Carcinogenicity of naturally occurring 1-hydroxyanthraquinone in rats: induction of large bowel, liver and stomach neoplasms

The carcinogenic potential of 1-hydroxyanthraquinone (HA), anaturally occurring compound, was examined. A total of 60 maleACI/IN rats, 1.5 months old at the commencement were dividedinto two groups. Group 1 (30 rats) were fed the diet containingHA at a concentration of 1% throughout the experIment (480 days).Group 2(30 rats) served as the control given a basal diet alone.Twenty-five of 29 effective animals in group 1 developed adenomasor adenocarcinomas in the cecum or upper portion of the colon,the mean number of large bowel tumors/tumor bearing rat being2.3. In addition to these intestinal tumors, liver neoplasms(neoplastic nodules and hepatocellular carcinomas) were observedin 12 rats and benign stomach tumors were obtained in five animals;no rats of group 2 demonstrating development of any of thesetumor types. The incidences of the large bowel, liver and stomachneoplasms in group 1 were all significant as compared with group2 (P < 2 x 10^–13, P < 5 x 10^–5 and P <3 x 10^–2 respectively) clearly indicating that HA is carcinogenicin rats.     

60Co radiation-induced transformation to anchorage independence of fibroblasts from normal persons and patients with inherited predisposition to retinoblastoma

Retinoblastoma (RB), cancer of the retina, occurs in an inheritedform which not only predisposes the patient to bilateral RB,but also to the risk of developing secondary tumors of mesenchymalorigin (osteosarcomas and fibrosar-comas). These tumors oftenarise in areas that were exposed to ionizing radiation duringtherapy and fibroblasts derived from patients with hereditaryRB have been reported to be more sensitive than normal to thekilling effects of ionizing radiation. Therefore, we compareddipioid fibroblast cell tines derived from two hereditary RBpatients (aged 1 and 3 years) with those of three normal persons(two newborns and a 2 year old) for their sensitivity to ionizingradiation-induced transformation to anchorage independence.The target cells were exposed to ⁶⁰Co radiation (1.0–3.5Gy), allowed to undergo an expression period (4–5 populationdoublings in 5 days), and assayed for ability to form coloniesin 0.33% agar. There was no detectable difference between theRB cells' and the normal cells' response to the transformingaction of the ⁶⁰Co. Both kinds of cells showed a linear, dose-dependentincrease in anchorage-independent cells from 100 to 800/10⁶cells assayed.     

Karyometric and DNA Content Analyses of Cancer Cells in Stage III Breast Cancer with Reference to Prognosis

Karyometric and DNA content analyses were simultaneously performedon 32 cases of stage III invasive ductal breast cancer usingan image analysis system. From the karyometric analysis, thenuclear areas (NAs; µm²) were (mean ± SD) 36.27± 9.40 in five-year survivors (n 17) and 57.14 ±13.26 in non-survivors (n 15). The nuclear shape factors (NSFs;NSF = 4 x NA/NP²; NP, nuclear perimeter) were 0.756 ±0.037 in survivors and 0.716 ± 0.040 in non-survivors.The NA was significantly larger (P<0.01) and the NSF significantlylower (P< 0.01) in non-survivors than in survivors. Fromthe DNA content analysis, the DNA content values (c; see Measurementssection) were ±2.59 ± 0.70 in survivors and 3.72± 1.08 in non-survivors. The percentages of aneuploidcells over 4c were 7.10 ± 9.89 in survivors and 23.07± 20.19 in non-survivors. The DNA content and the percentageof aneuploid cells over 4c were significantly higher (P<0.01)in non-survivors than in survivors. This method may be valuablefor estimating the prognosis of patients with invasive ductalcarcinoma of the breast.     

Expression and clinical significance of p73A in breast carcinoma tissues

p73,as one of the recently discovered p53familymembers,shows remarkable structural and functionalsimilarities to p53.p73gene can activate p53target genessuch as p21,inhibit cell growth and induce apoptosis[1].Currently many studies suggest that there is differencebetween p73and p53.In many tumor types,the expressionof p73is higher than in corresponding normal tissues[2,.3]We have not found p73mutations,but found that p73isimplicated in the tumorigenesis of many human tumors andin a poor clinic…     

Molecular effects of genistein on estrogen receptor mediated pathways

Genistein, a component of soy products, may play a role in theprevention of breast and prostate cancer. However, little isknown about the molecular mechanisms involved. In the presentstudy, we examined the effects of genistein on the estrogenreceptor positive human breast cancer cell line MCF-7. We observedthat genistein stimulated estrogen-responsive pS2 mRNA expressionat concentrations as low as 10^–8 M and these effects canbe inhibited by tamoxifen. We also showed that genistein competedwith (³H)estradiol binding to the estrogen receptor with 50%inhibition at 5 x 10^–7 M. Thus, the estrogenic effectof genistein would appear to be a result of an interaction withthe estrogen receptor. The effect of genistein on growth ofMCF-7 cells was also examined. Genistein produceda concentration-dependenteffect on the growth of MCF-7 cells. At lower concentrations(10^–8-10^–6 M) genistein stimulated growth, but athigher concentrations (>10^–5M) genistein inhibitedgrowth. The effects of genistein on growth at lower concentrationsappeared to be via the estrogen receptor pathway, while theeffects at higher concentrations were independent of the estrogenreceptor. We also found that genistein, thoughestrogenic, caninterfere with the effects of estradiol. In addition, prolongedexposure to genistein resulted in a decrease in estrogen receptormRNA level as well as a decreased response to stimulation byestradiol.     

Genotoxicity of the food mutagen 2-amino-3-methylimidazo-[4,5-f]quinoline (IQ) and analogs

The food mutagen 2-amino-3-methylimidazo[4,5-f]quinoline (IQ)is an analogue of quinoline, a hepatocarcinogen. 2-Aminofluorene,benzldine and 3,2'-dimethyl-4-aminobiphenyl (DMAB) are potentinducers of unscheduled DNA repair in primary culture rat liverhepatocytes, as was IQ (151 grains/ nucleus at 1 x 10^–6M). Quinoline, on the other hand, is only weakly positive inthis assay (15 grains/nucleus at 1 x 10^–3 M). IQ, quinolineand DMAB were applied topically to shaved skin of Sencar micewith promotion by 12-O-tetradecanoylphorbol 13-acetate (TPA)for 20 weeks, when 14 of 20 mice in the quinoline group had25 tumors, but only one of 30 animals in the IQ group and fiveof 30 in the DMAB group were tumor-bearing. Analogs of IQ synthesizedby substitution at the 2- or 3-position with amino or methylgroups were assayed with the Ames Salmonella typhimurium testerstrains TA98 and TA100. Mutagenicity for TA98 is reduced inthe absence of the 3-methyl group and is completely abolishedwith removal of the 2-amino moiety. None of these analogs arestrong mutagens for TA100. Exocyclic N-oxidation is a likelyobligatory step in the activation of IQ to a mutagen.     

Parity-related molecular signatures and breast cancer subtypes by estrogen receptor status

Introduction

Relationships of parity with breast cancer risk are complex. Parity is associated with decreased risk of postmenopausal hormone receptor–positive breast tumors, but may increase risk for basal-like breast cancers and early-onset tumors. Characterizing parity-related gene expression patterns in normal breast and breast tumor tissues may improve understanding of the biological mechanisms underlying this complex pattern of risk.

Methods

We developed a parity signature by analyzing microRNA microarray data from 130 reduction mammoplasty (RM) patients (54 nulliparous and 76 parous). This parity signature, together with published parity signatures, was evaluated in gene expression data from 150 paired tumors and adjacent benign breast tissues from the Polish Breast Cancer Study, both overall and by tumor estrogen receptor (ER) status.

Results

We identified 251 genes significantly upregulated by parity status in RM patients (parous versus nulliparous; false discovery rate = 0.008), including genes in immune, inflammation and wound response pathways. This parity signature was significantly enriched in normal and tumor tissues of parous breast cancer patients, specifically in ER-positive tumors.

Conclusions

Our data corroborate epidemiologic data, suggesting that the etiology and pathogenesis of breast cancers vary by ER status, which may have implications for developing prevention strategies for these tumors.     

Induction of oxygen-dependent lethal damage by monochromatic UVB (313 nm) radiation: strand breakage, repair and cell death

The action of 313 nm radiation in cellular inactivation (biologicalmeasurements) and induction and repair of DNA strand breaks(physical measurements) were studied in a repair proficientstrain and three repair deficient strains (polA, recA, uvrA)of Escherichia coli K-12. Although the induction of breaks waslinear in purified T₄ DNA (6.3 x 10^–4 breaks/2.5 x 10⁹daltons/Jm^–2) and the polA strain (4 x 10^–4 breaks/2.5x 10⁹ daltons/Jm^–2), simultaneous induction and repairof breaks were observed in the uvrA, recA and repair proficientstrains at doses <5 x 10⁴ Jm^–2. The final rates ofinduction in these strains were 1 x 10^–4, 7.5 x 10^–5and 7.5 x 10^–5 breaks/2.5 x 10⁹ daltons/Jm^–2, respectively.A highly efficient polA-dependent repair occurring at 0°Cin minimal buffer and a second slower type of repair occurringat 31°C in the polA strain were detected. Oxygen dependenceof cellular inactivation was observed for the polA and repairproficient strains irradiated at 313 nm thus providing biologicalevidence for an oxygen-dependent lesion involved in lethalityin the short wavelength range of the solar u.v. The lower hypoxicbreak induction rates of the pol4 (1.6 x 10^–4 breaks/2.5x 10⁹ daltons/Jm^–2) and the repair proficient (3.6 x 10^–5breaks/2.5 x 10⁹ daltons/Jm^–2) strains, indicate oxygen-enhancedDNA breakage by 313 nm radiation.     

Combined doxorubicin and paclitaxel in advanced breast cancer: Effective and cardiotoxic

BACKGROUND:: Pacitaxel has shown activity in metastatic breast cancer, includinganthracycline-resistant breast cancer. The efficacy, toxicityand optimal scheduling of the combina tion of the two drugsneeds to be defined. PATIENTS AND METHODS:: Thirty women with advanced breast cancer who had undergone atmost one prior adjuvant chemotherapy regimen, were treated atthree different dose levels with doxorubicin (50, 60 and 60mg/m²) followed 30 minutes later by paclitaxel (155, 175 and200 mg/m², respectively) every 3 weeks. RESULTS:: The overall response rate was 83% (95% CI: 64–94), with24% of patients achieving CR. The median response duration forcomplete responders was 11 months (range 4–14+) and mediansurvival 18 months (range 3–28+). Two hundred sixty-fivetreatment courses were given (median 9, range 3–13) andthe median cumulative dose of doxorubicin was 369 mg/m² (range114–550). The main toxicities were neutropenia, parestesia,nausea/vomiting, alopecia, myalgia and cardiotoxicity. Fifteenpatients (50%) had reductions of left ventricular ejection fractionto below normal levels and 6 of these patients (20%) developedcongestive heart failure. CONCLUSIONS:: The combination of doxorubicin and paclitaxel is highly active,but is accompanied by the dose-limiting toxic effects of neutropenia,neuropathy and cardiotoxicity. advanced breast cancer, cardiotoxicity, doxorubicin, paclitaxel     

Mammary carcinoma induced by oral administration of ethyl methanesulphonate. Determination of some of the parameters affecting tumor induction

The carcinogenic activity of ethyl methanesulphonate (EMS),an alkylating agent and a potent mutagen, was examined in WistarKing A and Sprague Dawley rats following oral administration.In the Wistar King A rats, mammary carcinomas were detectedin all of the young female rats by the 32nd week after initiationof the experiment. To determine the optimal experimental conditionsfor the rapid and invariable induction of mammary carcinomas,the relationship among age, sex, strain of the rats and concentrationand duration of EMS administration, and tumor production wasinvestigated. The tumor incidence was higher in the youngerfemale rats and the Wistar rats were more susceptible than Sprague-Dawleyrats. Mammary carcinomas were also induced in the younger malerats. In addition, concommitant production of renal tumors occurredby the 40th week in young rats administered 10^–2 M or2 x 10^–2 M of EMS solution, while renal and uterine tumorsdeveloped eoncommitantly in the older female rats given 3 x10^–3 EMS by the 56th week. Histologically, the prevailingfeatures of tumors were infiltrating ductal adenocarcinoma inthe mammary glands, mesenchymal tumor in the kidney, and leiomyosarcomain the uterus. Methyl methanesulphonate, an analogue of EMS,did not induce tumors in any organs.     

Bcl-2,Bax在乳腺癌中表达的临床意义

目的　探讨Bcl 2 ,Bax在乳腺癌中表达的临床意义。方法　免疫组化链霉菌素 生物素 (S P)法对术前未使用过化疗、放疗及免疫治疗的乳腺癌 82例 (其中有腋窝淋巴结转移的 61例 ) ,15例乳腺良性肿瘤和 15例正常乳腺组织作对照 ,检测Bcl 2 ,Bax的表达情况。结果　Bcl 2在癌组织中的表达 ( 5 6 10 % )与正常乳腺组织 ( 3 3 3 3 % )和良性肿瘤 ( 4 0 0 0 % )中的表达无统计学差异 ,在不同种类、不同分级的浸润性导管癌中无明显差异 (P >0 0 5 ) ,在有转移 ( 4 7 5 4% )和无转移组 ( 80 95 % )中有明显差异 (P <0 0 1)。Bax在癌组织中的 ( 60 98% )表达与正常乳腺组织 ( 73 3 3 % )和良性肿瘤中 ( 60 0 0 % )的表达无统计学差异 ,在不同种类癌中无明显差异 (P>0 0 5 ) ,在不同分级的浸润性导管癌中有显著差异 (P <0 0 5 ) ,在有转移 ( 67 2 1% )和无转移组 ( 4 2 86% )中有显著差异 (P <0 0 5 )。两者在乳腺癌中的表达有相关 (P <0 0 5 )。结论　检测乳腺癌Bcl 2 ,Bax基因的表达情况 ,有助于预测乳腺癌患者的淋巴结转移情况及预后     

Mutagenicity of butadiene and its epoxide metabolites: II. Mutational spectra of butadiene, 1,2-epoxybutene and diepoxybutane at the hprt locus in splenic T cells from exposed B6C3F1 mice

The mutagenic potential and mutational spectra of butadiene(BD), 1,2-epoxybutene (EB), and diepoxybutane (DEB) were determinedin splenic T cells from exposed B6C3F1 mice. Mice exposed byinhalation to 625 p.p.m. BD for 2 weeks displayed an averagehprt^– mutation frequency of 6.2 x10^–6 compared to1.2x10^–6 in controls. Mice were also given three dailyi.p. doses of 60, 80 and 100 mg EB/kg or 7, 14 and 21 mg DEB/kg.Average hprt^– frequencies of 5.4x10^–6, 4.lx10^–6and 8.6x10^–6 were seen in the EB groups, respectively,while average frequencies of 4.6x10^–6, 9.4x10^–6and 13x10^–6 were seen in the DEB groups. DNA sequencingrevealed that approximately half of the mutations induced invivo by BD, EB and DEB were frameshift mutations. A +1 frameshift‘hotspot’ in six consecutive guanine bases in exon3 was observed with all three compounds. The remaining mutationsproduced by BD, EB and DEB were transition and transversionmutations at both AT and GC base pairs. Base pair substitutionsinduced by BD were biased in favor of mutation at AT base pairs.The mutational spectra produced by BD, EB and DEB were verysimilar to that observed previously with ethylene oxide, suggestingthat these epoxide agents may be working through a similar mutagenicmechanism.     

Relationship between hprt mutant frequency, aromatic DNA adducts and genotypes for GSTM1 and NAT2 in bus maintenance workers

We have studied the mutant frequency in the human gene for hypoxanthine-guaninephosphoribayl transferase (hprt) using the T-cell cloning assay,the aromatic DNA adduct level using the ³²P-postlabelling assay,and related the levels of these biomarkers to the genotypesfor glutathione transferase (GSTµ) and N-acetyltransferase(NAT2) in non-smoking bus maintenance workers exposed to dieselexhaust. No difference in mutant frequency was observed betweenthe 47 exposed (8.6x10^–6, age range 27–45) and the22 control individuals (8.4x10^–6, age range 23–61),while the difference in adduct level (3.2 versus 23x10^–8)was highly significant (P = 0.0009). Both mutant frequency andadduct level were highest in the 16 most heavily exposed workers.Overall, a significant increase of mutant frequency was obsenedwith adduct level (P = 0.008) as well as with age (P < 0.0001).The age dependence was higher in the GSTM1-negative slow acetylators(3.l%year) as compared to the three other genotype combinations(2.4-2.5%/year). There was no signiEicant difference in mutantfrequency or in adduct level between the GSTM1- negative (49.3%of the population) and positive individuals, or between theslow (60.9% of the population) and rapid acetylators. Amongthe slow acetylators, however, a significantly higher adductlevel (P = 0.03) was obtained for the GSTM1-negative individualsas compared to the GSTM1-positive individuals. These resultssuggest a posible role of both GSTµ and NAT2 for individualsusceptibility to carcinogen exposure.     

Inhibition of gap junctional intercellular communication by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in rat hepatocytes

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a potent rodenthepatic tumor promoter. Unlike observations with the majorityof tumor promoting chemicals studied to date, most investigationshave failed to demonstrate down- regulation of gap junctionalintercellular communication (GJIC) in cultured cells by TCDD.The present study examined the effect of TCDD on GJIC in rathepatocytes in primary culture. At non-cytolethal doses TCDDinhibited GJIC In a time- (1, 4, 24 and 48 h) and concentration(1x10^–8–1x10^–14M)-dependent manner. This inhibitionoccurred within 4 h of treatment at doses of 1x10^–81x10–^–12MTCDD and persisted for up to 48 h, despite removal of TCDD.Treatment of rat hepatocytes with TCDD resulted in a decreasein hepatocyte connexin 32 mRNA, but had no apparent effect onconnexin 26 mRNA. Co-incubation of rat hepatocytes with TCDDand     

12-O-Tetradecanoylphorbol-13-acetate releases human diploid fibroblasts from contact-dependent inhibition of growth

Treatment of human diploid fibroblasts at varying cell densitieswith 12-O-tetradecanoylphorbol-13-acetate (TPA) (10^–7M) resulted in a bimodal response of proliferation rate: whileat low cell densities (3 x 10³-1.5 x 10⁴ cells/cm²) TPA inhibitedthe proliferation by up to 50%, at high cell densities (1–1.6x 10⁵ cells/cm²) a 2-fold higher proliferation rate as in untreatedcultures was observed. When sparsely seeded normal diploid fibroblastswere grown in the presence of immobilized plasma membrane giycoproteins,as in confluent cell cultures strongly decreased proliferationand enhanced collagen type III synthesis is found. Using thistest system, it emerged that the addition of plasma membraneproteins from untreated as well as from TPA-treated fibroblaststo untreated fibroblasts resulted in a strong inhibition ofproliferation rate. In contrast, the addition of either untreatedor TPA-treated plasma membrane proteins to cells cultured inthe presence of TPA had no effect on growth. It is suggestedthat TPA treatment of normal diploid cells in culture resultsin a loss of responsiveness against cell-cell contacts, leadingto an escape from the contact-dependent inhibition of growth.     

Analysis of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced DNA damage in tumor cell strains from Japanese patients and demonstration of MNNG hypersensitivity of Mer-xenografts in athymic nude mice

Among 15 human tumor cell strains from Japanese patients, onestrain derived from a patient with thyroid cancer showed inabilityto support the growth of adenovirus 5 treated with N-methyl-N'-nitro-N-nitrosoguanidine(MNNG). When plated on this Mer^– strain, adenovirus 5showed 3–4 times higher sensitivity to MNNG-induced killingthan when plated on any of the other 14 Mer⁺ tumor cell strains.Biochemical analysis showed that the Mer^– strain was defectivein demethylation repair of O⁶-methylguanine produced by MNNGtreatment. The sensitivities of 12 of the 15 human tumor strains,including the Mer^– strain, to MNNG were compared by measuringtheir colony-forming abilities. All the strains tested showedthe Rem^– phenotype (having higher sensitivity to MNNG-producedcell killing than normal fibroblasts). The differential killingeffects of MNNG on Mer^– and Mer⁺ tumor cells under invivo conditions were tested using the Mer⁺ HeLa S3 strain andits Mer^– variant. Mer⁺ cells and Mer^– cells wereimplanted sub-cutaneously into the left and right flanks, respectively,of 10 nude mice and the next day, MNNG solution (0.25 ml at1 mg/ml) was injected into the implantation sites of eight mice.Mer^– tumor cells in six of eight treated mice showed nogrowth and those in the other two mice did grow, but regressedafter 3 weeks. In contrast, Mer⁺ tumor cells continued to growin all the eight mice treated, indicating that Mer^– tumorcells may be selectively inactivated by suitable therapeuticregimens with appropriate methylating drugs.     

Dose escalation of high-dose cyclophosphamide and etoposide with high-dose doxorubicin (CDE) and filgrastim for poor-risk non-Hodgkin's lymphoma

PURPOSE:: To identify the highest possible dose of cyclophosphamide (C)and etoposide (E) to be given with high-dose doxorubicin (D)and filgrastim (G-CSF) but without stem cell support in high-risknon-Hodgkin's lymphoma. PATIENTS AND METHODS:: High-dose CDE was given to 18 evaluable patients, 5 had previouschemotherapy. All patients received D 90 mg/sqm and G-CSF 20µg/kg/day. The first cohort had C 1800 mg/sqm and E 450mg/sqm. Chemotherapy was given in equally divided doses overthree days. Dose escalation was performed thrice up to C 3900mg/sqm and E 975 mg/sqm. One to four courses were given. RESULTS:: The median number of days (quartile values) with neutrophils<0.5 x 10⁹/l was 9 days (7–10), untransfused platelets<20 x 10⁹/l 6 days (3–7), fever     

The effect of diethylstilboestrol on the in vitro growth of human ectocervical cells

The effect of chronic exposure to diethylstilboestrol (DES)over the concentration range 10^–4–10^–6 M onthe in vitro growth of cells derived from the squamo-columnarjunction of the human cervix has been examined. DES over thedose range 10^–4–2 x 10^–5M inhibits cervicalepithelial cell (HCE) growth in terms of colony formation andcolony expansion. This effect involves both an effect on cellproliferation, as measured by cell number and mitotic index,and an induction of differentiation as measured by an increasein the number of PAS positive cells (glycogen accumulating cells)and in the number of cells with cornified envelopes. At lowerdoses of DES, 10^–5–5 x 10^–6 M, the efficiencyof colony formation and colony size are not inhibited but mitoticindex and cell number are decreased and the fraction of differentiatingcells is increased. The effects of DES on HCE cell growth canbe modified to some extent by epidermal growth factor (EGF).EGF at 10 ng/ml, increases the fraction of proliferating cells,induces cellular hypertrophy, reduces stratification and thefraction of differentiating cells in HCE colonies. DES, at allconcentrations other than 10^–6 M, in the presence of EGFinhibits cell proliferation but does not prevent the EGF inducedcellular hypertrophy, reduction in stratification or reductionin the fraction of differentiating cells.     

Sequential Changes in Stem Cell Markers in Peripheral Blood and Leukapheresis Samples after Injections of Recombinant Human Granulocyte Colony-stimulating Factor in Patients with Urogenital Malignant Solid Tumors: A Preliminary Study

In order to evaluate the mobilization effect of recombinanthuman granulocyte colony-stimulating factor (rhG-CSF) on peripheralblood stem, cells (PBSCs), rhG-CSF was given to patients withurogenital malignancy before chemotherapy. Markers for the stemcells, such as colony forming unit-granulocyte/macrophage (CFU-GM)and burst forming unit-erythrocyte (BFU-E), were sequentiallymonitored in peripheral blood and leukapheresis samples. Fivepatients, including a 13-year-old boy, were given 5 µg/kgrhG-CSF subcutaneously: the pediatric case for four consecutivedays and the adult cases for six consecutive days (53–72years of age). None of the patients had received chemotherapywithin the four weeks prior to the start of the rhG-CSF series.PBSC collections were performed on the fifth day in the pediatriccase and on the fifth and seventh days in the adult cases. Progenitorcells were monitored by methylcellulose cell culture techniques.CFU-GM on day 5 of the rhG-CSF series in peripheral blood increased14- to 53-fold compared with samples taken immediately beforethe series. CFU-GM in the leukapheresis products on day 5 wasgreatest (70 x 10³/kg) in the pediatric case and least (14 x10³/kg) in the oldest patient's case. The totals of the CFU-GMcollected by two phereses in the adult cases were 21–73x10³/kg and the totals of CD34 positive cells were 0.6 to 1.4x10⁶/kg.The data suggest rhG-CSF to induce sufficient PBSCs for bonemarrow rescue into the peripheral blood without any precedingchemotherapy. The patient's age may, however, be a contributoryfactor in using this method.     

1,N6-etheno-2' -deoxyadenosine and 3,N4-etheno-2'-deoxycytidine detected by monoclonal antibodies in lung and liver DNA of rats exposed to vinyl chloride

1,N⁶-Etheno-2'-deoxyadenosine (dAdo) and 3,N⁴-Etheno-2'-deoxycytidine(dCyd) are formed in vitro by reaction of DNA with the electrophilicmetabolites of vinyl chloride (VC), chloroethylene oxide andchloroacetaldehyde. To detect and quantitate these DNA adductsin vivo, we have raised a series of specific monoclonal antibodies(Mab). Among those, Mab EM-A-1 and Mab EM-C-1, respectively,were used for detection of dAdo and dCyd by competitive radioimmunoassay(RIA), following pre-separation of the etheno adducts from DNAhydrolysates by high perfonnance liquid chromatography. At 50%inhibition of tracer-antibody binding, both Mab had a detectionlimit of 187 fmol and antibody affinity constants (K) of 2 x10⁹ l/mol. The levels of dAdo and dyd were quantitated in theDNA of lung and liver tissue of young Sprague-Dawley rats exposedto 2000 p.p.m. of VC for 10 days. The dAdo/2'-deoxyadenosineand dCyd/2'-deoxycytidine molar ratios were 1.3 x 10^–7and 3.3 x 10^–7 respectively, in lung DNA, and 5.0 x 10^–8and 1.6 x 10^–7 in liver DNA. When hydrolysates of 3 mgof DNA were analyzed by RIA at 25% inhibition of tracer-antibodybinding, dAdo and dCyd were not detected in liver DNA from untreatedrats above the limiting dAdo/2'-deoxyadenosine and dCyd/2'-deoxycytidinemolar ratios of 2.2 x 10^–8 and 3.1 x 10^–8, respectively.