801
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Cao Y, Chi Z, Li R, Han C, Zhu S. SU-E-T-857: Comparison of Nasopharyngeal Carcinoma IMRT Plans from Four Commercial Treatment Planning Systems (TPS). Med Phys 2011. [DOI: 10.1118/1.3612821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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802
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Sharp G, Li R. SU-E-I-104: Automatic Labeling of the T1 through T12 Vertebrae in CT. Med Phys 2011. [DOI: 10.1118/1.3611679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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803
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Lewis J, Li R, Jiang S. SU-E-J-158: Diaphragm-Based and Direct Tumor Tracking in KV Rotational Cone-Beam X-Ray Projections Using Templates Derived from 4DCT. Med Phys 2011. [DOI: 10.1118/1.3611926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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804
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Lu X, Guo J, Zhou X, Li R, Liu X, Zhao Y, Zhu B, Liu X, Xu J, Zhu P, Wu X, He J, Liu X, Zhang H, Li Z. Deletion of LCE3C_LCE3B is associated with rheumatoid arthritis and systemic lupus erythematosus in the Chinese Han population. Ann Rheum Dis 2011; 70:1648-51. [DOI: 10.1136/ard.2010.148072] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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805
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Bergom C, Hauser A, Lorimer EL, Li R, Mackinnon AC, Williams CL. SmgGDS splice variants: Potential novel targets for breast cancer therapeutics. J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.15_suppl.10567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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806
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He SM, Li R, Kanwar JR, Zhou SF. Structural and functional properties of human multidrug resistance protein 1 (MRP1/ABCC1). Curr Med Chem 2011; 18:439-81. [PMID: 21143116 DOI: 10.2174/092986711794839197] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Accepted: 11/22/2010] [Indexed: 11/22/2022]
Abstract
Multidrug ABC transporters such as P-glycoprotein (P-gp/MDR1/ABCB1) and multidrug resistance protein 1 (MRP1/ABCC1) play an important role in the extrusion of drugs from the cell and their overexpression can be a cause of failure of anticancer and antimicrobial chemotherapy. Recently, the mouse P-gp/Abcb1a structure has been determined and this has significantly enhanced our understanding of the structure-activity relationship (SAR) of mammalian ABC transporters. This paper highlights our current knowledge on the structural and functional properties and the SAR of human MRP1/ABCC1. Although the crystal structure of MRP1/ABCC1 has yet to be resolved, the current topological model of MRP1/ABCC1 contains two transmembrane domains (TMD1 and TMD2) each followed by a nucleotide binding domain (NBD) plus a third NH2-terminal TMD0. MRP1/ABCC1 is expressed in the liver, kidney, intestine, brain and other tissues. MRP1/ABCC1 transports a structurally diverse array of important endogenous substances (e.g. leukotrienes and estrogen conjugates) and xenobiotics and their metabolites, including various conjugates, anticancer drugs, heavy metals, organic anions and lipids. Cells that highly express MRP1/ABCC1 confer resistance to a variety of natural product anticancer drugs such as vinca alkaloids (e.g. vincristine), anthracyclines (e.g. etoposide) and epipodophyllotoxins (e.g. doxorubicin and mitoxantrone). MRP1/ABCC1 is associated with tumor resistance which is often caused by an increased efflux and decreased intracellular accumulation of natural product anticancer drugs and other anticancer agents. However, most compounds that efficiently reverse P-gp/ABCB1-mediated multidrug resistance have only low affinity for MRP1/ABCC1 and there are only a few effective and relatively specific MRP1/ABCC1 inhibitors available. A number of site-directed mutagenesis studies, biophysical and photolabeling studies, SAR and QSAR, molecular docking and homology modeling studies have documented the role of multiple residues in determining the substrate specificity and inhibitor selectivity of MRP1/ABCC1. Most of these residues are located in the TMs of TMD1 and TMD2, in particular TMs 4, 6, 7, 8, 10, 11, 14, 16, and 17, or in close proximity to the membrane/cytosol interface of MRP1/ABCC1. The exact transporting mechanism of MRP1/ABCC1 is unclear. MRP1/ABCC1 and other multidrug transporters are front-line mediators of drug resistance in cancers and represent important therapeutic targets in future chemotherapy. The crystal structure of human MRP1/ABCC1 is expected to be resolved in the near future and this will provide an insight into the SAR of MRP1/ABCC1 and allow for rational design of anticancer drugs and potent and selective MRP1/ABCC1 inhibitors.
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807
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Leblanc J, Zhang X, McKee D, Wang ZB, Li R, Ma C, Sun QY, Liu XJ. The small GTPase Cdc42 promotes membrane protrusion during polar body emission via ARP2-nucleated actin polymerization. Mol Hum Reprod 2011; 17:305-16. [PMID: 21511720 DOI: 10.1093/molehr/gar026] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Polar body emission is a specialized cell division throughout the animal kingdom, serving to reduce chromosome ploidy while preserving the egg cytoplasm. Critical to polar body emission are the asymmetric positioning of the meiotic spindle prior to anaphase, with one pole attached to the oocyte cortex, and the simultaneous membrane protrusion during subsequent cytokinesis. We have shown that, during Xenopus oocyte maturation, the small GTPase Cdc42 promotes membrane protrusion while a classical RhoA contractile ring forms and constricts at the base of the protrusion. We report here that treating oocytes with low concentrations of nocodazole diminished the size of metaphase I spindles and prevented polar body emission, and yet an active Cdc42 cap of correspondingly diminished size still developed, on time, atop of the spindle pole. Conversely, treating oocytes with low concentrations of taxol resulted in a spindle with multiple poles attached to the cortex, but still each of these poles were associated with activated cortical Cdc42 at the appropriate time. Therefore, the asymmetric positioning of the meiotic spindle with one pole anchored to the cortex is a prerequisite for Cdc42 activation. Furthermore, we demonstrated that the Cdc42-regulated F-actin nucleator ARP2/3 complex was similarly localized at the cortex of the protruding polar body membrane, suggesting that Cdc42 promotes membrane protrusion through an F-actin meshwork mechanism. Finally, we demonstrated that Cdc42 and RhoA formed similarly complementary activity zones during egg activation and that inhibition of Cdc42 prevented second polar body emission. Therefore, Cdc42 activation likely promotes membrane protrusion during polar body emission in widespread systems.
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808
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Leung HCM, Yiu SM, Yang B, Peng Y, Wang Y, Liu Z, Chen J, Qin J, Li R, Chin FYL. A robust and accurate binning algorithm for metagenomic sequences with arbitrary species abundance ratio. Bioinformatics 2011; 27:1489-95. [DOI: 10.1093/bioinformatics/btr186] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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809
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Manini TM, Patel KV, Bauer DC, Ziv E, Schoeller DA, Mackey DC, Li R, Newman AB, Nalls M, Zmuda JM, Harris TB. European ancestry and resting metabolic rate in older African Americans. Eur J Clin Nutr 2011; 65:663-7. [PMID: 21468093 DOI: 10.1038/ejcn.2011.22] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND/OBJECTIVES Resting metabolic rate (RMR) contributes 60-80% of total energy expenditure and is consistently lower in populations of African descent compared with populations of European populations. Determination of European ancestry (EA) through single nucleotide polymorphism (SNP) analysis would provide an initial step for identifying genetic associations that contribute to low RMR. We sought to evaluate the association between RMR and EA in African Americans. SUBJECTS/METHODS RMR was measured by indirect calorimetry in 141 African American men and women (aged 74.7±3.0 years) enrolled in a substudy of the Health, Aging and Body Composition Study. Ancestry informative markers were used to estimate individual percent EA. Multivariate regression was used to assess the association between RMR and EA after adjustments for soft tissue fat-free mass (STFFM), fat mass, age, study site, physical activity level and sex. RESULTS Mean EA was 23.8±16% (range: 0.1-70.7%) and there were no differences by sex. Following adjustments, each percent EA was associated with a 1.6 kcal/day (95% Confidence interval: 0.42, 2.7 kcal/day) higher RMR (P=0.008). This equates to a 160 kcal/day lower RMR in a population of completely African ancestry, with one of completely European ancestry. Additional adjustment for trunk STFFM that partially accounts for high-metabolic rate organs did not affect this association. CONCLUSIONS EA in African Americans is strongly associated with higher RMR. The data suggest that population differences in RMR may be due to genetic variants.
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810
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Auyeung M, Tsoi T, Cheung C, Fong DY, Li R, Chan JK, Lau K. Association of diffusion weighted imaging abnormalities and recurrence in transient global amnesia. J Clin Neurosci 2011; 18:531-4. [DOI: 10.1016/j.jocn.2010.08.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Revised: 05/13/2010] [Accepted: 08/02/2010] [Indexed: 10/18/2022]
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811
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Zhang G, Feng Q, Zheng D, Ma L, Li R, Jiang J, Ni Y. Early Aggressive Medical Treatment Associated with Selective Prophylactic Aortic Stent-Grafting for Aortic Intramural Hematoma. Thorac Cardiovasc Surg 2011; 59:342-8. [DOI: 10.1055/s-0030-1270761] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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812
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Hu XL, Tong KY, Li R, Chen M, Xue JJ, Ho SK, Chen PN. Effectiveness of functional electrical stimulation (FES)-robot assisted wrist training on persons after stroke. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2011; 2010:5819-22. [PMID: 21096914 DOI: 10.1109/iembs.2010.5627471] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A functional electrical stimulation (FES)-robot system controlled by subjects' motor intention was developed in our previous study. The effectiveness of the FES-robot on wrist training was investigated in this work. Five hemiplegic subjects with chronic stroke were recruited for an FES-robot assisted wrist training with 20 sessions. After the training, motor improvements were found in the wrist and fingers, represented by significant increase (P < 0.05) in clinical scores of the Fugl-Meyer Assessment (FMA), the Action Research Arm Test (ARAT), and the Modified Ashworth Score (MAS). Muscle coordination in the upper limb was also improved during the training as assessed by electromyography. The increased ARAT scores suggested improved upper limb motor functions, especially in the hand and fingers, compared to no improvement in previous study with only interactive robot-assisted wrist training without FES.
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813
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Yan P, Liu D, Long M, Ren Y, Pang J, Li R. Changes of serum omentin levels and relationship between omentin and adiponectin concentrations in type 2 diabetes mellitus. Exp Clin Endocrinol Diabetes 2011; 119:257-63. [PMID: 21374544 DOI: 10.1055/s-0030-1269912] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND Omentin has recently been characterized as a potent insulin-sensitizing adipokine, but its pathophysiologic roles in humans remain largely unknown. OBJECTIVE To investigate the change of fasting serum omentin levels and evaluate the relationship of omentin with adiponectin in patients with type 2 diabetes mellitus. DESIGN 35 patients with newly diagnosed type 2 diabetes (T2DM), 35 patients with impaired glucose regulation (IGT) and 35 patients with normal glucose tolerance (NGT) participated in this study. Fasting serum omentin and adiponectin levels were measured by enzyme-linked immunosorbent assay. The relationship between serum omentin, serum adiponectin levels and metabolic parameters was also analyzed. RESULTS Fasting serum omentin levels were significantly lower in T2DM and IGT groups than in NGT group (16.75±1.71 vs. 18.62±1.22 vs. 24.60±1.43 ng/ml, all P<0.01). Obesity subjects had significantly lower serum omentin levels than normal body weight subjects ( P<0.01 or P<0.05). Female subjects had moderately higher fasting serum omentin levels than male subjects. Fasting serum adiponectin levels showed a similar variation trend to omentin in T2DM and NGT groups, obesity and normal body weight subjects, female and male subjects. Fasting serum omentin levels were negatively correlated with HOMA-IR and positively correlated with adiponectin. Moreover, HOMA-IR and adiponectin were the independently predictors of fasting serum omentin levels. CONCLUSIONS Serum omentin levels possibly play an important role in the pathogenesis of insulin resistance and diabetes. More importantly, there is such a close connection between serum omentin and adiponectin levels that regulation of omentin may be dependent on adiponectin.
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814
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Yang Q, Li R, Zhong Z, Mao H, Fan J, Lin J, Yang X, Wang X, Li Z, Yu X. Is cystatin C a better marker than creatinine for evaluating residual renal function in patients on continuous ambulatory peritoneal dialysis? Nephrol Dial Transplant 2011; 26:3358-65. [DOI: 10.1093/ndt/gfr045] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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815
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Arvidson RE, Ashley JW, Bell JF, Chojnacki M, Cohen J, Economou TE, Farrand WH, Fergason R, Fleischer I, Geissler P, Gellert R, Golombek MP, Grotzinger JP, Guinness EA, Haberle RM, Herkenhoff KE, Herman JA, Iagnemma KD, Jolliff BL, Johnson JR, Klingelhöfer G, Knoll AH, Knudson AT, Li R, McLennan SM, Mittlefehldt DW, Morris RV, Parker TJ, Rice MS, Schröder C, Soderblom LA, Squyres SW, Sullivan RJ, Wolff MJ. Opportunity Mars Rover mission: Overview and selected results from Purgatory ripple to traverses to Endeavour crater. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010je003746] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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816
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He G, Qiu M, Li R, Song X, Zheng X, Shi J, Xu G, Han J, Yu L, Yang S, Chen L, Wei Y. Molecular docking-based 3D-QSAR studies of pyrrolo[3,4-c]pyrazole derivatives as Aurora-A inhibitors. MOLECULAR SIMULATION 2011. [DOI: 10.1080/08927022.2010.517529] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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817
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He C, Wang C, Chang Z, Guo B, Li R, Yue X, Lan X, Chen H, Lei C. AGPAT6 polymorphism and its association with milk traits of dairy goats. GENETICS AND MOLECULAR RESEARCH 2011; 10:2747-56. [DOI: 10.4238/2011.november.4.8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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818
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Islam R, Cartwright R, Zhen X, Qiao J, Li R, Wang L, Liu P, Kawachiya S, Bodri D, Matsumoto T, Kato K, Osada H, Takehara Y, Kato O, Jinno M, Takeuchi M, Watanabe A, Hirohama J, Hatakeyama N, Hiura R, Chen H, Peng XD, Yang YZ, Sun XX, Garcia Pascual CM, Zimmermann RC, Simon C, Sawber C, Pellicer A, Gomez R, Youssef MAFM, Aboulfoutouh I, Khattab S, van Wely M, van der Veen F, AL-Inany H. SELECTED ORAL COMMUNICATION SESSION, SESSION 69: ENDOCRINOLOGY AND POF Wednesday 6 July 2011 14:00 - 15:45. Hum Reprod 2011. [DOI: 10.1093/humrep/26.s1.69] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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819
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Liu Y, Østrup O, Li J, Vajta G, Kragh PM, Purup S, Li R, Callesen H. 49 IMPROVED PORCINE CLONING EFFICIENCY WITH CELLS CULTURED FOR SEVERAL GENERATIONS AFTER A SINGLE TREATMENT WITH XENOPUS EGG EXTRACT. Reprod Fertil Dev 2011. [DOI: 10.1071/rdv23n1ab49] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Extracts from eggs of Xenopus laevis frogs can induce nuclear remodelling or increase transcriptional reprogramming in somatic cells. However, it is not known if this effect is passed on from one cell generation to another, or how it affects somatic cell nuclear transfer in porcine cells. This study aimed to investigate the effect of extract-treated cells over several generations on porcine cloning. Extracts were prepared from 2 frogs (B1 and B2) by the same protocol (Higa et al. 2006 Methods 39, 284–290). Fetal fibroblasts grown on poly-L-lysine coated coverslips were permeabilized by digitonin (7 μg mL–1, 2 min, 4°C) and incubated with 1 extract batch at 37°C for 30 min. After resealing the membrane in DMEM supplemented with 2 mM CaCl2 at 37°C for 2 h, the remaining cells were cultured in ES medium (Vejlsted et al. 2005 Mol. Reprod. Dev. 70, 445–454) for 7 to 8 days when they formed colonies. The colonies were trypsinized and divided onto 2 coverslips for subculture, defined as Experimental Passage 1 (XP1). New subcultures were made every 7 to 8 days when 70 to 80% clusters become colonies until XP15. Colonies from XP3, 8 and 15 were isolated and trypsinized before being used in handmade cloning. Nontreated cells grown in DMEM were used as controls (no colony formation was observed). On each cloning day, cells from different XP number and controls were used. Rates of cleavage (Day 2) and blastocyst development (Day 6) were analysed with chi-square test (SAS version 9.2, SAS Institute Inc., Cary, NC, USA). Results are summarised in Table 1. No difference was observed in cleavage rate between groups. Blastocyst rates of all XP colony cells were significantly higher than their controls. For the same XP number and their controls, blastocyst rates were similar between the colony cells from the 2 extract batches, and there was no difference between their controls, either. In conclusion, the cloning efficiency in porcine cells could be increased with extract-treated cells used for several generations, and this effect was present at XP3, 8, and 15.
Table 1.Developmental competence of cloned porcine embryos with extract-treated cells from different batches of extract (B1 and B2) and Experimental Passage (XP) numbers
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820
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Li J, Adamsen J, Li R, Pedersen H, Liu Y, Purup S, Vajta G, Callesen H. 48 DEVELOPMENTAL COMPETENCE OF CLONED OR PARTHENOGENETICALLY ACTIVATED PORCINE EMBRYOS: EFFECT OF DIAMETER OF PREPUBERTAL GILT OOCYTES. Reprod Fertil Dev 2011. [DOI: 10.1071/rdv23n1ab48] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
One of the primary factors influencing the developmental ability of cloned embryos is the oocyte′s diameter (Hirao et al. 1994 J. Reprod. Fertil. 100, 333–339). However, the oocyte donor's age (i.e. its sexual maturity) is also important to consider, because a high proportion of immature oocytes can be expected (Ikeda and Takahashi 2003 Reprod. Fertil. Dev. 15, 215–221). The present study was to investigate the effect of diameter of oocytes collected from prepubertal gilts weighing 100 to 120 kg on the developmental ability of cloned and parthenogenetically activated (PA) embryos. Cumulus–oocyte complexes collected from ovaries of prepubertal gilts were in vitro matured for 42 to 44 h as described for sow oocytes (Li et al. 2008 Theriog 70, 800–808). After removal of the cumulus cells, the matured oocytes were sorted into 2 groups based on visual inspection: large (L) and small (S) oocytes, whereas non-sorted oocytes were used as control (C). In addition, 1 batch from each of the 3 groups of oocytes had their mean size measured. Subsequently, all 3 groups were used for handmade cloning (HMC; Li et al. 2009 Reprod. Domest. Anim. 44, 122–127) or parthenogenetic activation (PA; Kragh et al. 2005 Theriogenology 64, 1536–1545). Then a chemical activation with 5 μg mL–1 cytochalasin B and 10 μg mL–1 cycloheximide in PZM-3 medium was applied for 4 h on both HMC and PA embryos. Finally, the activated embryos were washed and cultured in PZM-3 medium using the WOW system. The embryo development was evaluated by cleavage rate (Day 2), blastocyst rate (Day 6), and total cell number in blastocysts. Data were analysed by ANOVA with single factor in Excel (Microsoft Excel 2007, Redmond, WA, USA). The results showed (Table 1) that by simple visual observation, oocytes could be easily sorted into the following groups: L group (mean diameter 110 μm, from 105 to 116 μm), S group (mean diameter 101 μm, from 93 to 106 μm) and C group (mean diameter 107 μm, from 93 to 116 μm). Cleavage rates and total cell number were similar in the 3 groups. However, the blastocyst rate in L group either for HMC or PA was higher than S group. The data confirm that prepubertal gilt oocytes are useful for cloning and PA, but developmental rates can be increased by selection of large oocytes by simple visual observation.
Table 1.Data analysis results
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Li R, Polat U, Scalzo F, Bavelier D. Reducing backward masking through action game training. J Vis 2010; 10:10.14.33. [DOI: 10.1167/10.14.33] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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822
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De K, Liu Z, Tekmal RR, Li R, Vadlamudi RK, Sun LZ. Abstract P5-03-01: Role of Aromatase and Its Inhibitor in Breast Cancer-Induced Tumorigenesis and Bone Metastasis. Cancer Res 2010. [DOI: 10.1158/0008-5472.sabcs10-p5-03-01] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Aromatase (Aro) is the rate-limiting enzyme that catalyzes the final step in estrogen (E2) biosynthesis. An important strategy to treat hormone-dependent BCa is suppression of estrogen receptor (ER) action by antiestrogens or aromatase inhibitors (AI). Letrozole is a very specific and potent AI. In postmenopausal women, the ovaries cease to make E2 but concentration of E2 in their BCa tissue are maintained at a certain level for survival and proliferation of BCa cells, which is dependent on local E2 formation catalyzed by Aro. Although BCa cells have been shown to express Aro, the local E2 is largely produced by adipose stromal cells in the breast. This raises the question of how ER positive (ER+) metastatic BCa cells survive after they enter blood circulation, where E2 level is very low.
We cultured human ER+ BCa CAMA-1, Aro-transfected MCF-7 and ZR-75-1 (ZR) cells in suspension to mimic circulating BCa cells. Interestingly, suspension culture increased Aro expression, suggesting circulating ER+ BCa may up-regulate intracrine E2 activity for survival after leaving the E2-rich adipose stroma at primary site. The expression of Aro also enhances cell proliferation and supplementation of testosterone (T), the substrate of Aro, stimulates this proliferation further. Notably, while these cells show an increased rate of apoptosis in suspension than in adherent culture, addition of T in suspension culture significantly suppressed the rate of apoptosis and addition of letrozole blocked the T-induced cell survival in suspension culture. To investigate the importance of intracrine E2 in promoting tumorigenesis and metastasis, we implanted Aro-expressing ZR cells orthotopically and intracardiacally (I.C.) into female athymic mice; vector-transfected ZR cells were used as control. While control ZR cells were incapable of forming tumors without E2 supplementation, Aro-expressing cells generated orthotopic tumors with no E2 supplementation after 3-weeks of inoculation. More interestingly, mice with I.C. inoculated Aro-expressing cells also presented distant bone metastasis in the mandible and tibiae/femora after 2-weeks of inoculation, detected by whole mouse fluorescence and bioluminescence imaging as the cells were stably transfected with a luciferase and GFP expression vector. To determine whether growth of orthotopic tumors can be inhibited by systemic administration of an AI, we treated the mice in one group with letrozole at 10 mg/mouse/day and the other group with the vehicle as control after the average tumor volume reached 150 mm3. After 3-weeks, the tumor burden in the letrozole treatment group reduced significantly while tumor burden in the control group increased continuously. Our studies show that suspension culture increases expression of Aro mRNA in several ER+ BCa cell lines, which likely results in increased intracrine E2 signaling and contributes to the survival of these BCa cellsin suspension. This provides a mechanistic insight into how ER+ BCa cells may survive the low E2 condition in circulation and subsequently induce distant metastasis as observed in the I.C. model. Our study provides an important foundation for future investigation on how hormone-dependent BCa cells up-regulate Aro expression in circulation and induce bone metastasis.
Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-03-01.
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Prusa K, Nederveld H, Runnels PL, Li R, King VL, Crane JP. Prevalence and relationships of sensory taint, 5α-androstenone and skatole in fat and lean tissue from the loin (Longissimus dorsi) of barrows, gilts, sows, and boars from selected abattoirs in the United States. Meat Sci 2010; 88:96-101. [PMID: 21237579 DOI: 10.1016/j.meatsci.2010.12.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Revised: 11/09/2010] [Accepted: 12/02/2010] [Indexed: 10/18/2022]
Abstract
This study assessed prevalence of boar taint in backfat and lean of barrows, gilts, sows, and boars, collected from abattoirs, without knowledge of the farms of origin, in different regions in the United States. Concentrations of 5α-androstenone (liquid chromatography/mass spectroscopy) and skatole (liquid chromatography with fluorescent detection) in backfat were measured. A trained panel evaluated boar taint aroma in heated samples. Mean 5α-androstenone and skatole levels were low among barrows, gilts, and sows, whereas 55.8% of boars scored above a 1.0 μg/g threshold for 5α-androstenone concentrations and 34.2% were above a 0.2 μg/g threshold for skatole concentrations. Mean aroma scores for backfat and lean from barrows, gilts, and sows were low. In comparison, 59.2% of boars had elevated mean aroma scores from fat samples and 31.7% from lean. Importantly, boar taint aroma was detectable by the trained panel in at least some animals in each of the sex classes.
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McGuinnes C, Duffin R, Brown S, L. Mills N, Megson IL, MacNee W, Johnston S, Lu SL, Tran L, Li R, Wang X, Newby DE, Donaldson K. Surface Derivatization State of Polystyrene Latex Nanoparticles Determines both Their Potency and Their Mechanism of Causing Human Platelet Aggregation In Vitro. Toxicol Sci 2010; 119:359-68. [DOI: 10.1093/toxsci/kfq349] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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Liu YN, Li R, Li J, Li DZ. Rapid identification of hemoglobin Quong Sze mutation using high-resolution melting analysis. Int J Lab Hematol 2010; 33:e5-6. [DOI: 10.1111/j.1751-553x.2010.01278.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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