Leukemogenic activity of ether-extracted Rauscher leukemia virus.

After rapid multiple extractions of mouse plasma virus with ether, the aqueous solution contained viral nucleoids that were infectious when inoculated intracranially into newborn BALB/c mice. The infectivity associated with the ether extract was not neutralized by the specific antibody prepared against the whole virus. No intact virus has been seen in these preparations. Treatment with ether completely removed the virus envelope from the particle and produced an apparently homogeneous preparation of viral nucleoids. After the extractions with ether, leukemogenic activity was inactivated by exposure to ribonuclease. The leukemogenic activity of the many-passaged Rauscher virus that has been propagated in tissue culture and that has low infectivity was also retained, and, in two experiments in which material was inoculated intracranially into mice, this activity appeared to have been enhanced by multiple extractions with ether.

Immunotherapy of a murine lymphoma by adoptive transfer of syngeneic macrophages activated with bisantrene.

Macrophages from mice treated with a novel antineoplastic agent, bisantrene, were shown previously to be highly active in inhibiting the proliferation of tumor cells in culture. These activated cells have now been found to protect mice from dying of progressive tumors when injected into animals. The effect was observed not only in a Winn-type tumor cell neutralization assay but also in a setting of therapeutic intervention. Multiple treatments with bisantrene-activated cells seemed more effective than a single treatment. Macrophages appeared to be the major effectors in this system, since treatment with carrageenan abolished the protective effect. Thus, present findings suggest that in addition to a direct cytotoxic effect of bisantrene, the activation of macrophages may contribute to the overall antitumor activity of the drug.

Activity of a novel anthracenedione, 1,4-dihydroxy-5,8-bis(((2-[(2-hydroxyethyl)amino]ethyl)amino])-9,10-anthracenedione dihydrochloride, against experimental tumors in mice.

1,4-Dihydroxy-5,8-bis(((2[(2-hydroxyethyl)amino]ethyl)amino))-9,-10-anthracenedione dihydrochloride (CL 232315; NSC 301739D), a representative of a new chemical class of compounds with antineoplastic properties, has been evaluated for antitumor activity in experimental mouse tumor systems. The compound produced significant increases in life span (ILS) and long-term survivors when tested against the P388 and L1210 leukemias as well as the solid neoplasms, B16 melanoma and Colon Tumor 26. The optimal treatment regimens resulted in a 173 to greater than 200% ILS with 20 to 80% 60-day survivors in mice with P388 leukemia, A 205% ILS with 55% 60-day survivors in mice with L1210 leukemia, and an ILS of greater than 300% with 80% 90-day survivors in mice with B16 melanoma. In contrast to Adriamycin, CL 232315 was active against the i.v. implanted L1210 leukemia and demonstrated moderate activity against P388/Adria, a subline of P388 resistant to Adriamycin. The compound was ineffective when tested against the Lewis lung carcinoma and the Ridgway osteogenic sarcoma. CL 232315 was active i.p., s.c., and i.v., but p.o. activity was not demonstrated. Schedule dependency was not observed when the compound was administered once daily for nine days, once every four days, or as a single dose.

Restoration of cytolytic T-lymphocyte response with a new immunopotentiator, N-(4-[(4-fluorophenyl)sulfonyl]phenyl)acetamide (CL 259, 763), in mice.

The immunorestorative characteristics of a novel synthetic immunomodulator, N-(4-[(4-fluorophenyl)sulfonyl]phenyl)acetamide (CL 259, 763), has been investigated in several experimental models. In one situation, the compound was shown to enhance the induction of a cytolytic T-lymphocyte response to the murine MBL-2 leukemia implanted in its syngeneic host in which only a minimal reactivity to the tumor is normally displayed. In a Vaccinia virus model, the compound similarly augmented the lytic activity of cytolytic T-lymphocyte to virus-infected targets in not only viral antigen-primed but also cyclosporin A-impaired mice. Likewise, the alloreactive cytolytic T-lymphocyte activity was recovered in animals immunocompromised by inoculation with murine plasmacytomas or cytoreductive anticancer drugs, such as cyclophosphamide and 5-fluorouracil. Thus, the present findings suggest that CL 259,763 is effective in potentiating the immune response to weak antigens as well as in restoring alloreactivity by sparing the immunotoxicity associated with the administration of cytotoxic drugs and the growth of neoplasms.

Preparation and characterization of monoclonal antibody conjugates of the calicheamicins: a novel and potent family of antitumor antibiotics.

The calicheamicin family of antitumor antibiotics are capable of producing double-stranded DNA breaks at sub-picomolar concentrations. Their potency suggested that the calicheamicins would be excellent candidates for targeted delivery and a hydrazide prepared from the most potent and abundant of the naturally occurring derivative, gamma 1I, was linked to oxidized sugars on CT-M-01, an internalizing anti-polyepithelial mucin antibody. The conjugates retained the immunoreactivity of the unmodified antibody and were specifically cytotoxic toward antigen positive tumor cells in vitro and in vivo. Hydrazide analogues of less potent calicheamicin derivatives were also prepared and conjugated to CT-M-01. Comparison of the therapeutic efficacy of the conjugates against the MX-1 xenograft tumor implanted s.c. in nude mice showed that conjugates of derivatives missing the rhamnose, a sugar residue that is part of the DNA binding region of the drug, were not as promising as antitumor therapies. However, conjugates of two derivatives, alpha 3I and N-acetyl-gamma 1I, in which the rhamnose residue is present but the amino sugar residue of the parent drug is either missing or modified, significantly inhibited tumor growth over a 4-fold dose range and produced long-term tumor-free survivors. Sterically hindering methyl groups adjacent to the disulfide in the linker further increased the therapeutic window of these potent conjugates.

Activation of tumor-cytostatic macrophages with the antitumor agent 9,10-anthracenedicarboxaldehyde bis[(4,5-dihydro-1H-imidazole-2-yl)hydrazone] dihydrochloride (bisantrene).

An investigation was carried out to determine the potential for activating tumor-inhibitory macrophages with the cytotoxic antitumor agent, bisantrene. Macrophages prepared from peritoneal exudates of mice treated i.p. with bisantrene were extremely active in inhibiting the growth of tumor cells. The minimal effective in vivo dose of this drug appeared to be 25 mg/kg, with peak activation being achieved at doses of 50 to 100 mg/kg. Effector cells became detectable 2 days after treatment and persisted for at least 4 weeks. Incubation of effector and target cells for 48 hr seemed necessary to achieve the maximum inhibitory effect. Treatment with carrageenan in vitro and in vivo abolished tumor cytostasis, whereas treatment with anti-T-cell antibody plus complement had no effect, suggesting that macrophages rather than T-lymphocytes were responsible for the observed results. Culture supernatants of activated macrophages were found to have antiproliferative effects on tumor cells, indicating that a cytostatic factor(s) was produced by these macrophages. Hydrogen peroxide and neutral proteases apparently did not function as cytostatic mediators since activated macrophages were resistant to treatment with catalase, N-alpha-p-tosyl-L-lysine chloromethyl ketone, and aprotinin. The present findings suggest that, in addition to direct toxicity to tumor cells, bisantrene may act as a macrophage-activating immunopotentiator. This observation may be of potential clinical usefulness in the design of immunochemotherapeutic trials for certain types of cancer.

Activity of a novel anthracenyl bishydrazone, 9,10-anthracenedicarboxyaldehyde Bis[(4,5-dihydro-1H-imidazol-2-yl)hydrazone] dihydrochloride, against experimental tumors in mice.

9,10-Anthracenedicarboxaldehyde bis[(4,5-dihydro-1H-imidazol-2-yl)hydrazone] dihydrochloride (CL 216942; bisantrene hydrochloride; NSC 337766), a member of a new chemical class of compounds with antineoplastic properties, has been evaluated for antitumor activity in experimental murine tumor systems. The compound produced significant increases in life span (LS) and long-term survivors among mice bearing transplantable leukemias and solid tumors. Optimal treatment regimens resulted in an ILS of greater than 173 and 151% in mice with P388 and L1210 leukemia, respectively, an ILS of greater than 85% in mice with Lieberman plasma cell tumor, and an ILS of greater than 200, 150, and 63%, respectively, in mice with B16 melanoma, colon tumor 26, and Ridgway osteogenic sarcoma. An adriamycin-resistant subline of P388 leukemia showed complete cross-resistance to CL of 216942. The compound was active when administered by the i.p., i.v., and s.c. routes, but p.o. activity was not observed. Significant schedule dependency was not observed when the drug was administered once daily for 9 days, once every 4 days, or as a single dose, but single doses typically produced the best effects. CL 216942 was a potent inhibitor of DNA and RNA synthesis in L5178Y lymphoma cells cultured in vitro, and preliminary studies indicated the drug was a DNA-intercalating agent. The drug was cytotoxic for rapidly proliferating and nonproliferating (G0) human colon carcinoma WiDR cells in vitro.U

[Parents' attitudes towards childhood fever. A cross-sectional survey in the Lyon metropolitan area (202 cases)]. / L'attitude des parents face à la fièvre de leurs enfants. Une enquête transversale des résidents de l'agglomération lyonnaise (202 cas).

INTRODUCTION: The patient overload in pediatric healthcare facilities is caused in part by parents bringing their children in for consultations for fever. We conducted a survey in the Lyon metropolitan area to improve our understanding of parents' attitudes towards their children's fever. OBJECTIVE: To assess the frequency and characteristics of healthcare utilization and evaluate parents' knowledge and attitudes before consulting. METHODS: A random sample of families with at least one child under 6 years of age and living in the Lyon metropolitan area was surveyed by telephone, according to a closed questionnaire that was answered by the person usually responsible for the child's health. RESULTS: 202 families were questioned: 58.9% defined fever as a temperature over 38 degrees C, and 82% used rectal thermometers to measure temperature. Among 144 parents of children with an episode of fever within the previous 12 months, 73% called a physician during the episode, 44% of them immediately. Working-class parents called more frequently (90%) than parents who were professionals or managers (74%). Most parents (94%) administered medication to the child several times before calling the physician. Paracetamol and ibuprofen were mentioned most often. 93% of fever episodes led to consultations. DISCUSSION: Our results show that 59% of the sample defined fever as a temperature equal to 38 degrees C and that fever episodes lead commonly and quickly to physician visits, but that parents do use physical methods and drugs to reduce fever before calling a physician.

Stimulation of integrin receptors using a magnetic drag force device induces an intracellular free calcium response.

Mechanical loading of cells is of fundamental relevance in physiological processes and induces several functional responses in cells. Integrins, a family of adhesion receptors, which are responsible for the interaction with the extracellular matrix, may play a role in transmission of mechanical signals into cells. The osteogenic cell line U-2 OS expresses different integrin subunits which are uniformly distributed over the cell surface. We applied defined physical forces on individual integrin receptor subunits using paramagnetic microbeads coated with anti-integrin antibodies. Application of an inhomogeneous magnetic field consequently leads to a mechanical stress on the receptor. Intracellular Ca2+ increased when the alpha 2 or the beta 1 integrin subunits were stressed, whereas mechanical loading of the transferrin receptor had a significantly lower effect. This result indicates that forces specifically exerted to individual integrin receptors induce signal transduction pathways.

Molecular and biochemical pharmacology of mitoxantrone.

Evidence has been presented which indicates that Nv: intercalates DNA and additionally causes inter- and intra-strand crosslinking possibly associated with its charged side arms; there is an apparent preference for G-C base pairs; induces single strand and double strand breaks in DNA; strongly inhibits DNA and RNA synthesis; causes nuclear aberrations and chromosomal scattering; induces a block in the G2 phase of the cell cycle with an increase in cellular RNA and polyploidy; is not cell cycle phase-specific with respect to cell kill; does not induce free-radical formation; does not induce lipid peroxidation or superoxide formation; rather it may inhibit ADR-stimulated lipid peroxidation and microsomal superoxide production; does not appear to have a strong potential for cardiotoxicity on the basis of currently postulated mechanisms of action; is capable of inducing cellular resistance in vitro; resistance is associated with an apparent alteration in the cell membrane impairing drug transport into the cell. Although the precise mechanism(s) of tumor cell killing has not been fully defined it is most likely associated with an interaction by Nv with chromosomes resulting in DNA damage, which if not efficiently repaired, will lead to inhibition of nucleic acid synthesis and eventual cell death.

Biologic and biochemical effects of mitoxantrone.

Mitoxantrone (1,4-dihydroxy-5,8-bis[(2-[(2-hydroxyethyl)-amino]-ethyl) amino]-9,10-anthracenedione dihydrochloride) is a representative of a new class of chemical compounds with antineoplastic activity. It was one of a number of polycyclic aromatic compounds tested at the American Cyanamid Laboratories and was the most effective and potent derivative synthesized. Mitoxantrone produced significant increases in life span and long-term survivors when tested against P388 and L1210 leukemias, B16 melanoma, and colon tumor 26 transplanted into mice. In comparative animal trials, it proved more effective than most of the other agents tested, including doxorubicin, cyclophosphamide, methotrexate, cytarabine, and 5-fluorouracil. It was also active against intravenously implanted L1210 leukemia, in contrast to doxorubicin, though this is considered to have a similar mode of action. Mitoxantrone also demonstrated moderate activity against sublines of the mouse leukemias, which were resistant to anthracyclines. Significant therapeutic synergism against P388 leukemia was observed when mitoxantrone was administered on the same day as methotrexate and cytarabine or in sequence with cyclophosphamide, cisplatin, or vincristine sulfate. Mitoxantrone is active intraperitoneally, intramuscularly, subcutaneously, and intravenously, but oral activity has not been demonstrated. Although dose schedule did not appear critical, treatment every 4 days X 3 appeared to be the most effective. The mechanism of action of mitoxantrone has not been fully elucidated, but it is known to inhibit DNA and RNA synthesis. In cell culture, mitoxantrone induces nuclear aberrations with chromosomal scattering and morphologic alterations similar to those induced by doxorubicin. Drug-induced cell kill was not phase specific. Experiments with a resistant human colon carcinoma cell line (WiDr) indicated that resistance may be due to alterations of the cell membrane with decreased uptake. Mitoxantrone has markedly less cardiotoxicity than doxorubicin, and this may be linked to the fact that the drug does not induce free radical formation but inhibits lipid peroxidation.

N-phosphoryl derivatives of bisantrene. Antitumor prodrugs with enhanced solubility and reduced potential for toxicity.

The selective phosphorylation of bisantrene (1) affords bis(phosphonoguanidinic acid) 6, a prodrug with enhanced aqueous solubility (as sodium salt 7) at physiological pH. Unlike 1, in a rat tail vein model, no precipitation was observed when bis(phosphonoguanidinic acid) 6 was injected. While in rats 6 hydrolyzed to monophosphonoguanidinic acid 9 with a half-life of ca. 12 min., complete hydrolysis to bisantrene required several hours. The corresponding monophosphonoguanidinic acid 9 was synthesized from bisantrene and also showed good solubility and antitumor activity. While the antitumor activities of 6 in mice were comparable to bisantrene against B-16 melanoma and P-388 and L-1210 leukemias, it was inactive in vitro vs several tumor cell types. Thus, its activity in vivo resulted from its ability to serve as a prodrug for bisantrene.

Antitumor agents. 1. 1,4-Bis[(aminoalkyl)amino]-9,10-anthracenediones.

The condensation of alkylenediamines with quinizarin or with 2,3-dihydro-1,4,5,8-tetrahydroxy-9,10-anthracenedione, followed by oxidation, gave 1,4-bis[aminoalkyl)amino]-9,10-anthracenediones. Some of these compounds and their 2,3-dihydro derivatives were markedly active against both leukemias and solid tumors in mice. Activity was maximal with 5,8-dihydroxylation and 1,4-bis[(2-aminoethyl)amino] substitution, in which the terminal nitrogen atoms were either unsubstituted (compound 50) or carried 2-hydroxyethyl groups (compound 40), indicating the importance of hydrophilicity. Against B-16 melanoma, 50 gave greater than 433% increase in median life span (ILS) with 7/10 80-day survivors. Against P-388 leukemia, 40 gave greater than 500% ILS with 4/5.60-day survivors; its efficacy and therapeutic index equaled or surpassed those of adriamycin, cyclophosphamide, daunorubicin, methotrexate, or 5-fluorouracil. Against L-1210 leukemia, B-16 melanoma, and colon tumor 26, 40 was generally as effective or more effective than adriamycin and is now undergoing preclinical toxicological evaluation.

A new family of water-soluble, third generation antitumor platinum complexes.

[1,1-Cyclobutanedicarboxylato(2)-O,O'](1,3-dioxane-5,5-dimethan amine- N,N')platinum(II), 3a, a third generation, very water-soluble platinum complex, has been synthesized along with several of its analogues. All members of the new family contain a 1,3-dioxane or 1,3-dioxolane-1,3-diamine as their basic ligand, a moiety which contributes to their increased water solubility, and a bidentate acid ligand, which is responsible for their good stability. They were all easily crystallized and characterized by 1H NMR and elemental analysis, and the parent complex 3a was further characterized by 13C NMR. Their very desirable physical properties combined with their broad spectrum of antitumor activity and reduced toxicity make them good candidates of further development.

Water-soluble third generation antitumor platinum complexes, [2,2-bis (aminomethyl)-1,3-propanediol-N,N']-[1,1-cyclobutanedicarboxylato (2-)-O,O']platinum(II) and [1,1-cyclobutanedicarboxylato(2-)-O,O'] [tetrahydro-4H-pyran-4,4-dimethanamine-N,N']platinum(II).

The synthesis, stability, and antitumor activity of a series of water-soluble third generation platinum(II) complexes have been described. Among these complexes, [2,2-bis(aminomethyl)-1,3- propanediol-N,N'] [1,1-cyclobutanedicarboxylato(2-)-O,O']platinum(II) and [1,1-cyclobutanedicarboxylate(2-)-O,O'](tetrahydro-4H-pyran-4,4- dimethanamine-N,N'-)platinum(II) have shown the greatest promise for further investigation and are currently under clinical evaluation.

Antitumor agents. 2. Bisguanylhydrazones of anthracene-9,10-dicarboxaldehydes.

9,10-Anthracenedicarboxaldehyde bis[(4,5-dihydro-1H-imidazol-2-yl)hydrazone] (bisantrene, VI-1) showed anticancer activity in mice vs. both leukemias and solid tumors. Increases in life span vs. the following neoplasms were: P-388 leukemia, 137%; B-16 melanoma, 122%; Lieberman plasma cell tumor, greater than 85%; colon tumor 26, 150%; Ridgway osteogenic sarcoma, 85%. There were significant numbers of long-term survivors. Both DNA and RNA synthesis were strongly inhibited. The drug was resistant to biodegradation and was bound strongly to tissues; in monkeys the half-life for disappearance from serum was 6 days. Related hydrazones were synthesized, and structure-activity relationships are discussed. Two routes to ring-substituted anthracene-9,10-dicarboxaldehyde intermediates were developed.

Hydrogen loading and UV-irradiation induced etch rate changes in phosphorus-doped fibers.

We show strong changes in chemical etching of phosphorus-doped fiber cores due to hydrogen loading and subsequent UV-irradiation using an atomic force microscope. The etch rate of the fiber core in a low concentration hydrofluoric acid solution (HF) is decreasing after hydrogen loading by as much as 30%. In contrast, UV-irradiation of the hydrogenated fiber increases the core etch rate to values of 27% above the etch rate of the pristine fiber. The UV-induced change in etch rate does not depend on pulse fluence, but only on total dose. We attribute the changes in etch rate to a hydrogen- and radiation-induced modification of color center population.

Stimulation of nonspecific immunity to reduce the risk of recurrent infections in children attending day-care centers. The Epicrèche Research Group.

A randomized, double blind, placebo-controlled clinical trial was performed in 423 children attending day-care centers to assess whether stimulating nonspecific immunity would reduce the incidence of recurrent infections. The drug used for the trial (Imocur) is an extract obtained from eight different species of bacteria. At the end of the total follow-up period (3 months with treatment and 4.5 months without), the risk for > or = 4 episodes of upper respiratory infections was not significantly lower in the treated group than in the placebo group (26.7% vs. 33.8%, relative risk, 0.79; 95% confidence interval, 0.59 to 1.06). In an exploratory analysis limited to the 3-month treatment period, however, we observed a 48% reduction in the risk of presenting > or = 3 episodes of upper respiratory infections: 9.5% vs. 18.3%, respectively, in the treatment group and the placebo group (relative risk, 0.52; 95% confidence interval, 0.31 to 0.86). Similar results were found for the risk of > or = 1 episode of gastroenteritis. We also observed a strong correlation between the drug efficacy and age; this observation is coherent with the underlying pathophysiologic model in which the immune system matures with age.

Arabinofuranosyl-5-azacytosine: activity against human tumors in athymic mice.

Arabinofuranosyl-5-azacytosine (Ara-AC), a new compound structurally related to arabinofuranosylcytosine (Ara-C) and 5-azacytidine (5-AC), has demonstrated significant therapeutic activity against a wide spectrum of murine tumors and three human tumor xenografts in the NCI tumor panel. Studies on the activity of Ara-AC in these and other human tumor xenograft models were undertaken to define its potential anti-human-tumor profile more completely. Ara-AC demonstrated marked antitumor activity against human tumor xenografts, including leukemias and solid tumors that do not respond to Ara-C or 5-AC. An important finding was the demonstration that Ara-AC was as effective by the oral route as when given intraperitoneally. Furthermore, the compound demonstrated synergism when combined with cisplatin in the treatment of refractory solid tumors and also induced monocyte-type differentiation of promyelocytic leukemia (HL-60) cells in vitro. Ara-AC is a promising new compound that may have utility in the treatment of human cancer beyond that anticipated for a cytotoxic nucleoside.

P-glycoprotein mediates profound resistance to bisantrene.

Bisantrene, mitoxantrone, and anthracyclines are anthracene derivatives that interact with DNA and are used for the treatment of cancers. The mechanisms of resistance to bisantrene are unknown. Here we show that cells that overexpress low levels of P-glycoprotein or are transfected with human MDR1 have approximately 10-fold greater resistance to bisantrene compared to vinblastine, doxorubicin, or colchicine. Furthermore, bisantrene can be used to select for high-level P-glycoprotein-mediated multiple drug resistance in a human colon carcinoma cell line, LS 174T, and the drug blocks photoaffinity labeling of P-glycoprotein. The data suggest that bisantrene is an excellent substrate for P-glycoprotein. These findings could influence subsequent clinical evaluation of bisantrene for the treatment of cancer.