bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relative sensitivity of the endogenous hprt gene and lacl transgene in ENU‐treated big blue™ B6C3F1 mice
Authors: Skopek Thomas R. , Kort Kristy L. , Marino Deborah R. 
Published: February 2007

AbstractThree‐week‐old Big Blue™ (BB) B6C3F1 mice were given a single i.p. injection of ENU. Three weeks later, splenic T cells were isolated from each animal by ficoll gradient centrifugation and divided into two samples. One sample was cultured to measure hprt− mutation and the other was used to extract DMA for lacl− analysis. T cells from BB mice exposed to 0, 4.5, 13.5, and 40 mg ENU/kg (9 or 10 animals per group) displayed dose‐related increases in the frequency of both hprt− and lacl− mutations. Within each treatment group, the ENU‐induced mutation frequency (average observed mutation frequency minus average control frequency) was remarkably similar at the two loci. This suggests that treatments that increase mutation frequency at the endogenous hprt gene also produce similar incremental increases at the BB lacl transgene. However, because of the ten‐fold higher spontaneous mutation rate at lacl, the fold‐increase over background produced by ENU at this locus was significantly less than the fold‐increase produced at hprt. For example, the 4.5 mg ENU/kg treatment produced a 5.2‐fold increase above background at hprt (P = 0.001), whereas only a 1.5‐fold increase was produced at lacl (P = 0.140). Consequently, mutagenic insults that produce up to a fivefold increase in mutation frequency at an endogenous locus may be difficult to detect at the lacl transgene. Finally, the ENU‐induced response at hprt in BB mice was identical to that in generic B6C3F1 mice, suggesting that there are no inherent differences between transgenic and normal mice in their response to this mutagenic agent. © 1995 Wiley‐Liss, Inc.
Improved sensitivity of the unscheduled DNA synthesis assay in primary rat hepatocytes following culture in serum‐free defined media
Authors: Parton Joseph W. , Yount David J. , Garriott Michael L. 
Published: February 2007

AbstractThe unscheduled DNA synthesis (UDS) assay has been used extensively for the in vitro detection of DNA damage caused by compound exposure. However, the in vitro UDS assay has been insensitive for the detection of certain chemicals, particularly nitroaromatic compounds, that are positive in bacterial mutation assays. Recently, studies have been reported which describe alterations in the he‐patocyte membrane following collagenase perfusion. Independently, a method for serum‐free tissue culture has been developed which results in the up‐regulation of cell surface receptors and which may restore membrane functions. Fourteen compounds, including seven nitroaromatics, were evaluated in the in vitro UDS assay employing a serum‐free procedure. Five compounds that were previously reported positive in the standard in vitro UDS assay were also found positive using the serum‐free method. In addition, five of the nitroaromatic compounds produced positive results with the serum‐free method. 1‐Methyl‐3‐nitro‐1‐nitrosoguanidine and 2‐acetylaminofluorene, routinely used as positive controls in the UDS assay, showed greater activity in the serum‐free assay. These results suggest that the use of serum‐free media improves the sensitivity of the in vitro UDS assay and that the serum‐free procedure potentially offers an effective alternative to the more labor intensive and more costly in vivo UDS assay. © 1995 Wiley‐Liss, Inc.
Sensitivity of somatic mutations in human umbilical cord blood to maternal environments
Authors: Manchester David K. , Nicklas Janice A. , O'Neill J. Patrick , Lippert Malcolm J. , Grant Stephen G. , Langlois Richard G. , Moore Dan H. , Jensen Ronald H. , Albertini Richard J. , Bigbee William L. 
Published: February 2007

AbstractTo assess the potential effect of maternal environments on human embryonic/fetal somatic mutation, we measured the frequencies of hypoxanthine‐guanine phosphoribosyltransferase (HPRT, hprt gene), mutant T lymphocytes (Mf), and glycophorin A (GPA) variant erythrocytes (Vf) of both allele‐loss (ø/N) and allele‐loss‐and‐duplication (N/N) phenotypes in umbilical cord blood. The mean hprt Mf (1.40 ± 1.11 × 10−6, N = 66) and GPA Vf (ø/N 4.0 ± 2.2 × 10−6, N = 114; N/N 2.7 ± 2.0 × 10−6, N = 91) were significantly lower than those previously reported for adult populations. In addition, the hprt Mf was significantly higher than that of a published study of newborn cord blood samples from a geographically distant population (0.64 ± 0.41 × 10−6, N = 45, P < 0.01; t test, P < 0.01, Mann‐Whitney U test). An examination of the demographic data from these two populations led to the sampling of 10 additional newborns specifically matched to the published study for maternal socioeconomic status. The hprt Mf (0.70 ± 0.49 × 10−6) of this selected population was consistent with the published report and significantly lower than that of our initial population (P < 0.03, t test; P < 0.01, Mann‐Whitney U test). These results indicate that there is an environmental effect related to maternal socioeconomic status on the frequency of embryonic/fetal somatic mutations. Molecular analyses of hprt mutants from this cohort with elevated Mf revealed a significant decrease in the relative contribution of gross structural mutations to the overall Mf (25 of 38, 66% vs. 34 of 41, 83%, P = 0.024, x2 test), suggesting that the higher Mf resulted from an elevated level of “point” mutations. No individual maternal demographic or environmental factor was identified as contributing more significantly than other any factor to the observed variability in hprt Mf or GPA Vf. © 1995 Wiley‐Liss, Inc.
Analysis of in vivo mutation induced by N‐ethyl‐N‐nitrosourea in the hprt gene of rat lymphocytes
Authors: Mittelstaedt Roberta A. , Smith Beverly A. , Heflich Robert H. 
Published: February 2007

AbstractThe rat lymphocyte hprt assay measures in vivo mutagenicity by quantifying the frequency of 6‐thioguanine‐resistant (TG') spleen lymphocytes cultured in vitro. In this study we have examined the types of mutations induced in the hprt gene of TG' lymphocyte clones from female Fischer 344 rats exposed to 100 mg/kg N‐ethyl‐N‐nitrosourea (ENU). Hprt exons 3 and 8 were amplified from DNA extracted from each of 249 clones, and the resulting products were screened for mutant:wild‐type heteroduplex formation by denaturing gradient gel electrophoresis. The analysis revealed 59 clones with mutations in exon 3, and 20 clones with mutations in exon 8. DNA sequence analysis of the heteroduplexes identified 84 mutations: all of the mutations were base pair substitutions, and 88% were mutations of A:T base pairs. At least 82% were induced independently. These results suggest that the mutations found in TG' rat lymphocytes from ENU‐treated rats were due mainly to ethylthymidine adducts. In addition, a comparison of these results with previously reported in vivo ENU mutational profiles indicates that the types of mutation detected by heteroduplex screening of rat hprt exons 3 and 8 are representative of mutation in the entire protein coding sequence. © 1995 Wiley‐Liss, Inc.This article is a US Government work and, as such, i s in the public domain in the United States of America.
Induction of micronuclei in human sperm‐hamster egg hybrids at the two‐cell stage after in vitro gamma‐irradiation of human spermatozoa
Authors: Tusell L. , Alvarez R. , Caballin M. R. , Genescà A. , Miró R. , Ribas M. , Egozcue J. 
Published: February 2007

AbstractThe efficiency of the micronucleus test to assess radiation‐induced chromosomal damage in human spermatozoa has been investigated. Micronuclei were scored in human sperm‐hamster egg hybrids at the two‐cell stage, after exposure of human spermatozoa to in vitro gamma‐rays at doses of 0.00, 0.10, 0.25, 0.50, 1.00, 2.00, and 4.00 Gy. The relationship between the yield of micronuclei per two‐cell stage as well as the percentage of two‐cell stages with micronuclei and the different doses of irradiation were fitted to linear equations. To evaluate whether scoring micronuclei is useful for the quantification of chromosomal damage occurring in human spermatozoa, induced micronuclei at the different doses of sperm irradiation were compared to the induction of breaks and fragments in sperm‐derived chromosomes. After interspecific fertilization of zona‐free hamster oocytes by irradiated spermatozoa, a total of 699 fertilized eggs at the two‐cell stage and a total of 387 sperm‐derived complements were analyzed. The incidence of fertilized eggs with micronuclei at the two‐cell stage coincided well with the incidence of sperm‐derived chromosome breaks and fragments (e.g., 8.9% vs. 6.7% in the 0.25 Gy group and 52.8% vs. 58.6% in the 4.00 Gy group). A similar correlation was found between the number of micronuclei per two‐cell stage and the number of breaks and fragments per sperm complement (0.09 vs. 0.07 in the 0.25 Gy group and 0.71 vs. 0.81 in the 4.00 Gy group). The results show that this test system can be used for the quantification of spontaneous or induced chromosomal damage in human spermatozoa. © 1995 Wiley‐Liss, Inc.
Genotoxicity of the natural cercaricides “sucupira” oil and eremanthine in mammalian cells in vitro and in vivo
Authors: Dias Francisca Da Luz , Takahashi Catarina Satie , Sakamoto‐Hojo Elza Tiemi , Vichnewski Walter , Sarti Silvio Jose 
Published: February 2007

Abstract“Sucupira” oil and the lactone eremanthine, extracted from Pterodon pubescens and Eremanthus elaeagnus, respectively, are known for their cercaricidal action in experimental animals. Because of their biological effect, they have the potential to be used for the prophylaxis of schistosomiasis caused by Schistosoma mansoni. To test the clastogenicity of these agents, “sucupira” oil, either pure or diluted in corn oil, was tested in vivo on Wistar rat bone marrow cells following dermal application. Metaphase analysis showed that the compound did not induce a significant increase in the frequencies of chromosomal aberrations. When eremanthine was tested on BALB/c mice following gavage at doses of 100, 200, and 300 mg/kg bw, it did not induce structural or numerical chromosomal aberrations. In the in vitro treatment of human lymphocyte cultures, eremanthine also did not cause any increase in chromosomal aberrations or sister chromatid exchanges at the following concentrations in culture medium: 1.25, 2.50, and 5.00 μg/ml. From these results, under our experimental conditions, neither “sucupira” oil nor eremanthine showed clastogenic effects on mammalian cells in vivo or in vitro. © 1995 Wiley‐Liss, Inc.
A study of copper recovery from copper‐contaminated sludge with ferrite and selective leaching processes
Authors: Hu S.H. , Wu J.Y. , Hsiao T.C. , Yen F.S. , Tsai M.S. 
Published: February 2007

AbstractThe purpose of this study was to develop an effective resource recovery and leached residue stabilization process for copper‐contaminated sludge. To this end, a treatment procedure utilizing ferrite and selective leaching processes was developed. The XRD examination of ferrite complex revealed the crystalline phases to be mainly Fe3O4, CuO, and 6CuO·Cu2O.A selective leaching process was followed to recover the copper content of the ferrite complex. To promote the dissolution percentage of copper and repress that of iron, additional 0.5 N sulfuric acid was added at intervals to the suspension in the second step of the selective leaching process. The purpose of this operation was to return the suspension pH back to 3 to promote the dissolution of copper oxide and repress the dissolution of iron.Finally, the heavy metal (i.e., Cu, Pb, Cr, and Cd) dissolution of the above residue was examined with toxicity characteristic leaching procedure (TCLP) testing and all met the regulatory standard. © 2007 American Institute of Chemical Engineers Environ Prog 26:104–112, 2007
Explicit formulations for evaluation of velocity gradients using boundary‐domain integral equations in 2D and 3D viscous flows
Authors: Gao Xiao‐Wei 
Published: February 2007

AbstractIn this paper, explicit boundary‐domain integral equations for evaluating velocity gradients are derived from the basic velocity integral equations. A free term is produced in the new strongly singular integral equation, which is not included in recent formulations using the complex variable differentiation method (CVDM) to compute velocity gradients (Int. J. Numer. Meth. Fluids 2004; 45:463–484; Int. J. Numer. Meth. Fluids 2005; 47:19–43). The strongly singular domain integrals involved in the new integral equations are accurately evaluated using the radial integration method (RIM). Considerable computational time for evaluating integrals of velocity gradients can be saved by using present formulation than using CVDM. The formulation derived in this paper together with those presented in reference (Int. J. Numer. Meth. Fluids 2004; 45:463–484) for 2D and in (Int. J. Numer. Meth. Fluids 2005; 47:19–43) for 3D problems constitutes a complete boundary‐domain integral equation system for solving full Navier–Stokes equations using primitive variables. Three numerical examples for steady incompressible viscous flow are given to validate the derived formulations. Copyright © 2007 John Wiley & Sons, Ltd.
Resolution of the Navier–Stokes equations on block‐structured meshes
Authors: Romé C. , Glockner S. , Caltagirone J. P. 
Published: February 2007

AbstractWe propose a non‐iterative method to connect non‐matching block‐structured meshes applied to the resolution of the Navier–Stokes equations. The present article gives a complete description of the method based on the implicit treatment of the connecting condition. We also extend it to curvilinear meshes. The spatial convergence order of the method is shown to be two and the approach is validated on different 2D laminar flows frequently found in the literature. Copyright © 2007 John Wiley & Sons, Ltd.
Characteristic karyotypic anomalies identify subtypes of malignant fibrous histiocytoma
Authors: Mandahl Nils , Heim Sverre , Willén Helena , Rydholm Anders , Eneroth Magnus , Nilbert Mef , Kreicbergs Andris , Mitelman Felix 
Published: February 2007

AbstractCytogenetic analysis of short‐term cultures from 25 malignant fibrous histiocytomas (MFH) revealed clonal chromosome abnormalities in 17 tumors: ten storiform‐pleomorphic and seven myxoid MFH. Telomeric associations, rings, and dicentric chromosomes were present in 11 tumors and cytogenetic signs of gene amplification (homogeneously staining regions and double minute chromosomes) in four. The breakpoint distribution of the numerous structural rearrangements was nonrandom. The chromosome bands most frequently affected were 19p13 (in eight tumors; eight rearrangements gave rise to 19p+ markers, some of which looked similar, and an r(19) was found in one case), 11p11 (in seven tumors; three translocations and four deletions), 1q11 (in seven tumors; one translocation and six deletions), and 3p12 (in six tumors; all deletions). Other bands involved at least four times were 1p36, 5p15, and 20q13. Of particular clinical interest was the observation that tumors with 19p+ seemed to have a pronounced tendency to recur locally (local recurrence in five of eight tumors with 19p+ compared to one of nine in tumors without this aberration; observation period 4–16 months).
Chromosome I deletions in human neuroblastomas: Generation and fine mapping of microclones from the distal Ip region
Authors: Martinsson Tommy , Weith Andreas , Cziepluch Celina , Schwab Manfred 
Published: February 2007

AbstractHuman neuroblastomas show a high incidence of deletions in the distal region of the short arm of chromosome 1. In pursuit of a molecular analysis of these deletions, we have generated a microclone bank from microdissected 1p35‐pter chromosomal fragments. To allow a rapid localization of the microclones, we have also generated a panel of (human X mouse) hybrid cell lines through microcell‐mediated chromosome transfer. The hybrid cells contained different portions of the human chromosome 1 on a murine background. A total of 20 randomly chosen single or low‐copy microclones were localized by Southern analysis on DNA of the hybrid panel: All probes were derived from chromosome 1. Sixteen mapped in region 1p36.I‐pter, two in 1p22‐p36.1, and another two in 1 cen‐qter. The mapping of ten of these microclones was further refined by in situ hybridization. Cells of the neuroblastoma line GI‐ME‐N carry two types of chromosome 1, one cytogenetically normal and another with a translocation reported to be in 1p36.2, i.e., a t(1;?)(p36.2;?) marker. Using cell hybridization, we separated the two chromosome 1 types of GI‐ME‐N into different hybrid cell clones. Southern hybridization of three microclones from distal 1p to DNA of the hybrid cell clones revealed that the breakpoint in the translocated chromosome 1 was located in 1p36.1.
Complex karyotypic anomalies in a bizarre leiomyoma of the uterus
Authors: Nilbert Mef , Heim Sverre , Mandahl Nils , Flodérus Ulla‐Maria , Willén Helena , Baldetorp Bo , Mitelman Felix 
Published: February 2007

AbstractCytogenetic investigation of short‐term cultures from a bizarre leiomyoma of the uterus, a tumor type not hitherto karyotypically characterized, revealed two abnormal clones with multiple complex rearrangements. Three‐fourths of the aberrant cells were hypodiploid with the composite karyotype 38–44, XX,−6,−7,−10,−11,+20,−22, r(1), der(2) (:2p23→cen→2q13::1q21→1qter), der(2)t(2;9)(p21;q13), t(5;?)(q35;?), t(5;?),(q35;?), + der(5)t(5;15)(q11;q15), der(8)t(8;11)(q24;q13), t(15;?)(p12;?), der(16)t(12;16)(q13;p13),+r,+mar. The remaining abnormal mitoses were hypotetraploid, with chromosome numbers ranging from 74 to 86. These massively rearranged cells showed the same markers that were found in the hypodiploid clone, but in duplicate, indicating that this clone had arisen through polyploidization of hypodiploid cells. Flow cytometry revealed a DNA index of 1.03.
Recurring loss involving chromosomes 1, 3, and 22 in malignant mesothelioma: Possible sites of tumor suppressor genes
Authors: Flejter Wendy L. , Li Frederick P. , Antman Karen H. , Testa Joseph R. 
Published: February 2007

AbstractCytogenetic analysis was performed on short‐term cultures of primary tumor tissue obtained from five patients with pleural malignant mesothelioma. Clonal karyotypic abnormalities were detected in four patients, none of whom had received cytotoxic therapy prior to karyotypic evaluation. Recurring chromosomal changes included partial deletions of 1p and 3p, and monosomy of 18, 19, and 22. We also reviewed data on 24 previously reported pretreatment patients and determined that alterations of chromosomes 1, 3, and 22 are frequently associated with malignant mesothelioma. Partial loss of chromosome 1 due to deletions or other rearrangements most frequently involve bands 1p11‐pter with the shortest region of overlap (SRO) occurring at 1p21–p22 in our patients. Deletions and other structural changes of chromosome 3 usually involve the region 3p14‐p25. The SRO of 3p deletions appeared to be at band 3p21. Monosomy 22 represents the most consistent specific whole chromosome loss seen in malignant mesothelioma, being observed in 11 of 28 cases summarized. In addition, structural changes of 22q have been observed in three patients, and a breakpoint at 22q11 was reported in each case. Taken collectively, these data suggest that a cascade of events involving alterations of genes on more than one specific chromosome may play a critical role in the development of malignant mesothelioma. The pattern of recurring chromosomal loss, particularly of 1p, 3p, and 22q, indicates that these regions should be targeted for future molecular investigations into the possible involvement of suppressor genes in this malignancy.
Neuroblastoma consensus deletion maps to 1p36.1–2
Authors: Weith Andreas , Martinsson Tommy , Cziepluch Celina , Brüderlein Silke , Amler Lukas C. , Berthold Frank , Schwab Manfred 
Published: February 2007

AbstractAt least 70% of human neuroblastomas display cytogenetically visible aberrations in the short arm of chromosome 1. We have used a panel of probes detecting polymorphic DNA loci, most of which were derived from a library of microdissected distal 1p chromosome fragments, to compare the hybridization pattern of DNA on nine different tumors and the corresponding normal tissue. In eight of the neuroblastomas allelic loss was observed with at least two probes. The deletions were of different size. Since a consensus deletion in all eight tumors included the segment 1p36.1–2, we conclude that genetic information related to neuroblastoma tumorigenesis is located within this approximately 10 megabase segment. Previous studies have revealed the amplification of MYCN in neuroblastomas. Our study did not provide evidence for a correlation between MYCN amplification and the 1p deletion, suggesting that the two genetic alterations result from molecular mechanisms that are not directly related to each other.
Use of fluorescent in situ hybridization to confirm trisomy of chromosome region 1q32‐qter as the sole karyotypic defect in a colon cancer cell line
Authors: Griffin Darren K. , Leigh Sarah E. A. , Delhanty Joy D. A. 
Published: February 2007

AbstractThe sole chromosome defect in a colon cancer cell line derived from a patient with inherited nonpolyposis colorectal cancer was karyotypically designated as 46, XY,−13,+der(13)t(1;13)(q32.1;p11) on the basis of banding homology. We have obtained molecular confirmation that the additional chromosome material is derived from chromosome region 1q32‐qter by the use of a highly specific fluorescent in situ hybridisation technique on G‐banded chromosomes and also by Southern hybridisation.
Immunohistochemical, molecular, and cytogenetic analysis of a consecutive series of 20 peripheral t‐cell lymphomas and lymphomas of uncertain lineage, including 12 Ki‐I positive lymphomas
Authors: Ebrahim Salah A. D. , Ladanyi Marc , Desai Suvas B. , Offit Kenneth , Jhanwar Suresh C. , Filippa Daniel A. , Lieberman Philip H. , Chaganti R. S. K. 
Published: February 2007

AbstractAlthough several independent series of non‐Hodgkin's lymphomas (NHLs) have been subjected to cytogenetic studies or analyses of lineages by assaying for clonal immunophenotypes and clonal rearrangements affecting immunoglobulin (IG) and T‐cell receptor (TCR) genes, no published reports exist of series of non‐B‐cell NHLs on which cytogenetic, immunohistochemical, and IG and TCR gene rearrangement studies have been undertaken together. Among 434 NHLs ascertained prospectively between January 1984 and December 1988 at the Memorial Sloan‐Kettering Cancer Center, 278 cases with clonal chromosome abnormalities were identified. Of the latter, 20 were non‐B‐cell NHLs, which in turn comprised 15 peripheral T‐cell lymphomas (PTCLs) and 5 lymphomas of uncertain lineage (LULs). The LULs either were bigenotypic, had discordant immunophenotype and immunogenotype, or showed no evidence of B‐cell, T‐cell, or histiocytic derivation. Of the 15 PTCLs, eight expressed the Ki‐1 antigen and four of these had translocations involving the band 5q35 [t(5q35)]. Of the five LULs, four expressed the Ki‐1 antigen and one of these had a translocations involving band 5q35. Previous studies have associated t(5q35) with Ki‐1 positive NHLs characterized histologically by a pleomorphic diffuse large cell morphology. In our series of 12 Ki‐positive non‐B‐cell NHLs, five (42%) had a 5q35 translocation. They were histologically indistinguishable from the subset without the translocation. The frequent lineage uncertainty exhibited by Ki‐1 positive NHLs of similar histology and cytogenetic abnormalities suggests their derivation from an early uncommitted lymphoid cells.