.6 wt%) dispersed in a copolyanhydride matrix of 1,3-bis(p-carboxyphenoxypropane) (CPP) and sebacic acid (SA) in a 20:80 molar ratio. Four groups of rabbits were implanted with wafers loaded with BCNU, one in a 14C-SA-labelled polymer, another in a 14C-CPP-labelled polymer and two groups with 14C-BCNU in a non-labelled polymer, one for BCNU disposition study and one for residual drug study. In the rabbits implanted with the 14C-SA-labelled polymer, approximately 10% of the radioactivity was found in the urine and 2% in the faeces, and about 10% remained in the device 7 d after implantation. In contrast, only 4% of the radioactivity of the 14C-CPP-labelled polymer was found in urine and faeces during this period. However, a drastic increase in the CPP excretion was found after 9 d, and at 21 d, 64% of the implanted 14C-CPP was found in the urine and faeces, and 29% was still in the recovered wafers. Approximately 50% of the BCNU in the wafers was released in 3 d, and over 95% was released after 6 d in the rabbit brain. This study demonstrates that BCNU-loaded polyanhydride is biodegradable and is excreted from the body primarily through the renal system. The water-soluble components SA and BCNU were rapidly excreted, while the insoluble CPP was gradually eliminated after a lag time of 9 d.     

Modulation of the antitumor activity of 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosoure a by O(6)-methyl-2'-deoxyguanosine--a new inhibitor of O(6)-alkylguanine-DNA-alkyltransferase

O6-Methyl-2'-deoxyguanosine (O6-MedG), a novel inhibitor of O6-alkylguanine-DNA alkyltransferase (O6-AGT), has been synthesized. The ability of O6-MedG to deplete the O6-AGT activity in leukemia L1210 and melanoma B16 cells in vivo has been studied. After intraperitoneal administration of O6-MedG to mice bearing leukemia L1210 or melanoma B16, the activity of O6-AGT in tumour cells decreased by 50%. Pretreatment of leukemia L1210 bearing mice with O6-MedG (200 mg/kg) 24 hours prior to ACNU (15 mg/kg) administration resulted in six out of seven 60-day survivors. Treatment of mice with ACNU (15 mg/kg) alone increased the life span by 200%. Treatment of melanoma B16 bearing mice with O6-MedG and 3 hours thereafter with ACNU resulted in a 50% inhibition of tumour growth, whereas the inhibiting effect of ACNU alone was 16%. There was no difference in leukemia growth when L1210/BCNU bearing mice were treated with O6-MedG followed by ACNU treatment. In vivo ACNU (15 mg/kg) produced a deep and prolonged inhibition of DNA, RNA and protein synthesis in leukemia L1210 cells. The DNA synthesis in leukemia L1210/BCNU cells was shown to recover more rapidly than in L1210 cells. The activities of DNA-polymerases alpha and beta and, especially, of O6-AGT were elevated in ACNU-resistant leukemia cells as compared with ACNU-sensitive cells. The activation of some repairing enzymes, such as O6-AGT, DNA-polymerases alpha and beta as well as increased levels of GSH may play a role in the development of drug resistance to ACNU.     

An experimental model for meningeal leukemia in rats (L5222). Effect of treatment with BCNU and cyclophosphamide

An experimental model of meningeal leukemia in rats is developed by intracerebral (IC) inoculation of leukemic cells from the transplantable acute leukemia L5222. The L5222 proliferates exponentially in the central nervous system (CNS) and the disease becomes systemic 2 days following IC inoculation. Chemotherapeutic studies with BCNU and cyclophosphamide yielded cures in a high percentage of cases when treatment began at an early stage of meningeal leukemia. When treatment was started at the advanced stage, only BCNU showed a large number of cures. However, cyclophosphamide resulted in a marked increase of life-span. The activity of cyclophosphamide against meningeal leukemia, which is in contrast to the results obtained by Skipper et. al. (1961) in the L1210 mouse leukemia, suggests that cyclophosphamide crosses in part the blood--brain barrier in a rat bearing meningeal leukemia. After subcutaneous inoculation, BCNU and cyclophosphamide showed the same rate of cures.     

Absorption of an oxytocin antagonist (antocin) and a vasopressin analogue (dDAVP) through a standardized skin erosion in volunteers

PURPOSE: Transdermal administration of the peptides [Mpa1, D-Tyr (Ethyl)2, Thr4, Orn8]-oxytocin (antocin) and [Mpa1, D-Arg8]-vasopressin (dDAVP) was studied in healthy volunteers. METHODS: A standardized skin erosion was formed preliminary by suctioning. The peptides were administered in plastic reservoirs through a 5 mm erosion and the absorption was followed for a six-day period with plasma concentration determinations on days 1, 3 and 6 with refilling the reservoirs daily with 15 microns and 10 mM solutions of dDAVP and antocin, respectively. Fourteen healthy non-smoking volunteers divided equally between the sexes, participated in the study. Plasma concentrations were measured using specific radioimmunoassays. Reservoir concentrations and metabolic stability of the peptides were determined using reverse-phase HPLC. RESULTS: Both antocin and dDAVP were absorbed across the skin erosion. The absorption pattern was biphasic with a high initial absorption during days 1 and 2 followed by a lower absorption on days 3 and 6. The absorption on day 1, which was estimated at more than 50% for both peptides during a 24 h period, corresponded to a simultaneous decrease in peptide concentration in the reservoirs. The extent of absorption for antocin on days 3 and 6 was 1/3 to 1/6, respectively, of that observed on day 1. Antocin was minimally degraded in the skin reservoir while dDAVP was intact. However, accumulation of cellular material appeared in the antocin reservoirs. The absorption of antocin was reduced by exposure to intact skin surrounding the skin erosion. No pain was experienced and no scar formation was observed. CONCLUSIONS: The observed biphasic absorption may be a consequence of the mild inflammatory response occurring subsequent to eroding the skin. The standardized skin erosion may provide a route for the short-term delivery of otherwise poorly absorbable peptide and protein drugs.     

2-Chloroethyl-3-sarcosinamide-1-nitrosourea, a novel chloroethylnitrosourea analogue with enhanced antitumor activity against human glioma xenografts

Nitrosoureas are among the most widely used agents used in the treatment of malignant gliomas. Here, the activity of 2-chloroethyl-3-sarcosinamide-1-nitrosourea (SarCNU) was compared with that of 1,3-bis-(2-chloroethyl)-1-nitrosourea (BCNU), in vivo against s.c. implanted SF-295 and U-251 central nervous system (CNS) tumor xenografts. When given i.v., q4d for 3 doses, to athymic mice bearing s.c. SF-295 tumors, SarCNU, at an optimum of 167 mg/kg/dose, produced 9 tumor-free animals of 10 total animals, 1 regression, and no evidence of overt toxicity (> or =20% body weight loss). With a similar dosing schedule, BCNU produced no tumor-free animals, six regressions, and one drug-related death at its optimum of 30 mg/kg/dose. Furthermore, SarCNU retained high antitumor activity at two lower dose levels, 66 and 45% of the optimal dose, whereas BCNU demonstrated a progressive loss of antitumor activity at lower doses. Following p.o. administration, SarCNU similarly demonstrated antitumor activity that was superior to that of BCNU. In the U-251 CNS tumor model, SarCNU yielded six of six tumor-free animals at 80 mg/kg/dose with i.p. administration q.d. for 5 days, starting on day 14, whereas BCNU, at 9 mg/kg/dose, yielded three of six tumor-free mice and one drug-related death. Again, SarCNU resulted in tumor-free animals at 66 and 45% of its optimal dose and was relatively nontoxic, in contrast to BCNU. Results of testing to date indicate that SarCNU is clearly more effective than BCNU against the human CNS tumors SF-295 and U-251 in vivo. These results encourage the initiation of clinical trials for SarCNU, in an effort to improve therapeutic approaches to glioma, but clinical trials must determine whether superiority of SarCNU in preclinical models can be extrapolated to patients.     

Retroviral-mediated gene transduction of human alkyltransferase complementary DNA confers nitrosourea resistance to human hematopoietic progenitors

Myelosuppression is the dose-limiting toxicity for nitrosourea chemotherapy due to low levels of the DNA repair protein O6-alkylguanine-DNA alkyltransferase in myeloid precursors. We have shown that high-efficiency myeloproliferative sarcoma virus (vM5MGMT)-mediated transduction of the human MGMT cDNA into murine bone marrow (BM) cells leads to high MGMT expression and increased progenitor resistance to 1,3-bis-(2-chloroethyl) nitrosourea (BCNU) in vitro immediately after infection and after BM transplantation. These experiments were designed to increase MGMT expression in human hematopoietic progenitors. CD34(+) BM cells were isolated over an immunoaffinity column (CEPRATE, CellPro, Inc.), resulting in a mean 66-fold enrichment in clonogenic progenitors (colony-forming unit granulocyte-macrophage + burst-forming unit erythroid + colony-forming unit granulocyte erythroid macrophage = megakaryocyte), with an average progenitor yield of 58 +/- 11.5% and a final population that was 54% CD34(+). Seventy % of progenitors derived from CD34(+) cells were transduced after coculture with AM12-vM5MGMT retroviral producers. vM5MGMT-transduced progenitors were over 2-fold more resistant to concentrations of BCNU between 30 and 50 micrometer than were concurrently LacZ-transduced progenitors (P < 0.003). In vitro selection of transduced, cytokine-stimulated CD34(+) cells with 20 micrometer BCNU resulted in survival of 4.7% of MGMT+ clonogenic progenitors compared to 0.05% of LacZ+ progenitors. These studies indicate that MGMT-transduced human hematopoietic progenitors have increased resistance to nitrosoureas, and in a clinical transplant setting, this strategy may reduce alkylating agent myelosuppression.     

Treatment of human brain tumor xenografts with O6-benzyl-2'-deoxyguanosine and BCNU

O6-Methylguanine-DNA methyltransferase (MGMT), a constitutively expressed DNA repair protein, removes alkyl groups from the O6-position of guanine in DNA. Tumor cells with high MGMT activity are resistant to nitrosoureas and other agents that form toxic O6-alkyl adducts. O6-Benzylguanine (BG) inactivates the MGMT protein and thereby enhances the sensitivity of tumor cells to alkylating drugs. However, the therapeutic potential of BG is limited by its poor solubility and its nonspecific inactivation of MGMT in normal tissues as well as in tumor tissues. Consequently, BG analogues are being developed to identify agents that have more favorable pharmacological characteristics. We evaluated O6-benzyl-2'-deoxyguanosine (dBG), the 2'-deoxyribonucleoside analogue of BG, for its ability to inhibit MGMT and to potentiate 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) in a MGMT-positive human brain tumor xenograft, Daoy. When given i.p. 1 h before BCNU (25 mg/m2) to animals bearing s.c. tumors, dBG (134 mg/m2) produced a growth delay of 24.7 days, compared to 21.6 days after treatment with an equimolar dose of BG (90 mg/m2) plus BCNU and -0.6 days after treatment with BCNU alone. The combination of dBG + BCNU also increased the survival of animals bearing intracranial tumors by 65%. By increasing the dose of dBG to 300 mg/m2 (the maximum dose that could be delivered i.p. in a standard treatment volume), the growth delay of s.c. tumors increased from -0.1 days with BCNU alone to 39.3 days. dBG suppressed both tumor and liver MGMT activity to less than 1.5% of baseline, and dBG + BCNU induced extensive perivascular apoptosis. Because dBG is a 10-fold less potent MGMT inhibitor than BG in HT-29 cell extracts, these results illustrate the capacity of BG analogues to potentiate BCNU toxicity, despite less in vitro activity than the parent compound, and emphasize the importance of in vivo evaluation of BG analogues.     

Polyethylene wear of the Optifix cementless acetabular component after 5 years

We describe seven patients who developed symptoms including severe headache, circumoral paresthesia, and facial flushing during high-dose carmustine (BCNU) infusion as part of the preparative regimen for autologous peripheral blood stem cell (PBSC) transplantation for metastatic breast cancer. Five patients responded to pain medications, including partial and complete opiate receptor agonists. Premedication of subsequent doses of BCNU with corticosteroids, pain medications, or benzodiazepines lessened, but did not prevent the same symptoms from recurring. The incidence and mechanism of this toxicity are unknown, but this adverse syndrome should be considered when administering high-dose BCNU infusions.     

Nitrosoureas in multiple myeloma

A number of cooperative-group and single-institution studies have shown that BCNU used in combination with prednisone alone or with melphalan,cyclophosphamide, and prednisone is useful for remission induction in patients with previously untreated multiple myeloma. In this setting, results with BCNU (and probably CCNU) are as good as (but not superior to)the results obtained to the frequency of remission induction, duration of remission, and survival. BCNU plus prednisone also appears to be equal to melphalan plus prednisone for remission-maintenance therapy, although it is still unclear whether maintenance therapy is superior to discontinuation of therapy during remission. At the present time, the major use of the nitrosoureas in multiple myeloma appears to be for patients who enter remission with conventional alkylating-agent therapy and later relapse. BCNU and CCNU are occasionally effective when used as single agents or in combination with other alkylating agents for relapsing patients. Results of a pilot study at the University of Arizona with low doses of BCNU and adriamycin for patients relapsing on alkylating-agent therapy have been encouraging, with a 54% (seven of 13 patients) incidence of CRs and PRs. The use of this combination in conjunction with vincristine and prednisone for relapsing patients is under investigation by the Southwest Oncology Group.     

Recombinant human granulocyte and granulocyte-macrophage colony-stimulating factor (G-CSF and GM-CSF) administered following cytotoxic chemotherapy have a similar ability to mobilize peripheral blood stem cells

The availability of hematopoietic growth factors has greatly facilitated the mobilization and collection of peripheral blood stem cells (PBSC). It was the aim of this double-blind study to compare the PBSC-mobilizing efficacy of recombinant human G-CSF and GM-CSF when administered post-chemotherapy. Twenty-six patients with relapsed Hodgkin's disease were included in the study. Their median age was 31 years (range, 22-59) and 14 patients were males and 12 were females. Patients were pretreated with a median of eight cycles of cytotoxic chemotherapy, while 18 patients had undergone extended field irradiation. The patients received dexamethasone 24 mg days 1-7, melphalan 30 mg/m2 day 3, BCNU 60 mg/m2 day 3, etoposide 75 mg/m2 days 4-7, Ara-C 100 mg/m2 twice daily days 4-7 (Dexa-BEAM). Twelve patients were randomized to receive 5/microg/kg/day G-CSF and 14 patients to receive 5 microg/kg/day GM-CSF, both administered subcutaneously starting on day 1 after the end of Dexa-BEAM. Primary endpoints of the study were the number of CD34+ cells harvested per kg body weight on the occasion of six consecutive leukaphereses and the time needed for hematological reconstitution following autografting. Twenty-one patients completed PBSC collection, and six patients of the G-CSF group and nine of the GM-CSF group were autografted. No difference was observed with respect to the median yield of CFU-GM and CD34+ cells: 32.5 x 10(4)/kg vs 31.3 x 10(4)/kg CFU-GM, and 7.6 x 10(6)/kg vs 5.6 x 10(6)/kg CD34+ cells, for G-CSF and GM-CSF, respectively (U test, P= 0.837 and 0.696). High-dose chemotherapy consisted of cyclophosphamide 1.7 g/m2 days 1-4, BCNU 150 mg/m2 days 1-4, etoposide 400 mg/m2 days 1-4. All patients transplanted with more than 5 x 10(6) CD34+ cells/kg had a rapid platelet recovery (20 x 10(9)/l) between 6 and 11 days and neutrophil recovery (0.5 x 10(9)/1) between 9 and 16 days, while patients transplanted with less than 5 x 10(6)/kg had a delayed reconstitution, regardless of the kind of growth factor used for PBSC mobilization. In conclusion, our data indicate that in patients with Hodgkin's disease G-CSF and GM-CSF given after salvage chemotherapy appear to be not different in their ability to mobilize PBSC resulting in a similar time needed for hematological reconstitution when autografted following high-dose therapy.     

Autologous stem cell transplantation (ASCT) for poor prognostic Hodgkin's disease (HD): comparative results with two CBV regimens and importance of disease status at transplant

Clinical outcome of 47 consecutive patients with advanced HD who underwent ASCT in our Department was analyzed retrospectively. Median age was 28 years (28 males and 19 females). At transplant, 15 (32%) patients were in CR (five in first CR after two chemotherapy regimens and 10 in second CR), eight (17%) in PR (seven without a prior CR), 22 (51%) had relapsing disease (19 with sensitive relapse) and two had primary refractory disease. The CVB regimen with two different schedules was used: 22 (47%) patients received standard CBV (CY 6 g/m2, BCNU 300 mg/m2 and etoposide 600 mg/m2) and 25 (53%) received an increased CBV dose (CY 7.2 g/m2, BCNU 440 mg/m2 and etoposide 2 g/m2). Antitumor response for 28 evaluable patients was similar for both CBV regimens: 87 and 75% (P=0.39). At 7.2 years, actuarial overall survival (OS), progression-free survival (PFS) and event-free survival (EFS) for the whole series were 51.7+/-8%, 34+/-9% and 28+/-8%, with a median follow-up for the surviving patients of 3 years (0.7-7.6). No differences in these survival functions according to the CBV regimen used were observed (P=0.57). A history of a prior CR (P=0.003), duration of first CR >1 year (P=0.04), absence of bulky nodal disease at transplant (P=0.054), absence of extranodal disease at transplant (P=0.01), and a CR status at transplant (P=0.0006) were associated with a better PFS on univariant analysis. On multivariate analysis, only CR status at transplant remained significant (P=0.05). When patients in second CR at transplant and those in first sensitive relapse were analyzed separately, no differences in clinical characteristics or in treatment received pretransplant were observed; however, PFS was significantly different (P=0.01). In conclusion, CR status at transplant is useful in identifying 'good risk' patients and is necessary to obtain the greatest benefit from ASCT independent of the CBV regimen used.     

Role of a sialyl Lewis(x)-like epitope selectively expressed on vascular endothelial cells in local skin inflammation of the rat

The role of the inducible L-selectin ligand was studied in complement-dependent acute dermatitis in rats. Although mAbs against typical sialyl Lewis(x) (CSLEX-1 and SNH-3) did not react with skin venules, a sialyl Lewis(x)-like epitope defined by mAb 2H5 (2H5-Ag) was de novo expressed on the endothelial cells of skin venules in the area of inflammation. Expression of 2H5-Ag increased concomitantly with the progression of inflammation. 2H5-Ag was identified at the 75-, 150-, and 180-kDa bands when inflammatory skin tissue was analyzed by Western blotting. In contrast, P- and E-selectins were not detectable. The role of 2H5-Ag in this model was studied in in vitro and in vivo methods. First, 2H5 was i.v. injected 15 min before induction of dermatitis. 2H5 bound to skin venules and significantly reduced the neutrophil infiltration and plasma protein leakage. In contrast, CSLEX-1, mAb ARP2-4 (P-selectin blocker), or mAb ARE-5 (E-selectin blocker) had no effects. Second, adhesion of isolated rat neutrophils to the inflammatory skin section was inhibited significantly when the sections, but not neutrophils, were preincubated with 2H5. Third, fluorescein-labeled normal rat neutrophils were injected into a rat 10 h after induction of dermatitis. The number of labeled neutrophils infiltrated into the inflammatory site was reduced significantly when they were preincubated with HRL-3 (blocking mAb against rat L-selectin), but not with 2H5 or HRL-4 (nonblocking mAb against rat L-selectin). These data show that de novo expressed 2H5-Ag/L-selectin adhesion pathway contributes to the development of acute complement-dependent inflammation in the skin.