26
|
Iodice M, Cusanno F, Acha A, Ambrozewicz P, Aniol KA, Baturin P, Bertin PY, Benaoum H, Blomqvist KI, Boeglin WU, Breuer H, Brindza P, Bydzovský P, Camsonne A, Chang CC, Chen JP, Choi S, Chudakov EA, Cisbani E, Colilli S, Coman L, Craver BJ, De Cataldo G, de Jager CW, De Leo R, Deur AP, Ferdi C, Feuerbach RJ, Folts E, Fratoni R, Frullani S, Garibaldi F, Gayou O, Giulani F, Gomez J, Gricia M, Hansen JO, Hayes D, Higinbotham DW, Holmstrom TK, Hyde CE, Ibrahim HF, Jiang X, Kaufman LJ, Kino K, Kross B, Lagamba L, LeRose JJ, Lindgren RA, Lucentini M, Margaziotis DJ, Markowitz P, Marrone S, Meziani ZE, McCormick K, Michaels RW, Millener DJ, Miyoshi T, Moffit B, Monaghan PA, Moteabbed M, Muñoz Camacho C, Nanda S, Nappi E, Nelyubin VV, Norum BE, Okasyasu Y, Paschke KD, Perdrisat CF, Piasetzky E, Punjabi VA, Qiang Y, Raue B, Reimer PE, Reinhold J, Reitz B, Roche RE, Rodriguez VM, Saha A, Santavenere F, Sarty AJ, Segal J, Shahinyan A, Singh J, Sirca S, Snyder R, Solvignon PH, Sotona M, Subedi R, Sulkosky VA, Suzuki T, Ueno H, Ulmer PE, Urciuoli GM, Veneroni P, Voutier E, Wojtsekhowski BB, Ye Y, Zheng X, Zhou S, Zorn C. High resolution spectroscopy of (lambda)(12)B by electroproduction. PHYSICAL REVIEW LETTERS 2007; 99:052501. [PMID: 17930747 DOI: 10.1103/physrevlett.99.052501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2007] [Indexed: 05/25/2023]
Abstract
An experiment measuring electroproduction of hypernuclei has been performed in hall A at Jefferson Lab on a 12C target. In order to increase counting rates and provide unambiguous kaon identification two superconducting septum magnets and a ring imaging Cherenkov detector were added to the hall A standard equipment. An unprecedented energy resolution of less than 700 keV FWHM has been achieved. Thus, the observed (Lambda)(12)B spectrum shows for the first time identifiable strength in the core-excited region between the ground-state s-wave Lambda peak and the 11 MeV p-wave Lambda peak.
Collapse
|
27
|
Giann L, Cole B, Panzini I, Snyder R, Holmberg S, Byrne M, Castiglione-Gertsch M, Goldhirsch A, Coates A, Ravaioli A. P107 Anemia during adjuvant chemotherapy for early breast cancer: incidence and risk factors – Results from the International Breast Cancer Study Group (IBCSG). Breast 2007. [DOI: 10.1016/s0960-9776(07)70167-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
|
28
|
Acha A, Aniol KA, Armstrong DS, Arrington J, Averett T, Bailey SL, Barber J, Beck A, Benaoum H, Benesch J, Bertin PY, Bosted P, Butaru F, Burtin E, Cates GD, Chao YC, Chen JP, Chudakov E, Cisbani E, Craver B, Cusanno F, De Leo R, Decowski P, Deur A, Feuerbach RJ, Finn JM, Frullani S, Fuchs SA, Fuoti K, Gilman R, Glesener LE, Grimm K, Grames JM, Hansen JO, Hansknecht J, Higinbotham DW, Holmes R, Holmstrom T, Ibrahim H, de Jager CW, Jiang X, Katich J, Kaufman LJ, Kelleher A, King PM, Kolarkar A, Kowalski S, Kuchina E, Kumar KS, Lagamba L, LaViolette P, LeRose J, Lindgren RA, Lhuillier D, Liyanage N, Margaziotis DJ, Markowitz P, Meekins DG, Meziani ZE, Michaels R, Moffit B, Nanda S, Nelyubin V, Otis K, Paschke KD, Phillips SK, Poelker M, Pomatsalyuk R, Potokar M, Prok Y, Puckett A, Qian X, Qiang Y, Reitz B, Roche J, Saha A, Sawatzky B, Singh J, Slifer K, Sirca S, Snyder R, Solvignon P, Souder PA, Stutzman ML, Subedi R, Suleiman R, Sulkosky V, Tobias WA, Ulmer PE, Urciuoli GM, Wang K, Whitbeck A, Wilson R, Wojtsekhowski B, Yao H, Ye Y, Zhan X, Zheng X, Zhou S, Ziskin V. Precision measurements of the nucleon strange form factors at Q2 approximately 0.1 GeV2. PHYSICAL REVIEW LETTERS 2007; 98:032301. [PMID: 17358678 DOI: 10.1103/physrevlett.98.032301] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2006] [Indexed: 05/14/2023]
Abstract
We report new measurements of the parity-violating asymmetry A(PV) in elastic scattering of 3 GeV electrons off hydrogen and 4He targets with <theta(lab)> approximately 6.0 degrees . The 4He result is A(PV)=(+6.40+/-0.23(stat)+/-0.12(syst))x10(-6). The hydrogen result is A(PV)=(-1.58+/-0.12(stat)+/-0.04(syst))x10(-6). These results significantly improve constraints on the electric and magnetic strange form factors G(E)(s) and G(M)(s). We extract G(E)(s)=0.002+/-0.014+/-0.007 at <Q(2)>=0.077 GeV2, and G(E)(s)+0.09G(M)(s)=0.007+/-0.011+/-0.006 at <Q(2)>=0.109 GeV2, providing new limits on the role of strange quarks in the nucleon charge and magnetization distributions.
Collapse
|
29
|
Lozner EL, Taylor FH, Lemish S, Snyder R, Newhouser LR. PRESERVATION OF NORMAL HUMAN PLASMA IN THE LIQUID STATE. III. STUDIES ON CHEMICAL AND PHYSICO-CHEMICAL CHANGES DURING THE SECOND YEAR OF STORAGE. J Clin Invest 2006; 23:357-60. [PMID: 16695113 PMCID: PMC435350 DOI: 10.1172/jci101502] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
30
|
Aniol KA, Armstrong DS, Averett T, Benaoum H, Bertin PY, Burtin E, Cahoon J, Cates GD, Chang CC, Chao YC, Chen JP, Choi S, Chudakov E, Craver B, Cusanno F, Decowski P, Deepa D, Ferdi C, Feuerbach RJ, Finn JM, Frullani S, Fuoti K, Garibaldi F, Gilman R, Glamazdin A, Gorbenko V, Grames JM, Hansknecht J, Higinbotham DW, Holmes R, Holmstrom T, Humensky TB, Ibrahim H, de Jager CW, Jiang X, Kaufman LJ, Kelleher A, Kolarkar A, Kowalski S, Kumar KS, Lambert D, LaViolette P, LeRose J, Lhuillier D, Liyanage N, Margaziotis DJ, Mazouz M, McCormick K, Meekins DG, Meziani ZE, Michaels R, Moffit B, Monaghan P, Munoz-Camacho C, Nanda S, Nelyubin V, Neyret D, Paschke KD, Poelker M, Pomatsalyuk R, Qiang Y, Reitz B, Roche J, Saha A, Singh J, Snyder R, Souder PA, Subedi R, Suleiman R, Sulkosky V, Tobias WA, Urciuoli GM, Vacheret A, Voutier E, Wang K, Wilson R, Wojtsekhowski B, Zheng X. Parity-violating electron scattering from 4He and the strange electric form factor of the nucleon. PHYSICAL REVIEW LETTERS 2006; 96:022003. [PMID: 16486563 DOI: 10.1103/physrevlett.96.022003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2005] [Indexed: 05/06/2023]
Abstract
We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from 4He at an average scattering angle <theta(lab)> = 5.7 degrees and a four-momentum transfer Q2 = 0.091 GeV2 . From these data, for the first time, the strange electric form factor of the nucleon G(E)s can be isolated. The measured asymmetry of A(PV) = (6.72 +/- 0.84(stat) +/- 0.21(syst) x 10(-6) yields a value of G(E)s = -0.038 +/- 0.042(stat) +/- 0.010(syst), consistent with zero.
Collapse
|
31
|
Extra JM, Cognetti F, Maraninchi D, Snyder R, Mauriac L, Tubiana-Hulin M, Chan S, Grimes D, Anton A, Marty M. Long-term survival demonstrated with trastuzumab plus docetaxel: 24-month data from a randomised trial (M77001) in HER2-positive metastatic breast cancer. J Clin Oncol 2005. [DOI: 10.1200/jco.2005.23.16_suppl.555] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
32
|
Bernhard J, Zahrieh D, Coates AS, Gelber RD, Castiglione-Gertsch M, Murray E, Forbes JF, Perey L, Collins J, Snyder R, Rudenstam CM, Crivellari D, Veronesi A, Thürlimann B, Fey MF, Price KN, Goldhirsch A, Hürny C. Quantifying trade-offs: quality of life and quality-adjusted survival in a randomised trial of chemotherapy in postmenopausal patients with lymph node-negative breast cancer. Br J Cancer 2005; 91:1893-901. [PMID: 15545973 PMCID: PMC2409769 DOI: 10.1038/sj.bjc.6602230] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
We evaluated quality of life (QL) and quality-adjusted survival in International Breast Cancer Study Group Trial IX, a randomised trial including 1669 eligible patients receiving tamoxifen for 5 years or three prior cycles of cyclophosphamide, methotrexate and 5-fluorouracil (CMF) followed by 57 months tamoxifen. During the time with CMF toxicity (Tox), without symptoms and toxicity (TWiST), and following relapse (Rel), patients scored their QL indicators and a utility indicator for subjective health estimation between ‘perfect’ and ‘worst’ health. Scores were averaged within Tox, TWiST and Rel and transformed to utilities. Mean durations for the three transition times were weighted with utilities to obtain mean quality-adjusted TWiST (Q-TWiST). Patients receiving CMF reported significantly worse scores for most QL domains at month 3, but less hot flushes. After completing chemotherapy, there were no differences by treatment groups. Benefits evaluated by Q-TWiST favoured the additional chemotherapy. CMF provided 3 more months of Q-TWiST for patients with ER-negative tumours, but CMF provided no benefit in Q-TWiST for patients with ER-positive tumours. Q-TWiST analysis based on patient ratings is feasible in large-scale cross-cultural clinical trials.
Collapse
|
33
|
Colleoni M, Gelber S, Snyder R, Holmberg SB, Fey M, Thuerlimann B, Lindtner J, Byrne M, Mendiola C, Coates AS. Randomized comparison of adjuvant tamoxifen (Tam) versus no hormonal treatment for premenopausal women with node-positive (N+), early stage breast cancer: first results of International Breast Cancer Study Group Trial 13–93. J Clin Oncol 2004. [DOI: 10.1200/jco.2004.22.90140.532] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
34
|
Gesler W, Smith R, DeDecker PG, Bernstam L, Snyder R, Freed PS, Kantrowitz A. Updated Feasibility Trial Experience with the Viaderm Percutaneous Access Device. ASAIO J 2004; 50:349-53. [PMID: 15307546 DOI: 10.1097/01.mat.0000131248.70074.e3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The percutaneous access device (PAD) is used to connect an external drive unit to the Kantrowitz CardioVad (KCV), a cardiac assist device for the treatment of chronic heart failure. The PAD conveys pneumatic power from a drive unit to the implanted blood pump and an electrocardiogram signal from the myocardium to the drive unit. The device-tissue interface of the PAD is precoated with autologous fibroblasts cultured from a skin sample of the intended recipient. This preparation demonstrated long-term stability in animals and was adopted for use in patients receiving the KCV. The KCV is activated intermittently, and the drive unit may be connected and disconnected by the patient, which subjects the PAD to frequent manipulation. To date, the PAD has been implanted in nine patients ranging in age from 41 to 74 years. Implant times ranged from 2 to 458 days, for a total of 1082 days, of which 557 days were in an outpatient setting. Two patients experienced episodes of infection that did not originate from the PAD-tissue interface. This feasibility study demonstrated that (1) the PAD is stable and infection resistant in long-term ambulatory patients, (2) the PAD withstood the challenge of daily manipulation (the KCV is turned on and off electively), and (3) PADs can be replaced, if necessary.
Collapse
|
35
|
Berclaz G, Li S, Price KN, Coates AS, Castiglione-Gertsch M, Rudenstam CM, Holmberg SB, Lindtner J, Erien D, Collins J, Snyder R, Thürlimann B, Fey MF, Mendiola C, Werner ID, Simoncini E, Crivellari D, Gelber RD, Goldhirsch A. Body mass index as a prognostic feature in operable breast cancer: the International Breast Cancer Study Group experience. Ann Oncol 2004; 15:875-84. [PMID: 15151943 DOI: 10.1093/annonc/mdh222] [Citation(s) in RCA: 186] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Current information on the prognostic importance of body mass index (BMI) for patients with early breast cancer is based on a variety of equivocal reports. Few have data on BMI in relationship to systemic treatment. PATIENTS AND METHODS Patients (6792) were randomized to International Breast Cancer Study Group trials from 1978 to 1993, studying chemotherapy and endocrine therapy. BMI was evaluated with eight other factors: menopausal status, nodal status, estrogen receptor status, progesterone receptor status, tumor size, vessel invasion, tumor grade and treatment. BMI was categorized as normal (< or =24.9), intermediate (25.0-29.9) or obese (> or =30.0). RESULTS Patients with normal BMI had significantly longer overall survival (OS) and disease-free survival (DFS) than patients with intermediate or obese BMI in pairwise comparisons adjusted for other factors. Subset analyses showed the same effect in pre- and perimenopausal patients and in those receiving chemotherapy alone. When assessed globally and adjusted for other factors, BMI significantly influenced OS (P = 0.03) but not DFS (P = 0.12). CONCLUSIONS BMI is an independent prognostic factor for OS in patients with breast cancer, especially among pre-/perimenopausal patients treated with chemotherapy without endocrine therapy.
Collapse
|
36
|
Extra JM, Cognetti F, Chan S, Maraninchi D, Snyder R, Lluch A, Tubiana-Hulin M, Grimes D, Mayne K, Marty M. 672 Randomised phase II trial (M77001) of trastuzumab (Herceptin®) plus docetaxel versus docetaxel alone, as first-line therapy in patients with HER2-positive metastitic breast cancer. EJC Suppl 2003. [DOI: 10.1016/s1359-6349(03)90703-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
|
37
|
Kalf GF, Hazel BA, Hoffmann MJ, Kim DD, Snyder R. The interaction of 1,4-benzoquinone, a bioreactive intermediate of benzene, with three proteins essential for differentiation/maturation of the mouse myeloid stem cell. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2002; 500:429-39. [PMID: 11764976 DOI: 10.1007/978-1-4615-0667-6_65] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
|
38
|
Hoffmann MJ, Sinko PJ, Meeker RJ, Snyder R. Pharmacokinetics of benzene following an oral or intradermal dose in FVB and Tg.AC mice. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2002; 500:455-8. [PMID: 11764980 DOI: 10.1007/978-1-4615-0667-6_68] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
|
39
|
Hoffmann MJ, Kim DD, Akbar MG, Kalf GF, Snyder R. The potential role of topoisomerase II inhibition in hydroquinone-induced alterations in the maturation of mouse myeloblasts. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2002; 500:315-8. [PMID: 11764958 DOI: 10.1007/978-1-4615-0667-6_48] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
|
40
|
Snyder R, Shine H, Leibbrand K, Tawney P. Additions and Corrections-The Oxidation of Hydrocarbons. Part II. The Oxidation of Cyclopentene, 3-Methylcyclohexene and Tetralin in Acetic Anhydride Solution. J Am Chem Soc 2002. [DOI: 10.1021/ja01485a606] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
41
|
Snyder R, Testa AC. Modification of benzophenone phosphorescence by molecular complexation. A reversible process. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100496a016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
42
|
|
43
|
Snyder R, Turgay A, Fisman S, Carroll A, Binder C. Long-Term Safety and Efficacy of Risperidone in Children with Subaverage Iq and Disruptive Behavior Disorders. Paediatr Child Health 2002. [DOI: 10.1093/pch/7.suppl_a.28aa] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
44
|
Snyder R, Testa AC. Reversible phosphorescence quenching of some aromatic ketones. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100486a022] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
45
|
Snyder R, Testa AC. Influence of electron-donor-acceptor complexation on electronic relaxation of quinoline. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j150668a040] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
46
|
Turgay A, Snyder R, Binder C, Fisman S, Carrol A. Risperidone in children with subaverage IQ and behavior disorders. Eur Psychiatry 2002. [DOI: 10.1016/s0924-9338(02)80523-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
|
47
|
Snyder R. The International Symposium on Biological Reactive Intermediates. Toxicol Sci 2002. [DOI: 10.1093/toxsci/66.2.173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
48
|
Snyder R, Freed PS, Anderson A, Jeevanandam V, Kantrowitz A. CLINICAL RELIABILITY OF THE KANTROWITZ CARDIOVAD BLOOD PUMP. ASAIO J 2002. [DOI: 10.1097/00002480-200203000-00173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
|
49
|
Haile DT, Hughes J, Vetter E, Kohner P, Snyder R, Patel R, Cockerill FR. Frequency of isolation of Staphylococcus lugdunensis in consecutive urine cultures and relationship to urinary tract infection. J Clin Microbiol 2002; 40:654-6. [PMID: 11825988 PMCID: PMC153380 DOI: 10.1128/jcm.40.2.654-656.2002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Recent reports associate Staphylococcus lugdunensis with severe infection in humans. The frequency of this microorganism in urine cultures is unknown. Five hundred isolates of coagulase-negative staphylococci (CoNS) were recovered from 4,652 consecutive urine specimens submitted for culture to the Mayo Clinic Microbiology Laboratory. Thirty-one (6%) of 500 isolates of CoNS were identified as S. lugdunensis. In no case was S. lugdunensis isolated in pure culture; 29 (94%) of 31 S. lugdunensis isolates were part of mixed nonpathogenic flora. Medical records were reviewed for 30 of the 31 patients from whom these 31 isolates were isolated. Twenty-one (70%) of the 30 evaluable patients were not treated with antibiotics; the remaining 9 (30%) of 30 patients were treated with antibiotics that may be effective against S. lugdunensis. S. lugdunensis may be an unrecognized yet infrequent cause of urinary tract infection.
Collapse
|
50
|
Iba MM, Ghosal A, Snyder R. Comparative metabolism of [14C]benzene to excretable products and bioactivation to DNA-binding derivatives in maternal and neonatal mice. Arch Toxicol 2001; 75:574-82. [PMID: 11808917 DOI: 10.1007/s00204-001-0290-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Lactating adult female mice treated with a single dose of 880 mg/kg i.p. [14C]benzene, and their 2-day-old sucklings similarly treated or nursed by their treated dams were compared in terms of their ability to metabolize benzene to urinary products or reactive intermediates as assessed by covalently-bound benzene derivatives in whole blood or liver DNA. Six metabolite fractions were identified in the urine of sucklings by high performance liquid chromatographic (HPLC) analysis at 5 h following intraperitoneal (direct) treatment with benzene. Three of the metabolite fractions co-chromatographed with authentic phenol, phenyl glucuronide, and muconic acid, and contributed 11, 6.9 and 0.6%, respectively, to the total urinary benzene metabolites. Two of the fractions were unidentified. The sixth and most polar fraction consisted of multiple metabolites, 21% of which were conjugates, and accounted for 72% of the total urinary metabolites. A similar metabolite profile was observed in 24-h urine samples from treated dams with the exception that one of the unidentified fractions in the sucklings was absent and levels of the metabolites were quantitatively higher than those observed in sucklings 5 h following their treatment with benzene. Furthermore, 78% of the most polar fraction from the dams consisted of conjugates compared with 21% of that from the sucklings. The metabolite pattern in urine of sucklings nursed by treated dams was qualitatively similar to, but quantitatively different from the pattern in treated dams. Five hours following intraperitoneal treatment with benzene, covalent binding of the compound to DNA (expressed as pmol benzene equivalents/mg DNA) in sucklings was slightly higher in whole blood (1.15+/-0.07) than in liver (0.77+/-0.07), whereas in the dam, it was slightly lower in whole blood (0.88+/-0.48) than in liver (1.63+/-0.61). Twenty four hours following benzene exposure in sucklings of benzene-treated dams, DNA binding by the compound in whole blood (3.85+/-1.05) and liver (0.11+/-0.03) was higher and lower, respectively than the binding observed in benzene-injected sucklings 5 h following the injection. Our results show that excretable as well as reactive metabolites of benzene are formed substantially by the neonatal mouse, and that the extent of bioactivation of the compound is comparable in the adult and the suckling mouse. The results show also that sucklings of benzene-exposed mothers are exposed to substantial levels of the compound and are potentially susceptible to its toxic effects.
Collapse
|