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1

Effect of preincubation of human spermatozoa in milk on penetration of zona-free hamster oocytes: Comparison to TEST yolk  

Microsoft Academic Search

Purpose  \\u000a To investigate the effect of preincubation of human sperm in milk on their ability to penetrate zona-free hamster oocytes,\\u000a 27 ejaculates were studied. Each ejaculate was divided into two portions and incubated in either milk or TEST yolk (TESTY)\\u000a for 22–24 hr at 5‡C prior to processing for the sperm penetration assay.\\u000a \\u000a \\u000a \\u000a Results  \\u000a Spermatozoa preincubated in milk penetrated a

M. Joseph Scobey; Wendy J. Holmgren; Rajasingam S. Jeyendran

1994-01-01

2

Induction of the Acrosome Reaction and Zona-Free Hamster Oocyte Penetration by a Bull With Complete Teratospermia Versus a Half Brother With Normal Sperm  

Microsoft Academic Search

A fertile bull producing normal sperm and a sterile half brother exhibiting 100% teratospermia were available to study an in- duced sperm acrosome reaction and oocyte penetration. Pedigree analysis indicated that this condition was inherited. Experiments were undertaken to study the induction of the acrosome reaction using di- laurylphosphatidylcholine (PC12) liposomes, because this procedure was previously established to be highly

SHELLEY R. HOUGH; MICHAEL T. KAPROTH; ROBERT H. FOOTE

3

Comparative study of extra and intrafollicular hamster oocyte maturation  

E-print Network

of intra- and extra-follicular maturation of hamster oocytes checked by in vitro fertilization showed many possibilities for in vitro studies on fertilization and on their further development. However of gonadotropins. The ability of hamster sperm to be capacitated in vitro and to fertilize ovulated oocytes (Barros

Paris-Sud XI, Université de

4

Thermostability of sperm nuclei assessed by microinjection into hamster oocytes  

EPA Science Inventory

Nuclei isolated from spermatozoa of various species (golden hamster, mouse, human, rooster, and the fish tilapia) were heated at 60 degrees-125 degrees C for 20-120 min and then microinjected into hamster oocytes to determine whether they could decondense and develop into pronucl...

5

THERMOSTABILITY OF SPERM NUCLEI ASSESSED BY MICROINJECTION INTO HAMSTER OOCYTES  

EPA Science Inventory

Nuclei isolated from spermatozoa of various species (golden hamster, mouse, human, rooster, and the fish tilapia) were heated at 60 degrees - 125 degrees for 20-120 min and then microinjected into hamster oocytes to determine whether they could decondense and develop into pronucl...

6

Chromatin decondensation, pronucleus formation, metaphase entry and chromosome complements of human spermatozoa after intracytoplasmic sperm injection into hamster oocytes.  

PubMed

Obtaining karyotypes from human spermatozoa after microinjection into Syrian golden hamster oocytes is difficult and the hitherto reported results are unsatisfactory. This may be related to the injection and culture technique or to the high susceptibility of the hamster oocytes to undergo parthenogenetic activation or both. Therefore, we investigated the hamster oocyte-human sperm microinjection model using the following two approaches: (i) application of contemporary techniques for injection (touching the sperm tail) and culture (hamster embryo culture medium, HECM-3, 10% CO2) and (ii) omission of Ca2+ from the injection medium. Thus, in the first series of experiments, 252 hamster oocytes were injected with human spermatozoa. Among the 219 (87%) oocytes that survived the injection procedure, the mean percentages of male pronucleus formation [two pronuclei (2PN), two polar bodies (PB)], mitotic metaphase entry and sperm chromosome spreads were 41.4, 27.8 and 18.2% respectively. Analysis of the oocytes which failed to develop the male pronucleus following injection revealed that most of them had developed only the hamster female PN while the sperm nuclei were either intact or swollen (partially decondensed), indicating that failure of oocyte activation was not the likely reason for the failure of male PN formation in these oocytes. In the next series of experiments, sibling oocytes were alternately injected with spermatozoa suspended either in the regular (1.9 mM Ca2+) or Ca2+-free injection medium (experiment set 2, n=278). A significant improvement was noted in the mean percentages of oocytes with 2PN, 2PB, metaphase entry and sperm chromosome spreads in the Ca2+-free group versus the regular group (2PN, 2PB: 51 versus 36.6%, metaphase entry: 36.3 versus 26.9% and sperm chromosome spreads: 28 versus 20.4%; all P < 0.04). Thus, parthenogenetic activation appears to be one of the contributing factors for the failure of male PN formation after heterospecific hamster ICSI. From these experiments it can be concluded that application of the advanced injection and culture techniques and omission of Ca2+ from the injection medium are promising for the routine application of the hamster oocyte microinjection for karyotyping of human spermatozoa with poor fertilizing capacity. PMID:9647569

Goud, P T; Goud, A P; Rybouchkin, A V; De Sutter, P; Dhont, M

1998-05-01

7

Human sperm chromosome analysis after subzonal sperm insemination of hamster oocytes  

SciTech Connect

Sperm microinjection techniques, subzonal sperm insemination (SUZI) and intracytoplasmic sperm injection (ICSI), have achieved a wide spread clinical application for the treatment of male infertility. To date, only one study has focused on sperm karyotypes after microinjection. Martin et al. reported a very high incidence of abnormal human sperm complements after ICSI into hamster oocytes. In the present study, are reported the first human sperm karyotypes after SUZI of hamster oocytes. Spermatozoa from two control donors were treated by calcium ionophore A23187 and injected under the zona of hamster eggs. The microinjected eggs were then cultured for cytogenetic analysis of the pronuclei. Out of 47 analyzed sperm chromosome metaphases, 5 (10.6%) were abnormal, 4 (8.5%) were hypohaploid and 1 (2.1%) had a structural abnormality. The sex ratio was not significantly different from the expected 1:1 ratio. Rates of chromosomal abnormalities in microinjected spermatozoa were similar to those observed in spermatozoa inseminated with zona free eggs, suggesting that SUZI procedure per se does not increase sperm chromosomal abnormalities.

Cozzi, J. [Medical School of Grenoble (France)

1994-09-01

8

The rates of premature chromosome condensation and embryo development after injection of irradiated sperms into hamster oocytes  

PubMed Central

Background: Irradiation is one of the major causes of induced sperm DNA damage. Various studies suggested a relation between sperm DNA damage and fertilization rate after intra-cytoplasmic sperm injection (ICSI). Objective: In this study, fertilization rate and premature chromosome condensation (PCC) formation after ICSI of hamster oocytes with irradiated sperms from normal and oligosperm individuals was investigated. Materials and Methods: Human sperms were classified according to counts to normal and oligosperm. Ten samples were used for each group. Golden hamster oocytes were retrieved after super ovulation by PMSG and HCG injection. From retrieved oocytes, 468 were in metaphase II. Control and 4 Gy gamma irradiated sperms were then injected into oocytes. After pronuclei formation in injected oocytes and formation of 8 cells embryos, slides were prepared using Tarkowskie's standard air-drying technique. The frequency of embryos and PCC were analyzed using 1000× microscope after staining in 5% Giemsa. Results: The extent of embryo development in oocytes injected by irradiated sperms was lower than those injected by non-irradiated sperms (p=0.0001). The frequency of PCC in failed fertilized oocytes was significantly higher in oligosperms (46%) compared with normal ones (0%), but there was no significant difference between irradiated and non-irradiated samples in each group (p=0.12). Conclusion: The results showed that irradiation of sperms might influence the fertilization outcome possibly due to sperm DNA damage. One possible cause of precluding oocytes from fertilization in oligosperm individuals might be the formation of PCC. PMID:24639771

Moghbelinejad, Sahar; Mozdarani, Hossein; Rezaeian, Zahra

2013-01-01

9

The effects of oocyte storage and cumulus cell presence on canine zona penetration by domestic dog spermatozoa  

Microsoft Academic Search

Zona penetration assays (ZPAs) have been developed in numerous species to evaluate sperm fertilizing potential. Preservation methods to stockpile oocytes would be beneficial because of the difficulty in obtaining sufficient numbers of fresh oocytes. Using a canine ZPA, the objectives of this study were to evaluate: (1) two methods of storing canine oocytes (salt storage and intrafollicular cooling) and (2)

Gabriela F. Mastromonaco; Margery A. Hay; Karen L. Goodrowe

2002-01-01

10

CARBENDAZIM (MBC) DISRUPTS OOCYTE SPINDLE FUNCTION AND INDUCES ANEUPLOIDY IN HAMSTERS EXPOSED DURING FERTILIZATION (MEIOSIS II)  

EPA Science Inventory

Peri-fertilization exposure to Carbendazim (MBC; a microtubule poison) induces infertility and early pregnancy loss (EPL) in hamsters. resently, both in vivo and in vitro techniques were employed to characterize the effects of MBC on cellular aspects of fertilization in hamsters....

11

IMPORTANCE OF GLUTATHIONE IN THE ACQUISITION AND MAINTENANCE OF SPERM NUCLEAR DECONDENSING ACTIVITY IN MATURING HAMSTER OOCYTES  

EPA Science Inventory

Sperm nuclear decondensing activity in mammalian oocytes is dependent upon the maturational state of the oocyte. It is maximal in mature, metaphase II oocytes and minimal or absent in immature germinal vesicle (GV) and fertilized pronuclear oocytes. Previous studies suggested tha...

12

GLUTATHIONE (GSH) CONCENTRATIONS VARY WITH THE CELL CYCLE IN MATURING HAMSTER OOCYTES, ZYGOTES AND PRE-IMPLANTATION STAGE EMBRYOS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Glutathione (GSH) is thought to play critical roles in oocyte function including spindle maintenance and provision of reducing power needed to initiate sperm chromatin decondensation. Previous observations that GSH concentrations are higher in mature than immature oocytes and decline after fertiliz...

13

GLUTATHIONE (GSH) CONCENTRATIONS VARY WITH THE CELL CYCLE IN MATURING HAMSTER OOCYTES, ZYGOTES AND PRE-IMPLANATION EMBRYOS  

EPA Science Inventory

Abstract Glutathione (GSH) is thought to play critical roles in oocyte function including spindle maintenance and provision of reducing power needed to initiate sperm chromatin decondensation. Previous observations that GSH concentrations are higher in mature than immature o...

14

Vitrification solution containing DMSO and EG can induce parthenogenetic activation of in vitro matured ovine oocytes and decrease sperm penetration  

Microsoft Academic Search

This study was designed to examine the reduced incidence of normal fertilization in vitrified ovine oocytes. After in vitro maturation for 24h, the oocytes were randomly allocated into three groups: (1) untreated (control), (2) exposed to vitrification solution (VS) without being plunged into liquid nitrogen (toxicity), or (3) vitrified by open-pulled straw method (vitrification). In experiment 1, the treated and

Shu-Jun Tian; Chang-Liang Yan; Hui-Xin Yang; Guang-Bin Zhou; Zhong-Qiang Yang; Shi-En Zhu

2007-01-01

15

USE OF THE FUNGICIDE CARBENDAZIM AS A MODEL COMPOUND TO DETERMINE THE IMPACT OF ACUTE CHEMICAL EXPOSURE DURING OOCYTE MATURATION AND FERTILIZATION ON PREGNANCY OUTCOME IN THE HAMSTER  

EPA Science Inventory

Here we use a hamster animal model to identify early pregnancy loss due to an acute chemical exposure to the female during the perifertilization interval. The fungicide carbendazim (methyl 1H-benzimidazole-2-carbamate), a microtubule poison with antimitotic activity, was selected...

16

Disposition and metabolic profiling of the penetration enhancer Azone. I. In vitro studies: Urinary profiles of hamster, rat, monkey, and man  

SciTech Connect

Chain-labeled {sup 14}C-Azone was intravenously administered to hamster, monkey, and rat, to compare its metabolic profile with that obtained previously in humans after dermal application. Azone-derived radioactivity was excreted predominantly in the urine for both hamster and monkey, which is similar to the disposition in humans. Metabolic profiling in urine revealed extensive systemic metabolism to occur in all species studied. The main fraction of the metabolites was most polar in man, followed by rat, monkey, and hamster. Traces of the parent compound were detectable only in hamster urine. Although some of the polar major human metabolites were also present in rat urine, the animals were unsuitable for collecting metabolites of Azone observed in humans. In rats, complete cleavage of the dodecyl side chain was ruled out by administering Azone that had been labeled at two distinct positions of the molecule. Additionally, oral administration of Azone to rats resulted in the same metabolic profile as intravenous administration, indicating that gastrointestinal metabolism does not occur or is similar to systemic metabolism.

Wiechers, J.W.; Drenth, B.F.; Adolfsen, F.A.; Prins, L.; de Zeeuw, R.A. (Groningen Centre for Drug Research (Netherlands))

1990-05-01

17

Cryopreservation of equine oocytes by 2-step freezing.  

PubMed

Immature equine oocytes were frozen-thawed with ethylene glycol (EG), 1,2-propanediol (PD) or glycerol (GL) in PBS and cultured to assess the rate of in vitro maturation (Experiment 1). Compact-cumulus oocyte complexes were collected from slaughterhouse ovaries and equilibrated for 10 min in the freezing medium containing 10% (V/V) cryoprotectant and 0.1 M sucrose. The 0.25-ml straws, loaded with 10 to 30 oocytes, were seeded at -6 degrees C and cooled to -35 degrees C at 0.3 degrees C/min before being plunged into liquid nitrogen. The straws were thawed rapidly in a 37 degrees C waterbath for 20 sec. The proportions of frozen-thawed oocytes reaching Metaphase II (MII) stage after in vitro maturation of 32 h were 15.8% (EG), 5.8% (PD) and 0% (GL), while 63.3% of the nonfrozen control oocytes matured in vitro. The fertilizing ability of immature and mature oocytes after freezing in EG was tested by the insemination of zona-free oocytes with stallion spermatozoa (Experiment 2). Spermatozoa were preincubated for 3 h with 5 mM caffeine, treated with 0.1 mu M ionophore A23187, and inseminated for 20 h at the concentration of 1 to 2 x 10(7)/ml with 6 to 10 oocytes in 50 mu l of Brackett and Oliphant (BO) medium. Immature oocytes (Group 1) were matured in vitro after thawing and then their zona pellucida removed using 0.5% protease. The zona of mature oocytes were removed immediately after thawing (Group 2) or maturation (nonfrozen controls). The oocytes, which had mechanically damaged plasma membrane or lost by artifact, were not examined for insemination. Significantly more control oocytes exhibited a polar body at the time of insemination (53.5%) than either frozen-thawed immature or mature oocytes (25.8 and 27.3%, respectively). Similar proportion of frozen-thawed and control oocytes were penetrated by spermatozoa (71.8 to 79.1%) and exhibited 2 or more pronuclei (73.6 to 80.8%). The mean numbers of spermatozoa per penetrated oocyte were 1.9, 3.0 and 2.5, respectively, for Groups 1 and 2 and for the control oocytes. These results indicate that immature equine oocytes mature to the MII stage in vitro following freezing and thawing in EG or PD but not in GL. Stallion spermatozoa can penetrate zona-free immature and mature oocytes following freezing/thawing in EG and form morphologically normal pronuclei. PMID:16727612

Hochi, S; Fujimoto, T; Choi, Y H; Braun, J; Oguri, N

1994-01-01

18

Reduction of polyspermic penetration using biomimetic microfluidic technology during in vitro fertilization  

E-print Network

of spermatozoa past the oocytes similar to the pattern in the oviduct. In vitro fertilization of porcine oocytes are similar. Here we demonstrate that the biomimetic microchannel in vitro fertilization system can reduce in vitro production efficiency. Introduction Polyspermic penetration of oocytes fertilized in vitro remains

Beebe, David J.

19

Cryopreservation of mammalian oocytes.  

PubMed

Two methods for the laboratory-focused cryopreservation of mammalian oocytes are described, based on work with murine oocytes. One method uses a relatively low concentration of the cryoprotectant propanediol plus sucrose and requires controlled rate cooling equipment to achieve a slow cooling rate. Such a method has also produced live births from cryopreserved human oocytes. The second method described employs a high concentration of the cryoprotectant dimethyl sulfoxide plus a low concentration of polyethylene glycol. This is a vitrification method which involves ultrarapid cooling by plunging standard straws into liquid nitrogen vapor, hence avoiding the need for specialized equipment, but requires technical ability to manipulate the oocytes quickly in the highly concentrated cryoprotectant solutions. Murine oocytes vitrified using this technique has resulted in live births. PMID:25428011

Keros, Victoria; Fuller, Barry J

2015-01-01

20

TIMING OF HAMSTER SPERM NUCLEAR DECONDENSATION AND MALE PRONUCLEUS FORMATION IS RELATED TO SPERM NUCLEAR DISULFIDE BOND CONTENT  

EPA Science Inventory

The relationship between the timing of both sperm nuclear decondensation and male pronucleus formation in the oocyte and the relative level of disulfide bonds within the sperm nucleus was evaluated. Four types of hamster sperm nuclei, in which the extent of S-S bonding differed, ...

21

In vitro fertilization rate of horse oocytes with partially removed zonae.  

PubMed

Frozen-thawed ejaculated stallion spermatozoa were preincubated for 3 h in BO medium containing 5 mM caffeine and then treated with 0.1 micro M calcium ionophore A23187 for 60 sec. Aliquots of the sperm suspension (final concentration 1-2 x 10(7)/ml) were added to the oocytes which had been matured in vitro for 32 h. In Experiment 1, there were 3 groups of oocytes; cumulus intact, denuded zona-intact, and zona-free. Cumulus cells were removed with 0.5% hyaluronidase and the zona pellucida with 0.1% protease. The oocytes were fixed 20 h after insemination with acetic acid:ethanol (1:3) and stained with 1% orcein. The sperm penetration rate of zona-free oocytes was 83%, whereas the sperm penetration rate was very low (1 to 3%) in the cumulus-enclosed or zona-intact oocytes. In Experiment 2, denuded zona-intact oocytes were placed in PBS supplemented with 10% fetal bovine serum 1 h before the end of in vitro maturation. The zona pellucida was micromanipulated with a metal microblade under x 100 magnification within 20 min of treatment with 0.3 M sucrose. For partial zona dissection, a slit in the zona pellucida was made. For partial zona removal, oocytes were transferred to protein-free PBS to fix the oocytes on the bottom of the Petri-dish and to remove a piece of the zona pellucida. Micromanipulated oocytes were subjected to in vitro fertilization as described above. Zona-intact and zona-free oocytes treated with sucrose solution for 20 min were used as controls. The penetration rates were 4 (2/57), 12 (7/58), 52 (31/60), and 86% (44/51) for zona-intact, partially zona dissected, partially zona removed, and zona-free oocytes, respectively. Proportions of oocytes with monospermic penetration were 100 (2/2), 57 (4/7), 58 (18/31), and 34% (15/44), respectively. In Experiment 3, sperm penetration and male pronucleus formation in the partially zona removed oocytes were examined at 2.5 to 20.0 h of insemination. Sperm penetration started 2.5 h post-insemination (22%, 11/49), and increased to 38% (21/55) at 5 h, to 46% (23/50) at 10 h, and to 56% (27/48) at 20 h. The transformation of sperm heads into male pronuclei was first observed 10 h post insemination. These results indicate that assisted fertilization techniques may be a useful tool for achieving fertilization and embryo production in vitro in horses. PMID:16727585

Choi, Y H; Okada, Y; Hochi, S; Braun, J; Sato, K; Oguri, N

1994-10-01

22

Human oocyte cryopreservation: new perspectives regarding oocyte survival  

Microsoft Academic Search

The success of human oocyte cryopreservation depends on morphological and biophysical factors that could influence oocyte survival after thawing. Various attempts to cryopreserve human oocytes have been performed with contrasting results. Therefore the effect of some factors, such as the presence or absence of the cumulus oophorus, the sucrose concentration in the freezing solution and the exposure time to cryoprotectants,

R. Fabbri; E. Porcu; T. Marsella; G. Rocchetta; S. Venturoli; C. Flamigni

2001-01-01

23

Penetration enhancers  

Microsoft Academic Search

One long-standing approach for improving transdermal drug delivery uses penetration enhancers (also called sorption promoters or accelerants) which penetrate into skin to reversibly decrease the barrier resistance. Numerous compounds have been evaluated for penetration enhancing activity, including sulphoxides (such as dimethylsulphoxide, DMSO), Azones (e.g. laurocapram), pyrrolidones (for example 2-pyrrolidone, 2P), alcohols and alkanols (ethanol, or decanol), glycols (for example propylene

Adrian C Williams; Brian W Barry

2004-01-01

24

Dose-dependent relationship between oocyte cytoplasmic volume and transformation of sperm nuclei to metaphase chromosomes.  

PubMed

We have studied the chromosome condensation activity of mouse oocytes that have been inseminated during meiotic maturation. These oocytes remain unactivated, and in those penetrated by up to three or four sperm, each sperm nucleus is transformed, without prior development of a pronucleus, into metaphase chromosomes. However, those penetrated by more than four sperm never transform any of the nuclei into metaphase chromosomes (Clarke, H. J., and Y. Masui, 1986, J. Cell Biol. 102:1039-1046). We report here that, when the cytoplasmic volume of oocytes was doubled or tripled by cell fusion, up to five or eight sperm nuclei, respectively, could be transformed into metaphase chromosomes. Conversely, when the cytoplasmic volume was reduced by bisection of oocytes after the germinal vesicle (GV) had broken down, no more than two sperm could be transformed into metaphase chromosomes. Thus, the capacity of the oocyte cytoplasm to transform sperm nuclei to metaphase chromosomes was proportional to its volume. The contribution of the nucleoplasm of the GV and the cytoplasm outside the GV to the chromosome condensation activity was investigated by bisecting oocytes that contained a GV and then inseminating the nucleate and anucleate fragments. The anucleate fragments never induced sperm chromosome formation, indicating that GV nucleoplasm is required for this activity. In the nucleate fragments, the capacity to induce sperm chromosome formation was reduced as compared with whole oocytes, in spite of the fact that the fragments contained the entire GV nucleoplasm. This implies that non-GV cytoplasmic material also was required for chromosome condensation activity. When inseminated oocytes were incubated in the presence of puromycin, the sperm nuclei were transformed into interphase-like nuclei, but no metaphase chromosomes developed. However, when protein synthesis resumed, the interphase nuclei were transformed to metaphase chromosomes. These results suggest that the transformation of sperm nuclei to metaphase chromosomes in the cytoplasm of mouse oocytes requires both the nucleoplasm of the GV and non-GV cytoplasmic substances, including proteins synthesized during maturation. PMID:3558483

Clarke, H J; Masui, Y

1987-04-01

25

The effects of taurine and hypotaurine on in vitro fertilization in the golden hamster  

Microsoft Academic Search

Summary. Using an experimental design in which the addition of hypotaurine or epinephrine was staggered through time, evidence was found that suggests these two compounds are working independently and sequentially to stimulate the fertilizing capacity of hamster spermatozoa in vitro. Prior exposure of spermatozoa to hypotaurine is a prerequisite for the action of epinephrine in causing activation and penetration of

M. Lorraine Leibfried; Barry D. Bavister

1981-01-01

26

Gynogenetic activation of porcine oocytes.  

PubMed

The possibility of fertilization without male contribution to the embryonic genome was investigated in pig oocytes. Mature oocytes were co-incubated with sperm, and in an attempt to prevent the incorporation of the sperm head into the ooplasm, the actin polymerization inhibitor cytochalasin B was added to the fertilization medium. We found that perturbing actin filament integrity did not affect the pattern of the sperm-induced Ca(2+) signal or the process of cortical granule exocytosis, and it did not alter the percentage of activated oocytes compared to the control (oocytes fertilized in the absence of the inhibitor). However, over 20% of the cytochalasin B-treated oocytes formed only a single pronucleus after fertilization, indicating that the inhibitor blocked sperm head incorporation at least in some oocytes. In most cases, cytochalasin B also prevented the integration of the male chromosomes into the embryonic genome as determined by the absence of the SRY gene in the embryonic blastomeres or by the frequency of embryos showing green fluorescence after sperm from a GFP-transgenic boar was used for fertilization. Finally, the percentage of embryos that developed beyond the four-cell stage and the total number of nuclei in the resultant blastocysts were higher when oocytes reconstructed by nuclear transfer were activated by fertilization in the presence of cytochalasin B compared to the control group, where activation was induced by electroporation. These results suggest that fertilization in the presence of cytochalasin B can induce oocyte activation while it also prevents integration of the male genome into the embryo. This method has the potential to be used as an alternative to inducing embryonic development after nuclear transfer. PMID:24661186

Lee, Kiho; Wang, Chunmin; Spate, Lee; Murphy, Clifton N; Prather, Randall S; Machaty, Zoltan

2014-04-01

27

Penetrating trauma.  

PubMed

Pneumothorax occurs when air enters the pleural space. Currently there is increasing incidence of road traffic accidents, increasing awareness of healthcare leading to more advanced diagnostic procedures, and increasing number of admissions in intensive care units are responsible for traumatic (non iatrogenic and iatrogenic) pneumothorax. Pneumothorax has a clinical spectrum from asymptomatic patient to life-threatening situations. Diagnosis is usually made by clinical examination and imaging techniques. In our current work we focus on the treatment of penetrating trauma. PMID:25337403

Kuhajda, Ivan; Zarogoulidis, Konstantinos; Kougioumtzi, Ioanna; Huang, Haidong; Li, Qiang; Dryllis, Georgios; Kioumis, Ioannis; Pitsiou, Georgia; Machairiotis, Nikolaos; Katsikogiannis, Nikolaos; Papaiwannou, Antonis; Lampaki, Sofia; Zaric, Bojan; Branislav, Perin; Dervelegas, Konstantinos; Porpodis, Konstantinos; Zarogoulidis, Paul

2014-10-01

28

Penetrating trauma  

PubMed Central

Pneumothorax occurs when air enters the pleural space. Currently there is increasing incidence of road traffic accidents, increasing awareness of healthcare leading to more advanced diagnostic procedures, and increasing number of admissions in intensive care units are responsible for traumatic (non iatrogenic and iatrogenic) pneumothorax. Pneumothorax has a clinical spectrum from asymptomatic patient to life-threatening situations. Diagnosis is usually made by clinical examination and imaging techniques. In our current work we focus on the treatment of penetrating trauma. PMID:25337403

Kuhajda, Ivan; Zarogoulidis, Konstantinos; Kougioumtzi, Ioanna; Huang, Haidong; Li, Qiang; Dryllis, Georgios; Kioumis, Ioannis; Pitsiou, Georgia; Machairiotis, Nikolaos; Katsikogiannis, Nikolaos; Papaiwannou, Antonis; Lampaki, Sofia; Zaric, Bojan; Branislav, Perin; Dervelegas, Konstantinos; Porpodis, Konstantinos

2014-01-01

29

Biochemical characterization of hamster oviductin as a sulphated zona pellucida-binding glycoprotein.  

PubMed Central

Oviductins are a family of glycoproteins, synthesized and released by oviductal secretory cells, which bind to the zona pellucida of the oocyte after ovulation. Hamster oviductin migrates as diffuse species of 160-350 kDa during SDS/PAGE under reducing as well as non-reducing conditions. In this report, we describe the one-step purification of hamster oviductin using either immuno- or lectin-affinity chromatography. Probing with specific lectins showed that the glycoprotein contains terminal alpha-D-GalNAc, and either terminal alpha-D-NeuAc or non-terminal beta-D-(GlcNAc)2 residues, but fails to react with concanavalin A and Ulex Europeus A-1 lectins which are specific for branched alpha-D-mannose and alpha-L-fucose moieties respectively. Intraovarian oocytes do not contain this glycoprotein and we demonstrate here that the immunoaffinity-purified oviductin readily binds to their zonae pellucidae in vitro, thus mimicking the in vivo phenomenon. Two major immunologically related forms of hamster oviductin (named alpha and beta) were characterized using one- and two-dimensional gel electrophoresis. The alpha-form (160-210 kDa) has an acidic pI of 3.5-4.5 and the beta-form (approx. 210-350 kDa) is localized at the cathodic site in the isoelectric focusing dimension; in between these two major forms lies a smear of minor-charge isomers. Peptide mapping of both major forms with papain and Staphylococcus aureus V8 protease yielded fragments of identical size. Moreover, the two forms share the same N-terminal sequence which display no significant homology with other reported proteins. Treatment with trifluoromethanesulphonic acid showed that a protein with the size and pI of the alpha-form can be generated from the beta-form. Both the alpha- and beta-forms are sulphated on O-linked oligosaccharide side chains but are not phosphorylated. Collectively, these results suggest that the hamster oviductin polymorphism observed in two-dimensional PAGE is a consequence of different glycosylation patterns and not the polypeptide chain itself. Hamster oviductin is mostly O-glycosylated and contains a few N-linked oligosaccharide side chains (approx. 10 kDa). We propose that hamster oviductin is a mucin-type glycoprotein which might act as a protective secretion influencing the first steps of the reproductive process necessary for the normal triggering of fertilization and early embryonic development. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 PMID:8240241

Malette, B; Bleau, G

1993-01-01

30

Embryological, clinical and ultrastructural study of human oocytes presenting indented zona pellucida.  

PubMed

Summary Human oocyte dysmorphisms attain a large proportion of retrieved oocytes from assisted reproductive technology (ART) treatment cycles. Extracytoplasmic defects involve abnormal morphology of the zona pellucida (ZP), perivitelline space and first polar body. The aim of the present study was to describe a novel dysmorphism affecting the ZP, indented ZP. We also evaluated the clinical, embryological and ultrastructural features of these cases. We evaluated all ART treatment cycles during 7 consecutive years and found 13 treatment cycles (six patients) with all oocytes presenting an indented ZP. In addition, these oocytes presented total or partial absence of the perivitelline space, absence of resistance to ZP and oolemma penetration during microinjection, and low ooplasm viscosity during aspiration. This novel described dysmorphism was recurrent and attained all oocytes in three cases that had more than one treatment cycle. When compared with controls, data showed significant low oocyte maturity (42% versus 81.6%) and high cycle cancellation (30.8% versus 8.5%) rates, normal degeneration (3.4% versus 6.3%) and fertilization rates (69% versus 69.5%), and low pregnancy (15.4% versus 33.3%) and live-birth delivery (7.7% versus 27.7%) rates per cycle. Ultrastructure analysis revealed a zona pellucida structure with large empty electrolucent regions, an outer ZP layer with an indented surface with protuberances and a thick inner ZP that obliterated the perivitelline space. There was evidence of exocytosis of ZP material by the oocyte. In conclusion, oocytes with this novel described dysmorphism (indented ZP) are associated with low maturity, pregnancy and live-birth delivery rates. PMID:23992046

Sousa, M; da Silva, J Teixeira; Silva, J; Cunha, M; Viana, P; Oliveira, E; Sá, R; Soares, C; Oliveira, C; Barros, A

2015-02-01

31

Cold-induced changes in amphibian oocytes  

SciTech Connect

Female Pleurodeles waltl newts (Amphibia, urodele), usually raised at 20 degrees C, were submitted to low temperatures; oocytes responded to this cold stress by drastic changes both in lampbrush chromosome structure and in protein pattern. Preexisting lateral loops of lampbrush chromosomes were reduced in size and number, while cold-induced loops which were tremendously developed, occurred on defined bivalents of the oocyte at constant, reproducible sites. A comparison of protein patterns in control and stressed oocytes showed two main differences: in stressed oocytes, overall protein synthesis was reduced, except for a set of polypeptides, the cold-stress proteins; second, there was a striking inversion of the relative amount of beta- and gamma-actin found in the oocyte nucleus before and after cold stress. Whereas beta-actin was the predominant form in control oocytes, gamma-actin became the major form in stressed oocytes.

Angelier, N.; Moreau, N.A.; N'Da, E.A.; Lautredou, N.F. (Centre de Biologie Cellulaire, Ivry-sur-Seine (France))

1989-08-01

32

Spindle Dynamics during Meiosis in Drosophila Oocytes  

PubMed Central

Mature oocytes of Drosophila are arrested in metaphase of meiosis I. Upon activation by ovulation or fertilization, oocytes undergo a series of rapid changes that have not been directly visualized previously. We report here the use of the Nonclaret disjunctional (Ncd) microtubule motor protein fused to the green fluorescent protein (GFP) to monitor changes in the meiotic spindle of live oocytes after activation in vitro. Meiotic spindles of metaphase-arrested oocytes are relatively stable, however, meiotic spindles of in vitro–activated oocytes are highly dynamic: the spindles elongate, rotate around their long axis, and undergo an acute pivoting movement to reorient perpendicular to the oocyte surface. Many oocytes spontaneously complete the meiotic divisions, permitting visualization of progression from meiosis I to II. The movements of the spindle after oocyte activation provide new information about the dynamic changes in the spindle that occur upon re-entry into meiosis and completion of the meiotic divisions. Spindles in live oocytes mutant for a lossof-function ncd allele fused to gfp were also imaged. The genesis of spindle defects in the live mutant oocytes provides new insights into the mechanism of Ncd function in the spindle during the meiotic divisions. PMID:9182665

Endow, Sharyn A.; Komma, Donald J.

1997-01-01

33

Laser-Assisted In Vitro Fertilization Facilitates Fertilization of Vitrified-Warmed C57BL/6 Mouse Oocytes with Fresh and Frozen-Thawed Spermatozoa, Producing Live Pups  

PubMed Central

The utility of cryopreserved mouse gametes for reproduction of transgenic mice depends on development of assisted reproductive technologies, including vitrification of unfertilized mouse oocytes. Due to hardening of the zona pellucida, spermatozoa are often unable to penetrate vitrified-warmed (V-W) oocytes. Laser-assisted in vitro fertilization (LAIVF) facilitates fertilization by allowing easier penetration of spermatozoa through a perforation in the zona. We investigated the efficiency of V-W C57BL/6NTac oocytes drilled by the XYClone laser, compared to fresh oocytes. By using DAP213 for cryoprotection, 83% (1,470/1,762) of vitrified oocytes were recovered after warming and 78% were viable. Four groups were evaluated for two-cell embryo and live offspring efficiency: 1) LAIVF using V-W oocytes, 2) LAIVF using fresh oocytes, 3) conventional IVF using V-W oocytes and 4) conventional IVF using fresh oocytes. First, the groups were tested using fresh C57BL/6NTac spermatozoa (74% motile, 15 million/ml). LAIVF markedly improved the two-cell embryo efficiency using both V-W (76%, 229/298) and fresh oocytes (69%, 135/197), compared to conventional IVF (7%, 12/182; 6%, 14/235, respectively). Then, frozen-thawed C57BL/6NTac spermatozoa (35% motile, 15 million/ml) were used and LAIVF was again found to enhance fertilization efficiency, with two-cell embryo rates of 87% (298/343) using V-W oocytes (P<0.05, compared to fresh spermatozoa), and 73% (195/266) using fresh oocytes. Conventional IVF with frozen-thawed spermatozoa using V-W (6%, 10/168) and fresh (5%, 15/323) oocytes produced few two-cell embryos. Although live offspring efficiency following embryo transfer was greater with conventional IVF (35%, 18/51; LAIVF: 6%, 50/784), advantage was seen with LAIVF in live offspring obtained from total oocytes (5%, 50/1,010; conventional IVF: 2%, 18/908). Our results demonstrated that zona-drilled V-W mouse oocytes can be used for IVF procedures using both fresh and frozen-thawed spermatozoa, producing live pups. The ability to cryopreserve mouse gametes for LAIVF may facilitate management of large-scale transgenic mouse production facilities. PMID:24618785

Woods, Stephanie E.; Qi, Peimin; Rosalia, Elizabeth; Chavarria, Tony; Discua, Allan; Mkandawire, John; Fox, James G.; García, Alexis

2014-01-01

34

Laser-assisted in vitro fertilization facilitates fertilization of vitrified-warmed C57BL/6 mouse oocytes with fresh and frozen-thawed spermatozoa, producing live pups.  

PubMed

The utility of cryopreserved mouse gametes for reproduction of transgenic mice depends on development of assisted reproductive technologies, including vitrification of unfertilized mouse oocytes. Due to hardening of the zona pellucida, spermatozoa are often unable to penetrate vitrified-warmed (V-W) oocytes. Laser-assisted in vitro fertilization (LAIVF) facilitates fertilization by allowing easier penetration of spermatozoa through a perforation in the zona. We investigated the efficiency of V-W C57BL/6NTac oocytes drilled by the XYClone laser, compared to fresh oocytes. By using DAP213 for cryoprotection, 83% (1,470/1,762) of vitrified oocytes were recovered after warming and 78% were viable. Four groups were evaluated for two-cell embryo and live offspring efficiency: 1) LAIVF using V-W oocytes, 2) LAIVF using fresh oocytes, 3) conventional IVF using V-W oocytes and 4) conventional IVF using fresh oocytes. First, the groups were tested using fresh C57BL/6NTac spermatozoa (74% motile, 15 million/ml). LAIVF markedly improved the two-cell embryo efficiency using both V-W (76%, 229/298) and fresh oocytes (69%, 135/197), compared to conventional IVF (7%, 12/182; 6%, 14/235, respectively). Then, frozen-thawed C57BL/6NTac spermatozoa (35% motile, 15 million/ml) were used and LAIVF was again found to enhance fertilization efficiency, with two-cell embryo rates of 87% (298/343) using V-W oocytes (P<0.05, compared to fresh spermatozoa), and 73% (195/266) using fresh oocytes. Conventional IVF with frozen-thawed spermatozoa using V-W (6%, 10/168) and fresh (5%, 15/323) oocytes produced few two-cell embryos. Although live offspring efficiency following embryo transfer was greater with conventional IVF (35%, 18/51; LAIVF: 6%, 50/784), advantage was seen with LAIVF in live offspring obtained from total oocytes (5%, 50/1,010; conventional IVF: 2%, 18/908). Our results demonstrated that zona-drilled V-W mouse oocytes can be used for IVF procedures using both fresh and frozen-thawed spermatozoa, producing live pups. The ability to cryopreserve mouse gametes for LAIVF may facilitate management of large-scale transgenic mouse production facilities. PMID:24618785

Woods, Stephanie E; Qi, Peimin; Rosalia, Elizabeth; Chavarria, Tony; Discua, Allan; Mkandawire, John; Fox, James G; García, Alexis

2014-01-01

35

The oocyte-to-embryo transition : regulation of oocyte maturation and egg activation in Drosophila  

E-print Network

In oogenesis, meiosis must be highly regulated to ensure that growth of the oocyte and chromosomal segregation are coordinated properly. To do this, meiosis arrests at two points to permit oocyte differentiation and ...

Weingarten, Lisa Suzanne

2013-01-01

36

FATE OF INHALED FLY ASH IN HAMSTERS  

EPA Science Inventory

To determine pulmonary deposition, translocation, and clearance of inhaled fly ash, hamsters received a single 95-min nose-only exposure to neutron-activated fly ash. Over a period of 99 days postexposure, the hamsters were sacrificed in groups of six animals. Lungs, liver, kidne...

37

[Human follicular oocytes (cytologic and physiologic characteristics)].  

PubMed

The morphology and the rate of degenerative changes were studied in the oocytes recovered from the antral follicles of the operated women. The rate of meiosis resumption, chromosome aberrations and electrophysiological properties were studied in the cultivated oocytes. These indices were compared in women of different age and pathology. A small part of the whole population of follicular oocytes is capable to complete in vitro cytoplasmic and nuclear transformations indispensable for fertilization and further development. A conclusion is drawn that the heterogeneity of follicular oocytes reflects the regular processes of follicle growth and elimination in the ovary. PMID:7088477

Nikitin, A I; Savitski?, G A; Kitaev, E M; Pimenova, M N; Sorina, V Ia

1982-01-01

38

[Oocyte vitrification in an ART laboratory].  

PubMed

Oocyte vitrification has been authorized in France after the modification of French bioethics law in July 2011. This evolution will bring a dramatic change in patients' management since, from 2011, infertile couples, oocyte donation and fertility preservation programs will benefit this technique in France. We have introduced oocyte vitrification in our ART laboratory through a validation of the method using Evidence-Based Medicine model: open system Cryotop, Ethylène-glycol 15% and DMSO 15%. Based on our 1-year experience, oocyte vitrification upgrades our daily practice while also minimizing embryo cryoconservation as recommended by the law. PMID:23969289

Boyer, P; Montjean, D; Tourame, P; Gervoise-Boyer, M

2013-09-01

39

Fourier analysis of mitochondrial distribution in oocytes  

NASA Astrophysics Data System (ADS)

This paper describes a novel approach to quantifying mitochondrial patterns which are typically described using the qualitative terms "diffuse" "aggregated" and are potentially key indicators for an oocyte's health and survival potential post-implantation. An oocyte was isolated in a confocal image and a coarse grid was superimposed upon it. The spatial spectrum was calculated and an aggregation factor was generated. A classifier for healthy cells was developed and verified. The aggregation factor showed a clear distinction between the healthy and unhealthy oocytes. The ultimate goal is to screen oocytes for viability preimplantation, thus improving the outcome of in vitro fertilization (IVF) treatments.

Hollmann, Joseph L.; Brooks, Dana H.; Newmark, Judith A.; Warner, Carol M.; DiMarzio, Charles A.

2011-03-01

40

NMR observation of Tau in Xenopus oocytes  

NASA Astrophysics Data System (ADS)

The observation by NMR spectroscopy of microinjected 15N-labelled proteins into Xenopus laevis oocytes might open the way to link structural and cellular biology. We show here that embedding the oocytes into a 20% Ficoll solution maintains their structural integrity over extended periods of time, allowing for the detection of nearly physiological protein concentrations. We use these novel conditions to study the neuronal Tau protein inside the oocytes. Spectral reproducibility and careful comparison of the spectra of Tau before and after cell homogenization is presented. When injecting Tau protein into immature oocytes, we show that both its microtubule association and different phosphorylation events can be detected.

Bodart, Jean-François; Wieruszeski, Jean-Michel; Amniai, Laziza; Leroy, Arnaud; Landrieu, Isabelle; Rousseau-Lescuyer, Arlette; Vilain, Jean-Pierre; Lippens, Guy

2008-06-01

41

Spindle Dynamics during Meiosis in Drosophila Oocytes  

Microsoft Academic Search

Mature oocytes of Drosophila are arrested in metaphase of meiosis I. Upon activation by ovulation or fertilization, oocytes undergo a series of rapid changes that have not been directly visualized previ- ously. We report here the use of the Nonclaret disjunc- tional (Ncd) microtubule motor protein fused to the green fluorescent protein (GFP) to monitor changes in the meiotic spindle

Sharyn A. Endow; Donald J. Komma

1997-01-01

42

Clinical experience and applications of oocyte cryopreservation  

Microsoft Academic Search

Oocyte cryopreservation is a viable solution for the ethical problems related to embryo storage, and the only available technique for preservation of fertility in women who have to undergo chemo- or radiotherapy. The main problems with oocyte cryopreservation are concerned with the survival rate and the fertilization rate. Recently the introduction of the intracytoplasmic sperm injection (ICSI) led to an

E Porcu; R Fabbri; G Damiano; S Giunchi; R Fratto; PM Ciotti; S Venturoli; C Flamigni

2000-01-01

43

Calcium waves occur as Drosophila oocytes activate.  

PubMed

Egg activation is the process by which a mature oocyte becomes capable of supporting embryo development. In vertebrates and echinoderms, activation is induced by fertilization. Molecules introduced into the egg by the sperm trigger progressive release of intracellular calcium stores in the oocyte. Calcium wave(s) spread through the oocyte and induce completion of meiosis, new macromolecular synthesis, and modification of the vitelline envelope to prevent polyspermy. However, arthropod eggs activate without fertilization: in the insects examined, eggs activate as they move through the female's reproductive tract. Here, we show that a calcium wave is, nevertheless, characteristic of egg activation in Drosophila. This calcium rise requires influx of calcium from the external environment and is induced as the egg is ovulated. Pressure on the oocyte (or swelling by the oocyte) can induce a calcium rise through the action of mechanosensitive ion channels. Visualization of calcium fluxes in activating eggs in oviducts shows a wave of increased calcium initiating at one or both oocyte poles and spreading across the oocyte. In vitro, waves also spread inward from oocyte pole(s). Wave propagation requires the IP3 system. Thus, although a fertilizing sperm is not necessary for egg activation in Drosophila, the characteristic of increased cytosolic calcium levels spreading through the egg is conserved. Because many downstream signaling effectors are conserved in Drosophila, this system offers the unique perspective of egg activation events due solely to maternal components. PMID:25564670

Kaneuchi, Taro; Sartain, Caroline V; Takeo, Satomi; Horner, Vanessa L; Buehner, Norene A; Aigaki, Toshiro; Wolfner, Mariana F

2015-01-20

44

Activation of oocytes after nuclear transfer.  

PubMed

After nuclear transfer, the recipient oocyte must be stimulated to initiate development. This stimulation is achieved by inducing changes in the oocyte cytoplasm that normally are triggered by the sperm during fertilization. In most cases, such changes include a transient increase in the intracellular-free calcium concentration induced by an electrical pulse or alternatively, by chemical agents. Many times, particularly in aged oocytes, this calcium signal is sufficient to stimulate the oocyte developmental program. Other activation protocols were designed to target pathways downstream of the initial calcium signal to affect the activity of regulatory proteins that play central roles in maintaining developmental arrest. This is achieved by the application of protein kinase or protein synthesis inhibitors; combined with a calcium stimulus such inhibitors are widely used for oocyte activation after nuclear transfer and are able to support embryonic development to term. PMID:16988371

Macháty, Zoltán

2006-01-01

45

Cryopreservation of immature bovine oocytes by vitrification in straws  

Microsoft Academic Search

The aim of this study was to cryopreserve by vitrification by ethylene glycol (EG) and dimethyl sulfoxide (DMSO) immature bovine oocytes in straws and to investigate the effects of vitrification on post-thaw oocyte maturation.A total of 575 cumulus oocyte complexes were obtained by follicle aspiration from 238 ovaries of cows slaughtered at a local abattoir. Following selection, oocytes with compacted

Yunus Cetin; Ayhan Bastan

2006-01-01

46

Induction of lyme arthritis in LSH hamsters.  

PubMed Central

In studies of experimental Lyme disease, a major obstacle has been the unavailability of a suitable animal model. We found that irradiated LSH/Ss Lak hamsters developed arthritis after injection of Borrelia burgdorferi in the hind paws. When nonirradiated hamsters were injected in the hind paws with B. burgdorferi, acute transient synovitis was present. A diffuse neutrophilic infiltrate involved the synovia and periarticular structures. The inflammation was associated with edema, hyperemia, and granulation tissue. Numerous spirochetes were seen in the synovial and subsynovial tissues. The histopathologic changes were enhanced in irradiated hamsters. The onset and duration of the induced swelling were dependent on the dose of radiation and the inoculum of spirochetes. Inoculation of irradiated hamsters with Formalin-killed spirochetes or medium in which B. burgdorferi had grown for 7 days failed to induce swelling. This animal model should prove useful for studies of the immune response to B. burgdorferi and the pathogenesis of Lyme arthritis. Images PMID:3410540

Schmitz, J L; Schell, R F; Hejka, A; England, D M; Konick, L

1988-01-01

47

Induction of lyme arthritis in LSH hamsters  

SciTech Connect

In studies of experimental Lyme disease, a major obstacle has been the unavailability of a suitable animal model. We found that irradiated LSH/Ss Lak hamsters developed arthritis after injection of Borrelia burgdorferi in the hind paws. When nonirradiated hamsters were injected in the hind paws with B. burgdorferi, acute transient synovitis was present. A diffuse neutrophilic infiltrate involved the synovia and periarticular structures. The inflammation was associated with edema, hyperemia, and granulation tissue. Numerous spirochetes were seen in the synovial and subsynovial tissues. The histopathologic changes were enhanced in irradiated hamsters. The onset and duration of the induced swelling were dependent on the dose of radiation and the inoculum of spirochetes. Inoculation of irradiated hamsters with Formalin-killed spirochetes or medium in which B. burgdorferi had grown for 7 days failed to induce swelling. This animal model should prove useful for studies of the immune response to B. burgdorferi and the pathogenesis of Lyme arthritis.

Schmitz, J.L.; Schell, R.F.; Hejka, A.; England, D.M.; Konick, L.

1988-09-01

48

Cryobiology of non-human primate oocytes.  

PubMed

The responses to various stresses involved with cryopreservation protocols were investigated using non-human primate oocytes. Fluorescence microscopy was used to assess the status of the F-actin microfilament system of rhesus monkey oocytes after exposure to different concentrations of glycerol. The F-actin organization around the cortex and in the transzonal processes was modified by exposure to 1.0 ot 2.0 M glycerol at ambient temperature. These effects were reduced significantly when exposure to glycerol was combined with cooling to O degrees C. Cynomolgus monkey oocytes were also subjected to hyperosmotic stress and observed for morphological changes. An irregular shrinkage phenomenon was observed with germinal vesicle or metaphase I but not metaphase II (MII) oocytes. The irregular shrinkage became uniform and spherical when the oocytes were pretreated with ethyleneglycol-bis-(beta-aminoethyl ether)N,N,N'N' tetraacetic acid (EGTA) before exposure to hypertonic solution. Also, in-vitro-matured MII oocytes from cynomolgus monkeys were used to determine crucial biophysical parameters for freezing primate oocytes. The permeability of oocyte plasma membrane to water, Lpg, and its activation energy, ELp, were determined between 0 and -12 degrees C in the absence of cryoprotective additives. The Lpg was found to be 3.8x10(-14) m3N/s and the ELp was 141.5 kJ/mol. the pre-exponential kinetic and exponential thermodynamic parameters of intracellular ice formation were determined to be 8x108 m2/S and 2. 2x10(9) K5 respectively. By combining models of water transport and intracellular ice formation, the cumulative fraction of oocytes with intracellular ice as a function of the cooling rate was also predicted, and it was shown to correlate reasonably with experimental observations. PMID:8671179

Younis, A I; Toner, M; Albertini, D F; Biggers, J D

1996-01-01

49

Raman spectroscopy of Xenopus laevis oocytes.  

PubMed

This work reports on the application of Raman spectroscopy for the analysis of Xenopus laevis oocytes (stage-I). A two-color home-made microscope has been used for this investigation. In particular, a 785nm Raman probe has been used to acquire the spontaneous Raman scattering from the oocyte cytoplasm, while a 532nm probe has been employed to detect carotenoids through Resonant Raman Scattering. Finally, the distribution of beta-carotene along a diameter of a single oocyte has been investigated. PMID:20035873

Rusciano, Giulia; Pesce, Giuseppe; Salemme, Marinella; Selvaggi, Lara; Vaccaro, Carmen; Sasso, Antonio; Carotenuto, Rosa

2010-05-01

50

Maternal factors required for oocyte developmental competence in mice  

PubMed Central

During mouse antral follicle development, the oocyte chromatin gradually transforms from a less condensed state with no Hoechst-positive rim surrounding the nucleolus (NSN) to a fully condensed chromatin state with a Hoechst-positive rim surrounding the nucleolus (SN). Compared with SN oocytes, NSN oocytes display a higher gene transcription activity and a lower rate of meiosis resumption (G2/M transition), and they are mostly arrested at the two-cell stage after in vitro fertilization. To explore the differences between NSN and SN oocytes, and the maternal factors required for oocyte developmental competence, we compared the whole-transcriptome profiles between NSN and SN oocytes. First, we found that the NSN and SN oocytes were different in their metabolic pathways. In the phosphatidylinositol signaling pathway, the SN oocytes tend to produce diacylglycerol, whereas the NSN oocytes tend to produce phosphatidylinositol (3,4,5)-trisphosphate. For energy production, the SN oocytes and NSN oocytes differed in the gluconeogenesis and in the synthesis processes. Second, we also found that the key genes associated with oocyte meiosis and/or preimplantation embryo development were differently expressed in the NSN and SN oocytes. Our results illustrate that during the NSN-SN transition, the oocytes change their metabolic activities and accumulate maternal factors for further oocyte maturation and post-fertilization embryo development. PMID:23673344

Ma, Jun-Yu; Li, Mo; Luo, Yi-Bo; Song, Shuhui; Tian, Dongmei; Yang, Jin; Zhang, Bing; Hou, Yi; Schatten, Heide; Liu, Zhonghua; Sun, Qing-Yuan

2013-01-01

51

Translational Control in Oocyte Development  

PubMed Central

Translational control of specific mRNAs is a widespread mechanism of gene regulation, and it is especially important in pattern formation in the oocytes of organisms in which the embryonic axes are established maternally. Drosophila and Xenopus have been especially valuable in elucidating the relevant molecular mechanisms. Here, we comprehensively review what is known about translational control in these two systems, focusing on examples that illustrate key concepts that have emerged. We focus on protein-mediated translational control, rather than regulation mediated by small RNAs, as the former appears to be predominant in controlling these developmental events. Mechanisms that modulate the ability of the specific mRNAs to be recruited to the ribosome, that regulate polyadenylation of specific mRNAs, or that control the association of particular mRNAs into translationally inert ribonucleoprotein complexes will all be discussed. PMID:21690213

Richter, Joel D.; Lasko, Paul

2011-01-01

52

Mouse oocyte vitrification: the effects of two methods on maturing germinal vesicle breakdown oocytes  

Microsoft Academic Search

Purpose  Evaluation of viability and subsequent developmental ability of mouse germinal vesicle breakdown oocytes vitrified in conventional\\u000a straws.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Oocytes with compact cumulus cells were cultured for 3 h in TCM199 medium GVBD and vitrified by two methods: the step-wise\\u000a and single-step. After vitrification, the oocytes were thawed, and subjected to in vitro maturation and in vitro fertilization.\\u000a Oocyte survival (post-thaw) was assessed

Somayeh Khosravi-Farsani; Aligholi Sobhani; Fardin Amidi; Reza Mahmoudi

2010-01-01

53

Halide transport in Xenopus oocytes.  

PubMed

1. Radioisotopes and intracellular microelectrodes were used to characterize the permeability of Xenopus oocytes to chloride and other halides. 2. Uptake of 36Cl had a half-time for equilibration of approximately 3 h, with an initial rate of Cl- entry corresponding to a permeability coefficient of 3.9 x 10(-7) cm/s, and an equilibrium uptake of 36Cl of 33 mM. 3. Replacement of bathing Na+ by K+ depolarized the oocytes from -46 to -7 mV and stimulated influx approximately 3-fold. 4. Influx was linearly dependent on bathing [Cl-] and was temperature dependent with an activation energy of 46 kJ/mol. Influx of 125I of 36Cl was not affected by the presence of equal concentrations of other halides or thiocyanate. These results are consistent with a channel-mediated entry mechanism. 5. Diphenylamine-2-carboxylate (DPAC) and 9-anthracene carboxylate (9-AC), blockers of Cl- channels in other cells, inhibited Cl- entry with dissociation constants (Kds) of approximately 5 x 10(-4) and approximately 10(-3) M, respectively. Inhibitors of Cl(-)-HCO3- exchange or Na(+)-K(+)-2Cl- co-transport did not affect Cl- influx. 6. Attempts to lower or raise intracellular Ca2+ with BAPTA or A23187, respectively, were also without effect on Cl- influx. 7. The halide selectivity sequence determined with isotopes was I- (3.2) greater than Br- (1.3) greater than Cl- (1.0). However, DPAC inhibited almost all of the 36Cl influx but only a small fraction of 125I influx. 8. Replacement of bathing Cl- by I- or Br-resulted in hyperpolarizations, from which the same selectivity sequence was determined. 9. Replacement of bathing Cl- by gluconate caused a marked depolarization, which was inhibited by DPAC and, less potently, by 9-AC. PMID:1822540

Katayama, Y; Widdicombe, J H

1991-11-01

54

Penetration of concrete targets  

SciTech Connect

We developed penetration equations for ogive-nosed projectiles that penetrated concrete targets after normal impact. Our penetration equations predict axial force on the projectile nose, rigid-body motion, and final penetration depth. For target constitutive models, we conducted triaxial material experiments to confining pressures of 600 MPa and curve-fit these data with a linear pressure-volumetric strain relation and with a linear Mohr-Coulomb, shear strength-pressure relation. To verify our penetration equations, we conducted eleven penetration experiments with 0.90 kg, 26.9-mm-diameter, ogive-nosed projectiles into 1.37-m-diameter concrete targets with unconfined compressive strengths between 32-40 MPa. Predictions from our penetration equation are compared with final penetration depth measurements for striking velocities between 280--800 m/s.

Forrestal, M.J. [Sandia National Labs., Albuquerque, NM (United States); Cargile, J.D. [Corps of Engineers, Vicksburg, MS (United States). Waterways Experiment Station; Tzou, R.D.Y. [New Mexico Univ., Albuquerque, NM (United States). Dept. of Mechanical Engineering

1993-08-01

55

Raman spectroscopy of Xenopus laevis oocytes  

Microsoft Academic Search

This work reports on the application of Raman spectroscopy for the analysis of Xenopus laevis oocytes (stage-I). A two-color home-made microscope has been used for this investigation. In particular, a 785nm Raman probe has been used to acquire the spontaneous Raman scattering from the oocyte cytoplasm, while a 532nm probe has been employed to detect carotenoids through Resonant Raman Scattering.

Giulia Rusciano; Giuseppe Pesce; Marinella Salemme; Lara Selvaggi; Carmen Vaccaro; Antonio Sasso; Rosa Carotenuto

2010-01-01

56

Repetitive oocyte donation: a committee opinion.  

PubMed

This Committee Opinion concludes that donors be advised of the number of cycles/donations that a given oocyte donor may undergo. Although existing data cannot permit conclusive recommendations, a concern for the issues of the safety and well-being of oocyte donors warrants consideration. This document replaces the document of the same name, previously published in 2008 (Fertil Steril 2008; 90:S194-5). PMID:25064399

2014-10-01

57

FAA fluorescent penetrant activities  

Microsoft Academic Search

The Federal Aviation Administration`s Airworthiness Assurance NDI Validation Center (AANC) and the Center for Aviation Systems Reliability (CASR) are currently working to develop a liquid penetrant inspection (LPI) system evaluation capability that will support the needs of the penetrant manufacturers, commercial airline industry and the FAA. The main focus of this facility is to support the evaluation of penetrant inspection

D. G. Moore; B. F. Larson

1997-01-01

58

Glycolytic Metabolites Are Critical Modulators of Oocyte Maturation and Viability  

PubMed Central

The maturation of an oocyte into an egg is a key step in preparation for fertilization. In Xenopus, oocyte maturation is independent of transcription, being regulated at the level of translation and post-translational modifications of proteins. To identify factors involved in the maturation process we used two-dimensional differential gel electrophoresis to compare the proteome of oocytes and eggs. Protein abundance changes were observed in multiple cellular pathways during oocyte maturation. Most prominent was a general reduction in abundance of enzymes in the glycolytic pathway. Injection into oocytes of the glycolytic intermediates glyceraldehyde-3-phosphate, phosphoenolpyruvate and glucose-6-phosphate prevented oocyte maturation. Instead, these metabolites stimulated ROS production and subsequent apoptosis of the oocyte. In contrast, all other metabolites tested had no effect on oocyte maturation and did not induce apoptosis. These data suggest that a subset of glycolytic metabolites have the capacity to regulate oocyte viability. PMID:24167578

Berger, Lloyd; Wilde, Andrew

2013-01-01

59

Expression of FSH receptor in the hamster ovary during perinatal development.  

PubMed

FSH plays an important role in ovarian follicular development, and it functions via the G-protein coupled FSH receptor. The objectives of the present study were to determine if full-length FSHR mRNA and corresponding protein were expressed in fetal through postnatal hamster ovaries to explain the FSH-induced primordial follicle formation, and if FSH or estrogen (E) would affect the expression. A full-length and two alternately spliced FSHR transcripts were expressed from E14 through P20. The level of the full-length FSHR mRNA increased markedly through P7 before stabilizing at a lower level with the formation and activation of primordial follicles. A predicted 87?kDa FSHR protein band was detected in fetal through P4 ovaries, but additional bands appeared as ovary developed. FSHR immunosignal was present in undifferentiated somatic cells and oocytes in early postnatal ovaries, but was granulosa cells specific after follicles formed. Both eCG and E significantly up-regulated full-length FSHR mRNA levels. Therefore, FSHR is expressed in the hamster ovary from the fetal life to account for FSH-induced primordial follicle formation and cAMP production. Further, FSH or E regulates the receptor expression. PMID:25462586

Chakraborty, Prabuddha; Roy, Shyamal K

2015-01-15

60

Computer-assisted oocyte morphometry before ICSI: correlation of oocyte measurements with fertilization and embryo development.  

PubMed

The present study aimed to correlate morphometric parameters of the oocytes with the occurrence of fertilization following intracytoplasmic sperm injection (ICSI). In a prospective, controlled cohort design, women (n = 32) who were candidates for ICSI had oocytes (n = 258) collected and submitted to morphometric evaluation using the Cronus3 software program. The morphometric parameters obtained were oocyte diameter, perivitelline space width, zona pellucida thickness, and first polar body diameter. The median oocyte diameter was similar in cases in which fertilization occurred compared with those in which fertilization failed (75.2 and 75.9 ?m, respectively; P = .218). The 2 groups also had similar measurements of perivitelline space, zona pellucida, and first polar body. However, the best quality zygotes identified by a morphological score resulted from oocytes with larger diameter (75.6 vs 74.0 ?m; P < .01) and narrow perivitelline space (5.3 vs 7.1 ?m; P < .01). Embryo development, as assessed by cleavage at second day of culture, was not significantly associated with oocyte morphometric parameters. These findings suggest that morphometric parameters of the oocytes do not correlate with the occurrence of fertilization following ICSI but may assist in selecting oocytes more likely to originate high-quality zygotes. PMID:22383779

Camargos, Maria das Graças R S; Lobach, Veronica N M; Pereira, Francisco A N; Lemos, Cláudia N C D; Reis, Fernando M; Camargos, Aroldo F

2012-03-01

61

Mouse oocyte vitrification: the effects of two methods on maturing germinal vesicle breakdown oocytes  

PubMed Central

Purpose Evaluation of viability and subsequent developmental ability of mouse germinal vesicle breakdown oocytes vitrified in conventional straws. Methods Oocytes with compact cumulus cells were cultured for 3 h in TCM199 medium GVBD and vitrified by two methods: the step-wise and single-step. After vitrification, the oocytes were thawed, and subjected to in vitro maturation and in vitro fertilization. Oocyte survival (post-thaw) was assessed by morphological appearance and staining, using propidium iodide (PI)/Hoechst 33342. The oocyte maturation and fertilization rates were examined in vitro. Results In the single-step method the rates of post thaw survival, maturation to metaphase II and cleavage (2-cell embryos) were 58.68%, 56.41% and 38.63%, respectively. In the step-wise method, the corresponding rates were 81.75%, 68.59% and 51.80%, respectively. Conclusion Vitrification of mouse germinal vesicle breakdown oocytes by the step-wise method had the advantage of maintaining the viability and subsequent production of 2-cell embryos. In comparison with that in unvitrified control oocytes, the development of MII oocytes to 2-cell embryos was impaired following vitrification. PMID:20407816

Khosravi-Farsani, Somayeh; Sobhani, Aligholi; Amidi, Fardin

2010-01-01

62

Successful Cryopreservation of Mouse Oocytes by Using Low Concentrations of Trehalose and Dimethylsulfoxide1  

PubMed Central

Sugars such as trehalose, sucrose, and glucose are effectively used by a variety of animals (e.g., brine shrimp, tardigrades, some frogs, and insects), as well as by bacteria, yeasts, and plant seeds to survive freezing and extreme drying. The objective of this study was to examine the potential application of sugars to mammalian oocyte cryopreservation. To this end, we used trehalose, a nonreducing disaccharide, and mouse metaphase II oocytes as models. Our experiments show that extracellular trehalose alone affords some protection at high subzero temperatures (e.g., ?15°C), which diminishes with further cooling of the oocytes to ?30°C and below. When present both intracellularly and extracellularly, trehalose dramatically improves the cryosurvival with increasing extracellular concentrations to 0.5 M, even after cooling to ?196°C. Furthermore, the combination of intracellular and extracellular trehalose with small amounts of a conventional penetrating cryoprotectant (i.e., 0.5 M dimethylsulfoxide) provide high survival, fertilization, and embryonic development rates statistically similar to untreated controls. When transferred to foster mothers, cryopreserved oocytes give rise to healthy offspring showing the proof of principle. Our experiments with differential scanning calorimetry indicate that when cooled using the same cryopreservation protocol, the mixture of 0.5 M trehalose and cryopreservation medium undergoes glass transition at high subzero temperatures, which further substantiates the use of sugars as intracellular and extracellular cryoprotectants. Taken together, our results are in agreement with the survival schemes in nature and demonstrate the successful use of sugars in cryopreservation of mammalian oocytes. PMID:18815355

Eroglu, Ali; Bailey, Sarah E.; Toner, Mehmet; Toth, Thomas L.

2008-01-01

63

Growth and maturation of oocytes in vitro.  

PubMed

The development of technologies to grow and mature oocytes from the most abundant primordial follicles holds many attractions for clinical practice, animal production technology and research. However, despite much research attention, it has proved difficult to grow follicles from early stages to maturity in vitro, as relatively little is known about the biology of oogenesis. It is clear that throughout oocyte development in vivo, follicle cell support is fundamental to provide the germ cell with nutrients and growth regulators to ensure progression through the protracted growth phase. Conversely, the oocyte actively promotes growth and differentiation of the follicular cells. Both of these characteristics must be mimicked in vitro. Replication of the normal follicular growth span from the primordial to Graafian follicle stages and the changes in the trophic requirements of the cells, cellular interactions, morphogenesis and the sheer increase in bulk as the antrum forms present major challenges for follicle culture technology. These observations could explain why methods that have proved successful for the culture of isolated rodent follicles are unable to support the growth of larger human and ruminant follicles in vitro and are incompatible with the requirements for primordial follicle growth activation. At present, the best option available for the complete growth and maturation of oocytes in vitro is to develop an extended multistage culture strategy which will provide a complex support system that closely resembles the ovary in vivo. In an attempt to achieve this goal primordial follicle growth is first initiated and maintained to the preantral stages through the culture of thin slices of ovarian cortex. The isolation and continued culture of these preantral follicles will support antral cavity formation and the induction of differentiated function in the somatic cell compartment. Finally, after exposure to an appropriate steroid milieu in vitro it should be possible to induce nuclear and cytoplasmic maturation in the fully grown oocytes. The prospects of succeeding at each stage, and of finally producing a fertile gamete, are likely to be increased by preserving cellular interactions and the phenotype of follicle cells as these provide the physiological environment in which oocytes develop. Although the technology for the in vitro maturation (IVM) of fully grown oocytes has been exploited successfully in ruminants, in human assisted reproduction IVM is still experimental as the efficiency of IVM is low and only a small number of pregnancies and live births have been reported. Thus, although complete in vitro growth and maturation may be achieved eventually, immediate goals must include the optimization of methods for isolating and culturing oocytes at both ends of the size spectrum and the full evaluation of the normality of the oocytes grown for extended periods in vitro. PMID:14635954

Picton, H M; Danfour, M A; Harris, S E; Chambers, E L; Huntriss, J

2003-01-01

64

CYTOPLASMIC MICROTUBULAR DYNAMIC AND CHROMATIN ORGANIZATION DURING MAMMALIAN OOCYTE MATURATION  

EPA Science Inventory

Coordinated alterations in oocyte chromosome and microtubule disposition occur during oogenesis and oocyte maturation in the mammal. imely transitions in meiotic spindle and cytoplasmic microtubules, due to modifications in both the assembly competence of the tubulin pool and nuc...

65

Motility contrast imaging of live porcine cumulus-oocyte complexes  

NASA Astrophysics Data System (ADS)

Freshly-harvested porcine oocytes are invested with cumulus granulosa cells in cumulus-oocyte complexes (COCs). The cumulus cell layer is usually too thick to image the living oocyte under a conventional microscope. Therefore, it is difficult to assess the oocyte viability. The low success rate of implantation is the main problem for in vitro fertilization. In this paper, we demonstrate our dynamic imaging technique called motility contrast imaging (MCI) that provides a non-invasive way to monitor the COCs before and after maturation. MCI shows a change of intracellular activity during oocyte maturation, and a measures dynamic contrast between the cumulus granulosa shell and the oocytes. MCI also shows difference in the spectral response between oocytes that were graded into quality classes. MCI is based on shortcoherence digital holography. It uses intracellular motility as the endogenous imaging contrast of living tissue. MCI presents a new approach for cumulus-oocyte complex assessment.

An, Ran; Turek, John; Machaty, Zoltan; Nolte, David

2013-02-01

66

Hamster female protein, a sex-limited pentraxin, is a constituent of Syrian hamster amyloid.  

PubMed Central

Female protein (FP) is a pentraxin of Syrian hamster which is a homologue of two human pentraxins, C-reaction protein (CRP) and amyloid P component (AP). Functionally, FP has been shown to be similar to CRP, although FP has more homology at the amino terminus with AP. The present work investigated amyloid in the Syrian hamster to determine whether FP was involved in a manner analogous to AP. FP was found to be a constituent of Syrian hamster amyloid. This conclusion was based on the following results: (a) FP was consistently detected in amyloid deposits by fluorescent microscopy with specific antisera; (b) The amount of FP extractable from hamster livers directly correlated with the presence of amyloid; and (c) 125I-FP injected intravenously into amyloidotic hamsters rapidly left the intravascular compartment and was found subsequently in amyloid deposits. This unusual alteration of plasma metabolism and amyloid localization of 125I-FP was a characteristic finding in amyloidotic hamsters and was specific for 125I-FP. Therefore, as an amyloid component, FP appears to be functionally similar to human AP. However, FP synthesis is under sex steroid control and the unique sex-limited expression of this pentraxin was associated with an equally novel propensity for deposition of amyloid in female hamsters under normal or experimental conditions. Thus, a high serum level of FP, as found in normal females or diethylstilbestrol-treated males, was associated with enhanced amyloidosis. Although speculative at present, a primary role for serum FP in hamster amyloid deposition may be experimentally approachable by hormonal manipulation of FP synthesis. Images PMID:4019787

Coe, J E; Ross, M J

1985-01-01

67

Case report: Goldenhar syndrome following donor oocyte IVF  

PubMed Central

Purpose To describe a case of Goldenhar syndrome in a couple receiving donated oocytes in an ‘egg sharing’ IVF cycle where the recipient of donor oocytes had Turner syndrome, hypothyroidism and gestational diabetes. Methods Case report Results Child born to oocyte recipient with Goldenhar syndrome Conclusions We believe this is the first reported case of a child born with Goldenhar syndrome following use of donated oocytes in IVF by a woman with Turner syndrome, hypothyroidism and gestational diabetes. PMID:20571890

Gittins, Victoria

2010-01-01

68

Calcium ion currents mediating oocyte maturation events  

PubMed Central

During maturation, the last phase of oogenesis, the oocyte undergoes several changes which prepare it to be ovulated and fertilized. Immature oocytes are arrested in the first meiotic process prophase, that is morphologically identified by a germinal vesicle. The removal of the first meiotic block marks the initiation of maturation. Although a large number of molecules are involved in complex sequences of events, there is evidence that a calcium increase plays a pivotal role in meiosis re-initiation. It is well established that, during this process, calcium is released from the intracellular stores, whereas less is known on the role of external calcium entering the cell through the plasma membrane ion channels. This review is focused on the functional role of calcium currents during oocyte maturation in all the species, from invertebrates to mammals. The emerging role of specific L-type calcium channels will be discussed. PMID:16684344

Tosti, Elisabetta

2006-01-01

69

Xenopus Nuclear Transport 301 Use of Intact Xenopus Oocytes  

E-print Network

Studies Nelly Panté Summary Because of its large nucleus, the Xenopus laevis oocyte offers an excellent Microinjection of Xenopus laevis oocytes has provided an excellent in vivo system to study nucleocytoplasmicXenopus Nuclear Transport 301 21 Use of Intact Xenopus Oocytes in Nucleocytoplasmic Transport

Panté, Nelly

70

OOCYTE DIFFERENTIATION AND VITELLOGENESIS IN THE ROACH PERIPLANETA AMERICANA  

Microsoft Academic Search

The ovary of the roach Periplaneta americana has been studied by techniques of light and electron microscopy. Each ovariole (panoistic type) contains a linear array of oocytes in varying stages of development. Newly formed oocytes become encased by a layer of follicle cells and begin pinocytosis. All subsequent growth stages of the oocytes are dependent, in part, on this phenomenon.

EVERETT ANDERSON

1964-01-01

71

Oocyte markets: women's reproductive work in embryonic stem cell research  

Microsoft Academic Search

Somatic cell nuclear transfer (SCNT) research, otherwise known as therapeutic cloning, requires large numbers of research oocytes, placing pressure on an already limited supply. In the UK, Canada, Australia, Singapore and most of Western Europe, oocytes are made available through modestly reimbursed donation, and, owing to the onerous nature of donation, the existing demand for reproductive oocytes far outstrips availability.

Catherine Waldby

2008-01-01

72

Ammonium sulfate induced nuclear changes in the oocyte of the fish, Channa punctatus (Bl. )  

SciTech Connect

One among the common pollutants present in our riverine and lacustrine system is the commonly used fertilizer ammonium sulfate ((NH/sub 4/)/sub 2/SO/sub 4/). The unionized ammonia (UIA) base in the water is responsible for the toxicity due to its distinctive penetrative properties. Prolonged exposure of the fish Clarias batrachus to (NH/sub 4/)/sub 2/SO/sub 4/ causes endocrine changes. However, the deleterious effect of this fertilizer on the reproduction of fishes is not well recorded. In this study, (NH/sub 4/)/sub 2/SO/sub 4/-induced degenerative changes in the nucleus of early vitellogenic oocytes of C. punctatus are described.

Ram, R.N.; Sathyanesan, A.G.

1986-06-01

73

Cannabinoids and hamster circadian activity rhythms.  

PubMed

Circadian activity rhythms in hamsters are entrained to the daily light:dark cycle by photic information arriving from the retina to the suprachiasmatic nucleus, the site of the master circadian pacemaker in mammals. The effects of light on adjusting the timing of the circadian pacemaker is modified, both positively and negatively, by a variety of transmitter systems, but the effects of endocannabinoids have not been reported. Therefore, in this study we evaluated cannabinoids specific for the cannabinoid type 1 receptor (CB(1)) for their ability to modulate light-induced phase advances in hamster circadian activity rhythms. All compounds were administered intraperitoneally. The CB(1) agonist CP55940 potently inhibited light-induced phase shifts with near 90% inhibition achieved with a dose of 0.125 mg/kg. The inhibitory effect of CP55940 was partially reversed by the CB(1) antagonist LY320135 and completely reversed with 1 mg/kg of the CB(1) antagonist AM 251. Neither LY320135 nor AM 251 had any effect on light-induced phase shifts when administered alone. Further evidence for CB(1) involvement in hamster circadian rhythms was provided by immunohistochemical detection of CB(1) receptors in four separate nuclei comprising the principal components of the hamster circadian system: the suprachiasmatic nucleus, intergeniculate leaflet of the thalamus, and dorsal and median raphe nuclei. Altogether these data indicate that the endocannabinoid system has the capability to modulate circadian rhythms in the hamster and cannabis use should be evaluated for adverse effects on circadian rhythms in humans. PMID:18582849

Sanford, Anna E; Castillo, Elizabeth; Gannon, Robert L

2008-07-30

74

High-velocity penetrators  

Microsoft Academic Search

This paper summarizes the results of studies, coupled with a series of tests, that investigated rigid-body projectiles (penetrators) at high (up to 5500 ft\\/sec) velocities. Before these studies, it had been hypothesized that a velocity limit would be reached at which increasing the velocity would not commensurately increase depth of penetration into a target. It was further inferred that a

Ronald G. Lundgren

1994-01-01

75

Session: Hard Rock Penetration  

SciTech Connect

This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of five presentations: ''Hard Rock Penetration - Summary'' by George P. Tennyson, Jr.; ''Overview - Hard Rock Penetration'' by James C. Dunn; ''An Overview of Acoustic Telemetry'' by Douglas S. Drumheller; ''Lost Circulation Technology Development Status'' by David A. Glowka; ''Downhole Memory-Logging Tools'' by Peter Lysne.

Tennyson, George P. Jr.; Dunn, James C.; Drumheller, Douglas S.; Glowka, David A.; Lysne, Peter

1992-01-01

76

Fbos, a novel oocyte-specific protein, interacts with proteins important for oocyte development in rainbow trout (Oncorhynchus mykiss)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Oogenesis is characterized by a series of developmentally regulated events, which result in the matured oocyte that can give rise to a new organism after fertilization. Oocyte-specific genes play critical roles in oogenesis; however, the molecular details of oocyte-specific genes are poorly defined....

77

Selection of ovine oocytes by brilliant cresyl blue staining.  

PubMed

Sheep oocytes derived from the ovaries collected from the slaughterhouse are often used for research on in vitro embryo production, animal cloning, transgenesis, embryonic stem cells, and other embryo biotechnology aspects. Improving the in vitro culture efficiency of oocytes can provide more materials for similar studies. Generally, determination of oocyte quality is mostly based on the layers of cumulus cells and cytoplasm or cytoplasm uniformity and colors. This requires considerable experience to better identify oocyte quality because of the intense subjectivity involved (Gordon (2003), Madison et al. (1992) and De Loos et al. (1992)). BCB staining is a function of glucose-6-phosphate dehydrogenase (G6PD) activity, an enzyme synthesized in developing oocytes, which decreases in activity with maturation. Therefore, unstained oocytes (BCB-) are high in G6PD activity, while the less mature oocytes stains are deep blue (BCB+) due to insuffcient G6PD activity to decolorize the BCB dye. PMID:22675245

Wang, Liqin; Lin, Jiapeng; Huang, Juncheng; Wang, Jing; Zhao, Yuncheng; Chen, Tong

2012-01-01

78

Pregnancy and birth rates after oocyte donation  

Microsoft Academic Search

Objective: To determine accumulated conception and live birth rates in ovum donation.Design: Retrospective study from a computer database. Pregnancies with one gestational sac observed by ultrasound have been included as conceptional cycles and pregnancies that resulted in one live child were recorded for the analysis of the live birth rates. Life table analysis was applied.Setting: Oocyte donation program at the

José Remohí; Bernard Gartner; Ernesto Gallardo; Sonia Yalil; Carlos Simón; Antonio Pellicer

1997-01-01

79

NUCLEOLAR DNA IN OOCYTES OF XENOPUS LAEVIS  

Microsoft Academic Search

SUMMARY The ovaries of newly metamorphosed Xenopus females contain oocytes in all stages of early meiotic prophase. In pachytene nuclei extrachromosomal nucleolar DNA appears in the form of a thin cap covering one side of the nucleus. During pachytene this cap of DNA enlarges to occupy half the nucleus. After pachytene the nucleus grows rapidly and the cap of DNA

H. C. MACGREGOR

1968-01-01

80

Genome Analyses of Single Human Oocytes  

E-print Network

Successful human sexual reproduction starts with meiosis of an oocyte, which, upon fusion with a sperm cellBiodynamic Optical Imaging Center, College of Life Sciences and Center for Reproductive Medicine, Third University, Cambridge, MA 02138, USA 3Key Laboratory of Assisted Reproduction, Ministry of Education

Xie, Xiaoliang Sunney

81

Ca2+ homeostasis regulates Xenopus oocyte maturation.  

PubMed

In contrast to the well-defined role of Ca2+ signals during mitosis, the contribution of Ca2+ signaling to meiosis progression is controversial, despite several decades of investigating the role of Ca2+ and its effectors in vertebrate oocyte maturation. We have previously shown that during Xenopus oocyte maturation, Ca2+ signals are dispensable for entry into meiosis and for germinal vesicle breakdown. However, normal Ca2+ homeostasis is essential for completion of meiosis I and extrusion of the first polar body. In this study, we test the contribution of several downstream effectors in mediating the Ca2+ effects during oocyte maturation. We show that calmodulin and calcium-calmodulin-dependent protein kinase II (CAMK2) are not critical downstream Ca2+ effectors during meiotic maturation. In contrast, accumulation of Aurora kinase A (AURKA) protein is disrupted in cells deprived of Ca2+ signals. Since AURKA is required for bipolar spindle formation, failure to accumulate AURKA may contribute to the defective spindle phenotype following Ca2+ deprivation. These findings argue that Ca2+ homeostasis is important in establishing the oocyte's competence to undergo maturation in preparation for fertilization and embryonic development. PMID:18094360

Sun, Lu; Hodeify, Rawad; Haun, Shirley; Charlesworth, Amanda; MacNicol, Angus M; Ponnappan, Subramaniam; Ponnappan, Usha; Prigent, Claude; Machaca, Khaled

2008-04-01

82

Role of focal adhesion kinase in oocyte-follicle communication  

PubMed Central

Germ cells require communication with associated somatic cells for normal gametogenesis as exemplified by the oocyte which interacts with granulosa cells via paracrine factors as well as gap junctions located at sites of contact between these two cell types. The objective of the present study was to define the mechanisms by which cell-cell contact with the oocyte is controlled and determine the extent to which the oocyte actively participates in this association. Focal adhesion kinase (PTK2) was found to be activated at sites of contact between the oocyte and trans-zonal cell processes from the surrounding granulosa cells. In order to determine the functional significance of oocyte-derived PTK2 signaling in oocyte-follicle communication, an oocyte-specific ptk2 knockout was produced through a breeding strategy pairing a floxed ptk2-CAT-eGFP mouse with the Zp3-cre line. Since ptk2-null mice never develop to birth, this represents the first opportunity to define the role of ptk2 in oocytefollicle communication. Ablation of ptk2 within the developing oocyte resulted in lower fertility with reduced numbers of pups, lower rates of blastocyst formation, and reduced cell numbers per blastocyst. Follicles containing ptk2-null oocytes exhibited reduced oocyte diameter, reduced numbers of connexin 37 and 43 foci at the oocyte surface, and impaired dye coupling between oocyte and granulosa cells. These findings are consistent with a model in which PTK2 plays a critical role in establishing or maintaining oocyte-granulosa cell contacts that are essential for gap junction - mediated communication between granulosa cells and the oocyte. PMID:25536210

McGinnis, Lynda K.; Kinsey, William H.

2015-01-01

83

9 CFR 3.36 - Primary enclosures used to transport live guinea pigs and hamsters.  

Code of Federal Regulations, 2010 CFR

...enclosures used to transport live guinea pigs and hamsters. 3.36 Section 3...Treatment, and Transportation of Guinea Pigs and Hamsters Transportation Standards...enclosures used to transport live guinea pigs and hamsters. No person...

2010-01-01

84

Age-associated telomere shortening in mouse oocytes  

PubMed Central

Background Oocytes may undergo two types of aging. The first is induced by exposure to an aged ovarian microenvironment before being ovulated, known as ‘reproductive or maternal aging’, and the second by either a prolonged stay in the oviduct before fertilization or in vitro aging prior to insemination, known as ‘postovulatory aging’. However, the molecular mechanisms underlying these aging processes remain to be elucidated. As telomere shortening in cultured somatic cells triggers replicative senescence, telomere shortening in oocytes during reproductive and postovulatory aging may predict developmental competence. This study aimed to ascertain the mechanisms underlying altered telomere biology in mouse oocytes during reproductive and postovulatory aging. Methods We studied Tert expression patterns, telomerase activity, cytosolic reactive oxygen species (ROS) production, and telomere length in fresh oocytes from young versus reproductively-aged female mice retrieved from oviducts at 14 h post-human chorionic gonadotropin (hCG), in vivo or in vitro postovulatory-aged mouse oocytes at 23 h post-hCG. Oocytes were collected from super-ovulated C57BL/6 J mice of 6–8 weeks or 42–48 weeks of age. mRNA and protein expressions of the Tert gene were quantified using real-time quantitative reverse transcriptase polymerase chain reaction (Q-PCR) and immunochemistry. Telomerase activity was measured by a telomeric repeat amplification protocol assay, while telomere length was measured by Q-PCR and quantitative fluorescence in situ hybridization analyses. Results The abundance of Tert expression in oocytes significantly decreased during reproductive and postovulatory aging. Immunofluorescent staining clearly demonstrated an altered pattern and intensity of TERT protein expression in oocytes during reproductive aging. Furthermore, relative telomerase activity (RTA) in oocytes from reproductively-aged females was significantly lower than that in oocytes from young females. In contrast, RTA in postovulatory-aged oocytes was similar to that in fresh oocytes. Oocytes from reproductively-aged females and postovulatory-aged oocytes showed higher ROS levels than oocytes from young females. Relative telomere length (RTL) was remarkably shorter in oocytes from reproductively-aged females compared to oocytes from young females. However, postovulatory aging had no significant effect on RTL of oocytes. Conclusions Long-term adverse effects of low telomerase activity and increased ROS exposure are likely associated with telomere shortening in oocytes from reproductively-aged female mice. PMID:24261933

2013-01-01

85

Coculturing cumulus oocyte complexes with denuded oocytes alters zona pellucida ultrastructure in in vitro matured bovine oocytes.  

PubMed

Oocyte quality is a key factor affecting success of in vitro embryo production in cattle. Improving the microenvironment of oocytes during in vitro maturation (IVM) can increase developmental rate and embryo quality. Therefore, the objective was to determine whether denuded oocytes (DO) affect embryo development and ultrastructure of the zona pellucida (ZP) in in vitro matured bovine oocytes. Intact immature cumulus-oocytes complexes (COC) obtained from a local abattoir or by ovum pick-up (OPU) were cocultured with and without abattoir-obtained DO at a COC:DO ratio of 1:5. After IVM, DO were removed and intact DO were either fertilized or observed by scanning electron microscopy. Blastocyst quality was evaluated using a TUNEL assay. The ZP pore size decreased after IVM in COC + DO coculture, regardless of their origin (OPU, 310.5 ± 92.5 vs. 428.9 ± 148.5 nm; abattoir, 317.5 ± 68.5 vs. 358.9 ± 128.5 nm; P < 0.05; mean values ± standard deviation). Moreover, the number of ZP pores in OPU COC + DO and COC + DO was greater than those in OPU COC and COC (control) groups (56 ± 4 and 55 ± 7 vs. 50 ± 6 and 42 ± 4; P < 0.05). The rate of blastocyst development in COC + DO and OPU COC + DO groups was greater those in control and OPU COC groups (36.6% and 55.5% vs. 28.1% and 40.0%; P < 0.05). Moreover, the total cell numbers of blastocysts in COC + DO group exceeded that of control (132.91 ± 30.90 vs. 115.44 ± 24.95; P < 0.05), with no significant between OPU COC + DO and OPU COC groups (139.31 ± 42.51 vs. 137.00 ± 61.34). In conclusion, in vitro embryo development competence and quality improved when oocytes were cocultured with DO. Furthermore, there more, but smaller, ZP pores. PMID:24084231

Choi, Byung-Hyun; Bang, Jae-Il; Jin, Jong-In; Kim, Seong-Su; Jo, Hyun-Tae; Deb, Gautam Kumar; Ghanem, Nasser; Cho, Kyu-Woan; Kong, Il-Keun

2013-12-01

86

SV40 induces mesotheliomas in hamsters.  

PubMed Central

In the course of studies to elucidate the relative contribution of simian virus 40 (SV40) large T and small t proteins during oncogenesis, we observed the appearance of pericardial and pleural tumors in 100% of Syrian hamsters injected in the pleural space with wild type SV40. When SV40 was injected via the intracardiac or intraperitoneal routes, more than 50% of hamsters developed mesothelial tumors. Macroscopic, microscopic, ultramicroscopic, and histochemical characteristics identify these neoplasms and derived cell lines as mesotheliomas and mesothelioma-derived cell lines. The SV40 genome was integrated and expressed in the mesotheliomas and derived cell lines. The absence of mesotheliomas in hamsters injected with SV40 small t deletion mutants indicates that the small t protein plays an important role in the development of SV40-induced mesotheliomas. To the best of our knowledge, this is the first definitive report of virus-induced mesotheliomas in mammals. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:8388174

Cicala, C.; Pompetti, F.; Carbone, M.

1993-01-01

87

Sex aneuploidy of unfertilized human oocytes after intracytoplasmic sperm injection  

SciTech Connect

Intracytoplasmic sperm injection (ICSI) has recently achieved successful fertilization and pregnancy in human in vitro fertilization, particularly in cases of severe male factor infertility. One criticism of this novel clinical technique is that it bypasses the natural selection process of fertilization. We use fluorescence in situ hybridization (FISH) to analyze oocytes which fail to fertilize after ICSI in the Yale IVF Program. The purpose of this study is to determine whether failed fertilization after ICSI can be attributed to sex chromosome aneuploidy in the oocyte. Fertilization of oocytes is determined by the presence of two pronuclei on light microscopic examination (400X). Multi-probe FISH with DAPI (4,6,-diamino-2-phenyl-indole) counterstain is then performed to determine oocyte ploidy and the presence of decondensed sperm. Centromeric probes for X, Y and 17 are used simultaneously in each oocyte for in situ hybridization to oocyte chromatin. In all oocytes examined after ICSI to date, unfertilized oocytes have decondensed sperm DNA present confirming appropriate intracytoplasmic placement of the sperm. Preliminary results obtained from 31 oocytes have not identified any sex chromosome aneuploidies. The FISH technique used in post-ICSI oocytes is a model system for delineating genetic causes of failed fertilization in the human.

Lee, G.; Ward, D.C.; Jones, E.E. [Yale Univ., New Haven, CT (United States)

1994-09-01

88

Ultrastructural evaluation of in vitro-matured canine oocytes.  

PubMed

Cumulus-oocyte complexes (COCs) were recovered from ovaries of bitches during anoestrus. The ultrastructural organisation of COCs was determined before and after 72 h in vitro maturation (IVM) by transmission electron microscopy. The aim of the study was to determine the quality of oocytes used for IVM and to assess cytoplasmic maturation of IVM metaphase (M) II oocytes. In addition, we examined whether the oocytes that did not reach MII were engaged in an erratic maturation process or whether they were blocked during their progression through a normal maturation process. Before IVM, there were two populations of oocytes: (1) oocytes with a centrally located germinal vesicle, a transcriptionally active aspect and an immature cytoplasm; and (2) oocytes with an eccentric nucleus, a transcriptionally inactive aspect and a more mature cytoplasm. After IVM, most oocytes were still at the germinal vesicle stage with three different patterns and all showing a good synchronisation between nuclear and cytoplasmic maturation. MI oocytes had a similar cytoplasmic maturation to that observed in vivo, but failed to complete meiosis; however, IVM MII oocytes had a very poor cytoplasmic maturation. Ultrastructural analysis demonstrated that even when nuclear maturation is achieved, cytoplasmic maturation may not be obtained in vitro. Thus, all IVM systems should be evaluated on both criteria. PMID:18577360

Viaris de Lesegno, Christine; Reynaud, Karine; Pechoux, Christine; Chebrout, Martine; Chastant-Maillard, Sylvie

2008-01-01

89

Accurate dispensing system for single oocytes using air ejection  

PubMed Central

In this study, we propose a new approach to increase the success rate of single-oocyte dispensing and investigate the subsequent viability of the dispensed oocytes. We used a pair of capacitance sensors placed in a microfluidic chip to detect the oocyte, and custom-designed a special buffer zone in the microchannel to decelerate the flow velocity and reduce the hydraulic pressure acting on the oocyte. In the buffer zone, a semicircular bay, formed by equally spaced micro-pillars, is used to stop the oocyte at the dispensing nozzle hole. Finally, the oocyte is ejected by airflow to the culture array. The novel feature of the developed microfluidic system is that the extraordinary improvement in success rate is accompanied by a lack of change in oocyte survival rate (as assessed by a comparison of survival rates before and after the dispensing procedure). By using this device, we achieved a highly accurate single-oocyte dispensing process with a success rate of 100%. The oocyte survival rate is approximately 70%, regardless of whether or not the oocyte is dispensed. The newly proposed system has the advantages of high operation speed and potential usage for two-dimensional micropatterning. PMID:24404076

Feng, Lin; Sun, Yiling; Ohsumi, Chisato; Arai, Fumihito

2013-01-01

90

Developmental potential of in vitro or in vivo matured oocytes.  

PubMed

Summary This study compared the embryological features of mature and immature oocytes (different stages) collected from stimulated cycles of in vitro fertilization (IVF). Immature oocytes were identified, classified as PI (prophase I - germinal vesicle, GV) or MI (metaphase I), were matured in vitro and fertilized using the intra-cytoplasmic sperm injection (ICSI) technique. Fertilization potential, cleavage, and subsequent transfer/cryopreservation of the embryos derived from these in vitro matured oocytes were compared with those of in vivo matured oocytes (collected at the MII stage). The characteristics of embryos derived from gametes recovered in the MI and MII stages were similar. The fertilization rate of immature oocytes recovered in PI was significantly lower than that of MII oocytes (P = 0.031), and the cleavage rate of the PI group was also lower than that of the MI (P = 0.004) and MII (P < 0.001) groups. In vitro maturation of MI oocytes is a suitable alternative when immature oocytes are recovered, as their characteristics and development are similar to those of in vivo matured oocytes. Optimization of outcomes for PI oocytes will require development of techniques that can distinguish which of these gametes will mature and fertilize. PMID:23735140

Alcoba, Diego D; Pimentel, Anita M; Brum, Ilma S; Corleta, Helena E

2015-02-01

91

Follicular steroid hormones as markers of oocyte quality and oocyte development potential  

PubMed Central

CONTEXT: Various components of follicular fluid are suggested as biochemical predictors of oocyte quality. Previous studies of follicular steroid hormone levels have shown disparate results when related with fertilization outcomes. AIM: The objective of the study was to relate the levels of steroid hormones of each individual follicle with oocyte maturation, fertilization results, embryo quality, and pregnancy rates. SETTINGS AND DESIGN: Prospective cohort study in a university hospital. METHODS: In 31 patients, who underwent intracytoplasmic sperm injection, it was performed an ultrasound guided aspiration of follicular fluid of the first two mature follicles from each ovary. Follicular levels of estradiol, progesterone, testosterone, and dehydroepiandrosterone sulfate were measured by chemiluminescent immunoassay. STATISTICAL ANALYSIS: Generalized estimating equation model. RESULTS: In follicular fluids with mature oocyte presence, in normal as well as in failed fertilization, there was a positive correlation between follicular testosterone and progesterone (r = 0.794, P = 0.0001 and r = 0.829, P = 0.0001). Progesterone levels were higher in cases of normal fertilization compared to failed fertilization (P = 0.003). B quality embryos came from oocytes immersed in follicular fluids with higher estradiol values and higher estradiol/progesterone and estradiol/testosterone ratios than those of C quality (P = 0.01; P = 0.0009; P = 0.001). Estradiol levels were higher in patients who achieved pregnancy (P = 0.02). CONCLUSION: The analysis of follicular hormone composition could be considered as an additional tool in oocyte selection. PMID:25395744

Carpintero, Nayara López; Suárez, Onica Armijo; Mangas, Carmen Cuadrado; Varea, Carolina González; Rioja, Rubén Gómez

2014-01-01

92

Deployable Wireless Camera Penetrators  

NASA Technical Reports Server (NTRS)

A lightweight, low-power camera dart has been designed and tested for context imaging of sampling sites and ground surveys from an aerobot or an orbiting spacecraft in a microgravity environment. The camera penetrators also can be used to image any line-of-sight surface, such as cliff walls, that is difficult to access. Tethered cameras to inspect the surfaces of planetary bodies use both power and signal transmission lines to operate. A tether adds the possibility of inadvertently anchoring the aerobot, and requires some form of station-keeping capability of the aerobot if extended examination time is required. The new camera penetrators are deployed without a tether, weigh less than 30 grams, and are disposable. They are designed to drop from any altitude with the boost in transmitting power currently demonstrated at approximately 100-m line-of-sight. The penetrators also can be deployed to monitor lander or rover operations from a distance, and can be used for surface surveys or for context information gathering from a touch-and-go sampling site. Thanks to wireless operation, the complexity of the sampling or survey mechanisms may be reduced. The penetrators may be battery powered for short-duration missions, or have solar panels for longer or intermittent duration missions. The imaging device is embedded in the penetrator, which is dropped or projected at the surface of a study site at 90 to the surface. Mirrors can be used in the design to image the ground or the horizon. Some of the camera features were tested using commercial "nanny" or "spy" camera components with the charge-coupled device (CCD) looking at a direction parallel to the ground. Figure 1 shows components of one camera that weighs less than 8 g and occupies a volume of 11 cm3. This camera could transmit a standard television signal, including sound, up to 100 m. Figure 2 shows the CAD models of a version of the penetrator. A low-volume array of such penetrator cameras could be deployed from an aerobot or a spacecraft onto a comet or asteroid. A system of 20 of these penetrators could be designed and built in a 1- to 2-kg mass envelope. Possible future modifications of the camera penetrators, such as the addition of a chemical spray device, would allow the study of simple chemical reactions of reagents sprayed at the landing site and looking at the color changes. Zoom lenses also could be added for future use.

Badescu, Mircea; Jones, Jack; Sherrit, Stewart; Wu, Jiunn Jeng

2008-01-01

93

Rapamycin rescues the poor developmental capacity of aged porcine oocytes.  

PubMed

Unfertilized oocytes age inevitably after ovulation, which limits their fertilizable life span and embryonic development. Rapamycin affects mammalian target of rapamycin (mTOR) expression and cytoskeleton reorganization during oocyte meiotic maturation. The goal of this study was to examine the effects of rapamycin treatment on aged porcine oocytes and their in vitro development. Rapamycin treatment of aged oocytes for 24 h (68 h in vitro maturation [IVM]; 44 h+10 ?M rapamycin/24 h, 47.52±5.68) or control oocytes (44 h IVM; 42.14±4.40) significantly increased the development rate and total cell number compared with untreated aged oocytes (68 h IVM, 22.04±5.68) (p<0.05). Rapamycin treatment of aged IVM oocytes for 24 h also rescued aberrant spindle organization and chromosomal misalignment, blocked the decrease in the level of phosphorylated-p44/42 mitogen-activated protein kinase (MAPK), and increased the mRNA expression of cytoplasmic maturation factor genes (MOS, BMP15, GDF9, and CCNB1) compared with untreated, 24 h-aged IVM oocytes (p<0.05). Furthermore, rapamycin treatment of aged oocytes decreased reactive oxygen species (ROS) activity and DNA fragmentation (p<0.05), and downregulated the mRNA expression of mTOR compared with control or untreated aged oocytes. By contrast, rapamycin treatment of aged oocytes increased mitochondrial localization (p<0.05) and upregulated the mRNA expression of autophagy (BECN1, ATG7, MAP1LC3B, ATG12, GABARAP, and GABARAPL1), anti-apoptosis (BCL2L1 and BIRC5; p<0.05), and development (NANOG and SOX2; p<0.05) genes, but it did not affect the mRNA expression of pro-apoptosis genes (FAS and CASP3) compared with the control. This study demonstrates that rapamycin treatment can rescue the poor developmental capacity of aged porcine oocytes. PMID:25049998

Lee, Seung Eun; Kim, Eun Young; Choi, Hyun Yong; Moon, Jeremiah Jiman; Park, Min Jee; Lee, Jun Beom; Jeong, Chang Jin; Park, Se Pill

2014-05-01

94

CORTICOTROPIN RELEASING FACTOR RECEPTORS AND AGONISTIC BEHAVIOR IN SYRIAN HAMSTERS  

Microsoft Academic Search

Social conflict is a part of everyday life, and it can be a potent stressor for both humans and other animals. In the laboratory, when two Syrian hamsters (Mesocricetus auratus) compete for territory, a dominance hierarchy is quickly formed. Becoming subordinate is a significant stressor resulting in increased release of adrenocorticotropic hormone, ?-endorphin, and cortisol. Defeated hamsters will also subsequently

ALICIA N. FARUZZI

95

Diazepam enhances conditioned defeat in hamsters ( Mesocricetus auratus)  

Microsoft Academic Search

Male hamsters that have been repeatedly defeated by larger, aggressive males subsequently flee from, rather than attack, nonaggressive male intruders that are introduced into their home cages. We have referred to this generalization of flight in response to nonaggressive intruders as “conditioned defeat” (CD). In an attempt to reverse CD pharmacologically, diazepam (DZP) was administered to hamsters at two different

M. A. Hebert; M. Potegal; T. Moore; A. R. Evenson; J. L. Meyerhoff

1996-01-01

96

Bidirectional communication between oocytes and follicle cells: ensuring oocyte developmental competence  

PubMed Central

Female fertility is determined to a large extent by the quality (developmental competence) of the oocyte as reflected in its ability to undergo meiosis, be fertilized, and give rise to a healthy embryo. Growth of the mammalian oocyte is coordinated with that of the follicle that encloses it by the actions of signals that pass in both directions between the germline and somatic components. This review summarizes what is known about the roles played by two different modes of intrafollicular signalling in oogenesis: paracrine factors activating receptors on the opposite cell type, and direct sharing of small molecules throughout the follicle via gap junction channels. Recent evidence indicates that these two modes of signalling interact to regulate oocyte growth and granulosa cell proliferation, and that defects in either can contribute to female infertility. PMID:20555408

Kidder, Gerald M.; Vanderhyden, Barbara C.

2011-01-01

97

Are oocytes from the anestrous bitch competent for meiosis?  

PubMed

In the bitch, oocyte meiosis resumption takes place in the oviduct. Using oocytes from anestrous bitches, in vitro maturation (IVM) generally gives very poor results. To investigate the contribution of oocyte competence to the low IVM yield, we compared in vivo maturation in an optimal environment with conventional IVM. A total of 418 grade 1 cumulus-oocyte complexes (COCs) from 10 anestrous bitches were transferred into the oviducts of recipient bitches either on Day -1 (n = 3 recipients), Day 0 (n = 2) or on Day +1 (n = 2) relative to ovulation. For each donor bitch, 20 grade 1 COCs were also cultured in vitro. After 72 h of in vivo or IVM, the nuclear stage of oocytes was determined after DNA and tubulin staining. Of the 154 oocytes recovered and examined after intratubal transfer, only 2% reached the metaphase I or II stage and 38.3% were degenerated. Oocytes cultured in vitro displayed a higher metaphase rate (7.6%, n = 170) and lower degeneration rate (12.9%) compared with transferred oocytes (p < 0.001). These results clearly demonstrate that the oocyte competence is the major limiting factor of IVM efficiency in the dog. Mimicking the tubal environment may thus not be sufficient to increase IVM yield in this species. PMID:23279470

Chastant-Maillard, S; Saint-Dizier, M; Grimard, B; Chebrout, M; Thoumire, S; Reynaud, K

2012-12-01

98

Effects of maternal age on oocyte developmental competence.  

PubMed

The widespread use of a variety of assisted reproductive technologies has removed many of the constraints that previously restricted mammalian reproduction to the period between onset of puberty and reproductive senescence. In vitro embryo production systems now allow oocytes from very young animals to undergo fertilization and form embryos capable of development to normal offspring, albeit at somewhat reduced efficiencies compared to oocytes from adult females. They also can overcome infertility associated with advanced age of animals and women. This review examines oocyte developmental competence as the limiting factor in applications of assisted reproductive technologies for both juvenile and aged females. Age of oocyte donor is a significant factor influencing developmental competence of the oocyte. Age-related abnormalities of oocytes include a) meiotic incompetence or inability to complete meiotic maturation resulting in oocytes incapable of fertilization; b) errors in meiosis that can be compatible with fertilization but lead to genetic abnormalities that compromise embryo viability; and c) cytoplasmic deficiencies that are expressed at several stages of development before or after fertilization. In general, oocytes from juvenile donors and the embryos derived therefrom appear less robust and may be less tolerant to suboptimal handling and in vitro culture conditions than are adult oocytes. Research to identify specific cytoplasmic deficiencies of juvenile oocytes may enable modifications of culture conditions to correct such deficiencies and thus enhance developmental competence. Use of oocytes from aged donors for assisted reproduction can have a variety of applications such as extending the reproductive life of individual old females whose offspring still have high commercial value, and conservation of genetic resources such as rare breeds of livestock and endangered species. In general, female fertility decreases with advancing age. Studies of women in oocyte donation programs have established reduced oocyte competence as the major cause of declining fertility with age, although inadequate endometrial function can also be a contributing factor. Most research has emphasized the importance of chromosomal abnormalities because of the well established increase in aneuploidy with increasing maternal age but little is known about the underlying cellular and molecular mechanisms. Research aimed at identifying the specific developmental deficiencies of oocytes from juvenile donors and abnormalities of oocytes from aged females will assist in overcoming present bottlenecks that limit the efficiency of assisted reproduction technologies. Such research will also be crucial to the development of new oocyte-based technologies for overcoming infertility and possibly subverting chromosomal abnormalities in women approaching menopause. PMID:11327686

Armstrong, D T

2001-04-01

99

Ultrastructure of immature and mature human oocytes after cryotop vitrification  

PubMed Central

In vitro maturation of vitrified immature germinal vesicle (GV) oocytes is a promising fertility preservation option. We analyzed the ultrastructure of human GV oocytes after Cryotop vitrification (GVv) and compared it with fresh GV (GVc), fresh mature metaphase II (MIIc) and Cryotop-vitrified mature (MIIv) oocytes. By phase contrast microscopy and light microscopy, the oolemmal and cytoplasmic organization of fresh and vitrified oocytes did not show significant changes. GVv oocytes showed significant ultrastructural alterations of the microvilli in 40% of the samples; small vacuoles and occasional large/isolated vacuoles were abnormally present in the ooplasm periphery of 50% of samples. The ultrastructure of nuclei and mitochondria-vesicle (MV) complexes, as well as the distribution and characteristics of cortical granules (CGs), were comparable with those of GVc oocytes. MIIv oocytes showed an abnormal ultrastructure of microvilli in 30% of the samples and isolated large vacuoles in 70% of the samples. MV complexes were normal, but mitochondria-smooth endoplasmic reticulum aggregates appeared to be of reduced size. CGs were normally located under the oolemma but presented abnormalities in distribution and matrix electron density. In conclusion, Cryotop vitrification preserved main oocyte characteristics in the GV and MII stages, even if peculiar ultrastructural alterations appeared in both stages. This study also showed that the GV stage appears more suitable for vitrification than the MII stage, as indicated by the good ultrastructural preservation of important structures that are present only in immature oocytes, like the nucleus and migrating CGs.

PALMERINI, Maria Grazia; ANTINORI, Monica; MAIONE, Marta; CERUSICO, Fabrizio; VERSACI, Caterina; NOTTOLA, Stefania Annarita; MACCHIARELLI, Guido; KHALILI, Mohammad Ali; ANTINORI, Severino

2014-01-01

100

An oocyte-specific ELAVL2 isoform is a translational repressor ablated from meiotically competent antral oocytes.  

PubMed

At the end of the growth phase, mouse antral follicle oocytes acquire full developmental competence. In the mouse, this event is marked by the transition from the so-called non-surrounded nucleolus (NSN) chromatin configuration into the transcriptionally quiescent surrounded nucleolus (SN) configuration, which is named after a prominent perinucleolar condensed chromatin ring. However, the SN chromatin configuration alone is not sufficient for determining the developmental competence of the SN oocyte. There are additional nuclear and cytoplamic factors involved, while a little is known about the changes occurring in the cytoplasm during the NSN/SN transition. Here, we report functional analysis of maternal ELAVL2 an AU-rich element binding protein. Elavl2 gene encodes an oocyte-specific protein isoform (denoted ELAVL2°), which acts as a translational repressor. ELAVL2° is abundant in fully grown NSN oocytes, is ablated during the NSN/SN transition and remains low during the oocyte-to-embryo transition (OET). ELAVL2° overexpression during meiotic maturation causes errors in chromosome segregation, indicating the significance of naturally reduced ELAVL2° levels in SN oocytes. On the other hand, during oocyte growth, prematurely reduced Elavl2 expression results in lower yields of fully grown and meiotically matured oocytes, suggesting that Elavl2 is necessary for proper oocyte maturation. Moreover, Elavl2 knockdown showed stimulating effects on translation in fully grown oocytes. We propose that ELAVL2 has an ambivalent role in oocytes: it functions as a pleiotropic translational repressor in efficient production of fully grown oocytes, while its disposal during the NSN/SN transition contributes to the acquisition of full developmental competence. PMID:24553115

Chalupnikova, Katerina; Solc, Petr; Sulimenko, Vadym; Sedlacek, Radislav; Svoboda, Petr

2014-04-01

101

Oocyte-specific expression of Gpr3 is required for the maintenance of meiotic arrest in mouse oocytes  

PubMed Central

The maintenance of meiotic prophase arrest in mouse oocytes within fully grown follicles, prior to the surge of luteinizing hormone (LH) that triggers meiotic resumption, depends on a high level of cAMP within the oocyte. cAMP is produced within the oocyte, at least in large part, by the Gs-linked G-protein-coupled receptor, GPR3. Gpr3 is localized in the mouse oocyte but is also present throughout the follicle. To investigate whether Gpr3 in the follicle cells contributes to the maintenance of meiotic arrest, RNA interference (RNAi) was used to reduce the amount of Gpr3 RNA within follicle-enclosed oocytes. Follicle-enclosed oocytes injected with small interfering double-stranded RNA (siRNA) targeting Gpr3, but not control siRNAs, stimulated the resumption of meiosis in the majority of oocytes following a 3-day culture period. Reduction of RNA was specific for Gpr3 because an unrelated gene was not reduced by microinjection of siRNA. Meiotic resumption was stimulated in isolated oocytes injected with the same siRNA and cultured for 1 to 2 days, but at a much lower rate than in follicle-enclosed oocytes that could be cultured for longer. These results demonstrate that GPR3 specifically in the oocyte, rather than in the follicle cells, is responsible for maintenance of meiotic arrest in mouse oocytes. Furthermore, the method developed here for specifically reducing RNA in follicle-enclosed oocytes, which can be cultured for a sufficient time to reduce the level of endogenous protein, should be generally useful for targeting a wide range of other proteins that may be involved in meiotic arrest, the resumption of meiosis, fertilization, or early embryonic development. PMID:16289135

Mehlmann, Lisa M.

2007-01-01

102

Preliminary characterization of calcium binding to melano-somes isolated from amphibian oocytes  

E-print Network

Preliminary characterization of calcium binding to melano- somes isolated from amphibian oocytes. The steroid hormone, progesterone, induces meiotic maturatilon of the full- grown amphibian oocyte (Smith

Paris-Sud XI, Université de

103

Absence of MSY2 in mouse oocytes perturbs oocyte growth and maturation, RNA stability, and the transcriptome.  

PubMed

Messenger RNA is remarkably stable during oocyte growth, thus enabling mRNAs to accumulate during the growth phase and thereby provide mRNAs that support early embryonic development. MSY2, a germ cell-specific RNA-binding protein, is implicated in regulating mRNA stability. MSY2 is essential for development because female Msy2(-/-) mice are infertile. We describe here the characterization of Msy2(-/-) oocytes. Mutant oocytes grow more slowly during the first wave of folliculogenesis, and maturation to and arrest at metaphase II is severely compromised because of aberrant spindle formation and chromosome congression. Consistent with MSY2 conferring mRNA stability is that the amount of poly(A)-containing RNA is reduced by ~25% in mutant oocytes. Stability of an exogenous mRNA injected into mutant oocytes is lower than when compared to their wild-type counterparts, and moreover, expression of wild-type MSY2 in mutant oocytes increases mRNA stability, whereas injection of a mutant form of MSY2 not capable of binding RNA does not. Transcription quiescence that normally occurs during the course of oocyte growth is not observed in mutant oocytes, and the transcriptome of mutant oocytes is markedly perturbed. These results, and those of previous studies, strongly implicate a central role of MSY2 in regulating mRNA stability. PMID:21613634

Medvedev, Sergey; Pan, Hua; Schultz, Richard M

2011-09-01

104

Hydrogen Sulfide Donor Protects Porcine Oocytes against Aging and Improves the Developmental Potential of Aged Porcine Oocytes  

PubMed Central

Porcine oocytes that have matured in in vitro conditions undergo the process of aging during prolonged cultivation, which is manifested by spontaneous parthenogenetic activation, lysis or fragmentation of aged oocytes. This study focused on the role of hydrogen sulfide (H2S) in the process of porcine oocyte aging. H2S is a gaseous signaling molecule and is produced endogenously by the enzymes cystathionine-?-synthase (CBS), cystathionine-?-lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (MPST). We demonstrated that H2S-producing enzymes are active in porcine oocytes and that a statistically significant decline in endogenous H2S production occurs during the first day of aging. Inhibition of these enzymes accelerates signs of aging in oocytes and significantly increases the ratio of fragmented oocytes. The presence of exogenous H2S from a donor (Na2S.9H2O) significantly suppressed the manifestations of aging, reversed the effects of inhibitors and resulted in the complete suppression of oocyte fragmentation. Cultivation of aging oocytes in the presence of H2S donor positively affected their subsequent embryonic development following parthenogenetic activation. Although no unambiguous effects of exogenous H2S on MPF and MAPK activities were detected and the intracellular mechanism underlying H2S activity remains unclear, our study clearly demonstrates the role of H2S in the regulation of porcine oocyte aging. PMID:25615598

Krejcova, Tereza; Smelcova, Miroslava; Petr, Jaroslav; Bodart, Jean-Francois; Sedmikova, Marketa; Nevoral, Jan; Dvorakova, Marketa; Vyskocilova, Alena; Weingartova, Ivona; Kucerova-Chrpova, Veronika; Chmelikova, Eva; Tumova, Lenka; Jilek, Frantisek

2015-01-01

105

Hydrogen Sulfide Donor Protects Porcine Oocytes against Aging and Improves the Developmental Potential of Aged Porcine Oocytes.  

PubMed

Porcine oocytes that have matured in in vitro conditions undergo the process of aging during prolonged cultivation, which is manifested by spontaneous parthenogenetic activation, lysis or fragmentation of aged oocytes. This study focused on the role of hydrogen sulfide (H2S) in the process of porcine oocyte aging. H2S is a gaseous signaling molecule and is produced endogenously by the enzymes cystathionine-?-synthase (CBS), cystathionine-?-lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (MPST). We demonstrated that H2S-producing enzymes are active in porcine oocytes and that a statistically significant decline in endogenous H2S production occurs during the first day of aging. Inhibition of these enzymes accelerates signs of aging in oocytes and significantly increases the ratio of fragmented oocytes. The presence of exogenous H2S from a donor (Na2S.9H2O) significantly suppressed the manifestations of aging, reversed the effects of inhibitors and resulted in the complete suppression of oocyte fragmentation. Cultivation of aging oocytes in the presence of H2S donor positively affected their subsequent embryonic development following parthenogenetic activation. Although no unambiguous effects of exogenous H2S on MPF and MAPK activities were detected and the intracellular mechanism underlying H2S activity remains unclear, our study clearly demonstrates the role of H2S in the regulation of porcine oocyte aging. PMID:25615598

Krejcova, Tereza; Smelcova, Miroslava; Petr, Jaroslav; Bodart, Jean-Francois; Sedmikova, Marketa; Nevoral, Jan; Dvorakova, Marketa; Vyskocilova, Alena; Weingartova, Ivona; Kucerova-Chrpova, Veronika; Chmelikova, Eva; Tumova, Lenka; Jilek, Frantisek

2015-01-01

106

Single wall penetration equations  

NASA Technical Reports Server (NTRS)

Five single plate penetration equations are compared for accuracy and effectiveness. These five equations are two well-known equations (Fish-Summers and Schmidt-Holsapple), two equations developed by the Apollo project (Rockwell and Johnson Space Center (JSC), and one recently revised from JSC (Cour-Palais). They were derived from test results, with velocities ranging up to 8 km/s. Microsoft Excel software was used to construct a spreadsheet to calculate the diameters and masses of projectiles for various velocities, varying the material properties of both projectile and target for the five single plate penetration equations. The results were plotted on diameter versus velocity graphs for ballistic and spallation limits using Cricket Graph software, for velocities ranging from 2 to 15 km/s defined for the orbital debris. First, these equations were compared to each other, then each equation was compared with various aluminum projectile densities. Finally, these equations were compared with test results performed at JSC for the Marshall Space Flight Center. These equations predict a wide variety of projectile diameters at a given velocity. Thus, it is very difficult to choose the 'right' prediction equation. The thickness of a single plate could have a large variation by choosing a different penetration equation. Even though all five equations are empirically developed with various materials, especially for aluminum alloys, one cannot be confident in the shield design with the predictions obtained by the penetration equations without verifying by tests.

Hayashida, K. B.; Robinson, J. H.

1991-01-01

107

Interactions between oocytes and cumulus cells during in vitro maturation of porcine cumulus-oocyte complexes in a chemically defined medium: Effect of denuded oocytes on cumulus expansion and oocyte maturation.  

PubMed

The aim of the present study was to clarify interactions between oocytes and cumulus cells (CCs) on the level of cumulus expansion and oocyte maturation during IVM of cumulus-oocyte complexes (COCs) in a chemically defined medium using a system that allows individual tracking of oocytes. Especially, the influence of oocyte-secreted factors was investigated by the aid of addition of denuded oocytes (DOs) as a possible approach to improve the IVM system. The basic maturation medium was porcine oocyte medium with addition of gonadotropins only during the first 20 hours of IVM. During IVM, COCs were kept fixed to the bottom of culture dish by adhesive Cell-Tak coating, which enabled individual tracking of COCs during IVM. Size changes in COCs during IVM were measured by digital image analysis. Cumulus expansion in a porcine oocyte medium of intact COCs increased in a typical manner until 20 hours and decreased in size subsequently until 48 hours of IVM (P < 0.05). Removal of oocytes from COCs by oocytectomy allowed the expansion of CCs to some extent, although their expansion ability was lower than that of COCs (P < 0.05). Addition of DOs (COCs to DOs ratio of 9:16) did not improve cumulus expansion and oocyte maturation rates of intact COCs (P > 0.05) but did enhance cumulus expansion of oocytectomized complexes (P < 0.05). Furthermore, removal of CCs before IVM increased oocyte maturation rates compared with COCs (52.3% and 32.9%, respectively) (P < 0.05) and a similar effect was observed in COCs when the gap junction inhibitor carbenoxolone was added to the IVM medium: carbenoxolone repressed the expansion of COCs at 20 hours of IVM. In conclusion, the porcine oocyte enhances cumulus expansion both by gap junctional communications and presumably by oocyte-secreted factor production. Nevertheless, the presence of oocytes is not a prerequisite for this process. In return, CCs maintain meiotic arrest in cumulus-enclosed oocytes during the initial culture through gap junctions. On the basis of these findings, future research could investigate if coculture with DOs during IVM is beneficial for fertilization and embryo development. PMID:25467769

Appeltant, R; Somfai, T; Nakai, M; Bodó, S; Maes, D; Kikuchi, K; Van Soom, A

2015-03-01

108

Cell volume regulation is initiated in mouse oocytes after ovulation.  

PubMed

Fertilized mouse eggs regulate their size principally by accumulating glycine as an intracellular osmolyte using the GLYT1 (SLC6A9) transporter, a mechanism of cell volume homeostasis apparently unique to early embryos before the morula stage. However, nothing was known of cell volume regulation in oocytes before fertilization. We show here that GLYT1 is quiescent in mouse germinal-vesicle-stage oocytes but becomes fully activated within hours after ovulation is triggered. This initiates accumulation of substantial amounts of intracellular glycine in oocytes during meiotic progression, reaching a maximal level in mature eggs. Measurements of endogenous free glycine showed that there were nearly undetectable levels in ovarian germinal-vesicle-stage oocytes, but high levels were present in mature ovulated eggs and in preimplantation embryos through the two-cell stage, but not in morulae. Furthermore, intracellular glycine was regulated in response to changes in external tonicity in eggs and embryos through the two-cell stage, but not in oocytes or embryos after the two-cell stage. Before activation of GLYT1, oocytes were unable to independently regulate their volume. As GLYT1 became active, however, oocyte volume decreased substantially and oocytes gained the ability to regulate their size, which required GLYT1 activity. Before ovulation, oocyte size was instead determined by a strong adhesion to the rigid extracellular matrix of the oocyte, the zona pellucida, which was released coincident with GLYT1 activation. The ability to acutely regulate cell size is thus acquired by the oocyte only after ovulation, when it first develops glycine-dependent cell volume regulation. PMID:19502485

Tartia, Alina P; Rudraraju, Nirmala; Richards, Tiffany; Hammer, Mary-Anne; Talbot, Prudence; Baltz, Jay M

2009-07-01

109

Analysis of programmed cell death in mouse fetal oocytes.  

PubMed

We report a short-term culture system that allows to define novel characteristic of programmed cell death (PCD) in fetal oocytes and to underscore new aspects of this process. Mouse fetal oocytes cultured in conditions allowing meiotic prophase I progression underwent apoptotic degeneration waves as revealed by TUNEL staining. TEM observations revealed recurrent atypical apoptotic morphologies characterized by the absence of chromatin margination and nuclear fragmentation; oocytes with autophagic and necrotic features were also observed. Further characterization of oocyte death evidenced DNA ladder, Annexin V binding, PARP cleavage, and usually caspase activation (namely caspase-2). In the aim to modulate the oocyte death process, we found that the addition to the culture medium of the pan-caspase inhibitors Z-VAD or caspase-2-specific inhibitor Z-VDVAD resulted in a partial and transient prevention of this process. Oocyte death was significantly reduced by the antioxidant agent NAC and partly prevented by KL and IGF-I growth factors. Finally, oocyte apoptosis was reduced by calpain inhibitor I and increased by rapamycin after prolonged culture. These results support the notion that fetal oocytes undergo degeneration mostly by apoptosis. This process is, however, often morphologically atypical and encompasses other forms of cell death including caspase-independent apoptosis and autophagia. The observation that oocyte death occurs mainly at certain stages of meiosis and can only be attenuated by typical anti-apoptotic treatments favors the notion that it is controlled at least in part by stage-specific oocyte-autonomous meiotic checkpoints and when activated is little amenable to inhibition being the oocyte able to switch back and forth among different death pathways. PMID:17660234

Lobascio, A M; Klinger, F G; Scaldaferri, M L; Farini, D; De Felici, M

2007-08-01

110

Zona-free hamster ovum penetration by human spermatozoa : influence of various sperm factors  

E-print Network

. Higher in vitro fertilization rates were obtained after sperm selection by « swim-up» migration, 4-h-ovum interaction seem to be analogous in heterospecific in vitro fertilization. In 1976, Yanagimachi et al. Mammalian fertilization needs intraspecific gamete recognition. However, some stages of sperm

Boyer, Edmond

111

The effect of oocyte size and bitch age upon oocyte nuclear maturation in vitro  

Microsoft Academic Search

In vitro maturation in the bitch has yet to be fully investigated, and perfection of the technique is essential for future gamete salvage programs in endangered canine species. For optimal success with these techniques, knowledge of the individual animal and of oocyte effects upon maturational competence would be useful. Two factors were therefore studied using an aceto-orcein staining technique, which

D. A Hewitt; G. C. W England

1998-01-01

112

Xenopus oocyte maturation: new lessons from a good egg  

E-print Network

to the steroid hormone progesterone, can be induced to develop into fertilizable eggs. This process is termed oocyte maturation. Oocyte maturation is initiated by a novel plasma membrane steroid hormone receptor meiotic prophase, during which the chromo- 1``Thy head is as full of quarrels as an egg is full of meat

113

Original article In vitro techniques of bovine oocyte maturation,  

E-print Network

Original article In vitro techniques of bovine oocyte maturation, fertilization and embryo culture PMSG 24 h before slaughter. Oocytes matured in culture were fertilized in vitro by heparinized freshly of unknown origin. fertilization in vitro - development ― bovine embryos Résumé ― Techniques de

Paris-Sud XI, Université de

114

The type and extent of injuries in vitrified mouse oocytes.  

PubMed

To improve the vitrification of mouse oocytes using straws, we attempted to estimate the type and extent of injuries during vitrification with a vitrification solution EAFS10/10. Injuries in oocytes were assessed based on cellular viability, the integrity of the plasma membrane, the status of the meiotic spindle/chromosomes, and morphological appearance. For morphologically normal oocytes, the ability to be fertilized and to develop into blastocysts was examined. Morphological assessment revealed 15% of oocytes to be injured by intracellular ice formed during vitrification, and 10% by osmotic swelling during removal of the cryoprotectant. When assessed by the status of spindles/chromosomes, the most sensitive criterion, damage was found in 16% of oocytes without any treatment. This value was similar to the proportion of fresh oocytes that did not cleave after insemination (13%). On exposure to EAFS10/10, the spindles/chromosomes were affected in 33% of oocytes. The exposure reduced the rate of cleavage by 18% points and the rate of development into blastocysts by 19 points. Vitrification reduced these rates by 15% and 36% points, respectively. Although the mechanism responsible for this moderate toxic effect on developmental ability is not known, information obtained in the present study will be useful to develop a practical method for the vitrification of mouse oocytes using straws. PMID:22202671

Liang, Yang; Ning, Fang-Yong; Du, Wen-Jing; Wang, Chun-Sheng; Piao, Shan-Hua; An, Tie-Zhu

2012-04-01

115

On-chip enucleation of an oocyte by untethered microrobots  

NASA Astrophysics Data System (ADS)

We propose a novel on-chip enucleation of an oocyte with zona pellucida by using a combination of untethered microrobots. To achieve enucleation within the closed space of a microfluidic chip, two microrobots, a microknife and a microgripper were integrated into the microfluidic chip. These microrobots were actuated by an external magnetic force produced by permanent magnets placed on the robotic stage. The tip of the microknife was designed by considering the biological geometric feature of an oocyte, i.e. the oocyte has a polar body in maturation stage II. Moreover, the microknife was fabricated by using grayscale lithography, which allows fabrication of three-dimensional microstructures. The microgripper has a gripping function that is independent of the driving mechanism. On-chip enucleation was demonstrated, and the enucleated oocytes are spherical, indicating that the cell membrane of the oocytes remained intact. To confirm successful enucleation using this method, we investigated the viability of oocytes after enucleation. The results show that the production rate, i.e. the ratio between the number of oocytes that reach the blastocyst stage and the number of bovine oocytes after nucleus transfer, is 100%. The technique will contribute to complex cell manipulation such as cell surgery in lab-on-a-chip devices.

Ichikawa, Akihiko; Sakuma, Shinya; Sugita, Masakuni; Shoda, Tatsuro; Tamakoshi, Takahiro; Akagi, Satoshi; Arai, Fumihito

2014-09-01

116

Gene amplification in the oocytes of dytiscid water beetles  

Microsoft Academic Search

A conspicuous mass of extrachromosomal DNA (Giardina's body) is found in oogonia and oocytes of Dytiscid water beetles. Since in older oocytes this DNA is associated with numerous nucleoli, it seemed probable that the ovary might contain extra copies of the genes for ribosomal RNA (rRNA). This hypothesis has been confirmed by centrifugation and molecular hybridization studies. —In Dytiscus marginalis

Joseph G. Gall; Herbert C. Macgregor; Mary Elizabeth Kidston

1969-01-01

117

Hypotonicity activates a native chloride current in Xenopus oocytes  

Microsoft Academic Search

Xenopus oocytes are frequently utilized for in vivo expression of cellular proteins, especially ion channel proteins. A thorough understanding of the endogenous conductances and their regulation is paramount for proper character- ization of expressed channel proteins. Here we detail a novel chloride current (Icl.swell) responsive to hypotonicity in Xenopus oocytes using the two-electrode voltage clamp technique. Reducing the extracellular osmolarity

MICHAEL J. ACKERMAN; KEVIN D. WICKMAN; DAVID E. CLAPHAM

1994-01-01

118

Role of Fyn kinase in oocyte developmental potential  

PubMed Central

Fyn kinase is highly expressed in oocytes, with inhibitor and dominant-negative studies suggesting a role in the signal transduction events during egg activation. The purpose of the present investigation was to test the hypothesis that Fyn is required for calcium signaling, meiosis resumption and pronuclear congression using the Fyn-knockout mouse as a model. Accelerated breeding studies revealed that Fyn-null females produced smaller litter sizes at longer intervals and exhibited a rapid decline in pup production with increasing age. Fyn-null females produced a similar number of oocytes, but the frequency of immature oocytes and mature oocytes with spindle chromosome abnormalities was significantly higher than in controls. Fertilized Fyn-null oocytes frequently (24%) failed to undergo pronuclear congression and remained at the one-cell stage. Stimulation with gonadotropins increased the number of oocytes ovulated, but did not overcome the above defects. Fyn-null oocytes overexpressed Yes kinase in an apparent effort to compensate for the loss of Fyn, yet still exhibited an altered pattern of protein tyrosine phosphorylation. In summary, Fyn-null female mice exhibit reduced fertility that appears to result from actin cytoskeletal defects rather than calcium signaling. These defects cause developmental arrest during oocyte maturation and pronuclear congression. PMID:20591331

Luo, Jinping; McGinnis, Lynda K.; Kinsey, William H.

2014-01-01

119

Penetrating craniofacial arrow injury.  

PubMed

Arrow injuries are an extinct form of injury in most parts of the developed world, but are still seen, albeit infrequently in developing countries. Reports of penetrating injuries of the craniofacial region secondary to projectiles are few and far between. The morbidity-free outcome of surgical removal, in case of penetrating arrow injuries, despite the delay in presentation and, moreover, in the emergency surgical practice, are the salient points to be remembered whilst managing such cases, for 'what the mind knows is what the eyes see and what the eyes see is what can be practiced'. We report the case of a patient who was attacked by a projectile fired from a crossbow. Immediate surgery under general anesthesia was required to remove the arrow, with utmost care to avoid any neurovascular compromise to the facial nerve, as well as minimize postoperative complications such as otitis media and subsequent meningitis. PMID:21799612

Jain, Dk; Aggarwal, Gaurav; Lubana, Ps; Moses, Sonia

2010-01-01

120

Hypervelocity jacketed penetrators  

Microsoft Academic Search

The use of steel jackets was found to significantly improve the penetration efficiency of tungsten alloy rods. Experiments and analyses were conducted with L\\/D=10 projectiles of constant exterior dimensions at a nominal impact velocity of 2.2 km\\/s. The fraction of jacket material was varied to see which geometry would have the best performance. For a core-to-jacket diameter ratio (?) of

Bradley A Pedersen; Stephan J Bless; James U Cazamias

2001-01-01

121

Penetrating Extremity Trauma.  

PubMed

Penetrating extremity trauma (PET) usually becomes less important when present along with multiple truncal injuries. The middle eastern wars documented the terrible mortality and morbidity resulting from PET. Even in civilian trauma, PET can lead to significant morbidity and mortality. There are now well-established principles in the evaluation and management of vascular, bony, soft tissue, and neurologic lesions that will lead to a reduction of the poor outcomes. This review will summarize some of these recent concepts. PMID:25413177

Ivatury, Rao R; Anand, Rahul; Ordonez, Carlos

2014-11-21

122

Antibody tumor penetration  

PubMed Central

Antibodies have proven to be effective agents in cancer imaging and therapy. One of the major challenges still facing the field is the heterogeneous distribution of these agents in tumors when administered systemically. Large regions of untargeted cells can therefore escape therapy and potentially select for more resistant cells. We present here a summary of theoretical and experimental approaches to analyze and improve antibody penetration in tumor tissue. PMID:18541331

Thurber, Greg M.; Schmidt, Michael M.; Wittrup, K. Dane

2009-01-01

123

Infertile couples with normal counts who require subzonal sperm insertion possess a fertility defect that affects zona pellucida penetration.  

PubMed

The results of subzonal sperm insertion (SUZI) have been retrospectively analysed in a subset of patients with normal sperm counts who were found to require SUZI because of poor or absent fertilization of zona-intact oocytes. This patient group is of particular interest because male factor-related infertility cannot be due to insufficient numbers of spermatozoa reaching the oocytes. Thus, failed fertilization can be attributed to deficiencies in one or more steps in the fertilization process, and SUZI provides a method of distinguishing defects of zona pellucida penetration from gamete fusion. A total of 26 such patients were treated identically to and concurrently with a much larger group of SUZI candidates who typically suffered from oligozoospermia, and fertilization results were compared. Fertilization rates after SUZI were higher in patients with normal counts than in oligozoospermic patients (51 and 26% respectively), indicating that the proportion of spermatozoa capable of fusing with the oocyte is the same or higher in the group with normal counts. In addition, nearly all SUZI procedures led to fertilization (23/26), with two out of three failed fertilizations occurring in cases where two or less oocytes were manipulated, results which further indicate that failed fertilization in these patients is not due to a defect at the level of gamete fusion. These findings suggest that infertility in these patients is based upon the inability of the spermatozoa to reach the oolemma and thus, that their fertility defect resides at the step of zona penetration. PMID:7714153

Lih, C H; Grunfeld, L; Sandler, B; Drews, M R; Navot, D; Gordon, J W

1994-12-01

124

Wee1B depletion promotes nuclear maturation of canine oocytes.  

PubMed

Most mammalian oocytes are arrested at the germinal vesicle stage by activation of Wee1B. Meiotic resumption is regulated by inactivation of Wee1B and activation of cell division cycle 25B. The aim of this study was to determine whether treatment with Wee1B-targeting small interfering RNA (Wee1B-siRNA) promotes nuclear maturation of canine oocytes from germinal vesicle stage to metaphase II (MII) stage. In experiment 1, the percentage of canine oocytes that matured to MII stage was higher (P < 0.05) among oocytes cultured in vitro for 72 hours than among those cultured for 24 and 48 hours (5.4 ± 2.5% vs. 0.0 ± 0.0% and 1.4 ± 1.0%, respectively). Furthermore, the percentage of oocytes that matured to metaphase I (MI) stage was higher (P < 0.05) among oocytes cultured for 48 and 72 hours than among those cultured for 24 hours (14.9 ± 10.0% and 22.4 ± 8.1%, respectively, vs. 5.7 ± 6.0%). In experiment 2, canine oocytes were intracytoplasmically microinjected with Wee1B-siRNA (50 ?M) at various culture time points (0, 24, 48, or 72 hours). The nuclear configuration of the exception of oocytes in the 72-hour group was examined after 84 hours of culture. The percentage of oocytes that matured to the MII stage was higher (P < 0.05) among those treated with Wee1B-siRNA at 0 hours than among control oocytes and those injected at 72 hours (18.0 ± 1.7% vs. 2.1 ± 2.8% and 0.0 ± 0.0%, respectively). Moreover, the percentage of oocytes that matured to the MI stage was higher (P < 0.05) among those injected at 0 hours than among control oocytes and those injected at 24 and 72 hours (45.9 ± 6.8% vs. 22.1 ± 3.5%, 22.8 ± 10.0%, and 10.0 ± 4.4%, respectively). In experiment 3, oocytes were intracytoplasmically microinjected with Wee1B-siRNA at 0 hours of IVM and cultured for 0, 24, 48, or 72 hours. Thereafter, maturation-related gene expression was analyzed by quantitative real-time polymerase chain reaction. Messenger RNA expression of cAMP and cell division cycle 25B was lower (P < 0.05) in oocytes injected at 48 hours than in the other groups. Messenger RNA expression of cAMP was lower (P < 0.05) in oocytes injected at 0 hours than in control oocytes and those injected at 72 hours. Messenger RNA expression of mitogen-activated protein kinase 1 and mitogen-activated protein kinase 3 was higher (P < 0.05) in oocytes injected at 72 hours than in the other groups. In conclusion, we confirmed that Wee1B-siRNA microinjection enhances the percentages of canine oocytes that reach the MI and MII stages. These data suggest that Wee1B-siRNA microinjection could be a useful strategy to obtain mature canine oocytes for research and assisted canine reproduction. PMID:25457679

Kim, Yu-Gon; Kim, Dong-Hoon; Song, Seok-Hwan; Lee, Kyeong-Lim; Yang, Byoung-Chul; Oh, Jeong Su; Lee, Sang-Ryeul; Kong, Il-Keun

2015-03-01

125

A role for glucose in hypothermic hamsters  

NASA Technical Reports Server (NTRS)

Hypothermic hamsters at a rectal temperature of 7 C showed a fivefold increase in survival times from 20 to 100.5 hr when infused with glucose which maintained a blood level at about 45 mg/100 ml. A potential role for osmotic effects of the infusion was tested and eliminated. There was no improvement in survival of 3-O-methylglucose or dextran 40-infused animals. The fact that death eventually occurs even in the glucose-infused animal after about 4 days and that oxygen consumption undergoes a slow decrement in that period suggests that hypothermic survival is not wholly substrate limited. Radioactive tracer showed that localization of the C-14 was greatest in brain tissue and diaphragm, intermediate in heart and kidney, and lowest in skeletal muscle and liver. The significance of the label at sites important to respiration and circulation was presented.

Resch, G. E.; Musacchia, X. J.

1976-01-01

126

Regulatory contribution of heterotrimeric G-proteins to oocyte maturation in the sea urchin  

E-print Network

Regulatory contribution of heterotrimeric G-proteins to oocyte maturation in the sea urchin-proteins regulate maturation in the sea urchin oocyte by identifying resident G-proteins in oocytes and eggs in both oocytes and eggs of the sea urchin. Three of them, Gai, Gaq, and Gas are present on the plasma

Wessel, Gary M.

127

E. Rodrguez-Gonzlez et al.BCB-selected-goat oocytes matured withcysteamine Original article  

E-print Network

E. Rodríguez-González et al.BCB-selected-goat oocytes matured withcysteamine Original article Developmental competence of prepubertal goat oocytes selected with brilliant cresyl blue and matured maturation (IVM) medium to improve the in vitro embryo development of prepubertal goat oocytes. The oocytes

Paris-Sud XI, Université de

128

Jia L. Song . Gary M. Wessel How to make an egg: transcriptional regulation in oocytes  

E-print Network

in oocyte development. We propose that oogenesis is reliant on a dynamic gene regulatory network that includes oocyte-specific tran- scriptional regulators. Key words oogenesis Á primordial germ cells Á, differentiate, and meiotically mature. Through- out the development of the oocyte, or oogenesis, the oocyte must

Wessel, Gary M.

129

Characterization of multiple Chinese hamster carbonyl reductases.  

PubMed

Carbonyl reductase (CR) is an enzyme which can catalyze the oxidoreduction of various carbonyl compounds in the presence of NAD(P)H. With the PCR method, using primers carrying the conserved nucleotide sequence among mammalian CRs, we isolated three different cDNAs (CHCR1, CHCR2 and CHCR3) which encode a unique carbonyl reductase from the Chinese hamster. The PCR products of CHCR1 and CHCR2 were clearly isolated with Bpu1102I, BspEI and XmaI restriction enzymes. The nucleotide-sequence of CHCR3 was completely different from those of CHCR1 and CHCR2. The predicted double-wound betaalphabetaalpha-structures of the CHCRs suggests the presence of a typical NADP(+)-binding motif and is similar to the corresponding region of 3alpha,20beta-hydroxysteroid dehydrogenase and mouse lung tetrameric carbonyl reductase. The deduced amino acid sequence of CHCR1 showed a high homology to CHCR2 (>96%) and the other mammalian CRs (>81%). However, CHCR3 showed a high homology to human CBR3 (>86%) and a relatively lower homology to the other CHCRs (<76%). Bacterial recombinant CHCRs showed typical carbonyl reductase activities towards 4-benzoylpyridine, 4-nitrobenzaldehyde and pyridine 4-carboxyaldehyde. These three CRs showed not only 3-keto reductase of steroids, but also 20-keto reductase. However, these CRs did not show any activity of 17-keto reductase activity. Both CHCR1 and CHCR2 have prostaglandin 9-keto reductase and 15-hydroxyprostaglandin dehydrogenase activities towards PGE(2) and PGF(2alpha) from the analyses of enzymatic reaction products. The results of Western blotting and RT-PCR suggest these CHCRs have a tissue-dependent-distribution in the Chinese hamster. PMID:11306100

Terada, T; Sugihara, Y; Nakamura, K; Sato, R; Sakuma, S; Fujimoto, Y; Fujita, T; Inazu, N; Maeda, M

2001-01-30

130

Evidence for a metabolic limitation of survival in hypothermic hamsters.  

NASA Technical Reports Server (NTRS)

The underlying factors limiting survival in the hypothermic state are studied. Hamsters of both sexes, clipped and unclipped, were inducted into profound hypothermia by the helium cold method until they reached a temperature between 7 and 10 C. It appears that the primary cause of death is failure of respiration due to the depletion of carbohydrate energy supplies and may explain why survival time in hypothermia is shorter than the normal hibernation time of the hamster.

Prewitt, R. L.; Anderson, G. L.; Musacchia, X. J.

1972-01-01

131

STUDIES ON THE HUMAN OOCYTE AND ITS FOLLICLE  

PubMed Central

Oocytes in primordial ("resting") follicles in adult human ovaries contain a complex paranuclear structure identified by light microscopists as Balbiani's vitelline body. By electron microscopy this structure is composed of a mass of mitochondria with associated endoplasmic reticulum, multiple compound aggregates which form a ring around the cytocentrum, and a single stack or coil of annulate lamellae either attached to the nuclear membrane or free in the cytoplasm. The compound aggregates contain vacuoles and finely divided electron-opaque material. Evidence is presented for the probable transport of this material between the oocyte and its environment. The cytocentrum contains a central aggregate of amorphous electron-opaque deposits which appear to become periodically aligned on fine fibrils to form the long coarse fibers at the periphery of the cytocentrum. The apparent prevalence of annulate lamellae attached or adjacent to the nuclear membrane of oocytes in ovaries removed during the mid-follicular (estrogenic) phase of the cycle indicates the need for further study of a possible hormonal influence on the resting oocyte. By light microscopy phosphatases were not found within the oocyte, but adenosine-monophosphatase activity is present in the cortical cells surrounding primordial follicles, and also at the periphery of each primitive follicle cell, most prominently at the oocyte side. Glucose-6-phosphate dehydrogenase activity is present within the oocyte cytoplasm. PMID:4292010

Hertig, Arthur T.; Adams, Eleanor C.

1967-01-01

132

Bringing up small oocytes to eggs in pigs and cows.  

PubMed

It has been known that the mammalian ovary contains a huge number of non-growing small oocytes, of which only a small number grow to their final size, mature, and are ovulated. Artificial maturation of small oocytes could provide a new source of mature eggs for livestock production and assisted reproduction in humans and in endangered species. Two methods have been used for oocyte growth, in vitro growth (IVG) culture and xenotransplantation. By these methods, oocytes in some species grow up to their final size and acquire developmental competence, although the methods are still at the experimental stage. The experiments remind us of many basic questions in mammalian oogenesis: Does the oocyte require certain stimuli to initiate growth? How are the few oocytes selected to grow to final size? How do they grow up in follicular units? How do they acquire meiotic competence during the growth phase? This paper will give some clues to answer these questions by presenting our recent data from IVG and xenotransplantation experiments, and by illustrating differences between the oocytes of mice and larger animals. PMID:12499018

Miyano, T

2003-01-01

133

Histone deacetylase induces accelerated maturation in Xenopus laevis oocytes.  

PubMed

In oocyte maturation in Xenopus laevis, nuclear material induces rapid maturation and is required for entry into meiosis II. Nuclear material contains a large number of RNAs and proteins, including histone deacetylase (HDAC); however, it is not known which materials induce accelerated maturation. The HDAC activity modifies transcription rate and is required for normal meiosis; however, its function in oocyte maturation is still unclear. We investigated the function of HDAC activity, which is localized in the nuclear material, in the regulation of the speed of oocyte maturation. Inhibition of HDAC activity with trichostatin A (TSA) induced hyperacetylation of histone H3 and prolonged oocyte maturation. In contrast, increase in HDAC activity with an injection of FLAG-tagged maternal histone deacetylase (HDACm-FLAG) mRNA induced deacetylation of histone H3 and reduced the duration of oocyte maturation. Cdc2 kinase, Cdc25C or mitogen-activated protein kinase (MAPK), which are key regulators of the meiosis, were activated coincidently with maturation progression. In oocytes, the mRNA level of Cdc25C, an activator of Cdc2, was increased by HDACm-FLAG mRNA-injection; in contrast, the mRNA level of Cdc2 inhibitor Wee1 was increased by TSA treatment. These results suggest that HDAC activity is involved in the control of maturation speed through the regulation of mRNA levels of cell cycle regulators. Thus, HDACm is a candidate for the nuclear material component that induces rapid maturation in Xenopus oocytes. PMID:23346879

Iwashita, Jun; Kodama, Ayumi; Konno, Yuuri; Abe, Tatsuya; Murata, Jun

2013-04-01

134

Penetrating Fire Extinguisher  

NASA Technical Reports Server (NTRS)

When Feecon Corporation, a manufacturer of fire protection systems, needed a piercing nozzle for larger aircraft, they were assisted by Kennedy Space Center who provided the company with a fire extinguisher with a hard pointed tip that had been developed in case of an orbiter crash landing. The nozzle can penetrate metal skins of aircraft, trains, etc. Feecon obtained a license and now markets its cobra ram piercing nozzle to airport firefighters. Its primary advantage is that the nozzle can be held in one spot during repeated blows of the ram. *This product has been discontinued and is no longer commercially available.

1985-01-01

135

Deep penetration calculations. [LMFBR  

SciTech Connect

Several Monte Carlo techniques are compared in the transport of neutrons of different source energies through two different deep-penetration problems each with two parts. The first problem involves transmission through a 200-cm concrete slab. The second problem is a 90/sup 0/ bent pipe jacketed by concrete. In one case the pipe is void, and in the other it is filled with liquid sodium. Calculations are made with two different Los Alamos Monte Carlo codes: the continuous-energy code MCNP and the multigroup code MCMG.

Thompson, W.L.; Deutsch, O.L.; Booth, T.E.

1980-04-01

136

Building penetration analysis  

NASA Technical Reports Server (NTRS)

The airborne exposure to carbon fibers experienced within a building may be substantially less than that outside the building. By their very nature, buildings provide a barrier to the free flow of airborne particulate contaminants through the air space they occupy. The objective of this report is an evaluation of the degree to which buildings and other structures will attenuate potential exposures to carbon fibers. Most if not all types of buildings, and all phenomena which may influence the extent to which fibers in outdoor air can penetrate structures are addressed.

1979-01-01

137

The deep penetrating nevus.  

PubMed

The deep penetrating nevus (DPN), also known as the plexiform spindle cell nevus, is a pigmented lesion that commonly arises on the head and neck in the first few decades of life. Histopathologically, the DPN is wedge-shaped and contains melanocytes that exhibit deep infiltration into the dermis. Given these features, DPN may clinically and histopathologically mimic malignant melanoma, sparking confusion about the appropriate evaluation and management of these lesions. The goal of this review is to summarize the clinical and histopathological features of DPN and to discuss diagnostic and treatment strategies for dermatologists. PMID:25175710

Strazzula, Lauren; Senna, Maryanne Makredes; Yasuda, Mariko; Belazarian, Leah

2014-12-01

138

Mutagenic effects of ionizing radiation on immature rat oocytes.  

PubMed

Estimates of genetic risks from radiation delivered to humans are derived largely from mouse studies. In males, the target is spermatogonia and a large amount of information is available. In contrast, in females, immature oocytes are the target, but extrapolations from mice to humans are not very definitive because immature mouse oocytes are highly sensitive to radiation and die by apoptosis, which is not the case in humans. Since mouse offspring derived from surviving immature oocytes have to date not shown any signs of mutation induction, two alternative hypotheses are proposed: 1. Apoptotic death effectively eliminates damaged oocytes in mice and therefore human immature oocytes may be highly mutable; and 2. Immature oocytes are inherently resistant to mutation induction and apoptotic death is not relevant to mutagenesis. To test these hypotheses, rat immature oocytes, which are not as sensitive as those in mice to radiation-induced apoptosis were exposed to 2.5 Gy of gamma rays and the offspring were examined using a two-dimensional DNA analysis method. Screening of a total of 2.26 million DNA fragments, we identified 32 and 18 mutations in the control and exposed groups, respectively. Of these, in the two groups, 29 and 14 mutations were microsatellite mutations, two and one were base changes, and one and three were deletions. Among the four deletions most relevant to radiation exposure, only one was possibly derived from the irradiated dam (but not determined) and three were paternal in origin. Although the number of mutations was small, the results appear to support the second hypothesis and indicate that immature oocytes are generally less sensitive than mature oocytes to mutation induction. PMID:25229977

Asakawa, Jun-ichi; Kamiguchi, Yujiroh; Kamiya, Kenji; Nakamura, Nori

2014-10-01

139

Donor motivations, associated risks and ethical considerations of oocyte donation.  

PubMed

Three decades after the first reported successful cases, oocyte donation continues to grow in popularity and regard as an established method to aid women in achieving their reproductive goals. As a result of the increased demand for donated oocytes, many young women in the U.S. volunteer to undergo complex medical procedures to donate their oocytes in return for financial compensation. To best care for these women before, during and after donation, it is important to explore donor characteristics and motivations, discuss the safety of the donation procedure and examine the ethical issues related to this process. PMID:24750650

Boutelle, Amy L

2014-01-01

140

Analysis of nuclear reprogramming following nuclear transfer to Xenopus oocyte.  

PubMed

Germinal vesicle of stage V-VI Xenopus Laevis oocytes (at the prophase I stage of meiosis) can be used to transplant mammalian nuclei. In this type of interspecies nuclear transfer no cell division occurs and no new cell types are generated. However, the transplanted nuclei undergo extensive transcriptional reprogramming. Here, it is first explained how to carry out transplantation of multiple mammalian cell nuclei to Xenopus oocytes. It is then described how to perform RT-qPCR, Western Blot, Chromatin Immunoprecipitation, and live imaging analysis to monitor transcriptional reprogramming of the nuclei transplanted to oocytes. PMID:25287339

Jullien, Jerome

2015-01-01

141

Monolithic ballasted penetrator  

DOEpatents

The present invention is a monolithic ballasted penetrator capable of delivering a working payload to a hardened target, such as reinforced concrete. The invention includes a ballast made from a dense heavy material insert and a monolithic case extending along an axis and consisting of a high-strength steel alloy. The case includes a nose end containing a hollow portion in which the ballast is nearly completely surrounded so that no movement of the ballast relative to the case is possible during impact with a hard target. The case is cast around the ballast, joining the two parts together. The ballast may contain concentric grooves or protrusions that improve joint strength between the case and ballast. The case further includes a second hollow portion; between the ballast and base, which has a payload fastened within this portion. The penetrator can be used to carry instrumentation to measure the geologic character of the earth, or properties of arctic ice, as they pass through it.

Hickerson, Jr., James P. (Cedar Crest, NM); Zanner, Frank J. (Sandia Park, NM); Baldwin, Michael D. (Albuquerque, NM); Maguire, Michael C. (Worcester, MA)

2001-01-01

142

Procedure used for denuding pig oocytes influences oocyte damage, and development of in vitro and nuclear transfer embryos.  

PubMed

The effects of different denuding procedures used during the in vitro culture of porcine embryos on oocyte damage and aspects of porcine embryo development were investigated in a series of studies. Oocytes were denuded by vortexing or pipetting after 44h in vitro maturation (IVM) or pre-denuded after 22h IVM. The total oocyte death rate was significantly (P<0.05) higher for pre-denuded (27.3±1.4%) than for vortexed (20.3±1.2%) or pipetted (16.2±2.2%) oocytes. There was no significant difference between the treatments in the percentage of oocytes that extruded the first polar body. The type I cortical granule distribution (reflecting complete maturity) and normal spindle formation rates were significantly lower in the pre-denuding than in the vortexing and pipetting treatments. Blastocyst formation rates were significantly lower for the pre-denuding treatment in PA (25.7±4.5%) and IVF (6.1±1.5%) culture than in the vortexing (PA 42.0±4.5%; IVF 11.2±0.5%) and pipetting (PA 43.4±3.1%; IVF 9.4±1.6%) treatments. The proportion of oocytes developing to blastocysts in SCNT culture was not significantly different between treatments ranging from 9.9±1.8% for pre-denuding to 12.3±2.7% for vortexing. No significant differences in apoptosis or embryonic fragmentation were observed. This study shows that the denuding procedure used for porcine oocytes during the in vitro production of embryos can significantly affect oocyte damage, spindle patterns, oocyte maturation, embryo development but not embryonic apoptosis or the frequency of fragmentation. PMID:25487568

Lin, Tao; Diao, Yun Fei; Choi, Hwa Sik; Oqani, Reza K; Kang, Jung Won; Lee, Jae Eun; Jin, Dong Il

2015-01-01

143

Repeated ultrasound-guided transvaginal oocyte retrieval from cyclic Murrah buffaloes (Bubalus bubalis): oocyte recovery and quality.  

PubMed

The present study was undertaken to explore the potential of the Murrah breed of buffaloes as donors of oocytes and to find out the recovery rate and oocyte quality in cyclic Murrah buffaloes subjected to oocyte recovery once a week. Murrah buffaloes (n = 5) were synchronized for estrus by a single prostaglandin injection schedule. The animals were subjected to transvaginal oocyte retrieval (TVOR) once weekly for 6 weeks, starting from Day 7 of the oestrous cycle (Day 0 = day of oestrus). TVOR was performed using an ultrasound machine with a 5 MHz transvaginal transducer, single lumen 19-gauge, 60 cm long needle and a constant vacuum pressure of 50 mmHg. The number and size of follicles in each ovary was determined before puncture. The follicles were characterized on the basis of their diameter as small (3-5 mm), medium (6-9 mm) and large (> or = 10 mm). The oocytes recovered were classified as grade A, cumulus-oocytes complexes (COCs) with > or = 5 layers of cumulus cells; grade B, those with two to four layers; grade C, partially denuded oocytes; and grade D, completely denuded oocytes. The mean (+/- S.E.M) number of small, medium and large follicles, and the number of total follicles observed per animal per session, which was 2.2 +/- 0.3, 0.6 +/- 0.2, 0.9 +/- 0.1 and 3.7 +/- 0.3, respectively, did not differ between animals or between puncture sessions. Small follicles constituted a major proportion (59%) of the total observed follicles. A mean (+/- S.E.M) number of 3.0 +/- 0.3 follicles were punctured and 2.0 +/- 0.3 oocytes recovered per animal per session, with a recovery rate of 68%. Out of the total 61 oocytes recovered, 36 (59%) were of grades A + B whereas 25 (41%) were of grades C + D. In conclusion, this study describes the potential of cyclic Murrah buffaloes as donors of oocytes collected by repeated TVOR once a week, without any adverse effects on follicular growth and oocyte recovery. It also describes an efficient system for carrying out TVOR in buffaloes. PMID:15913926

Gupta, V; Manik, R S; Chauhan, M S; Singla, S K; Akshey, Y S; Palta, P

2006-01-01

144

Selective protein incorporation by vitellogenic Salmo gairdneri oocytes in vitro  

E-print Network

in teleosts is vitellogenin, the precursor of oocyte yolk proteins. Introduction. In the model proposed for vitellogenesis of amphibia and birds, a yolk protein precursor, vitellogenin, is synthesised by the liver

Boyer, Edmond

145

Recent advances in oocyte and ovarian tissue cryopreservation and transplantation  

PubMed Central

Options for preserving fertility in women include well-established methods such as fertility-sparing surgery, shielding to reduce radiation damage to reproductive organs, and emergency in-vitro fertilisation after controlled ovarian stimulation, with the aim of freezing embryos. The practice of transfering frozen or thawed embryos has been in place for over 25 years, and today is a routine clinical treatment in fertility clinics. Oocytes may also be frozen unfertilised for later thawing and fertilisation by intracytoplasmic sperm injection in vitro. In recent years, oocyte cryopreservation methods have further developed, reaching promising standards. More than 1000 children are born worldwide after fertilisation of frozen and thawed oocytes. Nevertheless, this technique is still considered experimental. In this chapter, we focus on options for fertility preservation still in development that can be offered to women. These include freezing of oocytes and ovarian cortex and the transplantation of ovarian tissue. PMID:22301053

Rodriguez-Wallberg, Kenny A.; Oktay, Kutluk

2012-01-01

146

Functional expression of murine multidrug resistance in Xenopus laevis oocytes  

SciTech Connect

The development of multidrug resistance (MDR) is associated with the overproduction of a plasma membrane glycoprotein, P glycoprotein. Here the authors report the functional expression of a member of the murine MDR family of proteins and show that Xenopus oocytes injected with RNA encoding the mouse mdr1b P glycoprotein develop a MDR-like phenotype. Immunological analysis indicated that oocytes injected with the mdr1b RNA synthesized a protein with the size and immunological characteristics of the mouse mdr1b P glycoprotein. These oocytes exhibited a decreased accumulation of ({sup 3}H)vinblastine and showed an increased capacity to extrude the drug compared to control oocytes not expressing the P glycoprotein. In addition, competition experiments indicated that verapamil, vincristine, daunomycin, and quinidine, but not colchicine, can overcome the rapid drug efflux conferred by the expression of the mouse P glycoprotein.

Castillo, G.; Vera, J.C.; Rosen, O.M. (Memorial Sloan-Kettering Cancer Research Center, New York, NY (USA)); Yang, Chiaping Huang; Horwitz, S.B. (Albert Einstein College of Medicine, Bronx, NY (USA))

1990-06-01

147

Gratuitous messenger-RNA localization in drosophila oocyte  

E-print Network

Many of the genes that control pattern formation in Drosophila encode mRNAs that are localized to discrete regions of the oocyte during oogenesis, While such localization is generally assumed to be important for the ...

Serano, T. L.; Cohen, Robert S.

1995-09-01

148

Functional assays for insect olfactory receptors in Xenopus oocytes.  

PubMed

Reconstitution of olfactory or pheromone receptors in heterologous expression systems greatly facilitates the functional analysis of these receptors. Xenopus laevis oocytes can be used to efficiently express insect olfactory or pheromone receptors. In this chapter, we describe how to use Xenopus laevis oocytes for functional assays of insect olfactory receptors. The procedure can be subdivided into the four following steps: (1) in vitro complementary RNA (cRNA) synthesis, (2) isolation of oocytes from female Xenopus laevis, (3) cRNA microinjection into oocytes, and (4) two-electrode voltage-clamp recording. This system can be used to identify odor or pheromone ligands and to analyze structure-function relationships involving receptor proteins of interest. PMID:24014357

Nakagawa, Tatsuro; Touhara, Kazushige

2013-01-01

149

Effect of oocyte quality and sperm characteristics on the number of spermatozoa bound to the zona pellucida of human oocytes inseminated in vitro  

Microsoft Academic Search

Sperm characteristics and oocyte quality may play a role in in vitro fertilization. The objective of this paper is to analyze the effect of the quality of oocytes, the husband's semen characteristics, and category of the couple's infertility on the number of spermatozoa bound to the zona pellucida. One hundred eightyone oocytes which failed to fertilize or failed to cleave

Maha M. Mahadevan; Alan O. Trounson; Carl Wood; John F. Leeton

1987-01-01

150

Electrophysiological responses of crayfish oocytes to biogenic amines  

Microsoft Academic Search

Intracellular recordings were made from immature, growing oocytes of the crayfish Pacifastacus leniusciulus. Oocytes had a relatively negative resting potential of ?74.7±2.2 mV (n=26; range ?53 to ?90) and a mean input resistance of 0.86±0.19 M? (n=22; range 0.17–3.3). Octopamine induced a long-lasting response involving biphasic changes in input resistance, together with bi- or multiphasic changes in membrane potential. The

Peter Skorupski; Richard Melarange

2000-01-01

151

Selective degradation of transcripts during meiotic maturation of mouse oocytes  

Microsoft Academic Search

There is massive destruction of transcripts during the maturation of mouse oocytes. The objective of this project was to identify and characterize the transcripts that are degraded versus those that are stable during the transcriptionally silent germinal vesicle (GV)-stage to metaphase II (MII)-stage transition using a microarray approach. A system for oocyte transcript amplification using both internal and 3?-poly(A) priming

You-Qiang Su; Koji Sugiura; Yong Woo; Karen Wigglesworth; Sonya Kamdar; Jason Affourtit; John J. Eppig

2007-01-01

152

Receptor-mediated Endocytosis in the Caenorhabditis elegans Oocyte  

Microsoft Academic Search

The Caenorhabditis elegans oocyte is a highly amenable system for forward and reverse genetic analysis of receptor-mediated endocytosis. We describe the use of transgenic strains expressing a vitellogenin::green fluorescent protein (YP170::GFP) fusion to monitor yolk endocytosis by the C. elegans oocyte in vivo. This YP170::GFP reporter was used to assay the functions of C. elegans predicted proteins homologous to vertebrate

Barth Grant; David Hirsh

1999-01-01

153

Intracytoplasmic sperm injection of in vitro-matured equine oocytes.  

PubMed

Intracytoplasmic sperm injection (ICSI) was performed on equine oocytes matured in vitro. The oocytes were aspirated from abattoir ovaries and matured in vitro for 36 h at 38 degrees C. ICSI was performed using frozen/thawed stallion semen after swimup in medium containing human serum albumin. Sperm-injected oocytes were either 1) cultured in vitro for 10, 20, or 72 h; 2) transferred to oviducts of pseudopregnant mice; or 3) transferred to a synchronized mare after initial in vitro culture. The transferred ova were recovered after 72 h, and all ova were subsequently fixed, stained, and processed for light and transmission electron microscopy. Single pronucleus formation was observed in 2 out of 12 presumptive zygotes 10 h postinjection, at which time abundant cortical granules were observed in the subplasmalemmal region. Twenty hours postinjection, however, 2 pronuclei were observed in 6 of 12 injected oocytes (fertilization rate 50%), and almost all cortical granules were released. The cleavage rate in vitro was 16% after 72 h in culture, and the most advanced embryo stages obtained were 6- to 8-cell embryos. The cleavage rate in vivo was very low since only 1 of 10 recovered had cleaved to the 2-cell stage. Thus, in conclusion, ICSI fertilization of equine oocytes did result in fertilization, pronucleus formation, and cortical granule release. However, the observed fertilization rate and oocyte activation was not paralleled by substantial cleavage of the zygotes. PMID:9408260

Grøndahl, C; Hansen, T H; Hossaini, A; Heinze, I; Greve, T; Hyttel, P

1997-12-01

154

Resveratrol protects mouse oocytes from methylglyoxal-induced oxidative damage.  

PubMed

Methylglyoxal, a reactive dicarbonyl compound, is mainly formed from glycolysis. Methylglyoxal can lead to the dysfunction of mitochondria, the depletion of cellular anti-oxidation enzymes and the formation of advanced glycation ends. Previous studies showed that the accumulation of methylglyoxal and advanced glycation ends can impair the oocyte maturation and reduce the oocyte quality in aged and diabetic females. In this study, we showed that resveratrol, a kind of phytoalexin found in the skin of grapes, red wine and other botanical extracts, can alleviate the adverse effects caused by methylglyoxal, such as inhibition of oocyte maturation and disruption of spindle assembly. Besides, methylglyoxal-treated oocytes displayed more DNA double strands breaks and this can also be decreased by treatment of resveratrol. Further investigation of these processes revealed that methylglyoxal may affect the oocyte quality by resulting in excessive reactive oxygen species production, aberrant mitochondrial distribution and high level lipid peroxidation, and resveratrol can block these cytotoxic changes. Collectively, our results showed that resveratrol can protect the oocytes from methylglyoxal-induced cytotoxicity and this was mainly through the correction of the abnormity of cellular reactive oxygen species metabolism. PMID:24194906

Liu, Yu; He, Xiao-Qin; Huang, Xin; Ding, Lu; Xu, Lin; Shen, Yu-Ting; Zhang, Fei; Zhu, Mao-Bi; Xu, Bai-Hui; Qi, Zhong-Quan; Wang, Hai-Long

2013-01-01

155

Endoplasmic reticulum stress inhibition is a valid therapeutic strategy in vitrifying oocytes.  

PubMed

The aim of this study is to determine the link between oocyte cryopreservation and endoplasmic reticulum (ER) stress; whether ER stress inhibition improves the efficiency of oocyte vitrification is also explored. Oocytes from mice were exposure to tauroursodeoxycholic acid (TUDCA, an ER stress inhibitor) or TM (tunicamycin, an ER stress inducer) with or without vitrification. The expressions of X-box binding protein-1 (XBP-1) protein and caspase-12 protein, viability of vitrified-warmed oocytes, and their subsequent embryo competence were measured. The levels of XBP-1 protein and caspase-12 protein expression in vitrified-warmed oocytes were significantly higher than those of fresh control oocytes. TUDCA improved the viability of vitrified-warmed oocytes and their subsequent embryo competence. Mouse oocyte cryopreservation is associated with ER stress, and ER stress inhibition improves the efficiency of oocyte vitrification. PMID:25499542

Zhao, Nan; Liu, Xue-Jun; Li, Jun-Tao; Zhang, Ling; Fu, Yang; Zhang, Ya-Jie; Chen, Ru-Xin; Wei, Xiao-Qing; Wang, Rui; Wang, Yu; Zhang, Jian-Min

2015-02-01

156

Universal penetration test apparatus with fluid penetration sensor  

DOEpatents

A universal penetration test apparatus is described for measuring resistance of a material to a challenge fluid. The apparatus includes a pad saturated with the challenge fluid. The apparatus includes a compression assembly for compressing the material between the pad and a compression member. The apparatus also includes a sensor mechanism for automatically detecting when the challenge fluid penetrates the material. 23 figs.

Johnson, P.W.; Stampfer, J.F.; Bradley, O.D.

1999-02-02

157

Humoral and cellular response to infection with Echinostoma revolutum in the golden hamster, Mesocricetus auratus.  

PubMed

Laboratory hamsters (Mesocricetus auratus) were infected with Echinostoma revolutum (Trematoda). Immunoelectrophoretic studies of hamster serum showed no demonstrable antibody response to E. revolutum. Histopathologic examination of intestinal tissue of infected hamsters showed erosion of intestinal villi and lymphocytic infiltration as the primary host response. Spleens from infected hamsters were hyperplastic during the first 3 weeks of infection and atrophic from 4 to 8 weeks postinfection. Hamsters were unable to acquire a resistance to E. revolutum infection. Lack of resistance was demonstrated in hamsters where the parasite infection was no longer detected based on the absence of eggs in the faeces; these hamsters were then reinfected. Hamsters treated with the anthelmintic oxyclozanide were also reinfected with E. revolutum. PMID:3397514

Mabus, J; Huffman, J E; Fried, B

1988-06-01

158

Proteomic Analysis of Chinese Hamster Ovary Cells  

PubMed Central

In order to complement the recent genomic sequencing of Chinese hamster ovary (CHO) cells, proteomic analysis was performed on CHO including the cellular proteome, secretome, and glycoproteome using tandem mass spectrometry (MS/MS) of multiple fractions obtained from gel electrophoresis, multi-dimensional liquid chromatography, and solid phase extraction of glycopeptides (SPEG). From the 120 different mass spectrometry analyses generating 682,097 MS/MS spectra, 93,548 unique peptide sequences were identified with at most a 0.02 false discovery rate (FDR). A total of 6164 grouped proteins were identified from both glycoproteome and proteome analysis, representing an 8-fold increase in the number of proteins currently identified in the CHO proteome. Furthermore, this is the first proteomic study done using CHO genome exclusively which provides for more accurate identification of proteins. From this analysis, the CHO codon frequency was determined and found to be distinct from humans, which will facilitate expression of human proteins in CHO cells. Analysis of the combined proteomic and mRNA data sets indicated the enrichment of a number of pathways including protein processing and apoptosis but depletion of proteins involved in steroid hormone and glycosphingolipid metabolism. 504 of the detected proteins included N-acetylation modifications and 1292 different proteins were observed to be N-glycosylated. This first large-scale proteomic analysis will enhance the knowledge base about CHO capabilities for recombinant expression and provide information useful in cell engineering efforts aimed at modifying CHO cellular functions. PMID:22971049

Baycin-Hizal, Deniz; Tabb, David L.; Chaerkady, Raghothama; Chen, Lily; Lewis, Nathan E.; Nagarajan, Harish; Sarkaria, Vishaldeep; Kumar, Amit; Wolozny, Daniel; Colao, Joe; Jacobson, Elena; Tian, Yuan; O'Meally, Robert N.; Krag, Sharon S.; Cole, Robert N.; Palsson, Bernhard O.; Zhang, Hui; Betenbaugh, Michael

2013-01-01

159

Pineal melatonin synthesis in Syrian hamsters: A summary  

NASA Astrophysics Data System (ADS)

During the past decade there has been ample documentation of the proposition that the pineal gland mediates photoperiodic influences upon reproductive behavior of hamsters. It is commonly hypothesized that the pineal gland expresses its activity by transformation of photoperiodic information into an hormonal output, that hormone being melatonin. If this hypothesis is correct, there must be some essential diffrence in melatonin's output when hamsters are exposed to different photoperiodic environments. The experiments summarized in this communication analyze pineal melatonin contents in Syrian hamsters maintained in a variety of photoperiodic conditions during different physiological states. The results demonstrate that adult hamsters have a daily surge in pineal melatonin content throughout their lifetime when exposed to simulated annual photoperiodic cycles. There is some fluctuation in the amount of pineal melatonin produced during different physiological states and photoperiodic environments, but these fluctuations seem small when compared to those normally found for other regulatory hormones. When hamsters are exposed to different photoperiodic regimens, the daily melatonin surge maintains a relatively constant phase relationship with respect to the onset of daily activity. There is a concomitant change in its phase relationship with respect to light-dark transitions.

Rollag, M. D.

1982-12-01

160

The hamster flank organ model: Is it relevant to man  

SciTech Connect

The critical role that androgens play in the etiology of acne has led to a search for topically active antiandrogens and the frequent use of the flank organ of the golden Syrian hamster as an animal model. 17-alpha-propyltestosterone (17-PT) has been identified as having potent antiandrogenic activity in the hamster model, and this report describes its clinical evaluation. Two double-blind placebo controlled studies comparing 4% 17-PT in 80% alcohol versus vehicle alone were conducted. One study examined 17-PT sebosuppressive activity in 20 subjects. The second study examined its efficacy in 44 subjects having mild to moderate acne. A third study measured in vitro percutaneous absorption of 17-PT through hamster flank and monkey skin, and human face skin in-vivo, using radioactive drug. 17-PT was found to be ineffective in reducing either the sebum excretion rate or the number of inflammatory acne lesions. Failure of 17-PT to show clinical activity was not a result of poor percutaneous absorption. Total absorption in man was 7.7% of the dose and only 1.0% in the hamster. The sebaceous gland of hamster flank organ is apparently more sensitive to antiandrogens than the human sebaceous gland.

Franz, T.J.; Lehman, P.A.; Pochi, P.; Odland, G.F.; Olerud, J. (Univ. of Washington, Seattle (USA))

1989-10-01

161

Isolation, antimicrobial activities, and primary structures of hamster neutrophil defensins.  

PubMed Central

Hamster (Mesocricetus auratus) neutrophil granules contain at least four microbicidal peptides belonging to the defensin family. These compounds were purified from granule acid extracts by reverse-phase chromatography and termed HaNP-1 to -4 (hamster neutrophil peptide). HaNP-1 and HaNP-3 revealed the most bactericidal activity, with a 50% inhibitory concentration of 0.3 to 0.8 microg/ml for Staphylococcus aureus and Streptococcus pyogenes strains. The HaNP-4 was always isolated in concentrations exceeding about 10 times the concentrations of other hamster peptides, but its antibacterial activity as well as that of HaNP-2 was relatively lower, probably as a result of conserved Arg residue substitutions. Other microorganisms were also tested, and generally, hamster defensins exhibited less potency against gram-negative bacteria. The amino acid sequence of hamster defensins showed a high percentage of identity to the sequence of mouse enteric defensins, reaching about 60% identical residues in the case of HaNP-3 and cryptdin 3. PMID:8890190

Mak, P; Wójcik, K; Thogersen, I B; Dubin, A

1996-01-01

162

The Syrian hamster model of hantavirus pulmonary syndrome  

PubMed Central

Hantavirus pulmonary syndrome (HPS) is a relatively rare, but frequently fatal disease associated with New World hantaviruses, most commonly Sin Nombre and Andes viruses in North and South America, respectively. It is characterized by fever and the sudden, rapid onset of severe respiratory distress and cardiogenic shock, which can be fatal in up to 50% of cases. Currently there are no approved antiviral therapies or vaccines for the treatment or prevention of HPS. A major obstacle in the development of effective medical countermeasures against highly pathogenic agents like the hantaviruses is recapitulating the human disease as closely as possible in an appropriate and reliable animal model. To date, the only animal model that resembles HPS in humans is the Syrian hamster model. Following infection with Andes virus, hamsters develop HPS-like disease which faithfully mimics the human condition with respect to incubation period and pathophysiology of disease. Perhaps most importantly, the sudden and rapid onset of severe respiratory distress observed in humans also occurs in hamsters. The last several years has seen an increase in studies utilizing the Andes virus hamster model which have provided unique insight into HPS pathogenesis as well as potential therapeutic and vaccine strategies to treat and prevent HPS. The purpose of this article is to review the current understanding of HPS disease progression in Syrian hamsters and discuss the suitability of utilizing this model to evaluate potential medical countermeasures against HPS. PMID:22705798

Safronetz, David; Ebihara, Hideki; Feldmann, Heinz; Hooper, Jay W.

2012-01-01

163

Bidirectional communication between oocytes and ovarian follicular somatic cells is required for meiotic arrest of mammalian oocytes  

PubMed Central

Coordinated regulation of oocyte and ovarian follicular development is essential for fertility. In particular, the progression of meiosis, a germ cell-specific cell division that reduces the number of chromosomes from diploid to haploid, must be arrested until just before ovulation. Follicular somatic cells are well-known to impose this arrest, which is essential for oocyte–follicle developmental synchrony. Follicular somatic cells sustain meiotic arrest via the natriuretic peptide C/natriuretic peptide receptor 2 (NPPC/NPR2) system, and possibly also via high levels of the purine hypoxanthine in the follicular fluid. Upon activation by the ligand NPPC, NPR2, the predominant guanylyl cyclase in follicular somatic cells, produces cyclic guanosine monophosphate (cGMP), which maintains meiotic arrest after transfer to the oocyte via gap junctions. Here we report that both the NPPC/NPR2 system and hypoxanthine require the activity of inosine monophosphate dehydrogenase (IMPDH), the rate-limiting enzyme required for the production of guanylyl metabolites and cGMP. Furthermore, oocyte-derived paracrine factors, particularly the growth differentiation factor 9–bone morphogenetic protein 15 heterodimer, promote expression of Impdh and Npr2 and elevate cGMP levels in cumulus cells. Thus, although the somatic compartment of ovarian follicles plays an essential role in the maintenance of oocyte meiotic arrest, as has been known for many years, this function of the somatic cells is surprisingly regulated by signals from the oocyte itself. PMID:23980176

Wigglesworth, Karen; Lee, Kyung-Bon; O’Brien, Marilyn J.; Peng, Jia; Matzuk, Martin M.; Eppig, John J.

2013-01-01

164

Quantitative proteomics reveals the dynamics of protein changes during Drosophila oocyte maturation and the oocyte-to-embryo transition.  

PubMed

The onset of development is marked by two major, posttranscriptionally controlled, events: oocyte maturation (release of the prophase I primary arrest) and egg activation (release from the secondary meiotic arrest). Using quantitative mass spectrometry, we previously described proteome remodeling during Drosophila egg activation. Here, we describe our quantitative mass spectrometry-based analysis of the changes in protein levels during Drosophila oocyte maturation. This study presents the first quantitative survey, to our knowledge, of proteome changes accompanying oocyte maturation in any organism and provides a powerful resource for identifying both key regulators and biological processes driving this critical developmental window. We show that Muskelin, found to be up-regulated during oocyte maturation, is required for timely nurse cell nuclei clearing from mature egg chambers. Other proteins up-regulated at maturation are factors needed not only for late oogenesis but also completion of meiosis and early embryogenesis. Interestingly, the down-regulated proteins are predominantly involved in RNA processing, translation, and RNAi. Integrating datasets on the proteome changes at oocyte maturation and egg activation uncovers dynamics in proteome remodeling during the change from oocyte to embryo. Notably, 66 proteins likely act uniquely during late oogenesis, because they are up-regulated at maturation and down-regulated at activation. We find down-regulation of this class of proteins to be mediated partially by APC/C(CORT), a meiosis-specific form of the E3 ligase anaphase promoting complex/cyclosome (APC/C). PMID:25349405

Kronja, Iva; Whitfield, Zachary J; Yuan, Bingbing; Dzeyk, Kristina; Kirkpatrick, Joanna; Krijgsveld, Jeroen; Orr-Weaver, Terry L

2014-11-11

165

Sidewall penetrator for oil wells  

NASA Technical Reports Server (NTRS)

Penetrator bores horizontal holes in well casing to increase trapped oil drainage. Several penetrators operated by common drive are inserted into well at once. Shaft, made from spiraling cable, rotates and thrusts simultaneously through rigid curvilinear guide tube forcing bit through casing into strata. Device pierces more deeply than armor-piercing bullets and shaped explosive charges.

Collins, E. R., Jr.

1981-01-01

166

Cement penetration after patella venting  

Microsoft Academic Search

There is a high rate of patellofemoral complications following total knee arthroplasty. Optimization of the cement–bone interface by venting and suction of the tibial plateau has been shown to improve cement penetration. Our study was designed to investigate if venting the patella prior to cementing improved cement penetration.Ten paired cadaver patellae were allocated prior to resurfacing to be vented or

Christopher W. Jones; Li-On Lam; Adam Butler; David J. Wood; William R. Walsh

2009-01-01

167

Ground-penetrating radar methods  

Technology Transfer Automated Retrieval System (TEKTRAN)

Ground-penetrating radar geophysical methods are finding greater and greater use in agriculture. With the ground-penetrating radar (GPR) method, an electromagnetic radio energy (radar) pulse is directed into the subsurface, followed by measurement of the elapsed time taken by the radar signal as it ...

168

Distribution of the Serum Proteins of Syrian Hamster as revealed by Starch-gel Electrophoresis  

Microsoft Academic Search

ALTHOUGH considerable work has been published on the distribution of the serum proteins of various laboratory animals, little has been reported on the electrophoretic pattern of the serum proteins of hamster. Moore1 investigated the serum proteins of several species of animals, including that of the hamster, by moving boundary electrophoresis. He identified six components in the serum of hamster corresponding

Abolghassem Amin; K. D. Shamloo

1963-01-01

169

Mitotic Spindle Proteomics in Chinese Hamster Ovary Mary Kate Bonner1  

E-print Network

Mitotic Spindle Proteomics in Chinese Hamster Ovary Cells Mary Kate Bonner1 , Daniel S. Poole1 events. Here, we report a proteomic study of the mitotic spindle from Chinese Hamster Ovary (CHO) cells A, Yates JR III, et al. (2011) Mitotic Spindle Proteomics in Chinese Hamster Ovary Cells. PLoS ONE 6

Skop, Ahna

170

Gender differences in the development of hyperlipemia and atherosclerosis in hybrid hamsters  

Microsoft Academic Search

In response to a diet enriched in saturated fat and cholesterol (CH), male Syrian hamsters develop hyperlipemia and changes of early atherosclerosis. However, it has not been determined if female hamsters are equally susceptible to an atherogenic diet. Male and female hamsters of the F1B hybrid strain (Bio Breeders, Fitchburg, MA) were fed either a chow diet or this diet

Sander J. Robins; Joan M. Fasulo; George M. Patton; Ernst J. Schaefer; Donald E. Smith; Jose M. Ordovas

1995-01-01

171

Static penetration resistance of soils  

NASA Technical Reports Server (NTRS)

Model test results were used to define the failure mechanism associated with the static penetration resistance of cohesionless and low-cohesion soils. Knowledge of this mechanism has permitted the development of a new analytical method for calculating the ultimate penetration resistance which explicitly accounts for penetrometer base apex angle and roughness, soil friction angle, and the ratio of penetration depth to base width. Curves relating the bearing capacity factors to the soil friction angle are presented for failure in general shear. Strength parameters and penetrometer interaction properties of a fine sand were determined and used as the basis for prediction of the penetration resistance encountered by wedge, cone, and flat-ended penetrometers of different surface roughness using the proposed analytical method. Because of the close agreement between predicted values and values measured in laboratory tests, it appears possible to deduce in-situ soil strength parameters and their variation with depth from the results of static penetration tests.

Durgunoglu, H. T.; Mitchell, J. K.

1973-01-01

172

Electromagnetic Field Penetration Studies  

NASA Technical Reports Server (NTRS)

A numerical method is presented to determine electromagnetic shielding effectiveness of rectangular enclosure with apertures on its wall used for input and output connections, control panels, visual-access windows, ventilation panels, etc. Expressing EM fields in terms of cavity Green's function inside the enclosure and the free space Green's function outside the enclosure, integral equations with aperture tangential electric fields as unknown variables are obtained by enforcing the continuity of tangential electric and magnetic fields across the apertures. Using the Method of Moments, the integral equations are solved for unknown aperture fields. From these aperture fields, the EM field inside a rectangular enclosure due to external electromagnetic sources are determined. Numerical results on electric field shielding of a rectangular cavity with a thin rectangular slot obtained using the present method are compared with the results obtained using simple transmission line technique for code validation. The present technique is applied to determine field penetration inside a Boeing-757 by approximating its passenger cabin as a rectangular cavity filled with a homogeneous medium and its passenger windows by rectangular apertures. Preliminary results for, two windows, one on each side of fuselage were considered. Numerical results for Boeing-757 at frequencies 26 MHz, 171-175 MHz, and 428-432 MHz are presented.

Deshpande, M.D.

2000-01-01

173

[Fertilizing capacity of the ejaculate of nutria (Myocastor coypus) after the removal of the seminal vesicles as evaluated by the penetration test and natural mating].  

PubMed

The fertility of male coypu sperm following seminal vesicle extirpation was investigated using the penetration test into the egg of Syrian golden hamster (Mesocricetus auratus). Ejaculates were obtained from five males by means of electro-ejaculation under halothane narcosis. The results of the zona-free hamster eggs (ZFHE) penetration test showed that the ejaculates of all the surgically treated coypu males were fertile and that ZFHE value fluctuated from 54 to 76.6%. The results obtained in experiments with natural mating revealed that the extirpation of male coypu seminal vesicles did not affect their fertility. In total 47 foetuses were found post mortem in ten coypu females covered by surgically treated males, which on average represented 4.7 foetuses per female. PMID:2678717

Jakubicka, I; Barta, M; Babusík, P

1989-07-01

174

A Syrian Golden Hamster Model Recapitulating Ebola Hemorrhagic Fever  

PubMed Central

Ebola hemorrhagic fever (EHF) is a severe viral infection for which no effective treatment or vaccine is currently available. While the nonhuman primate (NHP) model is used for final evaluation of experimental vaccines and therapeutic efficacy, rodent models have been widely used in ebolavirus research because of their convenience. However, the validity of rodent models has been questioned given their low predictive value for efficacy testing of vaccines and therapeutics, a result of the inconsistent manifestation of coagulopathy seen in EHF. Here, we describe a lethal Syrian hamster model of EHF using mouse-adapted Ebola virus. Infected hamsters displayed most clinical hallmarks of EHF, including severe coagulopathy and uncontrolled host immune responses. Thus, the hamster seems to be superior to the existing rodent models, offering a better tool for understanding the critical processes in pathogenesis and providing a new model for evaluating prophylactic and postexposure interventions prior to testing in NHPs. PMID:23045629

Ebihara, Hideki; Zivcec, Marko; Gardner, Donald; Falzarano, Darryl; LaCasse, Rachel; Rosenke, Rebecca; Long, Dan; Haddock, Elaine; Fischer, Elizabeth; Kawaoka, Yoshihiro; Feldmann, Heinz

2013-01-01

175

Cryopreservation of Mammalian Oocytes by Using Sugars: Intra- and extracellular raffinose with small amounts of dimethylsulfoxide yields high cryosurvival, fertilization, and development rates  

PubMed Central

Accumulation of intra- and extracellular sugars such as trehalose, glucose, and raffinose is central to survival strategies of a variety of organisms coping with extreme conditions including freezing and almost complete drying. The objective of the present study was to investigate the potential application of intra- and extracellular raffinose in combination with low concentrations of dimethylsulfoxide (Me2SO) to mammalian oocyte cryopreservation. To this end, the fertilization and embryonic development of cryopreserved metaphase II (M II) mouse oocytes were studied in comparison to unfrozen controls. For cryopreservation, M II oocytes were microinjected with 0.1 M raffinose, and then cooled to -196°C in the presence of either 0.3 M raffinose and 0.5 M Me2SO (cryopreservation group 1) or 0.3 M raffinose and 1.0 M Me2SO (cryopreservation group 2). The control groups included untreated oocytes (untreated control) and oocytes microinjected with raffinose, but not frozen (injection control). The post-thaw survival rates were 83.9% and 80.6% for the cryopreservation group 1 and 2, respectively. The fertilization and blastocyst rates in the cryopreservation group 1 (90.0% and 77.8%, respectively) and 2 (94.6% and 72.5%, respectively) were also high and similar to the ones of the injection controls (97.8% and 78.5%, respectively) and untreated controls (98.8% and 83.6%, respectively). These results are consistent with the findings of our earlier studies and support the use of sugars as intra- and extracellular cryoprotectants. Furthermore, the results of the present study indicate that the presence of intra- and extracellular sugars alleviates high concentrations of conventional penetrating cryoprotectants, and thus minimizes their toxicity. PMID:19596315

Eroglu, Ali

2009-01-01

176

Lipoprotein mediated lipid uptake in oocytes of polychaetes (Annelida).  

PubMed

The uptake of the 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI)-labeled sex-unspecific Nereis lipoprotein was investigated in oocytes of the nereidid polychaetes Nereis virens and Platynereis dumerilii. The fluorescence label was first observed in endocytic vesicles (<1 microm diameter), which later fused to larger vesicles (2-3 microm); these were finally incorporated into existing unlabeled yolk granules (5-6 microm). In Platynereis oocytes, the fusion of endocytic vesicles was delayed in oocytes at their final stage of development compared with those at an early stage of development. Lipoprotein double-labeled with fluorescein isothiocyanate (FITC) and DiI revealed that both the protein and the lipid moiety remained co-localized during incorporation into the yolk granules of the oocyte. No labeling of the cytoplasmic lipid droplets was observed. In N. virens, unlabeled Nereis lipoprotein was effective as a competitive inhibitor of DiI-labeled Nereis lipoprotein. Ligand blot experiments demonstrated the presence of a lipoprotein receptor with an apparent molecular mass of 120 kDa, which is different from that of the known yolk protein receptor. This indicates the presence, in the polychaete oocyte, of two distinct receptors mediating yolk protein and lipoprotein uptake, respectively. Thus, the sex-unspecific lipoprotein contributes to the lipid supply of the growing oocyte in addition to the known uptake of the yolk-protein-associated lipids. The absence of label in the cytoplasmic lipid droplets, even after prolonged incubation with labeled lipoprotein, suggests that these lipids arise either by the breakdown and resynthesis of lipoprotein-derived lipids and/or by de novo synthesis within the oocyte. PMID:19533173

Schenk, Sven; Hoeger, Ulrich

2009-08-01

177

Maternal Photoperiodic History Affects Offspring Development in Syrian Hamsters  

PubMed Central

During the first 7 weeks of postnatal life, short day lengths inhibit the onset of puberty in many photoperiodic rodents, but not in Syrian hamsters. In this species, timing of puberty and fecundity are independent of the early postnatal photoperiod. Gestational day length affects postnatal reproductive development in several rodents; its role in Syrian hamsters has not been assessed. We tested the hypothesis that cumulative effects of pre- and postnatal short day lengths would restrain gonadal development in male Syrian hamsters. Males with prenatal short day exposure were generated by dams transferred to short day lengths 6 weeks, 3 weeks, and 0 weeks prior to mating. Additional groups were gestated in long day lengths and transferred to short days at birth, at 4 weeks of age, or not transferred (control hamsters). In pups of dams exposed to short day treatment throughout gestation, decreased testis growth was apparent by 3 weeks and persisted through 9 weeks of age, at which time maximum testis size was attained. A subset of males (14%), whose dams had been in short days for 3 to 6 weeks prior to mating displayed pronounced delays in testicular development, similar to those of other photoperiodic rodents. This treatment also increased the percentage of male offspring that underwent little or no gonadal regression postnatally (39%). By 19 weeks of age, males housed in short days completed spontaneous gonadal development. After prolonged long day treatment to break refractoriness, hamsters that initially were classified as nonregressors underwent testicular regression in response to a 2nd sequence of short day lengths. The combined action of prenatal and early postnatal short day lengths diminishes testicular growth of prepubertal Syrian hamsters no later than the 3rd week of postnatal life, albeit to a lesser extent than in other photoperiodic rodents. PMID:18838610

Beery, Annaliese K.; Paul, Matthew J.; Routman, David M.; Zucker, Irving

2009-01-01

178

Foodborne transmission of nipah virus in Syrian hamsters.  

PubMed

Since 2001, outbreaks of Nipah virus have occurred almost every year in Bangladesh with high case-fatality rates. Epidemiological data suggest that in Bangladesh, Nipah virus is transmitted from the natural reservoir, fruit bats, to humans via consumption of date palm sap contaminated by bats, with subsequent human-to-human transmission. To experimentally investigate this epidemiological association between drinking of date palm sap and human cases of Nipah virus infection, we determined the viability of Nipah virus (strain Bangladesh/200401066) in artificial palm sap. At 22°C virus titers remained stable for at least 7 days, thus potentially allowing food-borne transmission. Next, we modeled food-borne Nipah virus infection by supplying Syrian hamsters with artificial palm sap containing Nipah virus. Drinking of 5×10? TCID?? of Nipah virus resulted in neurological disease in 5 out of 8 hamsters, indicating that food-borne transmission of Nipah virus can indeed occur. In comparison, intranasal (i.n.) inoculation with the same dose of Nipah virus resulted in lethal respiratory disease in all animals. In animals infected with Nipah virus via drinking, virus was detected in respiratory tissues rather than in the intestinal tract. Using fluorescently labeled Nipah virus particles, we showed that during drinking, a substantial amount of virus is deposited in the lungs, explaining the replication of Nipah virus in the respiratory tract of these hamsters. Besides the ability of Nipah virus to infect hamsters via the drinking route, Syrian hamsters infected via that route transmitted the virus through direct contact with naïve hamsters in 2 out of 24 transmission pairs. Although these findings do not directly prove that date palm sap contaminated with Nipah virus by bats is the origin of Nipah virus outbreaks in Bangladesh, they provide the first experimental support for this hypothesis. Understanding the Nipah virus transmission cycle is essential for preventing and mitigating future outbreaks. PMID:24626480

de Wit, Emmie; Prescott, Joseph; Falzarano, Darryl; Bushmaker, Trenton; Scott, Dana; Feldmann, Heinz; Munster, Vincent J

2014-03-01

179

Foodborne Transmission of Nipah Virus in Syrian Hamsters  

PubMed Central

Since 2001, outbreaks of Nipah virus have occurred almost every year in Bangladesh with high case-fatality rates. Epidemiological data suggest that in Bangladesh, Nipah virus is transmitted from the natural reservoir, fruit bats, to humans via consumption of date palm sap contaminated by bats, with subsequent human-to-human transmission. To experimentally investigate this epidemiological association between drinking of date palm sap and human cases of Nipah virus infection, we determined the viability of Nipah virus (strain Bangladesh/200401066) in artificial palm sap. At 22°C virus titers remained stable for at least 7 days, thus potentially allowing food-borne transmission. Next, we modeled food-borne Nipah virus infection by supplying Syrian hamsters with artificial palm sap containing Nipah virus. Drinking of 5×108 TCID50 of Nipah virus resulted in neurological disease in 5 out of 8 hamsters, indicating that food-borne transmission of Nipah virus can indeed occur. In comparison, intranasal (i.n.) inoculation with the same dose of Nipah virus resulted in lethal respiratory disease in all animals. In animals infected with Nipah virus via drinking, virus was detected in respiratory tissues rather than in the intestinal tract. Using fluorescently labeled Nipah virus particles, we showed that during drinking, a substantial amount of virus is deposited in the lungs, explaining the replication of Nipah virus in the respiratory tract of these hamsters. Besides the ability of Nipah virus to infect hamsters via the drinking route, Syrian hamsters infected via that route transmitted the virus through direct contact with naïve hamsters in 2 out of 24 transmission pairs. Although these findings do not directly prove that date palm sap contaminated with Nipah virus by bats is the origin of Nipah virus outbreaks in Bangladesh, they provide the first experimental support for this hypothesis. Understanding the Nipah virus transmission cycle is essential for preventing and mitigating future outbreaks. PMID:24626480

de Wit, Emmie; Prescott, Joseph; Falzarano, Darryl; Bushmaker, Trenton; Scott, Dana; Feldmann, Heinz; Munster, Vincent J.

2014-01-01

180

Biotransport phenomena in freezing mammalian oocytes.  

PubMed

Water transport across the cell plasma membrane and intracellular ice formation (IIF)-the two biophysical events that may cause cell injury during cryopreservation-were studied by cryomicroscopy and modeling using mammalian (Peromyscus) oocytes. Unusually high activation energy for water transport across the cell plasma membrane was identified indicating that the water transport process is unusually sensitive to temperature (and cooling rate). Although literally all studies on IIF were conducted using protocols with ice-seeding (seeding extracellular ice usually at ?-7 °C), it is not used for cell cryopreservation by vitrification that is becoming increasingly popular today. In this article, we show that ice-seeding has a significant impact on IIF. With ice-seeding and cooling at 60 °C/min, IIF was observed to occur over a wide range from approximately -8 to -48 °C with a clear change of the ice nucleation mechanism (from surface- to volume-catalyzed nucleation) at approximately -43 °C. On the contrary, without ice-seeding, IIF occurred over a much narrower range from approximately -19 to -27 °C without a noticeable change of the nucleation mechanism. Moreover, the kinetics of IIF without ice-seeding was found to be strongly temperature (and cooling rate) dependent. These findings indicate the importance of quantifying the IIF kinetics in the absence of ice-seeding during cooling for development of optimal vitrification protocols of cell cryopreservation. PMID:20848315

Yang, Geer; Veres, Monika; Szalai, Gabor; Zhang, Aili; Xu, Lisa X; He, Xiaoming

2011-01-01

181

Time-lapse dynamics of the mouse oocyte chromatin organisation during meiotic resumption.  

PubMed

In the mammalian oocyte, distinct patterns of centromeres and pericentromeric heterochromatin localisation correlate with the gamete's developmental competence. Mouse antral oocytes display two main types of chromatin organisation: SN oocytes, with a ring of Hoechst-positive chromatin surrounding the nucleolus, and NSN oocytes lacking this ring. When matured to MII and fertilised, only SN oocytes develop beyond the 2-cell, and reach full term. To give detailed information on the dynamics of the SN or NSN chromatin during meiosis resumption, we performed a 9 hr time-lapse observation. The main significant differences recorded are: (1) reduction of the nuclear area only in SN oocytes; (2) ~17 min delay of GVBD in NSN oocytes; (3) chromatin condensation, after GVBD, in SN oocytes; (4) formation of 4-5 CHCs in SN oocytes; (5) increase of the perivitelline space, ~57 min later in NSN oocytes; (6) formation of a rosette-like disposition of CHCs, ~84 min later in SN oocytes; (7) appearance of the MI plate ~40 min later in NSN oocytes. Overall, we described a pathway of transition from the GV to the MII stage that is punctuated of discrete recordable events showing their specificity and occurring with different time kinetics in the two types of oocytes. PMID:24864231

Belli, Martina; Vigone, Giulia; Merico, Valeria; Redi, Carlo Alberto; Garagna, Silvia; Zuccotti, Maurizio

2014-01-01

182

Time-Lapse Dynamics of the Mouse Oocyte Chromatin Organisation during Meiotic Resumption  

PubMed Central

In the mammalian oocyte, distinct patterns of centromeres and pericentromeric heterochromatin localisation correlate with the gamete's developmental competence. Mouse antral oocytes display two main types of chromatin organisation: SN oocytes, with a ring of Hoechst-positive chromatin surrounding the nucleolus, and NSN oocytes lacking this ring. When matured to MII and fertilised, only SN oocytes develop beyond the 2-cell, and reach full term. To give detailed information on the dynamics of the SN or NSN chromatin during meiosis resumption, we performed a 9?hr time-lapse observation. The main significant differences recorded are: (1) reduction of the nuclear area only in SN oocytes; (2) ~17?min delay of GVBD in NSN oocytes; (3) chromatin condensation, after GVBD, in SN oocytes; (4) formation of 4-5 CHCs in SN oocytes; (5) increase of the perivitelline space, ~57?min later in NSN oocytes; (6) formation of a rosette-like disposition of CHCs, ~84?min later in SN oocytes; (7) appearance of the MI plate ~40?min later in NSN oocytes. Overall, we described a pathway of transition from the GV to the MII stage that is punctuated of discrete recordable events showing their specificity and occurring with different time kinetics in the two types of oocytes. PMID:24864231

Redi, Carlo Alberto; Zuccotti, Maurizio

2014-01-01

183

Photodynamic therapy of hamster Greene melanoma in vitro and in vivo using bacteriochlorin-a as photosensitizer  

NASA Astrophysics Data System (ADS)

Efficient photodynamic therapy (PDT) of malignant melanoma may be possible with photosensitizers having absorption maxima in the far-red region e.g., above 700 nm. Bacteriochlorin a (BCA), a non toxic derivative of bacteriochlorphyllin a, has a high molecular absorption coefficient (32.000 M-1.cm-1) at 760 nm. At this wavelength tissue penetration of light is almost optimal and melanin absorption is relatively low. In several series of experiments BCA was proven to be a very effective photosensitizer, in vitro and in vivo. It is preferentially retained in experimental hamster Greene melanoma, rhabdomyosarcoma, RIF- and mamma tumors. Its fluorescence can be detected in vivo, thus enabling early tumor detection and it is rapidly cleared from the tissues which promises no, or minor skin photosensitivity. The effects of BCA-PDT were studied in vitro and in vivo using the heavily pigmented Hamster Greene Melanoma (HGM) cell line as a model. In vitro it was found that the uptake of BCA was time, concentration and temperature dependant. Upon illumination (10 Mw/cm2, 756 nm) after incubation with 2.5 (mu) g/ml BCA for 1 h, almost complete cell kill was obtained within seconds. Hamster Greene Melanoma implanted in the anterior eye chamber of rabbits is an accepted in vivo model for ocular melanoma. The effects of BCA-PDT using this model were studied by light- and electron microscopy. Immediately after PDT intracellular spaces were enlarged and blood vessels were clotted with swollen erythrocytes. Electron microscopy showed fused inner and outer membranes and affected cristae mitchondriales of some mitochondria. With time, the severity of tissue and cell damage increased. One day after irradiation tumor growth had stopped; fluorescein angiography showed non perfusion of the tumor. Histopathology showed almost complete tumor necrosis with occasionally viable cells at the tumor periphery. It is concluded that the direct mitochondrial damage and the vascular damage both contribute to BCA-PDT induced tumor necrosis.

Schuitmaker, J. J.; Van Best, Jaap A.; van Delft, J. L.; Jannink, J. E.; Oosterhuis, J. A.; Vrensen, Gijs F.; Ms Wolff-Rouendaal, Didi; Dubbelman, T. M.

1996-01-01

184

Effects of coculture with cumulus-derived somatic cells on in vitro maturation of porcine oocytes.  

PubMed

In the process of IVM, cumulus-oocyte complexes (COCs) separate from the follicular microenvironment, leading to the loss of endocrine interactions between follicular mural somatic cells and COCs. To restore the microenvironment, a coculture system was established using cumulus-derived somatic cells (CSCs) for IVM. The CSCs were cultured in Dulbecco's modified Eagle's medium for 48 hours with varying numbers of CSCs (0.0, 2.5 × 10(4), 5.0 × 10(4), and 10.0 × 10(4)) and then cultured in tissue culture medium 199 (TCM 199) for 4 hours before adding the oocytes. Cumulus-oocyte complexes from 3- to 6-mm follicles were matured in 500 ?L of TCM 199 with eCG and hCG for 22 hours and then cultured in TCM 199 without hormones for 22 hours. After IVM, the group with 2.5 × 10(4) CSCs showed a significant increase in intracellular glutathione levels compared with the control group. In the evaluation of sperm penetration, efficient fertilization was increased in the groups with 2.5 × 10(4) and 5.0 × 10(4) CSCs compared with controls (44.9 and 46.5 vs. 32.1, respectively). The mRNA expression pattern analysis in matured COCs showed a significant upregulation of PCNA, COX-2, Has2, Ptx3, and Nrf2 in the 2.5 × 10(4) CSC group compared with controls. During COC maturation at 0, 11, 22, 33, and 44 hours, the 2.5 × 10(4) and 5.0 × 10(4) CSC groups showed a significantly altered mRNA expression of BMP15 and GDF9. The developmental competence of the matured oocytes in all groups was evaluated after IVF and parthenogenetic activation (PA). After IVF, the 2.5 × 10(4) CSC group showed significantly higher cleavage, blastocyst formation rate, and total cell numbers compared with controls (60.0%, 35.7%, and 127.3 vs. 43.2%, 21.1%, and 89.3, respectively). After PA, the 2.5 × 10(4) CSC group had significantly higher blastocyst formation rate and total cell number than the control group (52.0% and 120.4 vs. 35.4% and 90.9, respectively). In conclusion, these results suggest that the presence of a population of 2.5 × 10(4) CSCs during IVM synergistically improved the developmental potential of IVF- and PA-derived porcine embryos by increasing the intracellular glutathione level via changing of a specific gene expression pattern during oocyte maturation. PMID:25442018

Yoon, Junchul David; Jeon, Yubyeol; Cai, Lian; Hwang, Seon-Ung; Kim, Eunhye; Lee, Eunsong; Kim, Dae Y; Hyun, Sang-Hwan

2015-01-15

185

Transdermal penetration of UV filters.  

PubMed

A penetration study of 2-ethylhexyl-4-methoxycinnamate (EHMC), 4-methyl benzylidenecamphor (MBC), butyl methoxydibenzoylmethane (BMBM), 2-ethylhexyl-2,4,5-trimethoxycinnamate (EHTMC) and di(2-ethylhexyl)-2,4,5-trimethoxybenzalmalonate (TMB) through baby mouse skin (Mus musculus Linn.) was carried out using a vertical Franz diffusion cell. At 4.4 mg/cm(2) coverage of UV filter on the skin, 2.98 +/- 0.38, 1.15 +/- 0.14 and 0.80 +/- 0.28% of the applied EHMC, MBC and BMBM were detected in the receptor fluid at 24 h after application. Penetrations of UV filter in an ethanolic solution and lotion forms were comparable. EHTMC and TMB showed insignificant penetration across the baby mouse skins. Baby mouse skins kept at 4, -20 and -80 degrees C gave similar EHMC penetration results. Penetrations of EHMC, BMBM, EHTMC and TMB across human epidermis were carried out upon 5 volunteers using the suction blister technique. The results also confirmed the significant penetrations of EHMC and BMBM and the insignificant penetrations of EHTMC and TMB. PMID:17912021

Klinubol, P; Asawanonda, P; Wanichwecharungruang, S P

2008-01-01

186

Hamster (Mesocricetus auratus) enteritis caused by epithelial cell-invasive Escherichia coli.  

PubMed Central

When inoculated orally, Escherichia coli strain 1056 caused acute enteritis in 7 of 22 weanling hamsters. E. coli strain 1056 was isolated from the ileum of a hamster with proliferative ileitis. It was lactose negative, nonmotile, and anaerogenic. By electron microscopy and indirect fluorescent-antibody techniques, E. coli strain 1056 was detected in absorptive epithelial cells, resembling invasive E. coli and shigella infections of other species. Ileitis did not progress to epithelial cell hyperplasia, which is characteristic of proliferative ileitis of hamsters. A control group of 10 hamsters, inoculated with nonenteropathogenic E. coli isolated from a normal hamster, did not develop signs or lesions. Images PMID:7014460

Frisk, C S; Wagner, J E; Owens, D R

1981-01-01

187

Naturally occurring mastitis disrupts developmental competence of bovine oocytes.  

PubMed

We examined the effects of naturally occurring mastitis on bovine oocyte developmental competence in vitro. Specifically, we investigated the effects of intramammary infection on the ovarian pool of oocytes (i.e., follicle-enclosed oocytes) and their ability to undergo in vitro maturation, fertilization, and further development to the blastocyst stage. Culled Holstein cows (n=50) from 9 commercial dairy farms in Israel were allotted to 3 groups according to somatic cell count (SCC) records of the last 3 monthly milk tests as well as of quarter samples collected before slaughter: (1) low SCC (n=7), (2) medium SCC (n=16), or (3) high SCC (n=27). Means of SCC values differed among low-, medium-, and high-SCC groups: 148,000, 311,000 and 1,813,000 cell/mL milk, respectively. Milk yield and days in milk did not differ among the 3 groups. Bacterial isolates included coagulase-negative staphylococci, Escherichia coli, Streptococcus dysgalactiae, or no bacteria found. Ovaries were collected at the abattoir and brought to the laboratory. Cumulus oocyte complexes were recovered separately from each cow and subjected individually to in vitro maturation and fertilization, followed by 8d in culture. The number of aspirated oocytes did not differ among groups, with a range of 17 to 21 oocytes per cow. The proportion of oocytes that cleaved into 2- to 4-cell-stage embryos (86.1 ± 3.4%) did not differ among groups. In contrast, mean percentages of embryos developed to the blastocyst stage on d 7 and 8 after fertilization were less in both medium- and-high SCC groups than in the low-SCC group (5.6 ± 2.3 and 4.1 ± 1.8 vs. 18.1 ± 4.6%, respectively). Additional analysis indicated that cleavage and blastocyst-formation rates did not differ among the bacterial types in the low-, medium-, and high-SCC groups. These are the first results to demonstrate that naturally occurring mastitis disrupts the developmental competence of the ovarian pool of oocytes, (i.e., oocytes at the germinal vesicle stage). The disruption was associated with elevation of SCC rather than bacterial type. The results may provide a partial explanation for the low fertility of cows that have contracted mastitic pathogens before insemination. PMID:23957998

Roth, Z; Dvir, A; Kalo, D; Lavon, Y; Krifucks, O; Wolfenson, D; Leitner, G

2013-10-01

188

Discovery and characterization of a new cell-penetrating protein.  

PubMed

We describe a new cell-penetrating protein, B1, capable of delivering conjugated proteins and nucleic acids into mammalian cells. B1 is a 244-amino-acid product of a single-base frameshift in the gene encoding enhanced green fluorescent protein (eGFP). The molecule has a net positive charge of 43 and a very high charge-to-mass ratio of 1.5. eGFP-fused B1 potently penetrates both adherent and suspension cells with >80% of cells taking up the protein when exposed to concentrations as low as 1 ?M. The protein was found to cluster in the paranuclear region of TZM-bl cells. Most importantly, we show that B1 not only facilitates cellular uptake but allows biomolecular cargo to reach sites of biological relevance. For example, baby hamster kidney cells underwent DNA recombination when exposed to B1-tagged Cre recombinase at protein concentrations as low as 2.5 ?M, indicating potent nuclear delivery of functional protein cargos. Additionally, B1 delivers noncovalently conjugated RNA and DNA across the cell membrane to cytosolic and nuclear sites accessible to the cellular translation and transcription machinery, as gauged by detection of encoded reporter functions, with efficiency comparable to commercially available cationic lipid reagents. B1 appears to utilize cell-surface glycans and multiple competing endocytic pathways to enter and traffic through cells. These studies provide both a new tool for intracellular delivery of biomolecules and insights that could aid in the design of more effective cell penetrating proteins. PMID:24047285

Simeon, Rudo L; Chamoun, Ana Maria; McMillin, Thomas; Chen, Zhilei

2013-12-20

189

PTK2b function during fertilization of the mouse oocyte.  

PubMed

Fertilization triggers rapid changes in intracellular free calcium that serve to activate multiple signaling events critical to the initiation of successful development. Among the pathways downstream of the fertilization-induced calcium transient is the calcium-calmodulin dependent protein tyrosine kinase PTK2b or PYK2 kinase. PTK2b plays an important role in fertilization of the zebrafish oocyte and the objective of the present study was to establish whether PTK2b also functions in mammalian fertilization. PTK2b was activated during the first few hours after fertilization of the mouse oocyte during the period when anaphase resumption was underway and prior to the pronuclear stage. Suppression of PTK2b kinase activity in oocytes blocked sperm incorporation and egg activation although sperm-oocyte binding was not affected. Oocytes that failed to incorporate sperm after inhibitor treatment showed no evidence of a calcium transient and no evidence of anaphase resumption suggesting that egg activation did not occur. The results indicate that PTK2b functions during the sperm-egg fusion process or during the physical incorporation of sperm into the egg cytoplasm and is therefore critical for successful development. PMID:24667605

Luo, Jinping; McGinnis, Lynda K; Carlton, Carol; Beggs, Hilary E; Kinsey, William H

2014-08-01

190

Storage of Steindachneridion parahybae oocytes at different temperatures.  

PubMed

The objective of this study was to assess the influence of temperature and time on the storage of fresh Steindachneridion parahybae oocytes. Two experiments were carried out: (1) the fertilization rates of oocytes exposed to temperatures of 5, 15, 28 (room temperature) and 35°C were assessed 15min (control), 115, 235 and 355min after release; (2) the fertilization and hatching rates, as well as the percentage of normal larvae of oocytes exposed to 14, 17 or 20°C, 20min (control) were assessed 50, 80 and 110min after stripping. In the first experiment, the highest fertilization rates (P<0.05) were obtained in the control treatment (15min, 28°C), with 74.34±5.48% oocytes showing loss of viability over time. In the second experiment, there was a reduction (P<0.05) in the fertilization rates at the temperatures and times tested. The artificial fertilization of S. parahybae oocytes is recommended immediately after collection, and if storage is necessary, it should be conducted at temperatures between 17 and 20°C. PMID:25458322

Sanches, Eduardo Antônio; Okawara, Renan Yoshiharu; Caneppele, Danilo; Neumann, Giovano; Bombardelli, Robie Allan; Romagosa, Elizabeth

2014-12-30

191

High-throughput optofluidic system for the laser microsurgery of oocytes  

NASA Astrophysics Data System (ADS)

This study combines microfluidics with optical microablation in a microscopy system that allows for high-throughput manipulation of oocytes, automated media exchange, and long-term oocyte observation. The microfluidic component of the system transports oocytes from an inlet port into multiple flow channels. Within each channel, oocytes are confined against a microfluidic barrier using a steady fluid flow provided by an external computer-controlled syringe pump. This allows for easy media replacement without disturbing the oocyte location. The microfluidic and optical-laser microbeam ablation capabilities of the system were validated using surf clam (Spisula solidissima) oocytes that were immobilized in order to permit ablation of the 5 ?m diameter nucleolinus within the oocyte nucleolus. Oocytes were the followed and assayed for polar body ejection.

Chandsawangbhuwana, Charlie; Shi, Linda Z.; Zhu, Qingyuan; Alliegro, Mark C.; Berns, Michael W.

2012-01-01

192

High-throughput optofluidic system for the laser microsurgery of oocytes  

PubMed Central

Abstract. This study combines microfluidics with optical microablation in a microscopy system that allows for high-throughput manipulation of oocytes, automated media exchange, and long-term oocyte observation. The microfluidic component of the system transports oocytes from an inlet port into multiple flow channels. Within each channel, oocytes are confined against a microfluidic barrier using a steady fluid flow provided by an external computer-controlled syringe pump. This allows for easy media replacement without disturbing the oocyte location. The microfluidic and optical-laser microbeam ablation capabilities of the system were validated using surf clam (Spisula solidissima) oocytes that were immobilized in order to permit ablation of the 5 ?m diameter nucleolinus within the oocyte nucleolus. Oocytes were the followed and assayed for polar body ejection. PMID:22352645

Chandsawangbhuwana, Charlie; Shi, Linda Z.; Zhu, Qingyuan; Alliegro, Mark C.; Berns, Michael W.

2012-01-01

193

Efficient gene targeting in golden Syrian hamsters by the CRISPR/Cas9 system.  

PubMed

The golden Syrian hamster is the model of choice or the only rodent model for studying many human diseases. However, the lack of gene targeting tools in hamsters severely limits their use in biomedical research. Here, we report the first successful application of the CRISPR/Cas9 system to efficiently conduct gene targeting in hamsters. We designed five synthetic single-guide RNAs (sgRNAs)--three for targeting the coding sequences for different functional domains of the hamster STAT2 protein, one for KCNQ1, and one for PPP1R12C--and demonstrated that the CRISPR/Cas9 system is highly efficient in introducing site-specific mutations in hamster somatic cells. We then developed unique pronuclear (PN) and cytoplasmic injection protocols in hamsters and produced STAT2 knockout (KO) hamsters by injecting the sgRNA/Cas9, either in the form of plasmid or mRNA, targeting exon 4 of hamster STAT2. Among the produced hamsters, 14.3% and 88.9% harbored germline-transmitted STAT2 mutations from plasmid and mRNA injection, respectively. Notably, 10.4% of the animals produced from mRNA injection were biallelically targeted. This is the first success in conducting site-specific gene targeting in hamsters and can serve as the foundation for developing other genetically engineered hamster models for human disease. PMID:25299451

Fan, Zhiqiang; Li, Wei; Lee, Sang R; Meng, Qinggang; Shi, Bi; Bunch, Thomas D; White, Kenneth L; Kong, Il-Keun; Wang, Zhongde

2014-01-01

194

Lymphoma associated with an epizootic of lymphocytic choriomeningitis in Syrian hamsters (Mesocricetus auratus).  

PubMed

A hamster-associated epizootic of lymphocytic choriomeningitis (LCM) virus infection in medical center personnel at the University of Rochester in 1973 necessitated prompt termination of the Syrain hamster colony. Necropsies were performed on 130 hamsters, blood speciments were obtained from 60 for serotest, and viral isolation procedures were done on 47. Active virus infection, as shown by virus isolation, was associated with the presence of lymphoreticular infiltrate in liver and kidney. Intraabdominal lymphoma was seen only in groups of hamsters from which LCM virus was isolated, but LCM virus was not isolated from many of the hamsters with lymphoma. Although frequency of intraabdominal lymphoma could be markedly increased in LCM-positive hamsters treated with 7,12-dimethylbenz(a)anthracene, lymphoma was not induced in LCM-negative hamsters with this carcinogen. PMID:403837

Garman, R H; Bowen, G S; Fowler, E H; Kraus, A L; Newman, A I; Rifkin, B R; Andrews, E J; Winkler, W G

1977-04-01

195

The origin of yolk in the oocytes of Nereis virens (Annelida, Polychaeta)  

Microsoft Academic Search

Three different types of evidence are reported concerning the origin of yolk protein in the oocyte of the annelid Nereis virens. The fine structure of the oocyte and its different types of storage organelles are described; only few pinocytotic vesicles are found. Electron-microscopic autoradiography of oocytes incubated with 3H-leucine showed that the oocytes synthesize protein which, in part, becomes localized

Albrecht Fischer; André Dhainaut

1985-01-01

196

Birth of a healthy female after intracytoplasmic sperm injection of cryopreserved human oocytes  

Microsoft Academic Search

Objective: To describe the first birth achieved after intracytoplasmic sperm injection (ICSI) of cryopreserved human oocytes.Design: Case report.Setting: University of Bologna Hospital, Department of Obstetrics and Gynecology, Reproductive Endocrinology Unit, IVF and Infertility Center.Patient(s): One patient undergoing IVF.Intervention(s): Transvaginal ultrasound-guided oocyte retrieval followed by oocyte freezing. Artificial preparation of the endometrium with E2 and P, oocyte thawing, and ICSI.Result(s): Four

Eleonora Porcu; Raffaella Fabbri; Renato Seracchioli; Patrizia M. Ciotti; Otello Magrini; Carlo Flamigni

1997-01-01

197

Pendrin Function and Regulation in Xenopus Oocytes  

PubMed Central

SLC26A4/PDS mutations cause Pendred Syndrome and non-syndromic deafness. but some aspects of function and regulation of the SLC26A4 polypeptide gene product, pendrin, remain controversial or incompletely understood. We have therefore extended the functional analysis of wildtype and mutant pendrin in Xenopus oocytes, with studies of isotopic flux, electrophysiology, and protein localization. Pendrin mediated electroneutral, pH-insensitive, DIDS-insensitive anion exchange, with extracellular K(1/2) (in mM) of 1.9 (Cl?), 1.8 (I?), and 0.9 (Br?). The unusual phenotype of Pendred Syndrome mutation E303Q (loss-of-function with normal surface expression) prompted systematic mutagenesis at position 303. Only mutant E303K exhibited loss-of-function unrescued by forced overexpression. Mutant E303C was insensitive to charge modification by methanethiosulfonates. The corresponding mutants SLC26A2 E336Q, SLC26A3 E293Q, and SLC26A6 E298Q exhibited similar loss-of-function phenotypes, with wildtype surface expression also documented for SLC26A2 E336Q. The strong inhibition of wildtype SLC26A2, SLC26A3, and SLC26A6 by phorbol ester contrasts with its modest inhibition of pendrin. Phorbol ester inhibition of SLC26A2, SLC26A3, and SLC26A6 was blocked by coexpressed kinase-dead PKC? but was without effect on pendrin. Mutation of SLC26A2 serine residues conserved in PKC? -sensitive SLC26 proteins but absent from pendrin failed to reduce PKC? sensitivity of SLC26A2 (190). PMID:22116357

Reimold, Fabian R.; Heneghan, John F.; Stewart, Andrew K.; Zelikovic, Israel; Vandorpe, David H.; Shmukler, Boris E.; Alper, Seth L.

2011-01-01

198

Inspecting the reactor vessel penetrations  

SciTech Connect

The susceptibility of Alloy 600 to Primary Water Stress Corrosion Cracking (PWSCC) continues to plague nuclear power plants. Recently, the problem of PWSCC cracking has manifested itself in Control Rod Drive Mechanism (CRDM) head penetrations in nuclear plants in Europe. Framatome has been extensively involved in the performance of both inspections and repairs of CRDM head penetrations at Electricite de France (EdF) plants. B and W Nuclear Technologies (BWNT), building on Framatome technology, has developed a fully integrated service package and robotic manipulator to inspect and repair CRDM head penetrations for US utilities. Reactor vessel bottom penetration are also made of Alloy 600 and to tackle this potential PWSCC problem at EdF plants, Framatome has been performing specific inspections in order to detect the appearance of the phenomenon. This paper describes the overall range of inspection techniques and toolings developed to address these issues.

Bodson, F. [Framatome, Chalon-Sur-Saone (France); Fleming, K.W. [BWNT, Lynchburg, VA (United States)

1995-08-01

199

Anti-Müllerian hormone (AMH), inhibin-?, growth differentiation factor 9 (GDF9), and bone morphogenic protein-15 (BMP15) mRNA and protein are influenced by photoperiod-induced ovarian regression and recrudescence in Siberian hamster ovaries.  

PubMed

Exposure of Siberian hamsters to short photoperiod (SD) inhibits ovarian function, including folliculogenesis, whereas function is restored with their transfer to long photoperiods (LD). To investigate the mechanism of photo-stimulated recrudescence, we assessed key folliculogenic factors-anti-Müllerian hormone (AMH), inhibin-?, growth differentiation factor-9 (GDF9), and bone morphogenic protein-15 (BMP15)-across the estrus cycle and in photo-regressed and recrudescing ovaries. Adult hamsters were exposed to either LD or SD for 14 weeks, which respectively represent functional and regressed ovaries. Select regressed hamsters were transferred back to LD for 2 (post-transfer week 2; PTw2) or 8 weeks (PTw8). Ovaries were collected and fixed in formalin for immunohistochemistry or frozen in liquid nitrogen for real-time PCR. AMH, inhibin-?, GDF9, and BMP15 mRNA and protein were detected in all stages of the estrus cycle. Fourteen weeks of SD exposure increased (P?hamsters to stimulatory long photoperiod for 8 weeks returned AMH and GDF9 mRNA levels to LD-treated levels, and further increased mRNA levels for inhibin-? and BMP15. Immunostaining for AMH, inhibin-?, GDF9, and BMP15 proteins was most intense in preantral/antral follicles and oocytes. The overall immunostaining extent for AMH and inhibin-? generally mirrored the mRNA data, though no changes were observed for GDF9 or BMP15 immunostaining. Shifts in mRNA and protein levels across photoperiod conditions suggest possible syncretic roles for these folliculogenic factors in photo-stimulated recrudescence via potential regulation of follicle recruitment, preservation, and development. PMID:23877969

Shahed, Asha; Young, Kelly A

2013-11-01

200

Anti-Müllerian Hormone (AMH), Inhibin-?, Growth Differentiation Factor 9 (GDF-9), and Bone Morphogenic Protein-15 (BMP-15) mRNA and protein are influenced by photoperiod-induced ovarian regression and recrudescence in Siberian hamster ovaries  

PubMed Central

Exposure of Siberian hamsters to short photoperiod (SD) inhibits ovarian function, including folliculogenesis, whereas function is restored with transfer to long photoperiods (LD). To investigate the mechanism of photostimulated recrudescence, we assessed key folliculogenic factors: anti-Müllerian hormone (AMH), inhibin-?, growth differentiation factor-9 (GDF-9), and bone morphogenic protein-15 (BMP-15) across the estrus cycle and in photoregressed and recrudescing ovaries. Adult hamsters were exposed to either LD or SD for 14 weeks representing functional and regressed ovaries, respectively. Select regressed hamsters were transferred back to LD for two (post-transfer week 2; PTw2) or eight weeks (PTw8). Ovaries were collected and fixed in formalin for immunohistochemistry or frozen in liquid nitrogen for real-time PCR. AMH, inhibin-?, GDF-9 and BMP-15 mRNA and protein were detected in all stages of the estrus cycle. Fourteen weeks of SD exposure increased (p<0.05) ovarian AMH, GDF-9 and BMP-15, but not inhibin-? mRNA levels as compared to LD. Transfer of regressed hamsters to stimulatory long photoperiod for 8 weeks returned AMH and GDF-9 mRNA levels to LD levels levels, and further increased mRNA levels for inhibin-? and BMP-15. Immunostaining of AMH, inhibin-?, GDF-9 and BMP-15 proteins was most intense in preantral/antral follicles and oocytes. The overall immunostaining extent for AMH and inhibin-? generally mirrored mRNA data, though no changes were observed in GDF-9 or BMP-15 immunostaining extent. Shifts in mRNA and protein levels across photoperiod conditions suggest possible syncretic roles for these folliculogenic factors in photostimulated recrudescence via potential regulation of follicle recruitment, preservation and development. PMID:23877969

Shahed, Asha; Young, Kelly A.

2013-01-01

201

Cryopreservation of Mammalian Oocyte for Conservation of Animal Genetics  

PubMed Central

The preservation of the female portion of livestock genetics has become an international priority; however, in situ conservation strategies are extremely expensive. Therefore, efforts are increasingly focusing on the development of a reliable cryopreservation method for oocytes, in order to establish ova banks. Slow freezing, a common method for cryopreservation of oocytes, causes osmotic shock (solution effect) and intracellular ice crystallization leading to cell damage. Vitrification is an alternative method for cryopreservation in which cells are exposed to a higher concentration of cryoprotectants and frozen with an ultra rapid freezing velocity, resulting in an ice crystal free, solid glass-like structure. Presently, vitrification is a popular method for cryopreservation of embryos. However, vitrification of oocytes is still challenging due to their complex structure and sensitivity to chilling. PMID:20886016

Prentice, Jennifer R.; Anzar, Muhammad

2011-01-01

202

Oocyte differentiation is genetically dissociable from meiosis in mice  

PubMed Central

Oogenesis is the process by which ovarian germ cells undertake meiosis and differentiate to become eggs. In mice, Stra8 is required for the chromosomal events of meiosis to occur, but its role in differentiation remains unknown. Here we report Stra8-deficient ovarian germ cells that grow and differentiate into oocyte-like cells that synthesize zonae pellucidae, organize surrounding somatic cells into follicles, are ovulated in response to hormonal stimulation, undergo asymmetric cell division to produce a polar body, and cleave to form two-cell embryos upon fertilization. These events occur without premeiotic chromosomal replication, sister chromatid cohesion, synapsis, or recombination. Thus, oocyte growth and differentiation are genetically dissociable from the chromosomal events of meiosis. These findings open to study the independent contributions of meiosis and oocyte differentiation to the making of a functional egg. PMID:23770609

Dokshin, Gregoriy A.; Baltus, Andrew E.; Eppig, John J.; Page, David C.

2013-01-01

203

Telescience testbed experiments of intracellular recordings in the Xenopus oocyte.  

PubMed

The feasibility of intracellular recordings under constraints for experimental conditions in outer space were tested at a telescience testbed of the National Space Development Agency of Japan. We attempted to study the dose-response relationship of adenosine-induced potential changes in the Xenopus oocyte. The testbed simulated the distance from a ground control room to oocytes in an orbital laboratory; signals were delayed and compressed from one "station" to other. A microelectrode was inserted into the oocyte using remote control on the manipulator and on the xyz-planes of the platform with stereoscopic pictures observed through a head mounted display. When the transfer rate of the visual signals was decreased from 1.5 Mbps to 128 Kbps, insertion of the electrode became almost impossible because of reduced picture quality. Once the electrode was inserted, however, dose-dependent adenosine responses could be observed with little trouble. PMID:12703519

Ando, H; Watanabe, S; Mori, S; Tanaka, M; Wada, Y; Suzuki, H; Takagi, S; Nagaoka, S; Matsumoto, K; Suzuki, T; Fukai, K; Kanazawa, Y; Hirakawa, K; Ogasawara, K; Tsumura, K; Ogawa, K; Shimura, R; Ohshima, M; Yamashita, M

1994-01-01

204

Cement penetration after patella venting.  

PubMed

There is a high rate of patellofemoral complications following total knee arthroplasty. Optimization of the cement-bone interface by venting and suction of the tibial plateau has been shown to improve cement penetration. Our study was designed to investigate if venting the patella prior to cementing improved cement penetration. Ten paired cadaver patellae were allocated prior to resurfacing to be vented or non-vented. Bone mineral density (BMD) was measured by DEXA scanning. In vented specimens, a 1.6 mm Kirschner wire was used to breach the anterior cortex at the center. Specimens were resurfaced with standard Profix instrumentation and Versabond bone cement (Smith and Nephew PLC, UK). Cement penetration was assessed from Faxitron and sectioned images by a digital image software package (ImageJ V1.38, NIH, USA). Wilcoxon rank sum test was used to assess the difference in cement penetration between groups. The relationship between BMD and cement penetration was analyzed by Pearson correlation coefficient. There was a strong negative correlation between peak BMD and cement penetration when analyzed independent of experimental grouping (r(2)=-0.812, p=0.004). Wilcoxon rank sum testing demonstrated no significant difference (rank sum statistic W=27, p=0.579) in cement penetration between vented (10.53%+/-4.66; mean+/-std dev) and non-vented patellae (11.51%+/-6.23; mean+/-std dev). Venting the patella using a Kirschner wire does not have a significant effect on the amount of cement penetration achieved in vitro using Profix instrumentation and Versabond cement. PMID:19010682

Jones, Christopher W; Lam, Li-On; Butler, Adam; Wood, David J; Walsh, William R

2009-01-01

205

Maintenance of meiotic prophase arrest in vertebrate oocytes by a Gs protein-mediated pathway  

E-print Network

depends on an elevated level of cAMP in the oocyte. To investigate how the cAMP level is regulated, we-regulated generation of cAMP by the oocyte is a common mechanism for maintaining meiotic prophase arrest in vertebrate; Heterotrimeric G proteins; Zebrafish; Xenopus; Mouse Introduction Fully grown oocytes of mammals, frogs and fish

Terasaki, Mark

206

Involvement of the GTP binding protein Rho in constitutive endocytosis in Xenopus laevis oocytes  

Microsoft Academic Search

To study an endocytotic role of the GTP- binding protein RhoA in Xenopus oocytes, we have monitored changes in the surface expression of sodium pumps, the surface area of the oocyte and the uptake of the fluid-phase marker inulin. Xenopus oocytes possess intracellular sodium pumps that are continuously ex- changed for surface sodium pumps by constitutive endo- and exocytosis. Injection

Giinther Schmalzing; Hans-Peter Richter; Alexander Hansen; Wolfgang Schwarz; Ingo Just

1995-01-01

207

Route of egg yolk protein uptake in the oocytes of kuruma prawn, Penaeus japonicus  

Microsoft Academic Search

The route of egg yolk protein uptake into the oocytes of kuruma prawn, Penaeus japonicus, was studied using immunohistochemical and electron microscopical methods. Although a significant immunofluorescence with anti-vitellin-immunoglobulin was observed in the enlarged follicle cells surrounding oil globule stage oocytes of the early vitellogenic ovary, no fluorescence was detected in shrunken follicle cells surrounding oocytes in the yolk granule

I. Yano; R. M. Krol; R. M. Overstreet; W. E. Hawkins

1996-01-01

208

Dysferlin is essential for endocytosis in the sea star oocyte Nathalie Oulhen, Thomas M. Onorato 1  

E-print Network

Dysferlin is essential for endocytosis in the sea star oocyte Nathalie Oulhen, Thomas M. Onorato 1 Oocytes Endocytosis Gastrulation a b s t r a c t Dysferlin is a calcium-binding transmembrane protein leads to a decrease of endocytosis in oocytes, and to a developmental arrest during gastrulation

Wessel, Gary M.

209

Subcellular In Vivo 1 H MR Spectroscopy of Xenopus laevis Oocytes  

E-print Network

Subcellular In Vivo 1 H MR Spectroscopy of Xenopus laevis Oocytes Seung-Cheol Lee,* Jee-Hyun Cho voxel sizes of (180 mm)3 . In the large oocytes of the frog Xenopus laevis, this was small enough) microscopic imaging of a large single cell, the Xenopus laevis oocyte whose di- ameter is ;1.2 mm. Since then

Hammerton, James

210

A hyperpolarization-and acid-activated nonselective cation current in Xenopus oocytes  

E-print Network

chelator XENOPUS LAEVIS OOCYTES are one of the most widely used heterologous expression systemsA hyperpolarization- and acid-activated nonselective cation current in Xenopus oocytes AKINORI cation current in Xenopus oocytes. Am J Physiol Cell Physiol 279: C1401­C1413, 2000.--Heterologous

211

Vitrification of oocytes from endangered Mexican gray wolves ( Canis lupus baileyi)  

Microsoft Academic Search

Careful genetic management, including cryopreservation of genetic material, is central to conservation of the endangered Mexican gray wolf. We tested a technique, previously used to vitrify human and domestic animal oocytes, on oocytes from domestic dogs as a model and from the endangered Mexican wolf. This method provided a way to conserve oocytes from genetically valuable older female Mexican wolves

S. Boutelle; K. Lenahan; R. Krisher; K. L. Bauman; C. S. Asa; S. Silber

2011-01-01

212

Cyclin B synthesis is required for sea urchin oocyte maturation Ekaterina Voronina,a  

E-print Network

Cyclin B synthesis is required for sea urchin oocyte maturation Ekaterina Voronina,a William F Sea urchins are members of a limited group of animals in which meiotic maturation of oocytes for in vitro maturation of sea urchin oocytes, we analyzed the role of cyclin B, the regulatory component

Wessel, Gary M.

213

MOLECULAR REPRODUCTION AND DEVELOPMENT 60:553561 (2001) Apoptosis in Sea Urchin Oocytes, Eggs, and  

E-print Network

MOLECULAR REPRODUCTION AND DEVELOPMENT 60:553±561 (2001) Apoptosis in Sea Urchin Oocytes, Eggs of apoptosis assays in sea urchin oocytes, eggs, and early embryos experimentally induced to apoptose: apoptosis; sea urchin; oocyte; egg; staurosporine INTRODUCTION Apoptosis, or programmed cell death, plays

Wessel, Gary M.

214

Hormonal and follicular factors affecting maturation of sheep oocytes in vitro and their subsequent developmental capacity  

Microsoft Academic Search

Summary. Oocytes removed from, or retained within, non-atretic and atretic follicles of different sizes were cultured for 24 h in the presence of a variety of hormones in an attempt to identify the factors affecting oocyte maturation in vitro. Resumption of meiosis was assessed morphologically; the developmental capacity of oocytes after culture was determined by transfer to the oviducts of

R. M. Moor; A. O. Trounson

1977-01-01

215

Ongoing pregnancy after intracytoplasmic injection of testicular spermatozoa into cryopreserved human oocytes  

Microsoft Academic Search

Human oocyte cryopreservation has met with limited success in terms of both survival and subsequent fertilization. We recently reported the first birth of a healthy female infant after intracytoplasmic sperm injection of cryopreserved oocytes. The current report describes the first pregnancy achieved after intracytoplasmic injection of testicular sperm into cryopreserved human oocytes. (Am J Obstet Gynecol 1999;180:1044-5.)

Eleonora Porcu; Raffaella Fabbri; Simone Petracchi; Patrizia M. Ciotti; Carlo Flamigni

1999-01-01

216

INTRODUCTION The end-point of mammalian oocyte development is in the pro-  

E-print Network

fertile oocyte. The mouse oocyte grows from an initial diameter of 20 µm to 70 µm in size, during which be stimulated in vitro by releasing the oocyte from the follicle into a suitable culture medium (Pincus metaphase II where it arrests, awaiting fertilization. At fertilization the sperm triggers a series

Newcastle upon Tyne, University of

217

A Method for Viewing the Germinal Vesicle in Oocytes of Commercial Catfishes  

Microsoft Academic Search

Position of the germinal vesicle is a key indicator of stage of oocyte maturation, and thus it is a valuable assessment tool in studies of the reproductive biology of fishes. The germinal vesicle of untreated oocytes of commercially reared catfish species cannot be seen because oocytes of these species are opaque. However, submerging them in a bath of Serra's fixative

Joseph N. Stoeckel

2000-01-01

218

Utrastructural study of oogenesis and oocytic degeneration in Pecten maximus from the Bay of St. Brieuc  

Microsoft Academic Search

An ultrastructural study of oocytic development enabled the identification of changes occurring during oogenesis in Pecten maximus collected from the Bay of St. Brieuc, France, in 1987. “Auxiliary cells”, closely associated with developing oocytes were observed. Each oocyte seems to be associated with only one secretory cell, which is characterised by an abundant rough endoplasmic reticulum at the onset of

G. Dorange; M. Pennec

1989-01-01

219

Development of Taenia pisiformis in golden hamster (Mesocricetus auratus)  

PubMed Central

The life cycle of Taenia pisiformis includes canines as definitive hosts and rabbits as intermediate hosts. Golden hamster (Mesocricetus auratus) is a rodent that has been successfully used as experimental model of Taenia solium taeniosis. In the present study we describe the course of T. pisiformis infection in experimentally infected golden hamsters. Ten females, treated with methyl-prednisolone acetate were infected with three T. pisiformis cysticerci each one excised from one rabbit. Proglottids released in faeces and adults recovered during necropsy showed that all animals were infected. Eggs obtained from the hamsters' tapeworms, were assessed for viability using trypan blue or propidium iodide stains. Afterwards, some rabbits were inoculated with eggs, necropsy was performed after seven weeks and viable cysticerci were obtained. Our results demonstrate that the experimental model of adult Taenia pisiformis in golden hamster can replace the use of canines in order to study this parasite and to provide eggs and adult tapeworms to be used in different types of experiments. PMID:21787386

2011-01-01

220

RELATIONSHIP BETWEEN AUTONOMIC AND BEHAVIORAL THERMOREGULATION IN THE GOLDEN HAMSTER  

EPA Science Inventory

Preferred ambient temperature (Ta) of male golden hamsters (Mesocricitus auratus) was measured repeatedly by placing the animals in a temperature gradient for 80 min. A total of 180 observations were made during the last 20 min of treatment in the gradient. The mean preferred Ta ...

221

Melatonin Production Accompanies Arousal from Daily Torpor in Siberian Hamsters  

E-print Network

577 Melatonin Production Accompanies Arousal from Daily Torpor in Siberian Hamsters Jennie E of Chicago. All rights reserved. 1522-2152/2003/7604-2092$15.00 Introduction Production of melatonin (Mel is accompanied by a transient rise of melatonin (Mel) in circulation; there are no comparable analyses of Mel

Zucker, Irving

222

Mutagenicity of instant coffee on cultured Chinese hamster lung cells.  

PubMed

Coffee showed mutagenic activity in cultured Chinese hamster lung (CHL) cells as assessed by using diphtheria toxin resistance as a selective marker. Most of the mutagenicity was suppressed in the presence of sodium bisulfite. The contribution of methylglyoxal to the total mutagenicity of coffee was less than 3%. PMID:6493267

Nakasato, F; Nakayasu, M; Fujita, Y; Nagao, M; Terada, M; Sugimura, T

1984-10-01

223

Spontaneous atrial thrombosis in aged Syrian hamsters. II. Hemostasis.  

PubMed

Coagulation and fibrinolysis were studied in a colony of aged Syrian hamsters with spontaneous atrial thrombosis, and the results are consistent with concomitant consumption coagulopathy. In comparison to age- and sex-matched hamsters from the same colony, those with atrial thrombi had significantly prolonged prothrombin and partial thromboplastin times, reduced levels of factors II, VII, VIII and X activities and plasminogen; and concentrations of fibrinogen-fibrin split products in excess of 80 microgram/ml. Hematocrits of the thrombosed animals were significantly decreased, total plasma proteins were increased, leukocyte counts were within normal limits, and platelet counts were about half those of the controls. Thrombosed hamsters had significantly reduced plasma albumin content, increased alpha1-, beta-, and gamma-globulins, and reduced A/G ratios. Aged sick hamsters demonstrable thrombi also had reduced coagulation and fibrinolytic activities and platelet counts, but their fibrinogen levels were markedly elevated, and fibrinogen-fibrin split products were either absent or present in trace amounts. This suggests an earlier and/or less acute form of the thrombotic process. PMID:579488

Dodds, W J; Raymond, S L; Moynihan, A C; McMartin, D N

1977-08-31

224

Synergistic teratogenic effects of arsenic and hyperthermia in hamsters  

Microsoft Academic Search

Similar malformations of the central nervous system including encephaloceles and exencephaly are induced by treatment of pregnant hamsters with sodium arsenate or hyperthermia on the eight day of gestation. These two treatments are synergistic in that combinations of minimal teratogenic levels of each cause a marked increase in fetal resorptions and the frequency and severity of developmental malformations as compared

V. H. Ferm; L. Kilham

1977-01-01

225

EST sequencing for gene discovery in Chinese hamster ovary cells  

Microsoft Academic Search

Chinese hamster ovary (CHO) cells are one of the most important cell lines in biological research, and are the most widely used host for industrial production of recombinant therapeutic proteins. Despite their extensive applications, little sequence information is available for molecular based research. To facilitate gene discovery and genetic engineering, two cDNA libraries were con- structed from three CHO cell

Katie Fraass Wlaschin; Peter Morin Nissom; Marcela de Leon Gatti; Peh Fern Ong; Sanny Arleen; Kher Shing Tan; Anette Rink; Breana Cham; Kathy Wong; Miranda Yap; Wei-Shou Hu

2005-01-01

226

Early replication signals in nuclei of Chinese hamster ovary cells  

Microsoft Academic Search

DNA replication sites generally known as replicon domains were resolved as individual replication signals in interphase nuclei of permeabilized Chinese hamster ovary cells by immunofluorescent microscopy. Biotin-11-dUTP was utilized as a tool to label newly replicated DNA in permeable cells and to study the distribution of nascent DNA in pulselabel and in pulsechase experiments. Active sites of DNA replication were

G. Banfalvi; H. Tanke; A. K. Raap; J. Slats; M. van der Ploeg

1990-01-01

227

Pathogenesis of Sendai virus infection in the Syrian hamster.  

PubMed

Young adult male Syrian hamsters were inoculated intranasally with Sendai virus, then killed and examined at postinoculation days (PID) 3, 5, 7, 9, 12, 16, and 21. Evaluation included clinical assessment, histologic examination, immunohistochemistry, viral isolation, and antibody response. Inoculated and control hamsters remained asymptomatic throughout the study. There was a focal to segmental rhinitis involving respiratory tract epithelium lining the dorsal and ventral meatus and nasal septum, and segmental lesions involving all regions of the trachea. At PID 5 and 7, there was focal bronchitis and bronchioloalveolitis, respectively. In general, most lesions had resolved by PID 12, although in hamsters examined at PID 21, residual lesions were present in the nasal passages in one of three, and in the trachea in two of three animals. In immunoperoxidase-stained preparations, viral antigen was present in the respiratory tract epithelium of the nasal passages and trachea beginning at PID 3, with extension to scattered bronchi at PID 5. Sendai virus was recovered from the lungs of inoculated animals at PID 5. Antibodies to Sendai virus were first detected at PID 7, and titers remained high throughout the remainder of the 21-day study. This report provides additional evidence that Syrian hamsters are susceptible to Sendai virus infection, and that the lesions and sites of replication in the upper and lower portions of the respiratory tract are similar to those observed in susceptible strains of laboratory mice. PMID:9150490

Percy, D H; Palmer, D J

1997-04-01

228

CARCINOGENIC POTENTIAL OF ROTENONE. PHASE I: DIETARY ADMINISTRATION TO HAMSTERS  

EPA Science Inventory

Studies were performed to evaluate the potential carcinogenicity rotenone in the Syrian Golden hamster. Several ancillary range-finding studies were carried out including 14-day feeding trials and a reproduction experiment. The latter experiment indicated that rotenone at a level...

229

Effects of tannins on Chinese hamster cell line B14  

Microsoft Academic Search

Tannins, naturally occurring plant phenols, have been recognized as antioxidants, but toxic effects have also been observed. In the current investigation, the interaction of this type of compounds with Chinese hamster cells (cell line B14) has been examined. This study reports on the results of experiments in which B14 cells were exposed to tannins: tannic, ellagic and gallic acids in

Magdalena Labieniec; Teresa Gabryelak

2003-01-01

230

Mouse oocytes fertilised by ICSI during in vitro maturation retain the ability to be activated after refertilisation in metaphase II and can generate Ca2+ oscillations  

E-print Network

vesicle break- down (GVDB) were used for further manipulations. ICSI procedure One to four hours after GVBD oocytes were injected with spermatozoa according to the method of Kimura and Yan- agimachi [51]. A piezo-driven micropipette (MW Piezo Stepper PM 10... supplemented with PVA and in the same droplet the microinjection was performed. Several piezo pulses (speed 100 mm/s, step size 1 ?m) were given to allow zona pellucida penetration. The oolemma was per- forated with 2 – 3 piezo pulses and the spermatozoon...

Jedrusik, Agnieszka; Ajduk, Anna; Pomorski, Pawel; Maleszewski, Marek

2007-06-20

231

Self-administration of estrogen and dihydrotestosterone in male hamsters.  

PubMed

Anabolic-androgenic steroids (AAS) are drugs of abuse. Previous studies have shown that male and female hamsters self-administer testosterone (T) and other AAS, suggesting that androgens are reinforcing in a context where athletic performance is irrelevant. AAS are synthetic derivatives of T, which may be aromatizable to estrogen and/or reducible to dihydrotestosterone (DHT). However, we do not know which metabolites of T are reinforcing. To determine if DHT, estradiol (E(2)), or DHT + E(2) are reinforcing, we tested intracerebroventricular (icv) self-administration in male hamsters. The hypothesis was that androgen reinforcement is sensitive to both androgenic and estrogenic T metabolites. If so, hamsters would self-administer DHT, E(2), and DHT + E(2). Twenty four castrated male hamsters (n = 8/group) received icv cannulas and sc T implants for physiologic androgen replacement. One week later, hamsters self-administered DHT (0.1, 1.0, 2.0 microg/microl), E(2) (0.001, 0.01, 0.02 microg/microl), or DHT + E(2), each for 8 days in increasing concentration (4 h/day). Operant chambers were equipped with an active and inactive nose-poke. At the medium concentration, hamsters self-administered DHT (active nose-poke: 47.9 +/- 13.9 responses/4 h vs. inactive: 18.7 +/- 4.8), E(2) (active: 44.8 +/- 14.9 vs. inactive: 16.6 +/- 2.6), and DHT + E(2) (active: 19.1 +/- 2.4 vs. inactive: 10.4 +/- 2.4, P < 0.05). At the highest concentration, males self-administered DHT (active: 28.3 +/- 7.7 vs. inactive: 15.0 +/- 3.5, P < 0.05) and DHT + E(2) (active: 22.6 +/- 3.8 vs. inactive: 11.6 +/- 2.5, P < 0.05), but not E(2). Hamsters did not self-administer the lowest concentrations of DHT, E(2), or DHT + E(2). These results support our hypothesis that both androgenic and estrogenic T metabolites are reinforcing. Together, they do not exert synergistic effects. PMID:16388806

DiMeo, Anita N; Wood, Ruth I

2006-04-01

232

Human oocyte and ovarian tissue cryopreservation and its application  

Microsoft Academic Search

Purpose  To review the recent progress in human oocyte and ovarian tissue cryopreservation, and in the application of these two technologies\\u000a for preserving female fertility of patients who are undergoing cancer treatment.\\u000a \\u000a \\u000a \\u000a Design  The literature on human oocyte and ovarian tissue freezing was searched with PubMed. The scientific background, current developments\\u000a and potential future applications of these two methods were reviewed.\\u000a \\u000a \\u000a \\u000a Results  Chemotherapy

Tao Tao; Alfonso Del Valle

2008-01-01

233

Susceptibility of LSH hamsters to intraperitoneal inoculation with Legionella pneumophila.  

PubMed

The guinea pig is the most widely used animal model in the study of Legionellosis. The hamster should also be considered, since it acquires virtually no spontaneous epidemic lung infection, possesses similar cellular immune components observed in other mammals, has a normal body temperature identical to that of man, and is readily available for laboratory investigation. We studied the pathologic findings of four 12 week old inbred London School of Hygiene (LSH) hamsters inoculated intraperitoneally with 0.2 ml of 10(9) organisms per ml suspension of a viable Philadelphia 1 strain of Legionella pneumophila. Four LSH hamsters (control group) received 0.2 ml of sterile phosphate buffered saline, intraperitoneally. All animals of the test group became clinically ill and two of the four spontaneously expired on days 1 and 2 after inoculation. The remainder were sacrificed on day 3. In three out of four animals of the test group, a suppurative peritonitis and an interstitial pneumonitis were observed. It was characterized by infiltrates of neutrophils and macrophages. The test group also exhibited acute splenitis, including microabscesses, and two of four test animals showed hepatic congestion, vacuolization of hepatocytes, and microabscesses. None of the controls appeared sick or died after three days, and neither gross nor microscopic lesions were found at autopsy. Culture results documented L pneumophila in lung and spleen of all test animals and the absence of organisms in the control group. Hence, the LSH hamster is rapidly infected with the Philadelphia 1 strain of L pneumophila given intraperitoneally, and pathological changes can be readily observed. The findings of our study add hamsters to the list of animals susceptible to intraperitoneal infection by L pneumophila. PMID:3947031

Katz, S M; Poropatich, R

1986-01-01

234

280 effects of hot season on bovine oocyte quality: how to bypass the poor oocyte quality during this season?  

PubMed

Many authors attribute the decline of reproductive activity in summer to the heat stress, a multifactorial problem in which hyperthermia affects cellular function in various tissues of the female reproductive tract (Hansen et al. 2001; De Rensis et al. 2003). In particular, the combination of high temperatures and high humidity for a long period causes a reduced blood flow to uterus, oviducts, and ovaries, leading to a rise in the concentration of the degradation products of cellular activity. Therefore, the aim of this work was to elucidate the negative effect of the hot season on bovine oocyte quality and evaluate the influence of different factors on the acquisition of meiotic competence. In particular, meiotic competence of bovine oocytes recovered from animals housed at 44°28'00? N, 11°26'00? E during spring (March, 4-13°C) and summer (June, 16-27°C) was evaluated. Likewise, in summer the effect of an antioxidant, myo-inositol, the use of serum replacement (SR), and the use of oocytes recovered from cycling heifers (16-18 months) as compared to cows (>24 months) were tested. A total of 1346 abattoir-derived oocytes, equally divided for different experimental groups (over 6 replicates), were in vitro matured in TCM 199 supplemented with EGF (25ngmL(-1)), IGF1 (100ngmL(-1)), ITS supplement, pFSH-LH (0.1IU each), and 10% FBS. Myoinositol was added at a concentration of 0, 15, 30, and 50mM, while 10% SR was used alternatively to FBS. At the end of maturation period (20-22h), oocytes were denuded and stained with 10?gmL(-1) of Hoechst 33342 at room temperature in the dark. After 15min they were mounted on glass slides for evaluation of nuclear status using a Nikon Eclipse E400 microscope equipped with fluorescence filters. Nuclear configurations were classified as (a) germinal vesicle (GV), (b) germinal vesicle breakdown (GVBD), (c) metaphase I (M-I), (d) metaphase II (M-II), and (e) degenerated (DEG). Data are expressed as mean ± s.e.m. and were analysed by ANOVA (IBM SPSS Statistics) considering significance at P<0.05. Oocyte quality of summer oocytes was significantly lower than spring counterparts as result of a higher rate of DEG (8.2±0.6 v. 0.7±0.6) and GV (5.4±0.3 v. 0.4±0.4, respectively; P<0.05). Myo-inositol supplementation in IVM medium did not significantly affect either oocyte quality or meiotic competence in the hot season, such as the use of SR. When the oocytes were collected from cycling heifers ovaries during summer, the recovery rate of COC/ovary was significantly higher as compared to cows (4.5 v. 2.0), and a lower rate of DEG (1.8±0.2; 8.2±0.6) and GVBD (0.9±0.6; 6.1±0.3) was found (P<0.05), even if the rate of GV (22.4±0.1 v. 5.4±0.3) was higher (P<0.05) compared with cow. In conclusion, the hot season negatively affects oocyte quality, myo-inositol does not affect nuclear maturation, and SR can be used alternatively to FBS. The lower age of oocyte donor positively influenced the number of recoverable oocyte and degeneration rate. PMID:25472328

Boccia, L; Iacono, E; Rossi, B; Merlo, B

2014-12-01

235

Vitrification of oocytes from endangered Mexican gray wolves (Canis lupus baileyi).  

PubMed

Careful genetic management, including cryopreservation of genetic material, is central to conservation of the endangered Mexican gray wolf. We tested a technique, previously used to vitrify human and domestic animal oocytes, on oocytes from domestic dogs as a model and from the endangered Mexican wolf. This method provided a way to conserve oocytes from genetically valuable older female Mexican wolves as an alternative to embryos for preserving female genes. Oocytes were aspirated from ovaries of 36 female dogs in December and March (0 to 65 oocytes per female) and from six female wolves (4 to 73 per female) during their physiologic breeding season, or following stimulation with the GnRH agonist deslorelin. Oocytes from dogs were pooled; half were immediately tested for viability and the remainder vitrified, then warmed and tested for viability. All oocytes were vitrified by being moved through media of increasing cryoprotectant concentration, placed on Cryotops, and plunged into liquid nitrogen. There was no difference in viability (propidium iodide staining) between fresh and vitrified, warmed dog oocytes (65.7 and 61.0%, respectively, P = 0.27). Oocyte viability after warming was similarly assessed in a subset of wolves (4 to 15 oocytes from each of three females; total 29 oocytes). Of these, 57.1% of the post-thaw intact oocytes were viable, which was 41.4% of all oocytes warmed. These were the first oocytes from a canid or an endangered species demonstrated to have maintained viability after vitrification and warming. Furthermore, our results demonstrated that vitrification of oocytes with the Cryotop technique was an option for preserving female gametes from Mexican wolves for future use in captive breeding programs, although in vitro embryo production techniques must first be developed in canids for this technique to be used. PMID:21111469

Boutelle, S; Lenahan, K; Krisher, R; Bauman, K L; Asa, C S; Silber, S

2011-03-01

236

Winter Hibernation and UCHL1-p34cdc2 Association in Toad Oocyte Maturation Competence  

PubMed Central

Currently, it is believed that toad oocyte maturation is dependent on the physiological conditions of winter hibernation. Previous antibody-blocking experiments have demonstrated that toad ubiquitin carboxyl-terminal hydrolase L1 (tUCHL1) is necessary for germinal vesicle breakdown during toad oocyte maturation. In this paper, we first supply evidence that tUCHL1 is highly evolutionarily conserved. Then, we exclude protein availability and ubiquitin carboxyl-terminal hydrolase enzyme activity as factors in the response of oocytes to winter hibernation. In the context of MPF (maturation promoting factor) controlling oocyte maturation and to further understand the role of UCHL1 in oocyte maturation, we performed adsorption and co-immunoprecipitation experiments using toad oocyte protein extracts and determined that tUCHL1 is associated with MPF in toad oocytes. Recombinant tUCHL1 absorbed p34cdc2, a component of MPF, in obviously larger quantities from mature oocytes than from immature oocytes, and p13suc1 was isolated from tUCHL1 with a dependence on the ATP regeneration system, suggesting that still other functions may be involved in their association that require phosphorylation. In oocytes from hibernation-interrupted toads, the p34cdc2 protein level was significantly lower than in oocytes from toads in artificial hibernation, providing an explanation for the different quantities isolated by recombinant tUCHL1 pull-down and, more importantly, identifying a mechanism involved in the toad oocyte’s dependence on a low environmental temperature during winter hibernation. Therefore, in toads, tUCHL1 binds p34cdc2 and plays a role in oocyte maturation. However, neither tUCHL1 nor cyclin B1 respond to low temperatures to facilitate oocyte maturation competence during winter hibernation. PMID:24194953

Kuang, Zhichao; Yao, Yuwei; Shi, Yan; Gu, Zheng; Sun, Zhaogui; Tso, Jiake

2013-01-01

237

Increasing the cAMP concentration during in vitro maturation of pig oocytes improves cumulus maturation and subsequent fertilization in vitro.  

PubMed

Porcine IVF faces various problems such as incomplete cytoplasmic maturation of the oocyte and polyspermy. Previous studies proved the importance of cAMP in regulating nuclear and cytoplasmic maturation of oocytes. This study investigated the effect of the cAMP-modulating agents 3-isobutyl-1-methylxanthine (IBMX) and dibutyryl cAMP sodium salt (dbcAMP) on several parameters during in vitro production of porcine embryos. First, we wanted to see if oocyte collection in IBMX could meiotically arrest oocytes and, as such, improve synchronization of nuclear and cytoplasmic maturation. To this end, cumulus-oocyte complexes (COCs) were collected from gilts in HEPES-buffered Tyrode balanced salt solution medium with 0.5-mM IBMX or without IBMX. At the end of oocyte collection, the effect of IBMX on chromatin configuration was evaluated. However, no differences could be observed in nuclear configuration between IBMX- and IBMX+ oocytes (P > 0.05). Second, we added dbcAMP during IVM to improve cytoplasmic maturation and evaluated cumulus expansion (lack of adhesion), a disintegrin and metalloproteinase with thrombospondin-like repeats (ADAMTS-1) levels in cumulus cells, fertilization, and blastocyst rates. Cumulus-oocyte complexes were matured in modified North Carolina State University medium 37 with or without 1-mM dbcAMP. Frozen-thawed, epididymal, boar spermatozoa were used for IVF. After IVF, presumed zygotes were cultured for 7 days in North Carolina State University medium 23. Penetration rate decreased in dbcAMP+ (57.3%) compared with dbcAMP- (67.8%), but the polyspermy rate also decreased (43.3% vs. 53.4%, respectively) leading to an increased normal fertilization rate (56.7% vs. 46.6%, respectively; P < 0.05). Only 7.2% of the COCs showed adhesion in dbcAMP+ which was lower than 15.7% in dbcAMP- (P < 0.05) probably because of an upregulation of the ADAMTS-1 protein by dbcAMP. When the adherent oocytes were removed during maturation, no difference could be detected between the blastocyst rate of dbcAMP- and dbcAMP+ (17.1% and 21.0% on Day 7, respectively; P > 0.05). In conclusion, the use of IBMX during collection did not cause a meiotic arrest. Using dbcAMP during IVM caused a greater normal fertilization rate, a lower rate of adherent COCs during IVM, higher levels of ADAMTS-1 in cumulus cells, and an equal blastocyst rate after screening out adherent COCs. These findings contribute to a better understanding of cAMP involvement in porcine oocyte maturation and provide a basis to develop an improved system with less polyspermy and higher blastocyst rates. PMID:25442019

Appeltant, R; Beek, J; Vandenberghe, L; Maes, D; Van Soom, A

2015-02-01

238

A low-cost automated apparatus for investigating the effects of social defeat in Syrian hamsters.  

PubMed

We describe an automated apparatus that can be used to investigate the effects of defeat in hamsters. It consists of a covered alleyway that leads to a box, or arena, where hamsters can be kept separate or allowed to fight. The alleyway is divided into seven equal-sized chambers. Low-power lasers and laser detectors are used to keep track of a hamster's position in the alleyway. A CFL flood lamp placed over the chamber farthest from the arena generates a light gradient in the alleyway that engenders in the subjects a preference for the darker chambers near the arena. A computer automatically records the interruption of the laser beams and yields three measures: average position, the frequency of visits to each chamber, and the frequency of changes in direction of travel in each chamber. The results of a pilot study indicated that when a dominant hamster was placed behind a screened gate in the arena and a subordinate hamster was placed in the alleyway, the subordinate maintained a significantly greater distance from the dominant than did a nondefeated hamster. The subordinate hamster also changed its direction of travel more frequently than did the nondefeated hamster. The results suggest that conditioned fear was elicited in the defeated hamster by proximity to the dominant hamster, an effect that is consistent with published results in which the data were recorded manually or by using commercially available event-tracking software. PMID:24519494

Askew, Alicia; González, Fernando

2014-12-01

239

An immunoelectron study of karyosphere and nuclear bodies in oocytes of mealworm beetle, Tenebrio molitor (Coleoptera: Polyphaga)  

Microsoft Academic Search

The karyosphere and nuclear bodies (NBs) were studied in Tenebrio molitor oocytes using immunoelectron cytochemistry. During early diplotene (previtellogenic stage), oocyte chromosomes begin to unite in a small nuclear volume forming the karyosphere. In vitellogenic oocyte nuclei, the chromatin undergoes condensation, and the karyosphere acquires a ring-shaped structure. The karyosphere is the only structure containing DNA in the oocyte nucleus.

Dmitry Bogolyubov; Olga Alexandrova; Alexander Tsvetkov; Vladimir Parfenov

2000-01-01

240

Optimization of oxygen concentration for growing bovine oocytes in vitro: constant low and high oxygen concentrations compromise the yield of fully grown oocytes.  

PubMed

The oxygen environment in cell culture has a significant impact on the health and performance of cells. Here, we compared the effects of reduced (5%) and ambient (20%) oxygen concentrations on bovine oocyte-granulosa cell complexes, each containing a growing oocyte 90-102 µm in diameter, cultured for 14 days. Both oxygen concentrations showed some advantages and disadvantages; in 5% oxygen, the survival rate of oocytes was significantly higher than in 20% oxygen, but the resulting oocytes were significantly smaller, which was a serious disadvantage. During the first 4 days of culture, the growth and viability of oocytes were satisfactory using 5% oxygen. This observation led us to examine the effect of changing the oxygen concentration from 5% to 20% on Day 4 in order to minimize the expected disadvantages of constant 5% and 20% oxygen. The largest population of fully grown oocytes was obtained from cultures in which the oxygen concentration was changed in this way, which also led to higher oocyte viability than in constant 20% oxygen. A similar tendency was found in the frequency of oocytes becoming blastocysts after in vitro fertilization. Surviving oocytes eventually became located within an enlarged dome-like structure, and although the 5% oxygen environment may have been appropriate for oocyte growth in the early stages, 20% oxygen may have been necessary for the growth of oocytes in the dome-like structure. These results indicate an effective way of modulating oxygen concentration according to the growth of oocyte-granulosa cell complexes in vitro. PMID:22223441

Hirao, Yuji; Shimizu, Manabu; Iga, Kosuke; Takenouchi, Naoki

2012-01-01

241

Double-Plate Penetration Equations  

NASA Technical Reports Server (NTRS)

This report compares seven double-plate penetration predictor equations for accuracy and effectiveness of a shield design. Three of the seven are the Johnson Space Center original, modified, and new Cour-Palais equations. The other four are the Nysmith, Lundeberg-Stern-Bristow, Burch, and Wilkinson equations. These equations, except the Wilkinson equation, were derived from test results, with the velocities ranging up to 8 km/sec. Spreadsheet software calculated the projectile diameters for various velocities for the different equations. The results were plotted on projectile diameter versus velocity graphs for the expected orbital debris impact velocities ranging from 2 to 15 km/sec. The new Cour-Palais double-plate penetration equation was compared to the modified Cour-Palais single-plate penetration equation. Then the predictions from each of the seven double-plate penetration equations were compared to each other for a chosen shield design. Finally, these results from the equations were compared with test results performed at the NASA Marshall Space Flight Center. Because the different equations predict a wide range of projectile diameters at any given velocity, it is very difficult to choose the "right" prediction equation for shield configurations other than those exactly used in the equations' development. Although developed for various materials, the penetration equations alone cannot be relied upon to accurately predict the effectiveness of a shield without using hypervelocity impact tests to verify the design.

Hayashida, K. B.; Robinson, J. H.

2000-01-01

242

Penetration Experiments under Reduced Gravity  

NASA Astrophysics Data System (ADS)

Penetration experiments will find several applications in exploration missions in the near future. Penetrators are common tools for the investigation of physical surface properties. The techniques and theories are widely applied under 1g condition on Earth and the results are used by engineers and scientists. The main contribution to the bearing resistance of a soil is combined of shaft and base resistance [1]. The theories show, that the resistance scales with gravity. Penetration experiments during a parabolic flight campaign have been performed for evaluating this gravity scaling of the bearing resistance in different materials during a parabolic flight campaign in December 2012. The main part of the experiment is composed of a steel rod penetrating into a sample cell. Depth and penetration force are recorded during this process. A sieving mechanism provided the ability of sample preparation during flight. Different compaction regimes of the sample material could be created with a ruttler mounted underneath the sample cell. The parabolic flight campaign consisted of 4 flight days. On each day 13 parabolas with Martian gravity, 12 parabolas with lunar gravity and 6 microgravity parabolas could be performed. Three different sample materials have been examined within the 4 flight days: glass spheres, glass corn and Mojawe sand. The glass spheres and glass corn samples were made of the same material, but with different shape. The Mojawe sand is a natural soil from the Mojawe desert in California (US). The experimental description and the first results will be presented.

Krause, C.; Gehlen, M.; Jaquemet, A.; Heller, S.; Sperl, M.; Willnecker, R.

2013-09-01

243

Thioredoxin-Interacting Protein Regulates Glucose Metabolism and Affects Cytoplasmic Streaming in Mouse Oocytes  

PubMed Central

Thioredoxin-interacting protein (Txnip) regulates intracellular redox state and prompts oxidative stress by binding to and inhibiting Thioredoxin (Trx). In addition, via a Trx-independent mechanism, Txnip regulates glucose metabolism and thus maintains intracellular glucose levels. Previously, we found Txnip mRNA highly expressed in immature germinal vesicle (GV) oocytes, but currently there is no report describing the role of Txnip in oocytes. Therefore, we conducted the present study to determine the function of Txnip in mouse oocytes' maturation and meiosis by using RNA interference (RNAi) method. Upon specific depletion of Txnip, 79.5% of oocytes were arrested at metaphase I (MI) stage. Time-lapse video microscopy analysis revealed that the formation of granules in the oocyte cytoplasm increased concurrent with retarded cytoplasmic streaming after Txnip RNAi treatment. Txnip RNAi-treated oocytes had upregulated glucose uptake and lactate production. To confirm the supposition that mechanism responsible for these observed phenomena involves increased lactate in oocytes, we cultured oocytes in high lactate medium and observed the same increased granule formation and retarded cytoplasmic streaming as found by Txnip RNAi. The MI-arrested oocytes exhibited scattered microtubules and aggregated chromosomes indicating that actin networking was disturbed by Txnip RNAi. Therefore, we conclude that Txnip is a critical regulator of glucose metabolism in oocytes and is involved in maintaining cytoplasmic streaming in mouse oocytes. PMID:23976953

Lee, Su-Yeon; Lee, Hyun-Seo; Kim, Eun-Young; Ko, Jung-Jae; Yoon, Tae Ki; Lee, Woo-Sik; Lee, Kyung-Ah

2013-01-01

244

Gene Expression Profiling of Human Oocytes Developed and Matured In Vivo or In Vitro  

PubMed Central

The quality of the human oocyte determines the success of fertilization and affects the consequent embryo development, pregnancy and birth; it therefore serves as a basis for human reproduction and fertility. The possibility to evaluate oocyte quality in the in vitro fertilization programme is very limited. The only criterion which is commonly used to evaluate oocyte quality is its morphology. There is a mass of oocytes in the in vitro fertilization programme which are not fertilized in spite of normal morphology. In the past, several attempts focused on oocyte gene expression profiling by different approaches. The results elucidated groups of genes related to the human oocyte. It was confirmed that some factors, such as oocyte in vitro maturation, are detectable at the molecular level of human oocytes and their polar bodies in terms of gene expression profile. Furthermore, the first genetic evaluations of oocyte-like cells developed in vitro from human stem cells of different origin were performed showing that these cells express some genes related to oocytes. All these findings provide some new knowledge and clearer insights into oocyte quality and oogenesis that might be introduced into clinical practice in the future. PMID:23509795

Virant-Klun, Irma; Knez, Katja; Tomazevic, Tomaz; Skutella, Thomas

2013-01-01

245

Effects of Postmortem Interval on Mouse Ovary Oocyte Survival and Maturation  

PubMed Central

To study the time- and temperature-dependent survival of ovarian oocytes collected from postmortem carcass, ICR mice were killed and placed for different periods (0, 1, 2, 4, 6, 8 and 10 h) at different temperatures (25°C, 4°C and 37°C). After preservation, oocyte morphology, germinal vesicle (GV) oocyte number, oocyte meiotic maturation percentage, mitochondrial distribution and intracellular glutathione (GSH) level were evaluated. The results showed no surviving oocytes could be collected by 2h, 6h, and 12 h after carcass preservation at 37°C, 25°C and 4°C, respectively. The number of collected GV oocytes in the ovary deceased as the preservation time lasted at the same temperature. Meanwhile at the same point in time, the ratio of germinal vesicle breakdown (GVBD) and the first polar body emission (PBE) gradually reduced as preservation temperature increased. In addition, the percentage of abnormal mitochondrial distribution in the preserved oocytes was obviously higher than that in the control oocytes, while GSH level was not altered in collected oocytes. Unexpectedly, neither chromosome arrangement nor spindle organization was affected as long as the oocytes from preserved carcasses could complete maturation. These data are helpful for proper use of ovary oocytes from postmortem carcass of valuable individuals. PMID:24874949

Zhang, Guang-Li; Ma, Jun-Yu; Sun, Quan; Hu, Meng-Wen; Yang, Xiu-yan; Gao, Si-Hua; Jiang, Guang-Jian

2014-01-01

246

The activity and copy number of mitochondrial DNA in ovine oocytes throughout oogenesis in vivo and during oocyte maturation in vitro  

PubMed Central

Mitochondria are responsible for the production of ATP, which drives cellular metabolic and biosynthetic processes. This is the first study to quantify the mtDNA copy number across all stages of oogenesis in a large monovulatory species, it includes assessment of the activity of mitochondria in germinal vesicle (GV) and metaphase II (MII) oocytes through JC1 staining. Primordial to early antral follicles (n = 249) were isolated from the sheep ovarian cortex following digestion at 37°C for 1 h and all oocytes were disaggregated from their somatic cells. Germinal vesicle oocytes (n = 133) were aspirated from 3- to 5-mm diameter antral follicles, and mature MII oocytes (n = 71) were generated following in vitro maturation (IVM). The mtDNA copy number in each oocyte was quantified using real-time PCR and showed a progressive, but variable increase in the amount of mtDNA in oocytes from primordial follicles (605 ± 205, n = 8) to mature MII oocytes (744 633 ± 115 799, n = 13; P < 0.05). Mitochondrial activity (P > 0.05) was not altered during meiotic progression from GV to MII during IVM. The observed increase in the mtDNA copy number across oogenesis reflects the changing ATP demands needed to orchestrate cytoskeletal and cytoplasmic reorganization during oocyte growth and maturation and the need to fuel the resumption of meiosis in mature oocytes following the pre-ovulatory gonadotrophin surge. PMID:23468533

Cotterill, Matthew; Harris, Sarah E.; Collado Fernandez, Esther; Lu, Jianping; Huntriss, John D.; Campbell, Bruce K.; Picton, Helen M.

2013-01-01

247

Granulosa cell-oocyte interactions: the phosphorylation of specific proteins in mouse oocytes at the germinal vesicle stage is dependent upon the differentiative state of companion somatic cells  

SciTech Connect

The role of granulosa cells in the regulation of mouse ovarian oocyte metabolism was investigated. Fully grown antral oocytes, isolated from surrounding cumulus cells, were cultured on monolayers of preantral granulosa cells in the presence of dbcAMP to prevent the resumption of meiosis. Under these conditions metabolic cooperativity was established between the two cell types as early as 1 hr after seeding. Moreover, cocultured oocytes phosphorylated two polypeptides of 74 and 21 kDa which are normally phosphorylated in follicle-enclosed growing oocytes but not in cumulus cell-enclosed fully grown oocytes at the germinal vesicle stage. When cocultured oocytes were allowed to resume meiosis, the 74 and 21 kDa proteins were synthesized but no longer phosphorylated even though intercellular coupling between the two cell types was maintained during radiolabeling. It appears therefore: (a) that the different protein kinase activity of growing and fully grown germinal vesicle-stage mouse oocytes is related to the differentiative state of granulosa cells, and (b) that the regulation of oocyte protein phosphorylation activity by granulosa cells is dependent on the meiotic stage of the oocyte.

Cecconi, S.; Tatone, C.; Buccione, R.; Mangia, F.; Colonna, R. (Universita dell'Aquila, (Italy))

1991-05-01

248

Morphologic observations of experimental Campylobacter jejuni infection in the hamster intestinal tract.  

PubMed Central

The authors have developed a model for the diarrhea and intestinal lesions seen in Campylobacter jejuni enterocolitis by colonizing the hamster ileum and cecum with C jejuni. Erythematous inflammation of the ileum and cecum and distention of the cecum with fluid were observed at autopsy. The cecal mucosa appeared edematous. Epithelial abnormalities observed by light microscopy included focal edema, occasional hyperplasia, diffuse hyperemia, and infiltration of the lamina propria with leukocytes. C jejuni-like bacteria penetrated the epithelium and were seen in the lamina propria of infected animals but not in uninfected controls. Diverse microvillus lesions, including elongation, shortening, blebbing, and denudation, were seen by transmission electron microscopy. Occasional cytoplasmic aberrations included vacuoles, some containing C jejuni-like bacteria, swollen endoplasmic reticulum, and enlarged mitochondria. Campylobacter structures were vibrio and S-shaped types. Some C jejuni organisms had corrugated screwlike structures wrapped around their circumferences. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 PMID:3942198

Humphrey, C. D.; Montag, D. M.; Pittman, F. E.

1986-01-01

249

Full-grown oocytes from Xenopus laevis resume growth when placed in culture  

SciTech Connect

When most full-grown, follicle cell-invested oocytes from Xenopus laevis are placed in an appropriate culture medium, they resume growth and remain physiologically healthy for at least 2 to 3 weeks. Rates of growth by full-grown oocytes in vitro generally approximate and can even exceed the most rapid growth rate achieved by vitellogenic oocytes in vivo. Resumption of oocyte growth can be correlated with the loss of investing follicle cells, which under normal conditions appear to interfere with vitellogenin and nutrient access to the oocyte. The final size reached by the oocyte within the ovary is thus not an intrinsic property of the oocyte but is extrinsically imposed by the somatic environment.

Wallace, R.A.; Misulovin, Z.; Etkin, L.D.

1981-05-01

250

Hematoxylin Staining Reveals a Decrease in Nucleolar Diameter of Pig Oocytes Before Germinal Vesicle Breakdown  

PubMed Central

During oocyte growth, the morphology of the nucleolus changes into a compact and homogenous structure. The compact nucleoli in full-grown oocytes are not stained by aceto-orcein staining or immunofluorescence staining. In this study, we developed a hematoxylin staining method for pig oocytes in whole-mount preparations to visualize the nucleoli. Nucleoli of growing and full-grown oocytes were stained blue with hematoxylin. Using this staining method, the changes in the oocyte nucleolus during maturation were examined. The nucleolar diameter gradually decreased in maturing oocytes (10.7 ± 0.1 ?m to 9.0 ± 0.7 ?m, P<0.05) before germinal vesicle breakdown (GVBD). The results suggest that the nucleolar volume of oocytes decreases before GVBD. PMID:23856597

Nobata, Tadatoshi; Kyougoku, Hirohisa; Miyano, Takashi

2013-01-01

251

Is a decrease in cyclic AMP a necessary and sufficient signal for maturation of amphibian oocytes  

SciTech Connect

Acetylcholine rapidly lowered the intracellular levels of cyclic AMP in stage 5 and 6 Xenopus laevis oocytes. Acetylcholine alone did not induce oocyte maturation, though it did accelerate maturation induced by progesterone. The effect of acetylcholine on oocyte maturation was independent of extracellular calcium concentration. Adenosine increased cyclic AMP and abolished the progesterone-induced decrease in cyclic AMP levels in follicles and in denuded oocytes. This effect of adenosine was blocked by the Ra purinergic receptor antagonist, theophylline. Despite those effects, adenosine alone induced maturation in stage 6 oocytes and accelerated progesterone-induced maturation in both stage 5 and 6 cells. Adenosine also induced a significant increase in the rate of /sup 45/Ca efflux from oocytes in the presence and the absence of external calcium. We suggest that the activation of cell surface receptors involved in the release of calcium from cellular stores may induce or accelerate oocyte maturation independently of small changes in intracellular cyclic AMP concentration.

Gelerstein, S.; Shapira, H.; Dascal, N.; Yekuel, R.; Oron, Y.

1988-05-01

252

Attempted in vitro maturation and fertilization of postmortem Sumatran rhinoceros (Dicerorhinus sumatrensis) oocytes.  

PubMed

A study was conducted opportunistically to evaluate the potential of rescuing immature oocytes from the ovaries of the Sumatran rhinoceros postmortem. Recovered oocytes (n = 30) were placed in maturation culture for 36 hr and inseminated with frozen-thawed homologous spermatozoa. After culture, evaluation of nuclear maturation status revealed that a large number of oocytes were degenerated (n = 21), but nine oocytes were assessed at the germinal vesicle (n = 3), metaphase I (n = 3), and metaphase II (n = 3) stages. Frozen-thawed Sumatran rhinoceros spermatozoa were capable of binding to the zona pellucida of in vitro matured oocytes, but no fertilization or cleavage resulted. In conclusion, relatively large numbers of oocytes can be obtained by ovarian follicular aspiration postmortem in the Sumatran rhinoceros, and some of these oocytes are capable of achieving nuclear maturation in vitro. However, additional studies are required to improve maturation success and achieve fertilization in culture. PMID:22204070

Stoops, Monica A; Bateman, Helen L; Campbell, Mark K; Roth, Terri L

2011-12-01

253

Role of animal pole protuberance and microtubules during meiosis in sea cucumber Apostichopus japonicus oocytes  

NASA Astrophysics Data System (ADS)

Fully grown oocytes of Apostichopus japonicus have a cytoplasmic protuberance where the oocyte attaches to the follicle. The protuberance and the oolamina located on the opposite side of the oocyte indicate the animal-vegetal axis. Two pre-meiotic centrosomes are anchored to the protuberance by microtubules between centrosomes and protuberance. After meiosis reinitiation induced by DTT solution, the germinal vesicle (GV) migrates towards the protuberance. The GV breaks down after it migrates to the oocyte membrane on the protuberance side. The protuberance then contracts back into the oocyte and the first polar body extrudes from the site of the former protuberance. The second polar body forms beneath the first. Thus the oocyte protuberance indicates the presumptive animal pole well before maturation of the oocyte.

Pang, Zhenguo; Chang, Yaqing; Sun, Huiling; Yu, Jiaping

2010-05-01

254

The portrayal of healthy women requesting oocyte cryo-preservation.  

PubMed

The possibility to cryopreserve oocytes to be used in IVF treatment later in life has not only enlarged the reproductive options of cancer patients who are faced with gonadotoxic treatments, but also holds the promise of enlarging the reproductive options of healthy women whose personal circumstances (most often the absence of a partner) do not allow them to reproduce in their most fertile years. Opinions for and against this application of the cryopreservation technology are often based on different portrayals of the women who might use it. Three different portrayals can be discerned in the debate about the ethics of so-called 'social egg freezing' or 'non medical egg freezing'. First, these women have been portrayed as selfish career-pursuing women. Second, healthy women who might benefit from oocyte cryopreservation have been portrayed as victims of a male-oriented society that makes it difficult for women to combine motherhood with a good education or professional responsibilities. Third, healthy women -opting to cryopreserve oocytes have been portrayed as wise, proactive women who will not have to depend on -oocyte donors should they suffer from age-related infertility by the time they are ready to reproduce. Each of these three portrayals has its own shortcomings that one should be wary of, as they lead to an oversimplification of the ethical debate. PMID:24753939

Mertes, H

2013-01-01

255

Spiral Calcium Wave Propagation and Annihilation in Xenopus laevis Oocytes  

Microsoft Academic Search

Intracellular calcium (Ca2+) is a ubiquitous second messenger. Information is encoded in the magnitude, frequency, and spatial organization of changes in the concentration of cytosolic free Ca2+. Regenerative spiral waves of release of free Ca2+ were observed by confocal microscopy in Xenopus laevis oocytes expressing muscarinic acetylcholine receptor subtypes. This pattern of Ca2+ activity is characteristic of an intracellular milieu

James Lechleiter; Steven Girard; Ernest Peralta; David Clapham

1991-01-01

256

Aurelia aurita (Cnidaria) Oocytes' Contact Plate Structure and Development  

PubMed Central

One of the A. aurita medusa main mesoglea polypeptides, mesoglein, has been described previously. Mesoglein belongs to ZP-domain protein family and therefore we focused on A.aurita oogenesis. Antibodies against mesoglein (AB RA47) stain the plate in the place where germinal epithelium contacts oocyte on the paraffin sections. According to its position, we named the structure found the “contact plate”. Our main instrument was AB against mesoglein. ZP-domain occupies about half of the whole amino acid sequence of the mesoglein. Immunoblot after SDS-PAGE and AU-PAGE reveals two charged and high Mr bands among the female gonad germinal epithelium polypeptides. One of the gonads' polypeptides Mr corresponds to that of mesogleal cells, the other ones' Mr is higher. The morphological description of contact plate formation is the subject of the current work. Two types of AB RA47 positive granules were observed during progressive oogenesis stages. Granules form the contact plate in mature oocyte. Contact plate of A.aurita oocyte marks its animal pole and resembles Zona Pellucida by the following features: (1) it attracts spermatozoids; (2) the material of the contact plate is synthesized by oocyte and stored in granules; (3) these granules and the contact plate itself contain ZP domain protein(s); (4) contact plate is an extracellular structure made up of fiber bundles similar to those of conventional Zona Pellucida. PMID:23185235

Adonin, Leonid S.; Shaposhnikova, Tatyana G.; Podgornaya, Olga

2012-01-01

257

Epigenetic reprogramming of breast cancer cells with oocyte extracts  

Microsoft Academic Search

BACKGROUND: Breast cancer is a disease characterised by both genetic and epigenetic alterations. Epigenetic silencing of tumour suppressor genes is an early event in breast carcinogenesis and reversion of gene silencing by epigenetic reprogramming can provide clues to the mechanisms responsible for tumour initiation and progression. In this study we apply the reprogramming capacity of oocytes to cancer cells in

Cinzia Allegrucci; Michael D Rushton; James E Dixon; Virginie Sottile; Mansi Shah; Rajendra Kumari; Sue Watson; Ramiro Alberio; Andrew D Johnson

2011-01-01

258

Trichlorfon effects on mouse oocytes following in vivo exposure  

Microsoft Academic Search

Trichlorfon (TCF) is a widely used pesticide, which according to some epidemiological and experimental data, is suspected of being aneugenic in human and mouse cells. In particular, in vitro studies in mouse oocytes showed the induction of aneuploidy and polyploidy at the first meiotic division and of severe morphological alterations of the second meiotic spindle. We have tested the hypothesis

Roberto Ranaldi; Gloria Gambuti; Ursula Eichenlaub-Ritter; Francesca Pacchierotti

2008-01-01

259

Molecular Phenotype of the Human Oocyte by PCR–SAGE  

Microsoft Academic Search

Consecutive application of PCR and serial analysis of gene expression (SAGE) was used to generate a catalog of ?50,000 SAGEtags from nine human oocytes. Matches for known genes were identified using the National Institutes of Health SAGEtag database. This database links directly to the UniGene database, providing rapid discrimination between SAGEtags that match known genes and expressed sequence tags and

Lorna Neilson; Ali Andalibi; Douglas Kang; Christos Coutifaris; Jerome F Strauss; Jo-Ann L Stanton; David P. L Green

2000-01-01

260

Effects of freezing and thawing on mammalian oocyte.  

PubMed

In an attempt to study the deleterious effects which occur during the freezing and thawing of mammalian oocytes, we developed a cryomicroscope controlled by digital programmable equipment. The program permits any cooling rate between 0.1 and 60 degrees C/min with a precision of 0.6 degrees C. Using a precooled stage, it is possible to obtain rapid cooling (100 degrees C/min). The maximum thawing rate is about 60 degrees C/min. A copper-- constantan microthermocouple allows precise measurement of the specimen temperature. All information (specimen, temperature of the specimen, date, hour, and minutes) is recorded at the same time on photographic film by a camera fitted with a " Recordata Back" and a motor drive which allows three frames per second. Our preliminary results show that: (1) rapid cooling yields a supercooling with simultaneous extra- and intracellular crystallization; (2) slow cooling with seeding at -8 degrees C gives an extracellular crystallization which is achieved by -9 degrees C, followed by an extracellular recrystallization occurring at almost -8 degrees C which alters the morphology of the oocyte and the zona pellucida, without any visible intracellular crystallization; (3) during continued slow cooling the oocytes dehydrate without any intracellular freezing; and (4) during rewarming a partial rehydration of the cell occurs with a swelling of the oocytes to their original volumes after the thawing has been achieved. PMID:6538826

Jondet, M; Dominique, S; Scholler, R

1984-04-01

261

Establishment of animalvegetal polarity during maturation in ascidian oocytes  

E-print Network

/PEM RNAs move into the oocyte periphery at the end of oogenesis and that polarization along the a­v axis reserved. Keywords: Oogenesis; GVBD; Meiosis; Polarization; Cortical RNAs; Cortex; Ciona Introduction early during oogenesis (Huynh and St Johnston, 2004), while in the worm C. elegans polarization is only

Sardet, Christian

262

Protein tyrosine phosphorylation during meiotic divisions of starfish oocytes  

SciTech Connect

We have used an antibody specific for phosphotyrosine to investigate protein phosphorylation on tyrosine during hormone-induced maturation of starfish oocytes. Analysis of immunoprecipitates from cortices of in vivo labeled Marthasterias glacialis oocytes revealed the presence of labeled phosphotyrosine-containing proteins only after hormone addition. Six major phosphoproteins of 195, 155, 100, 85, 45, and 35 kDa were detected. Total activity in immunoprecipitates increased until first polar body emission and was greatly reduced upon completion of meiosis but some proteins exhibited different kinetics. The labeling of the 155-kDa protein reached a maximum at germinal vesicle breakdown, while the 35-kDa appeared later and disappeared after polar body emission. Similar results were obtained with Asterias rubens oocytes. In vitro phosphorylation of cortices showed that tyrosine kinase activity is a major protein kinase activity in this fraction, the main endogenous substrate being a 68-kDa protein. The proteins phosphorylated on tyrosine in vitro were almost similar in extracts from oocytes treated or not with the hormone.

Peaucellier, G.; Andersen, A.C.; Kinsey, W.H. (Univ. of Miami School of Medicine, FL (USA))

1990-04-01

263

Cytoplasmic flows localize injected oskar RNA in Drosophila oocytes  

Microsoft Academic Search

Background: The oskar (osk) gene encodes a determinant of posterior identity in Drosophila, and the localization of osk RNA to the pole plasm at the posterior pole of the oocyte is essential for development of the embryo. The mechanisms by which osk RNA is localized are unknown.Results: To study the mechanisms underlying localization of osk RNA, we have injected fluorescently

Jolanta B. Glotzer; Rainer Saffrich; Michael Glotzer; Anne Ephrussi

1997-01-01

264

HORMAD1-dependent checkpoint/surveillance mechanism eliminates asynaptic oocytes.  

PubMed

Meiotic pachytene checkpoints monitor the failure of homologous recombination and synapsis to ensure faithful chromosome segregation during gamete formation. To date, the molecular basis of the mammalian pachytene checkpoints has remained largely unknown. We here report that mouse HORMAD1 is required for a meiotic prophase checkpoint that eliminates asynaptic oocytes. Hormad1-deficient mice are infertile and show an extensive failure of homologous pairing and synapsis, consistent with the evolutionarily conserved function of meiotic HORMA domain proteins. Unexpectedly, Hormad1-deficient ovaries contain a normal number of oocytes despite asynapsis and consequently produce aneuploid oocytes, indicating a checkpoint failure. By the analysis of Hormad1/Spo11 double mutants, the Hormad1 deficiency was found to abrogate the massive oocyte loss in the Spo11-deficient ovary. The Hormad1 deficiency also causes the eventual loss of pseudo sex body in the Spo11-deficient ovary and testis. These results suggest the involvement of HORMAD1 in the repressive chromatin domain formation that is proposed to be important in the meiotic prophase checkpoints. We also show the extensive phosphorylation of HORMAD1 in the Spo11-deficient testis and ovary, suggesting an involvement of novel DNA damage-independent phosphorylation signaling in the surveillance mechanism. Our present results provide clues to HORMAD1-dependent checkpoint in response to asynapsis in mammalian meiosis. PMID:22530760

Kogo, Hiroshi; Tsutsumi, Makiko; Ohye, Tamae; Inagaki, Hidehito; Abe, Takaya; Kurahashi, Hiroki

2012-06-01

265

Oocyte cryopreservation: time to come in out of the cold…  

Microsoft Academic Search

Sperm cryopreservation as a means of preserving the fertility potential of men has existed for over 50 years, but oocytes (eggs) are such large, delicate structures (imagine a fluid-filled bubble the size of a pin point) that until recently there was little we could offer young women facing a choice between the chemotherapy that could save their lives and the

Gillian Lockwood

2006-01-01

266

Lunar regolith penetrators and cutters  

NASA Technical Reports Server (NTRS)

An apparatus was designed and built for conducting simulation experiments on cutting tool penetration in the centrifuge. This equipment is mounted on the laminar container which is used for the regolith densification study, so that the end product of the latter, i.e., a regolith bed with the proper density profile, can be used directly for the penetration tests. In this apparatus, an etching tool is suspended through a pulley system by the action of a double acting air cylinder. By adjusting the air pressure acting on each side of the cylinder, the net downward force acting on the tool can be controlled. The penetration of the tool is measured by an LVDT. This apparatus was proof-tested in the centrifuge and is ready for use in conjunction with the regolith densification experiments.

Barnes, Frank; Sture, Stein

1991-01-01

267

RNA transport to the vegetal cortex of Xenopus oocytes.  

PubMed

Xcat-2 RNA, a component of the germ plasm in Xenopus, localizes with the mitochondrial cloud material to the vegetal cortex in stage II oocytes. Vg1 RNA also localizes to the vegetal cortex, but later in stage III/IV oocytes, using a microtubule dependent pathway. To further analyze the mechanisms involved in RNA transport, in situ hybridization and autoradiography were used to follow the localization of endogenous Vg1 and injected Xcat-2 transcripts in stage IV oocytes. We show that Xcat-2 is competent to localize to the vegetal cortex quite independently of the mitochondrial cloud. Xcat-2 RNA appears to use the late Vg1 localization pathway, as depolymerization of microtubules by cold or nocodazole treatment prevented translocation of Xcat-2 transcripts, but did not result in the disruption of Xcat-2 anchored in the cortex. Furthermore, RNA transport was shown to be stage dependent for both Vg1 and Xcat-2 RNAs, as they did not localize in fully grown stage VI oocytes after injection. RNA sequences both required and sufficient to direct Xcat-2 to the vegetal cortex were mapped to a sequence of 150 nt immediately adjacent to the open reading frame and additional sequences at the end of the 3' untranslated region. Mapping was accomplished by injecting deletion mutant transcripts into stage IV oocytes and monitoring localization by RNase protection and autoradiography. All mutants competent for translocation were also capable of cortical anchoring, suggesting that the same signal is used for both steps. We speculate that two separate RNA pathways evolved during the course of Xenopus oogenesis. One pathway, specialized for the transport of germ plasm by way of the mitochondrial cloud, occurs early to ensure the segregation of the germ cell lineage. The other, late, pathway may serve as the more general transport system for localizing RNAs involved in somatic cell differentiation. PMID:8873762

Zhou, Y; King, M L

1996-10-10

268

[Penetrating transorbital intracranial foreign body].  

PubMed

We report a seven year-old boy who suffered left orbital penetration of an industrial sewing machine needle. The needle passing through the left orbit and sphenoid bone at the posterior was extending into the layers of the dura of the left temporal lobe. In this patient, we preferred surgical approach and there was no complication after surgery. Penetrating intraorbital foreign materials with intracranial extension may lead to complications such as intracerebral hematoma, brain abscess, CSF fistula, proptosis of the eye, diplopia, orbital cellulitis and periorbital abscess. They have to be removed by surgical approach to prevent potential complications. PMID:16850365

Civelek, Erdinç; Bilgiç, Salih; Kabata?, Serdar; Hepgül, Kemal Tanju

2006-07-01

269

Mars surface penetrator: System description  

NASA Technical Reports Server (NTRS)

A point design of a penetrator system for a Mars mission is described. A strawman payload which is to conduct measurements of geophysical and meteorological parameters is included in the design. The subsystems used in the point design are delineated in terms of power, mass, volume, data, and functional modes. The prospects for survival of the rigors of emplacement are described. Data handling and communications plans are presented to allow consideration of the requirements placed by the penetrator on the orbiter and ground operations. The point design is technically feasible and the payload selection scientifically desirable.

Manning, L. A. (editor)

1977-01-01

270

An ideal oocyte activation protocol and embryo culture conditions for somatic cell nuclear transfer using sheep oocytes.  

PubMed

Pluripotent stem cells are possibly the best candidates for regenerative medicine, and somatic cell nuclear transfer (SCNT) is one of the viable options to make patient-specific embryonic stem cells. Till date efficacy of SCNT embryos is very low and requires further improvement like ideal oocyte activation and in vitro culture system. The aim of the present study was to evaluate ideal oocyte activation using different stimulation protocols and to study the effect of cumulus co-culture conditions on embryo development. Results demonstrate that between electric stimulation and chemical stimulation using calcium ionomycin and ionophore, best oocyte activation was obtained using calcium ionomycin (5 microM for 5 min) which resulted in 83% cleavage followed by 7% of early blastocyst which further increased to 15% when a cumulus bed was also introduced during embryo culture. Sequential modified Charles Rosenkrans 2 (mCR2) medium was used for embryo culture in which glucose levels were increased from 1 mM to 5 mM from Day 3 onwards. SCNT using cumulus cells as donor somatic cell, calcium ionomycin to activate the reconstructed oocyte and embryo culture on a cumulus bed in sequential mCR2 medium, resulted in the development of 6% embryos to early blastocyst stage. Such technological advances will make SCNT a viable option to make patient-specific pluripotent stem cell lines in near future. PMID:25345241

Patel, Hiren; Chougule, Shruti; Chohan, Parul; Shah, Naval; Bhartiya, Deepa

2014-10-01

271

Perioperative and post-operative complications of transvaginal ultrasound-guided oocyte retrieval: prospective study of >1000 oocyte retrievals  

Microsoft Academic Search

BACKGROUND: Although transvaginal ultrasound-guided oocyte retrievals (OR) are performed routinely world- wide, there is very little systematic data about its complications. METHODS: We performed a prospective cohort study following the perioperative and post-operative complications of over 1058 ORs. Additionally, we assessed the pain experienced during the OR. RESULTS: A total of 1166 OR were performed during the study period, of

A. K. Ludwig; M. Glawatz; G. Griesinger; K. Diedrich; M. Ludwig

2006-01-01

272

Effect of Hyaluronan on Developmental Competence and Quality of Oocytes and Obtained Blastocysts from In Vitro Maturation of Bovine Oocytes  

PubMed Central

The objective of the present study was to evaluate the effect of hyaluronan (HA) during IVM on meiotic maturation, embryonic development, and the quality of oocytes, granulosa cells (GC), and obtained blastocysts. COCs were matured in vitro in control medium and medium with additional 0.035% or 0.07% of exogenous HA. The meiotic maturity did not differ between the analysed groups. The best rate and the highest quality of obtained blastocysts were observed when 0.07% HA was used. A highly significant difference (P < 0.001) was noted in the mean number of apoptotic nuclei per blastocyst and in the DCI between the 0.07% HA and the control blastocysts (P < 0.01). Our results suggest that addition of 0.035% HA and 0.07% HA to oocyte maturation media does not affect oocyte nuclear maturation and DNA fragmentation. However, the addition of 0.07% HA during IVM decreases the level of blastocysts DNA fragmentation. Finally, our results suggest that it may be risky to increase the HA concentration during IVM above 0.07% as we found significantly higher Bax mRNA expression levels in GC cultured with 0.07% HA. The final concentration of HA being supplemented to oocyte maturation media is critical for the success of the IVP procedure. PMID:24689043

Opiela, Jolanta; Romanek, Joanna; Lipi?ski, Daniel; Smor?g, Zdzis?aw

2014-01-01

273

Evaluation of oocyte competency in bovine and canine species via non-invasive assessment of oocyte quality  

E-print Network

between oocyte morphological parameters (as defined by a ratio of a shape factor (SF) to average fluorescence intensity (AFI) and AFI, followed by in vitro fertilization (IVF) and in vitro culture (IVC) using the Well of Well (WOW) method to evaluate...

Willingham-Rocky, Lauri A.

2009-05-15

274

Lifespan carcinogenicity tests with native carrageenan in rats and hamsters.  

PubMed

Native carrageenan (Gelcarin), a widely used food additive, was tested for carcinogenicity in MRC rats and Syrian golden hamsters through lifespan studies. Three groups of 30 males and 30 females from these species received carrageenan at dose levels of either 5%, 2.5% or 0.5% in the diet daily for the animal's lifespan. A trend toward an increased incidence of benign mammary tumors in females and testicular neoplasms in males occurred at the median dose level (2.5%); however, the incidence of these tumors was not statistically significant. Hamsters did not develop neoplasms in response to treatment at any dose levels. From the results of this experiment, carrageenan demonstrated no carcinogenic effects in either species. PMID:7226135

Rustia, M; Shubik, P; Patil, K

1980-11-01

275

Sarcolemmal phospholipid N-methylation in genetically determined hamster cardiomyopathy  

SciTech Connect

The heart sarcolemmal phosphatidylethanolamine N-methylation in UM-X7.1 strain of cardiomyopathic hamsters was examined by using 0.055, 10 and 150 microM S-adenosyl-L-(methyl-/sup 3/H) methionine as methyl donor for sites I, II and III, respectively. In comparison with control values, methylation activities at site I was increased in 40, 120 and 250 days old cardiomyopathic hamsters. On the other hand, methylation activities at sites II and III in 120 and 250 days old cardiomyopathic animals were depressed without any change in the 40 days old group. The alterations in N-methylation activities were associated with kinetic changes in apparent Vmax values without any changes in the apparent Km. These results indicate a defect in the phospholipid N-methylation process in heart sarcolemma during the development of genetically determined cardiomyopathy.

Okumura, K.; Panagia, V.; Jasmin, G.; Dhalla, N.S.

1987-02-27

276

Development and characterization of a Chinese hamster ovary cell-specific oligonucleotide microarray  

Microsoft Academic Search

The Chinese hamster ovary (CHO) cell line is one of the most widely used mammalian cell lines for biopharmaceutical production.\\u000a We have developed and characterized a gene expression microarray (WyeHamster2a) specific for CHO cells that has enabled the\\u000a study of ~3,500 sequences. Analysis of multiple sets of replicate scans showed that data derived from the WyeHamster2a array\\u000a is highly reproducible

Mark Melville; Padraig Doolan; William Mounts; Niall Barron; Louane Hann; Mark Leonard; Martin Clynes; Tim Charlebois

277

Hibernation, stress, intestinal functions, and catecholoamine turnover rate in hamsters and gerbils  

NASA Technical Reports Server (NTRS)

Bioenergetic studies on hamsters during depressed metabolic states are reported. External support of blood glucose extended the survival times of hibernating animals. Radioresistance increased in hibernating as well as in hypothermic hamsters. Marked changes in hamster catecholamine turnover rates were observed during acclimatization to high temperature stress. High radioresistance levels of the gerbil gastrointestinal system were attributed in part to the ability of the gut to maintain functional integrity.

Musacchia, X. J.

1973-01-01

278

Translocation and Endocytosis for Cell-penetrating Peptide Internalization  

PubMed Central

Cell-penetrating peptides (CPPs) share the property of cellular internalization. The question of how these peptides reach the cytoplasm of cells is still widely debated. Herein, we have used a mass spectrometry-based method that enables quantification of internalized and membrane-bound peptides. Internalization of the most used CPP was studied at 37 °C (endocytosis and translocation) and 4 °C (translocation) in wild type and proteoglycan-deficient Chinese hamster ovary cells. Both translocation and endocytosis are internalization pathways used by CPP. The choice of one pathway versus the other depends on the peptide sequence (not the number of positive changes), the extracellular peptide concentration, and the membrane components. There is no relationship between the high affinity of these peptides for the cell membrane and their internalization efficacy. Translocation occurs at low extracellular peptide concentration, whereas endocytosis, a saturable and cooperative phenomenon, is activated at higher concentrations. Translocation operates in a narrow time window, which implies a specific lipid/peptide co-import in cells. PMID:19833724

Jiao, Chen-Yu; Delaroche, Diane; Burlina, Fabienne; Alves, Isabel D.; Chassaing, Gérard; Sagan, Sandrine

2009-01-01

279

Photoperiodic Influences on Ultradian Rhythms of Male Siberian Hamsters  

PubMed Central

Seasonal changes in mammalian physiology and behavior are proximately controlled by the annual variation in day length. Long summer and short winter day lengths markedly alter the amplitude of endogenous circadian rhythms and may affect ultradian oscillations, but the threshold photoperiods for inducing these changes are not known. We assessed the effects of short and intermediate day lengths and changes in reproductive physiology on circadian and ultradian rhythms of locomotor activity in Siberian hamsters. Males were maintained in a long photoperiod from birth (15 h light/day; 15 L) and transferred in adulthood to 1 of 7 experimental photoperiods ranging from 14 L to 9 L. Decreases in circadian rhythm (CR) robustness, mesor and amplitude were evident in photoperiods ?14 L, as were delays in the timing of CR acrophase and expansion of nocturnal activity duration. Nocturnal ultradian rhythms (URs) were comparably prevalent in all day lengths, but 15 L markedly inhibited the expression of light-phase URs. The period (?’), amplitude and complexity of URs increased in day lengths ?13 L. Among hamsters that failed to undergo gonadal regression in short day lengths (nonresponders), ?’ of the dark-phase UR was longer than in photoresponsive hamsters; in 13 L the incidence and amplitude of light-phase URs were greater in hamsters that did not undergo testicular regression. Day lengths as long as 14 L were sufficient to trigger changes in the waveform of CRs without affecting UR waveform. The transition from a long- to a short-day ultradian phenotype occurred for most UR components at day lengths of 12 L–13 L, thereby establishing different thresholds for CR and UR responses to day length. At the UR-threshold photoperiod of 13 L, differences in gonadal status were largely without effect on most UR parameters. PMID:22848579

Prendergast, Brian J.; Zucker, Irving

2012-01-01

280

Cryopreservation of hamster pancreatic islets using a rapid cooling rate  

Microsoft Academic Search

To clarify the possibility of developing a rapid colling rate for islet cryopreservation, we used a cooling rate of 25C\\/min\\u000a for hamster pancreatic islet cryopreservation using 15 per cent dimethylsulfoxide as a cryoprotectant. After preservation,\\u000a these islets were examined for their morphology and function by assaying the insulin release after glucose stimulation and\\u000a the contents of the insulin and DNA

Wataru Fukushima; Yasuhiko Kojima; Gizo Nakagawara

1991-01-01

281

Effects of metronidazole, ipronidazole, and dibromochloropropane on rabbit and human sperm motility and fertility.  

PubMed

Treatment of protozoal pathogens in the reproductive system with chemical agents exposes flagellated sperm cells to potential toxicants. A widely used antiprotozoal agent is metronidazole. Its effect on rabbit and human sperm was compared with a more soluble 5-nitroazole compound, ipronidazole, and with a systemic environmental toxicant, dibromochloropropane (DBCP). The percentages of motile rabbit and human sperm incubated with the compounds, the velocity of sperm, migration of sperm in polyacrylamide gel, young born in rabbits, and penetration of hamster oocytes by treated human sperm were measured in seven experiments. Up to 10mg/ml metronidazole and 1mg/ml DBCP had little effect on most sperm characteristics. However, 10mg/ml metronidazole and 5mg/ml of ipronidazole increased attachment of human sperm to hamster oocytes, but oocyte penetration was unaffected. Rabbit sperm exposed to 5mg/ml ipronidazole were infertile. No oocytes were penetrated by DBCP-treated human sperm. PMID:12401502

Foote, Robert H

2002-01-01

282

CHARACTERIZATION OF VIRULENCE OF Leptospira ISOLATES IN A HAMSTER MODEL  

PubMed Central

Effort has been made to identify protective antigens in order to develop a recombinant vaccine against leptospirosis. Several attempts failed to conclusively demonstrate efficacy of vaccine candidates due to the lack of an appropriate model of lethal leptospirosis. The purposes of our study were: (i) to test the virulence of leptospiral isolates from Brazil, which are representative of important serogroups that cause disease in humans and animals; and (ii) to standardize the lethal dose 50% (LD50) for each of the virulent strains using a hamster (Mesocricetus auratus) model. Five of seven Brazilian isolates induced lethality in a hamster model, with inocula lower than 200 leptospires. Histopathological examination of infected animals showed typical lesions found in both natural and experimental leptospirosis. Results described here demonstrated the potential use of Brazilian isolates as highly virulent strains in challenge experiments using hamster as an appropriate animal model for leptospirosis. Furthermore these strains may be useful in heterologous challenge studies which aim to evaluate cross-protective responses induced by subunit vaccine candidates. PMID:18547690

Silva, Éverton F.; Santos, Cleiton S.; Athanazio, Daniel A.; Seyffert, Núbia; Seixas, Fabiana K.; Cerqueira, Gustavo M.; Fagundes, Michel Q.; Brod, Claudiomar S.; Reis, Mitermayer G.; Dellagostin, Odir A.; Ko, Albert I.

2008-01-01

283

Histogenesis of pancreatic carcinogenesis in the hamster: ultrastructural evidence  

SciTech Connect

Pancreatic carcinogenesis in the Syrian hamster, induced by ..beta..-oxidized derivatives of N-nitroso-di-n-propylamine, constitutes a valuable model of human cancer of the exocrine pancreas. In both species the majority of tumors are adenocarcinomas: superficially, on the basis of their histological appearance, these appear to be ductal in origin. However, sequential analysis, by electron microscopy, of the development of pancreatic neoplasia in the hamster model indicates that acinar cells may participate in the histogenesis of ductal adenomas and carcinomas. Acinar cells appear to undergo changes in differentiation, including pseudoductular transformation, giving rise to a new population of cells that resemble ductular or centroacinar types. This new population may then proliferate to form, first, cystic foci and subsequently cytadenomas and adenocarcinomas. Mucous metaplasia appears to develop at late stages of tumor development. Although the participation of ductular and centroacinar cells in pancreatic carcinogenesis cannot be excluded, very few tumors arise from the ductal epithelium. It is possible that some human pancreatic adenocarcinomas may also have their origin from dysplastic acinar cells, by analogy with the hamster model: focal acinar dyplasia being common in human pancreatic cancer patients. 90 references, 18 figures.

Flaks, B.

1984-06-01

284

Learned magnetic compass orientation by the Siberian hamster, Phodopus sungorus  

SciTech Connect

Magnetic orientation has been demonstrated in Siberian hamsters, Phodopus sungorus. The behavior, using a nest building assay, shows a directional preference in nest position and appears in this animal to be a learned behavior. Hamsters were housed prior to testing in rectangular cages aligned along perpendicular axes. When subsequently tested in a radially-symmetrical arena, the hamsters positioned their nests in a bimodal distribution that coincided with the magnetic direction of the long-axis of the holding cages. In addition, results are presented that illustrate some of the factors that can influence behavioral responses to the magnetic field. In particular for P. sungorus, holding conditions prior to testing and the presence of non-magnetic cues may influence the strength and expression of magnetic orientation. Failure to consider these and other factors may help to explain why previous attempts to demonstrate magnetic orientation in a number of rodent species have failed or, when positive results have been obtained, have been difficult to replicate in other laboratories.

Deutschlander, Mark E.; Freake, Michael J.; Borland, Christopher; Phillips, John B.; Madden, R C.; Anderson, Larry E.; Wilson, B W.

2003-04-01

285

Rowachol and ursodeoxycholic acid in hamsters with cholesterol gallstones.  

PubMed

Rowachol, a mixture of 6 terpenes in olive oil and under investigation for dissolution of gallstones in humans, was compared with UDCA in hamsters with induced cholesterol gallstones. Eighty hamsters were allocated to eight groups of ten animals each. One group received only standard rodent chow. The other seven groups received the lithogenic regime (standard chow containing ethinyl estradiol and increased cholesterol), either alone or with 20 mg/kg/day of UDCA, or 5, 10, or 20 mg/kg/day of mixed terpenes in olive oil or 10 mg ( of terpenes) kg/day of Rowachol or 0.2 cc/day of olive oil. The animals were sacrificed after 12 weeks. Two additional groups of six hamsters each received the lithogenic regime for 12 weeks, and then were switched to the standard diet, alone or with 10 mg/kg/day of Rowachol for eight weeks at the end of which time they were sacrificed. Rowachol decreased HMGCoA reductase activity 18%, but did not dissolve gallstones. Neither the terpenes nor Rowachol altered the biliary cholesterol saturation index, bile acid pool size or the activity of cholesterol 7-alpha hydroxylase or prevented formation of gallstones. UDCA unsaturated bile, increased the total bile acid pool size 38%, depressed the activity of HMGCoA reductase 29%, and prevented formation of gallstones. PMID:7148885

Handelsman, B; Bonorris, G; Marks, J W; Schoenfield, L J

1982-01-01

286

Nonhost Root Penetration by Soybean Cyst Nematode  

PubMed Central

A total of 66 plants in 50 species were inoculated with eggs and juveniles of soybean cyst nematode, Heterodera glycines. Roots were stained and observed for penetration and development of the nematode. Twenty-six plants were not penetrated; twenty-three were penetrated, but there was no development of the nematode; eight were penetrated with some nematode development; two were penetrated and had considerable nematode development, but few nematodes, if any, matured; and seven were penetrated with many nematodes maturing. The penetration of nonhosts may imply some susceptibility and that populations eventually would build up on the penetrated plants. Plants not penetrated may be useful as rotation plants because no reproduction would occur. PMID:19290137

Riggs, R. D.

1987-01-01

287

Percutaneous penetration--methodological considerations.  

PubMed

Studies on percutaneous penetration are needed to assess the hazards after unintended occupational skin exposures to industrial products as well as the efficacy after intended consumer exposure to topically applied medicinal or cosmetic products. During recent decades, a number of methods have been developed to replace methods involving experimental animals. The results obtained from these methods are decided not only by the chemical or product tested, but to a significant degree also by the experimental set-up and decisions made by the investigator during the planning phase. The present MiniReview discusses some of the existing and well-known experimental in vitro and in vivo methods for studies of percutaneous penetration together with some more recent and promising methods. After this, some considerations and recommendations about advantages and limitations of the different methods and their relevance for the prediction of percutaneous penetration are given. Which method to prefer will depend on the product to be tested and the question asked. Regulatory guidelines exist for studies on percutaneous penetration, but researchers as well as regulatory bodies need to pay specific attention to the vehicles and solvents used in donor and sampling fluids so that it reflects in-use conditions as closely as possible. Based on available experimental data, mathematical models have been developed to aid predictions of skin penetration. The authors question the general use of the present mathematical models in hazard assessment, as they seem to ignore outliers among chemicals as well as the heterogeneity of skin barrier properties and skin conditions within the exposed populations. PMID:24373389

Holmgaard, Rikke; Benfeldt, Eva; Nielsen, Jesper B

2014-07-01

288

Absence of cumulus cells during in vitro maturation affects lipid metabolism in bovine oocytes.  

PubMed

Cumulus cells (CC) surround the oocyte and are coupled metabolically through regulation of nutrient intake. CC removal before in vitro maturation (IVM) decreases bovine oocyte developmental competence without affecting nuclear meiotic maturation. The objective was to investigate the influence of CC on oocyte cytoplasmic maturation in relation to energy metabolism. IVM with either cumulus-enclosed (CEO) or -denuded (DO) oocytes was performed in serum-free metabolically optimized medium. Transmission electron microscopy revealed different distribution of membrane-bound vesicles and lipid droplets between metaphase II DO and CEO. By Nile Red staining, a significant reduction in total lipid level was evidenced in DO. Global transcriptomic analysis revealed differential expression of genes regulating energy metabolism, transcription, and translation between CEO and DO. By Western blot, fatty acid synthase (FAS) and hormone-sensitive phospholipase (HSL) proteins were detected in oocytes and in CC, indicating a local lipogenesis and lypolysis. FAS protein was significantly less abundant in DO that in CEO and more highly expressed in CC than in the oocytes. On the contrary, HSL protein was more abundant in oocytes than in CC. In addition, active Ser??³-phosphorylated HSL was detected in the oocytes only after IVM, and its level was similar in CEO and DO. In conclusion, absence of CC during IVM affected lipid metabolism in the oocyte and led to suboptimal cytoplasmic maturation. Thus, CC may influence the oocyte by orienting the consumption of nutritive storage via regulation of local fatty acid synthesis and lipolysis to provide energy for maturation. PMID:23321473

Auclair, Sylvain; Uzbekov, Rustem; Elis, Sébastien; Sanchez, Laura; Kireev, Igor; Lardic, Lionel; Dalbies-Tran, Rozenn; Uzbekova, Svetlana

2013-03-15

289

Follicle microenvironment-associated alterations in gene expression in the mouse oocyte and its polar body  

PubMed Central

Objective To determine whether the follicle environment modulates oocyte-specific gene transcript levels in cultured oocytes and polar bodies (PBs). Design Animal study. Setting Large academic research center. Animal(s) CD1 mice. Intervention(s) In vitro growth of secondary mouse follicles in 0.25% or 1.5% alginate (ALG) in a three-dimensional culture system. Main Outcome Measure(s) Relative transcript levels of Gdf9, Bmp15, Nlrp5, Tcl1, and Zp3 were measured by real-time quantitative reverse transcriptase–polymerase chain reaction in oocytes during in vitro follicle development and oocyte maturation and in their first PBs after removal from metaphase II (MII) eggs. Result(s) All transcripts decreased earlier in oocytes cultured in 1.5% ALG compared with 0.25% ALG. Transcript levels were lower in MII eggs cultured in 1.5% ALG compared with in 0.25% ALG. All genes were expressed in PBs, and transcript levels were lower in PBs cultured in 1.5% ALG compared with in 0.25% ALG. Abundance of all transcripts was lower in PBs than in their sibling oocytes. Conclusion(s) Local follicle environment modulates oocyte-specific gene expression in the oocyte and first PB. There is a significant difference in the transcript levels of oocyte-specific genes in PBs of 1.5% versus 0.25% ALG that correlates with ovarian environment-related decreases in oocyte competence. PMID:23312223

Jiao, Ze-Xu; Woodruff, Teresa K.

2014-01-01

290

Protein deubiquitination during oocyte maturation influences sperm function during fertilisation, antipolyspermy defense and embryo development.  

PubMed

Ubiquitination is a covalent post-translational modification of proteins by the chaperone protein ubiquitin. Upon docking to the 26S proteasome, ubiquitin is released from the substrate protein by deubiquitinating enzymes (DUBs). We hypothesised that specific inhibitors of two closely related oocyte DUBs, namely inhibitors of the ubiquitin C-terminal hydrolases (UCH) UCHL1 (L1 inhibitor) and UCHL3 (L3 inhibitor), would alter porcine oocyte maturation and influence sperm function and embryo development. Aberrant cortical granule (CG) migration and meiotic spindle defects were observed in oocytes matured with the L1 or L3 inhibitor. Embryo development was delayed or blocked in oocytes matured with the general DUB inhibitor PR-619. Aggresomes, the cellular stress-inducible aggregates of ubiquitinated proteins, formed in oocytes matured with L1 inhibitor or PR-619, a likely consequence of impaired protein turnover. Proteomic analysis identified the major vault protein (MVP) as the most prominent protein accumulated in oocytes matured with PR-619, suggesting that the inhibition of deubiquitination altered the turnover of MVP. The mitophagy/autophagy of sperm-contributed mitochondria inside the fertilised oocytes was hindered by DUB inhibitors. It is concluded that DUB inhibitors alter porcine oocyte maturation, fertilisation and preimplantation embryo development. By regulating the turnover of oocyte proteins and mono-ubiquitin regeneration, the DUBs may promote the acquisition of developmental competence during oocyte maturation. PMID:24848520

Yi, Young-Joo; Sutovsky, Miriam; Song, Won-Hee; Sutovsky, Peter

2014-05-22

291

Expression and localization of aquaporin 1b during oocyte development in the Japanese eel (Anguilla japonica)  

PubMed Central

To elucidate the molecular mechanisms underling hydration during oocyte maturation, we characterized the structure of Japanese eel (Anguilla japonica) novel-water selective aquaporin 1 (AQP1b) that thought to be involved in oocyte hydration. The aqp1b cDNA encodes a 263 amino acid protein that includes the six potential transmembrane domains and two Asn-Pro-Ala motifs. Reverse transcription-polymerase chain reaction showed transcription of Japanese eel aqp1b in ovary and testis but not in the other tissues. In situ hybridization studies with the eel aqp1b cRNA probe revealed intense eel aqp1b signal in the oocytes at the perinucleolus stage and the signals became faint during the process of oocyte development. Light microscopic immunocytochemical analysis of ovary revealed that the Japanese eel AQP1b was expressed in the cytoplasm around the yolk globules which were located in the peripheral region of oocytes during the primary yolk globule stage; thereafter, the immunoreactivity was observed throughout the cytoplasm of oocyte as vitellogenesis progressed. The immunoreactivity became localized around the large membrane-limited yolk masses which were formed by the fusion of yolk globules during the oocyte maturation phase. These results together indicate that AQP1b, which is synthesized in the oocyte during the process of oocyte growth, is essential for mediating water uptake into eel oocytes. PMID:21615964

2011-01-01

292

Optimising vitrification of human oocytes using multiple cryoprotectants and morphological and functional assessment.  

PubMed

Oocyte vitrification is a clinical practice that allows preservation of fertility potential in women. Vitrification involves quick cooling using high concentrations of cryoprotectants to minimise freezing injuries. However, high concentrations of cryoprotectants have detrimental effects on oocyte quality and eventually the offspring. In addition, current assessment of oocyte quality after vitrification is commonly based only on the morphological appearance of the oocyte, raising concerns regarding its efficiency. Using both morphological and functional assessments, the present study investigated whether combinations of cryoprotectants at lower individual concentrations result in better cryosurvival rates than single cryoprotectants at higher concentrations. Surplus oocytes from IVF patients were vitrified within 24h after retrieval using the Cryotop method with several cryoprotectants, either individually or in combination. The morphological and functional quality of the vitrified oocytes was investigated using light microscopy and computer-based quantification of mitochondrial integrity, respectively. Oocyte quality was significantly higher using a combination of cryoprotectants than vitrification with individual cryoprotectants. In addition, the quality of vitrified oocyte varied depending on the cryoprotectants and type of combination used. The results of the present study indicate that observations based purely on the morphological appearance of the oocyte to assess the cryosurvival rate are insufficient and sometimes misleading. The outcome will have a significant implication in the area of human oocyte cryopreservation as an important approach for fertility preservation. PMID:22967503

Seet, V Y K; Al-Samerria, S; Wong, J; Stanger, J; Yovich, J L; Almahbobi, G

2013-01-01

293

Src family kinases are involved in the meiotic maturation of porcine oocytes.  

PubMed

Mammalian meiotic maturation is regulated by changes in the phosphorylation state of proteins involved in signalling pathways. The regulatory proteins include the family of Src tyrosine kinases. Src family kinases (SFKs) are required for meiotic maturation of mouse oocytes, and it remains to be elucidated whether they play the same role in porcine oocytes. To clarify the role of SFKs in the meiotic maturation of porcine oocytes we used inhibition of SFKs, western blotting and immunolocalisation to determine the presence of SFKs and localisation in the oocytes and assays to determine the activity of maturation-promoting factor (MPF) and mitogen-activated protein kinase (MAPK). Inhibition of SFKs resulted in the disruption of oocyte maturation and led to a decline in MPF and MAPK activity. The fluorescence intensity of SFKs in the cytoplasm and membrane of MI oocytes decreased significantly compared with germinal vesicle oocytes. The highest fluorescence intensity for SFKs was detected on the membrane of MII oocytes. Only weak fluorescence was detected in the perichromosomal area of MI and MII oocytes. These results prove that SFKs play an active role in the meiotic maturation of porcine oocytes by regulating MPF and MAPK activity. PMID:25482830

Kheilová, Kate?ina; Petr, Jaroslav; Zalmanová, Tereza; Ku?erová-Chrpová, Veronika; Rehák, Dalibor

2014-04-23

294

Calcineurin expression and localisation during porcine oocyte growth and meiotic maturation.  

PubMed

The processes of oocyte growth, acquisition of meiotic competence and meiotic maturation are regulated by a large number of molecules. One of them could be calcineurin consisting of catalytic subunit A (A?, A?, A? isoforms) and regulatory subunit B (B1, B2 isoforms). Calcineurin is involved in the meiotic maturation of oocytes in invertebrates or in lower vertebrates. In the mammalian oocytes, the possible role of calcineurin in the regulation of oocyte meiosis has not been clarified to date. In this study, to investigate the role of calcineurin during porcine oocyte growth, acquisition of meiotic competence and meiotic maturation, we analysed the expression and localisation of calcineurin subunits and the mRNA expression of calcineurin isoforms. Calcineurin was expressed in growing porcine oocytes, in fully grown oocytes and during their in vitro meiotic maturation. We found both subunits of calcineurin. Calcineurin A and calcineurin B were localised mainly in the cortex in all porcine oocytes. The changes in the intracellular localisation of separate calcineurin subunits during meiotic maturation were determined. We detected mRNA for calcineurin isoforms A?, A?, B2 in oocytes and mRNA for calcineurin isoforms A?, A?, B1, and B2 in cumular cells. To our knowledge, this is the first confirmation of calcineurin presence in porcine oocytes. PMID:23972328

T?mová, Lenka; Petr, Jaroslav; Žalmanová, Tereza; Chmelíková, Eva; Kott, Tomáš; Tichovská, Hana; Ku?erová-Chrpová, Veronika; Hošková, Kristýna; Jílek, František

2013-10-01

295

Developmental competence of equine oocytes: impacts of zona pellucida birefringence and maternally derived transcript expression.  

PubMed

In the present study, equine oocytes were classified into groups of presumably high and low developmental competence according to cumulus morphology, as well as oocyte ability to metabolise brilliant cresyl blue (BCB) stain. All oocytes were evaluated individually in terms of morphometry, zona pellucida birefringence (ZPB) and relative abundance of selected candidate genes. Oocytes with an expanded cumulus (Ex), representing those with presumably high developmental competence, had a significantly thicker zona (18.2 vs 17.3µm) and a significantly higher ZPB (64.6 vs 62.1) than oocytes with a compacted cumulus (Cp). Concurrently, oocytes classified as highly developmentally competent (BCB+) had a significantly thicker zona (18.8 vs 16.1µm) and significantly higher ZPB (63.1 vs 61.3) compared with oocytes classified as having low developmental competence. Expression of TFAM, STAT3 and CKS2 was significantly higher in Ex compared with Cp oocytes, whereas expression of COX1, ATPV6E and DNMT1 was lower. Together, the data reveal that developmentally competent equine oocytes are larger in size, have higher ZPB values and exhibit a typical genetic signature of maternally derived transcripts compared with oocytes with lower in vitro developmental competence. PMID:23622680

Mohammadi-Sangcheshmeh, Abdollah; Held, Eva; Rings, Franca; Ghanem, Nasser; Salilew-Wondim, Dessie; Tesfaye, Dawit; Sieme, Harald; Schellander, Karl; Hoelker, Michael

2014-03-01

296

Metabolic control of oocyte development: linking maternal nutrition and reproductive outcomes.  

PubMed

Obesity, diabetes, and related metabolic disorders are major health issues worldwide. As the epidemic of metabolic disorders continues, the associated medical co-morbidities, including the detrimental impact on reproduction, increase as well. Emerging evidence suggests that the effects of maternal nutrition on reproductive outcomes are likely to be mediated, at least in part, by oocyte metabolism. Well-balanced and timed energy metabolism is critical for optimal development of oocytes. To date, much of our understanding of oocyte metabolism comes from the effects of extrinsic nutrients on oocyte maturation. In contrast, intrinsic regulation of oocyte development by metabolic enzymes, intracellular mediators, and transport systems is less characterized. Specifically, decreased acid transport proteins levels, increased glucose/lipid content and elevated reactive oxygen species in oocytes have been implicated in meiotic defects, organelle dysfunction and epigenetic alteration. Therefore, metabolic disturbances in oocytes may contribute to the diminished reproductive potential experienced by women with metabolic disorders. In-depth research is needed to further explore the underlying mechanisms. This review also discusses several approaches for metabolic analysis. Metabolomic profiling of oocytes, the surrounding granulosa cells, and follicular fluid will uncover the metabolic networks regulating oocyte development, potentially leading to the identification of oocyte quality markers and prevention of reproductive disease and poor outcomes in offspring. PMID:25280482

Gu, Ling; Liu, Honglin; Gu, Xi; Boots, Christina; Moley, Kelle H; Wang, Qiang

2015-01-01

297

Developmental Potential of Prepubertal Mouse Oocytes Is Compromised Due Mainly to Their Impaired Synthesis of Glutathione  

PubMed Central

Although oocytes from prepubertal animals are found less competent than oocytes from adults, the underlying mechanisms are poorly understood. Using the mouse oocyte model, this paper has tested the hypothesis that the developmental potential of prepubertal oocytes is compromised due mainly to their impaired potential for glutathione synthesis. Oocytes from prepubertal and adult mice, primed with or without eCG, were matured in vitro and assessed for glutathione synthesis potential, oxidative stress, Ca2+ reserves, fertilization and in vitro development potential. In unprimed mice, abilities for glutathione synthesis, activation, male pronuclear formation, blastocyst formation, cortical granule migration and polyspermic block were all compromised significantly in prepubertal compared to adult oocytes. Cysteamine and cystine supplementation to maturation medium significantly promoted oocyte glutathione synthesis and blastocyst development but difference due to maternal age remained. Whereas reactive oxygen species (ROS) levels increased, Ca2+ storage decreased significantly in prepubertal oocytes. Levels of both catalytic and modifier subunits of the ?-glutamylcysteine ligase were significantly lower in prepubertal than in adult oocytes. Maternal eCG priming improved all the parameters and eliminated the age difference. Together, the results have confirmed our hypothesis by showing that prepubertal oocytes have a decreased ability to synthesize glutathione leading to an impaired potential to reduce ROS and to form male pronuclei and blastocysts. The resulting oxidative stress decreases the intracellular Ca2+ store resulting in impaired activation at fertilization, and damages the microfilament network, which affects cortical granule redistribution leading to polyspermy. PMID:23469259

Cui, Wei; Lian, Hua-Yu; Miao, Yi-Long; Wu, Xiu-Fen; Han, Dong; Tan, Jing-He

2013-01-01

298

Prolonged exposure to hyaluronidase decreases the fertilization and development rates of fresh and cryopreserved mouse oocytes  

PubMed Central

Hyaluronidase is generally used to remove cumulus cells from mouse oocytes before oocyte cryopreservation, intracytoplasmic sperm injection or DNA injection. In general, use of cumulus-free mouse oocytes decreases in vitro fertilizing ability compared with cumulus-surrounded oocytes. The effect of hyaluronidase exposure on the quality of mouse oocytes is not fully understood. Here, we investigated the effect of hyaluronidase exposure time on the fertilization rate of fresh and vitrified mouse oocytes and their subsequent developmental ability in vitro. We found that the fertilization rate decreased with hyaluronidase treatments. This reduction in the fertilization rate following treatment with hyaluronidase was fully reversed by removal of the zona pellucida. In addition, oocytes treated with hyaluronidase for 5 min or longer had a reduced capacity to develop to the morula and blastocyst stage. The survival, fertilization, and developmental rates of vitrified-warmed oocytes were also reduced by longer exposure to hyaluronidase. In conclusion, these results suggest that prolonged exposure to hyaluronidase decreases the quality of mouse oocytes and shorter hyaluronidase treatment times may help achieve a stable and high fertilization rate in fresh and cryopreserved oocytes.

ISHIZUKA, Yuta; TAKEO, Toru; NAKAO, Satohiro; YOSHIMOTO, Hidetaka; HIROSE, Yumiko; SAKAI, Yuki; HORIKOSHI, Yuka; TAKEUJI, Shiori; TSUCHIYAMA, Shuuji; NAKAGATA, Naomi

2014-01-01

299

CRL4DCAF1 is required in activated oocytes for follicle maintenance and ovulation.  

PubMed

In mammals, oocytes within the primordial follicles require a number of essential factors to maintain their survival. However, the survival factors for activated oocytes have been poorly characterized. Recently we reported that damaged DNA binding protein-1 (DDB1), the linker subunit of the cullin ring-finger ubiquitin E3 ligase-4 (CRL4) complex, and its substrate adaptor, DDB1-CUL4 associated factor-1 (DCAF1), were essential for primordial follicle maintenance. In this study we specifically deleted these in the oocytes of growing follicles, to investigate if DDB1 and DCAF1 were also survival factors for activated oocytes. In the ovaries of Ddb1(fl/fl);Zp3-Cre mice, the primordial follicle pool was intact, but awakened oocytes and growing follicles beyond the primary stage were rapidly depleted. In the ovaries of Dcaf1(fl/fl);Pten(fl/fl);Gdf9-Cre and Ddb1(fl/fl);Pten(fl/fl);Gdf9-Cre mice, global primordial follicle activation was stimulated by enhanced PI3K signaling, but the awakened oocytes were rapidly lost due to no CRL4(DCAF1) activity. These mouse models provided original evidence that CRL4(DCAF1) was essential for maintaining oocyte survival, not only those in dormancy at the primordial follicle stage, but also naturally awakened oocytes and those awakened by hyper-activation of PI3K signaling. Interestingly, the oocyte-specific Ddb1 or Dcaf1 knockout mice had ovulation defects even before oocyte exhaustion. CRL4(DCAF1) within oocytes was required for cumulus expansion and ovulation-related somatic gene expression in a cell non-autonomous manner. Granulosa cells that surrounded these Ddb1 or Dcaf1-deleted oocytes exhibited increased rates of apoptosis and showed poor responses to ovulation signals. These results suggested that CRL4 in oocytes also regulated granulosa cell functions in a cell non-autonomous manner. PMID:25371539

Yu, Chao; Xu, Yi-Wen; Sha, Qian-Qian; Fan, Heng-Yu

2014-11-01

300

Messenger RNAs in metaphase II oocytes correlate with successful embryo development to the blastocyst stage.  

PubMed

The mRNAs accumulated in oocytes provide support for embryo development until embryo genomic activation. We hypothesized that the maternal mRNA stock present in bovine oocytes is associated with embryo development until the blastocyst stage. To test our hypothesis, we analyzed the transcriptome of the oocyte and correlated the results with the embryo development. Our goal was to identify genes expressed in the oocyte that correlate with its ability to develop to the blastocyst stage. A fraction of oocyte cytoplasm was biopsied using micro-aspiration and stored for further expression analysis. Oocytes were activated chemically, cultured individually and classified according to their capacity to develop in vitro to the blastocyst stage. Microarray analysis was performed on mRNA extracted from the oocyte cytoplasm fractions and correlated with its ability to develop to the blastocyst stage (good quality oocyte) or arrest at the 8-16-cell stage (bad quality oocyte). The expression of 4320 annotated genes was detected in the fractions of cytoplasm that had been collected from oocytes matured in vitro. Gene ontology classification revealed that enriched gene expression of genes was associated with certain biological processes: 'RNA processing', 'translation' and 'mRNA metabolic process'. Genes that are important to the molecular functions of 'RNA binding' and 'translation factor activity, RNA binding' were also enriched in oocytes. We identified 29 genes with differential expression between the two groups of oocytes compared (good versus bad quality). The content of mRNAs expressed in metaphase II oocytes influences the activation of the embryonic genome and enables further develop to the blastocyst stage. PMID:23046986

Biase, Fernando Henrique; Everts, Robin Edward; Oliveira, Rosane; Santos-Biase, Weruska Karyna Freitas; Fonseca Merighe, Giovana Krempel; Smith, Lawrence Charles; Martelli, Lúcia; Lewin, Harris; Meirelles, Flávio Vieira

2014-02-01

301

Oocyte development and fecundity type of the skipjack, Katsuwonus pelamis, in the Western Indian Ocean  

NASA Astrophysics Data System (ADS)

The study aims to define the oogenesis pattern of the skipjack (Katsuwonus pelamis) of the Western Indian Ocean basin in terms of oocyte growth and recruitment style. The main objective is to define the type of fecundity regulation (i.e. determinate or indeterminate) based on four lines of evidence: (a) oocyte size-frequency distribution; (b) seasonal variation of the relative number and percentage of oocyte stages, (c) diameter of the advanced vitellogenic oocytes in females in the spawning capable phase; and (d) incidence of atresia throughout the spawning season. The samples were collected from 2009 to 2010 in the Western Indian Ocean, and 673 ovaries were classified in the different reproductive phases using histological staging. Moreover, the oocyte size distribution of 93 mature individuals was described by the newly implemented image analysis method. This species showed a broad oocyte size frequency distribution with no gap formation between the primary and secondary oocyte growth stages. There was no seasonal variation in the percentage of oocyte stages in ovaries in the spawning capable phase, and the diameter of those oocytes at the most advanced vitellogenic stage was approximately constant during the sampling period. These facts provide evidence of continuous oocyte recruitment into the standing stock of developing oocytes. Moreover, when reaching the end of the active reproductive period (i.e. February and March) the prevalence of atresia increased. This is a mechanism adopted by fishes of the indeterminate fecundity type to reabsorb the surplus oocyte production. Based on the findings, we state that the skipjack in the Western Indian Ocean shows asynchronous oocyte growth and an indeterminate fecundity type.

Grande, Maitane; Murua, Hilario; Zudaire, Iker; Korta, Maria

2012-10-01

302

86 birth of healthy calves after intrafollicular oocyte transfer.  

PubMed

The in vitro production (IVP) of bovine embryos is a well-established technique that has been available for nearly 20 years. However, there remain major differences between IVP-derived blastocysts and their in vivo-derived counterparts. Many studies have pointed out that most of these differences are due to the in vitro developmental environment. To circumvent these negative effects due to in vitro culture conditions, a new method - intrafollicular oocyte transfer (IFOT) - was established in the present study. Using modified ovum pick-up (OPU) equipment, in vitro-matured oocytes derived from slaughterhouse ovaries were injected into the dominant preovulatory follicle of synchronised heifers (follicular recipients) enabling subsequent ovulation, in vivo fertilization, and in vivo development. A total of 810 in vitro-matured oocytes were transferred into 14 heifers. Subsequently, 222 embryos (27.3%) were recovered after uterine flushing at Day 7. Based on the number of cleaved embryonic stages, 64.2% developed to the blastocyst stage, which did not differ from the IVP-derived embryos (58.2%). Interestingly, lipid content of IFOT-derived blastocysts did not differ from the fully in vivo-produced embryos, whereas IVP-derived blastocysts showed significantly higher lipid droplet accumulation compared with fully in vivo-derived and IFOT-derived blastocysts (P<0.05). Accordingly, IFOT blastocysts showed significantly higher survival rates after cryopreservation than complete IVP-derived embryos (77% v. 10%), which might be attributed to a lower degree of lipid accumulation. In agreement, transfer of frozen-thawed IFOT blastocysts to synchronized recipients (uterine recipients) resulted in much higher pregnancy rates compared with transfer of IVP-derived blastocysts (42.1 v. 13.8%) but did not differ from frozen-thawed ex vivo blastocysts (52.4%). Of these presumed IFOT pregnancies, 7 went to term, and microsatellite analysis confirmed that 5 calves were indeed derived from IFOT, whereas 2 were caused by fertilization of the follicular recipient's own oocyte after AI. Taken together, IFOT-derived blastocysts closely resemble in vivo-derived blastocysts, confirming earlier suggestions that the ability to develop to the blastocyst stage is already determined in the matured oocyte, whereas the quality in terms of lipid content and survival rate after cryopreservation is affected by the environment thereafter. However, to the best of our knowledge, this is the first study reporting healthy calves after intrafollicular transfer of in vitro-matured oocytes. PMID:25472135

Hoelker, M; Kassens, A; Held, E; Wrenzycki, C; Besenfelder, U; Havlicek, V; Sieme, H; Tesfaye, D; Schellander, K

2014-12-01

303

Sequencing, Annotation and Analysis of the Syrian Hamster (Mesocricetus auratus) Transcriptome  

PubMed Central

Background The Syrian hamster (golden hamster, Mesocricetus auratus) is gaining importance as a new experimental animal model for multiple pathogens, including emerging zoonotic diseases such as Ebola. Nevertheless there are currently no publicly available transcriptome reference sequences or genome for this species. Results A cDNA library derived from mRNA and snRNA isolated and pooled from the brains, lungs, spleens, kidneys, livers, and hearts of three adult female Syrian hamsters was sequenced. Sequence reads were assembled into 62,482 contigs and 111,796 reads remained unassembled (singletons). This combined contig/singleton dataset, designated as the Syrian hamster transcriptome, represents a total of 60,117,204 nucleotides. Our Mesocricetus auratus Syrian hamster transcriptome mapped to 11,648 mouse transcripts representing 9,562 distinct genes, and mapped to a similar number of transcripts and genes in the rat. We identified 214 quasi-complete transcripts based on mouse annotations. Canonical pathways involved in a broad spectrum of fundamental biological processes were significantly represented in the library. The Syrian hamster transcriptome was aligned to the current release of the Chinese hamster ovary (CHO) cell transcriptome and genome to improve the genomic annotation of this species. Finally, our Syrian hamster transcriptome was aligned against 14 other rodents, primate and laurasiatheria species to gain insights about the genetic relatedness and placement of this species. Conclusions This Syrian hamster transcriptome dataset significantly improves our knowledge of the Syrian hamster's transcriptome, especially towards its future use in infectious disease research. Moreover, this library is an important resource for the wider scientific community to help improve genome annotation of the Syrian hamster and other closely related species. Furthermore, these data provide the basis for development of expression microarrays that can be used in functional genomics studies. PMID:25398096

Tchitchek, Nicolas; Safronetz, David; Rasmussen, Angela L.; Martens, Craig; Virtaneva, Kimmo; Porcella, Stephen F.; Feldmann, Heinz

2014-01-01

304

Role of oocyte-derived paracrine factors in follicular development  

PubMed Central

Mammalian oocytes secrete transforming growth factor ? (TGF-?) superfamily proteins, such as growth differentiation factor 9 (GDF9), bone morphogenetic protein 6 (BMP6) and BMP15, and fibroblast growth factors (FGFs). These oocyte-derived paracrine factors (ODPFs) play essential roles in regulating the differentiation and function of somatic granulosa cells as well as the development of ovarian follicles. In addition to the importance of individual ODPFs, emerging evidence suggests that the interaction of ODPF signals with other intra-follicular signals, such as estrogen, is critical for folliculogenesis. In this review, we will discuss the current understanding of the role of ODPFs in follicular development with an emphasis on their interaction with estrogen signaling in regulation of the differentiation and function of granulosa cells. PMID:24717179

Emori, Chihiro; Sugiura, Koji

2014-01-01

305

Deoxyribonucleic acid in germinal vesicles of oocytes of Rana pipiens.  

PubMed

The amount of DNA isolated from germinal vesicles of Rana pipiens oocytes is similar to that isolated from whole unfertilized eggs, and this suggests that oocyte nuclei are the source ofmuch of the DNA obtained from whole eggs. Fluorometric determinations of the isolated DNA show the presence of 0.004 microgram of DNA equivalents per germinal vesicle. Similar values were obtained by estimations from comparisons of the cesium chloride densitygradient profiles of sample DNA and a known amount of reference DNA from Pseudomonas aeruginosa. The buoyant density of DNA prepared from isolated germinal vesicles is the same as that of frog-liver DNA, 1.706 grams per cubic centimeter, as determined by equilibrium sedimentation in a cesium chloride density gradient. PMID:5951002

Haggis, A J

1966-11-01

306

Role of oocyte-derived paracrine factors in follicular development.  

PubMed

Mammalian oocytes secrete transforming growth factor ? (TGF-?) superfamily proteins, such as growth differentiation factor 9 (GDF9), bone morphogenetic protein 6 (BMP6) and BMP15, and fibroblast growth factors (FGFs). These oocyte-derived paracrine factors (ODPFs) play essential roles in regulating the differentiation and function of somatic granulosa cells as well as the development of ovarian follicles. In addition to the importance of individual ODPFs, emerging evidence suggests that the interaction of ODPF signals with other intra-follicular signals, such as estrogen, is critical for folliculogenesis. In this review, we will discuss the current understanding of the role of ODPFs in follicular development with an emphasis on their interaction with estrogen signaling in regulation of the differentiation and function of granulosa cells. PMID:24717179

Emori, Chihiro; Sugiura, Koji

2014-06-01

307

Using oocyte size to assess seasonal ovarian development in Solea solea (L.)  

NASA Astrophysics Data System (ADS)

Maximum oocyte size was used to assess seasonal ovarian development in sole. Fish age, especially the adolescent period, appeared to affect the start of vitellogenin-dependent oocyte development in the annual reproductive cycle and the subsequent oocyte growth rate. The majority of oocyte growth occurred between September and March. Several other aspects of ovarian development were also age-dependent, including the increase in ovary condition factor (ovary weight/fish length 3) and the size of oocytes commencing nuclear migration. Evidence is presented that in the recruiting year class of sole abortive maturation occurs where oocytes develop yolk but spawning does not take place. The implications of this study on the estimation of female spawning stock biomass are discussed.

Ramsay, K.; Witthames, P.

1996-12-01

308

Influence of corpus luteum and ovarian volume on the number and quality of bovine oocytes.  

PubMed

In order to evaluate whether ovarian volume, presence and diameter of the corpus luteum (CL) have effects on the number and quality of bovine recovered oocytes, 110 ovaries were obtained from the slaughterhouse. Cumulus oocytes complex were aspirated and evaluated under stereomicroscope. Oocytes were counted and classified according to their quality (Grades I, II, III and IV). Ovarian volume was weakly correlated to the number of good quality oocytes (P?oocytes than ovaries without CL (P?oocytes (P?

Penitente-Filho, Jurandy Mauro; Jimenez, Carolina Rodrigues; Zolini, Adriana Moreira; Carrascal, Erly; Azevedo, Jovana Luiza; Silveira, Camila Oliveira; Oliveira, Fabrício Albani; Torres, Ciro Alexandre Alves

2015-02-01

309

Host cell factors controlling vimentin organization in the Xenopus oocyte  

PubMed Central

To study vimentin filament organization in vivo we injected Xenopus oocytes, which have no significant vimentin system of their own, with in vitro-synthesized RNAs encoding Xenopus vimentins. Exogenous vimentins were localized primarily to the cytoplasmic surface of the nucleus and to the subplasma membrane "cortex." In the cortex of the animal hemisphere, wild-type vimentin forms punctate structures and short filaments. In contrast, long anastomosing vimentin filaments are formed in the vegetal hemisphere cortex. This asymmetry in the organization of exogenous vimentin is similar to that of the endogenous keratin system (Klymkowsky, M. W., L. A. Maynell, and A. G. Polson. 1987. Development (Camb.). 100:543-557), which suggests that the same cellular factors are responsible for both. Before germinal vesicle breakdown, in the initial stage of oocyte maturation, large vimentin and keratin filament bundles appear in the animal hemisphere. As maturation proceeds, keratin filaments fragment into soluble oligomers (Klymkowsky, M. W., L. A. Maynell, and C. Nislow. 1991. J. Cell Biol. 114:787-797), while vimentin filaments remain intact and vimentin is hyperphosphorylated. To examine the role of MPF kinase in the M-phase reorganization of vimentin we deleted the conserved proline of vimentin's single MPF-kinase site; this mutation had no apparent effect on the prophase or M-phase behavior of vimentin. In contrast, deletion of amino acids 19-68 or 18-61 of the NH2-terminal "head" domain produced proteins that formed extended filaments in the animal hemisphere of the prophase oocyte. We suggest that the animal hemisphere cortex of the prophase oocyte contains a factor that actively suppresses the formation of extended vimentin filaments through a direct interaction with vimentin's head domain. During maturation this "suppressor of extended filaments" appears to be inactivated, leading to the formation of an extended vimentin filament system. PMID:1429840

1992-01-01

310

Localization of the nucleolar protein NO38 in amphibian oocytes  

PubMed Central

To examine the role of primary amino acid sequence in the localization of proteins within the nucleus, we studied the nucleolar protein NO38 of amphibian oocytes. We synthesized NO38 transcripts in vitro, injected them into the oocyte cytoplasm, and followed the distribution of the translation products. The injected RNA contained a short sequence encoding an epitope derived from the human c-myc protein. We used an mAb against this epitope to detect translation products from injected RNAs by Western blots and by immunofluoresent staining of cytological preparations. When full-length transcripts of NO38 were injected into oocytes, the translation products accumulated efficiently in the germinal vesicle, and a major fraction was localized in the multiple nucleoli. To identify protein domains involved in this nucleolus-specific accumulation, we prepared a series of carboxy- terminal deletions of the cDNA. Oocytes injected with RNA encoding truncated forms of NO38 were examined for altered patterns of protein accumulation. We defined a domain of about 24 amino acids near the carboxy terminus that was essential for nucleolar localization of NO38. This domain is separated by more than 70 amino acids from two putative nuclear localization signals near the middle of the molecule. Hybrid constructs were made which encoded part of Escherichia coli beta- galactosidase or pyruvate kinase fused to a long segment of NO38 containing the essential domain. Injection of RNA from these constructs showed that the essential domain was not sufficient to target the hybrid proteins to the nucleolus. We suggest that nucleolar accumulation of NO38 requires more than a single linear domain. PMID:1730739

1992-01-01

311

A hyperpolarization-activated ion current of amphibian oocytes.  

PubMed

A comparative analysis of a hyperpolarization-activated ion current present in amphibian oocytes was performed using the two-electrode voltage-clamp technique in Xenopus laevis, Xenopus tropicalis, and Ambystoma mexicanum. This current appears to be driven mainly by Cl(-) ions, is independent of Ca(2+), and is made evident by applying extremely negative voltage pulses; it shows a slow activating phase and little or no desensitization. The pharmacological profile of the current is complex. The different channel blocker used for Cl(-), K(+), Na(+) and Ca(2+) conductances, exhibited various degrees of inhibition depending of the species. The profiles illustrate the intricacy of the components that give rise to this current. During X. laevis oogenesis, the hyperpolarization-activated current is present at all stages of oocytes tested (II-VI), and the amplitude of the current increases from about 50 nA in stage I to more than 1 ?A in stage VI; nevertheless, there was no apparent modification of the kinetics. Our results suggest that the hyperpolarization-activated current is present both in order Anura and Urodela oocytes. However, the electrophysiological and pharmacological characteristics are quite perplexing and seem to suggest a mixture of ionic conductances that includes the activation of both anionic and cationic channels, most probably transiently opened due to the extreme hyperpolarizion of the plasma membrane. As a possible mechanism for the generation of the current, a kinetic model which fits the data suggests the opening of pores in the plasma membrane whose ion selectivity is dependent on the extracellular Cl(-) concentration. The extreme voltage conditions could induce the opening of otherwise latent pores in plasma membrane proteins (i.e., carriers), resembling the ´slippage´ events already described for some carriers. These observations should be valuable for other groups trying to express cloned, voltage-dependent ion channels in oocytes of amphibian in which hyperpolarizing voltage pulses are applied to activate the channels. PMID:23440457

Ochoa-de la Paz, L D; Salazar-Soto, D B; Reyes, J P; Miledi, R; Martinez-Torres, A

2013-08-01

312

Chemical structure of sterols that activate oocyte meiosis  

Microsoft Academic Search

GONADOTROPHINS and various growth factors, but not sex steroids, can induce resumption of meiosis in vitro, but only in oocytes enclosed by cumulus-granulosa cells1. Follicular purines prevent resumption of meiosis2,3. This process can be overcome, in vitro, by a transient elevation of cyclic AMP resulting in the production of a diffusible meiosis-inducing substance secreted by the cumulus cells4. A meiosis-inducing

Anne Grete Byskov; Claus Yding Andersen; Lars Nordholm; Henning Thogersen; Xia Guoliang; Ole Wassmann; Jan Vanggaard Andersen; Erling Guddal; Tiny Roed

1995-01-01

313

Multiple Requirements of PLK1 during Mouse Oocyte Maturation  

PubMed Central

Polo-like kinase 1 (PLK1) orchestrates multiple events of cell division. Although PLK1 function has been intensively studied in centriole-containing and rapidly cycling somatic cells, much less is known about its function in the meiotic divisions of mammalian oocytes, which arrest for a long period of time in prophase before meiotic resumption and lack centrioles for spindle assembly. Here, using specific small molecule inhibition combined with live mouse oocyte imaging, we comprehensively characterize meiotic PLK1’s functions. We show that PLK1 becomes activated at meiotic resumption on microtubule organizing centers (MTOCs) and later at kinetochores. PLK1 is required for efficient meiotic resumption by promoting nuclear envelope breakdown. PLK1 is also needed to recruit centrosomal proteins to acentriolar MTOCs to promote normal spindle formation, as well as for stable kinetochore-microtubule attachment. Consequently, PLK1 inhibition leads to metaphase I arrest with misaligned chromosomes activating the spindle assembly checkpoint (SAC). Unlike in mitosis, the metaphase I arrest is not bypassed by the inactivation of the SAC. We show that PLK1 is required for the full activation of the anaphase promoting complex/cyclosome (APC/C) by promoting the degradation of the APC/C inhibitor EMI1 and is therefore essential for entry into anaphase I. Moreover, our data suggest that PLK1 is required for proper chromosome segregation and the maintenance of chromosome condensation during the meiosis I-II transition, independently of the APC/C. Thus, our results define the meiotic roles of PLK1 in oocytes and reveal interesting differential requirements of PLK1 between mitosis and oocyte meiosis in mammals. PMID:25658810

Solc, Petr; Kitajima, Tomoya S.; Yoshida, Shuhei; Brzakova, Adela; Kaido, Masako; Baran, Vladimir; Mayer, Alexandra; Samalova, Pavlina; Motlik, Jan; Ellenberg, Jan

2015-01-01

314

Extra- and intracellular ice formation in mouse oocytes.  

PubMed

The occurrence of intracellular ice formation (IIF) during freezing, or the lack there of, is the single most important factor determining whether or not cells survive cryopreservation. One important determinant of IIF is the temperature at which a supercooled cell nucleates. To avoid intracellular ice formation, the cell must be cooled slowly enough so that osmotic dehydration eliminates nearly all cell supercooling before reaching that temperature. This report is concerned with factors that determine the nucleation temperature in mouse oocytes. Chief among these is the concentration of cryoprotective additive (here, glycerol or ethylene glycol). The temperature for IIF decreases from -14 degrees C in buffered isotonic saline (PBS) to -41 degrees C in 1M glycerol/PBS and 1.5M ethylene glycol/PBS. The latter rapidly permeates the oocyte; the former does not. The initial extracellular freezing at -3.9 to -7.8 degrees C, depending on the CPA concentration, deforms the cell. In PBS that deformation often leads to IIF; in CPA it does not. The oocytes are surrounded by a zona pellucida. That structure appears to impede the growth of external ice through it, but not to block it. In most cases, IIF is characterized by an abrupt blackening or flashing during cooling. But in some cases, especially with dezonated oocytes, a pale brown veil abruptly forms during cooling followed by slower blackening during warming. Above -30 degrees C, flashing occurs in a fraction of a second. Below -30 degrees C, it commonly occurs much more slowly. We have observed instances where flashing is accompanied by the abrupt ejection of cytoplasm. During freezing, cells lie in unfrozen channels between the growing external ice. From phase diagram data, we have computed the fraction of water and solution that remains unfrozen at the observed flash temperatures and the concentrations of salt and CPA in those channels. The results are somewhat ambiguous as to which of these characteristics best correlates with IIF. PMID:15975568

Mazur, Peter; Seki, Shinsuke; Pinn, Irina L; Kleinhans, F W; Edashige, Keisuke

2005-08-01

315

Weld penetration and defect control  

SciTech Connect

Highly engineered designs increasingly require the use of improved materials and sophisticated manufacturing techniques. To obtain optimal performance from these engineered products, improved weld properties and joint reliability are a necessarily. This requirement for improved weld performance and reliability has led to the development of high-performance welding systems in which pre-programmed parameters are specified before any welding takes place. These automated systems however lack the ability to compensate for perturbations which arise during the welding process. Hence the need for systems which monitor and control the in-process status of the welding process. This report discusses work carried out on weld penetration indicators and the feasibility of using these indicators for on-line penetration control.

Chin, B.A.

1992-05-15

316

Jeeps Penetrating a Hostile Desert  

ERIC Educational Resources Information Center

Several jeeps are poised at base camp on the edge of a desert aiming to escort one of them as far as possible into the desert, while the others return to camp. They all have full tanks of gas and share their fuel to maximize penetration. In a friendly desert it is best to leave caches of fuel along the way to help returning jeeps. We solve the…

Bailey, Herb

2009-01-01

317

Dysferlin is essential for endocytosis in the sea star oocyte.  

PubMed

Dysferlin is a calcium-binding transmembrane protein involved in membrane fusion and membrane repair. In humans, mutations in the dysferlin gene are associated with muscular dystrophy. In this study, we isolated plasma membrane-enriched fractions from full-grown immature oocytes of the sea star, and identified dysferlin by mass spectrometry analysis. The full-length dysferlin sequence is highly conserved between human and the sea star. We learned that in the sea star Patiria miniata, dysferlin RNA and protein are expressed from oogenesis to gastrulation. Interestingly, the protein is highly enriched in the plasma membrane of oocytes. Injection of a morpholino against dysferlin leads to a decrease of endocytosis in oocytes, and to a developmental arrest during gastrulation. These results suggest that dysferlin is critical for normal endocytosis during oogenesis and for embryogenesis in the sea star and that this animal may be a useful model for studying the relationship of dysferlin structure as it relates to its function. PMID:24368072

Oulhen, Nathalie; Onorato, Thomas M; Ramos, Isabela; Wessel, Gary M

2014-04-01

318

Rearranged mitochondrial genomes are present in human oocytes  

SciTech Connect

Using quantitative PCR, we have determined that a human oocyte contains {approximately}100,000 mitochondrial genomes (mtDNAs). We have also found that some oocytes harbor measurable levels (up to 0.1%) of the so-called common deletion, an mtDNA molecule containing a 4,977-bp rearrangement that is present in high amounts in many patients with {open_quotes}sporadic{close_quotes} Kearns-Sayre syndrome (KSS) and progressive external ophthalmoplegia (PEO). This is the first demonstration that rearranged mtDNAs are present in human oocytes, and it provides experimental support for the supposition that pathogenic deletions associated with the ontogeny of sporadic KSS and PEO can be transmitted in the female germ line, from mother to child. The relevance of these findings to the accumulation of extremely low levels of deleted mtDNAs in both somatic and germ-line tissues during normal human aging is also discussed. 42 refs., 6 figs., 1 tab.

Xi, Chen; Prosser, R.; Simonetti, S. [Columbia Univ., New York, NY (United States)] [and others

1995-08-01

319

The gametic synapse: RNA transfer to the bovine oocyte.  

PubMed

Even after several decades of quiescent storage in the ovary, the female germ cell is capable of reinitiating transcription to build the reserves that are essential to support early embryonic development. In the current model of mammalian oogenesis, there exists bilateral communication between the gamete and the surrounding cells that is limited to paracrine signaling and direct transfer of small molecules via gap junctions existing at the end of the somatic cells' projections that are in contact with the oolemma. The purpose of this work was to explore the role of cumulus cell projections as a means of conductance of large molecules, including RNA, to the mammalian oocyte. By studying nascent RNA with confocal and transmission electron microscopy in combination with transcript detection, we show that the somatic cells surrounding the fully grown bovine oocyte contribute to the maternal reserves by actively transferring large cargo, including mRNA and long noncoding RNA. This occurrence was further demonstrated by the reconstruction of cumulus-oocyte complexes with transfected cumulus cells transferring a synthetic transcript. We propose selective transfer of transcripts occurs, the delivery of which is supported by a remarkable synapselike vesicular trafficking connection between the cumulus cells and the gamete. This unexpected exogenous contribution to the maternal stores offers a new perspective on the determinants of female fertility. PMID:25143353

Macaulay, Angus D; Gilbert, Isabelle; Caballero, Julieta; Barreto, Rodrigo; Fournier, Eric; Tossou, Prudencio; Sirard, Marc-André; Clarke, Hugh J; Khandjian, Édouard W; Richard, Francois J; Hyttel, Poul; Robert, Claude

2014-10-01

320

Factors useful in predicting the success of oocyte donation: a 3-year retrospective analysis  

Microsoft Academic Search

Objective: To establish prognostic relevance of parameters assessed in oocyte donation cycles.Design: Retrospective analysis.Setting: Large university-based donor oocyte program.Patient(s): All oocyte recipient cycles achieving embryo transfer from September 1995 to October 1998.Intervention(s): None.Main Outcome Measure(s): Pregnancy.Result(s): Recipient age and reproductive status, day 9 and 12 serum estradiol (E2) levels and a progesterone (P) level obtained 2 days after initiation of

Nicole Noyes; Brittany Starr Hampton; Alan Berkeley; Frederick Licciardi; James Grifo; Lewis Krey

2001-01-01

321

In Vitro Ovine Embryo Production: the Study of Seasonal and Oocyte Recovery Method Effects  

PubMed Central

Background: To current knowledge, different oocyte's recovery method and various seasons have profound impact on in vitro embryo production (IVEP). Objectives: The aim of this study was to define an efficient recovery method for oocytes harvesting from slaughterhouse material in different seasons, and their effects on IVEP yield. Materials and Methods: Ovaries from slaughtered ewes in breeding season (BS) and non-breeding season (NBS) were collected from a local abattoir. The oocytes were recovered through aspiration, centrifugation (ORC), puncture and slicing, and categorized into three classes (I, oocytes with more than three layers of cumulus cells; II, less than three layers with damaged cumulus cells; III, denuded oocytes). After cultivation in TCM 199 for 24 hours, matured oocytes were subjected to in vitro fertilization (IVF) and in vitro culture (IVC). The oocyte recovery using ORC in BS and NBS was significantly higher (P < 0.05) compared with other recovery methods. Results: No significant dissimilarities in the proportion of oocytes reaching M-II stage were recorded when using different oocyte recovery methods in different seasons. Aspiration resulted in lower (P < 0.05) proportion of class I (BS, 60.0 ± 2.1; NBS, 51.1 ± 2.1) compared to ORC (BS, 82.0 ± 1.2; NBS, 70.0 ± 1.2), slicing (BS, 80.0 ± 2.1; NBS, 71.0 ± 1.4) and puncture (BS, 80.0 ± 1.5; NBS, 72.0 ± 2.0). Monospermy and blastocyst development rates were significantly higher using ORC than other recovery techniques in both BS and NBS. More oocytes with high quality, greater blastocyst development and oocyte recovery rates were achieved in BS. Conclusions: The results revealed that oocytes harvesting technique and season are effective in the rate of cleavage and blastocysts’ development, and suggest that despite same meiotic resumption rate in all treatments, it would be better to use ORC. PMID:25593733

Dadashpour Davachi, Navid; Zare Shahneh, Ahmad; Kohram, Hamid; Zhandi, Mahdi; Dashti, Saeed; Shamsi, Helia; Moghadam, Razieh

2014-01-01

322

Expression and modification of PKA and AKAPs during meiosis in rat oocytes  

Microsoft Academic Search

Meiosis in oocytes is initiated during fetal life, arrested around birth and resumed after puberty. Meiotic arrest is controlled by a cAMP-dependent protein kinase (PKA)-mediated cAMP action. We examined oocytes for the presence and modulation of the regulatory (R) subunits of PKA and the A-kinase anchoring proteins (AKAPs) that target PKA to specific subcellular locations. We found that rat oocytes

M. Kovo; R. V. Schillace; D. Galiani; L. B. Josefsberg; D. W. Carr; N. Dekel

2002-01-01

323

The stability, toxicity and effectiveness of unmodified and phosphorothioate antisense oligodeoxynucleotides in Xenopus oocytes and embryos.  

PubMed Central

The properties of antisense phosphorothioate and unmodified oligodeoxynucleotides have been studied in Xenopus oocytes and embryos. We find that phosphorothioates, like unmodified oligodeoxynucleotides, can degrade Vg1 mRNA in oocytes via an endogenous RNase H-like activity. In oocytes, phosphorothioate oligodeoxynucleotides are more stable than unmodified oligodeoxynucleotides and are more effective in degrading Vg1 mRNA. In embryos, neither unmodified nor phosphorothioate deoxyoligonucleotides were effective in degrading Vg1 message at sub-toxic doses. Images PMID:1692405

Woolf, T M; Jennings, C G; Rebagliati, M; Melton, D A

1990-01-01

324

Proteomics-Based Systems Biology Modeling of Bovine Germinal Vesicle Stage Oocyte and Cumulus Cell Interaction  

PubMed Central

Background Oocytes are the female gametes which establish the program of life after fertilization. Interactions between oocyte and the surrounding cumulus cells at germinal vesicle (GV) stage are considered essential for proper maturation or ‘programming’ of oocytes, which is crucial for normal fertilization and embryonic development. However, despite its importance, little is known about the molecular events and pathways involved in this bidirectional communication. Methodology/Principal Findings We used differential detergent fractionation multidimensional protein identification technology (DDF-Mud PIT) on bovine GV oocyte and cumulus cells and identified 811 and 1247 proteins in GV oocyte and cumulus cells, respectively; 371 proteins were significantly differentially expressed between each cell type. Systems biology modeling, which included Gene Ontology (GO) and canonical genetic pathway analysis, showed that cumulus cells have higher expression of proteins involved in cell communication, generation of precursor metabolites and energy, as well as transport than GV oocytes. Our data also suggests a hypothesis that oocytes may depend on the presence of cumulus cells to generate specific cellular signals to coordinate their growth and maturation. Conclusions/Significance Systems biology modeling of bovine oocytes and cumulus cells in the context of GO and protein interaction networks identified the signaling pathways associated with the proteins involved in cell-to-cell signaling biological process that may have implications in oocyte competence and maturation. This first comprehensive systems biology modeling of bovine oocytes and cumulus cell proteomes not only provides a foundation for signaling and cell physiology at the GV stage of oocyte development, but are also valuable for comparative studies of other stages of oocyte development at the molecular level. PMID:20574525

Peddinti, Divyaswetha; Memili, Erdogan; Burgess, Shane C.

2010-01-01

325

Dietary Lipid Saturation Influences Environmental Temperature Preference but Not Resting Metabolic Rate in the Djungarian Hamster (Phodopus sungorus)  

Microsoft Academic Search

Heterothermic rodents increase self-selection of diets rich in polyunsaturated fatty acids (PUFAs) when exposed to cold, short days, or short-day melatonin profiles, and Djungarian hamsters (Phodopus sungorus) do so in long days in response to cold exposure alone. To determine whether Djungarian hamsters are also capable of selecting a thermal environment in response to dietary lipid composition, continuously normothermic hamsters

Ryan Pannorfi; Barry M. Zee; Itzick Vatnick; Nancy Berner; Sara M. Hiebert

2012-01-01

326

A Sex-Limited Serum Protein of Syrian Hamsters: Definition of Female Protein and Regulation by Testosterone  

Microsoft Academic Search

Normal Syrian hamster females contain a serum protein not found by simple gel diffusion assay in normal adult males. This sex-limited protein was called female protein (FP). Low levels of FP were found in sera from normal weanling male hamsters. Adult male hamsters castrated or treated with diethylstilbestrol also developed serum FP, which could be suppressed by administration of testosterone.

J. E. Coe

1977-01-01

327

Intraspecific organization of dwarf hamsters Phodopus campbelli and Phodopus sungorus (Rodentia: Cricetinae) basing on mtDNA analysis  

Microsoft Academic Search

35 Two dwarf hamster species of the genus Phodopus —Djungarian hamster ( Ph. sungorus ) and Campbell’ hamster (Ph. campbelli )—have been widely used since 1960s in many laboratories of the world as model objects for studying various aspects of physiology, behavior, and seasonal changes in the organism. We were the first to perform analysis of mitochondrial DNA polymorphism of

I. G. Meshchersky; N. Yu. Feoktistova

2009-01-01

328

Diet affects resting, but not basal metabolic rate of normothermic Siberian hamsters acclimated to winter  

Microsoft Academic Search

We examined the effect of different dietary supplements on seasonal changes in body mass (mb), metabolic rate (MR) and nonshivering thermogenesis (NST) capacity in normothermic Siberian hamsters housed under semi-natural conditions. Once a week standard hamster food was supplemented with either sunflower and flax seeds, rich in polyunsaturated fatty acids (FA), or mealworms, rich in saturated and monounsaturated FA. We

Jakub P. Gutowski; Micha? S. Wojciechowski; Ma?gorzata Jefimow

2011-01-01

329

Diet affects resting, but not basal metabolic rate of normothermic Siberian hamsters acclimated to winter.  

PubMed

We examined the effect of different dietary supplements on seasonal changes in body mass (m(b)), metabolic rate (MR) and nonshivering thermogenesis (NST) capacity in normothermic Siberian hamsters housed under semi-natural conditions. Once a week standard hamster food was supplemented with either sunflower and flax seeds, rich in polyunsaturated fatty acids (FA), or mealworms, rich in saturated and monounsaturated FA. We found that neither of these dietary supplements affected the hamsters' normal winter decrease in m(b) and fat content nor their basal MR or NST capacity. NST capacity of summer-acclimated hamsters was lower than that of winter-acclimated ones. The composition of total body fat reflected the fat composition of the dietary supplements. Resting MR below the lower critical temperature of the hamsters, and their total serum cholesterol concentration were lower in hamsters fed a diet supplemented with mealworms than in hamsters fed a diet supplemented with seeds. These results indicate that in mealworm-fed hamsters energy expenditure in the cold is lower than in animals eating a seed-supplemented diet, and that the degree of FA unsaturation of diet affects energetics of heterotherms, not only during torpor, but also during normothermy. PMID:21889598

Gutowski, Jakub P; Wojciechowski, Micha? S; Jefimow, Ma?gorzata

2011-12-01

330

Caries Activity and Prevalence of Streptococcus mutans in Mice Caged Together with Caries-Active Hamsters  

Microsoft Academic Search

Twelve male mice, 3 weeks old, were caged together with caries-active hamsters and the twin brothers of the mice served as controls. The hamsters harboured Streptococcus mutans and Streptococcus salivarius in their mouths, while neither of these streptococcal species could be recovered from the mice at the beginning of the experiment. At the end of the experiment after nine weeks

A. Strålfors; J. Carlsson; G. Sundqvist

1970-01-01

331

BODY TEMPERATURE IN THE MOUSE, HAMSTER, AND RAT EXPOSED TO RADIOFREQUENCY RADIATION: AN INTERSPECIES COMPARISON  

EPA Science Inventory

Colonic temperatures of BALB/c and CBA/J mice, golden hamsters, and Sprague-Dawley rats were taken immediately after exposure for 90 min to radiofrequency (RF) radiation. Exposures were made in 2450 MHz (mouse and hamster) or 600 MHz (rat) waveguide exposure systems while the dos...

332

Corn fiber oil and sitostanol decrease cholesterol absorption independently of intestinal sterol transporters in hamsters  

Technology Transfer Automated Retrieval System (TEKTRAN)

The aim of this study was to investigate the cholesterol-lowering mechanism of corn fiber oil (CFO), ferulate phytostanyl esters (FPE) and parent compounds including sitostanol and ferulic acid in hamsters. Method: Seventy male golden syrian hamsters were randomly assigned to six experimental diets ...

333

OBSERVATIONS OF SYRIAN HAMSTER FETUSES AFTER EXPOSURE TO 2450-MHZ MICROWAVES  

EPA Science Inventory

The teratogenic potential of microwaves was examined in a rodent species, the Syrian hamster. Exposure of hamsters to 2450-MHz CW microwaves at a power denisty of 20 mW/sq. cm. for 100 minutes daily on days 6-14 of gestation caused no significant change in fetal survival, body we...

334

Fine structural changes in the hamster pineal gland after blinding and superior cervical ganglionectomy  

Microsoft Academic Search

Pineal glands of male hamsters 8 weeks after removal of both eyes or both superior cervical ganglia and those of untreated animals were studied by electron microscopy. In the blinded hamsters the reproductive organs were remarkably involuted, whereas the pinealocytes enlarged and were characterized by a tremendous hypertrophy of the smoothsurfaced endoplasmic reticulum, in the mesh of which some dense

Huai-San Lin; Bang-Hsiung Hwang; Chang-Yean Tseng

1975-01-01

335

Vomeronasal Organ: Critical Role in Mediating Sexual Behavior of the Male Hamster  

Microsoft Academic Search

Sexual behavior in male hamsters is totally abolished by bilateral removal of the olfactory bulbs. This operation eliminates sensory input from both the olfactory and the vomeronasal systems. We previously demonstrated that peripheral destruction of the olfactory receptors caused anosmia but did not impair male hamster mating behavior. Here we demonstrate that peripheral deafferentation of the vomeronasal system produces severe

J. Bradley Powers; Sarah S. Winans

1975-01-01

336

Effects of Photoperiod and Melatonin Infusions on Body Weight in Pinealectomized Juvenile Siberian Hamsters (Phodopus sungorus)  

Microsoft Academic Search

We examined the effects of daily melatonin (Mel) infusions in pinealectomized prepubertal male Siberian hamsters in three different conditions. In one study we investigated the body weight maturation response to one hour daily infusions of 10 ng, 25 ng, or 50 ng of Mel in pinealectomized hamsters. Animals received, at day 15 of life, programmed subcutaneous infusions of Mel or

Bülent GÜNDÜZ

337

DNA SYNTHESIS IN THE FERTILIZING HAMSTER SPERM NUCLEUS: SPERM TEMPLATE AVAILABILITY AND EGG CYTOPLASMIC CONTROL  

EPA Science Inventory

To assess the role of sperm template availability in the regulation of DNA synthesis, the morphological status of the fertilizing hamster sperm nucleus was correlated with its ability to synthesize DNA after in vivo and in vitro fertilization. Fertilized hamster eggs were incubat...

338

USEFULNESS OF THE HAMSTER FOR FORAGE EVALUATION National Grassland Research Institute, Nishinasuno, Tochigi, Japan  

E-print Network

the caecum than the pregastric pouch. The hamster, like the ruminant, having such a digestive system fed with roughage. These results show that the digestive system of the hamster changes of digestive organ, changes in structure and function of digestive organ caused by roughage feeding, evaluation

Paris-Sud XI, Université de

339

Network Penetration Testing and Research  

NASA Technical Reports Server (NTRS)

This paper will focus the on research and testing done on penetrating a network for security purposes. This research will provide the IT security office new methods of attacks across and against a company's network as well as introduce them to new platforms and software that can be used to better assist with protecting against such attacks. Throughout this paper testing and research has been done on two different Linux based operating systems, for attacking and compromising a Windows based host computer. Backtrack 5 and BlackBuntu (Linux based penetration testing operating systems) are two different "attacker'' computers that will attempt to plant viruses and or NASA USRP - Internship Final Report exploits on a host Windows 7 operating system, as well as try to retrieve information from the host. On each Linux OS (Backtrack 5 and BlackBuntu) there is penetration testing software which provides the necessary tools to create exploits that can compromise a windows system as well as other operating systems. This paper will focus on two main methods of deploying exploits 1 onto a host computer in order to retrieve information from a compromised system. One method of deployment for an exploit that was tested is known as a "social engineering" exploit. This type of method requires interaction from unsuspecting user. With this user interaction, a deployed exploit may allow a malicious user to gain access to the unsuspecting user's computer as well as the network that such computer is connected to. Due to more advance security setting and antivirus protection and detection, this method is easily identified and defended against. The second method of exploit deployment is the method mainly focused upon within this paper. This method required extensive research on the best way to compromise a security enabled protected network. Once a network has been compromised, then any and all devices connected to such network has the potential to be compromised as well. With a compromised network, computers and devices can be penetrated through deployed exploits. This paper will illustrate the research done to test ability to penetrate a network without user interaction, in order to retrieve personal information from a targeted host.

Murphy, Brandon F.

2013-01-01

340

Effects of dimethyl sulfoxide on asymmetric division and cytokinesis in mouse oocytes  

PubMed Central

Background Dimethyl sulfoxide (DMSO) is used extensively as a permeable cryoprotectant and is a common solvent utilized for several water-insoluble substances. DMSO has various biological and pharmacological activities; however, the effect of DMSO on mouse oocyte meiotic maturation remains unknown. Results In DMSO-treated oocytes, we observed abnormal MII oocytes that contained large polar bodies, including 2-cell–like MII oocytes, during in vitro maturation. Oocyte polarization did not occur, due to the absence of actin cap formation and spindle migration. These features are among the primary causes of abnormal symmetric division; however, analysis of the mRNA expression levels of genes related to asymmetric division revealed no significant difference in the expression of these factors between the 3% DMSO-treated group and the control group. After each “blastomere” of the 2-cell–like MII stage oocytes was injected by one sperm head respectively, the oocytes still possessed the ability to extrude the second polar body from each “blastomere” and to begin cleavage. However, MII oocytes with large polar bodies developed to the blastocyst stage after intracytoplasmic sperm injection (ICSI). Furthermore, other permeable cryoprotectants, such as ethylene glycol and glycerol, also caused asymmetric division failure. Conclusion Permeable cryoprotectants, such as DMSO, ethylene glycol, and glycerol, affect asymmetric division. DMSO disrupts cytokinesis completion by inhibiting cortical reorganization and polarization. Oocytes that undergo symmetric division maintain the ability to begin cleavage after ICSI. PMID:24953160

2014-01-01

341

Association between nondisjunction and maternal age in meiosis-II human oocytes.  

PubMed Central

The relationship between advanced maternal age and increased risk of trisomic offspring is well known clinically but not clearly understood at the level of the oocyte. A total of 383 oocytes that failed fertilization from 107 patients undergoing in vitro fertilization were analyzed by FISH using X-, 18-, and 13/21-chromosome probes simultaneously. The corresponding polar bodies were also analyzed in 188 of these oocytes. The chromosomes in the oocyte and first polar body complement each other and provide an internal control to differentiate between aneuploidy and technical errors. Two mechanisms of nondisjunction were determined. First, nondisjunction of bivalent chromosomes resulting in two univalents going to the same pole and, second, nondisjunction by premature chromatid separation (predivision) of univalent chromosomes producing either a balanced (2 + 2) or unbalanced (3 + 1) distribution of chromatids into the first polar body and M-II oocytes. Balanced predivision of chromatids, previously proposed as a major mechanism of aneuploidy, was found to increase significantly with time in culture (P < .005), which suggests that this phenomenon should be interpreted carefully. Unbalanced predivision and classical nondisjunction were unaffected by oocyte aging. In comparing oocytes from women <35 years of age with oocytes from women > or = 40 years of age, a significant increase (P < .001) in nondisjunction of full dyads was found in the oocytes with analyzable polar bodies and no FISH errors. Premature predivision of chromatids was also found to cause nondisjunction, but it did not increase with maternal age. Images Figure 2 Figure 3 PMID:8659524

Dailey, T.; Dale, B.; Cohen, J.; Munné, S.

1996-01-01

342

Src-family Tyrosine Kinases in Oogenesis, Oocyte Maturation, and Fertilization: An Evolutionary Perspective  

PubMed Central

The oocyte is a highly specialized cell poised to respond to fertilization with a unique set of actions needed to recognize and incorporate a single sperm, complete meiosis, reprogram maternal and paternal genomes and assemble them into a unique zygotic genome, and finally initiate the mitotic cell cycle. Oocytes accomplish this diverse series of events through an array of signal transduction pathway components that include a characteristic collection of protein tyrosine kinases. The src-family protein kinases figure importantly in this signaling array and oocytes characteristically express certain SFKs at high levels to provide for the unique actions that the oocyte must perform. The SFKs typically exhibit a distinct pattern of subcellular localization in oocytes and perform critical functions in different subcellular compartments at different steps during oocyte maturation and fertilization. While many aspects of SFK signaling are conserved among oocytes from different species, significant differences exist in the extent to which src-family -mediated pathways are used by oocytes from species that fertilize externally vs those which are fertilized internally. The observation that several oocyte functions which require SFK signaling appear to represent common points of failure during assisted reproductive techniques in humans, highlights the importance of these signaling pathways for human reproductive health. PMID:25030759

Kinsey, William H.

2015-01-01

343

Ultrastructure of oocytes of the Urostreptus atrobrunneus (Diplopoda, Spirostreptida, Spirostreptidae): a potential urban centers plague.  

PubMed

The knowledge of the process of egg formation is indispensable for understanding the mechanisms involved in the reproduction of different species. In this context, the objective of this work was to describe the ultrastructure of the oocytes of Urostreptus atrobrunneus (Spirostreptida), a potential plague of urban centers in different locations of São Paulo State. The lack of knowledge about the morphology, physiology, and the reproductive behavior of the species have hindered an effective control of it. The oocytes of U. atrobrunneus presented three development stages: young oocyte or type I; intermediary oocyte or type II; and mature oocyte or type III. During the oocyte development, the cytoplasm become filled with several globules of protein, drops of lipids, and sphaerocrystals, and it was not observed in many organelles in the oocytes with exception of mitochondria, abundant, principally in young oocytes. The vitelline membrane is also deposited in a discontinuous form and the chorion does not present differentiation of layers. The follicular epithelium alters its shape according to the development phase of the oocyte. Part of the vitellus is from exogenous origin and part is endogenous. Before this, only two studies about the ultrastructural analysis of the female germ cells of diplopods were published. PMID:22791626

Fontanetti, Carmem S; Calligaris, Izabela Braggião; Souza, Tatiana Da Silva; Iamonte, Mônika

2012-11-01

344

The role of phosphatidylinositol signaling pathway in regulating serotonin-induced oocyte maturation in Mercenaria mercenaria  

NASA Astrophysics Data System (ADS)

Serotonin (5-HT) has been found to stimulate meiotic maturation of oocytes in many molluscs. During maturation, several signaling pathways are involved, especially the phosphatidylinositol and cAMP pathways. In order to examine the possible role of the phosphatidylinositol signaling pathway in regulating oocyte maturation in Mercenaria mercenaria, the effects of the activator/inhibitor of phospholipase (PLC) and protein kinase C (PKC) on serotonin-induced maturation were studied. Results show that high-concentrations of neomycin (inhibitor of PLC) blocked oocyte maturation, while 9, 10-dimethyl-1, 2-benzanthracene (DMBA, activator of PLC) promoted oocyte maturation in the presence of serotonin. It was also found that in the presence of serotonin, phorbol 12-myristate 13-acetate (PMA, activator of PKC) inhibited oocyte maturation, while sphingosine (inhibitor of PKC) stimulated oocyte maturation. These results indicate that serotonin-induced oocyte maturation requires the activation of the phosphatidylinositol pathway. Decrease of PLC inhibited serotonin-induced oocyte maturation, whereas a decrease of PKC stimulated the maturation. Thus, our study indicates that serotonin promotes maturation of M. mercenaria oocytes through PLC stimulated increase in calcium ion concentration via inositol-1, 4, 5-trisphosphate (IP3) but not PKC.

Wang, Qing; Zhang, Tao

2011-05-01

345

Induction of meiotic maturation in Xenopus oocytes by 12-O-tetradecanoylphorbol 13-acetate  

SciTech Connect

Fully grown Xenopus oocytes are physiologically arrested at the G2/prophase border of the first meiotic division. Addition in vitro of progesterone or insulin causes release of the G2/prophase block and stimulates meiotic cell division of the oocyte, leading to maturation of the oocyte into an unfertilized egg. The possibility that the products of polyphosphoinositide breakdown, diacylglycerol and inositol-1,4,5-trisphosphate are involved in occyte maturation was investigated. Microinjection of IP/sub 3/ into oocytes just prior to addition of progesterone or insulin accelerated the rate of germinal vesicle breakdown (GVBD) by up to 25%. Half-maximal acceleration occurred at an intracellular IP/sub 3/ concentration of 1 ..mu..M. Treatment of oocytes with the diacylglycerol analog and tumor promoter, 12-O-tetradecanoylphorbol 13-acetate (TPA) induced GVBD in the absence of hormone. Half-maximal induction of GVBD occurred with 150 nM TPA and was blocked by pretreatment of oocytes with 10 nM cholera toxin. Microinjection of highly purified protein kinase C from rat brain oocytes did not induce maturation but markedly accelerated the rate of insulin-induced oocyte maturation. However, injection of the enzyme had no effect on progesterone action. These results indicate that protein kinase C is capable of regulating oocyte maturation of Xenopus.

Stith, B.J.; Maller, J.L.

1987-04-01

346

Supplementation of canine oocyte in vitro maturation medium with progesterone, somatotropin, and epidermal growth factor  

E-print Network

mammalian species such as bovine, mouse, and human (Tesoriero et al. , 1981; Szabo, 1967). The size of canine oocytes as reported by Farstad at initial collection from the ovary, ranges from 70 pm to 130 pm, averaging 112 pm (without zona pellucida... or cumulus), while a mature oocyte with zona pellucida and cumulus cells produced in vivo is about 230-240 pm in diameter (Hoist and Phemister, 1971). Studies on oocyte size and competency have reported that canine oocytes greater than 110 pm have...

Willingham-Rocky, Lauri Ann

2012-06-07

347

Association between nondisjunction and maternal age in meiosis-II human oocytes  

SciTech Connect

The relationship between advanced maternal age and increased risk of trisomic offspring is well know clinically but not clearly understood at the level of the oocyte. A total of 383 oocytes that failed fertilization from 107 patients undergoing in vitro fertilization were analyzed by FISH using X-, 18-, and 13/21-chromosome probes simultaneously. The corresponding polar bodies were also analyzed in 188 of these oocytes. The chromosomes in the oocyte and first polar body complement each other and provide an internal control to differentiate between aneuploidy and technical errors. Two mechanisms of nondisjunction were determined. First, nondisjunction of bivalent chromosomes resulting in two univalents going to the same pole and, second, nondisjunction by premature chromatid separation (predivision) of univalent chromsomes producing either a balanced (2 + 2) or unbalanced (3 + 1) distribution of chromatids into the first polar body and M-II oocytes. Balanced predivision of chromatids, previously proposed as a major mechanism of aneuploidy, was found to increase significantly with time in culture (P < .005), which suggests that this phenomenon should be interpreted carefully. Unbalanced predivision and classical nondisjunction were unaffected by oocyte aging. In comparing oocytes from women <35 years of age with oocytes from women {ge}40 years of age, a significant increase (P < .001) in nondisjunction of full dyads was found in the oocytes with analyzable polar bodies and no FISH errors. Premature predivision of chromatids was also found to cause nondisjunction, but it did not increase with maternal age. 44 refs., 3 figs., 2 tabs.

Dailey, T.; Cohen, J.; Munne, S.; Dale, B.

1996-07-01

348

Fyn Kinase Activity Is Required for Normal Organization and Functional Polarity of the Mouse Oocyte Cortex  

PubMed Central

Summary The objective of the present study was to determine whether Fyn kinase participated in signaling events during sperm–egg interactions, sperm incorporation, and meiosis II. The functional requirement of Fyn kinase activity in these events was tested through the use of the protein kinase inhibitor SKI-606 (Bosutinib) and by analysis of Fyn-null oocytes. Suppression of Fyn kinase signaling prior to fertilization caused disruption of the functional polarity of the oocyte with the result that sperm were able to fuse with the oocyte in the immediate vicinity of the meiotic spindle, a region that normally does not allow sperm fusion. The loss of functional polarity was accompanied by disruption of the microvilli and cortical granule-free zone that normally overlie the meiotic spindle. Changes in the distribution of cortical granules and filamentous actin provided further evidence of disorganization of the oocyte cortex. Rho B, a molecular marker for oocyte polarity, was unaffected by suppression of Fyn activity; however, the polarized association of Par-3 with the cortex overlying the meiotic spindle was completely disrupted. The defects in oocyte polarity in Fyn-null oocytes correlated with a failure of the MII chromosomes to maintain a position close to the oocyte cortex which seemed to underlie the above defects in oocyte polarity. This was associated with a delay in completion of meiosis II, however, pronuclei eventually formed and subsequent mitotic cleavages and blastocyst formation occurred normally. PMID:19363790

Luo, Jinping; Mcginnis, Lynda K.; Kinsey, William H.

2014-01-01

349

Brilliant cresyl blue staining negatively affects mitochondrial functions in porcine oocytes.  

PubMed

Summary The aim of the present study was to examine the effects of brilliant cresyl blue (BCB) staining on mitochondrial functions in porcine oocytes. Cumulus-oocyte complexes (COCs) collected from slaughterhouse-derived porcine ovaries were cultured with (13 ?M) or without (0 ?M, control) BCB for 60 min. Mitochondrial functions in oocytes were examined immediately after staining or after in vitro maturation. The BCB-stained oocytes produced reactive oxygen species (ROS) at higher levels than control oocytes immediately after staining (2.2-fold, P < 0.001) and after maturation (1.7-fold, P < 0.001). The adenosine triphosphate (ATP) content and mitochondrial membrane potential (MMP) in oocytes were similar for the two groups immediately after staining. However, ATP and relative MMP levels were significantly (P < 0.05) lower in BCB-treated oocytes than in the control (2.18 versus 2.83 pM and 0.82 versus 1.0, respectively). There was no difference in mitochondrial DNA copy number between the two groups after maturation. The ATP content in early developmental stage embryos (3 days after parthenogenetic activation) was lower in the BCB-stained group than that in the control group but the difference was not significant. In conclusion, BCB staining of oocytes at the immature stage compromises mitochondrial functions throughout oocyte maturation, but function is restored during early embryo development. PMID:24355610

Santos, E C S; Sato, D; Lucia, T; Iwata, H

2013-12-20

350

Lipid content, active mitochondria and brilliant cresyl blue staining in bovine oocytes.  

PubMed

Bovine oocytes that stain with brilliant cresyl blue (BCB) have a relatively higher developmental competence. The aim of the present study was to investigate the relationships among BCB staining, lipid content, and active mitochondria. Bovine oocytes (N = 133) with at least three layers of cumulus cells were segregated as BCB retained (BCB+) or metabolized (BCB-) and then stained for active mitochondria (Mitotracker Red) and lipid (Bodipy), with analysis by confocal microscopy. The BCB+ oocytes (N = 45) contained approximately 26% more cytoplasmic lipid than BCB- oocytes (N = 26-27; P < 0.05). Staining for active mitochondria did not differ between the groups. In BCB- oocytes but not BCB+ oocytes, lipid content correlated with active mitochondrial staining (r = 0.48; P < 0.05). Diameter correlated with lipid content for BCB+ oocytes (r = 0.46; P < 0.05), but not for BCB- oocytes (r = 0.16; P > 0.05). Irrespective of BCB staining, both lipid and active mitochondrial content correlated with diameter. In conclusion, the higher lipid content of BCB+ bovine oocytes might provide a cellular and functional basis for their greater developmental competence. PMID:23199746

Castaneda, Cesar A; Kaye, Peter; Pantaleon, Marie; Phillips, Nancy; Norman, Scott; Fry, Richard; D'Occhio, Michael J

2013-02-01

351

Maternal Oct-4 is a potential key regulator of the developmental competence of mouse oocytes  

PubMed Central

Background The maternal contribution of transcripts and proteins supplied to the zygote is crucial for the progression from a gametic to an embryonic control of preimplantation development. Here we compared the transcriptional profiles of two types of mouse MII oocytes, one which is developmentally competent (MIISN oocyte), the other that ceases development at the 2-cell stage (MIINSN oocyte), with the aim of identifying genes and gene expression networks whose misregulated expression would contribute to a reduced developmental competence. Results We report that: 1) the transcription factor Oct-4 is absent in MIINSN oocytes, accounting for 2) the down-regulation of Stella, a maternal-effect factor required for the oocyte-to-embryo transition and of which Oct-4 is a positive regulator; 3) eighteen Oct-4-regulated genes are up-regulated in MIINSN oocytes and are part of gene expression networks implicated in the activation of adverse biochemical pathways such as oxidative phosphorylation, mitochondrial dysfunction and apoptosis. Conclusion The down-regulation of Oct-4 plays a crucial function in a sequence of molecular processes that leads to the developmental arrest of MIINSN oocytes. The use of a model study in which the MII oocyte ceases development consistently at the 2-cell stage has allowed to attribute a role to the maternal Oct-4 that has never been described before. Oct-4 emerges as a key regulator of the molecular events that govern the establishment of the developmental competence of mouse oocytes. PMID:18837968

Zuccotti, Maurizio; Merico, Valeria; Sacchi, Lucia; Bellone, Michele; Brink, Thore C; Bellazzi, Riccardo; Stefanelli, Mario; Redi, Carlo Alberto; Garagna, Silvia; Adjaye, James

2008-01-01

352

Expression of functional neurotransmitter receptors in Xenopus oocytes after injection of human brain membranes  

NASA Astrophysics Data System (ADS)

The Xenopus oocyte is a very powerful tool for studies of the structure and function of membrane proteins, e.g., messenger RNA extracted from the brain and injected into oocytes leads to the synthesis and membrane incorporation of many types of functional receptors and ion channels, and membrane vesicles from Torpedo electroplaques injected into oocytes fuse with the oocyte membrane and cause the appearance of functional Torpedo acetylcholine receptors and Cl channels. This approach was developed further to transplant already assembled neurotransmitter receptors from human brain cells to the plasma membrane of Xenopus oocytes. Membranes isolated from the temporal neocortex of a patient, operated for intractable epilepsy, were injected into oocytes and, within a few hours, the oocyte membrane acquired functional neurotransmitter receptors to -aminobutyric acid, -amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid, kainate, and glycine. These receptors were also expressed in the plasma membrane of oocytes injected with mRNA extracted from the temporal neocortex of the same patient. All of this makes the Xenopus oocyte a more useful model than it already is for studies of the structure and function of many human membrane proteins and opens the way to novel pathophysiological investigations of some human brain disorders.

Miledi, Ricardo; Eusebi, Fabrizio; Martínez-Torres, Ataúlfo; Palma, Eleonora; Trettel, Flavia

2002-10-01

353

Oocyte zona birefringence intensity is associated with embryonic implantation potential in ICSI cycles.  

PubMed

A retrospective study recently showed that oocytes presenting with a high birefringence of the inner zona layer were more often associated with conception cycles. To further investigate these findings, a prospective study was conducted between September 2005 and September 2006 including intracytoplasmic sperm injection (ICSI) cycles presenting with at least two embryos for transfer. Using a polarization imaging system, oocytes were classified prior to ICSI treatment as having either a high zona birefringence (HZB) or a low zona birefringence (LZB) of the zona pellucida. Using zona birefringence as the only selection criterion, two fertilized oocytes, preferably derived from HZB oocytes, were selected for further culture and transfer. The required criteria were met by 135 ICSI cycles (124 patients; 34.9 +/- 4.1 years of age). Embryos for transfer were used in 20 cycles derived from HZB/HZB oocytes, in 50 cycles from HZB/LZB oocytes and in 65 from LZB/LZB oocytes. The corresponding implantation (P < 0.025), pregnancy (P < 0.005) and live birth (P < 0.025) rates were significantly different between HZB/HZB and HZB/LZB versus LZB/LZB group. Embryo development was superior in embryos derived from HZB oocytes. This study concludes that oocyte zona birefringence is a good selection criterion and a good predictive criterion for embryo implantation potential. PMID:18284880

Montag, M; Schimming, T; Köster, M; Zhou, C; Dorn, C; Rösing, B; van der Ven, H; Ven der Ven, K

2008-02-01

354

Live Birth from Slow-Frozen Rabbit Oocytes after In Vivo Fertilisation  

PubMed Central

In vivo fertilisation techniques such as intraoviductal oocyte transfer have been considered as alternatives to bypass the inadequacy of conventional in vitro fertilisation in rabbit. There is only one study in the literature, published in 1989, that reports live offspring from cryopreserved rabbit oocytes. The aim of the present study was to establish the in vivo fertilisation procedure to generate live offspring with frozen oocytes. First, the effect of two recipient models (i) ovariectomised or (ii) oviduct ligated immediately after transfer on the ability of fresh oocytes to fertilise were compared. Second, generation of live offspring from slow-frozen oocytes was carried out using the ligated oviduct recipient model. Throughout the experiment, recipients were artificially inseminated 9 hours prior to oocyte transfer. In the first experiment, two days after unilateral transfer of fresh oocytes, oviducts and uterine horns were flushed to assess embryo recovery rates. The embryo recovery rates were low compared to control in both ovariectomised and ligated oviduct groups. However, ligated oviduct recipient showed significantly (P<0.05) higher embryo recovery rates compared to ovariectomised and control-transferred. In the second experiment, using bilateral oviduct ligation model, all females that received slow-frozen oocytes became pregnant and delivered a total of 4 live young naturally. Thus, in vivo fertilisation is an effective technique to generate live offspring using slow-frozen oocytes in rabbits. PMID:24358281

Jiménez-Trigos, Estrella; Vicente, José S.; Marco-Jiménez, Francisco

2013-01-01

355

Direct Real-Time Measurement of Intra-Oocyte Nitric Oxide Concentration In Vivo  

PubMed Central

Nitric oxide (NO) is reported to play significant a role in oocyte activation and maturation, implantation, and early embryonic development. Previously we have shown that NO forms an important component of the oocyte microenvironment, and functions effectively to delay oocyte aging. Thus, precise information about intra-oocyte NO concentrations [NO] will result in designing more accurate treatment plans in assisted reproduction. In this work, the direct, real-time and quantitative intra-oocyte [NO] was measured utilizing an L-shaped amperometric integrated NO-selective electrode. This method not only provides an elegant and convenient approach to real-time the measurement of NO in physiological environments, but also mimics the loss of NO caused by rapid NO diffusion combined with its reactivity in the biological milieu. This experiment suggests that the NO levels of oocytes obtained from young animals are significantly higher than those of oocytes obtained from old animals. Additionally the NO levels stay constant during the measurements; however, the intra-oocyte [NO] is reduced significantly (70–75% reduction) in response to L-NAME incubation, suggesting that NO measurements are truly NOS based rather than caused by an unknown interfering substance in our system. We believe this first demonstration of the direct quantitative measurement of [NO] in situ in an intact cellular complex should be useful in tracking real-time and rapid changes at nanomolar levels. Moreover, this finding confirms and extends our previous work showing that supplementation with NO delays the oocyte aging process. PMID:24887331

Goud, Pravin T.; Goud, Anuradha P.; Najafi, Tohid; Gonik, Bernard; Diamond, Michael P.; Saed, Ghassan M.; Zhang, Xueji; Abu-Soud, Husam M.

2014-01-01

356

Protein Profile Changes during Porcine Oocyte Aging and Effects of Caffeine on Protein Expression Patterns  

PubMed Central

It has been shown that oocyte aging critically affects reproduction and development. By using proteomic tools, in the present study, changes in protein profiles during porcine oocyte aging and effects of caffeine on oocyte aging were investigated. By comparing control MII oocytes with aging MII oocytes, we identified 23 proteins that were up-regulated and 3 proteins that were down-regulated during the aging process. In caffeine-treated oocytes, 6 proteins were identified as up-regulated and 12 proteins were identified as down-regulated. A total of 38 differentially expressed proteins grouped into 5 regulation patterns were determined to relate to the aging and anti-aging process. By using the Gene Ontology system, we found that numerous functional gene products involved in metabolism, stress response, reactive oxygen species and cell cycle regulation were differentially expressed during the oocyte aging process, and most of these proteins are for the first time reported in our study, including 2 novel proteins. In addition, several proteins were found to be modified during oocyte aging. These data contribute new information that may be useful for future research on cellular aging and for improvement of oocyte quality. PMID:22194971

Jiang, Guang-Jian; Wang, Ke; Miao, De-Qiang; Guo, Lei; Hou, Yi; Schatten, Heide; Sun, Qing-Yuan

2011-01-01

357

Effects of DNA damage and short-term spindle disruption on oocyte meiotic maturation.  

PubMed

DNA damage has recently been shown to inhibit or delay germinal vesicle breakdown (GVBD) in mouse oocytes, but once meiosis resumes, DNA-damaged oocytes are able to extrude the first polar body. In this study, using porcine oocytes, we showed that DNA damage did not affect GVBD, but inhibited the final stages of maturation, as indicated by failure of polar body emission. Unlike mitotic cells in which chromosome mis-segregation causes DNA double-strand breaks, meiotic mouse oocytes did not show increased DNA damage after disruption of chromosome attachment to spindle microtubules. Nocodazole-treated oocytes did not display increased DNA damage signals that were marked by ?H2A.X signal strength, but reformed spindles and underwent maturation, although aneuploidy increased after extended nocodazole treatment. By using the mouse for parthenogenetic activation studies, we showed that early cleavage stage embryos derived from parthenogenetic activation of nocodazole-treated oocytes displayed normal activation rate and normal ?H2A.X signal strength, indicating that no additional DNA damage occured. Our results suggest that DNA damage inhibits porcine oocyte maturation, while nocodazole-induced dissociation between chromosomes and microtubules does not lead to increased DNA damage either in mouse meiotic oocytes or in porcine oocytes. PMID:24477549

Zhang, T; Zhang, G L; Ma, J Y; Qi, S T; Wang, Z B; Wang, Z W; Luo, Y B; Jiang, Z Z; Schatten, H; Sun, Q Y

2014-08-01

358

Bovine cumulus-oocyte-complex-quality is reflected in sensitivity for ?-amanitin, oocyte-diameter and developmental capacity  

Microsoft Academic Search

The aim of the present study was to find more parameters to define developmental competence of cumulus-oocyte-complexes (COCs). Bovine COCs were divided into five groups based on their morphology. In order of increasing level of atresia: COC-A had a bright, compact cumulus investment; COC-B1 also had a compact cumulus investment, but was darker than COC-A; the color of COC-B2 was

A. A. C. de Wit; Th. A. M. Kruip

2001-01-01

359

RNA anchoring in the vegetal cortex of the Xenopus oocyte.  

PubMed

The body plan of the embryo is established by a polarized source of developmental information in the oocyte. The Xenopus laevis oocyte creates polarity by anchoring mRNAs in the vegetal cortex, including Vg1 and Xwnt-11, which might function in body plan specification, and Xcat-2, which might function in germ cell development. To identify components of the RNA anchoring mechanism, we used the manually isolated vegetal cortex (IVC) to assay loss or change in spatial arrangement of mRNAs caused by disruption of cortical elements. The role of cytoskeleton in mRNA anchoring was tested by treating oocytes with inhibitors that selectively disrupted actin microfilaments and cytokeratin filaments. Treatment of oocytes with cytochalasin B caused clumping of Vg1 and Xwnt-11 as revealed by in situ hybridization of the IVC, but did not cause their release, as confirmed by RT-PCR analysis. These mRNA clumps did not match the distribution of actin microfilament clumps, but were distributed similarly to the remnant cytokeratin filaments. Treatment of oocytes with monoclonal anti-cytokeratin antibody C11 released these mRNAs from the cortex. C11 altered the texture of the cytokeratin network, but did not affect the actin meshwork. These results show that Vg1 and Xwnt-11 are retained by a cytokeratin filament-dependent mechanism, and that organization of the cytokeratin network depend on an intact actin meshwork. Colcemid did not disrupt Vg1 and Xwnt-11 retention in the IVC, so anchoring of these mRNAs are independent of microtubules. Membrane disruption in the IVC by Triton X-100 decreased Vg1 and Xwnt-11. Loss of these mRNAs was due mainly to ribonuclease activity released from membrane components. However, when ribonuclease activity was suppressed under cold temperature, a higher amount of Vg1 and Xwnt-11 was recovered in the supernatant. This result suggested that a fraction of these mRNAs required membranes to be retained in the cortex. By contrast, Xcat-2 mRNA was neither released nor degraded following treatments with cytochalasin B, C11, colcemid and Triton X-100 under cold temperature, so no cortical element could be implicated in its anchoring. PMID:11309203

Alarcón, V B; Elinson, R P

2001-05-01

360

Infection of Syrian hamsters with lymphocytic choriomeningitis virus: comparison of detection methods.  

PubMed

The prevention of hamster-associated outbreaks of lymphocytic choriomeningitis virus infection in human beings requires rapid and reliable testing of large numbers of hamsters for the infection. To select the most effective test, the antibody response of infected hamsters was determined by the indirect fluorescent antibody and complement-fixation techniques. The indirect fluorescent antibody technique required less than 2 hours to complete, was the first to become positive after infection, and remained positive for at least several months. Infection in hamsters was also readily detected by the inoculation of mice with infected hamster tissues; virus could be isolated from several organs as early as postinoculation day (PID) 3, and all organs tested contained high concentrations of virus by PID 5. After PID 40, virus was detectable only in the kidney; this organ remained positive for over 3 months. PMID:7049024

Thacker, W L; Lewis, V J; Shaddock, J H; Winkler, W G

1982-08-01

361

Ultraviolet Light Induced Fade of Penetrant and Fluorescent Penetrant Indications  

SciTech Connect

While industry standards don't currently address the issue, one must be aware of the possible consequences of using ultraviolet light sources many times higher than the minimum specified intensity for FPI work. High UVA intensity, coupled with elevated specimen temperature and increased air flow, will fade a defect indication to a pale blue in minutes. Experimental work has shown that it is possible to reduce the brightness of a 0.060'' long crack indication by half within 3.5 minutes with commonly used intensities. Elevating the penetrant's temperature or increasing the airflow caused UVA-illuminated fluorescent dye to fade more quickly.

Lopez, R. D. [Center for Nondestructive Evaluation, Iowa State University, Ames, Iowa 50011 (United States)

2006-03-06

362

VHA-19 Is Essential in Caenorhabditis elegans Oocytes for Embryogenesis and Is Involved in Trafficking in Oocytes  

PubMed Central

There is an urgent need to develop new drugs against parasitic nematodes, which are a significant burden on human health and agriculture. Information about the function of essential nematode-specific genes provides insight to key nematode-specific processes that could be targeted with drugs. We have characterized the function of a novel, nematode-specific Caenorhabditis elegans protein, VHA-19, and show that VHA-19 is essential in the germline and, specifically, the oocytes, for the completion of embryogenesis. VHA-19 is also involved in trafficking the oocyte receptor RME-2 to the oocyte plasma membrane and is essential for osmoregulation in the embryo, probably because VHA-19 is required for proper eggshell formation via exocytosis of cortical granules or other essential components of the eggshell. VHA-19 may also have a role in cytokinesis, either directly or as an indirect effect of its role in osmoregulation. Critically, VHA-19 is expressed in the excretory cell in both larvae and adults, suggesting that it may have a role in osmoregulation in C. elegans more generally, probably in trafficking or secretion pathways. This is the first time a role for VHA-19 has been described. PMID:22768351

Knight, Alison J.; Johnson, Nicholas M.; Behm, Carolyn A.

2012-01-01

363

Photoperiodic regulation of FGF21 production in the Siberian hamster.  

PubMed

This article is part of a Special Issue "Energy Balance". FGF21 is an endocrine member of the fibroblast growth factor superfamily that has been shown to play an important role in the physiological response to nutrient deprivation. Food restriction enhances hepatic FGF21 production, which serves to engage an integrated response to energy deficit. Specifically, elevated FGF21 levels lead to reduced gluconeogenesis and increased hepatic ketogenesis. However, circulating FGF21 concentrations also paradoxically rise in states of metabolic dysfunction such as obesity. Furthermore, multiple peripheral tissues also produce FGF21 in addition to the liver, raising questions as to its endocrine and paracrine roles in the control of energy metabolism. The objectives of this study were to measure plasma FGF21 concentrations in the Siberian hamster, a rodent which undergoes a seasonal cycle of fattening and body weight gain in the long days (LD) of summer, followed by reduction of appetite and fat catabolism in the short days (SD) of winter. Groups of adult male hamsters were raised in long days, and then exposed to SD for up to 12 weeks. Chronic exposure of LD animals to SD led to a significant increase in circulating FGF21 concentrations. This elevation of circulating FGF21 was preceded by an increase in liver FGF21 protein production evident as early as 4 weeks of exposure to SD. FGF21 protein abundance was also increased significantly in interscapular brown adipose tissue, with a positive correlation between plasma levels of FGF21 and BAT protein abundance throughout the experimental period. Epididymal white adipose tissue and skeletal muscle (gastrocnemius) also produced FGF21, but levels did not change in response to a change in photoperiod. In summary, a natural programmed state of fat catabolism was associated with increased FGF21 production in the liver and BAT, consistent with the view that FGF21 has a role in adapting hamsters to the hypophagic winter state. PMID:24909854

Samms, Ricardo J; Fowler, Maxine J; Cooper, Scott; Emmerson, Paul; Coskun, Tamer; Adams, Andrew C; Kharitonenkov, Alexei; Tsintzas, Kostas; Ebling, Francis J P

2014-06-01

364

The hamster cheek pouch model for field cancerization studies.  

PubMed

External carcinogens, such as tobacco and alcohol, induce molecular changes in large areas of oral mucosa, which increase the risk of malignant transformation. This condition, known as 'field cancerization', can be detected in biopsy specimens using histochemical techniques, even before histological alterations are identified. The efficacy of these histochemical techniques as biomarkers of early cancerization must be demonstrated in appropriate models. The hamster cheek pouch oral cancer model, universally employed in biological studies and in studies for the prevention and treatment of oral cancer, is also an excellent model of field cancerization. The carcinogen is applied in solution to the surface of the mucosa and induces alterations that recapitulate the stages of cancerization in human oral mucosa. We have demonstrated that the following can be used for the early detection of cancerized tissue: silver staining of nucleolar organizer regions; the Feulgen reaction to stain DNA followed by ploidy analysis; immunohistochemical analysis of fibroblast growth factor-2, immunohistochemical labeling of proliferating cells to demonstrate an increase of epithelial cell proliferation in the absence of inflammation; and changes in markers of angiogenesis (i.e. those indicating vascular endothelial growth factor activity, endothelial cell proliferation and vascular density). The hamster cheek pouch model of oral cancer was also proposed and validated by our group for boron neutron capture therapy studies for the treatment of oral cancer. Clinical trials of this novel treatment modality have been performed and are underway for certain tumor types and localizations. Having demonstrated the efficacy of boron neutron capture therapy to control tumors in the hamster cheek pouch oral cancer model, we adapted the model for the long-term study of field cancerized tissue. We demonstrated the inhibitory effect of boron neutron capture therapy on tumor development in field cancerized tissue with acceptable levels of mucositis, a dose-limiting side-effect. PMID:25494606

Monti-Hughes, Andrea; Aromando, Romina F; Pérez, Miguel A; Schwint, Amanda E; Itoiz, Maria E

2015-02-01

365

Cholestasis induced by sodium taurolithocholate in isolated hamster liver  

PubMed Central

The mechanism of cholestasis (decreased bile flow) induced by taurolithocholate in the isolated perfused hamster liver was investigated. Taurocholate was infused to maintain bile acid output, and sulfobromophthalein (BSP) was administered to establish a BSP transport maximum in bile. The effects of taurolithocholate on bile flow and on the biliary secretion of BSP and bile acid anions were determined. A significant dose-response correlation was found between taurolithocholate and the degree of cholestasis. No significant hepatic morphologic alterations were observed. At low doses, cholestasis was reversible. A multiple regression equation was developed to validate the steroid dehydrogenase determination of total bile acids in bile that contained BSP. During cholestasis, output of bile acid was maintained by a significantly increased concentration of bile acid. Hepatic removal rate and transport maximum of BSP were significantly decreased, whereas BSP concentration, conjugation, and hepatic content were unaffected. The concentrating capacity for BSP in bile appeared to be the rate-limiting factor in BSP transport. Individual bile acids were determined by gas-liquid chromatography. Of the injected taurolithocholate, 40-50% was recovered in bile as lithocholic acid, 30% was converted to chenodeoxycholic acid, and only traces of lithocholic acid were detected in the perfusate after 4 hr. Cholic and chenodeoxycholic acids comprised 75-89%, and lithocholic acid comprised 11-25% of bile acids in bile after taurolithocholate injection; only traces of deoxycholic acid were seen. Small amounts of taurolithocholate sulfate were detected in bile by thinlayer chromatography. The outputs of sodium and potassium in bile were significantly diminished during cholestasis. A substantial fraction (75%) of basal bile flow in the isolated hamster liver was estimated to be independent of bile acid secretion. Cholestasis occurred after taurolithocholate, whereas bile acid secretion was maintained. The results indicate that the most likely mechanism for acute cholestasis induced by taurolithocholate in isolated hamster liver was interference with the bile acid—independent fraction of canalicular or ductular bile flow or both. Images PMID:5096514

King, John E.; Schoenfield, Leslie J.

1971-01-01

366

Improvement in in vitro fertilization outcome following in vivo synchronization of oocyte maturation in mice.  

PubMed

Synchronization of oocyte maturation in vitro has been shown to produce higher in vitro fertilization (IVF) rates than those observed in oocytes matured in vitro without synchronization. However, the increased IVF rates never exceeded those observed in oocytes matured in vivo without synchronization. This study was therefore designed to define the effect of in vivo synchronization of oocyte maturation on IVF rates. Mice were superovulated and orally treated with 7.5?mg cilostazol (CLZ), a phosphodiesterase 3A (PDE3A) inhibitor, to induce ovulation of immature oocytes at different stages depending on frequency and time of administration of CLZ. Mice treated with CLZ ovulated germinal vesicle (GV) or metaphase I (MI) oocytes that underwent maturation in vitro or in vivo (i.e. in the oviduct) followed by IVF. Superovulated control mice ovulated mature oocytes that underwent IVF directly upon collection. Ovulated MI oocytes matured in vitro or in vivo had similar maturation rates but significantly higher IVF rates, 2-4 cell embryos, than those observed in control oocytes. Ovulated GV oocytes matured in vitro showed similar maturation rates but significantly higher IVF rates than those observed in control oocytes. However, ovulated GV oocytes matured in vivo had significantly lower IVF rates than those noted in control oocytes. It is concluded that CLZ is able to synchronize oocyte maturation and improve IVF rates in superovulated mice. CLZ may be capable of showing similar effects in humans, especially since temporal arrest of human oocyte maturation with other PDE3A inhibitors in vitro was found to improve oocyte competence level. The capability of a clinically approved PDE3A inhibitor to improve oocyte fertilization rates in mice at doses extrapolated from human therapeutic doses suggests the potential scenario of the inclusion of CLZ in superovulation programs. This may improve IVF outcomes in infertile patients. PMID:25245076

Taiyeb, Ahmed M; Muhsen-Alanssari, Saeeda A; Dees, Wl; Ridha-Albarzanchi, Mundhir T; Kraemer, Duane C

2014-09-21

367

Essential role of ubiquitin C-terminal hydrolases UCHL1 and UCHL3 in mammalian oocyte maturation  

PubMed Central

Ubiquitin C-terminal hydrolases (UCHs) comprise a family of deubiquitinating enzymes that play a role in the removal of multi-ubiquitin chains from proteins that are posttranslationally modified by ubiquitination to be targeted for proteolysis by the 26S proteasome. The UCH-enzymes also generate free monomeric ubiquitin from precursor multi-ubiquitin chains and, in some instances, may rescue ubiquitinated proteins from degradation. This study examined the roles of two oocyte-expressed UCHs, UCHL1 and UCHL3 in murine and rhesus monkey oocyte maturation. The Uchl1 and Uchl3 mRNAs were highly expressed in GV and MII oocytes, and were associated with the oocyte cortex (UCHL1) and meiotic spindle (UCHL3). Microinjection of the UCH-family enzyme inhibitor, ubiquitin-aldehyde (UBAL) to GV oocytes prevented oocyte meiotic progression beyond metaphase I in a majority of treated oocytes and caused spindle and first polar body anomalies. Injection of antibodies against UCHL3 disrupted oocyte maturation and caused meiotic anomalies, including abnormally long meiotic spindles. A selective, cell permeant inhibitor of UCHL3, 4, 5, 6, 7-Tetrachloroidan-1, 3-dione also caused meiotic defects and chromosome misalignment. Cortical granule localization in the oocyte cortex was disrupted by UBAL injected after oocyte maturation. We conclude that the activity of oocyte UCHs contributes to oocyte maturation by regulating the oocyte cortex and meiotic spindle. PMID:21751213

Mtango, Namdori R.; Sutovsky, Miriam; VandeVoort, Catherine A.; Latham, Keith E.; Sutovsky, Peter

2015-01-01

368

Numerical method to predict projectile penetration  

SciTech Connect

The Simplified Analytical Model of Penetration with Lateral Loading (SAMPLL) computer code developed at Sandia National Laboratories has been modified to allow additional penetration capabilities. The new capabilities include the ability to model penetration by other than cylindrical penetrators (flares, tapers, and boattails) and the ability to calculate penetration/perforation of multiple layers of different materials. Additionally, updated soil and rock empirical equations have been added to the model. A broader range of problems can now be modeled more accurately with the modified SAMPLL. 7 refs., 6 figs.

Schoof, L.A.; Maestas, F.A.; Young, C.W.

1989-01-01

369

FAA Fluorescent Penetrant Activities - An Update  

SciTech Connect

The Federal Aviation Administration's Airworthiness Assurance NDI Validation Center (AANC) is currently characterizing low cycle fatigue specimens that will support the needs of penetrant manufacturers, commercial airline industry and the Federal Aviation Administration. The main focus of this characterization is to maintain and enhance the evaluation of penetrant inspection materials and apply resources to support the aircraft community needs. This paper discusses efforts to-date to document the Wright Laboratory penetrant evaluation process and characterize penetrant brightness readings in the initial set of sample calibration panels using Type 1 penetrant.

Moore, D.G.

1998-10-20

370

A helium burst biolistic device adapted to penetrate fragile insect tissues  

PubMed Central

To compensate for the extremely low penetration efficiency of the original PDS/1000-He Bio Rad biolistic® device and the deleterious blast effect, design modifications have been made to the launching module. These modifications were evaluated on Bombyx mori embryos and fragile tissues, such as oocytes and imaginal wing disks. The original floppy macrocarrier was replaced by a rigid macrocarrier to avoid the effects of the helium blast. The efficiency of the gene gun bombardment was reinforced by the addition of a focusing nozzle. The reduced blast effect allowed us to carry out high-pressure shootings to small organs with improved penetration. This system allowed potentially all the internal embryonic tissues to be transfected with optimal survival rates. The new module was effective on tissues that are difficult to transfect, such as the epithelial wing disk that is covered by a peripodial membrane, and the ovarian follicle cells that lie under the ovariole cell membrane. The new macrocarrier allowed both an aqueous delivery of particles and an ethanolic dry delivery. No significant differences were noted between these two modes of delivery. The major improvement is the possibility of high pressure shooting correlated with appreciable penetration and a weak blast effect. PMID:15455069

Thomas, Jean-Luc; Bardou, Jérôme; L'hoste, Sebastien; Mauchamp, Bernard; Chavancy, Gérard

2001-01-01

371

Distribution and metabolism of four different dimethylated arsenicals in hamsters  

SciTech Connect

Arsenic toxicity and distribution are highly dependent on animal species and its chemical species. Recently, thioarsenical has been recognized in highly toxic arsenic metabolites, which was commonly found in human and animal urine. In the present study, we revealed the mechanism underlying the distribution and metabolism of non-thiolated and thiolated dimethylarsenic compounds such as dimethylarsinic acid (DMA{sup V}), dimethylarsinous acid (DMA{sup III}), dimethylmonothioarsinic acid (DMMTA{sup V}), and dimethyldithioarsinic acid (DMDTA{sup V}) after the administration of them into femoral vein of hamsters. DMA{sup V} and DMDTA{sup V} distributed in organs and body fluids were in their unmodified form, while DMA{sup III} and DMMTA{sup V} were bound to proteins and transformed to DMA{sup V} in organs. On the other hand, DMA{sup V} and DMDTA{sup V} were mostly excreted into urine as their intact form 1 h after post-injection, and more than 70% of the doses were recovered in urine as their intact form. By contrast, less than 8-14% of doses were recovered in urine as DMA{sup V}, while more than 60% of doses were distributed in muscles and target organs (liver, kidney, and lung) of hamsters after the injection of DMMTA{sup V} and DMA{sup III}. However, in red blood cells (RBCs), only a small amount of the arsenicals was distributed (less than 4% of the doses) after the injection of DMA{sup III} and DMMTA{sup V}, suggesting that the DMA{sup III} and DMMTA{sup V} were hardly accumulated in hamster RBCs. Based on these observations, we suggest that although DMMTA{sup V} and DMDTA{sup V} are thioarsenicals, DMMTA{sup V} is taken up efficiently by organs, in a manner different from that of DMDTA{sup V}. In addition, the distribution and metabolism of DMMTA{sup V} are like in manner similar to DMA{sup III} in hamsters, while DMDTA{sup V} is in a manner similar to DMA{sup V}.

Naranmandura, Hua, E-mail: narenman@zju.edu.c [Institute of Pharmacology and Toxicology and Biochemical Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Graduate School of Pharmaceutical Sciences, Chiba University, Chuo, Chiba 260-8675 (Japan); Iwata, Katsuya; Suzuki, Kazuo T. [Graduate School of Pharmaceutical Sciences, Chiba University, Chuo, Chiba 260-8675 (Japan); Ogra, Yasumitsu [Laboratory of Chemical Toxicology and Environmental Health, Showa Pharmaceutical University, Machida, Tokyo 194-8543 (Japan)

2010-05-15

372

Demography of penetrating cardiac trauma.  

PubMed Central

All cases of penetrating cardiac trauma in 1985 and 1986 in Jefferson County, Alabama, where patients dying of penetrating trauma received autopsies, were retrospectively reviewed. All hospitals in the county plus the single coroner's office provided the records of the 72 patients comprising this study. Incidents occurred most often in the home or residence (70%) by a known assailant (83%) due to domestic/social disputes (73%). Frequency was greatest in the evening hours (73% between 6:00 PM and 3:00 AM), on weekends in spring and summer. Victims tended to be male (86%), black (72%), married (46%), blue collar workers (62%). There were 41 (57%) gunshot wounds, 3 (4%) shotgun wounds, and 28 (39%) stab wounds with an associated mortality rate of 97%, 100%, and 68%, respectively. Prehospital mortality rate (dead at the scene) was 54.2% (39/72), and death on arrival was 26.4% (19/72), for a combined pretreatment mortality rate of 80.6%. All patients who arrived with no vital signs died. Mortality appeared to be related to mechanism of injury, age, race, sex, vital signs on arrival, number and specific cardiac chambers injured, associated major vascular injury, hematocrit, and mode of transportation. Mortality was not related to caliber of weapon, ethanol level, transport time, time from arrival to operation, or transfusion requirements. There were only ten survivors (1 gunshot wound and 9 stab wounds), all of whom had ventricular injuries and no associated major vascular injuries. The ten survivors represented a 71.4% (10/14) salvage rate for those victims arriving with vital signs. Complications occurred in three patients. Hospitalization averaged 7.3 days in the survivors. Penetrating cardiac trauma remains a serious, socially linked disease with a high rate of mortality. Rapid transport, aggressive resuscitation and cardiorrhaphy remain the best treatment. PMID:2730180

Naughton, M J; Brissie, R M; Bessey, P Q; McEachern, M M; Donald, J M; Laws, H L

1989-01-01

373

Analysis of the Phospholipid Profile of Metaphase II Mouse Oocytes Undergoing Vitrification  

PubMed Central

Oocyte freezing confers thermal and chemical stress upon the oolemma and various other intracellular structures due to the formation of ice crystals. The lipid profiles of oocytes and embryos are closely associated with both, the degrees of their membrane fluidity, as well as the degree of chilling and freezing injuries that may occur during cryopreservation. In spite of the importance of lipids in the process of cryopreservation, the phospholipid status in oocytes and embryos before and after freezing has not been investigated. In this study, we employed mass spectrometric analysis to examine if vitrification has an effect on the phospholipid profiles of mouse oocytes. Freshly prepared metaphase II mouse oocytes were vitrified using copper grids and stored in liquid nitrogen for 2 weeks. Fresh and vitrified-warmed oocytes were subjected to phospholipid extraction procedure. Mass spectrometric analyses revealed that multiple species of phospholipids are reduced in vitrified-warmed oocytes. LIFT analyses identified 31 underexpressed and 5 overexpressed phospholipids in vitrified mouse oocytes. The intensities of phosphatidylinositol (PI) {18?2/16?0} [M?H]? and phosphatidylglycerol (PG) {14?0/18?2} [M?H]? were decreased the most with fold changes of 30.5 and 19.1 in negative ion mode, respectively. Several sphingomyelins (SM) including SM {d38?3} [M+H]+ and SM {d34?0} [M+K]+ were decreased significantly in positive ion mode. Overall, the declining trend of multiple phospholipids demonstrates that vitrification has a marked effect on phospholipid profiles of oocytes. These results show that the identified phospholipids can be used as potential biomarkers of oocyte undergoing vitrification and will allow for the development of strategies to preserve phospholipids during oocyte cryopreservation. PMID:25033391

Bang, Soyoung; Mok, Hyuck Jun; Suh, Chang Suk; Kim, Kwang Pyo; Lim, Hyunjung Jade

2014-01-01

374

Relation of Cumulus Cell Status with Single Oocyte Maturity, Fertilization Capability and Patient Age  

PubMed Central

Background The production of competent oocytes depends on a bi-directional communication between the oocyte and cumulus cells. The goal of this study was to determine whether simple parameters monitored in cumulus cells from individual human oocytes have any predictive value, and thus correlate with clinically relevant parameters. Methods 97 cumulus-oocyte complexes were recovered from 31 patients undergoing ICSI treatment. After the oocytes were denuded, cumulus cell density from individual oocytes was determined. Cells were probed for viability using propidium iodide and for apoptosis by Annexin V staining or by monitoring caspase activity. These parameters were correlated with oocyte status, fertilization ability and patient age (?29 years old and ?30 years old). All variables were checked for normal distribution and then compared by Kruskal-Wallis, Mann-Whitney or one-way ANOVA tests. Results Mature oocytes were surrounded by more cumulus cells (16073±2595, p = 0.026), which were also more viable and less apoptotic than atretic or degenerated oocytes. Mature oocytes that fertilized had higher caspase activity in the surrounding cumulus cells than those that did not fertilize. Younger patients presented lower cumulus cells density (8882±2380 vs. 15036±2143 cells; p = 0.034); and cumulus cells had higher apoptosis levels in younger patients than older ones (6775.5±1831.6 RLU vs. 2591±46.5 RLU, p = 0.002 for caspase activity). Conclusion The data suggests that high density and apoptosis of cumulus cells are promising parameters to indirectly predict individual oocyte status. Although more studies and a larger data set are needed, cumulus cells presented the potential to be used as simple predictors of female fertility and/or ovarian ageing. PMID:24696155

Lourenço, Bárbara; Sousa, Ana Paula; Almeida-Santos, Teresa; Ramalho-Santos, João

2014-01-01

375

Allometric study on the relationship between the growth of ovarian follicles and oocytes in domestic cats.  

PubMed

The relationship between the growth of preantral and antral follicles and that of their oocytes in ovaries of domestic cats (Felis catus) was analyzed. Eight hundred and five pairs of follicles and oocytes from the ovaries of 51 female cats were collected, and only healthy and fresh follicles and oocytes with or without zona pellucida were used in this study. Immediately after collection, the diameters of follicles and their oocytes were measured. The relationship of the follicle diameter to the oocyte diameter was applied to four regression models and statistically analyzed. The best fitting model was found to be a hyperbolic regression (the coefficient of determination was 0.976 between the follicles and their oocytes with a zona pellucida, y=184x/(x+0.0738); the coefficient of determination was 0.983 between the follicles and their oocytes without a zona pellucida, y=122x/(x+0.0301)). The differentiated equations for the hyperbolic curves in the oocytes with or without a zona pellucida and the follicles were found to be y'=13.6/(x+0.0738)² and y'=3.67/(x+0.0301)², where y and x were the diameters of the oocytes (?m) and follicles (mm), respectively. When follicles grew to a size larger than 0.4 mm in diameter, the growth rates of their oocytes calculated by the differentiation equations showed an asymptotic depression around zero. Thus, it was suggested that when the follicles grew to a size larger than 0.4 mm in diameter, their oocytes reached full size and ceased to grow and that the zona pellucida stopped growing when the diameter of the follicles reached 0.3 mm in domestic cats. PMID:22673008

Izumi, Tokukazu; Sakakida, Seishi; Muranishi, Yuki; Nagai, Takashi

2012-01-01

376

Penetrating abdominal injuries: management controversies  

PubMed Central

Penetrating abdominal injuries have been traditionally managed by routine laparotomy. New understanding of trajectories, potential for organ injury, and correlation with advanced radiographic imaging has allowed a shift towards non-operative management of appropriate cases. Although a selective approach has been established for stab wounds, the management of abdominal gunshot wounds remains a matter of controversy. In this chapter we describe the rationale and methodology of selecting patients for non-operative management. We also discuss additional controversial issues, as related to antibiotic prophylaxis, management of asymptomatic thoracoabdominal injuries, and the use of colostomy vs. primary repair for colon injuries. PMID:19374761

Butt, Muhammad U; Zacharias, Nikolaos; Velmahos, George C

2009-01-01

377

Transdermal Penetration of UV Filters  

Microsoft Academic Search

A penetration study of 2-ethylhexyl-4-methoxycinnamate (EHMC), 4-methyl benzylidenecamphor (MBC), butyl methoxydibenzoylmethane (BMBM), 2-ethylhexyl-2,4,5-trimethoxycinnamate (EHTMC) and di(2-ethylhexyl)-2,4,5-trimethoxybenzalmalonate (TMB) through baby mouse skin (Mus musculus Linn.) was carried out using a vertical Franz diffusion cell. At 4.4 mg\\/cm2 coverage of UV filter on the skin, 2.98 ± 0.38, 1.15 ± 0.14 and 0.80 ± 0.28% of the applied EHMC, MBC and BMBM

P. Klinubol; P. Asawanonda; S. P. Wanichwecharungruang

2008-01-01

378

CONCENTRATION DEPENDENT ACCUMULATION OF [3H]-DELTAMETHRIN IN SODIUM CHANNEL N AV1.2 EXPRESSING XENOPUS LAEVIS OOCYTES.  

EPA Science Inventory

Disruption of neuronal voltage-sensitive sodium channels (VSSCs) by pyrethroid insecticides such as deltamethrin (DLT) has been widely studied using Xenopus laevis oocytes transfected with VSSC. However, the extent of pyrethroid accumulation in VSSC-expressing oocytes is unknown....

379

Effect of Leptin on In Vitro Nuclear Maturation and Apoptosis of Buffalo (Bubalus bubalis) Oocyte  

PubMed Central

Background: Leptin, as a 16 kDa adipokine, is a pleiotropic cytokine-like hormone that primarily secreted from adipose tissue. It also involves in the regulation of energy homeostasis, neuroendocrine function, immunity, lipid and glucose homeostasis, fatty acid oxidation, angiogenesis, puberty and reproduction. The aim of this study was to investigate the effects of in vitro addition of leptin to in vitro maturation (IVM) medium on buffalo oocyte maturation and apoptosis. Materials and Methods: In this experimental study, Ovaries from apparently normal reproductive organs of slaughtered adult buffaloes (Bubalus bubalis) with unknown breeding history were collected from Urmia Abattoir, Urmia, Iran, and were transported immediately to the laboratory in a thermos flask containing sterile normal saline with added antibiotics. Oocytes were aspirated from 2-8 mm visible follicles of the ovaries using an 18-G needle attached to a 10 ml syringe. IVM medium included tissue culture medium-199 (TCM-199), 10% fetal bovine serum (FBS), 22 µg/ml sodium pyruvate, 0.5 IU/ml ovine follicle-stimulating hormone (oFSH), 0.5 IU/ml ovine luteinizing hormone (oLH), 1 ?g/ml oestradiol, 50 ?g/ml gentamycin, and leptin [0 (control), 10, 50, and 100 ng/ml]. The good quality buffalo oocytes (batches of 10 oocytes) were placed in a culture plate containing six 50 ?l droplets of maturation medium, covered with sterilized mineral oil, and then incubated at 38.5?C with 5% CO2 in air for 24 hours. The maturation of oocytes was evaluated under a stereomicroscope by detecting the first polar body extrusion of oocytes. FITC-Annexin V propidium iodide (PI) staining method was used to detect oocyte apoptosis. Results: From a total of 115 collected ovaries, 1100 oocytes were recovered among which 283 oocyte were suitable for IVM. In the groups of leptin treated with 0 (control), 10, 50 and 100 ng/ml, the percentage of oocytes maturation was 74.65, 83.81, 77.85, and 75.40%, while the percentage of oocytes apoptosis was 9.83, 9.54, 9.93, and 10.42%, respectively. Our results showed that addition of 10 ng/ml leptin to buffalo IVM medium increased oocyte maturation, significantly, as compared with that in control group. However, addition of leptin to IVM medium had no significant influence on buffalo oocyte apoptosis. Conclusion: Our findings suggested that addition of 10 ng/ml leptin to IVM medium of buffalo oocyte can improve oocyte nuclear maturation. Furthermore, we showed that there is no relation between in vitro addition of leptin to buffalo oocyte IVM medium and oocyte apoptos Conclusion: Our findings suggested that addition of 10 ng/ml leptin to IVM medium of buffalo oocyte can improve oocyte nuclear maturation. Furthermore, we showed that there is no relation between in vitro addition of leptin to buffalo oocyte IVM medium and oocyte apoptosis. PMID:24696768

Khaki1, Amir; Batavani, Rouzali; Najafi, Gholamreza; Tahmasbian, Hamid; Belbasi, Abolfazl; Mokarizadeh, Aram

2014-01-01

380

Possible involvement of integrin-mediated signalling in oocyte activation: evidence that a cyclic RGD-containing peptide can stimulate protein kinase C and cortical granule exocytosis in mouse oocytes  

Microsoft Academic Search

BACKGROUND: Mammalian sperm-oocyte interaction at fertilization involves several combined interactions between integrins on the oocyte and integrin ligands (disintegrins) on the sperm. Recent research has indicated the ability of peptides containing the RGD sequence that characterized several sperm disintegrins, to induce intracellular Ca2+ transients and to initiate parthenogenetic development in amphibian and bovine oocytes. In the present study, we investigate

Carla Tatone; Maria Cristina Carbone

2006-01-01

381

Role of luteinizing hormone in luteotropic complex of pregnant hamster  

SciTech Connect

Hamsters were hypophysectomized on day 4 of pregnancy and injected subcutaneously on days 4-7 with various combinations of 200 ..mu..g prolactin (Prl), 10 ..mu..g follicle-stimulating hormone (FSH), and 20 ..mu..g luteinizing hormone (LH) in polyvinylpyrrolidone (PVP) to decrease its rate of absorption or in saline. End points for luteal function on day 8 were maintenance of pregnancy, serum progesterone (P/sub 4/), luteal weight, and luteal binding for human chorionic gonadotropin, FSH, and Prl. After hypophysectomy, a drastic decline occurred in all parameters including an 89% decrease in luteal weight. Injection of Prl did not maintain pregnancy nor serum P/sub 4/ but partially maintained luteal weight and human chorionic gonadotropin binding sites per corpus luteum. The minimal luteotropic complex of Prl and FSH was effective in maintaining pregnancy and significantly increased serum P/sub 4/ and Prl and FSH receptors but not to control levels. Thus, the luteotropic activity of LH was only demonstrable when it was injected in a long-acting form; when delivered as a bolus, LH (saline) was luteolytic. P/sub 4/ and estradiol were measured by radioimmunoassay. Radioiodinated gonadotropins were prepared. The percentage of tracer reacting with an excess of receptor were 51% of /sup 125/I-FSH and 45.9% of /sup 125/I-hCG using whole homogenates of hamster ovaries.

Tamura, H.; Greenwald, G.S.

1987-04-01

382

SITES OF NUCLEOLUS PRODUCTION IN CULTURED CHINESE HAMSTER CELLS  

PubMed Central

Chinese hamster cell strains in the early passages in culture display wide variation in number of nucleolus-like bodies per cell, though such strains are characteristically euploid. A variety of criteria indicate that the nucleolus-like bodies are true nucleoli. Their Azure B- and fast green-staining properties indicate the presence of RNA and protein; they have typical nucleolar fine structure, including both fibrous and granular components; radioautography reveals that their patterns of uptake of uridine-3H into RNA are similar to those reported for nucleoli of other cell types; actinomycin D, at a level which selectively inhibits ribosomal RNA synthesis, greatly reduces their RNA synthesis and also causes segregation of fibrous and granular nucleolar components. Colchicine was used to experimentally fragment the nuclei of these cells into a number of separate karyomeres, each presumably containing some, or only one, of the chromosomes of the complement. Almost all the karyomeres contain nucleolus-like bodies which, by the same criteria applied to the multiple nucleolus-like bodies of uninuclear cells, appear to be true nucleoli. The nucleoli of individual karyomeres of the same cell often differ from each other in fine structure while the multiple nucleoli of a uninuclear cell generally resemble each other. The evidence presented in this study indicates that Chinese hamster cells contain many nucleolus-producing sites scattered through the genome. PMID:4177660

Phillips, Stephanie Gordon; Phillips, David M.

1969-01-01

383

Rift Valley Fever Virus Infection in Golden Syrian Hamsters  

PubMed Central

Rift Valley fever virus (RVFV) is a formidable pathogen that causes severe disease and abortion in a variety of livestock species and a range of disease in humans that includes hemorrhagic fever, fulminant hepatitis, encephalitis and blindness. The natural transmission cycle involves mosquito vectors, but exposure can also occur through contact with infected fluids and tissues. The lack of approved antiviral therapies and vaccines for human use underlies the importance of small animal models for proof-of-concept efficacy studies. Several mouse and rat models of RVFV infection have been well characterized and provide useful systems for the study of certain aspects of pathogenesis, as well as antiviral drug and vaccine development. However, certain host-directed therapeutics may not act on mouse or rat pathways. Here, we describe the natural history of disease in golden Syrian hamsters challenged subcutaneously with the pathogenic ZH501 strain of RVFV. Peracute disease resulted in rapid lethality within 2 to 3 days of RVFV challenge. High titer viremia and substantial viral loads were observed in most tissues examined; however, histopathology and immunostaining for RVFV antigen were largely restricted to the liver. Acute hepatocellular necrosis associated with a strong presence of viral antigen in the hepatocytes indicates that fulminant hepatitis is the likely cause of mortality. Further studies to assess the susceptibility and disease progression following respiratory route exposure are warranted. The use of the hamsters to model RVFV infection is suitable for early stage antiviral drug and vaccine development studies. PMID:25607955

Scharton, Dionna; Van Wettere, Arnaud J.; Bailey, Kevin W.; Vest, Zachary; Westover, Jonna B.; Siddharthan, Venkatraman; Gowen, Brian B.

2015-01-01

384

The utility of Brilliant Cresyl Blue (BCB) staining of mammalian oocytes used for in vitro embryo production (IVP).  

PubMed

The present article summarizes the results of experiments investigating the Brilliant Cresyl Blue (BCB) staining for selection of immature oocytes before in vitro embryo production or somatic cell nuclear transfer. Developmental competence of oocytes stained with BCB and quality of blastocysts derived from such oocytes as well as the expression of apoptosis-related genes, mitochondrial DNA (mtDNA) replication-related genes and the transcripts encoded by the mitochondrial genome in BCB stained oocytes are discussed. PMID:24011188

Opiela, Jolanta; K?tska-Ksi??kiewicz, Lucyna

2013-09-01

385

Developmental competence of ovine oocytes after vitrification: Differential effects of vitrification steps, embryo production methods, and parental origin of pronuclei.  

PubMed

Despite many advances in the field of oocyte cryopreservation, the adverse effects of cryopreservation on oocyte competence are still an open challenge in most mammalian species. Using ovine in vitro-matured oocytes, the differential effects of vitrification steps, embryo production methods, and parental origin of pronuclei were systemically investigated to unravel (1) the most critical stage (if any) of oocyte vitrification, (2) the most suitable method (if any) of embryo production for a vitrified oocyte, and (3) differential contributions of male or female pronuclear formation to the poor quality of vitrified oocyte. Although cryoprotectants used during vitrification had some inevitable adverse effects on oocyte competence, the damages caused by low temperature per se (chilling injury) were the main cause of poor quality of vitrified oocytes. When vitrified oocytes underwent either IVF or intracytoplasmic sperm injection (ICSI), embryo development rates were substantially lower than those of fresh ones. In contrast, when vitrified oocytes underwent either parthenogenetic activation (PA) or SCNT, embryo development rates were very similar to those of fresh ones. Evaluation of nuclear morphology after IVF, ICSI, PA, and SCNT oocytes revealed that vitrification had no apparent effect on the female (IVF, ICSI, and PA) and somatic (SCNT) pronuclear formation rates but significantly reduced male pronuclear formation after either IVF or ICSI compared with fresh counterparts. Quantitative analysis of transcripts revealed comparable mRNA abundances of CNX43, HSP90, GMNN, NPM, and OCT4 between vitrified and fresh oocytes, whereas CCNB, ATP1A1, and PAP transcripts were significantly lower in vitrified versus fresh oocytes. Although underlying mechanisms of poor quality of vitrified oocytes are multifactorial, the ability to obtain equivalent development after PA and SCNT, but not IVF and ICSI, in vitrified versus fresh oocytes may argue that the cytoplasm of vitrified oocyte has the necessary components to support in vitro embryonic development of the maternal, even adult somatic cell, chromosomes but fails to do so with sperm chromosomes. PMID:25468553

Hosseini, S M; Asgari, V; Ostadhosseini, S; Hajian, M; Ghanaei, H R; Nasr-Esfahani, M H

2015-02-01

386

Confocal fluorescence assessment of bioenergy/redox status of dromedary camel (Camelus dromedarius) oocytes before and after in vitro maturation  

PubMed Central

Background Reproductive biotechnologies in dromedary camel (Camelus dromedarius) are less developed than in other livestock species. The in vitro maturation (IVM) technology is a fundamental step for in vitro embryo production (IVP), and its optimization could represent a way to increase the success rate of IVP. The aim of the present study was to investigate the bioenergy/oxidative status of dromedary camel oocytes before and after IVM by confocal microscopy 3D imaging. Methods Oocytes were retrieved by slicing ovaries collected at local slaughterhouses. Recovered oocytes were examined before and after IVM culture for nuclear chromatin configuration and bioenergy/oxidative status, expressed as mitochondria (mt) distribution and activity, intracellular Reactive Oxygen Species (ROS) levels and distribution and mt/ROS colocalization. Results The mean recovery rate was 6 oocytes/ovary. After IVM, 61% of oocytes resumed meiosis and 36% reached the Metaphase II stage (MII). Oocyte bioenergy/redox confocal characterization revealed changes upon meiosis progression. Immature oocytes at the germinal vesicle (GV) stage were characterised by prevailing homogeneous mt distribution in small aggregates while MI and MII oocytes showed significantly higher rates of pericortical mt distribution organized in tubular networks (P?oocytes compared to GV stage oocytes was also observed. At any meiotic stage, homogeneous distribution of intracellular ROS was observed. Intracellular ROS levels also increased in MI (P?oocytes compared to GV stage oocytes. The mt/ROS colocalization signal increased in MI oocytes (P?oocytes are modified in relation with oocyte meiotic stage. These data may increase the knowledge of camel oocyte physiology, in order to enhance the efficiency of IVP procedures. PMID:24548378

2014-01-01

387

Potential Role for MATER in Cytoplasmic Lattice Formation in Murine Oocytes  

PubMed Central

Background Mater and Padi6 are maternal effect genes that are first expressed during oocyte growth and are required for embryonic development beyond the two-cell stage in the mouse. We have recently found that PADI6 localizes to, and is required for the formation of, abundant fibrillar Triton X-100 (Triton) insoluble structures termed the oocyte cytoplasmic lattices (CPLs). Given their similar expression profiles and mutant mouse phenotypes, we have been testing the hypothesis that MATER also plays a role in CPL formation and/or function. Methodology/Findings Herein, we show that PADI6 and MATER co-localize throughout the oocyte cytoplasm following Triton extraction, suggesting that MATER co-localizes with PADI6 at the CPLs. Additionally, the solubility of PADI6 was dramatically increased in Matertm/tm oocytes following Triton extraction, suggesting that MATER is involved in CPL nucleation. This prediction is supported by transmission electron microscopic analysis of Mater+/+ and Matertm/tm germinal vesicle stage oocytes which illustrated that volume fraction of CPLs was reduced by 90% in Matertm/tm oocytes compared to Mater+/+ oocytes. Conclusions Taken together, these results suggest that, similar to PADI6, MATER is also required for CPL formation. Given that PADI6 and MATER are essential for female fertility, these results not only strengthen the hypothesis that the lattices play a critical role in mediating events during the oocyte-to-embryo transition but also increase our understanding of the molecular nature of the CPLs. PMID:20830304

Kim, Boram; Kan, Rui; Anguish, Lynne; Nelson, Lawrence M.; Coonrod, Scott A.

2010-01-01

388

Nuclear staining and culture requirements for in vitro maturation of domestic bitch oocytes  

Microsoft Academic Search

Oocyte nuclear staining and culture requirements for in vitro maturation (IVM) in the bitch have yet to be fully investigated. In the first part of this study we investigated 7 methods for labeling nuclear material (573 oocytes). The most favorable method involved fixation plus aceto-orcein staining and light microscopy. The influence of serum supplementation of the culture medium for IVM

D. A Hewitt; P. F Watson; G. C. W England

1998-01-01

389

REPRODUCTIONRESEARCH Endocytosis in the mouse oocyte and its contribution to cAMP  

E-print Network

REPRODUCTIONRESEARCH Endocytosis in the mouse oocyte and its contribution to cAMP signaling during-mediated endocytosis, but a continuously high level of cAMP is needed for meiotic arrest. The aim of this study was to examine whether receptor-mediated endocytosis occurs in the mouse oocyte and whether this could affect

Terasaki, Mark

390

Pain relief during oocyte retrieval — exploring the role of different frequencies of electro-acupuncture  

Microsoft Academic Search

Electro-acupuncture has previously proven its analgesic effect in oocyte retrieval for IVF. The aim of the present prospective randomized study was to explore the optimal frequency for analgesia when electro-acupuncture was applied a few minutes prior to oocyte retrieval. A total of 152 patients were prospectively randomized to receive either a combination of high (80 Hz) and low frequency (2

Peter Humaidan; Kirsten Brock; Leif Bungum; Elisabet Stener-Victorin

2006-01-01

391

Nuclear actin depolymerization in transcriptionally active avian and amphibian oocytes leads to collapse of intranuclear structures  

PubMed Central

Actin, which is normally depleted in the nuclei of somatic cells, accumulates in high amounts in giant nuclei of amphibian oocytes. The supramolecular organization and functions of this nuclear pool of actin in growing vertebrate oocyte are controversial. Here, we investigated the role of nuclear actin in the maintenance of the spatial architecture of intranuclear structures in avian and amphibian growing oocytes. A meshwork of filamentous actin was not detected in freshly isolated or fixed oocyte nuclei of Xenopus, chicken or quail. We found that the actin meshwork inside the oocyte nucleus could be induced by phalloidin treatment. Actin polymerization is demonstrated to be required to stabilize the specific spatial organization of nuclear structures in avian and amphibian growing oocytes. In experiments with the actin depolymerizing drugs cytochalasin D and latrunculin A, we showed that disassembly of nuclear actin polymers led to chromosome condensation and their transportation to a limited space within the oocyte nucleus. Experimentally induced “collapsing” of chromosomes and nuclear bodies, together with global inhibition of transcription, strongly resembled the process of karyosphere formation during oocyte growth. PMID:22572951

Maslova, Antonina; Krasikova, Alla

2012-01-01

392

Xenopus tropicalis oocytes as an advantageous model system for the study of intracellular Ca2+  

E-print Network

and Xenopus laevis, with respect to their utility for studying Ca2+ signalling mechanisms and for expressionXenopus tropicalis oocytes as an advantageous model system for the study of intracellular Ca2-4550, U.S.A. 1 The purpose of this study was to compare oocytes from the pipid frogs Xenopus tropicalis

Marchant, Jonathan

393

Regulation of Oocyte and Cumulus Cell Interactions by Intermedin/Adrenomedullin 2*  

PubMed Central

Ovarian folliculogenesis has been studied as a model of hormonal regulation of development and differentiation, cell death, and cell-cell communication. In addition to gonadotropins from the pituitary and follicular paracrine factors, oocyte secreted factors have been shown to play critical roles in the regulation of follicular cell functions. Except for the well characterized BMP family proteins, including GDF9 and BMP15, oocytes are known to secrete oocyte secreted factors that are important for the regulation of cumulus cell survival and the maintenance of tertiary structure of cumulus cell-enclosed oocyte complexes (COCs). Based on genomic screening and studies of COCs cultured in vitro, we showed that intermedin (IMD)/adrenomedullin 2 (ADM2) is a novel oocyte-derived ligand important for the regulation of cell interactions in COCs that functions, in part, by suppressing cumulus cell apoptosis. Consistently, we showed that suppression of IMD/ADM2 signaling in growing rat ovaries in vivo leads to oocyte atresia and aberrant cell cycle progression in follicular cells. Together, our studies indicated that mammalian oocytes deploy a G protein-coupled receptor ligand to coordinate normal interactions of oocytes and cumulus cells and provided a better understanding of how the tertiary structure of a COC is maintained as follicles undergo exponential growth during the late stages of folliculogenesis. PMID:22009752

Chang, Chia Lin; Wang, Hsin-Shih; Soong, Yung-Kuei; Huang, Shang Yu; Pai, Shun Yuan; Hsu, Sheau Yu Teddy

2011-01-01

394

Analysis of vitelline envelope synthesis and composition during early oocyte development in gilthead seabream (Sparus aurata).  

PubMed

The oocyte vitelline envelope (VE) of gilthead seabream is composed of four known zona pellucida (ZP) proteins, ZPBa, ZPBb, ZPC, and ZPX. We have previously shown that the gilthead seabream ZP proteins are differentially transcribed in liver and ovary, with the expression in liver being under estrogenic control. However, although mRNA was found in both liver and ovary, only low ZPBa protein levels were detected in liver and plasma. Using isoform-specific ZP antibodies we show that ZPBa and ZPX translation products are present in the cytosol of stage I and II oocytes. In addition, the zpBa and zpX mRNAs were detected in early developing oocytes. During oocyte growth (vitellogenesis), the VE increased in thickness (>10 microm), and we show that the four ZP isoforms are present in different regions of the VE. ZPX was detected closest to the oocyte plasma membrane while the intermediate region was composed of ZPBa, ZPBb, and ZPC. At the outer layer, only ZPC was detected. When oocytes reach the fully grown stage they resume meiosis and hydration. As the oocyte expands, thinning to 4 microm, the VE acquire a striped and compact appearance at the electron microscopy level. This study provides further evidence for the oocyte origin of some ZP proteins in the gilthead seabream and suggests that the ZP proteins are differentially distributed within the VE. PMID:18247334

Modig, Carina; Raldúa, Demetrio; Cerdà, Joan; Olsson, Per-Erik

2008-08-01

395

Optimum number of oocytes for a successful first IVF treatment cycle  

Microsoft Academic Search

Ovarian stimulation in IVF allows selection of embryos for transfer, but may have detrimental effects on oocyte and embryo quality and endometrial receptivity. This study investigated the optimal response to ovarian stimulation in terms of number of oocytes for achieving pregnancy in a first IVF cycle. Data from 7422 women who underwent their first IVF cycle for standard indications were

MH van der Gaast; MJC Eijkemans; JB van der Net; EJ de Boer; CW Burger; FE van Leeuwen; BCJM Fauser; NS Macklon

2006-01-01

396

Hanging drop monoculture for selection of optimal antioxidants during in vitro maturation of porcine oocytes.  

PubMed

We analysed the effect of three antioxidants that have different functional mechanisms on the in vitro maturation (IVM) of porcine oocytes. Single oocyte monoculture using the hanging drop (HD) system has some advantages such as improving analysis efficiency brought by the smaller number of samples than the number of oocytes cultured in one drop. Direct effects of ligands on single oocytes could also be detected without considering the effects of paracrine factors from other oocytes. After 22 h of pre-culture, denuded oocytes were cultured for 22 h with 0.01 and 0.1 ?g/ml of L-carnitine (LC), lactoferrin (LF) or sulforaphane (SF) in the presence/non-presence of oxidant stress induced by H2O2 supplementation to evaluate the reducing effects against oxidative stress on nuclear maturation. As a result, compared with LC and SF, LF showed effective reduction in oxidative stress at a lower concentration (0.01 ?g/ml), suggesting that LF is a more effective antioxidant in porcine oocyte IVM. Additionally, LF also increased maturation rate even in culture without H2O2. Our results clearly suggest that the HD monoculture system is useful for screening the substances that affect porcine oocyte culture. PMID:24629146

Ishikawa, S; Machida, R; Hiraga, K; Hiradate, Y; Suda, Y; Tanemura, K

2014-04-01

397

Retinol improves in vitro oocyte nuclear maturation under heat stress in heifers.  

PubMed

Heat stress (HS) is especially harmful for bovine ovarian follicle development and oocyte competence. Furthermore, HS causes premature aging in oocytes due to high levels of reactive oxygen species (ROS), involved in the harmful effects over the oocyte maturation and the steroidogenic activity of follicular cells. In this study, the presumptive protective effects of antioxidant agents on heat-stressed oocytes were evaluated. Heifer oocytes were matured for 22 h under control (38°C) and HS conditions (41.5°C at 18-21 h of maturation). For each oocyte, nuclear stage and cortical granule (CG) distribution were evaluated. Steroidogenic activity of cumulus cells was also recorded. The antioxidant agents used in the study were: retinol (1.43 ?g/ml), retinyl (0.28 ?g/ml) and oleic acid (0.05 mg/ml). Based on a chi-squared test (P < 0.05), HS affected negatively the metaphase II (MII) progression and produced a premature CG exocytosis. Retinol improved the oocyte MII progression. However, retinyl and oleic acid, at the concentrations used in this study, could not counteract adverse effects of HS. A decrease in progesterone and increase in estradiol availability were observed when retinyl and oleic acid were supplemented to the maturation medium, respectively. In conclusion, retinol proved to be valuable in heat-stressed oocytes protecting nuclear maturation. PMID:22785151

Maya-Soriano, M J; Taberner, E; López-Béjar, M

2013-11-01

398

Evaluation of canine and ovine oviducts for maturation of canine oocytes from antral follicles  

E-print Network

's phosphate buffered saline with 3mg/ml polyvinylpyrrolidone for an additional 15 minutes. The cleared oocytes were stained with a Hoechst-glycerol solution and examined using UV microscopy. The oocytes were than classified as having a ruptured zona (RZ...

Epple-Farmer, Jessica A

2012-06-07

399

Effect of mycotoxin-containing diets on epigenetic modifications of mouse oocytes by fluorescence microscopy analysis.  

PubMed

Mycotoxins, such as aflatoxin (AF), fumonisin B1, zearalenone (ZEA), and deoxynivalenol (DON), are commonly found in many food commodities. Mycotoxins have been shown to increase DNA methylation levels in a human intestinal cell line. We previously showed that the developmental competence of oocytes was affected in mice that had been fed a mycotoxin-containing diet. In this study, we explored possible mechanisms of low mouse oocyte developmental competence after mycotoxin treatment in an epigenetic modification perspective. Mycotoxin-contaminated maize (DON at 3,875 ?g/kg, ZEA at 1,897 ?g/kg, and AF at 806 ?g/kg) was included in diets at three different doses (mass percentage: 0, 15, and 30%) and fed to mice for 4 weeks. The fluorescence intensity analysis showed that the general DNA methylation levels increased in oocytes from high dose mycotoxin-fed mice. Mouse oocyte histone methylation was also altered. H3K9me3 and H4K20me3 level increased in oocytes from mycotoxin-fed mice, whereas H3K27me3 and H4K20me2 level decreased in oocytes from mycotoxin-fed mice. Thus, our results indicate that naturally occurring mycotoxins have effects on epigenetic modifications in mouse oocytes, which may be one of the reasons for reduced oocyte developmental competence. PMID:24810297

Zhu, Cheng-Cheng; Hou, Yan-Jun; Han, Jun; Liu, Hong-Lin; Cui, Xiang-Shun; Kim, Nam-Hyung; Sun, Shao-Chen

2014-08-01

400

Cyclic AMP in oocytes controls meiotic prophase I and primordial folliculogenesis in the perinatal mouse ovary.  

PubMed

In mammalian ovaries, a fixed population of primordial follicles forms during the perinatal stage and the oocytes contained within are arrested at the dictyate stage of meiotic prophase I. In the current study, we provide evidence that the level of cyclic AMP (cAMP) in oocytes regulates oocyte meiotic prophase I and primordial folliculogenesis in the perinatal mouse ovary. Our results show that the early meiotic development of oocytes is closely correlated with increased levels of intra-oocyte cAMP. Inhibiting cAMP synthesis in fetal ovaries delayed oocyte meiotic progression and inhibited the disassembly and degradation of synaptonemal complex protein 1. In addition, inhibiting cAMP synthesis in in vitro cultured fetal ovaries prevented primordial follicle formation. Finally, using an in situ oocyte chromosome analysis approach, we found that the dictyate arrest of oocytes is essential for primordial follicle formation under physiological conditions. Taken together, these results suggest a role for cAMP in early meiotic development and primordial follicle formation in the mouse ovary. PMID:25503411

Wang, Yijing; Teng, Zhen; Li, Ge; Mu, Xinyi; Wang, Zhengpin; Feng, Lizhao; Niu, Wanbao; Huang, Kun; Xiang, Xi; Wang, Chao; Zhang, Hua; Xia, Guoliang

2015-01-15

401

Non-spindle microtubule organizing centers in metaphase II-arrested mouse oocytes  

Microsoft Academic Search

A human autoantiserum (5051) directed against pericentriolar material (PCM) was used to study the distribution of microtubule-organizing centers (MTOCs) in the oocyte and during the first cell cycle of mouse development. In oocytes, the PCM was found not only at the poles of the barrel-shaped metaphase II spindle but also at many discrete loci around the cytoplasm near the cell

BERNARD MARO; SARAH K. HOWLETT; MICHELLE WEBB

1985-01-01

402

The effect of glucocorticoids on mouse oocyte in vitro maturation and subsequent fertilization and embryo development  

E-print Network

The effect of glucocorticoids on mouse oocyte in vitro maturation and subsequent fertilization, and fertilization and developmen- tal capacity were examined in vitro. Corticosterone exposure during oocyte Fertilization Embryo development a b s t r a c t Increased glucocorticoid levels, due to medical therapy

Museo Nacional de Ciencias Naturales

403

Vitrification of in vitro matured oocytes: effects on meiotic spindle configuration and mitochondrial function  

PubMed Central

Background: In the assisted reproductive technique, cryopreserving in vitro-matured oocytes is a new strategy to extend the pool of total oocytes. However, oocyte cryopreservation technique is still unsatisfied. So the assessment of cyro-damage on meiotic spindle and mitochondrial function is necessary to evaluate and refine the current protocols. Material and Methods: The immature oocytes were donated from women undergoing ICSI cycles. Cytoskeleton was assessed by ?-tubulin and mitochondria through the fluorescent ??m reporter JC-1. Results: Relative inner membrane potential in MII oocytes from vIVM group sharply decreased, compared with the control (n=30) (1.397 vs. 1.019, P<0.05). 45.2% defective spindles were observed in fIVM group, compared with 48.0% in vIVM group (P>0.05). Oocytes in fIVM (35.5%, 11/31) and vIVM (40.0%, 10/25) displayed abnormal chromosome (P>0.05). Conclusion: In vitro maturation (IVM) has an adverse effect on the organization of spindle and chromosome, and no significantly effect on spindle and chromosome was discovered after vitrification-thaw cycle, while there was obvious damage of oocyte mitochondrial function of in vitro-matured oocyte detected after warming, which may be the reason of the low following developmental potential. PMID:24696732

Lei, Tao; Guo, Na; Liu, Jie-Qiong; Tan, Mei-Hua; Li, Yu-Feng

2014-01-01

404

The effects of heparin exposure on Equine oocytes matured in vitro  

E-print Network

. Oocytes were then transferred to holding media, and examined for loss of cumulus cells. Oocytes were scored as either cumulus free - less than one layer of cells attached to the zona pellucida, or cumulus intact - one or more layers of attached cells...

Evans, Garen Keith

2012-06-07

405

Ovarian steroidogenesis in white sturgeon ( Acipenser transmontanus) during oocyte maturation and induced ovulation  

Microsoft Academic Search

Ovarian follicles and plasma were collected from two female white sturgeon, Acipenser transmontanus, injected with sturgeon pituitary homogenate followed 12h later with GnRHa to induce ovulation. The oocytes of one female underwent germinal vesicle breakdown (GVBD) but ovulation did not occur in response to hormonal stimulation (Female 1), while the oocytes of the other female underwent GVBD and ovulation (Female

Molly A. H Webb; Grant W Feist; John M Trant; Joel P Van Eenennaam; Martin S Fitzpatrick; Carl B Schreck; Serge I Doroshov

2002-01-01

406

MicroRNA expression profile in bovine cumulus-oocyte complexes during late oogenesis  

Technology Transfer Automated Retrieval System (TEKTRAN)

During late oogenesis, the mammalian oocyte synthesizes and stores mRNA necessary to guide the early stages of embryo development prior to the activation of embryonic transcription. The oocyte also contains many post-transcriptional regulatory mechanisms that coordinate mRNA stability and translati...

407

Interaction between Polo and BicD proteins links oocyte determination and meiosis control in Drosophila  

E-print Network

1 Interaction between Polo and BicD proteins links oocyte determination and meiosis control and meiosis control Key words : Polo, BicD, oocyte, meiosis, polarized transport 6999 words 1 INSERM U384 Univ/2006; 133(20): 4005-13 #12;2 SUMMARY Meiosis is a specialized cell cycle limited to the gametes in Metazoa

Paris-Sud XI, Université de

408

Requirements for Phosphorylation of MAP Kinase During Meiosis in Xenopus Oocytes  

Microsoft Academic Search

Mitogen-activated protein (MAP) kinases are activated in response to a variety of extracellular stimuli by phosphorylation on tyrosine and threonine residues. Xp42 is a Xenopus laevis MAP kinase that is activated during oocyte maturation. Modified forms of Xp42 that lacked enzymatic activity or either of the phosphorylation sites were expressed in Xenopus oocytes. When meiotic maturation was induced with progesterone,

James Posada; Jonathan A. Cooper

1992-01-01

409

A Computational Model for Asynchronous Oocyte Growth Dynamics in Spawning Fish  

EPA Science Inventory

This manuscript describes the development of a computational model that simulates a time course of oocyte growth and spawning for asynchronous spawning fish, based upon plasma vitellogenin concentrations and a critical oocyte size for spawning. The model provides a framework that...

410

The origin of asymmetry : early polarisation of the Drosophila germline cyst and oocyte  

E-print Network

to a reversal of oocyte polarity later in oogenesis, which defines the anterior-posterior axis of the embryo are established during oogenesis by the asymmetric localisation of bicoid, oskar, and gurken mRNAs within and earlier in oogenesis, ultimately leading to the very first steps of oogenesis, when the oocyte

Boyer, Edmond

411

High-throughput optofluidic system for the laser microsurgery of oocytes  

E-print Network

of the system transports oocytes from an inlet port into multiple flow channels. Within each channel, oocytes are confined against a microfluidic barrier using a steady fluid flow provided by an external computer, the nucleolinus is a RNA-rich organelle located within the nucleolus (Fig. 1).11 It has a proposed role

Chen, Zhongping

412

A cytochemical study of oocyte growth in four species of millipedes  

Microsoft Academic Search

The cytochemistry of oocyte growth was investigated in four species of millipedes; Narceus americanus, Oxidus gracilis, Cheiropus plancus, and a Pleuroloma species, probably P. cala. The oocyte of all four species produced a yolk nucleus which arose in contact with the nuclear membrane, subsequently detached, migrated into the central ooplasm and disrupted coincident with the appearance of protein yolk granules

Douglas F. Crane; Ronald R. Cowden

1968-01-01

413

Risk Information Provided to Prospective Oocyte Donors in a Preliminary Phone Call  

Microsoft Academic Search

In order to accommodate for the present shortage of oocyte donors, oocyte-donation programs place ads in college newspapers and provide large monetary compensation to encourage participation. Large compensation acts as a strong incentive for young women to undergo the potentially risky procedure of donation. In this enticing situation, it is particularly important for programs to fully inform prospective donors of

Andrea D. Gurmankin

2001-01-01

414

Development . Author manuscript Interaction between Polo and BicD proteins links oocyte determination and  

E-print Network

its anterior part, named region 1, germline stem cell progeny undergoes a precise pattern of divisions is selected to become the oocyte, while the other 15 cells will differentiate as nurse cells. This progressive is a specialized cell cycle limited to the gametes in Metazoa. In oocyte determination and meiosis control are

Paris-Sud XI, Université de

415

Role of steroids in the maturation of ovine oocytes Institute of Animal Physiology, Animal Research Station  

E-print Network

Role of steroids in the maturation of ovine oocytes R. M. MOOR Institute of Animal Physiology of oocytes in sheep. Steroid function during the inductive phase is characterized by (i) elevated levels of progesterone (0.4 and 0.8 nmol/ml in vitro and in vivo respectively). Steroid support is not required

Paris-Sud XI, Université de

416

In vitro steroid stimulation of final maturation in oocytes of rock bass (Ambloplites rupestris) (*)  

E-print Network

In vitro steroid stimulation of final maturation in oocytes of rock bass (Ambloplites rupestris.S.A. Summary. The in vitro effects of various steroids on germinal vesicle break-down (GVBD) in oocytes of rock was peripheral were responsive to steroids in vitro. Of the stimulatory steroids, 17c!, 20(3-dihydroxy-4-pregnen

Paris-Sud XI, Université de

417

Characterization of nuclear protein kinases of Xenopus laevis oocytes  

SciTech Connect

Xenopus laevis oocytes contain large nuclei (germinal vesicles) that can be isolated in very pure form and which permit the study of enzymatic activities present in these organelles. Incubation of pure oocyte nuclear homogenates with /sup 32/P in a buffered solution containing 5 mM MgCl/sub 2/ results in the phosphorylation of a large number of proteins by endogenous protein kinases. This phosphorylation is not affected by the addition of cyclic nucleotides or calcium ion and calmodulin. On the other hand the nuclear kinases are considerably stimulated by spermine and spermidine and strongly inhibited by heparin (10 ..mu..g/ml). Addition of exogenous protein substrates shows that the major oocyte kinases are very active with casein and phosvitin as substrates but do not phosphorylate histones or protamines. DEAE-Sephadex chromatography of the nuclear extract fractionates the casein phosphorylating activity in two main peaks. The first peak is not retained on the column equilibrated with 0.1 M NH/sub 2/SO/sub 4/ and uses exclusively ATP as phosphate donor and is insensitive to polyamines or heparin. The second peak which corresponds to 70% of the casein phosphorylation elutes at 0.27 M NH/sub 2/SO/sub 4/ and uses both ATP and GTP as phosphate donors and is greatly stimulated by polyamines and completely inhibited by 10 ..mu..g/ml heparin. On this evidence the authors conclude that the major protein kinase peak corresponds to casein kinase type II which has been found in mammalian nuclei.

Leiva, L.; Gonzalez, C.; Allende, C.; Allende, J.

1986-05-01

418

Routing of Biomolecules and Transgenes’ Vectors in Nuclei of Oocytes  

PubMed Central

The molecular architecture of Nuclear Pore Complexes (NPCs), as well as the import and export of molecules through them, has been intensively studied in a variety of cells, including oocytes. However, the structures and mechanisms, involved in the transport of molecules beyond the NPCs, remained unclear, until now. The specific aim of this work was, therefore, to determine, if there exist any intranuclear structures in continuum with the NPCs. This information could help in explaining the mechanisms, which propel the distribution of biomolecules and vectors inside the cell nuclei. To attain this aim, we used rapid cryo-immobilization to capture molecular processes of living cells with millisecond resolution. We pursued molecular imaging, including electron energy loss spectroscopy and energy dispersive x-ray spectroscopy, to reveal structures with nanometer spatial resolution. We also bioengineered single chain variable fragments to track biomolecules and transgenes’ constructs. Herein, we reveal the Nuclear Routing Networks (NRNs) in the oocytes of Xenopus laevis. The NRNs originate at and extend from the tops of intranuclear baskets of the NPCs to interconnect them, while creating a complex, intra-nuclear, three-dimensional architecture. The NRNs guide the export of both tRNA, as well as the Nuclear Export Signal (NES) equipped vectors, from the nuclei. Moreover, the NRNs guide the import of both nucleoplasmin, as well as the Nuclear Localization Signals (NLS) modified transgenes’ vectors, into the nuclei. The vectors equipped with these NLS and NES shuttle back and forth through the NPCs and NRNs. To summarize, we reveal the NRN, which functions as the guided distribution system in the Xenopus laevis oocytes’ nuclei. We further proceed with the identification of its molecular components. PMID:22896814

Malecki, Marek; Malecki, Bianca

2012-01-01

419

High susceptibility of Djungarian hamsters (Phodopus sungorus) to the infection with Babesia microti supported by hemodynamics.  

PubMed

As the comparative study was carried out on the susceptibility by the pursuit of parasitemia among the Djungarian, Syrian, and Chinese hamsters as well as BALB/c mice infected with the Syrian hamster-adapted Babesia microti strain, and Djungarian hamsters showed the highest parasitemia among them. Then, the other hematological parameters were pursued in the Djungarian hamsters infected with the hamster-adapted B. microti strain. Remarkable symptoms observed were hemoglobinuria clinically, anemia hematologically, and splenomegaly macroscopically during all over the observation period for 24 weeks post infection (PI). Parasitemia began to rise at 2 weeks and peaked at 4 weeks PI. After that, parasitemia decreased gradually but was maintained with a level of about 10% on average until 24 weeks PI at the end of the experiment. A decrease in the RBC count, Hb, and PCV, and an increase in the reticulocyte and WBC counts due to the development of immature neutrophils, lymphocytes and monocytes were recognized together with a rise of parasitemia. The hamsters had macrocytic hypochromic anemia due to the increase of MCV and the decrease of MCHC in the growth phase of the parasite. It was considered that the Djungarian hamsters will be useful for the infection examination, isolation, maintenance, and passage of B. microti in laboratory. PMID:15942137

Ike, Kazunori; Komatsu, Tetsuya; Murakami, Takashi; Kato, Yousuke; Takahashi, Miwa; Uchida, Yuko; Imai, Soichi

2005-05-01

420

Daidzin suppresses ethanol consumption by Syrian golden hamsters without blocking acetaldehyde metabolism.  

PubMed Central

Daidzin is a potent, selective, and reversible inhibitor of human mitochondrial aldehyde dehydrogenase (ALDH) that suppresses free-choice ethanol intake by Syrian golden hamsters. Other ALDH inhibitors, such as disulfiram (Antabuse) and calcium citrate carbimide (Temposil), have also been shown to suppress ethanol intake of laboratory animals and are thought to act by inhibiting the metabolism of acetaldehyde produced from ingested ethanol. To determine whether or not daidzin inhibits acetaldehyde metabolism in vivo, plasma acetaldehyde in daidzin-treated hamsters was measured after the administration of a test dose of ethanol. Daidzin treatment (150 mg/kg per day i.p. for 6 days) significantly suppresses (> 70%) hamster ethanol intake but does not affect overall acetaldehyde metabolism. In contrast, after administration of the same ethanol dose, plasma acetaldehyde concentration in disulfiram-treated hamsters reaches 0.9 mM, 70 times higher than that of the control. In vitro, daidzin suppresses hamster liver mitochondria-catalyzed acetaldehyde oxidation very potently with an IC50 value of 0.4 microM, which is substantially lower than the daidzin concentration (70 microM) found in the liver mitochondria of daidzin-treated hamsters. These results indicate that (i) the action of daidzin differs from that proposed for the classic, broad-acting ALDH inhibitors (e.g., disulfiram), and (ii) the daidzin-sensitive mitochondrial ALDH is not the one and only enzyme that is essential for acetaldehyde metabolism in golden hamsters. PMID:7568058

Keung, W M; Lazo, O; Kunze, L; Vallee, B L

1995-01-01