bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cumulus cells accelerate aging of mouse oocytes by secreting a soluble factor(s)
Authors: Qiao Tian‐Wu , Liu Na , Miao De‐Qiang , Zhang Xia , Han Dong , Ge Li , Tan Jing‐He 
Published: September 2007

AbstractControl of oocyte aging in vitro is important for both human‐assisted reproduction and animal embryo technologies because fertilization or artificial activation of aged oocytes results in abnormal development. Interactions between somatic and germ cells are also an important issue in current biological research. The role of cumulus cells (CCs) in maturation, ovulation, and fertilization of oocytes has been extensively studied, yet little is known about their role in oocyte aging. Although our previous study has shown that CCs accelerate the aging progression of mouse oocytes, the mechanism by which CCs accelerate oocyte aging is unknown. In this study, cumulus‐denuded mouse oocytes (DOs) were co‐cultured with cumulus‐oocyte complexes (COCs) or CC monolayer or cultured in medium conditioned with these cells and changes in the susceptibility to activating stimuli and in MPF activity of oocytes were evaluated after different aging treatments. The results showed that culture with or in medium conditioned with COCs or CC monolayer promoted activation of DOs, indicating that a soluble factor is responsible for the aging‐promoting effect. The in vivo and in vitro‐matured DOs did not differ in responsiveness to the aging‐promoting factor (APF). Heat shock did not accelerate oocyte aging unless in the presence of CCs. The production of APF was not affected by the age or maturation system of COCs, but increased with their density and duration of culture. The results strongly suggest that CCs accelerated oocyte aging by secreting a soluble APF into the medium. Further analysis showed that the APF was heat labile but stable to freezing, it had a threshold effective concentration and can be depleted by DOs. Mol. Reprod. Dev. 75: 521–528, 2008. © 2007 Wiley‐Liss, Inc.
Vitrification of in vitro matured ovine oocytes affects in vitro pre‐implantation development and mRNA abundance
Authors: Succu Sara , Bebbere Daniela , Bogliolo Luisa , Ariu Federica , Fois Stefano , Leoni Giovanni Giuseppe , Berlinguer Fiammetta , Naitana Salvatore , Ledda Sergio 
Published: September 2007

AbstractThe impact of vitrification procedures on in vitro matured (IVM) ovine oocytes mRNA content and ability to undergo successful fertilization, cleavage and embronic development was assessed. Vitrified‐warmed (n = 113) and control (n = 140) IVM oocytes were in vitro fertilized and cultured up to blastocyst stage under standard conditions. Vitrified oocytes showed lower cleavage rate (47% vs. 75%, P < 0.001) and development to blastocyst stage (17% vs. 57%, P < 0.001) than controls. In addition, the timings of the first cleavage and blastocysts production were significantly delayed in the vitrified‐warmed group (P < 0.001 in both cases). In parallel, we analyzed by reverse transcriptase real‐time PCR the relative abundance of β‐actin, H2A.Z histone, Poli A Polimerase (PAP), Heat Shock Protein 90β (HSP90β), P34cdc2, Cyclin b, Na/K‐ATPase and Type I cadherin (E‐Cad) transcripts in single IVM controls (n = 24) and vitrified‐warmed oocytes (n = 40). Results were normalized against the exogenous rabbit α‐globin mRNA standard and the β‐actin housekeeping gene and similarly described a lower abundance of most mRNAs in oocytes subjected to vitrification procedures. When normalized against the exogenous standard mRNA, all transcripts except for β‐actin and H2A.Z showed a significantly different abundance in the two classes of oocytes. The same results were obtained after normalization against the internal standard, except for HSP90β and E‐Cad transcripts, whose lower abundance in vitrified‐warmed oocytes resulted prominent, but not significant (P = 0.083 and P = 0.068, respectively). The oocyte lower transcripts abundance following vitrification might be an early indicator of poor quality in good correlation with the developmental data to blastocyst stage. Mol. Reprod. Dev. 75: 538–546, 2008. © 2007 Wiley‐Liss, Inc.
Role of nonessential amino acids on porcine embryos produced by parthenogenesis or somatic cell nuclear transfer
Authors: Gupta Mukesh Kumar , Uhm Sang Jun , Lee Sung‐ho , Lee Hoon Taek 
Published: September 2007

AbstractAmino acids play a multitude of roles during early embryonic development and have been demonstrated to facilitate improved development of in vivo or in vitro fertilized and parthenogenetic embryos in several species. However, review of emerging literatures, shows that culture milieu of cloned embryos might be different from those of in vitro fertilized embryos. This study therefore, evaluated the effect of nonessential amino acids (NEAA) on yield and quality of porcine embryos produced by somatic cell nuclear transfer (SCNT) and compared them with parthenogenetic embryos as control. Analysis showed that, supplementation of NEAA to culture medium significantly improved the blastocyst rate of parthenogenetic (38.9 ± 8.8 vs. 27.5 ± 9.0%) as well as SCNT (22.5 ± 2.2 vs. 13.8 ± 3.4%) embryos although cleavage rates were not different (P < 0.05). These blastocysts also had higher hatching ability and contained higher cell number than control blastocysts (P < 0.05). TUNEL labeling revealed that blastocysts cultured in the presence of NEAA were less predisposed to biochemical apoptosis and showed lower indices of TUNEL, fragmentation, and total apoptosis than those cultured in the absence of NEAA (P < 0.05). Real‐time qRT‐PCR analysis further revealed that NEAA decreased the expression ratio of BAX:BCL‐xL and enhanced the relative abundance of IGF2 transcripts. Therefore, our study suggests that NEAA improves the yield and quality of cloned porcine embryos by enhancing blastocyst expansion, hatching, and total cell number and decreasing the apoptosis by positively modulating the expression of embryo survival related genes, similar to those reported for in vivo or in vitro fertilized embryos. Nonessential amino acids improve the yield and quality of cloned and parthenogenetic porcine embryos and modulate the expression of embryo survival related genes. Mol. Reprod. Dev. 75: 588–597, 2008. © 2007 Wiley‐Liss, Inc.
Properties of murine embryonic stem cells maintained on human foreskin fibroblasts without LIF
Authors: Meng G.L. , zur Nieden N.I. , Liu S.Y. , Cormier J.T. , Kallos M.S. , Rancourt D.E. 
Published: September 2007

AbstractIn embryonic stem (ES) cells, leukemia inhibitory factor (LIF)/STAT3, wnt and nodal/activin signaling are mainly active to control pluripotency during expansion. To maintain pluripotency, ES cells are typically cultured on feeder cells of varying origins. Murine ES cells are commonly cultured on murine embryonic fibroblasts (MEFs), which senesce early and must be frequently prepared. This process is laborious and leads to batch variation presenting a challenge for high‐throughput ES cell expansion. Although some cell lines can be sustained by exogenous LIF, this method is costly. We present here a novel and inexpensive culture method for expanding murine ES cells on human foreskin fibroblast (HFF) feeders. After 20 passages on HFFs without LIF, ES cell lines showed normal expression levels of pluripotency markers, maintained a normal karyotype and retained the ability to contribute to the germline. As HFFs do not senesce for at least 62 passages, they present a vast supply of feeders. Mol. Reprod. Dev. 75: 614–622, 2008. © 2007 Wiley‐Liss, Inc.
Global gene expression analysis of bovine blastocysts produced by multiple methods
Authors: Zhou Wenli , Xiang Tianhao , Walker Shawn , Farrar Vicki , Hwang Earl , Findeisen Brian , Sadeghieh Sanaz , Arenivas Fernando , Abruzzese Ronald V. , Polejaeva Irina 
Published: September 2007

AbstractReproductive efficiency using somatic cell nuclear transfer (SCNT) technology remains suboptimal. Of the various efforts to improve the efficiency, chromatin transfer (CT) and clone‐clone aggregation (NTagg) have been reported to produce live cloned animals. To better understand the molecular mechanisms of somatic cell reprogramming during SCNT and assess the various SCNT methods on the molecular level, we performed gene expression analysis on bovine blastocysts produced via standard nuclear transfer (NT), CT, NTagg, in vitro fertilization (IVF), and artificial insemination (AI), as well as on somatic donor cells, using bovine genome arrays. The expression profiles of SCNT (NT, CT, NTagg) embryos were compared with IVF and AI embryos as well as donor cells. NT and CT embryos have indistinguishable gene expression patterns. In comparison to IVF or AI embryos, the number of differentially expressed genes in NTagg embryos is significantly higher than in NT and CT embryos. Genes that were differentially expressed between all the SCNT embryos and IVF or AI embryos are identified. Compared to AI embryos, more than half of the genes found deregulated between SCNT and AI embryos appear to be the result of in vitro culture alone. The results indicate that although SCNT methods have altered differentiated somatic nuclei gene expression to more closely resemble that of embryonic nuclei, combination of insufficient reprogramming and in vitro culture condition compromise the developmental potential of SCNT embryos. This is the first set of comprehensive data for analyzing the molecular impact of various nuclear transfer methods on bovine pre‐implantation embryos. Mol. Reprod. Dev. 75: 744–758, 2008. © 2007 Wiley‐Liss, Inc.
Alterations in the testis of hormone sensitive lipase‐deficient mice is associated with decreased sperm counts, sperm motility, and fertility
Authors: Hermo Louis , Chung Shari , Gregory Mary , Smith Charles E. , Wang Shu Pei , El‐Alfy Mohamed , Cyr Daniel G. , Mitchell Grant A. , Trasler Jacquetta 
Published: September 2007

AbstractHormone‐sensitive lipase (HSL, Lipe, E.C.3.1.1.3) functions as a triglyceride and cholesteryl esterase, supplying fatty acids, and cholesterol to cells. Gene‐targeted HSL‐deficient (HSL−/−) mice reveal abnormal spermatids and are infertile at 24 weeks after birth. The purpose of this study was to follow the evolution of spermatid abnormalities as HSL−/− mice age, characterize sperm motility in older HSL−/− mice, and determine if mice expressing a human testicular HSL transgene (HSL−/−ttg) produce normal motile sperm. In situ hybridization indicated that HSL is expressed exclusively in steps 5–16 spermatids, but not in Sertoli cells. In HSL−/− mice, abnormalities were evident in step 16 spermatids at 5 weeks after birth, with defects progressively increasing in spermatids with age. The defects included multinucleation of spermatids, abnormal shapes and a reduction of elongating spermatids. In older HSL−/− mice, sperm counts appeared reduced by 42%, but this value was lower because samples were compromised by the presence of small degenerating germ cells in addition to sperm, both of which appeared of similar size and density. Sperm motility was dramatically reduced with only 11% classified as motile in HSL−/− mice compared to 76–78% of sperm in wild‐type and HSL−/−ttg mice. Sperm morphology, counts, and motility were normal in HSL−/−ttg mice, as was their fertility. Collectively, the data indicate that HSL deficiency results in abnormal spermatid development with defects arising at 5 weeks of age and progressively increasing at later ages. HSL−/− mice also show a dramatic reduction in sperm counts and motility and are infertile. Mol. Reprod. Dev. 75: 565–577, 2008. © 2007 Wiley‐Liss, Inc.
Enhancement of Bovine oocyte maturation by leptin is accompanied by an upregulation in mRNA expression of leptin receptor isoforms in cumulus cells
Authors: van Tol Helena T.A. , van Eerdenburg Frank J.C.M. , Colenbrander Ben , Roelen Bernard A.J. 
Published: September 2007

AbstractIn this study, the mechanisms of supposed leptin action on oocyte maturation were examined. Expression of leptin mRNA, as determined with RT‐PCR, was present in oocytes but not in cumulus cells. The long isoform of the leptin receptor (ObR‐L) was expressed exclusively in cumulus cells after 7 and 23 hr of maturation. In oocytes the expression of the short receptor isoform (ObR‐S) and all the receptor isoforms combined (ObR‐T) did not change during maturation, as determined by quantitative RT‐PCR, but in cumulus cells there was a significant increase in ObR‐S transcripts after 7 hr of maturation. To determine if leptin plays a role in resumption of meiosis, oocytes meiotically arrested by the connection of the cumulus to a piece of granulosa layer were exposed to leptin. After 23 hr of culture, the proportion of oocytes that had resumed meiosis did not differ from the control. Exposure of COCs to leptin (1,000 ng/ml) resulted after 17 hr of maturation in a smaller proportion of oocytes that was still in metaphase‐I stage (M‐I) compared to the control group. Fertilization of oocytes after maturation in the presence of leptin resulted in a larger proportion of embryos that had developed to the 8‐cell stage on Day 5 compared to the control group and in more blastocysts on Day 8 of culture. It is concluded that leptin enhances meiotic maturation of bovine oocytes, and that this effect is cumulus cell‐mediated. Mol. Reprod. Dev. 75: 578–587, 2008. © 2007 Wiley‐Liss, Inc.
Aberrant DNA methylation imprints in aborted bovine clones
Authors: Liu Jing‐He , Yin Shen , Xiong Bo , Hou Yi , Chen Da‐Yuan , Sun Qing‐Yuan 
Published: September 2007

AbstractGenomic imprinting plays a very important role during development and its abnormality may heavily undermine the developmental potential of bovine embryos. Because of limited resources of the cow genome, bovine genomic imprinting, both in normal development and in somatic cell nuclear transfer (SCNT) cloning, is not well documented. DNA methylation is thought to be a major factor for the establishment of genomic imprinting. In our study, we determined the methylation status of differential methylated regions (DMRs) of four imprinted genes in four spontaneously aborted SCNT‐cloned fetuses (AF). Firstly, abnormal methylation imprints were observed in each individual to different extents. In particular, Peg3 and MAOA were either seriously demethylated or showed aberrant methylation patterns in four aborted clones we tested, but Xist and Peg10 exhibited relatively better maintained methylation status in AF1 and AF4. Secondly, two aborted fetuses, AF2 and AF3 exhibited severe aberrant methylation imprints of four imprinted genes. Finally, MAOA showed strong heterogeneous methylation patterns of its DMR in normal somatic adult tissue, but largely variable methylation levels and relatively homogeneous methylation patterns in aborted cloned fetuses. Our data indicate that the aborted cloned fetuses exhibited abnormal methylation imprints, to different extent, in aborted clones, which partially account for the higher abortion and developmental abnormalities during bovine cloning. Mol. Reprod. Dev. 75: 598–607, 2008. © 2007 Wiley‐Liss, Inc.
A novel approach to identify bovine sperm membrane proteins that interact with receptors on the vitelline membrane of bovine oocytes
Authors: Pate Barry J. , White Kenneth L. , Chen Dong , Aston Kenneth I. , Sessions Benjamin R. , Bunch Thomas D. , Weimer Bart C. 
Published: September 2007

AbstractAt fertilization, the sperm triggers intracellular calcium oscillations, which are pivotal to oocyte activation and development. A working hypothesis for the interaction between the sperm and the oocyte is that disintegrin ligands on the inner acrosomal membrane of the sperm bind to integrin receptors on the oocyte vitelline membrane. The aim of these experiments was to find and identify the sperm protein ligands involved in bovine sperm–oocyte interactions. In situ fluorescent labeling of proteins and 2‐D gel electrophoresis were used to identify specific sperm membrane proteins that interact with proteins in the oocyte vitelline membrane. Sperm were labeled with a fluorescent dye and used to fertilize zona‐free oocytes. Sperm–oocyte complexes were either lysed immediately, or following covalent cross‐linking of proteins with dibromobimane. The cross‐linking reagent serves the critical function of covalently linking proteins together so that they will remain as a unit through lysis of the cells and 2‐D gel analysis, and which can be subsequently identified by mass spectrometry. Lysates were electrophoretically run on the same 2‐D gel. The comparison of uncross‐linked and cross‐linked protein spots revealed that some proteins shifted position based on binding. These spots were picked and proteins identified by mass spectrometry. These results provide a list of specific sperm proteins that interact with oocyte membrane proteins and establish a group of candidate ligands, one or more of which may be responsible for induction of outside‐in signaling resulting in oocyte activation and fusion of the gametes. Mol. Reprod. Dev. 75: 641–649, 2008. © 2007 Wiley‐Liss, Inc.
Siloxane/silane‐crosslinked systems from supercritical carbon dioxide: I. Fluorinated poly(ether/siloxane)s
Authors: Zhou Hui , Venumbaka Sreenu R. , Fitch John W. , Cassidy Patrick E. 
Published: September 2007

AbstractA series of new, fluorinated, silicone‐containing polymers with crosslinkable units has been synthesized by hydrosilation in toluene and supercritical carbon dioxide (70°C, 3000 psi) using platinum‐divinyltetramethyldisiloxane (Pt‐DVTMS) as a catalyst. The polymers were characterized by FTIR, NMR, GPC, TGA, and DSC. The molecular weights of these polymers ranged from 9,900 to 41,000. Comparison of the properties between reactions in toluene versus supercritical carbon dioxide indicated that the green solvent is a suitable alternative for hydrosilation. The hydrolysis and thermal curing of the crosslinkable precursor polymers produced higher molecular weight polymers with thermal stabilities ranging from 347 to 417°C. Copyright © 2007 John Wiley & Sons, Ltd.
Thermo and pH sensitive fluorescent polymer sensor for metal cations in aqueous solution
Authors: Liu Yunhai , Meng Lingzhi , Lu Xiaoju , Zhang Lifen , He Yongbing 
Published: September 2007

AbstractA new monomeric fluorophore N‐acryl‐N'‐(quinolin‐8‐yl)thiourea (AQT) was synthesized. Free radical copolymerization was carried out in order to prepare a water‐soluble fluorescent copolymer, based on N‐isopropylacrylamide. The fluorescent characteristic of the aqueous solutions of copolymers was investigated both in varied pH and in the presence of metal cations. The polymer‐ contained AQT was found to be a selective chemosensor for Ni, Pb, Co ions especially for Co ion. The obtained copolymers show thermo‐sensitive lower critical solution temperature (LCST) ranging from 32.5 to 37.5°C with varied ratios of AQT, N, N‐dimethylacrylamide and N‐isopropylamide. Copyright © 2007 John Wiley & Sons, Ltd.
Influence of doped polyaniline on the interaction of Pu/PAni blends and on its microwave absorption properties
Authors: Biscaro Rogério S. , Rezende Mirabel C. , Faez Roselena 
Published: September 2007

AbstractIn this work, the influence of polyaniline (PAni) doped with both camphorsulfonic acid (PAni‐CSA) and dodecylbenzenesulfonic acid (PAni‐DBSA) on polyurethane (PU)/PAni blends was studied by rheological and morphological analyses. The effect of doped polyaniline on the attenuation of incident microwave radiation, in the frequency range from 8.0 to 12.0 GHz, was also investigated. The complex viscosity (η*) of PAni‐DBSA blends is observed to vary more significantly as a function of resting time than PAni‐CSA blends. This behavior is attributed to a better dispersion of PAni particles into the matrix on account of the presence of smaller agglomerates, as observed by optical and electron microscopy. However, this behavior has not been determinant on microwave absorption by the blends, with those that contain PAni‐CSA showing higher attenuation values. Copyright © 2007 John Wiley & Sons, Ltd.
Prognostic significance of immunohistochemical expression of ezrin in non‐metastatic high‐grade osteosarcoma
Authors: Ferrari Stefano , Zanella Licciana , Alberghini Marco , Palmerini Emanuela , Staals Eric , Bacchini Patrizia 
Published: September 2007

AbstractBackgroundEzrin is a membrane‐cytoskeleton linker protein involved in regulating growth and metastatic behaviour of cancer cells. The study evaluated ezrin expression and its prognostic value in patients with non‐metastatic osteosarcoma.ProceduresEzrin expression and pattern of staining (cytoplasmic or membraneous and cytoplasmic) were assessed using immunohistochemistry on slides from tumour biopsy. We studied 95 patients (median 16 years, range: 4–39 years) with primary non‐metastatic osteosarcoma of the extremity treated by neoadjuvant chemotherapy based on methotrexate, cisplatin, doxorubicin and ifosfamide.ResultsSeventy‐six patients (80%) showed ezrin immunoreactivity: in cytoplasm (37, 47%) and in cytoplasm and membrane (42, 53%) of tumour cells. Immunohistochemical staining score was: 1+ (16, 24%), 2+ (10, 13%), 3+ (17, 21.5%) and 4+ (36, 45.5%). Ezrin and score expression were not related to gender, site, alkaline phosphatase (AP), LDH serum levels, chemotherapy‐induced tumour necrosis or patient outcome. A significant association was seen between expression pattern and prognosis. The 3‐year probability of disease‐free survival was 80% for patients with only cytoplasmic immunostaining and 54% for patients with cytoplasmic and membranous immunostaining (P < 0.02).ConclusionEzrin immunoreactivity can be detected in the majority of patients with non‐metastatic osteosarcoma of the extremity. The pattern of ezrin staining can identify patients with different risks of relapse. In patients who only have ezrin cytoplasmic expression, a probability of EFS >80% at 5 years can be expected. These results suggest further investigations to define the relation between expression pattern, ezrin functional status and outcome in patients with non‐metastatic osteosarcoma. Pediatr Blood Cancer 2008;50:752–756. © 2007 Wiley‐Liss, Inc.
Cordocentesis in multifetal pregnancies
Authors: Tongprasert Fuanglada , Tongsong Theera , Wanapirak Chanane , Sirichotiyakul Supatra , Piyamongkol Wirawit 
Published: September 2007

AbstractObjectiveTo describe the experiences in diagnostic cordocentesis in twin pregnancies at midpregnancyMethodsThe database and medical records of pregnant women attending Maternal Fetal Medicine Unit of the hospital for diagnostic cordocentesis at midpregnancy between January 1989 and September 2006 were retrospectively reviewed.ResultsDuring 17 years of experience, 4241 cordocenteses at midpregnancy were performed for prenatal diagnosis, including 59 procedures in 30 multiple pregnancies (29 twins and 1 triplet). The mean gestational age at the time of cordocentesis was 19.5 ± 1.6 weeks. Success rate of the samplings was 98.3% with one sample was maternal blood contamination. Averaged‐time used of the procedures was 8.2 minutes (range 1–45 minutes). The procedure‐related complications included transient bleeding at puncture site (8.5%) and transient fetal bradycardia (22.0%). The total fetal loss rate was 10.5% but there was no cordocentesis‐related fetal loss (0.0%), defined as a fetal loss within 2 weeks after the procedure.ConclusionThis study may provide a new insight on the safety of cordocentesis in multifetal pregnancies at midpregnancy. The procedure‐related fetal loss is not as high as reported in the past. This study suggests cordocentesis be a relatively safe and highly successful in obtaining fetal blood samples. Copyright © 2007 John Wiley & Sons, Ltd.