bluuebunny/crossref_metadata_2025_split huggingface dataset:
Alterations of multiple tumor suppressor genes (p53 (17p13), p16INK4 (9p21), and DBM (13q14)) in B‐CELL chronic lymphocytic leukemia
Authors: Newcomb Elizabeth W. , Rao Laxmi S. , Giknavorian Sonia S. , Lee Seung Y. 
Published: February 2007

AbstractB‐cell chronic lymphocytic leukemia (B‐CLL) samples were screened for alterations in multiple tumor suppressor genes (p53 (17p13), p16 INK4 (9p21), and disrupted in B‐cell malignancy (DBM) (13q14)) by using poly‐merase chain reaction‐based assays. Eleven percent (11 of 96) of the B‐CLL cases analyzed in this study and a previous study had mutations in the p53 gene. In contrast, analysis of the p 16 gene showed none of 80 B‐CLL cases had mutations and five cases (6%) had homozygous deletions. Deletions of 13q14 (DBM) occurred in 18% (17 of 96) of patients surveyed. Thus, 28 of 96 cases showed an alteration in one or more of the three tumor suppressor loci examined. However, cases with p53 mutations rarely showed simultaneous loss of DBM. Our results suggest that inactivation of the tumor suppressor genes p53 and DBM may be mutually exclusive, thus providing alternate pathways for tumor development in B‐CLL patients. © 1995 Wiley‐ Liss, Inc.
Activating mutations in human C‐Ha‐ras‐1 protooncogene induced by stereoisomeric fjord‐region benzo[c]chrysene diol‐epoxides
Authors: Du Ming‐Qing , Seidel Albrecht , Phillips David H. 
Published: February 2007

AbstractThe mutagenicity of fjord‐region benzo[c]chrysene diol‐epoxide (a) stereoisomers ((+) anti‐BcCDE, (‐)anti‐BcCDE, (+)syn‐BcCDE, and (‐)syn‐BcCDE) was studied in a forward‐mutation system. pEC plasmid containing the human c‐Ha‐ras‐1 proto‐oncogene was reacted in vitro with each optically active isomer separately and transfected into NIH/3T3 cells. Morphologically transformed foci were cloned, and DNA obtained from these foci was tested for the presence of Ha‐ras‐1 sequence by Southern blot analysis. A total of 50 transformed foci (11‐14 for each diastereomer) were generated. To determine the nature of mutations responsible for activating the proto‐oncogene, regions of the gene likely to contain the activating mutations were amplified by polymerase chain reaction and then subjected to hybridization with specific oligonucleotides. Gene mutations in 42 of 50 transformed foci were characterized by these methods, and most were found at codon 61 (27), followed by codons 12 (13) and 13 (a). All mutations observed were either G → T or A → T transversions. Thirty‐six were G → T transversion mutations occurring at codons 61, 12, and 13. The remaining six were A → T transversions at codon 61. BcCDE stereoisomers may specifically attack guanine and adenine and result in the mutations observed. Some differences in codon preference but not in the types of mutations were found among these optically active isomers. © 1995 Wiley‐ Liss, Inc.
Analysis of oncogenes, tumor suppressor genes, autocrine growth‐factor production, and differentiation state of human osteosarcoma cell lines
Authors: Isfort Robert J. , Cody David B. , Lovell Glenda , Doersen Claus‐Jens 
Published: February 2007

AbstractHuman osteosarcoma and fibrosarcoma cell lines were investigated for alterations in oncogenes, tumor suppressor genes, and growth factors, all of which have been implicated in tumor formation. Characterization of oncogenes that are involved in osteosarcoma formation, including the c‐fos and c‐myc oncogenes, indicated that all six osteosarcoma cell lines examined had 5‐ to 20‐fold amplification of the c‐myc oncogene, whereas neither of two fibrosarcoma cell lines had c‐myc amplification. Interestingly, only three of six osteosarcoma cell lines displayed altered c‐myc immediate‐early gene function. c‐fos was found to be normal, both at the gene and functional levels, in all six osteosarcoma and both fibrosarcoma cell lines tested. Characterization of two tumor suppressor genes, p53 and RB1, that have been implicated in osteosarcoma formation indicated that p53 was altered in five of six osteosarcoma cell lines, whereas RB1 was altered in only two of six of these cell lines. Neither RB1 nor p53 was found to be altered in the fibrosarcoma cell lines tested. An additional transformation marker, autocrine growth‐factor production, was observed in all six osteosarcoma cell lines and both fibrosarcoma cell lines examined. Finally, the differentiation state of the osteosarcoma cell lines was investigated via the bone differentiation markers alkaline phosphatase and osteocalcin. Alkaline phosphatase activity was observed in four of six osteosarcoma cell lines but not in the two fibrosarcoma cell lines examined. The alkaline phosphatase activity was a result of the expression of the bone/liver/kidney alkaline phosphatase isoform. High‐level osteocalcin expression was observed in one of the osteosarcoma cell lines but not in the two fibrosarcoma cell lines examined, although all cell lines demonstrated low‐level osteocalcin expression. Together, these data demonstrate that relatively undifferentiated osteosarcomas commonly display c‐myc amplification, p53 and RBI mutation, and autocrine growth‐factor production, all of which may play a role in osteosarcomagenesis. © 1995 Wiley‐ Liss, Inc.
Hepatocarcinogenesis in BXH recombinant inbred strains of mice: Analysis of diverse phenotypic effects of the hepatocarcinogen sensitivity loci
Authors: Lee Gang‐Hong , Drinkwater Norman R. 
Published: February 2007

AbstractThe hepatocarcinogen sensitivity (Hcs) loci were originally identified as determinants of the approximately 50‐fold higher susceptibility of male C3H/HeJ (C3H) mice to perinatally induced hepatocarcinogenesis relative to male C57BL/6J (B6) mice. These two inbred strains also differ in other phenotypes related to hepatocarcinogenesis, including their incidences of spontaneous liver tumors and the properties of neoplastic hepatic lesions. To test the hypothesis that the Hcs loci also influence these phenotypes, we characterized male mice from B6, C3H, and nine BXH recombinant inbred (a) strains for spontaneous liver tumor development, the frequency of activating mutations in tumors, and the presence of cytoplasmic inclusions in preneoplastic lesions. By comparing these results to the relative susceptibilities of the parental and Rl strains to N, N‐diethylnitrosamine (a) ‐and N‐ethyl‐N‐nitrosourea‐induced hepatocarcinogenesis in preweanling male mice, we concluded that the C3H alleles of the Hcs loci also positively influence the spontaneous development of liver tumors in male animals. While strain‐dependent differences in the frequency of Ha‐ras‐1 activation in DEN‐initiated liver tumors were observed, this phenotype was not correlated with susceptibility to liver tumor induction. The formation of eosinophilic intracytoplasmic inclusion bodies observed specifically in B6 liver tumors, which has been suggested to be associated with the resistance of this strain to hepatocarcinogenesis, also segregated independently of the Hcs loci. © 1995 Wiley‐ Liss, Inc.
Characterization of novel phorbol ester‐ and serum‐responsive sequences of the rat ornithine decarboxylase gene promoter
Authors: Mar Penny K. , Kumar Addanki P. , Kang Dong‐Chul , Zhao Biwei , Martinez Luis A. , Montgomery Raechelle L. , Anderson Larry , Butler Andrew P. 
Published: February 2007

AbstractOrnithine decarboxylase (a), the key regulatory enzyme in mammalian polyamine biosynthesis, is rapidly induced by mitogens and tumor promoters. We used transient expression assays and DNA‐protein binding studies to examine the regulation of ODC promoter activity by phorbol esters and serum growth factors. A fragment of the ODC 5′ flanking region (nt ‐1156 to + 13) was sufficient to confer 12‐O‐tetradecanoylphorbol‐13‐acetate (a) ‐responsive expression to a luciferase reporter gene when transfected into H35 cells. However, induction by TPA was not observed in Rat2 fibroblasts, although refeeding of serum‐starved Rat2 cells with fresh serum‐containing medium rapidly induced a fivefold to sixfold increase in ODC promoter activity, maximal about 8 h after refeeding. Deletion analysis demonstrated that several sequences contributed to basal ODC promoter activity but that nt ‐92 to +13 was sufficient for induction by TPA or by serum. This sequence lacked canonical TPA‐responsive elements, and an activator protein‐1 (AP‐1) consensus oligonucleotide failed to compete effectively for proteins binding to this region. Two of four protein complexes observed by gel‐shift analysis of nt ‐92 to +13 were competitively inhibited by wild‐type but not mutant oligonucleotides encompassing a variant cyclic AMP‐response element (a) (ODC nt ‐50 to ‐42); however, a consensus CRE did not compete. Mutagenesis of this site demonstrated that it contributes to basal expression of the ODC promoter but not to TPA or serum responsiveness. Thus, we conclude that the proximal ODC promoter (nt ‐92 to +13) responds to TPA and serum stimulation in a cell‐type‐specific manner that is not mediated by canonical AP‐1 elements. © 1995 Wiley‐ Liss, Inc.
Performance evaluation of a production/inventory system with periodic review and endogenous lead times
Authors: Boute Robert N. , Lambrecht Marc R. , Van Houdt Benny 
Published: February 2007

AbstractThis paper considers a discrete time, single item production/inventory system with random period demands. Inventory levels are reviewed periodically and managed using a base‐stock policy. Replenishment orders are placed with the production system which is capacitated in the sense that there is a single server that sequentially processes the items one at a time with stochastic unit processing times. In this setting the variability in demand determines the arrival pattern of production orders at the queue, influencing supply lead times. In addition, the inventory behavior is impacted by the correlation between demand and lead times: a large demand size corresponds to a long lead time, depleting the inventory longer. The contribution of this paper is threefold. First, we present an exact procedure based on matrix‐analytic techniques for computing the replenishment lead time distribution given an arbitrary discrete demand distribution. Second, we numerically characterize the distribution of inventory levels, and various other performance measures such as fill rate, base‐stock levels and optimal safety stocks, taking the correlation between demand and lead times into account. Third, we develop an algorithm to fit the first two moments of the demand and service time distribution to a discrete phase‐type distribution with a minimal number of phases. This provides a practical tool to analyze the effect of demand variability, as measured by its coefficient of variation, on system performance. We also show that our model is more appropriate than some existing models of capacitated systems in discrete time. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007
On the first come–first served rule in multi‐echelon inventory control
Authors: Axsäter Sven 
Published: February 2007

AbstractA two‐echelon distribution inventory system with a central warehouse and a number of retailers is considered. The retailers face stochastic demand and replenish from the warehouse, which, in turn, replenishes from an outside supplier. The system is reviewed continuously and demands that cannot be met directly are backordered. Standard holding and backorder costs are considered. In the literature on multi‐echelon inventory control it is standard to assume that backorders at the warehouse are served according to a first come–first served policy (FCFS). This allocation rule simplifies the analysis but is normally not optimal. It is shown that the FCFS rule can, in the worst case, lead to an asymptotically unbounded relative cost increase as the number of retailers approaches infinity. We also provide a new heuristic that will always give a reduction of the expected costs. A numerical study indicates that the average cost reduction when using the heuristic is about two percent. The suggested heuristic is also compared with two existing heuristics. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007
Effect of peroxide crosslinking on thermal and mechanical properties of poly(ε‐caprolactone)
Authors: Han Changyu , Ran Xianghai , Su Xuan , Zhang Kunyu , Liu Nanan , Dong Lisong 
Published: February 2007

AbstractPoly(ε‐caprolactone) (PCL), a saturated polyester, derived from ring‐opening polymerization of ε‐caprolactone, was chemically crosslinked with various amounts of benzoyl peroxide (BPO) by a two‐step method by first evenly dispersing the BPO into the PCL matrix and then crosslinking at elevated temperature. The gel fraction increased with an increase in BPO content. The modified Charlesby–Pinner equation was used to calculate the ratio of chain scission and crosslinking. The results showed that both scission and crosslinking occurred, and that crosslinking predominated over scission. The number‐average molecular weight between the crosslinks determined by the rubber elasticity theory using the hot set test showed a decrease with increasing BPO content. The melting temperature and crystallinity decreased with an increase in BPO content, and the crystallization temperature increased after crosslinking. Dynamic mechanical analysis results showed a decrease in the glass transition temperature as a result of chemical crosslinking of PCL. This was explained by the observed reduction in crystallinity and the increase in free volume due to restrictions in chain packing. Moreover, Young's modulus and elongation at break generally decreased with an increase in BPO content, but the tensile strength first increased with BPO content up to 1.0 wt%, reached a maximum, and then decreased. Copyright © 2007 Society of Chemical Industry
Effects of 1,2‐butadiene on the anionic copolymerization of styrene and 1,3‐butadiene in the presence of polar additives
Authors: Wang Qiang , Liao Mingyi , Wang Yurong , Zhang Chunqing 
Published: February 2007

Abstract1,2‐Butadiene is shown to be a chain terminating/transferring agent in butyllithium‐initiated diene polymerization. The influence of 1,2‐butadiene on the anionic copolymerization of 1,3‐butadiene and styrene is investigated using n‐butyllithium as initiator and tetrahydrofuran or N,N,N′,N′‐tetramethylethylenediamine as polar additive. A decrease of copolymerization rate is observed on the addition of 1,2‐butadiene. On introducing 1,2‐butadiene, the number average molecular weight (Mn) decreases and the molecular weight distribution broadens. The vinyl content of copolymer increases slightly with an increase of 1,2‐butadiene. During the copolymerization, 1,2‐butadiene in the presence of a high ratio of polar additives to n‐butyllithium greatly decreases the copolymerization rate, resulting in a lower value of Mn and a narrower molecular weight distribution than that found for a low ratio of polar additives to n‐butyllithium. This evolution can be explained by the base‐catalyzed isomerization of 1,2‐butadiene to form 1‐butylene in the presence of polar additives. With an increasing amount of 1,2‐butadiene, the vulcanized rubber exhibits an increased rolling resistance and a reduced wet skid resistance owing to the decrease of coupling efficiency. These results further indicate the activity of alkynyllithium derivatives produced by the reaction of alkyllithium and 1‐butyne is less than that of the alkyllithium. Copyright © 2007 Society of Chemical Industry
First identification of biradicals during thermal [2π + 2π] cyclopolymerization of trifluorovinyl aromatic ethers
Authors: Mifsud Nicolas , Mellon Veronique , Jin Jianyong , Topping Chris M , Echegoyen Luis , Smith Dennis W 
Published: February 2007

AbstractThe thermal cyclopolymerization of three trifluorovinyl aromatic ether monomers 1,1,1‐tris (4‐trifluorovinyloxyphenyl)ethane (1), 4,4′‐bis(4‐trifluorovinyloxy)biphenyl (2) and 2,2‐bis(4‐trifluorovinyloxy‐ phenyl)‐1,1,1,3,3,3‐hexafluoropropane (3) were monitored in situ using time‐resolved electron paramagnetic resonance spectroscopy over a temperature range of 150–210 °C. The signals observed during the early stages of perfluorocyclobutyl polymer production suggest the formation of a triplet state corresponding to the proposed biradical intermediate with a strong dipole–dipole interaction. A doublet splitting shows the presence of hyperfine coupling due to fluorine. The characterization of radical species formed during the polymerization of monomer 1 using model compounds and polymerization kinetics of monomer 2 are also presented. Copyright © 2007 Society of Chemical Industry
Dynamic light scattering and rheology studies of aqueous solutions of amphiphilic sodium maleate containing copolymers
Authors: Di Cola Emanuela , Waigh Thomas A. , Colby Ralph H. 
Published: February 2007

AbstractLight scattering techniques, video particle‐tracking microrheology, and bulk rheology were employed to examine the structure and dynamics of a series of alternating sodium maleate copolymers with moderately hydrophobic comonomers (diisobutylene, styrene, and isobutylene) in aqueous solutions. The scaling dependence of the specific viscosity (ηsp) on the polyelectrolyte concentration (c) was studied with and without added salt; similar trends were found in both conventional rheology and particle‐tracking microrheology measurements, showing good performance of the technique with flexible polyelectrolytes. Furthermore, with dynamic light scattering performed in high added salt conditions, we examined the behavior of the amplitude of the fast mode, which is in agreement with scaling predictions. In contrast, the slow modes are not understood and display three separate behaviors for the wavevectorqdependence of the decay rate (Γ), depending on the comonomer; superdiffusive (Γ∼q2.7, isobutylene) possibly because of sticky aggregates, wavevector independent (Γ∼q0, styrene) most likely because of coupled polyion‐ion diffusion and diffusive (Γ∼q2.0, diisobutylene) presumably because these aggregates are not sticky. The hydrophobicity of the comonomer appears to switch the aggregation process between “open,” “closed,” and “non” association for isobutylene, diisobutylene, and styrene respectively. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 774–785, 2007
An exploratory, interview study of oncology patients' and health‐care staff experiences of discussing resuscitation
Authors: Cox Karen , Wilson E. , Jones L. , Fyfe D. 
Published: February 2007

AbstractThere is little research about how patients and their families would like discussions surrounding resuscitation to take place. The purpose of this exploratory study was to investigate the experience of a discussion of resuscitation from the perspective of the participants. In‐depth interviews were undertaken with 21 patients, of whom nine were interviewed together with a relative and 14 staff in an oncology setting. Data were analysed using a constant comparative method and coded using NVIVO qualitative data analysis software. Patients appeared to be accepting resuscitation discussions as necessary and important. A minority felt that the timing of the discussion could have been better, particularly if they were newly diagnosed or had recently commenced treatment. Relatives generally found the discussions more difficult and felt that discussions should take place much closer to death. Patients identified that they needed time and privacy during the discussion. Staff identified a need to present a sensitive and individualised discussion which took into account the key elements of timing, place, space, manner and pace. Patients acknowledged that the resuscitation discussion enabled them to begin to address issues relating to dying and end of life. For staff on‐going communication skills training and support in this area were seen as important but often overlooked parts of the process. Copyright © 2007 John Wiley & Sons, Ltd.
Plasma estradiol, free testosterone, sex hormone binding globulin binding capacity, and prolactin in benign prostatic hyperplasia and prostatic cancer
Authors: Rannikko Sakari , Adlercreutz Herman 
Published: February 2007

AbstractThe nature of hormonal changes with age and the possible role of these changes in the development of benign prostatic hyperplasia (BPH) and prostatic cancer (PC) were studied by assaying the plasma levels of total and free testosterone (T), estradiol (E2), prolactin, and sex hormone binding globulin binding capacity (SHBG) in 20 normal healthy men aged 40‐59 years, in 30 patients with BPH aged 63‐79 years, and in 30 patients with PC of similar height, weight, and age as the BPH patients. The mean E2 was highly significantly (P < 0.0005) lower in the PC patients and in the young controls than in the BPH patients. The mean free T was significantly higher in the young controls than in the BPH patients (P < 0.025) and PC patients (P < 0.0005). The PC patients had a slightly lower (P < 0.05) mean free T and mean E2/free T ratio than the BPH patients. The mean E2/free T ratio was significantly higher in the BPH patients (P < 0.0005) and in the PC patients (P < 0.0025) than in the young controls. It seems possible that the observed age‐dependent significant increase in plasma estrogen concentration in the BPH patients may act as a protective factor against prostatic cancer.
Development of an in vitro clonogenic assay for the R3327 rat prostatic adenocarcinoma permits comparison of the proliferative potential of the R3327, R3327A, and R3327AT tumors
Authors: Dibner Julia J. , Nakeff Alexander 
Published: February 2007

AbstractThe R3327 class of rat prostate tumors consists of both the androgen‐dependent R3327 adenocarcinoma and androgen‐independent sublines, the R3327At spindle cell tumor, and the R3327A, a squamous cell carcinoma. We have developed in vitro clonogenic cell assays to measure and compare systematically the proliferative potential of these tumors following various monodispersion techniques. Linear relationships between the number of monodispersed tumor cells cultured at low cell density and the number of colonies formed 10 days later establish these assays as the first quantitative cellular approach to those proliferative subpopulations ultimately responsible for the growth of these tumors.We have chosen the name colony forming cell‐prostatic adenocarcinoma (CFC‐PA) to refer to the members of the proliferative subpopulation of the R3327 tumor. An ultrastructurd comparison of R3327 adenocarcinoma tissue sections with the cells produced during culture provides evidence that the cells of the proliferative subpopulation may be derived from the acinar epithelium of the tumor.
Suppression of antibody response of male mice exposed to diethylstilbestrol or estramustine phosphate (estracytR)
Authors: Haukaas Svein A. 
Published: February 2007

AbstractThe effects of treatment of male mice with diethylstilbestrol (DES) or estramustine phosphate (EMP) on the primary antibody response to sheep red blood cells (SRBC) and lipopolysaccharide (LPS) were investigated using a hemolytic plaque assay for enumeration of antibody‐producing cells. DES treatment at a daily dose of 1.4 or 5.6 mg/kg from 2 days prior to and up to 3 days after immunization significantly reduced the number of anti‐SRBC as well as anti‐LPS‐producing cells per 106 spleen cells. The 100 mg/kg EMP given as daily intraperitoneal injections significantly diminished the antibody response to both SRBC and LPS. No alteration in the number of anti‐SRBC‐producing cells per 106 spleen cells was detected in spleens from mice receiving 30 mg/kg/day EMP, while the number of anti‐LPS‐producing cells was reduced.The immunoregulatory effects of EMP are apparently not a pure estrogen effect, since treatment with doses of estradiol‐17β equivalent to the amounts of estradiol linked to the cytotoxic moiety in 100 mg/kg/day of EMP were without effect. EMP‐induced functional impairment in the T‐cell population is inferred from the reduced ability of adoptively transferred T cells from EMP‐exposed animals to support an antibody response to SRBC in syngeneic nude mice.